telapristone-acetate and Breast-Neoplasms

Oral breast cancer prevention medications entail systemic exposure, limiting acceptance by high-risk women. Delivery through the breast skin, although an attractive alternative, requires demonstration of drug distribution throughout the breast. We conducted a randomized double-blind, placebo-controlled phase II clinical trial comparing telapristone acetate, a progesterone receptor antagonist, administered orally (12 mg/day) or transdermally (12 mg/breast) for 4 ± 1 weeks to women planning mastectomy. Plasma and tissue concentrations, measured at five locations in the mastectomy specimen using liquid chromatography tandem mass spectrometry were compared. In 60 evaluable subjects, median drug concentration (ng/g tissue) was 103 (interquartile range (IQR): 46.3-336) in the oral vs. 2.82 (IQR: 1.4-5.5) in the transdermal group. Despite poor dermal permeation, within-breast drug distribution pattern was identical in both groups (R

Topics: Adiposity; Administration, Cutaneous; Administration, Oral; Adult; Antineoplastic Agents; Breast Neoplasms; Chemotherapy, Adjuvant; Chromatography, Liquid; Double-Blind Method; Drug Monitoring; Female; Humans; Mastectomy; Middle Aged; Neoadjuvant Therapy; Norpregnadienes; Skin Absorption; Tandem Mass Spectrometry; Time Factors; Tissue Distribution; Treatment Outcome; United States

Selective progesterone receptor modulators (SPRMs) show preclinical activity against hormone-sensitive breast cancer, but have not been tested in patients with early, treatment-naïve tumors.. In a double-blind presurgical window trial of oral telapristone acetate (TPA) 12 mg daily versus placebo, 70 patients with early-stage breast cancer were randomized 1:1 (stratified by menopause) and treated for 2 to 10 weeks. The primary endpoint was change in Ki67 between diagnostic biopsy and surgical specimens. Gene expression pre- and posttherapy was assessed using RNA-sequencing and gene set enrichment analysis was performed to determine pathways enriched in response to TPA and placebo treatments.. Among 61 evaluable women (29 placebo and 32 telapristone acetate), 91% of tumors were ER/PR positive. The mean Ki67 declined by 5.5% in all women treated with telapristone acetate (. Patients treated with telapristone acetate whose Ki67 decreased by ≥30% demonstrated a selective antiproliferative signal, with a potentially important effect on HER2 amplicon genes. Evaluation of SPRMs in a neoadjuvant trial is merited, with attention to predictors of response to SPRM therapy, and inclusion of pre- and postmenopausal women.

Topics: Antineoplastic Agents; Biomarkers, Tumor; Breast Neoplasms; Double-Blind Method; Female; Gene Expression Profiling; Hormone Antagonists; Humans; Ki-67 Antigen; Menopause; Middle Aged; Neoadjuvant Therapy; Neoplasm Staging; Norpregnadienes; Receptor, ErbB-2; Receptors, Progesterone; Sequence Analysis, RNA; Treatment Outcome

Women at high risk of breast cancer and those with carcinoma in situ need non-toxic, well-tolerated preventive interventions. One promising approach is drug delivery through the breast skin (local transdermal therapy, LTT). Our goal was to test novel drugs for LTT, to establish that LTT is applicable to non-steroidal drugs.. Athymic nude rats were treated with oral tamoxifen, transdermal 4-hydroxytamoxifen (4-OHT) or endoxifen gel applied daily to the axillary mammary gland for 6 weeks (Study 1). Study 2 was identical to Study 1, testing transdermal telapristone acetate (telapristone) gel versus subcutaneous implant. At euthanasia, mammary glands and blood were collected. In Study 3, consenting women requiring mastectomy were randomized to diclofenac patch applied to the abdomen or the breast for 3 days preoperatively. At surgery, eight tissue samples per breast were collected from predetermined locations, along with venous blood. Drug concentrations were measured using liquid chromatography-tandem mass spectroscopy.. Mammary tissue concentrations of 4-OHT, endoxifen, and telapristone were significantly higher in the axillary glands of the gel-treated animals, compared to inguinal glands or to systemically treated animals. Plasma concentrations were similar in gel and systemically treated animals. The clinical trial showed significantly higher mammary concentrations when diclofenac was applied to the breast skin versus the abdominal skin, but concentrations were variable.. These results demonstrate that lipophilic drugs can be developed for LTT; although the nude rat is suitable for testing drug permeability, delivery is systemic. In human, however, transdermal application to the breast skin provides local delivery.

