Effects Of Heavy Metal On Expression Of Heat Shock Protein70(HSP70) In Hela Cells

Heat shock proteins（HSPs） are a group of proteins widely exist in prokaryotic andeukaryotic cells. They are a family of functionally related proteins that help organisms tomodulate stress responses and protect organisms from cellular damages, and it plays animportant role in the body’s stress response. They are classified into several familiesaccording to their molecular weight, including HSP110, HSP90, HSP70, HSP60, HSP40and other small molecular weight hsp subfamily. HSP70is the most conserved and themost important one in HSPs family, it palys an important role in maintaining the stabilityof the cell and improve the cell tolerance to stressors. Cd²⁺, Cu²⁺and Zn²⁺were known asubiquitous environmental contaminant which caused damages to several major organs inhumans and other animals. HeLa cells are derived from cervical cancer cells andproliferate rapidly, so they are ideal cells for scientific research.In this experiment, use HeLa cells as material, and use different concentration of Cd²⁺,Cu2＋and Zn2＋to induce the cells, then study the relationship of the production of HSP70between the different concentration of the three kind of heavy metals by the method ofImmunofluorescence staining（IFS）, SDS-PAGE, western blotting and RT-PCR. The mainresults obtained are as follows:1. Reserch HSP70gene transcription level by RT-PCRThe expression of HSPs are significantly increased by heat stimulation or otherpressure stimulation. The HSP70was highly expressed after been treated by50-100μMCd²⁺and the expression was gradually increased with the concentration.100-200μM Zn2＋and Cu²⁺almost had the same influence on the HSP70expression while remarkablelydifferent from control group. Among three heavy metals, Cd²⁺caused of the strongestinduction of HSP70RNA.2. Reserch HSP70protein expression level by Western blottingWhen Hela cells treated with the concentration of0-100μM Cd²⁺, band intensity ofHSP70protein was significantly up-regulated. At the concentration of200μM, the bandcolor becomes weaker。After been treated by100μM and200μM Zn2＋and Cu²⁺, theexpression of HSP70increased.3. Reserch HSP70protein expression level by IFSThe expression level of HSP70was not significant at25μM of Cd²⁺compared withcontrol group（P>0.05）, this means low concentration of Cd²⁺don’t cause a significant hazard to HeLa cells. As the concentration of Cd²⁺increased, the amount of HSP70alsoincreased, and were significantly expressed（P<0.01）. Exposure HeLa cells to Zn2＋and Cu²⁺respectively induced significant elevations of HSP70in HeLa cells, the expression ofHSP70was positively correlated with the concentration of Zn2＋and Cu²⁺. The result showsthat the degree of influence of the metal to HSP70is Cd²⁺>Zn2＋>Cu2＋.Through the three research methods above, to establish a more effective detectionmethod of the expression of HSPs for future experimental study.