Similar Datasets
Project description:The mitotic inhibitor docetaxel (DTX) is often used to treat endocrine-refractory metastatic breast cancer, but initial responses are mitigated as patients eventually have disease progression. Using a cohort of ex vivo cultures of circulating tumor cells (CTCs) from patients with heavily pretreated breast cancer (n=18), we find two distinct patterns of DTX susceptibility, independent of clinical treatment history. In CTCs cultured from some patients, treatment with a single dose of DTX results in complete cell killing, associated with accumulation of non-viable polyploid (≥8N) cells arising from endomitosis. In others, a transient viable drug-tolerant persister (DTP) population emerges, ultimately enabling renewed proliferation of CTCs with preserved parental cell ploidy and DTX sensitivity. In these CTC cultures, efficient cell cycle exit generates a ≤4N drug-tolerant state dependent on CDKN1B (p27Kip1). Exposure to DTX triggers stabilization of CDKN1B through AKT-mediated phosphorylation at serine 10. Suppression of CDKN1B reduces the number of persister CTCs, increases ≥8N mitotic cells and abrogates regrowth after DTX exposure. Thus, CDKN1B-mediated suppression of endomitosis contributes to a reversible persister state following mitotic inhibitors in patient-derived treatment refractory breast cancer cells.
2025-06-14 | GSE261194 | GEO
Project description:The mitotic inhibitor docetaxel (DTX) is often used to treat endocrine-refractory metastatic breast cancer, but initial responses are mitigated as patients eventually have disease progression. Using a cohort of ex vivo cultures of circulating tumor cells (CTCs) from patients with heavily pretreated breast cancer (n=18), we find two distinct patterns of DTX susceptibility, independent of clinical treatment history. In CTCs cultured from some patients, treatment with a single dose of DTX results in complete cell killing, associated with accumulation of non-viable polyploid (≥8N) cells arising from endomitosis. In others, a transient viable drug-tolerant persister (DTP) population emerges, ultimately enabling renewed proliferation of CTCs with preserved parental cell ploidy and DTX sensitivity. In these CTC cultures, efficient cell cycle exit generates a ≤4N drug-tolerant state dependent on CDKN1B (p27Kip1). Exposure to DTX triggers stabilization of CDKN1B through AKT-mediated phosphorylation at serine 10. Suppression of CDKN1B reduces the number of persister CTCs, increases ≥8N mitotic cells and abrogates regrowth after DTX exposure. Thus, CDKN1B-mediated suppression of endomitosis contributes to a reversible persister state following mitotic inhibitors in patient-derived treatment refractory breast cancer cells.
2025-06-14 | GSE261193 | GEO
Project description:The mitotic inhibitor docetaxel (DTX) is often used to treat endocrine-refractory metastatic breast cancer, but initial responses are mitigated as patients eventually have disease progression. Using a cohort of ex vivo cultures of circulating tumor cells (CTCs) from patients with heavily pretreated breast cancer (n=18), we find two distinct patterns of DTX susceptibility, independent of clinical treatment history. In CTCs cultured from some patients, treatment with a single dose of DTX results in complete cell killing, associated with accumulation of non-viable polyploid (≥8N) cells arising from endomitosis. In others, a transient viable drug-tolerant persister (DTP) population emerges, ultimately enabling renewed proliferation of CTCs with preserved parental cell ploidy and DTX sensitivity. In these CTC cultures, efficient cell cycle exit generates a ≤4N drug-tolerant state dependent on CDKN1B (p27Kip1). Exposure to DTX triggers stabilization of CDKN1B through AKT-mediated phosphorylation at serine 10. Suppression of CDKN1B reduces the number of persister CTCs, increases ≥8N mitotic cells and abrogates regrowth after DTX exposure. Thus, CDKN1B-mediated suppression of endomitosis contributes to a reversible persister state following mitotic inhibitors in patient-derived treatment refractory breast cancer cells.
2025-06-14 | GSE261192 | GEO
Project description:BRx82 and BRx142 were cell cultures derived from breast cancer circulating tumor cells and propagated ex-vivo. To study early changes that transpire under mitosis inhibiting chemotherapy, these cultures were subjected to a 16 hours exposure to docetaxel (10nM or DMSO as vehicle control) and then cultured for a total of 4 days.
The experiments were done using an Orbitrap Fusion (proteomics) or an Orbitrap Fusion Lumos (phosphoproteomics) mass spectrometer. Multiplexing was achieved using either TMT10 reagents and the SPS-MS3 method. Basic pH reversed-phase chromatography (bRPLC) was used for off-line pre-fractionation; 12 fractions were analyzed for proteome mappings (PMID: 26700037) and 24 fractions sample for phosphoproteome mappings (PMID: 31606085). Phosphoproteome mappings were done using both HCD fragmentation with Orbitrap fragment ion detection and CID fragmentation with ion trap fragment ion detection (PMID: 29487189, PMID: 31606085).
