UBE2C-induced crosstalk between mono- and polyubiquitination of SNAT2 promotes lymphatic metastasis in bladder cancer
Wenjie Li, Changhao Chen, Hanhao Zheng, Yan Lin, Mingjie An, Daiyin Liu, Yonghai Zhang, Mingchao Gao, Tianhang Lan, Wang He
Wenjie Li, Changhao Chen, Hanhao Zheng, Yan Lin, Mingjie An, Daiyin Liu, Yonghai Zhang, Mingchao Gao, Tianhang Lan, Wang He
View: Text | PDF
Research Article Cell biology Oncology

UBE2C-induced crosstalk between mono- and polyubiquitination of SNAT2 promotes lymphatic metastasis in bladder cancer

Abstract

Ubiquitination plays an essential role in protein stability, subcellular localization, and interactions. Crosstalk between different types of ubiquitination results in distinct biological outcomes for proteins. However, the role of ubiquitination-related crosstalk in lymph node (LN) metastasis and the key regulatory factors controlling this process have not been determined. Using high-throughput sequencing, we found that ubiquitin-conjugating enzyme E2 C (UBE2C) was overexpressed in bladder cancer (BCa) and was strongly associated with an unfavorable prognosis. Overexpression of UBE2C increased BCa lymphangiogenesis and promoted LN metastasis both in vitro and in vivo. Mechanistically, UBE2C mediated sodium-coupled neutral amino acid transporter 2 (SNAT2) monoubiquitination at lysine 59 to inhibit K63-linked polyubiquitination at lysine 33 of SNAT2. Crosstalk between monoubiquitination and K63-linked polyubiquitination increased SNAT2 membrane protein levels by suppressing epsin 1–mediated (EPN1-mediated) endocytosis. SNAT2 facilitated glutamine uptake and metabolism to promote VEGFC secretion, ultimately leading to lymphangiogenesis and LN metastasis in patients with BCa. Importantly, inhibition of UBE2C significantly attenuated BCa lymphangiogenesis in a patient-derived xenograft model. Our results reveal the mechanism by which UBE2C mediates crosstalk between the monoubiquitination and K63-linked polyubiquitination of SNAT2 to promote BCa metastasis and identify UBE2C as a promising target for treating LN-metastatic BCa.

Authors

Wenjie Li, Changhao Chen, Hanhao Zheng, Yan Lin, Mingjie An, Daiyin Liu, Yonghai Zhang, Mingchao Gao, Tianhang Lan, Wang He

×

Figure 6

Inhibition of glutamine metabolism or VEGFC secretion suppresses lymphangiogenesis and LN metastasis.

Options: View larger image (or click on image) Download as PowerPoint
Inhibition of glutamine metabolism or VEGFC secretion suppresses lymphan...
(A) Representative images and quantification of tube formation and migration of HLECs treated with culture media from UBE2C-overexpressing UM-UC-3 cells with or without CB-839 and anti-VEGFC (αVEGFC) treatment. Scale bars: 100 μm. (B) Representative fluorescence images of popliteal LNs from mice treated with or without CB-839 or anti-VEGFC (n = 12). Scale bars: 100 μm. (C and D) Quantification of affected popliteal LNs from the mice treated with or without CB-839 and anti-VEGFC (n = 12). (E–G) Representative IHC images and quantification of VEGFC expression and LYVE1-indicated MLD in primary footpad tumor tissues from the mice treated with or without CB-839 and anti-VEGFC (n = 12). Scale bars: 50 μm. Original magnification, ×2 (enlarged insets). Significant differences were identified through 1-way ANOVA followed by Dunnett’s test (A, C, D, F, and G). The quantitative results are presented as the mean ± SEM of 3 separate experiments.