Prospective analysis of single nucleotide polymorphisms of the transforming growth factor beta-1 gene in Peyronie's disease

Unveiling the molecular Hallmarks of Peyronie's disease: a comprehensive narrative review

Peyronie's disease, a fibroinflammatory disorder, detrimentally impacts the sexual well-being of men and their partners. The manifestation of fibrotic plaques within penile tissue, attributed to dysregulated fibrogenesis, is pathognomonic for this condition. The onset of fibrosis hinges on the perturbation of the equilibrium between matrix metalloproteinases (MMPs), crucial enzymes governing the extracellular matrix, and tissue inhibitors of MMPs (TIMPs). In the context of Peyronie's disease, there is an elevation in TIMP levels coupled with a decline in MMP levels, culminating in fibrogenesis. Despite the scant molecular insights into fibrotic pathologies, particularly in the context of Peyronie's disease, a comprehensive literature search spanning 1995 to 2023, utilizing PubMed Library, was conducted to elucidate these mechanisms. The findings underscore the involvement of growth factors such as FGF and PDGF, and cytokines like IL-1 and IL-6, alongside PAI-1, PTX-3, HIF, and IgG4 in the fibrotic cascade. Given the tissue-specific modulation of fibrosis, comprehending the molecular underpinnings of penile fibrosis becomes imperative for the innovation of novel and efficacious therapies targeting Peyronie's disease. This review stands as a valuable resource for researchers and clinicians engaged in investigating the molecular basis of fibrotic diseases, offering guidance for advancements in understanding Peyronie's disease.

European Society of Sexual Medicine consensus statement on the use of animal models for studying Peyronie's disease

Introduction

Animal models are frequently used for translational research in Peyronie's disease (PD). However, due to lack of availability of guidelines, there is some heterogeneity in study design, data reporting, and outcome measures.

Aim

This European Society for Sexual Medicine consensus statement aims to provide guidance in utilization of animal models in PD research in a standardized and uniform fashion.

Methods

PubMed was searched for studies using animal models for PD. The following search terms were used: ("Peyronie's disease" OR "penile fibrosis" OR "penile curvature" OR "induration penis plastica" OR "erectile dysfunction") AND ("rodent" OR "mouse" OR "mice" OR "rat" OR "rabbit").

Outcomes

This European Society for Sexual Medicine statement describes best practice guidelines for utilization of animals in PD research: power calculation, details of available models, surgical procedures, and measurement techniques, while highlighting possible pitfalls and translational limitations of the models.

Results

In total, 2490 studies were retrieved and 2446 articles were excluded. A total of 44 studies were included, of which 40 studies used rats, 1 study used both rats and mice, 1 study used a genetic mouse model, and 2 studies used rabbits. A significant number of the studies (70.5%) used transforming growth factor β 1 for induction of fibrosis. Oxford 2011 Levels of Evidence criteria could not be applied due to the nature of the studies.

Conclusion

Despite certain limitations of PD animal models presented, we aimed to provide guidance for their appropriate use in translational research, with the purpose of improving study quality and reproducibility as well as facilitating interpretation of reported results and conclusions.

Molecular Mechanisms and Risk Factors Related to the Pathogenesis of Peyronie's Disease

Peyronie's disease (PD) is a benign condition caused by plaque formation on the tunica albuginea of the penis. It is associated with penile pain, curvature, and shortening, and contributes to erectile dysfunction, which worsens patient quality of life. In recent years, research into understanding of the detailed mechanisms and risk factors involved in the development of PD has been increasing. In this review, the pathological mechanisms and several closely related signaling pathways, including TGF-β, WNT/β-catenin, Hedgehog, YAP/TAZ, MAPK, ROCK, and PI3K/AKT, are described. Findings regarding cross-talk among these pathways are then discussed to elucidate the complicated cascade behind tunica albuginea fibrosis. Finally, various risk factors including the genes involved in the development of PD are presented and their association with the disease summarized. The purpose of this review is to provide a better understanding regarding the involvement of risk factors in the molecular mechanisms associated with PD pathogenesis, as well as to provide insight into disease prevention and novel therapeutic interventions.

Significant familial clustering of Peyronie's disease in close and distant relatives

BACKGROUND

Peyronie's disease (PD) has previously been observed to co-aggregate in a small number of first-degree relative pairs (e.g., father-son). However, the familial aggregation of PD in more distant relatives, as well as the aggregation of Dupuytren's disease (DD) in probands and relatives, has not been thoroughly investigated.

