Search Results (45)

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal oncological diseases, with a 5-year survival rate of approximately 13%—among the lowest in oncology. Poor survival is driven by aggressive tumor progression and metastasis, which may be influenced by the tumor microbiome. This study aimed to evaluate the role of microbiome in PDAC progression and metastasis. First, we assessed the microbial composition of control samples (surface swabs, empty paraffin, extraction controls, and sequencing controls) and removed contaminant taxa. Overall bacterial biomass was extremely low, with no significant differences in alpha or beta-diversity between tumor and normal tissue. Kocuria rosea was significantly enriched in tumors compared to normal tissue, and this difference persisted after decontamination. Metastatic tumors showed altered abundance of K. rosea and Herbaspirillum huttiense, whereas non-metastatic tumors differed in Lysobacter bugurensis, Caulobacter ginsengisoli, and H. huttiense relative to normal tissue. No global compositional differences were observed between KRAS-mutant and wild-type tumors; however, KRAS-mutant tumors exhibited differential enrichment of K. rosea and L. bugurensis relative to adjacent normal tissue. The PDAC microbiome harbors very low bacterial biomass and does not robustly distinguish tumor from normal tissue at the community level. Nonetheless, K. rosea emerges as a candidate taxon differentially enriched in PDAC, with potential stage- and KRAS-associated patterns. These findings highlight the need for orthogonal validation (qPCR, FISH, culture) and larger prospective cohorts to differentiate true biological associations from residual contamination or stochastic noise in low-biomass settings. Full article

Increasing evidence suggests that intratumoral microorganisms and their metabolites can modulate cancer initiation and progression. However, the composition and functional role of intratumoral bacteria in canine mammary tumors (CMTs) remain unclear. In this study, we investigated the functional significance of tumor-derived Staphylococcus in CMTs, focusing on its effects on the proliferation and migration of CMT-U27 cells. 16S rRNA sequencing revealed reduced alpha diversity in CMT tissues, with Staphylococcus pseudintermedius identified as the most frequently isolated species. Functional assays, including CCK-8, wound healing, RT-qPCR, and Western blot analyses, demonstrated that intratumoral Staphylococcus pseudintermedius significantly enhanced cellular proliferation and migration. Mechanistically, Staphylococcus pseudintermedius significantly upregulated the expression of TLR2, as well as the phosphorylation levels of PI3K, Akt and P70S6K. The inhibition of TLR2 using C29 suppressed the mRNA expression of VEGF, MMP9, MMP2, and EGFR. Collectively, these findings indicate that intratumoral Staphylococcus pseudintermedius promotes the proliferation and migration of CMT-U27 cells through activation of the TLR2/PI3K/Akt pathway, highlighting a functional link between tumor-associated bacteria and cancer progression. Full article

Genitourinary malignancies are characterized by marked heterogeneity in tumor biology, clinical behavior and therapeutic outcomes. Despite significant progress in surgical and systemic treatments, resistance to therapy remains a major challenge, highlighting the need to identify additional host-related determinants of disease progression and treatment response. Within this framework, converging experimental and clinical evidence indicates that host-associated microbial ecosystems may influence key biological processes involved in tumor–host interactions, including immune modulation, metabolic regulation and inflammatory pathways. Altered microbial profiles have been associated with oncogenic signaling, changes in the tumor microenvironment and differences in clinical benefit from systemic therapies, particularly immunotherapeutic approaches. This review brings together preclinical, translational and clinical evidence on the involvement of microbiota in renal, prostate, bladder and testicular cancers, with attention to biological mechanisms and clinically meaningful correlations with disease characteristics. While current data are largely observational, early interventional studies suggest that modulation of microbial ecosystems may influence therapeutic activity in selected clinical settings. Collectively, these findings support microbiota as a relevant component of genitourinary cancer biology with potential implications for precision medicine approaches. Full article

