Inflammation markers on benign breast biopsy are associated with risk of invasive breast cancer in African American women.

PURPOSE: Markers of inflammation, including crown-like structures of the breast (CLS-B) and infiltrating lymphocytes (IL), have been identified in breast tissue and associated with increased risk of breast cancer (BrCa), however most of this work has been performed in primarily non-Hispanic white women. Here, we examined whether CLS-B and IL are associated with invasive BrCa in African American (AA) women. METHODS: We assessed breast biopsies from three 5-year age-matched groups: BrCa-free AA women (50 Volunteer) from the Komen Normal Tissue Bank (KTB) and AA women with a clinically-indicated biopsy diagnosed with benign breast disease (BBD) from our Detroit cohort who developed BrCa (55 BBD-cancer) or did not develop BrCa (47 BBD only, year of biopsy matched to BBD-cancer). Mean adipocyte diameter and total adipose area were estimated from digital images using the Adiposoft plugin from ImageJ. Associations between CLS-B, IL, and BrCa among KTB and Detroit biopsies were assessed using multivariable multinomial and conditional logistic regression models. RESULTS: Among all biopsies, Volunteer and BBD only biopsies did not harbor CLS-B or IL at significantly different rates after adjusting for logarithm of adipocyte area, adipocyte diameter, and BMI. Among clinically-indicated BBD biopsies, BBD-cancer biopsies were more likely to exhibit CLS-B (odds ratio (OR) = 3.36, 95% Confidence Interval (CI): 1.33-8.48) or IL (OR = 4.95, 95% CI 1.76-13.9) than BBD only biopsies after adjusting for total adipocyte area, adipocyte diameter, proliferative disease, and BMI. CONCLUSIONS: CLS-B and IL may serve as histological markers of BrCa risk in benign breast biopsies from AA women.

Transcriptional activation of breast cancer-associated gene 2 by estrogen receptor.

RNF115, or Breast Cancer-Associated Gene 2 (BCA2), encodes a RING-finger ubiquitin E3 ligase, expression of which was associated with estrogen receptor (ER)-positive status in human breast tumors. Although the BCA2 promoter contains several estrogen response element (ERE) half-sites, the role of ER in the regulation of BCA2 transcription has not been reported. The aim of this study is to investigate the molecular mechanism by which estrogen regulates BCA2 transcription. BCA2 mRNA and protein levels were examined by RT-PCR and Western blot analysis, respectively, and localization was assessed by immunofluorescence. BCA2 promoter activity in response to E(2) was tested by a dual luciferase reporter assay and ER binding to the BCA2 promoter was examined by chromatin immunoprecipitation assay. We found that BCA2 mRNA and protein levels are regulated by estrogen in ER-positive MCF7 breast cancer cells and MDA MB 231 cells stably transfected with ER. Estrogen treatment in hormonal depleted MCF7 and MDA MB 231/ER stably transfected cells resulted in increased nuclear ER and cytoplasmic and nuclear BCA2 staining. Cycloheximide is not able to inhibit BCA2 mRNA levels, suggesting potential BCA2 regulation at the transcriptional level. Anti-estrogens like tamoxifen and ICI 182 178 counteracted E(2)-induced BCA2 protein and knockdown of ER by ER siRNA resulted in a significant decrease in BCA2 protein and a lower nuclear expression pattern. Estrogen treatment lead to a significant increase in BCA2 promoter response, associated with increased binding of ER to the ERE region of the BCA2 promoter. BCA2 is therefore a newly identified transcriptional target of estrogen receptor.

Biomarkers and Bone Imaging Dynamics Associated with Clinical Outcomes of Oral Cabozantinib Therapy in Metastatic Castrate-Resistant Prostate Cancer.

PURPOSE: Cabozantinib is a multitargeted tyrosine kinase inhibitor that demonstrated remarkable responses on bone scan in metastatic prostate cancer. Randomized trials failed to demonstrate statistically significant overall survival (OS). We studied the dynamics of biomarker changes with imaging and biopsies pretherapy and posttherapy to explore factors that are likely to be predictive of efficacy with cabozantinib.Experimental Design: Eligibility included patients with metastatic castrate-resistant prostate cancer with normal organ function and performance status 0-2. Cabozantinib 60 mg orally was administered daily. Pretherapy and 2 weeks post, 99mTc-labeled bone scans, positron emission tomography with 18F-sodium fluoride (NaF-PET) and 18F-(1-(2'-deoxy-2'-fluoro-ß-D-arabinofuranosyl) thymine (FMAU PET) scans were conducted. Pretherapy and posttherapy tumor biopsies were conducted, and serum and urine bone markers were measured. RESULTS: Twenty evaluable patients were treated. Eight patients had a PSA decline, of which 2 had a decline of ≥50%. Median progression-free survival (PFS) and OS were 4.1 and 11.2 months, respectively, and 3 patients were on therapy for 8, 10, and 13 months. The NaF-PET demonstrated a median decline in SUVmax of -56% (range, -85 to -5%, n = 11) and -41% (range, -60 to -25%, n = 9) for patients who were clinically stable and remained on therapy for ≥4 or <4 cycles, respectively. The FMAU PET demonstrated a median decline in SUVmax of -44% (-60 to -14%) and -42% (-63% to -23%) for these groups. The changes in bone markers and mesenchymal epithelial transition/MET testing did not correlate with clinical benefit. CONCLUSIONS: Early changes in imaging and tissue or serum/urine biomarkers did not demonstrate utility in predicting clinical benefit with cabozantinib therapy.

