Cisplatin-resistant Ovarian Cancer Research Articles

TGF β1 promotes the polarization of M2-type macrophages and activates PI3K/mTOR signaling pathway by inhibiting ISG20 to sensitize ovarian cancer to cisplatin

The involvement of Interferon-stimulated exonuclease gene 20 (ISG20) has been reported in renal clear cell carcinoma, hepatocellular carcinoma, and cervical cancer. However, its role in ovarian cancer chemotherapy remains unclear. In this study, we conducted a comparative analysis of TGF-β1 and ISG20 in cisplatin-sensitive and cisplatin-resistant ovarian cancer cells and tissues using qRT-PCR and a tissue immunofluorescence analysis. We also investigated the impact of ISG20-targeted drugs (IFN-γ) and TGF-β1 inhibitors on cisplatin response both in vivo and in vitro. Additionally, we assessed the effects of TGF-β1 or ISG20 on the polarization of tumor-associated macrophages through flow cytometry and ELISA analysis. Our findings revealed that ISG20 expression was lower in cisplatin-resistant tissues compared to cisplatin-sensitive tissues; however, overexpression of ISG20 sensitized ovarian cancer to cisplatin treatment. Furthermore, activation of ISG20 expression with IFN-γ or TGF-β1 inhibitors enhanced the sensitivity of ovarian cancer cells to cisplatin therapy. Notably, our results demonstrated that TGF-β1 promoted M2-type macrophage polarization as well as PI3K/mTOR pathway activation by suppressing ISG20 expression both in vivo and in vitro. In conclusion, our study highlights the critical role played by ISG20 within the network underlying cisplatin resistance in ovarian cancer. Targeting ISG20 using IFN-γ or TGF-β1 inhibitors may represent a promising therapeutic strategy for treating ovarian cancer.

Proto-oncogene c-Myb potentiates cisplatin resistance of ovarian cancer cells by downregulating lncRNA NKILA and modulating cancer stemness and LIN28A-let7 axis

Ovarian cancer is a major gynecological cancer that has poor prognosis associated mainly to its late diagnosis. Cisplatin is an FDA approved ovarian cancer therapy and even though the therapy is initially promising, the patients mostly progress to resistance against cisplatin. The underlying mechanisms are complex and not very clearly understood. Using two different paired cell lines representing cisplatin-sensitive and the cisplatin-resistant ovarian cancer cells, the ES2 and the A2780 parental and cisplatin-resistant cells, we show an elevated proto-oncogene c-Myb in resistant cells. We further show down-regulated lncRNA NKILA in resistant cells with its de-repression in resistant cells when c-Myb is silenced. NKILA negatively correlates with cancer cell and invasion but has no effect on cellular proliferation or cell cycle. C-Myb activates NF-κB signaling which is inhibited by NKILA. The cisplatin resistant cells are also marked by upregulated stem cell markers, particularly LIN28A and OCT4, and downregulated LIN28A-targeted let-7 family miRNAs. Whereas LIN28A and downregulated let-7s individually de-repress c-Myb-mediated cisplatin resistance, the ectopic expression of let-7s attenuates LIN28A effects, thus underlying a c-Myb-NKILA-LIN28A-let-7 axis in cisplatin resistance of ovarian cancer cells that needs to be further explored for therapeutic intervention.

Angelica sinensis polysaccharide combined with cisplatin reverses cisplatin resistance of ovarian cancer by inducing ferroptosis via regulating GPX4

Cisplatin (DDP) resistance poses a significant challenge in the treatment of ovarian cancer. Studies have shown that the combination of certain polysaccharides derived from plants with DDP is an effective approach to overcoming drug resistance in some cancers. Angelica sinensis (Oliv.) Diels has been used for centuries in China to treat gynecological ailments. Numerous studies indicate that Angelica sinensis polysaccharide (ASP), an extract from Angelica sinensis, can inhibit various forms of cancer. However, the impact of ASP on ovarian cancer remains unexplored. Through both in vitro and in vivo experiments, our study revealed the capability of ASP to effectively reversing DDP resistance in cisplatin-resistant ovarian cancer cells, while exhibiting acceptable safety profiles in vivo. To elucidate the mechanism underlying drug resistance reversal, we employed RNA-seq analysis and identified GPX4 as a key gene. Considering the role of GPX4 in ferroptosis, we conducted additional research to explore the effects of combining ASP with DDP on SKOV3/DDP cells. In summary, our findings demonstrate that the combination of ASP and DDP effectively suppresses GPX4 expression in SKOV3/DDP cells, thereby reversing their resistance to DDP.

