Kosuke Yoshida

Mesothelial cells promote peritoneal invasion and metastasis of ascites-derived ovarian cancer cells through spheroid formation

Patients with epithelial ovarian cancer (EOC) are often diagnosed with peritoneal metastasis and ascites, the accumulation of intraperitoneal fluid containing nonmalignant cells. However, the interactions between EOC and nonmalignant cells before peritoneal metastasis remain unclear. To investigate this, whole EOC spheroids were observed using a multiphoton microscope, and their invasion ability was assessed. Mesothelial cells were identified as notable components of ascites through morphological assessment, immunohistochemical/immunofluorescence staining, and single-cell RNA sequencing analyses. Almost all EOC cells were spheroids, with 60% containing mesothelial cells. EOC cells quickly generate aggregated spheroids with mesothelial cells, and these aggregated cancer-mesothelial spheroids (ACMSs) invade collagen or mesothelial layers. Mesothelial cells forming ACMSs initiated the invasion. RNA sequencing analysis revealed marked RNA expression changes in mesothelial cells, whereas the changes in EOC cells were minor. Transforming growth factor–β1–stimulated mesothelial cells showed increased invadopodium formation along with fascin-1 up-regulation. These findings suggest that EOC cells alter mesothelial cells through ACMSs, thereby elucidating the rapid spread of EOC in the abdominal cavity.

Genomic insights and therapeutic efficacy of PARP inhibitors in a high-LOH patient-derived xenograft from malignant transformation of ovarian teratoma

The malignant transformation of ovarian mature cystic teratoma (MTMCT) is a rare and aggressive condition often diagnosed at advanced stages with limited treatment options. Leveraging cancer genomic profiling (CGP), this study evaluated the efficacy of poly(ADP-ribose) polymerase (PARP) inhibitors in a patient-derived xenograft (PDX) model of MTMCT with high loss of heterozygosity (LOH). Tumor samples from a patient with MTMCT were used to establish the PDX model. CGP revealed high LOH and actionable mutations, including STK11 (E256*) and EMSY amplification, suggesting potential sensitivity to PARP inhibitors. Mice treated with PARP inhibitors exhibited significantly reduced tumor volumes compared to controls. Whole-exome sequencing (WES) performed on control and post-treatment residual tumors demonstrated that while total LOH levels remained stable, copy-neutral LOH (CN-LOH) increased significantly, indicating treatment-induced genomic instability. Notably, STK11 (E256*) underwent CN-LOH in residual tumors, suggesting a role in acquired resistance. Furthermore, EMSY amplification, initially observed in the tumor and associated with PARP inhibitor sensitivity, was absent after treatment, reflecting clonal selection or adaptive resistance. These findings underscore the therapeutic potential of PARP inhibitors in high-LOH MTMCT while highlighting the emergence of resistance mechanisms, including CN-LOH and loss of EMSY amplification. They emphasize the importance of considering tumor evolution and treatment timing when interpreting CGP results, providing a foundation for further research into predictive biomarkers and resistance mechanisms in rare gynecologic malignancies.

Development and Validation of Predictive Risk Scores for Ovarian Clear Cell Carcinoma: A Penalized Regression Model

ABSTRACT Background The precision management of ovarian clear cell carcinoma (OCCC) faces limitations due to the absence of personalized prognostic tools. This study aimed to establish predictive risk scores to enable effective stratification and tailored treatment of OCCC. Methods Retrospective data from 206 OCCC patients treated between 2004 and 2019 at two hospitals were analyzed. Penalized regression models were utilized to develop three risk scores based on preoperative laboratory results and intraoperative findings. These scores underwent internal and external validation. Results The median follow‐up periods were 65.7 and 44.0 months for the derivation and validation cohorts, respectively. In internal validation with the derivation cohort, all three risk scores effectively identified the high‐risk group for tumor recurrence. Upon validation with the external cohort, Risk Score 3, which incorporated variables selected in most cross‐validations by the penalized regression (Elastic Net), distinctly differentiated the high‐ and low‐risk groups ( p  = 0.03). Risk Score 2, consisting solely of preoperatively available variables, also demonstrated marginal significance ( p  = 0.08). Conclusion Our findings underscore the significance and utility of the developed risk scores in tailoring personalized treatments for patients with OCCC.

