Search Results (15)

Background and objectives: Extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Enterobacteriaceae represent an increasing One Health concern because food-producing animals may act as reservoirs of antimicrobial-resistant bacteria with potential transmission to humans. Therefore, this study aimed to assess the prevalence and genomic characteristics of ESBL- and carbapenemase-producing Enterobacteriaceae in livestock and farmers, and to evaluate genomic overlap between animal and human ESBL-producing Escherichia coli to explore potential shared origins and interspecies transmission. Methods: We conducted a cross-sectional study in Osona (Catalonia, Spain), sampling livestock (swine, cattle, poultry, and horses) and farmers. ESBL-, AmpC-, and carbapenemase-producing Enterobacteriaceae were identified and characterized using whole genome sequencing (WGS). Genomic analyses included sequence typing (ST), serotyping, virulence-associated genes, antimicrobial resistance determinants, and plasmid replicon profiling. Results: A total of 945 animals were analysed. ESBL-producing Enterobacteriaceae were predominantly detected in swine, with 63.5% (127/200) of animals testing positive, including four ESBL + AmpC-producing isolates and two carbapenem-resistant Enterobacteriaceae. No ESBL-, AmpC- or carbapenemase-producing isolates were identified in cattle (0/360) or poultry (0/171), and a low prevalence was observed in horses (7.0%, 15/214). A total of 64 farm workers were analysed. ESBL-producing E. coli were detected in 46.7% (7/15) of swine farmers and 8.3% (2/24) of cattle farmers, while no ESBL-producing isolates were found among poultry farmers (0/8) or equine caretakers (0/17). A total of 162 isolates were analyzed by WGS, showing high genetic diversity. Among the 127 Escherichia coli isolates, the most prevalent were ST10 (18/127, 14.2%), followed by ST453 (7/127, 5.5%), ST515 (7/127, 5.5%), and ST10562 (7/127, 5.5%). Virulence-associated gene profiles were heterogeneous, although genes related to stress tolerance and intestinal colonization predominated among ESBL-producing E. coli isolates from swine, including terC (54/127, 42.5%), csgA (41/127, 32.3%), nlpI (41/127, 32.3%), and fimH (39/127, 30.7%). ESBL production among E. coli isolates from swine was primarily mediated by blaCTX-M genes (89/127, 70.1%), with additional contributions from blaSHV (34/127, 26.8%) and blaTEM (40/127, 31.5%). Among swine isolates, IncX1 (100/127, 78.7%), IncFIB(AP001918) (82/127, 64.6%), IncI1-I(Alpha) (69/127, 54.3%), and IncFII (54/127, 42.5%) were the most frequently detected plasmid replicons. Two carbapenem-resistant isolates carrying blaOXA-48 were identified in swine, including E. coli ST58 and K. oxytoca ST145, both associated with IncL plasmids. Conclusions: Swine appear to constitute the primary reservoir of ESBL-producing E. coli. The genomic relatedness observed between animal and human isolates supports shared exposure to a common ecological pool of multidrug-resistant bacteria. The identification of blaOXA-48-producing Enterobacterales associated with IncL plasmids further highlights the public health relevance of livestock-associated antimicrobial resistance. However, the cross-sectional design precludes inference of transmission pathways or transmission directionality. Longitudinal studies are needed to elucidate the dynamics of interspecies transmission. Full article

Background/Objectives: Escherichia coli (E. coli) spans commensal, intestinal pathogenic, and extraintestinal pathogenic lineages distributed across human, animal, and environmental reservoirs, yet the extent to which virulence architectures are shared across these compartments remains incompletely understood. Using a One Health framework, we profiled putative virulence determinants in pooled multidrug-resistant (MDR) E. coli source groups representing human, animal, and environmental sectors. Methods: Virulence genes were predicted with VirulenceFinder, and presence–absence profiles were integrated to define functional composition, sector overlap, source-group distribution breadth, and pathotype-associated signatures. Predicted pathogenic potential was assessed with PathogenFinder and compared with pathogenic family richness. Results: Overall, 114 putative virulence genes were detected, with adhesion/colonization functions dominating the virulome (33/114), followed by toxin-associated genes (12/114). A conserved core of 50 virulence genes was shared across all three sectors, including determinants linked to serum resistance (iss, ompT, traT), adhesion (csgA, fimH), stress adaptation (terC), and iron acquisition (sitA, iutA, fyuA). ExPEC-associated determinants were most numerous in environmental source groups (n = 52), whereas diarrheagenic E. coli markers were most frequent in animal-associated groups (n = 42). LEE-associated effectors were infrequent and largely absent from human source groups. Despite ecological differences in virulence composition, pathogenicity scores remained consistently high across sectors (0.83–0.92) and showed no significant association with pathogenic family richness (Spearman’s ρ = 0.197, p = 0.392). Conclusions: Within the limits of pooled source-group analysis, these findings suggest that MDR E. coli across One Health compartments shares a broadly distributed, ExPEC-associated virulence repertoire overlaid with sector-specific pathotype signals, underscoring the value of integrated genomic surveillance while highlighting the need for isolate-resolved analysis. Full article

Early-onset colorectal cancer (EOCRC; age younger than 50 years) incidence has been steadily increasing in recent decades worldwide. The need for new biomarkers for EOCRC prevention strategies is undeniable. In this study, we aimed to explore whether an aging factor, such as telomere length (TL), could be a useful tool in EOCRC screening. The absolute leukocyte TL from 87 microsatellite stable EOCRC patients and 109 healthy controls (HC) with the same range of age, was quantified by Real Time Quantitative PCR (RT-qPCR). Then, leukocyte whole-exome sequencing (WES) was performed to study the status of the genes involved in TL maintenance (hTERT, TERC, DKC1, TERF1, TERF2, TERF2IP, TINF2, ACD, and POT1) in 70 sporadic EOCRC cases from the original cohort. We observed that TL was significantly shorter in EOCRC patients than in healthy individuals (EOCRC mean: 122 kb vs. HC mean: 296 kb; p < 0.001), suggesting that telomeric shortening could be associated with EOCRC susceptibility. In addition, we found a significant association between several SNPs of hTERT (rs79662648), POT1 (rs76436625, rs10263573, rs3815221, rs7794637, rs7784168, rs4383910, and rs7782354), TERF2 (rs251796 and rs344152214), and TERF2IP (rs7205764) genes and the risk of developing EOCRC. We consider that the measurement of germline TL and the status analysis of telomere maintenance related genes polymorphisms at early ages could be non-invasive methods that could facilitate the early identification of individuals at risk of developing EOCRC. Full article

The spread of carbapenemase-producing (CP) Enterobacterales is currently a worldwide concern, especially in the elderly. Twelve CP-E. coli isolated from rectal swabs of colonized inpatients aged ≥65 years from four hospitals in two Italian cities (Milan and Rome) were analyzed by whole genome sequencing (WGS) to obtain multi-locus sequence typing (MLST), identification of carbapenemase-encoding genes, resistome, plasmid content, and virulence genes. MLST analysis showed the presence of 10 unrelated lineages: ST410 (three isolates from three different hospitals in two cities) and ST12, ST38, ST69, ST95, ST131, ST189, ST648, ST1288, and ST1598 (one isolate each). Most isolates (9/12, 75%) contained a serine-β-lactamase gene (5 bla_KPC-3, 2 bla_KPC-2, and 2 bla_OXA-181), while three isolates harbored a metallo-β-lactamase gene (two bla_NDM-5 and one bla_VIM-1). In most CP-E. coli, the presence of more than one plasmid was observed, with the predominance of IncF. Several virulence genes were detected. All isolates contained genes enhancing the bacterial fitness, such as gad and terC, and all isolates but one, fimH, encoding type 1 fimbriae. In conclusion, CP-E. coli clones colonizing elderly patients showed heterogeneous genetic backgrounds. We recommend strict surveillance to monitor and prevent the spread of successful, high-risk clones in healthcare settings. Full article

Human papillomaviruses (HPVs) are common sexually transmitted infectious agents responsible for several anogenital and head and neck cancers. Cervical cancer (CC) is the fourth leading cause of death in women with cancer. The progression of a persistent HPV infection to cancer takes 15–20 years and can be preventable through screening. Cervical cytology (Pap smear) is the standard screening test for CC and precancerous lesions. For ASC-US and ASC-H lesions, a combination of Pap smear and HR-HPV analysis is recommended as a triage step before colposcopy. However, these tests cannot predict progression to CC. For this purpose, we summarized current scientific data on the role of p16/Ki-67 immunohistostaining, telomerase and fibronectin in predicting progression to CC. p16 and p16/Ki-67 dual staining (DS) were more specific than HR-HPV DNA testing for the detection of CIN2+/CIN3+ in women with ASC-US and LSIL. Similarly, hTERC FISH analysis significantly improved the specificity and positive predictive value of HPV DNA testing in differentiating CIN2+ from CIN2 cytological samples. In conclusion, p16 IHC, p16/Ki-67 DS and hTERC FISH amplification are all valid adjunctive biomarkers which significantly increase the sensitivity and specificity of cervical dysplasia diagnosis, especially when combined with HPV DNA testing. However, considering the global socioeconomic background, we can postulate that p16 and p16/ Ki-67 IHC can be used as a next step after positive cytology for ASC-US or LSIL specimens in low-income countries, instead of HPV DNA testing. Alternatively, if HPV DNA testing is covered by insurance, p16 or p16/Ki-67 DS and HPV DNA co-testing can be performed. In middle- and high-income countries, hTERC amplification can be performed as an adjunctive test to HPV DNA testing in women with ASC-US and LSIL. Full article

