Ryusuke Murakami

Oligoclonal B cell expansion and passenger fusion genes predict response to Nivolumab in recurrent ovarian cancer: phase II Kyoto trial

YAP1 Suppression by ZDHHC7 Is Associated with Ferroptosis Resistance and Poor Prognosis in Ovarian Clear Cell Carcinoma

Abstract Ovarian clear cell carcinoma (OCCC), which has unique clinical characteristics, arises from benign endometriotic cysts, forming an oxidative stress environment because of excess iron accumulation, and exhibits poor prognosis, particularly in advanced stages owing to resistance to conventional therapeutics. Ferroptosis is an iron-dependent form of programmed cell death induced by lipid peroxidation and controlled by Hippo signaling. We hypothesized that overcoming ferroptosis resistance is an attractive strategy because OCCC acquires oxidative stress resistance during its development and exhibits chemoresistant features indicative of ferroptosis resistance. This study aimed to determine whether OCCC is resistant to ferroptosis and clarify the mechanism underlying resistance. Unlike ovarian high-grade serous carcinoma cells, OCCC cells were exposed to oxidative stress. However, OCCC cells remained unaffected by lipid peroxidation. Cell viability assays revealed that OCCC cells exhibited resistance to the ferroptosis inducer erastin. Moreover, Samroc analysis showed that the Hippo signaling pathway was enriched in OCCC cell lines and clinical samples. Furthermore, patients with low expression of nuclear yes-associated protein 1 (YAP1) exhibited a significantly poor prognosis of OCCC. Moreover, YAP1 activation enhanced ferroptosis in OCCC cell lines. Furthermore, suppression of zinc finger DHHC-type palmitoyltransferase 7 (ZDHHC7) enhanced ferroptosis by activating YAP1 in OCCC cell lines. Mouse xenograft models demonstrated that ZDHHC7 inhibition suppressed tumor growth via YAP1 activation by erastin treatment. In conclusion, YAP1 activation regulated by ZDHHC7 enhanced ferroptosis in OCCC. Thus, overcoming ferroptosis resistance is a potential therapeutic strategy for OCCC.

Peritoneal dissemination of high-grade serous ovarian cancer: pivotal roles of chromosomal instability and epigenetic dynamics

Epithelial ovarian cancer remains the lethal gynecological malignancy in women. The representative histotype is high-grade serous carcinoma (HGSC), and most patients with HGSC present at advanced stages with peritoneal dissemination. Since the peritoneal dissemination is the most important factor for poor prognosis of the patients, complete exploration for its molecular mechanisms is mandatory. In this narrative review, being based on the clinical, pathologic, and genomic findings of HGSC, chromosomal instability and epigenetic dynamics have been discussed as the potential drivers for cancer development in the fallopian tube, acquisition of cancer stem cell (CSC)-like properties, and peritoneal metastasis of HGSC. The natural history of carcinogenesis with clonal evolution, and adaptation to microenvironment of peritoneal dissemination of HGSC should be targeted in the novel development of strategies for prevention, early detection, and precision treatment for patients with HGSC.

Histopathological subtyping of high-grade serous ovarian cancer using whole slide imaging

We have established 4 histopathologic subtyping of high-grade serous ovarian cancer (HGSOC) and reported that the mesenchymal transition (MT) type has a worse prognosis than the other subtypes. In this study, we modified the histopathologic subtyping algorithm to achieve high interobserver agreement in whole slide imaging (WSI) and to characterize the tumor biology of MT type for treatment individualization. Four observers performed histopathological subtyping using WSI of HGSOC in The Cancer Genome Atlas data. As a validation set, cases from Kindai and Kyoto Universities were independently evaluated by the 4 observers to determine concordance rates. In addition, genes highly expressed in MT type were examined by gene ontology term analysis. Immunohistochemistry was also performed to validate the pathway analysis. After algorithm modification, the kappa coefficient, which indicates interobserver agreement, was greater than 0.5 (moderate agreement) for the 4 classifications and greater than 0.7 (substantial agreement) for the 2 classifications (MT vs. non-MT). Gene expression analysis showed that gene ontology terms related to angiogenesis and immune response were enriched in the genes highly expressed in the MT type. CD31 positive microvessel density was higher in the MT type compared to the non-MT type, and tumor groups with high infiltration of CD8/CD103 positive immune cells were observed in the MT type. We developed an algorithm for reproducible histopathologic subtyping classification of HGSOC using WSI. The results of this study may be useful for treatment individualization of HGSOC, including angiogenesis inhibitors and immunotherapy.

