Introdução - A ressecção transuretral da próstata continua sendo uma das cirurgias mais realizadas em homens com idade acima de 50 anos e é considerada o padrão-ouro no tratamento cirúrgico de pacientes com sintomas de hiperplasia prostática benigna (HPB). Embora sua eficácia no alívio dos sintomas de pacientes com HPB já tenha sido extensamente documentada, seu impacto sobre os níveis séricos de antígeno prostático específico não é bem conhecido. O objetivo do presente estudo foi avaliar o comportamento dos níveis séricos do antígeno prostático específico (PSA) em pacientes submetidos à ressecção transuretral da próstata. Métodos - No período de abril de 2003 a julho de 2004, 30 pacientes portadores de hiperplasia prostática benigna, selecionados para tratamento cirúrgico por meio de ressecção transuretral da próstata foram avaliados prospectivamente. A idade dos pacientes variou de 46 a 84 anos (mediana de 68,5 anos). A avaliação pré-operatória incluiu quantificação dos sintomas do trato urinário inferior através do escore internacional de sintomas prostáticos (IPSS), dosagem sérica do PSA total, relação de PSA livre sobre total (PSAl/t) e avaliação do peso prostático por ultrassonografia transretal. Os fragmentos ressecados na cirurgia foram pesados e submetidos a exame histopatológico com coloração pela hematoxilina-eosina. Os pacientes foram avaliados após 30, 60 e 180 dias da cirurgia com IPSS, dosagem sérica do PSA total e relação de PSAl/t. Para estudar o impacto da presença de prostatite crônica sobre os níveis de PSA, os pacientes foram divididos em dois grupos com base na presença ou ausência de prostatite e foram comparados em relação às variáveis clínicas e níveis de PSA préoperatórios bem como evolução pós-operatória dos níveis de PSA. Resultados - Na avaliação pré-operatória, o I-PSS variou de 18 a 29, com média de 22,5 ± 2,9. O PSA total variou de 0,79 ng/ml a 33,46 ng/ml com média de 6,19 ng/ml e mediana de 3,79. A relação de PSAl/t foi de 18,18% ± 3,36. O peso prostático variou de 29,0 a 130,0g com média de 71,8g. O peso dos fragmentos prostáticos ressecados variou de 11g a 102g, com média de 29,87g ± 19,58g. O I-PSS reduziu-se significantemente em todos os momentos avaliados após a cirurgia, sendo 12,6 ± 2,0 no 30º dia pósoperatório (PO); 11,6 ± 1,6 no 60º PO; e 11,3 ± 1,8 no 180º PO (p< 0,01 para todas as comparações com o IPSS pré-operatório). O PSA total reduziu-se significantemente em todos os momentos avaliados após a cirurgia em comparação com o PSA pré-operatório, sendo 2,27ng/ml ± 2,20 no 30° PO; 1,75ng/ml ± 1,66 no 60° PO e 1,79 ng/ml ± 1,26 no 180° PO (p<0,001 para todas as comparações). Houve diferença estatisticamente significante quando se comparou o PSA total do 30° PO com o 60° e 180° PO (p<0,05) mas não na comparação entre o 60° e 180° PO. A relação de PSAl/t não variou de forma significante após a cirurgia em comparação com o pré-operatório, sendo 17,78% ± 8,59 no 30° PO; 18,69% ± 9,89 no 60°, e 21 ± 7,49 % no 180° (p =0,91). No exame histopatológico, foram identificados 12 (40%) pacientes com hiperplasia prostática benigna e prostatite crônica e 18 (60%) com diagnóstico somente de hiperplasia prostática benigna. Não houve diferenças estatisticamente significantes entre os pacientes com e sem prostatite em relação aos parâmetros préoperatórios idade, I-PSS, PSAt, relação do PSAl/t e peso ressecado da próstata. Os níveis de PSA total pós-operatório variaram de 8,1ng/ml ± 10,2 para 2,4ng/ml ± 2,3; 1,6ng/ml ± 1,0 e 1,9ng/ml ± 0,9, respectivamente nos 30, 60 e 180 dias pós-operatórios, entre os pacientes com prostatite. Entre os pacientes sem prostatite, o PSA total reduziu-se de 4,9ng/ml ± 3,7 para 2,2ng/ml ± 2,2; 1,8ng/ml ± 2,0 e 1,7ng/ml ± 1,5, respectivamente nos 30, 60 e 180 dias pós-operatórios. Não houve diferença estatisticamente significante na comparação dos pacientes com e sem prostatite em nenhum dos momentos avaliados. Conclusões - Os níveis séricos de PSA total dos pacientes com hiperplasia prostática reduzem-se significantemente após a cirurgia de ressecção transuretral da próstata, atingindo o valor mínimo de estabilização após 60 dias da cirurgia. A relação