Sex Hormones and Prostate Cancer

Single-cell sequencing revealed metabolic reprogramming and its transcription factor regulatory network in prostate cancer

BACKGROUND/AIMS

Prostate cancer is the most frequently diagnosed cancer among men in the United States and is the second leading cause of cancer-related deaths in men. The incidence of prostate cancer is gradually rising due to factors such as aging demographics and changes in dietary habits. The objective of this study is to investigate the metabolic reprogramming changes occurring in prostate cancer and identify potential therapeutic targets.

METHODS

In this study, we utilized single-cell sequencing to comprehensively characterize the alterations in metabolism and the regulatory role of transcription factors in various subtypes of prostate cancer.

RESULTS

In comparison to benign prostate tissue, prostate cancer displayed substantial metabolic variations, notably exhibiting heightened activity in fatty acid metabolism and cholesterol metabolism. This metabolic reprogramming not only influenced cellular energy utilization but also potentially impacted the activity of the androgen receptor (AR) pathway through the synthesis of endogenous steroid hormones. Through our analysis of transcription factor activity, we identified the crucial role of SREBPs, which are transcription factors associated with lipid metabolism, in prostate cancer. Encouragingly, the inhibitor Betulin effectively suppresses prostate cancer growth, highlighting its potential as a therapeutic agent for prostate cancer treatment.

Assessment of Anti-Prostate Cancer Activity among Four Seaweeds, with Focus on Caulerpa lentillifera J.Agardh

In response to a global shift towards health-conscious and environmentally sustainable food choices, seaweed has emerged as a focus for researchers due to its large-scale cultivation potential and the development of bioactive substances. This research explores the potential anticancer properties of seaweed extracts, focusing on analyzing the impact of four common edible seaweeds in Taiwan on prostate cancer (PCa) cells' activity. The study used bioassay-guided fractionation to extract Cl80 from various seaweeds with androgen receptor (AR)-inhibitory activity. Cl80 demonstrated effective suppression of 5α-dihydrotestosterone (DHT)-induced AR activity in 103E cells and attenuated the growth and prostate-specific antigen (PSA) protein expression in LNCaP and 22Rv1 cells. Additionally, Cl80 exhibited differential effects on various PCa cell lines. Concentrations above 5 μg/mL significantly inhibited LNCaP cell proliferation, while 22Rv1 cells were more resistant to Cl80. PC-3 cell proliferation was inhibited at 5 μg/mL but not completely at 50 μg/mL. A clonogenic assay showed that at a concentration of 0.5 μg/mL, the colony formation in LNCaP and PC-3 cells was significantly reduced, with a dose-dependent effect. Cl80 induced apoptosis in all PCa cell types, especially in LNCaP cells, with increased apoptotic cells observed at higher concentrations. Cl80 also decreased the mitochondrial membrane potential (ΔΨm) in a dose-dependent manner in all PCa cell lines. Furthermore, Cl80 suppressed the migration ability of PCa cells, with significant reductions observed in LNCaP, 22Rv1, and PC-3 cells at various concentrations. These compelling findings highlight the promising therapeutic potential of C. lentillifera J.Agardh and its isolated compound Cl80 in the treatment of PCa.

Deletion in a regulatory region is associated with underexpression of miR-148b‑3p in patients with prostate cancer

Prostate cancer (PCa) is the leading cause of cancer-related death in men. This pathology is complex and heterogeneous; therefore, elucidating the molecular mechanisms that lead to its origin and progression is imperative. MicroRNAs (miRNAs or miRs) are part of the epigenetic machinery that regulates the expression of human genes, therefore, mutations in the genes that encode them can lead to a dysregulation in their expression, which directly impacts their target genes, which could be oncogenes or tumor suppressor genes. In PCa several dysregulated expression levels of miRNAs are associated with perturbed cellular processes. A differential expression of miRNAs such as miR-145-5p and miR-148-3p has been observed in PCa, possibly due to mutations in regions near the miRNAs. However, the molecular mechanisms that lead to the dysregulation of these miRNAs still need to be clarified. Therefore, the present study aimed to analyze the expression of miRNAs and their relationship with mutations in patients with and without PCa. In total, 71 patients were analyzed: 41 of whom had PCa (CAP group) and 30 with benign pathology (BPD group). Underexpression was observed in miR-145-5p and miR-148b-3p in PCa patients (P=0.03 and P=0.001, respectively). In miR-145-5p, no mutations related to its expression were identified. For miR-148b-3p, a set of mutations were identified in the chr12:54337042/54337043 region, which were grouped into the mutation named DelsAAG. Although this mutation's abnormal allele is related to PCa (P=0.017), a statistically significant difference was observed in the expression of miR-148b-3p between carriers and non-carriers of the mutated allele, identifying a mechanism likely to be involved in the miR-148b-3p dysregulation.

Exploring the impact of PEGylation on pharmacokinetics: a size-dependent effect of polyethylene glycol on prostate-specific membrane antigen inhibitors

BACKGROUND

Prostate cancer is the second most frequent cancer and the fifth leading cause of cancer-related deaths in men. Prostate-specific membrane antigen (PSMA) as a target has gained increasing attention. This research aims to investigate and understand how altering size of PEG impacts the in vitro and in vivo behavior and performance of PSMA inhibitors, with a specific focus on their pharmacokinetic characteristics and targeting properties.

RESULTS

Two 68Ga-labeled PSMA-targeted radiotracers were developed, namely [68Ga]Ga-PP4-WD and [68Ga]Ga-PP8-WD, with varying sizes of polyethylene glycol (PEG). [68Ga]Ga-PP4-WD and [68Ga]Ga-PP8-WD had excellent affinity for PSMA with IC50 being 8.06 ± 0.91, 6.13 ± 0.79 nM, respectively. Both tracers enabled clear visualization of LNCaP tumors in PET images with excellent tumor-to-background contrast. They also revealed highly efficient uptake and internalization into LNCaP cells, increasing over time. The biodistribution studies demonstrated that both radioligands exhibited significant and specific uptake into LNCaP tumors. Furthermore, they were rapidly cleared through the renal pathway, as evidenced by [68Ga]Ga-PP4-WD and [68Ga]Ga-PP8-WD showing a tenfold and a fivefold less in renal uptake, respectively, compared to [68Ga]Ga-Flu-1 in 30 min. Both in vitro and in vivo experiments demonstrated that PEG size significantly impacted tumor-targeting and pharmacokinetic properties.

CONCLUSIONS

These radiotracers have demonstrated their effectiveness in significantly reducing kidney uptake while maintaining the absorbed dose in tumors. Both radiotracers exhibited strong binding and internalization characteristics in vitro, displayed high specificity and affinity for PSMA in vivo.

Sex-specific outcomes in cancer therapy: the central role of hormones

Sex hormones play a pivotal role in modulating various physiological processes, with emerging evidence underscoring their influence on cancer progression and treatment outcomes. This review delves into the intricate relationship between sex hormones and cancer, elucidating the underlying biological mechanisms and their clinical implications. We explore the multifaceted roles of estrogen, androgens, and progesterone, highlighting their respective influence on specific cancers such as breast, ovarian, endometrial, and prostate. Special attention is given to estrogen receptor-positive (ER+) and estrogen receptor-negative (ER-) tumors, androgen receptor signaling, and the dual role of progesterone in both promoting and inhibiting cancer progression. Clinical observations reveal varied treatment responses contingent upon hormonal levels, with certain therapies like tamoxifen, aromatase inhibitors, and anti-androgens demonstrating notable success. However, disparities in treatment outcomes between males and females in hormone-sensitive cancers necessitate further exploration. Therapeutically, the utilization of hormone replacement therapy (HRT) during cancer treatments presents both potential risks and benefits. The promise of personalized therapies, tailored to an individual's hormonal profile, offers a novel approach to optimizing therapeutic outcomes. Concurrently, the burgeoning exploration of new drugs and interventions targeting hormonal pathways heralds a future of more effective and precise treatments for hormone-sensitive cancers. This review underscores the pressing need for a deeper understanding of sex hormones in cancer therapy and the ensuing implications for future therapeutic innovations.

Thermosensitive hydrogel with emodin-loaded triple-targeted nanoparticles for a rectal drug delivery system in the treatment of chronic non-bacterial prostatitis

BACKGROUND

The complex etiology and pathogenesis underlying Chronic Non-Bacterial Prostatitis (CNP), coupled with the existence of a Blood Prostate Barrier (BPB), contribute to a lack of specificity and poor penetration of most drugs. Emodin (EMO), a potential natural compound for CNP treatment, exhibits commendable anti-inflammatory, anti-oxidant, and anti-fibrosis properties but suffers from the same problems as other drugs.

