Cytomegalovirus Infection Is a Risk Factor in Gastrointestinal Cancer: A Cross-Sectional and Meta-Analysis Study

Therapeutic bacteria and viruses to combat cancer: double-edged sword in cancer therapy: new insights for future

Cancer, ranked as the second leading cause of mortality worldwide, leads to the death of approximately seven million people annually, establishing itself as one of the most significant health challenges globally. The discovery and identification of new anti-cancer drugs that kill or inactivate cancer cells without harming normal and healthy cells and reduce adverse effects on the immune system is a potential challenge in medicine and a fundamental goal in Many studies. Therapeutic bacteria and viruses have become a dual-faceted instrument in cancer therapy. They provide a promising avenue for cancer treatment, but at the same time, they also create significant obstacles and complications that contribute to cancer growth and development. This review article explores the role of bacteria and viruses in cancer treatment, examining their potential benefits and drawbacks. By amalgamating established knowledge and perspectives, this review offers an in-depth examination of the present research landscape within this domain and identifies avenues for future investigation.

Human Cytomegalovirus Oncoprotection across Diverse Populations, Tumor Histologies, and Age Groups: The Relevance for Prospective Vaccinal Therapy

The oncogenicity of the human cytomegalovirus (CMV) is currently being widely debated. Most recently, mounting clinical evidence suggests an anti-cancer effect via CMV-induced T cell-mediated tumor destruction. However, the data were mostly obtained from single-center studies and in vitro experiments. Broad geographic coverage is required to offer a global perspective. Our study examined the correlation between country-specific CMV seroprevalence (across 73 countries) and the age-standardized incidence rate (of 34 invasive tumors). The populations studied were stratified according to decadal age periods as the immunologic effects of CMV seropositivity may depend upon age at initial infection. The International Agency for Research on Cancer of the World Health Organization (IARC WHO) database was used. The multivariate linear regression analysis revealed a worldwide inverse correlation between CMV seroprevalence and the incidences of 62.8% tumors. Notably, this inverse link persists for all cancers combined (Spearman's ρ = -0.732, p < 0.001; β = -0.482, p < 0.001, adjusted R2 = 0.737). An antithetical and significant correlation was also observed in particular age groups for the vast majority of tumors. Our results corroborate the conclusions of previous studies and indicate that this oncopreventive phenomenon holds true on a global scale. It applies to a wide spectrum of cancer histologies, additionally supporting the idea of a common underlying mechanism-CMV-stimulated T cell tumor targeting. Although these results further advance the notion of CMV-based therapies, in-depth investigation of host-virus interactions is still warranted.

The role of microbiomes in gastrointestinal cancers: new insights

Gastrointestinal (GI) cancers constitute more than 33% of new cancer cases worldwide and pose a considerable burden on public health. There exists a growing body of evidence that has systematically recorded an upward trajectory in GI malignancies within the last 5 to 10 years, thus presenting a formidable menace to the health of the human population. The perturbations in GI microbiota may have a noteworthy influence on the advancement of GI cancers; however, the precise mechanisms behind this association are still not comprehensively understood. Some bacteria have been observed to support cancer development, while others seem to provide a safeguard against it. Recent studies have indicated that alterations in the composition and abundance of microbiomes could be associated with the progression of various GI cancers, such as colorectal, gastric, hepatic, and esophageal cancers. Within this comprehensive analysis, we examine the significance of microbiomes, particularly those located in the intestines, in GI cancers. Furthermore, we explore the impact of microbiomes on various treatment modalities for GI cancer, including chemotherapy, immunotherapy, and radiotherapy. Additionally, we delve into the intricate mechanisms through which intestinal microbes influence the efficacy of GI cancer treatments.

Association between cytomegalovirus infection and cancer‑related mortality in the US adults

PURPOSE

In a nationwide cohort of US adults, an exploration of the association between cytomegalovirus (CMV) infection and cancer‑related mortality was conducted.