Phase I Trial of the Combination of Docetaxel, Prednisone, and Pasireotide in Metastatic Castrate-Resistant Prostate Cancer.

BACKGROUND: Pasireotide (SOM230; Novartis Inc, Basel, Switzerland) is a multitargeted somatostatin receptor analogue likely to treat the neuroendocrine, and docetaxel resistant components within metastatic castrate-resistant prostate cancer (mCRPC). This phase I trial tested the combination of pasireotide, docetaxel, and prednisone in pretreated mCRPC. PATIENTS AND METHODS: Chemotherapy naive mCRPC patients received docetaxel 75 mg/m2 intravenously every 21 days and pasireotide intramuscularly every 28 days at escalating dose levels of 40, 60, and 80 mg. Maximum tolerated dose and recommended phase II dose (RP2D) were assessed. RESULTS: Eighteen patients were enrolled with a median age of 65 (range, 49-75) years, and pretherapy prostate-specific antigen of 259.9 ng/mL. The dose-limiting toxicities were Grade 4 hyperglycemia unresponsive to therapy and Grade 4 neutropenia lasting for > 7 days in 1 patient each occurring at the 80-mg dose level of pasireotide. The RP2D was determined at 60 mg every 28 days. Four patients at the 60 mg dose had Grade 3 or 4 hyperglycemia, which responded adequately to therapy. Median time to progression and survival were 7.2 and 18.3 months, respectively. Three of 6 patients with circulating tumor cells ≥5 converted to circulating tumor cells < 5 post therapy. The insulin like growth factor-1 levels revealed a median 51% decrease after therapy. The neuron-specific enolase and chromogranin did not show any marked change. CONCLUSION: The addition of pasireotide to docetaxel and prednisone is clinically feasible at a dose level of 60 mg every 28 days. The combination showed potential for clinical efficacy but needs to be compared with the standard docetaxel and prednisone regimen.

Phase 0 Trial of AZD1775 in First-Recurrence Glioblastoma Patients.

Purpose: AZD1775 is a first-in-class Wee1 inhibitor with dual function as a DNA damage sensitizer and cytotoxic agent. A phase I study of AZD1775 for solid tumors suggested activity against brain tumors, but a preclinical study indicated minimal blood-brain barrier penetration in mice. To resolve this controversy, we examined the pharmacokinetics and pharmacodynamics of AZD1775 in patients with first-recurrence, glioblastoma.Patients and Methods: Twenty adult patients received a single dose of AZD1775 prior to tumor resection and enrolled in either a dose-escalation arm or a time-escalation arm. Sparse pharmacokinetic blood samples were collected, and contrast-enhancing tumor samples were collected intraoperatively. AZD1775 total and unbound concentrations were determined by a validated LC/MS-MS method. Population pharmacokinetic analysis was performed to characterize AZD1775 plasma pharmacokinetic profiles. Pharmacodynamic endpoints were compared to matched archival tissue.Results: The AZD1775 plasma concentration-time profile following a single oral dose in patients with glioblastoma was well-described by a one-compartment model. Glomerular filtration rate was identified as a significant covariate on AZD1775 apparent clearance. AZD1775 showed good brain tumor penetration, with a median unbound tumor-to-plasma concentration ratio of 3.2, and achieved potential pharmacologically active tumor concentrations. Wee1 pathway suppression was inferred by abrogation of G2 arrest, intensified double-strand DNA breakage, and programmed cell death. No drug-related adverse events were associated with this study.Conclusions: In contrast to recent preclinical data, our phase 0 study of AZD 1775 in recurrent glioblastoma indicates good human brain tumor penetration, provides the first evidence of clinical biological activity in human glioblastoma, and confirms the utility of phase 0 trials as part of an accelerated paradigm for drug development in patients with glioma. Clin Cancer Res; 24(16); 3820-8. ©2018 AACRSee related commentary by Vogelbaum, p. 3790.

Phase II Trial of Carboplatin, Everolimus, and Prednisone in Metastatic Castration-resistant Prostate Cancer Pretreated With Docetaxel Chemotherapy: A Prostate Cancer Clinical Trial Consortium Study.

