Resistant Ovarian Cancer Research Articles

Regulation of AUF1 alternative splicing by hnRNPA1 and SRSF2 modulate the sensitivity of ovarian cancer cells to cisplatin.

Clarification of cisplatin resistance may provide new targets for therapy in cisplatin resistant ovarian cancer. The current study aims to explore involvement of isoforms of AU-rich element RNA-binding protein 1 (AUF1) in cisplatin resistance in ovarian cancer. The cancer stem cell-like features were analyzed using colony formation assay, tumor sphere formation assay and nude mouse xenograft experiments. AUF1 isoforms expression was analyzed using immunoblotting, qRT-PCR, and immunohistochemistry. RIP and Biotin pulldown was used to analyze the interaction of SRSF2 and hnRNPA1 with AUF1 transcript. Transcriptome regulated by AUF1 isoforms was analyzed by RNA-seq. The current study demonstrated differential expression of AUF1 isoforms in cisplatin sensitive and resistant ovarian cancer tissues and cells. P37 isoform promoted proliferation, while p45 isoform enhanced responsiveness of ovarian cancer cells to cisplatin. the clonal formation capacity of the cells, and the restoration of p45 expression reduced the capacity with cisplatin treatment. The competitive binding of phosphorylated hnRNPA1 and O-GlcNAc-modified SRSF2 on AUF1 exon 2 and exon 7 regulated the alternative splicing of AUF1. The competitive binding of phosphorylated hnRNPA1 and O-GlcNAc modified SRSF2 on exon 2 and exon 7 regulated the alternative splicing of AUF1 and subsequent isoform expression. P37 isoform played a "cancer promoter" role, p42 and p45, especially p45 played a "cancer suppressor" role in ovarian cancer. This study provides a new target for exploring the drug resistance mechanism of ovarian cancer.

Salidroside overcomes cisplatin resistance in ovarian cancer via the inhibition of CRNDE-mediated autophagy.

Cisplatin (DDP) resistance significantly affects the survival rate of patients with ovarian cancer (OC). Autophagy is recognized as a common cause of resistance to DDP. This study aimed to investigate the impact of salidroside on OC progression and explore its potential regulatory effects on DDP resistance and autophagy. A DDP-resistant A2780 (A2780/DDP) cell line was induced by exposure to increasing DDP concentrations. The protein levels of autophagy proteins (p62, Beclin-1, ATG5, and LC3 II/LC3 I), apoptosis proteins (cleaved caspase-3 and cleaved caspase-9), and PI3K/AKT/mTOR pathway were determined by western blotting. Autophagic vacuoles in cells were observed with LC3 dyeing with confocal fluorescent microscopy. Cell viability and apoptosis were evaluated by cell counting kit-8 assays and flow cytometry. RT-qPCR was conducted to measure the relative levels of various lncRNAs in A2780 or A2780/DDP cells. A xenograft model was established by subcutaneous injection of 1 × 107 A2780 cells into the posterior flank of nude mice. Tumor size and weight were recorded. The expression of Ki67, cleaved caspase-3 and LC3 in tumor tissues was assessed by immunohistochemistry staining. The biodistribution of DDP in organs and blood of normal nude mice and tumors of tumor-bearing mice was detected using the ICP-MS. Hematoxylin-eosin staining was used to assess the histopathological changes of kidney, liver, and spleen sections. For in vitro analysis, autophagy was enhanced in DDP-resistant A2780 cells. Additionally, salidroside inhibits DDP resistance to A2780 cells via autophagy inhibition. Mechanistically, salidroside downregulated CRNDE in DDP-resistant A2780 cells. CRNDE knockdown inhibited autophagy, while CRNDE overexpression reversed the protective effects of salidroside. Additionally, salidroside activated the PI3K/AKT/mTOR pathway in DDP-resistant A2780 cells, and inhibition of PI3K reversed the effect of salidroside on inhibiting autophagy and apoptosis of A2780/DDP cells. For in vivo analysis, salidroside inhibited tumor growth, autophagy, and nephrotoxicity of DDP. Additionally, salidroside downregulated CRNDE and activated PI3K/AKT/mTOR signaling in vivo. Salidroside prevents autophagy-mediated DDP resistance in OC by downregulating lncRNA CRNDE and activating the PI3K/AKT/mTOR pathway.

