Effects Of LXRs Agonists On Proliferation Of SCL-1 Cells

BackgroudThe Cutaneous squamous cell Carcinom--a(SCC)is a common,high incidence malignant tumor,which is derived from skin keratinocytes.The cause of the disease is more complex,such as the long time exposure to the sun's ultraviolet rays,environmental or genetic factors,virus infection are all have a close relationships.now the commonly used treatment for the disease is mainly of surgical treatment.Liver X receptor as a transcription factor of the nuclear hormone receptor,researches found that it is involved in the regulation of the proliferation of a variety of normal and tumor cells,and it can inhibite the proliferation of vascular smooth muscle cells,endometrial cells,islet cells,liver cells,keratinocytes and lymphocytes,then as well as that varies of tumor cells,such as melanoma,breast cancer,lung cancer,prostate cancer cells.And earlier stage researches has found that LXR receptor is widely expressed in the skin,but there is no apparent evidence to explain its specific role in squamous cell carcinomas.As a kind of well-known important protein,KLF4 exists in various tissues and cells.it is widely expressed in lungs,intestines,skin,testicular,pleura,myocardial cell and so on.KLF4 is not only involved in regulating different tissue or cells in the body's biological processes such as cell growth,differentiation and apoptosis,but also participate the occurrence and development of tumor or diseaseis related of inflammation.However it is regulating the cell proliferation act as oncogene or tumor suppressor.And now it is also found that KLF4 plays inhibiting effect on proliferation of squamous cells,but the specific mechanism remains to be further confirmed.In view of the possible role of LXR and KLF4 in the occurrence and development of squamous cell carcinoma.To detect the effects of LXRs agonists T0901317 act on human cutaneous squamous cell carcinoma SCL-1 in vitro and in vivo in this study.And to discusses how the KLF4 factor will impact after LXRs agonists act on SCL-1.Methods1.Nude mice model was constructed by subcutaneous injection of SCL-1 cells.After treated with T0901317 for lavage ten days later,the tumor growth of experimental group and control group was measured every two days,and the tumor volume of two groups was compared.2.24,48 and 72 hours after T0901317(1,10,20?mol/L)with different concentrations act on SCL-1 cells,CCK-8 kit assay was performed to detect cell proliferation.3.After treated with T0901317(1,10,20 ?mol/L)for 24 hours,SCL-1 cells cycle progression was analyzed by flow cytometry.4.Real-time quantitative PCR were used to determine mRNA levels of cell cycle related factors after treated with T0901317(1,10,20 ?mol/L)for 24 hours on SCL-1 cells.5.Western blot were used to determine protein levels of cell cycle related factors and KLF4 after treated with T0901317(1,10,20 ?mol/L)for 24 hours on SCL-1 cells.Results1.The difference between the tumor growth curve of experimental group and control group was significantly,the tumor volume of the experimental group was less than that of the control group.IT is means in vivo that LXR agonists can inhibit tumor growth to a certain extent.2.T0901317 inhibited the proliferation of SCL-1 cells in the concentration and time dependant manners.3.The proportion of SCL-1 cells in G1-phase was increased,while that in G2-and S-phase was decreased after treated with T0901317(1,10,20 ?mol/L)for 24 hours.4.The result of PCR and Western Blot showed that expression of P21 and KLF4 was up-regulated,but the other cell cycle factors were no obviously relativity.ConclusionThe inhibition of SCL-1 cells proliferation in vivo and in vitro by LXRs agonists is involved in G1-phase arrest,which was might to be related to the expression increased in P21 factor.While through the process,KLF4 may play an important role,but the specific mechanism needs to be further experiments to detect.