Research Progress On The Association Between Streptococcus Anginosus And Oral Squamous Cell Carcinoma

Oral cancer is a common malignant tumor of the head and neck,more than 90% of which are squamous cell carcinoma(OSCC).With the low 5-year survival rate of 60%,this disease ranks sixth in the world's common cancers.Therefore,early detection,diagnosis and treatment are important for the prevention and treatment of this disease.More and more studies have found that oral microbial flora changes have a complex relationship with the development of oral squamous cell carcinoma.More and more studies have found that oral microbial flora have complex relationships with the development of oral squamous cell carcinoma.There are higher rate of Streptococcus,Porphyromonas,Veillonella,Fusobacterium on the surface of OSCC tissues.Streptococcus anginosus(S.anginosus)is a common bacterium in the oral cavity,gastrointestinal tract and genitourinary tract.There are reports that the total detection rate of Streptococcus angina DNA was as high as 88% in the oral cancer tissue samples from the tongue,mouth,cheeks,and gums,and the detection rate in esophageal cancer and gastric cancer was also increased.This study is a preliminary research on the effect of streptococcus anginosus on oral cancer cells for providing supplements and supports on the relationship between oral micro-ecology and diseases.Objective S.anginosus supernatant was applied to human OSCC cell in vitro to investigate its effects on the biological behavior of SCC-15 cells.Methods Determine the growth curve and concentration standard curve of S.anginosus and select the supernatant concentration and time co-cultivating with SCC-15;set up SCC-15/S.anginosus(SCC-15/ S) group as experimental group,SCC-15/ THB(SCC-15/T) group as conditional control group,SCC-15/S+3-MA as conditional control group,SCC-15/3-MA as negative control group and SCC-15 group with no treatment was a blank control group;MDC staining,qRT-PCR,Western blot were used to detect autophagy activity;CCK-8 assay was used to detect the proliferation activity of each group;flow cytometry and apoptosis were detected;and the cells were detected by wound healing test;transwell detects the invasive ability of each group of cells.Results According to the growth curve and concentration standard curve of S.anginosus,the 16 th hour supernatant was used to test,the ratio of supernatant to cell culture medium was 1:1,and the co-culture time was 16h;(1)The results of MDC staining,qRT-PCR and WB all indicated that the autophagy activity of SCC-15/S group was increased,indicating that S.anginosus increased the autophagy activity of SCC-15 cells;(2)It was illustrated by CCK-8 assays that the cell proliferation in SCC-15/S group was significantly inhibited compared with control groups(P<0.05);(3)SCC-15/S group showed a cell-cycle arrest at the G1 phase,a decrease in S phase and G2/M phase(P<0.05)in compared with the control groups(P>0.05);apoptosis assays illustrated that the percentage of apoptotic cell of SCC-15/S group was significantly higher than that of the control groups(P<0.01);(4)The results of Wound Healing test showed that the supernatant of S.anginosus significantly inhibited the migration ability of SCC-15/S group,which was significantly different from the control groups(P<0.05);(5)Transwell assays showed that the invasive ability of SCC-15/S group was significantly decreased(P<0.05);Conclusion Streptococcus anginosus can reduce the proliferation,migration and invasion of SCC-15 cells,inhibit cell growth and promote cell apoptosis by autophagy.