Targeting Tryptophan Catabolism in Ovarian Cancer to Attenuate Macrophage Infiltration and PD-L1 Expression.

High-grade serous carcinoma (HGSC) of the fallopian tube, ovary, and peritoneum is the most common type of ovarian cancer and is predicted to be immunogenic because the presence of tumor-infiltrating lymphocytes conveys a better prognosis. However, the efficacy of immunotherapies has been limited because of the immune-suppressed tumor microenvironment (TME). Tumor metabolism and immune-suppressive metabolites directly affect immune cell function through the depletion of nutrients and activation of immune-suppressive transcriptional programs. Tryptophan (TRP) catabolism is a contributor to HGSC disease progression. Two structurally distinct rate-limiting TRP catabolizing enzymes, indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase 2 (TDO2), evolved separately to catabolize TRP. IDO1/TDO2 are aberrantly expressed in carcinomas and metabolize TRP into the immune-suppressive metabolite kynurenine (KYN), which can engage the aryl hydrocarbon receptor to drive immunosuppressive transcriptional programs. To date, IDO inhibitors tested in clinical trials have had limited efficacy, but those inhibitors did not target TDO2, and we find that HGSC cell lines and clinical outcomes are more dependent on TDO2 than IDO1. To identify inflammatory HGSC cancers with poor prognosis, we stratified patient ascites samples by IL6 status, which correlates with poor prognosis. Metabolomics revealed that IL6-high patient samples had enriched KYN. TDO2 knockdown significantly inhibited HGSC growth and TRP catabolism. The orally available dual IDO1/TDO2 inhibitor, AT-0174, significantly inhibited tumor progression, reduced tumor-associated macrophages, and reduced expression of immune-suppressive proteins on immune and tumor cells. These studies demonstrate the importance of TDO2 and the therapeutic potential of AT-0174 to overcome an immune-suppressed TME. SIGNIFICANCE: Developing strategies to improve response to chemotherapy is essential to extending disease-free intervals for patients with HGSC of the fallopian tube, ovary, and peritoneum. In this article, we demonstrate that targeting TRP catabolism, particularly with dual inhibition of TDO2 and IDO1, attenuates the immune-suppressive microenvironment and, when combined with chemotherapy, extends survival compared with chemotherapy alone.

Exploring tisotumab vedotin in recurrent cervical cancer: A case series including an HPV-independent gastric type adenocarcinoma.

Metastatic and recurrent cervical cancer is difficult to treat with limited options following platinum-based chemotherapy. Tisotumab vedotin (TV) is an antibody drug conjugate (ADC) targeted at a tissue factor (TF), which is a cell surface protein that is upregulated in the majority of cervical cancers. Prior clinical trials have demonstrated efficacy of TV in metastatic and recurrent cervical cancer with an objective response rate of 24-26 % with an 8.3 month duration of response. In this case series, we present 3 patients with recurrent or progressive cervical cancer of three different histologies (squamous cell, adenocarcinoma, and human papillomavirus (HPV)-independent gastric type carcinomas). We demonstrate a 100 % complete response rate with average time of complete response of 4.33 months. The duration of response was not reached as none of our patients had a confirmed progression at the time of writing this manuscript, but the mean time since the initiation of treatment was 6.1 months. In concordance with the clinical trials, our patients tolerated TV well although the grade 3 ocular toxicities were higher in our patients compared to prior data. This case series presents data confirming the efficacy and tolerability of TV in patients with recurrent cervical cancer, including an HPV-independent gastric type cervical cancer.

The spatial structure of the tumor immune microenvironment can explain and predict patient response in high-grade serous carcinoma.

Despite ovarian cancer being the deadliest gynecological malignancy, there has been little change to therapeutic options and mortality rates over the last three decades. Recent studies indicate that the composition of the tumor immune microenvironment (TIME) influences patient outcomes but are limited by a lack of spatial understanding. We performed multiplexed ion beam imaging (MIBI) on 83 human high-grade serous carcinoma tumors - one of the largest protein-based, spatially-intact, single-cell resolution tumor datasets assembled - and used statistical and machine learning approaches to connect features of the TIME spatial organization to patient outcomes. Along with traditional clinical/immunohistochemical attributes and indicators of TIME composition, we found that several features of TIME spatial organization had significant univariate correlations and/or high relative importance in high-dimensional predictive models. The top performing predictive model for patient progression-free survival (PFS) used a combination of TIME composition and spatial features. Results demonstrate the importance of spatial structure in understanding how the TIME contributes to treatment outcomes. Furthermore, the present study provides a generalizable roadmap for spatial analyses of the TIME in ovarian cancer research.

Same day service: A genetic testing station model to improve germline genetic testing in patients with ovarian cancer.

OBJECTIVE: Genetic testing for ovarian cancer (OC) patients is essential to consideration of PARP inhibitor therapy. To improve access, we piloted a Genetic Testing Station (GTS) allowing patients to have a same-day genetic testing visit facilitated by Genetic Counselor Assistants (GCAs) under the supervision of Genetic Counselors (GCs). METHODS: The GTS was implemented December 2018 and operated through February 2020. Gynecologic Oncologists offered ovarian cancer patients a same-day GTS visit with a GCA. The patient received education via videos designed by GCs and then provided consent, a brief family history, and a sample for a standardized 133-gene panel. Results were provided by a GC. Patients were retrospectively identified by querying the medical record for OC patients seen 12 months prior to and 18 months after GTS implementation. RESULTS: A total of 482 patients pre-GTS were compared to 625 patients post-GTS. Genetic testing increased from 68.5% to 75.4% (p = 0.012) after implementation, primarily in patients with epithelial histologies (80% vs 89% in pre-GTS vs post-GTS, p = 0.005). Time from referral for genetic testing to obtaining results was evaluated in the post-GTS cohort, comparing patients who had traditional counseling to those who utilized the GTS. Time to obtaining results was 21 days in the GTS group (95% CI [10, 34]) compared to 56 days (95% CI [41,76]) in the traditional genetic counseling group. CONCLUSIONS: The GTS reduces barriers to care and facilitates discussion of precision treatment within a timely fashion while optimizing GC clinic time. Access improvement remains integral to improving uptake of genetic testing.

Palliative Total Pelvic Exenteration for Gynecologic Cancers: A Cross-sectional Study of Society of Gynecologic Oncology Members.

OBJECTIVE: The aim of this study was to evaluate contemporary practices and opinions among gynecologic oncologists regarding the use of total pelvic exenteration (TPE) for palliative intent. METHODS: This cross-sectional study of the membership of the Society of Gynecologic Oncology utilized an electronic survey to assess the opinions and practice patterns of gynecologic oncologists regarding TPEs. The primary outcome was willingness to consider a TPE for palliative intent, and demographic and practice characteristics were collected for correlation. Qualitative data were also collected. Descriptive statistics are presented, and χ tests, Fisher exact tests, and logistic regression analyses were used. RESULTS: We included 315 surveys for analysis, for a completed response rate of 23.5%. Approximately half (52.4%, n = 165) of respondents indicated willingness to consider palliative TPE. When controlled for all variables, gynecologic oncologists who were more than 10 years out of fellowship were less likely to perform a palliative exenteration (odds ratio, 0.55; 95% confidence interval, 0.30-0.98), whereas those who reported experience with minimally invasive exenteration were more likely to offer it for palliation (odds ratio, 2.20; 95% confidence interval, 1.07-4.73). Fifty-three respondents (16.8%) provided qualitative data. The themes that emerged as considerations for TPE as palliation were (1) symptoms and quality of life, (2) surgical and perioperative morbidity, (3) anticipated overall survival, (4) counseling and informed consent, (5) functional status and comorbidities, (6) likelihood of residual disease, and (7) alternative procedures available for palliation. CONCLUSION: Half of gynecologic oncologists seem to be willing to offer a palliative TPE, although more-experienced gynecologic oncologists are more likely to reserve the procedure for curative intent.