METHODS

By exploiting the recognition properties of lactoferrin (LF) receptors that target intestinal epithelial cells (NCM-460) and prostate epithelial cells (RWPE-1), a pathway is established for the transrectal absorption of EMO to effectively reach the prostate. Additionally, hyaluronic acid (HA) is employed, recognizing CD44 receptors which target macrophages within the inflamed prostate. This interaction facilitates the intraprostatic delivery of EMO, leading to its pronounced anti-inflammatory effects. A thermosensitive hydrogel (CS-Gel) prepared from chitosan (CS) and β-glycerophosphate disodium salt (β-GP) was used for rectal drug delivery with strong adhesion to achieve effective drug retention and sustained slow release. Thus, we developed a triple-targeted nanoparticle (NPs)/thermosensitive hydrogel (Gel) rectal drug delivery system. In this process, LF, with its positive charge, was utilized to load EMO through dialysis, producing LF@EMO-NPs. Subsequently, HA was employed to encapsulate EMO-loaded LF nanoparticles via electrostatic adsorption, yielding HA/LF@EMO-NPs. Finally, HA/LF@EMO-NPs lyophilized powder was added to CS-Gel (HA/LF@EMO-NPs Gel).

RESULTS

Cellular assays indicated that NCM-460 and RWPE-1 cells showed high uptake of both LF@EMO-NPs and HA/LF@EMO-NPs, while Raw 264.7 cells exhibited substantial uptake of HA/LF@EMO-NPs. For LPS-induced Raw 264.7 cells, HA/LF@EMO-NPs can reduce the inflammatory responses by modulating TLR4/NF-κB signaling pathways. Tissue imaging corroborated the capacity of HA/LF-modified formulations to breach the BPB, accumulating within the gland's lumen. Animal experiments showed that rectal administration of HA/LF@EMO-NPs Gel significantly reduced inflammatory cytokine expression, oxidative stress levels and fibrosis in the CNP rats, in addition to exerting anti-inflammatory effects by inhibiting the NF-κB signaling pathway without obvious toxicity.

CONCLUSION

This triple-targeted NPs/Gel rectal delivery system with slow-release anti-inflammatory, anti-oxidant, and anti-fibrosis properties shows great potential for the effective treatment of CNP.

A common germline variant in CYP11B1 is associated with adverse clinical outcome of treatment with abiraterone or enzalutamide

Extragonadal androgens play a pivotal role in prostate cancer disease progression on androgen receptor signaling inhibitors (ARSi), including abiraterone and enzalutamide. We aimed to investigate if germline variants in genes involved in extragonadal androgen synthesis contribute to resistance to ARSi and may predict clinical outcomes on ARSi. We included ARSi naive metastatic prostate cancer patients treated with abiraterone or enzalutamide and determined 18 germline variants in six genes involved in extragonadal androgen synthesis. Variants were tested in univariate and multivariable analysis for the relation with overall survival (OS) and time to progression (TTP) by Cox regression, and PSA response by logistic regression. A total of 275 patients were included. From the investigated genes CYP17A1, HSD3B1, CYP11B1, AKR1C3, SRD5A1 and SRD5A2, only rs4736349 in CYP11B1 in homozygous form (TT), present in 54 patients (20%), was related with a significantly worse OS (HR = 1.71, 95% CI 1.09 - 2.68, p = 0.019) and TTP (HR = 1.50, 95% CI 1.08 - 2.09, p = 0.016), and was related with a significantly less frequent PSA response (OR = 0.48, 95% CI 0.24 - 0.96, p = 0.038) on abiraterone or enzalutamide in a multivariable analysis. The frequent germline variant rs4736349 in CYP11B1 is, as homozygote, an independent negative prognostic factor for treatment with abiraterone or enzalutamide in ARSi naive metastatic prostate cancer patients. Our findings warrant prospective investigation of this potentially important predictive biomarker.

Pinostilbene inhibits full-length and splice variant of androgen receptor in prostate cancer

Prostate cancer is the most prevalent cancer in men worldwide and is promoted by the sex hormone androgen. Expression of androgen from the testis can be significantly reduced through castration. However, as most prostate cancer patients acquire castration resistance, additional therapeutic solutions are necessary. Although anti-androgens, such as enzalutamide, have been used to treat castration-resistant prostate cancer (CRPC), enzalutamide-resistant CRPC (Enz-resistant CRPC) has emerged. Therefore, development of novel treatments for Enz-resistant CRPC is urgent. In this study, we found a novel anti-androgen called pinostilbene through screening with a GAL4-transactivation assay. We confirmed that pinostilbene directly binds to androgen receptor (AR) and inhibits its activation and translocalization. Pinostilbene treatment also reduced the protein level and downstream gene expression of AR. Furthermore, pinostilbene reduced the protein level of AR variant 7 in the Enz-resistant prostate cancer cell line 22Rv1 and inhibited cell viability and proliferation. Our results suggest that pinostilbene has the potential to treat Enz-resistant CRPC.

Elevated periprostatic venous testosterone correlates with prostate cancer progression after radical prostatectomy

BACKGROUNDGenerally, clinical assessment of gonadal testosterone (T) in human physiology is determined using concentrations measured in peripheral blood. Prostatic T exposure is similarly thought to be determined from peripheral T exposure. Despite the fact that androgens drive prostate cancer, peripheral T has had no role in the clinical evaluation or treatment of men with localized prostate cancer.METHODSTo assess the role of local androgen delivery in prostate cancer, we obtained blood from the (periprostatic) prostatic dorsal venous complex in 266 men undergoing radical prostatectomy from July 2014 to August 2021 and compared dorsal T (DT) levels with those in circulating peripheral blood (PT) and prostatic tissue. Comprehensive targeted steroid analysis and unbiased metabolomics analyses were performed. The association between the DT/PT ratio and progression-free survival after prostatectomy was assessed.RESULTSSurprisingly, in some men, DT levels were enriched several-fold compared with PT levels. For example, 20% of men had local T concentrations that were at least 2-fold higher than peripheral T concentrations. Isocaproic acid, a byproduct of androgen biosynthesis, and 17-OH-progesterone, a marker of intratesticular T, were also enriched in the dorsal vein of these men, consistent with testicular shunting. Men with enriched DT had higher rates of prostate cancer recurrence. DT/PT concentration ratios predicted worse outcomes even when accounting for known clinical predictors.CONCLUSIONSThese data suggest that a large proportion of men have a previously unappreciated exposure to an undiluted and highly concentrated T supply. Elevated periprostatic T exposure was associated with worse clinical outcomes after radical prostatectomy.FUNDINGNational Cancer Institute (NCI), NIH grants R01CA172382, R01CA236780, R01CA261995, R01CA249279, and R50CA251961; US Army Medical Research and Development Command grants W81XWH2010137 and W81XWH-22-1-0082.

The roles of proteases in prostate cancer

Since the proposition of the pro-invasive activity of proteolytic enzymes over 70 years ago, several roles for proteases in cancer progression have been established. About half of the 473 active human proteases are expressed in the prostate and many of the most well-characterized members of this enzyme family are regulated by androgens, hormones essential for development of prostate cancer. Most notably, several kallikrein-related peptidases, including KLK3 (prostate-specific antigen, PSA), the most well-known prostate cancer marker, and type II transmembrane serine proteases, such as TMPRSS2 and matriptase, have been extensively studied and found to promote prostate cancer progression. Recent findings also suggest a critical role for proteases in the development of advanced and aggressive castration-resistant prostate cancer (CRPC). Perhaps the most intriguing evidence for this role comes from studies showing that the protease-activated transmembrane proteins, Notch and CDCP1, are associated with the development of CRPC. Here, we review the roles of proteases in prostate cancer, with a special focus on their regulation by androgens.

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.

Cancer-associated fibroblast-secreted glucosamine alters the androgen biosynthesis program in prostate cancer via HSD3B1 upregulation

After androgen deprivation, prostate cancer frequently becomes castration resistant (CRPC), with intratumoral androgen production from extragonadal precursors that activate the androgen receptor pathway. 3β-Hydroxysteroid dehydrogenase-1 (3βHSD1) is the rate-limiting enzyme for extragonadal androgen synthesis, which together lead to CRPC. Here, we show that cancer-associated fibroblasts (CAFs) increased epithelial 3βHSD1 expression, induced androgen synthesis, activated the androgen receptor, and induced CRPC. Unbiased metabolomics revealed that CAF-secreted glucosamine specifically induced 3βHSD1. CAFs induced higher GlcNAcylation in cancer cells and elevated expression of the transcription factor Elk1, which induced higher 3βHSD1 expression and activity. Elk1 genetic ablation in cancer epithelial cells suppressed CAF-induced androgen biosynthesis in vivo. In patient samples, multiplex fluorescent imaging showed that tumor cells expressed more 3βHSD1 and Elk1 in CAF-enriched areas compared with CAF-deficient areas. Our findings suggest that CAF-secreted glucosamine increases GlcNAcylation in prostate cancer cells, promoting Elk1-induced HSD3B1 transcription, which upregulates de novo intratumoral androgen synthesis to overcome castration.