RAW files from the proteome mapping experiment are named HorwitzMaheswaranHaber_proteome_fraction01 to 12.
RAW files from the phosphoproteome mapping experiment are named
TMT labeling was the same for the proteomics and the phosphoproteomics experiments:
BRx82_DTX-_#1 (129c)
BRx82_DTX-_#2 (130n)
BRx82_DTX+_#1 (127c)
BRx82_DTX+_#2 (128n)
BRx142_DTX-_#1 (126)
BRx142_DTX-_#2 (127n)
BRx142_DTX+_#1 (128c)
BRx142_DTX+_#2 (129n)
2024-03-05 | MSV000094243 | MassIVE
Project description:CDKN1B (p27kip1) enhances drug tolerant persister CTCs by restricting polyploidy following mitotic inhibitors.
| PRJNA1085729 | ENA
Project description:CDKN1B (p27kip1) enhances drug tolerant persister CTCs by restricting polyploidy following mitotic inhibitors [CTClineRNAseq]
| PRJNA1085736 | ENA
Project description:CDKN1B (p27kip1) enhances drug tolerant persister CTCs by restricting polyploidy following mitotic inhibitors [docetaxelRNAseq]
| PRJNA1085735 | ENA
Project description:CDKN1B (p27kip1) enhances drug tolerant persister CTCs by restricting polyploidy following mitotic inhibitors [scRNAseq]
| PRJNA1085740 | ENA
Project description:MLL, involved in many chromosomal translocations associated with acute myeloid and lymphoid leukemia, has >50 known partner genes with which it is able to form in-frame fusions. Characterizing important downstream target genes of MLL and of MLL fusion proteins may provide rational therapeutic strategies for the treatment of MLL-associated leukemia. We explored downstream target genes of the most prevalent MLL fusion protein, MLL-AF4. To this end, we developed inducible MLL-AF4 fusion cell lines in different backgrounds. Overexpression of MLL-AF4 does not lead to increased proliferation in either cell line, but rather, cell growth was slowed compared with similar cell lines inducibly expressing truncated MLL. We found that in the MLL-AF4-induced cell lines, the expression of the cyclin-dependent kinase inhibitor gene CDKN1B was dramatically changed at both the RNA and protein (p27kip1) levels. In contrast, the expression levels of CDKN1A (p21) and CDKN2A (p16) were unchanged. To explore whether CDKN1B might be a direct target of MLL and of MLL-AF4, we used chromatin immunoprecipitation (ChIP) assays and luciferase reporter gene assays. MLL-AF4 binds to the CDKN1B promoter in vivo and regulates CDKN1B promoter activity. Further, we confirmed CDKN1B promoter binding by ChIP in MLL-AF4 as well as in MLL-AF9 leukemia cell lines. Our results suggest that CDKN1B is a downstream target of MLL and of MLL-AF4, and that, depending on the background cell type, MLL-AF4 inhibits or activates CDKN1B expression. This finding may have implications in terms of leukemia stem cell resistance to chemotherapy in MLL-AF4 leukemias.
| S-EPMC1236570 | biostudies-literature
Project description:ContextTypical nonfamilial (sporadic) parathyroid adenomas are common endocrine tumors for which no predisposing germline DNA variants and only a few clonally altered genes that drive parathyroid tumorigenesis have been identified. CDKN1B, encoding cyclin-dependent kinase inhibitor p27(kip1), has recently been implicated in a multiple endocrine tumor phenotype in rats and, rarely, in a human familial MEN1 (multiple endocrine neoplasia type 1)-like disorder.ObjectiveWe sought to determine whether mutation of CDKN1B might contribute to the development of common sporadic parathyroid adenomas.Patients and designWe sequenced the CDKN1B gene in 86 parathyroid adenomas from patients with typical, sporadic presentations of primary hyperparathyroidism. Identified alterations were categorized as somatic or germline, and their functional consequences were examined.ResultsCDKN1B sequence abnormalities were identified in four parathyroid adenomas. Acquired biallelic alteration of CDKN1B, resulting from somatic mutation plus loss of heterozygosity, was detected in one tumor. Germline origin was documented in two cases despite nonfamilial presentations. None of the observed alterations were found in 240 CDKN1B alleles from normal individuals, nor among more than 2,000 previously reported alleles. Most identified variants reduced p27(kip1) protein levels or altered in vitro stability.ConclusionsIn typical, sporadic parathyroid adenomas, CDKN1B mutation can be somatic and clonal, indicative of a directly conferred selective advantage in parathyroid tumorigenesis. Additionally, the identification of germline CDKN1B variants in patients with sporadic presentations provides evidence for CDKN1B as a susceptibility gene in the development of typical parathyroid adenomas.
| S-EPMC3070245 | biostudies-literature