Topics: Administration, Cutaneous; Administration, Oral; Adult; Animals; Antineoplastic Agents; Breast; Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Diclofenac; Drug Evaluation, Preclinical; Female; Gels; Humans; Mammary Glands, Animal; Middle Aged; Norpregnadienes; Outcome Assessment, Health Care; Pilot Projects; Preoperative Period; Random Allocation; Rats, Nude; Tamoxifen

Pharmacological approaches to breast cancer risk-reduction for BRCA1 mutation carriers would provide an alternative to mastectomy. BRCA1-deficiency dysregulates progesterone signaling, promoting tumorigenesis. Selective progesterone receptor (PR) modulators (SPRMs) are therefore candidate prevention agents. However, their efficacy varies in different BRCA1-deficient mouse models. We examined chemopreventive efficacy of telapristone acetate (TPA), ulipristal acetate (UPA) and mifepristone (MFP) in mice with a conditional knockout of the Brca1 C-terminal domain. The SPRMs displayed a spectrum of efficacy: UPA was most effective, TPA less, and MFP ineffective. Compared to no-treatment controls, UPA reduced tumorigenesis (p = 0.04), and increased tumor latency (p = 0.03). In benign mammary glands, UPA decreased Ki67 (p < 0.001) and increased PR expression (p < 0.0001). RNA sequencing analysis revealed distinct gene expression in response to UPA and MFP. UPA downregulated glycolysis and extracellular matrix-inflammation genes (Fn1, Ptgs2, Tgfb2, Tgfb3) whereas MFP downregulated claudin genes and upregulated amino acid metabolism and inflammation genes. The anti-glucocorticoid effects of MFP appeared not to be tumor-protective, while altering estrogen receptor signaling and NF-kB activation. Our study points to an important role of epithelial PR and its paracrine action on the microenvironment in BRCA1-deficient mammary tumorigenesis, and prevention.

Topics: Animals; BRCA1 Protein; Breast Neoplasms; Carcinogenesis; Disease Models, Animal; Epithelial Cells; Female; Humans; Mammary Glands, Animal; Mastectomy; Mice; Mifepristone; Norpregnadienes; Receptors, Progesterone; Stromal Cells; Tumor Microenvironment

Progesterone is a steroid hormone that plays an important role in the breast. Progesterone exerts its action through binding to progesterone receptor (PR), a transcription factor. Deregulation of the progesterone signaling pathway is implicated in the formation, development, and progression of breast cancer. Next-generation selective progesterone receptor modulators (SPRMs) have potent antiprogestin activity and are selective for PR, reducing the off-target effects on other nuclear receptors. To date, there is limited information on how the newer generation of SPRMs, specifically telapristone acetate (TPA), affect PR function at the molecular level. In this study, T47D breast cancer cells were used to investigate the molecular mechanism by which TPA antagonizes PR action. Global profiling of the PR cistrome and interactome was done with chromatin immunoprecipitation sequencing (ChIP-seq) and rapid immunoprecipitation mass spectrometry. Validation studies were done on key genes and interactions. Our results demonstrate that treatment with the progestin (R5020) alone resulted in robust PR recruitment to the chromatin, and addition of TPA reduced PR recruitment globally. TPA significantly changed coregulator recruitment to PR compared with R5020. Upon conservative analysis, three proteins (TRPS1, LASP1, and AP1G1) were identified in the R5020+TPA-treated group. Silencing TRPS1 with small interfering RNA increased PR occupancy to the known PR regulatory regions and attenuated the inhibition of gene expression after TPA treatment. TRPS1 silencing alleviated the inhibition of proliferation by TPA. In conclusion, TPA decreases PR occupancy on chromatin and recruits coregulators such as TRPS1 to the PR complex, thereby regulating PR target gene expression and associated cellular responses.

Topics: Animals; Breast Neoplasms; Cell Line, Tumor; DNA-Binding Proteins; Female; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; MCF-7 Cells; Norpregnadienes; Promegestone; Protein Binding; Receptors, Progesterone; Repressor Proteins; Transcription Factors

The synthesis of specific, potent progesterone antagonists adds potential agents to the breast cancer prevention and treatment armamentarium. The identification of individuals who will benefit from these agents will be a critical factor for their clinical success.. We utilized telapristone acetate (TPA; CDB-4124) to understand the effects of progesterone receptor (PR) blockade on proliferation, apoptosis, promoter binding, cell cycle progression, and gene expression. We then identified a set of genes that overlap with human breast luteal-phase expressed genes and signify progesterone activity in both normal breast cells and breast cancer cell lines.. TPA administration to T47D cells results in a 30 % decrease in cell number at 24 h, which is maintained over 72 h only in the presence of estradiol. Blockade of progesterone signaling by TPA for 24 h results in fewer cells in G2/M, attributable to decreased expression of genes that facilitate the G2/M transition. Gene expression data suggest that TPA affects several mechanisms that progesterone utilizes to control gene expression, including specific post-translational modifications, and nucleosomal organization and higher order chromatin structure, which regulate access of PR to its DNA binding sites.. By comparing genes induced by the progestin R5020 in T47D cells with those increased in the luteal-phase normal breast, we have identified a set of genes that predict functional progesterone signaling in tissue. These data will facilitate an understanding of the ways in which drugs such as TPA may be utilized for the prevention, and possibly the therapy, of human breast cancer.

