circ_0067934 promotes the progression of papillary thyroid carcinoma cells through miR-1301-3p/HMGB1 axis.

Papillary thyroid carcinoma (PTC) is the most prevalent form of thyroid cancer (TC). There is increasing evidence that circular RNAs play a role in the tumorigenesis of PTC. The aim of our study was to evaluate the potential function of circ_0067934 in PTC and the underlying molecular mechanism. In our study, cell viability assay, quantitative real-time PCR (qRT-PCR), colony formation assay, flow cytometry, wound-healing assay, Transwell invasion assay, western blot, soft agar assay, RNA immunoprecipitation (RIP), dual-luciferase reporter assay, immunohistochemical (IHC) staining, and tumor xenograft formation were conducted to evaluate the effects of circ_0067934 in PTC cells. We found that circ_0067934 was upregulated in PTC tissues and cell lines. Knockdown of circ_0067934 inhibited growth, colony formation, migration, invasion, EMT, and tumor xenograft growth, and induced apoptosis of PTC cells. Moreover, circ_0067934 acted as a molecular sponge for miR-1301-3p, and depletion of miR-1301-3p abrogated the effects of circ_0067934 knockdown in PTC cells. In addition, HMGB1 was a target of miR-1301-3p, and miR-1301-3p overexpression inhibited the malignant effects of PTC cells via suppressing HMGB1. Furthermore, knockdown of circ_0067934 suppressed HMGB1 expression, PI3K/Akt, and MAPK activation by sponging miR-1301-3p. In nude mice, circ_0067934 depletion repressed tumor xenograft growth of PTC cells. In conclusion, our results provided a novel insight into circ_0067934 in the tumorigenesis and progression of PTC. circ_0067934 might be a prognostic marker or therapeutic target for PTC treatment.

IGF2BP2 knockdown suppresses thyroid cancer progression by reducing the expression of long non-coding RNA HAGLR.

BACKGROUND: N6-methyladenosine (m6A), a common internal modification on RNAs, has been found to be closely linked with RNA biosynthesis/metabolism and cancer development. In this text, the roles and molecular mechanisms of m6A-bind protein IGF2BP2 in the development of thyroid cancer (TC) were investigated in vitro. METHODS: IGF2BP2 and lncRNA HAGLR were screened out through multiple public databases such as TCGA, Ualcan, POSTAR2, Starbase, and GEPIA. Cell proliferative, migratory and invasive abilities were assessed by CCK-8, Transwell migration and invasion assays, respectively. Cell cycle distribution and cell apoptotic patterns were measured by flow cytometry. The interaction between HAGLR and IGF2BP2 was examined by RIP, RNA pull-down and luciferase assays and bioinformatics analysis. The effect of IGF2BP2 knockdown on the m6A level of HAGLR was explored by meRIP assay. RESULTS: IGF2BP2 was highly expressed in TC tumor tissues. IGF2BP2 knockdown weakened cell proliferative, migratory, and invasive abilities, and induced cell cycle arrest and cell apoptosis in TC cells. LncRNA HAGLR expression was markedly upregulated and positively associated with IGF2BP2 expression in TC tissues. IGF2BP2 knockdown reduced HAGLR expression and transcript stability in TC cells. IGF2BP2 regulated HAGLR expression in an m6A-dependent manner. HAGLR overexpression weakened the effects of IGF2BP2 loss on cell proliferation, migration, invasion, apoptosis, and cell cycle progression in TC cells. CONCLUSION: IGF2BP2 loss inhibited cell proliferation, migration and invasion, and induced cell apoptosis and cell cycle arrest by down-regulating HAGLR expression in an m6A-dependent manner in TC cells, providing some potential diagnostic and therapeutic targets for TC.

Long noncoding RNA CASC2 promotes paclitaxel resistance in breast cancer through regulation of miR-18a-5p/CDK19.

