title: E-cadherin knockdown increases β-catenin reducing colorectal cancer chemosensitivity only in three-dimensional cultures.
abstract: Decreased expression of E-cadherin correlates with poor prognosis in colorectal cancer. Certain E-cadherin signaling cascades are triggered by intercellular force or binding to cadherins on adjacent cells. Three-dimensional (3D) cell cultures represent a better approximation of cell-cell adhesion in vivo than two-dimensional (2D) cultures. Here, we explored the role of E-cadherin in colorectal cancer chemosensitivity in 3D cultures. Cell-cell junctions, including tight junctions, gap junctions, intermediate junctions and desmosomes, were commonly found in 3D cultures. Knockdown of E-cadherin by lentiviral delivery of shRNA significantly reduced chemosensitivity to 5-fluorouracil and irinotecan, increased β-catenin protein level in HCT116 3D cultures. However, these effects were not observed in 2D cultures. Knockdown of β-catenin significantly increased chemosensitivity to 5-fluorouracil and irinotecan in HCT116 3D cultures and LoVo 3D cultures. 5-Fluorouracil activated p38, ERK1/2 and JNK1/2 in a time-dependent manner in HCT116 3D cultures. E-cadherin knockdown enhanced p-p38 and p-ERK1/2, except p-JNK1/2 in HCT116 3D cultures. Knockdown of β-catenin attenuated p-p38 and p-ERK1/2 in HCT116 3D cultures and LoVo 3D cultures. Inhibition of p-p38 or p-ERK1/2 in HCT116 3D cultures significantly increased chemosensitivity. Our results indicate E-cadherin knockdown increases β-catenin resulting in reduction of chemosensitivity only in 3D cultures, and β-catenin increasing the p-p38/p-ERK1/2 is involved in this mechanism.
authors: Department of Oncology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China.
authors: Xi
authors: X
authors: Liang
authors: Molecular Biology Center, State Key Laboratory of Trauma, Burn, and Combined Injury, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China.
authors: Xueqing
authors: X
authors: Xu
authors: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University, Chongqing 400038, P.R. China.
authors: Fengchao
authors: F
authors: Wang
authors: Department of Medical Genetics, Third Military Medical University, Chongqing 400038, P.R. China.
authors: Xuedan
authors: X
authors: Chen
authors: Department of Oncology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China.
authors: Ni
authors: N
authors: Li
authors: Department of Oncology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China.
authors: Cancan
authors: C
authors: Wang
authors: Department of Oncology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China.
authors: Jianming
authors: J
authors: He
mesh_terms: D015153:Blotting, Western; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D018929:Cell Culture Techniques / Q000379:methods*; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000473:pathology*; D019008:Drug Resistance, Neoplasm / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D055785:Gene Knockdown Techniques; D006801:Humans; D007150:Immunohistochemistry; D046529:Microscopy, Electron, Transmission; D034741:RNA, Small Interfering; D015398:Signal Transduction / Q000502:physiology; D014162:Transfection; D051176:beta Catenin / Q000378:metabolism*
chemical_list: C495270:CTNNB1 protein, human; D015820:Cadherins; D034741:RNA, Small Interfering; D051176:beta Catenin