Premium
Involvement of JNK/p73/NOXA in vitamin E analog‐induced apoptosis of human breast cancer cells
Author(s) -
Wang Pei,
Yu Weiping,
Hu Zhanzhi,
Jia Li,
Iyer Vishwanath R.,
Sanders Bob G.,
Kline Kimberly
Publication year - 2008
Publication title -
molecular carcinogenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 97
eISSN - 1098-2744
pISSN - 0899-1987
DOI - 10.1002/mc.20400
Subject(s) - biology , apoptosis , signal transduction , kinase , cancer research , small interfering rna , cancer cell , gene silencing , downregulation and upregulation , microbiology and biotechnology , cancer , transfection , gene , biochemistry , genetics
Microarray analyses of human MDA‐MB‐435 breast cancer cells treated with vitamin E analog 2,5,7,8‐tetramethyl‐2R‐(4R,8R,12‐trimethyltridecyl) chroman‐6‐yloxy acetic acid (α‐TEA) showed over 400 genes to be modulated. Thirty‐four genes deemed of interest based on potential involvement in anticancer activities of α‐TEA fell into six categories: apoptosis related, signal transduction, cell cycle related, cell adhesion and motility, transcriptional regulators, and membrane traffic related. The gene ( PMAIP1 ) for NOXA was studied further. NOXA mRNA and protein levels were elevated in a time and dose‐dependent fashion following α‐TEA treatment. Functional knockdowns using small interfering RNA (siRNA) showed NOXA to contribute to α‐TEA‐induced apoptosis. A correlation between α‐TEA's ability to upregulate NOXA and induce apoptosis was seen among several human breast cancer cell lines. Efforts to identify upstream regulators of NOXA in α‐TEA‐induced apoptosis identified the necessity of both c‐Jun N‐terminal kinase (JNK) activation and p73 expression. Additionally, protein levels of full length p73 were decreased by JNK siRNA treatment, suggesting that the signal transduction module of JNK‐p73‐NOXA is involved in α‐TEA induced apoptosis of human breast cancer cells. Taken together, these findings suggest a role for JNK activation in mediating full length p73 expression and add to our understanding of the mechanisms of anticancer actions of α‐TEA, a potential chemotherapeutic agent. © 2007 Wiley‐Liss, Inc.