[Expression of human cytochrome P450 2E1 gene in embryonic nasopharynx, nasopharyngeal cancer cell lines and tissue].
OBJECTIVE
Research results in the past suggested that nitrosamines(chemicals) can induce nasopharyngeal carcinogenesis in vivo and in vitro. As the indirect carcinogens, their activation are mainly dependent on cytochrome P450 2E1. The study here was to investigate the roles of human cytochrome P450 2E1 (hCYP 2E1) gene in chemical cancinogen-induced nasopharyngeal carcinogenesis, and to provide new evidence about etiology and pathogenesis of nasopharyngeal carcinoma(NPC).


METHODS
RT-PCR were used to detect the expression of CYP2E1 in 8 embryonic nasopharyngeal epithelial tissues(ENET), 10 NPC biopsys, 5 NPC cell lines(CNE-1, CNE-2, HNE-1, HNE-2, and HNE-3), 1 transformed nasopharyngeal cell line(7429) and 3 human embryonic nasopharyngeal epithelial(HENE) cell lines treated with 200, 250, and 300 micrograms/ml of chemical carcinogen N, N'-dinitrosopiperazine(DNP) in vitro for 24 h, respectively.


RESULTS
(1) All of ENET(8/8), NPC cell lines(6/6, including 7429 cell line) and 80% of NPC biopsys(8/10) showed expression of hCYP2E1; (2) The hCYP 2E1 expression in HENE cell lines was elevated after treatment with different concentration of DNP.


CONCLUSIONS
Human nasopharynx exist inducible CYP2E1 expression, suggesting that hCYP2E1 may play an important role in the course of nasopharyngeal carcinogenesis caused by indirect carcinogens nitrosamines(such as DNP).
He
Zhi-Min
ZM
Cancer Research Institute, Xiangya Medical College, Central South University, Changsha 410078, P. R. China.
Wang
Shui-liang
SL
Yuan
Jian-hui
JH
Chen
Zhu-chu
ZC
D002273:Carcinogens / Q000494:pharmacology; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009305:Nasopharynx / Q000196:embryology / Q000378:metabolism* / Q000473:pathology; D009602:Nitrosamines / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D002273:Carcinogens; D009602:Nitrosamines; D019392:Cytochrome P-450 CYP2E1; C026156:N,N'-dinitrosopiperazine