scholarly journals Characterization of SOX2, OCT4 and NANOG in Ovarian Cancer Tumor-Initiating Cells

Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 262
Author(s):  
Mikella Robinson ◽  
Samuel F. Gilbert ◽  
Jennifer A. Waters ◽  
Omar Lujano-Olazaba ◽  
Jacqueline Lara ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Chemotherapy Resistance ◽  
Tumor Initiating Cells ◽  
In Vivo Experiments ◽  
Nanog Expression ◽  
Ovarian Cancer Cell Lines ◽  
Cancer Tumor ◽  
Early Tumor ◽  
Cycle Regulation

The identification of tumor-initiating cells (TICs) has traditionally relied on surface markers including CD133, CD44, CD117, and the aldehyde dehydrogenase (ALDH) enzyme, which have diverse expression across samples. A more reliable indication of TICs may include the expression of embryonic transcription factors that support long-term self-renewal, multipotency, and quiescence. We hypothesize that SOX2, OCT4, and NANOG will be enriched in ovarian TICs and may indicate TICs with high relapse potential. We evaluated a panel of eight ovarian cancer cell lines grown in standard 2-D culture or in spheroid-enriching 3-D culture, and correlated expression with growth characteristics, TIC marker expression, and chemotherapy resistance. RNA-sequencing showed that cell cycle regulation pathways involving SOX2 were elevated in 3-D conditions. HGSOC lines had longer doubling-times, greater chemoresistance, and significantly increased expression of SOX2, OCT4, and NANOG in 3-D conditions. CD117+ or ALDH+/CD133+ cells had increased SOX2, OCT4, and NANOG expression. Limiting dilution in in vivo experiments implicated SOX2, but not OCT4 or NANOG, with early tumor-initiation. An analysis of patient data suggested a stronger role for SOX2, relative to OCT4 or NANOG, for tumor relapse potential. Overall, our findings suggest that SOX2 may be a more consistent indicator of ovarian TICs that contribute to tumor repopulation following chemotherapy. Future studies evaluating SOX2 in TIC biology will increase our understanding of the mechanisms that drive ovarian cancer relapse.

scholarly journals Characterization of SOX2, OCT4 and NANOG in ovarian cancer tumor-initiating cells

2020 ◽  
Author(s):  
Mikella Robinson ◽  
Samuel F Gilbert ◽  
Jennifer A Waters ◽  
Omar Lujano-Olazaba ◽  
Jacqueline Lara ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cell Lines ◽  
Cancer Cell ◽  
Ovarian Cancer Cell ◽  
Chemotherapy Resistance ◽  
Cancer Cell Lines ◽  
Ovarian Cancer Cells ◽  
Tumor Initiation ◽  
Tumor Initiating Cells ◽  
Ovarian Cancer Cell Lines

AbstractIdentification of tumor initiating cells (TICs) has traditionally relied on expression of surface markers such as CD133, CD44, and CD117 and enzymes such as aldehyde dehydrogenase (ALDH). Unfortunately, these markers are often cell type specific and not reproducible across patient samples. A more reliable indication of TICs may include elevated expression of stem cell transcription factors such as SOX2, OCT4, and NANOG that function to support long-term self-renewal, multipotency, and quiescence. RNA-sequencing studies presented here highlight a potential role for SOX2 in cell cycle progression in cells grown as 3-D spheroids, which are more tumorigenic and contain higher numbers of TICs than their 2-D monolayer cultured counterparts. SOX2, OCT4, and NANOG have not been comprehensively evaluated in ovarian cancer cell lines, although their expression is often associated with tumorigenic cells. We hypothesize that SOX2, OCT4, and NANOG will be enriched in ovarian TICs and will correlate with chemotherapy resistance, tumor initiation, and expression of traditional TIC markers. To investigate this hypothesis, we evaluated SOX2, OCT4, and NANOG in a panel of eight ovarian cancer cell lines grown as a monolayer in standard 2-D culture or as spheroids in TIC-enriching 3-D culture. Our data show that the high-grade serous ovarian cancer (HGSOC) lines CAOV3, CAOV4, OVCAR4, and OVCAR8 had longer doubling-times, greater resistance to chemotherapies, and significantly increased expression of SOX2, OCT4, and NANOG in TIC-enriching 3-D culture conditions. We also found that in vitro chemotherapy treatment enriches for cells with significantly higher expression of SOX2. We further show that the traditional TIC marker, CD117 identifies ovarian cancer cells with enhanced SOX2, OCT4, and NANOG expression. Tumor-initiation studies and analysis of The Cancer Genome Atlas (TCGA) suggest a stronger role for SOX2 in ovarian cancer relapse compared with OCT4 or NANOG. Overall, our study clarifies the expression of SOX2, OCT4, and NANOG in TICs from a variety of ovarian cancer cell lines. Our findings suggest that SOX2 expression is a stronger indicator of ovarian TICs with enhanced tumor-initiation capacity and potential for relapse. Improved identification of ovarian TICs will advance our understanding of TIC biology and facilitate the design of better therapies to eliminate TICs and overcome chemotherapy resistance and disease relapse.

