Evidence for a time-dependent association between FOLR1 expression and survival from ovarian carcinoma: implications for clinical testing. An Ovarian Tumour Tissue Analysis consortium study

Folate receptor alpha expression in low-grade serous ovarian cancer: Exploring new therapeutic possibilities

OBJECTIVE

Mirvetuximab soravtansine may be a potentially effective therapeutic option for ovarian low-grade serous carcinoma (LGSC), but the prevalence of folate receptor alpha (FRα) overexpression in this tumor type is unknown. We sought to characterize FRα expression in LGSC and its association with clinical and molecular features.

METHODS

FRα immunohistochemistry was performed on a tissue microarray comprised of 89 LGSCs and 42 ovarian serous borderline tumors (SBTs). Clinical tumor-normal panel-based sequencing was performed on 78 LGSCs. Associations between FRα-high status and clinicopathologic characteristics and survival outcomes were examined.

RESULTS

Of 89 LGSCs, 36 (40%) were FRα-high (≥75% of viable tumor cells exhibiting moderate-to-strong membranous expression). Of 9 patients with LGSC and samples from different timepoints, 4 (44%) had discordant results, with conversion from FRα-negative to FRα-high in 3 (33%) cases. There was no association between FRα-high status with age, race, or progression-free/overall survival. A MAPK pathway genetic alteration, most commonly involving KRAS (n = 23), was present in 45 (58%) LGSCs. Those lacking MAPK pathway alterations were more likely to be FRα-high compared to MAPK-altered LGSCs (61% vs 20%, p < 0.001). In SBTs, FRα-high expression was associated with high-risk (micropapillary) histology and/or subsequent LGSC recurrence compared to conventional SBTs without malignant recurrence (53% vs 9%, p = 0.008).

CONCLUSIONS

Future studies of FRα-directed therapy in patients with LGSC are warranted. Discordant FRα status at recurrence suggests potential benefit for retesting. A biomarker-driven approach to direct treatment selection in LGSC is recommended. As high FRα expression is more common amongst tumors lacking MAPK pathway genetic alterations, FRα testing to determine eligibility for mirvetuximab soravtansine therapy is particularly recommended for this subgroup.

Emerging role of mucins in antibody drug conjugates for ovarian cancer therapy

Ovarian cancer stands as the deadliest gynecologic malignancy, responsible for nearly 65% of all gynecologic cancer-related deaths. The challenges in early detection and diagnosis, coupled with the widespread intraperitoneal spread of cancer cells and resistance to chemotherapy, contribute significantly to the high mortality rate of this disease. Due to the absence of specific symptoms and the lack of effective screening methods, most ovarian cancer cases are diagnosed at advanced stages. While chemotherapy is a common treatment, it often leads to tumor recurrence, necessitating further interventions. In recent years, antibody-drug conjugates (ADCs) have emerged as a valuable tool in targeted cancer therapy. These complex biotherapeutics combine an antibody that specifically targets tumor specific/associated antigen(s) with a high potency anti-cancer drug through a linker, offering a promising approach for ovarian cancer treatment. The identification of molecular targets in various human tumors has paved the way for the development of targeted therapies, with ADCs being at the forefront of this innovation. By delivering cytotoxic agents directly to tumors and metastatic lesions, ADCs show potential in managing chemo-resistant ovarian cancers. Mucins such as MUC16, MUC13, and MUC1 have shown significantly higher expression in ovarian tumors as compared to normal and/or benign samples, thus have become promising targets for ADC generation. While traditional markers are limited by their elevated levels in non-cancerous conditions, mucins offer a new possibility for targeted treatment in ovarian cancer. This review comprehensively described the potential of mucins for the generation of ADC therapy, highlighting their importance in the quest to improve the outcome of ovarian cancer patients.

Innovations in Rare Gynecologic Cancer: Melanoma, Neuroendocrine, and Low-Grade Serous Ovarian

In the field of gynecologic cancer, low-grade serous ovarian cancer (LGSOC) has been poorly understood and underinvestigated until recently. Similarly, understanding of the distinct properties and therapeutic sensitivities of gynecologic melanoma and cervical neuroendocrine tumors has recently accelerated. For each of these rare cancers, we explore the epidemiology and natural history, discuss the prognosis, diagnostic testing, and contemporary molecular classification, and then deliberate existing and emerging therapeutic strategies. In LGSOC, we focus on the clinical relevance of recent molecular studies that shed light on the importance of mitogen-activated protein kinase (MAPK) pathway gene mutation and chromosome 1 copy-number change on prognosis and MEK inhibitor sensitivity. We also discuss the relative chemoresistance of this disease and the fact that attention is shifting to combinations of molecular therapies such as endocrine agents plus cyclin-dependent kinase 4/6 inhibitors or MEK inhibitors plus FAK inhibitors. Gynecologic tract melanomas harbor a lower frequency of canonical BRAF mutations, and have lower tumor mutational burden and immune cell infiltration than cutaneous melanomas (CMs). As a result, patients with this disease are less likely to respond to BRAF/MEK or immune checkpoint inhibition than patients with CM. Emerging strategies include the combination of antiangiogenic agents with immune checkpoint inhibitors and the use of adoptive cellular therapies. In cervical neuroendocrine cancer, we discuss the use of surgery in early-stage disease, and the uncertainties regarding the role of radiotherapy. We also explore the evidence for chemotherapy and emerging investigational strategies including the use of poly (ADP-ribose) polymerase inhibitors. For all situations, we explore the shared decision-making process with the patient.

Loss of mitochondrial pyruvate carrier 1 supports proline-dependent proliferation and collagen biosynthesis in ovarian cancer

The pyruvate transporter MPC1 (mitochondrial pyruvate carrier 1) acts as a tumour-suppressor, loss of which correlates with a pro-tumorigenic phenotype and poor survival in several tumour types. In high-grade serous ovarian cancers (HGSOC), patients display copy number loss of MPC1 in around 78% of cases and reduced MPC1 mRNA expression. To explore the metabolic effect of reduced expression, we demonstrate that depleting MPC1 in HGSOC cell lines drives expression of key proline biosynthetic genes; PYCR1, PYCR2 and PYCR3, and biosynthesis of proline. We show that altered proline metabolism underpins cancer cell proliferation, reactive oxygen species (ROS) production, and type I and type VI collagen formation in ovarian cancer cells. Furthermore, exploring The Cancer Genome Atlas, we discovered the PYCR3 isozyme to be highly expressed in a third of HGSOC patients, which was associated with more aggressive disease and diagnosis at a younger age. Taken together, our study highlights that targeting proline metabolism is a potential therapeutic avenue for the treatment of HGSOC.

High-Grade Serous Ovarian Cancer-A Risk Factor Puzzle and Screening Fugitive

High-grade serous ovarian cancer (HGSOC) is the most lethal tumor of the female genital tract. Despite extensive studies and the identification of some precursor lesions like serous tubal intraepithelial cancer (STIC) or the deviated mutational status of the patients (BRCA germinal mutation), the pathophysiology of HGSOC and the existence of particular risk factors is still a puzzle. Moreover, a lack of screening programs results in delayed diagnosis, which is accompanied by a secondary chemo-resistance of the tumor and usually results in a high recurrence rate after the primary therapy. Therefore, there is an urgent need to identify the substantial risk factors for both predisposed and low-risk populations of women, as well as to create an economically and clinically justified screening program. This paper reviews the classic and novel risk factors for HGSOC and methods of diagnosis and prediction, including serum biomarkers, the liquid biopsy of circulating tumor cells or circulating tumor DNA, epigenetic markers, exosomes, and genomic and proteomic biomarkers. The novel future complex approach to ovarian cancer diagnosis should be devised based on these findings, and the general outcome of such an approach is proposed and discussed in the paper.

A tumor-restricted glycoform of podocalyxin is a highly selective marker of immunologically cold high-grade serous ovarian carcinoma

Introduction

Targeted-immunotherapies such as antibody-drug conjugates (ADC), chimeric antigen receptor (CAR) T cells or bispecific T-cell engagers (eg, BiTE®) all aim to improve cancer treatment by directly targeting cancer cells while sparing healthy tissues. Success of these therapies requires tumor antigens that are abundantly expressed and, ideally, tumor specific. The CD34-related stem cell sialomucin, podocalyxin (PODXL), is a promising target as it is overexpressed on a variety of tumor types and its expression is consistently linked to poor prognosis. However, PODXL is also expressed in healthy tissues including kidney podocytes and endothelia. To circumvent this potential pitfall, we developed an antibody, named PODO447, that selectively targets a tumor-associated glycoform of PODXL. This tumor glycoepitope is expressed by 65% of high-grade serous ovarian carcinoma (HGSOC) tumors.

