KDM4 Inhibition Targets Breast Cancer Stem-like Cells

Area of Science:

• Oncology
• Epigenetics
• Cancer Stem Cell Biology

Background:

• Traditional breast cancer treatments often fail against therapy-resistant cancer stem-like cells.
• Epigenetic regulators, like lysine demethylase KDM4, are altered in these resistant cells.

Purpose of the Study:

• To evaluate the preclinical efficacy of a novel, orally available KDM4 inhibitor, QC6352.
• To validate a new method for isolating and propagating breast cancer stem-like cells (BCSC) for drug screening.

Main Methods:

• Isolated and propagated BCSCs from patient-derived triple-negative breast tumors post-neoadjuvant chemotherapy.
• Utilized limiting-dilution orthotopic xenografts to assess BCSC regeneration and tumor formation.
• Administered QC6352 and evaluated its effects on BCSC proliferation, sphere formation, and xenograft growth.

Main Results:

• QC6352 effectively blocked BCSC proliferation, sphere formation, and xenograft tumor development.
• The inhibitor abrogated the expression of EGFR, a key driver in therapy-resistant triple-negative breast cancer.
• The established BCSC culture system successfully regenerated patient tumor characteristics.

Conclusions:

• KDM4 inhibition represents a promising therapeutic strategy for triple-negative breast cancer.
• QC6352 demonstrates significant preclinical antitumor activity against therapy-resistant BCSCs.
• The developed BCSC culture system serves as a valuable platform for preclinical drug discovery in breast cancer.