OBJECTIVE

This study explored the evidence for familial clustering of PD and DD in close and distant relatives.

MATERIALS AND METHODS

The Utah Population Database, which includes genealogy information linked to electronic medical records (available since 1995), was used to identify men and their relatives with PD and DD based on ICD9/10 codes. All cases were required to have high-quality genealogy data. We estimated relative risk (RR) of PD and DD in first- through fifth-degree relatives compared to matched population rates of disease. We also investigated the average relatedness of cases compared to the average relatedness of sets of matched controls. Outcome measures include estimation of relative risk and excessive relatedness as measured by a Genealogical Index of Familiality (GIF) analysis.

RESULTS

We analyzed 307 individuals with PD, and their first- through fifth-degree relatives. Approximately 0.12% of the population had PD, 95% of these were diagnosed over the age of 30 years (age range: 10-92 years), and 1.3% of PD probands had a comorbid diagnosis of DD. RR estimates for PD were significant for first- and fifth-degree relatives. RR estimates for DD were significant only for probands. The average relatedness of cases was significantly greater than matched controls, even after removing first- and second-degree relatives. We also found that 74.9% of identified PD probands belonged to pedigrees with a statistical excess of PD.

CONCLUSION

Despite the low prevalence of PD in our healthcare records, the results provide evidence that support a genetic contribution to at least a subset of PD cases.

ABO Blood Type and Risk of Peyronie's Disease in Japanese Males

PURPOSE

Although multiple mechanisms associated with Peyronie's disease (PD) have been proposed, details regarding etiologic factors, especially genetic, remain unclear. We examined the relationship of the ABO blood type system, known as a genetic factor associated with susceptibility to a number of diseases, with PD in Japanese males.

MATERIALS AND METHODS

We compared 202 Japanese PD patients treated with surgery at our hospital between March 2004 and December 2019 with 846 randomly selected non-PD male patients who underwent urological surgery during the same period regarding distribution of ABO blood types. In addition, we assessed the risk of PD according to blood type group among all study participants using odds ratio (OR) and 95% confidence interval (CI) calculations.

RESULTS

The distribution of individual blood types in the control group was nearly the same as that in the general Japanese population. In contrast, O, A, B, and AB blood types were noted in 37.6%, 36.1%, 14.9% and 11.4%, respectively, of the PD patients, which was significantly different from the control group, where blood type O was found in 29.1% and B in 23.2% (p<0.05). Our results showed that as compared with patients with blood group B, those with another blood type were more likely to develop PD, among which type O had a significantly increased OR of 2.018 (CI, 1.271-3.205).

CONCLUSIONS

These are the first reported results showing that ABO blood type may be associated with risk of PD, though further investigations are needed.

SINGLE NUCLEOTIDE POLYMORPHISMS IN RETINAL DETACHMENT PATIENTS WITH AND WITHOUT PROLIFERATIVE VITREORETINOPATHY

PURPOSE

To investigate differences in genotype distributions of single nucleotide polymorphisms within genes, encoding inflammatory mediators, among patients with rhegmatogenous retinal detachment (RRD) and patients with proliferative vitreoretinopathy (PVR).

METHODS

A genetic association study was performed on 191 Slovenian patients, divided into 2 groups: 113 RRD patients with PVR and 78 RRD patients without PVR. Genotype distributions were investigated within the following 13 single nucleotide polymorphisms: rs3760396 (CCL2), rs9990554 (FGF2), rs17561 (IL1A), rs2069763 (IL2), rs1800795 (IL6), rs1800871 (IL10), rs3008 (JAK3), rs2229094 (LTA), rs1042522 (TP53), rs7656613 (PDGFRA), rs7226855 (SMAD7), rs1800471 (TGFB1), and rs1800629 (TNF).

RESULTS

Differences in genotype distributions between patients with RRD with or without PVR were detected in rs1800795 (IL6) (P = 0.04), rs1800871 (in the vicinity of the IL10) (P = 0.034), and rs1800471 (TGFB1) (P = 0.032). After adjustment none of the 13 analyzed single nucleotide polymorphisms showed statistically significant associations in single nucleotide polymorphism genotype distributions between patients with RRD with and without PVR.

