Characterization of a DNA Aptamer for Ovarian Cancer Clinical Tissue Recognition and in Vivo Imaging

Backgrounds/Aims: Ovarian cancer is the most lethal gynaecologic malignancy and is difficult to detect early. The inefficient early diagnosis of ovarian cancer is the main contributor to its high mortality rate. Aptamers, as chemical antibodies, are single-stranded DNA or RNA oligonucleotides that target cells or molecules with high affinity. Methods: Binding ability of R13 was measured by flow cytometry analysis. Stability of R13 was tested in blood serum of an ovarian cancer patient. Internalization of R13 was verified by confocal microscope imaging. 80 cases ovarian cancer tissues, 10 cases normal ovary tissues in a microarray and 6 fallopian tube tissues were prepared for this study. R13’s target ability was further confirmed in vivo tumor models in NOD/SCID mice. Results: In this study, we found aptamer R13 bound to ovarian cancer cells with dissociation constants in the nanomolar range. Moreover, these results were further confirmed by tissue imaging. Next we demonstrated that the targets of R13 are membrane proteins and that its internalization occurs in a caveolae-mediated and clathrin-mediated manner. The target function of R13 was determined by imaging A2780 tumours in mouse models. Conclusion: These findings suggest that R13 is a promising novel tool to diagnose and deliver drugs to treat ovarian cancer.

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METTL3 promotes the initiation and metastasis of ovarian cancer by inhibiting CCNG2 expression via promoting the maturation of pri-microRNA-1246

Cell Death Discovery ◽

10.1038/s41420-021-00600-2 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Xuehan Bi ◽

Xiao Lv ◽

Dajiang Liu ◽

Hongtao Guo ◽

Guang Yao ◽

...

Keyword(s):

Ovarian Cancer ◽

Molecular Mechanisms ◽

High Expression ◽

Ovarian Cancer Cells ◽

Inadequate Knowledge ◽

And Migration ◽

Cancer Tissues

AbstractOvarian cancer is a common gynecological malignant tumor with a high mortality rate and poor prognosis. There is inadequate knowledge of the molecular mechanisms underlying ovarian cancer. We examined the expression of methyltransferase-like 3 (METTL3) in tumor specimens using RT-qPCR, immunohistochemistry, and Western blot analysis, and tested the methylation of METTL3 by MSP. Levels of METTL3, miR-1246, pri-miR-1246 and CCNG2 were then analyzed and their effects on cell biological processes were also investigated, using in vivo assay to validate the in vitro findings. METTL3 showed hypomethylation and high expression in ovarian cancer tissues and cells. Hypomethylation of METTL3 was pronounced in ovarian cancer samples, which was negatively associated with patient survival. Decreased METTL3 inhibited the proliferation and migration of ovarian cancer cells and promoted apoptosis, while METTL3 overexpression exerted opposite effects. Mechanistically, METTL3 aggravated ovarian cancer by targeting miR-1246, while miR-1246 targeted and inhibited CCNG2 expression. High expression of METTL3 downregulated CCNG2, promoted the metabolism and growth of transplanted tumors in nude mice, and inhibited apoptosis. The current study highlights the promoting role of METTL3 in the development of ovarian cancer, and presents new targets for its treatment.

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

Endocrine Related Cancer ◽

10.1530/erc-17-0261 ◽

2018 ◽

Vol 25 (1) ◽

pp. 69-82 ◽

Cited By ~ 16

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.

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LGR4 Maintains HGSOC Cell Epithelial Phenotype and Stem-Like Traits

10.21203/rs.3.rs-34651/v1 ◽

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.

