Objective To investigate the mechanism of metformin for regulating tumor-stromal cell cross-talk in breast cancer.Methods Tumor associated fibroblasts(CAFs)co-cultured with breast cancer cells were treated with metformin,and the changes in expressions of hypoxia-inducible factor-1α(HIF-1α),p-AMPK,stroma-derived factor-1(SDF-1)and interleukin-8(IL-8)in the CAFs were detected using ELISA,RT-qPCR or Western blotting;Transwell assay was used to evaluate the invasiveness of the tumor cells and its changes following treatment with exogenous SDF-1,IL-8 and TGF-β1.The effects of HIF-1α shRNA or overexpression plasmid,AMPK shRNA,and treatment with OG(a proline hydroxylase inhibitor)or 2-OXO(a proline hydroxylase activator)were examined on p-AMPK,HIF-1α,SDF-1 and IL-8 expressions and invasiveness of the CAFs.Results Metformin treatment significantly increased the expression levels of p-AMPK,SDF-1 and IL-8(P<0.05)and decreased HIF-1α expression(P<0.05)without affecting AMPK expression level(P>0.05)in the CAFs.The invasion ability of metformin-treated breast cancer cells was significantly decreased(P<0.05).Exogenous SDF-1 and IL-8,HIF-1α overexpression,and OG-induced upregulation of HIF-1α all significantly attenuated the inhibitory effects of metformin on breast cancer cell invasion(P<0.05)and HIF-1α,SDF-1 and IL-8 expressions in CAFs(P<0.05).Transfection with HIF-1α shRNA or treatment with 2-OXO significantly decreased the invasiveness of breast cancer cells(P<0.05).P-AMPK knockdown significantly suppressed the inhibitory effect of metformin on HIF-1α expression in CAFs and on invasion of breast cancer cells(P<0.05).Treatment with TGF-β1 partially decreased the inhibitory effect of metformin on HIF-1α expression in CAFs and invasiveness of the breast cancer cells(P<0.05).Conclusion Metformin suppresses HIF-1α expression in CAFs to block tumor-stromal cross talk in breast cancer.

Objective:To explore clustered epidemic of COVID-19 in Liaocheng city and analyze infection status and chain of transmission of the cases.Methods:A joint investigation team of emergency response for COVID-19 epidemic by CDC professional workers of Liaocheng city and district at two levels on January 30, 2020. According to a indicator case from ZH supermarkets, close contacts and related subjects were tracked and screened on February 1, including ZH supermarket employees, family members having contact history with related cases during January 13-26, supermarket clients during January 16-30 and family members of related cases. an epidemiological investigation was carried on and their swab of nose/throat were collected and were sent to Liaocheng CDC laboratory, real-time fluorescence quantitative RT-PCR was used to detect nucleic acids of SARS-CoV-2.Results:a total of 8 437 people were screened during January 30 to February 9, 2020 (120 employees of supermarket, 93 family members, and 8224 clients of supermarket). The epidemic was caused by ZH cases and brought clustered cases in four families. A total 25 cases of SARS-CoV-2 infection, the total infection rate of subjects was 0.30% (25/8 437) with 22 confirmed cases (0.26%, 22/8 437) and 3 asymptomatic patients (0.04%, 3/8 437), asymptomatic patients accounted for 12.00% (3/25) of all infection cases. The infection rates of supermarket employees, family members of confirmed cases and supermarket clients were 9.17% (11/120), 12.90% (12/93) and 0.02% (2/8 224).Conclusions:This was a cluster epidemic caused by one imported case of COVID-19 in a supermarket of Liaocheng city. Prevention and control of cluster epidemic should be focused on chain of community transmission and family cluster cases. It must also be an attention for transmission risk of asymptomatic patients.

Objective To investigate the mechanism of metformin for regulating tumor-stromal cell cross-talk in breast cancer.Methods Tumor associated fibroblasts(CAFs)co-cultured with breast cancer cells were treated with metformin,and the changes in expressions of hypoxia-inducible factor-1α(HIF-1α),p-AMPK,stroma-derived factor-1(SDF-1)and interleukin-8(IL-8)in the CAFs were detected using ELISA,RT-qPCR or Western blotting;Transwell assay was used to evaluate the invasiveness of the tumor cells and its changes following treatment with exogenous SDF-1,IL-8 and TGF-β1.The effects of HIF-1α shRNA or overexpression plasmid,AMPK shRNA,and treatment with OG(a proline hydroxylase inhibitor)or 2-OXO(a proline hydroxylase activator)were examined on p-AMPK,HIF-1α,SDF-1 and IL-8 expressions and invasiveness of the CAFs.Results Metformin treatment significantly increased the expression levels of p-AMPK,SDF-1 and IL-8(P<0.05)and decreased HIF-1α expression(P<0.05)without affecting AMPK expression level(P>0.05)in the CAFs.The invasion ability of metformin-treated breast cancer cells was significantly decreased(P<0.05).Exogenous SDF-1 and IL-8,HIF-1α overexpression,and OG-induced upregulation of HIF-1α all significantly attenuated the inhibitory effects of metformin on breast cancer cell invasion(P<0.05)and HIF-1α,SDF-1 and IL-8 expressions in CAFs(P<0.05).Transfection with HIF-1α shRNA or treatment with 2-OXO significantly decreased the invasiveness of breast cancer cells(P<0.05).P-AMPK knockdown significantly suppressed the inhibitory effect of metformin on HIF-1α expression in CAFs and on invasion of breast cancer cells(P<0.05).Treatment with TGF-β1 partially decreased the inhibitory effect of metformin on HIF-1α expression in CAFs and invasiveness of the breast cancer cells(P<0.05).Conclusion Metformin suppresses HIF-1α expression in CAFs to block tumor-stromal cross talk in breast cancer.