MATERIALS AND METHODS

We acquired data from the National Health and Nutrition Examination Survey III (1988-1994), including 11,138 individuals who were aged 18-90 years at enrollment and underwent CMV serology assessments. CMV infection was determined by CMV antibody testing. Cancer‑related mortality status was ascertained until December 2019 utilizing the National Death Index linkage data and determined by neoplasms. The Cox proportional hazard model was applied to estimate the potential association between CMV infection and the risk of cancer-related mortality.

RESULTS

During a median follow-up of 26.1 years, 1514 cancer‑related deaths were identified in the study cohort. After adjusting for age, sex, and ethnicity, CMV infection was associated with a higher hazard of cancer‑related mortality (hazard ratio [HR]: 1.39, 95 % CI: 1.13, 1.70). Further adjustments for body mass index, family income, and smoking status slightly attenuated the magnitude of the association (HR: 1.24, 95 % CI: 1.00, 1.53). However, no significant interaction was observed among gender by subgroup analysis.

CONCLUSIONS

CMV infection might be an independent risk factor for cancer‑related mortality among US adults. Future studies could focus on the mechanisms through which CMV infection influences mortality induced by neoplasms and develop targeted interventions to reduce the risk.

The Unmasking of Cytomegalovirus as an Accomplice to Helicobacter pylori-Induced Severe Acute Gastroenteritis in a Healthy Host

Cytomegalovirus (CMV) belongs to the Herpesviridae family, and it is considered the largest virus to infect humans. Primary CMV infection frequently targets immunodeficient patients and is often symptomatic. However, it may remain latent or clinically unapparent for years in immunocompetent individuals. CMV infection rarely presents as an invasive disease in the latter group of individuals, in which case, the most common site of involvement in the gastrointestinal tract. When CMV affects the gastrointestinal tract, the colon and stomach are the 2 frequently involved sites. This case report describes a unique case of an immunocompetent patient who presented with acute excruciating periumbilical pain and was diagnosed with acute gastritis secondary to CMV infection and possible Helicobacter pylori-associated chronic active gastritis. Symptoms resolved entirely soon after treatment with antimicrobials that cover for both infections. The diagnosis was based on histopathologic findings from biopsies taken from the stomach during the endoscopic evaluation combined with positive CMV serology and positive CMV-deoxyribonucleic acid.

Associations between human cytomegalovirus infection and type 2 diabetes mellitus: a systematic review and meta-analysis

OBJECTIVE

Multiple studies have reported a potential contribution of human cytomegalovirus (HCMV) to the pathogenesis of type 1 diabetes and post-transplantation diabetes. However, the association between HCMV and type 2 diabetes mellitus (T2DM) remains unclear. In this paper, we employ the meta-analysis approach to investigate the potential correlation between HCMV infection and T2DM.

METHOD

The data of our study were collected from PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure and WAN FANG databases from inception to November 2022. Using the Review Manager V.5.4 software, the meta-analysis was performed.

RESULTS

A total of 18 139 patients from 22 studies were included in our analysis. In the Asian subgroup, the patients with T2DM group had a significantly higher frequency of HCMV infection and older age compared with the healthy group. In the European, the frequency of HCMV infection in the T2DM was lower than the healthy group, although this difference was not statistically significant. After adjusting for demographic factors, the adjusted OR of T2DM for risk of by HCMV status was not found to be significant (adjusted OR=1.19, 95% CI=0.88 to 1.62, p>0.05). Additionally, T2DM with vasculopathy had a significantly higher rate of HCMV infection compared with those without vasculopathy (OR=1.87, 95% CI=1.24 to 2.83, p<0.05). Among T2DM with HCMV infection, there were significant increases in fasting blood glucose levels and the proportion of CD8+ T lymphocytes. Conversely, fasting blood insulin levels, the proportion of CD4+ T lymphocyte and the CD4+/CD8+ ratio were significantly decreased compared with the healthy group.

CONCLUSION

At present, the available evidence does not provide a clear understanding of whether there is a significant association between T2DM and HCMV infection. Additionally, T2DM with HCMV infection exhibited significantly worse blood glucose regulation and immune markers, as well as a higher frequency of vasculopathy.

