Magtibay, Paul M.

Increased infiltration of CD3 + and CD8 + T cells into ovarian cancer (OC) is linked to better prognosis, but the specific antigens involved are unclear. Recent reports suggest that HLA class I can present peptides from noncoding genomic regions, known as noncanonical or cryptic peptides, but their immunogenicity is underexplored. To address this, we used immunopeptidomic analysis and RNA sequencing on five metastatic OC samples, which identified 311 cryptic peptides (40 to 83 per patient). Despite comprising less than 1% of total peptides, cryptic peptides from noncoding transcripts emerged as the predominant antigen class when compared to the other major classes of known tumor-specific and tumor-associated antigens in OC samples. Notably, nearly 70% of the prioritized cryptic peptides elicited T cell activation, as evidenced by increased 4-1BB and IFN-γ expression in autologous CD8 + T cells. This study reveals noncoding cryptic peptides as an important class of immunogenic antigens in OC.

Background: Granulomatosis with polyangiitis (GPA) is a vasculitis with multi-organ involvement. Some cases of gynecologic involvement have been described, but there are no systematic reviews in the literature. Objectives: to provide a systematic review of the literature of GPA patients with gynecological involvement. Search Strategy: PubMed and Embase, were searched from inception to July 2012 for GPA patients with gynecological involvement Medical Subject Headings (MeSH) and free-text terms. Selection Criteria: Patients with GPA and primary gynecologic involvement, and/or genital recurrence. Exclusion criteria were other language, review articles, pregnancy, fertility or male patients. Data Collection and Analysis: Data were extracted on clinical evolution, symptoms, examinations findings, diagnosis delay, treatment, outcome, patient status, and follow-up. The main limitation of the studies was the high heterogeneity, which resulted in a narrative review and could lead to publication bias. Main Results: Seventeen studies included data from patients with GPA and primary or relapsed gynecological involvement. In GPA patients, the genitourinary system is affected in <1%. 61% of the authors of this review thought the patient had cancer. The main gynecological symptom is bleeding, but exclusive gynecologic symptomatology is rare (ENT: 63%, lungs: 44%, kidneys-urinary tract: 53%). GPA could affect all areas of the genital tract, but the most frequent location is the uterine cervix. Medical treatment for GPA is effective. Conclusions: GPA of the female genital tract must be considered when biopsies of an ulcerated malignant-appearing cervical or vaginal mass are negative for malignancy even when they are unspecific. Rheumatology consultation is indicated.

Abstract Background: Increased infiltration of T cells into ovarian tumors has been repeatedly shown to be predictive of enhanced patient survival. However, despite the evidence of an active immune response in OC, immune checkpoint blockade therapy has been ineffective. Recently studies have shown that deficiencies in the DNA damage response (DDR) can drive increased genomic instability and tumor immunogenicity. One target involved in the DDR that has the potential to be of therapeutic value is protein phosphatase 4 (PP4); however, the effect of PP4 deficiency on anti-tumor immunity remain unknown. Results: Our results show that PP4 inhibition combined with carboplatin leads to increased carboplatin sensitivity, DNA damage, and micronuclei formation. Using a panel of ovarian cancer cells, we show that PP4 inhibition triggers inflammatory signaling via NF-κB and STAT1 activation resulting in increased expression of pro-inflammatory cytokines including IFNβ1, CCL5, CXCL10, and IL-6. Moreover, conditioned media from OC cells treated with the combination of PP4 inhibitor and carboplatin significantly increased migration of both CD8 T cell and NK cells over carboplatin treatment alone. Knockdown of STING in OC cells significantly abrogated the increase in CD8 T cell migration induced by PP4 inhibition. PPP4C or PPP4R3B knockdown resulted in strong induction of NK cell IFN-γ, increased degranulation, and increased NK cell-mediated cytotoxicity against OC cells. Stable knockdown of PP4C in a syngeneic, immunocompetent mouse model of ovarian cancer resulted in significant reduction of tumor growth in vivo. PP4C low tumors had increased infiltration of CD161+ NK cells and CD4+ T cells. Addition of low dose carboplatin treatment in vivo led to increased CD8+ T cell infiltration in PP4C low tumors when compared to the untreated groups. Conclusions: Our work has identified a role for PP4 inhibition in promoting anti-tumor immune activation. These findings provide the rationale for combining PP4 inhibitors with immunotherapy as a new approach in ovarian cancer treatment. Citation Format: Remya Raja, Christopher Wu, Esen Y. Bassoy, Thomas Rubino, Emma Utagawa, Paul Magtibay, Kristina Butler, Marion Curtis. Protein phosphatase 4 inhibition stimulates anti-tumor immunity in ovarian cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4455.

Abstract Background Increased infiltration of T cells into ovarian tumors has been repeatedly shown to be predictive of enhanced patient survival. However, despite the evidence of an active immune response in OC, immune checkpoint blockade therapy has been ineffective. Recently studies have shown that deficiencies in the DNA damage response (DDR) can drive increased genomic instability and tumor immunogenicity. One target involved in the DDR that has the potential to be of therapeutic value is protein phosphatase 4 (PP4); however, the effect of PP4 deficiency on anti-tumor immunity remain unknown. Results Our results show that PP4 inhibition combined with carboplatin leads to increased carboplatin sensitivity, DNA damage, and micronuclei formation. Using a panel of ovarian cancer cells, we show that PP4 inhibition triggers inflammatory signaling via NFκB and STAT1 activation resulting in increased expression of pro-inflammatory cytokines including IFNβ1, CCL5, CXCL10, and IL-6. We further show that PP4 inhibition and carboplatin-induced STAT1 activation is significantly blunted upon STING knockdown in ovarian cancer cells. Moreover, using mouse ID8 ovarian cancer cell line and OT-I cells, we demonstrate that the combination of PP4 inhibition and carboplatin significantly increased CD8 T cell migration over carboplatin treatment alone. In addition, the same treatment resulted in enhanced NK cell-mediated tumor cell killing and T cell killing in an autologous human organoid model. Conclusions Our work has identified a role for PP4 inhibition in promoting anti-tumor immune activation. These findings provide the rationale for combining PP4 inhibitors with immunotherapy as a new approach in ovarian cancer treatment. Supported by DOD W81XWH2110489

