Finasteride to prevent prostate cancer: should all men or only a high-risk subgroup be treated?

Endoplasmic reticulum stress, autophagic and apoptotic cell death, and immune activation by a natural triterpenoid in human prostate cancer cells

Though the current therapies are effective at clearing an early stage prostate cancer, they often fail to treat late-stage metastatic disease. We aimed to investigate the molecular mechanisms underlying the anticancer effects of a natural triterpenoid, ganoderic acid DM (GA-DM), on two human prostate cancer cell lines: the androgen-independent prostate carcinoma (PC-3), and androgen-sensitive prostate adenocarcinoma (LNCaP). Cell viability assay showed that GA-DM was relatively more toxic to LNCaP cells than to PC-3 cells (IC₅₀ s ranged 45-55 µM for PC-3, and 20-25 µM for LNCaP), which may have occurred due to differential expression of p53. Hoechst DNA staining confirmed detectable nuclear fragmentation in both cell lines irrespective of the p53 status. GA-DM treatment decreased Bcl-2 proteins while it upregulated apoptotic Bax and autophagic Beclin-1, Atg5, and LC-3 molecules, and caused an induction of both early and late events of apoptotic cell death. Biochemical analyses of GA-DM-treated prostate cancer cells demonstrated that caspase-3 cleavage was notable in GA-DM-treated PC-3 cells. Interestingly, GA-DM treatment altered cell cycle progression in the S phase with a significant growth arrest in the G2 checkpoint and enhanced CD4 ⁺ T cell recognition of prostate tumor cells. Mechanistic study of GA-DM-treated prostate cancer cells further demonstrated that calpain activation and endoplasmic reticulum stress contributed to cell death. These findings suggest that GA-DM is a candidate for future drug design for prostate cancer as it activates multiple pathways of cell death and immune recognition.

Possible association between androgenic alopecia and risk of prostate cancer and testicular germ cell tumor: a systematic review and meta-analysis

BACKGROUND

A number of studies have investigated the association between androgenic alopecia (AGA) and cancer risk, but they have yielded inconsistent results. Therefore, this study was conducted to explore this controversial subject.

METHODS

A literature database search was performed according to predefined criteria. An odds ratio (OR) or a hazard ratio (HR) with 95% confidence intervals (CIs) was retained to evaluate the relationship between the incidence of cancer or cancer-specific mortality and categories of AGA. Then a pooled OR or HR was derived.

RESULTS

The pooled results showed that no specific degree of baldness had an influence on the incidence of cancer or cancer-specific mortality. However, AGA, especially frontal baldness, with the incidence of testicular germ cell tumor (TGCT) (OR = 0.69; 95% CI = 0.58-0.83). A significant increase of risk was observed in relation to high grade prostate cancer (PC) (OR = 1.42; 95% CI 1.02-1.99) and vertex with/without frontal baldness was associated with PC risk.

CONCLUSIONS

The study results supported the hypothesis that AGA is negatively associated with TGCT risk and suggested an overlapping pathophysiological mechanism between them, while the viewpoint that AGA can be used as a phenotypic marker for PC risk was poorly supported.

Decision analysis of dutasteride use for patients with negative prostate biopsy

OBJECTIVE

To determine whether the additional benefits of improved prostate cancer detection associated with 5α-reductase inhibitors are sufficient to warrant chemoprevention in the case where the degree of prostate cancer risk reduction is deemed inadequate.

METHODS

We reanalyzed data from REDUCE, a randomized trial of dutasteride for prostate cancer chemoprevention in men with prior negative biopsy. We evaluated whether statistical models using prostate-specific antigen (PSA) and PSA velocity could help predict the result of repeat prostate biopsy separately for dutasteride and placebo groups. Area under the curve was evaluated by 10-fold cross-validation.

RESULTS

PSA velocity improved discrimination at 4 years in the dutasteride group but not at 2 years nor in the placebo group. At 2 years, dutasteride improved discrimination of PSA slightly (0.616 vs. 0.603 for any grade cancer; 0.681 vs. 0.676 for high-grade disease). Between-group differences in cancer rates at 4 years were small.

