The Relationship between Mycoplasmas and Cancer: Is It Fact or Fiction ? Narrative Review and Update on the Situation

Relationship between purinergic P2X7 receptor and colorectal cancer: Research progress and future prospect

Purinergic P2X7 receptor (P2X7R) is a cellular transmembrane protein. Its activation leads to the release of cytokines, causing the migration and invasion of cancer cells. The expression of P2X7R is associated with tumor inflammation, survival, proliferation, angiogenesis, and metastasis in colorectal cancer (CRC). Evidence suggests that P2X7R expression appears to be epigenetically regulated by DNA methylation and miRNA regulation. With the in-depth study of P2X7R, the application of P2X7R agonists and antagonists has been discussed in the treatment of CRC. This article reviews the relationship between P2X7R and CRC, focusing on the research progress and future prospects of P2X7R in CRC diagnosis and treat-ment.

Cross-laboratory replication of pseudomyxoma peritonei tumor microbiome reveals reproducible microbial signatures

Recent work has demonstrated that cancer-specific microbial communities often colonize tumor tissues. However, untangling low-biomass signals from environmental contamination makes this research technically challenging. We utilize pseudomyxoma peritonei (PMP), a cancer characterized by the spread of mucus-secreting cells throughout the peritoneal cavity, to develop a robust workflow for identifying reproducible tumor microbiomes. Typically originating from the rupture of an appendiceal tumor into the peritoneal cavity, metastasized tumors have been previously shown to harbor a core set of microbes. However, that work did not control for the potential contamination of these low microbial biomass samples. We expand upon these prior findings by characterizing the microbiome of 70 additional PMP tumors and six normal peritoneal control tissues along with appropriate laboratory controls. Additionally, DNA from a subset of 25 tissues was extracted and sequenced at an independent laboratory. We found evidence of reproducible microbial signatures between the replicates of six different PMP tumors that include a set of core taxa that may be introduced from surgical contamination, as well as patient-specific taxa that are also commonly implicated in colorectal cancer. In addition, preoperative chemotherapy treatment was found to reduce tumor microbiome diversity. Our findings demonstrate how independent sample replication can be a powerful approach to investigate low-biomass microbial communities associated with tumor tissues that will improve low microbial biomass research.IMPORTANCERecent work has demonstrated that microbial communities colonize over 30 different types of tumor tissues. The origin of these communities and their possible involvement in carcinogenesis or cancer treatment outcomes remains an unclear, yet important area of research. A current major challenge in characterizing low-biomass, tumor-associated microbiomes is the introduction of environmental contamination during collection, handling, DNA extraction, PCR, and sequencing. Here, we provide a framework for replicating low-biomass tumor microbiome samples to help identify tumors with robust microbial signals and low background contamination. Using this replication approach, we show that pseudomyxoma peritonei (PMP) tumors host reproducible microbial communities, including organisms that have previously been associated with colorectal cancer. Incorporating sample replication into future tumor microbiome studies is a promising approach that will help identify robust signals and increase reproducibility in the field.

Comprehensive appraisal of the association between sexually transmitted infections and prostate cancer: A scoping review of empirical studies, reviews, and meta-analyses

We performed a scoping review on the association of sexually transmitted infections (STIs) with prostate cancer and identified knowledge gaps. Searching four databases (Medline, Embase, Scopus, and Cochrane) identified 286 eligible records. Most empirical studies (n = 191) were cross-sectional (n = 66) and case-control (n = 52). The most studied STIs were human papillomavirus (HPV) (n = 82), human immunodeficiency virus (HIV) (n = 52), and herpes simplex virus (HSV) (n = 30). We included 68 narrative reviews, 10 systematic reviews, and 17 meta-analyses. Most effect estimates (odds ratios, hazard ratios, risk ratios and standardised incidence ratios) did not support an association between STIs and prostate cancer: 373 and 218 of 591 effect estimates were above and below the null, respectively, except for HIV where 74 of 108 estimates were below the null. Knowledge gaps included case-control studies, insights into HIV-related mechanisms for a lower risk for prostate cancer, studies on Mycoplasma and Ureaplasma, studies adjusting for co-infection with other STIs, and studies assessing whether STIs predispose men to a more aggressive form of prostate cancer. A key research priority identified is the need for more evidence on the biological mechanisms driving infection-mediated prostate carcinogenesis.