CONCLUSION

Further research is needed, particularly expanded multicentric population-based studies, to clarify the issue of genetic contribution to PVR from different genetic, clinical, and population-based aspects.

New insights into the pathogenesis of Peyronie's disease: A narrative review

Peyronie's disease (PD) is a benign, progressive fibrotic disorder characterized by scar or plaques within the tunica albuginea (TA) of the penis. This study provides new insights into the pathogenesis of PD based on data from different studies regarding the roles of cytokines, cell signaling pathways, biochemical mechanisms, genetic factors responsible for fibrogenesis. A growing body of literature has shown that PD is a chronically impaired, localized, wound healing process within the TA and the Smith space. It is caused by the influence of different pathological stimuli, most often the effects of mechanical stress during sexual intercourse in genetically sensitive individuals with unusual anatomical TA features, imbalanced matrix metalloproteinase/tissue inhibitor of metalloproteinase (MMP/TIMP), and suppressed antioxidant systems during chronic inflammation. Other intracellular signal cascades are activated during fibrosis along with low expression levels of their negative regulators and transforming growth factor-β1 signaling. The development of multikinase agents with minimal side effects that can block several signal cell pathways would significantly improve fibrosis in PD tissues by acting on common downstream mediators.

The Natural History of Peyronie's Disease

Peyronie's disease (PD), a fibrotic disorder of the tunica albuginea fully described in 1793 by French physician Francois de la Peyronie, is characterized by pain, plaque formation, penile deformity, and ultimately sexual function decline. The epidemiological data on PD vary considerably across previous studies, with recent evidence reporting a prevalence of up to 9%. PD is generally divided into two different phases: active or acute and stable or chronic. Plaque formation generally occurs during the acute phase, while during chronic phase pain usually tends to complete resolution and penile deformity stabilizes. PD's pathophysiology is still subject of great discussion. Tunical mechanical stress and microvascular trauma are major contributory factors. However, better understanding of the molecular pathophysiology of this condition remains paramount towards an in-depth comprehension of the disorder and the development of newer and more effective disease-targeted interventions. In this review we provide a detailed overview of natural history of PD, specifically focusing on clinical manifestations and the underlying molecular regulation patterns.

Rat as an animal model for Peyronie's disease research: a review of current methods and the peer-reviewed literature

While the exact mechanism of Peyronie's disease (PD) remains an enigma, the pathophysiology of PD is considered to be multifactorial, with interactions of genetic predisposition, trauma, tissue inflammation and aberrant wound healing. A non-systematic review of the existing English language literature pertaining to the use of rodent models in the evaluation of PD was performed using the Medline database. Multiple free-text searches were performed on key words: animal models of PD, transforming growth factor β1 (TGF β1), tunical and/or corporal fibrosis, subtunical injection and penile myofibroblasts. The most frequently reported models of PD can be classified as TGF β1, fibrin and surgical trauma-induced models. In vitro studies using Peyronie's fibroblast culture media have also provided further insights into cellular mechanism of PD. At the present time, the research in PD is hampered by the lack of universally accepted animal model and this is likely attributed to the limited insight into PD mechanisms and the difficulties faced by current animal models to truly represent the complexity and complete spectrum of human disease.

Peyronie's disease: perspectives on therapeutic targets

INTRODUCTION

Peyronie's disease (PD) is an acquired benign connective tissue disorder of the penis, characterized by the development of fibrotic plaques, that can cause different degrees of bending, narrowing or shortening. Medical treatment for PD remains a major challenge. Impressive progress in our understanding of the molecular mechanisms of PD pathogenesis has uncovered several promising molecular targets for antifibrotic treatments.

AREAS COVERED

This review covers the literature pertaining to the exploration of therapeutic targets for PD. The search included: i) a MEDLINE search from 1941 to January 2011, limited to English-language medical literature, ii) relevant abstracts from 2009 and 2010, iii) relevant textbooks and iv) a pipeline search for therapeutics in development.

EXPERT OPINION

Rapid translational research depends on our ability to develop rational therapies targeted to penile tunical fibrosis, which necessitate a sound knowledge of the biology, biochemistry and the physiological role of fibroblasts, myofibroblasts and stem cells in PD. Much remains to be learned about the pathogenesis of PD. Although there are many interesting therapeutic targets, we are confronted with some questions when identifying new targets, or when validating potential therapeutic options.

