Revealing the alternative promoter usage of SAF/MAZ gene by bichromatic fluorescent reporter construct

Comprehensive analysis of the tumor-promoting effect and immune infiltration correlation MAZ from pan-cancer to hepatocellular carcinoma

BACKGROUND

Myc-associated zinc-finger protein (MAZ) is a transcription factor, which has been confirmed to be abnormally expressed in many tumors and involved in regulating the proliferation, migration, apoptosis, and autophagy of tumor cells. Currently, there is a lack of comprehensive analysis of MAZ in pan-cancer, and the mechanism of MAZ in hepatocellular carcinoma (HCC) and its association with immunotherapy remains unclear.

METHODS

The expression, prognostic mutation, sCNA, and tumor immunity characteristics of MAZ in 33 types of tumors were analyzed by The Cancer Genome Atlas (TCGA), GEPIA, and TIMER databases. The association of MAZ expression levels with drug sensitivity, immunotherapy, immune checkpoints, and HLA-associated genes was further analyzed. Transwell, CCK-8, wound healing, and flow cytometry verified that MAZ affected the malignant cell behavior of HCC. The signaling pathways and cellular functions affected by MAZ in HCC were revealed by GSEA enrichment analysis.

RESULTS

The expression level of MAZ was up-regulated, and the high expression of MAZ indicated a high-risk prognostic factor in most tumors, including ACC, BLCA, KIRP, LIHC, PRAD, SKCM, and THCA (p < 0.05). MAZ expression was positively correlated with the sensitivity of most chemotherapy drugs (p < 0.05). HLA-DQB2, HLA-H, and most immune checkpoint genes were remarkably up-regulated in the high MAZ expression group (p < 0.05). GSEA analysis revealed that MAZ expression was highly correlated with the intracellular immune-related functions and cancer-related signaling pathway, including the B cell receptor signaling pathway, complement activation, humoral immune response, TGF-β signaling pathway, and Wnt signaling pathway. The overexpression of MAZ in HCC cells could promote the abilities of cell proliferation and migration and inhibit tumor cell apoptosis.

CONCLUSION

Our study revealed that MAZ might play a role in promoting the progression of HCC. It was closely related to the tumor microenvironment, immune cell infiltration, and immune escape in pan-cancer. Moreover, this study provides new insights into MAZ as a prognostic marker and potential therapeutic target in HCC.

MicroRNA-29b-3p Inhibits the Migration and Invasion of Gastric Cancer Cells by Regulating the Autophagy-Associated Protein MAZ

Purpose

The purpose of this study was to investigate the relationship between microRNA-29b-3p (miR-29b-3p) and myc-associated zinc finger protein (MAZ) expression and the effects of this interaction on the proliferation, migration, and invasion of gastric cancer cells.

Methods

qPCR and Western blots were used to detect the expression of miR-29b-3p and MAZ. The dual luciferase reporter gene system was used to explore whether MAZ is the target of miR-29b-3p. Cell function experiments and a mouse tumorigenesis model were used to determine the effects of miR-29b-3p overexpression and MAZ depletion on proliferation, migration, and invasion in gastric cancer cell lines and on tumor growth.

Results

The expression level of miR-29b-3p was low and the expression level of MAZ was high in gastric cancer cells compared with normal human gastric mucosal epithelial cells. MAZ was the target gene of miR-29b-3p. The upregulation of miR-29b-3p reduces the expression of MAZ. Overexpression of miR-29b-3p and downregulation of MAZ inhibited the proliferation and migration of cancer cells and induced apoptosis by controlling the expression of autophagy-related proteins. MiR-29b-3p mimics inhibit tumor growth in mice.

Conclusion

MiR-29b-3p inhibits the migration and invasion of gastric cancer cells by regulating the autophagy-related protein MAZ.