Regulation of N-Formyl Peptide Receptor Signaling and Trafficking by Arrestin-Src Kinase Interaction.

Arrestins were originally described as proteins recruited to ligand-activated, phosphorylated G protein-coupled receptors (GPCRs) to attenuate G protein-mediated signaling. It was later revealed that arrestins also mediate GPCR internalization and recruit a number of signaling proteins including, but not limited to, Src family kinases, ERK1/2, and JNK3. GPCR-arrestin binding and trafficking control the spatial and temporal activity of these multi-protein complexes. In previous reports, we concluded that N-formyl peptide receptor (FPR)-mediated apoptosis, which occurs upon receptor stimulation in the absence of arrestins, is associated with FPR accumulation in perinuclear recycling endosomes. Under these conditions, inhibition of Src kinase and ERK1/2 prevented FPR-mediated apoptosis. To better understand the role of Src kinase in this process, in the current study we employed a previously described arrestin-2 (arr2) mutant deficient in Src kinase binding (arr2-P91G/P121E). Unlike wild type arrestin, arr2-P91G/P121E did not inhibit FPR-mediated apoptosis, suggesting that Src binding to arrestin-2 prevents apoptotic signaling. However, in cells expressing this mutant, FPR-mediated apoptosis was still blocked by inhibition of Src kinase activity, suggesting that activation of Src independent of arrestin-2 binding is involved in FPR-mediated apoptosis. Finally, while Src kinase inhibition prevented FPR-mediated-apoptosis in the presence of arr2-P91G/P121E, it did not prevent FPR-arr2-P91G/P121E accumulation in the perinuclear recycling endosome. On the contrary, inhibition of Src kinase activity mediated the accumulation of activated FPR-wild type arrestin-2 in recycling endosomes without initiating FPR-mediated apoptosis. Based on these observations, we conclude that Src kinase has two independent roles following FPR activation that regulate both FPR-arrestin-2 signaling and trafficking.

CTLA-4 Blockade Synergizes Therapeutically with PARP Inhibition in BRCA1-Deficient Ovarian Cancer.

Immune checkpoint blockade has shown significant therapeutic efficacy in melanoma and other solid tumors, but results in ovarian cancer have been limited. With evidence that tumor immunogenicity modulates the response to checkpoint blockade, and data indicating that BRCA-deficient ovarian cancers express higher levels of immune response genes, we hypothesized that BRCA(-) ovarian tumors would be vulnerable to checkpoint blockade. To test this hypothesis, we used an immunocompetent BRCA1-deficient murine ovarian cancer model to compare treatment with CTLA-4 or PD-1/PD-L1 antibodies alone or combined with targeted cytotoxic therapy using a PARP inhibitor. Correlative studies were performed in vitro using human BRCA1(-) cells. We found that CTLA-4 antibody, but not PD-1/PD-L1 blockade, synergized therapeutically with the PARP inhibitor, resulting in immune-mediated tumor clearance and long-term survival in a majority of animals (P < 0.0001). The survival benefit of this combination was T-cell mediated and dependent on increases in local IFNγ production in the peritoneal tumor environment. Evidence of protective immune memory was observed more than 60 days after completion of therapy. Similar increases in the cytotoxic effect of PARP inhibition in the presence of elevated levels of IFNγ in human BRCA1(-) cancer cells support the translational potential of this treatment protocol. These results demonstrate that CTLA-4 blockade combined with PARP inhibition induces protective antitumor immunity and significant survival benefit in the BRCA1(-) tumor model, and support clinical testing of this regimen to improve outcomes for women with hereditary ovarian cancer.

G protein-coupled estrogen receptor regulates mammary tumorigenesis and metastasis.