Sex steroid hormones and DNA repair regulation: Implications on cancer treatment responses

The role of sex steroid hormones (SSHs) has been shown to modulate cancer cytotoxic treatment sensitivity. Dysregulation of DNA repair associated with genomic instability, abnormal cell survival and not only promotes cancer progression but also resistance to cancer treatment. The three major SSHs, androgen, estrogen, and progesterone, have been shown to interact with several essential DNA repair components. The presence of androgens directly regulates key molecules in DNA double-strand break (DSB) repair. Estrogen can promote cell proliferation and DNA repair, allowing cancer cells to tolerate chemotherapy and radiotherapy. Information on the role of progesterone in DNA repair is limited: progesterone interaction with some DNA repair components has been identified, but the biological significance is still unknown. Here, we review the roles of how each SSH affects DNA repair regulation and modulates response to genotoxic therapies and discuss future research that can be beneficial when combining SSHs with cancer therapy. We also provide preliminary analysis from publicly available databases defining the link between progesterone/PR and DDRs & DNA repair regulation that plausibly contribute to chemotherapy response and breast cancer patient survival.

Constructing 3D In Vitro Models of Heterocellular Solid Tumors and Stromal Tissues Using Extrusion-Based Bioprinting

Malignant tumor tissues exhibit inter- and intratumoral heterogeneities, aberrant development, dynamic stromal composition, diverse tissue phenotypes, and cell populations growing within localized mechanical stresses in hypoxic conditions. Experimental tumor models employing engineered systems that isolate and study these complex variables using in vitro techniques are under development as complementary methods to preclinical in vivo models. Here, advances in extrusion bioprinting as an enabling technology to recreate the three-dimensional tumor milieu and its complex heterogeneous characteristics are reviewed. Extrusion bioprinting allows for the deposition of multiple materials, or selected cell types and concentrations, into models based upon physiological features of the tumor. This affords the creation of complex samples with representative extracellular or stromal compositions that replicate the biology of patient tissue. Biomaterial engineering of printable materials that replicate specific features of the tumor microenvironment offer experimental reproducibility, throughput, and physiological relevance compared to animal models. In this review, we describe the potential of extrusion-based bioprinting to recreate the tumor microenvironment within in vitro models.

Halogen Replacement on the Lysine Side Chain of Lys-Urea-Glu-Based PSMA Inhibitors Leads to Significant Changes in Targeting Properties

PURPOSE

Investigate the impact of various halogens on pharmacokinetics, biodistribution, and micro positron emission tomography/computed tomography (PET/CT) imaging of Glu-urea-Lys-based prostate-specific membrane antigen (PSMA) inhibitors.

PROCEDURES

Based on the modification of SC691, a small molecule inhibitor of PSMA previously developed by our group, we synthesized ⁶⁸Ga-labeled compounds by modifying the lysine terminal amino with different halogenated phenyl substituents. After complete characterization, in vitro and in vivo properties were studied.

RESULTS

The [⁶⁸Ga]Ga-DOTA-SC691-R possesses a high radiochemical yield (98-99%). The internalization values of [⁶⁸Ga]Ga-DOTA-SC691-H, [⁶⁸Ga]Ga-DOTA-SC691-Cl, and [⁶⁸Ga]Ga-DOTA-SC691-Br in LNCaP cells all displayed time-dependent pattern enhanced with time. The results of in vitro competitive inhibition assay showed that the affinity of ^natGa-DOTA-SC691-R for PSMA had a trend of H < F < Cl < Br < I. The blocking imaging and dynamic imaging on micro-PET/CT of male non-obese diabetic/severe combined immunodeficiency mice with LNCaP tumors showed the rapid tumor targeting properties of [⁶⁸Ga]Ga-DOTA-SC691-R with specificity for PSMA. Static imaging of micro-PEC/CT of these compounds could rapidly localize LNCaP tumors with decent image quality (except for [⁶⁸Ga]Ga-DOTA-SC691-H). Biodistribution data showed that [⁶⁸Ga]Ga-DOTA-SC691-R were metabolized via the kidney and tumor accumulation followed the order of H ≈ F ≈ Cl < I < Br uptake values at 1 h. [⁶⁸Ga]Ga-DOTA-SC691-Br showed the highest tumor accumulation and retention (15.21 ± 5.57%ID/g at 30 min, 20.39 ± 4.38%ID/g at 60 min, and 13.30 ± 4.39%ID/g at 120 min), which is consistent with the results of the competitive inhibition assay and cell binding assay.

CONCLUSIONS

It was demonstrated that the halogen substituent on the lysine terminal amino group on the Glu-urea-Lys backbone did positively affect the binding of [⁶⁸Ga]Ga-DOTA-SC691-R to PSMA. The bulkier and less electronegative Br (or I) elements are preferred for structural modifications here.

BMX controls 3βHSD1 and sex steroid biosynthesis in cancer

Prostate cancer is highly dependent on androgens and the androgen receptor (AR). Hormonal therapies inhibit gonadal testosterone production, block extragonadal androgen biosynthesis, or directly antagonize AR. Resistance to medical castration occurs as castration-resistant prostate cancer (CRPC) and is driven by reactivation of the androgen-AR axis. 3β-hydroxysteroid dehydrogenase-1 (3βHSD1) serves as the rate-limiting step for potent androgen synthesis from extragonadal precursors, thereby stimulating CRPC. Genetic evidence in men demonstrates the role of 3βHSD1 in driving CRPC. In postmenopausal women, 3βHSD1 is required for synthesis of aromatase substrates and plays an essential role in breast cancer. Therefore, 3βHSD1 lies at a critical junction for the synthesis of androgens and estrogens, and this metabolic flux is regulated through germline-inherited mechanisms. We show that phosphorylation of tyrosine 344 (Y344) occurs and is required for 3βHSD1 cellular activity and generation of Δ4, 3-keto-substrates of 5α-reductase and aromatase, including in patient tissues. BMX directly interacts with 3βHSD1 and is necessary for enzyme phosphorylation and androgen biosynthesis. In vivo blockade of 3βHSD1 Y344 phosphorylation inhibits CRPC. These findings identify what we believe to be new hormonal therapy pharmacologic vulnerabilities for sex-steroid dependent cancers.

Molecular and metabolic alterations of 2,3-dihydroquinazolin-4(1H)-one derivatives in prostate cancer cell lines

Prostate cancer (PC) is the second most common tumor in males worldwide. The lack of effective medication and the development of multidrug resistance towards current chemotherapeutic agents urge the need to discover novel compounds and therapeutic targets for PC. Herein, seven synthesized 2,3-dihydroquinazolin-4(1H)-one analogues were evaluated for their anticancer activity against PC3 and DU145 cancer cell lines using MTT, scratch-wound healing, adhesion and invasion assays. Besides, a liquid chromatography mass spectrometry (LC-MS)-based metabolomics approach was followed to identify the biochemical pathways altered in DU145 cancer cells upon exposure to dihydroquinazolin derivatives. The seven compounds showed sufficient cytotoxicity and significantly suppressed DU145 and PC3 migration after 48 and 72 h. C2 and C5 had the most potent effect with IC₅₀ < 15 µM and significantly inhibited PC cell adhesion and invasion. Metabolomics revealed that C5 disturbed the level of metabolites involved in essential processes for cancer cell proliferation, progression and growth including energy production, redox homeostasis, amino acids and polyamine metabolisms and choline phospholipid metabolism. The data presented herein highlighted the importance of these compounds as potential anticancer agents particularly C5, and pointed to the promising role of metabolomics as a new analytical approach to investigate the antiproliferative activity of synthesized compounds and identify new therapeutic targets.

Effects of the intestinal microbiota on prostate cancer treatment by androgen deprivation therapy

Prostate cancer (PC) can be kept in check by androgen deprivation therapy (ADT, usually with the androgen synthesis inhibitor abiraterone acetate or the androgen receptor antagonist such as enzalutamide) until the tumor evolves to castration-resistant prostate cancer (CRPC). The transition of hormone-sensitive PC (HSPC) to CPRC has been explained by cancer cell-intrinsic resistance mechanisms. Recent data indicate that this transition is also marked by cancer cell-extrinsic mechanisms such as the failure of ADT-induced PC immunosurveillance, which depends on the presence of immunostimulatory bacteria in the gut. Moreover, intestinal bacteria that degrade drugs used for ADT, as well as bacteria that produce androgens, can interfere with the efficacy of ADT. Thus, specific bacteria in the gut serve as a source of testosterone, which accelerates prostate cancer progression, and men with CRPC exhibit an increased abundance of such bacteria with androgenic functions. In conclusion, the response of PC to ADT is profoundly influenced by the composition of the microbiota with its immunostimulatory, immunosuppressive and directly ADT-subversive elements.

