DNA methylation of the immediate upstream region of BRCA1 major transcription start sites is an independent favorable prognostic factor in patients with high-grade serous ovarian cancer.

OBJECTIVE: To establish a quantitative method to evaluate the DNA methylation level of an immediate upstream region of major BRCA1 transcriptional start sites (TSSs), and to investigate whether methylation of the region is a prognostic factor in high-grade serous ovarian cancer patients after neoadjuvant chemotherapy. METHODS: Ninety-two FFPE samples of advanced high-grade serous ovarian cancers after neoadjuvant chemotherapy between 2011 and 2018 were used for mutation and methylation analysis. DNA methylation levels were assessed by pyrosequencing and DNA methylation microarray. An association between methylation level (or a mutation) and progression-free survival was assessed by Kaplan-Meier analysis. RESULT: Major BRCA1 transcripts and CpG sites immediately upstream of their TSSs were identified, and a pyrosequencing method was developed. BRCA1 methylation, BRCA1/2 mutations, and a RAD51C mutation were detected in 17/79 (21.5%), 17/92 (18.5%), and 1/92 (1.1%) high-grade serious ovarian cancer samples. In univariate analysis, BRCA1 methylation and no residual tumor were associated with progression-free survival (BRCA1 methylation: P = 0.025, no residual tumor: P = 0.0026). Multivariate analysis showed that both BRCA1 methylation (P = 0.038, HR = 0.47, 95% CI: 0.21-0.96) and no residual tumor (P = 0.012, HR = 0.49, 95% CI: 0.28-0.85) were significant favorable prognostic factors. CONCLUSION: A quantitative method to estimate the methylation level of the immediate upstream region of major BRCA1 TSSs was established. Methylation of the region of was an independent favorable prognostic factor in high-grade serous ovarian cancer patients.

Effect of murine double-minute 2 inhibitors in preclinical models of advanced clear cell carcinomas originating from ovaries and kidneys.

Advanced clear cell carcinomas originating from both ovaries and kidneys with cancerous peritonitis have poor prognoses. Murine double-minute 2 (MDM2) is a potential therapeutic target for clear cell ovarian carcinomas with WT TP53. Herein, we characterized the antiangiogenic and antitumor effects of the MDM2 inhibitors DS-3032b and DS-5272 in 6 clear cell ovarian carcinoma cell lines and 2 clear cell renal carcinoma cell lines, as well as in clear cell ovarian carcinomas s.c. xenograft and ID8 (murine ovarian cancer cells with WT TP53) cancer peritonitis mouse models. In clear cell ovarian carcinoma s.c. xenograft mouse models, DS-3032b significantly reduced WT TP53 clear cell ovarian carcinoma- and clear cell renal carcinoma-derived tumor volumes. In ID8 mouse models, DS-5272 significantly inhibited ascites production, reduced body weight, and significantly improved overall survival. Additionally, DS-5272 reduced the tumor burden of peritoneal dissemination and decreased CD31+ cells in a dose-dependent manner. Furthermore, DS-5272 significantly decreased vascular endothelial growth factor concentrations in both sera and ascites. Combined therapy with MDM2 inhibitors and everolimus showed synergistic, and dose-reduction potential, for clear cell carcinoma treatment. Our findings suggest that MDM2 inhibitors represent promising molecular targeted therapy for clear cell carcinomas, thereby warranting further studies to evaluate the efficacy and safety of dual MDM2/mTOR inhibitors in clear cell carcinoma patients.

Histone methyltransferase SMYD2 selective inhibitor LLY-507 in combination with poly ADP ribose polymerase inhibitor has therapeutic potential against high-grade serous ovarian carcinomas.

