Tumor Glucocorticoid Receptor Expression Research Articles

THU475 Ovarian Tumor-cell Glucocorticoid Receptor Activity Modulates Cytokine Secretion Promoting Recruitment And Activation of Immunosuppressive Cells Into The Tumor Microenvironment

Abstract Disclosure: M. Taya: None. E. LeBlanc: None. L. Bennett: None. S.D. Conzen: None. Elevated levels of immunosuppressive myeloid-derived suppressor cells (MDSCs) circulate in the peripheral blood or infiltrate both tumors and ascites in ovarian cancer patients, however the cause for this observed phenotype is unknown. MDSCs contribute to tumor immune tolerance primarily via inhibition of cytotoxic T-cells or by activation of immunosuppressive T-regulatory cells. We previously showed that high tumor cell glucocorticoid receptor (GR) expression is associated with a relatively poor prognosis in ovarian cancer patients. Additionally, using primary tumor data retrieved from the ovarian cancer TCGA dataset, we show high tumor GR expression is associated with significantly higher expression of Foxp3, a marker of immunosuppressive T-regulatory cells, as well as CD33, a marker of immunosuppressive myeloid cells, further suggesting an immunosuppressive phenotype in ovarian cancer patients. We thus hypothesize that tumor-intrinsic GR activation in ovarian cancer is associated with increased MDSC infiltration into the tumor microenvironment partly due to the modulation of tumor cell cytokine secretion. To determine whether tumor-cell GR activation modulates the cytokine secretome, we previously showed that GR activation in ovarian cancer cells upregulates secretion of immunomodulatory factors including G-CSF, TGFb and CXCL5. Moreover, co-treatment of cells with a selective GR modulator (SGRM) reverses this effect. Preliminary gene expression data indicate GR mediated cytokine secretion and signaling may involve post-transcriptional or post-translational mechanisms. Considering that elevated levels of these cytokines are necessary for the production and recruitment of MDSCs, these data highlight the relevance of this evident glucocorticoid receptor-cytokine circuit in ovarian cancer cells. Furthermore, we show that this tumor-cell cytokine secretome has the capacity to promote differentiation of MDSCs from precursor myeloid cells in healthy PBMCs. Importantly, measuring expression of activation markers such as Arginase-1 and NOS2 illustrated that these MDSCs are in their functional state. To our knowledge, this is the first evidence that a nuclear receptor in ovarian cancer tumor cells is actively driving MDSC differentiation. Finally, employing ovarian cancer xenograft models as well as a syngeneic ID8 tumor model, treatment with SGRMs demonstrated reduced levels of circulating MDSCs in the peripheral blood as well as tumor infiltrated MDSCs. Using neutralizing antibodies for cytokines, we will now identify key mechanisms, specifically, which targetable immunomodulatory factors are contributing to immune suppression. Based on the insight provided by these data, we propose to determine whether targeting ovarian tumor cell-intrinsic GR activation and resulting MDSC infiltration contributes to improved anti-tumor immune response. Presentation: Thursday, June 15, 2023

Abstract 654: Ovarian cancer-cell glucocorticoid receptor activity modulates cytokine secretion promoting infiltration of immunosuppressive cells into the tumor microenvironment

