Comorbid thrombosis as an adverse prognostic factor in patients with ovarian clear cell carcinoma regardless of staging.

OBJECTIVE: Patients with ovarian clear cell carcinoma (OCCC) often present with thrombosis. While cancer patients with concomitant thrombosis were generally reported to have worse prognoses than those without, the association between thrombosis and prognosis has not been elucidated in OCCC. This study aimed to determine how the co-occurrence of thrombosis affects OCCC prognoses. METHODS: We retrospectively examined 115 patients with OCCC who were diagnosed and treated at the University of Tokyo Hospital between 2009 and 2019. RESULTS: Of 115 patients with OCCC, thrombosis was present in 12.5% of 80 patients and in 42.8% of 35 patients who had OCCC stage I/II and stage III/IV, respectively. In stage I/II, the 5-year progression-free survival was 20.6% and 91.8% among patients with thrombosis and among those without, respectively, while the corresponding 5-year overall survival rates were 50.0% and 94.1%. Therefore, the outcomes were significantly poorer among patients with thrombosis (p < 0.0001 and p < 0.0001, respectively). In stage III/IV, the 5-year progression-free survival was 26.7% and 52.8% among patients with thrombosis and among those without, respectively, while the corresponding 5-year overall survival rates were 32.0% and 62.2%. Similarly, the outcomes were significantly poorer among patients with thrombosis (p = 0.0139 and p = 0.369, respectively). CONCLUSION: We determined that thrombosis is more likely to develop in advanced OCCC stages than in early stages, and its co-occurrence is associated with a poor prognosis, regardless of disease stage.

A nationwide survey of diagnostic procedures for abnormal uterine bleeding in Japan.

AIM: To clarify the diagnostic process of the causative disease of abnormal uterine bleeding (AUB) in Japan according to the International Federation of Gynecology and Obstetrics AUB diagnostic system. METHODS: Patients diagnosed with AUB were included in a nationwide survey of AUB conducted during any 2-week period between December 2019 and January 2020. The second survey included information on patient background, AUB symptoms, examinations for diagnosing AUB, the order in which they were performed, and the causative diseases of AUB. RESULTS: Correspondence analysis showed an association between hormonal testing, hysterosalpingography, and magnetic resonance imaging (MRI) in patients with amenorrhea, and heavy menstrual bleeding was strongly correlated with various examinations, such as coagulation tests, pelvic MRI, and endometrial cytology or biopsy. The results also indicated that each AUB causative disease can be diagnosed based on a specific examination profile. CONCLUSION: We clarified the process of diagnosing the causative disease of AUB in our country and determined that it was mainly diagnosed by imaging and pathological examination in cases of structural disease. The high rate of AUB-E and the low rate of AUB-C are possibly associated with specific examination trends in Japan. The results of this study will be useful for the development of a standard protocol for AUB diagnosis in our country.

Cellular senescence of granulosa cells in the pathogenesis of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age, but its pathology has not been fully characterized and the optimal treatment strategy remains unclear. Cellular senescence is a permanent state of cell-cycle arrest that can be induced by multiple stresses. Senescent cells contribute to the pathogenesis of various diseases, owing to an alteration in secretory profile, termed 'senescence-associated secretory phenotype' (SASP), including with respect to pro-inflammatory cytokines. Senolytics, a class of drugs that selectively eliminate senescent cells, are now being used clinically, and a combination of dasatinib and quercetin (DQ) has been extensively used as a senolytic. We aimed to investigate whether cellular senescence is involved in the pathology of PCOS and whether DQ treatment has beneficial effects in patients with PCOS. We obtained ovaries from patients with or without PCOS, and established a mouse model of PCOS by injecting dehydroepiandrosterone. The expression of the senescence markers p16INK4a, p21, p53, γH2AX, and senescence-associated ß-galactosidase and the SASP-related factor interleukin-6 was significantly higher in the ovaries of patients with PCOS and PCOS mice than in controls. To evaluate the effects of hyperandrogenism and DQ on cellular senescence in vitro, we stimulated cultured human granulosa cells (GCs) with testosterone and treated them with DQ. The expression of markers of senescence and a SASP-related factor was increased by testosterone, and DQ reduced this increase. DQ reduced the expression of markers of senescence and a SASP-related factor in the ovaries of PCOS mice and improved their morphology. These results indicate that cellular senescence occurs in PCOS. Hyperandrogenism causes cellular senescence in GCs in PCOS, and senolytic treatment reduces the accumulation of senescent GCs and improves ovarian morphology under hyperandrogenism. Thus, DQ might represent a novel therapy for PCOS.

The Association between Endometriosis and Obstructive Müllerian Anomalies.

It is unclear whether clinical background differs between endometriosis in adolescent patients with obstructive Müllerian anomalies and those without anomalies. The aim of the study is to identify the difference in clinical characteristics of endometriosis in patients with or without obstructive Müllerian anomalies. The study involved 12 patients aged under 24 years old who underwent primary surgery for obstructive Müllerian anomalies and 31 patients aged under 24 years old who underwent surgery for ovarian endometrioma. A total of 6 out of 12 cases with obstructive Müllerian anomalies developed endometriosis (4 Herlyn-Werner-Wunderlich syndrome, 2 non-communicating functional uterine horn, 2 cervical aplasia). The age at surgery was significantly younger in endometriosis with obstructive Müllerian anomalies, compared with those without obstructive Müllerian anomalies (17.8 ± 4.4 vs. 23.1 ± 1.3, p = 0.0007). The rate of endometrioma was 50.0% and the rate of hydrosalpinx was significantly higher (66.7% vs. 0%, p = 0.0002) in the group of obstructive Müllerian anomalies. The recurrence rate of endometriosis was 20.0% in the group of anomalies and 25.9% in the group of those without anomalies. Adolescent patients with obstructive Müllerian anomalies more easily developed endometriosis and co-occurred with higher rate of hematosalipinx.

Ulipristal (UPA) effects on rat ovaries: Unraveling follicle dynamics, ovulation inhibition, and safety implications for prolonged use.

Ulipristal (UPA), a selective progesterone receptor modulator, has both agonistic and antagonistic effects on progesterone receptors. UPA suppresses ovulation by inhibiting the luteinizing hormone (LH) surge from the pituitary gland; however, the direct effect of UPA on ovarian tissue remains poorly studied. In the present study, we examined the effects of UPA on the ovaries of rats. Rats were treated for 28 days with UPA, and the effects of UPA on ovarian tissue were examined histologically and the expression of antioxidant genes and cell death markers were also investigated. UPA treatment increased the number of primordial follicles at each treatment group, primordial follicles increased at all dose levels, but the size/magnitude of the effect decreased with the increasing dose. The number of primary and antral follicles tended to increase with increasing UPA levels. Furthermore, the decrease in primary follicle number could be attributed to the exhaustion of follicles, but the examination of proliferation markers, oxidative stress markers, and cell death markers revealed no remarkable toxic effects on ovarian tissues. These results suggest that UPA treatment promotes follicle development at each stage but inhibits ovulation by suppressing the LH surge, resulting in an increase in atretic follicles or unruptured luteinized cysts. These results suggest that UPA may not have both toxic effects on the ovary and a direct local effect on ovarian follicles, but we should be careful about the effects of prolonged UPA treatment in patients with uterine fibroids on their future fecundity.

Inhibition of protein arginine methyltransferase 6 activates interferon signaling and induces the apoptosis of endometrial cancer cells via histone modification.

