GalNAc-T14 may be involved in regulating the apoptotic action of IGFBP-3.
Insulin-like growth factor binding protein-3 (IGFBP-3) is known to induce apoptosis in an insulin-like growth factor (IGF)-dependent and IGF-independent manner, but the mechanism underlying the IGF-independent effects remains unclear. Polypeptide N-acetylgalactosaminyltransferase 14 (GalNAc-T14) is a novel IGFBP-3 binding partner. In this paper, small interference RNA (siRNA) targeting GalNAc-T14 was used to examine whether GalNAc-T14 affects the apoptotic action of IGFBP-3. Using semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and western blot analysis, we determined that GalNAc-T14 expression was downregulated by the siRNA directed against GalNAc-T14. Apoptosis analysis of IGFBP-3-overexpressing cells treated with siRNA against GalNAc-T14 was performed to determine if GalNAc-T14 was specifically involved in IGFBP-3 signalling. The results, as determined by flow cytometric analysis and caspase-3 assay, showed that the extent of apoptosis induced by IGFBP-increased with RNA interference (RNAi) knockdown of GalNAc-T14. Our data suggest that GalNAc-T14 influences the apoptotic action of IGFBP-3 and might mediate the signalling pathway of IGFBP-3. Experiments to determine the role of GalNAc-T14 in the regulation of apoptosis induced by IGFBP-3 are under way.
Wu
Chen
C
College of Life Sciences, Hebei University, Baoding, Hebei, 071002, P R China.
Shan
Yaojun
Y
Liu
Xinxia
X
Song
Wenqian
W
Wang
Jiali
J
Zou
Minji
M
Wang
Min
M
Xu
Donggang
D
D017209:Apoptosis / Q000502:physiology*; D002292:Carcinoma, Renal Cell / Q000378:metabolism; D053148:Caspase 3 / Q000032:analysis / Q000378:metabolism; D045744:Cell Line, Tumor; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics / Q000378:metabolism*; D017350:N-Acetylgalactosaminyltransferases / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference / Q000187:drug effects; D012333:RNA, Messenger / Q000032:analysis; D034741:RNA, Small Interfering / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D014162:Transfection; D000097763:Polypeptide N-acetylgalactosaminyltransferase
D053148:Caspase 3; D018972:Insulin-Like Growth Factor Binding Protein 3; D017350:N-Acetylgalactosaminyltransferases; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D000097763:Polypeptide N-acetylgalactosaminyltransferase