Integrated structural proteomics and machine learning-guided mapping of a highly protective precision vaccine against mycoplasma pulmonis

Mycoplasma pulmonis (M. pulmonis) is an emerging respiratory infection commonly linked to prostate cancer, and it is classified under the group of mycoplasmas. Improved management of mycoplasma infections is essential due to the frequent ineffectiveness of current antibiotic treatments in completely eliminating these pathogens from the host. The objective of this study is to design and construct effective and protective vaccines guided by structural proteomics and machine learning algorithms to provide protection against the M. pulmonis infection. Through a thorough examination of the entire proteome of M. pulmonis, four specific targets Membrane protein P80, Lipoprotein, Uncharacterized protein and GGDEF domain-containing protein have been identified as appropriate for designing a vaccine. The proteins underwent mapping of cytotoxic T lymphocyte (CTL), helper T lymphocyte (HTL) (IFN)-γ ±, and B-cell epitopes using artificial and recurrent neural networks. The design involved the creation of mRNA and peptide-based vaccine, which consisted of 8 CTL epitopes associated by GGS linkers, 7 HTL (IFN-positive) epitopes, and 8 B-cell epitopes joined by GPGPG linkers. The vaccine designed exhibit antigenic behavior, non-allergenic qualities, and exceptional physicochemical attributes. Structural modeling revealed that correct folding is crucial for optimal functioning. The coupling of the MEVC and Toll-like Receptors (TLR)1, TLR2, and TLR6 was examined through molecular docking experiments. This was followed by molecular simulation investigations, which included binding free energy estimations. The results indicated that the dynamics of the interaction were stable, and the binding was strong. In silico cloning and optimization analysis revealed an optimized sequence with a GC content of 49.776 % and a CAI of 0.982. The immunological simulation results showed strong immune responses, with elevated levels of active and plasma B-cells, regulatory T-cells, HTL, and CTL in both IgM+IgG and secondary immune responses. The antigen was completely cleared by the 50th day. This study lays the foundation for creating a potent and secure vaccine candidate to combat the newly identified M. pulmonis infection in people.

Persistent Activation of the P2X7 Receptor Underlies Chronic Inflammation and Carcinogenic Changes in the Intestine

Aberrant signaling through damage-associated molecular patterns (DAMPs) has been linked to several health disorders, attracting considerable research interest over the last decade. Adenosine triphosphate (ATP), a key extracellular DAMP, activates the purinergic receptor P2X7, which acts as a danger sensor in immune cells and is implicated in distinct biological functions, including cell death, production of pro-inflammatory cytokines, and defense against microorganisms. In addition to driving inflammation mediated by immune and non-immune cells, the persistent release of endogenous DAMPs, including ATP, has been shown to result in epigenetic modifications. In intestinal diseases such as inflammatory bowel disease (IBD) and colorectal cancer (CRC), consequent amplification of the inflammatory response and the resulting epigenetic reprogramming may impact the development of pathological changes associated with specific disease phenotypes. P2X7 is overexpressed in the gut mucosa of patients with IBD, whereas the P2X7 blockade prevents the development of chemically induced experimental colitis. Recent data suggest a role for P2X7 in determining gut microbiota composition. Regulatory mechanisms downstream of the P2X7 receptor, combined with signals from dysbiotic microbiota, trigger intracellular signaling pathways and inflammasomes, intensify inflammation, and foster colitis-associated CRC development. Preliminary studies targeting the ATP-P2X7 pathway have shown favorable therapeutic effects in human IBD and experimental colitis.

