Back to Search
Start Over
RAD6B Loss Disrupts Expression of Melanoma Phenotype in Part by Inhibiting WNT/β-Catenin Signaling
- Source :
- Am J Pathol
- Publication Year :
- 2021
- Publisher :
- Elsevier BV, 2021.
-
Abstract
- Canonical Wnt signaling is critical for melanocyte lineage commitment and melanoma development. RAD6B, a ubiquitin-conjugating enzyme critical for translesion DNA synthesis, potentiates β-catenin stability/activity by inducing proteasome-insensitive polyubiquitination. RAD6B expression is induced by β-catenin, triggering a positive feedback loop between the two proteins. RAD6B function in melanoma development/progression was investigated by targeting RAD6B using CrispR/Cas9 or an RAD6-selective small-molecule inhibitor #9 (SMI#9). SMI#9 treatment inhibited melanoma cell proliferation but not normal melanocytes. RAD6B knockout or inhibition in metastatic melanoma cells downregulated β-catenin, β-catenin–regulated microphthalmia-associated transcription factor (MITF), sex-determining region Y-box 10, vimentin proteins, and MITF-regulated melan A. RAD6B knockout or inhibition decreased migration/invasion, tumor growth, and lung metastasis. RNA-sequencing and stem cell pathway real-time RT-PCR analysis revealed profound reductions in WNT1 expressions in RAD6B knockout M14 cells compared with control. Expression levels of β-catenin–regulated genes VIM, MITF-M, melan A, and TYRP1 (a tyrosinase family member critical for melanin biosynthesis) were reduced in RAD6B knockout cells. Pathway analysis identified gene networks regulating stem cell pluripotency, Wnt signaling, melanocyte development, pigmentation signaling, and protein ubiquitination, besides DNA damage response signaling, as being impacted by RAD6B gene disruption. These data reveal an important and early role for RAD6B in melanoma development besides its bonafide translesion DNA synthesis function, and suggest that targeting RAD6B may provide a novel strategy to treat melanomas with dysregulated canonical Wnt signaling.
- Subjects :
- 0301 basic medicine
Mice, Nude
Melanocyte
Biology
Cell Line
Pathology and Forensic Medicine
Mice
03 medical and health sciences
0302 clinical medicine
medicine
Animals
Humans
Melanoma
Wnt Signaling Pathway
Transcription factor
Cell growth
Wnt signaling pathway
Regular Article
medicine.disease
Microphthalmia-associated transcription factor
Protein ubiquitination
Cell biology
Gene Expression Regulation, Neoplastic
Phenotype
030104 developmental biology
medicine.anatomical_structure
030220 oncology & carcinogenesis
Ubiquitin-Conjugating Enzymes
Heterografts
Stem cell
Subjects
Details
- ISSN :
- 00029440
- Volume :
- 191
- Database :
- OpenAIRE
- Journal :
- The American Journal of Pathology
- Accession number :
- edsair.doi.dedup.....b74acf8c707383654a32781417bf8f4c