Objective To investigate the mechanism by which Scutellaria barbata D.Don water extract(SBW)inhibits lung metastasis of breast cancer by regulating the immune microenvironment.Methods A mouse model of lung metastasis was established using 4T1 breast cancer cells.Mice were divided into a control group(n=6)and an SBW treatment group(n=6).The effect of SBW on tumor growth was assessed by measuring the volume of the primary tumor,and the inhibitory effect on lung metastasis was evaluated by observing the number and area of metastatic nodules in lung tissue using H&E staining.Flow cytometry was used to analyze changes in the composition of immune cells in the tumor,peripheral blood,and lung tissue.Results Compared with the control group,the SBW treatment group inhibited the growth of the primary tumor(P<0.01)and reduced the number and area of lung metastatic nodules(P<0.01).Flow cytometry analysis showed that after SBW treatment,the numbers of CD86+macrophages(P<0.001)and polymorphonuclear myeloid-derived suppressor cells(PMN-MDSCs)(P<0.05)in the tumor tissue were increased.In lung tissue,the numbers of CD86+macrophages,natural killer T(NKT)cells,natural killer(NK)cells,and PMN-MDSCs were also elevated(P<0.05).Meanwhile,the numbers of regulatory T cells(Tregs)(P<0.05),CD206+macrophages(P<0.01),and monocytic myeloid-derived suppressor cells(M-MDSCs)(P<0.05)in both tumor and lung tissues were decreased.Conclusion SBW inhibits the breast cancer growth and lung metastasis by regulating the recruitment and distribution of immune cells in the tumor,peripheral blood,and lung tissue,thereby enhancing anti-tumor immune responses and reducing immune suppression.

Exosomes are microvesicles ranging from approximately 40-150 nm in size,which mediate the exchange of information between cells by releasing proteins,nucleic acids,etc.Tumor-derived exosomes (TEXs) may facilitate tumor metastasis through various mechanisms such as forming the premetastatic niche in the terminal organs,they can regulate immune cells and immune-related molecules in the tumor microenvironment to promote tumor immune escape,they can also induce tumor angiogenesis and increase vascular permeability,promoting the epithelial-mesenchymal transformation of tumor cells,etc.Understanding the mechanism of TEXs in tumor metastasis can provide new ideas for effective prevention and treatment of tumor metastasis.

Background and purpose:In recent years, the studies indicated that postoperatively induced myeloid-derived suppressor cells (MDSCs) were qualified with potent proangiogenic and tumor-promotive ability. Bone marrow mesenchymal stem cells (BMSCs) significantly inhibited the induction and proliferation of MDSCs. However, the relationship of MDSCs and tumor metastasis during perioperative period, and whether BMSCs could prevent tumor metastasis through inhibiting MDSCs are not clariifed. This study aimed to investigate the change of MDSCs during perioperative period and its correlation with tumor metastasis after surgery, and the inlfuence of BMSCs on the induction of MDSCs and the development of postoperative tumor metastasis.Methods:LLC cells were injected intravenously into C57BL/6 mice. Two hours later, these mice were divided into 4 groups: controls (C group); mice given anesthesia (A group); mice given anesthesia and laparotomy (AL group) and mice given anesthesia, laparotomy, and hepatic lobectomy (ALH group). The AL mice were divided into 2 groups after surgical operation: the AL mice without treatment (ALL group) and the AL mice treated with syngeneic BMSCs (ALB group). The percentage of Gr-1+CD11b+ cells in peripheral blood mononuclear cells (PBMCs) was detected by flow cytometry. The numbers of metastases on the lung surface were counted on the 14th day after LLC infusion. BMSCs were also co-culturedin vitro with myeloid cells in order to illustrate the effects of BMSCs on the generation of MDSCs.Results:The numbers of lung metastases in AL and ALH group signiifcantly increased as compared with C and A group (P<0.01). The number of lung metastases in ALH group signiifcantly increased as compared with AL group (P<0.05). The percentage of Gr-1+CD11b+ cells in PBMCs during postoperative period signiifcantly increased in AL and ALH group as compared with C and A group, and the percentage of Gr-1+CD11b+ cells in ALH group also signiifcantly increased as compared with AL group. The numbers of lung metastases in AL and ALB group were (38.00±9.57) and (6.54±1.49), the difference was statistically signiifcant (P<0.01) on day 14 after LLC infusion. Meanwhile, the percentage of Gr-1+CD11b+ cells in ALB group signiifcantly decreased as compared with AL1 group. This study also demonstrated that BMSCs inhibited the induction and proliferation of MDSCs from myeloid cells in vitro.Conclusion:Surgery stress induces MDSCs and promotes tumor metastasis. Syngeneic BMSCs could inhibit the generation of MDSCs and further suppress tumor metastasis after surgery.

Objetive To investigate a method of collecting lung cancer cells with bronchofibroscopic biopsy for primary culture and to improve the success rate of primary culture. Methods Thirty lung cancer specimens were obtained through bronchoscopic biopsy for primary culture. The correlation of cancer morphology under bronchofi-broscopy and success rate of primary culture was analyzed. Results Among the lung cancer specimens obtained through bronchoscopic biopsy, primary culture was successful in 17 of 30 cases (56.67%) . The success rate of cauliflower-like tumor mass under bronchofibroscopy was 84.62% (11/13) . The success rate of infiltrating tumor mass under bronchial mucosa with luminal stenosis with or without cristate were 66.67% (2/3) and 37.5%(3/8), respectively. The primary culture of a globular and stiff tumor mass was successful only 1 in 6 cases (16.67%) .Conclusions The primary culture of lung cancer cells obtained from bronchofibroscopic biopsy is simple and effective with a total success rate of 56.67%. Furthermore, the success rate of primary culture is signifi-cantly correlated with the cancer morphology under bronchofibroscopy.

Objective To establish a method of cultivation of dendritic cells (DC) from mouse bone marrow in vitro and identify their phenotype and function. Methods Under aseptic condition, bone marrow cells were extracted from the tibia and femur bones of BALB/c mice. Bone marrow cells were cultured with recombinant mouse granulocyte-macrophage colony-stimulating factor ( rmGM-CSF) in vitro. The expansion and morphological changes of DC were observed with light inverted microscope. Phenotype was identified with flow cytometry and biological function was studied with antigen phagocytosis test. Results A large number of immature and mature DC with typical dendritic morphological characteristics could be generated from murine bone marrow. Immature DC, which had high expression in CD11c and low expression in CD40, MHC-II and CD86, could phagocytize antigen. Mature DC, which could be induced from immature DC by lipopolysaccharides, had high expression in CD11c, CD40, CD86 and MHC-II molecules. Conclusion Immature and mature DC can be generated from mouse bone marrow cells through cytokine induction in vitro and be used for further study associated with DC.