纤连蛋白通过激活 mTOR 信号通路促进胆囊癌细胞增殖和侵袭。
Fibronectin promotes cell proliferation and invasion through mTOR signaling pathway activation in gallbladder cancer.
机构信息
Department of General Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Institute of Biliary Tract Disease, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Department of Molecular Pharmacology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA.
出版信息
Cancer Lett. 2015 May 1;360(2):141-50. doi: 10.1016/j.canlet.2015.01.041. Epub 2015 Feb 2.
Fibronectin (FN), a heterodimeric glycoprotein overexpressed in several types of tumors, has been implicated in cancer progression via the activation of integrin-mediated pro-oncogenic pathways. The FN level in human bile fluid is dramatically increased in malignant biliary diseases; however, FN expression and its biological functions in gallbladder cancer (GBC) remain unknown. In this study, we found that FN was overexpressed in GBC tissues and was associated with a worse prognosis in GBC patients. In vitro experimental studies indicated that exogenous FN significantly enhanced cell proliferation, invasion and active MMP-9 secretion in human GBC cell lines (GBC-SD and NOZ). Moreover, the key kinases of the mTOR signaling pathway, including FAK, Akt, mTOR and 4E-BP1, were markedly activated in a time-dependent manner in FN-treated GBC-SD and NOZ cells. The IHC statistical analyses validated that FN expression was positively correlated with the phosphorylation levels of the 4E-BP1 protein in GBC tissues. Furthermore, rapamycin, a specific inhibitor of mTOR, almost completely blocked FN-induced phosphorylation of 4E-BP1 and also partially abrogated the stimulatory effects of FN on GBC cell proliferation and invasion. In vivo, FN treatment significantly promoted the proliferation and metastasis of GBC cells and markedly activated Akt/mTOR/4E-BP1 signaling cascade. These findings demonstrate that FN may play a critical role in the modulation of cell proliferation and invasion via mTOR signaling pathway activation during GBC progression.
纤连蛋白(FN)是一种在多种类型肿瘤中过度表达的异二聚体糖蛋白,通过激活整合素介导的致癌途径参与癌症进展。恶性胆道疾病患者胆汁中的 FN 水平显著升高;然而,FN 在胆囊癌(GBC)中的表达及其生物学功能仍不清楚。在这项研究中,我们发现 FN 在 GBC 组织中过度表达,并与 GBC 患者的预后不良相关。体外实验研究表明,外源性 FN 可显著增强人 GBC 细胞系(GBC-SD 和 NOZ)的细胞增殖、侵袭和活性 MMP-9 分泌。此外,FN 处理的 GBC-SD 和 NOZ 细胞中 mTOR 信号通路的关键激酶,包括 FAK、Akt、mTOR 和 4E-BP1,以时间依赖性方式明显被激活。免疫组化统计分析验证了 FN 表达与 GBC 组织中 4E-BP1 蛋白磷酸化水平呈正相关。此外,雷帕霉素,一种 mTOR 的特异性抑制剂,几乎完全阻断了 FN 诱导的 4E-BP1 磷酸化,并且部分阻断了 FN 对 GBC 细胞增殖和侵袭的刺激作用。在体内,FN 处理显著促进 GBC 细胞的增殖和转移,并显著激活 Akt/mTOR/4E-BP1 信号级联。这些发现表明,FN 可能通过激活 mTOR 信号通路在 GBC 进展过程中调节细胞增殖和侵袭中发挥关键作用。