Dysfunction of histone methylation is known to be related to cancer progression. The histone methyltransferase SMYD2 methylates histone protein H3 and non-histone proteins, including poly ADP ribose polymerase 1 (PARP1). There have been reports of SMYD2 overexpression in several types of cancers. However, there are no reports regarding its role in high-grade serous ovarian carcinomas (HGSOCs). Therefore, we investigated the expression profile and conducted functional analysis on SMYD2 in HGSOC cells. In addition, we verified whether SMYD2 inhibition increases the susceptibility of HGSOC cells to PARP inhibitors. We analyzed the expression of histone methyltransferase SMYD2 by quantitative real-time polymerase chain reaction and immunohistochemistry using HGSOC clinical tissues (n = 35). We performed functional analyses, including cell proliferation assay, cell cycle analysis, and immunoblotting, after treatment with SMYD2 siRNAs and SMYD2 selective inhibitor LLY-507 in HGSOC cells. We also performed colony-formation assay after combination treatment with LLY-507 and PARP inhibitor olaparib in HGSOC cells. The expression profiles of SMYD2 showed significant overexpression of SMYD2 in HGSOC clinical tissues. The knockdown or inhibition of SMYD2 by siRNAs or LLY-507, respectively, suppressed cell growth by increasing the proportion of apoptotic cells. LLY-507 showed additive effect with olaparib in the colony-formation assay. These findings suggest that LLY-507 can be used alone or in combination with a PARP inhibitor for the treatment of patients with HGSOC.

The histone methyltransferase WHSC1 is regulated by EZH2 and is important for ovarian clear cell carcinoma cell proliferation.

BACKGROUND: Wolf-Hirschhorn syndrome candidate gene-1 (WHSC1), a histone methyltransferase, has been found to be upregulated and its expression to be correlated with expression of enhancer of zeste homolog 2 (EZH2) in several cancers. In this study, we evaluated the role of WHSC1 and its therapeutic significance in ovarian clear cell carcinoma (OCCC). METHODS: First, we analyzed WHSC1 expression by quantitative PCR and immunohistochemistry using 23 clinical OCCC specimens. Second, the involvement of WHSC1 in OCCC cell proliferation was evaluated by MTT assays after siRNA-mediated WHSC1 knockdown. We also performed flow cytometry (FACS) to address the effect of WHSC1 on cell cycle. To examine the functional relationship between EZH2 and WHSC1, we knocked down EZH2 using siRNAs and checked the expression levels of WHSC1 and its histone mark H3K36m2 in OCCC cell lines. Finally, we checked WHSC1 expression after treatment with the selective inhibitor, GSK126. RESULTS: Both quantitative PCR and immunohistochemical analysis revealed that WHSC1 was significantly overexpressed in OCCC tissues compared with that in normal ovarian tissues. MTT assay revealed that knockdown of WHSC1 suppressed cell proliferation, and H3K36me2 levels were found to be decreased in immunoblotting. FACS revealed that WHSC1 knockdown affected the cell cycle. We also confirmed that WHSC1 expression was suppressed by EZH2 knockdown or inhibition, indicating that EZH2 is upstream of WHSC1 in OCCC cells. CONCLUSIONS: WHSC1 overexpression induced cell growth and its expression is, at least in part, regulated by EZH2. Further functional analysis will reveal whether WHSC1 is a promising therapeutic target for OCCC.

Anti-tumor activity of dual inhibition of phosphatidylinositol 3-kinase and MDM2 against clear cell ovarian carcinoma.

