Effects Of Emodin On Proliferation And Apoptosis Of Oral Squamous Cell Carcinoma

Background:Oral cancer is common in the maxillofacial region,of which about90%are oral squamous cell carcinoma.In recent years,the comprehensive sequential therapy based on surgery and supplemented by radiotherapy and chemotherapy has been gradually adopted into the clinical treatment scheme.However,the diagnosis and treatment methods of oral cancer are constantly improving,due to its high metastasis rates and recurrence rates,patients’five-year survival rate has not improved significantly on the whole.Now,traditional Chinese medicine has become a research hotspot.Emodin is a natural active compound mainly existing in rhubarb rhizomes and seabuckthorn.Except of its anti-inflammatory and antibacterial effects,its anti-tumor effect has more attention.Studies have proved that emodin can inhibit tumor growth and promotes tumor cell apoptosis.Moreover,compared with the commonly used chemotherapeutic drugs,its toxicity is less and its side effects are relatively less.However,there are very seldom studies on whether emodin also has a certain antitumor effect in oral cancer.Objective:To investigate the molecular mechanism of emodin in CAL-27 and SCC-15 cells.Methods:（1）CAL-27 and SCC-15 cells’proliferation activity was detected by CCK-8,then calculated the half maximal inhibitory concentration of emodin(IC₅₀);（2）Annexin V-FITC/PI double staining can detect the effects of emodin and miR-21 on the apoptosis of these two kinds of cells.（3）Mitochondrial apoptosis fluorescence assay can detect the effects of emodin and miR-21 on the apoptotic ability of mitochondrial apoptosis pathway of these two kinds of cells;（4）Western blot can detect the effects of emodin and miR-21 on the expression levels of PTEN,Akt,p-Akt and Bax proteins in these two kinds of cells;（5）qRT-PCR can detect the effect of emodin on the expression levels of miR-21and PTEN mRNA in these two kinds of cells and the changes of PTEN mRNA expression after miR-21 transfection.Results:（1）Different concentrations of emodin could inhibit the proliferation of CAL-27and SCC-15 cells when contrast to the control group（P<0.05）,and it is time-concentration dependent;（2）Emodin could significantly improve the apoptotic ability of the two cells when contrast to the control group（P<0.05）,concentration dependent;（3）The expression levels of miR-21 mRNA and protein in the two kinds of cells treated with emodin were significantly down-regulated when contrast to the control group（P<0.05）,while the expression levels of PTEN mRNA and protein were significantly up-regulated（P<0.05）;（4）The expression level of p-Akt protein was significantly decreased in the two cells treated with emodin when contrast to the control group,on the contrary,the expression level of Bax protein was significantly increased（P<0.05）;（5）Compared with NC group,after miR-21 transfection,the apoptosis rate of the two cells decreased,and the expression levels of PTEN and Bax protein were significantly down regulated.Conclusion:Emodin can inhibit the proliferation and promote apoptosis of OSCC CAL-27 and SCC-15 cell lines in vitro,and its effect probably related to the less expression of miR-21 and p-Akt and more expression of PTEN and Bax.