Abstract Elevated levels of immunosuppressive myeloid-derived suppressor cells (MDSCs) circulate in the peripheral blood or infiltrate the tumors as well as ascites in ovarian cancer patients, however the cause for this observed phenotype is unknown. MDSCs contribute to tumor immune tolerance primarily via inhibition of cytotoxic T-cells or by activation of immunosuppressive T-regulatory cells. We previously showed that high tumor cell glucocorticoid receptor (GR) expression is associated with a relatively poor prognosis in ovarian cancer patients. Additionally, using primary tumor data retrieved from the ovarian cancer TCGA dataset, we show high tumor GR expression is associated with significantly higher expression of Foxp3, a marker of immunosuppressive T-regulatory cells, as well as CD33, a marker of immunosuppressive myeloid cells, further suggesting an immunosuppressive phenotype in ovarian cancer patients. We thus hypothesize that tumor-intrinsic GR activation in ovarian cancer is associated with increased MDSC infiltration into the tumor microenvironment in part via modulating tumor cell cytokine secretion. To determine whether tumor-cell GR activation modulates the cytokine secretome, we previously showed that GR activation in ovarian cancer cells upregulated secretion of immunomodulatory factors including G-CSF, TGFb and CXCL5. Moreover, co-treatment of cells with a selective GR modulator (SGRM), reverses this secretome effect. Considering that elevated levels of these cytokines are necessary for the production and recruitment of MDSCs, these data highlight the relevance of this evident glucocorticoid receptor-cytokine circuit in ovarian cancer tumor cells. Furthermore, we show that this tumor-cell cytokine secretome has the capacity to promote differentiation of MDSCs from precursor myeloid cells in healthy PBMCs. Importantly, measuring expression of activation markers such as Arginase-1 and NOS2 illustrated that these MDSCs are in their functional state. To our knowledge this is the first evidence that a nuclear receptor in ovarian cancer tumor cells is actively driving MDSC differentiation. Finally, employing ovarian cancer xenograft models as well as a syngeneic ID8 tumor model, treatment with SGRMs demonstrated reduced levels of circulating MDSCs in the peripheral blood as well as tumor infiltrated MDSCs. Using neutralizing antibodies for cytokines, we will now identify key mechanisms, specifically, identify which targetable immunomodulatory factors are contributing to immune suppression. Based on the insight provided by these data, we propose to determine whether targeting ovarian tumor cell-intrinsic GR activation and resulting MDSC infiltration contributes to improved anti-tumor immune response. Citation Format: Manisha Taya, Eleanore LeBlanc, Lynda Bennett, Suzanne D. Conzen. Ovarian cancer-cell glucocorticoid receptor activity modulates cytokine secretion promoting infiltration of immunosuppressive cells into the tumor microenvironment [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 654.

Phase 1 efficacy and pharmacodynamic results of exicorilant + enzalutamide in patients with metastatic castration-resistant prostate cancer.

145 Background: Metastatic castration-resistant prostate cancer (mCRPC) remains an incurable disease with significant morbidity. Androgen receptor (AR) signaling is a key driver of tumor growth in mCRPC, and AR-targeted therapies are the mainstay for patients (pts) with locally advanced or metastatic disease. Enzalutamide (ENZA) is commonly used, but resistance typically develops within 1–2 years. The glucocorticoid receptor (GR) can substitute for the AR, providing a tumor escape pathway (Arora et al. Cell 2013). In the 22Rv1 CRPC xenograft model, the selective GR modulator exicorilant (EXI) combined with ENZA reduced tumor growth, supporting the hypothesis that dual antagonism of GR + AR may block this escape pathway. Safety and pharmacokinetics from the first study of EXI + ENZA in pts with mCRPC (NCT03437941) were previously presented (Linch et al. ESMO 2022). Here, we report efficacy and pharmacodynamic (PD) results from the same study. Methods: Segment 1 (Seg 1) of this phase 1 study evaluated open-label, fasting, BID dosing of EXI (140 or 180 mg) + ENZA 160 mg QD. Segment 2 (Seg 2) tested QD dosing of EXI with food in a double-blind design: All pts received EXI 240 mg + ENZA and were randomized 3:1 to EXI titration (to 280 mg followed by 320 mg) or to remain on EXI 240 mg + placebo. Efficacy assessments included radiographic response and changes in prostate-specific antigen (PSA) levels. PSA was collected prior to study entry and PSA doubling times were calculated before and during treatment. PD analyses included baseline (BL) tumor GR expression and modulation of GR target genes in whole blood. As not all pts enrolled in Seg 1 were ENZA naïve, efficacy data are reported for Seg 2 only. Data cutoff date: July 7, 2022. Results: 39 pts were enrolled (Seg 1: 14, irrespective of prior ENZA exposure; Seg 2: 25, on a stable ENZA dose with rising PSA, defined as a 25% increase over nadir and absolute value >1 ng/mL). In Seg 2, there were no radiographic responses, 18 pts had a best overall response of stable disease per PCWG3, and 1 pt achieved a PSA response (≥50% PSA reduction from BL). BL tumor GR expression was detectable in all assessed tumors. PD analyses demonstrated EXI modulation of GR target genes, such as CDKN1C. Comparable PD effects were observed across EXI doses (240–320 mg QD). While BL 24-h urinary free cortisol (UFC) for most pts was within the normal range, improvements in PSA doubling times after treatment with EXI + ENZA were predominantly observed in pts with higher BL UFC ( P<0.05). Conclusions: This study did not include an ENZA-alone arm and was thus not designed to assess the contribution of EXI to the efficacy of the EXI + ENZA combination. In heavily pretreated pts with prior ENZA exposure, 1 PSA response and no radiographic responses were observed. PD analysis confirmed systemic GR modulation. Instances of PSA doubling time improvements were observed in pts with relatively higher UFC. Clinical trial information: NCT03437941 .