CONCLUSION

Clinicians who are willing to treat at least 23 patients with dutasteride for 2 years to avoid 1 prostate cancer diagnosis should offer dutasteride after initial negative biopsy. Clinicians not willing to do so might consider dutasteride for its additional benefit of reducing unnecessary biopsy, although this benefit is apparent only under very restrictive conditions. It is difficult to justify extending treatment with dutasteride for >2 years.

Chinese urologists' views of practice patterns in the diagnosis and treatment of benign prostatic hyperplasia: a nationwide survey

Purpose

To assess the compliance of Chinese urologists with China's benign prostatic hyperplasia (BPH) clinical practice guideline and to explore the diagnosis and therapy modalities for geriatric patients with BPH.

Methods

A cross-sectional survey study was carried out in 33 medical centers in 11 different cities in China. A total of 190 urologists participated in a survey to record their preferences for diagnostic tests and treatment options for BPH outpatients. Diagnostic test results as well as health care demands were collected by surveying 2,027 outpatients aged 60 years and older.

Results

The survey response rate was 97.4%. The respondents generally used the diagnostic tests recommended in China's BPH clinical practice guideline at varying rates. The used rates for medical history, ultrasonography, and urinalysis were above 90.0%; that for uroflowmetry was 31.2%. In addition, the rate of use of recommended tests was higher among doctors in the north than among those in the south. Combination therapy with α-adrenoceptor antagonists and 5α-reductase inhibitors was the preferred treatment option for BPH, and was increasingly used with worsening lower urinary tract symptoms. Finasteride was the most prescribed medication (48.0%), followed by tamsulosin (22.7%).

Conclusions

This study assessed the preferences of urologists in the diagnosis and treatment of BPH, which will serve as an important reference for updating and improving China's current BPH clinical practice guideline.

Inhibition of JNK-1 by small interfering RNA induces apoptotic signaling in PC-3 prostate cancer cells

Previous studies have shown that c-Jun-N-terminal kinase-1 (JNK-1) is involved in the transformation of primary fibroblasts and plays a role in tumor cell growth. A number of observations suggest that JNK-1 is a growth promoting factor in prostate cancer cells and blocking its function may induce apoptosis. To test this further, we used a small interfering RNA (siRNA) against JNK-1 mRNA that efficiently inhibits JNK-1 expression in the prostate cancer cell line, PC-3. The application of siRNA against JNK-1 decreased the expression of JNK-1 and affected the expression of p21, XIAP and Bcl-2, but had no effect on the expression of VEGF. In contrast, a control scramble siRNA did not affect the expression of the above indicated proteins. The downregulation of JNK-1 expression at both the mRNA and protein levels was detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis. Cell proliferation inhibition rates were determined by the MTT assay. The effect of JNK-1-siRNA on cell cycle distribution and cell apoptosis was determined by flow cytometry, DNA fragmentation and caspase activity. Our data showed that siRNA against JNK-1 mRNA, could efficiently suppress the expression of JNK-1 in PC-3 cells. After 5 days of transfection, the cell death rate was 52%, the apoptotic rate 26% and the viability rate 22%. In conclusion, downregulation of JNK-1 expression by siRNA against JNK-1 mRNA induces apoptotic signaling in prostate cancer PC-3 cells. The use of siRNA against JNK-1 as a novel approach to cancer therapy deserves further investigation.

Prostate cancer and androgenic alopecia

Prostate cancer is a burden on society. Its prevalence can reach up to 80% in males aged 70 years and older. Current screening programs based on prostate-specific antigen testing lead to overdiagnosis and overtreatment with uncertain benefits on survival. Androgenic alopecia is also highly prevalent in elderly males. Observational studies have found that androgenic alopecia is linked to prostate cancer, but studies have been conflictual. Further research should focus on finding the exact mechanism linking these two pathologies. This should help clinicians improve screening programs and guide research into novel molecules to help in the prevention and treatment of both androgenic alopecia and prostate cancer.