Expression of human dCTP pyrophosphatase 1 (DCTPP1) and its association with cisplatin resistance characteristics in ovarian cancer.

Cisplatin (DDP) resistance is a major challenge in treating ovarian cancer patients. A recently discovered enzyme called dCTP pyrophosphatase 1 (DCTPP1) has been implicated in regulating cancer characteristics, including drug responses. In this study, we aimed to understand the role of DCTPP1 in cancer progression and cisplatin response. Using publicly available databases, we analysed the expression and clinical significance of DCTPP1 in ovarian cancer. Our bioinformatics analysis confirmed that DCTPP1 is significantly overexpressed in ovarian cancer and is closely associated with tumour progression and poor prognosis after cisplatin treatment. We also found that DCTPP1 located in oxidoreductase complex and may be involved in various biological processes related to cisplatin resistance, including pyrimidine nucleotide metabolism, the P53 signalling pathway and cell cycle signalling pathways. We observed higher expression of DCTPP1 in cisplatin-resistant cells (SKOV3/DDP) and samples compared to their sensitive counterparts. Additionally, we found that DCTPP1 expression was only enhanced in SKOV3/S cells when treated with cisplatin, indicating different expression patterns of DCTPP1 in cisplatin-sensitive and cisplatin-resistant cancer cells. Our study further supports the notion that cisplatin induces intracellular reactive oxygen species (ROS) and triggers cancer cell death through excessive oxidative stress. Knocking out DCTPP1 reversed the drug resistance of ovarian cancer cells by enhancing the intracellular antioxidant stress response and accumulating ROS. Based on our research findings, we conclude that DCTPP1 has prognostic value for ovarian cancer patients, and targeting DCTPP1 may be clinically significant in overcoming cisplatin resistance in ovarian cancer.

MAP7 drives EMT and cisplatin resistance in ovarian cancer via wnt/β-catenin signaling

MethodsOur approach encompasses analyzing MAP7's expression levels across various datasets and clinical specimens, evaluating its association with patient outcomes, and probing its influence on ovarian cancer cell dynamics such as proliferation, migration, invasion, and apoptosis. ResultsWe have identified significant upregulation of MAP7 in ovarian cancer tissues, which correlates with advanced disease stages, higher pathological grades, and unfavorable prognoses. Functionally, the inhibition of MAP7 suppresses cancer cell proliferation, migration, and invasion while promoting apoptosis. Notably, the silencing of MAP7 attenuates the epithelial-mesenchymal transition (EMT) and disrupts Wnt/β-catenin pathway signaling—two critical processes implicated in metastasis and chemoresistance. In cisplatin-resistant A2780-DDP cells, the downregulation of MAP7 effectively reverses their resistance to cisplatin. Furthermore, the nuclear localization of MAP7 in these cells underscores its pivotal role in driving cisplatin resistance by modulating the transcriptional regulation and interaction dynamics of β-catenin. ConclusionOur findings position MAP7 as a pivotal element in ovarian cancer advancement and cisplatin resistance, primarily through its modulation of EMT and the Wnt/β-catenin pathway. Its association with poor clinical outcomes underscores its potential as both a prognostic marker and a therapeutic target. Strategies aimed at MAP7 could represent a new frontier in combating chemotherapy resistance in ovarian cancer, emphasizing its significance in crafting complementary treatments for this disease.

Exploring the Antiproliferative and Modulatory Effects of 1-Methoxyisobrassinin on Ovarian Cancer Cells: Insights into Cell Cycle Regulation, Apoptosis, Autophagy, and Its Interactions with NAC.