Methods

In this study we characterize these PODO447-expressing tumors as a distinct subset of HGSOC using four different patient cohorts that include pre-chemotherapy, post-neoadjuvant chemotherapy (NACT) and relapsing tumors as well as tumors from various peritoneal locations.

Results

We find that the PODO447 epitope expression is similar across tumor locations and negligibly impacted by chemotherapy. Invariably, tumors with high levels of the PODO447 epitope lack infiltrating CD8+ T cells and CD20+ B cells/plasma cells, an immune phenotype consistently associated with poor outcome.

Discussion

We conclude that the PODO447 glycoepitope is an excellent biomarker of immune "cold" tumors and a candidate for the development of targeted-therapies for these hard-to-treat cancers.

Cancer-associated fibroblasts induce sorafenib resistance of hepatocellular carcinoma cells through CXCL12/FOLR1

BACKGROUND

Due to the high drug resistance of hepatocellular carcinoma (HCC), sorafenib has limited efficacy in the treatment of advanced HCC. Cancer-associated fibroblasts (CAFs) play an important regulatory role in the induction of chemoresistance. This study aimed to clarify the mechanism underlying CAF-mediated resistance to sorafenib in HCC.

METHODS

Immunohistochemistry and immunofluorescence showed that the activation of CAFs was enhanced in HCC tissues. CAFs and paracancerous normal fibroblasts (NFs) were isolated from the cancer and paracancerous tissues of HCC, respectively. Cell cloning assays, ELISAs, and flow cytometry were used to detect whether CAFs induced sorafenib resistance in HCC cells via CXCL12. Western blotting and qPCR showed that CXCL12 induces sorafenib resistance in HCC cells by upregulating FOLR1. We investigated whether FOLR1 was the target molecule of CAFs regulating sorafenib resistance in HCC cells by querying gene expression data for human HCC specimens from the GEO database.

RESULTS

High levels of activated CAFs were present in HCC tissues but not in paracancerous tissues. CAFs decreased the sensitivity of HCC cells to sorafenib. We found that CAFs secrete CXCL12, which upregulates FOLR1 in HCC cells to induce sorafenib resistance.

CONCLUSIONS

CAFs induce sorafenib resistance in HCC cells through CXCL12/FOLR1.

Uncovering the Hidden Dangers and Molecular Mechanisms of Excess Folate: A Narrative Review

This review delves into the intricate relationship between excess folate (vitamin B9) intake, especially its synthetic form, namely, folic acid, and its implications on health and disease. While folate plays a pivotal role in the one-carbon cycle, which is essential for DNA synthesis, repair, and methylation, concerns arise about its excessive intake. The literature underscores potential deleterious effects, such as an increased risk of carcinogenesis; disruption in DNA methylation; and impacts on embryogenesis, pregnancy outcomes, neurodevelopment, and disease risk. Notably, these consequences stretch beyond the immediate effects, potentially influencing future generations through epigenetic reprogramming. The molecular mechanisms underlying these effects were examined, including altered one-carbon metabolism, the accumulation of unmetabolized folic acid, vitamin-B12-dependent mechanisms, altered methylation patterns, and interactions with critical receptors and signaling pathways. Furthermore, differences in the effects and mechanisms mediated by folic acid compared with natural folate are highlighted. Given the widespread folic acid supplementation, it is imperative to further research its optimal intake levels and the molecular pathways impacted by its excessive intake, ensuring the health and well-being of the global population.

Folate receptor alpha is widely expressed and a potential therapeutic target in uterine and ovarian carcinosarcoma

OBJECTIVE

Folate receptor alpha (FRα), which is expressed in various cancers, is a potential therapeutic target. However, its expression and clinical significance in uterine (UCS) and ovarian carcinosarcoma (OCS) remain to be elucidated.

METHODS

This retrospective study included patients with gynecologic carcinosarcoma who underwent primary surgery between 1997 and 2019 at our institution. Immunohistochemical staining of surgical FFPE specimens was performed for FRα and HER2. FRα was evaluated using the H-score and the 4-tired scoring system (0 to 3+). Subsequently, FRα expression (≥5% of tumor cells with ≥1+ intensity) and FRα-high (score 2+ and 3+) were evaluated. HER2 was scored according to the modified ASCO/CAP criteria. The association between FRα-high and clinicopathological features, HER2 expression, and survival was assessed in UCS.

RESULTS

A total of 120 patients with UCS and nine patients with OCS were included. In UCS, FRα expression was observed in all patients, whereas FRα-high status was present in 20% of patients. Among HER2-negative UCS, 34% exhibited FRα-high. No significant association was observed between clinicopathological characteristics and FRα status. During the follow-up period (median 34.5 mo), FRα-high was not strongly associated with progression, free survival, and overall survival. All the OCS tumor specimens showed FRα-high expression.

CONCLUSIONS

FRα expression was observed in all the UCS and OCS specimens, including HER2-negative UCS patients. This widespread FRα expression suggests that FRα-targeted therapies may hold promise for the treatment for gynecologic carcinosarcoma. However, in uterine carcinosarcoma, no significant relationship was observed between FRα expression and clinicopathological features or prognosis.

Mirvetuximab Soravtansine in Platinum-Resistant Ovarian Cancer

Ovarian cancer is the second leading cause of death from gynecologic malignancies worldwide. Management of platinum-resistant disease is challenging and clinical outcomes with standard chemotherapy are poor. Over the past decades, significant efforts have been made to understand drug resistance and develop strategies to overcome treatment failure. Antibody drug conjugates (ADCs) are a rapidly growing class of oncologic therapeutics, which combine the ability to target tumor-specific antigens with the cytotoxic effects of chemotherapy. Mirvetuximab soravtansine is an ADC comprising an IgG1 monoclonal antibody against the folate receptor alpha (FRα) conjugated to the cytotoxic maytansinoid effector molecule DM4 that has shown promising clinical activity in patients with FR-α-positive ovarian cancer. This review summarizes current evidence of mirvetuximab soravtansine in platinum-resistant ovarian cancer, focusing on clinical activity, toxicity, and future directions.

Recent advances in using folate receptor 1 (FOLR1) for cancer diagnosis and treatment, with an emphasis on cancers that affect women

A glycosylphosphatidylinositol (GPI)-anchored glycoprotein called the folate receptor 1 (FOLR1) facilitates the transportation of folate by mediating receptor-mediated endocytosis in response to ligand binding. While FOLR1 expression is typically restricted to the apical surfaces of the epithelium in the lung, kidney, and choroid plexus in healthy people, it is overexpressed in a number of solid tumours, including high-grade osteosarcoma, breast cancer, ovarian cancer, and non-small cell lung cancer. As a result, FOLR1 has become an attractive target for cancer detection and therapy, particularly for cancers that affect women. A number of methods have been developed to target FOLR1 in cancer therapy, including the development of FOLR1-targeted imaging agents for cancer diagnosis and the use of folate conjugates to deliver cytotoxic agents to cancer cells that overexpress FOLR1. Therefore, we focus on the most recent developments in employing FOLR1 for cancer diagnosis and treatment in this review, particularly with regard to cancers that affect women.

Strategy for Pre-Clinical Development of Active Targeting MicroRNA Oligonucleotide Therapeutics for Unmet Medical Needs

We present here an innovative modular and outsourced model of drug research and development for microRNA oligonucleotide therapeutics (miRNA ONTs). This model is being implemented by a biotechnology company, namely AptamiR Therapeutics, in collaboration with Centers of Excellence in Academic Institutions. Our aim is to develop safe, effective and convenient active targeting miRNA ONT agents for the metabolic pandemic of obesity and metabolic-associated fatty liver disease (MAFLD), as well as deadly ovarian cancer.

