ABSTRACT
BACKGROUND/AIM: Engulfment and cell motility 1 (ELMO1) plays a crucial role in the process of migration, chemotaxis, and metastasis of tumor cells. ELMO1 has been implicated in the pathogenesis of various cancers. However, the distinct function of ELMO1 in colorectal cancer (CRC) is unclear. We determined whether ELMO1 affects the oncogenic behavior of CRC cells and investigated its prognostic value in CRC patients. MATERIALS AND METHODS: We investigated the impact of ELMO1 on tumor cell behavior using small interference RNA (siRNA) in CRC cell lines, including SW480 and DLD1. The expression of ELMO1 was investigated by reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) in cancer tissues and sera obtained from CRC patients. RESULTS: ELMO1 knockdown suppressed tumor cell proliferation in SW480 and DLD1 cells. ELMO1 knockdown-induced apoptosis through up-regulation of caspase-3, -7, and PARP activities and down-regulation of the anti-apoptotic Mcl-1 protein. ELMO1 knockdown-induced cell-cycle arrest by decreasing cyclin D1, cyclin-dependent kinase 2, 4 and 6, and the 25C cell division cycle (CDC25C). ELMO1 knockdown suppressed tumor cell invasion and migration. The expression of E-cadherin was increased, while that of Vimentin and Claudin 1 decreased following ELMO1 knockdown. The phosphorylation levels of PDK1, Akt, and GSK-3ß and were down-regulated after ELMO1 knockdown. The expression of ELMO1 was found up-regulated in cancer tissues and sera taken from CRC patients. ELMO1 expression was significantly associated with tumor stage, lymph node metastasis, distant metastases, and poor survival. CONCLUSION: ELMO1 mediates tumor progression by increasing tumor cell motility and inhibiting apoptosis in human CRC.
Subject(s)
Colorectal Neoplasms , Cyclin D1 , Humans , Cyclin D1/metabolism , Vimentin/metabolism , Caspase 3/metabolism , Cyclin-Dependent Kinase 2/metabolism , Glycogen Synthase Kinase 3 beta/metabolism , RNA, Small Interfering/genetics , Cell Movement/genetics , Proto-Oncogene Proteins c-akt/metabolism , Claudin-1/metabolism , Myeloid Cell Leukemia Sequence 1 Protein/genetics , Poly(ADP-ribose) Polymerase Inhibitors , Colorectal Neoplasms/pathology , Prognosis , Cell Proliferation/genetics , Cadherins/metabolism , Cell Line, Tumor , Gene Expression Regulation, NeoplasticABSTRACT
Extrahepatic recurrence (EHR) after curative hepatectomy for hepatocellular carcinoma (HCC) is associated with a poor prognosis. We investigated the features of EHR and identified its predictive factors. This retrospective study included 398 treatment-naive patients who underwent curative hepatectomy for HCC at two tertiary hospitals. Multivariate Cox-regression analysis was performed to identify the variables associated with EHR. EHR was diagnosed in 94 patients (23.6%) over a median follow-up period of 5.92 years, most commonly in the lungs (42.6%). The 5-/10-year cumulative rates of HCC recurrence and EHR were 63.0%/75.6% and 18.1%/35.0%, respectively. The median time to EHR was 2.06 years. Intrahepatic HCC recurrence was not observed in 38.3% of patients on EHR diagnosis. On multivariate analysis, pathologic modified Union for International Cancer Control stage (III, IVa), surgical margin involvement, tumor necrosis, sum of tumor size > 7 cm, and macrovascular invasion were predictive factors of EHR. Four risk levels and their respective EHR rates were defined as follows: very low risk, 1-/5-year, 3.1%/11.6%; low risk, 1-/5-year, 12.0%/27.7%; intermediate risk, 1-/5-year, 36.3%/60.9%; and high risk, 1-year, 100.0%. Our predictive model clarifies the clinical course of EHR and could improve the follow-up strategy to improve outcomes.
