Expression Of Hedgehog Pathway And CyclinD1in HaCaT Cells Treated By As₂O₃

At present, the arsenic pollution is still important threat of the health, at least100million people around the world are faced with the threat of local arsenicpoisoning, through the water, coal, drugs, such as long-term exposure to arsenicoccupational factors, that can cause skin, lung and bladder tissue organ of canceroustumors. In recent years, the arsenic carcinogenic mechanism was found to relatereactive oxygen species, DNA repair and methylation patterns of change, andestablish a variety of genetically modified cells and animal model, but the specificmechanism is not clear. There is important scientific significance to study the arseniccarcinogenic mechanism in our country.The skin is the important target organs of chronic arsenic poisoning, andlong-term arsenic poisoning can cause a variety of skin tumors. The keratinocytecultured by arsenic is an important model to study arsenic carcinogenic mechanism invitro. Arsenic affecting on target cells to produce duplex effect, high levels of inhibitthe proliferation and apoptosis-oriented role; low concentration (<0.5u mol)long-term stimulate proliferation KC.In recent years, it was found in a number of studies that the Hedgehog signalingpathways activate anomalies exist in the skin basal cell carcinoma, lung cancer, breastcancer, and so on many kinds of tumor tissue. The over-expression of Hedgehogpathway may play a crucial role in the tumor proliferation and differentiation andapoptosis. Some scholars reported that there was Hedgehog pathway activation in thecells cultured in vitro by arsenic. We assume that the Hedgehog pathway may beinvolved in the long-term exposure to arsenic related skin hyperkeratosis andcancerous tumors.We conducted a study to determine the expression of Hedgehog pathway and CyclinD1in HaCaT Cells cultured by arsenic in vitro. And analyze the possiblearsenic carcinogenic mechanism by Real Time Fluorescence Quantitative and Westernblot.Part Ⅰ The mRNA expression of PTCH、SMO、GLI1、SFRP1in HaCaT cells treated by arsenic.Objective: To study the mRNA expression of PTCH、SMO、GLI1、SFRP1in HaCaT cells treated by arsenic.Methods: The mRNA expression of PTCH、SMO、GLI1、SFRP1wasdetected by Real Time Fluorescence Quantitative PCR(RT-PCR) in HaCaT cellstreated by arsenic.Results: After treatment with arsenic (0.1umol/L) for72h，the mRNAexpression of PTCH、SMO、GLI1、SFRP1was increased in HaCaT cellstreated by arsenic（.P<0.05）The Gli1mRNA increased more than four times as much.（P<0.05）Conclusion：The over-expression of Hedgehog pathway may play a crucial rolein abnormal proliferation of HaCaT cells treated by arsenic.Part Ⅱ The protein expression of CyclinD1in HaCaTcells treated by arsenicObjective: To study the protein expression of CyclinD1in HaCaT cells treatedby arsenic.Methods: The protein expression of CyclinD1was detected by Western blotrespectively in HaCaT cells treated by arsenic.Results: After treatment with arsenic (5umol/L、1umol/L、0.5umol/L、0.1umol/L、0.05umol/L、0.01umol/L、0.005umol/L、0.001umol/L) for72h， theprotein expression of CyclinD1was increased in HaCaT cells treated byarsenic. Conclusion：The over-expression CyclinD1may play a crucial role in abnormalproliferation of treated HaCaT cells by arsenic.