TY - JOUR
T1 - HPV16 E6-mediated stabilization of ErbB2 in neoplastic transformation of human cervical keratinocytes
AU - Narisawa-Saito, M.
AU - Handa, K.
AU - Yugawa, T.
AU - Ohno, S.
AU - Fujita, M.
AU - Kiyono, T.
N1 - Funding Information:
We would like to express our sincere thanks to Takako Ishiyama for providing expert technical assistance and Akihiro Nawa for providing cervical specimens. This work was supported in part by the Grant-in-Aid for Cancer Research from the Ministry of Health Labor and Welfare, and a Grant-in-Aid for Scientific Research on the Priority Area ‘Cancer’ from the Ministry of Education, Culture, Sports, Science and Technology of Japan to TK.
PY - 2007/3/10
Y1 - 2007/3/10
N2 - 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.
AB - 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.
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U2 - 10.1038/sj.onc.1210118
DO - 10.1038/sj.onc.1210118
M3 - Article
C2 - 17146442
AN - SCOPUS:34248393855
SN - 0950-9232
VL - 26
SP - 2988
EP - 2996
JO - Oncogene
JF - Oncogene
IS - 21
ER -