scholarly journals Hypoxia Regulated Inhibin Promotes Tumor Growth and Vascular Permeability By ACVRL1 and CD105 Dependent VE-Cadherin Internalization

2021 ◽  
Author(s):  
Karthikeyan Mythreye ◽  
Ben Horst ◽  
Shrikant Pradhan ◽  
Roohi Chaudhary ◽  
Eduardo Listik ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Tumor Growth ◽  
Ovarian Cancer Cell ◽  
Vascular Normalization ◽  
Cancer Management ◽  
Vessel Normalization ◽  
Ovarian Cancer Cell Lines ◽  
Tumor Growth And Metastasis ◽  
Early Tumor

Abstract Hypoxia, a driver of tumor growth and metastasis, regulates angiogenic pathways that are targets for vessel normalization and ovarian cancer management. However, toxicities and resistance to anti-angiogenics limits their use making identification of new targets vital. Inhibin, a heteromeric TGFb ligand, is a contextual regulator of tumor progression acting as an early tumor suppressor, yet also an established biomarker for ovarian cancers. Here, we demonstrate a previously unknown role for inhibins and find that hypoxia increases inhibin levels in ovarian cancer cell lines, xenograft tumors, and patients. Inhibin is regulated specifically through HIF-1, shifting the balance from activins to inhibins. Hypoxia regulated inhibin promotes tumor growth, endothelial cell invasion and permeability. Targeting inhibin in vivo through knockdown and anti-inhibin strategies robustly reduces permeability in vivo and alters the balance of pro and anti-angiogenic mechanisms resulting in vascular normalization. Mechanistically, inhibin regulates permeability by increasing VE-cadherin internalization via ACVRL1 and CD105, a receptor complex that we find stabilized directly by inhibin. Our findings are the first to demonstrate direct roles for inhibins in vascular normalization via TGF-b receptors providing new insights into the therapeutic significance of inhibins as a strategy to normalize the tumor vasculature in ovarian cancer.

Abstract 4960: Sox2, Oct4, and Nanog expression for identification of ovarian cancer tumor initiating cells

2020 ◽  
Author(s):  
Mikella Robinson ◽  
Samuel F. Gilbert ◽  
Logan J. Alexander ◽  
Samuel E. Green ◽  
Omar Lujano-Olazaba ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Tumor Initiating Cells ◽  
Nanog Expression ◽  
Cancer Tumor

scholarly journals Hypoxia-induced up-regulation of miR-27a promotes paclitaxel resistance in ovarian cancer

2020 ◽  
Vol 40 (4) ◽  
Author(s):  
Lanlan Feng ◽  
Fangrong Shen ◽  
Jinhua Zhou ◽  
Yan Li ◽  
Rong Jiang ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Regulatory Mechanism ◽  
Chemotherapy Resistance ◽  
Paclitaxel Resistance ◽  
In Vivo Experiments ◽  
Hypoxic Environment ◽  
Skov3 Cells