5-Hydroxyeicosatetraenoic Acid Controls Androgen Reduction in Diverse Types of Human Epithelial Cells

Androgens regulate broad physiologic and pathologic processes, including external genitalia development, prostate cancer progression, and anti-inflammatory effects in both cancer and asthma. In prostate cancer, several lines of evidence have implicated dietary and endogenous fatty acids in cell invasion, angiogenesis, and treatment resistance. However, the role of fatty acids in steroidogenesis and the mechanisms by which alterations in this pathway occur are not well understood. Here, we show that, of a panel of fatty acids tested, arachidonic acid and its specific metabolite 5-hydroxyeicosatetraenoic acid (5-HETE) regulate androgen metabolism. Arachidonic acid is metabolized to 5-HETE and reduces androgens by inducing aldo-keto reductase (AKR) family members AKR1C2 and AKR1C3 expression in human prostate, breast, and lung epithelial cells. Finally, we provide evidence that these effects require the expression of the antioxidant response sensor, nuclear factor erythroid 2-related factor 2 (Nrf2). Our findings identify an interconnection between conventional fatty acid metabolism and steroid metabolism that has broad relevance to androgen physiology and inflammatory regulation.

Association Between Adrenal-Restrictive HSD3B1 Inheritance and Hormone-Independent Subtypes of Endometrial and Breast Cancer

BACKGROUND

The germline variant rs1047303 (HSD3B1[1245A/C]), restricting or enabling production of potent androgens and estrogens from adrenal precursors, affects outcomes of castration-resistant prostate cancer and is associated with estrogen receptor positivity in postmenopausal breast cancer. Like breast cancer, endometrial cancer is another malignancy with hormone-dependent and hormone-independent subtypes. We hypothesized that adrenal-restrictive HSD3B1 genotype would associate with hormone-independent cancer subtypes.

METHODS

We employed a previously described classification of tumors in The Cancer Genome Atlas into genomic clusters. We determined HSD3B1 genotype frequencies by endometrial cancer genomic cluster and calculated the odds per adrenal-restrictive A allele for the largely hormone-independent copy-number (CN) high subtype vs other subtypes. An equivalent analysis was performed for the genomically similar, hormone-independent basal breast cancer subtype. Last, we performed survival analyses for UK Biobank participants with endometrial cancer by HSD3B1 genotype. All statistical tests were 2-sided.

RESULTS

The adrenal-restrictive HSD3B1(1245A) allele was associated with the CN-high endometrial cancer subtype (odds ratio [OR] = 1.63, 95% confidence interval [CI] = 1.14 to 2.32; P = .007). Similarly, HSD3B1(1245A) was associated with the basal breast cancer subtype (OR = 1.54, 95% CI = 1.13 to 2.08; P = .006). In the UK Biobank, endometrial cancer patients homozygous for HSD3B1(1245A) had worse overall (hazard ratio [HR] = 1.39, 95% CI = 1.16 to 1.68; P < .001) and cancer-specific (HR = 1.39, 95% CI = 1.14 to 1.70; P = .001) survival, consistent with the A allele being enriched in the more aggressive CN-high subtype.

CONCLUSIONS

These findings suggest roles for adrenal-restrictive vs adrenal-permissive steroidogenesis, by way of rs1047303 genotype, in the development of and/or outcomes from at least 3 commonly hormone-associated types of cancer: prostate, breast, and endometrial.

Basics of androgen synthesis and action

Androgens are essential sex steroid hormones for both sexes. Testosterone (T) is the predominant androgen in males, while in adult females, T concentrations are about 15-fold lower and androgen precursors are converted to estrogens. T is produced primarily in testicular Leydig cells in men, while in women precursors are biosynthesised in the adrenal cortex and ovaries and converted into T in the periphery. The biosynthesis of T occurs via a series of enzymatic reactions in steroidogenic organs. Notably, the more potent androgen, dihydrotestosterone, may be synthesized from T in the classic pathway, however, alternate metabolic pathways also exist. The classic action of androgens on target organs is mediated through the androgen receptor, which regulates nuclear receptor gene transcription. However, the androgen-androgen receptor complex may also interact directly with membrane proteins or signaling molecules to exert more rapid effects. This review summarizes the current knowledge of androgen biosynthesis, mechanisms of action and endocrine effects in human biology, and relates these effects to respective human congenital and acquired disorders.

Potent Stimulation of the Androgen Receptor Instigates a Viral Mimicry Response in Prostate Cancer

Inhibiting the androgen receptor (AR), a ligand-activated transcription factor, with androgen deprivation therapy is a standard-of-care treatment for metastatic prostate cancer. Paradoxically, activation of AR can also inhibit the growth of prostate cancer in some patients and experimental systems, but the mechanisms underlying this phenomenon are poorly understood. This study exploited a potent synthetic androgen, methyltestosterone (MeT), to investigate AR agonist-induced growth inhibition. MeT strongly inhibited growth of prostate cancer cells expressing AR, but not AR-negative models. Genes and pathways regulated by MeT were highly analogous to those regulated by DHT, although MeT induced a quantitatively greater androgenic response in prostate cancer cells. MeT potently downregulated DNA methyltransferases, leading to global DNA hypomethylation. These epigenomic changes were associated with dysregulation of transposable element expression, including upregulation of endogenous retrovirus (ERV) transcripts after sustained MeT treatment. Increased ERV expression led to accumulation of double-stranded RNA and a "viral mimicry" response characterized by activation of IFN signaling, upregulation of MHC class I molecules, and enhanced recognition of murine prostate cancer cells by CD8+ T cells. Positive associations between AR activity and ERVs/antiviral pathways were evident in patient transcriptomic data, supporting the clinical relevance of our findings. Collectively, our study reveals that the potent androgen MeT can increase the immunogenicity of prostate cancer cells via a viral mimicry response, a finding that has potential implications for the development of strategies to sensitize this cancer type to immunotherapies.

Significance

Our study demonstrates that potent androgen stimulation of prostate cancer cells can elicit a viral mimicry response, resulting in enhanced IFN signaling. This finding may have implications for the development of strategies to sensitize prostate cancer to immunotherapies.

Emerging treatment for congenital adrenal hyperplasia

PURPOSE OF REVIEW

Although the basic treatment of congenital adrenal hyperplasia (CAH) is well established, there are active clinical research projects to more closely mimic the normal diurnal rhythm of cortisol secretion and to reduce total glucocorticoid doses to minimize adverse metabolic effects.

RECENT FINDINGS

We review clinical studies on CAH treatment published in the last 18 months or currently underway according to ClinicalTrials.gov listings. These can be grouped into several broad themes: alternative dosing forms of hydrocortisone with altered pharmacokinetics or easier dose titration; corticotropin-releasing hormone receptor antagonists that reduce corticotropin (ACTH) secretion and thereby reduce adrenal androgen secretion; androgen biosynthesis inhibitors; a first clinical trial of a gene therapy vector.

SUMMARY

Alternative dosing forms of hydrocortisone are, or will shortly be, marketed, but cost may be a barrier to utilization, at least in the US market. Trials of corticotropin releasing hormone receptor antagonists and androgen biosynthesis inhibitors are currently underway. The author believes that trials of gene therapy for CAH are premature.

The kinesin KIF20A promotes progression to castration-resistant prostate cancer through autocrine activation of the androgen receptor

Prostate cancer that recurs following androgen-deprivation therapy is termed castration-resistant, which is incurable and is marked by reactivation of androgen receptor (AR) signaling. KIF20A, a kinesin with unique structural features, is overexpressed in human castration-resistant prostate cancer (CRPC) compared to androgen-dependent PC and benign tissue. KIF20A has well-described roles in mitotic processes, but it has a less characterized function in vesicle fission and trafficking within Golgi-driven secretory pathways. Stable expression of KIF20A in androgen-dependent PC cells promoted progression to CRPC through the activation of AR signaling in vitro and in vivo. KIF20A expression resulted in the secretion of autocrine factors in the conditioned media that activated AR and caused castration-resistant proliferation of naïve androgen-dependent cells. Pharmacologic disruption of vesicle biogenesis blocked KIF20A-driven castration-resistant proliferation of androgen-dependent PC. KIF20A depletion or treatment with the KIF20A-specific inhibitor, paprotrain, reduced CRPC. These data are the first to establish KIF20A as a driver of CRPC progression through AR activation and as a promising therapeutic target against CRPC.

Calcium signaling in prostate cancer cells of increasing malignancy

Calcium signaling controls a large variety of cell functions, including proliferation and apoptosis, and plays a major role in neoplastic transformation. Prostate cancer (PCa) is one of the most common malignancies in men. The transition to castration-resistant prostate cancer (CRPC), a lethal form that is still lacking an effective cure, could be influenced by fine tuning intracellular calcium ([Ca²⁺]_i) homeostasis. This study investigates [Ca²⁺]_i dynamics in metastatic PCa cell lines that mimic the progression of PCa to CRPC: (i) well differentiated LNCaP cells that require androgen for survival, and (ii) poorly differentiated, highly aggressive androgen-insensitive prostate cancer (AIPC) PC3 and DU145 cells. In AIPC cells, ATP induces a fast rise in [Ca²⁺]_i, due to release from intracellular stores and sensitive to phospholipase C inhibitors, while LNCaP cells do not respond to ATP challenge. Moreover, AIPC cells showed a reduced capacity to store Ca²⁺ in thapsigargin-sensitive stores and limited store-operated calcium entry, with respect to androgen-dependent LNCaP cells. Finally, green tea extract causes [Ca²⁺]_i elevation and inhibits proliferation in PC3 and DU145 cells, but is ineffective in LNCaP cells. The consequences of these differences are discussed and interpreted in this study with reference to previously proposed models for Ca²⁺ dependence of prostate carcinogenesis.