Update on the oncologic and obstetric outcomes of medroxyprogesterone acetate treatment for atypical endometrial hyperplasia and endometrial cancer

Abstract Aims To evaluate the safety and effectiveness of high‐dose oral medroxyprogesterone acetate (MPA) therapy as a fertility‐sparing treatment for patients diagnosed with atypical endometrial hyperplasia (AEH) and endometrioid carcinoma G1 without myometrial invasion (G1EC). Particular attention was given to the extended administration and readministration of MPA for patients with persistent disease following initial treatment and those with recurrence. Methods We conducted a retrospective analysis of data from 79 patients who underwent daily oral MPA treatment between 2005 and 2024 at Nagoya University Hospital. Patient characteristics, treatment outcomes, factors contributing to recurrence, and post‐MPA therapy pregnancies were examined. Results MPA therapy achieved a remarkable complete response (CR) rate of 91.1%. The median time to achieve CR was 26.0 and 40.0 weeks for AEH and G1EC patients, respectively. Importantly, 27 patients (39.7%) attained CR after more than 6 months of treatment, including 8 patients (11.8%) who achieved CR after more than a year of treatment. The recurrence rates were 52.9% for AEH and 64.7% for G1EC. Twenty eight patients resumed MPA treatment, and 23 achieved second CR. Notably, recurrence was not associated with clinical factors such as age, body mass index, or post‐CR pregnancy. Among patients who attempted pregnancy after achieving CR, 22 live births were successfully achieved. Conclusions High‐dose oral MPA therapy demonstrated both safety and efficacy for preserving fertility in patients with AEH and G1EC, resulting in a high CR rate. MPA extension and readministration proved to be beneficial strategies for managing patients with recurrence and persistent disease following initial treatment.

Spatial distribution of tumor‐resident macrophages as predictive biomarkers in endometrial cancer

Abstract Background To investigate the role of CD47 expression and its relationship with tumor‐resident macrophages, specifically at the tumor margin, in patients with type II endometrial cancer. This study aims to elucidate whether CD47 could serve as a prognostic marker and to understand the dynamics between CD47 and macrophages, which could inform new therapeutic strategies. Methods A retrospective cohort study was conducted involving 75 patients of type II endometrial. Immunohistochemical analysis was performed to assess CD47 expression and macrophage markers (CD68 and CD163). Results The study found no direct correlation between CD47 expression levels and overall survival ( p  = 0.32), challenging its role as an independent prognostic marker in type II endometrial cancer. The higher expression of CD47 had significantly less incidence of endometrioid carcinoma G3 ( p  = 0.047). The negative correlation between CD47 H‐score and the density of CD68‐positive macrophages at tumor margin was statistically significant ( p  = 0.049). A high density of CD68‐positive macrophages at the tumor margin but a low density of CD163‐positive macrophages at the tumor margin were associated with poorer prognosis ( p  = 0.036). Conclusions The complex interaction between CD47 and macrophages, particularly at the tumor margin, suggests new avenues for targeted therapy in type II endometrial cancer.

