| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2004: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2003: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Research Abstract |
High level of CCR6 mRNA expression was quantified in human HCC cell lines, HuH7, PLC/PRF/5, and HepG2 cells as examined by TaqMan PCR. In flow cytometric analysis, also, CCR6 expression was enhanced on the surface of three HCC cell lines, HuH7, PLC/PRF/5, and HepG2 cells, similar to the results of mRNA expression by TaqMan PCR. The mRNA expression of CCL20, the ligand (chemokine) for CCR6, was demonstrated in HuH7, PLC/PRF/5, and HepG2 cells, all are identical to the cell lines expressing CCR6. CCL20 was secreted into the culture supernatant of HuH7, PLC/PRF/5, and HepG2 cells, but it was undetectable in the culture supernatant of other cell lines. MTT assay revealed that addition of CCL20 to the culture medium of HuH7 cells significantly (by approximately 170%, p<0.01) stimulated the proliferation of these cells expressing CCR6. Western blotting analysis clarified that the downstream signal transduction pathway of CCL20/CCR6 in HuH7 cells was mediated by p44/42 MAP kinase, but not by p38 MAP kinase or SPAK/JNK. Chemokines CCL20 did not show significant chemotactic activity towards hepatoma cell lines expressing high levels of their receptors, CCR6 on their surface. The present study indicates that some of the human hepatoma cells stimulate their own growth via the autocrine or paracrine mechanism mediated by chemokine-chemokine receptor system.
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