Cancer Molecular Pathology, School of Medicine , Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia.
Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh.
Mol Carcinog. 2018 Nov;57(11):1480-1491. doi: 10.1002/mc.22871. Epub 2018 Jul 18.
FAM134B is an autophagy regulator of endoplasmic reticulum and acts as a cancer suppressor in colon cancer. However, the molecular signaling pathways by which FAM134B interacts within colon carcinogenesis is still unknown. Herein, this study aims to determine the interacting partners of FAM134B for the first time in colon cancer and to explore the precise location of FAM134B in cancer signalling pathways. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) followed by anti-FAM134B co-immune precipitation of FAM134B interacting complex was used to identify the potential interactors of FAM134B in colon cancer cells. Western blot and confocal microscopic analysis were used to validate the physical interactions of FAM134B with the interactors. Lentiviral shRNA mediated silencing of FAM134B was used to examine the modulation of FAM134B interactors in cells. We have identified 29 novel binding partners, including CAP1, RPS28, FTH1, KDELR2, MAP4, EB1, PSMD6, PPIB/CYPB etc. Subsequent immunoassays confirmed the direct physical interactions of FAM134B with CAP1, EB1, CYPB, and KDELR2 in colon cancer cells. Exogenous suppression of FAM134B has led to significant upregulation of EB1 as well as reduction of KDELR2 expression. It was noted that overexpression of EB1 promotes WNT/β-catenin signaling pathways via inactivating tumor suppressor APC followed by activating β-catenin in colorectal carcinogenesis. This study has first time reported the gene signaling networks with which FAM134B interacts and noted that FAM134B is involved in the regulation of WNT/β-catenin pathway by EB1-mediated modulating of APC in colon cancer cells.
FAM134B 是内质网的自噬调节剂，在结肠癌中作为一种肿瘤抑制因子发挥作用。然而，FAM134B 在结肠癌发生过程中相互作用的分子信号通路仍不清楚。本研究旨在首次确定 FAM134B 在结肠癌中的相互作用伙伴，并探讨 FAM134B 在癌症信号通路中的精确位置。采用液相色谱串联质谱（LC-MS/MS）法结合 FAM134B 相互作用复合物的抗 FAM134B 共免疫沉淀法，鉴定结肠癌细胞中 FAM134B 的潜在相互作用蛋白。采用 Western blot 和共聚焦显微镜分析验证 FAM134B 与相互作用蛋白的物理相互作用。采用慢病毒 shRNA 介导的 FAM134B 沉默技术，检测 FAM134B 相互作用蛋白在细胞中的表达变化。我们鉴定了 29 种新的结合伴侣，包括 CAP1、RPS28、FTH1、KDELR2、MAP4、EB1、PSMD6、PPIB/CYPB 等。随后的免疫测定证实了 FAM134B 与 CAP1、EB1、CYPB 和 KDELR2 在结肠癌细胞中的直接物理相互作用。外源性抑制 FAM134B 可显著上调 EB1 并降低 KDELR2 的表达。值得注意的是，EB1 的过表达通过使肿瘤抑制因子 APC 失活，随后激活β-连环蛋白，从而促进结直肠癌发生过程中的 WNT/β-连环蛋白信号通路。本研究首次报道了 FAM134B 相互作用的基因信号网络，并指出 FAM134B 通过 EB1 介导的 APC 调节参与结肠癌中 WNT/β-连环蛋白通路的调节。
