The Experimental Study Of Ki67and Her-2Expression In Human Breast Cancer Cells MCF-7（ER+） And MDA-MB-453（ER-） Treated By1,25Dihydroxyvitamin D₃

【Objective】The different concentrations of1,25-(OH)2D3(a active form of vitamin D) wereused to treat the human breast cancer MCF-7(ER+) and MDA-MB-453(ER-) cellswhen they were in logarithmic growth phase, mRNA and protein of Ki67and Her-2intwo breast cancer cells were measured at different time points, and the effects oftamoxifen (TAM) positive control group treatment were compared. Analysis the effectof vitamin D to the expression of Ki67and Her-2in breast cancer cells, compare themolecular pathway association with the estrogen receptor pathway.【Methods】The human breast cancer cells MCF-7(ER+/VDR+) and MDA-MB-453(ER-/VDR+) were dealt with different concentration of1,25-(OH)2D3(1×10-9mol/L,1×10-8mol/L,1×10-7mol/L) when they were in the logarithmic growth phase. At thesame time, we using TAM to teated the two kinds of breast caner cells as positivecontrol. Cells were collected from24h,48h,72h three time points respectively, themRNA of Ki67and Her-2were detected by Real-time RT–PCR and the protein weredetected by Western Blot.【Results】1.The1,25-(OH)2D3can reduce the expression of Ki67and Her-2in breast cancercells MCF-7and MDA-MB-453. And with the increase of drug concentration andaction time the expression of ki67and Her-2is less, the difference was statisticallysignificant (P <0.05), show that1,25-(OH)2D3has inhibitory effect on theexpression of Ki67and Her-2in these two kinds of breast cancer cells.2. The inhibitory effect of1,25-(OH)2D3to Ki67and Her-2in MCF-7cells is betterthan MDA-MB-453cells, and the difference was statistically significant (P <0.05). 3. Compared with TAM group,1,25-(OH)2D3inhibitory effect on the expression ofKi67and Her-2in MDA-MB-453cells is stronger, compared two groups, thedifference was statistically significant (P <0.05); while in the MCF-7cells, nosignificant difference between the two groups. Indicate that the inhibitory effect of1,25(OH)2D3is stronger than TAM in ER negative breast cancer cells.4. The expression of Ki67and Her-2in MCF-7and MDA-MB-453breast cancer cellswere reduced when they were treated by different concentration of1,25-(OH)2D3,and the two are positively related. In MCF-7breast cancer cells,(r=0.875, P=0.00<0.01); in MDA-MB-453cells (r=0.855, P=0.00<0.01).【Conclusion】1.1,25-(OH)2D3can reduce Ki67and Her-2expression in MCF-7and MDA-MB-453cells, and showed dose effect relationship and time effect relationship, and the effecton MCF-7cells is stronger than MDA-MB-453cells.2. The expression of Ki67positively correlated with Her-2in MCF-7andMDA-MB-453breast cancer cells when they were treated by1,25-(OH)2D3.