Gliomas, particularly glioblastoma multiforme, remain among the most lethal brain tumours despite multimodal therapy. Increasing evidence indicates that systemic factors, including the gut microbiota, may influence glioma progression through immune, metabolic, and neurochemical pathways. We conducted a comprehensive systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines to synthesize recent evidence on the role of gut and intratumoral microbiota in glioma biology. Peer-reviewed studies published within the last five years were identified through structured searches of major biomedical databases, and original studies using human cohorts, animal models, or Mendelian randomization approaches were included. The 17 studies met the eligibility criteria. Glioma was consistently associated with gut dysbiosis characterized by a reduced Firmicutes:Bacteroidetes ratio and enrichment of Verrucomicrobia, particularly Akkermansia, alongside decreased short-chain fatty acids and altered neurotransmitter profiles, contributing to neuroinflammation, immune suppression, and blood–brain barrier dysfunction. Antigenic mimicry by Bacteroidetes-derived peptides may impair antitumour T-cell responses, while intratumoral Fusobacteriota and Proteobacteria appear to promote angiogenesis and pro-inflammatory chemokine expression. In contrast, SCFA-producing taxa such as Ruminococcaceae and probiotic genera including Lactobacillus and Bifidobacterium show protective associations. Evidence is limited by small cohorts and methodological heterogeneity. Standardized humanized models and integrated multi-omics approaches are required to clarify causal mechanisms and support microbiome-targeted therapies in glioma. Full article

The intratumoral microbiota, comprising bacteria, fungi, and viruses within the tumor microenvironment, actively influences carcinogenesis. Key mechanisms include the induction of host DNA damage, modulation of critical oncogenic signaling pathways such as WNT-β-catenin, NF-κB, and PI3K, and the orchestration of inflammatory processes. The microbiome’s interaction with the host immune system is complex and bidirectional. On one hand, specific microbes can foster a pro-tumorigenic niche by suppressing the activity of cytotoxic T cells and natural killer (NK) cells or by promoting the accumulation of immunosuppressive cell types like tumor-associated macrophages (TAMs). On the other hand, microbial components can serve as neoantigens for T cell recognition or produce metabolites that reprogram the immune landscape to enhance anti-tumor responses. The composition of this microbiome is emerging as a crucial factor influencing the outcomes of immunotherapies. Prospective investigations in cancer immunotherapy ought to prioritize mechanistic inquiry employing integrative multi-omics methodologies. The execution of meticulously designed clinical trials for the validation of microbial biomarkers, and the systematic, evidence-based development of microbiome-targeted therapeutic interventions aimed at enhancing antitumor immune responses. Full article

Brain tumors (BTs), including glioblastoma (GBM) and meningioma (MGM), contribute significantly to the global cancer burden. The microbiome has been implicated in carcinogenesis, yet its role in BTs remains underexplored. We performed 16S rRNA gene sequencing of the gut microbiota (GM) and intratumoral microbiome (ItM) from fresh tissue samples of 9 patients with GBM and 18 with MGM. 12 age- and sex-matched healthy controls (HCs) were also enrolled. GM profiling revealed reduced alpha diversity and distinct microbial communities in BT patients versus HCs. Notably, Verrucomicrobiota and Synergistaceae were enriched, while Lachnospiraceae, Peptostreptococcaceae, and Muribacter spp. were depleted. GBM patients showed reductions in Peptostreptococcaceae and the Eubacterium hallii group, while MGM patients had increased Synergistia and Erysipelatoclostridium. Compared with MGM, GBM patients were enriched in Peptostreptococcales–Tissierellales, Coprobacillus, and Peptoniphilus but depleted in Weissella. Venn analysis revealed 176 genera shared across groups with unique taxa distinguishing tumor patients and HCs. ItM profiling revealed enrichment of Proteobacteria, Actinomycetota, and Campylobacterota in GBM, while MGM contained higher levels of Bacillota and Bacteroidota. GBM tissues harbored Burkholderia-Caballeronia-Paraburkholderia, Helicobacter, and Leifsonia, whereas MGM tissues were dominated by Bacteroides and Blautia. Notably, stool and tumor samples shared 91 genera in GBM and 105 in MGM. This study provides novel insights by (i) characterizing ItM from fresh samples, (ii) comparing ItM profiles of GBM and MGM, (iii) linking GM and ItM within the same patients, and (iv) suggesting potential clinical implications for BT management. Full article