PROSPERO REGISTRATION NUMBER

CRD42022342066.

Detection of Human cytomegalovirus UL55 Gene and IE/E Protein Expression in Colorectal Cancer Patients in Egypt

BACKGROUND

A possible relation between Human cytomegalovirus (HCMV) and colorectal cancer (CRC) has been widely explored with an unclear role yet speculated.

AIM

The study aimed at detecting HCMV UL55 gene, immediate early and early (IE/E) proteins in colorectal tumor tissues and adjacent non neoplastic tissues (ANNT). Also, it aimed to correlate HCMV presence with CRC clinicopathological features.

SUBJECTS AND METHODS

A prospective study of 50 HCMV seropositive patients with resectable CRC were enrolled in the study. Demographic, clinical, and radiological findings were recorded. Pathological assessment was done. Paired CRC tumorous and ANNT were examined for HCMV UL55 by PCR and for IE/ E proteins by immunohistochemistry (IHC).

RESULTS

70% of CRC patients enrolled were females and 36% were elderly (> 60y). Adenocarcinoma was the prevalent histopathological type (92%) with Grade 2, higher stages, and nodal involvement accounting for (64%, 64% and 56%) respectively. HCMV detection was significantly higher in tumoral tissue versus ANNT by PCR and IHC (P < 0.001, P < 0.008) respectively. Moderate agreement was found between the two techniques (κ = 0.572, P < 0.001). Univariate analysis identified HCMV presence to be significantly higher in elderly patients, in tumors with higher stage and with nodal involvement (P = 0.041, P = 0.008, P = 0.018 respectively). In multivariate analysis, the latter two retained significance (P = 0.010, P = 0.008).

CONCLUSION

CRC tumor tissues are more infected by HCMV than ANNT. A significant association of HCMV presence with a higher CRC tumor stage and nodal involvement in an age-dependent manner was detected. HCMV oncomodulatory and a disease progression role is suspected.

Synthesis of 1-[ω-(Bromophenoxy)alkyl]-3-naphthalenylmethyl Derivatives of Uracil and Their Analogues As Probable Inhibitors of Human Cytomegalovirus Replication

The synthesis of a new series of 1-[ω-(bromophenoxy)alkyl]-uracil derivatives containing in position 3 naphthalen-1-yl-, naphthalen-2-yl-, 1-bromonaphthalen-2-ylmethyl, benzyl, and anthracene 9-methyl fragment was carried out. The antiviral properties of the synthesized compounds were studied against human cytomegalovirus. It was found that the compound that contained a bridge of five methylene groups has a high anti-cytomegalovirus activity in vitro.

Cancer risk associated with cytomegalovirus infection among solid organ transplant recipients in the United States

BACKGROUND

Cytomegalovirus (CMV) is among the most common viral infections after solid organ transplantation (SOT). Associations of CMV with cancer risk among SOT recipients have been incompletely evaluated.

METHODS

The authors used linked data from the US SOT registry and 32 cancer registries. Poisson regression was used to compare cancer incidence across CMV risk groups based on donor (D) and recipient (R) immunoglobulin G (IgG) serostatus: high risk (R-negative/D-positive), moderate risk (R-positive), and low risk (R-negative/D-negative).

RESULTS

In total, 247,318 SOT recipients were evaluated during 2000-2017 (R-negative/D-positive, 20.3%; R-positive, 62.9%; R-negative/D-negative, 16.8%). CMV-seropositive recipients were older, more racially/ethnically diverse, and had lower socioeconomic status than CMV-seronegative recipients. Compared with R-negative/D-negative recipients, recipients in the R-negative/D-positive and R-positive groups had a lower incidence of diffuse large B-cell lymphoma (DLBCL; R-negative/D-positive: adjusted incidence rate ratio [aIRR], 0.74; 95% confidence interval [CI], 0.59-0.91; R-positive: aIRR, 0.83; 95% CI, 0.69-1.00). CMV serostatus modified the association between Epstein-Barr virus (EBV) status and DLBCL (p = .0006): DLBCL incidence was increased for EBV R-negative/D-positive recipients (aIRR, 3.46; 95% CI, 1.50-7.95) among CMV R-negative/D-negative recipients but not among the other CMV risk groups. Compared with recipients who were CMV R-negative/D-negative, those who were R-negative/D-positive had a lower incidence of small intestine cancer (aIRR, 0.23; 95% CI, 0.09-0.63), and R-positive recipients had a higher incidence of lung cancer (aIRR, 1.24; 95% CI, 1.05-1.46). CMV status was not associated with risk for other cancers.