Telomerase RNA has long been considered to be a noncoding component of telomerase. However, the expression of the telomerase RNA gene is not always associated with telomerase activity. The existence of distinct TERC gene expression products possessing different functions were demonstrated recently. During biogenesis, hTR is processed by distinct pathways and localized in different cell compartments, depending on whether it functions as a telomerase complex component or facilitates antistress activities as a noncoding RNA, in which case it is either processed in the mitochondria or translated. In order to identify the factors responsible for the appearance and localization of the exact isoform of hTR, we investigated the roles of the factors regulating transcription DSIF (Spt5) and NELF-E; exosome-attracting factors ZCCHC7, ZCCHC8, and ZFC3H1; ARS2, which attracts processing and transport factors; and transport factor PHAX during the biogenesis of hTR. The data obtained revealed that ZFC3H1 participates in hTR biogenesis via pathways related to the polyadenylated RNA degradation mechanism. The data revealed essential differences that are important for understanding hTR biogenesis and that are interesting for further investigations of new, therapeutically significant targets. Full article

Proper telomere length is essential for indefinite self-renewal of embryonic stem (ES) cells and cancer cells. Telomerase-deficient late generation mouse ES cells and human ALT cancer cells are able to propagate for numerous passages, suggesting telomerase-independent mechanisms responding for telomere maintenance. However, the underlying mechanisms ensuring the telomere length maintenance are unclear. Here, using late generation telomerase KO (G4 Terc^-/-) ESCs as a model, we show that Zscan4, highly upregulated in G4 Terc^-/- ESCs, is responsible for the prolonged culture of these cells with stably short telomeres. Mechanistically, G4 Terc^-/- ESCs showed reduced levels of DNA methylation and H3K9me3 at Zscan4 promoter and subtelomeres, which relieved the expression of Zscan4. Similarly, human ZSCAN4 was also derepressed by reduced H3K9me3 at its promoter in ALT U2 OS cells, and depletion of ZSCAN4 significantly shortened telomeres. Our results define a similar conserved pathway contributing to the telomere maintenance in telomerase-deficient late generation mESCs and human ALT U2OS cancer cells. Full article

Colorectal cancer (CRC) is the most common cancer among males and females, which is associated with the increment of telomerase level and activity. Some plant-derived compounds are telomerase inhibitors that have the potential to decrease telomerase activity and/or level in various cancer cell lines. Unfortunately, a deeper understanding of the effects of telomerase inhibitor compound(s) on CRC cells is still lacking. Therefore, in this study, the aspects of telomerase inhibitors on a CRC cell line (HCT 116) were investigated. Screening on HCT 116 at 48 h showed that berberine (10.30 ± 0.89 µg/mL) is the most effective (lowest IC₅₀ value) telomerase inhibitor compared to boldine (37.87 ± 3.12 µg/mL) and silymarin (>200 µg/mL). Further analyses exhibited that berberine treatment caused G₀/G₁ phase arrest at 48 h due to high cyclin D1 (CCND1) and low cyclin-dependent kinase 4 (CDK4) protein and mRNA levels, simultaneous downregulation of human telomerase reverse transcriptase (TERT) mRNA and human telomerase RNA component (TERC) levels, as well as a decrease in the TERT protein level and telomerase activity. The effect of berberine treatment on the cell cycle was time dependent as it resulted in a delayed cell cycle and doubling time by 2.18-fold. Telomerase activity and level was significantly decreased, and telomere erosion followed suit. In summary, our findings suggested that berberine could decrease telomerase activity and level of HCT 116, which in turn inhibits the proliferative ability of the cells. Full article

