Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai, China.
Int J Immunopathol Pharmacol. 2012 Jul-Sep;25(3):627-36. doi: 10.1177/039463201202500309.
Phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway plays a crucial role in the formation and progression of many malignancies, and has been shown to be an important therapeutic target for cancer. In the present study, human gastric adenocarcinoma tissues of different grades (N=45) were collected. The protein expression of PI3Kp85α and phosphorylated AKT (p-AKT) was evaluated immunohistochemically in the biopsy samples. PI3K/AKT pathway was blocked by constructed recombinant small hairpin RNA adenovirus vector rAd5-PI3Kp85α (rAd5-P) used to transfect into human gastric cancer SGC-7901cell line. The transfection efficiency of rAd5-P in SGC-7901 cells was observed under fluorescent microscope. The expression of PI3Kp85α, p-AKT, Ki-67 and matrix metallopeptidase-2 (MMP-2) was detected by real-time PCR and Western blot assays. Cell proliferative activities and metastatic capabilities were determined by MTT and Transwell assays. As a consequence, the protein expression of PI3Kp85α and p-AKT was respectively observed in 80.0% and 82.2% gastric adenocarcinoma tissues, elevating with the ascending order of tumor malignancy. Targeted blockade of PI3K pathway decreased the expression of PI3Kp85α, p-AKT, Ki-67 and MMP-2, and inhibited the proliferative activities and metastatic capabilities of gastric cancer cells. In conclusion, PI3Kp85α and p-AKT were strongly expressed in gastric adenocarcinoma tissues, and targeted blockade of PI3K pathway may inhibit gastric cancer growth and metastasis through down-regulation of Ki-67 and MMP-2 expression. PI3K/AKT pathway may represent an important therapeutic target for gastric cancer.
磷酸肌醇 3-激酶（PI3K）/蛋白激酶 B（AKT）信号通路在许多恶性肿瘤的发生和发展中起着至关重要的作用，并且已被证明是癌症的重要治疗靶点。在本研究中，收集了不同分级的人胃腺癌组织（N=45）。通过免疫组织化学方法评估活检样本中 PI3Kp85α 和磷酸化 AKT（p-AKT）的蛋白表达。使用构建的重组短发夹 RNA 腺病毒载体 rAd5-PI3Kp85α（rAd5-P）阻断 PI3K/AKT 通路，并用 rAd5-P 转染人胃癌 SGC-7901 细胞系。在荧光显微镜下观察 rAd5-P 在 SGC-7901 细胞中的转染效率。通过实时 PCR 和 Western blot 检测 PI3Kp85α、p-AKT、Ki-67 和基质金属蛋白酶-2（MMP-2）的表达。通过 MTT 和 Transwell 测定细胞增殖活性和转移能力。结果，PI3Kp85α 和 p-AKT 的蛋白表达分别在 80.0%和 82.2%的胃腺癌组织中观察到，随着肿瘤恶性程度的升高而升高。PI3K 通路的靶向阻断降低了 PI3Kp85α、p-AKT、Ki-67 和 MMP-2 的表达，并抑制了胃癌细胞的增殖活性和转移能力。总之，PI3Kp85α 和 p-AKT 在胃腺癌组织中强烈表达，靶向阻断 PI3K 通路可能通过下调 Ki-67 和 MMP-2 的表达来抑制胃癌的生长和转移。PI3K/AKT 通路可能是胃癌的一个重要治疗靶点。
