The influence of alpha1-antagonist on the expression pattern of TNF receptor family in primary culture of prostate epithelial cells from BPH patients

Apoptotic Pathways Linked to Endocrine System as Potential Therapeutic Targets for Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is a chronic condition common in older men that can result in bothersome lower urinary tract symptoms. The molecular mechanisms and networks underlying the development and the progression of the disease are still far from being fully understood. BPH results from smooth muscle cell and epithelial cell proliferation, primarily within the transition zone of the prostate. Apoptosis and inflammation play important roles in the control of cell growth and in the maintenance of tissue homeostasis. Disturbances in molecular mechanisms of apoptosis machinery have been linked to BPH. Increased levels of the glycoprotein Dickkopf-related protein 3 in BPH cause an inhibition of the apoptosis machinery through a reduction in B cell lymphoma (Bcl)-2 associated X protein (Bax) expression. Inhibitors of apoptosis proteins influence cell death by direct inhibition of caspases and modulation of the transcription factor nuclear factor-κB. Current pharmacotherapy targets either the static component of BPH, including finasteride and dutasteride, or the dynamic component of BPH, including α-adrenoceptor antagonists such as tamsulosin and alfuzosin. Both these classes of drugs significantly interfere with the apoptosis machinery. Furthermore, phytotherapic supplements and new drugs may also modulate several molecular steps of apoptosis.

Terazosin treatment induces caspase-3 expression in the rat ventral prostate

BACKGROUND

Quinazoline-based alpha1-adrenergic receptor antagonists may not act solely on smooth muscle contractility. We evaluated the in vivo effect of terazosin on the expression of caspase-3 in the rat ventral prostate.

METHODS

Fifteen Wistar rats were treated with terazosin (1.2 mg/kg body weight, given orally every second day) for 120 days. Another 15 control animals received the same amount of distilled water. The expression of caspase-3 was assessed immunohistochemically in formalin-fixed, paraffin-embedded tissue sections.

RESULTS

Terazosin treatment did not affect prostate weight and histomorphology. In controls caspase-3 was expressed weakly and sporadically. In contrast, strong and weak expression was evident in 67% and 33% of the terazosin-treated specimens, respectively.

CONCLUSIONS

These findings implicate the induction of caspase-3 expression by terazosin as a potential molecular mechanism of its apoptotic action on prostate cells.

Prostate epithelial stem cells are resistant to apoptosis after α1-antagonist treatment. The impact for BPH patients

INTRODUCTION

Induction of apoptosis in prostatic epithelial cells by doxazosin, terazosin and prazosin has been well documented. However, the biochemical pathways of doxazosin action is still unclear. Aforementioned drugs should lead to decrease of prostate volume, although this effect was never observed in patients suffering from BPH after treatment with α1-antagonists. Probably, it is connected with cancer stem cells' resistance on chemotherapeutic agents. The aim of this study was to compare incidence of apoptosis induced by doxazosin in progenitor and differentiated cells isolated from human prostate epithelium.

MATERIAL AND METHODS

For this purpose tissue specimens were obtained from 10 patients suffering from BPH, the primary cultures of prostate epithelium were established and CD133 MicroBeads sorting was prepared. Both, CD133(+)/CD133(-) co-cultures and CD133(+) cells were incubated with different concentration of doxazosin for 12 h. Cell viability and apoptosis was estimated with Annexin V-FITC.

RESULTS

12 h incubation of CD133(+)/CD133(-) co-cultures with doxazosin resulted in increase of apoptotic cells, while in CD133(+) cultures no changes were observed. Correlation between apoptotic cell number and doxazosin concentration in CD133(+)/ CD133(-) co-cultures group was high (R = 0.99).

CONCLUSION

Doxazosin induced apoptosis in co-cultures of progenitor and differentiated epithelial cells. However, progenitor cells were not susceptible to apoptosis, what can be a reason of treatment failure in BPH patients.

Cancer biomarker discovery: the entropic hallmark

Background

It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods.

Methodology/Principal Findings

Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer.

Conclusions/Significance

We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-througput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases.