RNA interference for epidermal growth factor receptor enhances the radiosensitivity of esophageal squamous cell carcinoma cell line Eca109

Abstract

Abstract. The present study investigated the effects of small interfering RNAs (siRNAs) specific to the epidermal growth factor receptor (EGFR) gene, on the radiosensitivity of esophageal squamous cell carcinoma cells. EGFR gene siRNAs (EGFR-siRNA) were introduced into esophageal cancer Eca109 cells using Lipofectamine ® 2000. The EGFR messenger (m)RNA expression levels, EGFR protein expression and cell growth were assessed using reverse transcription-polymerase chain reaction analysis, western blot analysis and a Cell Counting Kit-8 (CCK-8), respectively. In addition, colony assays were used to determine the inhibitory effects of X-ray radiation on EGFR-silenced cells. EGFR mRNA and protein levels were reduced in the Eca109 cells transfected with EGFR-siRNA. The relative EGFR mRNA expression levels were reduced to 26.74, 9.52 and 4.61% in Eca109 cells transfected with EGFR-siRNA1, 2 and 3, respectively. These mRNA levels were significantly reduced compared with the those of the control group (42.44%; P<0.0001). Transfection with siRNA3 resulted in the greatest reduction in EGFR mRNA expression, with an inhibition rate of 85%. The relative EGFR protein expression levels were reduced to 24.05, 34.91 and 34.14% in Eca109 cells transfected with EGFR-siRNA1, 2 and 3, respectively. These protein levels were significantly reduced compared with those of the control group (78.57%; P<0.0001). Transfection with siRNA1 resulted in the greatest reduction in EGFR protein expression, with an inhibition rate of 72.84%. This reduction in EGFR expression inhibited the proliferation of Eca109 cells, which was identified using the CCK-8 assay. The proliferation inhibition ratio was 28.2%. The cells treated with irradiation in addition to EGFR-siRNA, demonstrated reduced radiobiological parameters (D0, Dq and SF2) compared with those of cells treated with irradiation only, with a sensitization enhancing ratio of 1.5. In conclusion, suppression of EGFR expression may enhance the radiosensitivity of esophageal cancer Eca109 cells and therefore may represent a promising approach for future clinical practice.

Structure and activity of ananti‐epidermal growth factor receptor antibody without galactose‐α‐1,3‐galactose residues

“…AB01 and cAb showed similar binding capacity with EGFR, indicating that the change of α‐Gal does not affect the affinity of tested antibody. To further evaluate the effect on the proliferation of tumor cells, EGFR‐positive DiFi, A431, HCC827, FaDu, SW48 and Eca109 cells were chosen (Amann et al, 2005; Kol et al, 2017; Meira et al, 2009; Troiani et al, 2014; Yonesaka et al, 2019; Zhang et al, 2015). Results suggested that both AB01 and cAb significantly inhibited the proliferation of EGFR‐positive tumor cells.…”

Composites of Nucleic Acids and Boron Clusters (C2B10H12) as Functional Nanoparticles for Downregulation of EGFR Oncogene in Cancer Cells

“…Phosphorothioate-modified ASOs (PS-ASOs) have been shown to downregulate EGFR via RNase H activation [ 30 ]. Short interfering RNAs downregulating the expression of epidermal growth factor receptors have been shown to enhance the chemosensitivity of well-established anticancer compounds (cisplatin, 5-fluorouracil, and docetaxel) [ 31 ] and radiosensitivity [ 32 ] in various cancer cells, including head and neck squamous cell carcinoma (HNSCCs). The anti-EGFR aptamer [ 33 ] induces selective apoptotic cell death and, upon structural optimization [the use of 2′- O -methyl (2′-OMe) units], its human serum stability and toxic potential are increased in breast cancer, liver cancer, and malignant glioblastoma cells [ 34 ].…”