UNLABELLED: The role of 17ß-estradiol (E2) in breast cancer development and tumor growth has traditionally been attributed exclusively to the activation of estrogen receptor-α (ERα). Although targeted inhibition of ERα is a successful approach for patients with ERα(+) breast cancer, many patients fail to respond or become resistant to anti-estrogen therapy. The discovery of the G protein-coupled estrogen receptor (GPER) suggested an additional mechanism through which E2 could exert its effects in breast cancer. Studies have demonstrated clinical correlations between GPER expression in human breast tumor specimens and increased tumor size, distant metastasis, and recurrence, as well as established a proliferative role for GPER in vitro; however, direct in vivo evidence has been lacking. To this end, a GPER-null mutation [GPER knockout (KO)] was introduced, through interbreeding, into a widely used transgenic mouse model of mammary tumorigenesis [MMTV-PyMT (PyMT)]. Early tumor development, assessed by the extent of hyperplasia and proliferation, was not different between GPER wild-type/PyMT (WT/PyMT) and those mice harboring the GPER-null mutation (KO/PyMT). However, by 12 to 13 weeks of age, tumors from KO/PyMT mice were smaller with decreased proliferation compared with those from WT/PyMT mice. Furthermore, tumors from the KO/PyMT mice were of histologically lower grade compared with tumors from their WT counterparts, suggesting less aggressive tumors in the KO/PyMT mice. Finally, KO/PyMT mice displayed dramatically fewer lung metastases compared with WT/PyMT mice. Combined, these data provide the first in vivo evidence that GPER plays a critical role in breast tumor growth and distant metastasis. IMPLICATIONS: This is the first description of a role for the novel estrogen receptor GPER in breast tumorigenesis and metastasis, demonstrating that it represents a new target in breast cancer diagnosis, prognosis, and therapy.

Adaptor protein-2 interaction with arrestin regulates GPCR recycling and apoptosis.

G protein-coupled receptors (GPCRs) are integral to cellular function in nearly all physiologic and many pathologic processes. GPCR signaling represents an intricate balance between receptor activation, inactivation (desensitization, internalization and degradation) and resensitization (recycling and de novo synthesis). Complex formation between phosphorylated GPCRs, arrestins and an ever-increasing number of effector molecules is known to regulate cellular function. Previous studies have demonstrated that, although N-formyl peptide receptor (FPR) internalization occurs in the absence of arrestins, FPR recycling is arrestin-dependent. Furthermore, FPR stimulation in the absence of arrestins leads to receptor accumulation in perinuclear endosomes and apoptosis. In this study, we show that the interaction of GPCR-bound arrestin with adaptor protein-2 (AP-2) is a critical anti-apoptotic event. In addition, AP-2 associates with the receptor-arrestin complex in perinuclear endosomes and is required for proper post-endocytic GPCR trafficking. Finally, we observed that depletion of endogenous AP-2 results in the initiation of apoptosis upon stimulation of multiple GPCRs, including P2Y purinergic receptors and CXCR2, but not CXCR4. We propose a model in which the abnormal accumulation of internalized GPCR-arrestin complexes in recycling endosomes, resulting from defective arrestin-AP-2 interactions, leads to the specific initiation of aberrant signaling pathways and apoptosis.

Regulatory role of G protein-coupled estrogen receptor for vascular function and obesity.

We found that the selective stimulation of the intracellular, transmembrane G protein-coupled estrogen receptor (GPER), also known as GPR30, acutely lowers blood pressure after infusion in normotensive rats and dilates both rodent and human arterial blood vessels. Stimulation of GPER blocks vasoconstrictor-induced changes in intracellular calcium concentrations and vascular tone, as well as serum-stimulated cell proliferation of human vascular smooth muscle cells. Deletion of the GPER gene in mice abrogates vascular effects of GPER activation and is associated with visceral obesity. These findings suggest novel roles for GPER in protecting from cardiovascular disease and obesity.