AIM: To determine the expression and function of epithelial membrane protein 1 (EMP1) in colorectal carcinoma. METHODS: Colorectal samples were taken from cancer lesions and adjacent normal tissue in colorectal cancer patients immediately after endoscopic biopsy. A portion of the sample was either fixed in 4% paraformaldehyde and embedded in paraffin for immunohistochemistry or stored in liquid nitrogen for Western blot. In order to determine protein expression of EMP1 in colorectal cancer (n = 63) and normal tissue (n = 31), semi-quantitative immunohistochemistry and Western blot were utilized. For in vitro studies, the human colorectal cancer cell line SW-480 was maintained in RPMI-1640 medium supplemented with 10% fetal bovine serum. Recombinant lentivirus mediated overexpression of EMP1 in SW-480 cells was quantified by real-time reverse transcription-polymerase chain reaction and Western blot. Control SW-480 cells were transfected with an empty vector. To further study the effect of EMP1 overexpression in SW-480 cells, cell proliferation, apoptosis, migration and invasion assays were conducted. RESULTS: Expression of EMP1 was significantly lower in colorectal cancer tissue than in normal tissue using both immunohistochemistry (39.7% vs 90.3% of tissues, P < 0.05) and Western blot (0.126 ± 0.022 vs 0.632 ± 0.053, P < 0.05). The level of EMP1 protein expression was not correlated with gender, age, or tumor location. Decreased expression of EMP1 was significantly correlated with T stage, lymph node metastasis, clinic stage, and histological grade in patients with colorectal cancer (P < 0.05). According to Kaplan-Meier analysis, low EMP1 expression correlated significantly with poor overall five-year survival (34.2% vs 64.0% survival, P < 0.05). SW-480 cells transfected with EMP1 had a lower survival fraction, higher cell apoptosis (12.1% ± 1.3% vs 3.1% ± 0.6%, P < 0.05), a significant decrease in migration and invasion (124.0 ± 17.0 and 87.0 ± 12.0, respectively vs 213.0 ± 29.0 and 178.0 ± 21.0, respectively, P < 0.05), higher caspase-9 (0.635 ± 0.063 vs 0.315 ± 0.032, P < 0.05), and lower VEGFC protein expression (0.229 ± 0.021 vs 0.519 ± 0.055, P < 0.05) relative to cells not transfected with EMP1. CONCLUSION: Low EMP1 expression in colorectal cancer is associated with increased disease severity, suggesting that EMP1 may be a negative regulator of colorectal cancer.
AIM: To determine the expression and function of epithelial membrane protein 1 (EMP1) in colorectal carcinoma. METHODS: Colorectal samples were taken from cancer lesions and adjacent normal tissue in colorectal cancerpatients immediately after endoscopic biopsy. A portion of the sample was either fixed in 4% paraformaldehyde and embedded in paraffin for immunohistochemistry or stored in liquid nitrogen for Western blot. In order to determine protein expression of EMP1 in colorectal cancer (n = 63) and normal tissue (n = 31), semi-quantitative immunohistochemistry and Western blot were utilized. For in vitro studies, the humancolorectal cancer cell line SW-480 was maintained in RPMI-1640 medium supplemented with 10% fetal bovine serum. Recombinant lentivirus mediated overexpression of EMP1 in SW-480 cells was quantified by real-time reverse transcription-polymerase chain reaction and Western blot. Control SW-480 cells were transfected with an empty vector. To further study the effect of EMP1 overexpression in SW-480 cells, cell proliferation, apoptosis, migration and invasion assays were conducted. RESULTS: Expression of EMP1 was significantly lower in colorectal cancer tissue than in normal tissue using both immunohistochemistry (39.7% vs 90.3% of tissues, P < 0.05) and Western blot (0.126 ± 0.022 vs 0.632 ± 0.053, P < 0.05). The level of EMP1 protein expression was not correlated with gender, age, or tumor location. Decreased expression of EMP1 was significantly correlated with T stage, lymph node metastasis, clinic stage, and histological grade in patients with colorectal cancer (P < 0.05). According to Kaplan-Meier analysis, low EMP1 expression correlated significantly with poor overall five-year survival (34.2% vs 64.0% survival, P < 0.05). SW-480 cells transfected with EMP1 had a lower survival fraction, higher cell apoptosis (12.1% ± 1.3% vs 3.1% ± 0.6%, P < 0.05), a significant decrease in migration and invasion (124.0 ± 17.0 and 87.0 ± 12.0, respectively vs 213.0 ± 29.0 and 178.0 ± 21.0, respectively, P < 0.05), higher caspase-9 (0.635 ± 0.063 vs 0.315 ± 0.032, P < 0.05), and lower VEGFC protein expression (0.229 ± 0.021 vs 0.519 ± 0.055, P < 0.05) relative to cells not transfected with EMP1. CONCLUSION: Low EMP1 expression in colorectal cancer is associated with increased disease severity, suggesting that EMP1 may be a negative regulator of colorectal cancer.
Entities:
Keywords:
Caspase-9; Colorectal carcinoma; Epithelial membrane protein 1; Prognosis; Vascular endothelial growth factor C
Authors: Yu Tian; Andre E Kim; Stephanie A Bien; Yi Lin; Conghui Qu; Tabitha A Harrison; Robert Carreras-Torres; Virginia Díez-Obrero; Niki Dimou; David A Drew; Akihisa Hidaka; Jeroen R Huyghe; Kristina M Jordahl; John Morrison; Neil Murphy; Mireia Obón-Santacana; Cornelia M Ulrich; Jennifer Ose; Anita R Peoples; Edward A Ruiz-Narvaez; Anna Shcherbina; Mariana C Stern; Yu-Ru Su; Franzel J B van Duijnhoven; Volker Arndt; James W Baurley; Sonja I Berndt; D Timothy Bishop; Hermann Brenner; Daniel D Buchanan; Andrew T Chan; Jane C Figueiredo; Steven Gallinger; Stephen B Gruber; Sophia Harlid; Michael Hoffmeister; Mark A Jenkins; Amit D Joshi; Temitope O Keku; Susanna C Larsson; Loic Le Marchand; Li Li; Graham G Giles; Roger L Milne; Hongmei Nan; Rami Nassir; Shuji Ogino; Arif Budiarto; Elizabeth A Platz; John D Potter; Ross L Prentice; Gad Rennert; Lori C Sakoda; Robert E Schoen; Martha L Slattery; Stephen N Thibodeau; Bethany Van Guelpen; Kala Visvanathan; Emily White; Alicja Wolk; Michael O Woods; Anna H Wu; Peter T Campbell; Graham Casey; David V Conti; Marc J Gunter; Anshul Kundaje; Juan Pablo Lewinger; Victor Moreno; Polly A Newcomb; Bens Pardamean; Duncan C Thomas; Konstantinos K Tsilidis; Ulrike Peters; W James Gauderman; Li Hsu; Jenny Chang-Claude Journal: J Natl Cancer Inst Date: 2022-08-08 Impact factor: 11.816