scholarly journals Genome-wide CRISPR/Cas9 library screen identifies PCMT1 as a critical driver of ovarian cancer metastasis

2022 ◽  
Vol 41 (1) ◽  
Author(s):  
Jingjing Zhang ◽  
Yun Li ◽  
Hua Liu ◽  
Jiahui Zhang ◽  
Jie Wang ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Cancer Metastasis ◽  
Ovarian Cancer Cells ◽  
Skov3 Cell ◽  
Anoikis Resistance ◽  
Primary Tumors ◽  
Genome Wide

Abstract Background The development of lethal cancer metastasis depends on the dynamic interactions between cancer cells and the tumor microenvironment, both of which are embedded in the extracellular matrix (ECM). The acquisition of resistance to detachment-induced apoptosis, also known as anoikis, is a critical step in the metastatic cascade. Thus, a more in-depth and systematic analysis is needed to identify the key drivers of anoikis resistance. Methods Genome-wide CRISPR/Cas9 knockout screen was used to identify critical drivers of anoikis resistance using SKOV3 cell line and found protein-L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1) as a candidate. Quantitative real-time PCR (qRT-PCR) and immune-histochemistry (IHC) were used to measure differentially expressed PCMT1 in primary tissues and metastatic cancer tissues. PCMT1 knockdown/knockout and overexpression were performed to investigate the functional role of PCMT1 in vitro and in vivo. The expression and regulation of PCMT1 and integrin-FAK-Src pathway were evaluated using immunoprecipitation followed by mass spectrometry (IP-MS), western blot analysis and live cell imaging. Results We found that PCMT1 enhanced cell migration, adhesion, and spheroid formation in vitro. Interestingly, PCMT1 was released from ovarian cancer cells, and interacted with the ECM protein LAMB3, which binds to integrin and activates FAK-Src signaling to promote cancer progression. Strikingly, treatment with an antibody against extracellular PCMT1 effectively reduced ovarian cancer cell invasion and adhesion. Our in vivo results indicated that overexpression of PCMT1 led to increased ascites formation and distant metastasis, whereas knockout of PCMT1 had the opposite effect. Importantly, PCMT1 was highly expressed in late-stage metastatic tumors compared to early-stage primary tumors. Conclusions Through systematically identifying the drivers of anoikis resistance, we uncovered the contribution of PCMT1 to focal adhesion (FA) dynamics as well as cancer metastasis. Our study suggested that PCMT1 has the potential to be a therapeutic target in metastatic ovarian cancer.

scholarly journals Exosomes in ovarian cancer ascites promote epithelial–mesenchymal transition of ovarian cancer cells by delivery of miR-6780b-5p

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Jing Cai ◽  
Lanqing Gong ◽  
Guodong Li ◽  
Jing Guo ◽  
Xiaoqing Yi ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Tumor Metastasis ◽  
Cancer Metastasis ◽  
Epithelial Mesenchymal Transition ◽  
Ovarian Cancer Cells ◽  
Specific Mechanism ◽  
Mesenchymal Transition

AbstractThe poor prognosis of ovarian cancer is mainly due to metastasis, and the specific mechanism underlying ovarian cancer metastasis is not clear. Ascites-derived exosomes (ADEs) play an important role in the progression of ovarian cancer, but the mechanism is unknown. Here, we found that ADEs promoted ovarian cancer metastasis not only in vitro but also in vivo. This promotive function was based on epithelial–mesenchymal transition (EMT) of ovarian cancer cells. Bioinformatics analysis of RNA sequencing microarray data indicated that miR-6780b-5p may be the key microRNA (miRNA) in ADEs that facilitates cancer metastasis. Moreover, the expression of exosomal miR-6780b-5p correlated with tumor metastasis in ovarian cancer patients. miR-6780b-5p overexpression promoted and miR-6780b-5p downregulation suppressed EMT of ovarian cancer cells. These results suggest that ADEs transfer miR-6780b-5p to ovarian cancer cells, promoting EMT and finally facilitating ovarian cancer metastasis.

scholarly journals Plasma cells shape the mesenchymal identity of ovarian cancers through transfer of exosome-derived microRNAs

2021 ◽  
Vol 7 (9) ◽  
pp. eabb0737
Author(s):  
Zhengnan Yang ◽  
Wei Wang ◽  
Linjie Zhao ◽  
Xin Wang ◽  
Ryan C. Gimple ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Plasma Cell ◽  
Plasma Cells ◽  
Ovarian Cancer Cells ◽  
Mesenchymal Phenotype ◽  
Ovarian Cancers ◽  
Novel Approach