INTRODUCTION: PI3K pathway signaling has received attention as a molecular target in clear cell ovarian carcinoma (CCOC). MDM2 is one of the AKT effectors in the PI3K pathway, which binds to and degrades p53. In this study, we aimed to clarify the prognostic significance of PIK3CA and MDM2 expression, and potential therapeutic effect of a dual inhibition of the PI3K pathway and MDM2. MATERIALS AND METHODS: cDNA expression was evaluated by using microarray data using 75 samples of CCOC. DS-7423 (dual inhibitor of pan-PI3K and mTOR) and RG7112 (MDM2 inhibitor) were used on CCOC cell lines to evaluate cell proliferation, expression level of MDM2 related proteins, and apoptosis by MTT assay, western blotting, and flow cytometry. DS-7423 (3 mg/kg) and/or RG7112 (50 mg/kg) were orally administrated every day for three weeks, and the anti-tumor effect was evaluated using tumor xenografts, along with immunohistochemistry. RESULTS: Tumors with high expression of both PIK3CA and MDM2 showed significantly worse prognosis in expression array of 71 CCOCs (P = 0.013). Dual inhibition of the PI3K pathway by DS-7423 and MDM2 by RG7112 showed synergistic anti-proliferative effect in 4 CCOC cell lines without TP53 mutations. The combination therapy more robustly induced pro-apoptotic proteins (PUMA and cleaved PARP) with increase of sub G1 population and apoptotic cells, compared with either single agent alone. The combination therapy significantly reduced tumor volume in mice (P < 0.001 in OVISE, and P = 0.038 in RMG-I) without severe body weight loss. Immunohistochemistry from the xenograft tumors showed that the combination treatment significantly reduced vascularity and cell proliferation, with an increase of apoptotic cell death. CONCLUSION: A combination therapy targeting the PI3K pathway and MDM2 might be a promising therapeutic strategy in CCOC.

Usefulness of cell-free and concentrated ascites reinfusion therapy in the therapeutic management of advanced ovarian cancer patients with massive ascites.

BACKGROUND: The management of refractory ascites in advanced ovarian cancer (AOC) is vital for patients with abdominal distention, respiratory distress, and anorexia due to massive ascites with cancer peritonitis. We analyzed the benefits of concentrated ascites reinfusion therapy (CART) in the management of AOC. METHODS: We reviewed records of AOC patients who underwent CART between January 2011 and March 2017. We retrospectively analyzed patients' backgrounds and physiological changes, including body weight, abdominal girth, urine volume, blood component values, blood pressure, heart rate, and body temperature before and after CART. We investigated the clinicopathological significance of CART by measuring the mean number of ascites tumor cell (ATC) clusters before CART. RESULTS: A retrospective analysis was performed on 29 cases of AOC with massive ascites involving 47 CART sessions. The patients' mean age was 56.6 ± 12.8 years, and the mean number of sessions was 1.7 ± 1.2. The mean volume of the processed ascites was 2,937 ± 820 mL, which was concentrated to 272 ± 84 mL containing 85.0 ± 33.2 g protein on average. Significant reductions in abdominal girth (- 5.30 ± 0.65 cm; p < 0.0001) and body weight (- 2.97 ± 0.26 kg; p = 0.0011), increased urine volume (+ 824.29 ± 145.21 mL; p < 0.0001), and improved serum albumin levels (+ 0.18 ± 0.34; p < 0.0001) were observed after CART. Analysis of variance revealed significant elevations in body temperature after CART in 11 patients with a small number of ATC clusters. CONCLUSIONS: CART is useful for the therapeutic management of AOC patients with refractory massive ascites. Elevations of body temperature after CART may be avoided by the investigation of patients' peritoneal cytology before CART.

The oncogene KRAS promotes cancer cell dissemination by stabilizing spheroid formation via the MEK pathway.

