Abstract 3654: Olaparib combined with entinostat exerts differential effects on tumor-associated macrophages in tumors compared to ascites in syngeneic HR-proficient murine models of ovarian cancer

Poly ADP ribose inhibitors (PARPi) are most effective in ovarian cancer tumors with homologous recombination (HR) deficiency. Our group has shown that histone deacetylase inhibitors (HDACi) sensitize HR proficient ovarian cancer cells to PARPi. Our current efforts are directed towards understanding how this therapeutic regimen alters tumor-associated macrophages (TAMs) in murine models of high grade serous ovarian cancer. To investigate the effects of Ola combined with Ent, we used HR-proficient ID8 P53 wild-type and ID8 P53−/− syngeneic murine models. Mice were randomized into 4 groups: control, Ola, Ent and Ola+Ent. Mice (Ent and Ola+Ent) were pre-treated with 15 mg/kg entinostat or vehicle (Ola and Ola+Ent) for one week via oral gavage and then treated with vehicle/Ent/Ola (100 mg/kg)/Ola+Ent for two weeks. Mice were sacrificed 24 h after the last dose to harvest tumors and ascites. Tumors were processed for histology to determine cell proliferation (Ki67) and immune cell markers (CCL2, M1 and M2-like macrophages). Ascites fluid was processed for flow cytometric analysis of immune cells. Tumors from parental ID8 P53 wild type mice showed significantly lower cell proliferation marker Ki67 (P<0.05), higher anti-tumorigenic M1-like CCL2 (P<0.05), and lower pro-tumorigenic M2-like mannose receptor (P<0.05) in Ent and Ola+Ent groups compared to vehicle and Ola. Ascites showed no significant change in anti-tumorigenic M1-like macrophages, but significantly increased pro-tumorigenic M2-like macrophages (P<0.005). ID8 P53−/− mice tumors showed significantly lower Ki-67 (P<0.05) in Ola+Ent group compared to vehicle and mono-treatments. Ascites showed no significant change in total macrophage or pro-tumorigenic M2-like macrophages, but a significant decrease in anti-tumorigenic M1-like macrophages in Ent and Ola+Ent groups compared to vehicle. To summarize, in HR proficient ID8 P53 wildtype and ID8 P53−/− syngeneic mouse models, Ola and Ent treatment exerted anti-tumorigenic effects in tumors but potentially pro-tumorigenic effects in ascites. In conclusion, concomitant targeting of tumor TAMs and ascites TAMs may be a therapeutic regimen to investigate in the future.

Citation Format: Vijayalaxmi G. Gupta, Tyler Woodard, Simona Miceska, Bisiyao Fashemi, Sangappa Chadchan, Wendy Zhang, Katherine Roby, Andrew Wilson, Fiona Yull, Marta Crispens, Sumanta Naik, Asya Smimov, Christina Stallings, Dineo Khabele. Olaparib combined with entinostat exerts differential effects on tumor-associated macrophages in tumors compared to ascites in syngeneic HR-proficient murine models of 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 3654.

Abstract A32: Combination panobinostat and olaparib treatment promotes DNA damage and antitumor immunity in ovarian cancer

Background and Objective: High-grade serous ovarian cancers (HGSOC) retaining functional homologous recombination (HR) have poorer clinical outcomes and show relative resistance to DNA-damaging poly ADP ribose polymerase inhibitors (PARPi). We have shown that epigenetic drugs such as histone deacetylase inhibitors (HDACi) sensitize ovarian cancer cells to PARPi, in part through reduction of HR efficiency. However, these studies were conducted in immunocompromised mouse models, and drug effects on immune cell populations could not be fully examined. In this study, we will identify novel mechanisms of antitumor effects of combined HDACi/PARPi treatment by transcriptome analysis, and test drug effects in an established immune competent mouse model of ovarian cancer.

