Manako Yamaguchi

Genomic profiling of meiotic errors and early malignant transformation events in ovarian mature teratoma

Abstract Ovarian mature teratoma (OMT) exhibits copy-neutral loss of heterozygosity (CN-LOH) derived from meiotic errors. Studies have classified OMT into five types using these CN-LOH patterns. However, tumor purity issues have hindered accurate classification and molecular characterization. Moreover, the relationship between OMT genomic abnormalities and malignant transformation remains unclear. Here, we used laser microdissection to selectively collect 29 epithelial regions from 22 OMT cases and 1 carcinoma in situ (CIS) region from a squamous cell carcinoma case arising from OMT. We then conducted whole-exome sequencing. Copy number analysis enabled classification according to the established system. In cases with multi-regional sampling, the CN-LOH patterns were identical within the same tumor, while bilateral tumors showed distinct patterns, indicating that each tumor originated independently. Among the type II OMTs, which are believed to result from meiosis II error, 2 cases exhibited a chromosomal gain. Assessment of heterozygosity suggested that these cases had meiosis I error before meiosis II error. Somatic mutation analysis revealed an extremely low mutation burden, with 1 case harboring a PIK3CA mutation. In the CIS region, additional copy number alterations were present alongside the underlying CN-LOH pattern. TP53 mutations and loss of the wild-type allele were detected. The tumor mutation burden of CIS was 6.2 mutations per megabase. Mutational signature analysis showed enrichment of apolipoprotein B mRNA editing enzyme catalytic subunit-associated signatures. This study suggests novel perspectives on the mechanisms of OMT tumor development and malignant transformation.

SLFN11 is a BRCA Independent Biomarker for the Response to Platinum-Based Chemotherapy in High-Grade Serous Ovarian Cancer and Clear Cell Ovarian Carcinoma

Abstract BRCA1/2 mutations are robust biomarkers for platinum-based chemotherapy in epithelial ovarian cancers. However, BRCA1/2 mutations in clear cell ovarian carcinoma (CCC) are less frequent compared with high-grade serous ovarian cancer (HGSC). The discovery of biomarkers that can be applied to CCC is an unmet need in chemotherapy. Schlafen 11 (SLFN11) has attracted attention as a novel sensitizer for DNA-damaging agents including platinum. In this study, we investigated the utility of SLFN11 in HGSC and CCC for platinum-based chemotherapy. SLFN11 expression was analyzed retrospectively by IHC across 326 ovarian cancer samples. The clinicopathologic significance of SLFN11 expression was analyzed across 57 advanced HGSC as a discovery set, 96 advanced HGSC as a validation set, and 57 advanced CCC cases, all of whom received platinum-based chemotherapy. BRCA1/2 mutation was analyzed using targeted-gene sequencing. In the HGSC cohort, the SLFN11-positive and BRCA mutation group showed significantly longer whereas the SLFN11-negative and BRCA wild-type group showed significantly shorter progression-free survival and overall survival. Moreover, SLFN11-positive HGSC shrunk significantly better than SLFN11-negative HGSC after neoadjuvant chemotherapy. Comparable results were obtained with CCC but without consideration of BRCA1/2 mutation due to a small population. Multivariate analysis identified SLFN11 as an independent factor for better survival in HGSC and CCC. The SLFN11-dependent sensitivity to platinum and PARP inhibitors were validated with genetically modified non-HGSC ovarian cancer cell lines. Our study reveals that SLFN11 predicts platinum sensitivity in HGSC and CCC independently of BRCA1/2 mutation status, indicating that SLFN11 assessment can guide treatment selection in HGSC and CCC.

Effectiveness of human papillomavirus vaccine against cervical precancer in Japan: Multivariate analyses adjusted for sexual activity

AbstractJapanese girls aged 12–16 years are offered free human papillomavirus (HPV) vaccination and cervical cancer screening is conducted with cytology and not HPV testing from the age of 20 years. So far, no study has analyzed the effect of HPV vaccination against cervical precancers considering HPV infection status and sexual activity. We aimed to analyze the vaccine effectiveness (VE) against HPV infection and cytological abnormalities, adjusted for sexual activity. This study comprised women aged 20–26 years who underwent cervical screening in Niigata. We obtained HPV vaccination status from municipal records and a questionnaire along with information concerning sexual activity. Of 5194 women registered for this study, final analyses included 3167 women in the vaccinated group (2821 vaccinated women prior to sexual debut) and 1386 women in the unvaccinated group. HPV 16/18 (0.2% vs 3.5%), 31/45/52 (3.4% vs 6.6%), and 31/33/45/52/58 (5.0% vs 9.3%) positive rates were significantly lower in the vaccinated group (P < 0.001). No women vaccinated before sexual debut had HPV 16/18‐related cytological abnormalities. VE for HPV 16/18 infection and high‐grade cytological abnormalities in women vaccinated prior to sexual debut were 95.8% (95% CI 81.9–99.0%; P < 0.001) and 78.3% (95% CI 11.3–94.7%; P = 0.033), respectively, in multivariate analyses adjusted for age and number of sexual partners. However, analyses of all vaccinated women did not show significant effectiveness against cytological abnormalities. Our results showed the effectiveness of HPV vaccine against high‐grade cervical cytological abnormalities and the importance of the vaccination before sexual debut.