Histone modification, a major epigenetic mechanism regulating gene expression through chromatin remodeling, introduces dynamic changes in chromatin architecture. Protein arginine methyltransferase 6 (PRMT6) is overexpressed in various types of cancer, including prostate, lung and endometrial cancer (EC). Epigenome regulates the expression of endogenous retrovirus (ERV), which activates interferon signaling related to cancer. The antitumor effects of PRMT6 inhibition and the role of PRMT6 in EC were investigated, using epigenome multi­omics analysis, including an assay for chromatin immunoprecipitation sequencing (ChIP­seq) and RNA sequencing (RNA­seq). The expression of PRMT6 in EC was analyzed using reverse transcription­quantitative polymerase chain reaction (RT­qPCR) and immunohistochemistry (IHC). The prognostic impact of PRMT6 expression was evaluated using IHC. The effects of PRMT6­knockdown (KD) were investigated using cell viability and apoptosis assays, as well as its effects on the epigenome, using ChIP­seq of H3K27ac antibodies and RNA­seq. Finally, the downstream targets identified by multi­omics analysis were evaluated. PRMT6 was overexpressed in EC and associated with a poor prognosis. PRMT6­KD induced histone hypomethylation, while suppressing cell growth and apoptosis. ChIP­seq revealed that PRMT6 regulated genomic regions related to interferons and apoptosis through histone modifications. The RNA­seq data demonstrated altered interferon­related pathways and increased expression of tumor suppressor genes, including NK6 homeobox 1 and phosphoinositide­3­kinase regulatory subunit 1, following PRMT6­KD. RT­qPCR revealed that eight ERV genes which activated interferon signaling were upregulated by PRMT6­KD. The data of the present study suggested that PRMT6 inhibition induced apoptosis through interferon signaling activated by ERV. PRMT6 regulated tumor suppressor genes and may be a novel therapeutic target, to the best of our knowledge, in EC.

Characteristic hysteroscopy appearance considerations for detecting uterine endometrial malignancies.

AIM: The effectiveness of hysteroscopy in diagnosing endometrial lesions has been demonstrated, showing high diagnostic accuracy for malignant endometrial lesions. Although the characteristic appearances of atypical and malignant endometria have been reported, they are not definitive and sometimes complicated. This study aimed to identify a small number of characteristic features to detect endometrial abnormalities using a simple judgment system and analyze the diagnostic characteristics and their accuracy in endometrial malignancy diagnosis. METHODS: We performed a retrospective analysis of hysteroscopy video data of 250 patients, of which we selected for analysis based on pathology examination 152 cases with benign changes, 16 with atypical endometrium, and 18 with carcinoma in situ or endometrial cancer. Endometrial characteristics assessed included protrusion, desquamation, extended vessel, atypical vessel, and white/yellow lesion. RESULTS: Multivariable analysis revealed that desquamation (p = 0.001, odds ratio [OR] 5.28), atypical vessels (p < 0.001, OR 8.50), and white/yellow lesions (p = 0.011, OR 1.37) were significant predictors for endometrial malignancy. From their contribution status, scoring points of 4, 6, and 1 were settled according to the odds ratio proportions. When scores ≥5 (at least both desquamation and white/yellow lesions or only atypical vessels) were used to define endometrial malignancy, sensitivity and specificity were 100% and 92%, respectively. When detecting cancer, atypical, and benign cases, sensitivity and specificity were 88% and 90%, respectively. CONCLUSION: Our characteristics hysteroscopic findings showed a higher predictive ability in detecting endometrial malignancies. However, further examination with more cases would be needed to accurately diagnose endometrial malignancy by hysteroscopy.

The Role of Cellular Senescence in Cyclophosphamide-Induced Primary Ovarian Insufficiency.

Young female cancer patients can develop chemotherapy-induced primary ovarian insufficiency (POI). Cyclophosphamide (Cy) is one of the most widely used chemotherapies and has the highest risk of damaging the ovaries. Recent studies elucidated the pivotal roles of cellular senescence, which is characterized by permanent cell growth arrest, in the pathologies of various diseases. Moreover, several promising senolytics, including dasatinib and quercetin (DQ), which remove senescent cells, are being developed. In the present study, we investigated whether cellular senescence is involved in Cy-induced POI and whether DQ treatment rescues Cy-induced ovarian damage. Expression of the cellular senescence markers p16, p21, p53, and γH2AX was upregulated in granulosa cells of POI mice and in human granulosa cells treated with Cy, which was abrogated by DQ treatment. The administration of Cy decreased the numbers of primordial and primary follicles, with a concomitant increase in the ratio of growing to dormant follicles, which was partially rescued by DQ. Moreover, DQ treatment significantly improved the response to ovulation induction and fertility in POI mice by extending reproductive life. Thus, cellular senescence plays critical roles in Cy-induced POI, and targeting senescent cells with senolytics, such as DQ, might be a promising strategy to protect against Cy-induced ovarian damage.