CONCLUSIONS

CMV status was not associated with risk for most cancers among SOT recipients. The inverse association with DLBCL may reflect the protective effects of CMV prophylaxis or treatment with off-target efficacy against EBV infection (the major cause of lymphoma in SOT recipients).

Prognosis of Human Cytomegalovirus in Cancer Patients Undergoing Chemotherapeutic Treatment in Egypt and an Emergent Prevalence of Glycoprotein B-5

The human cytomegalovirus (HCMV) is a global opportunistic β-herpes virus causing severe diseases in immune-compromised patients, such as malignant tumor patients, especially those undergoing chemotherapeutic treatment. This study aimed to determine the prevalence of HCMV-DNA in chemotherapeutic treatment naive cancer patients, and after chemotherapy, to compare between conventional nested PCR and ELISA techniques for the detection of HCMV, and to detect glycoprotein B genotypes. Plasma and serum samples before and after three chemotherapy cycles were collected from 49 chemotherapy-naive cancer patients. DNA was extracted from plasma samples using QIAamp® DNA Mini kit. HCMV-DNA was detected using a nested PCR technique. Multiplex nested PCR was used for HCMV-glycoprotein B (gB) genotyping. HCMV-IgG and -IgM were detected using ELISA technique. Thirty one (63.3 %) of the 49 plasma samples of the chemotherapy-naïve cancer patients were positive for HCMV-DNA; 21 of which remained positive after chemotherapy. However, 18 samples were negative of which 16 became positive after chemotherapy. gB-5 was the most common glycoprotein genotype detected (80.6 %), followed by gB-1, gB-3, gB-4, and gB-2. HCMV IgG was detected in the 49 serum samples of chemotherapy-naïve patients, and after exposure to chemotherapy. HCMV-DNA is commonly identified in cancer patients. Its detection after chemotherapy exposure may suggest HCMV reactivation. The most common genotype detected in cancer patients in Egypt is gB-5 in contrast to earlier research. IgG was detected in all patients. This indicates that HCMV is endemic in Egypt, necessitating the development of public awareness campaigns about HCMV infection and preventive strategies.

Synthesis of 1-[ω-(Bromophenoxy)alkyl]-3-Naphthalenylmethyl Uracil Derivatives and Their Analogues as Probable Inhibitors of Human Cytomegalovirus Replication

A new series of 1-[ω-(bromophenoxy)alkyl]-uracil derivatives containing naphthalen-1-yl, naphthalen-2-yl, 1-bromonaphthalen-2-ylmethyl, benzyl, and anthracene-9-ylmethyl fragments in position 3 of uracil residue was synthesized. The antiviral properties of the synthesized compounds against human cytomegalovirus were studied. It was found that the compound containing a bridge consisting of five methylene groups exhibits a high anti-cytomegalovirus activity in vitro.