524MO Glucocorticoid receptor expression and activity in a phase II ovarian cancer trial of the glucocorticoid receptor modulator relacorilant in combination with nab-paclitaxel

Cortisol activity at the glucocorticoid receptor (GR) contributes to chemotherapy resistance by suppressing apoptotic pathways that taxanes utilize, and high tumor GR expression is associated with poor chemotherapy response in ovarian cancer. A phase 2 ovarian cancer study (NCT03776812) demonstrated the clinical benefit of adding relacorilant (RELA), a selective GR modulator, to nab-paclitaxel (NP) compared to NP alone. We present biomarker analyses from this study.

Abstract ES9-3: Androgen, progesterone and glucocorticoid receptors: Drivers of breast tumor progression or reprogramming of steroid receptors during breast tumor progression

Abstract In normal physiology, glucocorticoid receptor (GR) activity regulates thousand of genes whose products modulate metabolism, inflammation, cell cycle and apoptosis/cell survival pathways. Synthetic GR agonists, or glucocorticoids (GCs), are often used to treat hematologic malignancies because of GR's ability to induce proapoptotic gene expression, inhibit nuclear factor – κB, and induce cell cycle arrest. In contrast, recent examination of GR expression and activity in human breast cancer models and clinical specimens has suggested that GR expression has remarkably diverse roles in breast cancer subtypes. In ER+ breast cancer, GR appears to modulate ER-regulated transcriptional activity through ER/GR receptor crosstalk resulting in antagonism of ER-associated proliferation. However, in ER-negative breast cancer (including TNBC), high tumor GR expression is associated with poor prognosis, anti-apoptotic signaling, and chemotherapy resistance. In addition, high GR activity in the tumor microenvironment is predicted to be immunosuppressive. Recently described selective GR modulators are expected to help dissect divergent GR mechanisms present in breast cancer subtypes. Citation Format: Conzen SD. Androgen, progesterone and glucocorticoid receptors: Drivers of breast tumor progression or reprogramming of steroid receptors during breast tumor progression [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr ES9-3.

Relationship of tumor glucocorticoid receptor expression with overall survival in ovarian cancer TCGA data

Relationship of tumor glucocorticoid receptor expression with overall survival in ovarian cancer TCGA data

A phase I trial of mifepristone (M), carboplatin (C), and gemcitabine (G) in advanced breast and ovarian cancer.

1083 Background: Glucocorticoid receptor (GR) activity inhibits chemotherapy-induced apoptosis, and GR antagonism with m enhances chemotherapy sensitivity in GR+ breast (B) and ovarian cancer (OC) cells. C+G is a commonly used regimen for B and OC. We report the results of a phase I trial of the GR antagonist m plus C+G in patients with advanced B and OC. Methods: A standard “3+3” dose escalation phase I study was performed. Objectives were to assess the safety and tolerability of the regimen, and to determine the recommended phase 2 (RP2D) dose of M+C+G. C+G was administered on days 1 and 8 of a 21 day cycle, and m was administered the day prior to and the day of chemotherapy. The starting dose level (DL) was 1, with additional DLs as follows in the table. Results: 31 patients (pts) with a median age of 54 years (range 32-76) were enrolled. 18 pts had BC (3 ER+, 15 triple-negative), and 13 had high grade serous OC (11 platinum-sensitive, 2 platinum-resistant). The median number of prior therapies for advanced BC was 1 (range 0-5) and for OC was 2 (range 1-3). Dose de-escalation was necessary due to the DLT of neutropenia. After DL -3, prophylactic G-CSF (PGF) was instituted. The RP2D was C AUC 2, G 600 mg/m2, m 300 mg with PGF administered on day 9. Of the BC pts, 2 had a complete response (CR), 2 had a partial response (PR), 8 had stable disease (SD), 4 had progressive disease (PD). Of the OC pts, there was 1 CR (CR2 lasted > 27 mos; CR1 lasted only 8 mos), 1 PR, 6 SD, and 3 PD. 4 pts were inevaluable for response. Conclusions: These data suggest that M+C+G is safe and tolerable, and the most common DLT is neutropenia. This was easily managed with the institution of PGF. Studies correlating tumor GR expression with response are ongoing, and may help identify patients who are most likely to benefit from this combination. Clinical trial information: NCT02046421. [Table: see text]