The role of mycoplasmas as an infectious agent in carcinogenesis

The review presents data on studies of the role of mycoplasmas as infectious agents in carcinogenesis, as well as their participation in cancer drug therapy and the impact on the outcome of treatment. Mycoplasmas are of particular interest because they have unique abilities to readily attach to and enter eukaryotic cells, modulate their functional state, and induce chronic inflammation while evading the host’s immune system. The review will highlight the data confirming the increased colonization of tumor tissue by mycoplasmas compared to healthy ones, describe the molecular mechanisms by which mycoplasmas activate the expression of oncogenes and growth factors, inactivate tumor suppressors, promote NF-κB-dependent migration of cancer cells and modulate apoptosis, which results in abnormal growth and transformation of host cells. The review also presents data on the effectiveness of anticancer drugs in mycoplasmal infections.

Eating the Enemy: Mycoplasma Strategies to Evade Neutrophil Extracellular Traps (NETs) Promoting Bacterial Nucleotides Uptake and Inflammatory Damage

Neutrophils are effector cells involved in the innate immune response against infection; they kill infectious agents in the intracellular compartment (phagocytosis) or in the extracellular milieu (degranulation). Moreover, neutrophils release neutrophil extracellular traps (NETs), complex structures composed of a scaffold of decondensed DNA associated with histones and antimicrobial compounds; NETs entrap infectious agents, preventing their spread and promoting their clearance. NET formation is triggered by microbial compounds, but many microorganisms have evolved several strategies for NET evasion. In addition, the dysregulated production of NETs is associated with chronic inflammatory diseases. Mycoplasmas are reduced genome bacteria, able to induce chronic infections with recurrent inflammatory symptoms. Mycoplasmas' parasitic lifestyle relies on metabolite uptake from the host. Mycoplasmas induce NET release, but their surface or secreted nucleases digest the NETs' DNA scaffold, allowing them to escape from entrapment and providing essential nucleotide precursors, thus promoting the infection. The presence of Mycoplasma species has been associated with chronic inflammatory disorders, such as systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, Crohn's disease, and cancer. The persistence of mycoplasma infection and prolonged NET release may contribute to the onset of chronic inflammatory diseases and needs further investigation and insights.

Intratumor microbiome in cancer progression: current developments, challenges and future trends

Cancer is a complicated disease attributed to multifactorial changes, which causes difficulties with treatment strategies. Various factors have been regarded as the main contributors, and infectious etiological factors have recently attracted interest. Several microbiomes contribute to carcinogenesis, cancer progression, and modulating cancer treatment by inducing cancerous epithelial cells and chronic inflammation. Most of our knowledge on the role of microbiota in tumor oncogenesis and clinical efficiency is associated with the intestinal microbiome. However, compelling evidence has also confirmed the contribution of the intratumor microbiome in cancer. Indeed, the findings of clinical tumor samples, animal models, and studies in vitro have revealed that many intratumor microbiomes promote tumorigenesis and immune evasion. In addition, the intratumor microbiome participates in regulating the immune response and even affects the outcomes of cancer treatment. This review summarizes the interplay between the intratumor microbiota and cancer, focusing on the contribution and mechanism of intratumor microbiota in cancer initiation, progression, and potential applications to cancer therapy.

Mycoplasmas as Host Pantropic and Specific Pathogens: Clinical Implications, Gene Transfer, Virulence Factors, and Future Perspectives

Mycoplasmas as economically important and pantropic pathogens can cause similar clinical diseases in different hosts by eluding host defense and establishing their niches despite their limited metabolic capacities. Besides, enormous undiscovered virulence has a fundamental role in the pathogenesis of pathogenic mycoplasmas. On the other hand, they are host-specific pathogens with some highly pathogenic members that can colonize a vast number of habitats. Reshuffling mycoplasmas genetic information and evolving rapidly is a way to avoid their host's immune system. However, currently, only a few control measures exist against some mycoplasmosis which are far from satisfaction. This review aimed to provide an updated insight into the state of mycoplasmas as pathogens by summarizing and analyzing the comprehensive progress, current challenge, and future perspectives of mycoplasmas. It covers clinical implications of mycoplasmas in humans and domestic and wild animals, virulence-related factors, the process of gene transfer and its crucial prospects, the current application and future perspectives of nanotechnology for diagnosing and curing mycoplasmosis, Mycoplasma vaccination, and protective immunity. Several questions remain unanswered and are recommended to pay close attention to. The findings would be helpful to develop new strategies for basic and applied research on mycoplasmas and facilitate the control of mycoplasmosis for humans and various species of animals.

