Human Papillomavirus 16 E7 DNA and E7 Protein Expression in Chinese Colorectal Carcinoma Patients

Background The relationship between Human papillomavirus (HPV) 16 infection and the natural course of colorectal adenocarcinoma has not been fully defined. In this study, to investigate the correlation between HPV 16 infection and colorectal carcinoma HPV 16 E7 DNA and E7 protein were observed in 106 patients with primary colorectal adenocarcinoma. Material and methods 106 patients with primary colorectal adenocarcinoma were enrolled in this study. Fresh tissues were taken from both the tumors and the adjacent normal area of each patient. HPV16 E7 DNA and E7 protein were detected using polymerase chain reaction (PCR) and immunohistochemistry (IHC). Results HPV16 E7 expression was significantly higher in colorectal carcinoma (48/106) than that in adjacent normal mucosa (7/106)(P<0.001). A correlation was found between HPV16 E7 mRNA expression and tumor locations, 4/17 in the ascending colon carcinoma and 25/42 in the rectal carcinoma (P<0.05). Higher HPV16 E7 mRNA expression was also associated with lower Dukes stages(Dukes stages between A and C, P<0.05). IHC shows HPV16 E7 oncoprotein expressed in the nucleus of both tumor and normal mucosal cells. There was a correlation between the expression of E7 oncoprotein and E7 gene. Conclusions Our findings indicated that there was a correlation between colorectal adenocarcinoma and HPV 16 infection. HPV16 infection was relatively higher in the colorectal carcinoma and rare in the adjacent normal mucosa. Specimens expressing higher levels of HPV 16 E7 DNA were associated with lower Dukes stages and more distal locations. [Jian Cheng Zhang, Gang Wu, PeiChun Sun, Yi Kang, HongGuang Li, Bao Ping Zhai, Yuan Zeng Zhu, Yi Ding. Human Papillomavirus 16 E7 DNA and E7 Protein Expression in Chinese Colorectal Carcinoma Patients. Life Sci J 2012; 9(3): 2419-2423] (ISSN: 1097-8135). http://www.lifesciencesite.com.348