Breast cancer is one of the most prevalent cancers in women. Chemoresistance is a major obstacle for the treatment of breast cancer. We investigated the role of long noncoding RNA (lncRNA) cancer susceptibility candidate 2 (CASC2) in paclitaxel (PTX) resistance in breast cancer. CASC2 expression was increased in PTX-resistant clinical samples and cell lines. PTX induced CASC2 expression in a concentration-dependent manner. Downregulation of CASC2 increased PTX toxicity and decreased IC50 value, while upregulation of CASC2 decreased PTX toxicity and increased IC50 value in MCF-7/PTX and MDA-MB-231/PTX cells. Moreover, downregulation of CASC2 decreased tumor growth in xenograft mice implanted with MCF-7/PTX cells. miR-18a-5p possessed a putative binding site in 3'-UTR of CASC2 and cyclin-dependent kinase 19 (CDK19). In PTX-resistant breast cancer cells, miR-18a-5p expression was decreased. CASC2 and miR-18a-5p could negatively regulate the expression of each other. CDK19 expression could be negatively regulated by miR-18a-5p, but positively regulated by CASC2. miR-18a-5p mimics or downregulation of CDK19 decreased tumor growth in xenograft mice implanted with MCF-7/PTX cells. In summary, we identified that CASC2 activated PTX resistance in breast cancer through regulation of miR-18a-5p/CDK19. We highlight the importance of CASC2/miR-18a-5p/CDK19 axis in the chemoresistance of breast cancer and provide potential targets for the improving chemotherapy of breast cancer.

High expression of astrocyte elevated gene-1 is associated with clinical staging, metastasis, and unfavorable prognosis in gastric carcinoma.

More and more evidence has demonstrated that astrocyte elevated gene-1 (AEG-1) is tightly associated with progression, metastasis, and unfavorable prognosis in many malignancies. However, the potential biological role of AEG-1 in gastric carcinoma (GC) has not been thoroughly delineated. In the current study, we found that AEG-1 mRNA and protein levels in GC tissues were significantly higher than those in normal gastric mucosa (P < 0.05). Simultaneously, statistical analysis displayed a significant correlation of high AEG-1 mRNA and protein expressions with differentiation status, TNM staging, invasive depth, and lymph node metastasis (P < 0.05). Most importantly, expressions of AEG-1 mRNA and protein in high clinical staging and metastatic GC tissues were dramatically higher than those in low clinical staging and non-metastatic GC tissues (P < 0.05). Stepwise investigation confirmed that the survival time of the patients with high AEG-1 level was shorter than those with low AEG-1 level or negative AEG-1 staining. Taken altogether, our data presented herein suggest that AEG-1 may be a novel predictor for metastasis and prognosis of the patients with GC.

Association between miR-146aG>C and miR-196a2C>T polymorphisms and the risk of hepatocellular carcinoma in a Chinese population.

MicroRNAs have been demonstrated to have a role in susceptibility and prognosis of various types of human cancer. We investigated the association between polymorphisms in miR-146aG>C, miR-196a2C>T, and miR-499A>G and hepatocellular carcinoma (HCC) risk and interaction with HCC and hepatitis B virus (HBV) infection. Two hundred sixty-six cases with HCC and 281 health controls were enrolled in the present study. Genotyping of the miR-146aG>C, miR-196a2C>T, and miR-499A>G genotypes was conducted by duplex polymerase chain reaction with the confronting two-pair primer (PCR-RFLP). Subjects with miR-146a GG and G allele had an increased risk of HCC compared with the homozygote CC genotype. Similarly, HCC patients carrying microRNA (miRNA)-196a2 computed tomography, TT, and T allele significantly decreased the risk of HCC relative to the CC genotype. Stratified analysis indicated that miR-196a2C>T polymorphism was associated with reduced risk of HBV-related HCC, but not in hepatitis C virus- and nonviral-related HCC cases. In conclusion, miR-146aG>C and miR-196a2C>T polymorphism are associated with risk of HCC patients in China, especially in patients with HBV infection. SNPs in miRNA sequences can be used as a diagnostic biomarker for HCC.

[Effect of silencing AEG-1 with small interfering RNA on the proliferation and cell cycle of gastric carcinoma SGC-7901 cells].