Ovarian cancer represents a highly lethal disease that poses a substantial burden for females, with four main molecular subtypes carrying distinct clinical outcomes. Here, we demonstrated that plasma cells, a subset of antibody-producing B cells, were enriched in the mesenchymal subtype of high-grade serous ovarian cancers (HGSCs). Plasma cell abundance correlated with the density of mesenchymal cells in clinical specimens of HGSCs. Coculture of nonmesenchymal ovarian cancer cells and plasma cells induced a mesenchymal phenotype of tumor cells in vitro and in vivo. Phenotypic switch was mediated by the transfer of plasma cell–derived exosomes containing miR-330-3p into nonmesenchymal ovarian cancer cells. Exosome-derived miR-330-3p increased expression of junctional adhesion molecule B in a noncanonical fashion. Depletion of plasma cells by bortezomib reversed the mesenchymal characteristics of ovarian cancer and inhibited in vivo tumor growth. Collectively, our work suggests targeting plasma cells may be a novel approach for ovarian cancer therapy.

scholarly journals Splicing factor USP39 promotes ovarian cancer malignancy through maintaining efficient splicing of oncogenic HMGA2

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Shourong Wang ◽  
Zixiang Wang ◽  
Jieyin Li ◽  
Junchao Qin ◽  
Jianping Song ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Malignant Tumors ◽  
Splicing Factor ◽  
Ovarian Cancer Cells ◽  
Nuclear Speckles ◽  
Aberrant Expression ◽  
Intergenic Regions

AbstractAberrant expression of splicing factors was found to promote tumorigenesis and the development of human malignant tumors. Nevertheless, the underlying mechanisms and functional relevance remain elusive. We here show that USP39, a component of the spliceosome, is frequently overexpressed in high-grade serous ovarian carcinoma (HGSOC) and that an elevated level of USP39 is associated with a poor prognosis. USP39 promotes proliferation/invasion in vitro and tumor growth in vivo. Importantly, USP39 was transcriptionally activated by the oncogene protein c-MYC in ovarian cancer cells. We further demonstrated that USP39 colocalizes with spliceosome components in nuclear speckles. Transcriptomic analysis revealed that USP39 deletion led to globally impaired splicing that is characterized by skipped exons and overrepresentation of introns and intergenic regions. Furthermore, RNA immunoprecipitation sequencing showed that USP39 preferentially binds to exon-intron regions near 5′ and 3′ splicing sites. In particular, USP39 facilitates efficient splicing of HMGA2 and thereby increases the malignancy of ovarian cancer cells. Taken together, our results indicate that USP39 functions as an oncogenic splicing factor in ovarian cancer and represents a potential target for ovarian cancer therapy.

scholarly journals Downregulation of TRIM27 expression inhibits the proliferation of ovarian cancer cells in vitro and in vivo

2015 ◽  
Vol 96 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Yanyan Ma ◽  
Zengtao Wei ◽  
Robert C Bast ◽  
Zhanying Wang ◽  
Yan Li ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Ovarian Cancer Cells

scholarly journals Discovery of a novel HDACi structure that inhibits the proliferation of ovarian cancer cells in vivo and in vitro

2021 ◽  
Vol 17 (13) ◽  
pp. 3493-3507
Author(s):  
Miao Bai ◽  
Mengqi Cui ◽  
Mingyue Li ◽  
Xinlei Yao ◽  
Yulun Wu ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Ovarian Cancer Cells

scholarly journals MGMT-activated DUB3 stabilizes MCL1 and drives chemoresistance in ovarian cancer

2019 ◽  
Vol 116 (8) ◽  
pp. 2961-2966 ◽  
Author(s):  
Xiaowei Wu ◽  
Qingyu Luo ◽  
Pengfei Zhao ◽  
Wan Chang ◽  
Yating Wang ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Dna Methyltransferase ◽  
Essential Role ◽  
Histone Deacetylase Inhibitors ◽  
Combined Treatment ◽  
Ovarian Cancer Cells ◽  
Methylguanine Dna Methyltransferase

Chemoresistance is a severe outcome among patients with ovarian cancer that leads to a poor prognosis. MCL1 is an antiapoptotic member of the BCL-2 family that has been found to play an essential role in advancing chemoresistance and could be a promising target for the treatment of ovarian cancer. Here, we found that deubiquitinating enzyme 3 (DUB3) interacts with and deubiquitinates MCL1 in the cytoplasm of ovarian cancer cells, which protects MCL1 from degradation. Furthermore, we identified that O6-methylguanine-DNA methyltransferase (MGMT) is a key activator of DUB3 transcription, and that the MGMT inhibitor PaTrin-2 effectively suppresses ovarian cancer cells with elevated MGMT-DUB3-MCL1 expression both in vitro and in vivo. Most interestingly, we found that histone deacetylase inhibitors (HDACis) could significantly activate MGMT/DUB3 expression; the combined administration of HDACis and PaTrin-2 led to the ideal therapeutic effect. Altogether, our results revealed the essential role of the MGMT-DUB3-MCL1 axis in the chemoresistance of ovarian cancer and identified that a combined treatment with HDACis and PaTrin-2 is an effective method for overcoming chemoresistance in ovarian cancer.

scholarly journals Celastrol Inhibits the Growth of Ovarian Cancer Cells in vitro and in vivo

2019 ◽  
Vol 9 ◽  
Author(s):  
Li-Na Xu ◽  
Na Zhao ◽  
Jin-Yan Chen ◽  
Piao-Piao Ye ◽  
Xing-Wei Nan ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Ovarian Cancer Cells
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