Characterization of a fluorescence imaging probe that exploits metabolic dependency of ovarian clear cell carcinoma.

The purpose of this study is to clarify the metabolic dependence of ovarian clear cell carcinoma (CCC) by comparing normal tissues and to examine the applicability of fluorescence imaging probe to exploit these metabolic differences. Enhanced glutathione synthesis was supported by the increased uptake of related metabolites and elevated expression levels of genes. Accumulation of intracellular iron and lipid peroxide, induction of cell death by inhibition of the glutathione synthesis pathway indicated that ferroptosis was induced. The activation of γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG), a fluorescent imaging probe that recognizes γ-glutamyl transferase, which is essential for the synthesis of glutathione, was investigated in fresh-frozen surgical specimens. gGlu-HMRG detected extremely strong fluorescent signals in the tumor lesions of CCC patients, compared to normal ovaries or endometrium. These results revealed that CCC occurs in the stressful and unique environment of free radical-rich endometrioma, and that glutathione metabolism is enhanced as an adaptation to oxidative stress. Furthermore, a modality that exploits these metabolic differences would be useful for distinguishing between CCC and normal tissues.

Validation of an on-chip p16ink4a/Ki-67 dual immunostaining cervical cytology system using microfluidic device technology.

More specific screening systems for cervical cancer may become necessary as the human papillomavirus (HPV) vaccine becomes more widespread. Although p16/Ki-67 dual-staining cytology has several advantages, it requires advanced diagnostic skills. Here, we developed an automated on-chip immunostaining method using a microfluidic device. An electroactive microwell array (EMA) microfluidic device with patterned thin-film electrodes at the bottom of each microwell was used for single-cell capture by dielectrophoresis. Immunostaining and dual staining for p16/Ki-67 were performed on diagnosed liquid cytology samples using the EMA device. The numbers of p16/Ki-67 dual-stained cells captured by the EMA device were determined and compared among the cervical intraepithelial neoplasia (CIN) lesion samples. Seven normal, fifteen CIN grade 3, and seven CIN grade 2 samples were examined. The percentage of dual-positive cells was 18.6% in the CIN grade 2 samples and 23.6% in the CIN grade 3 samples. The percentages of dual-positive staining increased significantly as the severity of the cervical lesions increased. p16/Ki67 dual immunostaining using the EMA device is as sensitive as the conventional method of confirming the histopathological diagnosis of cervical samples. This system enables a quantified parallel analysis at the individual cell level.

Pregnancy is associated with reduced progression of symptomatic adenomyosis: a retrospective pilot study.

BACKGROUND: Adenomyosis is a common gynecological disease in women of reproductive age and causes various symptoms such as dysmenorrhea and heavy menstrual bleeding. However, the influence of pregnancy on the progression of adenomyosis remains unclear. The insight into whether the size of adenomyosis is increased, decreased, or unchanged during pregnancy is also undetermined. The current study aimed to evaluate the influence of pregnancy in patients with symptomatic adenomyosis. METHODS: This study retrospectively enrolled patients diagnosed with adenomyosis by magnetic resonance imaging between 2015 and 2022 at The University of Tokyo Hospital. Uterine size changes were evaluated by two imaging examinations. In the pregnancy group, the patients did not receive any hormonal and surgical treatments, except cesarean section, but experienced pregnancy and delivery between the first and second imaging examinations. In the control group (nonpregnancy group), the patients experienced neither hormonal and surgical treatments nor pregnancy from at least 1 year before the first imaging to the second imaging. The enlargement rate of the uterine size per year (percentage) was calculated by the uterine volume changes (cm3) divided by the interval (years) between two imaging examinations. The enlargement rate of the uterine size per year was compared between the pregnancy group and the control group. RESULTS: Thirteen and 11 patients with symptomatic adenomyosis were included in the pregnancy group and in the control group, respectively. The pregnancy group had a lower enlargement rate per year than the control group (mean ± SE: -7.4% ± 3.6% vs. 48.0% ± 18.5%, P < 0.001), indicating that the size of the uterus with adenomyosis did not change in the pregnancy group. CONCLUSIONS: Pregnancy is associated with reduced progression of symptomatic adenomyosis.