PDK2 leads to cisplatin resistance through suppression of mitochondrial function in ovarian clear cell carcinoma

AbstractOvarian clear cell carcinoma (CCC) exhibits an association with endometriosis, resistance to oxidative stress, and poor prognosis owing to its resistance to conventional platinum‐based chemotherapy. A greater understanding of the molecular characteristics and pathogenesis of ovarian cancer subtypes may facilitate the development of targeted therapeutic strategies, although the mechanism of drug resistance in ovarian CCC has yet to be determined. In this study, we assessed exome sequencing data to identify new therapeutic targets of mitochondrial function in ovarian CCC because of the central role of mitochondria in redox homeostasis. Copy number analyses revealed that chromosome 17q21‐24 (chr.17q21‐24) amplification was associated with recurrence in ovarian CCC. Cell viability assays identified an association between cisplatin resistance and chr.17q21‐24 amplification, and mitochondrion‐related genes were enriched in patients with chr.17q21‐24 amplification. Patients with high expression of pyruvate dehydrogenase kinase 2 (PDK2) had a worse prognosis than those with low PDK2 expression. Furthermore, inhibition of PDK2 synergistically enhanced cisplatin sensitivity by activating the electron transport chain and by increasing the production of mitochondrial reactive oxygen species. Mouse xenograft models showed that inhibition of PDK2 with cisplatin inhibited tumor growth. This evidence suggests that targeting mitochondrial metabolism and redox homeostasis is an attractive therapeutic strategy for improving drug sensitivity in ovarian CCC.

UGT1A1 polymorphism has a prognostic effect in patients with stage IB or II uterine cervical cancer and one or no metastatic pelvic nodes receiving irinotecan chemotherapy: a retrospective study

Abstract Background Uridine diphosphate glucuronosyltransferase 1 family polypeptide A1 ( UGT1A1 ) is a predictive biomarker for the side-effects of irinotecan chemotherapy, which reduces the volume of tumors harboring UGT1A1 polymorphisms. We aimed to determine whether UGT1A1 polymorphisms can predict progression-free survival in patients with local cervical cancer treated with irinotecan chemotherapy. Methods We retrospectively analyzed the data of 51 patients with cervical cancer treated at a single institution between 2010 and 2015. All patients were diagnosed with 2009 International Federation of Gynecology and Obstetrics (FIGO) stage IB1, IB2, IIA, or IIB squamous cell carcinoma, underwent radical hysterectomy, and received irinotecan chemotherapy as neoadjuvant and/or adjuvant treatment. All patients were examined for irinotecan side effects using UGT1A1 tests. Conditional inference tree and survival analyses were performed considering the FIGO stage, age, the UGT1A1 status, and the number of metastatic lymph nodes to determine primary factors associated with progression-free survival. Results The tree-structured survival model determined high recurrence-risk factors related to progression-free survival. The most relevant factor was ≥2 metastatic lymph nodes ( p  = 0.004). The second most relevant factor was UGT1A1 genotype ( p  = 0.024). Among patients with ≤1 metastatic lymph node, those with UGT1A1 polymorphisms benefited from irinotecan chemotherapy and demonstrated significantly longer progression-free survival ( p  = 0.020) than those with wild-type UGT1A1 . Conclusions Irinotecan chemotherapy might be beneficial in patients with cervical cancer, UGT1A1 polymorphisms, and ≤ 1 metastatic lymph nodes.

Comparison of postoperative adjuvant platinum-based chemotherapy and no further therapy after radical surgery in intermediate-risk early-stage cervical cancer

To identify a relatively high-risk population in postoperative intermediate-risk cervical cancer and evaluate the effect of platinum-based adjuvant chemotherapy (CT). We retrospectively reviewed the medical records of patients with stage IA2-IIA cervical cancer who had been treated with radical hysterectomy and pelvic lymphadenectomy and classified as the intermediate-risk group for recurrence by postoperative pathological examination from January 2007 to December 2018 at 3 medical centers in Japan. First, patients with intermediate-risk were stratified by histological type and the number of intermediate-risk factors (IRF; large tumor diameter, lymph vascular space invasion, and deep cervical stromal invasion) and then divided into 2 groups: high and low-risk population (estimated 5-year recurrence-free survival [RFS] rate with no further therapy [NFT] <90% and ≥90%, respectively). Second, the efficacy of CT for the high-risk population was evaluated by comparing RFS and overall survival (OS) between the patients receiving CT and those with NFT. In total, 133 patients were included in the analysis. Among patients with squamous cell carcinoma (SCC) with all IRF or those with non-SCC with 2 to 3 IRF, the 5-year estimated RFS was <90% when treated with NFT. In this population, adjuvant CT was significantly superior to NFT regarding RFS (log-rank, p=0.014), although there was no statistical difference in OS. Patients with SCC with all 3 IRFs and those with non-SCC with 2 to 3 IRFs were at high risk for recurrence. Adjuvant CT is a valid treatment option for these populations.