The P2X7 Receptor Promotes Colorectal Inflammation and Tumorigenesis by Modulating Gut Microbiota and the Inflammasome

Background: Given the role of the P2X7 receptor (P2X7R) in inflammatory bowel diseases (IBD), we investigated its role in the development and progression of colitis-associated colorectal cancer (CA-CRC). Methods: CA-CRC was induced in P2X7R^+/+ and P2X7R^−/− mice with azoxymethane (AOM) combined with dextran sodium sulfate (DSS). In a therapeutic protocol, P2X7R^+/+ mice were treated with a P2X7R-selective inhibitor (A740003). Mice were evaluated with follow-up video endoscopy with endoluminal ultrasound biomicroscopy. Colon tissue was analyzed for histological changes, densities of immune cells, expression of transcription factors, cytokines, genes, DNA methylation, and microbiome composition of fecal samples by sequencing for 16S rRNA. Results: The P2X7R^+/+ mice displayed more ulcers, tumors, and greater wall thickness, than the P2X7R^−/− and the P2X7R^+/+ mice treated with A740003. The P2X7R^+/+ mice showed increased accumulation of immune cells, production of proinflammatory cytokines, activation of intracellular signaling pathways, and upregulation of NLRP3 and NLRP12 genes, stabilized after the P2X7R-blockade. Microbial changes were observed in the P2X7R^−/− and P2X7R^+/+-induced mice, partially reversed by the A740003 treatment. Conclusions: Regulatory mechanisms activated downstream of the P2X7R in combination with signals from a dysbiotic microbiota result in the activation of intracellular signaling pathways and the inflammasome, amplifying the inflammatory response and promoting CA-CRC development.

Co-infection of human papillomavirus and other sexually transmitted bacteria in cervical cancer patients in the Philippines

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The prevalence of HPV 16/18/33/52 was 75% in Filipino cervical cancer patients.

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Infection with HPV 16/18/33/52 was significantly associated with cervical cancer (OR: 9.00; 95% CI: 2.18–37.18).

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HPV-16 was the most prevalent HPV genotype among Filipino cervical cancer patients.

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HPV-18 and HPV-52 were only detected from cervical cancer patients.

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Among HPV-positive patients, we noted a 22.73% co-infection with Ureaplasma spp. and 9.09% with Mycoplasma spp.

Cervical cancer is the fourth most common cancer in women globally. Based on several epidemiologic studies, human papillomavirus is strongly associated with cervical neoplasia. Aside from HPV, other bacterial infections in the genital tract were associated with cervical neoplasia. This study aimed to determine the prevalence of HPV infection; and co-infection with Ureaplasma spp., Mycoplasma spp., Chlamydia trachomatis, and Neisseria gonorrheae in Filipino cervical cancer patients. Forty-four patients (28 patients with cervical carcinoma and 16 patients with non-malignant cervix) who consulted in the Philippine General Hospital from 2016 to 2017 were included in this study. HPV genotyping and genetic detection of Ureaplasma spp., Mycoplasma spp., C. trachomatis, and N. gonorrheae were done using different PCR assays. The prevalence of HPV 16/18/33/52 was 75% in cervical cancer patients and 25% in control patients. Infection with HPV 16/18/33/52 was significantly associated with having cervical cancer (OR: 9.00; 95% CI: 2.18–37.18; p = 0.0024). HPV-16 was the most prevalent HPV genotype among Filipino cervical cancer patients. HPV-18 and HPV-52 were only detected from cervical cancer patients. Among HPV-positive patients, we noted a 22.73% co-infection with Ureaplasma spp. and 9.09% co-infection with Mycoplasma spp. To our knowledge, this is the first study on the co-infection of HPV and sexually transmitted infections among cervical cancer patients in the Philippines.