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PSMC2/CCND1 axis promotes development of ovarian cancer through regulating cell growth, apoptosis and migration

Cell Death and Disease ◽

10.1038/s41419-021-03981-5 ◽

2021 ◽

Vol 12 (8) ◽

Author(s):

Dawei Zhu ◽

Jie Huang ◽

Ning Liu ◽

Wei Li ◽

Limei Yan

Keyword(s):

Ovarian Cancer ◽

Poor Prognosis ◽

Tumor Grade ◽

Ovarian Cancer Cells ◽

Mutual Regulation ◽

Regulatory Effects ◽

And Migration ◽

Cancer Tissues ◽

Lower Expression

AbstractOvarian cancer is known as one of the most common malignancies of the gynecological system, whose treatment is still not satisfactory because of the unclear understanding of molecular mechanism. PSMC2 is an essential component of 19 S regulatory granules in 26 S proteasome and its relationship with ovarian cancer is still not clear. In this study, we found that PSMC2 was upregulated in ovarian cancer tissues, associated with tumor grade and could probably predict poor prognosis. Knocking down the endogenous PSMC2 expression in ovarian cancer cells could decrease colony formation ability, cell motility and cell proliferation rate, along with increasing cell apoptosis rate. Cells models or xenografts formed by cells with relatively lower expression of PSMC2 exhibited weaker oncogenicity and slower growth rate in vivo. Moreover, gene microarray was used to analyze the alteration of gene expression profiling of ovarian cancer induced by PSMC2 knockdown and identify CCND1 as a potential downstream of PSMC2. Further study revealed the mutual regulation between PSMC2 and CCND1, and demonstrated that knockdown of CCND1 could enhance the regulatory effects induced by PSMC2 knockdown and overexpression of CCND1 reverses it. In summary, PSMC2 may promote the development of ovarian cancer through CCND1, which may predict poor prognosis of ovarian cancer patients.

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Forkhead Box Protein C2 (FOXC2) Promotes the Resistance of Human Ovarian Cancer Cells to Cisplatin In Vitro and In Vivo

Cellular Physiology and Biochemistry ◽

10.1159/000445620 ◽

2016 ◽

Vol 39 (1) ◽

pp. 242-252 ◽

Cited By ~ 15

Author(s):

Chanjuan Li ◽

Hongjuan Ding ◽

Jing Tian ◽

Lili Wu ◽

Yun Wang ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Cell Line ◽

Mapk Signaling ◽

Ovarian Cancer Cells ◽

Human Ovarian Cancer ◽

Cancer Tissues ◽

Mapk Signaling Pathways

Background/Aims: FOXC2 has been reported to play a role in tumor progression, but the correlations of FOXC2 with the cisplatin (CDDP) resistance of ovarian cancer cells are still unclear. The purpose of the present study is to investigate the roles of FOXC2 in the CDDP resistance of ovarian cancer cells and its possible mechanisms. Methods: Quantitative real-time PCR (qRT-PCR) was performed to detect the expression of FOXC2 mRNA in CDDP-resistant or sensitive ovarian cancer tissues and cell lines (SKOV3/CDDP and SKOV3). Gain- and loss-of-function assays were performed to analyze the effects of FOXC2 knockdown or overexpression on the in vitro and in vivo sensitivity of ovarian cancer cells to CDDP and its possible molecular mechanisms. Results: The relative expression level of FOXC2 mRNA in CDDP-resistant ovarian cancer tissues was higher than that in CDDP-sensitive tissues. Also, the expression of FOXC2 mRNA and protein in CDDP-resistant ovarian cancer cell line (SKOV3/CDDP) cell line was higher than that in its parental cell line (SOKV3). Small hairpin RNA (shRNA)-mediated FOXC2 knockdown significantly increased the in vitro and in vive sensitivity of SKOV3/CDDP cells to CDDP by enhancing apoptosis, while upregulation of FOXC2 significantly decreased the in vitro and in vivo sensitivity of SKOV3 cells to CDDP by reducing apoptosis. Furthermore, FOXC2 activates the Akt and MAPK signaling pathways, and then induced the decreased expression of Bcl-2 protein and the increased expression of Bax and cleaved caspase-3 proteins. Conclusions: FOXC2 mediates the CDDP resistance of ovarian cancer cells by activation of the Akt and MAPK signaling pathways, and may be a potential novel therapeutic target for overcoming CDDP resistance in human ovarian cancer.

