LncRNA WWC2-AS1 functions AS a novel competing endogenous RNA in the regulation of FGF2 expression by sponging miR-16 in radiation-induced intestinal fibrosis.

BACKGROUND: Recently, long non-coding RNAs (lncRNAs) were considered as important gene expression regulators involving various biological processes. In this study, we explored the role of lncRNAs in the pathogenesis of radiation-induced intestinal fibrosis (RIF). METHODS: LncRNAs were screened by microarray (Human LncRNA Array v3.0, Arraystar, Inc.) and the differentially expressed lncRNAs in RIF and non-RIF were analyzed by bioinformatics methods. The expression of WWC2-AS1/miR-16/FGF2 axis was compared on mRNA and protein level between human intestinal CCD-18Co fibroblasts cell lines and subepithelial SEMFs in response to radiation treatment. The significance of WWC2-AS1 in regulating FGF2 associated proliferation, migration, invasion and fibrosis of CCD-18Co and SEMFs by exposure to radiation was analyzed by shRNA (WWC2-AS1 shRNA) knock-down of endogenous WWC2-AS1. RESULTS: WWC2-AS1 and FGF2 level was significantly higher while miR-16 was down-regulated in radiation-treated intestinal tissues. WWC2-AS1 more potently boosted FGF2 expression via reducing miR-16, and WWC2-AS1 shRNA remarkably inhibited FGF2 associated proliferation, migration, invasion and fibrosis of radiation treatment in vitro, further demonstrating physical interaction between miR-16 and WWC2-AS1 in radiation-induced fibrosis progress. CONCLUSIONS: WWC2-AS1 was highly expressed in RIF, may function as a ceRNA in the regulation of FGF2 by binding miR-16. Targeting WWC2-AS1 thus may benefit radiation-induced fibrosis treatment.

Overexpression of NDUFA4L2 is associated with poor prognosis in patients with colorectal cancer.

BACKGROUND: NDUFA4L2 (NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 4-like 2, also called NADH-ubiquinone oxidoreductase MLRQ subunit homologue) was clearly enriched in the mitochondrial fraction under hypoxic conditions, and immunofluorescence showed a clear colocalization of NDUFA4L2 and cytochrome c in some tumour cells. However, little study has investigated its prognostic value in colorectal cancer (CRC). METHODS: In our study, mRNA-NDUFA4L2 and protein expression were analysed in 150 cases of CRC and adjacent normal tissues using immunohistochemistry, semi-quantitative reverse transcriptase-polymerase chain reaction. The correlation between NDUFA4L2 expression and clinicopathological factors was evaluated by the Chi-square test. Overall survival of patients was analysed by the Kaplan-Meier method. RESULTS: NDUFA4L2 overexpression was observed in 84% (126/150) of CRC tissues, but only in 24.7% (37/150) of adjacent normal tissues (P < 0.05). Semi-quantitative reverse transcriptase-polymerase chain reaction showed average mRNA expression levels to be 23.34 ± 1.356 and 4.34 ± 1.132 for CRC tissue and adjacent normal tissue (P < 0.05). Statistical analysis showed a significant correlation of NDUFA4L2 expression with histological grade, Dukes' stages, lymph node metastasis and liver metastasis. More importantly, multivariate analysis indicated that overexpression of NDUFA4L2 was an independent prognostic factor for CRC patients (P = 0.002). NDUFA4L2-negative patients had a higher tumour-free/overall survival rate than patients with high NDUFA4L2 expression (P = 0.001 and 0.002, respectively). CONCLUSIONS: Our data suggest that NDUFA4L2 overexpression is associated with tumour progression and a poor prognosis in CRC patients.

MicroRNA-1246 promotes growth and metastasis of colorectal cancer cells involving CCNG2 reduction.

Colorectal cancer (CRC) is the third most common cancer type and the fourth leading cause of cancer­associated mortality worldwide. MicroRNA (miR)­1246 is involved in differentiation, invasion, metastasis and chemoresistance of certain types of tumor cells. CCNG2 encodes an unconventional cyclin homolog, cyclin G2 (CycG2), associated with growth inhibition, which correlated significantly with lymph node metastasis, clinical stage, histological grade and poor overall survival in numerous cancer types. To investigate the regulation of miR­1246 on CycG2 expression, and their effects on proliferation and metastasis of CRC, HCT­116 and LOVO cells were transfected with pre­miR­1246 anti­miR­1246 and their negative controls. It was demonstrated that the expression of miR­1246 was significantly increased in CRC tissues and cell lines, which was the opposite of CycG2. miR­1246 negatively regulated the expression of CycG2 in HCT­116 and LOVO CRC cells. CCNG2 is a direct target of miR­1246 in CRC cells. Overexpression of miR­1246 induced cell proliferation, migration and invasion, while knockdown of miR­1246 inhibited proliferation, migration and invasion in the CRC cells. Upregulation of miR­1246 mediated the malignant progression of CRC and is partly attributed to the downregulation of the expression of CycG2. Consequently, these findings provided a molecular basis for the role of miR­1246/CCNG2 in the progression of human CRC and suggested a novel target for the treatment of CRC.

Basic transcription factor 3 is involved in gastric cancer development and progression.

AIM: To further analyse cancer involvement of basic transcription factor 3 (BTF3) after detection of its upregulation in gastric tumor samples. METHODS: BTF3 transcription rates in human gastric tumor tissue samples (n = 20) and adjacent normal tissue (n = 18) specimens as well as in the gastric cancer cell lines AGS, SGC-7901, MKN-28, MKN-45 and MGC803 were analyzed via quantitative real-time polymerase chain reaction. The effect of stable BTF3 silencing via infection with a small interfering RNA (siRNA)-BTF3 expressing lentivirus on SGC-7901 cells was measured via Western blotting analysis, proliferation assays, cell cycle and apoptosis profiling by flow cytometry as well as colony forming assays with a Cellomic Assay System. RESULTS: A significant higher expression of BTF3 mRNA was detected in tumors compared to normal gastric tissues (P < 0.01), especially in section tissues from female patients compared to male patients, and all tested gastric cancer cell lines expressed high levels of BTF3. From days 1 to 5, the relative proliferation rates of stable BTF3-siRNA transfected SGC7901 cells were 82%, 70%, 57%, 49% and 44% compared to the control, while the percentage of cells arrested in the G1 phase was significantly decreased (P = 0.000) and the percentages of cells in the S (P = 0.031) and G2/M (P = 0.027) phases were significantly increased. In addition, the colony forming tendency was significantly decreased (P = 0.014) and the apoptosis rate increased from 5.73% to 8.59% (P = 0.014) after BTF3 was silenced in SGC7901 cells. CONCLUSION: BTF3 expression is associated with enhanced cell proliferation, reduced cell cycle regulation and apoptosis and its silencing decreased colony forming and proliferation of gastric cancer cells.