Altered mRNA expression of specific molecular species of fucosyl- and sialyl-transferases in human colorectal cancer tissues

Transfection of miRNAs targeting the FUT3 gene inhibits cell proliferation in human gastric cancer cell line KATO-III

AIM: To investigate the effect of inhibition of FUT3 gene expression with miRNAs on the proliferation of gastric cancer cells (KATO-Ⅲ).

METHODS: Vectors carrying two miRNAs targeting the FUT3 gene were constructed and transiently transfected into KATO-III cells using lipidosome-mediated method. RT-PCR was performed to detect the expression of FUT3 mRNA, and immunocytochemistry and flow cytometry analysis were carried out to test expression variation of sLeA antigen. MTT assay and colony-forming assay were used to analyze cell proliferation and to detect the effect of decreased FUT3 expression on cell growth.

RESULTS: Compared to non-transfected cells and cells transfected with empty vector, the relative expression levels of FUT3 mRNA were significantly decreased (0.41 ± 0.01 vs 0.71 ± 0.05, 0.65 ± 0.03, both P < 0.05; 0.36 ± 0.02 vs 0.71 ± 0.05, 0.65 ± 0.03, both P < 0.05); the sLeA antigen expression levels were also significantly reduced (35.51% ± 0.36% vs 52.79% ± 2.62%, 49.75% ± 1.29%, both P < 0.05; 26.05% ± 1.14% vs 52.79% ± 2.62%, 49.75% ± 1.29%, both P < 0.05); cell growth was significantly inhibited (38.10% ± 1.96% vs 5.6% ± 0.63%, 8.9% ± 0.91%, both P < 0.05; 49.04% ± 2.37% vs 5.6% ± 0.63%, 8.9% ± 0.91%, both P < 0.05); and colony-forming ability was significantly reduced (14.10% ± 1.70% vs 29.79% ± 3.05%, 28.92% ± 2.10%, both P < 0.05; 12.50% ± 1.96% vs 29.79% ± 3.05%, 28.92% ± 2.10%, both P < 0.05) in FUT3-miRNA and FUT3-miRNA2 transfeced cells.

CONCLUSION: Transfection of miRNAs targeting the FUT3 gene can effectively inhibit the proliferation of KATO-Ⅲ cells.

Construction of human FUT3 eukaryotic expression vector and its expression in human breast adenocarcinoma cells

AIM: To construct the human FUT3 (α 1, 3-fucosyltransferase) eukaryotic expression vector and analyze its expression in human breast adenocarcinoma MDA-MB-231 cells.

METHODS: The full-length FUT3 cDNA was obtained by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into pMD18-T simple vector for sequence analysis. Then the FUT3 gene was subcloned into pEGFP-C1 plasmid. The resulting recombinant vector pEGFP-C1-FUT3 was identified by digestion with restriction endonucleases and transfected into MDA-MB-231 cells. A stably transfected cell line was established using G418 selection. The expression of FUT3 was observed under a fluorescence microscope and examined by semi-quantitative RT-PCR.

RESULTS: The full-length human FUT3 cDNA was successfully obtained, and the recombinant plasmid pEGFP-C1-FUT3 was successfully constructed. After transfection into MDA-MB-231 cells, green fluorescence (green fluorescent protein) was observed. Semi-quantitative RT-PCR analysis showed that FUT3 was highly expressed in MDA-MB-231 cells.

CONCLUSION: The FUT3 eukaryotic expression vector pEGFP-C1-FUT3 that can express FUT3 in MDA-MB-231 cells is constructed successfully and can be used to study the biological functions of the FUT3 gene.