Selective targeting of the androgen receptor-DNA binding domain by the novel antiandrogen SBF-1 and inhibition of the growth of prostate cancer cells

Identification of a targetable JAK-STAT enriched androgen receptor and androgen receptor splice variant positive triple-negative breast cancer subtype

Triple-negative breast cancer (TNBC) is an aggressive subtype with no targeted therapeutics. The luminal androgen receptor (LAR) subtype constitutes 15% of TNBC and is enriched for androgen receptor (AR) and AR target genes. Here, we show that a cohort of TNBC not only expresses AR at a much higher rate (∼80%) but also expresses AR splice variants (AR-SVs) (∼20%), further subclassifying LAR-TNBC. Higher AR and AR-SV expression and corresponding aggressive phenotypes are observed predominantly in specimens obtained from African American women. LAR TNBC specimens are enriched for interferon, Janus kinase (JAK)-signal activator and transducer (STAT), and androgen signaling pathways, which are exclusive to AR-expressing epithelial cancer cells. AR- and AR-SV-expressing TNBC cell proliferation and xenograft and patient-tumor explant growth are inhibited by AR N-terminal domain-binding selective AR degrader or by a JAK inhibitor. Biochemical analysis suggests that STAT1 is an AR coactivator. Collectively, our work identifies pharmacologically targetable TNBC subtypes and identifies growth-promoting interaction between AR and JAK-STAT signaling.

The Potential of Hormonal Therapies for Treatment of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is considered one of the most aggressive forms of breast cancer with poor survival rates compared to other breast cancer subtypes. TNBC is characterized by the absence of the estrogen receptor alpha, progesterone receptor, and the human epidermal growth factor receptor 2, limiting those viable treatment options available to patients with other breast cancer subtypes. Furthermore, due to the particularly high heterogeneity of TNBC, conventional treatments such as chemotherapy are not universally effective, leading to drug resistance and intolerable side effects. Thus, there is a pressing need to discover new therapies beneficial to TNBC patients. This review highlights current findings regarding the roles of three steroid hormone receptors, estrogen receptor beta, the androgen receptor, and the glucocorticoid receptor, in the progression of TNBC. In addition, we discussed several ongoing and completed clinical trials targeting these hormone receptors in TNBC patients.

Integrative profiling of extrachromosomal circular DNA in placenta and maternal plasma provides insights into the biology of fetal growth restriction and reveals potential biomarkers

Introduction: Fetal growth restriction (FGR) is a placenta-mediated pregnancy complication that predisposes fetuses to perinatal complications. Maternal plasma cell-free DNA harbors DNA originating from placental trophoblasts, which is promising for the prenatal diagnosis and prediction of pregnancy complications. Extrachromosomal circular DNA (eccDNA) is emerging as an ideal biomarker and target for several diseases. Methods: We utilized eccDNA sequencing and bioinformatic pipeline to investigate the characteristics and associations of eccDNA in placenta and maternal plasma, the role of placental eccDNA in the pathogenesis of FGR, and potential plasma eccDNA biomarkers of FGR. Results: Using our bioinformatics pipelines, we identified multi-chromosomal-fragment and single-fragment eccDNA in placenta, but almost exclusively single-fragment eccDNA in maternal plasma. Relative to that in plasma, eccDNA in placenta was larger and substantially more abundant in exons, untranslated regions, promoters, repetitive elements [short interspersed nuclear elements (SINEs)/Alu, SINEs/mammalian-wide interspersed repeats, long terminal repeats/endogenous retrovirus-like elements, and single recognition particle RNA], and transcription factor binding motifs. Placental multi-chromosomal-fragment eccDNA was enriched in confident enhancer regions predicted to pertain to genes in apoptosis, energy, cell growth, and autophagy pathways. Placental eccDNA-associated genes whose abundance differed between the FGR and control groups were associated with immunity-related gene ontology (GO) terms. The combined analysis of plasma and placental eccDNA-associated genes in the FGR and control groups led to the identification of potential biomarkers that were assigned to the GO terms of the epigenetic regulation of gene expression and nutrient-related processes, respectively. Conclusion: Together, our results highlight links between placenta functions and multi-chromosomal-fragment and single-fragment eccDNA. The integrative analysis of placental and plasma eccDNA confirmed the potential of these molecules as disease-specific biomarkers of FGR.

