Effects of PLCE1 Gene Silencing by RNA Interference on Cell Cycling and Apoptosis in Esophageal Carcinoma Cells

Abstract

Esophageal squamous cell carcinoma (ESCC) is one of the most malignancies with a poor prognosis. The phospholipase Cε gene (PLCE1) encodes a novel ras-related protein effector mediating the effects of R-Ras on the actin cytoskeleton and membrane protrusion. However, molecular mechanisms pertinent to ESCC are unclear. We therefore designed PLCE1-special small interfering RNA and transfected to esophageal squamous cell (EC) 9706 cells to investigat the effects of PLCE1 gene silencing on the cell cycle and apoptosis of ESCC and indicate its important role in the development of ESCC. Esophageal cancer tissue specimens and normal esophageal mucosa were obtained and assayed by immunohistochemical staining to confirm overexpression of PLCE1 in neoplasias. Fluorescence microscopy was used to examine transfection efficiency, while the result of PLCE1 silencing was examined by reverse transcription (RT-PCR). Flow cytometry and annexin V apoptosis assays were used to assess the cell cycle and apoptosis, respectively. Expression of cyclin D1 and caspase-3 was detected by Western-blotting. The level of PLCE1 protein in esophageal cancer tissue was significantly higher than that in normal tissue. After transfection, the expression of PLCE1 mRNA in EC 9706 was significantly reduced, compared with the control group. Furthermore, flow cytometry results suggested that the PLCE1 gene silencing arrested the cell cycle in the G0/G1 phase; apoptosis was significantly higher than in the negative control group and mock group. PLCE1 gene silencing by RNAi resulted in decreased expression of cyclin D1 and increased expression of caspase-3. Our study suggests that PLCE1 may be an oncogene and play an important role in esophageal carcinogenesis through regulating proteins which control cell cycling and apoptosis.

Prognostic Value of PLCE1 Expression in Upper Gastrointestinal Cancer: a Systematic Review and Meta-analysis

“…Recent studies have shown that PLCE1 may serve a critical function in the carcinogenesis process of esophageal and gastric cancers (Yu et al, 2014;Zhao et al, 2014) and have identified its involvement in various cancers, such as carcinoma of bladder (Ou et al, 2010), colorectal (Wang et al, 2012b), head and neck (Bourguignon et al, 2006), and skin (Bai et al, 2004) cancers. In previous studies of esophageal and gastric cancers, increased PLCE1 expression was significantly correlated with invasion depth, lymph node metastasis, and histologic grade.…”

Clinical Observation and Therapeutic Evaluation of Rh-endostatin Combined with DP Regimen in Treating Patients with Advanced Esophageal Cancer

“…About 50% of patients were found with the advanced period of esophageal cancer when diagnosed, with unfavorable prognosis, about 6~8 months of natural course, 5%~7% five-year survival rate (; Liu et al, 2014;Mai et al, 2014;Zhao et al, 2014;Jiang et al, 2014;Wang et al, 2014;Stefani et al, 2014). Additionally, even though patients accepted surgical treatment, there still exists postoperative recurrence and metastasis in nearly 90% of patients.…”

PLCE1 rs2274223 Polymorphism and Susceptibility to Esophageal Cancer: a Meta-analysis

“…PLCE1 encodes the phospholipase C epsilon 1 (PLCe1) that catalyses the hydrolysis of phosphatidylinositol-4, 5-bisphosphate into the secondary messengers inositol 1, 4, 5-trisphosphate and diacylglycerol (DAG), which participate in cell growth, differentiation and gene expression. Recent studies have reported that PLCE1 plays crucial roles in carcinogenesis (Zhao et al, 2014) several types of cancer, and it has been a hot topic to investigate and study the relationship between PLCE1 rs2274223 polymorphism and susceptibility to esophageal cancer (Yu et al, 2013). Numerous case-control studies and cohort studies on the association of PLCE1 rs2274223 polymorphisms with esophageal cancer susceptibility have been conducted.…”