de PSAl/t não é afetada pela cirurgia. A presença de prostatite crônica não tem influencia sobre a evolução dos níveis séricos de PSA. Estes achados deverão ajudar no seguimento de pacientes submetidos à ressecção transuretral da próstata / Introduction - Transurethral resection of the prostate (TURP) remains as one of the most common surgeries in men over 50 years old and is considered the gold standard in the surgical treatment of patients with benign prostatic hyperplasia (BPH). Although its efficacy in the relief of lower urinary symptoms in patients with BPH have been extensively demonstrated, it is not clear how it affects the serum levels of prostate-specific antigen (PSA). The objective of this study was to evaluate the progression of the serum levels of PSA after TURP in patients with BPH. Materials - From April 2003 to July 2004, 30 patients with BPH were selected for TURP and were prospectively evaluated. The age of the patients varied from 46 to 84 years (median 68,5 years). Preoperative evaluation included quantification of the lower urinary tract symptoms with the international prostatic symptom score (IPSS), assessment of the serum levels of total and free PSA and evaluation of the prostate weight bytransrectal ultrasound. Prostate fragments resected in the surgery were weighed and histologically evaluated. Postoperatively, patients were evaluated after 30, 60 and 180 days of the surgery, with IPSS, free-tototal PSA ratio (PSAf/t). To evaluate the influence of the presence of chronic prostatitis on the PSA levels, patients were divided in two groups based on the presence or absence of prostatitis and compared in terms of preoperative clinical variables and PSA levels as well as the postoperative progression of the PSA levels. Results - In the preoperative evaluation, I-PSS varied from 18 to 29, with a mean of 22,5 ± 2,9. Total PSA levels varied from 0,79 ng/ml to 33,46 ng/ml with a mean of 6,19 ng/ml and median of 3,79. The mean PSAf/t ration was 18,18% ± 3,36. Prostate weight varied from 29,0 to 130,0g with a mean of 71,8g. Resected prostate weight varied from 11g to 102g, mean 29,87g ± 19,58g. A significant decrease of the IPSS was observed in all moments of postoperative evaluation, with a mean of 12,6 ± 2,0 on the 30th postoperative day (PO); 11,6 ± 1,6 on the 60 PO and 11,3 ± 1,8 on the 180 PO (p< 0,01 for all comparisons with the preoperative IPSS). Total PSA was significantly reduced in all moments of postoperative evaluation in comparison with the preoperative levels, with a mean of 2,27ng/ml ± 2,20 on the 30 PO; 1,75ng/ml ± 1,66 on the 60 PO and 1,79 ng/ml ± 1,26 on the 180 PO (p<0,001 for all comparisons). A significant difference was observed in the PSA levels of the 30 PO in comparison with the 60 and 180 PO (p<0,05) but not in the comparison of the 60 PO with 180 PO. The PSAf/t ration did not significantly varied in comparison with the preoperative values, with a mean of 17,78% ± 8,59 on the 30 PO; 18,69% ± 9,89 on the 60 PO and 21 ± 7,49 % on the 180 PO (p =0,91). On the histopathological studies, 12 (40%) patients were diagnosed with chronic prostatitis and BPH and e 18 (60%) with isolated BPH. There was no statisticaly significant differences between patients with and without prostatitis in terms of the preoperative parameters age, I-PSS, total PSA, PSAf/t ration and resected prostate weight. Among the patients with prostatitis, serum levels of total PSA varied from 8,1ng/ml ± 10,2 preoperatively, to 2,4ng/ml ± 2,3; 1,6ng/ml ± 1,0 e 1,9ng/ml ± 0,9, respectively after 30, 60 and 180 days postoperatively. Among the patients without prostatitis, serum levels of total PSA varied from 4,9ng/ml ± 3,7 preoperatively, to 2,2ng/ml ± 2,2; 1,8ng/ml ± 2,0 e 1,7ng/ml ± 1,5, respectively after 30, 60 and 180 days postoperatively. There was no significant differences between the groups in any of the evaluations. Conclusions - Serum levels of total PSA in patients with benign prostatic hyperplasia reduce significantly after transurethral resection of the prostate, reaching the lowest stabilization value 60 days after the surgery. The PSAf/t ration is not altered by the surgery. The presence of chronic prostatitis has no influence on the progression of the serum levels of total PSA. These findings should help the clinician in the management of patients submitted to transurethral resection of the prostate

