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Objective: Vulvar squamous cell carcinoma (VSCC) can be either HPV-dependent (HPVd) or HPV-independent (HPVi). HPVd VSCC typically occurs in younger women, has a more favorable prognosis, and develops from high-grade squamous intraepithelial lesions (HSIL). HPVi VSCC predominantly affects older women and arises within areas of chronic inflammation, particularly lichen sclerosis (LS). We utilized sequencing-based spatial transcriptomics to explore gene expression in a cohort of patients with HPVi and HPVd VSCC., Methods: We analysed gene expression in distinct areas (SCC, inflammation, LS, HSIL) from four early-stage VSCC cases (two HPVi, two HPVd) using the 10× Genomics Visium spatial transcriptomics platform. Cell-specific type expression was inferred using CIBERSORTx., Results: 28,183 Visium spots were detected; each contained an estimated 20-50 cells. Reads per spot ranged from 9903 to 68,527. More genes were upregulated in HPVd (N = 601) than HPVi (N = 72) with distinct differences in Keratin and Collagen genes between etiologies. Gene expression was strikingly similar between SCC and adjacent inflammatory areas, regardless of etiology. IL-17 signaling was upregulated in HPVd samples. Surprisingly, CIBERSORTx inferred significantly more CD45+ cells in HPVi tissues than HPVd, especially CD4+ resting memory and follicular helper T cells in SCC areas. Immune cells moved from resting states in the pre-invasive tissues to activated states in the SCC and peri-tumoral inflammatory areas., Conclusions: This study represents the first application of spatial transcriptomics in VSCC, with significantly more immune cells identified in HPVi SCC than in HPVd SCC. These data will act as a baseline for future studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

High-grade serous ovarian carcinoma (HGSC) remains a disease with poor prognosis that is unresponsive to current immune checkpoint inhibitors. Although PI3K pathway alterations, such as PTEN loss, are common in HGSC, attempts to target this pathway have been unsuccessful. We hypothesized that aberrant PI3K pathway activation may alter the HGSC immune microenvironment and present a targeting opportunity. Single-cell RNA sequencing identified populations of resident macrophages specific to Pten-null omental tumors in murine models, which were confirmed by flow cytometry. These macrophages were derived from peritoneal fluid macrophages and exhibited a unique gene expression program, marked by high expression of the enzyme heme oxygenase-1 (HMOX1). Targeting resident peritoneal macrophages prevented the appearance of HMOX1hi macrophages and reduced tumor growth. In addition, direct inhibition of HMOX1 extended survival in vivo. RNA sequencing identified IL33 in Pten-null tumor cells as a likely candidate driver, leading to the appearance of HMOX1hi macrophages. Human HGSC tumors also contained HMOX1hi macrophages with a corresponding gene expression program. Moreover, the presence of these macrophages was correlated with activated tumoral PI3K/mTOR signaling and poor overall survival in patients with HGSC. In contrast, tumors with low numbers of HMOX1hi macrophages were marked by increased adaptive immune response gene expression. These data suggest targeting HMOX1hi macrophages as a potential therapeutic strategy for treating poor prognosis HGSC. Significance: Macrophages with elevated HMOX1 expression are enriched in PTEN-deficient high-grade serous ovarian carcinoma, promote tumor growth, and represent a potential therapeutic target., (©2024 The Authors; Published by the American Association for Cancer Research.)

Ovarian high-grade serous carcinoma (HGSC) originates in the fallopian tube, with secretory cells carrying a TP53 mutation, known as p53 signatures, identified as potential precursors. p53 signatures evolve into serous tubal intraepithelial carcinoma (STIC) lesions, which in turn progress into invasive HGSC, which readily spreads to the ovary and disseminates around the peritoneal cavity. We recently investigated the genomic landscape of early- and late-stage HGSC and found higher ploidy in late-stage (median 3.1) than early-stage (median 2.0) samples. Here, to explore whether the high ploidy and possible whole-genome duplication (WGD) observed in late-stage disease were determined early in the evolution of HGSC, we analysed archival formalin-fixed paraffin-embedded (FFPE) samples from five HGSC patients. p53 signatures and STIC lesions were laser-capture microdissected and sequenced using shallow whole-genome sequencing (sWGS), while invasive ovarian/fallopian tube and metastatic carcinoma samples underwent macrodissection and were profiled using both sWGS and targeted next-generation sequencing. Results showed highly similar patterns of global copy number change between STIC lesions and invasive carcinoma samples within each patient. Ploidy changes were evident in STIC lesions, but not p53 signatures, and there was a strong correlation between ploidy in STIC lesions and invasive ovarian/fallopian tube and metastatic samples in each patient. The reconstruction of sample phylogeny for each patient from relative copy number indicated that high ploidy, when present, occurred early in the evolution of HGSC, which was further validated by copy number signatures in ovarian and metastatic tumours. These findings suggest that aberrant ploidy, suggestive of WGD, arises early in HGSC and is detected in STIC lesions, implying that the trajectory of HGSC may be determined at the earliest stages of tumour development. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland., (© 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.)

The drivers of recurrence and resistance in ovarian high grade serous carcinoma remain unclear. We investigate the acquisition of resistance by collecting tumour biopsies from a cohort of 276 women with relapsed ovarian high grade serous carcinoma in the BriTROC-1 study. Panel sequencing shows close concordance between diagnosis and relapse, with only four discordant cases. There is also very strong concordance in copy number between diagnosis and relapse, with no significant difference in purity, ploidy or focal somatic copy number alterations, even when stratified by platinum sensitivity or prior chemotherapy lines. Copy number signatures are strongly correlated with immune cell infiltration, whilst diagnosis samples from patients with primary platinum resistance have increased rates of CCNE1 and KRAS amplification and copy number signature 1 exposure. Our data show that the ovarian high grade serous carcinoma genome is remarkably stable between diagnosis and relapse and acquired chemotherapy resistance does not select for common copy number drivers., (© 2023. The Author(s).)