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ADAR1 Prevents R-loop Accumulation-Driven ATR Pathway Activation in Ovarian Cancer

10.21203/rs.3.rs-103651/v1 ◽

2020 ◽

Author(s):

hanwei cui ◽

Qian Yi ◽

Min Tian ◽

Yuteng Liang ◽

Jie Huang ◽

...

Keyword(s):

Cell Cycle ◽

Ovarian Cancer ◽

Cancer Cells ◽

Ovarian Cancer Cell ◽

Ovarian Cancer Cells ◽

Pathway Activation ◽

Rna Immunoprecipitation ◽

Cancer Tissues

Abstract BackgroundAdenosine (A)-to-inosine (I) RNA editing is the most prevalent RNA editing mechanism, in which adenosine deaminases acting on RNA 1 (ADAR1) is a major adenosine deaminase. Increasing evidence suggests that editing dysregulation of ADAR1 plays an important role in human tumorigenesis, while the underlying mechanism remains elusive. MethodsThe clinical relevance of ADAR1 was analyzed by real-time PCR, western blotting and immunohistochemistry of ovarian cancer tissues. ADAR1 function on ovarian cancer cells in vitro were explored by colony formation assay, transwell assay and Brdu-based cell cycle assay in vitro and xenograft models in vivo. Western blotting, immunostaining and DNA/RNA immunoprecipitation-qPCR were conducted to confirm DNA damage and R-loop accumulation in ovarian cancer cells. Co-immunoprecipitation and DNA/RNA immunoprecipitation were performed to detect interaction of DHX9, ADAR1 and R-loop complex in ovarian cancer cells.ResultsWe demonstrated that ADAR1 was highly expressed in ovarian cancer tissues and negatively correlated with progression free survival of ovarian cancer patients. Importantly, silence of ADAR1 repressed ovarian cancer cell growth and colony formation in vitro and inhibited ovarian cancer cell tumorigenesis in vivo. Further cell cycle and transcriptome profile analysis revealed that silence of ADAR1 in ovarian cancer cells induced cell cycle arrest at G1/G0 stage. Mechanically, loss of ADAR1 caused R-loop abnormal accumulation, thereby contributing to single stand DNA break and ATR pathway activation. Additionally, ADAR1 interacted with DHX9 to regulate R-loop complex formation, and A-to-I editing of nascent RNA repressed R-loop formation during co-transcriptional process. ConclusionsOur results identify a novel ADAR1/R-loop/ATR axis critical for ovarian cancer progression and a potential target for ovarian cancer therapy.

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Down-regulation of ZNF252P-AS1 alleviates ovarian cancer progression by binding miR-324-3p to downregulate LY6K

Journal of Ovarian Research ◽

10.1186/s13048-021-00933-7 ◽

2022 ◽

Vol 15 (1) ◽

Author(s):

Li Geng ◽

Zhongqiu Wang ◽

Yongju Tian

Keyword(s):