Ovarian cancer, a highly lethal malignancy among reproductive organ cancers, poses a significant challenge with its high mortality rate, particularly in advanced-stage cases resistant to platinum-based chemotherapy. This study explores the potential therapeutic efficacy of 1-methoxyisobrassinin (MB-591), a derivative of indole phytoalexins found in Cruciferae family plants, on both cisplatin-sensitive (A2780) and cisplatin-resistant ovarian cancer cells (A2780 cis). The findings reveal that MB-591 exhibits an antiproliferative effect on both cell lines, with significantly increased potency against cisplatin-sensitive cells. The substance induces alterations in the distribution of the cell cycle, particularly in the S and G2/M phases, accompanied by changes in key regulatory proteins. Moreover, MB-591 triggers apoptosis in both cell lines, involving caspase-9 cleavage, PARP cleavage induction, and DNA damage, accompanied by the generation of reactive oxygen species (ROS) and mitochondrial dysfunction. Notably, the substance selectively induces autophagy in cisplatin-resistant cells, suggesting potential targeted therapeutic applications. The study further explores the interplay between MB-591 and antioxidant N-acetylcysteine (NAC), in modulating cellular processes. NAC demonstrates a protective effect against MB-591-induced cytotoxicity, affecting cell cycle distribution and apoptosis-related proteins. Additionally, NAC exhibits inhibitory effects on autophagy initiation in cisplatin-resistant cells, suggesting its potential role in overcoming resistance mechanisms.

Long noncoding RNA TUG1 promotes cisplatin resistance in ovarian cancer via upregulation of DNA polymerase eta.

Chemoresistance is a major cause of high mortality and poor survival in patients with ovarian cancer (OVCA). Understanding the mechanisms of chemoresistance is urgently required to develop effective therapeutic approaches to OVCA. Here, we show that expression of the long noncoding RNA, taurine upregulated gene 1 (TUG1), is markedly upregulated in samples from OVCA patients who developed resistance to primary platinum-based therapy. Depletion of TUG1 increased sensitivity to cisplatin in the OVCA cell lines, SKOV3 and KURAMOCHI. Combination therapy of cisplatin with antisense oligonucleotides targeting TUG1 coupled with a drug delivery system effectively relieved the tumor burden in xenograft mouse models. Mechanistically, TUG1 acts as a competing endogenous RNA by downregulating miR-4687-3p and miR-6088, both of which target DNA polymerase eta (POLH), an enzyme required for translesion DNA synthesis. Overexpression of POLH reversed the effect of TUG1 depletion on cisplatin-induced cytotoxicity. Our data suggest that TUG1 upregulation allows OVCA to tolerate DNA damage via upregulation of POLH; this provides a strong rationale for targeting TUG1 to overcome cisplatin resistance in OVCA.

MicroRNA Expression Profiles in Human Samples and Cell Lines Revealed Nine miRNAs Associated with Cisplatin Resistance in High-Grade Serous Ovarian Cancer.

Metastasis and drug resistance are major contributors to cancer-related fatalities worldwide. In ovarian cancer (OC), a staggering 70% develop resistance to the front-line therapy, cisplatin. Despite proposed mechanisms, the molecular events driving cisplatin resistance remain unclear. Dysregulated microRNAs (miRNAs) play a role in OC initiation, progression, and chemoresistance, yet few studies have compared miRNA expression in OC samples and cell lines. This study aimed to identify key miRNAs involved in the cisplatin resistance of high-grade-serous-ovarian-cancer (HGSOC), the most common gynecological malignancy. MiRNA expression profiles were conducted on RNA isolated from formalin-fixed-paraffin-embedded human ovarian tumor samples and HGSOC cell lines. Nine miRNAs were identified in both sample types. Targeting these with oligonucleotide miRNA inhibitors (OMIs) reduced proliferation by more than 50% for miR-203a, miR-96-5p, miR-10a-5p, miR-141-3p, miR-200c-3p, miR-182-5p, miR-183-5p, and miR-1206. OMIs significantly reduced migration for miR-183-5p, miR-203a, miR-296-5p, and miR-1206. Molecular pathway analysis revealed that the nine miRNAs regulate pathways associated with proliferation, invasion, and chemoresistance through PTEN, ZEB1, FOXO1, and SNAI2. High expression of miR-1206, miR-10a-5p, miR-141-3p, and miR-96-5p correlated with poor prognosis in OC patients according to the KM plotter database. These nine miRNAs could be used as targets for therapy and as markers of cisplatin response.