BACKGROUND: Peritoneal dissemination is a critical prognostic factor in ovarian cancer. Although stabilized spheroid formation promotes cancer cell peritoneal dissemination in ovarian cancer, the associated oncogenes are unknown. In this study, we assessed the role of the KRAS oncogene in ovarian cancer cell dissemination, focusing on the stability of cells in spheroid condition, as well as the modulation of intracellular signaling following spheroid transformation. METHODS: We used ID8, a murine ovarian cancer cell line, and ID8-KRAS, an oncogenic KRAS (G12 V)-transduced ID8 cell line in this study. Spheroid-forming (3D) culture and cell proliferation assays were performed to evaluate the growth characteristics of these cells. cDNA microarray analysis was performed to identify genes involved in KRAS-associated signal transduction in floating condition. A MEK inhibitor was used to evaluate the effect on cancer peritoneal dissemination. RESULTS: Cell viability and proliferation in monolayer (2D) cultures did not differ between ID8 and ID8-KRAS cells. However, the proportions of viable and proliferating ID8-KRAS cells in 3D culture were approximately 2-fold and 5-fold higher than that of ID8, respectively. Spheroid-formation was increased in ID8-KRAS cells. Analysis of peritoneal floating cells obtained from mice intra-peritoneally injected with cancer cells revealed that the proportion of proliferating cancer cells was approximately 2-fold higher with ID8-KRAS than with ID8 cells. Comprehensive cDNA microarray analysis revealed that pathways related to cell proliferation, and cell cycle checkpoint and regulation were upregulated specifically in ID8-KRAS cells in 3D culture, and that some genes partially regulated by the MEK-ERK pathway were upregulated only in ID8-KRAS cells in 3D culture. Furthermore, a MEK inhibitor, trametinib, suppressed spheroid formation in 3D culture of ID8-KRAS cells, although trametinib did not affect 2D-culture cell proliferation. Finally, we demonstrated that trametinib dramatically improved the prognosis for mice with ID8-KRAS tumors in an in vivo mouse model. CONCLUSIONS: Our data indicated that KRAS promoted ovarian cancer dissemination by stabilizing spheroid formation and that the MEK pathway is important for stabilized spheroid formation. Disruption of spheroid formation by a MEK inhibitor could be a therapeutic target for cancer peritoneal dissemination.

Combined thoraco-laparoscopic hepatectomy concomitant with resection of the diaphragm for solitary peritoneal seeding from cervical cancer: A case report.

Combined thoraco-laparoscopic resection can aid in precise resection of an invasive tumor of the diaphragm. A 44-year-old woman was referred to our department for resection of solitary peritoneal seeding from cervical cancer following systemic chemotherapy. The tumor was located in the right diaphragm with an ill-defined border of the liver. Combined thoraco-laparoscopic resection was proposed. Laparoscopy portrayed that the right diaphragm was partially attached to the liver, and the depth of tumor invasion to the diaphragm was ambiguous. Observation from the thoracic cavity indicated a white-colored distortion following the location of peritoneal seeding. Partial resection and repair of the diaphragm were made using the thoracoscopic-assisted approach, followed by laparoscopic hepatectomy. The postoperative course was uneventful, and pathological findings revealed that peritoneal metastases of the diaphragm and surgical margin was negative for cancer. Combined thoraco-laparoscopic resection can cover the drawbacks of each approach and is among the options for minimally invasive surgery for invasive tumor of the diaphragm.

DNA methylation marker to estimate ovarian cancer cell fraction.

Evaluation of a cancer cell fraction is important for accurate molecular analysis, and pathological analysis is the gold standard for evaluation. Despite the potential convenience, no established molecular markers for evaluation are available. In this study, we aimed to identify ovarian cancer cell fraction markers using DNA methylation highly specific to ovarian cancer cells. Using genome-wide DNA methylation data, we screened candidate marker genes methylated in 30 ovarian cancer FFPE samples and 12 high-grade serous ovarian cancer cell lines, and unmethylated in two female leucocytes and two normal fallopian epithelial cell samples. Methylation levels of two genes, SIM1, and ZNF154, showed high correlation with pathological cancer cell fractions among the 30 ovarian cancer FFPE samples (R = 0.61 for SIM1, 0.71 for ZNF154). For cost-effective analysis of FFPE samples, pyrosequencing primers were designed, and successfully established for SIM1 and ZNF154. Correlation between a pathological cancer cell fraction and methylation levels obtained by pyrosequencing was confirmed to be high (R = 0.53 for SIM1, 0.64 for ZNF154). Finally, an independent validation cohort of 29 ovarian cancer FFPE samples was analyzed. ZNF154 methylation showed a high correlation with the pathological cancer cell fraction (R = 0.77, P < 0.0001). Therefore, the ZNF154 methylation level was considered to be useful for the estimation of ovarian cancer cell fraction, and is expected to help accurate molecular analysis.

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.

Development of a deep learning method for improving diagnostic accuracy for uterine sarcoma cases.