Abstract P4-16-05: Hsp90 inhibition potentiates chemotherapy effectiveness in triple negative breast cancer: Role of glucocorticoid receptor signaling

Abstract Background: Few promising molecular targets exist for chemoresistant triple negative breast cancer (TNBC). Our laboratory has previously demonstrated that a subset of TNBCs express high glucocorticoid receptor (GR) levels. In breast epithelial cells, GR transcriptional activity directly upregulates the expression of several anti-apoptotic target genes including serum/glucocorticoid regulated kinase 1 (SGK1). High GR and/or SGK1 expression are both associated with decreased chemotherapy-induced cell death in TNBC models. A meta-analysis of patients with early-stage TNBC found that high primary tumor GR (NR3C1) expression significantly associates with earlier relapse compared to GR-non expressing TNBC. Inhibiting GR/SGK1 activity is therefore a testable strategy for improving TNBC responsiveness to chemotherapy. Both GR and SGK1 require Hsp90 for their activity; therefore, Hsp90 inhibition is predicted to disrupt both GR and SGK1 cell survival signaling in TNBC. Employing a second-generation Hsp90 inhibitor, ganetespib (Synta Pharmaceuticals), we determined the effectiveness of Hsp90 inhibition on GR/SGK1 activity and chemotherapy sensitivity using in vitro and in vivo TNBC models. Hypothesis: Hsp90 inhibition will decrease GR and SGK1 activity in TNBC in association with improved chemotherapy effectiveness. Results: Using TNBC cell lines treated with ganetespib at clinically relevant concentrations, we found that total GR and the relative proportion of phosphorylated Ser211 GR were significantly reduced beginning 2 hours following treatment. Reduced glucocorticoid-induced (SGK1) mRNA expression was also seen when cells were pre-treated with ganetespib. We next used fluorescent microscopy and live cell imaging to measure TNBC cell death over a 96 hour time course following chemotherapy +/- ganetespib therapy. Addition of ganetespib to paclitaxel treatment of MDA-MB-231 cells led to significant in vitro cytotoxic synergy; as hypothesized, this synergy was diminished in GR-depleted MDA-MB-231 cells. Cytotoxic synergy following ganetespib and chemotherapy treatment was also seen in vivo in MDA-MB-231 xenografts. Interestingly, tumor GR expression following Hsp90 inhibitor and paclitaxel treatment was significantly reduced compared to tumors from mice treated with paclitaxel alone. Using GR-depleted or control MDA-MB-231 xenografts, studies are currently underway to further characterize the role of GR/SGK1 activity as a target of Hsp90 inhibition to reverse TNBC chemoresistance. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-16-05.

Abstract P2-16-21: A randomized phase I trial of nanoparticle albumin bound paclitaxel (nab-paclitaxel, Abraxane®) with or without mifepristone for advanced breast cancer