Mitochondrial and cytosolic one-carbon metabolism is a targetable metabolic vulnerability in cisplatin-resistant ovarian cancer.

One-carbon (C1) metabolism is compartmentalized between the cytosol and mitochondria with the mitochondrial C1 pathway as the major source of glycine and C1 units for cellular biosynthesis. Expression of mitochondrial C1 genes including SLC25A32, serine hydroxymethyl transferase (SHMT) 2, 5,10-methylene tetrahydrofolate dehydrogenase 2, and 5,10-methylene tetrahydrofolate dehydrogenase 1-like was significantly elevated in primary epithelial ovarian cancer (EOC) specimens compared to normal ovaries. 5-Substituted pyrrolo[3,2-d]pyrimidine antifolates (AGF347, AGF359, AGF362) inhibited proliferation of cisplatin sensitive (A2780, CaOV3, IGROV1) and resistant (A2780-E80, SKOV3) EOC cells. In SKOV3 and A2780-E80 cells, colony formation was inhibited. AGF347 induced apoptosis in SKOV3 cells. In IGROV1 cells, AGF347 was transported by folate receptor (FR) α. AGF347 was also transported into IGROV1 and SKOV3 cells by the proton-coupled folate transporter (SLC46A1) and the reduced folate carrier (SLC19A1). AGF347 accumulated to high levels in the cytosol and mitochondria of SKOV3 cells. By targeted metabolomics with [2,3,3-2H]L-serine, AGF347, AGF359 and AGF362 inhibited SHMT2 in the mitochondria. In the cytosol, SHMT1 and de novo purine biosynthesis (i.e., glycinamide ribonucleotide formyltransferase, 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase) were targeted; AGF359 also inhibited thymidylate synthase. Antifolate treatments of SKOV3 cells depleted cellular glycine, mitochondrial NADH and glutathione, and showed synergistic in vitro inhibition toward SKOV3 and A2780-E80 cells when combined with cisplatin. In vivo studies with subcutaneous SKOV3 EOC xenografts in SCID mice confirmed significant antitumor efficacy of AGF347. Collectively, our studies demonstrate a unique metabolic vulnerability in EOC involving mitochondrial and cytosolic C1 metabolism that offers a promising new platform for therapy.

Abstract 7155: Dichloroacetate reverses cisplatin resistance in ovarian cancer through promoting ROS production

Abstract Chemotherapy resistance and the high rate of ovarian cancer relapse pose major challenges in the treatment of ovarian cancer. The development of chemoresistance contributes to poor overall prognosis associated with ovarian cancer and high cancer-related mortality in women worldwide. Herein, we found that Dichloroacetate (DCA), a pan-pyruvate dehydrogenase kinase (PDK) inhibitor, is a potent agent to overcome Cisplatin (CP) resistance in ovarian cancer treatment. Firstly, we elucidated that phosphorylation of pyruvate dehydrogenase (pPDH) was elevated in CP-resistant ovarian cancer cells. Then, blockage of pPDH by DCA treatment significantly inhibited cell migratory and invasive capacity in CP-resistant ovarian cancer cells through the transition of motile mesenchymal phenotypes into epithelial characteristics. DCA markedly decreased the number of sphere formations and attenuated the stem cell-like properties in CP-resistant ovarian cancer cells. In combination with CP treatment, DCA effectively inhibited cell proliferation in chemoresistant ovarian cancer cells by triggering apoptosis. Collectively, we suggested that DCA is a promising drug to reverse CP resistance for ovarian cancer treatment. We further tested the underlying mechanisms of DCA to restore CP sensitivity in ovarian cancer. We found that CP treatment promoted reactive oxygen species (ROS) production to induce cell death in CP-sensitive ovarian cancer. However, CP-resistant ovarian cancer cells exhibited higher basal levels of ROS compared with sensitive cancer cells, and CP treatment failed to generate ROS production. That means ovarian cancer cells steadily adapted to elevated ROS levels, then becoming ROS-adapted ovarian cancer cells to survive. Interestingly, DCA treatment results in the buildup of ROS production, causing cell death in CP-resistant ovarian cancer. Therefore, our study suggests that ROS production can be an attractive target in DCA treatment to restore CP sensitivity in ovarian cancer. Citation Format: Yen Thi Do, Seungmee Lee, Changmin Shin, Hyewon Chung, Jin Young Kim, Eunyoung Ha, Sojin Shin, Ji Hae Seo. Dichloroacetate reverses cisplatin resistance in ovarian cancer through promoting ROS production [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7155.