Real‐world data of poly (ADP‐ribose) polymerase inhibitor response in Japanese patients with ovarian cancer

AbstractBackgroundPoly (ADP‐ribose) polymerase (PARP) inhibitors have been increasingly used in the treatment of ovarian cancer, with BRCA positivity and homologous recombination deficiency (HRD) being common biomarkers used for predicting their efficacy. However, given the limitations of these biomarkers, new ones need to be explored.MethodsThis retrospective study included 181 ovarian cancer patients who received olaparib or niraparib at two independent hospitals in Japan between May 2018 and December 2022. Clinical information and blood sampling data were collected. Patient characteristics, treatment history, and predictability of treatment duration based on blood data before treatment initiation were examined.ResultsHigh‐grade serous carcinoma, BRCA positivity, HRD, and maintenance therapy after recurrence treatment were observed more frequently in the olaparib group than in the niraparib group. The most common reasons for treatment interruption were anemia, fatigue, and nausea in the olaparib group and thrombocytopenia in the niraparib group. Regarding response to olaparib treatment, complete response to the most recent treatment, maintenance therapy after the first chemotherapy, high‐grade serous carcinoma, and germline BRCA positivity were observed significantly more frequently among responders than among non‐responders. Furthermore, neutrophil counts were significantly higher among responders than among non‐responders.ConclusionsInflammation‐related blood data, such as neutrophil count, obtained at the initial pre‐treatment visit might serve as potential predictors for prolonged olaparib treatment. While this study offers valuable insights into potential indicators for prolonged olaparib treatment, it underscores the need for more expansive research to strengthen our understanding of PARP inhibitors and optimize treatment strategies in ovarian cancer.

Spatial exosome analysis using cellulose nanofiber sheets reveals the location heterogeneity of extracellular vesicles

AbstractExtracellular vesicles (EVs), including exosomes, are recognized as promising functional targets involved in disease mechanisms. However, the intravital heterogeneity of EVs remains unclear, and the general limitation for analyzing EVs is the need for a certain volume of biofluids. Here, we present cellulose nanofiber (CNF) sheets to resolve these issues. We show that CNF sheets capture and preserve EVs from ~10 μL of biofluid and enable the analysis of bioactive molecules inside EVs. By attaching CNF sheets to moistened organs, we collect EVs in trace amounts of ascites, which is sufficient to perform small RNA sequence analyses. In an ovarian cancer mouse model, we demonstrate that CNF sheets enable the detection of cancer-associated miRNAs from the very early phase when mice did not have apparent ascites, and that EVs from different locations have unique miRNA profiles. By performing CNF sheet analyses in patients, we identify further location-based differences in EV miRNA profiles, with profiles reflecting disease conditions. We conduct spatial exosome analyses using CNF sheets to reveal that ascites EVs from cancer patients exhibit location-dependent heterogeneity. This technique could provide insights into EV biology and suggests a clinical strategy contributing to cancer diagnosis, staging evaluation, and therapy planning.

Downregulation of Chromosome 19 miRNA Cluster and the Tumor‐Suppressive Role of miR ‐517a‐3p in Choriocarcinoma

ABSTRACT Choriocarcinoma is a rare gynecologic malignancy. MicroRNAs, which are noncoding RNAs approximately 22 nucleotides in length, are known to regulate gene expression and play important roles in various cancers; however, their functions in choriocarcinoma remain largely unknown. This study aimed to identify disease‐specific microRNAs involved in choriocarcinoma development. Eleven cases of choriocarcinoma and five cases of complete hydatidiform mole treated at our institution were analyzed. Total RNA was extracted from trophoblast cells in formalin‐fixed, paraffin‐embedded specimens using laser capture microdissection, and microRNA sequencing was performed. The analysis revealed that 87 microRNAs were significantly upregulated, whereas 28 were downregulated in choriocarcinoma compared to complete hydatidiform mole. Notably, 13 of the 28 downregulated microRNAs belonged to the chromosome 19 microRNA cluster. In vitro experiments demonstrated that overexpression of miR‐517a‐3p, a representative member of this cluster, significantly suppressed cell proliferation, migration, and invasion in JEG‐3 and BeWo cell lines. Further transcriptome sequencing and computational analysis identified SRSF1 as a target gene of miR‐517a‐3p, which was validated by dual‐luciferase reporter assays. Knockdown of SRSF1 also led to significant reductions in proliferation, migration, and invasion, supporting its functional relevance. Immunohistochemical analysis confirmed that SRSF1 protein was highly expressed in choriocarcinoma tissues compared to complete hydatidiform mole. These findings indicate that downregulation of the chromosome 19 microRNA cluster is a characteristic feature of choriocarcinoma and that miR‐517a‐3p functions as a tumor suppressor by directly regulating SRSF1 expression.