Nomogram for predicting the overall survival of patients with early-onset prostate cancer: A population-based retrospective study

Background

The incidence of early‐onset prostate cancer (PCa) has increased significantly over the past few decades. It is necessary to develop a prognostic nomogram for the prediction of overall survival (OS) in early‐onset PCa patients.

Methods

A total of 23,730 early‐onset PCa patients (younger than 55 years old) between 2010 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database were enrolled for the current study, and randomly separated into the training cohort and the validation cohort. 361 eligible early‐onset PCa patients from The Cancer Genome Atlas‐Prostate Adenocarcinoma (TCGA‐PRAD) cohort were obtained as the external validation cohort. Independent predictors were selected by univariate and multivariate Cox regression analysis, and a prognostic nomogram was constructed for 1‐, 3‐, and 5‐year OS. The accurate and discriminative abilities of the nomogram were evaluated by the concordance index (C‐index), receiver operating characteristic curve (ROC), calibration plot, net reclassification index (NRI), and integrated discrimination improvement (IDI).

Results

Multivariate Cox analysis showed that race, marital status, TNM stage, prostate‐specific antigen, Gleason score, and surgery were significantly associated with poor prognosis of PCa. A nomogram consisting of these variables was established, which had higher C‐indexes than the TNM system (training cohort: 0.831 vs. 0.746, validation cohort: 0.817 vs. 0.752). Better AUCs of the nomogram than the TNM system at 1, 3, and 5 years were found in both the training cohort and the validation cohort. The 3‐year and 5‐year AUCs of the nomogram in the TCGA‐PRAD cohort were 0.723 and 0.679, respectively. The calibration diagram, NRI, and IDI also showed promising prognostic value in OS.

Conclusions

We developed an effective prognostic nomogram for OS prediction in early‐onset PCa patients, which will further assist both the precise clinical treatment and the assessment of long‐term outcomes.

Inhibiting 3βHSD1 to eliminate the oncogenic effects of progesterone in prostate cancer

Prostate cancer continuously progresses following deprivation of circulating androgens originating from the testis and adrenal glands, indicating the existence of oncometabolites beyond androgens. In this study, mass-spectrometry-based screening of clinical specimens and a retrospective analysis on the clinical data of prostate cancer patients indicate the potential oncogenic effects of progesterone in patients. High doses of progesterone activate canonical and non-canonical androgen receptor (AR) target genes. Physiological levels of progesterone facilitate cell proliferation via GATA2. Inhibitors of 3β-hydroxysteroid dehydrogenase 1 (3βHSD1) has been discovered and shown to suppress the generation of progesterone, eliminating its transient and accumulating oncogenic effects. An increase in progesterone is associated with poor clinical outcomes in patients and may be used as a predictive biomarker. Overall, we demonstrate that progesterone acts as an oncogenic hormone in prostate cancer, and strategies to eliminate its oncogenic effects may benefit prostate cancer patients.

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High doses of progesterone activate canonical and non-canonical AR signaling

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Progesterone of physiological levels exerts its chronic oncogenic effect via GATA2

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Targeting 3βHSD1 to suppress progesterone synthesis blocks its oncogenic effects

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Serum progesterone might be a predictive biomarker for abiraterone response

Personalized Medicine for Prostate Cancer: Is Targeting Metabolism a Reality?

Prostate cancer invokes major shifts in gene transcription and metabolic signaling to mediate alterations in nutrient acquisition and metabolic substrate selection when compared to normal tissues. Exploiting such metabolic reprogramming is proposed to enable the development of targeted therapies for prostate cancer, yet there are several challenges to overcome before this becomes a reality. Herein, we outline the role of several nutrients known to contribute to prostate tumorigenesis, including fatty acids, glucose, lactate and glutamine, and discuss the major factors contributing to variability in prostate cancer metabolism, including cellular heterogeneity, genetic drivers and mutations, as well as complexity in the tumor microenvironment. The review draws from original studies employing immortalized prostate cancer cells, as well as more complex experimental models, including animals and humans, that more accurately reflect the complexity of the in vivo tumor microenvironment. In synthesizing this information, we consider the feasibility and potential limitations of implementing metabolic therapies for prostate cancer management.

Congenital Adrenal Hyperplasia-Current Insights in Pathophysiology, Diagnostics, and Management

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders affecting cortisol biosynthesis. Reduced activity of an enzyme required for cortisol production leads to chronic overstimulation of the adrenal cortex and accumulation of precursors proximal to the blocked enzymatic step. The most common form of CAH is caused by steroid 21-hydroxylase deficiency due to mutations in CYP21A2. Since the last publication summarizing CAH in Endocrine Reviews in 2000, there have been numerous new developments. These include more detailed understanding of steroidogenic pathways, refinements in neonatal screening, improved diagnostic measurements utilizing chromatography and mass spectrometry coupled with steroid profiling, and improved genotyping methods. Clinical trials of alternative medications and modes of delivery have been recently completed or are under way. Genetic and cell-based treatments are being explored. A large body of data concerning long-term outcomes in patients affected by CAH, including psychosexual well-being, has been enhanced by the establishment of disease registries. This review provides the reader with current insights in CAH with special attention to these new developments.

Network models of prostate cancer immune microenvironments identify ROMO1 as heterogeneity and prognostic marker

Prostate cancer (PCa) is the fifth leading cause of death from cancer in men worldwide. Its treatment remains challenging due to the heterogeneity of the tumor, mainly because of the lack of effective and targeted prognostic markers at the system biology level. First, the data were retrieved from TCGA dataset, and valid samples were obtained by consistent clustering and principal component analysis; next, key genes were analyzed for prognosis of PCa using WGCNA, MEGENA, and LASSO Cox regression model analysis, while key genes were screened based on disease-free survival significance. Finally, TIMER data were selected to explore the relationship between genes and tumor immune infiltration, and GSCAlite was used to explore the small-molecule targeted drugs that act with them. Here, we used tumor subtype analysis and an energetic co-expression network algorithm of WGCNA and MEGENA to identify a signal dominated by the ROMO1 to predict PCa prognosis. Cox regression analysis of ROMO1 was an independent influence, and the prognostic value of this biomarker was validated in the training set, the validated data itself, and external data, respectively. This biomarker correlates with tumor immune infiltration and has a high degree of infiltration, poor prognosis, and strong correlation with CD8+T cells. Gene function annotation and other analyses also implied a potential molecular mechanism for ROMO1. In conclusion, we putative ROMO1 as a portal key prognostic gene for the diagnosis and prognosis of PCa, which provides new insights into the diagnosis and treatment of PCa.

KLK3 in the Regulation of Angiogenesis-Tumorigenic or Not?

In this focused review, we address the role of the kallikrein-related peptidase 3 (KLK3), also known as prostate-specific antigen (PSA), in the regulation of angiogenesis. Early studies suggest that KLK3 is able to inhibit angiogenic processes, which is most likely dependent on its proteolytic activity. However, more recent evidence suggests that KLK3 may also have an opposite role, mediated by the ability of KLK3 to activate the (lymph)angiogenic vascular endothelial growth factors VEGF-C and VEGF-D, further discussed in the review.

Novel Strategy of Proxalutamide for the Treatment of Prostate Cancer through Coordinated Blockade of Lipogenesis and Androgen Receptor Axis

Objective: Prostate cancer (PCa) is the most common malignant tumor diagnosed in men in developed countries. In developing countries, the PCa morbidity and mortality rates are also increasing rapidly. Since androgen receptor (AR) is a key driver and plays a critical role in the regulation of PCa development, AR-targeted agents provide a key component of current therapy regimens. However, even new-generation AR antagonists are prone to drug resistance, and there is currently no effective strategy for overcoming advanced PCa aggressiveness, including drug-resistance progression. The aim of this study was to evaluate the potential efficacy and novel therapy strategy of proxalutamide (a newly developed AR antagonist) in PCa. Methods: Four PCa cell lines with various biological heterogeneities were utilized in this study, namely, androgen-sensitive/-insensitive with/without AR expression. Proliferation, migration and apoptosis assays in PCa cells were used to evaluate the effective therapeutic activity of proxalutamide. The changes in lipid droplet accumulation and lipidomic profiles were analyzed to determine the influence of proxalutamide on lipogenesis in PCa cells. The molecular basis of the effects of proxalutamide on lipogenesis and the AR axis was then further investigated. Results: Proxalutamide significantly inhibited the proliferation and migration of PCa cells, and its inhibitory effect was superior to that of enzalutamide (Enz, second-generation AR antagonist). Proxalutamide induced the caspase-dependent apoptosis of PCa cells. Proxalutamide significantly diminished the level of lipid droplets in PCa cells, changed the lipid profile of PCa cells and reduced the content of most lipids (especially triglycerides) in PCa cells. Proxalutamide attenuated de novo lipogenesis by inhibiting the expression of ATP citrate lyase (ACL), acetyl CoA carboxylase (ACC), fatty acid synthase (FASN) and sterol regulatory element-binding protein-1 (SREBP-1). Moreover, proxalutamide also decreased AR expression in PCa cells, and its inhibitory effect on lipogenesis did not depend on its ability to down-regulate AR expression. However, Enz had no effect on AR expression, lipid accumulation or lipid de novo synthesis in PCa cells. Conclusions: By co-targeting the AR axis and endogenous adipogenesis, a novel and promising strategy was established for proxalutamide to combat the progress of PCa. The unique effect of proxalutamide on the metabolic reprogramming of PCa provides a potential solution to overcome the resistance of current AR-targeted therapy, which will help to effectively prolong its clinical service life.