Abstract 5860: Understanding the biological role of MMP16 in cisplatin resistance in ovarian cancer

Abstract High-Grade Serous Ovarian Cancer (HGSOC) is the most common and lethal of Ovarian Cancer (OC) types, which accounts for eighty percent of deaths. Treatment for OC includes surgery and platinum-based therapy. However, around 70% of women with HGSOC become resistant to chemotherapy. Therefore, new therapeutic agents with higher specificity and efficacy are needed for women with advanced and drug-resistant OC. Matrix metalloproteases (MMPs) are a group of enzymes involved in the degradation of the extracellular matrix (ECM). Deregulation of MMPs contributes to tumor growth and metastasis in several cancer types. Preliminary studies of our research team found that MMP16 is higher in cisplatin-resistant as compared with cisplatin-sensitive OC cells. The aim of this project is to understand the role of MMP16 in the cisplatin resistance of OC cells. We hypothesize that MMP16 increased expression may contribute to cancer progression and drug-resistance. We performed experiments in A2780/A2780CP20 and OVCAR3/OVCAR3CIS human OC cells. To assess the MMP16 protein levels we used western blot analysis. To measure the mRNA levels, we used qRT-PCR. Kaplan-Meier survival curves were generated by interrogation of the KM Plotter patient database. The MMP16 protein and qRT-PCR experiments confirmed that protein and mRNA levels are more abundant in cisplatin-resistant as compared with cisplatin-sensitive cells. Interrogation of the KM plotter database showed that OC patients with higher MMP16 mRNA levels live less as compared with OC patients with lower MMP16 levels. Ongoing experiments are testing the biological effect of small interference RNA (siRNA) targeting MMP16 in cisplatin-resistant OC cells. Citation Format: Jesennia Bonilla-Liriano, Mariela Rivera-Serrano, Victor Reyes-Burgos, Jose Rolon-Perez, Fatima Valiyeva, Pablo Vivas-Mejia. Understanding the biological role of MMP16 in cisplatin resistance in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5860.

Abstract 4318: CD24 enhances cisplatin resistance in ovarian cancer by suppressing autophagy

Abstract Ovarian cancer is one of the most common gynecological cancers with the highest mortality rate. Most patients are diagnosed with advanced disease and will relapse due to chemoresistance. CD24, a highly glycosylated GPI-anchored membrane protein. Recent studies have shown that CD24 expression is significantly up-regulated in ovarian cancer and is associated with chemotherapy resistance, and CD24 also plays an inhibitory role in tumor immunity by binding to Siglec-10 on macrophages. However, the molecular mechanisms of how CD24 affects chemotherapy resistance in ovarian cancer remain unclear. In this study, we used shRNAs to knockdown CD24 and explore the impact and mechanism of CD24 on the chemotherapy resistance of ovarian cancer cells. The results showed that knockdown of CD24 in ovarian cancer cells SKOV3 and TOV21G significantly reduced cell proliferation and arrested the cell cycle in S phase. Knockdown of CD24 also significantly increased the sensitivity of ovarian cancer cells to cisplatin but had no effect on paclitaxol treatment. Further experiments showed that knockdown of CD24 increased cisplatin sensitivity by promoting autophagy-induced cell death. In addition, Gene Set Enrichment Analysis (GSEA) was used to analyze the correlation between the expression of CD24 and its biological functions in the TCGA ovarian cancer dataset. The results showed that CD24 is mostly correlated to cell proliferation and autophagy-related pathways in ovarian cancers. Further mouse xenograft tumor transplantation experiments also confirmed that knockdown of CD24 reduced tumor size and increased sensitivity to cisplatin treatment by increasing cell autophagy. Taken together, these results indicate that CD24 regulates cell growth and chemoresistance in ovarian cancer cells and that inhibition of CD24 may be helpful in the treatment of ovarian cancer. Citation Format: Yuh-Ling Chen, Tse-Ming Hong, Yu-Yi Wen. CD24 enhances cisplatin resistance in ovarian cancer by suppressing autophagy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4318.