Folate receptor alpha in ovarian cancer tissue and patient serum is associated with disease burden and treatment outcomes

BACKGROUND

Survival rates for ovarian cancer remain poor, and monitoring and prediction of therapeutic response may benefit from additional markers. Ovarian cancers frequently overexpress Folate Receptor alpha (FRα) and the soluble receptor (sFRα) is measurable in blood. Here we investigated sFRα as a potential biomarker.

METHODS

We evaluated sFRα longitudinally, before and during neo-adjuvant, adjuvant and palliative therapies, and tumour FRα expression status by immunohistrochemistry. The impact of free FRα on the efficacy of anti-FRα treatments was evaluated by an antibody-dependent cellular cytotoxicity assay.

RESULTS

Membrane and/or cytoplasmic FRα staining were observed in 52.7% tumours from 316 ovarian cancer patients with diverse histotypes. Circulating sFRα levels were significantly higher in patients, compared to healthy volunteers, specifically in patients sampled prior to neoadjuvant and palliative treatments. sFRα was associated with FRα cell membrane expression in the tumour. sFRα levels decreased alongside concurrent tumour burden in patients receiving standard therapies. High concentrations of sFRα partly reduced anti-FRα antibody tumour cell killing, an effect overcome by increased antibody doses.

CONCLUSIONS

sFRα may present a non-invasive marker for tumour FRα expression, with the potential for monitoring patient response to treatment. Larger, prospective studies should evaluate FRα for assessing disease burden and response to systemic treatments.

Targeted therapy and immunotherapy: Diamonds in the rough in the treatment of epithelial ovarian cancer

Currently, for ovarian cancer, which has the highest mortality rate among all gynecological cancers, the standard treatment protocol is initial tumor cytoreductive surgery followed by platinum-based combination chemotherapy. Although the survival rate after standard treatment has improved, the therapeutic effect of traditional chemotherapy is very limited due to problems such as resistance to platinum-based drugs and recurrence. With the advent of the precision medicine era, molecular targeted therapy has gradually entered clinicians' view, and individualized precision therapy has been realized, surpassing the limitations of traditional therapy. The detection of genetic mutations affecting treatment, especially breast cancer susceptibility gene (BRCA) mutations and mutations of other homologous recombination repair defect (HRD) genes, can guide the targeted drug treatment of patients, effectively improve the treatment effect and achieve a better patient prognosis. This article reviews different sites and pathways of targeted therapy, including angiogenesis, cell cycle and DNA repair, and immune and metabolic pathways, and the latest research progress from preclinical and clinical trials related to ovarian cancer therapy.

Nucleic acid vaccination strategies for ovarian cancer

High grade serous carcinoma (HGSC) is one of the most lethal ovarian cancers that is characterised by asymptomatic tumour growth, insufficient knowledge of malignant cell origin and sub-optimal detection. HGSC has been recently shown to originate in the fallopian tube and not in the ovaries. Conventional treatments such as chemotherapy and surgery depend upon the stage of the disease and have resulted in higher rates of relapse. Hence, there is a need for alternative treatments. Differential antigen expression levels have been utilised for early detection of the cancer and could be employed in vaccination strategies using nucleic acids. In this review the different vaccination strategies in Ovarian cancer are discussed and reviewed. Nucleic acid vaccination strategies have been proven to produce a higher CD8+ CTL response alongside CD4+ T-cell response when compared to other vaccination strategies and thus provide a good arena for antitumour immune therapy. DNA and mRNA need to be delivered into the intracellular matrix. To overcome ineffective naked delivery of the nucleic acid cargo, a suitable delivery system is required. This review also considers the suitability of cell penetrating peptides as a tool for nucleic acid vaccine delivery in ovarian cancer.

A Phase I Trial of CT900, a Novel α-Folate Receptor-Mediated Thymidylate Synthase Inhibitor, in Patients with Solid Tumors with Expansion Cohorts in Patients with High-Grade Serous Ovarian Cancer

PURPOSE

CT900 is a novel small molecule thymidylate synthase inhibitor that binds to α-folate receptor (α-FR) and thus is selectively taken up by α-FR-overexpressing tumors.

PATIENTS AND METHODS

A 3+3 dose escalation design was used. During dose escalation, CT900 doses of 1-6 mg/m2 weekly and 2-12 mg/m2 every 2 weeks (q2Wk) intravenously were evaluated. Patients with high-grade serous ovarian cancer were enrolled in the expansion cohorts.

RESULTS

109 patients were enrolled: 42 patients in the dose escalation and 67 patients in the expansion cohorts. At the dose/schedule of 12 mg/m2/q2Wk (with and without dexamethasone, n = 40), the most common treatment-related adverse events were fatigue, nausea, diarrhea, cough, anemia, and pneumonitis, which were predominantly grade 1 and grade 2. Levels of CT900 more than 600 nmol/L needed for growth inhibition in preclinical models were achieved for >65 hours at a dose of 12 mg/m2. In the expansion cohorts, the overall response rate (ORR), was 14/64 (21.9%). Thirty-eight response-evaluable patients in the expansion cohorts receiving 12 mg/m2/q2Wk had tumor evaluable for quantification of α-FR. Patients with high or medium expression had an objective response rate of 9/25 (36%) compared with 1/13 (7.7%) in patients with negative/very low or low expression of α-FR.

CONCLUSIONS

The dose of 12 mg/m2/q2Wk was declared the recommended phase II dose/schedule. At this dose/schedule, CT900 exhibited an acceptable side effect profile with clinical benefit in patients with high/medium α-FR expression and warrants further investigation.

Molecular Biomarkers for the Early Detection of Ovarian Cancer

Ovarian cancer is the deadliest gynecological cancer, leading to over 152,000 deaths each year. A late diagnosis is the primary factor causing a poor prognosis of ovarian cancer and often occurs due to a lack of specific symptoms and effective biomarkers for an early detection. Currently, cancer antigen 125 (CA125) is the most widely used biomarker for ovarian cancer detection, but this approach is limited by a low specificity. In recent years, multimarker panels have been developed by combining molecular biomarkers such as human epididymis secretory protein 4 (HE4), ultrasound results, or menopausal status to improve the diagnostic efficacy. The risk of ovarian malignancy algorithm (ROMA), the risk of malignancy index (RMI), and OVA1 assays have also been clinically used with improved sensitivity and specificity. Ongoing investigations into novel biomarkers such as autoantibodies, ctDNAs, miRNAs, and DNA methylation signatures continue to aim to provide earlier detection methods for ovarian cancer. This paper reviews recent advancements in molecular biomarkers for the early detection of ovarian cancer.

High expression of folate receptor alpha is associated with poor prognosis in patients with cervical cancer

OBJECTIVE

Folate receptor α (FRα) is a membrane protein expressed in various solid tumors but has limited expression in normal cells. Therefore, FRα is an attractive target for cancer treatment. This study aimed to investigate the relationship between FRα expression and the clinicopathological characteristics and survivals of cervical cancer.

METHODS

This retrospective study included patients with cervical cancer who underwent primary surgery between 2000 and 2020 at our institution. Immunohistochemical staining of FRα was performed using an anti-folate-binding protein/FBP antibody. FRα-positive staining was defined as ≥5% of tumor staining and FRα-high as ≥50% tumor staining with ≥2+ intensity. The association between FRα expression and survival was assessed using multivariate Cox regression analysis, adjusting for established prognostic factors.

RESULTS

Overall, 123 patients were identified, and 140 tumor samples, including 17 paired primary and metastatic samples, were evaluated. As histological types, 67 patients had squamous cell carcinoma (SCC), and 56 patients had non-SCC. All primary tumors were FRα-positive. High FRα expression was observed in 25% of the cases and differed according to histology (SCC vs. non-SCC, 14.9% vs. 37.5%, p=0.004). FRα expression was significantly higher in metastatic tumors than in primary (170 [IQR, 140-205] vs. 125 [IQR, 110-150], p=0.0006). High FRα expression was significantly associated with worse overall survival (hazard ratio, 6.73; 95% confidence interval, 2.21-20.53; p=0.001).

CONCLUSION

In cervical cancer, FRα expression was elevated in metastatic tumors and high expression was associated with a worse prognosis. Our study supports the development of FRα-targeted therapy for advanced cervical cancer.

A T-cell engaging bispecific antibody with a tumor-selective bivalent folate receptor alpha binding arm for the treatment of ovarian cancer

The use of T-cell engagers (TCEs) to treat solid tumors is challenging, and several have been limited by narrow therapeutic windows due to substantial on-target, off-tumor toxicities due to the expression of low levels of target antigens on healthy tissues. Here, we describe TNB-928B, a fully human TCE that has a bivalent binding arm for folate receptor alpha (FRα) to selectively target FRα overexpressing tumor cells while avoiding the lysis of cells with low levels of FRα expression. The bivalent design of the FRα binding arm confers tumor selectivity due to low-affinity but high-avidity binding to high FRα antigen density cells. TNB-928B induces preferential effector T-cell activation, proliferation, and selective cytotoxic activity on high FRα expressing cells while sparing low FRα expressing cells. In addition, TNB-928B induces minimal cytokine release compared to a positive control TCE containing OKT3. Moreover, TNB-928B exhibits substantial ex vivo tumor cell lysis using endogenous T-cells and robust tumor clearance in vivo, promoting T-cell infiltration and antitumor activity in mouse models of ovarian cancer. TNB-928B exhibits pharmacokinetics similar to conventional antibodies, which are projected to enable favorable administration in humans. TNB-928B is a novel TCE with enhanced safety and specificity for the treatment of ovarian cancer.

Identification and Validation of the Diagnostic Characteristic Genes of Ovarian Cancer by Bioinformatics and Machine Learning

Background: Ovarian cancer (OC) has a high mortality rate and poses a severe threat to women’s health. However, abnormal gene expression underlying the tumorigenesis of OC has not been fully understood. This study aims to identify diagnostic characteristic genes involved in OC by bioinformatics and machine learning.

Methods: We utilized five datasets retrieved from the Gene Expression Omnibus (GEO) database, The Cancer Genome Atlas (TCGA) database, and the Genotype-Tissue Expression (GTEx) Project database. GSE12470 and GSE18520 were combined as the training set, and GSE27651 was used as the validation set A. Also, we combined the TCGA database and GTEx database as validation set B. First, in the training set, differentially expressed genes (DEGs) between OC and non-ovarian cancer tissues (nOC) were identified. Next, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Disease Ontology (DO) enrichment analysis, and Gene Set Enrichment Analysis (GSEA) were performed for functional enrichment analysis of these DEGs. Then, two machine learning algorithms, Least Absolute Shrinkage and Selector Operation (LASSO) and Support Vector Machine-Recursive Feature Elimination (SVM-RFE), were used to get the diagnostic genes. Subsequently, the obtained diagnostic-related DEGs were validated in the validation sets. Then, we used the computational approach (CIBERSORT) to analyze the association between immune cell infiltration and DEGs. Finally, we analyzed the prognostic role of several genes on the KM-plotter website and used the human protein atlas (HPA) online database to analyze the expression of these genes at the protein level.

Results: 590 DEGs were identified, including 276 upregulated and 314 downregulated DEGs.The Enrichment analysis results indicated the DEGs were mainly involved in the nuclear division, cell cycle, and IL−17 signaling pathway. Besides, DEGs were also closely related to immune cell infiltration. Finally, we found that BUB1, FOLR1, and PSAT1 have prognostic roles and the protein-level expression of these six genes SFPR1, PSAT1, PDE8B, INAVA and TMEM139 in OC tissue and nOC tissue was consistent with our analysis.

Conclusions: We screened nine diagnostic characteristic genes of OC, including SFRP1, PSAT1, BUB1B, FOLR1, ABCB1, PDE8B, INAVA, BUB1, TMEM139. Combining these genes may be useful for OC diagnosis and evaluating immune cell infiltration.

Protein Expression of Folate Receptor Alpha in Adenoid Cystic Carcinoma of the Head and Neck

Purpose

Folate receptor alpha (FRα) is overexpressed in various cancer entities while expression in normal tissue is limited. Thus, FRα is an attractive target in cancer therapy. Currently, various therapeutic and diagnostic approaches are under investigation in clinical trials. The aim of this study was to assess the expression and clinical relevance of FRα in adenoid cystic carcinoma of the head and neck.

Patients and Methods

In this retrospective cohort study, 43 patients with adenoid cystic carcinoma (ACC) of the head and neck were included. FRα expression was analyzed in tumor tissue and tumor-free margin in a tissue microarray using immunohistochemical staining. Protein levels were correlated with clinical parameters.

Results

FRα staining was positive in 47% of ACC patients. The tumor-free margin was positive in 22%. Patients with positive tumor tissue showed positive margin staining in 55%. FRα expression was not associated with the clinical parameters (sex, age, staging, grading, perineural invasion, lymphovascular invasion).

Conclusion

FRα expression is common in ACC of the head and neck. Therefore, FRα should be further evaluated as a therapeutic target in ACC.

Sonosensitizer nanoplatform-mediated sonodynamic therapy induced immunogenic cell death and tumor immune microenvironment variation

Epithelial ovarian cancer (EOC) is one of the most lethal gynecologic malignancies, and effective treatments are still lacking due to drug tolerance and tumor recurrence. In this study, we aimed to investigate the effects of sonodynamic therapy (SDT) on ovarian cancer and its potential mechanism. Folate receptor-targeted and ultrasound-responsive nanoparticles (NPs) were constructed using PLGA-PEG-FA (PLGA: poly (lactic-co-glycolic) acid, polyethylene glycol (PEG), FA: folate), the reactive oxygen species (ROS)-generating sonosensitizer IR780 and the oxygen-carrying material perfluorohexane (PFH), termed IRO@FA NPs. The antitumor effect of NPs triggered by ultrasound (US) was measured by an apoptosis assay in a C57/BL6 mouse model. Immunochemistry and flow cytometry were used to detect the proportion of CD3⁺ T, CD4⁺ T, CD8⁺ T cells and activated dendritic cells (DCs) in spleens and tumor tissues to assess variation in the immune response. Moreover, endoplasmic reticulum (ER) stress and immunogenic cell death (ICD) markers (high mobility group protein box-1, ATP and calreticulin) were detected to identify potential mechanisms. The results showed that IRO@FA NP-mediated SDT promoted ID8 cell apoptosis both in vitro and in vivo. The densities of CD3⁺ and CD8⁺ T lymphocytes and inflammatory markers were upregulated in tumor tissues. IRO@FA NP-mediated SDT prompted DC maturation and T lymphocyte infiltration by inducing ID8 cell ICD.

BRCA1 mutations in high-grade serous ovarian cancer are associated with proteomic changes in DNA repair, splicing, transcription regulation and signaling

Despite recent advances in the management of BRCA1 mutated high-grade serous ovarian cancer (HGSC), the physiology of these tumors remains poorly understood. Here we provide a comprehensive molecular understanding of the signaling processes that drive HGSC pathogenesis with the addition of valuable ubiquitination profiling, and their dependency on BRCA1 mutation-state directly in patient-derived tissues. Using a multilayered proteomic approach, we show the tight coordination between the ubiquitination and phosphorylation regulatory layers and their role in key cellular processes related to BRCA1-dependent HGSC pathogenesis. In addition, we identify key bridging proteins, kinase activity, and post-translational modifications responsible for molding distinct cancer phenotypes, thus providing new opportunities for therapeutic intervention, and ultimately advance towards a more personalized patient care.

Prognostic and Theranostic Biomarkers in Ovarian Clear Cell Carcinoma

In this study, we aimed to test whether prognostic biomarkers can achieve a clinically relevant stratification of patients with stage I ovarian clear cell carcinoma (OCCC) and to survey the expression of 10 selected actionable targets (theranostic biomarkers) in stage II to IV cases. From the population-based Alberta Ovarian Tumor Type study, 160 samples of OCCC were evaluated by immunohistochemistry and/or silver-enhanced in situ hybridization for the status of 5 prognostic (p53, p16, IGF2BP3, CCNE1, FOLR1) and 10 theranostic biomarkers (ALK, BRAF V600E, ERBB2, ER, MET, MMR, PR, ROS1, NTRK1-3, VEGFR2). Kaplan-Meier survival analyses were performed. Cases with abnormal p53 or combined p16/IFG2BP3 abnormal expression identified a small subset of patients (6/54 cases) with stage I OCCC with an aggressive course (5-yr ovarian cancer-specific survival of 33.3%, compared with 91.5% in the other stage I cases). Among theranostic targets, ERBB2 amplification was present in 11/158 (7%) of OCCC, while MET was ubiquitously expressed in OCCC similar to a variety of normal control tissues. ER/PR showed a low prevalence of expression. No abnormal expression was detected for any of the other targets. We propose a combination of 3 biomarkers (p53, p16, IGF2BP3) to predict prognosis and the potential need for adjuvant therapy for patients with stage I OCCC. This finding requires replication in larger cohorts. In addition, OCCC could be tested for ERBB2 amplification for inclusion in gynecological basket trials targeting this alteration.

High Expression of Folate Receptor Alpha (FOLR1) is Associated With Aggressive Tumor Behavior, Poor Response to Chemoradiotherapy, and Worse Survival in Rectal Cancer

Objectives: Recently, molecular medicine targeting Folate Receptor Alpha (FOLR1), which mediates intracellular folate uptake and tumor cell proliferation, has been identified in several malignancies. However, the association between FOLR1 expression and rectal cancer remains unclear. Methods: Immunostaining of FOLR1 was performed on biopsy specimens from 172 rectal cancer patients undergoing preoperative chemoradiotherapy (CRT). FOLR1 expression was measured and divided into low (0+-2+) or high (3+-4+) level. Correlations between FOLR1 status and clinicopathologic features, tumor regression grade, disease-specific survival (DSS), local recurrence-free survival, and metastasis-free survival (MeFS) were analyzed, retrospectively. Results: High FOLR1 expression was significantly associated with advanced post-treatment tumor and nodal status (T3-4; N1-2, P = .001), vascular invasion (P = .042), perineural invasion (P = .012), and poor regression change after CRT (P = .001). In uni- and multi-variable survival analysis, FOLR1 overexpression remained a significant predictor of lower DSS (hazard ratio [HR], 2.328; 95% confidence interval [CI], 1.014-5.344; P = .046) and MeFS (HR, 2.177; 95% CI, 1.000-1.1286; P = .050). Conclusion: These results indicate that high FOLR1 status is associated with aggressive tumor behavior, poor response to CRT, and worse survival. Therefore, FOLR1 expression at initial biopsy may be useful in predicting outcomes and also be a target for the exploration of FOLR1-based therapeutic agents.

Folate Transport and One-Carbon Metabolism in Targeted Therapies of Epithelial Ovarian Cancer

New therapies are urgently needed for epithelial ovarian cancer (EOC), the most lethal gynecologic malignancy. To identify new approaches for targeting EOC, metabolic vulnerabilities must be discovered and strategies for the selective delivery of therapeutic agents must be established. Folate receptor (FR) α and the proton-coupled folate transporter (PCFT) are expressed in the majority of EOCs. FRβ is expressed on tumor-associated macrophages, a major infiltrating immune population in EOC. One-carbon (C1) metabolism is partitioned between the cytosol and mitochondria and is important for the synthesis of nucleotides, amino acids, glutathione, and other critical metabolites. Novel inhibitors are being developed with the potential for therapeutic targeting of tumors via FRs and the PCFT, as well as for inhibiting C1 metabolism. In this review, we summarize these exciting new developments in targeted therapies for both tumors and the tumor microenvironment in EOC.

Revisiting antibody-drug conjugates and their predictive biomarkers in platinum-resistant ovarian cancer

Until to date, platinum derived drugs are still the backbone of treating ovarian cancer (OC). Most patients treated with platinum-based chemotherapy develop resistance during the course of their management. The treatment of platinum-resistant ovarian cancer (PROC) is challenging. Few therapeutic options are available for patients with this aggressive disease. Besides, there are liminal advances regarding new anticancer drugs as well as validated predictive biomarkers of clinical outcomes in this setting. The enrollment of PROC patients in interventional studies is limited as compared to newly launched clinical trials for platinum-sensitive OC. Enthusiastically, the emergence of antibody-drug conjugates (ADCs) has provided promising findings for further clinical development in PROC. ADCs have the advantage to selectively deliver cytotoxic drugs to cancer cells expressing several of antigens using specific monoclonal antibodies based on the concept of immune bioconjugation. This innovative class of therapeutics showed encouraging early signs of clinical efficacy in PROC particularly mirvetuximab soravtansine that has been successfully introduced into three randomized and controlled phase III studies. In this review, the evidence from clinical trials supporting the development of ADCs targeting folate receptor alpha, sodium-dependent phosphate transporter 2B, dipeptidase 3, mesothelin, mucin 16, and tissue factor using various cytotoxic payloads in PROC is reviewed.

The Protein Landscape of Mucinous Ovarian Cancer: Towards a Theranostic

MOC is a rare histotype of epithelial ovarian cancer, and current management options are inadequate for the treatment of late stage or recurrent disease. A shift towards personalised medicines in ovarian cancer is being observed, with trials targeting specific molecular pathways, however, MOC lags due to its rarity. Theranostics is a rapidly evolving category of personalised medicine, encompassing both a diagnostic and therapeutic approach by recognising targets that are expressed highly in tumour tissue in order to deliver a therapeutic payload. The present review evaluates the protein landscape of MOC in recent immunohistochemical- and proteomic-based research, aiming to identify potential candidates for theranostic application. Fourteen proteins were selected based on cell membrane localisation: HER2, EGFR, FOLR1, RAC1, GPR158, CEACAM6, MUC16, PD-L1, NHE1, CEACAM5, MUC1, ACE2, GP2, and PTPRH. Optimal proteins to target using theranostic agents must exhibit high membrane expression on cancerous tissue with low expression on healthy tissue to afford improved disease outcomes with minimal off-target effects and toxicities. We provide guidelines to consider in the selection of a theranostic target for MOC and suggest future directions in evaluating the results of this review.

A Novel Overall Survival Prediction Signature Based on Cancer Stem Cell-Related Genes in Osteosarcoma

Background: Osteosarcoma is the most general bone malignancy that mostly affects children and adolescents. Numerous stem cell-related genes have been founded in distinct forms of cancer. This study aimed at identifying a stem cell-related gene model for the expected assessment of the prognosis of osteosarcoma patients.

Methods: We obtained the genes expression data and relevant clinical materials from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) and Gene Expression Omnibus (GEO) databases. We identified differentially expressed genes (DEGs) from the GEO dataset, whereas prognostic stem cell-related genes were obtained from the TARGET database. Subsequently, univariate, LASSO and multivariate Cox regression analyses were applied to establish the stem cell-related signature. Finally, the prognostic value of the signature was validated in the GEO dataset.

Results: Twenty-five genes were prognostic ferroptosis-related DEGs. Consequently, we identified eight stem cell-related genes as a signature of prognosis of osteosarcoma patients. Then, the Kaplan–Meier (K-M) curve, the AUC value of ROC, and Cox regression analysis verified that the eight stem cell-related gene model were a new and substantial prognostic marker independent of other clinical traits. Moreover, the nomogram on the foundation of risk score and other clinical traits was established for predicting the survival rate of osteosarcoma patients. Biological function analyses displayed that tumor related pathways were affluent.

Conclusion: The expression level of stem cell-related genes offers novel prognostic markers as well as underlying therapeutic targets for the therapy and prevention of osteosarcoma.

Chemotherapy resistance in epithelial ovarian cancer: Mechanisms and emerging treatments

Ovarian cancer (OC) remains a fatal malignancy because most patients experience recurrent disease, which is resistant to chemotherapy. The outcomes for patients with platinum-resistant OC are poor, response rates to further chemotherapy are low and median survival is lower than 12 months. The complexity of platinum-resistant OC, which comprises a heterogeneous spectrum of diseases, is indeed far from being completely understood. Therefore, comprehending tumors' biological behaviour to identify reliable biomarkers, which may predict responses to therapies, is a demanding challenge to improve OC management. In the age of precision medicine, efforts to overcome platinum resistance in OC represent a dynamic and vast field in which innovative drugs and clinical trials rapidly develop. This review will present the exceptional biochemical environment implicated in OC and highlights mechanisms of chemoresistance. Furthermore, innovative molecules and new therapeutic opportunities are presented, along with currently available therapies and ongoing clinical trials.

Non-viral vector mediated CKb11 with folic acid modification regulates macrophage polarization and DC maturation to elicit immune response against cancer

The immunosuppressive tumor microenvironment (TME) of cancer strongly hinders the anti-tumor immune responses, thereby resulting in disappointing responses to immunotherapy. Chemoattractive and promotive traits of chemokines exerted on leukocytes have garnered interest in improving the efficiency of immunotherapy by increasing the infiltration of immune cells in the TME. In this study, a folic acid (FA) -modified gene delivery system based on the self-assembly of DOTAP, MPEG-PCL-MPEG, and FA-PEG-PCL-PEG-FA, namely F-PPPD, was developed to deliver plasmids encoding the immunostimulating chemokine CKb11. The delivery of plasmid CKb11 (pCKb11) by F-PPPD nanoparticles resulted in the high secretion of CKb11 from tumor cells, which successfully activated T cells, suppressed the M2 polarization of macrophages, promoted the maturation of dendritic cells (DCs), facilitated the infiltration of natural killer (NK) cells and inhibited the infiltration of immunosuppressive cells in tumor tissues. Administration of F-PPPD/pCKb11 also significantly suppressed the cancer progression. Our study demonstrated a nanotechnology-enabled delivery of pCKb11, that remodeled the immunosuppressive TME, for cancer treatment.

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Immunosuppressive tumor microenvironment hinders the intratumoral immune responses.

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Immunogene therapy is one of new therapies, which brings dawn to the cancer patients.

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Non-viral vectors have shown great potential in immunogene therapy.

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FA modified non-viral vector carrying CKb11 activates the immunity against cancer.

Driving Immune Responses in the Ovarian Tumor Microenvironment

Ovarian cancer is the leading cause of death among gynecological neoplasms, with an estimated 14,000 deaths in 2019. First-line treatment options center around a taxane and platinum-based chemotherapy regimen. However, many patients often have recurrence due to late stage diagnoses and acquired chemo-resistance. Recent approvals for bevacizumab and poly (ADP-ribose) polymerase inhibitors have improved treatment options but effective treatments are still limited in the recurrent setting. Immunotherapy has seen significant success in hematological and solid malignancies. However, effectiveness has been limited in ovarian cancer. This may be due to a highly immunosuppressive tumor microenvironment and a lack of tumor-specific antigens. Certain immune cell subsets, such as regulatory T cells and tumor-associated macrophages, have been implicated in ovarian cancer. Consequently, therapies augmenting the immune response, such as immune checkpoint inhibitors and dendritic cell vaccines, may be unable to properly enact their effector functions. A better understanding of the various interactions among immune cell subsets in the peritoneal microenvironment is necessary to develop efficacious therapies. This review will discuss various cell subsets in the ovarian tumor microenvironment, current immunotherapy modalities to target or augment these immune subsets, and treatment challenges.

Co-expression patterns of chimeric antigen receptor (CAR)-T cell target antigens in primary and recurrent ovarian cancer

OBJECTIVE

Chimeric antigen receptor (CAR)-T cell strategies ideally target a surface antigen that is exclusively and uniformly expressed by tumors; however, no such antigen is known for high-grade serous ovarian carcinoma (HGSC). A potential solution involves combinatorial antigen targeting with AND or OR logic-gating. Therefore, we investigated co-expression of CA125, Mesothelin (MSLN) and Folate Receptor alpha (FOLRA) on individual tumor cells in HGSC.

METHODS

RNA expression of CA125, MSLN, and FOLR1 was assessed using TCGA (HGSC) and GTEx (healthy tissues) databases. Antigen expression profiles and CD3+, CD8+ and CD20+ tumor-infiltrating lymphocyte (TIL) patterns were assessed in primary and recurrent HGSC by multiplex immunofluorescence and immunohistochemistry.

RESULTS

At the transcriptional level, each antigen was overexpressed in >90% of cases; however, MSLN and FOLR1 showed substantial expression in healthy tissues. At the protein level, CA125 was expressed by the highest proportion of cases and tumor cells per case, followed by MSLN and FOLRA. The most promising pairwise combination was CA125 and/or MSLN (OR gate), with 51.9% of cases containing ≥90% of tumor cells expressing one or both antigens. In contrast, only 5.8% of cases contained ≥90% of tumor cells co-expressing CA125 and MSLN (AND gate). Antigen expression patterns showed modest correlations with TIL. Recurrent tumors retained expression of all three antigens and showed increased TIL densities.

CONCLUSIONS

An OR-gated CAR-T cell strategy against CA125 and MSLN would target the majority of tumor cells in most cases. Antigen expression and T-cell infiltration patterns are favorable for this strategy in primary and recurrent disease.

Protease-activation using anti-idiotypic masks enables tumor specificity of a folate receptor 1-T cell bispecific antibody

T-cell bispecific antibodies (TCBs) crosslink tumor and T-cells to induce tumor cell killing. While TCBs are very potent, on-target off-tumor toxicity remains a challenge when selecting targets. Here, we describe a protease-activated anti-folate receptor 1 TCB (Prot-FOLR1-TCB) equipped with an anti-idiotypic anti-CD3 mask connected to the anti-CD3 Fab through a tumor protease-cleavable linker. The potency of this Prot- FOLR1-TCB is recovered following protease-cleavage of the linker releasing the anti-idiotypic anti-CD3 scFv. In vivo, the Prot-FOLR1-TCB mediates antitumor efficacy comparable to the parental FOLR1-TCB whereas a noncleavable control Prot-FOLR1-TCB is inactive. In contrast, killing of bronchial epithelial and renal cortical cells with low FOLR1 expression is prevented compared to the parental FOLR1-TCB. The findings are confirmed for mesothelin as alternative tumor antigen. Thus, masking the anti-CD3 Fab fragment with an anti-idiotypic mask and cleavage of the mask by tumor-specific proteases can be applied to enhance specificity and safety of TCBs.

A systematic review and meta-analysis of higher expression of folate receptor alpha (FOLR1) predicts poor cancer prognosis

Folate receptor alpha (FOLR1), a glycosylphosphatidylinositol-linked protein, is a well characterized folate transporter. However, the prognostic power of FOLR1 in cancer remains controversial. We conducted a meta-analysis to assess the prognostic roles of FOLR1 on different cancers. Twelve studies involving 4471 patients were included in this meta-analysis. The pooled analysis indicated that high FOLR1 significantly predicted poor overall survival (OS) (pooled hazard ratio (HR) = 0.78, 95% confidence interval (CI) = 0.64-0.94, p = 0.009) and the disease-free survival (DFS) (HR = 1.25, 95% CI = 1.07-1.47, p = 0.005). Subgroup analyses based on tumour type found that high FOLR1 level was associated with poor OS in breast cancer (HR = 2.66, 95% CI = 1.54-4.59, p = 0.0005) and endometrial carcinoma (HR = 1.30, 95% CI = 1.05-1.61, p = 0.02). However, FOLR1 has relatively weakly correlation with gender, tumour size and chemotherapy. Additionally, overexpression of FOLR1 was correlated with grade, FIGO stage, vital status and nodule status. The present meta-analysis indicated that the high expression of FOLR1 is associated with the poor survival of cancer patients, which is helpful for the clinical decision-making process.

Exploiting the folate receptor α in oncology

Folate receptor α (FRα) came into focus as an anticancer target many decades after the successful development of drugs targeting intracellular folate metabolism, such as methotrexate and pemetrexed. Binding to FRα is one of several methods by which folate is taken up by cells; however, this receptor is an attractive anticancer drug target owing to the overexpression of FRα in a range of solid tumours, including ovarian, lung and breast cancers. Furthermore, using FRα to better localize effective anticancer therapies to their target tumours using platforms such as antibody-drug conjugates, small-molecule drug conjugates, radioimmunoconjugates and, more recently, chimeric antigen receptor T cells could further improve the outcomes of patients with FRα-overexpressing cancers. FRα can also be harnessed for predictive biomarker research. Moreover, imaging FRα radiologically or in real time during surgery can lead to improved functional imaging and surgical outcomes, respectively. In this Review, we describe the current status of research into FRα in cancer, including data from several late-phase clinical trials involving FRα-targeted therapies, and the use of new technologies to develop FRα-targeted agents with improved therapeutic indices.

CD24-targeted intraoperative fluorescence image-guided surgery leads to improved cytoreduction of ovarian cancer in a preclinical orthotopic surgical model

BACKGROUND

The completeness of resection is a key prognostic indicator in patients with ovarian cancer, and the application of tumour-targeted fluorescence image-guided surgery (FIGS) has led to improved detection of peritoneal metastases during cytoreductive surgery. CD24 is highly expressed in ovarian cancer and has been shown to be a suitable biomarker for tumour-targeted imaging.