Abstract Ovarian cancer (OC) is a malignant tumor with high mortality in women. Although cancer patients initially respond to paclitaxel chemotherapy following surgery, most patients will relapse after 12–24 months and gradually die from chemotherapy resistance. In OC, cancer cells become resistant to paclitaxel chemotherapy under hypoxic environment. The miR-27a has been identified as an oncogenic molecular in ovarian cancer, prostate cancer, liver cancer etc. In addition, the miR-27a is involved in hypoxia-induced chemoresistance in various cancers. However, the role of miR-27a in hypoxia-induced OC resistance remains unclear. The aim of the present study was to investigate the regulatory mechanism of miR-27a in hypoxia-induced OC resistance. The expression of HIF-1α induced Hypoxia overtly up-regulated. At the same time, hypoxia increased viability of Skov3 cells and decreased cell apoptosis when treated with paclitaxel. The expression of the miR-27a was obviously up-regulated under hypoxia and involved in hypoxia-induced paclitaxel resistance. Follow-up experiments portray that miR-27a improved paclitaxel resistance by restraining the expression of APAF1 in OC. Finally, we further elucidated the important regulatory role of the miR-27a-APAF1 axis in OC through in vivo experiments. According to our knowledge, we first reported the regulation of miR-27a in hypoxia-induced chemoresistance in OC, providing a possible target for chemoresistance treatment of OC.

scholarly journals Investigating Patterns of Immune Interaction in Ovarian Cancer: Probing the O-glycoproteome by the Macrophage Galactose-Like C-Type Lectin (MGL)

Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2841
Author(s):  
Chiara Napoletano ◽  
Catharina Steentoff ◽  
Federico Battisti ◽  
Zilu Ye ◽  
Hassan Rahimi ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cell ◽  
Immune Modulation ◽  
Therapeutic Interventions ◽  
Immune Recognition ◽  
Vicia Villosa ◽  
Ovarian Cancer Cell Lines ◽  
Input Material ◽  
Cancer Tissues

Glycosylation, the posttranslational linking of sugar molecules to proteins, is notoriously altered during tumor transformation. More specifically in carcinomas, GalNAc-type O-glycosylation, is characterized by biosynthetically immature truncated glycans present on the cancer cell surface, which profoundly impact anti-tumor immune recognition. The tumor-associated glycan pattern may thus be regarded as a biomarker of immune modulation. In epithelial ovarian cancer (EOC) there is a particular lack of specific biomarkers and molecular targets to aid early diagnosis and develop novel therapeutic interventions. The aim of this study was to investigate the ovarian cancer O-glycoproteome and identify tumor-associated glycoproteins relevant in tumor–dendritic cell (DC) interactions, mediated by macrophage galactose-like C type lectin (MGL), which recognizes the tumor-associated Tn O-glycan. Lectin weak affinity chromatography (LWAC) was employed to probe the O-glycopeptidome by MGL and Vicia villosa agglutinin (VVA) lectin using glycoengineered ovarian cancer cell lines and ovarian cancer tissues as input material. Biochemical and bioinformatics analysis gave information on the glycan arrangement recognized by MGL in tumor cells. The potential MGL binders identified were located, as expected, at the cell membrane, but also within the intracellular compartment and the matrisome, suggesting that MGL in vivo may play a complex role in sensing microenvironmental cues. The tumor glycoproteins binders for MGL may become relevant to characterize the interaction between the immune system and tumor progression and contribute to the design of glycan targeting-based strategies for EOC immunotherapeutic interventions.

scholarly journals Knockdown of BRCA2 enhances cisplatin and cisplatin-induced autophagy in ovarian cancer cells

2018 ◽  
Vol 25 (1) ◽  
pp. 69-82 ◽  
Author(s):  
Biao Wan ◽  
Leheyi Dai ◽  
Li Wang ◽  
Ying Zhang ◽  
Hong Huang ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Median Time ◽  
Progression Free Survival ◽  
Ovarian Cancer Cells ◽  
Intact Cells ◽  
Ovarian Cancer Cell Lines ◽  
Tumor Tissues ◽  
Cancer Tissues