New benzothieno[2,3-c]pyridines as non-steroidal CYP17 inhibitors: design, synthesis, anticancer screening, apoptosis induction, and in silico ADME profile studies

A series of [1]benzothieno[2,3-c]pyridines was synthesised. Most compounds were chosen by NCI-USA to evaluate their anticancer activity. Compounds 5a-c showed prominent growth inhibition against most cell lines. 5c was selected at five dose concentration levels. It exhibited potent broad-spectrum anticancer activity with a GI50 of 4 nM-37 µM. Cytotoxicity of 5a-c was further evaluated against prostate, renal, and breast cancer cell lines. 5c showed double and quadruple the activity of staurosporine and abiraterone, respectively, against the PC-3 cell line with IC50 2.08 µM. The possible mechanism of anti-prostate cancer was explored via measuring the CYP17 enzyme activity in mice prostate cancer models compared to abiraterone. The results revealed that 5c suppressed the CYP17 enzyme to 15.80 nM. Moreover, it was found to be equipotent to abiraterone in testosterone production. Cell cycle analysis and apoptosis were performed. Additionally, the ADME profile of compound 5c demonstrated both good oral bioavailability and metabolic stability.

Clinical advances in the pharmacotherapy of congenital adrenal hyperplasia

BACKGROUND

Patients with 21-hydroxylase deficiency congenital adrenal hyperplasia (21OHD-CAH) have poor health outcomes with increased mortality, short stature, impaired fertility, and increased cardiovascular risk factors such as obesity. To address this, there are therapies in development that target the clinical goal of treatment, which is to control excess androgens with an adrenal replacement dose of glucocorticoid.

METHODS

Narrative review of publications on recent clinical developments in the pharmacotherapy of congenital adrenal hyperplasia.

SUMMARY

Therapies in clinical development target different levels of the hypothalamo-pituitary-adrenal axis. Two corticotrophin-releasing factor type 1 (CRF1) receptor antagonists, Crinecerfont and Tildacerfont, have been trialled in poorly controlled 21OHD-CAH patients, and both reduced ACTH and androgen biomarkers while patients were on stable glucocorticoid replacement. Improvements in glucocorticoid replacement include replacing the circadian rhythm of cortisol that has been trialled with continuous s.c. infusion of hydrocortisone and Chronocort, a delayed-release hydrocortisone formulation. Chronocort optimally controlled 21OHD-CAH in 80% of patients on an adrenal replacement dose of hydrocortisone, which was associated with patient-reported benefits including restoration of menses and pregnancies. Adrenal-targeted therapies include the steroidogenesis-blocking drug Abiraterone acetate, which reduced adrenal androgen biomarkers in poorly controlled patients.

CONCLUSIONS

CRF1 receptor antagonists hold promise to avoid excess glucocorticoid replacement in patients not controlled on standard or circadian glucocorticoid replacement such as Chronocort. Gene and cell therapies are the only therapeutic approaches that could potentially correct both cortisol deficiency and androgen excess.

Type I Interferon Promotes Antitumor T Cell Response in CRPC by Regulating MDSC

Simple Summary

Despite initial tumor regression following androgen blockade treatment, relapse of castration-resistant prostate cancer (CRPC) eventually occurs in most patients. Immunotherapy aims to activate the host immune system to fight against cancer and has achieved significant therapeutic effects in various solid tumors. The purpose of our research was to investigate the mechanisms underlying the immune response during CRPC development and to screen effective immunotherapies against CRPC. We found that interferon-α (IFNα) directly inhibited the progression of CRPC, reduced the accumulation of the immune suppressive granulocytic myeloid-derived suppressor cells (G-MDSCs) in the tumor microenvironment (TME), and impaired the inhibitory function of G-MDSCs on T cell activation. This research provides a potential strategy for the clinical treatment of CRPC.

Abstract

Background: Metastatic castration-resistant prostate cancer (CRPC) is the leading cause of death among prostate cancer patients. Here, our aim was to ascertain the immune regulatory mechanisms involved in CRPC development and identify potential immunotherapies against CRPC. Methods: A CRPC model was established using Myc-CaP cells in immune-competent FVB mice following castration. The immune cell profile of the tumor microenvironment (TME) was analyzed during CRPC development. Different immunotherapies were screened in the CRPC tumor model, and their efficacies and underlying mechanisms were investigated in vitro and in vivo. Results: During CRPC development, the proportion of granulocytic myeloid-derived suppressor cells (G-MDSCs) in the TME increased. Among the immunotherapies tested, IFNα was more effective than anti-PD-L1, anti-CTLA-4, anti-4-1BB, IL-2, and IL-9 in reducing Myc-CaP CRPC tumor growth. IFNα reduced the number of G-MDSCs both in vitro during differentiation and in vivo in CRPC mice. Furthermore, IFNα reduced the suppressive function of G-MDSCs on T cell proliferation and activation. Conclusion: G-MDSCs are crucial to effective immunotherapy against CRPC. Treatment with IFNα presents a promising therapeutic strategy against CRPC. Besides the direct inhibition of tumor growth and the promotion of T cell priming, IFNα reduces the number and the suppressive function of G-MDSCs and restores T cell activation.

In Silico Approaches In Carcinogenicity Hazard Assessment: Current Status and Future Needs

Historically, identifying carcinogens has relied primarily on tumor studies in rodents, which require enormous resources in both money and time. In silico models have been developed for predicting rodent carcinogens but have not yet found general regulatory acceptance, in part due to the lack of a generally accepted protocol for performing such an assessment as well as limitations in predictive performance and scope. There remains a need for additional, improved in silico carcinogenicity models, especially ones that are more human-relevant, for use in research and regulatory decision-making. As part of an international effort to develop in silico toxicological protocols, a consortium of toxicologists, computational scientists, and regulatory scientists across several industries and governmental agencies evaluated the extent to which in silico models exist for each of the recently defined 10 key characteristics (KCs) of carcinogens. This position paper summarizes the current status of in silico tools for the assessment of each KC and identifies the data gaps that need to be addressed before a comprehensive in silico carcinogenicity protocol can be developed for regulatory use.

Adrenal-permissive HSD3B1 genetic inheritance and risk of estrogen-driven postmenopausal breast cancer

BACKGROUND

Genetics of estrogen synthesis and breast cancer risk has been elusive. The 1245A→C missense-encoding polymorphism in HSD3B1, which is common in White populations, is functionally adrenal permissive and increases synthesis of the aromatase substrate androstenedione. We hypothesized that homozygous inheritance of the adrenal-permissive HSD3B1(1245C) is associated with postmenopausal estrogen receptor–positive (ER-positive) breast cancer.

METHODS

A prospective study of postmenopausal ER-driven breast cancer was done for determination of HSD3B1 and circulating steroids. Validation was performed in 2 other cohorts. Adrenal-permissive genotype frequency was compared between postmenopausal ER-positive breast cancer, the general population, and postmenopausal ER-negative breast cancer.

RESULTS

Prospective and validation studies had 157 and 538 patients, respectively, for the primary analysis of genotype frequency by ER status in White female breast cancer patients who were postmenopausal at diagnosis. The adrenal-permissive genotype frequency in postmenopausal White women with estrogen-driven breast cancer in the prospective cohort was 17.5% (21/120) compared with 5.4% (2/37) for ER-negative breast cancer (P = 0.108) and 9.6% (429/4451) in the general population (P = 0.0077). Adrenal-permissive genotype frequency for estrogen-driven postmenopausal breast cancer was validated using Cambridge and The Cancer Genome Atlas data sets: 14.4% (56/389) compared with 6.0% (9/149) for ER-negative breast cancer (P = 0.007) and the general population (P = 0.005). Circulating androstenedione concentration was higher with the adrenal-permissive genotype (P = 0.03).

CONCLUSION

Adrenal-permissive genotype is associated with estrogen-driven postmenopausal breast cancer. These findings link genetic inheritance of endogenous estrogen exposure to estrogen-driven breast cancer.

FUNDING

National Cancer Institute, NIH (R01CA236780, R01CA172382, and P30-CA008748); and Prostate Cancer Foundation Challenge Award.

Osteoblasts Generate Testosterone From DHEA and Activate Androgen Signaling in Prostate Cancer Cells

Bone metastasis is a complication of prostate cancer in up to 90% of men afflicted with advanced disease. Therapies that reduce androgen exposure remain at the forefront of treatment. However, most prostate cancers transition to a state whereby reducing testicular androgen action becomes ineffective. A common mechanism of this transition is intratumoral production of testosterone (T) using the adrenal androgen precursor dehydroepiandrosterone (DHEA) through enzymatic conversion by 3β- and 17β-hydroxysteroid dehydrogenases (3βHSD and 17βHSD). Given the ability of prostate cancer to form blastic metastases in bone, we hypothesized that osteoblasts might be a source of androgen synthesis. RNA expression analyses of murine osteoblasts and human bone confirmed that at least one 3βHSD and 17βHSD enzyme isoform was expressed, suggesting that osteoblasts are capable of generating androgens from adrenal DHEA. Murine osteoblasts were treated with 100 nM and 1 μM DHEA or vehicle control. Conditioned media from these osteoblasts were assayed for intermediate and active androgens by liquid chromatography-tandem mass spectrometry. As DHEA was consumed, the androgen intermediates androstenediol and androstenedione were generated and subsequently converted to T. Conditioned media of DHEA-treated osteoblasts increased androgen receptor (AR) signaling, prostate-specific antigen (PSA) production, and cell numbers of the androgen-sensitive prostate cancer cell lines C4-2B and LNCaP. DHEA did not induce AR signaling in osteoblasts despite AR expression in this cell type. We describe an unreported function of osteoblasts as a source of T that is especially relevant during androgen-responsive metastatic prostate cancer invasion into bone. © 2021 American Society for Bone and Mineral Research (ASBMR). This article has been contributed to by US Government employees and their work is in the public domain in the USA.

A Selective Androgen Receptor Modulator (OPK-88004) in Prostate Cancer Survivors: A Randomized Trial

BACKGROUND

Androgen deficiency is common among prostate cancer survivors, but many guidelines consider history of prostate cancer a contraindication for testosterone replacement. We determined the safety and efficacy of a selective androgen receptor modulator (OPK-88004) in symptomatic, testosterone-deficient men who had undergone radical prostatectomy for low-grade, organ-confined prostate cancer.

METHODS

In this placebo-controlled, randomized, double-blind trial, 114 men, ≥19 years of age, who had undergone radical prostatectomy for low-grade, organ-localized prostate cancer, undetectable PSA (<0.1 ng/mL) for ≥2 years after radical prostatectomy and testosterone deficiency were randomized in stages to placebo or 1, 5, or 15 mg OPK-88004 daily for 12 weeks. Outcomes included PSA recurrence, sexual activity, sexual desire, erectile function, body composition, muscle strength and physical function measures, mood, fatigue, and bone markers.

RESULTS

Participants were on average 67.5 years of age and had severe sexual dysfunction (mean erectile function and sexual desire domain scores 7.3 and 14.6, respectively). No participant experienced PSA recurrence or erythrocytosis. OPK-88004 was associated with a dose-related increase in whole-body (P < 0.001) and appendicular (P < 0.001) lean mass and a significantly greater decrease in percent body fat (P < 0.001) and serum alkaline phosphatase (P < 0.001) than placebo. Changes in sexual activity, sexual desire, erectile function, mood, fatigue, physical performance, and bone markers did not differ among groups (P = 0.73).

CONCLUSIONS

Administration of OPK-88004 was safe and not associated with PSA recurrence in androgen-deficient men who had undergone radical prostatectomy for organ-confined prostate cancer. OPK-88004 increased lean body mass and decreased fat mass but did not improve sexual symptoms or physical performance.

Differential but Concerted Expression of HSD17B2, HSD17B3, SHBG and SRD5A1 Testosterone Tetrad Modulate Therapy Response and Susceptibility to Disease Relapse in Patients with Prostate Cancer

Simple Summary

Over the last two decades, our improved understanding of the pathobiology of androgen-addicted prostate cancer (PCa), and documented therapeutic advances/breakthroughs have not translated into any substantial or sustained curative benefit for patients treated with traditional ADT or novel immune checkpoint blockade therapeutics. This is invariably connected with the peculiar biology and intratumoral heterogeneity of PCa. Castration-resistant PCa, constituting ~30% of all PCa, remains a clinically enigmatic and therapeutically challenging disease sub-type, that is therapy-refractory and characterized by high risk for recurrence after initial response. Our findings highlight the role and exploitability of testosterone metabolic reprogramming in prostate TME for patient stratification and personalized/precision medicine based on the differential but concerted expression of molecular components of the proposed testosterone tetrad in patients with therapy-refractory, locally advanced, or recurrent PCa. The therapeutic exploitability and clinical feasibility of our proposed approach is suggested by our preclinical findings.

Abstract

Background: Testosterone plays a critical role in prostate development and pathology. However, the impact of the molecular interplay between testosterone-associated genes on therapy response and susceptibility to disease relapse in PCa patients remains underexplored. Objective: This study investigated the role of dysregulated or aberrantly expressed testosterone-associated genes in the enhanced dissemination, phenoconversion, and therapy response of treatment-resistant advanced or recurrent PCa. Methods: Employing a combination of multi-omics big data analyses, in vitro, ex vivo, and in vivo assays, we assessed the probable roles of HSD17B2, HSD17B3, SHBG, and SRD5A1-mediated testosterone metabolism in the progression, therapy response, and prognosis of advanced or castration-resistant PCa (CRPC). Results: Our bioinformatics-aided gene expression profiling and immunohistochemical staining showed that the aberrant expression of the HSD17B2, HSD17B3, SHBG, and SRD5A1 testosterone metabolic tetrad characterize androgen-driven PCa and is associated with disease progression. Reanalysis of the TCGA PRAD cohort (n = 497) showed that patients with SRD5A1-dominant high expression of the tetrad exhibited worse mid-term to long-term (≥5 years) overall survival, with a profoundly shorter time to recurrence, compared to those with low expression. More so, we observed a strong association between enhanced HSD17B2/SRD5A1 signaling and metastasis to distant lymph nodes (M1a) and bones (M1b), while upregulated HSD17B3/SHBG signaling correlated more with negative metastasis (M0) status. Interestingly, increased SHBG/SRD5A1 ratio was associated with metastasis to distant organs (M1c), while elevated SRD5A1/SHBG ratio was associated with positive biochemical recurrence (BCR) status, and shorter time to BCR. Molecular enrichment and protein–protein connectivity network analyses showed that the androgenic tetrad regulates testosterone metabolism and cross-talks with modulators of drug response, effectors of cell cycle progression, proliferation or cell motility, and activators/mediators of cancer stemness. Moreover, of clinical relevance, SHBG ectopic expression (SHBG_OE) or SRD5A1 knockout (sgSRD5A1) induced the acquisition of spindle fibroblastoid morphology by the round/polygonal metastatic PC-3 and LNCaP cells, attenuated their migration and invasion capability, and significantly suppressed their ability to form primary or secondary tumorspheres, with concomitant downregulation of stemness KLF4, OCT3/4, and drug resistance ABCC1, ABCB1 proteins expression levels. We also showed that metronomic dutasteride synergistically enhanced the anticancer effect of low-dose docetaxel, in vitro, and in vivo. Conclusion: These data provide proof of concept that re-reprogramming of testosterone metabolism through “SRD5A1 withdrawal” or “SHBG induction” is a workable therapeutic strategy for shutting down androgen-driven oncogenic signals, reversing treatment resistance, and repressing the metastatic/recurrent phenotypes of patients with PCa.

Hexose-6-phosphate dehydrogenase blockade reverses prostate cancer drug resistance in xenograft models by glucocorticoid inactivation

Prostate cancer resistance to next-generation hormonal treatment with enzalutamide is a major problem and eventuates into disease lethality. Biologically active glucocorticoids that stimulate glucocorticoid receptor (GR) have an 11β-OH moiety, and resistant tumors exhibit loss of 11β-HSD2, the oxidative (11β-OH → 11-keto) enzyme that normally inactivates glucocorticoids, allowing elevated tumor glucocorticoids to drive resistance by stimulating GR. Here, we show that up-regulation of hexose-6-phosphate dehydrogenase (H6PD) protein occurs in prostate cancer tissues of men treated with enzalutamide, human-derived cell lines, and patient-derived prostate tissues treated ex vivo with enzalutamide. Genetically silencing H6PD blocks NADPH generation, which inhibits the usual reductive directionality of 11β-HSD1, to effectively replace 11β-HSD2 function in human-derived cell line models, suppress the concentration of biologically active glucocorticoids in prostate cancer, and reverse enzalutamide resistance in mouse xenograft models. Similarly, pharmacologic blockade of H6PD with rucaparib normalizes tumor glucocorticoid metabolism in human cell lines and reinstates responsiveness to enzalutamide in mouse xenograft models. Our data show that blockade of H6PD, which is essential for glucocorticoid synthesis in humans, normalizes glucocorticoid metabolism and reverses enzalutamide resistance in mouse xenograft models. We credential H6PD as a pharmacologic vulnerability for treatment of next-generation androgen receptor antagonist-resistant prostate cancer by depleting tumor glucocorticoids.

Underestimated reactions and regulation patterns of adrenal cytochromes P450

Although cytochrome P450 (CYP) systems including the adrenal ones are being investigated since many years, there are still reactions and regulation patterns that have been underestimated ever since. This review discusses neglected ones to bring them into the focus of investigators working in the field. Novel substrates and reactions described for adrenal CYPs recently point to the fact that different from what has been believed for many years, adrenal CYPs are less selective than previously thought. The conversion of steroid sulfates, intermediates of steroid biosynthesis as well as of exogenous compounds are being discussed here in more detail and consequences for further studies are drawn. Furthermore, it was shown that protein-protein interactions may have an important effect not only on the activity of adrenal CYPs, but also on the product pattern of the reactions. It was found that, as expected, the stoichiometry of CYP:redox partner plays an important role for tuning the activity. In addition, competition between different CYPs for the redox partner and for electrons and possible alterations by mutants in the efficiency of electron transfer play an important role for the activity and product pattern. Moreover, the influence of phosphorylation and small charged molecules like natural polyamines on the activity of adrenal systems has been demonstrated in-vitro indicating a possible regulation of adrenal CYP reactions by affecting redox partner recognition and binding affinity. Finally, an effect of the genetic background on the consequences of mutations in adrenal CYPs found in patients was suggested from corresponding in-vitro studies indicating that a different genetic background might be able to significantly affect the activity of a CYP mutant.

Tracing steroidogenesis in prostate biopsy samples to unveil prostate tissue androgen metabolism characteristics and potential clinical application

Androgens are essential for prostate cancer development. However, steroidogenesis has mainly been investigated in a limited number of prostate cancer cell lines, leading to varied conclusions and elusive clinical significance. Here, we established an ex vivo research platform with fresh biopsy samples transiently cultured with tritium- labelled androgens to trace steroidogenesis in prostate tissues and investigate its potential clinical application. DHEA was confirmed as the major precursor for androgen synthesis in the prostate. Significant amounts of oxidized DHEA and 5α-androstanedione were generated from DHEA in prostate biopsy samples. Prostatic steroidogenesis was independent of other clinical factors. Furthermore, prostatic steroidogenesis was suppressed after androgen deprivation therapy but increased upon treatment resistance, indicating that prostatic steroidogenesis was affected by clinical treatments. Overall, we provide an accessible research platform to characterize steroidogenesis in prostate tissue and indicate the correlation between prostatic steroidogenesis and disease progression.

Hormonal Therapy for Prostate Cancer

Huggins and Hodges demonstrated the therapeutic effect of gonadal testosterone deprivation in the 1940s and therefore firmly established the concept that prostate cancer is a highly androgen-dependent disease. Since that time, hormonal therapy has undergone iterative advancement, from the types of gonadal testosterone deprivation to modalities that block the generation of adrenal and other extragonadal androgens, to those that directly bind and inhibit the androgen receptor (AR). The clinical states of prostate cancer are the product of a superimposition of these therapies with nonmetastatic advanced prostate cancer, as well as frankly metastatic disease. Today's standard of care for advanced prostate cancer includes gonadotropin-releasing hormone agonists (e.g., leuprolide), second-generation nonsteroidal AR antagonists (enzalutamide, apalutamide, and darolutamide) and the androgen biosynthesis inhibitor abiraterone. The purpose of this review is to provide an assessment of hormonal therapies for the various clinical states of prostate cancer. The advancement of today's standard of care will require an accounting of an individual's androgen physiology that also has recently recognized germline determinants of peripheral androgen metabolism, which include HSD3B1 inheritance.

CPT1A Over-Expression Increases Reactive Oxygen Species in the Mitochondria and Promotes Antioxidant Defenses in Prostate Cancer

Simple Summary

Prostate cancer (PCa) is the most common cancer in men and the second highest contributor to cancer deaths. Targeting lipid catabolism enzymes in PCa may offer new avenues for therapeutic approaches. During the last decade, carnitine palmitoyl transferase I (CPT1A) has been identified as a potential therapeutic target for a growing list of cancers. In this study, we have tested the hypothesis that excess CPT1A plays a key role in supporting adaptation to stress and antioxidant defense production in PCa cells. Specifically, we have studied molecular differences between CPT1A gain and loss of function models, revealing genetic and metabolic vulnerabilities that could be targeted to avoid progression to neuroendocrine differentiation, a lethal form of the disease. Examining public datasets, we have also found that excess CPT1A expression leads to worse progression-free survival in PCa patients.

Abstract

Cancers reprogram their metabolism to adapt to environmental changes. In this study, we examined the consequences of altered expression of the mitochondrial enzyme carnitine palmitoyl transferase I (CPT1A) in prostate cancer (PCa) cell models. Using transcriptomic and metabolomic analyses, we compared LNCaP-C4-2 cell lines with depleted (knockdown (KD)) or increased (overexpression (OE)) CPT1A expression. Mitochondrial reactive oxygen species (ROS) were also measured. Transcriptomic analysis identified ER stress, serine biosynthesis and lipid catabolism as significantly upregulated pathways in the OE versus KD cells. On the other hand, androgen response was significantly downregulated in OE cells. These changes associated with increased acyl-carnitines, serine synthesis and glutathione precursors in OE cells. Unexpectedly, OE cells showed increased mitochondrial ROS but when challenged with fatty acids and no androgens, the Superoxide dismutase 2 (SOD2) enzyme increased in the OE cells, suggesting better antioxidant defenses with excess CPT1A expression. Public databases also showed decreased androgen response correlation with increased serine-related metabolism in advanced PCa. Lastly, worse progression free survival was observed with increased lipid catabolism and decreased androgen response. Excess CPT1A is associated with a ROS-mediated stress phenotype that can support PCa disease progression. This study provides a rationale for targeting lipid catabolic pathways for therapy in hormonal cancers.

Androgen Receptor Signaling and Metabolic and Cellular Plasticity During Progression to Castration Resistant Prostate Cancer

Metabolic reprogramming is associated with re/activation and antagonism of androgen receptor (AR) signaling that drives prostate cancer (PCa) progression to castration resistance, respectively. In particular, AR signaling influences the fates of citrate that uniquely characterizes normal and malignant prostatic metabolism (i.e., mitochondrial export and extracellular secretion in normal prostate, mitochondrial retention and oxidation to support oxidative phenotype of primary PCa, and extra-mitochondrial interconversion into acetyl-CoA for fatty acid synthesis and epigenetics in the advanced PCa). The emergence of castration-resistant PCa (CRPC) involves reactivation of AR signaling, which is then further targeted by androgen synthesis inhibitors (abiraterone) and AR-ligand inhibitors (enzalutamide, apalutamide, and daroglutamide). However, based on AR dependency, two distinct metabolic and cellular adaptations contribute to development of resistance to these agents and progression to aggressive and lethal disease, with the tumor ultimately becoming highly glycolytic and with imaging by a tracer of tumor energetics, ¹⁸F-fluorodoxyglucose (¹⁸F-FDG). Another major resistance mechanism involves a lineage alteration into AR-indifferent carcinoma such a neuroendocrine which is diagnostically characterized by robust ¹⁸F-FDG uptake and loss of AR signaling. PCa is also characterized by metabolic alterations such as fatty acid and polyamine metabolism depending on AR signaling. In some cases, AR targeting induces rather than suppresses these alterations in cellular metabolism and energetics, which can be explored as therapeutic targets in lethal CRPC.

Signaling through estrogen receptors modulates long non-coding RNAs in prostate cancer

Prostate cancer (PCa) is a sex-steroid hormone-dependent cancer in which estrogens play a critical role in both initiation and progression. Recently, several long non-coding RNAs (lncRNAs) have been associated with PCa and are supposedly playing a pivotal role in the biology and progression of this type of cancer. In this review, we focused on some lncRNAs that are known for their androgen and estrogen transcriptional responsiveness in PCa. Specifically, we summarized recent pieces of evidence about lncRNAs NEAT1, H19, MALAT1, and HOTAIR, in estrogen signaling, emphasizing their role in PCa progression and the acquisition of a castration-resistant phenotype. Here, the reader will find information about lncRNAs present in estrogen-dependent transcriptional complexes. The potential role of lncRNA/estrogen signaling as a novel pathway for PCa treatment will be discussed.