ABSTRACT
@#[Abstract] Objective: To investigate the changes in malignant biological behaviors and expression of programmed cell death-ligand 1 (PD-L1) in esophageal squamous cell carcinoma (ESCC) YES-2 cell line after cis-dichlorodiammine platinum (CDDP) induction (YES-2/CDDP-R). Methods: YES-2 cells were treated with CDDP from low concentration to high concentration (0.25-2.0 μg/ml) with intermittent impact (15-25 days per concentration) to establish ESCC CDDP-resistant cell line YES-2/CDDP-R. The morphological change of YES-2/CDDP-R cells was observed under the inverted microscope. Methyl thiazolyl tetrazolium (MTT) was used to detect cell sensitivity to CDDP. Wound healing assay was used to detect cell migration ability. qPCR and Western blotting were used to detect mRNA and protein expressions of PD-L1. Results: After CDDP gradien ttreatment for9 months,YES-2/CDDP-R cells were successfully established. The morphology of the YES-2/CDDP-R cells showed uneven size, intracellular vacuoles and significantly increased black particles along with the appearance of huge cells. The IC50 of CDDP for YES-2/CDDP-R cells was significantly higher than that for parental cells, indicating decreased sensitivity to CDDP (P<0.05). Compared to theYES-2 cells, the proliferation and migration of YES-2/CDDP-R cells were significantly increased (P<0.05 or P<0.01), and the mRNA and protein expressions of PD-L1 were significantly up-regulated (all P<0.001). Conclusion: YES-2 cells with CDDP resistance (YES-2/CDDP-R) were successfully established. The sensitivity of YES-2/CDDP-R cells to CDDP was significantly reduced while the abilities of cell proliferation and migration were enhanced. The up-regulation of PD-L1 in YES-2/CDDP-R cells suggests that CDDP-resistance could promote immune escape by inducing PD-L1 up-regulation.
ABSTRACT
@#Objective: To detect the expression of non-receptor protein tyrosine phosphatase 6 (PTPN6) in different esophageal squamous cell carcinoma (ESCC) cell lines, and to investigate its effect on proliferation, migration and invasion ability of Eca109 and Yes-2 cell lines. Methods: qPCR was applied to detect the mRNA expression of PTPN6 in different ESCC cell lines (TE1, Eca109, Kyse150, Kyse170 and Yes-2). pcDNA3.1-PTPN6 plasmid was transiently transfected into Eca109 and Yes-2 cells respectively. The expression of PTPN6 was detected by real-time PCR and Wb. The effects of PTPN6 over-expression on the biological behaviors of ESCC cells were detected by MTS, colony formation assay, wound healing assay and Transwell assay, respectively. Results: The mRNA expression of PTPN6 was remarkably reduced in ESCC cell lines (TE1, Eca109, Kyse150, Kyse170 and Yes-2) compared to normal esophageal epithelial cells (HEEpiC) (P<0.05). Compared to the mock cells, significant up-regulation of PTPN6 was detected in pcDNA3.1-PTPN6 transfected Eca109 and Yes-2 cells (all P<0.05 or P<0.01); PTPN6 over-expression led to a significant inhibition in migration and invasion ability of Eca109 and Yes-2 cells (all P<0.05). Conclusions: Over-expression of PTPN6 may inhibit the proliferation, migration and invasion of ESCC cells, which might be an important factor influencing the biological characteristics of ESCC cells.