Abstract 2989: MicroRNA profiling in human samples and cell lines uncovers eight key players in the cisplain resistance of HGSOC

Abstract Metastasis and drug resistance remain significant contributors to cancer-related mortality globally. In ovarian cancer, a substantial 70% of cases develop resistance to the front-line therapy, cisplatin. Despite numerous proposed mechanisms for cisplatin resistance, the complete molecular events leading to this phenomenon in ovarian cancer remain incompletely understood. Mounting evidence suggests that dysregulation of microRNAs (miRNAs) plays a pivotal role in carcinogenesis, including the development of drug resistance. While various miRNAs have been identified in ovarian cancer samples and cell lines, few studies have compared miRNA expression in human paraffin ovarian samples and cisplatin-resistant high-grade serous ovarian cancer (HGSOC), the most prevalent and malignant of gynecological malignancies. This study aimed to identify key miRNAs implicated in cisplatin resistance. We performed miRNA expression profiles in RNA isolated from human paraffin ovarian tumors and ovarian cancers cell lines. Eight miRNAs were commonly increased in paraffin samples and cisplatin resistant ovarian cancer cells. Targeting these miRNAs with inhibitors significantly reduced cell proliferation by more than 50% for miR-203a, miR-96-5p, miR-10a-5p, miR-141-3p, miR-200c-3p, and miR-182-5p, and to a lesser extent, miR-296-5p and miR-1206. Inhibitors demonstrated a reduction in cell migration for all targets except miR-200c-3p and miR-10a-5p. Analysis of online databases, literature reports, and molecular pathway construction revealed that these eight miRNAs regulate key molecular pathways associated with cell proliferation, primarily through PTEN regulation in cisplatin-resistant HGSOC cells. Interrogation of the KM plotter patient database revealed that high expression of miR-1206, miR-10a, miR-141, and miR-96 correlates with a poor prognosis in ovarian cancer patients. These findings position these eight miRNAs as potential therapeutic targets and markers for cisplatin response in ovarian cancer therapy. Citation Format: Mariela Rivera-Serrano, Marienid Flores, Jose Rolon, Victor Reyes, Fatma Valiyeva, Pablo E. Vivas-Mejia. MicroRNA profiling in human samples and cell lines uncovers eight key players in the cisplain resistance of HGSOC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2989.

Abstract 4473: Targeting matrix metalloproteinase-3 (MMP-3) in high-grade serous ovarian cancer

Abstract High-Grade Serous Ovarian Cancer (HGSOC) is the most aggressive and lethal gynecological malignancy. Surgery and chemotherapy (with platinum compounds) are the main treatments. Many patients relapse and develop chemotherapy resistance, limiting the therapeutic utility of these therapies. This persistent resistance makes HGSOC treatment difficult. Cisplatin-resistant ovarian cancer cells upregulate Matrix Metalloproteinase-3. MMP3 is an enzyme involved in active tissue remodeling and extracellular matrix protein breakdown during dynamic physiological processes. The structure of MMP3 includes the prodomain, the catalytic domain and the hemopexin domain. We showed that MMP3 protein levels are higher in cisplatin resistant as compared with cisplatin sensitive HGSOC cells. Our research team showed that small interference RNA (siRNA)-mediated MMP3 knockdown reduced cisplatin-resistant ovarian cancer cell growth and invasion. This data indicates that MMP3 may be a promising HGSOC treatment target. Targeting MMP3 with small chemical inhibitors (SCI) could represent a better option than siRNA because SCI are more stable and easier to deliver. The purpose of this project is to design SCI of MMP3 in the propeptide, catalytic, and hemopexin domains of MMP3. We used in silico methods to identify MMP3 inhibitors in these domains. The ZINC20 database of commercially compounds was used for virtual screening using Python Prescription (PyRx) software. We identified 25 ligands out of 370,000 with the greatest affinity for each MMP3 functional domains. SwissADME was then used to evaluate in silico absorption, distribution, metabolism, pharmacokinetics, drug-likeliness, and medicinal chemistry. This research lays the groundwork for HGSOC therapeutic strategies to improve treatment efficacy, especially for chemotherapy-resistant patients. Citation Format: Víctor G. Reyes-Burgos, Eliud Hernández-O'Farrill, Luis E. Vazquez Quiñones, Marienid Flores-Colón, Fatima Valiyeva, Pablo E. Vivas-Mejía. Targeting matrix metalloproteinase-3 (MMP-3) in high-grade serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4473.