Serial prostate-specific antigen (PSA) measurements (PSA velocity) as an additional instrument to detect prostatic cancer was introduced in 1992. It has previously been reported that PSA increase per year differed in the last 5 years prior to diagnosis in patients with benign prostatic hyperplasia (0.18 ng/ml/year), locally confined (0.75 ng/ml/year) and metastasized (4.4 ng/ml/year) cancer of the prostate (CaP) in contrast to healthy men (0.04 ng/ml/year). The ability of PSA velocity to detect organ-confined CaP in patients with intermediate PSA serum values depends therefore on a reliable and reproducible PSA result. The present study comprised 85 men with PSA values between 3 and 8 ng/ml (Abbott IMx). PSA measurements were repeated with Abbott IMx (n = 85 patients) and Hybritech Tandem-E (n = 59 patients) assays. The PSA serum values differed from one examination to the other from 0.02 to 2.74 ng/ml with the Abbott IMx. Standard deviation amounted to 0.35 ng/ml with the Abbott IMx PSA assay. Using the Hybritech Tandem-E assay, mean standard deviation was 1.15 ng/ml and therefore higher than with the Abbott IMx assay. The difference from one test to the other ranged from 0.05 to 4.05 ng/ml with the Hybritech Tandem-E. Using the Abbott IMx assay, 10.6% of all repeat measurements exceeded 1 ng/ml whereas in the Hybritech Tandem-E assay 62.7% of the second measurements differed >1 ng/ml from the first PSA result. An increase in PSA serum values may therefore be due to intratest variation, physiological day-to-day variation as well as prostatic disease. It is important to notice that the intra-assay variation may be greater than the PSA increase per year in a patient with CaP. Therefore, PSA velocity seems to be of limited value. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Hiperplasia prostática benigna (HPB) é considerada a neoplasia masculina mais comum, além de ser a principal causa de sintomas do trato urinário baixo (STUB) em homens idosos. Se não tratada ou mal tratada, poderá levar o paciente a quadro de retenção urinária aguda, incontinência e infecção do trato urinário, progredindo em gravidade com a idade. Apesar do desenvolvimento de técnicas alternativas, a ressecção transuretral da próstata (RTU) continua sendo considerada o tratamento cirúrgico padrão ouro para HPB. Não obstante, a RTU pode estar associada a muitas comorbidades como, sangramento, sintomas urinários irritativos, disfunção sexual e ejaculação retrógrada. Por essa razão, o desenvolvimento de modalidades de tratamentos minimamente invasivos para o tratamento de HPB constitui um campo interessante de pesquisa clínica. Os objetivos deste estudo foram: (1) avaliar a viabilidade, a segurança e a eficácia da embolização das artérias prostáticas (EAP) nos pacientes com retenção urinária devido à HPB, (2) avaliar a porcentagem de redução volumétrica da próstata e a qualidade de vida após a EAP nos pacientes com retenção urinária devido à HPB. No presente estudo, Fase I prospective centro único, 11 pacientes portadores de retenção urinária devido à HPB foram tratados por meio da EAP entre agosto de 2009 e novembro de 2011. Exame físico, questionários de sintomas e qualidade de vida (International Prostate Symptom Score (IPSS) e Quality of Life (QoL)), dosagem do antígeno prostático específico (PSA), exames de imagens de ultrassom (US) e ressonância magnética (RM), e estudos urodinâmicos foram realizados antes e 1, 3, 6, e 12 meses depois da EAP. O tamanho da próstata variou de 30 a 90 gramas, e as embolizações foram realizadas com microesferas (Embospheres) de 300-500?m. O sucesso técnico (EAP bilateral) foi atingido em 75%, e o sucesso clínico (retirada do cateter vesical de demora e melhora dos sintomas) foi obtido em 91% (10 de 11 pacientes) dos casos. Síndrome pósembolização manifestou-se com dor leve no períneo, retropúbica e uretral. Não foram observadas complicações maiores. Ao final do primeiro ano de seguimento, sintomas eram leves com a média do IPSS de 2,8 pontos (p = 0,04), a média da QoL era de 0,4 pontos (p = 0,001), a média do PSA diminuiu de 10,1 para 4,3 ng/mL (p = 0,003), a média do volume prostático reduziu de 69,7 para 46,3 gramas (p = 0,002) e de 62 para 42,7 gramas (p = 0,004) medidos por RM e US, respectivamente, a média do pico de fluxo máximo (Qmax) aumentou de 4,2 para 10,8 mL/sec (p = 0,009), a média da pressão detrusora (Pdet) diminuiu de 85,7 para 51,5 cmH2O (p = 0,007), a média do resíduo final pós-miccional diminuiu de 160,5 para 60ml (p = 0,04) e não foi observada disfunção sexual. A EAP para o tratamento da retenção urinária causada por HPB demonstrou ser um procedimento viável, seguro e eficaz, além de poder reduzir o volume prostático em mais de 30% e melhorar os STUB e a qualidade de vida / Benign prostatic hyperplasia (BPH) is considered the most common neoplasm in men and is the main cause of lower urinary tract symptoms (LUTS) in the aging male. If left untreated or not effectively treated, can lead to acute urinary retention, incontinence, and urinary tract infections, progressing in severity with age. Despite the development of alternative techniques, transurethral resection of the prostate (TURP) is still considered the gold standard surgical treatment for BPH. However, TURP procedures can be associated with substantial morbidities such as bleeding, irritative urinary symptoms, erectile dysfunction and ejaculatory disorders. For this reason, the development of minimally invasive modalities for treatment of BPH has constituted an interesting field of research. The study objectives were: (1) to evaluate the feasibility, safety and efficacy of the prostatic artery embolization (PAE) in patients with urinary retention due to BPH, (2) to evaluate the percentage of reduction in prostate volume and quality of life after PAE in patients with urinary retention due to BPH. In the present study, a single-center prospective phase I study, 11 patients with urinary retention due to BPH were treated by PAE between August 2009 and November 2011. Physical examination, International Prostate Symptom Score (IPSS) and Quality of Life (QoL), prostate specific antigen (PSA) measurement, ultrasound (US) and magnetic resonance imaging (MRI), and urodynamic tests were performed at baseline, 1, 3, 6 and 12 months after PAE. Prostate size ranged from 30 to 90g, and embolizations were performed with 300- 500-?m Embosphere microspheres. Technical success (ie, bilateral PAE) was obtained in 75%, and clinical success (ie, catheter removal and symptom improvement) was obtained in 91% (10 of 11patients) of the cases. Postembolization syndrome manifested as mild pain in the perineum, retropúbica area, and/ or urethra. No major complications were observed. At the first year follow-up, symptoms were mild with the mean IPSS score was 2.8 points (p = 0.04), mean QoL was 0.4 points (p = 0.001), mean PSA decreased from 10.1 to 4.3 ng/mL (p = 0.003), mean prostate volume reduce from 69.7 to 46.3g (p = 0.002) and from 62 to 42.7 (p = 0.004) by MRI and US respectively, maximum urinary flow (Qmax) improved from 4.2 to 10.8 mL/sec (p = 0.009), detrusor pressure (Pdet) decreased from 85.7 to 51.5 cmH2O (p = 0.007), post-void residual decreased from 160.5 to 60ml (p = 0.04) and no erectile dysfunction was observed. PAE for the treatment of urinary retention caused by BPH demonstrated to be a feasible, safe and effective procedure. PAE can reduce the prostate volume greater than 30% and improve clinical symptoms and QoL

