Drugs online research references
Anticancer Res. 2002 May-Jun;22(3):1673-9.
Alpha1-adrenoceptor antagonists radiosensitize prostate cancer cells via apoptosis induction.
Cuellar DC, Rhee J, Kyprianou N.
Division of Urology, The University of Maryland School of Medicine, Baltimore, USA.
BACKGROUND: Androgen-independent prostate cancer cells can undergo apoptosis in response to non-androgen ablative means such as ionizing radiation. Recent evidence documented the ability of alpha-adrenoceptor antagonists, a widely used medical therapy for the treatment of benign prostatic hypertrophy (BPH), to induce apoptosis in benign and malignant prostate cells. In this study, we evaluated the potential additive/synergistic apoptotic effect of alpha1-adrenoceptor antagonists with ionizing radiation against human prostate cancer cells in vitro. MATERIALS AND METHODS: Androgen-independent human prostate cancer cells (PC-3) were treated with two alpha1-adrenoceptor antagonists, doxazosin and terazosin, for various periods of time prior to and after exposure to ionizing radiation. Apoptosis induction, cell viability and clonogenic assays were then performed to determine loss of clonogenic survival Hoechst staining was performed to detect the apoptotic morphology in prostate cancer cells and the temporal protein expression of the apoptosis regulators bax and caspase-3, was determined using Western blot analysis. RESULTS: No significant difference in cell death of PC-3 cells was detected when either doxazosin or terazosin was combined with ionizing radiation. Terazosin treatment however, 24 hours prior to, or 24 hours post-irradiation resulted in a significant enhancement of radiation-induced loss of clonogenic survival compared to radiation alone (p<0.05). Furthermore, there was a further significant increase in apoptosis induction when cells were pre-treated with terazosin (15%), compared to treatment with radiation alone (6%). Western blot analysis revealed a significant increase in bax protein expression (but not caspase-3) in response to radiation, with no additional effect with the combination treatment (terazosin and ionizing irradiation) compared to radiation alone. CONCLUSION: This is the first study to document the ability of alpha1-adrenoceptor antagonists to enhance the apoptotic effect of ionizing radiation against human prostate cancer cells. As this alpha1-adrenoceptor-mediated elevation of the apoptotic threshold involves neither bax deregulation nor caspase-3 activation, a differential mechanism might be underlying this radiosensitizing effect. The present findings may have important clinical relevance in identifying a more effective therapeutic approach for androgen-independent prostate cancer based on the combined apoptotic effects of quinazoline-based alpha1-adrenoceptor-antagonsists and radiotherapy.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12168853&dopt=Abstract
J Neurochem. 2002 Nov;83(3):623-34.
Mice expressing the alpha(1B)-adrenergic receptor induces a synucleinopathy with excessive tyrosine nitration but decreased phosphorylation.
Papay R, Zuscik MJ, Ross SA, Yun J, McCune DF, Gonzalez-Cabrera P, Gaivin R, Drazba J, Perez DM.
Department of Molecular Cardiology, The Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
We had previously reported that systemic overexpression of the alpha(1B)-adrenergic receptor (AR) in a transgenic mouse induced a neurodegenerative disease that resembled the parkinsonian-like syndrome called multiple system atrophy (MSA). We now report that our mouse model has cytoplasmic inclusion bodies that colocalize with oligodendrocytes and neurons, are positive for alpha-synuclein and ubiquitin, and therefore may be classified as a synucleinopathy. Alpha-synuclein monomers as well as multimers were present in brain extracts from both normal and transgenic mice. However, similar to human MSA and other synucleinopathies, transgenic mice showed an increase in abnormal aggregated forms of alpha-synuclein, which also increased its nitrated content with age. However, the same extracts displayed decreased phosphorylation of alpha-synuclein. Other traits particular to MSA such as Purkinje cell loss in the cerebellum and degeneration of the intermediolateral cell columns of the spinal cord also exist in our mouse model but differences still exist between them. Interestingly, long-term therapy with the alpha(1)-AR antagonist, terazosin, resulted in protection against the symptomatic as well as the neurodegeneration and alpha-synuclein inclusion body formation, suggesting that signaling of the alpha(1B)-AR is the cause of the pathology. We conclude that overexpression of the alpha(1B)-AR can cause a synucleinopathy similar to other parkinsonian syndromes.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12390524&dopt=Abstract
netone.com.tr
INTRODUCTION: The induction of apoptosis has emerged as a potential target for optimization of the medical management of benign prostatic hyperplasia (BPH), recently. The influence of alpha1-adrenoceptor antagonist (alpha1-ARA), 5-alpha reductase inhibitor and their combination on prostatic cell apoptotic and proliferative indices of benign hyperplastic prostate gland were investigated. MATERIALS AND METHODS: A total of 49 male patients with BPH (mean age: 66.5 years) treated with alpha1-ARA and/or finasteride were retrospectively evaluated. Patients treated with alpha1-ARA (doxazosin n = 12 and terazosin n = 10), finasteride (n = 9) and combination of finasteride and alpha1-ARA (n = 9) were enrolled in the study. Primary antibodies were Ki-67 and proliferating cell nuclear antigen for the evaluation of proliferation in prostate stromal and epithelial cells. In situ apoptotic DNA fragmentation was evaluated using TUNEL assay. RESULTS: All treatment groups had no significant changes in the rate of prostate stromal and epithelial cell proliferation. Epithelial apoptotic index (AI) was not statistically significant for finasteride vs. alpha1- ARA, alpha1-ARA vs. finasteride + alpha1-ARA and finasteride + alpha1-ARA vs. finasteride groups. While alpha1-ARA was more effective than finasteride on stromal apoptosis, alpha1-ARA-induced stromal apoptosis was not significantly different from alpha1-ARA plus finasteirde treatment. CONCLUSION: Not only androgen variabilities but also alterations in sympathetic neurotransmission with age could have important implications for pathophysiological prostate growth. The combination of finasteride and alpha1-ARA is not superior to alpha1-ARA therapy with their similar epithelial and stromal apoptotic effects with unaffected cell proliferation. Copyright 2002 S. Karger AG, Basel
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12444285&dopt=Abstract
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