Expression of calbindin-D28k is inversely correlated with proapototic gene expression in hydrogen peroxide-induced cell death in endometrial cancer cells.
Calbindin-D28k (CaBP-28k) is a calcium binding protein important for intracellular Ca2+ buffering and known to have anti-apoptotic properties in neurons, osteoblasts and male germ cells. Although endometrial cancer is a common invasive gynecologic malignancy, the involvement of uterine CaBP-28k in apoptotic signaling of endometrial cancer is poorly understood. The present study investigates the role of CaBP-28k in hydrogen peroxide (H2O2)-induced apoptotic signaling in human endometrial Ishikawa cells. The dose- and time-dependent effect of H2O2 on Bax, p53 and Bcl-2 expression was assessed by Western blot analysis. Treatment of cells with 1 mM H2O2 for 1 h induced an increase in Bax and p53 expression, but the expression of Bcl-2 was not affected by H2O2 treatment. Interestingly, overexpression of CaBP-28k inhibited cell death and caused a decrease in Bax, p53 and caspase 3 expression during H2O2-induced apoptosis, suggesting that CaBP-28k blocks the up-regulation of apoptosis-related gene expression. siRNA knockdown of CaBP-28k resulted in an elevation of H2O2-induced cell death and an increase in Bax, p53 and caspase 3, providing additional evidence that induction of the CaBP-28k gene might be associated with survival signaling during H2O2-mediated cell death. Overall, these results suggest that CaBP-28k expression is inversely correlated with pro-apoptotic gene expression in human endometrial Ishikawa cells.
Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
Eui-Man
EM
Jung
Kyung-Chul
KC
Choi
Eui-Bae
EB
Jeung
D000230:Adenocarcinoma / Q000378:metabolism*; D017209:Apoptosis; D064092:Calbindin 1; D064026:Calbindins; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival; D016889:Endometrial Neoplasms / Q000378:metabolism*; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity*; D008297:Male; D016877:Oxidants / Q000633:toxicity*; D018384:Oxidative Stress; D034622:RNA Interference; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D064030:S100 Calcium Binding Protein G / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D015854:Up-Regulation; D051028:bcl-2-Associated X Protein / Q000378:metabolism
C576498:CALB1 protein, human; D064092:Calbindin 1; D064026:Calbindins; D016877:Oxidants; D011994:Recombinant Proteins; D064030:S100 Calcium Binding Protein G; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D006861:Hydrogen Peroxide; D053148:Caspase 3