Telomeres protect chromosomal ends and they are maintained by the specialised enzyme, telomerase. Endometriosis is a common gynaecological disease and high telomerase activity and higher hTERT levels associated with longer endometrial telomere lengths are characteristics of eutopic secretory endometrial aberrations of women with endometriosis. Our ex-vivo study examined the levels of hTERC and DKC1 RNA and dyskerin protein levels in the endometrium from healthy women and those with endometriosis (n = 117). The in silico study examined endometriosis-specific telomere- and telomerase-associated gene (TTAG) transcriptional aberrations of secretory phase eutopic endometrium utilising publicly available microarray datasets. Eutopic secretory endometrial hTERC levels were significantly increased in women with endometriosis compared to healthy endometrium, yet dyskerin mRNA and protein levels were unperturbed. Our in silico study identified 10 TTAGs (CDKN2A, PML, ZNHIT2, UBE3A, MCCC2, HSPC159, FGFR2, PIK3C2A, RALGAPA1, and HNRNPA2B1) to be altered in mid-secretory endometrium of women with endometriosis. High levels of hTERC and the identified other TTAGs might be part of the established alteration in the eutopic endometrial telomerase biology in women with endometriosis in the secretory phase of the endometrium and our data informs future research to unravel the fundamental involvement of telomerase in the pathogenesis of endometriosis. Full article

Telomerase provides cancer cells with replicative immortality, and its overexpression serves as a near-universal marker of cancer. Anti-cancer therapeutics targeting telomerase have garnered interest as possible alternatives to chemotherapy and radiotherapy. Oligonucleotide-based therapies that inhibit telomerase through direct or indirect modulation of its subunits, human telomerase reverse transcriptase (hTERT) and human telomerase RNA gene (hTERC), are a unique and diverse subclass of telomerase inhibitors which hold clinical promise. MicroRNAs that play a role in the upregulation or downregulation of hTERT and respective progression or attenuation of cancer development have been effectively targeted to reduce telomerase activity in various cancer types. Tumor suppressor miRNAs, such as miRNA-512-5p, miRNA-138, and miRNA-128, and oncogenic miRNAs, such as miRNA-19b, miRNA-346, and miRNA-21, have displayed preclinical promise as potential hTERT-based therapeutic targets. Antisense oligonucleotides like GRN163L and T-oligos have also been shown to uniquely target the telomerase subunits and have become popular in the design of novel cancer therapies. Finally, studies suggest that G-quadruplex stabilizers, such as Telomestatin, preserve telomeric oligonucleotide architecture, thus inhibiting hTERC binding to the telomere. This review aims to provide an adept understanding of the conceptual foundation and current state of therapeutics utilizing oligonucleotides to target the telomerase subunits, including the advantages and drawbacks of each of these approaches. Full article

Senescence is defined as a stress-induced durable cell cycle arrest. We herein revisit the origin of two of these stresses, namely mitochondrial metabolic compromise, associated with reactive oxygen species (ROS) production, and replicative senescence, activated by extreme telomere shortening. We discuss how replication stress-induced DNA damage of telomeric DNA (telDNA) and mitochondrial DNA (mtDNA) can be considered a common origin of senescence in vitro, with consequences on ageing in vivo. Unexpectedly, mtDNA and telDNA share common features indicative of a high degree of replicative stress, such as G-quadruplexes, D-loops, RNA:DNA heteroduplexes, epigenetic marks, or supercoiling. To avoid these stresses, both compartments use similar enzymatic strategies involving, for instance, endonucleases, topoisomerases, helicases, or primases. Surprisingly, many of these replication helpers are active at both telDNA and mtDNA (e.g., RNAse H1, FEN1, DNA2, RecQ helicases, Top2α, Top2β, TOP3A, DNMT1/3a/3b, SIRT1). In addition, specialized telomeric proteins, such as TERT (telomerase reverse transcriptase) and TERC (telomerase RNA component), or TIN2 (shelterin complex), shuttle from telomeres to mitochondria, and, by doing so, modulate mitochondrial metabolism and the production of ROS, in a feedback manner. Hence, mitochondria and telomeres use common weapons and cooperate to resist/prevent replication stresses, otherwise producing common consequences, namely senescence and ageing. Full article