Abstract Up to 40% of breast cancers have been shown to express the glucocorticoid receptor (GR), and activation of the GR is associated with poor prognosis in ER-negative breast cancer. We hypothesize that GR activation in breast cancer cells initiates anti-apoptotic signaling contributing to chemotherapy resistance. Based on our compelling preclinical data demonstrating that GR antagonism with mifepristone (mif) increases paclitaxel (pac) induced breast cancer cell death in vitro and in vivo, we conducted the first clinical trial of the combination of anti-GR therapy and chemotherapy in patients (pts) with metastatic breast cancer (MBC). Because the combination of mif and nab-paclitaxel (nab) had not previously been administered to pts, and because nab can result in cumulative neurotoxicity, a randomized, placebo-controlled, phase I design was used. Mif is known to inhibit CYP2C8, an enzyme involved in the metabolism of pac, thus plasma pac levels were monitored to evaluate for significant changes in clearance. A 3+3 dose escalation scheme was planned, with an initial nab dose of 100mg/m2 weekly and a mif dose of 300 mg/d for 2 days (day prior to and of nab infusion). For each dose level (DL), patients were randomized 3:2 to mif:placebo (p) for cycle 1 (C1). After C1, pts randomized to p were crossed over to receive mif at their assigned DL for the duration of study treatment. DL1 was deemed intolerable due to neutropenia, so the nab dose was decreased to 80 mg/m2 for DL2, and dose escalation of mif beyond 300 mg was halted. Serum cortisol and ACTH levels—biomarkers of effective GR blockade—were measured before and after mif treatment. Archival tumor was collected to determine tumor GR expression, and peripheral blood lymphocytes (PBLs) were collected to evaluate GR-target gene expression after mif. 9 pts were enrolled. Median age was 56 yrs (range 47-74). Median number of prior therapies for MBC was 2 (range 0-3). 8 pts had triple-negative breast cancer (TNBC), and 1 had ER+ disease. 8 of 9 pts had recurred after taxane-based therapy. 1 pt had a CR, 4 pts a PR, and 4 pts POD. 4 of 5 pts who responded to nab plus mif had previously relapsed after taxane-based therapy. 4 pts were treated at DL1 (2 mif, 2 p). Both pts randomized to mif experienced a dose-limiting toxicity (DLT) of neutropenia during C1. 5 pts were treated at DL2 (3 mif, 2 p), and 2 of the 3 pts randomized to mif for C1 experienced a DLT (neutropenia). Plasma pac levels were consistent with delayed clearance of nab when co-administered with mif for most pts. All pts were found to have a 2-fold or greater rise in their serum cortisol levels, demonstrating effective adrenal GR inhibition. Mif delays clearance of nab in most pts, and results in DLT. Given the inter-patient variability in delay of nab clearance by mif, co-administration produces unpredictable toxicity. However, given the responses seen in taxane-pretreated TNBC pts, GR antagonism is a promising approach for treating aggressive TNBCs. As neither carboplatin nor gemcitabine are metabolized, mif is unlikely to affect clearance of these agents. As they are widely used for advanced TNBC, both agents represent attractive chemotherapy partners for future clinical investigation. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-21.

Activation of the Glucocorticoid Receptor Is Associated with Poor Prognosis in Estrogen Receptor-Negative Breast Cancer

Estrogen receptor-negative (ER(-)) breast cancers have limited treatment options and are associated with earlier relapses. Because glucocorticoid receptor (GR) signaling initiates antiapoptotic pathways in ER(-) breast cancer cells, we hypothesized that activation of these pathways might be associated with poor prognosis in ER(-) disease. Here we report findings from a genome-wide study of GR transcriptional targets in a premalignant ER(-) cell line model of early breast cancer (MCF10A-Myc) and in primary early-stage ER(-) human tumors. Chromatin immunoprecipitation with massively parallel sequencing (ChIP-seq) coupled to time-course expression profiling led us to identify epithelial-to-mesenchymal transition (EMT) pathways as an important aspect associated with GR activation. We validated these findings by carrying out a meta-analysis of primary breast tumor gene expression from 1,378 early-stage breast cancer patients with long-term clinical follow-up, confirming that high levels of GR expression significantly correlated with shorter relapse-free survival in ER(-) patients who were treated or untreated with adjuvant chemotherapy. Notably, in ER(+) breast cancer patients, high levels of GR expression in tumors were significantly associated with better outcome relative to low levels of GR expression. Gene expression analysis revealed that ER(-) tumors expressing high GR levels exhibited differential activation of EMT, cell adhesion, and inflammation pathways. Our findings suggest a direct transcriptional role for GR in determining the outcome of poor-prognosis ER(-) breast cancers.

Glucocorticoid receptor expression in breast cancer associates with older patient age

Breast cancer can be classified according to estrogen (ER), progesterone (PR), and HER2 receptor expression. Recent evidence suggests that activation of the glucocorticoid receptor (GR) contributes to breast cell survival, although the incidence of GR expression in primary human breast tumors is not well established. We therefore evaluated ER, PR, HER2, and GR by immunohistochemistry from 231 patients and found that while African American (AA) patient tumors were much more likely to be ER negative compared to tumors from non-AA patients, GR expression was significantly higher in tumors from patients >or=50 regardless of ancestry. Prospective examination of GR expression in tumors should be considered to determine whether GR contributes to long-term clinical outcome.