Changes of the expression of CCNL2 gene during the differentiation of P19 cells to cardiac myocytes

Objective： To investigate the changes of cyclin L2（CCNL2） gene mRNA and protein during the differentiation of P19 cells to cardiac myocytes, and to explore the relationship between CCNL2 gene and the differentiation of cardiac myocytes. Methods： P19 cells were cultured with 0.9% DMSO for 18 days. Western blots of cardiac troponin I （cTnI） were used to identify cell differentiation. Total RNA was extracted from P19 cells during the process of differentiation at various time points：pre-differentiation（Day 0）, and Day 1 to Day 18. The expression levels of CCNL2 gene mRNA and protein were evaluated by RT-PCR and Western blot, respectively. Results： After being induced to differentiate by DMSO for 4 days in suspension, spontaneously and rhythmically beating ceils were seen at 8 day, which were cTnI-positive. In P19 cells, both the expression level of CCNL2 gene mRNA and protein were gradually down-regulated. Conclusion： Both the expression of CCNL2 gene and protein were down-regulated during the process of the differentiation of P19 cells into cardiac myocytes, suggesting a possible role for this cyclin in their differentiation.

Effect of Artemisia species on cellular proliferation and apoptosis in human breast cancer cells via estrogen receptor-related pathway

OBJECTIVE:To investigate the mechanism underlying the anticancer effect of Artemisia species through the inhibition of cell growth and induction of apoptosis in breast carcinoma cells.METHODS:To evaluate the anticancer activity of methanol extracts of eight Artemisia species(Artemisia stolonifera,Artemisia selengensis,Artemisia japonica,Artemisia Montana,Artemisia capillaris,Artemisia sylvatica,Artemisia keiskeana,and Artemisia scoparia),we first investigated the proliferation of estrogen receptor(ER)-positive MCF-7breast carcinoma cells exposed to 5 or 200 g/mL for72 h.Apoptosis induction was assessed by an Annexin V binding assay in cells exposed to extracts at a high concentration(200 g/mL).To verify the mechanism of apoptosis,ER expression and its related signaling was investigated using an immunoblot assay under the same conditions.RESULTS:MCF-7 cells showed the strongest antiproliferative response to the tested extracts.Howev-er,a biphasic effect was observed:the extracts inhibited proliferation at high concentrations whereas they stimulated it at low ones.ER expression was similarly modulated by the extracts.However,all of the extracts induced apoptosis at a high concentration(200 g/mL).Compared to the control level,exposure to the extracts resulted in a remarkable increase in the shift of cell populations.CONCLUSION:The present study suggests that the tested Artemisia species exerted their anticancer effects through the induction of apoptosis via an ER-related pathway.