Clinical implications of the BRCA2 expression level on treatments of ovarian cancer are controversial. Here, we demonstrated that platinum-resistant cancer had a higher percentage of high BRCA2 level (87.5% vs 43.6%, P = 0.001), and that patients with a low BRCA2 level in cancer tissues had longer progression-free survival (with a median time of 28.0 vs 12.0 months, P < 0.001) and platinum-free duration (with a median time of 19.0 vs 5.0 months, P < 0.001) compared with those with a high BRCA2 level. In human ovarian cancer cell lines CAOV-3 and ES-2, cisplatin induced an upregulation of the RAD51 protein, which was inhibited after silencing BRCA2; silencing BRCA2 enhanced the action of cisplatin in vitro and in vivo. Knockdown of BRCA2 promoted cisplatin-induced autophagy. Interestingly, the autophagy blocker chloroquine enhanced cisplatin in BRCA2-silenced cells accompanied by an increase in apoptotic cells, which did not occur in BRCA2-intact cells; chloroquine enhanced the efficacy of cisplatin against BRCA2-silenced CAOV-3 tumors in vivo, with an increase in LC3-II level in tumor tissues. Sensitization of cisplatin was also observed in BRCA2-silenced CAOV-3 cells after inhibiting ATG7, confirming that chloroquine modulated the sensitivity via the autophagy pathway. These data suggest that a low BRCA2 level can predict better platinum sensitivity and prognosis, and that the modulation of autophagy can be a chemosensitizer for certain cancers.

scholarly journals NEAT1 Overexpression Indicates a Poor Prognosis and Induces Chemotherapy Resistance via the miR-491-5p/SOX3 Signaling Pathway in Ovarian Cancer

2021 ◽  
Vol 12 ◽  
Author(s):  
Xinzhuan Jia ◽  
Lan Wei ◽  
Zhengmao Zhang
Keyword(s):  
Ovarian Cancer ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Expression Patterns ◽  
Chemotherapy Resistance ◽  
Direct Interaction ◽  
Luciferase Reporter ◽  
Tissue Samples ◽  
Qrt Pcr

BackgroundAccumulated studies have reported that dysregulated long non-coding RNAs (lncRNAs) are crucial in ovarian cancer (OC) initiation and development. However, detailed biological functions of lncRNA NEAT1 during the progression of OC remains to be uncovered.PurposeOur aim was to identify the role of NEAT1 in cisplatin resistance of ovarian cancer and the underlying mechanisms.MethodsThe expression patterns of NEAT1 in OC cell lines and tissue samples were identified by qRT-PCR. The cisplatin (DDP) sensitivity of OC cells was detected by MTT and CCK8 assay, while OC cell apoptosis and cell cycle were detected using flow cytometer assays. In addition, effects of NEAT1 on tumor growth were determined by xenograft tumor model. Luciferase reporter assay was conducted to prove the regulatory relation of miR-491-5p, NEAT1, and SOX3. Importantly, the expression of NEAT1 in exosomes from cisplatin-resistant patients was also determined by using qRT-PCR.ResultsIn this study, upregulated NEAT1 was detected in OC cell lines and tissues. Meanwhile, NEAT1 was also increased in cisplatin-resistant OC cell lines and tissues. Upregulation of NEAT1 inhibited cisplatin-induced OC cell apoptosis and promoted cell proliferation, while knockdown of NEAT1 played the opposite role. These effects were also observed in vivo. Furthermore, direct interaction was observed between NEAT1 and miR-491-5p. NEAT1 led to the upregulation of miR-491-5p-targeted SOX3 mRNA. Importantly, this study also showed upregulated NEAT1 expression in serum exosomes derived from cisplatin-resistant patients.ConclusionNEAT1 is vital in the chemoresistance of ovarian cancer through regulating miR-491-5p/SOX3 pathway, showing that NEAT1 might be a potential target for OC resistance treatment.