Lung cancer is the most prevalent and deadliest cancer worldwide. A significant part of lung cancer studies is dedicated to the expression alterations of non-coding RNAs. The non-coding RNAs are transcripts that cannot be translated into proteins. While the study of microRNAs and siRNAs in lung cancer received a lot of attention over the last decade, highly efficient therapeutic option or the diagnostic methods based on non-coding RNAs are still lacking. Because of this, it is of utmost importance to direct future research on lung cancer towards analyzing other RNA types for which the currently available data indicates that are essential at modulating lung tumorigenesis. Through our review of studies on this subject, we identify the following non-coding RNAs as tumor suppressors: ts-46, ts-47, ts-101, ts-53, ts-3676, ts-4521 (tRNA fragments), SNORD116-26, HBII-420, SNORD15A, SNORA42 (snoRNAs), piRNA-like-163, piR-35127, the piR-46545 (piRNAs), CHIAP2, LOC100420907, RPL13AP17 (pseudogenes), and uc.454 (T-UCR). We also found non-coding RNAs with tumor-promoting function: tRF-Leu-CAG, tRNA-Leu, tRNA-Val (tRNA fragments), circ-RAD23B, circRNA 100146, circPVT1, circFGFR3, circ_0004015, circPUM1, circFLI1, circABCB10, circHIPK3 (circRNAs), SNORA42, SNORA3, SNORD46, SNORA21, SNORD28, SNORA47, SNORD66, SNORA68, SNORA78 (snoRNAs), piR-65, piR-34871, piR-52200, piR651 (piRNAs), hY4 5’ fragments (YRNAs), FAM83A-AS1, WRAP53, NKX2-1-AS1 (NATs), DUXAP8, SFTA1P (pseudogene transcripts), uc.338, uc.339 (T-UCRs), and hTERC. Full article

The telomerase ribonucleoprotein complex has a pivotal role in regulating the proliferation and senescence of normal somatic cells as well as cancer cells. This complex is comprised mainly of telomerase reverse transcriptase (TERT), telomerase RNA component (TERC) and other associated proteins that function to elongate telomeres localized at the end of the chromosomes. While reactivation of telomerase is a major hallmark of most cancers, together with the synergistic activation of other oncogenic signals, deficiency in telomerase and telomeric proteins might lead to aging and senescence-associated disorders. Therefore, it is critically important to understand the canonical as well as non-canonical functions of telomerase through TERT to develop a therapeutic strategy against telomerase-related diseases. In this review, we shed light on the regulation and function of telomerase, and current therapeutic strategies against telomerase in cancer and age-related diseases. Full article

Telomerase is a reverse transcriptase capable of utilizing an integrated RNA component as a template to add protective tandem telomeric single strand DNA repeats, TTAGGG, to the ends of chromosomes. Telomere dysfunction and telomerase reactivation are observed in approximately 90% of human cancers; hence, telomerase activation plays a unique role as a nearly universal step on the path to malignancy. In the past two decades, multiple telomerase targeting therapeutic strategies have been pursued, including direct telomerase inhibition, telomerase interference, hTERT or hTERC promoter driven therapy, telomere-based approaches, and telomerase vaccines. Many of these strategies have entered clinical development, and some have now advanced to phase III clinical trials. In the coming years, one or more of these new telomerase-targeting drugs may be expected to enter the pharmacopeia of standard care. Here, we briefly review the molecular functions of telomerase in cancer and provide an update about the preclinical and clinical development of telomerase targeting therapeutics. Full article

Telomeres consist of repeat DNA sequences located at the terminal portion of chromosomes that shorten during mitosis, protecting the tips of chromosomes. During chronic degenerative conditions associated with high cell replication rate, progressive telomere attrition is accentuated, favoring senescence and genomic instability. Several lines of evidence suggest that this process is involved in liver disease progression: (a) telomere shortening and alterations in the expression of proteins protecting the telomere are associated with cirrhosis and hepatocellular carcinoma; (b) advanced liver damage is a feature of a spectrum of genetic diseases impairing telomere function, and inactivating germline mutations in the telomerase complex (including human Telomerase Reverse Transcriptase (hTERT) and human Telomerase RNA Component (hTERC)) are enriched in cirrhotic patients independently of the etiology; and (c) experimental models suggest that telomerase protects from liver fibrosis progression. Conversely, reactivation of telomerase occurs during hepatocarcinogenesis, allowing the immortalization of the neoplastic clone. The role of telomere attrition may be particularly relevant in the progression of nonalcoholic fatty liver, an emerging cause of advanced liver disease. Modulation of telomerase or shelterins may be exploited to prevent liver disease progression, and to define specific treatments for different stages of liver disease. Full article