ABSTRACT
Objective To study the effects of TRβ△ on apoptosis and proliferation of liver cancer cell line RH-35 from rat in vitro. Methods RH-35 cells were transfected by empty vector pcDNA3. 1 and expression plasmid pcDNA3. 1-TRβ△, then exposure to 10 nmol/ L T3 . RH-35 cells apoptosis and proliferation were observed by flow cytometry and MTT colorimetric assay; Levels of catenin β-1(CTNNB1), senescence marker protein-30(SMP-30) and BCL2-antagonist/ killer ( BAK ) mRNA evaluation were detected by quantitative real-time RT-PCR (RT-qPCR). Results In the presence of T3 , overexpression of TRβ△ significantly inhibited the proliferation, increased the percentage of apoptotic, down-regulated CTNNB1and SMP-30 expression, up-regulated BAK expression in RH-35 cells( P < 0. 05). Conclusion TRβ△ could inhibit the proliferation of RH-35 cells and promote their apoptosis, which may be related to upregulation of BAK genes expression and downregulation of CTNNB1 and SMP-30 gene expression, and these effects could be regulated by T3 .
ABSTRACT
Objective To study whether osteoblast is necessary for IGF-Ⅰ to promote bone resorption by osteoclast.Methods Mouse MC3T3 osteoblast cells and mature osteoclasts induced by RANKL were cultured in vitro.These osteoblasts and osteoclasts were subjected to treatment with recombinant human insulin-like growth factor-1 (rhIGF-Ⅰ),and the activation of IGF-Ⅰ receptor was verified by Western blotting.Thereafter,osteoclasts were cultured individually or co-cultured with osteoblast,in the absence or presence of rhIGF-Ⅰ.Osteoclast proliferation and apoptosis were observed by MTT colorimetric assay and flow cytometry.Cathepsin K gene expression was detected by real-time PCR; bone adsorption activity of osteoclast was determined by resorption pits formation on calf cortex slice with toluidine blue staining.Results Western blotting result confirmed that rhIGF-Ⅰ could effectively activate IGF-Ⅰ receptors either in osteoblast or osteoclast.In co-cultured group,in the presence of rhIGF-Ⅰ osteoclast showed inhibited apoptosis,enhanced proliferation and up-regulated cathepsin K expression (P ＜ 0.05).The functional experiment revealed that osteoclasts collected from IGF-Ⅰ treated co-cultured group resulted in more resorption pits formation (P ＜ 0.05); rhIGF-Ⅰ did not show any significant effect on the individually cultured osteoclasts.Conclusion Osteoblast is necessary for osteoclast induced bone resorption resulting from IGF-Ⅰ treatment.