KLF4 promotes cisplatin resistance by activating mTORC1 signaling in ovarian cancer

Ovarian cancer (OC) is a highly fatal gynecological malignancy worldwide, and cisplatin (CDDP) is commonly used as an initial chemotherapy treatment for OC. Nonetheless, most patients ultimately face recurrence because of resistance to cisplatin. Therefore, it is imperative to investigate the underlying mechanisms of drug resistance in OC. By analyzing differential gene expression using TCGA, GDSC, and GEO public databases, we discovered that increased KLF4 expression is strongly linked to chemotherapy resistance and unfavorable outcomes in OC. Subsequent validation through immunohistochemistry and western blotting confirmed the upregulated KLF4 expression in cisplatin-resistance OC cells lines and tissues. To investigate the function of KLF4, functional experiments were performed both in vitro and in vivo. We observed that knocking down KLF4 impaired cisplatin-resistance of OC. Further mechanism research based on RNA-seq and gene enrichment analysis revealed that interfering KLF4 suppressed the activation of mTORC1 pathway. Finally, rescue experiment demonstrated that using mTORC1 pathway inhibitor could attenuate the cisplatin resistance induced by the overexpression of KLF4. In conclusion, our research indicates that KLF4 promotes cisplatin resistance through the activation of mTORC1 signaling, and proposes that inhibiting KLF4 might serve as a viable therapeutic approach to overcoming drug resistance in ovarian cancer.

IRE1α inhibitor reduces cisplatin resistance in ovarian cancer by modulating IRE1α/XBP1 pathway.

Ovarian cancer, a leading cause of gynecological cancer deaths globally, poses significant treatment challenges. Cisplatin (CDDP) is the first treatment choice for ovarian cancer and it is initially effective. However, 80% of ovarian cancer patients eventually relapse and develop resistance, resulting in chemotherapy failure. Therefore, finding new treatment combinations to overcome ovarian cancer resistance can provide a new tactic to improve the ovarian cancer patients' survival rate. We first identified activation of the Unfolded Protein Response (UPR) in CDDP-resistant ovarian cancer cells, implicating the IRE1α/XBP1 pathway in promoting resistance. Our findings demonstrate that inhibiting IRE1α signaling can re-sensitizes resistant cells to CDDP in vivo and in vitro, suggesting that IRE1α inhibitor used in conjunction with CDDP presumably could merge as a novel therapeutic strategy. Here, our research highlights the critical role of IRE1α signaling in mediating CDDP resistance, and paves the way for improved treatment options through combinatorial therapy.

Nutritional status, hemoglobin, and albumin levels in predicting platinum resistance in ovarian cancer at Dr. Saiful Anwar Hospital, Malang, Indonesia

HIGHLIGHTS Nutrition status, hemoglobin, and albumin levels are not predictors for platinum resistance. Hemoglobin and albumin levels increased in both platinum-sensitive or platinum-resistant. ABSTRACT Objective: This study aimed to determine whether nutritional status, hemoglobin, and albumin levels could serve as reliable predictors for predicting platinum resistance in patients with ovarian cancer. Materials and Methods: Conducted as a cross-sectional analysis, this study included 80 ovarian cancer patients who had completed six cycles of platinum-based chemotherapy. Patients were divided into two categories: those with platinum-resistant cancer and those with platinum-sensitive cancer, based on recurrence status following chemotherapy. Nutritional status was assessed through body mass index (BMI), and both hemoglobin and albumin levels were measured pre- and post-chemotherapy to investigate potential differences between the groups. Results: The analysis revealed no significant difference in BMI between the platinum-sensitive and platinum-resistant groups (p = 0.743), suggesting that nutritional status, as measured by BMI, did not correlate with platinum resistance. Hemoglobin levels were similarly non-significant before (p = 0.072) and after chemotherapy (p = 0.055), indicating no clear association between hemoglobin levels and platinum response. However, hemoglobin levels showed significant increases post-chemotherapy in both the platinum-sensitive (p = 0.002) and platinum-resistant (p = 0.025) groups, though without affecting resistance outcomes. Pre-chemotherapy albumin levels did not significantly differ between the two groups (p = 0.218); but a significant post-chemotherapy difference was observed (p = 0.027), with both groups experiencing substantial increases from pre- to post-chemotherapy (p = 0.000). Conclusion: The findings suggest that BMI, hemoglobin, and albumin levels are not reliable predictors of platinum resistance in ovarian cancer patients. Although both hemoglobin and albumin increased significantly after chemotherapy, these changes did not correspond with platinum resistance status.

TMEM158, as plasma cfRNA marker, promotes proliferation and doxorubicin resistance in ovarian cancer.

The current study aimed to identify the potential biomarker for the diagnosis of ovarian cancer within plasma cell-free RNA (cfRNA) species and to characterize their oncogenic properties. cfRNAs were isolated from the peripheral blood of ovarian cancer patients and sequenced using an NGS platform. Principal component analysis (PCA) was performed using Salmon software. Gene ontology (GO) analysis was conducted with clusterProfiler. The relative abundance of TMEM158 transcripts was determined by real-time PCR. Cell viability and proliferation was monitored using the MTT and cell counting assays, respectively. The protein levels of TMEM158 and ABCG2 were quantified by immunoblotting. We observed a clear separation of cfRNAs between ovarian cancer patients and healthy individuals. Additionally, we identified TMEM158 as the most significantly differential gene in both peripheral blood and tumor tissues. Overexpression of TMEM158 stimulated cell viability and promoted cell proliferation in ovarian cancer cells. Notably, the aberrant upregulation of TMEM158 was closely associated with doxorubicin resistance in ovarian cancer. Mechanistically, we demonstrated that TMEM158 positively regulates ABCG2 expression, which consequently contributes to drug resistance. In summary, we identified cfRNA TMEM158 as a potential diagnostic biomarker for ovarian cancer and elucidated the critical involvement of TMEM158-ABCG2 signaling axis in the development of doxorubicin resistance.

Abstract B025: Redox reprogramming by SOD1 knockdown: A novel liposomal siRNA strategy to overcome platinum resistance in ovarian cancer

Abstract Platinum resistance remains a significant obstacle in the treatment of advanced-stage ovarian cancer, frequently leading to therapeutic failure. Our previous research identified Superoxide Dismutase 1 (SOD1) as a key antioxidant target for re-sensitizing platinum-resistant ovarian cancer cells to platinum-based therapies through both enzymatic inhibition and RNA interference (RNAi) utilizing a graphene-based siRNA delivery platform. Building on these findings, we have now developed a liposomal formulation of chemically modified siRNA targeting SOD1, which demonstrates potent knockdown efficiency and significantly enhances the sensitivity of resistant ovarian cancer cells to cisplatin in vivo. While SOD1 inhibition or knockdown via RNAi effectively re-sensitizes resistant cells to cisplatin, the underlying redox-sensitive signaling pathways remain largely unexplored in ovarian cancer. Our current study reveals that SOD1 knockdown acts as a redox switch, triggering cellular reprogramming in drug-resistant cells through post-translational cysteine modifications. This reprogramming leads to the rewiring of critical cancer hallmarks, culminating in the restoration of a cisplatin-sensitive phenotype. These findings suggest that a liposomal, chemically modified SOD1 siRNA formulation could serve as a promising therapeutic approach for reversing platinum resistance in ovarian cancer by exploiting redox-mediated reprogramming of cancer hallmarks. This study not only underscores the therapeutic potential of targeting SOD1 but also highlights the broader implications of redox signaling in the etiology of platinum resistance, providing a novel avenue for therapeutic intervention. Citation Format: Attila Szenasi, Sonia Rocha, Mu Wang. Redox reprogramming by SOD1 knockdown: A novel liposomal siRNA strategy to overcome platinum resistance in ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr B025.

Tasquinimod promotes the sensitivity of ovarian cancer cells to cisplatin by down-regulating the HDAC4/p21 pathway.