Background: Triple-negative breast cancer (TNBC) is an aggressive subtype with limited treatment options and poor clinical outcomes. Emerging evidence suggests that the tumor-associated microbiome may influence disease progression and therapy response. Methods: We investigated how the Gram-negative bacterium Pseudomonas aeruginosa and Gram-positive bacterium Staphylococcus aureus, together with their cell wall components lipopolysaccharide (LPS) and lipoteichoic acid (LTA), modulate doxorubicin (DOX) efficacy in TNBC cells. Using gentamicin protection combined with flow cytometry of eFluor 450-labeled bacteria and CFU quantification, we assessed bacterial uptake, persistence, and effects on drug response in MDA-MB-468, MDA-MB-231, and MDA-MB-453 cells. Results: Both bacteria entered TNBC cells and survived for several days in a cell line-dependent manner. Notably, bacterial infection and purified cell wall ligands (LPS and LTA) significantly increased DOX accumulation and enhanced cytotoxicity in MDA-MB-468 and MDA-MB-231, but not in MDA-MB-453. The similar effects of LPS and LTA implicate Toll-like receptor signaling (TLR2 and TLR4) in modulating drug uptake. Conclusions: These findings demonstrate that bacterial infection and associated ligands can enhance doxorubicin uptake and cytotoxicity in TNBC cells, implicating TLR signaling as a potential contributor. Our results highlight the importance of host–microbe interactions in shaping chemotherapy response and warrant further investigation into their therapeutic relevance. Full article

Colorectal cancer (CRC) is one of the most common cancers, accounting for approximately 10% of all new cancer cases globally. An increasing number of studies have revealed that the gut microbiome is strongly associated with the pathogenesis and progression of CRC. Based on these advances, this review delineates the mechanistic links between specific microbes and CRC, as well as emerging food-related nutritional intervention strategies. In vivo and in vitro studies have pinpointed the implications of key microbes such as Fusobacterium nucleatum, certain strains of Escherichia coli, enterotoxigenic Bacteroides fragilis, and Enterococcus faecalis, among others, and metabolite involvement and immune responses. Particular attention is paid to the roles of intratumoral microbiota in the development and treatment of CRC, given their direct interaction with tumor cells. Various food-related nutritional intervention strategies have been developed to mitigate CRC risk, including probiotics, antibiotics, or the administration of bioactive compounds such as luteoloside. Finally, we outline critical research directions regarding the influence of animal lineage, carcinoma location, population demographics, the application of advanced in vitro models, and the mediatory roles of gut-associated epithelial cells. In summary, this review might consolidate our current knowledge on the contribution of gut microbiota to CRC and highlights the microbe-based strategies to enhance nutritional interventions for this disease. Full article

Background: The involvement of the intratumoral microbiome in prostate cancer progression is becoming increasingly acknowledged. This study analyzed the microbiome of prostate cancer tissues from patients with localized prostate cancer (LPC, stages 1–2) and advanced prostate cancer (APC, stages 3–4) to determine its association with cancer progression. Methods: Paraffin-embedded tissue samples obtained during radical prostatectomy underwent 16S rRNA amplicon-based profiling. Results: The profile of the bacterial communities in LPC and APC differed remarkably. While species diversity remained stable, species richness (as determined by the ACE analysis) was significantly lower in APC, correlating with a decrease in Enhydrobacter (which is more abundant in LPC) and an increase in Lautropia (enriched in APC). The role of Lautropia in the progression of cancer was confirmed by in vitro studies employing cell lines from prostate cancer. Conclusions: These findings demonstrate the potential of microbiome-targeted interventions in the management of prostate cancer. Full article