Hiperplasia prostática benigna (HPB) é considerada a neoplasia masculina mais comum, além de ser a principal causa de sintomas do trato urinário baixo (STUB) em homens idosos. Se não tratada ou mal tratada, poderá levar o paciente a quadro de retenção urinária aguda, incontinência e infecção do trato urinário, progredindo em gravidade com a idade. Apesar do desenvolvimento de técnicas alternativas, a ressecção transuretral da próstata (RTU) continua sendo considerada o tratamento cirúrgico padrão ouro para HPB. Não obstante, a RTU pode estar associada a muitas comorbidades como, sangramento, sintomas urinários irritativos, disfunção sexual e ejaculação retrógrada. Por essa razão, o desenvolvimento de modalidades de tratamentos minimamente invasivos para o tratamento de HPB constitui um campo interessante de pesquisa clínica. Os objetivos deste estudo foram: (1) avaliar a viabilidade, a segurança e a eficácia da embolização das artérias prostáticas (EAP) nos pacientes com retenção urinária devido à HPB, (2) avaliar a porcentagem de redução volumétrica da próstata e a qualidade de vida após a EAP nos pacientes com retenção urinária devido à HPB. No presente estudo, Fase I prospective centro único, 11 pacientes portadores de retenção urinária devido à HPB foram tratados por meio da EAP entre agosto de 2009 e novembro de 2011. Exame físico, questionários de sintomas e qualidade de vida (International Prostate Symptom Score (IPSS) e Quality of Life (QoL)), dosagem do antígeno prostático específico (PSA), exames de imagens de ultrassom (US) e ressonância magnética (RM), e estudos urodinâmicos foram realizados antes e 1, 3, 6, e 12 meses depois da EAP. O tamanho da próstata variou de 30 a 90 gramas, e as embolizações foram realizadas com microesferas (Embospheres) de 300-500?m. O sucesso técnico (EAP bilateral) foi atingido em 75%, e o sucesso clínico (retirada do cateter vesical de demora e melhora dos sintomas) foi obtido em 91% (10 de 11 pacientes) dos casos. Síndrome pósembolização manifestou-se com dor leve no períneo, retropúbica e uretral. Não foram observadas complicações maiores. Ao final do primeiro ano de seguimento, sintomas eram leves com a média do IPSS de 2,8 pontos (p = 0,04), a média da QoL era de 0,4 pontos (p = 0,001), a média do PSA diminuiu de 10,1 para 4,3 ng/mL (p = 0,003), a média do volume prostático reduziu de 69,7 para 46,3 gramas (p = 0,002) e de 62 para 42,7 gramas (p = 0,004) medidos por RM e US, respectivamente, a média do pico de fluxo máximo (Qmax) aumentou de 4,2 para 10,8 mL/sec (p = 0,009), a média da pressão detrusora (Pdet) diminuiu de 85,7 para 51,5 cmH2O (p = 0,007), a média do resíduo final pós-miccional diminuiu de 160,5 para 60ml (p = 0,04) e não foi observada disfunção sexual. A EAP para o tratamento da retenção urinária causada por HPB demonstrou ser um procedimento viável, seguro e eficaz, além de poder reduzir o volume prostático em mais de 30% e melhorar os STUB e a qualidade de vida / Benign prostatic hyperplasia (BPH) is considered the most common neoplasm in men and is the main cause of lower urinary tract symptoms (LUTS) in the aging male. If left untreated or not effectively treated, can lead to acute urinary retention, incontinence, and urinary tract infections, progressing in severity with age. Despite the development of alternative techniques, transurethral resection of the prostate (TURP) is still considered the gold standard surgical treatment for BPH. However, TURP procedures can be associated with substantial morbidities such as bleeding, irritative urinary symptoms, erectile dysfunction and ejaculatory disorders. For this reason, the development of minimally invasive modalities for treatment of BPH has constituted an interesting field of research. The study objectives were: (1) to evaluate the feasibility, safety and efficacy of the prostatic artery embolization (PAE) in patients with urinary retention due to BPH, (2) to evaluate the percentage of reduction in prostate volume and quality of life after PAE in patients with urinary retention due to BPH. In the present study, a single-center prospective phase I study, 11 patients with urinary retention due to BPH were treated by PAE between August 2009 and November 2011. Physical examination, International Prostate Symptom Score (IPSS) and Quality of Life (QoL), prostate specific antigen (PSA) measurement, ultrasound (US) and magnetic resonance imaging (MRI), and urodynamic tests were performed at baseline, 1, 3, 6 and 12 months after PAE. Prostate size ranged from 30 to 90g, and embolizations were performed with 300- 500-?m Embosphere microspheres. Technical success (ie, bilateral PAE) was obtained in 75%, and clinical success (ie, catheter removal and symptom improvement) was obtained in 91% (10 of 11patients) of