Gupta Shilpi, Kumar Prabhat, Kaur Harsimrut, Sharma Nishi, Saluja Daman, Bharti Alok C, Das Bhudev C
Department of Molecular Oncology, Dr. B.R. Ambedkar Centre for Biomedical Research (ACBR), University of Delhi, New Delhi-110007, India.
Amity Institute of Molecular Medicine &Stem Cell Research (AIMMSCR), Amity University Campus, Uttar Pradesh, Sector-125, Noida-201313, India.
Sci Rep. 2015 Nov 19;5:16811. doi: 10.1038/srep16811.
Tongue squamous cell carcinoma (TSCC) is most aggressive head and neck cancer often associated with HR-HPV infection. The role of AP-1 which is an essential regulator of HPV oncogene expression and tumorigenesis is not reported in tongue cancer. One hundred tongue tissue biopsies comprising precancer, cancer and adjacent controls including two tongue cancer cell lines were employed to study the role of HPV infection and AP-1 family proteins. An exclusive prevalence (28%) of HR-HPV type 16 was observed mainly in well differentiated tongue carcinomas (78.5%). A higher expression and DNA binding activity of AP-1 was observed in tongue tumors and cancer cell lines with c-Fos and Fra-2 as the major binding partners forming the functional AP-1 complex but c-Jun participated only in HPV negative and poorly differentiated carcinoma. Knocking down of Fra-2 responsible for aggressive tongue tumorigenesis led to significant reduction in c-Fos, c-Jun, MMP-9 and HPVE6/E7 expression but Fra-1 and p53 were upregulated. The binding and expression of c-Fos/Fra-2 increased as a function of severity of tongue lesions, yet selective participation of c-Jun appears to promote poor differentiation and aggressive tumorigenesis only in HPV negative cases while HPV infection leads to well differentiation and better prognosis preferably in nonsmokers.
舌鳞状细胞癌(TSCC)是最具侵袭性的头颈癌,常与高危型人乳头瘤病毒(HR-HPV)感染相关。AP-1作为HPV癌基因表达和肿瘤发生的重要调节因子,其在舌癌中的作用尚未见报道。本研究采用100例舌组织活检标本,包括癌前病变、癌组织及相邻对照组织,并选取2种舌癌细胞系,以研究HPV感染及AP-1家族蛋白的作用。结果发现,HR-HPV 16型的独特流行率(28%)主要见于高分化舌癌(78.5%)。在舌肿瘤及癌细胞系中观察到AP-1的表达及DNA结合活性更高,其中c-Fos和Fra-2作为主要结合伙伴形成功能性AP-1复合物,但c-Jun仅参与HPV阴性及低分化癌。敲低导致侵袭性舌肿瘤发生的Fra-2,可使c-Fos、c-Jun、基质金属蛋白酶-9(MMP-9)及HPV E6/E7表达显著降低,但Fra-1和p53上调。c-Fos/Fra-2的结合及表达随舌病变严重程度增加而升高,然而c-Jun的选择性参与似乎仅在HPV阴性病例中促进低分化及侵袭性肿瘤发生,而HPV感染则导致高分化且预后较好,这在非吸烟者中更为明显。