AMP-activated protein kinase α2 protects against liver injury from metastasized tumors via reduced glucose deprivation-induced oxidative stress.

It is well known that tumors damage affected tissues; however, the specific mechanism underlying such damage remains elusive. AMP-activated protein kinase (AMPK) senses energetic changes and regulates glucose metabolism. In this study, we examined the mechanisms by which AMPK promotes metabolic adaptation in the tumor-bearing liver using a murine model of colon cancer liver metastasis. Knock-out of AMPK α2 significantly enhanced tumor-induced glucose deprivation in the liver and increased the extent of liver injury and hepatocyte death. Mechanistically, we observed that AMPK α2 deficiency resulted in elevated reactive oxygen species, reduced mitophagy, and increased cell death in response to tumors or glucose deprivation in vitro. These results imply that AMPK α2 is essential for attenuation of liver injury during tumor metastasis via hepatic glucose deprivation and mitophagy-mediated inhibition of reactive oxygen species production. Therefore, AMPK α2 might represent an important therapeutic target for colon cancer metastasis-induced liver injury.

[Study on inhibitory effect of combined administration of bear bile powder and cyclophosphamide on colorectal cancer liver metastasis by regulating tumor microenvironment].

OBJECTIVE: To explore the inhibitory effect of combined administration of bear bile powder (BBP) and cyclophosphamide (Cytoxan, CTX) on colorectal cancer liver metastasis by regulating tumor promotion inflammation microenvironment. METHOD: The CRC liver metastasis mode in mice was established through in situ spleenic injection of SL4 tumor cells into spleens. The mice were randomly divided into 5 groups: the model group, the CTX (80 mg x kg(-1)) treatment group, the CTX + BBP high dose (300 mg x kg(-1)) group, the CTX + BBP middle dose (150 mg x kg(-1)) group and the CTX + BBP low dose (75 mg x kg(-1)) group. Mice were orally administered with drugs for 12 days, and sacrificed on the 13'h day for weighing their spleens and lives, HE staining, and immunofluorescence analysis. Their peripheral blood, and metastatic tumor in spleens and lives were analyzed with flow cytometry. RESULT: Spleen and liver weights of the: CTX treatment group and other doses groups were significantly lower than that of the model group. HE staining and immunofluorescence analysis showed that lymphocyte infiltration was detected in normal tissues, and macrophages infiltration was observed around the tumor tissues. Flow cytometry analysis showed that the number of T-lymphocytes in peripheral blood of different doses groups were much higher than that of the CTX treatment group (P < 0.05), with the rise in the ratio of CD4/CD8; the total number of lymphocytes in spleen cell suspension increased in different doses groups, compared to the CTX treatment group, with notable increase in B cells (P < 0.05) and significant decrease in CD11b, F4/80 cells (P < 0.05). The combined treatment showed less monocyte macrophages in liver metastasis than that of the CTX treatment group. CONCLUSION: The combined treatment of bear bile powder and cyclophosphamide has the effect in not only protecting liver and increase immunity, but also in anti-inflammation and antitumor by regulating tumor microenvironment and reducing the collection of mononuclear macrophages. Particularly, the combined administration of low dose of bear bile powder and CTX shows the most significant effect in reducing inflammatory cell infiltration.

[Comparative study of whole blood lysis reagents for analysis of immunocytes in peripheral blood of mice by flow cytometry].

This study was purposed to investigate the efficacy of different whole flow lysis reagents for lysis of red blood cells in flow cytometric analysis. The expression of immunocytes was detected by flow cytometry after lysis of red blood cells using commercial reagents (Optilyse C, FACS Lysing Solution) and self-made red blood cell lysis reagents (RBC Lysis Buffer), the detection results were analyzed comparatively. The results showed that there was no significant difference in the percentage of CD3e(+), CD3e(+)CD4(+), CD3e(+)CD8a(+), CD3e(-)CD19(+), CD3e(-)NK1.1(+) and Gr-1(+) cells between 3 different lysis reagent groups. However OptiLyse C solution was suitable to Gr-1(+) cell detection, but did not suit to Foxp3(+) Treg detection. The self-made RBC Lysis Buffer and FACS Lysing Solution were suited to Foxp3(+) Treg detection. It is concluded that the use of self-made RBC Lysis Buffer for flow cytometry can get the lysis efficiency of commercially available lysis solutions when samples are prepared in accordance with standardized procedure. The self-made RBC Lysis Buffer not only can satisfy experimental requirements, but also can reduce the experimental costs.