HPV16 E6-mediated stabilization of ErbB2 in neoplastic transformation of human cervical keratinocytes
HPV16 E6-mediated stabilization of ErbB2 in neoplastic transformation of human cervical keratinocytes
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DOI：
10.1038/sj.onc.1210118
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发表时间：
2007-05-10
期刊：
影响因子：
8
通讯作者：
Kiyono, T.
中科院分区：
文献类型：
--
作者：
Narisawa-Saito, M.;Handa, K.;Kiyono, T.
ErbB2受体酪氨酸激酶是否与宫颈癌有关尚存争议。我们检测了人类乳头瘤病毒16型(HPV-16)的E6和E7基因对hTERT永生化的原代人宫颈角质形成细胞(HCK)中ErbB2表达的影响。在E6阳性细胞(HCK1T-E6和HCK1T-E6E7)中，ErbB2的表达水平随着细胞密度的增加而增加。HCK1T-E6E7在软琼脂中表现出接触抑制和锚定无关生长的损害，而引入ErbB2特异性短发夹状RNA(ShRNA)或ErbB2特异性抑制剂AG825后，这种抑制作用被取消。此外，在HPV16阳性的宫颈癌细胞系中也观察到ErbB2的表达增加，这种增加可以通过HPV16E6-或E6AP-shRNA的引入而减弱。在融合后的细胞密度下，ErbB2蛋白在E6的存在下稳定下来，而在E6突变株不能降解P53的情况下，ErbB2表达的增加并不明显。此外，将P53-shRNA导入HCK1T后，ErbB2蛋白的稳定性增加，提示可能通过P53对ErbB2进行调控。最后，我们发现ErbB2-shRNA导入的SiHA细胞的成瘤作用几乎被消除。综上所述，这些数据表明HPV16E6对ErbB2的调节在人宫颈角质形成细胞的致癌转化中起重要作用。
Whether ErbB2 receptor tyrosine kinase contributes to cervical cancer is controversial. We have examined the effects of E6 and E7 genes of human papillomaviruses type 16 ( HPV-16) on ErbB2 expression in primary human cervical keratinocytes ( HCK) immortalized with hTERT ( HCK1T). In E6-positive cells ( HCK1T-E6 and HCK1T-E6E7), ErbB2 expression levels increased with the cell density. HCK1T-E6E7 showed impaired contact inhibition and anchorage-independent growth in soft agar which were abrogated with introduction of ErbB2-specific short hairpin RNA ( shRNA) or an ErbB2 specific inhibitor AG825. Furthermore, increased ErbB2 expression was also observed in HPV16 positive cervical cancer cell lines and this was diminished by introduction of HPV16E6- or E6AP-shRNA. At post-confluence cell densities, ErbB2 protein was stabilized in the presence of E6 whereas increased ErbB2 expression was not obvious with E6 mutants incapable of degrading p53. Furthermore, introduction of p53-shRNA to HCK1T resulted in increased ErbB2 protein stability, indicating possible ErbB2 regulation through p53. Finally, we showed that tumor formation of ErbB2-shRNA introduced SiHa cells were almost abolished. Taken together, these data indicate an important role of ErbB2 regulation by HPV16 E6 in oncogenic transformation of human cervical keratinocytes.