Investigator
The University Of Tokyo
DNA Methylation in Ovarian and Endometrial Cancers: Predictive and Mechanistic Roles in PARP Inhibitor and ICI Response
ABSTRACT Cancer treatment is shifting from an organ‐based approach to one driven by biological phenotypes, emphasizing the need to understand molecular mechanisms. DNA methylation plays a pivotal role in tumor biology, not only through gene silencing but also by inducing distinct behaviors beyond genetic mutations. In gynecologic cancers, molecular diagnostics, such as homologous recombination deficiency status guiding poly(ADP‐ribose) polymerase (PARP) inhibitor therapy in ovarian cancer and deficient mismatch repair/microsatellite instability‐high status informing immune checkpoint inhibitor (ICI) therapy in endometrial cancer have already been used in clinical practice. However, tumors with epigenetically driven functional deficiencies, such as BRCA1 promoter methylation in homologous recombination‐deficient ovarian cancers or MLH1 promoter methylation in deficient mismatch repair/microsatellite instability‐high endometrial cancers, often exhibit poorer prognoses and reduced therapeutic responses compared to their genetically mutated counterparts. Given the unique impact of DNA methylation, precise detection is crucial. Integrating methylation analysis into molecular classification could refine diagnostics—both by identifying mechanistic contributors to treatment response and by serving as predictive biomarkers for therapy selection—thereby optimizing patient management. This review explores the role of DNA methylation in modulating responses to PARP inhibitors and ICIs, highlights its promise as a biomarker in precision oncology, and outlines current developments and clinical challenges in BRCA1 and MLH1 methylation assays.
Targeting Epigenetic Regulators for Endometrial Cancer Therapy: Its Molecular Biology and Potential Clinical Applications
Endometrial cancer is one of the most frequently diagnosed gynecological malignancies worldwide. However, its prognosis in advanced stages is poor, and there are only few available treatment options when it recurs. Epigenetic changes in gene function, such as DNA methylation, histone modification, and non-coding RNA, have been studied for the last two decades. Epigenetic dysregulation is often reported in the development and progression of various cancers. Recently, epigenetic changes in endometrial cancer have also been discussed. In this review, we give the main points of the role of DNA methylation and histone modification in endometrial cancer, the diagnostic tools to determine these modifications, and inhibitors targeting epigenetic regulators that are currently in preclinical studies and clinical trials.
Characteristic hysteroscopy appearance considerations for detecting uterine endometrial malignancies
AbstractAimThe 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.MethodsWe 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.ResultsMultivariable 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.ConclusionOur 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.
A Survey of Current Practice and Perspectives on Lymphadenectomy in Minimally Invasive Surgery for Endometrial Cancer in Japan
ABSTRACT Objective This study investigated the reasons behind the decreasing trend of lymph node dissection for endometrial cancer (EC) in Japan, focusing on the impact of minimally invasive surgery (MIS) adoption, evolving clinical guidelines, and physician work‐style reform. Methods A cross‐sectional survey of the Japan Society of Gynecologic Oncology and Endoscopy (JSGOE) members was conducted to investigate facility demographics, MIS adoption, lymphadenectomy practices, factors influencing omission, impact of work‐style reform, and perspectives on future EC management, such as molecular classification and sentinel lymph node biopsy (SLNB). Results In total, 424 responses were received, representing a response rate of 67.8%. MIS adoption for EC is widespread in Japan, with laparoscopy preferred over robotic surgery. Lymphadenectomy is commonly performed; however, the criteria for omission varied among institutions, with clinical guidelines published by the Japanese Society of Gynecologic Oncology having the greatest impact. Physician work‐style reform significantly affected surgical practices such as surgical scheduling, adherence to time limits, and the number of surgeons participating in surgeries, while it had little impact on the criteria for lymphadenectomy omission. The adoption of molecular classifications is increasing with approximately half of the institutions planning to implement or having partially implemented them, while SLNBs remained relatively low. Conclusion This study highlights the significant impact of evolving clinical guidelines on lymphadenectomy practices for MIS for EC in Japan, and the limited impact of physician work‐style reform.
