Molecular mechanisms of the modulatory effects of HCMV infection in tumor cell biology

Recently, the term oncomodulation has been proposed to express the ability of human cytomegalovirus (HCMV) to modify tumor cell biology, a phenomenon that is independent from transformation. Because past studies have failed to show that HCMV can transform normal human cells, HCMV has not been regarded as an oncogenic tumor virus. However, recent investigations have revealed a high frequency of HCMV in tumor cells of malignancies such as colon cancer, malignant glioma, prostatic intraepithelial neoplasia, and carcinoma. Data from experiments with HCMV-infected tumor cell lines have highlighted the oncomodulatory potential of HCMV and provided important insights into the patho-mechanisms associated with aberrant signaling pathways and transcription factor and/or tumor suppressor function of the host cell.