Human papillomavirus oncoprotein E6 upregulates c-Met through p53 downregulation. (September 2016)

• Record Type: Journal Article
• Authors: Qian, Guoqing; Wang, Dongsheng; Magliocca, Kelly R.; Hu, Zhongliang; Nannapaneni, Sreenivas; Kim, Sungjin; Chen, Zhengjia; Sun, Shi-Yong; Shin, Dong M.; Saba, Nabil F.; Chen, Zhuo G.
• Is Part Of: European journal of cancer. Volume 65(2016)
• Page Start: 21
• Page End: 32
• Publication Date: 2016-09
• Subjects: Human papillomavirus -- c-Met -- p53 -- Head and neck cancer; Cancer -- Periodicals; Neoplasms -- Periodicals; Cancer -- Périodiques; Cancer; Tumors; Electronic journals; Periodicals; Electronic journals; 616.994
• DOI: 10.1016/j.ejca.2016.06.006
• Languages: English
• ISSNs: 0959-8049

Abstract

Abstract: Purpose: Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) carries a distinct clinical behaviour. c-Met oncogene is an important driver for tumour progression and its relationship with HPV in OPSCC was explored in the present study. Experimental design: Knockdown of HPV oncogene E6 or p53 alone and in combination was performed to examine their effects on c-Met expression by Western blot and quantitative real-time polymerase chain reaction. The effects of c-Met inhibition on cell proliferation, migration, and colony formation were examined in HPV-positive head and neck squamous cell carcinoma (HNSCC) cells. Retrospectively collected OPSCC patient specimens (N = 78) were stained for c-Met by immunohistochemistry and the staining levels were correlated with HPV status and patient outcomes. Results: E6 knockdown decreased c-Met protein and mRNA expression in HPV-positive HNSCC cells, which was partially abolished by the elimination of p53. Reducing c-Met decreased cell proliferation, migration, and colony formation in HPV-positive HNSCC cells. In OPSCC patient samples, high c-Met expression was associated with HPV-positive status (OR = 4.11, 95%CI: 1.16–14.55, P = 0.028) and tumour stage (OR = 0.27, 95%CI: 0.08–0.93, P = 0.039) by multivariable analysis. In T3/T4 stage patients, high c-Met expression was associated with HPV positivity and low p53 levels, supporting an axis of E6-p53-c-Met regulation. Furthermore, high c-Met expression was marginally associated with poor disease-free survival in HPV-positive patients. Conclusions: Our results suggest that c-Met may serve as a novel target for treating HPV-associated OPSCC. The data also demonstrate that HPV E6 upregulates c-Met expression partially through p53 downregulation. Highlights: Reducing human papillomavirus (HPV) oncogene E6 decreased both mRNA and protein expressions of c-Met. The upregulation of c-Met by HPV E6 is mediated by p53. High c-Met protein levels correlated with HPV positivity in oropharyngeal squamous cell carcinoma specimens. High c-Met protein levels correlated with worse disease-free survival in HPV-positive oropharyngeal squamous cell carcinoma patients.