Overexpression of the Long Noncoding RNA FOXD2-AS1 Promotes Cisplatin Resistance in Esophageal Squamous Cell Carcinoma Through the miR-195/Akt/mTOR Axis

Emerging evidence has demonstrated that long noncoding RNAs (lncRNAs) mediate the development of esophageal squamous cell carcinoma (ESCC) via various pathophysiological pathways. This study explored the impact of the lncRNA FOXD2-AS1 on cisplatin resistance in ESCC and its possible mechanisms. Upregulation of FOXD2-AS was detected in patients with ESCC and ESCC cells that are resistant to cisplatin. In an in vitro assay, knockdown of FOXD2-AS1 noticeably inhibited cell invasion and growth, triggered cell death, and repressed the stimulation of the Akt/mTOR axis in cisplatin-resistant ESCC cells (TE-1/DDP). Conversely, the overexpression of FOXD2-AS1 remarkably increased cell invasion and growth, repressed cell death, and triggered the stimulation of the Akt/mTOR axis in TE-1/DDP cells. These findings, along with bioinformatics and validation tests, showed that FOXD2-AS1 targeted miR-195 by acting as a competing endogenous RNA. FOXD2-AS1/miR-195/Akt/mTOR axis plays a crucial role in resistance to cisplatin in ESCC cells, offering an innovative strategy to treat ESCC.     

食管鳞状细胞癌YES-2细胞顺铂耐药致其恶性生物学行为及PD-L1表达的变化

目的：探讨食管鳞状细胞癌（esophageal squamous cell carcinoma,ESCC）YES-2 细胞顺铂（cis-dichlorodiammine platinum,CDDP）耐药后（YES-2/CDDP-R）细胞恶性生物学行为的变化和程序性死亡受体-配体1（programmed cell death-ligand 1 ,PD-L1）表达的变化。方法：用CDDP 由低质量浓度到高质量浓度（0.25~2.0 μg/ml）间断冲击（间隔15~25 d）的方法处理YES-2 细胞,建立CDDP耐药细胞株YES-2/CDDP-R。倒置显微镜下观察YES-2/CDDP-R 细胞的形态学变化,MTT法检测细胞对CDDP敏感性的变化,划痕愈合实验检测耐药前后细胞迁移能力的变化,qPCR和Western blotting 检测耐药前后细胞中PD-L1 mRNA和蛋白表达水平的变化。结果：经过CDDP梯度给药9 个月后成功建立YES-2/CDDP-R 细胞。显微镜下见YES-2/CDDP-R 细胞的形态大小不一、胞内空泡及黑色颗粒明显增多且出现巨大细胞。与YES-2 细胞比较,YES-2/CDDP-R细胞的IC50值显著升高,表明其对CDDP的敏感程度降低（P<0.05）;YES-2/CDDP-R 细胞的增殖和迁移能力显著增强（P<0.05 或P<0.01）,PD-L1 mRNA和蛋白表达水平显著升高（均P<0.01）。结论：成功建立的CDDP耐药细胞株YES-2/CDDP-R 对CDDP的敏感程度降低,其增殖和迁移能力增强。YES-2/CDDP-R 细胞中PD-L1 表达水平升高,提示CDDP耐药可能通过上调YES-2细胞PD-L1表达水平促进免疫逃逸。     

Disease-specific expression of VEGF and its receptors in AML cells: possible autocrine pathway of VEGF/type1 receptor of VEGF in t(15;17) AML and VEGF/type2 receptor of VEGF in t(8;21) AML

Various angiogenic factors, such as vascular endothelial growth factor (VEGF) and an associated molecule, placenta growth factor (PlGF), are thought to be important for normal and malignant hematopoiesis. This study examined mRNA expression of VEGF, PlGF and receptors for these molecules in AML cells and identified the disease-specific patterns of expression. AML M₃ having t(15;17) abnormality showed highest expression of VEGF and VEGF receptor type 1 (VEGFR1), suggesting the autocrine pathway of VEGF-VEGFR1. Then, t(8;21) AML demonstrated augmented expression of VEGF and VEGF receptor type 2 (VEGFR2), suggesting VEGF-VEGFR2 autocrine pathway. Then, addition of VEGFR2 kinase inhibitor in Kasumi-1, a t(8;21) AML cell line, resulted in marked inhibition of cell growth, although growth inhibitory effect of R2 kinase inhibitor to HL-60 was marginal. In addition, cell cycle analysis study showed S-phase cell population reduction by R2 kinase inhibitor in Kasumi-1, but not in HL-60. This observation is thought to be the rationale for novel molecular target therapy directed to angiogenic molecules.