Published papers

In the mitotic exit network of budding yeast, Dbf2 kinase phosphorylates and regulates Cdc14 phosphatase. In contrast, no phosphatase substrates of LATS1/WARTS kinase, the mammalian equivalent of Dbf2, has been reported. To address this discrepancy, we performed phosphoproteomic screening using LATS1 kinase. Screening identified MYPT1 (myosin phosphatase- targeting subunit 1) as a new substrate for LATS1. LATS1 directly and preferentially phosphorylated serine 445 (S445) of MYPT1. An MYPT1 mutant (S445A) failed to dephosphorylate Thr 210 of PLK1 (pololike kinase 1), thereby activating PLK1. This suggests that LATS1 promotes MYPT1 to antagonize PLK1 activity. Consistent with this, LATS1-depleted HeLa cells or fibroblasts from LATS1 knockout mice showed increased PLK1 activity. We also found deoxyribonucleic acid (DNA) damage-induced LATS1 activation caused PLK1 suppression via the phosphorylation of MYPT1 S445. Furthermore, LATS1 knockdown cells showed reduced G2 checkpoint arrest after DNA damage. These results indicate that LATS1 phosphorylates a phosphatase as does the yeast Dbf2 and demonstrate a novel role of LATS1 in controlling PLK1 at the G2 DNA damage checkpoint.

Uterine carcinosarcoma (CS) is usually classified as uterine endometrial carcinoma (EC). However, CS is more aggressive even compared with high grade EC. CS is also reported to undergo epithelial to mesenchymal transition (EMT). In this study, we compared the gene expression profiles of CS, EC, and uterine sarcoma (US) and evaluated the role of EMT and chromosomal aberrations in CS tumor formation. Frozen tissues of 46 patients (14 CS, 24 EC, and 8 US) were included. The similarity was examined by Gene Set Enrichment Analysis (GSEA), Fisher's exact test, and clustering using "intrinsic gene set". We examined the expression of 39 EMT-related genes and evaluated TGF-beta signaling by phospho-SMAD2/3 (p-SMAD2/3) staining. Chromosomal regions differing between CS and EC were identified by chromosomal GSEA and comparative genomic hybridization (CGH) microarrays. Three statistical methods confirmed that CS resembled US rather than EC. Acquired markers of EMT were upregulated and attenuated markers of EMT were downregulated in CS. Immunohistochemistry showed that carcinomatous region of CS have higher expression of p-SMAD2/3 than EC (P = 0.008). Chromosomal GSEA showed that genes located at 19q13 had higher expression in CS. Furthermore, CGH microarray indicated that the TGFB1 locus at 19q13.1 was amplified in 4 of 7 samples. Based on the expression profile, CS resembles US rather than EC. TGF-beta signaling is activated in CS and chromosomal gains at 19q13, which includes the TGFB1 locus, suggest that this may contribute to high expression of TGF-beta and thereby EMT phenotype of CS.

Wepreviously showed that depletion of the retinoblastoma protein (RB) induces down-regulation of the adhesion molecule E-cadherin and thereby triggers the epithelial-mesenchymal transition. To further characterize the effect of RB inactivation on the phenotype of cancer cells, we have now examined RB expression in human breast cancer cell lines and clinical specimens. We found that RB-inactive cells exhibit a mesenchymal-like morphology and are highly invasive. We also found that ZEB proteins, transcriptional repressors of the E-cadherin gene, are markedly up-regulated in these cells in a manner sensitive to the miR-200 family of microRNAs. Moreover, depletion of ZEB in RB-inactive cells suppressed cell invasiveness and proliferation and induced epithelial marker expression. These results implicate ZEB in induction of the epithelial-mesenchymal transition, as well as in maintenance of the mesenchymal phenotype in RB-inactive cells. We also developed a screening program for inhibitors of ZEB1 expression and thereby identified several cyclin-dependent kinase inhibitors that blocked both ZEB1 expression and RB phosphorylation. Together, our findings suggest that RB inactivation contributes to tumor progression not only through loss of cell cycle control but also through up-regulation of ZEB expression and induction of an invasive phenotype.

For both cervical cancer (UCC) and endometrial cancer (EMC) there are no effective prognostic markers. In this study, we evaluated HIG2 protein expression in 332 uterine cancers (186 UCCs and 146 EMCs) and examined the relationship between HIG2 protein expression and clinical factors, including prognosis. Totally, HIG2 expression was detected in 58% of UCC and 66% of EMC. However, there was no significant relationship between HIG2 expression and age, clinical stage and histology in either UCC or EMC. In addition, HIG2 protein expression was not related to prognosis of UCC or EMC. The positivity rate of HIG2 protein was 56% and 61% in early-stage UCC and EMC, respectively and 67% in non-squamous cell carcinoma of UCC. The positivity rate of HIG2 protein was high even in early-stage UCC and EMC.