Ovarian Cancer ◽

Cancer Cell ◽

Cancer Progression ◽

Epithelial To Mesenchymal Transition ◽

Ovarian Cancer Cells ◽

Mesenchymal Transition ◽

In Vivo Experiments ◽

Cancer Tissues

Abstract Background Ovarian cancer is a common gynecological malignant disease in women. Our work aimed to study the specific functions of ZNF252P antisense RNA 1 (ZNF252P-AS1) in ovarian cancer. Methods ZNF252P-AS1, miR-324-3p, and lymphocyte antigen 6 family member K (LY6K) expression were analyzed by bioinformatics tools in ovarian cancer tissues and was quantified by qRT-PCR in ovarian cancer cells. The effect of ZNF252P-AS1 knockdown, miR-324-3p suppression, and LY6K over-expression on apoptosis, cell viability, invasion, migration, and epithelial to mesenchymal transition (EMT) was determined in vitro by using colony formation and EdU assays, flow cytometry, transwell assay, and Western blot. The interactions between ZNF252P-AS1 and miR-324-3p and between miR-324-3p and LY6K were validated by luciferase assays. The effects of restraining ZNF252P-AS1 in vivo were studied using BALB/c male nude mice. Results ZNF252P-AS1 and LY6K levels were up-regulated, while miR-324-3p was declined in ovarian cancer tissues and cells. ZNF252P-AS1 knockdown reduced ovarian cancer cell proliferation, invasion, migration, and EMT, whereas promoted its apoptosis. Besides, ZNF252P-AS1 interacted with miR-324-3p and reversely regulated its level, and miR-324-3p was directly bound to LY6K and negatively regulated its expression. Moreover, ZNF252P-AS1 knockdown reversed the effect of miR-324-3p on cancer cell apoptosis, growth, migration, invasion, and EMT. Similar results were discovered in the rescue experiments between miR-324-3p and LY6K. Additionally, mouse models in vivo experiments further validated that ZNF252P-AS1 knockdown distinctly inhibited tumor growth. Conclusion ZNF252P-AS1 mediated miR-324-3p/LY6K signaling to facilitate progression of ovarian cancer.

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RETRACTED ARTICLE: Long noncoding RNA MLK7-AS1 promotes ovarian cancer cells progression by modulating miR-375/YAP1 axis

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-018-0910-4 ◽

2018 ◽

Vol 37 (1) ◽

Cited By ~ 28

Author(s):

Huan Yan ◽

Hong Li ◽

Pengyun Li ◽

Xia Li ◽

Jianjian Lin ◽

...

Keyword(s):

Ovarian Cancer ◽

Wound Healing ◽

Cancer Cells ◽

Cell Lines ◽

Colony Formation ◽

Ovarian Cancer Cells ◽

Human Ovarian Cancer ◽

Cancer Tissues

Abstract Background Long noncoding RNAs (LncRNAs) have been reported to be abnormally expressed in human ovarian cancer and associated with the proliferation and metastasis of cancer cells. The objective of this study was to investigate the role and the underlying mechanisms of LncRNA MAP3K20 antisense RNA 1 (MLK7-AS1) in ovarian cancer. Methods The expression level of MLK7-AS1 was investigated in human ovarian cancer tissues and cell lines. The effects of MLK7-AS1 knockdown on ovarian cancer cell proliferation, migration, invasion and apoptosis were evaluated in vitro using MTT, colony formation assays, wound healing assays, transwell assays and flow cytometry. Furthermore, the in vivo effects were determined using the immunodeficient NSG female mice. Luciferase reporter assays were employed to identify interactions among MLK7-AS1 and its target genes. Results In the current study, MLK7-AS1 was specifically upregulated in ovarian cancer tissues and cell lines. Knockdown of MLK7-AS1 inhibited the ability of cell migration, invasion, proliferation, colony formation and wound healing, whereas promoted cell apoptosis in vitro. By using online tools and mechanistic analysis, we demonstrated that MLK7-AS1 could directly bind to miR-375 and downregulate its expression. Besides, MLK7-AS1 reversed the inhibitory effect of miR-375 on the growth of ovarian cancer cells, which might be involved in the upregulation of Yes-associated protein 1 (YAP1) expression. Moreover, knockdown MLK7-AS1 expression inhibited primary tumor growth in ovary and metastatic tumors in multiple peritoneal organs including liver and spleen in vivo, which were partly abolished by miR-375 inhibition. Mechanically, we found that MLK7-AS1 modulated the epithelial-mesenchymal transition (EMT) process by interacting with miR-375/YAP1 both in vivo and vitro, which promoted the expression of Slug. Conclusions Taken together, our study showed for the first time that MLK7-AS1 interacted with miR-375 to promote proliferation, metastasis, and EMT process in ovarian cancer cells through upregulating YAP1.