Background Increased infiltration of T cells into ovarian tumors has been repeatedly shown to be predictive of enhanced patient survival. However, despite the evidence of an active immune response in ovarian cancer (OC), the frequency of responses to immune checkpoint blockade (ICB) therapy in OC is much lower than other cancer types. Recent studies have highlighted that deficiencies in the DNA damage response (DDR) can drive increased genomic instability and tumor immunogenicity, which leads to enhanced responses to ICB. Protein phosphatase 4 (PP4) is a critical regulator of the DDR; however, its potential role in antitumor immunity is currently unknown. Results Our results show that the PP4 inhibitor, fostriecin, combined with carboplatin leads to increased carboplatin sensitivity, DNA damage, and micronuclei formation. Using multiple OC cell lines, we show that PP4 inhibition or PPP4C knockdown combined with carboplatin triggers inflammatory signaling via Nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 1 (STAT1) activation. This resulted in increased expression of the pro-inflammatory cytokines and chemokines: CCL5 , CXCL10 , and IL-6 . In addition, IFNB1 expression was increased suggesting activation of the type I interferon response. Conditioned media from OC cells treated with the combination of PP4 inhibitor and carboplatin significantly increased migration of both CD8 T cell and natural killer (NK) cells over carboplatin treatment alone. Knockdown of stimulator of interferon genes (STING) in OC cells significantly abrogated the increase in CD8 T-cell migration induced by PP4 inhibition. Co-culture of NK-92 cells and OC cells with PPP4C or PPP4R3B knockdown resulted in strong induction of NK cell interferon-γ, increased degranulation, and increased NK cell-mediated cytotoxicity against OC cells. Stable knockdown of PP4C in a syngeneic, immunocompetent mouse model of OC resulted in significantly reduced tumor growth in vivo . Tumors with PP4C knockdown had increased infiltration of NK cells, NK T cells, and CD4 + T cells. Addition of low dose carboplatin treatment led to increased CD8 + T-cell infiltration in PP4C knockdown tumors as compared with the untreated PP4C knockdown tumors. Conclusions Our work has identified a role for PP4 inhibition in promoting inflammatory signaling and enhanced immune cell effector function. These findings support the further investigation of PP4 inhibitors to enhance chemo-immunotherapy for OC treatment.

Neoadjuvant chemotherapy allows a minimally invasive approach for interval debulking in patients with ovarian cancer considered unresectable to no residual disease by laparotomy at diagnosis. The aim of the study was to evaluate the type of surgical approach at interval debulking (ID) after three courses of carboplatin and taxol in patients with unresectable ovarian cancer at diagnosis compared with the type of surgical approach at primary debulking (PD). A secondary objective was to compare the perioperative outcomes of MIS vs. laparotomy at ID. A retrospective review of the type of surgical approach at ID following three courses of carboplatin and taxol was compared with the surgical approach at PD, and a review of the perioperative outcomes of MIS vs. open at ID was performed during the period from 21 January 2012, through 21 February 2013, for stage IIIC > 2 cm or IV epithelial ovarian cancer (EOC) unresectable at diagnosis and the surgical approach at PD. During the study period, 127 patients with stage IIIC or IV EOC met the inclusion criteria. Minimally invasive surgery (MIS), laparoscopic or robotic, was used in 21.6% of patients at ID and in 23.3% of patients at PD. At ID, MIS patients had a shorter hospital stay as compared to laparotomy (2 vs. 8 days; p < 0.001). At 5 year follow-up, 31.5% of EOC patients were alive (ID MIS: 47.5% vs. ID open: 30%; PD MIS: 41% vs. PD open: 28%), while 24.4% had no evidence of disease (ID MIS: 39% vs. ID open: 19.5%; PD MIS: 32% vs. PD open: 22%). Among living patients, 22% had evidence of disease. Neoadjuvant chemotherapy is a form of chemo-debulking and allows a minimally invasive approach at interval debulking in about one-fifth of the patients, with initial disease deemed unresectable to no residual tumor at initial diagnosis.

(1) Background: Granulomatosis with polyangiitis (GPA) is a necrotizing vasculitis that mimics gynecologic cancer. In GPA patients, the genitourinary system is affected in <1%. The objective of the study was to provide a systematic review of the literature of GPA patients with gynecological involvement. (2) Methods: PubMed and Embase were searched from inception to July 2021 for GPA patients with gynecological involvement Medical Subject Headings (MeSH) and free-text terms. Exclusion criteria were other language, review articles, pregnancy, fertility, or male patients. Data were extracted on clinical evolution, symptoms, examinations findings, diagnosis delay, treatment, outcome, patient status, and follow-up. (3) Results: Seventeen studies included data from patients with GPA and primary or relapsed gynecological involvement. 68% of the authors of this review thought the patient had cancer. The main gynecological symptom is bleeding, but exclusive gynecologic symptomatology is rare (ENT: 63%, lungs: 44%, kidneys-urinary tract: 53%). GPA could affect all areas of the genital tract, but the most frequent location is the uterine cervix. Medical treatment for GPA is effective. (4) Conclusions: GPA of the female genital tract must be considered when biopsies of an ulcerated malignant-appearing cervical or vaginal mass are negative for malignancy even when they are unspecific. Rheumatology consultation is indicated.