Dataset Information

APOBEC3B enhances the efficacy of PARP inhibitors in elimination of ovarian cancer stem cell

ABSTRACT: Late detection and tumor recurrence are major factors driving the lethality of high-grade serous ovarian carcinoma (HGSOC). PARP inhibitors (PARPi) have achieved significant clinical efficacy by selectively targeting DNA repair deficiencies in HGSOC patients with BRCA mutations and homologous recombination deficiency (HRD). However, a subset of patients ultimately develops resistance to PARPi, necessitating alternative effective treatment options. The mutational signatures of APOBEC3 family of DNA deaminases are widespread across a broad array of cancer types. Here, we report that cancer stem cell (CSC)-like tumorspheres exhibit reduced A3B expression compared to non-CSC adherent counterparts. Importantly, inhibition of A3B leads to PARPi resistance, elevated frequency of CSCs, and enhanced expression of stemness factors. In addition, we found that high A3B-expressing cells are under strong replication stress and thus synchronize efficiently with PARPi. In this study we knocked down of A3B in A2780 3D tumorsphere by lentiviral tranduction, followed by treated of DMSO control or Olaparib, and performed bulk RNA-sequencing to compare gene expression changes (n=3 for each condition).

ORGANISM(S): Homo sapiens

PROVIDER: GSE309870 | GEO | 2025/11/18

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other
	GSE309870_TPM_all_Sample.txt.gz	Txt

Items per page:

1 - 2 of 2

Similar Datasets

Project description:BACKGROUND: Triple-negative breast cancer (TNBC) is insensitive to the most effective therapies for other breast cancers, including endocrine and Her2-directed therapies, thus the lack of specific treatments prompted us to search for new TNBC-associated molecules to be used as targets for cancer therapy. As patients with TNBC usually experience a quicker relapse and metastatic progression compared to other breast cancer subtypes, we hypothesized that cancer stem cells (CSC) could play a central role in TNBC. We thus directed our focus on genes differentially expressed between CSC and differentiated cancer cells of TNBC cell lines. RESULTS: We established tumorsphere cultures from mouse and human mammary cancer cell lines to enrich the CSC population. RNA-Seq was used to identify differences in gene expression between tumorspheres and their monolayer counterparts. Seventy-four transcripts were found up-regulated in the tumorspheres, while forty-two genes were down-regulated. Enrichment analysis of biological processes showed an up-regulation in genes involved in regulation of apoptosis in tumorspheres, and a down-regulation in genes involved in lipid metabolism and cell cycle regulation. By focusing on up-regulated genes coding for cell membrane-associated proteins, we selected Teneurin-4 (TENM4) as a candidate for further studies. Meta-analysis of publicly available datasets revealed that TENM4 mRNA is up-regulated in both lobular and ductal invasive carcinoma specimens compared to normal breast, and that high expression of TENM4 in TNBC patients shows a trend of correlation with a shorter relapse-free survival. 4T1 tumorspheres treated with a siRNA specific to TENM4 showed a decrease in TENM4 mRNA and protein levels, which was reflected by a significant impairment of tumorsphere-forming ability. TENM4 silencing also led to a decrease in Focal Adhesion Kinase (FAK) phosphorylation, which has been previously linked to CSC biology, thus strengthening the possible link between TENM4 and a CSC-like phenotype. CONCLUSIONS: Overall, our results indicate that the stem-like status of TNBC cells is accompanied by altered regulation of apoptosis, cell cycle and lipid metabolism pathways. Furthermore, we identified TENM4 as a potential novel player in CSC biology, and its potential role as a novel target to improve the outcome of TNBC patients in the future.

Dataset Information

APOBEC3B enhances the efficacy of PARP inhibitors in elimination of ovarian cancer stem cell

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets