Effects of Dutasteride on Prostate Carcinoma Primary Cultures: A Comparative Study With Finasteride and MK386

Deep learning identifies explainable reasoning paths of mechanism of action for drug repurposing from multilayer biological network

The discovery and repurposing of drugs require a deep understanding of the mechanism of drug action (MODA). Existing computational methods mainly model MODA with the protein-protein interaction (PPI) network. However, the molecular interactions of drugs in the human body are far beyond PPIs. Additionally, the lack of interpretability of these models hinders their practicability. We propose an interpretable deep learning-based path-reasoning framework (iDPath) for drug discovery and repurposing by capturing MODA on by far the most comprehensive multilayer biological network consisting of the complex high-dimensional molecular interactions between genes, proteins and chemicals. Experiments show that iDPath outperforms state-of-the-art machine learning methods on a general drug repurposing task. Further investigations demonstrate that iDPath can identify explicit critical paths that are consistent with clinical evidence. To demonstrate the practical value of iDPath, we apply it to the identification of potential drugs for treating prostate cancer and hypertension. Results show that iDPath can discover new FDA-approved drugs. This research provides a novel interpretable artificial intelligence perspective on drug discovery.

Dutasteride monotherapy in men with serologic relapse following radical therapy for adenocarcinoma of the prostate: a pilot study

OBJECTIVE

The objective of this study was to assess the effect of dutasteride on serum prostate specific antigen (PSA) levels in men with serologic relapse following radical prostatectomy and/or radiation therapy for clinically localized adenocarcinoma of the prostate.

METHODS

A prospective, single institution, IRB approved trial was conducted. Entry criteria required that all participants have serologic disease relapse only with serum PSA levels between 0.4 and 10.0 ng/ml. Enrolled participants were treated with 0.5 mg dutasteride daily. The primary endpoints were serum PSA level and clinical recurrence. The rate of durable decline in PSA was assessed according to the recommendations of the Prostate-Specific Antigen Working Group.

RESULTS

Thirty-five patients provided informed consent and participated in the present study. At a median follow-up duration of 27 months (range, 4-42 months), 46% of enrolled men had a serum PSA decrease of greater than 10%, and 25% had a serum PSA decrease of greater than 50% (P < 0.001). Pre-study PSA doubling time (PSADT) (≥12 months vs. <12 months), and Gleason score (≤6 vs. ≥7) were associated with a better response to dutasteride, but only PSADT was statistically significant (P < 0.001). Thirty percent of patients experienced PSA progression (increase in serum PSA of greater than 50%). Two (6%) patients developed bone metastasis. No patient was removed from the study for drug-related toxicity.

CONCLUSIONS

In the present pilot study, treatment with dutasteride resulted in a significant decrease in serum PSA in men with serologic relapse following radical treatment for adenocarcinoma of the prostate. These data appear to suggest that dutasteride may delay or prevent progression of prostate cancer in some men with biochemical relapse after radical therapy. These findings require confirmation in the setting of a larger, longer trial.

Association between serum sex hormone levels and prostate cancer: effect of prostate cancer on serum testosterone levels

Androgens are essential for prostatic growth and development, but also play a significant role in the pathogenesis of prostate disease. The traditional view that higher testosterone levels represent a risk factor for prostate cancer (PCa) appears to have little evidentiary support. Some studies have described a relationship between lower testosterone levels and more advanced disease. Serum androgen levels, within a broad range, are thus suggested to show no association with PCa risk, whereas low rather than high serum testosterone levels have been found to be associated with advanced or high-grade disease at the time of PCa diagnosis. Dihydrotestosterone, the principal prostatic androgen, is transformed from testosterone by type 1 and type 2 5alpha-reductase, and therapeutic benefits may thus be potentially achieved through the inhibition of 5alpha-reductase.

Overexpression of 5 alpha-reductase type 1 increases sensitivity of prostate cancer cells to low concentrations of testosterone

INTRODUCTION

Conversion of testosterone to dihydrotestosterone (DHT) by the enzymes 5 alpha-reductase types 1 (5 alpha R1) and 2 (5 alpha R2) is important for normal and pathological growth of the prostate. The predominant isoenzyme in normal prostate is 5 alpha R2. However, prostate cancer (PCa) development is accompanied by a decrease in 5 alpha R2 and an increase in 5 alpha R1. The biological significance of increased 5 alpha R1 expression is not fully understood. Therefore, the aim of this study was to determine the effect of overexpression of 5 alpha R1 on growth and prostate-specific antigen (PSA) production in PCa cells.

MATERIALS AND METHODS

LNGK-9 PCa cells, transiently transfected with pTRE-5 alpha R1 or pTRE alone, were cultured in the presence or absence of testosterone at varying concentrations. Cell growth and PSA secretion were measured after 4-6 days. Cyclin E1, Ki67, and PSA mRNA levels were evaluated using RT-PCR after 24 hr of treatment.

RESULTS

10 pM testosterone increased growth of pTRE-5 alpha R1 transfectants by 54.1% over cells grown in the absence of testosterone, compared to 25.0% in pTRE transfectants (P < 0.01). Likewise, PSA secretion was increased by 56-fold in pTRE-5 alpha R1 transfectants treated with 10 pM testosterone, compared to 26-fold in pTRE transfectants (P < 0.01). At concentrations of testosterone above 10 pM, the stimulatory effect on growth and PSA secretion was not distinguishable between pTRE-5 alpha R1 and pTRE transfectants.

CONCLUSIONS

These results demonstrate that upregulation of 5 alpha R1 enhances the cellular response to low, but not high, concentrations of testosterone. This explains one mechanism by which castration-recurrent PCa can proliferate in the presence of castrate levels of circulating testosterone.