Elucidating Alterations in Viral and Human Gene Expression Due to Human Papillomavirus Integration by Using Multimodal RNA Sequencing
Human papillomavirus (HPV) infection is a primary driver of cervical cancer. Integration of HPV into the human genome causes persistent expression of viral oncogenes E6 and E7, which promote carcinogenesis and disrupt host genomic function. However, the impact of integration on host gene expression remains incompletely understood. We used multimodal RNA sequencing, combining total RNA-seq and Cap Analysis of Gene Expression (CAGE), to clarify virus–host interactions after HPV integration. HPV-derived transcripts were detected in 17 of 20 clinical samples. In most specimens, transcriptional start sites (TSSs) showed predominant early promoter usage, and transcript patterns differed with detectable E4 RNA region. Notably, the high RNA expressions of E4 region and viral-human chimeric RNAs were mutually exclusive. Chimeric RNAs were identified in 13 of 17 samples, revealing 16 viral integration sites (ISs). CAGE data revealed two patterns of TSS upregulation centered on the ISs: a two-sided pattern (43.8%) and a one-sided pattern (31.3%). Total RNA-seq showed upregulation of 12 putative cancer-related genes near ISs, including MAGI1-AS1, HAS3, CASC8, BIRC2, and MMP12. These findings indicate that HPV integration drives transcriptional activation near ISs, enhancing expression of adjacent oncogenes. Our study deepens understanding of HPV-induced carcinogenesis and informs precision medicine strategies for cervical cancer.
Epigenetic Modifier SETD8 as a Therapeutic Target for High-Grade Serous Ovarian Cancer
The histone methyltransferase SETD8, which methylates the lysine 20 of histone H4 (H4K20), is reportedly involved in human carcinogenesis along with nonhistone proteins such as p53. However, its expression profiles and functions in the context of high-grade serous ovarian carcinoma (HGSOC) are still unknown. The purpose of this study was to investigate the role of SETD8 in HGSOC. We performed quantitative real-time PCR and immunohistochemistry to detect the expression of SETD8 in HGSOC samples and normal ovarian specimens. Then, we assessed the effect of the inhibition of SETD8 expression using small interfering RNA (siRNA) and a selective inhibitor (UNC0379) on cell proliferation and apoptosis in HGSOC cells. The expression of SETD8 was significantly upregulated in clinical ovarian cancer specimens compared to that in the corresponding normal ovary. In addition, suppression of SETD8 expression in HGSOC cells with either siRNA or UNC0379 resulted in reduced levels of H4K20 monomethylation, inhibition of cell proliferation, and induction of apoptosis. Furthermore, UNC0379 showed a long-term antitumor effect against HGSOC cells, as demonstrated by colony-formation assays. SETD8 thus constitutes a promising therapeutic target for HGSOC, warranting further functional studies.
Recurrent cervical cancer with PD‐L1 amplification treated with nivolumab: A case enrolled in the BELIEVE trial
AbstractPatients with cervical cancer benefiting from immune checkpoint inhibitors (ICIs) are limited. Recently, PD‐L1 amplification has been attracted attention as a reliable marker of ICIs. A 47‐year‐old woman with stage IIB cervical cancer experienced disease progression during postoperative adjuvant chemotherapy. Cancer genomic profiling revealed that the tumor was microsatellite stable with PD‐L1 amplification, therefore, nivolumab was administered by enrolling in the BELIEVE trial. Despite nivolumab treatment, remarkable disease progression was observed. At the beginning of nivolumab treatment, the patient already had multiple liver metastases with severe systemic inflammation as indicated by a high neutrophil‐to‐lymphocyte ratio (NLR), both of which are negative predictive markers for ICI. Despite the presence of PD‐L1 amplification, nivolumab was ineffective in cancer progression, which may be attributable to the presence of liver metastasis and high NLR. ICI is recommended to be administered at an early stage of cancer treatment to enhance its effectiveness.
Identification of target cells of human papillomavirus 18 using squamocolumnar junction organoids
AbstractHuman papillomavirus 18 (HPV18) is a highly malignant HPV genotype among high‐risk HPVs, characterized by the difficulty of detecting it in precancerous lesions and its high prevalence in adenocarcinomas. The cellular targets and molecular mechanisms underlying its infection remain unclear. In this study, we aimed to identify the cells targeted by HPV18 and elucidate the molecular mechanisms underlying HPV18 replication. Initially, we established a lentiviral vector (HPV18LCR‐GFP vector) containing the HPV18 long control region promoter located upstream of EGFP. Subsequently, HPV18LCR‐GFP vectors were transduced into patient‐derived squamocolumnar junction organoids, and the presence of GFP‐positive cells was evaluated. Single‐cell RNA sequencing of GFP‐positive and GFP‐negative cells was conducted. Differentially expressed gene analysis revealed that 169 and 484 genes were significantly upregulated in GFP‐positive and GFP‐negative cells, respectively. Pathway analysis showed that pathways associated with cell cycle and viral carcinogenesis were upregulated in GFP‐positive cells, whereas keratinization and mitophagy/autophagy‐related pathways were upregulated in GFP‐negative cells. siRNA‐mediated luciferase reporter assay and HPV18 genome replication assay validated that, among the upregulated genes, ADNP, FHL2, and NPM3 were significantly associated with the activation of the HPV18 early promoter and maintenance of the HPV18 genome. Among them, NPM3 showed substantially higher expression in HPV‐related cervical adenocarcinomas than in squamous cell carcinomas, and NPM3 knockdown of HPV18‐infected cells downregulated stem cell‐related genes. Our new experimental model allows us to identify novel genes involved in HPV18 early promoter activities. These molecules might serve as therapeutic targets in HPV18‐infected cervical lesions.
