MicroRNA-33a regulates the invasion of cervical cancer cells via targeting Twist1 / 中南大学学报(医学版)

OBJECTIVE@#To examine the expression of Twist1 in cervical cancer and to explore its biological function in the progression of cervical cancer.
@*METHODS@#The expressions of Twist1 in 32 cervical cancers and matched normal tissues were examined by immunohistochemistry (IHC). Cell invasive ability and the expression of invasion-related genes were determined in RNAi-based Twist1-silencing HeLa cells. The relationship between Twist1 and microRNA-33a (miR-33a) in cervical cancer was studied by Pearson correlation analysis, and the roles of miR-33a in regulation of Twist1 and cell invasiveness were studied.
@*RESULTS@#The positive expression rate of Twist1 was 75.0% (24/32) and 21.9% (7/32) in the cervical cancer and the matched normal tissues, respectively, with significant difference between them (P<0.05). Twist1 shRNA significantly decreased the invasiveness of HeLa cells (P<0.05). Compared with the matched normal tissues, the expression of miR-33a was increased in the cervical cancer tissues, which was negatively correlated with Twist1 (r=-0.661, P<0.05). Overexpression of miR-33a could significantly suppress Twist1 expression as well as cell invasiveness (P<0.05).
@*CONCLUSION@#Twist1 is critical for the invasiveness of cervical cancer cells; miR-33a, as a tumor suppressor gene, functions as an upstream regulator of Twist1 and is involved in the invasiveness of cervical cancer cell.

Effect of gamma-aminobutyric acid on malignant phenotypes of hepatocellular carcinoma cell line HepG-2 / 中南大学学报(医学版)

OBJECTIVE@#To determine the effect of gamma-aminobutyric acid(GABA) on proliferation and malignant phenotypes of hepatocellular carcinoma cell line HepG-2.@*METHODS@#HepG-2 cells were cultured by routine method, and then treated with different concentrations of GABA. The proliferation of HepG-2 cells was measured through MTT, doubling time and cell cycles by flow cytometry. The malignant phenotypes were investigated by soft agar colony formation assay.@*RESULTS@#Compared with the control group, GABA efficiently stimulated the proliferation of HepG-2 cells in a dose-dependent manner and affected the distribution of cell cycles of HepG-2 cells. The doubling time of the control group and the GABA-treated group were 39.0, 30.6, 30.0, 27.3, 26.6, and 38.2 h, respectively. The colony formation rates were 3.2%, 4.2%, 5.4%, 6.6%,6.5%, and 3.5%, respectively. Tumorigenicity testing showed that the average weights of tumor was 1.382 g, and 0.285 g for the 2 groups. The difference between the control group and the GABA-treated groups was significant (P<0.01).@*CONCLUSION@#GABA can enhance the proliferation and malignant phenotypes of HepG-2 cells.

Screening and characterization of human scFv antibodies against nasopharyngeal carcinoma / 中国医师杂志

Objective To screen the anti-nasopharyngeal carcinoma scFv from a human anti-nasopharyngeal carcinoma single-chain phage antibody library, and identify its characteristics. Methods The single-chain phage antibody library was subjected to three rounds of positive and negative cell panning and enrichment, and then it was selected by ELISA. The binding specificity of phage antibodies with naso-pharyngeal carcinoma cells was confirmed by immunohistochemistry. Results After panning, enrichment and testing by ELISA, 3 phage an-tibody clones reacting with CNE2 more strongly than HUVEC and NP69 were picked out from 4212 clones. One clone, HNSAO33, was fur-ther analyzed after DNA sequencing. The results of immunohistochemistry with cultured cells were similar to those of ELISA. HNSAO33 spe-cifically reacted to nasopharyngeal carcinoma cells in most human nasopharyngeal carcinoma tissue sections except a few human normal naso-pharyngeal tissue sections. The distinction of positive rates was of a great statistical significance. Conclusion ELISA and immunohisto-chemistry results confirmed HNSAO33 specifically bind with nasopharyngeal carcinoma cells. The seFv fragment against nasopharyngeal carci-noma may be further developed and applied in clinical diagnosis and therapy of nasopharyngeal carcinoma.

Construct a subtractive library of Caski cell lines induced by exposing to the space environment by suppression subtractive hybridization / 中国医师杂志

Objectives Construct a subtractive library of Caski cell line induced by exposing to the space environment by suppression subtractive hybridization and pave the way to explain the molecular mechanisms of the changes at the gene level. Methods Super SMART cDNA synthesis and suppression subtractive hybridization (SSH) were performed to isolate differentially expressed cDNA fragments from strains subclonal 48A9 cell line. cDNA from the 48A9 cell line were used as " tester" , and the other from the control Caski cell line as "driver". Subtractive products were directly inserted into T/A cloning vector, and then transformed into host bacteria to set up a subtractive cDNA library of specially or highly expressed genes in strains subclonal 48A9 cell line. Results mRNA were directly extracted and purified with good quality. Double strand cDNA were reverse transcripted integratedly, and then cut by Rsa I into even length short segments. Liga-tion was identified as high effective. After two hybridizations, a subtractive library of differentially expressed genes in strains subclonal 48A9 cell line was successfully constructed by SSH. Conclusion SSH is an effective approach to isolate differentially expressed genes.