Unconventional T (UC T) cells, including invariant natural killer T (iNKT) cells, mucosal-associated invariant T (MAIT) cells, γδ T cells, and double-negative (DN) T cells, are key players in immune surveillance and response due to their properties combining innate-like and adaptive-like features. These cells are widely present in mucosal tissues, where they can rapidly respond to infections and tumor-associated changes. In fact, UC T cells can have both pro- and anti-tumoral effects, with their activity influenced by factors such as microbial composition and the tumor microenvironment. In particular, intratumoral microbiota significantly impacts the development, function, and activation of UC T cells, influencing cytokine production and shaping the immune response in various cancers. The complex crosstalk between UC T cells and the surrounding factors is discussed in this review, with a focus on how these cells might be interesting candidates to explore and exploit as anticancer therapeutic agents. However, the great potential of UC T cells, not only demonstrated in the context of adoptive cell transfer, but also enhanced through techniques of engineering, is still flanked by different challenges, like the immunosuppressive tumor microenvironment and heterogeneity of target molecules associated with some specific categories of tumors, like gastrointestinal cancers. Full article

Recent clinical trials have suggested that solid cancers with mismatch repair (MMR) deficiency are highly responsive to immunotherapy, regardless of cancer types. Previous MMR-related studies on breast cancer have predominantly focused on germline variants. However, the somatic MMR alterations have not been comprehensively characterized in breast cancer. In this study, we integrated genomic, transcriptomic, and clinical data from over 3000 breast cancer cases across six public cohorts. Our findings revealed that 1.2% of breast cancers harbored oncogenic somatic MMR alterations, with triple-negative breast cancer (TNBC) demonstrating the highest mutation rate at 3.1%. Additionally, somatic MMR alterations were significantly associated with microsatellite instability-high (MSI-H) and MMR-related mutational signatures, indicating that somatic MMR alterations led to impaired function of the MMR system. Biallelic inactivation of MMR genes resulted in a more pronounced loss of MMR function compared to monoallelic inactivation. Importantly, these MMR alterations significantly increased the tumor mutational burden (TMB) and neoantigen load in breast cancer, regardless of MSI-H status. These findings indicate that the frequency of MMR alterations is highest in TNBC and that MMR alterations in breast cancer can lead to MMR functional deficiencies, suggesting that some patients harboring such alterations may benefit from immunotherapy. Full article

Urogenital cancer is very common in the male population of Western countries, a problem of major concern for public health systems, and a frequent test subject for oncological research. In this narrative, we identify the main hot topics for clinics and the basic science of urological cancer in the last few years (from 2021 onwards), considering the information given in the abstracts of almost 300 original articles published in outstanding journals of pathology, urology, and basic science. Once defined, for the top ten list of hot topics (the 2022 WHO update on the classification of urinary and male genital tumors, new entities in kidney cancer, urinary cancer-omics, update on the Gleason grading system, targeted therapies and other novel therapies in renal cancer, news on non-muscle invasive urothelial carcinoma, artificial intelligence in urologic cancer, intratumor heterogeneity influence in therapeutic failures in urologic neoplasms, intratumor microbiome and its influence in urologic tumor aggressiveness, and ecological principles and mathematics applied to urogenital cancer study), each issue is independently reviewed in an attempt to put together the most relevant updates and/or useful features accompanied by selected illustrations. This review article addresses some of the most interesting and current hot spots in urogenital basic cancer research and clinics and is mainly aimed toward clinicians, including pathologists, urologists, and oncologists. Readers are invited to explore each topic for further, more detailed information, in addition to the references provided. Full article

CRC remains a significant public health challenge due to its high prevalence and mortality rates. Emerging evidence highlights the critical role of the gut microbiota in both the pathogenesis of CRC and the efficacy of treatment strategies, including chemotherapy and immunotherapy. Dysbiosis, characterized by imbalances in microbial communities, has been implicated in CRC progression and therapeutic outcomes. This review examines the intricate relationship between gut microbiota composition and CRC, emphasizing the potential for microbial profiles to serve as biomarkers for early detection and prognosis. Various interventions, such as prebiotics, probiotics, postbiotics, fecal microbiota transplantation, and dietary modifications, aim to restore microbiota balance and shift dysbiosis toward eubiosis, thereby improving health outcomes. Additionally, the integration of microbial profiling into clinical practice could enhance diagnostic capabilities and personalize treatment strategies, advancing the field of oncology. The study of intratumoral microbiota offers new diagnostic and prognostic tools that, combined with artificial intelligence algorithms, could predict treatment responses and assess the risk of adverse effects. Given the growing understanding of the gut microbiome–cancer axis, developing microbiota-oriented strategies for CRC prevention and treatment holds promise for improving patient care and clinical outcomes. Full article