the cases. Postembolization syndrome manifested as mild pain in the perineum, retropúbica area, and/ or urethra. No major complications were observed. At the first year follow-up, symptoms were mild with the mean IPSS score was 2.8 points (p = 0.04), mean QoL was 0.4 points (p = 0.001), mean PSA decreased from 10.1 to 4.3 ng/mL (p = 0.003), mean prostate volume reduce from 69.7 to 46.3g (p = 0.002) and from 62 to 42.7 (p = 0.004) by MRI and US respectively, maximum urinary flow (Qmax) improved from 4.2 to 10.8 mL/sec (p = 0.009), detrusor pressure (Pdet) decreased from 85.7 to 51.5 cmH2O (p = 0.007), post-void residual decreased from 160.5 to 60ml (p = 0.04) and no erectile dysfunction was observed. PAE for the treatment of urinary retention caused by BPH demonstrated to be a feasible, safe and effective procedure. PAE can reduce the prostate volume greater than 30% and improve clinical symptoms and QoL

At present, prostate cancer is a significant public health issue throughout the world and is the second leading cause of cancer deaths in older men. The prostate specific antigen or PSA (which is encoded by the kallikrein 3/KLK3 gene) test is the current most valuable tool for the diagnosis and management of prostate cancer. However, it is insufficiently sensitive and specific for early diagnosis, for staging of prostate cancer or for discriminating between benign prostatic hyperplasia (BPH) and prostate cancer. Recent research has revealed another potential tumour marker, glandular kallikrein 2 (KLK2 gene/hK2 protein), which may be used alone or in conjunction with PSA to overcome some of the limitations of the PSA test. Twelve new kallikrein gene family members have been recently identified and, like hK2 and PSA, many of these genes have been suggested to be involved in carcinogenesis. In this study, the cellular localisation and level of expression of several of these newer kallikreins (KLK4, KLK5, KLK7, KLK8 and KLK11) was examined in prostate tissue, to provide an understanding of the association of their expression with prostatic diseases and their potential as additional biomarkers. Like PSA and hK2, the present observation indicated that each of these proteins, hK4, hK5, hK7, hK8 and hK11, was detected within the cytoplasm of the secretory cells of the prostate glands. For the first time, all of these newly-identified proteins were shown to be expressed in prostatic intraepithelial neoplasia (PIN) lesions, in comparison to normal glands and cancer lesions. In addition to cytoplasmic secretory cell expression, the localisation of hK4 to the basal cells and nuclei in prostatic lesions was intriguing. The intensity of hK4 staining in prostate tissue was strongest in comparison to the other newly-identified kallikrein proteins (hK5, hK7, hK8 and hK11). Therefore, KLK4/hK4 expression was characterised further to define this cellular localisation and examined in non-prostatic tissue and also in a larger number of prostate tissues in an attempt to determine its potential value as a biomarker for prostate disease. Three hK4 antipeptide polyclonal antibodies, derived against N-terminal, mid-region and C-terminal hK4 amino acid sequences, were used. The hK4 N-terminal antipeptide antibody was used to demonstrate the cellular localisation of hK4 in kidney, salivary glands, liver, testis, colon carcinoma, heart, endometrium and ovarian cancer, for the first time. The presence of hK4 in these non-prostate tissues was consistent with the previous reports using RT-PCR. The dual cytoplasmic and nuclear localisation of hK4 observed in the prostate above was also seen in these tissues. Although hK4 was found widely expressed in many human tissue types, indicating that it is not prostate specific in its expression, the highest expression level of hK4 was seen in the prostate. Therefore, detailed expression patterns and levels of KLK4 mRNA and hK4 protein in the normal prostate and prostatic diseases and histopathological lesions were investigated and reported for the first time in this study. Twelve benign prostatic hyperplasia (BPH), 19 adenocarcinoma (Gleason grade 2-5) and 34 bone metastases from prostate cancer