METHODS

CD24 expression was investigated in cell lines and heterogenous patient-derived xenograft (PDX) tumour samples of high-grade serous ovarian carcinoma (HGSOC). After conjugation of the monoclonal antibody CD24 to the NIR dye Alexa Fluor 750 and the evaluation of the optimal pharmacological parameters (OV-90, n = 21), orthotopic HGSOC metastatic xenografts (OV-90, n = 16) underwent cytoreductive surgery with real-time feedback. The impact of intraoperative CD24-targeted fluorescence guidance was compared to white light and palpation alone, and the recurrence of disease was monitored post-operatively (OV-90, n = 12). CD24-AF750 was further evaluated in four clinically annotated orthotopic PDX models of metastatic HGSOC, to validate the translational potential for intraoperative guidance.

FINDINGS

CD24-targeted intraoperative NIR FIGS significantly (47•3%) improved tumour detection and resection, and reduced the post-operative tumour burden compared to standard white-light surgery in orthotopic HGSOC xenografts. CD24-AF750 allowed identification of minuscule tumour lesions which were undetectable with the naked eye in four HGSOC PDX.

INTERPRETATION

CD24-targeted FIGS has translational potential as an aid to improve debulking surgery of ovarian cancer.

FUNDING

This study was supported by the H2020 program MSCA-ITN [675743], Helse Vest RHF, and Helse Bergen HF [911809, 911852, 912171, 240222, 911974, HV1269], as well as by The Norwegian Cancer Society [182735], and The Research Council of Norway through its Centres of excellence funding scheme [223250, 262652].

New strategies in ovarian cancer treatment

Insights from basic science dissecting carcinogenesis in the fallopian tube and ovary have led to a deeper understanding of the origin, molecular characteristics, and types of ovarian cancers. This logically then has led to the development of novel approaches to treat ovarian cancer. Increasingly, novel agents are being developed to target the different growth pathways. The identification of molecular markers associated with different histopathologies has resulted in newer clinical trial designs to capture both clinical and translational endpoints. Unique molecular characteristics in DNA damage and repair pathways and unique cell surface markers have driven new drug development, yielding promise for both patients with platinum-sensitive and platinum-resistant ovarian cancers. Specific examples described include the histology-selective mutations, such as ARID1A in clear cell and endometrioid ovarian cancers; the rationale for using cell cycle checkpoint inhibitors when there already is a p53-mediated loss of cell cycle checkpoint regulation or combinations of agents that will both induce neoantigen formation and unleash immune modulators; and techniques to enhance the therapeutic delivery of known agents. A systematic and thoughtful approach to combining agents in clinical trials is needed so that irrespective of the trial outcomes, the results inform both clinical and translational endpoints.

Folate receptor alpha expression associates with improved disease-free survival in triple negative breast cancer patients

Triple negative breast cancer (TNBC) comprises 15-20% of all invasive breast cancer and is associated with a poor prognosis. As therapy options are limited for this subtype, there is a significant need to identify new targeted approaches for TNBC patient management. The expression of the folate receptor alpha (FRα) is significantly increased in patients with TNBC and is therefore a potential biomarker and therapeutic target. We optimized and validated a FRα immunohistochemistry method, specific to TNBC, to measure FRα expression in a centrally confirmed cohort of 384 patients with TNBC in order to determine if expression of the protein is associated with invasive disease-free survival (IDFS) and overall survival (OS). The FRα IHC demonstrated exceptional performance characteristics with low intra- and interassay variability as well as minimal lot-to-lot variation. FRα expression, which varied widely from sample to sample, was detected in 274 (71%) of the TNBC lesions. In a multivariable model adjusted for baseline characteristics, FRα expression was associated with improved IDFS (HR = 0.63, p = 0.01) but not with OS. The results demonstrate the potential of targeting the FRα in the majority of TNBC patients and suggest that variable expression may point to a need to stratify on FRα expression in clinical studies.

Bioinformatic profiling identifies a platinum-resistant-related risk signature for ovarian cancer

Most high-grade serous ovarian cancer (HGSOC) patients develop resistance to platinum-based chemotherapy and recur. Many biomarkers related to the survival and prognosis of drug-resistant patients have been delved by mining databases; however, the prediction effect of single-gene biomarker is not specific and sensitive enough. The present study aimed to develop a novel prognostic gene signature of platinum-based resistance for patients with HGSOC. The gene expression profiles were obtained from Gene Expression Omnibus and The Cancer Genome Atlas database. A total of 269 differentially expressed genes (DEGs) associated with platinum resistance were identified (P < .05, fold change >1.5). Functional analysis revealed that these DEGs were mainly involved in apoptosis process, PI3K-Akt pathway. Furthermore, we established a set of seven-gene signature that was significantly associated with overall survival (OS) in the test series. Compared with the low-risk score group, patients with a high-risk score suffered poorer OS (P < .001). The area under the curve (AUC) was found to be 0.710, which means the risk score had a certain accuracy on predicting OS in HGSOC (AUC > 0.7). Surprisingly, the risk score was identified as an independent prognostic indicator for HGSOC (P < .001). Subgroup analyses suggested that the risk score had a greater prognostic value for patients with grade 3-4, stage III-IV, venous invasion and objective response. In conclusion, we developed a seven-gene signature relating to platinum resistance, which can predict survival for HGSOC and provide novel insights into understanding of platinum resistance mechanisms and identification of HGSOC patients with poor prognosis.

Overexpression of IGF2BP3 as a Potential Oncogene in Ovarian Clear Cell Carcinoma

Ovarian Clear Cell Carcinoma (OCCC) displays distinctive clinical and molecular characteristics and confers the worst prognosis among all ovarian carcinoma histotypes when diagnosed at advanced stage, because of the lack of effective therapy. IGF2BP3 is an RNA binding protein that modulates gene expression by post-transcriptional action. In this study, we investigated the roles of IGF2BP3 in the progression of OCCC. We used 328 OCCCs from the AOVT (the Alberta Ovarian Tumor Type study) and the COEUR (the Canadian Ovarian Experimental Unified Resource) cohorts to elucidate the associations between IGF2BP3 expression and clinicopathological parameters, with positive IGF2BP3 expression defined as diffuse block staining, being more frequently observed at stage III (P = 0.0056) and significantly associated with unfavorable overall survival (HR = 1.59, 95% CI 1.09-2.33) in multivariate analysis. IGF2BP3 mRNA gene expression was markedly increased in OCCC cell lines compared to normal tissues such as ovarian surface epithelium. We chose two IGF2BP3-overexpressing cell lines ES2 and OVMANA for in vitro and in vivo knockdown experiments. The proliferation and viability of both cell lines were significantly inhibited by two IGF2BP3 siRNAs and similar suppression was observed in cell migration and invasion by Wound Healing and Transwell assays. The percentage of apoptotic cancer cells was enhanced by both IGF2BP3 siRNAs. In vivo experiments showed significantly reduced sizes of tumors when treated with IGF2BP3 siRNA compared to controls. Furthermore, cancer metastasis-indicators MMP2 and MMP9 proteins were down-regulated. In conclusion, our study shows that IGF2BP3 expression is a promising biomarker for prognostication of women diagnosed with OCCC with multiple effects on key cell functions, supporting its role as an important cellular regulator with potential oncogenic activity, and as a potential target for future intervention strategies.

