Immunohistochemical Analysis Of The Relationship Between SIRT1Expression And Benign Prostatic Hyperplasia

BackgroundBenign prostatic hyperplasia (BPH) is the most common disease in old men, andits incidence is age related. The clinical symptoms usually appear after50years old,Frequent urination is the earliest symptoms, dysuria is the most typical clinicalmanifestations. Accompanied by the improvement of living level, the average lifeexpectancy rising, The incidence of BPH increases too. Incidence of histological BPHcould be over70%at60years old and over90%at80years old. Although domesticand overseas have to do a lot of research on BPH already, but its etiology andpathogenesis are not clear, it has been suggested that an imbalance between cellapoptosis and cell proliferation may result in the development of BPH.Silent Mating-type Information Regulation2homolog1(SIRT1) play a veryimportant role in the regulation of life and antagonizes cellular senescence. Twoamino acid residues composed of human SIRT1, Its coding gene is located onchromosome10q21.3,about33kb, contain8introns and9exons, the5’ and3’ endswith53bp and1793bp untranslated region,SIRT1gene translation protein has amolecular weight of about60Ku and no splice variants, with NAD dependentdeacetylase activity. SIRT1as nicotinamide adenine dinucleotide (NAD+)-dependentprotein deacetylasesmay (histone deacetylase, HDAC), can interact with a variety of protein, its main function is to reduced apoptosis or senescence under stressconditions, Increase chances of self-healing and survival, SIRT1function are closelyrelated with gene silencing, longevity, senescence, energy metabolism and regulationof stress response. A further study on its function and mechanism of action, whichmaybe offer more information about the BPH mechanism.PurposeThe aim of the present study was to investigate the association between theexpression of silent mating-type information regulation2homolog1（SIRT1）andmore commonly clinical indicators, such as prostate volume, Prostate specificantigen(PSA),age,Bcl-2,Ki67in benign prostate hyperplasia(BPH) progression. Studyof molecular apoptosis mechanism of SIRT1in BPH clinical progression.Materials and Methods1. tissue selection：Data relating to patients and samples were obtained from theDepartment of Urology， Third Affiliated Hospital of Guangzhou MedicalCollege,.All patients underwent treatment for TURP（Transurethral Resection ofProstate）.2. To evaluate the histological types：Specimens histopathological type are all benignprostate hyperplasia tissue which identification by the pathologist. All BPH tissuesection were reevaluated, using the World Health Organization(WTO) criteria forBPH.BPH with inflammation specimens were excluded after the histologicreevaluation.3. BPH clinical progress index：The prostate volume, serum PSA level and age of eachpatient were recorded before surgery. Measurements of prostatic anteroposteriordiameter(A), transverse diameter(T) and vertical diameter(V) by abdominal B-modeultrasonography. The prostate volume Volume calculation by A×T×V×0.52.4.The expression of SIRT1and Bcl-2, and proliferative index (PI)(immunoexpressionof Ki-67) were evaluated immunohistochemically in BPH(n=43). 5. The correlation of SIRT1expression with BPH clinic progression risk factors, PIand Bcl2expression level was analyzed.Results1. This study contains43cases BPH patients. Age from49to88, average age is71.56±8.65. Serum PSA levels from0.34to27.05ng/ml, average value is7.55±6.91.prostate volume form19.66to167.74ml,average value is58.95±33.07.2. The nuclei and cytoplasm of most prostate epithelial cells were strongly stained inSIRT1positive expression group, rarely seen in stromal cells. SIRT1Positiveexpression rate is BPH tissue60.47%（26/43）.3. In SIRT1positive expression group, the mean serum PSA level and prostatevolume was higher than that in SIRT1negative expression group (p=0.037,0.009respectively). In addition, SIRT1expression was not related to patient age（P=0.657）。4. SIRT1expression was closely related to the Bcl2expression (P=0.014), but was notrelated to PI(P=0.555).Conclusions1.Bcl-2positive expression rate is higher in SIRT1positive expression group thanSIRT1positive expression group.2.The expression of SIRT1in BPH development highlighted by the strong correlationbetween Bcl-2expression、PSA level and prostate volume.3. SIRT1is closely related to BPH clinical progress and SIRT1may be closely relatedto progression of benign prostatic.