Methods: HR-proficient SKOV-3 ovarian cancer cells were treated with vehicle (CON), PARPi olaparib (OLA; 10μM), HDACi panobinostat (PANO; 50nM) or OLA/PANO for 12h, and RNA-seq analysis performed. Differentially expressed genes between treatment groups were detected by DESeq2, based on fold change >1.5 and the corrected P value (FDR) <0.05. Functional group analysis of differentially expressed genes was performed using WebGestalt, with enrichment p-values generated by the Fisher’s exact test with Benjamini/Hochberg correction. C57BL/6 mice with intraperitoneal ID8-luc tumors were treated with vehicle, PANO (2.5 mg/kg), OLA (100mg/kg) and OLA/PANO for 4 weeks, starting 30 days after tumor injection. Tumor burden was measured by bioluminescence imaging of the constitutive luc reporter, and harvested tumors assayed for IHC markers of proliferation, apoptosis and DNA damage, and for total (CD3) and cytotoxic (CD8) T cells. Differences in group means were evaluated by Student’s t-test (p<0.05 is significant).

Results: Functional group analysis of RNA-seq data showed significant enrichment of genes involved in cell proliferation, apoptosis, and DNA damage and repair with OLA/PANO treatment compared to CON or OLA alone. For a panel of 37 HR pathway genes, OLA/PANO treatment significantly reduced expression of 20 genes (e.g., BRCA1, BRCA2, WEE1). Examples of other significantly enriched functional pathways were cytokine secretion, inflammatory response genes, T cell activation (e.g., CD274/PD-L1, TNFSF9) and immune cell recruitment (e.g., IL-8, CXCL3). Consistent with these RNA-seq data, combined OLA/PANO treatment significantly reduced ID8-luc tumor burden and cell growth, and increased apoptosis and DNA damage, compared to CON or either drug alone. Moreover, there was increased infiltration of CD8+ T cells into OLA/PANO tumors, indicative of enhanced antitumor immunity.

Conclusions: We have confirmed mechanisms such as reduced HR and identified a novel role for T-cell recruitment for OLA/PANO treatment of ovarian tumors. These findings support expanding the use of PARPi in HR-proficient HGSOC through rational combinations with HDACi and have the potential to benefit a substantial number of women with this devastating disease.

Citation Format: Andrew J. Wilson, Xiaozhuan Dai, Qi Liu, Scott Hiebert, Marta Crispens, Dineo Khabele. Combination panobinostat and olaparib treatment promotes DNA damage and antitumor immunity in ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A32.

Abstract NT-088: PROGNOSTIC SIGNIFICANCE OF NR4A1/TR3 EXPRESSION IN OVARIAN CANCER

BACKGROUND: A key clinical challenge in ovarian cancer is identifying new strategies to treat patients who do not respond to poly ADP-ribose polymerase (PARP) inhibitor (PARPi) therapy. We previously linked the nuclear orphan receptor NR4A1/TR3 to pro-growth and pro-survival effects in ovarian cancer cells. However, it is unknown whether inhibiting NR4A1 function has therapeutic effects alone or in combination with PARPi in vitro. Moreover, the prognostic value of NR4A1 expression in patient tumors remains ill-defined, as two prior reports had contradictory findings for associations with ovarian cancer survival.

OBJECTIVE: We undertook this study to test the therapeutic potential of inhibiting NR4A1 in ovarian cancer cells, and to clarify the prognostic value of NR4A1 expression in patient tumors.

METHODS: In a panel of established ovarian cancer cell lines (OVCAR-3, OVCAR-4, SKOV-3), we inhibited NR4A1 using the chemical antagonist, 1,1-Bis(3'-indolyl)-1-(p-hydroxyphenyl) methane (C-DIM) and siRNA targeting NR4A1 (siNR4A1). Effects of C-DIM on cell growth, alone and in combination with the PARPi, olaparib and rucaparib, were assessed in sulforhodamine B (SRB) in vitro assays. Markers of apoptosis (cleaved PARP, cleaved caspase-3) and proliferation (Ki67, PCNA, p21) were measured by western blot or immunohistochemistry (IHC). In ovarian tumors, NR4A1 was measured by IHC in 203 clinically annotated formalin-fixed paraffin-embedded (FFPE) tissue samples from the Vanderbilt University Medical Center (VUMC) Tissue Repository for Ovarian Cancer (TROC). Staining intensity (1: weak; 2: moderate; 3: strong) and percent of positive nuclei (0-100) were multiplied to yield an H score for NR4A1 expression. Associations with progression-free survival (PFS) and overall survival (OS) were quantified by Hazards Ratios (HR) and 95% Confidence Intervals (CI) from proportional hazards regression.