Study Objective To evaluate hysteroscopic transcervical resection (TCR) for atypical polypoid adenomyoma of the uterus (APA). Design Retrospective study (Canadian Task Force classification II-2). Setting Single tertiary hospital. Patients Women who underwent TCR for APA at Kawasaki Municipal Hospital between 2003 and 2015. Interventions Clinical records were obtained. Measurements and Main Results Thirty-five patients with APA were evaluated. The median patient age was 35 years (range, 23–43 years), and the median tumor diameter was 22 mm (range, 9–51 mm). The median duration of observation after the first TCR was 34.0 months (range, 4.2–133.7 months). In 19 patients, the tumor recurred after the first TCR. A second TCR was performed in 13 patients, 11 of whom experienced recurrence. A third TCR was performed in 7 patients, all 7 of whom experienced recurrence. A fourth TCR was performed in 4 patients, 3 of whom experienced recurrence. The recurrence rate after the second TCR was higher than that after the first TCR (71.4%–84.6% vs 54.3% p < .01, t test). The median disease-free interval was 12.4 months after the first TCR, 15.3 months after the second TCR, 10.5 months after the third TCR, and 10.9 months after the fourth TCR. Seven patients progressed to endometrial cancer however, there was no mortality. Six of the 35 patients conceived, and 4 had a normal spontaneous delivery. Conclusion Owing to disease-free intervals that follow treatment, TCR is a promising treatment modality as a fertility-preserving option for patients with APA under careful observation. Twenty percent of patients with APA develop cancer however, the present study showed no mortality.

Mutations in the breast cancer susceptibility gene 1 (BRCA1) are associated with an increased risk of developing epithelial ovarian cancer. However, beyond the role of BRCA1 in DNA repair, little is known about other mechanisms by which BRCA1 impairment promotes carcinogenesis. Given that altered metabolism is now recognized as important in the initiation and progression of cancer, we asked whether the loss of BRCA1 changes metabolism in the cells of origin of ovarian cancer. The findings show that silencing BRCA1 in ovarian surface epithelial and fallopian tube cells increased glycolysis. Furthermore, when these cells were transfected with plasmids carrying deleterious BRCA1 mutations (5382insC or the P1749R), there was an increase in hexokinase-2 (HK2), a key glycolytic enzyme. This effect was mediated by MYC and the STAT3. To target the metabolic phenotype induced by loss of BRCA1, a drug-repurposing approach was used and aspirin was identified as an agent that counteracted the increase in HK2 and the increase in glycolysis induced by BRCA1 impairment. Evidence from this study indicates that the tumor suppressor functions of BRCA1 extend beyond DNA repair to include metabolic endpoints and identifies aspirin as an ovarian cancer chemopreventive agent capable of reversing the metabolic derangements caused by loss of BRCA1.

In budding yeast, the Mitotic Exit Network (MEN) regulates anaphase promoting complex/cyclosome (APC/C) via the Dbf2-Cdc14 signaling cascade. Dbf2 kinase phosphorylates and activates Cdc14 phosphatase, which removes the inhibitory phosphorylation of the APC/C cofactor Cdh1. Although each component of the MEN was highly conserved during evolution, there is presently no evidence supporting direct phosphorylation of CDC14 by large tumor suppressor kinase 1 (LATS1), the human counterpart of Dbf2; hence, it is unclear how LATS1 regulates APC/C. Here, we demonstrate that LATS1 phosphorylates the Thr7 (T7) residue of the APC/C component CDC26 directly. Nocodazole-induced phosphorylation of T7 was reduced by knockdown of LATS1 and LATS2 in HeLa cells, indicating that both of these kinases contribute to the phosphorylation of CDC26 in vivo. The T7 residue of CDC26 is critical for its interaction with APC6, a tetratricopeptide repeat-containing subunit of APC/C, and mutation of this residue to Asp (T7D) reduced the interaction of CDC26 with APC6. Replacement of endogenous CDC26 in HeLa cells with exogenous phosphor-mimic T7D-mutated CDC26 increased the elution size of APC/C subunits in a gel filtration assay, implying a change in the APC/C assembly upon phosphorylation of CDC26. Furthermore, T7D-mutated CDC26 promoted the ubiquitination of polo-like kinase 1, a well-known substrate of APC/C. Overall, these results suggest that LATS1/2 are novel kinases involved in APC/C phosphorylation and indicate a direct regulatory link between LATS1/2 and APC/C.

© 2021, The Author(s). Assessing Erb-b2 receptor tyrosine kinase 2 (ERBB2) amplification status in breast and gastric cancer is necessary for deciding the best therapeutic strategy. Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are currently used for assessing protein levels and gene copy number (CN), respectively. The use of next-generation sequencing (NGS) to measure ERBB2 CN in breast cancer is approved by the United States Federal Drug Administration as a companion diagnostic. However, a CN of less than 8 is evaluated as “equivocal”, which means that some ERBB2 amplification cases diagnosed as “HER2 negative” might be false-negative cases. We reviewed the results of gene profiling targeting 160 cancer-related genes in breast (N = 90) and non-breast (N = 19) cancer tissue, and compared the ERBB2 CN results with the IHC/FISH scores. We obtained an estimated CN from the measured CN by factoring in the histological proportion of tumor cells and found that an ERBB2-estimated CN of 3.2 or higher was concordant with the combined IHC/FISH outcome in 98.4% (88/90) of breast cancer cases, while this was not always evident among non-breast cancer cases. Therefore, NGS-estimated ERBB2 CN could be considered a diagnostic test for anti-HER2 therapy after the completion of adequate prospective clinical trials.

© 2020 International Federation of Gynecology and Obstetrics Objective: To determine the efficacy of drainage following pelvic lymph node (PLN) dissection, especially for cases involving laparoscopic surgery. Methods: In this retrospective study, 368 patients with malignant gynecological tumors who underwent systemic PLN dissection at Keio University Hospital between January 2012 and October 2018 were enrolled. Drainage tubes were placed in the retroperitoneal fossa in all patients. Medical records were used for data collection. Results: Laparoscopy was performed on 81 patients, and laparotomy was performed on 287 patients. In the laparoscopy group, tubes were removed 1 day post surgery. In the laparotomy group, tubes were removed 1 day post surgery in 167 patients and 4 days post surgery in 120 patients. Compared with the laparotomy group, we determined the laparoscopy group to have a significantly lower prevalence of lymphocyst (6.2% vs 20.2%, p = 0.002) but a similar prevalence of lymphedema (4.9% vs 5.2%), and symptomatic lymphocyst (2.5% vs 4.5%). The two laparotomy groups did not differ significantly with respect to the prevalence of lymphedema (4.8% vs 5.8%), lymphocyst (20.4% vs 20.0%), or symptomatic lymphocyst (4.2% vs 5.0%). Conclusion: Our results suggest that routine drainage should be omitted, especially in cases involving laparoscopic surgery.

Uterine leiomyoma is one of the most common gynaecologic benign tumours, but its genetic basis remains largely unknown. Six previous GWAS identified 33 genetic factors in total. Here, we performed a two-staged GWAS using 13,746 cases and 70,316 controls from the Japanese population, followed by a replication analysis using 3,483 cases and 4,795 controls. The analysis identified 9 significant loci, including a novel locus on 12q23.2 (rs17033114, P=6.12x10(-25) with an OR of 1.177 (1.141-1.213), LINC00485). Subgroup analysis indicated that 5 loci (3q26.2, 5p15.33, 10q24.33, 11p15.5, 13q14.11) exhibited a statistically significant effect among multiple leiomyomas, and 2 loci (3q26.2, 10q24.33) exhibited a significant effect among submucous leiomyomas. Pleiotropic analysis indicated that all 9 loci were associated with at least one proliferative disease, suggesting the role of these loci in the common neoplastic pathway. Furthermore, the risk T allele of rs2251795 (3q26.2) was associated with longer telomere length in both normal and tumour tissues. Our findings elucidated the significance of genetic factors in the pathogenesis of leiomyoma.

Stromal components interact with cancer cells to promote growth and metastasis. The purpose of this study was to identify genes expressed in stroma, which could provide prognostic information in epithelial ovarian cancer (EOC). Seventy-four patients were included. We performed gene expression profiling and confirmed array data using RT-PCR and immunohistochemistry. By microarray analysis, 52 candidate genes associated with progression free survival (PFS) were identified (P < 0.005). Expression of the early growth response 1 (EGR1) and FBJ murine osteosarcoma viral oncogene homolog B (FOSB) genes was further analyzed. Array data were confirmed by RT-PCR and multivariate analysis demonstrated that both EGR1 and FOSB expression in cancer stroma, and EGR1 expression in cancer are independent prognostic factors in EOC. Immunohistochemically, EGR1 protein is localized in cancer cells and α-smooth muscle actin positive stromal fibroblasts. The EGR1 and FOSB expression in stromal cells and EGR1 expression in cancer cells are prognostic indicators in EOC.

