Expression of N-myristoyltransferase inhibitor protein and its relationship to c-Src levels in human colon cancer cell lines.
Earlier, we have reported that N-myristoyltransferase (NMT) activity is higher in colonic epithelial neoplasms than in normal appearing colonic tissue and that increase in NMT activity appears at an early stage in colonic carcinogenesis [Magnuson, B., Raju, R. V. S., Moyana, T. N., and Sharma, R. K. (1995) J. Natl. Cancer Inst. 87, 1630-1635]. In this study, we demonstrate increased NMT mRNA in well-differentiated adenocarcinomas. NMT and c-Src mRNA levels were generally elevated in a subset of human colon cancer cell lines. Western blotting analysis employing N-myristoyltransferase inhibitory protein (NIP(71)) antibody demonstrated low levels of NIP(71) in high-expressing c-Src cell lines and high levels of NIP(71) in low-expressing c-Src cell lines. Interestingly, down regulation of c-Src by antisense expression in the HT-29 cell line resulted in increased expression of NIP(71), suggesting c-Src may negatively regulate NIP(71) expression. Furthermore, this is the first study demonstrating the expression of NIP(71) in human colon cancer cell lines and a possible relationship to colon carcinogenesis.
Rajala
R V
RV
Department of Pathology, Saskatchewan Cancer Agency, Saskatoon, Saskatchewan, S7N 4H4, Canada.
Dehm
S
S
Bi
X
X
Bonham
K
K
Sharma
R K
RK
D000217:Acyltransferases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D003110:Colonic Neoplasms / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000378:metabolism*; D006801:Humans; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D014407:Tumor Cells, Cultured
D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D000217:Acyltransferases; C050480:glycylpeptide N-tetradecanoyltransferase; D016392:Proto-Oncogene Proteins pp60(c-src)