Trial study of capecitabine metronomic chemotherapy combined with exemestane inhibit proliferation of breast cancer cells by PI3K-AKT signaling pathway
	    		
		   		
		   			
		   		
	    	
    	 
    	10.3760/cma.j.cn115355-20201203-00682
   		
        
        	
        		- VernacularTitle:卡培他滨节拍化疗联合依西美坦通过PI3K-AKT信号通路抑制乳腺癌细胞增殖的实验研究
 
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Yulan GU
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Jinlian ZHU
			        		
			        		;
		        		
		        		
		        		
			        		Yeqiong XU
			        		
			        		;
		        		
		        		
		        		
			        		Chuandan WAN
			        		
			        		;
		        		
		        		
		        		
			        		Jun QIAN
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. 江苏省常熟市第二人民医院肿瘤科 215500
			        		
		        		
	        		
        		 
        	
        	
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		Breast neoplasms;
			        		
			        		
			        		
				        		Antineoplastic combined chemotherapy protocols;
			        		
			        		
			        		
				        		Capecitabine;
			        		
			        		
			        		
				        		Exemestane
			        		
			        		
	        			
        			
        		
 
        	
            
            
            	- From:
	            		
	            			Cancer Research and Clinic
	            		
	            		 2021;33(6):401-407
	            	
            	
 
            
            
            	- CountryChina
 
            
            
            	- Language:Chinese
 
            
            
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		        	Abstract:
			       	
			       		
				        
				        	Objective:To investigate effects of capecitabine metronomic chemotherapy combined with exemestane on the proliferation of breast cancer MCF-7 cells and PI3-K/AKT signaling pathway.Methods:MCF-7 cells cultured in vitro were divided into the control group (adding DMEM without drugs), 30 μmol/L exemestane group, capecitabine metronomic chemotherapy combined drugs group [30 μmol/L exemestane combined with different concentrations (50, 33, 17 μmol/L) of capecitabine]. CCK-8 assay was used to detect the cell proliferation inhibition rate, the half-maximal inhibitory concentration ( IC50) was calculated, and the changes of cell cycle and apoptosis rate of MCF-7 in different drug groups were assessed by using flow cytometry. The related-protein expression of PI3K-AKT signaling pathway of MCF-7 cells was detected by using Western blot. Results:The IC50 of capecitabine and exemestane on MCF-7 cells for 72 h was 101.2 μmol/L and 60.6 μmol/L, respectively. The proliferation inhibition rate of MCF-7 cells in 30 μmol/L exemestane for 24 h and 48 h combined with 50, 33 and 17 μmol/L capecitabine group was higher than that in 30 μmol/L exemestane group (all P<0.01). The apoptosis rates were (18.1±2.6)%, (34.6±3.0)%, (27.6±1.3)%, (23.1±1.6)%, respectively in 30 μmol/L exemestane group, 30 μmol/L exemestane + 50 μmol/L capecitabine group, 30 μmol/L exemestane + 33 μmol/L capecitabine group, 30 μmol/L exemestane + 17 μmol/L capecitabine group, and the difference was statistically significant ( F = 23.652, P<0.01). Compared with the control group, the proportion of MCF-7 cells in phase G 2 of 30 μmol/L exemestane group was increased [(16.7±2.6)% vs. (10.6±2.2)%], while that in phase G 1 was decreased [(53.3±4.0)% vs. (56.3±3.2)%]. The proportion of MCF-7 cells in phase S of 30 μmol/L exemestane + 50 μmol/L capecitabine group was increased [(39.0±3.6)% vs. (33.1±2.0)%]. MCF-7 cells of 30 μmol/L of exemestane + 33 μmol/L capecitabine group were more blocked in phase S [(51.7±4.1)%], and cells in phase G 2 were nearly disappeared [(1.2±0.5)%]; the cell proportion MCF-7 cells in phase G 2 of 30 μmol/L exemestane plus 17 μmol/L capecitabine group was increased [(26.2±3.1)%]. Western blot analysis showed that low dose capecitabine metronomic chemotherapy promoted exemestane to inhibit the expression of PI3K, motivated AKT serine phosphorylated at protein 473 [the increased expression of p-AKT (473)], promoted S6 protein expression at downstream of signaling pathway and increased its phosphorylation level (the increased expression of p-S6), thereby activating apoptosis signal. Conclusion:Capecitabine metronomic chemotherapy combined with exemestane can synergistically inhibit the proliferation of breast cancer MCF-7 cells and activate apoptosis mechanisms of MCF-7 cells through affecting PI3K-AKT signaling pathway.