Gestational choriocarcinoma is a malignant trophoblastic tumor. The development of novel molecular-targeted therapies is needed to reduce the toxicity of current multiagent chemotherapy and to treat successfully the chemoresistant cases. The molecular mechanisms underlying choriocarcinoma tumorigenesis remain uncharacterized, however, and appropriate choriocarcinoma animal models have not yet been developed. In this study, we established a choriocarcinoma model by inoculating mice with induced-choriocarcinoma cell1 (iC 3-1) cells, generated from HTR8/SVneo human trophoblastic cells retrovirally transduced with activated H-RAS (HRASV12). The iC 3-1 cells exhibited constitutive activation of the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) pathways and developed into lethal tumors in all inoculated mice. Histopathological analysis revealed that the tumors consisted of two distinct types of cells, reminiscent of syncytiotrophoblasts and cytotrophoblasts, as seen in the human choriocarcinoma. The tumors expressed HLA-G and cytokeratin (trophoblast markers) and hCG (a choriocarcinoma marker). Comparative analysis of gene expression profiles between iC 3-1 cells and parental HTR8/SVneo cells revealed that iC 3-1 cells expressed matrix metalloproteinases, epithelialmesenchymal transition-related genes, and SOX3 at higher levels than parental trophoblastic cells. Administration of SOX3-specific short-hairpin RNA decreased SOX3 expression and attenuated the tumorigenic activity of iC 3-1 cells, suggesting that SOX3 overexpression might be critically involved in the pathogenesis of choriocarcinoma. Our murine model represents a potent new tool for studying the pathogenesis and treatment of choriocarcinoma.

Purpose: At present, it remains unclear whether the third-line chemotherapy has clinical benefit. In this study, we retrospectively evaluated the effect of third-line chemotherapy. Methods: We reviewed the medical records of 40 women with recurrent epithelial ovarian cancer (EOC) who received third-line chemotherapy after platinum/taxan regimens as first line chemotherapy. Results: In the first recurrence, 23 cases were platinum-sensitive and 17 cases were platinum-resistant. The cases for which the treatment-free interval from second-line chemotherapy (TFI) was ≥ 3 months had a higher non-PD rate than those with TFI < 3 months (86% vs 33%, p = 0.002). In addition, the median overall survival (OS) was longer for TFI ≥ 3 months than for TFI < 3 months (1195 days vs 235 days, p = 0.004). Finally, TFI was an independent significant prognostic factor by univariate (HR 3.28, p = 0.006) and multivariate (HR 3.21, p = 0.018) proportional hazard tests. Conclusion: TFI from second-line chemotherapy may predict a survival benefit of third-line chemotherapy.

Uterine cervical and endometrial cancers are common malignant solid neoplasms for which there are no useful prognostic markers. In this study, we evaluate the relationship between ATP-binding cassette superfamily F2 (ABCF2) expression and clinical factors including clinical stage, histologic type, grade and prognosis in uterine cervical and endometrial cancer. Two hundred and sixty seven cervical and 103 endometrial cancers were studied. ATP-binding cassette superfamily F2 cytoplasmic expression was detected by immunohistochemical staining and scored as positive or negative. Among cervical cancer cases, 149 (55.8%) expressed ABCF2. The overall survival was longer in ABCF2-negative than ABCF2-positive cases (P=0.0069). Statistically significant prognostic factors for survival were ABCF2 positivity (risk ratio (rr)=1.437), old age (rr=1.550) and advanced stage (rr=2.577). ATP-binding cassette superfamily F2 positivity was an independent prognostic factor by multivariate proportional hazard test (P=0.0002). Among endometrial cancer cases, 72 (69.9%) were cytoplasmic ABCF2 positive. However, there was no significant relationship between ABCF2 expression and age, clinical stage, histologic type, histologic grade, oestrogen receptor status or prognosis. ATP-binding cassette superfamily F2 expression may be a useful prognostic marker in cervical but not endometrial cancer. The role of ABCF2 protein may differ depending on the type of cancer.

Cesarean scar pregnancy (CSP) is a rare type of ectopic pregnancy. It is becoming more common, but it can lead to uterine rupture and severe hemorrhage. Here, we report a case of a 37-year-old woman with CSP complicated with pseudoaneurysm. The pseudoaneurysm emerged following focal injection of methotrexate (MTX) and potassium chloride with systemic MTX treatment. Due to a risk of sudden bleeding, uterine artery embolization (UAE) was recommended, but the patient hoped to avoid this if possible. Because the serum human chorionic gonadotropin level and the gestational sac were still persistent, dilation and curettage were performed with interventional radiologists on standby. Severe hemorrhage occurred and continued during the procedure, which necessitated emergent UAE. We reviewed six CSP case reports with vascular abnormalities, and all of them necessitated UAE, surgical excision, or hysterectomy. In the case of CSP combined with pseudoaneurysm, treatment should be planned carefully considering the risk of massive hemorrhage.

