title: DLC-1 induces mitochondrial apoptosis and epithelial mesenchymal transition arrest in nasopharyngeal carcinoma by targeting EGFR/Akt/NF-κB pathway.
abstract: Loss of deleted in liver cancer-1 (DLC-1) can induce apoptosis and inhibit the mobility, migration and metastasis in several cancers. Previously, we revealed that ectopic expression of DLC-1 can suppress proliferation, mobility, migration and tumorigenesis in nasopharyngeal carcinoma (NPC). However, the molecular mechanisms accounting for the roles of DLC-1 in NPC are still obscure. In the present work, we attempted to study and uncover the mechanisms underlying the functions of DLC-1 in NPC. The apoptosis of 5-8F-DLC-1 cells, established previously, was analyzed by mitochondrial membrane potentials assay and flow cytometer analysis. And the antibodies involving pathways such as mitochondrial-associated apoptosis, epithelial mesenchymal transition and metastasis were applied to detect and compare the expression level of targeted proteins. The obvious apoptosis of 5-8F-DLC-1 cells was observed reflected by mitochondrial depolarization and lower ratio in cell viability. Subsequently, the activation of mitochondrial apoptosis was verified by the increased expressions of Bax, Apaf1, cleave-caspases and cleave-PARP, etc, and the decreased expressions of Bcl-2, Bcl-xL, Mcl-1, Survivin, etc, in 5-8F-DLC-1 cells. Then, the inhibited epithelial mesenchymal transition of 5-8F-DLC-1 cells was validated by upregulated expression of E-cadherin and downregulated expression of N-cadherin, Snail, Vimentin. Subsequently, downregulated expressions of proteins such as FAK, RhoA, ROCK1 and cdc25 related to cell adhesion and cytoskeleton organization were also observed. And expressions of MMPs were inhibited in 5-8F-DLC-1 cells. At last, the inhibited activity of EGFR/Akt/NF-κB axis was revealed by the decreased expressions of phosho-EGFR, phosho-Akt, phosho-p38MAPK, phosho-IKKα and phosho-p65. Here, we systematically explored the mechanisms underlying the negative roles of DLC-1 in NPC cells. For the first time, we confirmed that the ectopic expression DLC-1 can induce mitochondrial apoptosis, inhibit EMT and related processes by targeting the EGFR/Akt/NF-κB pathway, which, beyond all doubt, offered beneficial guidelines for other studies and laid a good foundation for its clinical applications ultimately.
authors.affiliation: Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, Central South University, Xiangya Road 110, Changsha, 410078, Hunan, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Xiangling
authors.initials: X
authors.lastname: Feng
authors.forename: Huan
authors.initials: H
authors.lastname: Chen
authors.forename: Liang
authors.initials: L
authors.lastname: Zeng
authors.forename: Guoling
authors.initials: G
authors.lastname: Huang
authors.forename: Weidong
authors.initials: W
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Jia
authors.forename: Jiawen
authors.initials: J
authors.lastname: Chen
authors.forename: Caiping
authors.initials: C
authors.lastname: Ren
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002277:Carcinoma; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D058750:Epithelial-Mesenchymal Transition; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000378:metabolism; D005434:Flow Cytometry; D020690:GTPase-Activating Proteins / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins / Q000494:pharmacology*
chemical_list: C112352:DLC1 protein, human; D020690:GTPase-Activating Proteins; D016328:NF-kappa B; D025521:Tumor Suppressor Proteins; C512478:EGFR protein, human; D066246:ErbB Receptors; C494918:AKT1 protein, human; D051057:Proto-Oncogene Proteins c-akt