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FBW7 suppresses ovarian cancer development by targeting the N6-methyladenosine binding protein YTHDF2

Molecular Cancer ◽

10.1186/s12943-021-01340-8 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Fei Xu ◽

Jiajia Li ◽

Mengdong Ni ◽

Jingyi Cheng ◽

Haiyun Zhao ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Progression ◽

Biological Effects ◽

Ovarian Cancer Cells ◽

Promoting Effect ◽

In Vivo Models ◽

Cancer Cell Survival ◽

Cancer Tissues

Abstract Background The tumor suppressor FBW7 is the substrate recognition component of the SCF E3-ubiquitin ligase complex that mediates proteolytic degradation of various oncogenic proteins. However, the role of FBW7 in ovarian cancer progression remains inadequately understood. Methods IP-MASS, co-IP, immunohistochemistry, and western blotting were used to identify the potential substrate of FBW7 in ovarian cancer. The biological effects of FBW7 were investigated using in vitro and in vivo models. LC/MS was used to detect the m6A levels in ovarian cancer tissues. MeRIP-Seq and RNA-Seq were used to assess the downstream targets of YTHDF2. Results We unveil that FBW7 is markedly down-regulated in ovarian cancer tissues and its high expression is associated with favorable prognosis and elevated m6A modification levels. Consistently, ectopic FBW7 inhibits ovarian cancer cell survival and proliferation in vitro and in vivo, while ablation of FBW7 empowers propagation of ovarian cancer cells. In addition, the m6A reader protein, YTHDF2, is identified as a novel substrate for FBW7. FBW7 counteracts the tumor-promoting effect of YTHDF2 by inducing proteasomal degradation of the latter in ovarian cancer. Furthermore, YTHDF2 globally regulates the turnover of m6A-modified mRNAs, including the pro-apoptotic gene BMF. Conclusions Our study has demonstrated that FBW7 suppresses tumor growth and progression via antagonizing YTHDF2-mediated BMF mRNA decay in ovarian cancer.

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NTNG1 Modulates Cisplatin Resistance in Epithelial Ovarian Cancer Cells via the GAS6/AXL/Akt Pathway

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.652325 ◽

2021 ◽

Vol 9 ◽

Author(s):

Shanyu Fang ◽

Yuanyuan Luo ◽

Ying Zhang ◽

Houmei Wang ◽

Qianfen Liu ◽

...

Keyword(s):

Ovarian Cancer ◽

Epithelial Ovarian Cancer ◽

Cancer Cells ◽

Cisplatin Resistance ◽

Progression Free Survival ◽

Akt Pathway ◽

Ovarian Cancer Cells ◽

Skov3 Cells ◽

Cancer Tissues

Cisplatin resistance is a challenge in the treatment of epithelial ovarian cancer. Here, clinical data showed that the level of netrin-G1 (NTNG1) in cisplatin-resistant cancer was higher than that in cisplatin-sensitive cancer (2.2-fold, p = 0.005); patients with a high NTNG1 level in cancer tissues had shorter progression-free survival (11.0 vs. 25.0 months, p = 0.010) and platinum-free interval (5.0 vs. 20.0 months, p = 0.021) compared with patients with a low level. Category- or stage-adjusted analyses demonstrated that the association between the NTNG1 level and prognosis occurred in type II or FIGO III/IV cancer. The basal level of NTNG1 in SKOV3/DDP cells (a cisplatin-resistant subline) was higher than that in SKOV3 cells; therefore, NTNG1 was overexpressed in SKOV3 cells, or silenced in SKOV3/DDP cells. Knocking in NTNG1 reduced the action of cisplatin to decrease cell death and apoptosis of SKOV3 cells, accompanied by upregulation of p-AXL, p-Akt and RAD51; however, opposite effects were observed in SKOV3/DDP cells after knocking down NTNG1. Co-immunoprecipitation demonstrated that NTNG1 bound GAS6/AXL. Silencing NTNG1 enhanced cisplatin effects in vivo, decreasing tumor volume/mass. These data suggested that a high NTNG1 level can result in cisplatin resistance in ovarian cancer cells via the GAS6/AXL/Akt pathway and that NTNG1 may be a useful target to overcome resistance.

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