Essential role of PLD2 in hypoxia-induced stemness and therapy resistance in ovarian tumors
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ABSTRACT:
PROVIDER: PRJNA866399 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR20853990_1.fastq.gz | Fastqsanger.gz | |||
| SRR20853990_2.fastq.gz | Fastqsanger.gz | |||
| SRR20853991_1.fastq.gz | Fastqsanger.gz | |||
| SRR20853991_2.fastq.gz | Fastqsanger.gz | |||
| SRR20853992_1.fastq.gz | Fastqsanger.gz |
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Project description:Ovarian cancer (OC) is the most lethal gynecological cancer due to its late diagnosis and, importantly, its high rate of chemoresistance. Hypoxia in solid tumors is an important source of chemoresistance that can determine poor patient prognosis. Such chemoresistance relies on the presence of cancer stem cells (CSCs), and hypoxia promotes their generation through transcriptional activation by HIF transcription factors. We use OC cell lines, xenograft models, OC patient samples, transcriptional databases, iPSCs and ATAC-seq. We show here that hypoxia induces the formation of ovarian CSCs through transcriptional activation of the PLD2 gene encoding phospholipase D2. HIF-1 activates PLD2 transcription through hypoxia response elements located within PLD2 promoter and an intronic enhancer. PLD2 overexpression leads to similar effects than hypoxia, increasing CSC-like features, stemness gene expression and enhancing cell reprogramming in OC cells, as well as chromatin accessibility around stemness genes detected by ATAC-seq. Conversely, PLD2 depletion in hypoxia partially suppresses these effects, indicating that PLD2 is a major determinant of hypoxia-induced CSC generation in OC. Indeed, PLD2 expression is high in OC patients leading to poor survival and a transcriptional switch in the genes related to the response to hypoxia and stemness. Finally, we demonstrate that PLD2 overexpression provokes resistance to platinum-based chemotherapy and that combination of cisplatin with pharmacological inhibition of PLD2 suppresses such resistance. Altogether, our work highlights the importance of the HIF-1-PLD2 axis for CSC generation and chemoresistance in OC and proposes an alternative treatment for patients with high PLD2 expression.
2023-08-06 | GSE210599 | GEO
Project description:BackgroundHypoxia in solid tumors is an important source of chemoresistance that can determine poor patient prognosis. Such chemoresistance relies on the presence of cancer stem cells (CSCs), and hypoxia promotes their generation through transcriptional activation by HIF transcription factors.MethodsWe used ovarian cancer (OC) cell lines, xenograft models, OC patient samples, transcriptional databases, induced pluripotent stem cells (iPSCs) and Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq).ResultsHere, we show that hypoxia induces CSC formation and chemoresistance in ovarian cancer through transcriptional activation of the PLD2 gene. Mechanistically, HIF-1α activates PLD2 transcription through hypoxia response elements, and both hypoxia and PLD2 overexpression lead to increased accessibility around stemness genes, detected by ATAC-seq, at sites bound by AP-1 transcription factors. This in turn provokes a rewiring of stemness genes, including the overexpression of SOX2, SOX9 or NOTCH1. PLD2 overexpression also leads to decreased patient survival, enhanced tumor growth and CSC formation, and increased iPSCs reprograming, confirming its role in dedifferentiation to a stem-like phenotype. Importantly, hypoxia-induced stemness is dependent on PLD2 expression, demonstrating that PLD2 is a major determinant of de-differentiation of ovarian cancer cells to stem-like cells in hypoxic conditions. Finally, we demonstrate that high PLD2 expression increases chemoresistance to cisplatin and carboplatin treatments, both in vitro and in vivo, while its pharmacological inhibition restores sensitivity.ConclusionsAltogether, our work highlights the importance of the HIF-1α-PLD2 axis for CSC generation and chemoresistance in OC and proposes an alternative treatment for patients with high PLD2 expression.