RESULTS: In ovarian cancer cell lines, C-DIM induced concentration-dependent decreases in cell growth and markers of proliferation, and stimulated apoptosis. These effects were mimicked in cells transfected with siNR4A1 compared to a non-targeting siRNA-transfected control. In combination with PARPi, C-DIM induced synergistic growth inhibition and apoptosis in vitro. In tumors, NR4A1 expression lower than the median (H score <153.6) was more common among later stage, higher grade, serous tumors with suboptimal cytoreduction or platinum resistant disease. Higher NR4A1 expression was associated with better OS (HR: 0.52, 95% CI: 0.37–0.74) in unadjusted analyses. However, after adjustment for important prognostic covariates, including age, stage, grade, and histologic subtype, higher NR4A1 was associated with significantly shorter PFS (HR: 2.35, 95% CI: 1.29–4.28).

CONCLUSIONS: Our current results reconcile the discrepancy between prior NR4A1 reports, as associations differed due to confounding by clinical covariates. Shorter survival among cases with higher NR4A1 expression is supported by experimental evidence showing reduced ovarian cancer cell growth and increased apoptosis following NR4A1 inhibition, both alone and when combined with a PARPi. Together, our findings support further development of NR4A1 inhibition as a novel therapeutic approach that could improve response to PARPi therapy among ovarian cancer patients with chemoresistant disease.

Citation Format: Alicia Beeghly-Fadiel, Johnathan Cooks, Dajah Chase, Marta Crispens, Dineo Khabele, and Andrew J Wilson. PROGNOSTIC SIGNIFICANCE OF NR4A1/TR3 EXPRESSION IN OVARIAN CANCER [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr NT-088.

Abstract A42: TR3/NR4A1 as a therapeutic target for ovarian cancer

Background: A key clinical challenge in ovarian cancer is identifying new targets and strategies to treat recurrent and platinum-resistant disease. We and others have previously linked the nuclear orphan receptor NR4A1/Nur77 (TR3) to multiple malignancies; however, the role of TR3 in cancer is complex. In ovarian cancer cells, multiple chemotherapeutic agents stimulate translocation of TR3 to mitochondria to induce apoptosis, whereas nuclear TR3 is a transcription factor with progrowth and prosurvival effects. Moreover, the prognostic value of TR3 expression in ovarian tumors is not fully defined. Two prior reports had contradictory findings, with both positive and negative associations with ovarian cancer survival observed.

Objective: We undertook this study to test the therapeutic potential of inhibiting TR3 in ovarian cancer cells and to clarify the prognostic value of TR3 expression in ovarian tumors.

Methods: In a panel of established ovarian cancer cell lines, including cisplatin-resistant A2780CP20 and NCI/ADR-RES and their respective isogenic counterparts, A2780PAR and OVCAR-8, we inhibited TR3 function using established chemical antagonists, 1,1-bis(3′-indolyl)-1-(p-methoxyphenyl)methane, 3,3′-[(4-methoxyphenyl)methylene]bis-1H-indole, which is metabolized to an active p-hydroxyphenyl form in cells (C-DIM), and ethyl-2-(2,3,4-trimethoxy-6-(1-octanoyl)phenyl)acetate (TMPA), as well as two distinct siRNAs that targeted TR3. Cell growth was assessed in sulforhodamine B assays; apoptosis was measured by Western blot analysis of cleaved caspase-3 expression. A luciferase reporter plasmid with three consensus TR3 binding sites was used to measure TR3 transactivation and DNA binding activity. In ovarian tumors, TR3 was measured by immunohistochemistry (IHC) on 203 formalin-fixed, paraffin-embedded tissue samples from the Vanderbilt University Medical Center Tissue Repository for Ovarian Cancer (TROC) with linked clinical data abstracted from electronic medical records. TR3 staining intensity (1: weak; 2: moderate; 3: strong) and percent of positive nuclei (0-100) were multiplied to yield an H score. Associations with progression-free survival (PFS) and overall survival (OS) were quantified by hazards ratios (HR) and 95% confidence intervals (CI) from multivariable proportional hazards regression.

