Background Patients diagnosed with gallbladder carcinoma (GBC) accompanied by hepatic metastasis exhibit unfavorable prognoses generally. Mitochondrial dysfunction promotes cellular transformation and cancer cell survival implicating its importance in cancer development. Previous studies have indicated that dynamin 1 like (DNM1L) is a key mediator of mitochondrial fission. However, whether DNM1L regulates mitochondrial homeostasis in GBC remains unknown. Methods The morphological changes of mitochondria were investigated by transmission electron microscopy and mitoTracker red staining. Co-immunoprecipitation assay was performed to detect the interaction of ubiquitin-specific protease-3 (USP3) and DNM1L. The cell-derived xenograft and liver metastasis tumor models were established to validate the function of DNM1L in vivo . The metabolomics data from transcriptomics/metabolomics were analyzed to identify the differentially expressed genes/metabolites of DNM1L in GBC. Results DNM1L exhibited a marked upregulation in clinical GBC tissues compared to the adjacent tissues, and it promoted proliferation, invasiveness, and migration capability of GBC cells by inducing mitochondrial dysfunction. Mice subcutaneously injected with DNM1L overexpression cells exhibited elevated intrahepatic metastatic nodules within their livers. USP3, a deubiquitinating enzyme, was demonstrated to directly interact with DNM1L and it specifically cleaved the K48-linked polyubiquitin chains to deubiquitinate and stabilize DNM1L. By integrating two omics, we found several altered pathways and speculated that DNM1L disturbed DNA synthesis and glycine, serine, threonine, and pyrimidine metabolism pathways. Conclusion Our findings suggest that DNM1L is a promising clinical target for GBC treatment and that focusing on DNM1L may provide new insights into GBC strategy.
Ruo-Peng Liang,Xiao-Xue Zhang,Jie Zhao,Rong-Tao Zhu,Wei-Jie Wang,Qin-Wei Lu,Yu-Ling Sun
Ubiquitin-specific protease 3 (USP3), a kind of cysteine protease, is a crucial family member of deubiquitinating enzymes. USP3 is aberrantly expressed in several tumors, which may contribute to cancer progression. However, the role of USP3 in gallbladder cancer (GBC) is still unknown. In the current study, we detected the expression of USP3 in GBC tissues, measured its contribution to the cell proliferation in GBC progression, and further studied the underlying mechanism of USP3 in GBC through pyruvate kinase L/R (PKLR; a kind of glycolytic enzyme). We found that the expression of USP3 in GBC tissues were higher than that of adjacent tissues, and the protein levels of USP3 and PKLR were positively correlated. Additionally, overexpressed USP3 significantly promoted cell proliferation in vitro and tumor growth in vivo, while the silencing of USP3 inhibited proliferation and tumor growth. Glycolysis in GBC cells ws promoted by the USP3 overexpression and inhibited bye USP3 downregulation. Moreover, the loss of USP3 promoted the ubiquitination and weakened the stability of PKLR. Results of the rescue assay confirmed that PKLR knockdown suppressed USP3-induced oncogenic activity in USP3 overexpressed GBC cells. These findings imply that USP3 is an essential positive regulator in GBC progression, and USP3-PKLR plays a vital role in the progression and metabolism of GBC. Ubiquitin-specific protease 3 (USP3), a cysteine protease, is deubiquitinating enzyme. USP3 is aberrantly expressed in several types of tumors. The authors show that USP3 is an important positive regulator in gallbladder cancer progression, and that pyruvate kinase L/R plays a key role in the progression of GBC.