Department of Pathology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China.
J Exp Clin Cancer Res. 2010 Aug 5;29(1):104. doi: 10.1186/1756-9966-29-104.
Drug resistance remains a great challenge in the treatment of pancreatic cancer. The goal of this study was to determine whether TGF-beta1 is associated with drug resistance in pancreatic cancer.
Pancreatic cancer BxPC3 cells were stably transfected with TGF-beta1 cDNA. Cellular morphology and cell cycle were determined and the suppressive subtracted hybridization (SSH) assay was performed to identify differentially expressed genes induced by TGF-beta1. Western blotting and immunohistochemistry were used to detect expression of TGF-beta1-related genes in the cells and tissue samples. After that, the cells were further treated with an anti-cancer drug (e.g., cisplatin) after pre-incubated with the recombinant TGF-beta1 plus PKCalpha inhibitor Gö6976. TGF-beta1 type II receptor, TbetaRII was also knocked down using TbetaRII siRNA to assess the effects of these drugs in the cells. Cell viability was assessed by MTT assay.
Overexpression of TGF-beta1 leads to a markedly increased invasion potential but a reduced growth rate in BxPC3 cells. Recombinant TGF-beta1 protein increases expression of PKCalpha in BxPC3 cells, a result that we confirmed by SSH. Moreover, TGF-beta1 reduced the sensitivity of BxPC3 cells to cisplatin treatment, and this was mediated by upregulation of PKCalpha. However, blockage of PKCalpha with Gö6976 and TbetaRII with siRNA reversed the resistance of BxPC3 cells to gemcitabine, even in the presence of TGF-beta1. Immunohistochemical data show that pancreatic cancers overexpress TGF-beta1 and P-gp relative to normal tissues. In addition, TGF-beta1 expression is associated with P-gp and membranous PKCalpha expression in pancreatic cancer.
TGF-beta1-induced drug resistance in pancreatic cancer cells was associated with PKCalpha expression. The PKCalpha inhibitor Gö6976 could be a promising agent to sensitize pancreatic cancer cells to chemotherapy.
耐药性仍然是胰腺癌治疗的一大挑战。本研究旨在确定 TGF-β1 是否与胰腺癌的耐药性有关。
用 TGF-β1 cDNA 稳定转染胰腺癌细胞 BxPC3。观察细胞形态和细胞周期，并进行抑制性消减杂交（SSH）实验以鉴定 TGF-β1 诱导的差异表达基因。Western blot 和免疫组化检测细胞和组织样本中 TGF-β1 相关基因的表达。然后，用重组 TGF-β1 预处理细胞，再用抗癌药物（如顺铂）处理，同时用 PKCalpha 抑制剂 Gö6976 预处理。用 TbetaRII siRNA 敲低 TGF-β1 型 II 受体（TbetaRII），以评估这些药物在细胞中的作用。MTT 法评估细胞活力。
TGF-β1 的过表达导致 BxPC3 细胞的侵袭能力显著增加，但生长速度降低。重组 TGF-β1 蛋白增加了 BxPC3 细胞中 PKCalpha 的表达，SSH 实验证实了这一点。此外，TGF-β1 降低了 BxPC3 细胞对顺铂治疗的敏感性，这是通过上调 PKCalpha 介导的。然而，用 Gö6976 阻断 PKCalpha 和用 siRNA 阻断 TbetaRII 可逆转 BxPC3 细胞对吉西他滨的耐药性，即使存在 TGF-β1 也是如此。免疫组化数据显示，胰腺癌组织中 TGF-β1 和 P-糖蛋白的表达高于正常组织。此外，TGF-β1 的表达与胰腺癌中 P-糖蛋白和膜 PKCalpha 的表达有关。
TGF-β1 诱导的胰腺癌细胞耐药性与 PKCalpha 的表达有关。PKCalpha 抑制剂 Gö6976 可能是一种有前途的药物，可使胰腺癌细胞对化疗敏感。
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