OE21

CCT6A Promoted Cell Proliferation in OE21 and TE-1 Cells

Chaperonin-containing TCP1 subunit 6A (CCT6A) has been found to be a promoter of malignancy in a variety of cancers. However, its function in esophageal squamous cell carcinoma (ESCC) remains unclear. Zhao's team investigated whether CCT6A regulates ESCC cell proliferation, apoptosis, invasion, and epithelial-mesenchymal transition (EMT) by modulating the TGF-β/Smad/c-Myc pathway, potentially identifying a novel therapeutic target.

In order to minimize the off-target effect of siRNA, three CCT6A siRNAs were transfected into OE21 and TE-1 cells. In OE21 cells (Fig. 1A) and TE-1 cells (Fig. 1B), CCT6A expression was reduced in the CCT6A-siRNA1, CCT6A-siRNA2 and CCT6A-siRNA3 groups compared with the NC-siRNA group; cell proliferation (as reflected by OD value) at 72 h was inhibited in the CCT6A-siRNA1, CCT6A-siRNA2 and CCT6A-siRNA3 groups compared with the NC-siRNA group (Fig. 1D). Meanwhile, CCT6A-encoding plasmids were transfected into OE21 cells (Fig. 1E) and TE-1 cells (Fig. 1F), and CCT6A expression was increased in the CCT6A-pEX2 group compared with the NC-pEX2 group; cell proliferation (as reflected by OD value) at 72 h was promoted in the CCT6A-pEX2 group compared with the NC-pEX2 group (Fig. 1H). Notably, since CCT6A siRNA1 had the greatest inhibitory effect on CCT6A expression, CCT6A siRNA1 (referred to as CCT6A-siRNA below) was selected for subsequent cellular experiments.

Fig. 1. CCT6A's effect on cell proliferation (Xia X L, Zhao S S, et al., 2023).

Esophageal Cancer Cell Lines have Variable Expression of Mxa and Exhibit a Range of Sensitivity to Oxaliplatin and 5-Fluorouracil

Esophageal cancer is one of the deadliest malignancies due to resistance to chemotherapy regimens. MxA expression is dysregulated in a variety of cancers and is also known to be associated with the induction of apoptosis. However, its role in determining the response to drugs in esophageal cancer was unclear. In this study, Hayers et al. measured the expression of MxA in five esophageal cancer cell lines (Fig. 2A). MxA was not expressed in KYSE450 and KYSE140 cells, while FLO-1, KYSE270, and OE21 had variable expression of MxA (Fig. 2B). MxA-expressing cancer cells were more sensitive to 5-FU and oxaliplatin, with evidence of cellular toxicity within 24 h and caspase-3-mediated apoptosis (Fig. 2B). In MxA-negative cancer cells, the onset of toxicity was delayed to 48 h, and the apoptotic response to 5-FU or oxaliplatin was significantly lower (Fig. 2B).

Fig. 2. MxA protein expression and apoptosis competency in a panel of esophageal cancer cell lines (Hayes RM, O'Donovan TR, et al., 2024).