Abstract B028: Unraveling the role of matrix metalloproteinase 3 (mmp3) in cisplatin resistance of ovarian cancer

Abstract B028: Unraveling the role of matrix metalloproteinase 3 (mmp3) in cisplatin resistance of ovarian cancer

CD147 facilitates cisplatin resistance in ovarian cancer through FOXM1 degradation inhibition

CD147 facilitates cisplatin resistance in ovarian cancer through FOXM1 degradation inhibition

Statement of Retraction: Protein tyrosine phosphatase receptor type Z1 inhibits the cisplatin resistance of ovarian cancer by regulating PI3K/AKT/mTOR signal pathway

Statement of Retraction: Protein tyrosine phosphatase receptor type Z1 inhibits the cisplatin resistance of ovarian cancer by regulating PI3K/AKT/mTOR signal pathway

HIF-2α-dependent TGFBI promotes ovarian cancer chemoresistance by activating PI3K/Akt pathway to inhibit apoptosis and facilitate DNA repair process

Hypoxia-mediated chemoresistance plays a crucial role in the development of ovarian cancer (OC). However, the roles of hypoxia-related genes (HRGs) in chemoresistance and prognosis prediction and theirs underlying mechanisms remain to be further elucidated. We intended to identify and validate classifiers of hub HRGs for chemoresistance, diagnosis, prognosis as well as immune microenvironment of OC, and to explore the function of the most crucial HRG in the development of the malignant phenotypes. The RNA expression and clinical data of HRGs were systematically evaluated in OC training group. Univariate and multivariate Cox regression analysis were applied to construct hub HRGs classifiers for prognosis and diagnosis assessment. The relationship between classifiers and chemotherapy response and underlying pathways were detected by GSEA, CellMiner and CIBERSORT algorithm, respectively. OC cells were cultured under hypoxia or transfected with HIF-1α or HIF-2α plasmids, and the transcription levels of TGFBI were assessed by quantitative PCR. TGFBI was knocked down by siRNAs in OC cells, CCK8 and in vitro migration and invasion assays were performed to examine the changes in cell proliferation, motility and metastasis. The difference in TGFBI expression was examined between cisplatin-sensitive and -resistant cells, and the effects of TGFBI interference on cell apoptosis, DNA repair and key signaling molecules of cisplatin-resistant OC cells were explored. A total of 179 candidate HRGs were extracted and enrolled into univariate and multivariate Cox regression analysis. Six hub genes (TGFBI, CDKN1B, AKAP12, GPC1, TGM2 and ANGPTL4) were selected to create a HRGs prognosis classifier and four genes (TGFBI, AKAP12, GPC1 and TGM2) were selected to construct diagnosis classifiers. The HRGs prognosis classifier could precisely distinguish OC patients into high-risk and low-risk groups and estimate their clinical outcomes. Furthermore, the high-risk group had higher percentage of Macrophages M2 and exhibited higher expression of immunecheckpoints such as PD-L2. Additionally, the diagnosis classifiers could accurately distinguish OC from normal samples. TGFBI was further verified as a specific key target and demonstrated that its high expression was closely correlated with poor prognosis and chemoresistance of OC. Hypoxia upregulated the expression level of TGFBI. The hypoxia-induced factor HIF-2α but not HIF-1α could directly bind to the promoter region of TGFBI, and facilitate its transcription level. TGFBI was upregulated in cisplatin-sensitive and resistant ovarian cancer cells in a cisplatin time-dependent manner. TGFBI interference downregulated DNA repair-related markers (p-p95/NBS1, RAD51, p-DNA-PKcs, DNA Ligase IV and Artemis), apoptosis-related marker (BCL2) and PI3K/Akt pathway-related markers (PI3K-p110 and p-Akt) in cisplatin-resistant OC cells. In summary, the HRGs prognosis risk classifier could be served as a predictor for OC prognosis and efficacy evaluation. TGFBI, upregulated by HIF-2α as an HRG, promoted OC chemoresistance through activating PI3K/Akt pathway to reduce apoptosis and enhance DNA damage repair pathway.