The management of Peyronie's disease: evidence-based 2010 guidelines

INTRODUCTION

The field of Peyronie's disease is evolving and there is need for a state-of-the-art information in this area.

AIM

To develop an evidence-based state-of-the-art consensus report on the management of Peyronie's disease.

METHODS

To provide state-of-the-art knowledge regarding the prevalence, etiology, medical and surgical management of Peyronie's Disease, representing the opinion of leading experts developed in a consensus process over a 2-year period.

MAIN OUTCOME MEASURES

Expert opinion was based on grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate.

CONCLUSIONS

The real etiology of Peyronie's disease and the mechanisms of formation of the plaque still remain obscure. Although conservative management is obtaining a progressively larger consensus among the experts, surgical correction still remains the mainstay treatment for this condition.

Pharmacogenetics and pharmacogenomics of sexual dysfunction: current status, gaps and potential applications

Although treatment of different types of sexual dysfunction has improved in the past decade with the introduction of phosphodiesterase type 5 inhibitors and selective serotonin reuptake inhibitors, response rates to these targeted therapies are variable. There are a number of studies in the published literature that provide proof-of-concept that genetic variation contributes to the variable response. Pharmacogenomics will most likely be one part of our therapeutic armamentarium in the future and will provide a stronger scientific basis for optimizing drug therapy on the basis of each patient’s genetic constitution. This article will review English language medical literature on the state-of-the-art genetic polymorphisms of drug targets, transporters and signaling molecules as well as pharmacogenetic studies of sexual dysfunction and suggested possible applications. Collectively, the data demonstrate that pharmacogenomics in the field of sexual medicine is still in its infancy. More research will provide further intriguing new discoveries in years to come.

Association of genetic variation in the transforming growth factor beta-1 gene with serum levels and risk of colorectal neoplasia

In the normal intestinal epithelium transforming growth factor beta-1 (TGFbeta-1) acts as a growth inhibitor, but in malignant cells it may act as a tumor promoter. However, only limited information is available on genetic variation in the TGFB1 gene and its relationship to circulating levels and risk of colorectal cancer. To characterize associations of genetic variation [tagging single-nucleotide polymorphisms (tagSNP) and haplotypes with frequency >0.05] at the TGFB1 locus with circulating TGFbeta-1 and risk of colorectal neoplasia, we conducted two case-control studies (including 271 colorectal adenoma cases and 544 controls, and 535 colorectal adenocarcinoma cases and 656 controls) among Japanese Americans, Caucasians, and Native Hawaiians in Hawaii. Serum TGFbeta-1 was measured by sandwich ELISA among the subjects of the first study. The variant A allele for tagSNP rs6957 was associated with higher serum TGFbeta-1 [means (in ng/mL) and 95% confidence interval (95% CI) for AA or AG, 32.6 (30.6-34.7); GG, 29.0 (25.1-32.9); P(difference) = 0.05] after adjusting for age and other factors. Homozygous carriers of the variant G allele for tagSNP rs11466345 had a statistically significantly lower risk of adenocarcinoma [AG versus AA: odds ratio (OR), 0.9 (95% CI, 0.7-1.2); GG versus AA: OR, 0.4 (95% CI, 0.2-0.7); P(trend) = 0.01]. The haplotype carrying both variants was also statistically significantly associated with a reduced risk of adenocarcinoma (OR, 0.3; 95% CI, 0.1-0.8). Although not statistically significant, the direction and magnitude of the corresponding ORs were similar for adenoma. These results suggest that a haplotype containing SNP rs11466345 at the 3' end of TGFB1 is associated with genetic susceptibility to colorectal neoplasia.

The natural history of Peyronie's disease: an ultrasonography-based study

OBJECTIVES

To define ultrasonographic patterns reflecting different states of Peyronie's disease (PD) and to use them to evaluate the natural history of the disease.

MATERIAL AND METHODS

Diagnosis of PD was based on medical and sexual history, physical examination, intracavernosal injection test, and penile ultrasonography. Patients with penile fracture history were excluded from the study. Three groups were formed according to ultrasonographic patterns: solitary hyperechoic lesion without acoustic shadow (group A), moderately hyperechoic multiple scattered calcified lesions with acoustic shadows (group B), dense calcified hyperechoic plaque with acoustic shadow (group C). All patients entered a watchful waiting protocol for 1 yr followed by a new penile ultrasonography.

