The aim of this study was to determine a role of microRNA-21 (miR-21) in colorectal cancer (CRC) and to elucidate the regulation of phosphatase and tensin homologue (PTEN) gene by miR-21. MiR-21 expression was investigated in 30 CRC samples and five CRC cell lines. In this study, we show that the expression of miR-21 was overexpressed in CRC compared with adenomas and normal tissues. Patients with poor differentiation, lymph node metastasis and advanced TNM stage showed significantly high expression of miR-21. Inhibition of miR-21 in the HCT116 cell line reduced cellular proliferation, migration and invasion, induced apoptosis and inhibited cell cycle progression. The PTEN protein levels in CRC tissues and cells had an inverse correlation with miR-21 expression. Anti-miR-21-transfected cells increased PTEN protein expression without changing the PTEN mRNA level and increased a luciferase-reporter activity. MiR-21 targets PTEN at the post-transcriptional level and regulates cell proliferation and invasion in CRC. It may serve as a novel therapeutic target in CRC.

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies and has a poor prognosis. Circular RNA (circRNA) has been increasingly recognized as a crucial contributor to carcinogenesis. circRNA_0000140 has been aberrantly expressed in OSCC, but its role in tumor growth and metastasis remains largely unclear. Sanger sequencing, actinomycin D, and RNase R treatments were used to confirm head-to-tail junction sequences and the stability of circ_0000140. In vitro cell activities, including proliferation, migration, invasion, and apoptosis, were determined by colony formation, transwell, and flow cytometry assays. The expression levels of circ_0000140, Hippo signaling pathway, and serial epithelial-mesenchymal transition (EMT) markers were measured by quantitative real-time PCR, western blotting, immunofluorescence, and immunohistochemistry. Dual luciferase reporter assays and Argonaute 2-RNA immunoprecipitation assays were performed to explore the interplay among circ_0000140, miR-31, and LATS2. Subcutaneous tumor growth was observed in nude mice, in which in vivo metastasis was observed following tail vein injection of OSCC cells. circ_0000140 is derived from exons 7 to 10 of the KIAA0907 gene. It was down-regulated in OSCC tissues and cell lines, and correlated negatively with poor prognostic outcomes in OSCC patients. Gain-offunction experiments demonstrated that circ_0000140 enhancement suppressed cell proliferation, migration, and invasion, and facilitated cell apoptosis in vitro. In xenograft mouse models, overexpression of circ_0000140 was able to repress tumor growth and lung metastasis. Furthermore, mechanistic studies showed that circ_0000140 could bind with miR-31 and up-regulate its target gene LATS2, thus affecting OSCC cellular EMT. Our findings demonstrated the roles of circ_0000140 in OSCC tumorigenesis as well as in metastasis, and circ_0000140 exerts its tumor-suppressing effect through miR-31/LATS2 axis of Hippo signaling pathway in OSCC.

ABSTRACT

A I M : To i n v e s t i g a t e t h e s u p p r e s s i v e e f f e c t o f saikosaponin-d (SSd) on hepatic fibrosis in rats inducedby CCl4 injections in combination with alcohol and high fat, low protein feeding and its relationship with the expression of nuclear factor-κB (NF-κB), tumor necrosis factor-alpha (TNF-α) and interleukins-6 (IL-6). METHODS:Hepatic fibrosis models were induced by subcutaneous injection of CCl4 at a dosage of 3 mL/kg in rats. At the same time, rats in treatment groups were injected intraperitoneally with SSd at different doses (1.0, 1.5 and 2.0 mg/kg) once daily for 6 wk in combination with CCl4, while the control group received olive oil instead of CCl4. At the end of the experiment, rats were anesthetized and killed (except for 8 rats which died during the experiment; 2 from the model group, 3 in high-dose group, 1 in medium-dose group and 2 in lowdose group). Hematoxylin and eosin (HE) staining and Van Gieson staining were used to examine the changes in liver pathology. The levels of alanine aminotransferase (ALT), triglyeride (TG), albumin (ALB), globulin (GLB), hyaluronic acid (HA) and laminin (LN) in serum and the content of hydroxyproline (HYP) in liver were measured by biochemical examinations and radioimmuneoassay, respectively. In addition, the expression of TNF-α and IL-6 in liver homogenate was evaluated by enzymelinked immunosorbent assay (ELISA) and the levels of NF-κBp65 and I-κBα in liver tissue were analyzed by Western blotting. 42.15 ± 8.25 ng/mL vs 19.83 ± 3.12 ng/mL, LN: 27.56 ± 4.21 ng/mL vs 13.78 ± 2.57 ng/mL, HYP: 27.32 ± 4.32 μg/mg vs 16.20 ± 3.12 μg/mg, TNF-α: 4.38 ± 0.76 ng/L vs 1.94 ± 0.27 ng/L, IL-6: 28.24 ± 6.37 pg/g vs 12.72 ± 5.26 pg/g, respectively, P < 0.01). SSd also decreased ALB in serum (28.49 ± 4.93 g/L vs 37.51 ± 3.17 g/L, P < 0.05). Moreover, the expression of NF-κB p65 in the liver of treated groups was lower than that in model groups while the expression of I-κBα was higher in treated group than in model group (P < 0.01). The expression of NF-κBp65 and TNF-α had a positive correlation with the level of HA in serum of rats after treatment with CCl4 (r = 0.862, P < 0.01; r = 0.928, P < 0.01, respectively). RESULTS: CONCLUSION:SSd attenuates CCl4-induced hepatic fibrosis in rats, which may be related to its effects of hepato-protective and anti-inflammation properties, the down-regulation of liver TNF-α, IL-6 and NF-κBp65 expression and the increased I-κBα activity in liver.

The Wnt/β-catenin signaling pathway plays a key role during hepatocellular carcinoma (HCC) genesis and development. The present study aimed to investigate the effects of the Wnt/β-catenin signaling pathway on the expression of angiogenic growth factors involved in HCC. The HCC HepG2 cell line was transfected with small interfering RNA (siRNA) against β-catenin. After 72 and 96 h, protein was extracted and the expression levels of β-catenin, matrix metalloproteinase (MMP)-2, MMP-9, vascular endothelial growth factor (VEGF)-A, VEGF-C and basic fibroblast growth factor (bFGF) were detected by western blot analysis. β-catenin protein expression was inhibited at both time points. Notably, MMP-2, MMP-9, VEGF-A, VEGF-C and bFGF protein expression levels decreased at 72 h and then increased at 96 h after transfection. Our results demonstrated that in HCC cells, the Wnt/β-catenin signaling pathway may regulate the protein expression of the angiogenic factors, MMP-2, MMP-9, VEGF-A, VEGF-C and bFGF. These proteins were downstream of β-catenin signaling and were also regulated by other factors. In conclusion, the Wnt/β-catenin signaling pathway may contribute to the regulation of HCC angiogenesis, infiltration and metastasis through regulating the expression of these angiogenic factors.