Adrenal Steroids and Resistance to Hormonal Blockade of Prostate and Breast Cancer

Unveiling hormone-stimulated gene mechanisms in prostate cancer: A prognostic model, immune infiltration analysis, and drug sensitivity study

Hormones promote the progression of prostate cancer (PRCA) through the activation of a complex regulatory network. Inhibition of hormones or modulation of specific network nodes alone is insufficient to suppress the entire oncogenic network. Therefore, it is imperative to elucidate the mechanisms underlying the occurrence and development of PRCA in order to identify reliable diagnostic markers and therapeutic targets. To this end, we used publicly available data to analyze the potential mechanisms of hormone-stimulated genes in PRCA, construct a prognostic model, and assess immune infiltration and drug sensitivity. The single-cell RNA-sequencing data of PRCA were subjected to dimensionality reduction clustering and annotation, and the cells were categorized into two groups based on hormone stimulus-related scores. The differentially expressed genes between the two groups were screened and incorporated into the least absolute shrinkage and selection operator machine learning algorithm, and a prognostic model comprising six genes (ZNF862, YIF1A, USP22, TAF7, SRSF3, and SPARC) was constructed. The robustness of the model was validation through multiple methods. Immune infiltration scores in the two risk groups were calculated using three different algorithms. In addition, the relationship between the model genes and immune cell infiltration, and that between risk score and immune cell infiltration were analyzed. Drug sensitivity analysis was performed for the model genes and risk score using public databases to identify potential candidate drugs. Our findings provide novel insights into the mechanisms of hormone-stimulated genes in PRCA progression, prognosis, and drug screening.

Chronic hypoxia stabilizes 3βHSD1 via autophagy suppression

Progression of prostate cancer depends on androgen receptor, which is usually activated by androgens. Therefore, a mainstay treatment is androgen deprivation therapy. Unfortunately, despite initial treatment response, resistance nearly always develops, and disease progresses to castration-resistant prostate cancer (CRPC), which remains driven by non-gonadal androgens synthesized in prostate cancer tissues. 3β-Hydroxysteroid dehydrogenase/Δ5-->4 isomerase 1 (3βHSD1) catalyzes the rate-limiting step in androgen synthesis. However, how 3βHSD1, especially the "adrenal-permissive" 3βHSD1(367T) that permits tumor synthesis of androgen from dehydroepiandrosterone (DHEA), is regulated at the protein level is not well understood. Here, we investigate how hypoxia regulates 3βHSD1(367T) protein levels. Our results show that, in vitro, hypoxia stabilizes 3βHSD1 protein by suppressing autophagy. Autophagy inhibition promotes 3βHSD1-dependent tumor progression. Hypoxia represses transcription of autophagy-related (ATG) genes by decreasing histone acetylation. Inhibiting deacetylase (HDAC) restores ATG gene transcription under hypoxia. Therefore, HDAC inhibition may be a therapeutic target for hypoxic tumor cells.

Recent insights into the role of hormones during development and their functional regulation

Introduction

Hormones play a vital role in development from conception to birth and throughout the human lifespan. These periods are logically divided into fetal development, pre-pubertal growth, puberty, and adulthood. Deviations from standard physiological levels and release patterns of constituent hormones can lead to pathology affecting the normal developmental trajectory. Research is ongoing to better understand the mechanisms of these hormones and how their modulation affects development.

Methods

This article focuses on recent developments in understanding the role hormones play in development. We also cover recent discoveries in signaling pathways and hormonal regulation.

Results

New and continuing research into functional hormone regulation focuses on sex hormones, gonadotropic hormones, growth hormones, insulin-like growth factor, thyroid hormone, and the interconnectedness of each of these functional axes. Currently, the abundance of work focuses on fertility and correction of sex hormone levels based on an individual's condition and stage in life.

Discussion

Continuing research is needed to fully understand the long-term effects of hormone modulation in growth and sexual development. The role of each hormone in parallel endocrine axes should also be more thoroughly investigated to help improve the safety and efficacy in endocrine pharmacotherapeutics.

Approaches to assessing 3β-hydroxysteroid dehydrogenase-1

The enzyme 3β-hydroxysteroid dehydrogenase-1 (3βHSD1), encoded by the gene HSD3B1, plays an essential role in the peripheral conversion of 3β-OH, Δ5-steroids to 3-keto, Δ4-steroids. In human physiology, the adrenal produces dehydroepiandrosterone (DHEA) and DHEA-sulfate, which are major precursors for the biosynthesis of potent androgens and estrogens. DHEA is converted by 3βHSD1 and subsequently is converted by steroid-5α-reductase to potent androgens or by aromatase to estrogens. Assessment of 3βHSD1 is therefore critical under various conditions. In this chapter, we detail several approaches to assessing 3βHSD1. First, we describe a genotyping protocol for the identification of a common missense-encoding variation that regulates 3βHSD1 cellular metabolic activity. This protocol distinguishes between the HSD3B1(1245A) and the HSD3B1(1245C) allele which have lower and higher metabolic activity, respectively. Second, we detail mass spectrometry approaches to determining 3βHSD1 activity using stable isotope dilution. Third, we describe methods for using tritiated DHEA and high performance liquid chromatography coupled with a beta-RAM to also determine 3βHSD1 activity. Together, we provide multiple methods of directly assessing 3βHSD1 activity or anticipated 3βHSD1 activity.