Topics: Breast Neoplasms; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Female; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Regulatory Networks; Humans; MCF-7 Cells; Norpregnadienes; Oligonucleotide Array Sequence Analysis; Promegestone

Aromatase inhibitors (AI) are considered as a first line therapy for ER+PR+ breast cancers. However, many patients acquire resistance to AI. In this study, we determined the response of antiprogestin CDB-4124 (Proellex) on the aromatase overexpressing and Letrozole resistant cell lines and also studies its mechanism of action in inhibition of breast cancer cell proliferation. For these studies we generated aromatase overexpressing T47D (T47Darom) and respective control (T47Dcon) breast cancer cell lines by stable transfection with plasmid containing CYP19A1 gene, or empty vector respectively. Letrozole resistant cell line (T47DaromLR) was generated by incubating T47Darom for 75 weeks in the presence of 10 μM Letrozole. Cell proliferation was determined by MTT or crystal violet assays. Gene expressions were quantified by QRT-PCR whereas proteins were identified by western blot analyses, flow cytometry and immunofluorescence staining. Aromatase activity was determined by estradiol ELISA. The effects of Proellex on the anchorage independent growth were measured by soft agar colony formation. Statistical differences between the various groups were determined by Student's 't' test or ANOVA followed by Bonferroni's post hoc test. Results showed that T47Darom and T47DaromLR cell lines had significantly higher aromatase expression (mRNA; 80-90 fold and protein) and as a result exhibited increased aromatization of testosterone to estradiol as compared to T47Dcon. Both these cell lines showed enhanced growth in the presence of Testosterone (50-60%). In T47DaromLR cells increased PR-B and EGFR expression as compared to T47Dcon cells was observed. Proellex and other known aromatase inhibitors (Letrozole, Anastrozole, and Exemestane) inhibited testosterone induced cell proliferation and anchorage independent growth of T47Darom cells. Cell growth inhibition was significantly greater when cells were treated with Proellex alone or in combination with other AIs as compared to AIs alone. Proellex inhibited mRNA and protein levels of PR-B, reduced PRB/p300 complex formation in the nuclei and significantly reduced EGFR expression in T47Darom cells. Our results in the present study indicate that antiproliferative effect of Proellex is probably due to PR-B/EGFR modulation in ER+PR+, aromatase expressing cells. Overall these results suggest that antiprogestin, Proellex can be developed as a possible treatment strategy for aromatase overexpressing ER+/PR+ breast cancer patients

Topics: Antineoplastic Agents, Hormonal; Aromatase; Aromatase Inhibitors; Base Sequence; Breast Neoplasms; Cell Adhesion; Cell Line, Tumor; Cell Proliferation; Drug Resistance, Neoplasm; Female; Gene Expression; Genes, erbB-1; Humans; Letrozole; Nitriles; Norpregnadienes; Progestins; Promegestone; Receptors, Progesterone; RNA, Messenger; RNA, Neoplasm; Tamoxifen; Testosterone; Triazoles; Tumor Stem Cell Assay

It is known that progesterone receptor (PR) isoform A (PR-A) and isoform B (PR-B) may mediate different effects of progesterone. The objective of this study was to determine if the functions of PR isoforms also vary in response to different PR modulators (PRM). The effects of 7 synthetic PRM were tested in MDA-MB-231 cells engineered to express PR-A, PR-B, or both PR isoforms. The effects of progesterone were similar in cells expressing PR-A or PR-B in which it inhibited growth and induced focal adhesion. On the other hand, synthetic PRM modulated the activity of the PR isoforms differently. RU486, CDB4124, 17alpha-hydroxy CDB4124 and VA2914 exerted agonist activities on cell growth and adhesion via PR-B. Via PR-A, however, these compounds displayed agonist effect on cell growth but induced stellate morphology which was distinct from the agonist's effect. Their dual properties via PR-A were also displayed at the gene expression level: the compounds acted as agonists on cell cycle genes but exhibited antagonistic effect on cell adhesion genes. Introduction of ERalpha by adenoviral vector to these cells did not change PR-A or PR-B mediated effect of PRM radically, but it causes significant cell rounding and modified the magnitudes of the responses to PRM. The findings suggest that the activities of PR isoforms may be modulated by different PRM through gene-specific regulatory mechanisms. This raises an interesting possibility that PRM may be designed to be PR isoform and cellular pathway selective to achieve targeted therapy in breast cancer.

Topics: Adenoviridae; Blotting, Western; Breast Neoplasms; Cell Cycle; Cell Division; Collagen; Drug Combinations; Female; Fluorescent Antibody Technique; Hormone Antagonists; Humans; Laminin; Ligands; Mifepristone; Neoplasm Invasiveness; Norpregnadienes; Polymerase Chain Reaction; Progesterone; Protein Isoforms; Proteoglycans; Receptors, Progesterone; Transfection; Tumor Cells, Cultured; Wound Healing