The Cancer BioChip System: a functional genomic assay for anchorage-independent three-dimensional breast cancer cell growth

miR-125a-5p-targeted regulation of TRA2β expression inhibits proliferation and metastasis of hepatocellular carcinoma cells

OBJECTIVE

To explore the regulation of miR-125a-5p in hepatocellular carcinoma (HCC) and its mechanisms.

METHODS

By transfecting a miR-125a-5p sequence and an interfering sequence of miR-125a-5p-s into human HCC cell lines HCC-LM3 and HepG2, miR-125a-5p-related levels were assesed by Western blot. The abilities of cell proliferation and migration were assessed by cell culture and Transwell assay, respectively.

RESULTS

HepG2 cells showed increased miR-125a-5p levels compared with HCC-LM3 cells (P < 0.01). However, compared with QZG cells, the level of miR-125a-5p in HepG2 and HCC-LM3 cells was down-regulated. Compared with miR-125a-5p groups, miR-125a-5p-s groups showed increased colony formation rate and mobility (P < 0.01). After being transfected with miR-125a-5p, the transformation factor 2β (TRA2β) and mRNA levels were decreased, whereas 5p-s expression was increased (P < 0.01). Inhibition of TRA2β by small interfering RNA (siRNA) diminished the ability of cells.

CONCLUSION

miR-125a-5p inhibits the invasive capacity of HCC cells through targeting the TRA2β pathway.

miR-196b regulates gastric cancer cell proliferation and invasion via PI3K/AKT/mTOR signaling pathway

miR-196b plays a significant role in the regulation of tumor pathogenesis and progression by promoting tumor cell proliferation, invasion and metastasis. In order to explore the effects of miR-196b on the proliferation and invasion ability of gastric cancer cells and the involved mechanisms, in the present study the lentivirus expression vector miR-196b was constructed and transfected into the human gastric cancer cell line MKN28. The cell proliferation and invasion ability were observed and the expression of PI3K/AKT/mTOR protein and mRNA were analyzed following upregulation of the expression of miR-196b. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) results revealed that the proliferation of MKN28 cells was notably increased following upregulation of the expression of miR-196b (P<0.01). Flow cytometry analysis demonstrated that miR-196b decreased the ratios of cells in the GO/G1 stage but increased the ratios in S and G2 stage (P<0.05). Furthermore, the cell clone formation and trans-membrane rates were increased following upregulation of the expression of miR-196b (P<0.01). The nude mouse tumor growth test revealed that tumor growth was more rapid following upregulation of the expression of miR-196b. The expression of PI3K/AKT/mTOR protein and mRNA were increased following upregulation of the expression of miR-196b. We concluded that upregulation of miR-196b promotes the proliferation and invasion ability of gastric cancer cells by regulating the PI3K/AKT/mTOR pathway.

miR-125a inhibits the migration and invasion of liver cancer cells via suppression of the PI3K/AKT/mTOR signaling pathway

In order to explore the regulation of the invasive ability of hepatocellular carcinoma cells and the underlying mechanism, mimics sequences of microRNA (miR)-125a (miR-125a-3p/5p) and scramble sequences (miR-125a-3p-s/5p-s) were transfected into human hepatocellular carcinoma cell lines, HCC-LM3 and HepG2, and the non-malignant epithelioid hepatic cell line QZG. To inhibit and upregulate the expression of miR-125a individually. Protein expression was detected by western blotting, and the cell proliferation and migration abilities were evaluated by soft agar colony formation and Transwell assay, respectively. It was revealed that the expression of miR-125a was downregulated in HepG2 and HCC-LM3 cells compared with that of QZG cells, and expression was markedly lower in HCC-LM3 cells than that in HepG2 cells (P<0.01). The colony formation and migration rates of the cells transfected with miR-125a-3p/5p were decreased compared with negative controls, but were increased in cells transfected with miR-125a-3p-3/5p-s (P<0.01). The protein and messenger RNA expression of phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) was decreased following transfection with miR-125a-5p, whereas expression was increased compared with negative controls following transfection with miR-125a-5p-s (P<0.01). Furthermore, the proliferation and migration abilities of cells were attenuated following inhibition of the PI3K/AKT/mTOR pathway by LY294002. The results of the present study indicated that miR-125a inhibits the invasive ability of hepatocellular carcinoma cells via regulation of the PI3K/AKT/mTOR pathway.

Validation of the Cancer BioChip System as a 3D siRNA screening tool for breast cancer targets

Genomic studies have revealed that breast cancer consists of a complex biological process with patient-specific genetic variations, revealing the need for individualized cancer diagnostic testing and selection of patient-specific optimal therapies. One of the bottlenecks in translation of genomic breakthroughs to the clinic is the lack of functional genomic assays that have high clinical translatability. Anchorage-independent three-dimensional (3D) growth assays are considered to be the gold-standard for chemosensitivity testing, and leads identified with these assays have high probability of clinical success. The Cancer BioChip System (CBCS) allows for the simultaneous, quantitative, and real time evaluation of multitudes of anchorage-independent breast cancer cell growth inhibitors. We employed a Test Cancer BioChip that contains silencing RNAs (siRNAs) targeting cancer-related genes to identify 3D-specific effectors of breast cancer cell growth. We compared the effect of these siRNAs on colony growth of the hormone receptor positive (MCF7) and Human Epidermal Growth Factor Receptor 2/c- Erythroblastic Leukemia Viral Oncogene Homolog 2 (HER2/c-erb-b2) positive (SK-BR-3) cells on the Test Cancer BioChip. Our results confirmed cell-specific inhibition of MCF7 and SK-BR-3 colony formation by estrogen receptor α (ESR1) and (ERBB2) siRNA, respectively. Both cell lines were also suppressed by Phosphoinositide-3-kinase Catalytic, alpha Polypeptide (PIK3CA) siRNA. Interestingly, we have observed responses to siRNA that are unique to this 3D setting. For example, ß-actin (ACTB) siRNA suppressed colony growth in both cell types while Cathepsin L2 (CTSL2) siRNA caused opposite effects. These results further validate the importance of the CBCS as a tool for the identification of clinically relevant breast cancer targets.