Viscosalactone B, a natural LSD1 inhibitor, inhibits proliferation in vitro and in vivo against prostate cancer cells

Lysine-specific demethylase 1 (LSD1) has been a promising target to treat prostate cancer, and discovery of novel LSD1 inhibitors would have great clinical significance. In this work, viscosalactone B was first identified as a novel LSD1 inhibitor. Viscosalactone B isolated from Withania Somnifera displayed antiproliferative activity against PC3, DU145, C42B, PC3/MDVR, DU145/MDVR, and C42B/MDVR cells with IC₅₀ values of 1.17, 0.72, 3.86, 2.06, 0.96 and 1.15 μM, respectively. In comparison, it was a selective LSD1 inhibitor with an IC₅₀ value of 970.27 nM and could induce a significant accumulation of LSD1 substrates H3K9me1, H3K9me2, and H3K4me1 in a concentration-dependent manner in DU145 cells. According to docking studies, it formed hydrogen bonds with the Thr11, Lys14, and Arg8 residues of LSD1. Importantly, while it displayed potent antitumor efficacy in vivo, it did not show obvious cytotoxicity on the major organs of nude mice. Therefore, viscosalactone B, as a novel LSD1 inhibitor, is a potential candidate that can be used for the treatment of prostate cancer in clinics.

Second generation androgen receptor antagonists and challenges in prostate cancer treatment

Prostate cancer is a hormone-dependent malignancy, whose onset and progression are closely related to the activity of the androgen receptor (AR) signaling pathway. Due to this critical role of AR signaling in driving prostate cancer, therapy targeting the AR pathway has been the mainstay strategy for metastatic prostate cancer treatment. The utility of these agents has expanded with the emergence of second-generation AR antagonists, which began with the approval of enzalutamide in 2012 by the United States Food and Drug Administration (FDA). Together with apalutamide and darolutamide, which were approved in 2018 and 2019, respectively, these agents have improved the survival of patients with prostate cancer, with applications for both androgen-dependent and castration-resistant disease. While patients receiving these drugs receive a benefit in the form of prolonged survival, they are not cured and ultimately progress to lethal neuroendocrine prostate cancer (NEPC). Here we summarize the current state of AR antagonist development and highlight the emerging challenges of their clinical application and the potential resistance mechanisms, which might be addressed by combination therapies or the development of novel AR-targeted therapies.

Allosteric binding on nuclear receptors: Insights on screening of non-competitive endocrine-disrupting chemicals

Endocrine-disrupting chemicals (EDCs) can compete with endogenous hormones and bind to the orthosteric site of nuclear receptors (NRs), affecting normal endocrine system function and causing severe symptoms. Recently, a series of pharmaceuticals and personal care products (PPCPs) have been discovered to bind to the allosteric sites of NRs and induce similar effects. However, it remains unclear how diverse EDCs work in this new way. Therefore, we have systematically summarized the allosteric sites and underlying mechanisms based on existing studies, mainly regarding drugs belonging to the PPCP class. Advanced methods, classified as structural biology, biochemistry and computational simulation, together with their advantages and hurdles for allosteric site recognition and mechanism insight have also been described. Furthermore, we have highlighted two available strategies for virtual screening of numerous EDCs, relying on the structural features of allosteric sites and lead compounds, respectively. We aim to provide reliable theoretical and technical support for a broader view of various allosteric interactions between EDCs and NRs, and to drive high-throughput and accurate screening of potential EDCs with non-competitive effects.