were analysed. Using in situ hybridisation, the expression of KLK4 mRNA was detected in the cytoplasm of the secretory cells of both normal and diseased prostate tissue. KLK4 mRNA was also noted in both secretory and basal cells of PIN lesions, but the basal cells of normal glands were negative. Using the hK4 N-terminal and mid-region antipeptide antibodies, hK4 was predominantly localised in the cytoplasm of the secretory cells. The intensity of hK4 staining appeared lowest in normal and BPH, and increased in PIN lesions, high Gleason grade prostate cancer and bone metastases indicating the potential of hK4 as a histopathological marker for prostatic neoplasias. Further studies are required with a larger cohort to determine its utility as a clinical biomarker. Small foci of atypical cells, which were found within normal glands, were also intensely stained. Surprisingly, hK4 protein was found in the nucleus of the secretory cells (but not the basal cells) of high grade PIN and Gleason grade 3 prostate cancer. The detection of KLK4 mRNA and hK4 protein in PIN lesions and small foci of atypical cells suggests that up-regulation of KLK4 expression occurs early in the pathology of prostate carcinogenesis. The finding of basal cell expression is not typical for the kallikreins and it is not clear what role hK4 would play in this cell type. With the use of the hK4 C-terminal antipeptide antibody, the staining was mainly localised in the nuclei of the secretory cells of the prostate glands. Although the nuclear localisation was readily noted in more than 90% of epithelial cells of the prostate gland with the C-terminal antibody, no difference in staining intensity was observed among the histopathological lesions of the prostate. The prominent nuclear localisation with the C-terminal antipeptide antibody was also shown to be distributed throughout the nucleus by using confocal microscopy. Further, by using gold-labelled particles for electron microscopy, the intracellular localisation of these hK4 antipeptide antibodies was reported here for the first time. Similar to the immunohistochemical results, the cytoplasm was the major site of localisation with the N-terminal and mid-region antipeptide antibodies. To further characterise the involvement of KLK4/hK4 in human prostate cancer progression, the transgenic adenocarcinoma mouse prostate (TRAMP) model was used in this study. In this study, mouse KLK4 (also known as enamel matrix serine protease -1, EMSP-1) was shown to be expressed in the TRAMP prostate for the first time. Previous studies had only shown the developing tooth as a site of expression for EMSP-1. The level of EMSP-1 mRNA expression was increased in PIN and prostate cancer lesions of the TRAMP model, while negative or low levels of EMSP-1 mRNA were seen in normal glands or in control mouse prostate tissue. The normal mouse prostate did not stain with any the three hK4 antipeptide antibodies. hK4 N-terminal and mid-region antipeptide antibodies showed positive staining in the cytoplasm of the epithelial cells of PIN and cancer lesions of the mouse prostate. The C-terminal antipeptide antibody showed distinctively nuclear staining and was predominantly localised in the nuclei of the glandular cells of PIN and cancer lesions of the mouse prostate. The expression patterns of both the mRNA and protein level for mouse KLK4 strongly supported the observations of KLK4/hK4 expression in the human prostate and further support the utility of the TRAMP model. Overall, the findings in this thesis indicate a clear association of KLK4/hK4 expression with prostate cancer progression. In addition, several intriguing findings were made in terms of cellular localisation (basal as well as secretory cells; nuclear and cytoplasmic) and high expression in atypical glandular cells and PIN, perhaps indicating an early involvement in prostate disease progression and, additionally, utility as basal cell and PIN histological markers. These findings provide the basis for future studies to confirm the utility of hK4 as a biomarker for prostate cancer progression and identify functional roles in the different cellular compartments.