Stroma-Mediated Resistance to S63845 and Venetoclax through MCL-1 and BCL-2 Expression Changes Induced by miR-193b-3p and miR-21-5p Dysregulation in Multiple Myeloma

Cells. 2021 Mar 4;10(3):559. doi: 10.3390/cells10030559.

Abstract

BH3-mimetics targeting anti-apoptotic proteins such as MCL-1 (S63845) or BCL-2 (venetoclax) are currently being evaluated as effective therapies for the treatment of multiple myeloma (MM). Interleukin 6, produced by mesenchymal stromal cells (MSCs), has been shown to modify the expression of anti-apoptotic proteins and their interaction with the pro-apoptotic BIM protein in MM cells. In this study, we assess the efficacy of S63845 and venetoclax in MM cells in direct co-culture with MSCs derived from MM patients (pMSCs) to identify additional mechanisms involved in the stroma-induced resistance to these agents. MicroRNAs miR-193b-3p and miR-21-5p emerged among the top deregulated miRNAs in myeloma cells when directly co-cultured with pMSCs, and we show their contribution to changes in MCL-1 and BCL-2 protein expression and in the activity of S63845 and venetoclax. Additionally, direct contact with pMSCs under S63845 and/or venetoclax treatment modifies myeloma cell dependence on different BCL-2 family anti-apoptotic proteins in relation to BIM, making myeloma cells more dependent on the non-targeted anti-apoptotic protein or BCL-XL. Finally, we show a potent effect of the combination of S63845 and venetoclax even in the presence of pMSCs, which supports this combinatorial approach for the treatment of MM.

Keywords: BH3-mimetics; anti-apoptotic proteins; mesenchymal stromal cells; miR-193; miR-21; multiple myeloma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents / therapeutic use*
  • Bridged Bicyclo Compounds, Heterocyclic / pharmacology
  • Bridged Bicyclo Compounds, Heterocyclic / therapeutic use*
  • Drug Resistance, Neoplasm / drug effects
  • Humans
  • Multiple Myeloma / drug therapy*
  • Multiple Myeloma / pathology
  • Proto-Oncogene Proteins c-bcl-2 / metabolism*
  • Pyrimidines / pharmacology
  • Pyrimidines / therapeutic use*
  • Sulfonamides / pharmacology
  • Sulfonamides / therapeutic use*
  • Thiophenes / pharmacology
  • Thiophenes / therapeutic use*

Substances

  • Antineoplastic Agents
  • BCL2 protein, human
  • Bridged Bicyclo Compounds, Heterocyclic
  • Proto-Oncogene Proteins c-bcl-2
  • Pyrimidines
  • S63845
  • Sulfonamides
  • Thiophenes
  • venetoclax