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with poor prognosis, primarily due to its immunosuppressive tumor microenvironment (TME), which contributes to treatment resistance. Recent research shows that the microbiome, including microbial communities in the oral cavity, gut, bile duct, and intratumoral environments, plays a key role in PDAC development, with microbial imbalances (dysbiosis) promoting inflammation, cancer progression, therapy resistance, and treatment side effects. Microbial metabolites can also affect immune cells, especially natural killer (NK) cells, which are vital for tumor surveillance, therapy response and treatment-related side effects. Dysbiosis can affect NK cell function, leading to resistance and side effects. We propose that a combined biomarker approach, integrating microbiome composition and NK cell profiles, can help predict treatment resistance and side effects, enabling more personalized therapies. This review examines how dysbiosis contributes to NK cell dysfunction in PDAC and discusses strategies (e.g., antibiotics, probiotics, vaccines) to modulate the microbiome and enhance NK cell function. Targeting dysbiosis could modulate NK cell activity, improve the effectiveness of PDAC treatments, and reduce side effects. However, further research is needed to develop unified NK cell–microbiome interaction-based biomarkers for more precise and effective patient outcomes. Full article

The gut microbiome plays an important role in the carcinogenesis of luminal gastrointestinal malignancies and response to antineoplastic therapy. Preclinical studies have suggested a role of intratumoral gammaproteobacteria in mediating response to gemcitabine-based chemotherapy in pancreatic ductal adenocarcinoma (PDAC). To our knowledge, this is the first study to evaluate the impact of the PDAC microbiome on chemotherapy response using samples from human pancreatic tumor resections. We performed 16S rRNA gene amplification and sequencing on both formalin-fixed paraffin-embedded (FFPE) and fresh frozen human PDAC resection samples. We analyzed frozen samples from 26 patients with resected PDAC and examined tumor and tumor-adjacent normal tissue. These patients represented nine long-term survivors (LTS) and nine short-term survivors (STS) after neoadjuvant gemcitabine therapy and eight control patients who did not receive any neoadjuvant therapy prior to resection. We also included FFPE samples from five patients, including tumor samples (3 samples per patient), tumor-adjacent normal tissue (2 per patient) and tumor-adjacent paraffin (1 per patient). Within frozen tissue, total DNA yields were high, but bacterial DNA was generally low, comparable to those seen in negative controls. In FFPE tissue, DNA yields were low and bacterial abundances were comparable in paraffin, tumor and normal PDAC samples. Gammaproteobacteria concentrations did not correlate with outcomes in patients treated with neoadjuvant gemcitabine-based chemotherapy. Our study found low microbial biomass in pancreatic tumor tissue, with no detectable association between bacterial taxa and chemotherapy outcomes. These results suggest a limited role of the microbiome in gemcitabine-based chemotherapy response in PDAC. Preclinical studies have implicated the pancreatic tumor microbiome in driving response to therapy. Cytidine deaminase, an enzyme produced by gammaproteobacteria, can metabolize gemcitabine and has been hypothesized to inhibit pancreatic tumor response to chemotherapy. Several clinical trials have evaluated the role of the tumor microbiome in pancreatic cancer treatment. We evaluated the impact of the pancreatic tumor microbiome on chemotherapy response using samples from human pancreatic tumor resections. We found a low microbial load that is partially attributable to contaminants and that gammaproteobacteria levels did not correlate with outcomes in patients with pancreatic cancer treated with gemcitabine-based chemotherapy. Full article