RESULTS

Ninety-five 95 patients with PD were included in the study (mean age, 57.2+/-9.1 yr; mean duration of disease, 12.9+/-8.9 mo). Risk factors associated with cardiovascular disease were present in 79 of 95 patients (83.16%). Eleven (11.6%), 35 (36.8%), and 49 (51.6%) patients were classified into groups A, B and C, respectively. At the end of the study, in group A, reduction of fibrotic lesions and curvature angle was noticed in 9 of 11 (81.8%) patients, whereas plaque formation was noticed in 2 of 11 (18.2%) patients. In group B, plaque and curvature reduction was noticed in 15 of 35 (42.9%) and 12 of 35 (34.3%) respectively, whereas in the rest a dense calcified plaque was noticed. In group C, no ultrasonographic evidence of improvement was noticed; curvature angle was reduced in 4 of 49 (8.2%), owing to the extension of the plaque circumferentially. Significant hemodynamic changes were noticed at the two time points tested (30.53% diagnosed with vascular disease at baseline vs. 46.32% at the end of the study, p=0.03).

CONCLUSIONS

Corporal ultrasonography in patients with PD allows objective evaluation and classification of disease. The density of echogenic areas and presence of acoustic shadows are predictors of disease stability.

Alterations in the Transforming Growth Factor (TGF)-β Pathway as a Potential Factor in the Pathogenesis of Peyronie’s Disease

OBJECTIVES

The development of fibrotic diseases is associated with alterations in the transforming growth factor beta (TGF-beta) pathway. We have investigated the expression and activity of Smad transcription factors of the TGF-beta pathway in primary tunical fibroblasts derived from patients with Peyronie's disease and from controls.

METHODS

Primary fibroblasts were established from biopsies obtained from plaques of 16 patients with Peyronie's disease or the tunica albuginea of 8 control patients. The expression and activity of Smad transcription factors in control and TGF-beta-stimulated primary fibroblasts were investigated at the RNA and protein level by reverse transcription-polymerase chain reaction, Western blotting, and immunofluorescence.

RESULTS

RNA expression levels of Smad3 and Smad4 were significantly increased in fibroblasts from patients with Peyronie's disease. When stimulated with TGF-beta1, fibroblasts showed rapid nuclear translocation of Smad2/3, as soon as 15 min after stimulation. This effect was more pronounced and exhibited an earlier onset in fibroblasts from patients with Peyronie's disease, compared with controls. In addition, an increased nuclear retention time of Smad4 was observed in fibroblasts from patients with Peyronie's disease.

CONCLUSIONS

The expression and activity of Smad transcription factors of the TGF-beta pathway is increased in fibroblasts of patients with Peyronie's disease. Alterations in the TGF-beta pathway seem to be a pathogenetic factor in the development of Peyronie's disease.

TGFbeta1 polymorphisms and late clinical radiosensitivity in patients treated for gynecologic tumors

PURPOSE

To investigate the association between six transforming growth factor beta1 gene (TGFbeta1) polymorphisms (-1.552delAGG, -800G>A, -509C>T, Leu10Pro, Arg25Pro, Thr263Ile) and the occurrence of late normal tissue reactions after gynecologic radiotherapy (RT).

METHODS AND MATERIALS

Seventy-eight women with cervical or endometrial cancer and 140 control individuals were included in the study. According to the Common Terminology Criteria for Adverse Events version 3.0 (CTCAEv3.0) scale, 25 patients showed late adverse RT reactions (CTC2+), of whom 11 had severe complications (CTC3+). Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), single base extension and genotyping assays were performed to examine the polymorphic sites in TGFbeta1.

RESULTS

Homozygous variant -1.552delAGG, -509TT, and 10Pro genotypes were associated with the risk of developing late severe RT reactions. Triple (variant) homozygous patients had a 3.6 times increased risk to develop severe RT reactions (p=0.26). Neither the -800A allele, nor the 25Pro allele or the 263Ile allele were associated with clinical radiosensitivity. There was perfect linkage disequilibrium (LD) between the -1.552delAGG and the -509C>T polymorphisms, and tight LD between the -1.552/-509 and the Leu10Pro polymorphisms. Haplotype analysis revealed two major haplotypes but could not distinguish radiosensitive from nonradiosensitive patients.