Downregulation of HLA Class I Expression through HLA-A DNA Methylation Is Associated with Reduced CD8+ T-cell Infiltration in Cervical Cancer
Abstract Human leukocyte antigen class I (HLA-I) is central to tumor immune recognition, but its regulatory mechanisms in cervical cancer remain poorly understood. This study aimed to elucidate the impact of HLA-I regulatory mechanisms on CD8+ T-cell infiltration and identify distinct histotype-specific immune escape strategies across cervical cancer subtypes. Using 98 cervical cancer cases, including squamous cell carcinoma (SCC; n = 53), adenocarcinoma (n = 32), gastric-type adenocarcinoma (GAS; n = 5), small cell carcinoma (Small, n = 4), and mixed histologic types (n = 4), we examined the relationship between CD8+ T-cell infiltration patterns (categorized as infiltrated, excluded, or absent) and HLA-I expression, HLA-A DNA methylation, and HLA-I loss of heterozygosity (LOH). CD8+ T-cell infiltration patterns varied significantly by histologic subtype (P &lt; 0.0001). SCC showed the highest frequency of the infiltrated pattern (73.6%), whereas GAS and Small predominantly displayed an absent pattern. Reduced CD8+ T-cell infiltration correlated with poor survival (P &lt; 0.0001). HLA-I expression mirrored these trends being highest in SCC and lowest in Small and GAS. HLA-A DNA methylation emerged as a key driver of HLA-I downregulation, leading to reduced CD8+ infiltration (P &lt; 0.05). In SCC, both HLA-A methylation and HLA-I LOH contributed to immune evasion; cases lacking these alterations exhibited the highest CD8+ T-cell infiltration levels (P &lt; 0.01). This study identifies distinct HLA-I regulatory mechanisms in cervical cancer, highlighting HLA-A methylation—and particularly HLA-I LOH in SCC—as key drivers of immune evasion. These findings provide a foundation for developing predictive biomarkers and suggest that targeting these specific HLA-I regulatory mechanisms could enhance immunotherapy efficacy.
The automatic diagnosis artificial intelligence system for preoperative magnetic resonance imaging of uterine sarcoma
Magnetic resonance imaging (MRI) is efficient for the diagnosis of preoperative uterine sarcoma; however, misdiagnoses may occur. In this study, we developed a new artificial intelligence (AI) system to overcome the limitations of requiring specialists to manually process datasets and a large amount of computer resources. The AI system comprises a tumor image filter, which extracts MRI slices containing tumors, and sarcoma evaluator, which diagnoses uterine sarcomas. We used 15 types of MRI patient sequences to train deep neural network (DNN) models used by tumor filter and sarcoma evaluator with 8 cross-validation sets. We implemented tumor filter and sarcoma evaluator using ensemble prediction technique with 9 DNN models. Ten tumor filters and sarcoma evaluator sets were developed to evaluate fluctuation accuracy. Finally, AutoDiag-AI was used to evaluate the new validation dataset, including 8 cases of sarcomas and 24 leiomyomas. Tumor image filter and sarcoma evaluator accuracies were 92.68% and 90.50%, respectively. AutoDiag-AI with the original dataset accuracy was 89.32%, with 90.47% sensitivity and 88.95% specificity, whereas AutoDiag-AI with the new validation dataset accuracy was 92.44%, with 92.25% sensitivity and 92.50% specificity. Our newly established AI system automatically extracts tumor sites from MRI images and diagnoses them as uterine sarcomas without human intervention. Its accuracy is comparable to that of a radiologist. With further validation, the system could be applied for diagnosis of other diseases. Further improvement of the system's accuracy may enable its clinical application in the future.
