Biomedical subjects

Weigang Fang

Publications and source records attributed to Weigang Fang.

4 recordsLinked to original sources

PubMed2003

[Controlled expression of matrix metalloproteinase 9 promotes expression of invasive phenotype of human melanoma cells].

OBJECTIVE: To investigate the correlation between matrix metalloproteinase 9 (MMP-9) expression and tumor metastasis, and explore the potential application of controlled expression of target gene in tumor gene therapy. METHODS: One self-contained tetracycline-regulated retroviral vector containing sense cDNA of MMP-9 was constructed and transfected into an early-stage human melanoma cell line WM35, which did not express MMP-9. In vitro tests such as growth rate, MTT method, 3H-thymidine incorporation, colony forming ability in soft agar, in vitro invasion assay in Boyden chambers, as well as zymography and Western Blot experiment were used to analyze expression of MMPs and in vitro behavior of tumor cells before and after gene transfection. RESULTS: In the presence of exogenous tetracycline, the expression of the transfected MMP-9 were under detectable level and no significant changes in cell behaviors were found when compared with vector-transfected control cells. But when the tetracycline was withdrew from the medium, the expression and activity of MMP-9 were significantly increased. The capacity of in vitro growth, colony forming ability in soft agar, invasion through Matrigel were enhanced remarkably. CONCLUSION: Transfection of sense MMP-9 can enhance growth and invasion of melanoma cells, further confirming its important role in tumor invasion and metastasis.

Cell Division↗

PubMed2003

[The effects of TMSG-1 gene transfection on metastatic phenotype of pg cancer cells].

OBJECTIVE: To observe the relationship between TMSG-1 gene and tumor metastatic phenotype. METHODS: TMSG-1 cDNA fragment which contained full length open reading frame of TMSG-1 gene was cloned into pcDNA3 plasmid to reconstruct sense and antisense eukaryotic expression plasmids of TMSG-1 gene containing neo selection marker. Both sense and antisense eukaryotic expression plasmids of TMSG-1 gene were transfected into the highly metastatic subclone PG-BE1 by LipofectAMINE method and the positive clones were selected by G418. RT-PCR was used to examine the expression level of the transfected gene and the changes of biological characteristics were checked by a series of in vitro and in vivo assays. RESULTS: The results showed that higher expression levels of TMSG-1 gene in BE1-S cells (cells transfected by sense TMSG-1 cDNA) than the control BE1 cells and BE1-V cells (cells transfected by pcDNA3 plasmid). The expression levels of TMSG-1 gene in BE1-AS cells (cells transfected by antisense TMSG-1 cDNA) were lower than those of the control BE1 cells and BE1-V cells. Compared with the control BE1 cells and BE1-V cells, BE1-AS cells grew more rapidly, and produced more foci in soft agar. Although the BE1-S cells did not reveal significant different growth capacity, the infiltrating ability and colony formation potential of BE1-S cells were decreased, compared with the control BE1 cells and BE1-V cells. Flow cytometry showed higher percentage of BE1-S cells in G0G1 phase than that of BE1 cells, and the presence of apoptotic peak in BE1-S cells. CONCLUSION: The results suggest TMSG-1 gene may represent a tumor metastasis suppressor gene.

Cell Cycle↗

PubMed2003

[Role of matrix metalloproteinases (MMPs) in tumor invasion and metastasis: serial studies on MMPs and TIMPs].

We have conducted serial studies on the role of matrix metalloproteinases (MMPs), especially MMP-9, in tumor invasion and metastasis. In 9 human carcinoma cell lines derived from lung, prostate and melanoma, we found, by zymography and Western blot, that the expression levels of MMP-2 and MMP-9 correlated well with their invasive as well as metastatic abilities both in vitro and in nude mice. When anti-sense MMP-9 cDNA was introduced into WM451, a highly metastatic human melanoma cell line with high expression level of MMP-9, a significant down-regulation of MMP-9 protein expression was found. Meanwhile, the number of cells passing through Matrigel-coated membrane (in vitro invasion assay) and spontaneous metastases to lymph nodes and lungs were significantly reduced. Furthermore, when tissue inhibitors of metalloproteinases-1, -2 or -3 (TIMP-1, TIMP-2 or TIMP-3) cDNAs were individually transtected into metastatic cancer cells, remarkable inhibition of invasion and metastasis were also noticed in each group. These results demonstrate that either up-regulation of TIMPs or down-regulation of MMPs could significantly inhibit the expression of malignant phenotypes, suggesting the important role MMP-9 plays in tumor invasion and metastasis.

Animals↗

PubMed2002

[Pathology].

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Biomedical Research↗