Evolution of a surgical system using deep learning in minimally invasive surgery (Review).

Recently, artificial intelligence (AI) has been applied in various fields due to the development of new learning methods, such as deep learning, and the marked progress in computational processing speed. AI is also being applied in the medical field for medical image recognition and omics analysis of genomes and other data. Recently, AI applications for videos of minimally invasive surgeries have also advanced, and studies on such applications are increasing. In the present review, studies that focused on the following topics were selected: i) Organ and anatomy identification, ii) instrument identification, iii) procedure and surgical phase recognition, iv) surgery-time prediction, v) identification of an appropriate incision line, and vi) surgical education. The development of autonomous surgical robots is also progressing, with the Smart Tissue Autonomous Robot (STAR) and RAVEN systems being the most reported developments. STAR, in particular, is currently being used in laparoscopic imaging to recognize the surgical site from laparoscopic images and is in the process of establishing an automated suturing system, albeit in animal experiments. The present review examined the possibility of fully autonomous surgical robots in the future.

Questionnaire survey regarding current status of minimally invasive surgery for endometrial cancer in Japan: A cross-sectional survey for JSGOE members.

AIM: Minimally invasive surgery (MIS) has been introduced as an alternative to more radical surgical procedures. The Japan Society of Gynecologic and Obstetric Endoscopy and Minimally Invasive Therapy conducted a cross-sectional questionnaire survey to ascertain the status of MIS for endometrial cancer. METHODS: The survey was conducted between May 10 and June 30, 2022. The questionnaire included information on personal attributes, academic affiliations, qualifications, hysterectomies, and intraoperative procedures performed. RESULTS: The total number of questionnaire respondents was 436 (9.2% of the membership). The hysterectomy methods and percentage performed were as follows: simple total hysterectomy (equivalent to benign surgery), 3%; simple total hysterectomy with care to avoid shaving the cervix, 31%; extended total hysterectomy, 48%; and modified radical hysterectomy, 15%. An analysis of hysterectomies performed using MIS for endometrial cancer by qualified gynecologists of endoscopy or board-certified gynecologic oncologists showed a tendency not to choose simple total hysterectomy compared to the gynecologists who did not hold certification (p = 0.019, p = 0.045, and p = 0.010, respectively). Additionally, 67% of respondents did not use uterine manipulators, and 59% of the respondents did not perform lymph node dissection following the guidelines for treating endometrial cancer in Japan. CONCLUSION: This study provided the current status of MIS for endometrial cancer in Japan. The hysterectomy method, use of uterine manipulators, and criteria for omitting lymph node dissection were generally in agreement with the guidelines. Currently, an extra-fascial simple hysterectomy, including at least not shaving the cervix, was a major method for early invasive endometrial cancer using MIS.

Text mining in a literature review of abnormal uterine bleeding according to the FIGO classification.

AIM: Abnormal uterine bleeding, as proposed in 2007, is defined as unexpected uterine bleeding in women of reproductive age; the cause of the bleeding is categorized using the PALM-COEIN system. Identifying the diagnostic and treatment modalities for each cause might be intriguing. To summarize the options for abnormal uterine bleeding assessment, we employed text-mining analysis for each of its causes. METHODS: We analyzed abstracts based on PALM-COEIN from PubMed and Web of Science in March 2022. The literature was divided into categories; topics about the disorders were retrieved, and covalent network analysis was conducted to find information for evaluating abnormal uterine bleeding. RESULTS: Diagnostic approaches for PALM included histological and image analysis, including computerized tomography, magnetic resonance imaging, sonography, and hysteroscopy. The therapeutic approaches varied according to the cause. Diagnostic approaches for COEIN were mostly medical history interviews and blood sampling, and the therapeutic approaches for COEIN were ablation, hysteroscopy, and hormonal treatment. The PALM-COEIN classification co-occurrence search revealed each cause's diagnostic procedures, symptoms, and treatment procedures. CONCLUSION: Our text-mining methodology revealed comprehensive insights, important study themes, and clinical trends for abnormal uterine bleeding. A tailored approach to medical realities is required for treating abnormal uterine bleeding properly.