O impacto na expressão agnors e apoptose na próstata do hamster-mesocricetus auratus (HMA) submetido à aplicação de finasterida

OBJETIVO: Avaliar o impacto na expressão AgNORs e apoptose na próstata do hamster-Mesocricetus auratus (hMa) submetido à aplicação de finasterida. MÉTODOS: Vinte roedores da espécie hMa (n=20), machos foram separados aleatoriamente em grupos de dez animais: grupo-Finasterida (n=10) e grupo-Controle (n=10). No grupo-finasterida foi administrado 7,14 ng/mL de finasterida, subcutâneo (SC), no dorso, três vezes por semana, por 90 dias. Foi avaliada a expressão AgNORs como marcador de proliferação celular e a apoptose como marcador de morte celular. RESULTADOS: A expressão de AgNORs foi menor no grupo-finasterida, 2,846±0,877 versus 3,68 ±1,07 grumos argilófilos por micrômetro ao quadrado (µm²) no grupo-controle, p= < 0,0001. A apoptose foi mais frequente no grupo-finasterida, 53,62±1,389 versus 14,76 ± 2,137 µm² no grupo-controle, p= 0,0408. CONCLUSÃO: Observou-se diminuição da expressão de AgNORs e promoção da apoptose na próstata dos roedores em estudo, que foram submetidos à aplicação de finasterida.

5-α reductase inhibitors and prostate cancer prevention: where do we turn now?

With the lifetime risk of being diagnosed with prostate cancer so great, an effective chemopreventive agent could have a profound impact on the lives of men. Despite decades of searching for such an agent, physicians still do not have an approved drug to offer their patients. In this article, we outline current strategies for preventing prostate cancer in general, with a focus on the 5-α-reductase inhibitors (5-ARIs) finasteride and dutasteride. We discuss the two landmark randomized, controlled trials of finasteride and dutasteride, highlighting the controversies stemming from the results, and address the issue of 5-ARI use, including reasons why providers may be hesitant to use these agents for chemoprevention. We further discuss the recent US Food and Drug Administration ruling against the proposed new indication for dutasteride and the change to the labeling of finasteride, both of which were intended to permit physicians to use the drugs for chemoprevention. Finally, we discuss future directions for 5-ARI research.

Finasteride metabolism and pharmacogenetics: new approaches to personalized prevention of prostate cancer

Incidences of prostate cancer in most countries are increasing owing to better detection methods; however, prevention with the use of finasteride, a very effective steroid 5α-reductase type II inhibitor, has been met with mixed success. A wide interindividual variation in response exists and is thought to be due to heritable factors. This article summarizes the literature that attempts to elucidate the molecular mechanisms of finasteride in terms of its metabolism, excretion and interaction with endogenous steroid molecules. We describe previously reported genetic variations of steroid-metabolizing genes and their potential association with finasteride efficacy. Based on the literature, we outline directions of research that may contribute to understanding the interindividual variation in finasteride prevention and to the future development of personalized medicine.

Ganoderic Acid DM: An Alternative Agent for the Treatment of Advanced Prostate Cancer

Prostate cancer is the most commonly diagnosed cancer in men and accounts for significant morbidity and mortality in the western world. While traditional therapies are effective at clearing early stage cancer, they often fail to treat late stage metastatic disease. Thus, an effective therapy that targets prostate tumor growth and metastasis is desired for alleviating the disease and improving patient outcomes. Natural extracts have been the focus of recent investigation, particularly those with reduced cellular toxicity to healthy tissue. In this review, we discuss one potential candidate, ganoderic acid, an extract from the Ganoderma lucidum mushroom that has been tested in multiple cancer models. Interestingly, ganoderic acid DM (GA-DM) has shown toxicity to both androgen-dependent and independent prostate cancer cells with reduced osteoclastogenesis in late stage metastatic disease. This review will discuss the current knowledge on this GA-DM extract and the potential benefit in treating advanced prostate cancer. We will also provide an overview on the targeted delivery of GA-DM through nanoparticles that would reduce bystander toxicity and improve the drug's effectiveness. An improved understanding of this drug and its uses will advance the field of natural chemotherapeutics, particularly in treating advanced prostate cancer.