| S-EPMC10895852 | biostudies-literature
Project description:Cancer stem cells (CSCs) play crucial roles in cancer progression, immune evasion, drug resistance, and recurrence. Understanding the mechanisms behind CSCs generation and stemness maintenance is vital for early cancer diagnosis and treatment. Here, we unveil that carnitine palmitoyltransferase 1A (CPT1A) is highly expressed in ovarian cancer stem cells (OCSCs) and is essential for maintaining stemness by regulating lipid desaturation. Studies confirmed that CPT1A enhances SREBP1 activation, upregulating SCD1 expression, and promoting lipid desaturation in OCSCs. Mechanistic studies reveal that CPT1A promotes succinylation of mitochondrial fission factor (MFF) through its lysine succinyltransferase (LSTase) activity, crucial for mitochondria-associated membranes formation and SREBP1 activation. Inhibiting CPT1A's LSTase activity with Glyburide reduces OCSCs' stemness and enhances cisplatin's anti-tumor effects against ovarian cancer in vitro and in vivo. Together, our studies highlight the significance of CPT1A's LSTase activity in maintaining OCSCs' stemness, offering potential targets and therapeutic strategies for ovarian cancer treatment.
2025-05-07 | PXD059026 | Pride
Project description:Widespread intraperitoneal metastases and chemoresistance render ovarian cancer the leading cause of gynecological malignancy–related deaths, wherein TGF-β signaling plays the pivotal role by promoting cancer stem cells (CSCs) activity. The activation mechanism and key protumorigeneic events downstream of TGF-β signaling remain incompletely understood. Here, we identify hypoxic tumor microenvironment as an initiator of TGF-β signaling to promote HIF-2α positive CSC-mediated chemoresistance in high-grade serous ovarian cancer (HGSOC). Mechanistically, deubiquitinase USP9X, as a TGF-β downstream effector, stabilizes HIF-2ɑ in a hydroxylation- and ubiquitylation-dependent manner, thus promoting stemness reprogramming. Hypoxia and TGF-β signals converge on USP9X-HIF-2ɑ axis via multi-level regulations, which in turn facilitates Smad/HIF responses. Clinically, USP9X expression correlates with TGF-β signatures, CSCs characteristics, EMT behaviors, and chemotherapy responsiveness, along with HIF-2ɑ. Antagonizing USP9X efficiently represses tumor formation, metastasis, CSCs occurrence, while increasing chemosensitivity in orthotopic tumors, patient derived xenograft (PDX), organoid, and chemoresistant cell models, in part via restricting TGF-β and hypoxia activities. This study deciphers the critical role of hypoxic niche in stimulating TGF-β signaling, and a downstream USP9X-HIF-2ɑ proteostatic regulatory axis in priming the HGSOC stemness, thereby provides novel targeting venues to counteract TGF-β signaling in CSCs and meliorate clinical chemoresistance.
2025-04-05 | GSE286397 | GEO
Project description:Cancer stem cells (CSCs) are key players in cancer progression, immune evasion, drug resistance, and recurrence, particularly in ovarian cancer. Mitochondria-associated membranes (MAMs) are dynamic structures linking mitochondria and the endoplasmic reticulum, essential for cellular processes. Whether MAMs supports CSCs and the underlying mechanisms remain largely unknown. Here, we unveil that CPT1A is highly expressed in ovarian cancer stem cells (OCSCs) and is essential for stemness maintenance. CPT1A facilitates stemness maintenance by regulating lipid desaturation in ovarian cancer. Further studies confirmed that CPT1A enhances SREBP1 cleavage and nuclear translocation, thereby upregulating SCD1 expression and promoting lipid desaturation in OCSCs. Furthermore, MAMs are found to be critical for SREBP1 activation. Mechanistic studies have shown that CPT1A promotes mitochondrial fission factor (MFF) succinylation (succK-MFF) through its lysine succinyltransferase (LSTase) activity, with succK-MFF being crucial for MAMs formation and SREBP1 activation. Additionally, inhibiting the LSTase activity of CPT1A with Glyburide reduced OCSCs' stemness and enhanced cisplatin's anti-tumor effects against ovarian cancer both in vitro and in vivo. Together, our studies reveal the importance of CPT1A's LSTase activity in MAMs formation and OCSCs' stemness maintenance, providing potential targets and therapeutic strategies for ovarian cancer treatment.