Natural-killer-cell–dominant immune landscape and HLA-E–mediated immune evasion in choriocarcinoma

Choriocarcinoma is a rare cancer associated with antecedent pregnancy. Therefore, its development may be influenced by an immune-evasive tumor microenvironment. In this study, we focused on natural killer (NK) cells to elucidate the immune microenvironment of choriocarcinoma. Peripheral blood and intratumoral NK cells were isolated from six samples of four patients with choriocarcinoma. Flow cytometry was used to analyze the NK cell proportion. Immunohistochemistry was performed to assess the expression of NK cell inhibitory ligands using choriocarcinoma tissues from 17 patients. In addition, choriocarcinoma cell lines (JAR, BeWo, and JEG-3) were cocultured with interleukin-2-stimulated NK cells, and loss-of-function analyses of HLA-E were conducted to investigate the impact of NK cells on choriocarcinoma cells. Flow cytometry revealed that NK cells were more abundant in choriocarcinoma tissues than in the peripheral blood. Immunohistochemistry confirmed the expression of NK cell inhibitory ligands, including HLA-E. Moreover, JAR cells were cocultured with NK cells, and viable JAR cells were isolated by flow cytometry. Subsequent mRNA sequencing showed that HLA-E was upregulated, and multiple cytokine-related pathways were activated in the cocultured JAR cells compared with monocultured JAR cells. Functional assays demonstrated that HLA-E knockdown enhanced NK-cell-mediated cytotoxicity, whereas interferon-gamma treatment increased HLA-E expression and promoted tumor cell survival. These findings suggest that NK cells may play an important role in the tumor immune microenvironment of choriocarcinoma through HLA-E expression.

Tumor growth direction predicts surgical difficulty in large uterine fibroids: A retrospective imaging‐based study

Abstract Objective To identify preoperative imaging features associated with retroperitoneal growth of large uterine fibroids and evaluate their impact on surgical outcomes. Methods This retrospective study included 20 patients who underwent hysterectomy for uterine fibroids measuring ≥10 cm between 2014 and 2024. Preoperative CT or MRI was evaluated for four features: bladder displacement, sigmoid colon deviation, cecal displacement, and hydronephrosis. Tumor growth direction (intraperitoneal vs. retroperitoneal) was determined intraoperatively. Operative time, blood loss, and complications were compared between groups. Results Eight tumors exhibited retroperitoneal growth. Bladder displacement, cecal shift, sigmoid colon deviation, and hydronephrosis were significantly more common in retroperitoneal cases (all p  < 0.05). Retroperitoneal tumors were associated with significantly greater median blood loss (1591 mL vs. 651 mL, p  = 0.043), although operative time did not differ significantly (301 vs. 232 min, p  = 0.237). Organ injury or resection occurred only in the retroperitoneal group. A bubble plot illustrated the trend of increased surgical burden in retroperitoneal cases. Conclusion Retroperitoneal growth of large uterine fibroids is associated with increased intraoperative blood loss and surgical complexity. Four simple imaging features may serve as reliable indicators of growth direction and help guide preoperative planning.

Outcomes of cases with complete hydatidiform mole coexisting with a fetus: a single-center study

Abstract Background Complete hydatidiform moles coexisting with a fetus (CHMCF) are uncommon. Although CHMCF is associated with perinatal complications and post-molar gestational trophoblastic neoplasia (GTN), necessitating post-delivery chemotherapy, live birth remains feasible. This report presents 14 cases of CHMCF in Japan. Methods  We reviewed medical records of patients with CHMCF treated at our hospital from 2000 to 2020 and summarized clinical data, including maternal age, pregnancy details, delivery outcomes, fertility treatments, serum human chorionic gonadotropin (hCG) levels, and ultrasonography findings. Results Fourteen cases of CHMCF were diagnosed. The average age of the mothers was 30.6 years, with the majority conceiving following fertility treatment. The mean gestational age at diagnosis was 12 weeks. Six patients maintained their pregnancies, leading to two live births through emergency cesarean section. Eight patients exhibited spontaneous regression following treatment and pregnancy interruption, achieving negative serum hCG levels within 17.4 weeks. Six patients experienced post-molar GTN, including the two who had live births. One patient presented with FIGO stage I disease, while five patients had stage III lung metastases. All patients received chemotherapy, averaging nine courses, achieving remission within 13.7 weeks. Conclusion  The occurrence of GTN was higher after CHMCF than after typical complete hydatidiform moles. Despite the heightened risk of premature birth, some patients with CHMCF who maintain their pregnancies can successfully deliver live babies. Informed consent is essential for patients with CHMCF when considering pregnancy continuation. A team approach involving gynecological oncologists, obstetricians, and neonatologists is essential for effective diagnosis and treatment.

Utility of manual vacuum aspiration followed by curettage in the treating hydatidiform mole: A retrospective analysis

AbstractAimWhile manual vacuum aspiration (MVA) is commonly employed for early first‐trimester abortions, its effectiveness in treating hydatidiform mole is still unclear. This study sought to evaluate the efficacy and safety of MVA in comparison to dilation and curettage (D&C) for managing hydatidiform mole.MethodsWe conducted a retrospective review of medical records for 198 patients with hydatidiform mole treated at Nagoya University Hospital between 2004 and 2023. After excluding cases with incomplete data, we compared 106 patients who underwent D&C with 60 patients treated with MVA followed by curettage. We evaluated the surgical duration, intraoperative blood loss, and the occurrence of post‐molar gestational trophoblastic neoplasia (GTN) in both groups.ResultsThe surgical duration and blood loss were similar between the MVA and D&C groups. The average surgical time was 13.2 min for D&C and 11.8 min for MVA (p = 0.145). Most cases in both groups experienced blood loss of less than 10 mL, with no significant difference (p = 0.066). Over a median follow‐up period of 33.4 months, 25 cases developed post‐molar GTN. All GTN cases originated from complete hydatidiform mole (25 of 132 cases, 18.9%), and none were from partial hydatidiform mole. Kaplan–Meier analysis, focusing only on patients with complete hydatidiform mole, indicated no significant difference in the time to onset of GTN between the D&C and MVA groups (p = 0.632).ConclusionsMVA followed by curettage is a viable approach for treating molar pregnancy.

Expression of the chrXq27.3 miRNA cluster in recurrent ovarian clear cell carcinoma and its impact on cisplatin resistance

AbstractOvarian clear cell carcinoma (OCCC) is a histological subtype of epithelial ovarian cancer and exhibits dismal prognosis due to chemoresistance. Moreover, only few effective therapeutic options exist for patients with recurrent OCCC, and an understanding of its molecular characteristics is essential for the development of novel therapeutic approaches. In the present study, we investigated unique MicroRNAs (miRNA) profiles in recurrent/metastatic OCCC and the role of miRNAs in cisplatin resistance. Comprehensive miRNA sequencing revealed that expression of several miRNAs, including miR-508-3p, miR-509-3p, miR-509-3-5p, and miR-514a-3p was remarkably less in recurrent cancer tissues when compared with that in paired primary cancer tissues. These miRNAs are located in the chrXq27.3 region on the genome. Moreover, its expression was negative in omental metastases in two patients with advanced OCCC. In vitro analyses revealed that overexpression of miR-509-3p and miR-509-3-5p reversed cisplatin resistance and yes-associated protein 1 (YAP1) was partially responsible for the resistance. Immunohistochemistry revealed that YAP1 expression was inversely correlated with the chrXq27.3 miRNA cluster expression. In conclusion, these findings suggest that alteration of the chrXq27.3 miRNA cluster could play a critical role in chemoresistance and miRNAs in the cluster and their target genes can be potential therapeutic targets.

Significance of Concurrent Chemoradiotherapy as Primary Treatment in Patients with Metastatic Cervical Cancer

(1) This study investigated the prognostic impact of tumor size in patients with metastatic cervical cancer. (2) Methods: Seventy-three cervical cancer patients in our institute were stratified into two groups based on distant metastasis: para-aortic lymph node metastasis alone (IIIC2) or spread to distant visceral organs with or without para-aortic lymph node metastasis (IVB) to identify primary tumor size and concurrent chemoradiotherapy. (3) Results: The overall survival (OS) for patients with a tumor >6.9 cm in size was significantly poorer than that for patients with a tumor ≤6.9 cm in the IVB group (p = 0.0028); the corresponding five-year OS rates in patients with a tumor ≤6.9 and >6.9 cm were 53.3% and 13.4%, respectively. In the multivariate analysis, tumor size and primary treatment were significantly associated with survival in metastatic cervical cancer. (4) Conclusions: Tumor size ≤6.9 cm and concurrent chemoradiotherapy as the primary treatment were favorable prognostic factors for patients with metastatic cervical cancer.

An update of oncologic and obstetric outcomes of radical trachelectomy for early‐stage cervical cancer: The need for further minimally invasive treatment

AbstractAimsTo investigate the oncologic and obstetric outcomes of radical trachelectomy (RT) in patients with early‐stage cervical cancer and to evaluate the potential role of fertility‐preserving treatments in improving pregnancy outcomes while oncologic status is stable.MethodsIn this single‐institution study, we analyzed the oncologic and obstetric outcomes of 67 patients with early‐stage cervical cancer who underwent RT at Nagoya University Hospital.ResultsThe cancer recurrence rate (6.0%) and the mortality rate (1.5%) were comparable with those of previous studies. Of the 46 patients who attempted to conceive after RT, 19 (41.3%) became pregnant, and 16 gave birth. Of these 37.5% delivered at term, and delivery at less than 28 weeks of gestation occurred in 31.3% of pregnancies.ConclusionsRT is a viable treatment option for selected patients with early‐stage cervical cancer. However, the use of less invasive techniques, such as conization/simple trachelectomy and pelvic lymph node dissection, may improve pregnancy outcomes while oncologic status is stable.

A rare case of signet ring cell carcinoma with diffuse cutaneous systemic sclerosis: A case report

AbstractSystemic sclerosis, an autoimmune disease characterized by fibrosis and vasculopathy of the skin and other multiple organs has been associated with an increased risk of malignancy. We present the case of a 74‐year‐old woman who had diffused cutaneous systemic sclerosis and uterine cervical cancer. The patient was initially diagnosed with stage IIB squamous cell carcinoma and concurrent chemoradiotherapy was planned. However, cisplatin could not be administered due to acute renal failure, so the patient was treated solely with radiotherapy. However, complications of systemic sclerosis progressed rapidly, and the patient died 63 days later from pulmonary edema. An autopsy later revealed that uterine cervix had primary signet ring cell carcinoma. We suspected that this patient had a combination of signet ring cell carcinoma and squamous cell carcinoma, with squamous cell carcinoma disappearing after radiotherapy. This case highlighted the importance of systemic management for cancers associated with systemic sclerosis.

Overcoming platinum-resistant ovarian cancer targeting the activated JAK-STAT pathways via extracellular vesicles

Abstract Platinum-resistant ovarian cancer (PROC) is a clinically severe unresolved issue, and it remains unclearly defined by molecular biology. Extracellular vesicles (EVs) play an essential role in cell-to-cell communication in the tumor microenvironment. This study aimed to investigate the molecular mechanisms of PROC, focusing on the unique ascites environment of ovarian cancer. Multi-transcriptome analyses using clinical samples revealed that PROC exhibited an activated Janus kinase (JAK)/signal transducer and activator of transcription pathway with high JAK1 expression in cancer cells. Immunohistochemistry for patient tissues confirmed the negative association between JAK1 expression and platinum response. JAK inhibitors were effective in PROC cell lines and cell- and patient-derived xenograft models, as well as synergistic with platinum. Furthermore, small RNA sequencing indicated that activated peritoneal mesothelial cell-derived EVs enriched in miR135a-5p increased JAK expression and platinum resistance in cancer cells. Collectively, EVs in ascites regulated platinum sensitivity in ovarian cancer cells, and JAK targeting therapeutic strategy overcomes PROC.

Single‐Nucleus RNA Sequencing and Spatial Transcriptomics for Squamous Cell Carcinoma Arising From Ovarian Mature Teratoma

ABSTRACTSquamous cell carcinoma arising from mature teratoma (SCC‐MT) is a rare ovarian malignancy. The detailed molecular pathology of SCC‐MT is not well understood. Moreover, the prognosis of the patients remains poor because no standard treatment has been established. In this study, we performed single‐nucleus RNA sequencing and spatial transcriptomics using clinical SCC‐MT samples to identify novel therapeutic candidates. snRNA‐seq revealed three epithelial cell clusters, of which one was significantly associated with epidermis and keratinocyte development. Moreover, spatial transcriptomics revealed that the epithelial‐mesenchymal transition was significantly inhibited, and the MYC and E2F targets were significantly activated in cancer spots on specimen sections. We focused on KLF5, which was one of the upregulated genes in cancer cells, and performed a functional analysis using NOSCC‐1, a cell line derived from an SCC‐MT. KLF5 downregulation significantly decreased cell proliferation and increased apoptosis. Furthermore, we previously identified miR‐145‐5p as a downregulated miRNA in SCC‐MT. We demonstrated that miR‐145‐5p overexpression attenuated cell proliferation and decreased KLF5 expression. In conclusion, through multi‐omics analyses, we identified unique gene expression profiles of SCC‐MT and determined a role for KLF5 in SCC‐MT development. Therefore, KLF5‐related factors may be novel therapeutic targets, and further studies are needed to improve the diagnosis and treatment of SCC‐MT.

Circulating serum miRNAs predict response to platinum chemotherapy in high‐grade serous ovarian cancer

Abstract Background Platinum chemotherapy is the cornerstone of treatment for high‐grade serous ovarian cancer (HGSOC); however, validated biomarkers that can accurately predict platinum response are lacking. Based on their roles in the underlying pathophysiology, circulating microRNAs are potential, noninvasive biomarkers in cancer. In the present study, we aimed to evaluate the circulating miRNA profiles of patients with HGSOC and to assess their potential utility as biomarkers to predict platinum response. Methods Pretreatment serum samples collected from patients who received platinum chemotherapy for Stage III–IV HGSOC between 2008 and 2016 were analyzed using miRNA microarray. LASSO logistic regression analysis was used to construct predictive models for treatment‐free interval of platinum (TFIp). Results The median follow‐up was 54.6 (range, 3.5–144.1) months. The comprehensive analysis of 2588 miRNAs was performed in serum samples of 153 eligible patients, and predictive models were constructed using a combination of circulating miRNAs with an area under the receiver operating characteristic curve of 0.944 for TFIp >1 month, 0.637 for TFIp ≥6 months, 0.705 for TFIp ≥12 months, and 0.938 for TFIp ≥36 months. Each predictive model provided a significant TFIp classification ( p  = 0.001 in TFIp >1 month, p  = 0.013 in TFIp ≥6 months, p  < 0.001 in TFIp ≥12 months, and p  < 0.001 in TFIp ≥36 months). Conclusion Circulating miRNA profiles has potential utility in predicting platinum response in patients with HGSOC and can aid clinicians in choosing appropriate treatment strategies.

Small Extracellular Vesicles from adipose-derived stem cells suppress cell proliferation by delivering the let-7 family of microRNAs in ovarian cancer

Ovarian cancer is the leading cause of death among women with gynecological cancer, and novel treatment options are urgently needed. Extracellular vesicles (EVs), including exosomes, may be one of the most promising therapeutic tools for various diseases. In this study, we aimed to investigate the therapeutic effects of adipose-derived stem cell-derived EVs (ADSC-EVs) on ovarian cancer cell lines. ADSCs and the ovarian cancer cell lines SKOV3 and OV90 were used for analysis. ADSC-EVs were isolated through ultracentrifugation and validated using a cryotransmission electron microscope, nanoparticle tracking analysis, and western blotting. Then, the effect of ADSC-EVs on ovarian cancer cells was investigated using IncuCyte and microRNA sequencing. Moreover, the potential functions of miRNAs were evaluated by gain-of function analysis and in silico analysis. ADSC-EVs suppressed SKOV3 and OV90 cell proliferation. In particular, small EVs (sEVs) from ADSCs exhibited a stronger antitumor effect than ADSC-medium/large EVs (m/lEVs). Comparison of the miRNA profiles between ADSC-sEVs and ADSC-m/lEVs, along with downstream pathway analysis, suggested the involvement of the let-7 family. Overexpression of hsa-let-7b-5p and hsa-let-7e-5p significantly suppressed the proliferation of SKOV3 cells. In silico analysis revealed that four potential target genes of hsa-let-7b-5p and hsa-let-7e-5p were significantly associated with the prognoses of the patients. ADSC-sEVs had a stronger antitumor effect than ADSC-m/lEVs. Hsa-let-7b-5p and hsa-let-7e-5p, which are highly abundant in ADSC-sEVs, suppressed cell proliferation. These findings may open up new possibilities for therapeutic approaches using ADSC-sEVs.

In‐Tumor CRISPR ‐Cas9 Knockout Screening and Novel Therapy Development for Malignant Transformation of Ovarian Teratoma

ABSTRACT Malignant transformation of mature cystic teratoma (MTMCT) of the ovary is a rare but aggressive malignancy for which no standardized chemotherapy or effective targeted therapies currently exist. To identify therapeutic vulnerabilities in MTMCT, we performed a genome‐wide CRISPR‐Cas9 knockout screen using the MTMCT‐derived NOSCC1 cell line. Two parallel selective pressures were applied: in vivo tumorigenicity in immunodeficient mice and cisplatin exposure in vitro. From this screen, 67 negatively selected genes were identified, among which SOD1 and NDUFB4 emerged as top candidates based on high basal expression levels and clinical relevance. Integration with spatial transcriptomic data from three independent MTMCT patient tumors further supported the prioritization of these targets. SOD1 was selected for further investigation due to the availability of known pharmacological inhibitors. Both siRNA‐mediated knockdown and small‐molecule inhibition of SOD1 using LCS‐1 significantly suppressed MTMCT cell proliferation in vitro by inducing oxidative stress and impairing cell cycle progression. This antiproliferative effect was reversed by co‐treatment with N ‐acetylcysteine, a reactive oxygen species scavenger. In vivo validation using patient‐derived xenograft models demonstrated that oral administration of LCS‐1 led to significant tumor growth suppression and increased expression of apoptotic and DNA damage markers, including cleaved caspase‐3 and γH2AX. These findings establish SOD1 as a critical vulnerability in MTMCT and provide preclinical evidence supporting redox modulation as a therapeutic strategy for this highly chemoresistant and understudied ovarian cancer subtype. Our integrative approach combining functional genomics, spatial transcriptomics, and pharmacologic validation offers a framework for the discovery of novel targets in rare gynecologic malignancies.