Viruses in colorectal cancer

Increasing evidence suggests that microorganisms might represent at least highly interesting cofactors in colorectal cancer (CRC) oncogenesis and progression. Still, associated mechanisms, specifically in colonocytes and their microenvironmental interactions, are still poorly understood. Although, currently, at least seven viruses are being recognized as human carcinogens, only three of these – Epstein–Barr virus (EBV), human papillomavirus (HPV) and John Cunningham virus (JCV) – have been described, with varying levels of evidence, in CRC. In addition, cytomegalovirus (CMV) has been associated with CRC in some publications, albeit not being a fully acknowledged oncovirus. Moreover, recent microbiome studies set increasing grounds for new hypotheses on bacteriophages as interesting additional modulators in CRC carcinogenesis and progression. The present Review summarizes how particular groups of viruses, including bacteriophages, affect cells and the cellular and microbial microenvironment, thereby putatively contributing to foster CRC. This could be achieved, for example, by promoting several processes – such as DNA damage, chromosomal instability, or molecular aspects of cell proliferation, CRC progression and metastasis – not necessarily by direct infection of epithelial cells only, but also by interaction with the microenvironment of infected cells. In this context, there are striking common features of EBV, CMV, HPV and JCV that are able to promote oncogenesis, in terms of establishing latent infections and affecting p53‐/pRb‐driven, epithelial–mesenchymal transition (EMT)‐/EGFR‐associated and especially Wnt/β‐catenin‐driven pathways. We speculate that, at least in part, such viral impacts on particular pathways might be reflected in lasting (e.g. mutational or further genomic) fingerprints of viruses in cells. Also, the complex interplay between several species within the intestinal microbiome, involving a direct or indirect impact on colorectal and microenvironmental cells but also between, for example, phages and bacterial and viral pathogens, and further novel species certainly might, in part, explain ongoing difficulties to establish unequivocal monocausal links between specific viral infections and CRC.

The Human Cytomegalovirus US31 Gene Predicts Favorable Survival and Regulates the Tumor Microenvironment in Gastric Cancer

Human cytomegalovirus (HCMV) is an oncogenic virus associated with tumorigenesis. Our previous study revealed that the HCMV US31 gene interacted with NF-κB2 and mediated inflammation through macrophages. However, there are few reports on the role of US31 in gastric cancer (GC). The aim of this study was to investigate the expression of the US31 gene in GC tissue and assess its role in the occurrence and development of GC. US31 expression in 573 cancer tissues was analyzed using immunohistochemistry. Results showed that US31 was significantly associated with tumor size (P = 0.005) and distant metastasis (P < 0.001). Higher US31 expression indicated better overall survival in GC patients. Overexpression of US31 significantly inhibited the proliferation, migration, and invasion of GC cells in vitro (P < 0.05). Furthermore, expression levels of CD4, CD66b, and CD166 were positively correlated with US31, suggesting that it was involved in regulating the tumor immune microenvironment of GC. RNA sequencing, along with quantitative real-time polymerase chain reaction, confirmed that the expression of US31 promoted immune activation and secretion of inflammatory cytokines. Overall, US31 inhibited the malignant phenotype and regulated tumor immune cell infiltration in GC; these results suggest that US31 could be a potential prognostic factor for GC and may open the door for a new immunotherapy strategy.

Role of Bacterial and Viral Pathogens in Gastric Carcinogenesis

Simple Summary

Stomach cancer is one of the most common cancers in the world, with over one million new cases diagnosed in 2020. Despite recent advances in cancer treatments, gastric cancer remains a serious clinical problem. This disease is tightly linked to gastric infections with Helicobacter pylori bacterium, Epstein–Barr virus, and some other less known pathogens. Here, we discuss how gastric pathogens induce tumorigenic changes in the stomach.

Abstract

Gastric cancer (GC) is one of the deadliest malignancies worldwide. In contrast to many other tumor types, gastric carcinogenesis is tightly linked to infectious events. Infections with Helicobacter pylori (H. pylori) bacterium and Epstein–Barr virus (EBV) are the two most investigated risk factors for GC. These pathogens infect more than half of the world’s population. Fortunately, only a small fraction of infected individuals develops GC, suggesting high complexity of tumorigenic processes in the human stomach. Recent studies suggest that the multifaceted interplay between microbial, environmental, and host genetic factors underlies gastric tumorigenesis. Many aspects of these interactions still remain unclear. In this review, we update on recent discoveries, focusing on the roles of various gastric pathogens and gastric microbiome in tumorigenesis.