High-risk HPVs in human breast cancer and normal mammary tissues

High-risk human papillomavirus in mammary gland carcinomas and non-neoplastic tissues of Mexican women: no evidence supporting a cause and effect relationship

Human papillomavirus (HPV) has been implicated in breast carcinogenesis. Consecutive and non-selected mastectomy specimens from Mexican patients harboring breast carcinomas were sampled in order to look for the presence of HPV DNA. HPV-16 was detected in 6 (10%) of 60 breast carcinomas. Two of these also had HPV genome in adjacent non-neoplastic mammary-tissues. Seven cases had HPV DNA only in non-neoplastic tissue specimens. HPV DNA was also detected in 4 (25%) of 10 tumor-bed specimens without residual neoplastic lesions that were obtained from patients who underwent neoadjuvant chemotherapy or neoadjuvant chemotherapy/radiotherapy. HPV-positive tumors tended to be smaller in size, than HPV-negative tumors (p=0.047). Histological distributions of HPV-positive and -negative cases showed no significant difference. Although all the HPV-16 DNA were found integrated, its low viral load rendered it difficult to incriminate this virus in breast carcinogenesis. However, the possibility that HPV infection occurred during carcinoma development cannot be ruled out.

High-risk human papillomavirus infections in breast cancer in Syrian women and their association with Id-1 expression: a tissue microarray study

High-risk human papillomaviruses (HPVs) could be important risk factors for breast carcinogenesis and metastasis. Based on this hypothesis, we recently studied the effect of E6/E7 onco-proteins of high-risk HPV type 16 in two non-invasive human breast cancer cell lines, BT20 and MCF7; we reported that E6/E7 converts these cell lines to invasive cells. This is accompanied by an overexpression of Id-1, which is an important regulator of breast metastasis. In this investigation, we examined the presence of high-risk HPVs (16, 18, 31, 33 and 35) and the expression of their E6 onco-protein as well as their correlation with Id-1 gene expression, using polymerase chain reaction (PCR) and tissue microarray (TMA) analysis, respectively, in a cohort of 113 Syrian breast cancer patients. We found that high-risk HPV types 16, 18, 31, 33 and 35 are present in 8.84, 9.73, 7.07, 55.75 and 37.16% of our samples, respectively, which represent invasive breast cancers. Overall, 69 (61.06%) of the 113 samples are HPV positive; among these specimens 24 tissues (34.78%) are coinfected with more than one HPV type. Furthermore, we report that the expression of the E6 onco-protein of these high-risk HPVs is correlated with Id-1 overexpression in the majority of invasive breast cancer tissue samples. Our data suggest that high-risk HPV infections are associated with human breast cancer progression in Syrian women.

Involvement of human papillomavirus infections in prostate cancer progression

High-risk human papillomaviruses (HPVs) are sexually transmitted and have been associated with several human carcinomas especially cervical and colorectal. On the other hand, a small number of studies have examined the presence of high-risk HPV in human prostate cancer tissues. Currently, the presence and role of high-risk HPV infections in prostate carcinogenesis remain unclear because of the limited number of investigations. This raises the question whether high-risk HPV infections play any role in human prostate cancer development. However, other investigators and our group were able to immortalize normal and cancer prostate epithelial cells in vitro by E6/E7 of HPV type 16. In this paper, we propose the hypothesis that normal and cancer prostate epithelial cells are susceptible to persistent HPV infections; therefore, high-risk HPV infections play an important role in the progression of prostate cancer. We believe that an international collaboration of epidemiological studies and more molecular biology investigations are necessary to answer these important questions.