Promising effect of cisplatin and melatonin combination on the inhibition of cisplatin resistance in ovarian cancer

Background Ovarian cancer management has not yet given a satisfactory result, and the recurrence rate is still high. One of the reasons for this is resistance to chemotherapy. Melatonin and cisplatin may be involved in the chemotherapy resistance of ovarian cancer. Methods A laboratory experiment was performed using melatonin and cisplatin in the SKOV3 cell, from September 2020 to November 2021 at the SCTE and Integrated Laboratory & Research Center Universitas Indonesia. Several variables were used, such as doxorubicin, melatonin, cisplatin, and combination of cisplatin and melatonin at several concentrations (1×, 3/4×, 1/2×, and 1/4×). A total of 24 samples were included and divided into 8 groups. The IC50 values of melatonin, doxorubicin, and cisplatin as well as cell viability was calculated via MTS assay. Subsequently, flow cytometry was performed to assess the effect of cisplatin and melatonin on the mechanisms of CTR1, p-glycoprotein, GSH, ERCC1, e-cadherin, and apoptosis. Analysis of variance and Bonferroni test were employed for the study. Results The IC50 values of melatonin, cisplatin, and doxorubicin were 1.841 mM, 117.5 mM, and 14.72 mM, respectively. The combination groups of cisplatin and melatonin reduced cell viability; decreased the CTR1 mean (19.73), Pgp (6.7), GSH (11.73), and ERCC1 (4.27) in the combination 1 (C1) group; and increased e-cadherin (32.2) and annexin V (53.57) also in the combination 1 (C1) group. Conclusions The combination of melatonin and cisplatin might have an impact on drug resistance via several mechanisms in ovarian cancer.

TMCO1 regulates cell proliferation, metastasis and EMT signaling through CALR, promoting ovarian cancer progression and cisplatin resistance.

This study aimed to explore the involvement of Transmembrane and coiled-coil domains 1 (TMCO1) in ovarian cancer progression and its regulatory mechanisms in cisplatin resistance. Using the GEPIA database, we analyzed TMCO1 expression in ovarian cancer and normal tissues. In a cohort of 99 ovarian cancer patients, immunohistochemistry and immunofluorescence were employed to assess TMCO1 expression in tumor and adjacent tissues, correlating findings with clinical and pathological characteristics. TMCO1 overexpression and knockout cell models were constructed, and their impact on non-cisplatin-resistant (SK-OV-3) and cisplatin-resistant (SK-OV-3-CDDP) ovarian cancer cells was investigated through cloning, wound healing, Fluo 4, and Transwell experiments. Knocking down CALR and VDAC1 was performed to examine their effects on TMCO1, cell proliferation, and malignant markers. Subcutaneous tumor models in nude mice elucidated the in vivo role of TMCO1 in tumor growth. Expression levels of CALR, VDAC1, angiogenesis indicators (CD34), and epithelial-mesenchymal transition (EMT) markers were evaluated. TMCO1 expression in ovarian cancer tissue significantly differed from normal tissue, correlating with survival rates. TMCO1 overexpression was associated with lymph node metastases, late FIGO stage, and larger tumors. TMCO1 promoted proliferation, calcium ion elevation, cytoskeletal remodeling, and metastasis in SK-OV-3 and SK-OV-3-CDDP cells, upregulating VDAC1, CALR, Vimentin, N-cadherin, β-catenin, and downregulating E-cadherin. Silencing TMCO1 inhibited cell growth, proliferation, and angiogenesis in vivo, suppressing the expression of CALR, VDAC1, Vimentin, N-cadherin, and β-catenin. Overall, this study highlighted TMCO1 as a crucial regulator in ovarian cancer progression, influencing VDAC1 through CALR and impacting diverse cellular processes, offering potential as a targeted therapeutic strategy for ovarian cancer.