OBJECTIVE: To conduct a phase II trial of the combination of carboplatin, prednisone, and everolimus in metastatic castrate-resistant prostate cancer (mCRPC) as mTOR inhibition can overcome resistance to chemotherapy in prostate cancer. METHODS: Patients with progressive mCRPC pretreated with docetaxel-based regimen were eligible. Performance status of 0-1 and adequate bone marrow, renal, and liver function were required. Primary end point was time to progression. Treatment consisted of carboplatin (starting dose equal to area under the curve (AUC of 5) intravenously every 21 days along with oral everolimus 5 mg once daily and prednisone 5 mg twice daily. RESULTS: Twenty-six patients were enrolled with median age of 69 years with 8 patients of African American origin. Grade 3 or 4 thrombocytopenia or neutropenia in 4 of 6 initial patients required dose adjustment of carboplatin to AUC of 4 for subsequent patients. There were no pharmacokinetic interactions between carboplatin and everolimus. The median time to progression was 2.5 months (90% confidence interval [CI], 1.8-4.3 months), and median overall survival was 12.5 months (90% CI, 7.7-18.7 months). Of 10 patients, 8 that demonstrated positive nuclear phosphorylated AKT (pAKT) staining on immunohistochemistry progressed within 9 weeks, whereas 2 patients with negative staining continued without progression for prolonged durations of 30 and 48 weeks. TSC1 gene mutations did not correlate with clinical outcome. CONCLUSION: The addition of the mTOR inhibitor everolimus to carboplatin demonstrated minimal clinical efficacy in metastatic prostate cancer. pAKT testing warrants further evaluation as a predictive marker of response to everolimus therapy.

Protein expression of DNA damage repair proteins dictates response to topoisomerase and PARP inhibitors in triple-negative breast cancer.

Patients with metastatic triple-negative breast cancer (TNBC) have a poor prognosis. New approaches for the treatment of TNBC are needed to improve patient survival. The concept of synthetic lethality, brought about by inactivating complementary DNA repair pathways, has been proposed as a promising therapeutic option for these tumors. The TNBC tumor type has been associated with BRCA mutations, and inhibitors of Poly (ADP-ribose) polymerase (PARP), a family of proteins that facilitates DNA repair, have been shown to effectively kill BRCA defective tumors by preventing cells from repairing DNA damage, leading to a loss of cell viability and clonogenic survival. Here we present preclinical efficacy results of combining the PARP inhibitor, ABT-888, with CPT-11, a topoisomerase I inhibitor. CPT-11 binds to topoisomerase I at the replication fork, creating a bulky adduct that is recognized as damaged DNA. When DNA damage was stimulated with CPT-11, protein expression of the nucleotide excision repair enzyme ERCC1 inversely correlated with cell viability, but not clonogenic survival. However, 4 out of the 6 TNBC cells were synergistically responsive by cell viability and 5 out of the 6 TNBC cells were synergistically responsive by clonogenic survival to the combination of ABT-888 and CPT-11. In vivo, the BRCA mutant cell line MX-1 treated with CPT-11 alone demonstrated significant decreased tumor growth; this decrease was enhanced further with the addition of ABT-888. Decrease in tumor growth correlated with an increase in double strand DNA breaks as measured by γ-H2AX phosphorylation. In summary, inhibiting two arms of the DNA repair pathway simultaneously in TNBC cell lines, independent of BRCA mutation status, resulted in un-repairable DNA damage and subsequent cell death.

Reactivation of estrogen receptor α by vorinostat sensitizes mesenchymal-like triple-negative breast cancer to aminoflavone, a ligand of the aryl hydrocarbon receptor.

OBJECTIVE: Aminoflavone (AF) acts as a ligand of the aryl hydrocarbon receptor (AhR). Expression of estrogen receptor α (ERα) and AhR-mediated transcriptional induction of CYP1A1 can sensitize breast cancer cells to AF. The objective of this study was to investigate the combined antitumor effect of AF and the histone deacetylase inhibitor vorinostat for treating mesenchymal-like triple-negative breast cancer (TNBC) as well as the underlying mechanisms of such treatment. METHODS: In vitro antiproliferative activity of AFP464 (AF prodrug) in breast cancer cell lines was evaluated by MTS assay. In vitro, the combined effect of AFP464 and vorinostat on cell proliferation was assessed by the Chou-Talalay method. In vivo, antitumor activity of AFP464, given alone and in combination with vorinostat, was studied using TNBC xenograft models. Knockdown of ERα was performed using specific, small-interfering RNA. Western blot, quantitative RT-PCR, immunofluorescence, and immunohistochemical staining were performed to study the mechanisms underlying the combined antitumor effect. RESULTS: Luminal and basal A subtype breast cancer cell lines were sensitive to AFP464, whereas basal B subtype or mesenchymal-like TNBC cells were resistant. Vorinostat sensitized mesenchymal-like TNBC MDA-MB-231 and Hs578T cells to AFP464. It also potentiated the antitumor activity of AFP464 in a xenograft model using MDA-MB-231 cells. In vitro and in vivo mechanistic studies suggested that vorinostat reactivated ERα expression and restored AhR-mediated transcriptional induction of CYP1A1. CONCLUSION: The response of breast cancer cells to AF or AFP464 was associated with their gene expression profile. Vorinostat sensitized mesenchymal-like TNBC to AF, at least in part, by reactivating ERα expression and restoring the responsiveness of AhR to AF.