血管活性肠肽对HT29结肠癌细胞系原癌基因c－myc蛋白表达的影响

THE EFFECT OF VASOACTIVE INTESTINAL PEPTIDE ON THE EXPRESSIONOF PROTOONCOGENE C-MYC IN HT29 CELL LINE

采用３Ｈ－ＴｄＲ掺入法及免疫组化方法研究了ＶＩＰ对ＨＴ２９细胞生长及ｃ－ｍｙｃ癌基因蛋白表达的影响。结果表明：ＶＩＰ单独可刺激细胞生长，而ＶＩＰ＋ＩＢＭＸ及ｄｂ－ｃＡＭＰ有相反的作用。ＶＩＰ、ｄｂ－ｃＡＭＰ单独对细胞ｃ－ｍｙｃ癌基因蛋白表达无明显影响，ＶＩＰ＋ＩＢＭｘ则抑制ｃ－ｍｙｃ癌基因蛋白的表达。作者认为，ＶＩＰ对ＨＴ２９细胞生长的调节作用与ｃＡＭＰ信使系统密切相关，ｖＩＰ对ＨＴ２９细胞生长的抑制作用至少在部分上是通过抑制ｃ－ｍｙｃ癌基因表达而实现的。

The effect of VIP on the growth and expression of protooncogene c-myc in HT29 cell line was investigated using 3H-TdR incorportion and immunohistochemistry. The resulte showed that VIP could promote DNA synthesis in HT 29 cells, however, opposite resulte were gained while using VIP with IBMX. In addition,the expression of c-myc onco-protein was not affected by given VIP or db-cAMP alone,but was inhibited by VIP with IBMX. The results suggested that the iuhibitory effect of VIP with IBMX on the growth of cancer cells appears to be due, in part, to reduced expression of c-myc protein by enhancing the cAMP level of cancer cells.