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不同的乳腺癌细胞株对肿瘤坏死因子相关凋亡诱导配体(TRAIL)的敏感性不同. 为了揭示其分子机制, 分别以对TRAIL敏感和不敏感的乳腺癌细胞株(MDA-MB-231和MCF-7)为模型, 比较分析了这2株细胞对重组可溶性TRAIL(rsTRAIL)的不同敏感性的分子机制. 首先使用不同的抑制剂分别阻断细胞内3条主要存活通路(PKCd, MAPK, PI3K)后, 研究细胞对rsTRAIL的敏感性, 结果表明, 阻断这3条存活通路, 都不影响MD-MB-231细胞对rsTRAIL的敏感性, 说明MD-MB-231细胞对rsTRAIL敏感与这3条存活通路无关; 以MEK1/2抑制剂阻断MAPK途径或以Ly294002阻断PI3K途径都不影响MCF-7细胞对rsTRAIL的敏感性; 但以PKCd抑制剂rottlerin抑制PKCd活性, 能显著促进rsTRAIL诱导的MCF-7细胞凋亡, 提示PKCd高表达可能是MCF-7细胞对rsTRAIL不敏感的重要原因. 应用RNA干扰技术抑制PKCd的表达, 确证PKCd高表达是MCF-7细胞对rsTRAIL不敏感的关键因素. 同时, 进一步证明 caspase-3 表达重建不能改变MCF-7 细胞中PKCd的总体表达水平, 说明凋亡执行蛋白酶caspase-3缺陷, 不是PKCd高表达的主要原因.
Different breast cancer cell lines have different sensitivities to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). To reveal the molecular mechanism, different breast cancer cell lines (MDA-MB-231 and MCF-7) was used as a model to analyze the molecular mechanism of the different sensitivity of these two cell lines to recombinant TRAIL (rsTRAIL) by blocking the three major intracellular survival pathways (PKCd, MAPK, PI3K) to study the sensitivity of cells to rsTRAIL. The results showed that blocking these three survival pathways did not affect the sensitivity of MD-MB-231 cells to rsTRAIL, indicating that MD-MB-231 cells were sensitive to rsTRAIL 3 cell viability pathway. However, MEK1 / 2 inhibitor blocked MAPK pathway or Ly294002 blocked PI3K pathway did not affect the sensitivity of MCF-7 cells to rsTRAIL. However, PKCd inhibitor rottlerin inhibited PKCd activity and significantly promoted rsTRAIL Induced MCF-7 cell apoptosis, suggesting that high expression of PKCd may be MCF-7 cells is not sensitive to rsTRAIL an important reason.Application of RNA interference technology to inhibit the expression of PKCd, PKCd confirm the high expression of MCF-7 cells are not sensitive to rsTRAIL The key factor at the same time , Further evidence that caspase-3 expression and reconstruction can not change the overall expression level of PKCd in MCF-7 cells, indicating that caspase-3 deficiency in protease execution is not the main reason for the high expression of PKCd.