2024-08-26 | GSE273383 | GEO
Project description:We leverage RNA sequencing to identify the transcriptional changes assocaited with several experimental conditions that induce a stemness phenotype in the ovarian surface epithelium, including spheroid culture, Snail overexpression, and BRCA1 deletion
2020-06-01 | GSE122875 | GEO
Project description:USP9X integrates TGF-β and hypoxia signalings to promote ovarian cancer chemoresistance via HIF-2α-maintained stemness
| PRJNA1209069 | ENA
Project description:Ovarian cancer (OC) displays the highest mortality among gynecological tumors, mainly due to early peritoneal dissemination, the high frequency of tumor relapse following primary debulking and the development of chemoresistance. All these events are thought to be initiated and sustained by a subpopulation of neoplastic cells, termed ovarian cancer stem cells (OCSC), that are endowed with self-renewing and tumor-initiating properties. This implies that interfering with OCSC function should offer novel therapeutic perspectives to defeat OC progression. To this aim, a better understanding of the molecular and functional makeup of OCSC in clinically relevant model systems is essential. We have profiled the transcriptome of OCSC vs. their bulk cell counterpart from a panel of patient-derived OC cell cultures. This revealed that Matrix Gla Protein (MGP), classically known as a calcification-preventing factor in cartilage and blood vessels, is markedly enriched in OCSC. Functional assays showed that MGP confers several stemness-associated traits to OC cells, including a transcriptional reprogramming. Patient-derived organotypic cultures pointed to the peritoneal microenvironment as a major inducer of MGP expression in OC cells. Furthermore, MGP was found to be necessary and sufficient for tumor initiation in OC mouse models, by shortening tumor latency and increasing dramatically the frequency of tumor-initiating cells. Mechanistically, MGP-driven OC stemness was mediated by the stimulation of Hedgehog signaling, in particular through the induction of the Hedgehog effector GLI1, thus highlighting a novel MGP/Hedgehog pathway axis in OCSC. Finally, MGP expression was found to correlate with poor prognosis in OC patients, and was increased in tumor tissue after chemotherapy, supporting the clinical relevance of our findings. Thus, MGP is a novel driver in OCSC pathophysiology, with a major role in stemness and in tumor initiation.
2023-05-10 | PXD037543 | Pride
Project description:Transcriptional profile of stemness in the ovarian surface epithelium
| PRJNA506731 | ENA
Project description:Cancer cell plasticity is an emerging hallmark of the disease where cells can transition into different cellular states, contributing to tumor heterogeneity. Cellular plasticity is linked to cancer progression, treatment resistance, and relapse. Cancer Stem Cells (CSCs) play an important role in cancer cell plasticity, and molecular factors contributing to stemness maintenance are still poorly understood. Here, we investigate the role of XIST (X-inactive specific transcript) long noncoding RNA (lncRNA) in ovarian cancer cellular plasticity. We perform in silico and in vitro analyses to better understand its function. Our findings demonstrate a significant downregulation of XIST in ovarian tumors. cancer patients.Tumors with low XIST expression have higher stemness index and decreased overall survival. This reduction is associated with an increased stemness in tumors with XIST index and decreased overall survival rates. XIST knockdown (KD) in ovarian cancer cell lines increases stem cell population. Transcriptomic data show that low XIST expression correlates with the upregulation of the stem cell-specific pathways MYC and MTOR, as well as the metabolic pathway OXPHO. Our study also demonstrates that XIST KD increases specifically mesenchymal cancer stem cell (MCSC) population. Finally, ovarian cancer cells with XIST KD show higher plasticity under hypoxic conditions by transitioning into Epithelial Cancer Stem CellsCell (ECSC). Our data reveal that XIST loss induces CSC enrichment, leading to higher cellular plasticity. These findings highlight the important role of XIST in protecting cell identity in ovarian cancer and open the door to new therapeutic approaches for patients with low XIST expression
2024-11-05 | GSE271117 | GEO