Importance: Patients with platinum-resistant or refractory ovarian high-grade serous carcinoma (PR-HGSC) have a poor prognosis and few therapeutic options. Preclinical studies support targeting PI3K/AKT/mTOR signaling in this setting, and a phase 1 study of the dual mTORC1/mTORC2 inhibitor vistusertib with weekly paclitaxel showed activity., Objective: To evaluate whether the addition of vistusertib to weekly paclitaxel improves clinical outcomes in patients with PR-HGSC., Design, Setting, and Participants: This phase 2, double-blind, placebo-controlled multicenter randomized clinical trial recruited patients from UK cancer centers between January 2016 and March 2018. Patients with PR-HGSC of ovarian, fallopian tube, or primary peritoneal origin and with measurable or evaluable disease (Response Evaluation Criteria in Solid Tumors version 1.1 and/or Gynecological Cancer Intergroup cancer antigen 125 criteria) were eligible. There were no restrictions on number of lines of prior therapy. Data analysis was performed from May 2019 to January 2022., Interventions: Patients were randomized (1:1) to weekly paclitaxel (80 mg/m2 days 1, 8, and 15 of a 28-day cycle) plus oral vistusertib (50 mg twice daily) or placebo., Main Outcomes and Measures: The primary end point was progression-free survival in the intention-to-treat population. Secondary end points included response rate, overall survival, and quality of life., Results: A total of 140 patients (median [range] age, 63 [36-86] years; 17.9% with platinum-refractory disease; 53.6% with ≥3 prior therapies) were randomized. In the paclitaxel plus vistusertib vs paclitaxel plus placebo groups, there was no difference in progression-free survival (median, 4.5 vs 4.1 months; hazard ratio [HR], 0.84; 80% CI, 0.67-1.07; 1-sided P = .18), overall survival (median, 9.7 vs 11.1 months; HR, 1.21; 80% CI, 0.91-1.60) or response rate (odds ratio, 0.86; 80% CI, 0.55-1.36). Grade 3 to 4 adverse events were 41.2% (weekly paclitaxel plus vistusertib) vs 36.7% (weekly paclitaxel plus placebo), and there was no difference in quality of life., Conclusions and Relevance: In this randomized clinical trial of weekly paclitaxel and dual mTORC1/2 inhibition in patients with PR-HGSC, vistusertib did not improve clinical activity of weekly paclitaxel., Trial Registration: isrctn.org Identifier: ISRCTN16426935.

Ovarian carcinosarcoma (OCS) is an aggressive and rare tumor type with limited treatment options. OCS is hypothesized to develop via the combination theory, with a single progenitor resulting in carcinomatous and sarcomatous components, or alternatively via the conversion theory, with the sarcomatous component developing from the carcinomatous component through epithelial-to-mesenchymal transition (EMT). In this study, we analyzed DNA variants from isolated carcinoma and sarcoma components to show that OCS from 18 women is monoclonal. RNA sequencing indicated that the carcinoma components were more mesenchymal when compared with pure epithelial ovarian carcinomas, supporting the conversion theory and suggesting that EMT is important in the formation of these tumors. Preclinical OCS models were used to test the efficacy of microtubule-targeting drugs, including eribulin, which has previously been shown to reverse EMT characteristics in breast cancers and induce differentiation in sarcomas. Vinorelbine and eribulin more effectively inhibited OCS growth than standard-of-care platinum-based chemotherapy, and treatment with eribulin reduced mesenchymal characteristics and N-MYC expression in OCS patient-derived xenografts. Eribulin treatment resulted in an accumulation of intracellular cholesterol in OCS cells, which triggered a downregulation of the mevalonate pathway and prevented further cholesterol biosynthesis. Finally, eribulin increased expression of genes related to immune activation and increased the intratumoral accumulation of CD8+ T cells, supporting exploration of immunotherapy combinations in the clinic. Together, these data indicate that EMT plays a key role in OCS tumorigenesis and support the conversion theory for OCS histogenesis. Targeting EMT using eribulin could help improve OCS patient outcomes., Significance: Genomic analyses and preclinical models of ovarian carcinosarcoma support the conversion theory for disease development and indicate that microtubule inhibitors could be used to suppress EMT and stimulate antitumor immunity., (©2022 The Authors; Published by the American Association for Cancer Research.)

Acquisition of new genetic material through horizontal gene transfer has been shown to be an important feature in the evolution of many pathogenic bacteria. Changes in the genetic repertoire, occurring through gene acquisition and deletion, are the major events underlying the emergence and evolution of bacterial pathogens. However, horizontal gene transfer across the domains i.e. archaea and bacteria is not so common. In this context, we explore events of horizontal gene transfer between archaea and bacteria. In order to determine whether the acquisition of archaeal genes by lateral gene transfer is an important feature in the evolutionary history of the pathogenic bacteria, we have developed a scheme of stepwise eliminations that identifies archaeal-like genes in various bacterial genomes. We report the presence of 9 genes of archaeal origin in the genomes of various bacteria, a subset of which is also unique to the pathogenic members and are not found in respective non-pathogenic counterparts. We believe that these genes, having been retained in the respective genomes through selective advantage, have key functions in the organism's biology and may play a role in pathogenesis.