To investigate whether Tasquinimod can influence cisplatin resistance in drug-resistant ovarian cancer (OC) cell lines by regulating histone deacetylase 4 (HDAC4) or p21, we explored its effects on the cell cycle, and associated mechanisms. RT-PCR and Western blot analyses, flow cytometry, CCK8 assay, and immunofluorescence were utilized to investigate the effects of Tasquinimod on gene expression, cell cycle, apoptosis, viability, and protein levels in OC cells. The results showed that Tasquinimod inhibited cell viability and promoted apoptosis in SKOV3/DDP (cisplatin) and A2780/DDP cells more effectively than DDP alone. In combination with cisplatin, Tasquinimod further enhanced cell apoptosis and reduced cell viability in these cell lines, an effect that could be reversed following HDAC4 overexpression. Tasquinimod treatment down-regulated HDAC4, Bcl-2, and cyclin D1, and CDK4 expression and up-regulated the cleaved-Caspase-3, and p21 expression in SKOV3/DDP and A2780/ DDP cells. Additionally, Tasquinimod inhibited DDP resistance in OC/DDP cells. These effects were similarly observed in OC mouse models treated with Tasquinimod. In conclusion, Tasquinimod can improve OC cells' sensitivity to DDP by down-regulating the HDAC4/p21 axis, offering insights into potential strategies for overcoming cisplatin resistance in OC.

Drug resistance biomarkers in ovarian cancer: a bibliometric study from 2017 to 2022.

Late diagnosis and patient relapse, mainly due to chemoresistance, are the key reasons for the high mortality rate of ovarian cancer patients. Hence, the search for biomarkers of high predictive value within the phenomenon of chemoresistance is vital. This study performs a bibliometric analysis of the scientific literature concerning biomarkers of drug resistance in ovarian cancer, considering the period from 2017 to 2022. The terms "drug resistance biomarker" and "ovarian cancer" were linked by the Boolean operator "AND". The search was done in PubMed, selecting documents published over the last 5 years (2017-2022), which were analyzed with the open-source tool Bibliometrix developed in the R package. The language of the publications was restricted to English. Several types of papers such as case reports, clinical trials, comparative studies, and original articles were considered. A total of 335 scientific articles were analyzed. The United States and China were the leading contributors and established the largest number of scientific collaborations. The Huazhong University of Science and Technology and the University of Texas MD Anderson Cancer Center were the most influential institutions. The Journal of Ovarian Research, International Journal of Molecular Science, and Scientific Reports are among the most relevant journals. The study identified high-profile, relevant thematic niches and important descriptors that indicate topics of interest, including studies on women, cell lines, solid tumors, and gene expression regulation. As well as studies involving middle-aged and adult participants, and those focusing on prognosis evaluation. Descriptors such as "drug resistance," "neoplasm," "genetics," "biomarker," "gene expression profile," and "drug therapy" would indicate new research trends. In addition, we propose that BCL-2, CHRF, SNAIL, miR-363, iASPP, ALDH1, Fzd7, and EZH2 are potential biomarkers of drug resistance. This paper contributes to the global analysis of the scientific investigation related to drug resistance biomarkers in ovarian cancer to facilitate further studies and collaborative networks, which may lead to future improvements in therapy for this lethal disease.

STUB1 suppresses paclitaxel resistance in ovarian cancer through mediating HOXB3 ubiquitination to inhibit PARK7 expression

Paclitaxel (PTX) is a first-line drug for ovarian cancer (OC) treatment. However, the regulatory mechanism of STUB1 on ferroptosis and PTX resistance in OC remains unclear. Genes and proteins levels were evaluated by RT-qPCR, western blot and IHC. Cell viability and proliferation were measured by CCK-8 and clone formation. The changes of mitochondrial morphology were observed under a transmission electron microscope (TEM). Reactive oxygen species (ROS), iron, malondialdehyde (MDA) and glutathione (GSH) were measured using suitable kits. The interactions among STUB1, HOXB3 and PARK7 were validated using Co-IP, and dual luciferase reporter assay. Our study found that STUB1 was decreased and PARK7 was increased in tumor tissue, especially from chemotherapy resistant ovarian cancer tissue and resistant OC cells. STUB1 overexpression or PARK7 silencing suppressed cell growth and promoted ferroptosis in PTX-resistant OC cells, which was reversed by HOXB3 overexpression. Mechanistically, STUB1 mediated ubiquitination of HOXB3 to inhibit HOXB3 expression, and HOXB3 promoted the transcription of PARK7 by binding to the promoter region of PARK7. Furthermore, STUB1 overexpression or PARK7 silencing suppressed tumor formation in nude mice. In short, STUB1 promoted ferroptosis through regulating HOXB3/PARK7 axis, thereby suppressing chemotherapy resistance in OC.

Targeting the SPC25/RIOK1/MYH9 Axis to Overcome Tumor Stemness and Platinum Resistance in Epithelial Ovarian Cancer.

In epithelial ovarian cancer (EOC), platinum resistance, potentially mediated by cancer stem cells (CSCs), often leads to relapse and treatment failure. Here, the role of spindle pole body component 25 (SPC25) as a key determinant promoting stemness and platinum resistance in EOC cells, with its expression being correlated with adverse clinical outcomes is delineated. Mechanistically, SPC25 acts as a scaffolding platform, orchestrating the assembly of an SPC25/RIOK1/MYH9 trimeric complex, triggering RIOK1-mediated phosphorylation of MYH9 at Ser1943. This prompts MYH9 to disengage from the cytoskeleton, augmenting its nuclear accumulation, thus potentiating CTNNB1 transcription and subsequent activation of Wnt/β-catenin signaling. CBP1, a competitive inhibitory peptide, can disrupt the formation of the aforementioned trimeric complex, diminishing the activity of the SPC25/RIOK1/MYH9 axis-mediated Wnt/β-catenin signaling, and thus attenuate CSC phenotypes, thereby enhancing platinum efficacy in vitro, in vivo, and in patient-derived organoids. Therefore, targeting the SPC25/RIOK1/MYH9 axis, which mediates the maintenance of stemness and platinum resistance in EOC cells, may enhance platinum sensitivity and increase survival in patients with EOC.

BET inhibition modulates the functional phenotype and plasticity of tumor-associated macrophages and improves survival: Next frontier in overcoming immunotherapy resistance in ovarian cancer

BET inhibition modulates the functional phenotype and plasticity of tumor-associated macrophages and improves survival: Next frontier in overcoming immunotherapy resistance in ovarian cancer

Zebrafish patient-derived xenograft system for predicting carboplatin resistance and metastasis of ovarian cancer

AimsOvarian cancer (OC) remains a significant challenge in oncology due to high rates of drug resistance and disease relapse following standard treatment with surgery and platinum-based chemotherapy. Despite the widespread use of these treatments, no effective biomarkers currently exist to identify which patients will respond favorably to therapy. This study introduces a zebrafish patient-derived xenograft (PDX) system, capable of replicating both the carboplatin response and metastatic behavior observed in OC patients, within a rapid 3-day assay period. MethodsTwo OC cell lines: carboplatin-sensitive (A2780) and resistant (OVCAR8) were used to assess differential responses to treatment in murine and zebrafish xenograft models. Tumor tissues from 16 OC patients were implanted into zebrafish embryos to test carboplatin responses and predict metastasis. Additionally, eight clinical OC samples were directly implanted into zebrafish embryos as part of a proof-of-concept demonstration. ResultsThe zebrafish xenografts accurately reflected the carboplatin sensitivity and resistance patterns seen in in vitro and murine models. The zebrafish PDX model demonstrated a 67% success rate for implantation and a 100% success rate for engraftment. Notably, the model effectively distinguished between metastatic and non-metastatic disease, with an area under the ROC curve (AUC) of 0.818. Furthermore, the zebrafish PDX model showed a high concordance with patient-specific responses to carboplatin. ConclusionsThis zebrafish PDX model offers a fast, accurate, and clinically relevant platform for evaluating carboplatin response and predicting metastasis in OC patients. It holds significant potential for advancing personalized medicine, allowing for more precise therapeutic outcome predictions and individualized treatment strategies.

Platinum Resistance in Ovarian Cancer: Is This the End of the Line?

Approximately 80% of females with ovarian cancer are diagnosed with advanced disease, and around 70% of these females relapse within 3 years of first-line treatment. Five-year survival for newly diagnosed advanced ovarian cancer is less than 50%. Platinum-based chemotherapy is the cornerstone of systemic treatment; however, it is not appropriate for patients with relapsed ovarian cancer who had disease progression during previous platinum treatment, early symptomatic progression post-platinum treatment, or who are platinum intolerant. New drugs are needed to address the unmet need in patients with relapsed ovarian cancer who are not eligible for platinum-based chemotherapy. This article presents highlights from a satellite symposium conducted as part of the European Society for Medical Oncology (ESMO) Congress 2024, which took place from 13th–17th September 2024 in Barcelona, Spain. The objectives of the symposium were to improve understanding of the current treatment pathways and unmet needs for patients with ovarian cancer who are ineligible for platinum-based therapies, to raise awareness of the rationale for targeting folate receptor α (FRα) in a variety of novel therapeutics for platinum-resistant ovarian cancer (PROC), and to review the efficacy outcomes and side effects from recent clinical trials involving antibody–drug conjugates (ADC) in PROC. In this symposium, Ana Oaknin, Vall d’Hebron University Hospital, Barcelona, Spain, described the current landscape in advanced ovarian cancer and the unmet need in relapsed disease; Philipp Harter, Evangelische Kliniken Essen-Mitte, Germany, explored FRα-targeted therapeutics in PROC; and Kathleen Moore, Stephenson Cancer Center, University of Oklahoma, Norman, USA, discussed ADC development beyond FRα in PROC. The symposium concluded with a lively discussion, including questions from the audience, key examples of which are included in this article.

Delivery of doxorubicin by Fe3O4 nanoparticles, reduces multidrug resistance gene expression in ovarian cancer cells

BackgroundOvarian cancer is one of the most common malignancy in women with significant mortality rate due to the resistance to chemotherapy drugs. Doxorubicin (DOX) is a chemotropic agent in ovarian cancer treatment. Overexpression of multidrug resistance (MDR) genes, such as ABCB1, in cancer cells after chemotherapy is one of main problems in clinical applications. Here we have compared the efficiency of doxorubicin-loaded (NIPAAM-DMAEMA) Fe3O4 nanocomposite (DOX-NANO) against DOX on ABCB1(MDR1) gene expression in the ovarian cancer cell line. Materials and methodsThe cell viability of SKOV-3 cells were evaluated by MTT assay. Real Time PCR was used to measure the expression level of MDR1. MTT data were normalized in 10 different attribute weighting models, also to reveal the interaction between DOX, ABCB1, and ovarian cancer genes, Pathway Studio Database (Elsevier) was used. ResultsCell viability of SKOV-3cells was significantly decreased after 24, 48 and 72 hours (P < 0.0001) of either DOX with IC50 22.38, 0.61 and 0.072 µg/ml or DOX-NANO treatment with IC50 11.54, 1.01, 0.0126 µg/ ml respectively. treatment. Notable decrease in the expression of MDR gene, ABCB1, was observed 48 hours after treatment with DOX-NANO (P < 0.0001) with 26 % in the assessed with control group. Meta-analysis showed the concentration of 10 μg/ml variables was the second most significant feature, whereas the concentration of 0.01 μg/ml recognized the lowest weights. Also, LGALS3 is an extra cellular receptor with upregulation in ovarian cancer that interacts with ABCB1. ConclusionOur findings highlight the beneficial effects of DOX delivery in ovarian cancer cells by nanocomposite as efficient drug delivery method. DOX-NANO is a promising therapeutic reagent to overcome chemotherapy resistance in ovarian cancer.

Anti-ovarian cancer migration and toxicity characteristics of a platinum(IV) pro-drug with axial HDAC inhibitor ligands in zebrafish models

SummaryOvarian cancer is the fifth leading cause of cancer related death in the United States. Cisplatin is a platinum-based anti-cancer drug used against ovarian cancer that enters malignant cells and then damages DNA causing cell death. Typically, ovarian cancer cells become resistant to cisplatin making it necessary to increase subsequent dosage, which usually leads to side-effects including irreversible damage to kidney and auditory system tissue. Ovarian cancer resistance is often associated with upregulation of histone deacetylase (HDAC) enzymes that cause DNA to adopt a closed configuration which reduces the ability of cisplatin to target and damage DNA. Compound B, a platinum(IV) complex with two axial phenylbutyrate (PBA) HDAC inhibitor ligands attached to a cisplatin core, can simultaneously inhibit HDAC activity and damage DNA causing decreased cancer cell viability in cisplatin-sensitive (A2780) and -resistant (A2780cis) ovarian cancer cell lines. However, compound B was not previously evaluated in vivo. As simultaneously inhibiting HDAC-mediated resistance with cisplatin treatment could potentiate the platinum drug’s effect, we first confirmed the anti-cancer effect of compound B in the A2780 and A2780cis cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide spectrophotometric assay. Then, we used zebrafish embryo and transgenic animal models to comparatively analyze the effect of cisplatin, compound B, and controls on general organismal, auditory, and renal system toxicity, and cancer metastasis. We found that lower dosages of compound B (0.3 or 0.6 µM) than of cisplatin (2.0 µM) could cause similar or decreased levels of general, auditory, and renal tissue toxicity, and at 0.6 µM, compound B reduces cancer metastasis more than 2.0 µM cisplatin.

SHCBP1 promotes cisplatin resistance of ovarian cancer through AKT/mTOR/Autophagy pathway.

Ovarian cancer caused the highest cancer-related mortality among female reproductive system malignancies. Platinum-based chemotherapy is still the footstone of the chemotherapy for ovarian cancer. However, the molecular mechanisms underlying cisplatin insensitivity and resistance remain unclear. SHC SH2 domain-binding protein 1 (SHCBP1) plays critical roles in the progression and drug resistance of different types of cancer. However, the biological function of SHCBP1 in ovarian cancer progression and cisplatin resistance remains obscure. In this study, we found that SHCBP1 was upregulated in ovarian cancer and the upregulated SHCBP1 has growth-promoting effect on ovarian cancer cells. Furthermore, SHCBP1 silencing sensitize ovarian cancer cells to cisplatin (hereafter referred to as CDDP). Mechanism analysis revealed that SHCBP1 activated the Akt/mTOR pathway and further inhibited autophagy in ovarian cancer cells. Meanwhile, autophagy inhibitors combined with SHCBP1 knockdown enhances CDDP sensitivity. In addition, knockdown of SHCBP1 restricted the proliferation of tumors and increased the cisplatin sensitivity in vivo. These findings suggested that upregulated SHCBP1 promoted the proliferation and CDDP resistance of ovarian cancer. The combination of SHCBP1 inhibition and cisplatin treatment might lead to substantial progress in ovarian cancer targeted therapy.

MCL1 inhibitor S63845 delivered by follicle-stimulating hormone modified liposome potentiates carboplatin efficacy in ovarian cancer

Platinum resistance cause therapeutic failure and poor prognosis in ovarian cancer, and evasion of apoptosis is a critical factor in chemoresistance. A limited number of FDA-approved anticancer drugs directly target apoptotic pathways. Here, we discovered that MCL1, a critical anti-apoptotic protein, is amplified and associated with platinum resistance and survival in ovarian cancer, assisting in personalized treatment. We further identified S63845 through drug-based screening, the most potent MCL1 inhibitor, which efficiently enhanced carboplatin (CBP) sensitivity in various ovarian cancer models, including primary ovarian cancer cells, orthotopic ovarian cancer, peritoneal metastasis, and human patient-derived xenograft (PDX) models. Mechanistically, S63845 competitively binds to MCL1, disrupts the binding of apoptosis effector (BAK and BAX) or pro-apoptotic BH3 protein (BIM) to MCL1 respectively, and eventually enhances CBP-induced apoptosis.To promote the clinical transformation of S63845, we developed follicle-stimulating hormone-modified liposome nanoparticles (S63845@Lipo-FSH) to enhance stability, membrane penetration, and tumor-targeting capabilities. S63845@Lipo-FSH exhibits a superior therapeutic efficacy and tumor targeting compared to free S63845, even when the dose of S63845 is reduced to one-fifth. Overall, targeting MCL1 by S63845@Lipo-FSH enhances CBP efficiency in ovarian cancer, with safety and efficacy, suggesting that this strategy is effective and promising for clinical application.

18F-Fluoro-2-Deoxyglucose Positron Emission Tomography/Computed Tomography Measures of Spatial Heterogeneity for Predicting Platinum Resistance of High-Grade Serous Ovarian Cancer.

The purpose of this study is to construct models for predicting platinum resistance in high-grade serous ovarian cancer (HGSOC) derived from quantitative spatial heterogeneity indicators obtained from 18F-FDG PET/CT images. A retrospective study was conducted on patients diagnosed with HGSOC. Quantitative indicators of spatial heterogeneity were generated using conventional features and Haralick texture features from both CT and PET images. Three groups of predictive models (conventional, heterogeneity, and integrated) were built. Each group's optimal model was the one with the highest area under curve (AUC). Postoperative immunohistochemical staining for Ki-67 and p53 was conducted. The correlation between the heterogeneity indicators and scores for Ki-67 and p53 was assessed by Spearman's correlation coefficient (ρ). A total of 286 patients (54.6 ± 9.3 years) were enrolled. And 107 spatial heterogeneity indicators were extracted. The optimal models for each group were obtained using the Gradient Boosting Machine (GBM) algorithm. There was an AUC of 0.790 (95% CI: 0.696, 0.885) in the conventional model for the validation set, and an AUC of 0.904 (95% CI: 0.842, 0.966) in the heterogeneity model for the validation set. The integrated model achieved the highest predictive performance, with an AUC value of 0.928 (95% CI: 0.872, 0.984) for the validation set. Spearman's correlation showed that HU_Kurtosis had the strongest correlation with p53 scores with ρ = 0.718, while cluster site entropy had the strongest correlation with Ki-67 scores with ρ = 0.753. Adding quantitative spatial heterogeneity indicators derived from PET/CT images can improve the prediction of platinum resistance in patients with HGSOC. Spatial heterogeneity indicators were related to Ki-67 and p53 scores.

The up-regulation of PAK2 indicates unfavorable prognosis in patients with serous epithelial ovarian cancer and contributes to paclitaxel resistance in ovarian cancer cells

BackgroundThe main challenge in treating ovarian cancer is chemotherapy resistance. Previous studies have shown that PAK2 is highly expressed in various cancers. This research investigates whether increased PAK2 expression contributes to chemo-resistance and poor prognosis in ovarian cancer.MethodsInitially, bioinformatics analysis was used to assess the importance of PAK2 mRNA up-regulation in ovarian cancer. This was then validated using tissue microarray to confirm PAK2 protein expression and localization in clinical samples. Univariate and multivariate logistic regression analyses were carried out to identify potential risk factors for chemo-resistance in serous epithelial ovarian cancer (EOC), while multivariate Cox regression and Kaplan-Meier analysis were conducted to ascertain prognostic factors for overall survival (OS) and disease-free survival (DFS) in patients with serous EOC. In vitro experiments were conducted to verify if inhibiting PAK2 expression could increase A2780/Taxol cells’ sensitivity to paclitaxel, as shown by evaluating cell proliferation, apoptosis, transwell, and clone formation. Additionally, the interaction between PAK2, lnc-SNHG1, and miR-216b-5p was verified using RIP and luciferase reporter assays. Rescue experiments were undertaken to examine the influence of the lnc-SNHG1/miR-216b-5p/PAK2 axis on the development of paclitaxel resistance in A2780/Taxol cells.ResultsThe bioinformatics analysis indicated a notable increase in PAK2 expression in ovarian malignant tumors compared to adjacent tissues, particularly in patients with stage III-IV disease compared to those with stage I-II disease (P = 0.0056). Elevated levels of PAK2 were linked to reduced OS in ovarian cancer patients, although no significant association was observed with DFS. Immunohistochemistry findings further supported these results, showing positive PAK2 protein expression in chemo-resistant serous EOC tissues, predominantly localized in the cytoplasm, which correlated with poorer OS and DFS outcomes. In vitro experiments demonstrated that the downregulation of PAK2 in A2780/Taxol cells led to a reduction in colony formation, an increase in apoptosis, and a diminished capacity for cell invasion. Subsequent analysis confirmed that lnc-SNHG1 functions as a competitive endogenous RNA (ceRNA) by interacting with miR-216b-5p and regulating PAK2 expression. Rescue experiments demonstrated that lnc-SNHG1 induces resistance to paclitaxel in A2780/Taxol cells by modulating the miR-216b-5p/PAK2 axis.ConclusionsPAK2 shows promise as a predictor of chemotherapy resistance and poor outcomes in ovarian cancer, indicating its potential use as a treatment target to overcome this resistance.