Nocardia rubra cell‐wall skeleton influences the development of cervical carcinoma by promoting the antitumor effect of macrophages and dendritic cells

BACKGROUND: As an immune enhancer, Nocardia rubra cell‐wall skeleton (Nr‐CWS) has been used to treat persistent human papillomavirus infection and cervical precancerous lesions. However, it is still unclear whether it can be used to treat cervical carcinoma. METHODS: In our study, the aim was to determine whether Nr‐CWS affects the apoptosis of cervical carcinoma cells by enhancing the antitumor effect of dendritic cells and macrophages in vivo and in vitro. RESULTS: The experimental results showed that Nr‐CWS can promote the activity of dendritic cells and macrophages and reduce their apoptosis. It also increased the cytokines IL‐6, IL‐12, TNF‐ɑ, and IL‐1β secreted by dendritic cells and macrophages and reduced their PD‐L1 expression. In vitro, Nr‐CWS inhibited the proliferation, colony forming ability of HeLa and SiHa cervical carcinoma cell lines cultured with macrophages, and more cells were blocked in G2/M phase. Nr‐CWS promoted TNF‐ɑ/TNFR1/caspase‐8‐mediated apoptosis by increasing macrophages secretion of TNF‐ɑ and inhibited cell migration and invasion regulated by the WNT/β‐catenin‐EMT pathway. Nr‐CWS also reduced the expression of the cervical carcinoma genes E6 and E7 thereby increasing expression of p53 gene and decreasing expression of PD‐L1 gene. In vivo, Nr‐CWS inhibited tumor growth and decreased the expression of E6, E7, PD‐L1, P16, Ki67, and PCNA in tumors. CONCLUSIONS: Therefore, our results suggest that Nr‐CWS can promote apoptosis of cervical carcinoma cells by enhancing the antitumor effect of dendritic cells and macrophages.