OBJECTIVE: To explore the effect of down-regulation of astrocyte elevated gene-1 (AEG-1) expression on cell proliferation and cell cycle of gastric carcinoma cells, and its possible molecular mechanism. METHODS: Control siRNA and AEG-1 siRNA were transfected into gastric carcinoma SGC-7901 cells. 48 h after transfection, the cells were divided into 3 groups including untransfected, siRNA control and AEG-1 siRNA transfection groups. Expressions of AEG-1 mRNA and protein in the 3 group cells were detected by real-time quantitative PCR and Western blot. The changes of cell proliferation were examined using CCK-8 kit, and the cell cycle distribution was detected by flow cytometry. Finally, expressions of cell proliferation and cell cycle related proteins were detected by Western blot. RESULTS: Real-time quantitative PCR and Western blot demonstrated that compared with the untransfected and siRNA control groups, expressions of AEG-1 mRNA and protein were significantly down-regulated in the AEG-1 siRNA transfection group (P < 0.05), but there was no significant difference between the untransfected and siRNA control groups (P > 0.05). Furthermore, in vivo experiment confirmed a significant down-regulation of AEG-1 protein in the AEG-1 siRNA transfection group (P < 0.05). In addition, AEG-1 siRNA obviously inhibited the proliferation of SGC-7901 cells at different time points after transfection with AEG-1 siRNA. The percentage of cells in G0/G1 phase in the AEG-1 siRNA transfection group [(61.26 ± 1.25)%] was significantly higher than those in the untransfected group [(46.17 ± 1.91)%] and siRNA control group [(46.46 ± 1.96)%], and there was a significant difference between them (all P < 0.001). Furthermore, the result of Western blotting revealed that down-regulation of AEG-1 expression evoked the down-regulation of cdk2 and cyclin D1 expressions and elevation of p21 expression in vitro and in vivo. CONCLUSIONS: The inhibition of cell proliferation and cell cycle arrest mediated by down-regulation of AEG-1 expression may be closely associated with the changes of expression of cell cycle related proteins including cdk2, cyclin D1 and p21.

[Effects of KIAA0101 expression on proliferation and invasion of gastric carcinoma MKN-45 cells].

OBJECTIVE: To investigate the expression of KIAA0101 protein in gastric carcinoma cells, and to explore the effects of its down-regulation on the cell proliferation, cell cycle and invasion. METHODS: Western blot was used to detect KIAA0101 protein expression in three gastric carcinoma cell lines including MKN-28, SGC-7901 and MKN-45. KIAA0101 siRNA and control siRNA were utilized to transfect MKN-45 cells, respectively. CCK-8 was used to analyze the changes of cell proliferation, and flow cytometry to examine the changes of cell cycle distribution. Finally, Boyden chamber was used to detect the ability of cell invasion. RESULTS: Relative level of KIAA0101 protein in MKN-45 cells was significantly higher than those in MKN-28 and SGC-7901 cells, and there was significant difference among the three cell lines (P < 0.05). The result of CCK-8 study demonstrated that, compared with untreated group and control siRNA group, the proliferation of MKN-45 cells in KIAA0101 siRNA group was significantly inhibited (P < 0.05). Additionally, the result of cell cycle analysis revealed that the percentage of cell number in G(0)/G(1) phase in KIAA0101 siRNA group [(61.47 ± 0.89)%] was significantly higher than those in untreated group [(47.43 ± 0.85)%] and control siRNA group [(48.43 ± 0.73)%; F = 271.653, P = 0.000]. Further, Boyden chamber assay showed that the cell numbers migrated to Matrigel in KIAA0101 siRNA group (61.51 ± 4.76) were significantly lower than those in untreated group (138.74 ± 10.16) and control siRNA group (132.93 ± 11.25; F = 65.949, P = 0.000). CONCLUSIONS: Down-regulation of KIAA0101 expression leads to an inhibition of cell proliferation, cell cycle and cell invasion. It may provide a novel target for the treatment of patients with gastric carcinoma.

Influence of personal character on quality of life of patients with esophageal cancer in north Henan province and influencing factors.

The aim of this study was to investigate QoL (quality of life) of patients with esophageal cancer in northern Henan province, China, and to accurate evaluate and reflect the relationship between patient characteristics and QoL. In the high risk area of esophageal cancer in the north of Henan province, 735 patients with esophageal cancer were investigated. The Eysenck personality questionnaire (EPQ) and QoL were analyzed by using the questionnaire of general situation, EPQ, QLQ-C30 and QLQ-OES18. The effects of personal character on the QoL of esophageal carcinoma patients were analyzed by SPSS 11.0 software. The QoL of esophageal cancer patients in Northern Henan region was significantly affected by character. The difference between choleric and type of melancholic temperament types was significant (P<0.01), also in OESEAT, OESTA, OESCO and OESSP (P<0.05). Differences in personal character can thus influence the quality of esophageal cancer patient lives.