Cytomegalovirus infection in malignant pleural mesothelioma

Human cytomegalovirus tegument protein UL23 promotes gastric cancer immune evasion by facilitating PD-L1 transcription

Immune checkpoint therapy targeting PD-1/PD-L1 has shown promise in treating tumors, however, its clinical benefits are limited to a subset of gastric cancer (GC) patients. Recent research has highlighted a the correlation between PD-L1 expression and the clinical efficacy of anti-PD-1/PD-L1 therapies. Human cytomegalovirus (HCMV) has been implicated in GC, but its specific role in modulating this disease remains elusive. In this study, we analyzed clinical tissue samples using bioinformatics and real-time quantitative polymerase chain reaction (RT-qPCR). We found that GC tissues infected with HCMV presented higher PD-L1 expression compared to those without virus. Furthermore, we demonstrated that HCMV infection enhances PD-L1 expression in GC cells. Cytotoxicity assays revealed that HCMV modulates cancer immune responses via the PD-1/PD-L1 pathway. Mechanistically, we showed that HCMV activates the PI3K-Akt signaling cascade and modulates PD-L1 expression through its tegument protein UL23. Functionally, increased UL23 expression leads to elevated PD-L1 levels, which diminishes tumor cell sensitivity to T-cell-mediated cytotoxicity and triggers T-cell apoptosis. Additionally, in vivo experiments revealed that UL23-induced PD-L1 upregulation inhibits CD8+ T-cell infiltration and reduces the expression of inflammatory factors in tumor microenvironment, ultimately weakening antitumor immunity. Our findings reveal a novel mechanism whereby HCMV and its tegument protein UL23 contribute to cancer immunosuppression through the regulation of PD-L1 expression. This discovery may serve as a potential therapeutic target for enhancing the efficacy of cancer immunotherapy.

The power of mumps virus: Matrix protein activates apoptotic pathways in human colorectal cell lines

New therapeutic approaches can significantly impact the control of colorectal cancer (CRC), which is increasing worldwide. In this study, we investigated the potential of targeting viral proteins to combat cancer cells. Specifically, we examined the anticancer potential of the matrix (M) protein of the mumps virus Hoshino strain in SW480 CRC cell lines. To begin, we individually transfected SW480 cells with pcDNA3 plasmids containing the mumps virus M gene. We then investigated the percentage of cell death, caspase activity, and the expression levels of genes involved in apoptosis pathways. Following this, we performed bioinformatics analysis on the M protein to identify any similarities with Bcl-2 family members and their viral homologs. Our diagnostic methods showed that treatment with the mumps M protein induced apoptosis and upregulated the expression and activity of pro-apoptotic proteins in SW480 CRC cells compared to the control and vector groups. Based on our bioinformatics studies, we proposed that the BH3 motif in the M protein may trigger apoptosis in CRC cells by interacting with cellular Bax. Overall, our study showed for the first time that the mumps virus M protein could be considered as a targeted treatment for CRC by inducing apoptotic pathways.

Prevalence of active cytomegalovirus infection at diagnosis of ovarian cancer and during chemotherapy and subsequent changes in cognitive functioning

PURPOSE

One of the most frequently reported effects of cancer and its treatments is cancer-related cognitive impairment (CRCI). Viral infections may affect inflammation and immune function and therefore may influence patient symptoms, including CRCI. The goal of this study was to describe the prevalence of cytomegalovirus (CMV) infections at diagnosis, during, and after chemotherapy in individuals with ovarian cancer and explore CMV infection at diagnosis with cancer-related cognitive impairment (CRCI) following chemotherapy.

METHODS

We recruited adults newly diagnosed with ovarian, primary peritoneal or fallopian tube cancer at a single academic cancer center into two prospective studies. In Study 1 (N = 71), participants provided blood samples at diagnosis. In Study 2 (N = 18), participants provided blood samples and completed symptom surveys before, during and after front-line adjuvant chemotherapy. Serum CMV DNA levels were assessed using digital PCR; >100 copies/mL of serum was considered positive for active CMV infection (CMV+). CRCI was measured using the Functional Assessment of Cancer Therapy - Cognitive Function (FACT-Cog) questionnaire. Changes in FACT-Cog scores were compared by CMV status at diagnosis using t-tests at each time point.

RESULTS

At diagnosis, 29.2% were CMV+ (28.2% in Study 1, 33.3% in Study 2). Following three cycles of chemotherapy (Study 2), CMV positivity rose to 60.0% and then back down to 31.3% after chemotherapy. We observed significant differences in CRCI following chemotherapy by CMV status at diagnosis.

CONCLUSION

Our data suggest that active CMV infection is common among patients undergoing treatment for ovarian cancer and may contribute to symptoms of CRCI.

Current management of CMV infection in cancer patients (solid tumors). Epidemiology and therapeutic strategies

Little evidence is available regarding the incidence of CMV disease in patients with solid cancers. Latest data show that approximately 50 % of these patients with CMV PCR positivity developed clinically relevant CMV-viremia, and would require specific therapy. In the clinical arena, CMV reactivation is an important differential diagnosis in the infectological work up of these patients, but guidelines of management on this subject are not yet available. CMV reactivation should be considered during differential diagnosis for patients with a severe decline in lymphocyte counts when receiving chemoradiotherapy or immunochemotherapy with lymphocyte-depleting or blocking agents. Monitoring of CMV reactivation followed by the implementation of preemptive strategies or the establishment of early antiviral treatment improves the prognosis and reduces the morbidity and mortality of these patients.