A combination of the immunohistochemical markers CK7 and SATB2 is highly sensitive and specific for distinguishing primary ovarian mucinous tumors from colorectal and appendiceal metastases

Primary ovarian mucinous tumors can be difficult to distinguish from metastatic gastrointestinal neoplasms by histology alone. The expected immunoprofile of a suspected metastatic lower gastrointestinal tumor is CK7-/CK20+/CDX2+/PAX8-. This study assesses the addition of a novel marker SATB2, to improve the diagnostic algorithm. A test cohort included 155 ovarian mucinous tumors (105 carcinomas and 50 borderline tumors) and 230 primary lower gastrointestinal neoplasms (123 colorectal adenocarcinomas and 107 appendiceal neoplasms). All cases were assessed for SATB2, PAX8 CK7, CK20, and CDX2 expression on tissue microarrays. Expression was scored in a 3-tier system as absent, focal (1-50% of tumor cells) and diffuse ( >50% of tumor cells) and then categorized into either absent/present or nondiffuse/diffuse. SATB2 and PAX8 expression was further evaluated in ovarian tumors from an international cohort of 2876 patients (expansion cohort, including 159 mucinous carcinomas and 46 borderline mucinous tumors). The highest accuracy of an individual marker in distinguishing lower gastrointestinal from ovarian mucinous tumors was CK7 (91.7%, nondiffuse/diffuse cut-off) followed by SATB2 (88.8%, present/absent cut-off). The most effective combination was CK7 and SATB2 with accuracy of 95.3% using the 3-tier interpretation, absent/focal/diffuse. This combination outperformed the standard clinical set of CK7, CK20 and CDX2 (87.5%). Re-evaluation of outlier cases confirmed ovarian origin for all but one case. The accuracy of SATB2 was confirmed in the expansion cohort (91.5%). SATB2 expression was also detected in 15% of ovarian endometrioid carcinoma but less than 5% of other ovarian histotypes. A simple two marker combination of CK7 and SATB2 can distinguish lower gastrointestinal from ovarian primary mucinous tumors with greater than 95% accuracy. PAX8 and CDX2 have value as second-line markers. The utility of CK20 in this setting is low and this warrants replacement of this marker with SATB2 in clinical practice.

Serum folate receptor α (sFR) in ovarian cancer diagnosis and surveillance

Novelty and Impact Statement: Our findings suggest that soluble folate receptor (sFR) could be used in both the initial diagnosis and surveillance of patients with ovarian cancer. Our cohort constitutes one of the largest comparison groups for sFR analyzed so far. We have defined the background level of sFR using healthy volunteers. This is also the first study to prospectively follow patients in the surveillance setting to concurrently identify differential changes in tumor markers CA-125 and sFR.

Serum folate receptor α (sFR) in ovarian cancer diagnosis and surveillance

Novelty and Impact Statement: Our findings suggest that soluble folate receptor (sFR) could be used in both the initial diagnosis and surveillance of patients with ovarian cancer. Our cohort constitutes one of the largest comparison groups for sFR analyzed so far. We have defined the background level of sFR using healthy volunteers. This is also the first study to prospectively follow patients in the surveillance setting to concurrently identify differential changes in tumor markers CA-125 and sFR.

Serum folate receptor α (sFR) in ovarian cancer diagnosis and surveillance

Novelty and Impact Statement: Our findings suggest that soluble folate receptor (sFR) could be used in both the initial diagnosis and surveillance of patients with ovarian cancer. Our cohort constitutes one of the largest comparison groups for sFR analyzed so far. We have defined the background level of sFR using healthy volunteers. This is also the first study to prospectively follow patients in the surveillance setting to concurrently identify differential changes in tumor markers CA‐125 and sFR.

Association of p16 expression with prognosis varies across ovarian carcinoma histotypes: an Ovarian Tumor Tissue Analysis consortium study

We aimed to validate the prognostic association of p16 expression in ovarian high-grade serous carcinomas (HGSC) and to explore it in other ovarian carcinoma histotypes. p16 protein expression was assessed by clinical-grade immunohistochemistry in 6525 ovarian carcinomas including 4334 HGSC using tissue microarrays from 24 studies participating in the Ovarian Tumor Tissue Analysis consortium. p16 expression patterns were interpreted as abnormal (either overexpression referred to as block expression or absence) or normal (heterogeneous). CDKN2A (which encodes p16) mRNA expression was also analyzed in a subset (n = 2280) mostly representing HGSC (n = 2010). Association of p16 expression with overall survival (OS) was determined within histotypes as was CDKN2A expression for HGSC only. p16 block expression was most frequent in HGSC (56%) but neither protein nor mRNA expression was associated with OS. However, relative to heterogeneous expression, block expression was associated with shorter OS in endometriosis-associated carcinomas, clear cell [hazard ratio (HR): 2.02, 95% confidence (CI) 1.47-2.77, p < 0.001] and endometrioid (HR: 1.88, 95% CI 1.30-2.75, p = 0.004), while absence was associated with shorter OS in low-grade serous carcinomas (HR: 2.95, 95% CI 1.61-5.38, p = 0.001). Absence was most frequent in mucinous carcinoma (50%), and was not associated with OS in this histotype. The prognostic value of p16 expression is histotype-specific and pattern dependent. We provide definitive evidence against an association of p16 expression with survival in ovarian HGSC as previously suggested. Block expression of p16 in clear cell and endometrioid carcinoma should be further validated as a prognostic marker, and absence in low-grade serous carcinoma justifies CDK4 inhibition.

Association of p16 expression with prognosis varies across ovarian carcinoma histotypes: an Ovarian Tumor Tissue Analysis consortium study

We aimed to validate the prognostic association of p16 expression in ovarian high-grade serous carcinomas (HGSC) and to explore it in other ovarian carcinoma histotypes. p16 protein expression was assessed by clinical-grade immunohistochemistry in 6525 ovarian carcinomas including 4334 HGSC using tissue microarrays from 24 studies participating in the Ovarian Tumor Tissue Analysis consortium. p16 expression patterns were interpreted as abnormal (either overexpression referred to as block expression or absence) or normal (heterogeneous). CDKN2A (which encodes p16) mRNA expression was also analyzed in a subset (n = 2280) mostly representing HGSC (n = 2010). Association of p16 expression with overall survival (OS) was determined within histotypes as was CDKN2A expression for HGSC only. p16 block expression was most frequent in HGSC (56%) but neither protein nor mRNA expression was associated with OS. However, relative to heterogeneous expression, block expression was associated with shorter OS in endometriosis-associated carcinomas, clear cell [hazard ratio (HR): 2.02, 95% confidence (CI) 1.47-2.77, p < 0.001] and endometrioid (HR: 1.88, 95% CI 1.30-2.75, p = 0.004), while absence was associated with shorter OS in low-grade serous carcinomas (HR: 2.95, 95% CI 1.61-5.38, p = 0.001). Absence was most frequent in mucinous carcinoma (50%), and was not associated with OS in this histotype. The prognostic value of p16 expression is histotype-specific and pattern dependent. We provide definitive evidence against an association of p16 expression with survival in ovarian HGSC as previously suggested. Block expression of p16 in clear cell and endometrioid carcinoma should be further validated as a prognostic marker, and absence in low-grade serous carcinoma justifies CDK4 inhibition.

Association of p16 expression with prognosis varies across ovarian carcinoma histotypes: an Ovarian Tumor Tissue Analysis consortium study

We aimed to validate the prognostic association of p16 expression in ovarian high-grade serous carcinomas (HGSC) and to explore it in other ovarian carcinoma histotypes. p16 protein expression was assessed by clinical-grade immunohistochemistry in 6525 ovarian carcinomas including 4334 HGSC using tissue microarrays from 24 studies participating in the Ovarian Tumor Tissue Analysis consortium. p16 expression patterns were interpreted as abnormal (either overexpression referred to as block expression or absence) or normal (heterogeneous). CDKN2A (which encodes p16) mRNA expression was also analyzed in a subset (n = 2280) mostly representing HGSC (n = 2010). Association of p16 expression with overall survival (OS) was determined within histotypes as was CDKN2A expression for HGSC only. p16 block expression was most frequent in HGSC (56%) but neither protein nor mRNA expression was associated with OS. However, relative to heterogeneous expression, block expression was associated with shorter OS in endometriosis-associated carcinomas, clear cell [hazard ratio (HR): 2.02, 95% confidence (CI) 1.47-2.77, p < 0.001] and endometrioid (HR: 1.88, 95% CI 1.30-2.75, p = 0.004), while absence was associated with shorter OS in low-grade serous carcinomas (HR: 2.95, 95% CI 1.61-5.38, p = 0.001). Absence was most frequent in mucinous carcinoma (50%), and was not associated with OS in this histotype. The prognostic value of p16 expression is histotype-specific and pattern dependent. We provide definitive evidence against an association of p16 expression with survival in ovarian HGSC as previously suggested. Block expression of p16 in clear cell and endometrioid carcinoma should be further validated as a prognostic marker, and absence in low-grade serous carcinoma justifies CDK4 inhibition.