CONCLUSIONS

The present study shows that homozygous variant TGFbeta1 -1.552delAGG, -509TT, and 10Pro genotypes may be associated with severe clinical radiosensitivity after gynecologic RT.

Cytokine gene polymorphisms in retinal detachment patients with and without proliferative vitreoretinopathy: a preliminary study

PURPOSE

Cytokines and other growth factors such as interleukins play an important role in the pathogenesis of proliferative vitreoretinopathy (PVR). Interindividual variations in cytokine production seem to correlate with some cytokine gene polymorphisms. The purpose of this study was to analyse the distribution of these cytokine gene variants in patients with rhegmatogenous retinal detachment (RD) with and without PVR.

METHODS

Single nucleotide polymorphisms were analysed for five cytokines: tumour necrosis factor-alpha (TNF-alpha), transforming growth factor-beta1 (TGF-beta1), interferon-gamma (IFN-gamma), interleukin-6 (IL-6) and interleukin-10 (IL-10). Patients were divided into two surgically treated groups of RD patients: group RD had 27 patients with RD, and group PVR had 31 patients with RD complicated by PVR. A control group was composed of 46 ethnically matched healthy individuals.

RESULTS

The genotype distribution of the TGF-beta1 codon 10 polymorphism differed between PVR and RD patients (p = 0.018) and between PVR patients and controls in codon 25 (p = 0.011). There was a higher frequency of TGF-beta1 codon 10 allele T in PVR patients compared with RD patients (p = 0.023). No statistically significant differences between groups were observed for the other polymorphisms examined.

CONCLUSION

An association between the TGF-beta1 genetic profile and the development of PVR was detected in this study. Further studies are necessary to confirm this finding and to establish its clinical relevance.

Gender-related association between the TGFB1+869 polymorphism and multiple sclerosis

Our objective was to investigate whether polymorphisms and haplotypes in the TGFB1 gene are associated with susceptibility or disease characteristics of multiple sclerosis (MS). In 247 MS patients and 194 controls, single nucleotide polymorphisms (SNPs) at position +869 (Leu10Pro) and position +915 (Arg25Pro) in the signaling sequence of the TGFB1 gene were determined, and the distribution of alleles, genotypes, and haplotypes was related to clinical data. In addition, magnetic resonance imaging (MRI) data were studied in a subgroup of patients (n = 96). The allele distribution of the two polymorphisms studied was in Hardy-Weinberg equilibrium in patients and in controls. No association was found with any of the three haplotypes found in the Dutch population, denoted as haplotype 1 (TGFB1+869T-TGFB1+915G), haplotype 2 (TGFB1+869C-TGFB1+915G), and haplotype 3 (TGFB1+869C-TGFB1+915C). However, the TGFB1+869 genotype CC was significantly more frequent in patients (p = 0.031, chi2 test). The highest frequency of the TGFB1+869 genotype CC was observed in male patients (25.2% vs. 10.0% in controls, p = 0.004, chi2 test), and carriership of TGFB1+869 allele C was correspondingly increased in male patients (74.8% vs. 56.7%, p = 0.008, chi2 test, OR 2.27, 95% CI 1.23-4.17). Although there was no association with clinical markers of disease progression, patients homozygous for TGFB1+869 allele C showed a significantly higher annual increase in two MRI parameters: ventricular fraction (central atrophy) and T1-hypointense lesion load (matrix destruction). The TGFB1 T+869C (Leu10Pro) gene polymorphism is associated with MS susceptibility, especially in males, and with a more destructive course of the disease as illustrated by MRI.

Analysis of the transforming growth factor-beta1 (TGF-beta1) codon 25 gene polymorphism by LightCycler-analysis in patients with chronic hepatitis C infection

The polymorphism at position 25 of the gene encoding transforming growth factor-beta1 (TGF-beta1), which changes the amino acid sequence of the signal peptide sequence (arginine to proline), is causing a variation in TGF-beta1 production. The homozygous genotype (Arg25Arg) is associated with higher TGF-beta1 production than the heterozygous (Arg25Pro) genotype. Therefore, the possible involvement of this genetic variation in the TGF-beta1 gene for induction and progression of various diseases is under close investigation. At present, several labor-intensive established assays ranging from amplification refractory mutation system (ARMS)-PCR methodologies, sequence specific oligonucleotide probing (SSOP), restriction fragment length polymorphism (RFLP) analysis, 5' nuclease assays, and specialized fingerprinting protocols are applied to analyze the polymorphism in question. We developed a novel approach for analyzing this polymorphism in a LightCycler system and determined the allele frequency distributions between patients with different degrees of hepatic fibrosis induced by chronic hepatitis C virus infection. In patients with severe hepatic fibrosis (METAVIR-score 3-4), the Pro25 allele was twice as frequent compared to patients with mild fibrosis (METAVIR-score 0-2). However, we found no association of necroinflammatory activity and genotype distribution. This suggests that the stage of hepatic fibrosis, rather than the grade (inflammation), is influenced by the presence of proline at codon 25 in patients with chronic hepatitis C.

