Activation of the Ubiquitin Proteasome Pathway in a Mouse Model of Inflammatory Myopathy: A Potential Therapeutic Target

Abstract BackgroundKRAS mutation is one of the dominant gene mutations in colorectal cancer (CRC). Up to present, targeting KRAS for CRC treatment remains a clinical challenge. WNT974 (LGK974) is a porcupine inhibitor that interferes Wnt signaling pathway. Artesunate (ART) is a water-soluble semi-synthetic derivative of artemisinin.MethodsThe synergistic effect of ART and WNT974 combination in reducing CRC cell viability was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RT-PCR was utilized for the mRNA levels of KRAS, CUL7, ANAPC2, UBE2M, RNF123, SYVN1, or β-TrCP. Western blot assay was utilized for the protein levels of KRAS, ANAPC2, β-TrCP, or GSK-3β. Xenograft mouse model assay was performed for the anti-CRC effect of combination of ART and WNT974 in vivo. IHC assay was utilized for the levels of KRAS, β-TrCP, or GSK-3β in tumor tissues. Results Our study shows that the combination of WNT974 and ART exhibits synergistic effect in reducing CRC growth. The combination treatment significantly reduces KRAS protein level and activity in CRC cells. Interestingly, the combination treatment increases E3 ligases ANAPC2 expression. Our data show that overexpression of ANAPC2 significantly reduces KRAS protein levels, which is reversed by MG132. Knockdown of ANAPC2 in CRC abolishes the combination treatment-reduce KRAS expression. Besides, the treatment also increases the expressions of GSK-3β and E3 ligase β-TrCP that is known to degrade GSK-3β-phosphorylated KRAS protein. Knockdown of β-TrCP- and inhibition of GSK-3β abolish the combination treatment-induce KRAS ubiquitination and reduction in expression.ConclusionsOur data clearly show that the combination treatment significantly enhances KRAS protein degradation via the ubiquitination ubiquitin–proteasome pathway, which is also demonstrated in xenograft mouse model. The study provides strong scientific evidence for the development of the combination of WNT974 and ART as KRAS-targeting therapeutics for CRC treatment.

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The Molecular Basis of Ubiquitin-Conjugating Enzymes (E2s) as a Potential Target for Cancer Therapy

International Journal of Molecular Sciences ◽

10.3390/ijms22073440 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3440

Author(s):

Xiaodi Du ◽

Hongyu Song ◽

Nengxing Shen ◽

Ruiqi Hua ◽

Guangyou Yang

Keyword(s):

Therapeutic Target ◽

Molecular Basis ◽

Biological Processes ◽

Ubiquitin Proteasome Pathway ◽

Ubiquitin Proteasome ◽

Proteasome Pathway ◽

Conjugating Enzymes ◽

The Stability ◽

Ubiquitin Conjugating Enzymes ◽

Effective Drugs

Ubiquitin-conjugating enzymes (E2s) are one of the three enzymes required by the ubiquitin-proteasome pathway to connect activated ubiquitin to target proteins via ubiquitin ligases. E2s determine the connection type of the ubiquitin chains, and different types of ubiquitin chains regulate the stability and activity of substrate proteins. Thus, E2s participate in the regulation of a variety of biological processes. In recent years, the importance of E2s in human health and diseases has been particularly emphasized. Studies have shown that E2s are dysregulated in variety of cancers, thus it might be a potential therapeutic target. However, the molecular basis of E2s as a therapeutic target has not been described systematically. We reviewed this issue from the perspective of the special position and role of E2s in the ubiquitin-proteasome pathway, the structure of E2s and biological processes they are involved in. In addition, the inhibitors and microRNAs targeting E2s are also summarized. This article not only provides a direction for the development of effective drugs but also lays a foundation for further study on this enzyme in the future.

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Role of Ubiquitin-Conjugating Enzyme UBE2C in Gastrointestinal Cancers

Proceedings of Anticancer Research ◽

10.26689/par.v5i5.2548 ◽

2021 ◽

Vol 5 (5) ◽

pp. 64-72

Author(s):

Ce Guo ◽

Xing Guo ◽

Zhen Wei ◽

Qian Wang ◽

Huiqing Zhang

Keyword(s):

Prognostic Marker ◽

Therapeutic Target ◽

Potential Role ◽

Gastrointestinal Cancers ◽

Ubiquitin Proteasome Pathway ◽

Ubiquitin Conjugating Enzyme ◽

Ubiquitin Proteasome ◽

Proteasome Pathway ◽

Conjugating Enzyme

Ubiquitin-conjugating enzyme UBE2C is one of the important members of ubiquitin-proteasome pathway (UPP). Amplification and/or overexpression of UBE2C have been reported in many malignancies, and a high expression of UBE2C is associated with poor clinical outcomes. In this review, the pathological role of dysregulated UBE2C in gastrointestinal cancers and its potential role as a diagnostic and/or a prognostic marker as well as a therapeutic target in these cancers are discussed.

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Combination of Artesunate and WNT974 Induces KRAS Protein Degradation by Upregulating E3 Ligase ANACP2 and β-TrCP in the Ubiquitin–proteasome Pathway

10.21203/rs.3.rs-744967/v1 ◽

2021 ◽

Author(s):

Rui-Hong Gong ◽

Minting Chen ◽

Chunhua Huang ◽

Hoi Leong Xavier Wong ◽

Hiu Yee Kwan ◽

...

Keyword(s):

Mouse Model ◽

Synergistic Effect ◽

Protein Degradation ◽

Combination Treatment ◽

Ubiquitin Proteasome Pathway ◽

Protein Levels ◽

Ubiquitin Proteasome ◽

Proteasome Pathway ◽

Kras Protein ◽

Gsk 3Β

Abstract BackgroundKRAS mutation is one of the dominant gene mutations in colorectal cancer (CRC). Up to present, targeting KRAS for CRC treatment remains a clinical challenge. WNT974 (LGK974) is a porcupine inhibitor that interferes Wnt signaling pathway. Artesunate (ART) is a water-soluble semi-synthetic derivative of artemisinin.MethodsThe synergistic effect of ART and WNT974 combination in reducing CRC cell viability was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RT-PCR was utilized for the mRNA levels of KRAS, CUL7, ANAPC2, UBE2M, RNF123, SYVN1, or β-TrCP. Western blot assay was utilized for the protein levels of KRAS, ANAPC2, β-TrCP, or GSK-3β. Xenograft mouse model assay was performed for the anti-CRC effect of combination of ART and WNT974 in vivo. IHC assay was utilized for the levels of KRAS, β-TrCP, or GSK-3β in tumor tissues.Results Our study shows that the combination of WNT974 and ART exhibits synergistic effect in reducing CRC growth. The combination treatment significantly reduces KRAS protein level and activity in CRC cells. Interestingly, the combination treatment increases E3 ligases ANAPC2 expression. Our data show that overexpression of ANAPC2 significantly reduces KRAS protein levels, which is reversed by MG132. Knockdown of ANAPC2 in CRC abolishes the combination treatment-reduce KRAS expression. Besides, the treatment also increases the expressions of GSK-3β and E3 ligase β-TrCP that is known to degrade GSK-3β-phosphorylated KRAS protein. Knockdown of β-TrCP- and inhibition of GSK-3β abolish the combination treatment-induce KRAS ubiquitination and reduction in expression.ConclusionsOur data clearly show that the combination treatment significantly enhances KRAS protein degradation via the ubiquitination ubiquitin–proteasome pathway, which is also demonstrated in xenograft mouse model. The study provides strong scientific evidence for the development of the combination of WNT974 and ART as KRAS-targeting therapeutics for CRC treatment.

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