Uterine sarcomas have very poor prognoses and are sometimes difficult to distinguish from uterine leiomyomas on preoperative examinations. Herein, we investigated whether deep neural network (DNN) models can improve the accuracy of preoperative MRI-based diagnosis in patients with uterine sarcomas. Fifteen sequences of MRI for patients (uterine sarcoma group: n = 63; uterine leiomyoma: n = 200) were used to train the models. Six radiologists (three specialists, three practitioners) interpreted the same images for validation. The most important individual sequences for diagnosis were axial T2-weighted imaging (T2WI), sagittal T2WI, and diffusion-weighted imaging. These sequences also represented the most accurate combination (accuracy: 91.3%), achieving diagnostic ability comparable to that of specialists (accuracy: 88.3%) and superior to that of practitioners (accuracy: 80.1%). Moreover, radiologists' diagnostic accuracy improved when provided with DNN results (specialists: 89.6%; practitioners: 92.3%). Our DNN models are valuable to improve diagnostic accuracy, especially in filling the gap of clinical skills between interpreters. This method can be a universal model for the use of deep learning in the diagnostic imaging of rare tumors.

Use of Cap Analysis Gene Expression to detect human papillomavirus promoter activity patterns at different disease stages.

Transcription of human papillomavirus (HPV) genes proceeds unidirectionally from multiple promoters. Direct profiling of transcription start sites (TSSs) by Cap Analysis Gene Expression (CAGE) is a powerful strategy for examining individual HPV promoter activity. The objective of this study was to evaluate alterations of viral promoter activity during infection using CAGE technology. We used CAGE-based sequencing of 46 primary cervical samples, and quantitatively evaluated TSS patterns in the HPV transcriptome at a single-nucleotide resolution. TSS patterns were classified into two types: early promoter-dominant type (Type A) and late promoter-dominant type (Type B). The Type B pattern was more frequently found in CIN1 and CIN2 lesions than in CIN3 and cancer samples. We detected transcriptomes from multiple HPV types in five samples. Interestingly, in each sample, the TSS patterns of both HPV types were the same. The viral gene expression pattern was determined by the differentiation status of the epithelial cells, regardless of HPV type. We performed unbiased analyses of TSSs across the HPV genome in clinical samples. Visualising TSS pattern dynamics, including TSS shifts, provides new insights into how HPV infection status relates to disease state.

The histone methyltransferase SMYD2 is a novel therapeutic target for the induction of apoptosis in ovarian clear cell carcinoma cells.

Previous studies have suggested that histone methylation can modulate carcinogenesis and cancer progression. For instance, the histone methyltransferase SET and MYND domain containing 2 (SMYD2) is overexpressed in several types of cancer tissue. The aim of the present study was to determine whether SMYD2 could serve a therapeutic role in ovarian clear cell carcinoma (OCCC). Reverse transcription-quantitative PCR was used to examine SMYD2 expression in 23 clinical OCCC specimens. Moreover, OCCC cell proliferation and cell cycle progression were also examined following small interfering RNA-mediated SMYD2 silencing or treatment with a selective SMYD2 inhibitor. SMYD2 was significantly upregulated in clinical OCCC specimens, compared with normal ovarian tissue. In addition, SMYD2 knockdown decreased cell viability as determined via a Cell Counting Kit-8 assay. Moreover, the proportion of cells in the sub-G1 phase increased following SMYD2 knockdown, suggesting increased apoptosis. Treatment with the SMYD2 inhibitor LLY-507 suppressed OCCC cell viability. These results suggested that SMYD2 could promote OCCC viability, and that SMYD2 inhibition induced apoptosis in these cells. Thus, SMYD2 inhibitors may represent a promising molecular targeted approach for OCCC treatment.

Anti-Tumor Effect of Inhibition of DNA Damage Response Proteins, ATM and ATR, in Endometrial Cancer Cells.

: While the incidence of endometrial cancer continues to rise, the therapeutic options remain limited for advanced or recurrent cases, and most cases are resistant to therapy. The anti-tumor effect of many chemotherapeutic drugs and radiotherapy depends on the induction of DNA damage in cancer cells; thus, activation of DNA damage response (DDR) pathways is considered an important factor affecting resistance to therapy. When some DDR pathways are inactivated, inhibition of other DDR pathways can induce cancer-specific synthetic lethality. Therefore, DDR pathways are considered as promising candidates for molecular-targeted therapy for cancer. The crosstalking ataxia telangiectasia mutated and Rad3 related and checkpoint kinase 1 (ATR-Chk1) and ataxia telangiectasia mutated and Rad3 related and checkpoint kinase 2 (ATM-Chk2) pathways are the main pathways of DNA damage response. In this study, we investigated the anti-tumor effect of inhibitors of these pathways in vitro by assessing the effect of the combination of ATM or ATR inhibitors and conventional DNA-damaging therapy (doxorubicin (DXR), cisplatin (CDDP), and irradiation) on endometrial cancer cells. Both the inhibitors enhanced the sensitivity of cells to DXR, CDDP, and irradiation. Moreover, the combination of ATR and Chk1 inhibitors induced DNA damage in endometrial cancer cells and inhibited cell proliferation synergistically. Therefore, these molecular therapies targeting DNA damage response pathways are promising new treatment strategies for endometrial cancer.

The proteasome deubiquitinase inhibitor bAP15 downregulates TGF-ß/Smad signaling and induces apoptosis via UCHL5 inhibition in ovarian cancer.

The ubiquitin-proteasome pathway plays an important role in the regulation of cellular proteins. As an alternative to the proteasome itself, recent research has focused on methods to modulate the regulation of deubiquitinating enzymes (DUBs) upstream of the proteasome, identifying DUBs as novel therapeutic targets in breast, endometrial, and prostate cancers, along with multiple myeloma. bAP15, an inhibitor of the 19S proteasome DUBs UCHL5 and USP14, results in cell growth inhibition in several human cancers; however, the mechanism remains poorly understood in ovarian cancer. Here, we found that aberrant UCHL5 expression predicted shorter progression-free survival (PFS) in a cohort of 1435 patients with ovarian cancer described in the Gene Expression Omnibus and The Cancer Genome Atlas databases. The subgroup of patients with TP53 mutations was significantly more likely to exhibit poor PFS (p <0.001). Moreover, we found bAP15 could suppress TP53-mutant ovarian cancer cell survival by regulating TGF-ß signaling through inhibiting UCHL5 expression and dephosphorylating Smad2, consequently inducing apoptosis. bAP15 (2.5 and 5.0 mg/kg) also exerted significant anti-tumor effect on nude mice bearing subcutaneous SKOV3 xenografts. As activated TGF-ß signaling is involved in ovarian cancer progression, these findings suggest that UCHL5 inhibition offers potential opportunities for a novel targeted therapy against TGF-ß-activated ovarian cancer.

On-chip immunofluorescence analysis of single cervical cells using an electroactive microwell array with barrier for cervical screening.

Several specific tests for cervical screening have been developed recently, including p16/Ki67 dual immunostaining for diagnosing high-risk human papillomavirus positive squamous intraepithelial lesion in the cervix. However, manual screening of cells in an entire glass slide is currently a standard clinical procedure for quantification and interpretation of immunocytochemical features of the cells. Here, we developed a microfluidic device containing an electroactive microwell array with barriers (EMAB) for highly efficient single-cell trapping followed by on-chip immunofluorescence analysis with minimum loss of the sample. EMAB utilizes patterned electrodes at the bottom of cell-sized microwells to trap single cells using dielectrophoresis (DEP) and cell-holding structures behind the microwells to stabilize the position of trapped cells even without DEP. Using the device, we evaluated the performance of p16/Ki67 dual immunostaining of HeLa cells on the chip. The device shows 98% cell-trapping efficiency as well as 92% cell-holding efficiency against the fixed HeLa cells, and we successfully demonstrated high-efficiency on-chip immunofluorescence analysis with minimal loss of sample. p16/Ki67 dual immunostaining using EMAB may be useful for complementary tests for cervical screening in confirming the histopathological diagnosis.