Prediction of normal tissue radiosensitivity from polymorphisms in candidate genes

BACKGROUND AND PURPOSE

Single nucleotide polymorphisms (SNPs) in genes related to the biological response to radiation injury may affect clinical normal tissue radiosensitivity. This study investigates whether seven selected SNPs in five candidate genes influence risk of subcutaneous fibrosis and telangiectasia after radiotherapy.

PATIENTS AND METHODS

The 41 patients included in this study were given post-mastectomy radiotherapy in 1978-1982 and subsequently evaluated in detail with regard to several different normal tissue reactions. SNPs in TGFB1 (codons 10, 25 and position -509), SOD2 (codon 16), XRCC3 (codon 241), XRCC1 (codon 399) and APEX (codon 148) were analyzed by PCR and single nucleotide primer extension. Dose-response curves were established for subcutaneous fibrosis and telangiectasia in patients with different genotypes. Differences in radiosensitivity were quantified in terms of ED(50) values and enhancement ratios.

RESULTS

For TGFB1, the Pro/Pro genotype in codon 10 and the T/T genotype in position -509 correlated positively with risk of subcutaneous fibrosis. The SOD 2 codon 16 Val/Ala genotype was associated with increased risk of subcutaneous fibrosis when compared to the Val/Val genotype. The Thr/Thr genotype in XRCC3 codon 241 correlated with increased risk of subcutaneous fibrosis as well as telangiectasia. The Arg/Arg genotype in XRCC1 codon 399 was associated with increased risk of radiation-induced subcutaneous fibrosis. For these polymorphisms, enhancement ratios between 1.09 and 1.25 were found. Combined analysis of multiple SNPs demonstrated that the risk of subcutaneous fibrosis correlated with the number of risk alleles in such a manner that patients with few risk alleles exhibited a remarkable degree of radioresistance.

CONCLUSION

The present study established significant correlations between five SNPs and risk of radiation-induced normal tissue reactions. These findings support the assumption that clinical normal tissue radiosensitivity should be regarded as a phenomenon dependent on the combined effect of variation in several genes and indicate that models based on multiple genetic markers may have the potential to predict normal tissue responses after radiotherapy.

Peyronie's disease: a review

PURPOSE OF REVIEW

This review is aimed to summarize the most recent findings about this topic, by reviewing the literature published in 2002 and 2003 regarding the epidemiology, pathophysiology, diagnosis and treatment of Peyronie's disease.

RECENT FINDINGS

Although many aspects in pathophysiology, diagnosis, medical and surgical treatment of Peyronie's disease still remain under debate, recent interesting advances have been made regarding the different aspects of this condition. Topical and systemic medical therapies have been associated with varying degrees of results, depending on modalities and timing of the treatment itself. A wide range of surgical modalities have been recently developed, although the ideal surgical procedure especially in case of severe and complex curvature does not seem to be reached yet. Furthermore this condition is often associated with psychological distress that could be responsible for performance anxiety, leading to improvement of abnormalities in erectile functioning eventually associated with Peyronie's disease.

SUMMARY

Peyronie's disease consists of an acquired penile deformity caused by the formation of fibrous plaques within the tunica albuginea, leading to bio-mechanical and vascular abnormalities. In the last decade numerous advances have been made regarding pathophysiology, diagnosis and treatment of this condition, allowing for improved patient clinical prognosis. Nevertheless, although improvements in medical and surgical therapies have substantially increased the successful patients' outcome rate, Peyronie's disease is still not completely understood and its treatment remains often frustrating for the practicing urologist. Clinical presentations of this disease include penile deformities or shortening during erection, painful erection, palpable plaque or induration throughout the length of the penile shaft and erectile dysfunction.