Next Article in Journal
piRNA-823 Is a Unique Potential Diagnostic Non-Invasive Biomarker in Colorectal Cancer Patients
Next Article in Special Issue
miR-542-3p Contributes to the HK2-Mediated High Glycolytic Phenotype in Human Glioma Cells
Previous Article in Journal
Protective Role of a TMPRSS2 Variant on Severe COVID-19 Outcome in Young Males and Elderly Women
Previous Article in Special Issue
Expression of Estrogen Receptor- and Progesterone Receptor-Regulating MicroRNAs in Breast Cancer
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

MicroRNA Changes in Gastric Carcinogenesis: Differential Dysregulation during Helicobacter pylori and EBV Infection

1
Medizinische Klinik 2, Helios Universitätsklinikum Wuppertal, 42283 Wuppertal, Germany
2
Lehrstuhl Innere Medizin 1, University of Witten/Herdecke gGmbH, 42283 Wuppertal, Germany
3
Institute of Virology, University of Göttingen, 37075 Göttingen, Germany
*
Author to whom correspondence should be addressed.
Genes 2021, 12(4), 597; https://doi.org/10.3390/genes12040597
Submission received: 15 March 2021 / Revised: 5 April 2021 / Accepted: 14 April 2021 / Published: 19 April 2021
(This article belongs to the Special Issue The Role of MicroRNA in Cancer)

Abstract

:
Despite medical advances, gastric-cancer (GC) mortality remains high in Europe. Bacterial infection with Helicobacter pylori (H. pylori) and viral infection with the Epstein–Barr virus (EBV) are associated with the development of both distal and proximal gastric cancer. Therefore, the detection of these infections and the prediction of further cancer development could be clinically significant. To this end, microRNAs (miRNAs) could serve as promising new tools. MiRNAs are highly conserved noncoding RNAs that play an important role in gene silencing, mainly acting via translational repression and the degradation of mRNA targets. Recent reports demonstrate the downregulation of numerous miRNAs in GC, especially miR-22, miR-145, miR-206, miR-375, and miR-490, and these changes seem to promote cancer-cell invasion and tumor spreading. The dysregulation of miR-106b, miR-146a, miR-155, and the Let-7b/c complex seems to be of particular importance during H. pylori infection or gastric carcinogenesis. In contrast, many reports describe changes in host miRNA expression and outline the effects of bamHI-A region rightward transcript (BART) miRNA in EBV-infected tissue. The differential regulation of these miRNA, acting alone or in close interaction when both infections coexist, may therefore enable us to detect cancer earlier. In this review, we focus on the two different etiologies of gastric cancer and outline the molecular pathways through which H. pylori- or EBV-induced changes might synergistically act via miR-155 dysregulation to potentiate cancer risk. The three markers, namely, H. pylori presence, EBV infection, and miR-155 expression, may be checked in routine biopsies to evaluate the risk of developing gastric cancer.

1. Introduction

Gastric-cancer (GC) outcomes remain poor despite therapeutic advances. In Europe in 2012, an estimated 139,600 GC cases were diagnosed, with an incidence rate of 13.7/100,000 person years (age-standardized rate), and approximately 107,000 deaths, with a mortality rate of 10.3 per 100,000 person years [1]. In 2019, it was reported that these rates only slightly decreased within European countries [2]. European GC patients have an overall 5-year survival rate of only 30–40%, whereas Japan achieved a 70% survival rate [3]. European countries with high incidence and mortality rates include Germany, Italy, Spain, and Portugal, even though endoscopic monitoring is easily available in these countries [4]. Numerous factors contribute to these poor outcomes, including poor detection during endoscopies, limited surgical experience, and aspects of chemotherapy. Most importantly, the majority of tumors are detected in the advanced stages, resulting in poor prognoses and outcomes since GC is generally not highly sensitive to chemotherapy, a treatment that is only successful in certain patient subgroups.
Recent trials investigated neoadjuvant chemotherapy in GC. Most prominently, the Medical Research Council Adjuvant Gastric Chemotherapy (MAGIC) trial demonstrated a clear benefit of perioperative and postoperative chemotherapy [4]. However, although this protocol is a current treatment standard, the overall survival rate of patients treated under this regimen in Europe remains only at around 40–45%. An evaluation of the clinical response to chemotherapy revealed that not all patients benefit from neoadjuvant, perioperative, and postoperative regimens. It is, therefore, of enormous clinical value to identify markers from biopsies that could predict the chemotherapy response in patients with or without subsequent surgery.
Infections with Helicobacter pylori [5] and with Epstein–Barr Virus (EBV) [6] were correlated with GC development; therefore, it seems rational to examine biomarkers indicating malignant developments during these infections. In particular, microRNA (miRNA) dysregulation may be a promising tool [7]. Current evidence highlights that coinfection with EBV can potentiate injury in gastric diseases [8,9]. In the current review, we focus on the two different etiologies of GC and outline the molecular pathways through which both agents might act synergistically to potentiate cancer risk.

2. Dysregulation of miRNAs in GC: Significance and Critical Roles as Diagnostic or Prognostic Biomarkers in Biopsies and in Human Plasma

miRNAs affected by EBV and/or H. pylori infections may provide new biomarkers for GC. They were recently associated with cancer development and progression in other gastrointestinal (GI) cancers. miRNAs recognize specific base pairings in mRNA and bind to them, thereby regulating gene translation and protein synthesis. They can also induce the deadenylation of mRNA, shortening the half-life of the corresponding mRNA molecule, and potentially triggering protein binding to certain DNA sections, modifying chromatin structure and gene expression [10]. Through these mechanisms, miRNAs play an important role in cell proliferation and differentiation, and in controlling apoptosis. On the basis of these molecular findings, the up- or downregulation of miRNAs may be associated with cancer development and progression, highlighting the potential use of miRNAs as predictive markers in various cancer stages [10,11,12,13].
Pioneering work by Lu et al. revealed the general downregulation of miRNAs in GI tumors when compared with that of normal tissue [12]. Moreover, their results demonstrated the identification of GI cancers using miRNA expression profiles, which were clearly superior to mRNA profiles, thus supporting the potential of miRNAs as diagnostic biomarkers. The investigators found that certain miRNAs were downregulated in cancer tissue, but upregulated in corresponding normal epithelia. However, they could not determine whether the miRNAs that were highly dysregulated in the gut-associated cluster (such as the Let-7 group, miR-192, miR-194, and miR-215) had specific diagnostic or prognostic value in GC. Moreover, the possible functional role of these miRNAs in such tumors remains unclear. Some of these miRNAs clearly have pleiotropic functional roles; for example, Let-7 microRNAs play a key role in development, stem cells, and cancer, and were detected in other cancer tissue types [13].
Recent studies described miR-21 expression [14,15] as both a diagnostic and a prognostic biomarker in GC, since the miRNA is highly upregulated in GC and significantly associated with tumor differentiation, local invasion, and lymph-node metastasis. The overexpression of miR-21 promotes GC cell growth, invasion, and migration in vitro, whereas miR-21 downregulation yields an inhibitory effect [16]. Zhang et al. reported that miR-21 plays a pivotal role in GC pathogenesis and progression through a process involving microsatellite instability [16]. The high miR-21 expression in GC is similar to the findings of Yan et al. in breast cancer [17]. Another study found that miR-370 downregulation is highly associated with more advanced nodal metastasis and a higher clinical stage of GC, acting via the inhibition of transforming growth factor-β receptor II expression [18].
Recent studies attempted to determine the value of certain miRNAs in human plasma as diagnostic markers for early-stage GC, including miR-17, miR-25, and miR-133b [19], miR-425-5p, miR-1180-3p, miR-122-5p, miR-24-3p, and miR-4632-5p [20]. A previous report that was inconsistent with previous data found miR-185, miR-20a, miR-210, miR-25, and miR-92b to be dysregulated in plasma from GC patients [21]. Overall, on the basis of the contradictory results, available data must be interpreted with caution. Discrepancies may be due to the complexity of human gene regulation in blood; however, all studies were hampered by a small sample size.

3. Importance of miRNAs in GC: Critical Roles in Tumorigenesis and Tumor Spreading, and as Molecular Targets

Numerous studies investigated dysregulated miRNA expression during GC development, invasion, and metastasis. In most tumors, potential oncogenes may become activated due to the downregulation of miRNAs that normally function in the repression of translated products, including miR-375. In GC cells, miR-375 is downregulated, allowing for the increased activation of PDK1 (a kinase with antiapoptotic effects) and the JAK2 oncogene, which is a process that leads to cancer-cell proliferation, migration, and invasion [22,23,24]. However, miR-375 cannot be regarded as a specific marker for GC, as it was recently found to be a biomarker that differentiates rectal cancer from colon cancer, potentially interfering with IGF-2 expression [25].
Studies showed that miR-181c overexpression causes the decreased growth of GC cell lines. Moreover, miR-181c may be downregulated in GC and play an important role through its target genes, such as NOTCH4 [26]. Recent studies indicate that NOTCH4 signaling is essential for vascular morphogenesis [27].
Recent reports also demonstrated the downregulation of miR-22, miR-145, and miR-490 in GC, and these changes seem to promote cancer-cell invasion and tumor spreading. In one study, miR-22 upregulation led to a decrease in GC cell migration and invasion through targeting oncogenic gene Sp1, while miR-22 downregulation allowed for increased infiltration [28]. Additionally, miR-145 reportedly suppresses cancer spreading through the inhibition of N-cadherin protein translation, acting via the downregulation of matrix metallopeptidase (MMP)-9 [29]. GC also exhibits downregulated miR-490-3p expression, which normally exerts growth- and metastasis-suppressive effects in cell lines by targeting SMARCD1 [30]. In turn, SMARCD1 expression is upregulated in the gastric tissue of patients with GC, and high SMARCD1 expression was associated with shorter patient survival independent of TNM staging [30]. GC also shows significantly decreased expression of miR-206 [31], which is a potential tumor suppressor acting via cyclin D2 (CCND2), a protein that plays a key role in controlling the cell cycle. MiR-206 suppresses GC cell proliferation, and reduces cell growth and colony-forming abilities [31]. Additionally, miRNA-331-3p is a potential tumor suppressor in GC that directly targets E2F1, a transcription factor with important functions in cell-cycle regulation, mediating the G1-to-S phase transition [32]. Furthermore, miR-107 may exert a tumor-suppressor function by directly targeting CDK6, a protein kinase that increases cell growth and blood-vessel supply. The ectopic expression of miR-107 inhibits proliferation, induces G1 cell-cycle arrest and blockades the invasion of GC cells [33].
In other tumor types, miRNAs are reportedly upregulated and exert different carcinogenic functions. For example, miR-221 and miR-222 are upregulated in GC cells, affecting cell growth and invasion possibly via the direct modulation of phosphatase and tensin homolog (PTEN) [34]. PTEN interacts with the PI3K–Akt signaling pathway by dephosphorylating PIP2, PIP3, and protein kinase B, thereby counteracting the antiapoptotic PI3K–Akt signaling pathway and inhibiting cell proliferation. Additionally, miR-616 acts through the PTEN/mTOR signaling cascade, thereby activating angiogenesis and tumor invasion through an increase in epithelial–mesenchymal transition [35]. Accordingly, miR-21 inhibition reportedly upregulates PTEN expression [35], indicating that PTEN may be a specific target gene for GC initiation and development.
A remarkably high number (15–30%) of gastric tumors exhibit microsatellite instability (MSI), which is characterized by the accumulation of mutations, namely, at repetitive sequences (microsatellites) due to a defective DNA mismatch repair system (MMR) [36] or mutations in different genes involved in DNA damage response (e.g., ATR or CHK1) [37]. Appropriate cellular responses to DNA damage and the integrity of DNA repair systems are critical for maintaining genomic stability, which is lost in many gastrointestinal tumors including GC. Table 1 presents an overview of miRNAs that are upregulated and downregulated in GC.

4. Roles of miRNA Dysregulation in H. pylori-Induced Gastric Adenocarcinoma

H. pylori is classified as a Type I class carcinogen due to the overwhelming scientific evidence that this bacterium colonizes the gastric mucosa in the presence of acid, leading to chronic gastric inflammation and gastric carcinogenesis. Several guidelines strongly recommend the eradication of this bacterium at the chronic gastric infection stage to prevent GC development [5]. However, true predictors and an exact time point of “no return” for a malignant transformation over decades remain to be determined.
miRNAs are a promising tool for addressing this important clinical question. H. pylori infection leads miR-210 to undergo CpG island methylation, thus inducing STMN1 expression [39]. The let-7 family members also exhibit involvement in H. pylori-induced cancer development. In vitro and in vivo data confirmed that certain miRNAs act as tumor suppressors in the GC development process, including Ras, Myc, and HMGA-2 [10,13,45]. The expression of Let-7c was assessed in biopsies from different stages of gastric inflammation and cancer, including H. pylori-related gastritis, atrophy, and intestinal metaplasia. Findings show let-7c dysregulation in the different stages, with increasing downregulation through the different stages of gastritis to atrophic and metaplastic gastritis, neoplasia, and invasive GC. Moreover, following H. pylori eradication, let-7c expression was significantly increased [46]. The downregulation of Let-7c was also observed in a mouse model following inoculation with H. pylori. Overall, available data suggest that early phases are characterized by let-7c dysregulations [46]. A similar function was detected for let-7b miRNA [47]. The expression of let-7b was reportedly decreased in gastric adenocarcinoma, with tumor stage, and in lymphatic metastasis. Collagen triple helix repeat containing 1 (Cthrc1) was described as a potential direct target of let-7b since Cthrc1 is significantly upregulated in GC. These findings suggest that let-7b may directly act as a tumor-suppressor gene in GC [47].
Investigations in H. pylori-infected patients show that low expression levels of miR-375 and miR-106b were correlated with inflammation scores and colonization density [48]. MiR-375 reportedly targets the Janus kinase JAK 2 [23]; thus, its downregulation may be responsible for increased tumor growth. In a recent study, Helicobacter lipopolysaccharide (LPS) led to the downregulation of miR-375 and miR-106b, which are associated with MDM2 expression, yielding JAK1 and STAT3 dysregulation, which serve as downstream target genes of the two miRNAs. These new targets within the crucial carcinogenic process seem to be especially associated with infection with the Type 1 cagA+ strains of H. pylori, following the tyrosine phosphorylation of JAK1, JAK2, and STAT3. Thus, the dysregulation of miR-375 and miR-106b during the H. pylori LPS-induced signal cascade may substantially alter JAK1/JAK2 and STAT3 signaling [49]. This suggests that STAT3 levels in the gastric mucosa may be of further prognostic impact [50].
The expression of miR-146a is also of particular interest in the pathway of H. pylori-induced gastric carcinogenesis, and it is reportedly dysregulated in GC [42,51]. This miRNA inhibits the cytokine-induced inflammatory responses during infection [51], and was also described and investigated in H. pylori-infected gastric tumors. In one study, the overexpression of miR-146a was associated with the progression of gastric tumors, with greater stages and lymph-node metastasis; furthermore, miR-146a expression was found to be independent of H. pylori infection [42]. In other studies, the treatment of immune cells with bacterial LPS resulted in the induction of both miR-146a and miR-155 [52], outlining a direct effect of H. pylori on the dysregulation of these miRNAs.

Importance of EBV Infection for GC Development

Certain types of GC and nasopharyngeal carcinoma are dependent on EBV infection [53,54,55]. EBV-infected GC constitutes a latent Type I infection and does not express BHRF miRNAs [56,57]. In contrast, EBV-associated nasopharyngeal cancer is a latent Type II infection [57]. Moreover, while EBV infection is commonly present in patients with nasopharyngeal carcinoma, it is found in only 8–10% of GCs [6]. EBV-positive tumors occur at both sites of GC, i.e., in both proximal and distal types [56]. Previous studies determined differential localization in patients with EBV-positive vs. EBV-negative GC [58]; however, sample sizes were not representative. Regarding EBV and miRNA, many reports described changes in host miRNA expression and particularly the effects of bamHI-A region rightward transcript (BART) miRNA [59]. In EBV-induced GC, targets of BART miRNAs were described. For example, mutations were detected in PIK3CA (80%), which regulates the PI3K/Akt signaling pathway, and in ARID1A (55%), which has DNA helicase and ATPase functions [52,53,54]. On the other hand, chromosomal abnormalities are not common in EBV-associated cancer [60,61,62].
EBV presence differs in the acute- and latent-infection periods. During the latent-infection period, few EBV proteins are expressed, but there is high expression of EBV miRNAs, such as BART miRNAs [60,61,62]. EBV-coded miRNA-BARTs are expressed in B-cell lymphoma (latency I), NK/T cell lymphoma (Latency I), Hodgkin’s disease (Latency II), and in EBV-associated PTLD (Latency III). In EBV-infected cells, three miRNAs are produced in the BHRF1 locus; these miRNAs flank the BHRF1 open-reading frame encoding a Bcl2 viral homolog, and are especially expressed in EBV Latent III infections [60,63,64]. Furthermore, 22 miRNAs [57] can be divided into two subsets of BART-miRNAs [57]. BART Group 1 members include miRNA-BART1, 3–6, and 15–17, while BART Group 2 members include miR-BART-18–21 and miR-BART-7–14 [61]. BART Group 2 members (including miRNA-BART18–3p, 7–5p, 10–3p, 10–5p, 11–3p, 13–5p, and 14–5p) are also expressed in Type III latent EBV infections [65,66]. Reportedly, miRNA-BART2-5p and miRNA-BART2-3p are the rear members of these two subgroups [67].
In EBV-associated GC, tumor cells show latent infections with EBV I and express the small RNA encoded in EBV EBNA1 [68]. In EBV-transformed B cells and infected GC cells, miRNA-BART16 directly targets and regulates the CREB-binding protein, which is an important transcriptional coactivator in the interferon signaling pathway (IFN). Therefore, miRNA–BART16 facilitates the establishment of latent EBV infection and promotes viral replication by diminishing the antiviral action of interferon-α [69]. Furthermore, EBV-associated miRNAs have important impact on the production of interleukin-1 (IL-1) [70].

5. Research Perspective Given Functional Importance of H. pylori- and EBV-Induced Changes in GC Acting Synergistically

Various studies investigated the correlation between EBV and H. pylori infection of the stomach, and infection with both pathogens is associated with stomach-cancer development. The spectrum of miRNAs induced in both infections seems to differ widely between the two types of infection in vivo and, especially, in vitro. However, it seems rational from a clinical perspective that both infections might act together to promote further cancer development.
Given the importance of EBV in GC and the possible interactions with H. pylori infection, presently available data suggest the importance of using molecular methods to directly evaluate the presence of both H. pylori and EBV in biopsy samples [71]. Moreover, current data suggest that the two different etiologies may synergistically act to induce GC, and that miR-155 may play a special role in this process.
With regards to the carcinogenic potential during H. pylori infection, the induction of miR-155 by H. pylori is dependent on the Type IV secretion system and is related to the presence of the cagA pathogenicity island [72]. These findings may explain why only the so-called Type 1 strains are associated with GC development. Recent data also indicate that miR-155-5p overexpression plays a notable role in H. pylori-induced inflammation and carcinogenesis [73]. Furthermore, miR-155 overexpression was observed in GC biopsies upon H. pylori infection and in gastric adenocarcinoma [14,15,52,74]. Interestingly, miR-155 regulation is dependent on the activator protein 1 (AP-1) pathway in B cells and seems to enable the persistence of EBV in immune cells [14,15]. Thus, this molecule may be of particular importance for evaluating GC risk.
Infection with H. pylori and EBV may lead to the infiltration of regulatory T cells; in turn, increased Foxp3 expression reportedly controls miR-155 expression in T cells [14,15,52,74]. Additionally, bacterial LPS exposure induces miR-155 expression in immune cells [52,75]. Thus, this interesting miRNA could be a critical determinant of GC development during the initial steps of tumor formation and may serve as a diagnostic biomarker in early cancer stages.
On the basis of available data (shown in Table 2), coinfection with H. pylori could activate EBV-infected B cells, and miR-155 plays a pivotal role in this process [52]. B cells express the CD21 receptor, a known EBV receptor. In turn, infected B cells might infiltrate the chronically inflamed tissue of the gastric epithelial cells, and this cell-to-cell binding between B cells and gastric epithelial cells may result in viral entry into gastric epithelial cells, permitting the initiation of its oncogenic potential. Further details of the mechanism underlying this phenomenon remain unclear, but miRNA activation might be involved in additional relevant pathways during these processes [76,77]. The targeted screening of EBV-associated and H. pylori-induced miRNAs offers the possibility of establishing more individualized therapy. For this purpose, the entire spectrum of miRNAs (and particularly, the total amount of miR-155 expression) could be examined at the cellular level in H. pylori- and EBV-associated tumor diseases, and the tumorigenic potential may be deducted from those observations. Table 2 presents an illustration of this process.

Author Contributions

Conceptualization, C.P.; Methodology, C.P.; Validation, C.P. and K.M.; Formal analysis, C.P.; Investigation, C.P., K.M. and D.W.; Resources, C.P.; Writing—original draft preparation, C.P. and K.M.; Writing—review and editing, C.P. and D.W.; Visualization, C.P. and D.W.; supervision, C.P.; Funding acquisition, C.P. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Ferlay, J.; Steliarova-Foucher, E.; Lortet-Tieulent, J.; Rosso, S.; Coebergh, J.W.W.; Comber, H.; Forman, D.; Bray, F. Cancer incidence and mortality patterns in Europe: Estimates for 40 countries in 2012. Eur. J. Cancer (Oxf. Engl.) 2013, 49, 1374–1403. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  2. Malvezzi, M.; Carioli, G.; Bertuccio, P.; Boffetta, P.; Levi, F.; La Vecchia, C.; Negri, E. European cancer mortality predictions for the year 2019 with focus on breast cancer. Ann. Oncol. 2019, 30, 781–787. [Google Scholar] [CrossRef] [Green Version]
  3. Shukla, P.J.; Pavoor, R.S.K.; Barreto, G.S. Gastric cancer in Europe. Br. J. Surg. 2008, 95, 406–408. [Google Scholar]
  4. Cunningham, D.; Allum, W.H.; Stenning, S.P.; Thompson, J.N.; Van De Velde, C.J.; Nicolson, M.; Scarffe, J.H.; Lofts, F.J.; Falk, S.J.; Iveson, T.J.; et al. Perioperative Chemotherapy versus Surgery Alone for Resectable Gastroesophageal Cancer. N. Engl. J. Med. 2006, 355, 11–20. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  5. Uemura, N.; Okamoto, S.; Yamamoto, S.; Matsumura, N.; Yamaguchi, S.; Yamakido, M.; Taniyama, K.; Sasaki, N.; Schlemper, R.J. Helicobacter pyloriInfection and the Development of Gastric Cancer. N. Engl. J. Med. 2001, 345, 784–789. [Google Scholar] [CrossRef]
  6. Iizasa, H.; Nanbo, A.; Nishikawa, J.; Jinushi, M.; Yoshiyama, H. Epstein-Barr Virus (EBV)-associated Gastric Carcinoma. Viruses 2012, 4, 3420–3439. [Google Scholar] [CrossRef] [Green Version]
  7. Cancer Genome Atlas Research Network, Integrated genomic characterization of oesophageal carcinoma. Nature 2017, 541, 169–175. [CrossRef] [Green Version]
  8. Teresa, F.; Serra, N.; Capra, G.; Mascarella, C.; Gagliardi, C.; Di Carlo, P.; Cannella, S.; Simonte, M.R.; Lipari, D.; Sciortino, M.; et al. Helicobacter pylori and Epstein–Barr Virus Infection in Gastric Diseases: Correlation with IL-10 and IL1RN Polymorphism. J. Oncol. 2019, 2019, 1–8. [Google Scholar] [CrossRef] [Green Version]
  9. Fasciana, T.; Capra, G.; Calà, C.; Zambuto, S.; Mascarella, C.; Colomba, C.; Di Carlo, P.; Giammanco, A. Helicobacter pylori and Epstein-Barr Co-Infection in Gastric Disease. PhOL 2017, 1, 73–82. [Google Scholar]
  10. Cech, T.R.; Steitz, J.A. The Noncoding RNA Revolution—Trashing Old Rules to Forge New Ones. Cell 2014, 157, 77–94. [Google Scholar] [CrossRef] [Green Version]
  11. Nana-Sinkam, S.P.; Fabbri, M.; Croce, C.M. MicroRNAs in cancer: Personalizing diagnosis and therapy. Ann. N. Y. Acad. Sci. 2010, 1210, 25–33. [Google Scholar] [CrossRef]
  12. Lu, J.; Getz, G.; Miska, E.A.; Alvarez-Saavedra, E.; Lamb, J.; Peck, D.; Sweet-Cordero, A.; Ebert, B.L.; Mak, R.H.; Ferrando, A.A.; et al. MicroRNA expression profiles classify human cancers. Nat. Cell Biol. 2005, 435, 834–838. [Google Scholar] [CrossRef]
  13. Büssing, I.; Slack, F.J.; Grosshans, H. let-7 microRNAs in development, stem cells and cancer. Trends Mol. Med. 2008, 14, 400–409. [Google Scholar] [CrossRef]
  14. Lu, F.; Weidmer, A.; Liu, C.G.; Volinia, S.; Croce, C.M.; Lieberman, P.M. Epstein-Barr virus-induced miR-155 attenuates NF-kappaB signaling and stabilizes latent virus persistence. J. Virol. 2008, 82, 10436–10443. [Google Scholar] [CrossRef] [Green Version]
  15. Rokhlin, O.W.; Scheinker, V.S.; Taghiyev, A.F.; Bumcrot, D.; A Glover, R.; Cohen, M.B. MicroRNA-34 mediates AR-dependent p53-induced apoptosis in prostate cancer. Cancer Biol. Ther. 2008, 7, 1288–1296. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  16. Zhang, B.G.; Li, J.F.; Yu, B.Q.; Zhu, Z.G.; Liu, B.Y.; Yan, M. microRNA-21 promotes tumor proliferation and invasion in gastric cancer by targeting PTEN. Oncol. Rep. 2012, 27, 1019–1026. [Google Scholar] [CrossRef] [Green Version]
  17. Yan, L.-X.; Huang, X.-F.; Shao, Q.; Huang, M.-Y.; Deng, L.; Wu, Q.-L.; Zeng, Y.-X.; Shao, J.-Y. MicroRNA miR-21 overexpression in human breast cancer is associated with advanced clinical stage, lymph node metastasis and patient poor prognosis. RNA 2008, 14, 2348–2360. [Google Scholar] [CrossRef] [Green Version]
  18. Lo, S.-S.; Hung, P.-S.; Chen, J.-H.; Tu, H.-F.; Fang, W.-L.; Chen, C.-Y.; Chen, W.-T.; Gong, N.-R.; Wu, C.-W. Overexpression of miR-370 and downregulation of its novel target TGFβ-RII contribute to the progression of gastric carcinoma. Oncogene 2011, 31, 226–237. [Google Scholar] [CrossRef] [Green Version]
  19. ZiaSarabi, P.; Sorayayi, S.; Hesari, A.; Ghasemi, F. Circulating microRNA-133, microRNA-17 and microRNA-25 in serum and its potential diagnostic value in gastric cancer. J. Cell. Biochem. 2019, 120, 12376–12381. [Google Scholar] [CrossRef] [PubMed]
  20. Zhu, X.-L.; Ren, L.-F.; Wang, H.-P.; Bai, Z.-T.; Zhang, L.; Meng, W.-B.; Zhu, K.-X.; Ding, F.-H.; Miao, L.; Yan, J.; et al. Plasma microRNAs as potential new biomarkers for early detection of early gastric cancer. World J. Gastroenterol. 2019, 25, 1580–1591. [Google Scholar] [CrossRef] [PubMed]
  21. Zhou, X.; Zhu, W.; Li, H.; Wen, W.; Cheng, W.; Wang, F.; Wu, Y.; Qi, L.; Fan, Y.; Chen, Y.; et al. Diagnostic value of a plasma microRNA signature in gastric cancer: A microRNA expression analysis. Sci. Rep. 2015, 5, 11251. [Google Scholar] [CrossRef]
  22. Tsukamoto, Y.; Nakada, C.; Noguchi, T.; Tanigawa, M.; Nguyen, L.T.; Uchida, T.; Hijiya, N.; Matsuura, K.; Fujioka, T.; Seto, M.; et al. MicroRNA-375 is downregulated in gastric carcinomas and regulates cell survival by targeting PDK1 and 14-3-3zeta. Cancer Res. 2010, 70, 2339–2349. [Google Scholar] [CrossRef] [Green Version]
  23. Ding, L.; Xu, Y.; Zhang, W.; Deng, Y.; Si, M.; Du, Y.; Yao, H.; Liu, X.; Ke, Y.; Si, J.; et al. MiR-375 frequently downregulated in gastric cancer inhibits cell proliferation by targeting JAK2. Cell Res. 2010, 20, 784–793. [Google Scholar] [CrossRef] [PubMed]
  24. Xu, Y.; Jin, J.; Liu, Y.; Huang, Z.; Deng, Y.; You, T.; Zhou, T.; Si, J.; Zhuo, W. Snail-Regulated MiR-375 Inhibits Migration and Invasion of Gastric Cancer Cells by Targeting JAK2. PLoS ONE 2014, 9, e99516. [Google Scholar] [CrossRef] [PubMed]
  25. Weber, D.; Amar, L.; Godde, D.; Prinz, C. Extensive screening of microRNA populations identifies hsa-miR-375 and hsa-miR-133a-3p as selective markers for human rectal and colon cancer. Oncotarget 2018, 9, 27256–27267. [Google Scholar] [CrossRef]
  26. Hashimoto, Y.; Akiyama, Y.; Otsubo, T.; Shimada, S.; Yuasa, Y. Involvement of epigenetically silenced microRNA-181c in gastric carcinogenesis. Carcinogenesis 2010, 31, 777–784. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  27. Krebs, L.T.; Xue, Y.; Norton, C.R.; Shutter, J.R.; Maguire, M.; Sundberg, J.P.; Gallahan, D.; Closson, V.; Kitajewski, J.; Callahan, R.; et al. Notch signaling is essential for vascular morphogenesis in mice. Genome Res. 2000, 14, 1343–1352. [Google Scholar]
  28. Guo, M.-M.; Hu, L.-H.; Wang, Y.-Q.; Chen, P.; Huang, J.-G.; Lu, N.; He, J.-H.; Liao, C.-G. miR-22 is down-regulated in gastric cancer, and its overexpression inhibits cell migration and invasion via targeting transcription factor Sp1. Med. Oncol. 2013, 30. [Google Scholar] [CrossRef]
  29. Gao, P.; Xing, A.-Y.; Zhou, G.-Y.; Zhang, T.-G.; Zhang, J.-P.; Gao, C.; Li, H.; Shi, D.-B. The molecular mechanism of microRNA-145 to suppress invasion–metastasis cascade in gastric cancer. Oncogene 2012, 32, 491–501. [Google Scholar] [CrossRef] [Green Version]
  30. Shen, J.; Xiao, Z.; Wu, W.K.; Wang, M.H.; To, K.F.; Chen, Y.; Yang, W.; Li, M.S.; Shin, V.Y.; Tong, J.H.; et al. Epigenetic Silencing of miR-490-3p Reactivates the Chromatin Remodeler SMARCD1 to Promote Helicobacter pylori–Induced Gastric Carcinogenesis. Cancer Res. 2015, 75, 754–765. [Google Scholar] [CrossRef] [Green Version]
  31. Zhang, L.; Liu, X.; Jin, H.; Guo, X.; Xia, L.; Chen, Z.; Bai, M.; Liu, J.; Shang, X.; Wu, K.; et al. MiR-206 inhibits gastric cancer proliferation in part by repressing cyclinD2. Cancer Lett. 2013, 332, 94–101. [Google Scholar] [CrossRef] [PubMed]
  32. Guo, X.; Guo, L.; Ji, J.; Zhang, J.; Zhang, J.; Chen, X.; Cai, Q.; Li, J.; Gu, Q.; Liu, B.; et al. miRNA-331-3p directly targets E2F1 and induces growth arrest in human gastric cancer. Biochem. Biophys. Res. Commun. 2010, 398, 1–6. [Google Scholar] [CrossRef] [PubMed]
  33. Feng, L.; Xie, Y.; Zhang, H.; Wu, Y. miR-107 targets cyclin-dependent kinase 6 expression, induces cell cycle G1 arrest and inhibits invasion in gastric cancer cells. Med. Oncol. 2011, 29, 856–863. [Google Scholar] [CrossRef]
  34. Zhang, C.-Z.; Han, L.; Zhang, A.-L.; Fu, Y.-C.; Yue, X.; Wang, G.-X.; Jia, Z.-F.; Pu, P.-Y.; Zhang, Q.-Y.; Kang, C.-S. MicroRNA-221 and microRNA-222 regulate gastric carcinoma cell proliferation and radioresistance by targeting PTEN. BMC Cancer 2010, 10, 367. [Google Scholar] [CrossRef] [Green Version]
  35. Wu, Z.-H.; Lin, C.; Liu, C.-C.; Jiang, W.-W.; Huang, M.-Z.; Liu, X.; Guo, W.-J. MiR-616-3p promotes angiogenesis and EMT in gastric cancer via the PTEN/AKT/mTOR pathway. Biochem. Biophys. Res. Commun. 2018, 501, 1068–1073. [Google Scholar] [CrossRef] [PubMed]
  36. Velho, S.; Fernandes, M.S.; Leite, M.; Figueiredo, C.; Seruca, R. Causes and consequences of microsatellite instability in gastric carcinogenesis. World J. Gastroenterol. 2014, 20, 16433–16442. [Google Scholar] [CrossRef] [PubMed]
  37. Menoyo, A.; Alazzouzi, H.; Espín, E.; Armengol, M.; Yamamoto, H.; Schwartz, S. Somatic mutations in the DNA damage-response genes ATR and CHK1 in sporadic stomach tumors with microsatellite instability. Cancer Res. 2001, 61, 7727–7730. [Google Scholar] [PubMed]
  38. Zhu, E.-D.; Li, N.; Li, B.-S.; Li, W.; Zhang, W.-J.; Mao, X.-H.; Guo, G.; Zou, Q.-M.; Xiao, B. miR-30b, Down-Regulated in Gastric Cancer, Promotes Apoptosis and Suppresses Tumor Growth by Targeting Plasminogen Activator Inhibitor. PLoS ONE 2014, 9, e106049. [Google Scholar] [CrossRef]
  39. Kiga, K.; Mimuro, H.; Suzuki, M.; Shinozaki-Ushiku, A.; Kobayashi, T.; Sanada, T.; Kim, M.; Ogawa, M.; Iwasaki, Y.W.; Kayo, H.; et al. Epigenetic silencing of miR-210 increases the proliferation of gastric epithelium during chronic Helicobacter pylori infection. Nat. Commun. 2014, 5, 4497. [Google Scholar] [CrossRef] [PubMed]
  40. He, Z.; Li, Z.; Zhang, X.; Yin, K.; Wang, W.; Xu, Z.; Li, B.; Zhang, L.; Xu, J.; Sun, G.; et al. MiR-422a regulates cellular metabolism and malignancy by targeting pyruvate dehydrogenase kinase 2 in gastric cancer. Cell Death Dis. 2018, 9, 1–16. [Google Scholar] [CrossRef] [Green Version]
  41. Jia, L.; Chen, J.; Xie, C.; Shao, L.; Xu, Z.; Zhang, L. microRNA-1228⁎ impairs the pro-angiogenic activity of gastric cancer cells by targeting macrophage migration inhibitory factor. Life Sci. 2017, 180, 9–16. [Google Scholar] [CrossRef] [PubMed]
  42. Ghaedi, K.; Adami, B.; Tabatabaeian, H.; Talebi, A.; Azadeh, M.; Dehdashtian, E. miR-146a is deregulated in gastric cancer. J. Cancer Res. Ther. 2018, 15, 108–114. [Google Scholar] [CrossRef] [PubMed]
  43. Li, N.; Xu, X.; Xiao, B.; Zhu, E.D.; Li, B.S.; Liu, Z.; Tang, B.; Zou, Q.M.; Liang, H.P.; Mao, X.H.H. pylori related proinflammatory cytokines contribute to the induction of miR-146a in human gastric epithelial cells. Mol. Biol. Rep. 2012, 39, 4655–4661. [Google Scholar] [CrossRef]
  44. Ning, T.; Zhang, H.; Wang, X.; Li, S.; Zhang, L.; Deng, T.; Zhou, L.; Wang, X.; Liu, R.; Bai, M.; et al. miR-221 and miR-222 synergistically regulate hepatocyte growth factor activator inhibitor type 1 to promote cell proliferation and migration in gastric cancer. Tumor Biol. 2017, 39. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  45. Lim, L.P.; Lau, N.C.; Garrett-Engele, P.; Grimson, A.; Schelter, J.M.; Castle, J.; Bartel, D.P.; Linsley, P.S.; Johnson, J.M. Microarray analysis shows that some microRNAs downregulate large numbers of target mRNAs. Nat. Cell Biol. 2005, 433, 769–773. [Google Scholar] [CrossRef] [PubMed]
  46. Fassan, M.; Saraggi, D.; Balsamo, L.; Cascione, L.; Castoro, C.; Coati, I.; De Bernard, M.; Farinati, F.; Guzzardo, V.; Valeri, N.; et al. Let-7c down-regulation in Helicobacter pylori-related gastric carcinogenesis. Oncotarget 2015, 7, 4915–4924. [Google Scholar] [CrossRef] [Green Version]
  47. Yu, J.; Feng, J.; Zhi, X.; Tang, J.; Li, Z.; Xu, Y.; Yang, L.; Hu, Z.; Xu, Z. Let-7b inhibits cell proliferation, migration, and invasion through targeting Cthrc1 in gastric cancer. Tumor Biol. 2014, 36, 3221–3229. [Google Scholar] [CrossRef]
  48. Matsushima, K.; Isomoto, H.; Inoue, N.; Nakayama, T.; Hayashi, T.; Nakayama, M.; Nakao, K.; Hirayama, T.; Kohno, S. MicroRNA signatures in Helicobacter pylori-infected gastric mucosa. Int. J. Cancer 2010, 128, 361–370. [Google Scholar] [CrossRef]
  49. Ye, F.; Tang, C.; Shi, W.; Qian, J.; Xiao, S.; Gu, M.; Dang, Y.; Liu, J.; Chen, Y.; Shi, R.; et al. A MDM2-dependent positive-feedback loop is involved in inhibition of miR-375 and miR-106b induced by Helicobacter pylori lipopolysaccharide. Int. J. Cancer 2015, 136, 2120–2131. [Google Scholar] [CrossRef]
  50. Käbisch, R.; Mejías-Luque, R.; Gerhard, M.; Prinz, C. Involvement of Toll-Like Receptors on Helicobacter pylori-Induced Immunity. PLoS ONE 2014, 9, e104804. [Google Scholar] [CrossRef]
  51. Li, N.; Wang, J.; Yu, W.; Dong, K.; You, F.; Si, B.; Tang, B.; Zhang, Y.; Wang, T.; Qiao, B. MicroRNA-146a inhibits the inflammatory responses induced by interleukin-17A during the infection of Helicobacter pylori. Mol. Med. Rep. 2018, 19, 1388–1395. [Google Scholar] [CrossRef] [Green Version]
  52. Fassi Fehri, L.; Koch, M.; Belogolova, E.; Khalil, H.; Bolz, C.; Kalali, B.; Mollenkopf, H.J.; Beigier-Bompadre, M.; Karlas, A.; Schneider, T.; et al. Helicobacter pylori induces miR-155 in T cells in a cAMP-Foxp3-dependent manner. PLoS ONE 2010, 5, e9500. [Google Scholar] [CrossRef] [Green Version]
  53. Macsween, K.F.; Crawford, D.H. Epstein-Barr virus-recent advances. Lancet Infect. Dis. 2003, 3, 131–140. [Google Scholar] [CrossRef]
  54. Cohen, J.I. Epstein-Barr virus infection. N. Engl. J. Med. 2000, 343, 481–492. [Google Scholar] [CrossRef] [PubMed]
  55. Wang, H.-B.; Zhang, H.; Zhang, J.-P.; Li, Y.; Zhao, B.; Feng, G.-K.; Du, Y.; Xiong, D.; Zhong, Q.; Liu, W.-L.; et al. Neuropilin 1 is an entry factor that promotes EBV infection of nasopharyngeal epithelial cells. Nat. Commun. 2015, 6, 6240. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  56. Sun, K.; Jia, K.; Lv, H.; Wang, S.-Q.; Wu, Y.; Lei, H.; Chen, X. EBV-Positive Gastric Cancer: Current Knowledge and Future Perspectives. Front. Oncol. 2020, 10. [Google Scholar] [CrossRef] [PubMed]
  57. Qiu, J.; Cosmopoulos, K.; Pegtel, M.; Hopmans, E.; Murray, P.; Middeldorp, J.; Shapiro, M.; Thorley-Lawson, D.A. A Novel Persistence Associated EBV miRNA Expression Profile Is Disrupted in Neoplasia. PLoS Pathog. 2011, 7, e1002193. [Google Scholar] [CrossRef] [Green Version]
  58. Murphy, G.; Pfeiffer, R.; Camargo, M.C.; Rabkin, C.S. Meta-analysis Shows That Prevalence of Epstein–Barr Virus-Positive Gastric Cancer Differs Based on Sex and Anatomic Location. Gastroenterology 2009, 137, 824–833. [Google Scholar] [CrossRef] [Green Version]
  59. Caetano, B.F.R.; Jorge, B.A.S.; Müller-Coan, B.G.; de Oliveira, D.E. Epstein-Barr virus microRNAs in the pathogenesis of human cancers. Cancer Lett. 2021, 499, 14–23. [Google Scholar] [CrossRef]
  60. Pfeffer, S.; Zavolan, M.; Grässer, F.A.; Chien, M.; Russo, J.J.; Ju, J.; John, B.; Enright, A.J.; Marks, D.; Sander, C.; et al. Identification of Virus-Encoded MicroRNAs. Science 2004, 304, 734–736. [Google Scholar] [CrossRef]
  61. Tsai, C.-Y.; Liu, Y.Y.; Liu, K.-H.; Hsu, J.-T.; Cheng-Tang, C.; Chiu, C.-T.; Yeh, T.-S. Comprehensive profiling of virus microRNAs of Epstein-Barr virus-associated gastric carcinoma: Highlighting the interactions of ebv-Bart9 and host tumor cells. J. Gastroenterol. Hepatol. 2017, 32, 82–91. [Google Scholar] [CrossRef] [Green Version]
  62. Edwards, R.H.; Marquitz, A.R.; Raab-Traub, N. Epstein-Barr Virus BART MicroRNAs Are Produced from a Large Intron prior to Splicing. J. Virol. 2008, 82, 9094–9106. [Google Scholar] [CrossRef] [Green Version]
  63. Busson, P.; Keryer, C.; Ooka, T.; Corbex, M. EBV-associated nasopharyngeal carcinomas: From epidemiology to virus-targeting strategies. Trends Microbiol. 2004, 12, 356–360. [Google Scholar] [CrossRef] [PubMed]
  64. Zhu, J.Y.; Pfuhl, T.; Motsch, N.; Barth, S.; Nicholls, J.; Grasser, F.; Meister, G. Identification of Novel Epstein-Barr Virus MicroRNA Genes from Nasopharyngeal Carcinomas. J. Virol. 2009, 83, 3333–3341. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  65. Sakamoto, K.; Sekizuka, T.; Uehara, T.; Hishima, T.; Mine, S.; Fukumoto, H.; Sato, Y.; Hasegawa, H.; Kuroda, M.; Katano, H. Next-generation sequencing of miRNAs in clinical samples of Epstein-Barr virus-associated B-cell lymphomas. Cancer Med. 2017, 6, 605–618. [Google Scholar] [CrossRef] [PubMed]
  66. Lo, A.K.-F.; Dawson, C.W.; Jin, D.-Y.; Lo, K.-W. The pathological roles of BART miRNAs in nasopharyngeal carcinoma. J. Pathol. 2012, 227, 392–403. [Google Scholar] [CrossRef] [PubMed]
  67. Baer, R.; Bankier, A.T.; Biggin, M.D.; Deininger, P.L.; Farrell, P.J.; Gibson, T.J.; Hatfull, G.; Hudson, G.S.; Satchwell, S.C.; Séguin, C.; et al. DNA sequence and expression of the B95-8 Epstein—Barr virus genome. Nat. Cell Biol. 1984, 310, 207–211. [Google Scholar] [CrossRef] [PubMed]
  68. Fukayama, M. Epstein-Barr virus and gastric carcinoma. Pathol. Int. 2010, 60, 337–350. [Google Scholar] [CrossRef]
  69. Hooykaas, M.J.G.; Van Gent, M.; Soppe, J.A.; Kruse, E.; Boer, I.G.J.; Van Leenen, D.; Koerkamp, M.J.A.G.; Holstege, F.C.P.; Ressing, M.E.; Wiertz, E.J.H.J.; et al. EBV MicroRNA BART16 Suppresses Type I IFN Signaling. J. Immunol. 2017, 198, 4062–4073. [Google Scholar] [CrossRef] [Green Version]
  70. Skinner, C.M.; Ivanov, N.S.; Barr, S.A.; Chen, Y.; Skalsky, R.L. An Epstein-Barr Virus MicroRNA Blocks Interleukin-1 (IL-1) Signaling by Targeting IL-1 Receptor 1. J. Virol. 2017, 91, e00530-17. [Google Scholar] [CrossRef] [Green Version]
  71. Lorusso, F.; Caleca, M.P.; Bellavia, C.; Pistoia, D.; Gallina, S.; Speciale, R.; Dispenza, F.; Fasciana, T.; Capra, G. The EBV-DNA Can be Used as a Diagnostic and Follow-up Parameter of the Rhinopharyngeal Tumors in the Non-Endemic Population of the Western Sicily. Indian J. Otolaryngol. Head Neck Surg. 2019, 71, 396–400. [Google Scholar] [CrossRef] [PubMed]
  72. Koch, M.; Mollenkopf, H.-J.; Klemm, U.; Meyer, T.F. Induction of microRNA-155 is TLR- and type IV secretion system-dependent in macrophages and inhibits DNA-damage induced apoptosis. Proc. Natl. Acad. Sci. USA 2012, 109, E1153–E1162. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  73. Prinz, C.; Weber, D. MicroRNA (miR) dysregulation during Helicobacter pylori-induced gastric inflammation and cancer development: Critical importance of miR-55. Oncotarget 2020, 11, 894–904. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  74. Xiao, B.; Liu, Z.; Li, B.; Tang, B.; Li, W.; Guo, G.; Shi, Y.; Wang, F.; Wu, Y.; Tong, W.; et al. Induction of microRNA-155 duringHelicobacter pyloriInfection and Its Negative Regulatory Role in the Inflammatory Response. J. Infect. Dis. 2009, 200, 916–925. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  75. Tili, E.; Michaille, J.-J.; Cimino, A.; Costinean, S.; Dumitru, C.D.; Adair, B.; Fabbri, M.; Alder, H.; Liu, C.G.; Calin, G.A.; et al. Modulation of miR-155 and miR-125b Levels following Lipopolysaccharide/TNF-α Stimulation and Their Possible Roles in Regulating the Response to Endotoxin Shock. J. Immunol. 2007, 179, 5082–5089. [Google Scholar] [CrossRef] [PubMed]
  76. Zhang, Z.; Li, Z.; Li, Y.; Zang, A. MicroRNA and signaling pathways in gastric cancer. Cancer Gene Ther. 2014, 21, 305–316. [Google Scholar] [CrossRef] [Green Version]
  77. Krump, N.A.; You, J. Molecular mechanisms of viral oncogenesis in humans. Nat. Rev. Genet. 2018, 16, 684–698. [Google Scholar] [CrossRef]
Table 1. Overview of microRNAs (miRNAs) upregulated and downregulated in gastric cancer (GC) and potential targets.
Table 1. Overview of microRNAs (miRNAs) upregulated and downregulated in gastric cancer (GC) and potential targets.
Downregulated miRNAs in GC and Potential TargetsImportance
miR-22Downregulation seems to activate oncogenic gene Sp1 [28].Promotes cell migration and invasion in GC cell lines.
miR-30bDownregulation targets plasminogen activator inhibitor [38].Reduced apoptosis of cancer cells.
miR-107Tumor-suppressor functions by targeting CDK6 [33].Expression inhibits proliferation and induction of G1 cell cycle arrest; promotes invasion of GC cells.
miR-145Inhibits N-cadherin protein translation and acts via downregulation of matrix metallopeptidase 9 [29],
downregulation of potential tumor suppressor [30].
Hypermethylation leads to miRNA downregulation, which is associated with increased tumor growth and spreading.
miR-181cTargets genes such as NOTCH4 and KRAS [26].Downregulation in tumors leads to increased growth of GC cell lines.
miR-206A potential tumor suppressor targeting cyclin D2 (CCND2) [31].Countereffect: miR-206 suppresses GC cell proliferation, reducing cell growth and colony-forming abilities.
miR-210Alters CpG methylation [39].Downregulation enhances growth of GC cells.
miR-331-3pA potential tumor suppressor in GC; directly targets E2F1 [32].Downregulation enhances growth of GC cells.