scholarly journals LGR4 Maintains HGSOC Cell Epithelial Phenotype and Stem-Like Traits

2020 ◽  
Author(s):  
Zhuo Wang ◽  
Ping Yin ◽  
Yu Sun ◽  
Lei Na ◽  
Jian Gao ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Luciferase Reporter ◽  
Ovarian Cancer Cells ◽  
Sox2 Expression ◽  
In Vivo Experiments ◽  
Epithelial Phenotype ◽  
Reporter Assays ◽  
Regulatory Loop ◽  
Cancer Tissues

Abstract Background: High-grade serous ovarian cancer (HGSOC) is lethal mainly due to extensive metastasis. Cancer cell stem-like properties are responsible for HGSOC metastasis. LGR4, a G-protein-coupled receptor, is involved in the maintenance of stem cell self-renewal and activity in some human organs. Methods: TCGA and CCLE database was interrogated for gene mRNA analysis in ovarian cancer tissues and cell lines. The interactions between LGR4 and ELF3 were validated through dual-luciferase reporter assays, Chip assays and Co-IP assays. Gain- and loss-of functions of LGR4, ELF3, FZD5 and WNT7B were performed to identify their roles in the behaviors of ovarian cancer cells. Flowcytometry analysis and tumorisphere formation assays were performed to identified their stem-like properties. In vivo experiments were performed as well.Results: LGR4 was shown to be overexpressed in HGSOCs and maintain the epithelial phenotype of HGSOC cells. LGR4 knockdown suppressed POU5F1, SOX2, PROM1 (CD133) and ALDH1A2 expression. Furthermore, LGR4 knockdown reduced CD133+ and ALDH+ subpopulations and impaired tumorisphere formation. To the contrary, LGR4 overexpression enhanced POU5F1 and SOX2 expression and tumorisphere formation capacity. LGR4 knockdown inhibited HGSOC cell growth and peritoneal seeding in xenograft models. Mechanistically, LGR4 and ELF3, an epithelium-specific transcription factor, formed a reciprocal regulatory loop, which was positively modulated by WNT7B/FZD5 pair. Consistently, knockdown of ELF3, WNT7B, and FZD5, respectively, disrupted HGSOC cell epithelial phenotype and stem-like properties. Conclusion: Together, these data demonstrate that WNT7B/FZD5-LGR4/ELF3 axis maintains HGSOC cell epithelial phenotype and stem-like traits; targeting this axis may prevent HGSOC metastasis.

scholarly journals Circ-VPS13C enhances cisplatin resistance in ovarian cancer via modulating miR-106b-5p/YWHAZ axis

2021 ◽  
Author(s):  
Hairong Yao ◽  
Dantong Liu ◽  
Fangyuan Gao ◽  
Qian Li ◽  
Shikai Liu
Keyword(s):  
Ovarian Cancer ◽  
Western Blot ◽  
Chemotherapy Resistance ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Western Blot Assay ◽  
Inhibition Concentration ◽  
And Migration

IntroductionOvarian cancer (OC) is the malignant tumor with the highest mortality among gynecological cancers. Chemotherapy resistance is a major obstacle to OC therapy. Circular RNAs (circRNAs) play crucial roles in cancer development and chemoresistance. However, the role and potential mechanism of has-circ-001567 (circ-VPS13C) in chemoresistance of OC remain unknown.Material and methodsThe levels of circ-VPS13C, miR-106b-5p and 14-3-3 zeta (YWHAZ) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assay. Cell Counting Kit-8 (CCK-8) assay was used to assess cell viability and calculate the half inhibition concentration (IC50) of cisplatin (DDP). The levels of autophagy-related markers were measured by western blot assay. Cell apoptosis and migration were evaluated by flow cytometry and transwell assay, respectively. The binding relationship between miR-106b-5p and circ-VPS13C or YWHAZ was confirmed by dual-luciferase reporter assay. Xenograft assay was performed to explore the role of circ-VPS13C in vivo.ResultsCirc-VPS13C and YWHAZ were up-regulated, while miR-106b-5p was down-regulated in DDP-resistant OC tissues and cells. Knockdown of circ-VPS13C enhanced DDP sensitivity by repressing autophagy in DDP-resistant cells. Circ-VPS13C increased DDP resistance via sponging miR-106b-5p. Moreover, miR-106b-5p directly targeted YWHAZ. Up-regulation of YWHAZ alleviated the decrease in DDP resistance caused by circ-VPS13C depletion. In addition, circ-VPS13C silencing decreased DDP resistance in vivo.ConclusionsCirc-VPS13C knockdown enhanced DDP sensitivity of OC through modulation of autophagy via the miR-106b-5p/YWHAZ axis, providing a new biomarker for improving the efficacy of OC chemotherapy.

