Background Chemoresistance is a major obstacle to improving the survival rate of colorectal cancer (CRC) patients. Forkhead box protein C2 (FOXC2), a member of the forkhead box (Fox) transcription factor family, is reported to be an important regulator of epithelial-to-mesenchymal transition (EMT) and plays a key role in tumor progression. However, little is known about the effects of FOXC2 on oxaliplatin (OXA) resistance in CRC. Methods OXA-resistant cells were generated from HCT116 cells. CCK-8, colony formation, flow cytometry and Transwell assays were used to compare the characteristics of OXA-resistant HCT116/OXA cells and the corresponding parental HCT116 cells. The expression of FOXC2 was confirmed by qRT-PCR and Western blotting in HCT116/OXA and HCT116 cells. Gain- and loss-of-function assays were performed to evaluate the effects of FOXC2 on OXA sensitivity and EMT in HCT116/OXA and HCT116 cells both in vitro and in vivo, and the possible molecular mechanisms were investigated. Results The relative expression of FOXC2 was significantly increased in HCT116/OXA cells compared with the parental HCT116 cells. Upregulation of FOXC2 in HCT116 cells reduced OXA sensitivity and promoted EMT. However, knockdown of FOXC2 in HCT116/OXA cells markedly increased the in vitro and in vivo sensitivity of HCT116/OXA cells to OXA by regulating EMT progression. Furthermore, FOXC2 activated MAPK/ERK signaling, and blockade of ERK attenuated FOXC2-induced EMT and FOXC2-enhanced OXA resistance. Conclusion FOXC2 induced EMT to promote oxaliplatin resistance by activating the MAPK/ERK signaling pathway. FOXC2 may be a potential therapeutic target for overcoming OXA resistance in human CRC. © 2020 Chen et al.Background Circular RNAs (circRNAs) play important regulatory roles in cancer development. However, the mechanisms by which circRNAs regulate gene expression in gastric cancer (GC) remain unclear. Methods Human GC samples and their matched normal adjacent tissues were obtained from 30 patients to assess the expression of circHIPK3 and its relationship with GC proliferation and migration. A series of in vitro and in vivo functional experiments were carried out to elucidate the role of circHIPK3 in GC proliferation and migration, and its underlying molecular mechanisms. Results Using a circRNA microarray we found a circRNA termed circHIPK3 that performed a significant regulatory role in GC. https://www.selleckchem.com/products/adt-007.html circHIPK3 was further confirmed to be upregulated in all GC tissues and cells tested. Furthermore, circHIPK3 levels were associated with Tumor & Lymph Node & Metastasis(TNM) stage (P = 0.032). The area under the receiver operating characteristic curve (ROC) was 0.743 (95% confidence interval 0.615-0.872; P = 0.001). CCK-8, colony formation, Transwell and EdU assays were performed to evaluate the effects of circHIPK3 on cell proliferation and migration in GC. Moreover, circHIPK3 was identified as a sponge of miR-107, and as such it regulated brain-derived neurotrophic factor (BDNF), which plays a pivotal role in the development of GC. Conclusion circHIPK3 represents a novel potential biomarker and therapeutic target of GC. © 2020 Wei et al.Background miR-26b-5p is reported to be involved in the progression of multiple cancers, but its function and mechanism in human papillary thyroid cancer (PTC) remain unknown. We aimed to uncover the function and mechanism of miR-26b-5p in PTC. Methods We performed qRT-PCR to detect the differences in miR-26b-5p expression between normal tissue and PTC. In vitro, we established cell lines stably overexpressing miR-26b-5p and investigated the function and underlying mechanism of miR-26b-5p in PTC. Results miR-26b-5p was downregulated in PTC compared with normal tissue. miR-26b-5p was correlated with the clinical stage. miR-26b-5p inhibited the proliferation, invasion and migration of PTC cell lines. We next detected EMT and proliferation markers. miR-26b-5p was shown to exert its function in a β-catenin-dependent manner. Conclusion Taken together, our results showed that miR-26b-5p inhibits proliferation, migration, invasion and EMT by degrading β-catenin. © 2020 Zhou et al.Introduction DNA repair systems play essential roles in genomic stability and carcinogenesis. Therefore, genotypes at DNA repair loci may contribute to the determination of personal susceptibility to cancers. The contribution of human 8-oxoguanine DNA N-glycosylase 1 (hOGG1) genotypes to renal cell carcinoma (RCC) is largely unknown. This study aimed to evaluate the contributions of hOGG1 rs1052133 genotypes to the RCC risk. Methods We evaluated the contribution of hOGG1 rs1052133 (G/C) genotypes among 118 cases and 590 controls and analyzed the interactions of hOGG1 genotypes with smoking, alcohol drinking, hypertension, and diabetes status. Results The hOGG1 rs1052133 CC genotype was significantly associated with a decreased RCC risk compared with that of the GG genotype (odds ratio [OR] = 0.25, 95% confidence interval [CI] = 0.09-0.72, p = 0.0049). The frequency of the rs1052133 C allele was significantly low in the RCC group (22.5% vs 31.2%; OR = 0.64; 95% CI = 0.46-0.89, p = 0.0074). Stratifying the analysis according to smoking, alcohol drinking, and diabetes status revealed no difference in the rs1052133 genotype distribution among these subgroups. A significant differential distribution of rs1052133 genotypes was observed among subjects with hypertension. Conclusion The CC genotype of rs1052133 may play a role in determining RCC susceptibility among Taiwanese people and may serve as a biomarker of RCC, particularly in patients with hypertension. © 2020 Chang et al.Background Thyroid cancer (TC) is an endocrine disease, and its progression is regulated by many factors, including circular RNAs (circRNAs). However, as a new circRNA, the role of circ_0058124 in TC is worth further exploration. Methods The expression levels of circ_0058124, microRNA-940 (miR-940) and mitogen-activated protein kinase 1 (MAPK1) were assessed by quantitative polymerase chain reaction (q-PCR). The circular characteristic of circ_0058124 was identified by oligo (dT)18 primers, Ribonuclease R (RNase R) and Actinomycin D (ActD), and its localization was determined by nuclear-cytoplasmic separation assay. Also, cell proliferation was detected by colony formation assay, and cell migration and invasion were assessed by transwell assay. Further, Seahorse XF Extracellular Flux Analyzer was used to measure the oxygen consumption rate (OCR) of cells. Besides, dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull-down assays were used to identify the mechanism of circ_0058124. Western blot (WB) analysis was used to test the MAPK1 protein level.