Results: In our ovarian cancer cell line panel, C-DIM and TMPA induced concentration-dependent decreases in cell growth and TR3 transactivation and stimulated apoptosis. The magnitude of growth inhibition and apoptosis induction in cisplatin-resistant cells was strikingly similar to that seen in isogenic counterparts. Cells with high basal TR3 expression (OVCAR-3 and OVCAR-4) showed greater responses to TR3 inhibitors than those with low TR3 expression (SKOV-3). These effects were mimicked in cells transfected with TR3-targeting siRNA compared to non-targeting siRNA-transfected controls. In 203 TROC cases, TR3 expression lower than the median (<153.6) was more likely among later-stage, higher-grade, type II tumors, with suboptimal cytoreduction and platinum resistant disease. Higher TR3 was associated with better OS (HR: 0.52, 95% CI: 0.37-0.74) in unadjusted analyses. However, after adjustment for prognostic covariates, higher TR3 was associated with significantly shorter PFS (HR: 2.35, 95% CI: 1.29-4.28).

Conclusions: Our current results reconcile the discrepancy between prior TR3 reports, as associations differed due to confounding by clinical covariates. Worse outcomes among cases with high TR3 expression are supported by new experimental evidence showing reduced ovarian cancer cell growth and survival following TR3 inhibition. Our findings support further development of TR3 inhibition as a novel therapeutic approach, which could benefit a large number of ovarian cancer cases with recurrent and platinum-resistant disease.

Citation Format: Alicia Beeghly-Fadiel, Dajah Chase, Johnathan Cooks, Marta Crispens, Dineo Khabele, Andrew J. Wilson. TR3/NR4A1 as a therapeutic target for ovarian cancer. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr A42.

Contrast-enhanced transvaginal sonography of benign versus malignant ovarian masses: preliminary findings

OBJECTIVE

The aim of this prospective study was to evaluate differences in contrast enhancement and contrast enhancement kinetics in benign versus malignant ovarian masses with pulse inversion harmonic transvaginal sonography.

METHODS

Seventeen consecutive patients with 23 morphologically abnormal ovarian masses (solid or cystic with papillary excrescences, focally thickened walls, or irregular solid areas) smaller than 10 cm received a microbubble contrast agent intravenously while undergoing pulse inversion harmonic transvaginal sonography. The following parameters were assessed in all tumors: detectable contrast enhancement, time to peak enhancement (wash-in), peak contrast enhancement, half wash-out time, and area under the enhancement curve. Tumor histologic analysis was used to distinguish benign from malignant ovarian tumors.

RESULTS

Fourteen benign masses and 9 malignancies were studied. There was a statistically significant difference in the peak enhancement (mean +/- SD, 23.3 +/- 2.8 versus 12.3 +/- 3.9 dB; P < .01), half wash-out time (139.9 +/- 43.6 versus 46.3 +/- 19.7 seconds; P < .01), and area under the enhancement curve (2012.9 +/- 532.9 versus 523.9 +/- 318 seconds(-1); P < .01) in malignant masses compared with benign disease. There was no statistically significant difference in the time to peak enhancement (26.1 +/- 6.3 versus 24.9 +/- 7.6 seconds; P = .07).

CONCLUSIONS

Overall, our data showed a significant difference in the contrast enhancement kinetic parameters between benign and malignant ovarian masses.

Intraperitoneal chemotherapy for ovarian cancer: overview and perspective

Intraperitoneal (IP) chemotherapy has theoretical, pharmacologic, and clinical advantages over intravenous (IV) chemotherapy in women with optimally debulked epithelial ovarian cancer confined to the abdominal cavity. Consistent, statistically significant improvements in both progression-free and overall survival have been demonstrated in three large phase III trials conducted in the United States during the past 10 years. Nevertheless, concerns over IP drug distribution and systemic absorption, technical challenges of IP catheter placement and the incidence of IP catheter-related complications, and the clinical relevance of these studies have limited the adoption of IP therapy in ovarian cancer. Current interest in the evaluation of molecularly targeted therapies should build on the progress that has been made through the use of IP chemotherapy in women with optimally debulked ovarian cancer.

Comparison of the clinical behavior of newly diagnosed stages II–IV low-grade serous carcinoma of the ovary with that of serous ovarian tumors of low malignant potential that recur as low-grade serous carcinoma

BACKGROUND

Serous ovarian tumors of low malignant potential (STLMP) frequently coexist with low-grade serous carcinoma of the ovary (LGSC) and, when they recur, frequently do so as LGSC. The purpose of this study was to compare the outcomes of patients with these two tumor types.