scholarly journals Hedgehog−Gli2 Signaling Promotes Chemoresistance in Ovarian Cancer Cells by Regulating MDR1

2022 ◽  
Vol 11 ◽  
Author(s):  
Qian Wang ◽  
Xin Wei ◽  
Lanyan Hu ◽  
Lingling Zhuang ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Nude Mice ◽  
Chemotherapy Resistance ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Ovarian Cancer Cells ◽  
Luciferase Reporter Gene ◽  
Downstream Target ◽  
Skov3 Cells

BackgroundCisplatin (DDP) resistance remains a key challenge in improving the clinical outcome of patients with ovarian cancer (OC). Gli2 overexpression can lead to DDP resistance in OC cells, but the specific underlying regulatory mechanism remains unclear. The membrane transporter encoding gene MDR1 positively regulates chemotherapy resistance in various cancer types. We evaluated MDR1 as a potential Gli2 downstream target and the contribution of the Gli2/MDR1 axis in promoting DDP resistance in OC cells.MethodsTo generate drug-resistant SKOV3/DDP cells, SKOV3 cells were grown for six months under continuous induction wherein the DDP concentration was steadily increased. Gli2 expression in OC cells with varying DDP sensitivities was detected using western blot. Cell counting kit-8 assays were used to assess the DDP sensitivity of SKOV3, SKOV3/DDP, A2780, and A2780/DDP cells and reversal of DDP resistance in SKOV3/DDP and A2780/DDP cells. Cell proliferation was analyzed using 5-ethynyl-2′-deoxyuridine (EdU) incorporation assays. The transcriptional regulation of MDR1 by Gli2 was determined using luciferase reporter assays. Finally, xenograft OC tumors were generated in nude mice, which were then treated with intraperitoneal DDP or phosphate-buffered saline (PBS) injections to investigate if Gli2 affected DDP resistance in OC in vivo.ResultsDDP-resistant SKOV3/DDP and A2780/DDP cells showed higher expression of Gli2 and MDR1 as compared with that in DDP-sensitive OC cells. Gli2 knockdown in SKOV3/DDP cells significantly reduced MDR1 expression, whereas it increased DNA damage, thereby sensitizing OC cells to DDP. Similar results were obtained after targeting Gli2 expression with the Gli-antagonist 61 inhibitor (GANT61) in SKOV3/DDP and A2780/DDP cells. In cells stably overexpressing Gli2, treatment with gradient concentrations of verapamil, an MDR1 inhibitor, significantly inhibited MDR1 expression. Our findings indicate that downregulation of MDR1 expression may reverse OC cell resistance to DDP. Moreover, dual-luciferase reporter gene assays confirmed that MDR1 is a direct downstream target of Gli2, with Gli2 positively regulating MDR1 expression. Finally, subcutaneous xenotransplantation in nude mice demonstrated that Gli2 plays a key role in regulating OC drug resistance.ConclusionsWe identified a mechanism by which Hedgehog-Gli signaling regulates OC chemoresistance by modulating MDR1 expression. Hence, Gli2 and MDR1 are potential biomarkers and therapeutic targets in patients with chemoresistant OC.

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