Constitutive BAK/MCL1 complexes predict paclitaxel and S63845 sensitivity of ovarian cancer

Cell Death Dis. 2021 Aug 12;12(8):789. doi: 10.1038/s41419-021-04073-0.

Abstract

We previously found that preformed complexes of BAK with antiapoptotic BCL2 proteins predict BH3 mimetic sensitivities in lymphohematopoietic cells. These complexes have not previously been examined in solid tumors or in the context of conventional anticancer drugs. Here we show the relative amount of BAK found in preformed complexes with MCL1 or BCLXL varies across ovarian cancer cell lines and patient-derived xenografts (PDXs). Cells bearing BAK/MCL1 complexes were more sensitive to paclitaxel and the MCL1 antagonist S63845. Likewise, PDX models with BAK/MCL1 complexes were more likely to respond to paclitaxel. Mechanistically, BIM induced by low paclitaxel concentrations interacted preferentially with MCL1 and displaced MCL1-bound BAK. Further studies indicated that cells with preformed BAK/MCL1 complexes were sensitive to the paclitaxel/S63845 combination, while cells without BAK/MCL1 complexes were not. Our study suggested that the assessment of BAK/MCL1 complexes might be useful for predicting response to paclitaxel alone or in combination with BH3 mimetics.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bcl-2-Like Protein 11 / metabolism
  • Cell Line, Tumor
  • Drug Synergism
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Myeloid Cell Leukemia Sequence 1 Protein / metabolism*
  • Ovarian Neoplasms / genetics
  • Ovarian Neoplasms / pathology*
  • Paclitaxel / pharmacology*
  • Protein Binding / drug effects
  • Pyrimidines / pharmacology*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Thiophenes / pharmacology*
  • Xenograft Model Antitumor Assays
  • bcl-2 Homologous Antagonist-Killer Protein / metabolism*

Substances

  • Bcl-2-Like Protein 11
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Pyrimidines
  • RNA, Messenger
  • S63845
  • Thiophenes
  • bcl-2 Homologous Antagonist-Killer Protein
  • Paclitaxel