Application of organoid culture from HPV18-positive small cell carcinoma of the uterine cervix for precision medicine.

BACKGROUND: Small cell carcinoma of the uterine cervix (SCCC) is a rare and highly malignant human papillomavirus (HPV)-associated cancer in which human genes related to the integration site can serve as a target for precision medicine. The aim of our study was to establish a workflow for precision medicine of HPV-associated cancer using patient-derived organoid. METHODS: Organoid was established from the biopsy of a patient diagnosed with HPV18-positive SCCC. Therapeutic targets were identified by whole exome sequencing (WES) and RNA-seq analysis. Drug sensitivity testing was performed using organoids and organoid-derived mouse xenograft model. RESULTS: WES revealed that both the original tumor and organoid had 19 somatic variants in common, including the KRAS p.G12D pathogenic variant. Meanwhile, RNA-seq revealed that HPV18 was integrated into chromosome 8 at 8q24.21 with increased expression of the proto-oncogene MYC. Drug sensitivity testing revealed that a KRAS pathway inhibitor exerted strong anti-cancer effects on the SCCC organoid compared to a MYC inhibitor, which were also confirmed in the xenograft model. CONCLUSION: In this study, we confirmed two strategies for identifying therapeutic targets of HPV-derived SCCC, WES for identifying pathogenic variants and RNA sequencing for identifying HPV integration sites. Organoid culture is an effective tool for unveiling the oncogenic process of rare tumors and can be a breakthrough for the development of precision medicine for patients with HPV-positive SCCC.

Is there a need for a technical certification system for gynecological robotic surgery? Questionnaire survey of members of the Japan Society of Gynecologic and Obstetric Endoscopy and Minimally Invasive Therapy.

The Japan Society of Gynecologic and Obstetric Endoscopy and Minimally Invasive Therapy (JSGOE) introduced a system for the certification of laparoscopic surgeons in 2002 and a system for the certification of facilities in 2014. We examined the opinions of the members of the Japan Society of Gynecologic and Obstetric Endoscopy and Minimally Invasive Therapy (JSGOE) regarding the necessity of a certification training system and a technical certification system for robotic surgery skills in Japan. Members of the JSGOE were surveyed with two questionnaires. Overall, 870 and 519 participants responded to the first and second questionnaires, respectively. Half of the respondents indicated that both systems were necessary. The breakdown by age and qualifications showed that this was especially true for the younger generation and respondents with more experience with robotic surgery. Overall, 40% of the respondents judged that a certification system for robotic surgery alone (with or without certification in laparoscopic surgery but with a requirement of experience in laparoscopic surgery) would be necessary. The opinions of the JSGOE members on making a certification system for robotic surgery were split into two clear-cut camps. Thus, we must further seek the extent of public demand for using a public survey so that a final decision can be made on whether to establish this system.

Cells with stem-like properties are associated with the development of HPV18-positive cervical cancer.

The cellular origins of cervical cancer and the histological differentiation of human papillomavirus (HPV)-infected cells remain unexplained. To gain new insights into the carcinogenesis and histological differentiation of HPV-associated cervical cancer, we focused on cervical cancer with mixed histological types. We conducted genomic and transcriptomic analyses of cervical cancers with mixed histological types. The commonality of the cellular origins of these cancers was inferred using phylogenetic analysis and by assessing the HPV integration sites. Carcinogenesis was estimated by analyzing human gene expression profiles in different histological types. Among 42 cervical cancers with known HPV types, mixed histological types were detected in four cases, and three of them were HPV18-positive. Phylogenetic analysis of these three cases revealed that the different histological types had a common cell of origin. Moreover, the HPV-derived transcriptome and HPV integration sites were common among different histological types, suggesting that HPV integration could occur before differentiation into each histological type. Human gene expression profiles indicated that HPV18-positive cancer retained immunologically cold components with stem cell properties. Mixed cervical cancer has a common cellular origin among different histological types, and progenitor cells with stem-like properties may be associated with the development of HPV18-positive cervical cancer.