METHODS

All patients with stages II-IV LGSC (group 1) or with STLMP that recurred as LGSC (group 2) seen at our institution from 1973 to 2003 were identified, and demographic data were obtained. For group 1, progression-free and overall survival times were calculated from the date of primary diagnosis to the date of disease progression/recurrence or the date of last contact/death, respectively. For group 2, progression-free and overall survival times were calculated from the date of first relapse as a LGSC to the date of progression or the date of last contact/death, respectively. The method of Kaplan and Meier was used to estimate survival, and the log-rank test was used to compare differences between survival curves.

RESULTS

We identified 112 patients in group 1 and 41 in group 2. There were no statistically significant differences between the two groups in median age (42.7 vs. 45.4 years [at relapse]; P=0.37), progression-free survival time (19.5 vs. 25 months; P=0.92), or overall survival time (81.8 vs. 82.8 months; P=0.84).

CONCLUSIONS

The age at diagnosis, progression-free survival time, and overall survival time associated with newly diagnosed stages II-IV LGSC of the ovary are similar to those of STLMP that recur as LGSC, providing further evidence of an association between these two tumor types.

Retroperitoneal Fibrosis Secondary to Actinomycosis With No Intrauterine Device

BACKGROUND

Actinomycotic pelvic infection usually occurs in the presence of an intrauterine device. It can result in pelvic inflammatory disease, tubo-ovarian abscess, and retroperitoneal fibrosis.

CASE

A 35-year-old multipara who had never used an intrauterine device presented with a 5-month history of progressively worsening, colicky, right-sided abdominal pain, dysuria, weight loss, and constipation. She was found to have retroperitoneal fibrosis. The diagnosis of actinomycotic pelvic infection was made at laparotomy.

CONCLUSION

Actinomycosis may be considered in the differential diagnosis of women with retroperitoneal fibrosis, even when there is no history of an intrauterine device.

Squamous cell carcinoma of the cervix presenting as lymphangitic carcinomatosis: a case report and review of the literature

BACKGROUND

Lymphangitic carcinomatosis (LC) secondary to carcinoma of the cervix is rare. The presenting symptoms are misleading and nonspecific, which often leads to delayed diagnosis.

CASE

We present the case of a 24-year-old woman with dyspnea and lower back pain, who was found to have stage IIIb squamous cell carcinoma of the cervix complicated by pulmonary LC.

CONCLUSIONS

Pulmonary LC is a rare but important manifestation of metastatic cervical cancer. Patients present with severe respiratory compromise, which mimics other, more common disease states. Diagnosis can be achieved by transbronchial biopsy. Optimal treatment of the patient with LC is not well defined, but a trial of chemotherapy and/or intravenous steroids may be warranted. Prognosis for this condition is poor.

Complications of midtrimester pregnancy termination: the effect of prior cesarean delivery

OBJECTIVE

Our purpose was to determine whether a prior cesarean delivery affects the incidence of complications in women having an indicated midtrimester medical pregnancy termination.

STUDY DESIGN

A retrospective review of women who underwent a midtrimester medical termination of pregnancy from January 1980 to July 1995 ascertained obstetric history, uterotonic agent(s), and the occurrence of uterine rupture, blood transfusion, or curettage. The frequencies of maternal complications were compared in women with and without a prior cesarean section.

RESULTS

Our study population included 606 women with a mean gestational age of 21.1 +/- 3.1 weeks and a mean maternal age of 26.3 +/- 7 years. Seventy-nine (13%) had undergone a prior cesarean section. There was no significant difference in the need for curettage between women with and without a prior cesarean section. However, there was an increased need for blood transfusions in women with a prior cesarean delivery (11.4% vs 5.3%, odds ratio 2.3, 95% confidence interval 1.1 to 5.0, p = 0.04). The incidence of uterine rupture was significantly higher among women with a prior cesarean (3.8% vs 0.2%, odds ratio 20.8, 95% confidence interval 14.1 to 104, p = 0.008).

CONCLUSION

Our data suggest that a prior cesarean section is a risk factor for uterine rupture and blood transfusion in women having a midtrimester pregnancy termination.