The novel low molecular weight MYC antagonist MYCMI-6 inhibits proliferation and induces apoptosis in breast cancer cells.

Abstract

Background The MYC oncogene is one of the most frequently altered driver genes in cancer. MYC is thus a potential target for cancer treatment as well as a biomarker for the disease. However, as a target for treatment, MYC has traditionally been regarded as "undruggable" or difficult to target. We set out to evaluate the efficacy of a novel MYC inhibitor known as MYCMI-6, which acts by preventing MYC from interacting with its cognate partner MAX. Methods MYCMI-6 response was assessed in a panel of breast cancer cell lines using MTT assays and flow cytometry. MYC gene amplification, mRNA and protein expression was analysed using the TCGA and METABRIC databases. Results MYCMI-6 inhibited cell growth in breast cancer cell lines with IC50 values varying form 0.3 μM to >10 μM. Consistent with its ability to decrease cell growth, MYCMI-6 was found to induce apoptosis in two cell lines in which growth was inhibited but not in two cell lines that were resistant to growth inhibition. Across all breast cancers, MYC was found to be amplified in 15.3% of cases in the TCGA database and 26% in the METABRIC database. Following classification of the breast cancers by their molecular subtypes, MYC was most frequently amplified and exhibited highest expression at both mRNA and protein level in the basal subtype. Conclusions Based on these findings, we conclude that for patients with breast cancer, anti-MYC therapy is likely to be most efficacious in patients with the basal subtype.

• Authors: Dalal AlSultan, Emma Kavanagh, Shane O'Grady, Alex J Eustace, Alina Castell, Lars-Gunnar Larsson, John Crown, Stephen F Madden, Michael J Duffy
• Journal: Investigational new drugs (Invest New Drugs) Vol. 39 Issue 2 Pg. 587-594 (04 2021) ISSN: 1573-0646 [Electronic] United States
• PMID: 33052557 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Acridines
• Antineoplastic Agents
• Biomarkers, Tumor
• MYCMI-6
• Pyridines
• RNA, Messenger

Topics

• Acridines (pharmacology)
• Antineoplastic Agents (pharmacology)
• Apoptosis (drug effects)
• Biomarkers, Tumor
• Breast Neoplasms (pathology)
• Cell Cycle
• Cell Line, Tumor
• Cell Proliferation (drug effects)
• Dose-Response Relationship, Drug
• Gene Expression Regulation, Neoplastic
• Genes, myc (drug effects)
• Humans
• Inhibitory Concentration 50
• Molecular Weight
• Pyridines (pharmacology)
• RNA, Messenger