miR-370Inhibits expression of transforming growth factor-β receptor II [18].Downregulation associated with more advanced nodal metastasis and a higher clinical stage of GC.
miR-375Acts as tumor suppressor by targeting JAK2 oncogene [22,23,24].Downregulated in GC cells, reduces cell viability via caspase-mediated apoptosis pathway through downregulation of PDK1.
miR-422Targets pyruvate dehydrogenase kinase 2 (PDK 2) [40].Downregulation of miR-422 enhances tumor growth.
miR-490Downregulation of potential tumor suppressor [30].Enhances tumor growth.
miR-490-3p [30]miR-490-3p suppresses growth and metastasis in cell lines by targeting SMARCD1 [30].Prognostic biomarker due to close correlation with shorter patient survival independent of TNM staging.
miR-1228Targets macrophage migration inhibitory factor [41].Downregulated in GC; impairs the proangiogenic activity of GC cells.
Upregulated miRNAs in GC
and Potential Targets
Importance
miR-21Affects microsatellite instability (MSI); significantly associated with poor tumor differentiation [16].miR-21 overexpression promotes GC cell growth, invasion, and migration in vitro; prognostic marker for local invasion, and lymph-node metastasis.
miR-107Upregulated in gastric cancer [12].Continuing upregulation from normal mucosa, adenoma, and cancer.
miR-146aGastric tumors and chronic gastric inflammation show miR-146a overexpression [42,43].miR-146a dysregulation may promote gastric tumorigenesis and metastasis.
miR-221 and
miR-616-3p
Direct modulation of PTEN [34].Upregulated in GC cells, affecting angiogenesis and invasion.
miR-222Inhibition of hepatocyte growth factor and activator-inhibitor type 1 protein expression [44].Overexpression of miR-221 and miR-222 promotes cell proliferation and migration.
miR-300Upregulated in gastrointestinal cancer [12].Continuing upregulation from normal mucosa, adenoma, and cancer.
Table 2. Overview of diagnostic and prognostic relevance of certain miRNAs during Helicobacter pylori and Epstein–Barr virus (EBV)-induced gastric inflammation, and gastric carcinogenesis, outlining that most miRNAs are not involved in both EBV and H. pylori infection, and only one miRNA (miR-155) seems to be affected by both etiologies. Three miRNAs of the let-7 group, and miR-106b and miR-145, are dysregulated both during the H. pylori-induced process of inflammatory changes and during gastric-cancer progression, and may thus be considered to be new and interesting biomarkers during the continuing and chronic disease.
Table 2. Overview of diagnostic and prognostic relevance of certain miRNAs during Helicobacter pylori and Epstein–Barr virus (EBV)-induced gastric inflammation, and gastric carcinogenesis, outlining that most miRNAs are not involved in both EBV and H. pylori infection, and only one miRNA (miR-155) seems to be affected by both etiologies. Three miRNAs of the let-7 group, and miR-106b and miR-145, are dysregulated both during the H. pylori-induced process of inflammatory changes and during gastric-cancer progression, and may thus be considered to be new and interesting biomarkers during the continuing and chronic disease.
Dysregulated miRNA during H. pylori InfectionRoles and Functions of Involved miRNAsDysregulated miRNA during EBV InfectionRoles and Functions of Involved miRNAs
BamHI-A region rightward transcript (BART)-miRNA dysregulation reported during Type 1 latent infections relevant to GC development.BART-miRNAs are divided into two subsets [61]; miRNA-BART2-5p and miRNA-BART2-3p are reported to be the rear members of these two subgroups, and may affect bcl2-dependent pathways [67].
miRNA-BART16 [69,70]Targets and regulates CREB binding, a transcriptional coactivator in the interferon signaling pathway (IFN); facilitates latent EBV infection by inhibiting IFN Type I-induced antiviral response.
miR-155 [74]Involved in immune response; bacterial lipopolysaccharide (LPS) exposure induces miR-155 expression in immune cells; potential role as diagnostic marker; increased expression upon H. pylori infection and in gastric adenocarcinoma.miR-155 [14,15]Dysregulation of miR-155 enables persistence of EBV in immune cells; miR-155 regulation is dependent on activator protein 1 (AP-1) pathway in B cells [14,15].
Let-7b [47]
Let-7c [46]
Correlates with inflammatory process, tumor stage, and lymphatic metastasis in H. pylori-induced gastric adenocarcinoma.
miR-106b [49]Inhibition of miR-106b associated with STAT3 signaling, a key molecule during H. pylori-induced immune responses; varies with inflammatory scores and cancer development.
miR-146a [42,43]Gastric tumors and chronic gastric inflammation show miR-146a overexpression.
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Prinz, C.; Mese, K.; Weber, D. MicroRNA Changes in Gastric Carcinogenesis: Differential Dysregulation during Helicobacter pylori and EBV Infection. Genes 2021, 12, 597. https://doi.org/10.3390/genes12040597

AMA Style

Prinz C, Mese K, Weber D. MicroRNA Changes in Gastric Carcinogenesis: Differential Dysregulation during Helicobacter pylori and EBV Infection. Genes. 2021; 12(4):597. https://doi.org/10.3390/genes12040597

Chicago/Turabian Style

Prinz, Christian, Kemal Mese, and David Weber. 2021. "MicroRNA Changes in Gastric Carcinogenesis: Differential Dysregulation during Helicobacter pylori and EBV Infection" Genes 12, no. 4: 597. https://doi.org/10.3390/genes12040597

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop