Temporal trends and regional variations in operative vaginal deliveries in Japan: A national representative cohort study.

AIM: To analyze temporal trends and regional variations in operative vaginal delivery (OVD) in Japan. METHODS: Using the National Database of Health Insurance Claims and Specific Health Checkups of Japan from 2014 to 2021, we identified the numbers of vacuum and forceps deliveries. We analyzed annual totals and proportions of OVDs and calculated the mean age of women undergoing these deliveries. We also predicted trends in OVD for the next 20 years and compared geographical differences in the proportions of forceps deliveries among OVDs. RESULTS: During the observation period, out of 7 368 814 total births, 8.4% were through OVD, including 7.6% by vacuum and 0.8% by forceps. Both delivery methods showed an increasing trend from 2014 to 2021: vacuum deliveries rose from 7.0% to 8.7%, and forceps deliveries increased from 0.6% to 1.0%. Notably, the proportion of forceps deliveries in OVD increased from 8.1% to 10.5%. The mean age was higher for forceps deliveries than vacuum deliveries. According to our predictions, vacuum deliveries may continue to increase, but forceps deliveries may stabilize. The proportion of forceps deliveries among OVDs ranged from 0% to 38% across Japanese prefectures. CONCLUSIONS: This study shows an increase in the use of OVD in Japan from 2014 to 2021. There are large regional differences in the choice between vacuum and forceps deliveries. These findings can help us understand the practice of OVD in Japan.

Unexpected uterine body placenta accreta spectrum with placenta previa in a subsequent pregnancy after uterine artery embolization: a case report.

BACKGROUND: A subsequent pregnancy after uterine artery embolization (UAE) raises several concerns, one of which is placenta accreta spectrum (PAS). Placenta previa is the strongest risk factor for PAS, which is most likely to occur in the lower uterine segment. PAS without placenta previa (i.e., uterine body PAS) is considered relatively rare. CASE PRESENTATION: A 35-year-old woman, gravida 2 para 1, had undergone UAE for postpartum hemorrhage due to uterine atony after vaginal delivery in her previous pregnancy. She developed placenta previa during her subsequent pregnancy and was therefore evaluated for PAS in the lower uterine segment. On the basis of examination findings, we considered PAS to be unlikely. During cesarean section, we found that the placenta was not detached from the uterine body, and the patient was determined to have uterine body PAS. Ultimately, a hysterectomy was performed. CONCLUSIONS: PAS can occur in a subsequent pregnancy after UAE. When a subsequent pregnancy after UAE is accompanied by placenta previa, it is important to maintain a high index of suspicion of uterine body PAS without being misled by the presence of placenta previa.

Biological significance of KRAS mutant allele expression in ovarian endometriosis.

KRAS is the most frequently mutated in ovarian endometriosis. However, it is unclear whether the KRAS mutant allele's mRNA is expressed and plays a biological role in ovarian endometriosis. Here, we performed mutation-specific RNA in situ hybridization to evaluate mutant allele expression of KRAS p.G12V, the most frequently detected mutation in ovarian endometriosis in our previous study, in formalin-fixed paraffin-embedded tissue (FFPE) samples of ovarian endometriosis, cancer cell lines, and ovarian cancers. First, we verified that mutant or wild-type allele of KRAS were expressed in all 5 cancer cell lines and 9 ovarian cancer cases corresponding to the mutation status. Next, we applied this assay to 26 ovarian endometriosis cases, and observed mutant allele expression of KRAS p.G12V in 10 cases. Mutant or wild-type allele of KRAS were expressed in line with mutation status in 12 available endometriosis cases for which KRAS gene sequence was determined. Comparison of clinical features between ovarian endometriosis with KRAS p.G12V mutant allele expression and with KRAS wild-type showed that KRAS p.G12V mutant allele expression was significantly associated with inflammation in ovarian endometriosis. Finally, we assessed the spatial distribution of KRAS mutant allele expression in 5 endometriosis cases by performing multiregional sampling. Intratumor heterogeneity of KRAS mutant allele expression was observed in two endometriosis cases, whereas the spatial distribution of KRAS p.G12V mutation signals were diffuse and homogenous in ovarian cancer. In conclusion, evaluation of oncogene mutant expression will be useful for clarifying the biological significance of oncogene mutations in benign tumors.

MCM10 compensates for Myc-induced DNA replication stress in breast cancer stem-like cells.

Cancer stem-like cells (CSCs) induce drug resistance and recurrence of tumors when they experience DNA replication stress. However, the mechanisms underlying DNA replication stress in CSCs and its compensation remain unclear. Here, we demonstrate that upregulated c-Myc expression induces stronger DNA replication stress in patient-derived breast CSCs than in differentiated cancer cells. Our results suggest critical roles for mini-chromosome maintenance protein 10 (MCM10), a firing (activating) factor of DNA replication origins, to compensate for DNA replication stress in CSCs. MCM10 expression is upregulated in CSCs and is maintained by c-Myc. c-Myc-dependent collisions between RNA transcription and DNA replication machinery may occur in nuclei, thereby causing DNA replication stress. MCM10 may activate dormant replication origins close to these collisions to ensure the progression of replication. Moreover, patient-derived breast CSCs were found to be dependent on MCM10 for their maintenance, even after enrichment for CSCs that were resistant to paclitaxel, the standard chemotherapeutic agent. Further, MCM10 depletion decreased the growth of cancer cells, but not of normal cells. Therefore, MCM10 may robustly compensate for DNA replication stress and facilitate genome duplication in cancer cells in the S-phase, which is more pronounced in CSCs. Overall, we provide a preclinical rationale to target the c-Myc-MCM10 axis for preventing drug resistance and recurrence of tumors.

Myomectomy scar ectopic pregnancy following a cryopreserved embryo transfer.

CASE: A 40 year old woman with a history of a myomectomy visited the Department of Obstetrics and Gynecology, Niigata University Medical and Dental Hospital, Niigata, Japan, following 2 years of infertility. Magnetic resonance imaging detected an abnormal endometrial-like pseudo-cavity. A hysterosalpingography also revealed an abnormal accumulation of contrast medium at the myometrial scar site. A transvaginal ultrasound showed a thin myometrium at the lower uterine body. The patient conceived via in vitro fertilization under a luteal phase down-regulation protocol (long protocol) for controlled ovarian stimulation, followed by a cryopreserved embryo transfer during her natural ovulation cycle. After the embryo transfer, the gestational sac was located at the subserosal site of the myomectomy scar. OUTCOME: An emergent laparoscopic operation was performed and the embryo was removed successfully via laparoscopy under transvaginal ultrasonography. CONCLUSION: A subserosal uterine pregnancy is a rare form of intramural pregnancy, which is a rare subtype of an ectopic pregnancy, which could occur at the myomectomy site, especially after an embryo transfer. It is believed that this rare ectopic pregnancy resulted from embryo implantation under the serosa through a micro-sinus tract that was a site of suture failure of the myomectomy scar and was partially affected by the embryo transfer. Clinicians should consider the possibility of an ectopic pregnancy after uterine surgery, including a myomectomy.

Tumor-derived spheroids: Relevance to cancer stem cells and clinical applications.

Recently, many types of in vitro 3-D culture systems have been developed to recapitulate the in vivo growth conditions of cancer. The cancer 3-D culture methods aim to preserve the biological characteristics of original tumors better than conventional 2-D monolayer cultures, and include tumor-derived organoids, tumor-derived spheroids, organotypic multicellular spheroids, and multicellular tumor spheroids. The 3-D culture methods differ in terms of cancer cell sources, protocols for cell handling, and the required time intervals. Tumor-derived spheroids are unique because they are purposed for the enrichment of cancer stem cells (CSCs) or cells with stem cell-related characteristics. These spheroids are grown as floating spheres and have been used as surrogate systems to evaluate the CSC-related characteristics of solid tumors in vitro. Because eradication of CSCs is likely to be of clinical importance due to their association with the malignant nature of cancer cells, such as tumorigenicity or chemoresistance, the investigation of tumor-derived spheroids may provide invaluable clues to fight against cancer. Spheroid cultures have been established from cancers including glioma, breast, colon, ovary, and prostate cancers, and their biological and biochemical characteristics have been investigated by many research groups. In addition to the investigation of CSCs, tumor-derived spheroids may prove to be instrumental for a high-throughput screening platform or for the cultivation of CSC-related tumor cells found in the circulation or body fluids.

Sox2-dependent inhibition of p21 is associated with poor prognosis of endometrial cancer.

Sex-determining region Y-box 2 (SOX2) is an essential factor involved in the self-renewal and pluripotency of embryonic stem cells and has functions in cell survival and progression in many types of cancers. Here, we found that several endometrial cancer cell lines expressed SOX2, which was required for cell growth. Additionally, SOX2 overexpression regulated the expression of cyclin-dependent kinase inhibitor 1A (CDKN1A), and SOX2 specifically bound to p21 promoter DNA in endometrial cancer cell lines expressing SOX2. Expressions of SOX2 in endometrial cancer patients were significantly correlated with histological grade and poor prognosis. Moreover, low p21 together with high SOX2 expressions in advanced endometrial cancer patients were associated with the most unfavorable outcomes of patients. These results indicated that simultaneous measurement of SOX2 and p21 expression in endometrial cancer patients may be a useful biomarker for patient prognosis.

SLFN11 is a BRCA Independent Biomarker for the Response to Platinum-Based Chemotherapy in High-Grade Serous Ovarian Cancer and Clear Cell Ovarian Carcinoma.

BRCA1/2 mutations are robust biomarkers for platinum-based chemotherapy in epithelial ovarian cancers. However, BRCA1/2 mutations in clear cell ovarian carcinoma (CCC) are less frequent compared with high-grade serous ovarian cancer (HGSC). The discovery of biomarkers that can be applied to CCC is an unmet need in chemotherapy. Schlafen 11 (SLFN11) has attracted attention as a novel sensitizer for DNA-damaging agents including platinum. In this study, we investigated the utility of SLFN11 in HGSC and CCC for platinum-based chemotherapy. SLFN11 expression was analyzed retrospectively by IHC across 326 ovarian cancer samples. The clinicopathologic significance of SLFN11 expression was analyzed across 57 advanced HGSC as a discovery set, 96 advanced HGSC as a validation set, and 57 advanced CCC cases, all of whom received platinum-based chemotherapy. BRCA1/2 mutation was analyzed using targeted-gene sequencing. In the HGSC cohort, the SLFN11-positive and BRCA mutation group showed significantly longer whereas the SLFN11-negative and BRCA wild-type group showed significantly shorter progression-free survival and overall survival. Moreover, SLFN11-positive HGSC shrunk significantly better than SLFN11-negative HGSC after neoadjuvant chemotherapy. Comparable results were obtained with CCC but without consideration of BRCA1/2 mutation due to a small population. Multivariate analysis identified SLFN11 as an independent factor for better survival in HGSC and CCC. The SLFN11-dependent sensitivity to platinum and PARP inhibitors were validated with genetically modified non-HGSC ovarian cancer cell lines. Our study reveals that SLFN11 predicts platinum sensitivity in HGSC and CCC independently of BRCA1/2 mutation status, indicating that SLFN11 assessment can guide treatment selection in HGSC and CCC.

Targeting PDGF signaling of cancer-associated fibroblasts blocks feedback activation of HIF-1α and tumor progression of clear cell ovarian cancer.

Ovarian clear cell carcinoma (OCCC) is a gynecological cancer with a dismal prognosis; however, the mechanism underlying OCCC chemoresistance is not well understood. To explore the intracellular networks associated with the chemoresistance, we analyze surgical specimens by performing integrative analyses that combine single-cell analyses and spatial transcriptomics. We find that a chemoresistant OCCC subpopulation with elevated HIF activity localizes mainly in areas populated by cancer-associated fibroblasts (CAFs) with a myofibroblastic phenotype, which is corroborated by quantitative immunostaining. CAF-enhanced chemoresistance and HIF-1α induction are recapitulated in co-culture assays, which show that cancer-derived platelet-derived growth factor (PDGF) contributes to the chemoresistance and HIF-1α induction via PDGF receptor signaling in CAFs. Ripretinib is identified as an effective receptor tyrosine kinase inhibitor against CAF survival. In the co-culture system and xenograft tumors, ripretinib prevents CAF survival and suppresses OCCC proliferation in the presence of carboplatin, indicating that combination of conventional chemotherapy and CAF-targeted agents is effective against OCCC.

Cyclic intravenous pamidronate for an infant with osteogenesis imperfecta type II.

A woman in her 30s underwent a 17-week ultrasound which revealed short bowed long bones. Fetal CT at 28 weeks' gestation showed decreased ossification of the skull, a small bell-shaped thorax, hypoplastic vertebrae, and shortening and bowing of the long bones, leading to the diagnosis of osteogenesis imperfecta (OI) type II. The newborn was delivered via caesarean delivery, and tracheal intubation was performed due to the respiratory distress. A heterozygous variant in COL1A1 (c.1679G>T, p. Gly358Val) was ascertained, confirming the diagnosis of OI type II.Cyclic intravenous pamidronate was started at 41 days old with dose modification and was successfully administered every month. Currently, the infant is 8 months old without any new bone fracture. He was extubated successfully at 7 months of age and is now stable using high flow nasal cannula. The efficacy, safety, and optimal dose and timing of cyclic pamidronate for OI type II remain undefined. We report our experience of successful cyclic intravenous pamidronate treatment for an infant with OI type II.

Pathologically diagnosed placenta accreta spectrum without placenta previa: a systematic review and meta-analysis.

OBJECTIVE: This systematic review and meta-analysis aimed to assess clinical characteristics related to pathologically proven placenta accreta spectrum without placenta previa. DATA SOURCES: A literature search of PubMed, the Cochrane database, and Web of Science was performed from inception to September 7, 2022. STUDY ELIGIBILITY CRITERIA: The primary outcomes were invasive placenta (including increta or percreta), blood loss, hysterectomy, and antenatal diagnosis. In addition, maternal age, assisted reproductive technology, previous cesarean delivery, and previous uterine procedures were investigated as potential risk factors. The inclusion criteria were studies evaluating the clinical presentation of pathologically diagnosed PAS without placenta previa. METHODS: Study screening was conducted after duplicates were identified and removed. The quality of each study and the publication bias were assessed. Forest plots and I2 statistics were calculated for each study outcome for each group. The main analysis was a random-effects analysis. RESULTS: Among 2598 studies that were initially retrieved, 5 were included in the review. With the exception of 1 study, 4 studies were included in the meta-analysis. This meta-analysis showed that placenta accreta spectrum without placenta previa was associated with less risk of invasive placenta (odds ratio, 0.24; 95% confidence interval, 0.16-0.37), blood loss (mean difference, -1.19; 95% confidence interval, -2.09 to -0.28) and hysterectomy (odds ratio, 0.11; 95% confidence interval, 0.02-0.53), and more difficult to diagnose prenatally (odds ratio, 0.13; 95% confidence interval, 0.04-0.45) than placenta accreta spectrum with placenta previa. In addition, assisted reproductive technology and a previous uterine procedure were strong risk factors for placenta accreta spectrum without placenta previa, whhereas previous cesarean delivery was a strong risk factor for placenta accreta spectrum with placenta previa. CONCLUSION: The differences in clinical aspects of placenta accreta spectrum with and without placenta previa need to be understood.

Incidence of Recurrent Uterine Rupture: A Systematic Review and Meta-analysis.

OBJECTIVE: We aimed to quantify the incidence of recurrent uterine rupture in pregnant women. DATA SOURCES: A literature search of PubMed, Web of Science, Cochrane Central, and ClinicalTrials.gov for observational studies was performed from 2000 to 2023. METHODS OF STUDY SELECTION: Of the 7,440 articles screened, 13 studies were included in the final review. We included studies of previous uterine ruptures that were complete uterine ruptures , defined as destruction of all uterine layers, including the serosa. The primary outcome was the pooled incidence of recurrent uterine rupture. Between-study heterogeneity was assessed with the I2 value. Subgroup analyses were conducted in terms of the country development status, year of publication, and study size (single center vs national study). The secondary outcomes comprised the following: 1) mean gestational age at which recurrent rupture occurred, 2) mean gestational age at which delivery occurred without recurrent rupture, and 3) perinatal complications (blood loss, transfusion, maternal mortality, and neonatal mortality). TABULATION, INTEGRATION, AND RESULTS: A random-effects model was used to pool the incidence or mean value and the corresponding 95% CI with R software. The pooled incidence of recurrent uterine rupture was 10% (95% CI 6-17%). Developed countries had a significantly lower uterine rupture recurrence rate than less developed countries (6% vs 15%, P =.04). Year of publication and study size were not significantly associated with recurrent uterine rupture. The mean number of gestational weeks at the time of recurrent uterine rupture was 32.49 (95% CI 29.90-35.08). The mean number of gestational weeks at the time of delivery without recurrent uterine rupture was 35.77 (95% CI 34.95-36.60). The maternal mortality rate was 5% (95% CI 2-11%), and the neonatal mortality rate was 5% (95% CI 3-10%). Morbidity from hemorrhage, such as bleeding and transfusion, was not reported in any study and could not be evaluated. CONCLUSION: This systematic review estimated a 10% incidence of recurrent uterine rupture. This finding will enable appropriate risk counseling in patients with prior uterine rupture. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42023395010.

Comparison of maternal outcomes and clinical characteristics of prenatally vs nonprenatally diagnosed placenta accreta spectrum: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to compare maternal outcomes of prenatally and nonprenatally diagnosed placenta accreta spectrum. DATA SOURCES: A systematic literature search was performed in PubMed, the Cochrane database, and Web of Science until November 28, 2022. STUDY ELIGIBILITY CRITERIA: Studies comparing the clinical presentation of prenatally and nonprenatally diagnosed placenta accreta spectrum were included. The primary outcomes were emergent cesarean delivery, hysterectomy, blood loss volume, number of transfused blood product units, urological injury, coagulopathy, reoperation, intensive care unit admission, and maternal death. In addition, the pooled mean values for blood loss volume and the number of transfused blood product units were calculated. The secondary outcomes included maternal age, gestational age at birth, nulliparity, previous cesarean delivery, previous uterine procedure, assisted reproductive technology, placenta increta and percreta, and placenta previa. METHODS: Study screening was performed after duplicates were identified and removed. The quality of each study and the publication bias were assessed. Forest plots and I2 statistics were calculated for each study outcome for each group. The main analysis was a random-effects analysis. RESULTS: Overall, 415 abstracts and 157 full-text studies were evaluated. Moreover, 31 studies were analyzed. Prenatally diagnosed placenta accreta spectrum was associated with a significantly lower rate of emergency cesarean delivery (odds ratio, 0.37; 95% confidence interval, 0.21-0.67), higher hysterectomy rate (odds ratio, 1.98; 95% confidence interval, 1.02-3.83), lower blood loss volume (mean difference, -0.65; 95% confidence interval, -1.17 to -0.13), and lower number of transfused red blood cell units (mean difference, -1.96; 95% confidence interval, -3.25 to -0.68) compared with nonprenatally diagnosed placenta accreta spectrum. The pooled mean values for blood loss volume and the number of transfused blood product units tended to be lower in the prenatally diagnosed placenta accreta spectrum groups than in the nonprenatally diagnosed placenta accreta spectrum groups. Nulliparity (odds ratio, 0.14; 95% confidence interval, 0.10-0.20), previous cesarean delivery (odds ratio, 6.81; 95% confidence interval, 4.12-11.25), assisted reproductive technology (odds ratio, 0.19; 95% confidence interval, 0.06-0.61), placenta increta and percreta (odds ratio, 3.97; 95% confidence interval, 2.24-7.03), and placenta previa (odds ratio, 6.81; 95% confidence interval, 4.12-11.25) showed statistical significance. No significant difference was found for the other outcomes. CONCLUSION: Despite its severity, the positive effect of prenatally diagnosed placenta accreta spectrum on outcomes underscores the necessity of a prenatal diagnosis. In addition, the pooled mean values provide a preoperative preparation guideline.

Endometrial Cancer with and without Endometriosis: Clinicopathological Differences.

Endometriosis is known to be associated with an increased risk of endometrioid and clear cell ovarian cancer. However, the association between endometriosis and endometrial cancer is controversial. Therefore, we retrospectively analyzed the medical records of women with endometrial cancer who had undergone surgery at our institution to evaluate the clinicopathological relationship between endometrial cancer and endometriosis. The study included 720 women pathologically diagnosed with endometrial cancer at our hospital between 2000 and 2020. The participants were allocated to two groups of patients with endometrial cancer: patients with endometriosis (n = 101) and patients without endometriosis (n = 619). Endometrial cancer patients with endometriosis were significantly younger (median age 54.0 vs. 58.0; p = 0.002). In addition, endometrial cancer patients with endometriosis had fewer pregnancies and deliveries (median pregnancy 1.58 vs. 1.99; p = 0.019, median delivery 1.25 vs. 1.56; p = 0.012). The percentage of patients classified as stage IA was significantly higher in those with endometrial cancer with endometriosis (68.3% vs. 56.4%; p = 0.029). In the analysis of synchronous ovarian cancer, the percentage of dual primary cancer was higher in patients with endometriosis (14.9% vs. 1.6%; p < 0.001). The association of young-onset early-stage endometrial cancer with endometriosis is an important finding that cannot be ignored clinically.

Spatiotemporal dynamics of clonal selection and diversification in normal endometrial epithelium.

It has become evident that somatic mutations in cancer-associated genes accumulate in the normal endometrium, but spatiotemporal understanding of the evolution and expansion of mutant clones is limited. To elucidate the timing and mechanism of the clonal expansion of somatic mutations in cancer-associated genes in the normal endometrium, we sequence 1311 endometrial glands from 37 women. By collecting endometrial glands from different parts of the endometrium, we show that multiple glands with the same somatic mutations occupy substantial areas of the endometrium. We demonstrate that "rhizome structures", in which the basal glands run horizontally along the muscular layer and multiple vertical glands rise from the basal gland, originate from the same ancestral clone. Moreover, mutant clones detected in the vertical glands diversify by acquiring additional mutations. These results suggest that clonal expansions through the rhizome structures are involved in the mechanism by which mutant clones extend their territories. Furthermore, we show clonal expansions and copy neutral loss-of-heterozygosity events occur early in life, suggesting such events can be tolerated many years in the normal endometrium. Our results of the evolutionary dynamics of mutant clones in the human endometrium will lead to a better understanding of the mechanisms of endometrial regeneration during the menstrual cycle and the development of therapies for the prevention and treatment of endometrium-related diseases.

Integrative analyses of gene expression and chemosensitivity of patient-derived ovarian cancer spheroids link G6PD-driven redox metabolism to cisplatin chemoresistance.

Patient-derived cells and xenografts retain the biological characteristics of clinical cancers and are instrumental in gaining a better understanding of the chemoresistance of cancer cells. Here, we have established a panel of patient-derived spheroids from clinical materials of ovarian cancer. Systematic evaluation using therapeutic agents indicated that sensitivity to platinum-based compounds significantly varied among the spheroids. To understand the molecular basis of drug sensitivity, we performed integrative analyses combining chemoresistance data and gene expression profiling of the ovarian cancer patient-derived spheroids. Correlation analyses revealed that cisplatin resistance was significantly associated with elevated levels of glucose-6-phosphate dehydrogenase (G6PD) and glutathione-producing redox enzymes. Accordingly, cisplatin-resistant spheroids established in vitro showed elevated levels of G6PD and active glutathione. Moreover, treatment with a G6PD inhibitor in combination with cisplatin suppressed spheroid proliferation in vitro and largely eradicated peritoneal metastasis in mouse xenograft models. Furthermore, G6PD expression was elevated during carcinogenesis and associated with poor prognosis. Thus, the combination of gene expression data and chemosensitivity revealed the essential roles of G6PD-driven redox metabolism in cisplatin resistance, underscoring the significance of an integrative approach using patient-derived cells.

Three-dimensional understanding of the morphological complexity of the human uterine endometrium.

The fundamental morphology of the endometrial glands is not sufficiently understood by 2D observation because these glands have complicated winding and branching patterns. To construct a large picture of the endometrial gland structure, we performed tissue-clearing-based 3D imaging of human uterine endometrial tissue. Our 3D immunohistochemistry and layer analyses revealed that the endometrial glands form a plexus network in the stratum basalis and expand horizontally along the muscular layer, similar to the rhizome of grass. We then extended our method to assess the 3D morphology of tissue affected by adenomyosis, a representative "endometrium-related disease," and observed its 3D morphological features, including the direct invasion of endometrial glands into the myometrium and an ant colony-like network of ectopic endometrial glands within the myometrium. Thus, further understanding of the morphology of the human endometrium based on 3D analysis will lead to the identification of the pathogenesis of endometrium-related diseases.

Establishment of in vitro 3D spheroid cell cultivation from human gynecologic cancer tissues.

Advanced-stage gynecologic cancer remains a life-threatening disease. Here, we present a protocol for establishment of stable in vitro 3D spheroid cells derived from human uterine endometrial and ovarian cancer tissues. The tumor-derived spheroid cells have cancer stem cell-related characteristics, including tumorigenesis, and can be used for biological and biochemical analyses and drug efficacy assays. Because these cells possess the biological characteristics of original human tumors, spheroid cells and spheroid-derived xenografts will have applications in personalized medicine in the future. For complete details on the use and execution of this protocol, please refer to Ishiguro et al. (2016) and Mori et al. (2019).

Evaluating the Angiogenetic Properties of Ovarian Cancer Stem-like Cells using the Three-dimensional Co-culture System, NICO-1.

Cancer stem cells (CSCs) reside in a supportive niche, constituting a microenvironment comprised of adjacent stromal cells, vessels, and extracellular matrix. The ability of CSCs to participate in the development of endothelium constitutes an important characteristic that directly contributes to the general understanding of the mechanisms of tumorigenesis and tumor metastasis. The purpose of this work is to establish a reproducible methodology to investigate the tumor-initiation capability of ovarian cancer stem cells (OCSCs). Herein, we examined the neovascularization mechanism between endothelial cells and OCSCs along with the morphological changes of endothelial cells using the in vitro co-culture model NICO-1. This protocol allows visualization of the neovascularization step surrounding the OCSCs in a time course manner. The technique can provide insight regarding the angiogenetic properties of OCSCs in tumor metastasis.

ARID1A protein expression is retained in ovarian endometriosis with ARID1A loss-of-function mutations: implication for the two-hit hypothesis.

ARID1A loss-of-function mutation accompanied by a loss of ARID1A protein expression is considered one of the most important driver events in endometriosis-associated ovarian cancer. Although our recent genomic study clarified that ARID1A loss-of-function mutations were detected in 13% of ovarian endometriosis, an association between the ARID1A mutation status and ARID1A protein expression in ovarian endometriosis remains unclear. We performed immunohistochemical staining for ARID1A in 78 ovarian endometriosis samples and 99 clear cell carcinoma samples. We revealed that not only 70 endometriosis samples without ARID1A mutations but also eight endometriosis samples with ARID1A loss-of-function mutations retained ARID1A protein expression. On the other hand, most of clear cell carcinomas with ARID1A loss-of-function mutations showed a loss of ARID1A protein expression. In particular, clear cell carcinoma samples which harbor multiple ARID1A loss-of-function mutations or both a single ARID1A loss-of-function mutation and ARID1A allelic imbalance lost ARID1A protein expression. However, ARID1A protein expression was retained in seven clear cell carcinomas with ARID1A loss-of-function mutations. These results suggest that a single ARID1A loss-of-function mutation is insufficient for ARID1A loss in ovarian endometriosis and some clear cell carcinoma. Further driver events may be needed for the malignant transformation of ovarian endometriosis with ARID1A loss-of-function mutations.