SFMBT1 facilitates colon cancer cell metastasis and drug resistance combined with HMG20A.

In colorectal cancer (CRC), the development of reagents that increase sensitivity to chemotherapeutic agents could prevent drug resistance and improve patient survival. Scm-like with four malignant brain tumor domains 1 (SFMBT1) is up-regulated in CRC tumor tissues and cells and may be associated with drug resistance. We detected the expression of SFMBT1 in CRC tissue microarrays by immunohistochemistry. The role of SFMBT1 in the migration, proliferation and invasion of CRC or resistance to 5-fluorouracil (5-FU) was determined using scratch assay, colony formation and Transwell assay. Fluorescence co-localization and immunoprecipitation were used to analyze the correlation between SFMBT1 and high mobility group domain-containing protein 20 A (HMG20A). Xenograft experiments were conducted to investigate the role of SFMBT1 and HMG20A in tumor growth and metastasis in vivo. We found that SFMBT1 is up-regulated in CRC and its expression is further amplified in 5-FU resistance. SFMBT1 drives 5-FU resistance and CRC proliferation, migration and invasion. Correlation analysis shows that SFMBT1 and HMG20A are positively correlated. Mechanistically, fluorescence co-localization and immunoprecipitation assay indicate an interaction between SFMBT1 and HMG20A. Depletion of SFMBT1 down-regulates HMG20A downstream. These results were verified by murine xenograft and lung metastasis models. Our results indicate that the SFMBT1/HMG20A axis could be targeted to increase the resistance of CRC cells to 5-FU.