Aim: To examine the usefulness of the neutrophil : lymphocyte (N/L) ratio as a cost-effective and simple diagnostic marker of mature cystic teratoma (MCT) with malignant transformation (MT). Methods: A retrospective chart review was performed between 1998 and 2013 of 12 MCT patients with MT and between 2009 and 2013 of 130 patients with benign MCT. Data were collected on age, tumor size, white blood cell count with differential counts, tumor marker levels, and presenting features. Results: Older age, greater tumor size, higher CA19-9 or CA125, higher neutrophil count, and higher N/L ratio were associated with MT on univariate analysis. White blood cell count; lymphocyte count; and the tumor marker squamous cell carcinoma antigen were not associated with MT. Older age (≥median), larger tumor size (≥10 cm), and high N/L ratio (≥5.0) were predictors of MT (hazard ratio, 11.51, 5.87, and 11.11, respectively). Six of 12 patients were diagnosed with MT on preoperative magnetic resonance imaging and five of 12 had an N/L ratio ≥5.0. Conclusions: Neutrophil : lymphocyte ratio is a potential preoperative diagnostic marker of MT. The optimal cut-off should be determined in future large-scale studies.

Objective: Despite recent advances in the treatment of recurrent ovarian cancer, little evidence exists describing the benefit of third-line chemotherapy. The present authors previously reported that the treatment-free interval (TFI) after second-line chemotherapy may predict a survival benefit of third-line chemotherapy, however the length of TFI was uncertain due to limited cases. In this study, the authors evaluated the length of TFI, which is correlated with the effectiveness of third-line chemotherapy and a prognostic factor of third-line chemotherapy. Materials and Methods: The authors reviewed the medical records of 85 women with recurrent ovarian cancer who received third-line chemotherapy after a paclitaxel/carboplatin (PC) regimen as first-line chemotherapy. Results: The response rate [complete response (CR) + partial response (PR)] and clinical benefit rate [(CBR): CR + PR + stable disease (SD)] during the TFI after second-line chemotherapy for 0-3 months, 3-6 months, and 6-12 months and ≥ 12 months were 9.8%, 0%, 0%, 43.8% and 15.7%, 50%, 66.7%, and 93.8%, respectively. The median overall survival (OS) from the onset of third-line chemotherapy was longer for TFI ≥3 months than for TFI 0-3 months (795 days vs. 281 days, p < 0.001). Finally, according to univariate (HR = 0.256;p < 0.001) and multivariate (HR = 0.264; p < 0.001) analyses, TFI was the independent significant prognostic factor for OS. Conclusions: TFI less than three months after second-line chemotherapy may predict little survival benefit of third-line chemotherapy.

© 2021 Japan Society of Obstetrics and Gynecology Aim: Tamoxifen (TAM) is widely used in adjuvant endocrine therapy for invasive breast cancer as a selective estrogen modulator, but this treatment has a risk of developing endometrial malignancy. However, hysteroscopic findings during or after TAM treatment are unclear. The aim of this study is to examine the association between hysteroscopic patterns and malignant histological findings during or after treatment with TAM. Methods: The subjects were patients who received TAM after surgery for breast cancer and underwent hysteroscopy at our institution from January 2016 to December 2019. Clinicopathological factors and hysteroscopic findings were collected from medical records and investigated retrospectively. Histologically, atypical endometrial hyperplasia, endometrial cancer, and carcinosarcoma were classified as malignant diseases. Results: A total of 26 patients were eligible for the study. Hysteroscopic findings included an irregular surface of the endometrium (n = 3, 11.5%), atypical vessels (n = 10, 38.5%), papillary structure (n = 3, 11.5%), and polypoid structure (n = 18, 69.2%). Histological examination revealed malignancy in six patients (23.0%). The percentage of atypical vessels in patients with malignancies was significantly higher than that in patients with a normal endometrium or benign lesion (100% vs. 20%, p = 0.0009). The sensitivity and specificity of atypical vessels in hysteroscopy for diagnosis of malignant diseases were 100% and 80%, respectively. Conclusions: Hysteroscopic findings of atypical vessels may be useful for prediction of malignant diseases in patients treated with TAM.