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@# Objective: To study the miR-28-3p expression in triple negative breast cancer (TNBC) tissues and cell lines, and explore its effect on the malignant biological behaviors of MDA-MB-468 cells. Methods： ：Tumor tissues and matched para-cancerous tissues were collected from 83 TNBC patients, who underwent tumor resection and pathological confirmation in the Fourth Hospital of Hebei Medical University between Jan. 2013 and Jan. 2014. TNBC cell lines (MDA-MB-468, HCC-1937, MDA-MB-231, MDA-MB436, MDA-MB-453) and human normal breast epithelial cell line MCF10A were also used in this study. qPCR was used to detect the expression of miR-28-3p in above mentioned tissues and cell lines. The correlation between miR-28-3p expression and clinical parameters was analyzed.After transfection with miR-28-3p inhibitor, the proliferation, apoptosis, invasion and migration ability of MDA-MB468 cells were detected with CCK-8, Flow cytometry, Transwell and Wound-healing experiment, respectively. And Western blotting was used to examine the protein expression of bridging integrator-1 (BIN1) in MDA-MB-468 cells. Bioinformatics BIN1 tool waere used to predict the target gene of miR-28-3p. Luciferase reporter gene assay was performed to validate the regulatory effect of miR-28-3p on BIN1. Results: The expression of miR-28-3p in TNBC tissues and cell lines was higher than that in matched paracancerous tissues and MCF10Acells (all P<0.01), respectively.Among the total 83 TNBC tissues, 56 (67.47%) showed high miR-28-3p expression. High expressionofmiR-28-3pwascloselycorrelated with the Ki-67 expression, tumor size and TNM stage (all P<0.05 or P<0.01). Compared with miR-NC group, transfection of miR-28-3p inhibitor significantly decreased the proliferation, invasion and migration of MDA-MB-468 cells while increased the apoptosis rate (all P<0.05 or P<0.01). Luciferase reporter gene assay confirmed that BIN1 was a target gene of miR-28-3p, and miR-28-3p inhibitor could up-regulate BIN1 expression in MDA-MB-468 cells (P<0.05). Conclusion: miR-28-3p is highly expressed in TNBC tissues and cell lines. miR-28-3p inhibitor up-regulates the expression of BIN1 to inhibit the proliferation, invasion and migration ability while promote the apoptosis of MDA-MB-468 cells.
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@#[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.
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@#[Abstract] Objective: To investigate the effects and mechanisms of long non-coding RNA (lncRNA) non-coding RNA-activated by DNA damage (NORAD) on the proliferation and migration of esophageal squamous cell carcinoma (ESCC) EC9706 cells. Methods: RT-PCR was used to detect the mRNA expression level of NORAD in different ESCC cells (EC9706, TE1, YES-2, KYSE150). Small interfering RNA (siRNA) targeting NORAD gene was transfected into EC9706 cells (as si-NORAD group) with RNA interference technique to knockdown NORAD expression; in addition, blank control group (as Ctrl group, without any transfection) as well as negative control group (as NC group, transfected with siRNAnegative control sequence)werealsoestablished. qPCR was used to verify the transfection efficiency. MTT, Colony formation assay and Wound-healing test were used to detect the abilities of proliferation and migration of EC9706 cells before and after NORAD knockdown. Western blotting was used to detect the expressions of E-cadherin, N-cadherin and Snail in EC9706 cells before and after NORAD knockdown. Results: NORAD mRNAwas highly expressed in 4 ESCC cell lines. Comparing with TE1, YES-2 and KYSE150 cells, the expression of NORAD mRNA was significantly higher in EC9706 cells (P<0.01). After transfection of NORAD-siRNA into EC9706 cells, the expression of NORAD was down-regulated significantly as comparing with Ctrl group and NC group (all P<0.01), in the meanwhile, the proliferation and migration abilities of EC9706 cells were also significantly suppressed (P<0.05).After NORAD knockdown, the expression of E-cadherin was up-regulated while the expressions of N-cadherin and Snail were down-regulated in EC9706 cells (all P<0.05). Conclusion: NORAD is highly expressed in EC9706 cells;knockdown of NORAD expression can inhibit the proliferation and migration ability of EC9706 probably through up-regulating E-cadherin and down-regulating N-cadherin and Snail.