A nationwide survey of the use of the laparoscopic power morcellator.

AIM: Laparoscopic power morcellator (LPM) can be used for tissue retrieval through laparoscopic port site, but the dissemination of uterine and/or myoma tissues is a serious complication. To study the use of LPM for uterine fibroid treatment in Japan, we aimed to perform two national cross-sectional surveys comprising multiple questionnaires. METHODS: The first survey (2011-2013) was conducted in November 2014, and 203 medical institutions responded. The second survey (2017-2019) was conducted in December 2020, and 302 medical institutions were investigated. RESULTS: Overall, 72 104 and 120 425 surgeries and 0.04% and 0.05% cases of postoperative malignancy diagnosis were reported in the first and second surveys, respectively. Magnetic resonance imaging was performed in >90% of the cases in the first and second surveys as preoperative examinations. The frequency of LPM at hysterectomy was 8.9% and 4.6% and the frequency of LPM at laparoscopic myomectomy was 80.4% and 54.8% in the first and second surveys, respectively; both the parameters decreased in the second survey. CONCLUSIONS: It is impossible to completely exclude malignant diseases even if extensive preoperative diagnosis has been done before surgery. Therefore, the use of LPM in patients requires careful attention and informed consent in Japan.

The Histone Methyltransferase SETD8 Regulates the Expression of Tumor Suppressor Genes via H4K20 Methylation and the p53 Signaling Pathway in Endometrial Cancer Cells.

The histone methyltransferase SET domain-containing protein 8 (SETD8), which methylates histone H4 lysine 20 (H4K20) and non-histone proteins such as p53, plays key roles in human carcinogenesis. Our aim was to determine the involvement of SETD8 in endometrial cancer and its therapeutic potential and identify the downstream genes regulated by SETD8 via H4K20 methylation and the p53 signaling pathway. We examined the expression profile of SETD8 and evaluated whether SETD8 plays a critical role in the proliferation of endometrial cancer cells using small interfering RNAs (siRNAs). We identified the prognostically important genes regulated by SETD8 via H4K20 methylation and p53 signaling using chromatin immunoprecipitation sequencing, RNA sequencing, and machine learning. We confirmed that SETD8 expression was elevated in endometrial cancer tissues. Our in vitro results suggest that the suppression of SETD8 using siRNA or a selective inhibitor attenuated cell proliferation and promoted the apoptosis of endometrial cancer cells. In these cells, SETD8 regulates genes via H4K20 methylation and the p53 signaling pathway. We also identified the prognostically important genes related to apoptosis, such as those encoding KIAA1324 and TP73, in endometrial cancer. SETD8 is an important gene for carcinogenesis and progression of endometrial cancer via H4K20 methylation.

MED1, a novel binding partner of BRCA1, regulates homologous recombination and R-loop processing.

Homologous recombination (HR) is a major repair pathway of DNA double-strand breaks and is closely related to carcinogenesis. HR deficiency has been established as a therapeutic target. The aim of this study was to elucidate the functions of a novel HR factor, Mediator complex subunit 1 (MED1), and its association with BRCA1. Formation of the MED1/BRCA1 complex was examined by immunoprecipitation and GST-pull down assays. The transcription cofactor role of BRCA1 was evaluated using luciferase assays. The roles of MED1 on DNA damage response and HR were analyzed by immunofluorescence and HR assays. R-loop accumulation was analyzed using immunofluorescence. R-loop-induced DNA damage was analyzed by comet assays. Immunoprecipitation and GST-pull down assays demonstrated that MED1 is a novel binding partner of BRCA1 and binds to the BRCT domain. Luciferase assays showed that MED1 potentiated the transcription ability of BRCT by two-fold. In MED1-depleted cells, recruitment of HR genes, such as RPA and γH2AX, to DNA damage sites was severely impaired. HR assays showed that MED1 knockdown significantly decreased HR activity. R-loop nuclear accumulation and R-loop-induced comet tails were observed in MED1-depleted cells. We conclude that the transcription factor MED1 contributes to the regulation of the HR pathway and R-loop processing.