Herpes simplex virus-infected squamous cell carcinoma: a case report.

BACKGROUND: Herpes simplex virus (HSV)-1 is a highly prevalent, non-oncogenic virus that has higher morbidity in immunocompromised hosts. Its most common clinical manifestation is superficial ulceration of the integument or mucus membranes. CASE PRESENTATION: A 65-year-old woman with a history of acute myelogenous leukemia treated with allogenic peripheral blood stem cell transplant presented for resection of an ulcerated buccal squamous cell carcinoma. We report a case of HSV-1-infected malignant cells discovered on histopathological examination of the carcinoma specimen ultimately treated with valacyclovir. CONCLUSIONS: HSV-1 is not considered an oncogenic virus itself but may increase risk of malignant progression. Cancer cells are vulnerable to superimposed viral infections, including HSV-1, which likely led to the findings in this case.

Overexpression of hsa-miR-186 induces chromosomal instability in arsenic-exposed human keratinocytes.

The mechanism of arsenic-induced skin carcinogenesis is not yet fully understood. Chromosomal instability contributes to aneuploidy and is a driving force in carcinogenesis. Arsenic causes mitotic arrest and induces aneuploidy. hsa-miR-186 overexpression is associated with metastatic cancers as well as arsenic-induced squamous cell carcinoma and is reported to target several mitotic regulators. Decreased levels of these proteins can dysregulate chromatid segregation contributing to aneuploidy. This work investigates the potential aneuploidogenic role of hsa-miR-186 in arsenic carcinogenesis. Clones of immortalized human keratinocytes (HaCaT) stably transfected with a hsa-miR-186 expression or empty vector were isolated. Three clones with high and low hsa-miR-186 expression determined by RT-qPCR were selected for further analysis and cultured with 0 or 100 nM NaAsO2 for 8 weeks. Analysis of mitoses revealed that chromosome number and structural abnormalities increased in cells overexpressing hsa-miR-186 and were further increased by arsenite exposure. Double minutes were the dominant structural aberrations. The peak number of chromosomes also increased. Cells with >220 to >270 chromosomes appeared after 2 months in hsa-miR-186 overexpressing cells, indicating multiple rounds of endomitosis had occurred. The fraction of cells with increased chromosome number or structural abnormalities did not increase in passage matched control cells. Levels of selected target proteins were determined by western blot. Expression of BUB1, a predicted hsa-miR-186 target was suppressed in hsa-miR-186 overexpressing clones, but increased with arsenite exposure. CDC27 remained constant under all conditions. These results suggest that overexpression of miR-186 in arsenic exposed tissues likely induces aneuploidy contributing to arsenic-induced carcinogenesis.