Human tissue kallikrein-1 protects against the development of erectile dysfunction in a rat model of hyperhomocysteinemia / 亚洲男科学杂志(英文版)

The aim of this study was to investigate the mechanism by which a diet inducing high hyperhomocysteinemia (HHcy) leads to the deterioration of erectile function in rats and whether this is inhibited by expression of the human tissue kallikrein-1 (hKLK1) gene. We established a rat model of HHcy by feeding methionine (Met)-rich diets to male Sprague-Dawley (SD) rats. Male wild-type SD rats (WTRs) and transgenic rats harboring the hKLK1 gene (TGRs) were fed a normal diet until 10 weeks of age. Then, 30 WTRs were randomly divided into three groups as follows: the control (n = 10) group, the low-dose (4% Met, n = 10) group, and the high-dose (7% Met, n = 10) group. Another 10 age-matched TGRs were fed the high-dose diet and designated as the TGR+7% Met group. After 30 days, in all four groups, erectile function was measured and penile tissues were harvested to determine oxidative stress, endothelial cell content, and penis fibrosis. Compared with the 7% Met group, the TGR+7% Met group showed diminished HHcy-induced erectile dysfunction (ED), indicating the improvement caused by hKLK1. Regarding corpus cavernosum endothelial cells, hKLK1 preserved endothelial cell-cell junctions and endothelial cell content, and activated protein kinase B/endothelial nitric oxide synthase (Akt/eNOS) signaling. Fibrosis assessment indicated that hKLK1 preserved normal penis structure by inhibiting apoptosis in the corpus cavernosum smooth muscle cells. Taken together, these findings showed that oxidative stress, impaired corpus cavernosum endothelial cells, and severe penis fibrosis were involved in the induction of ED by HHcy in rats, whereas hKLK1 preserved erectile function by inhibiting these pathophysiological changes.

Human Tissue Kallikrein Activity in Angiographically Documented Chronic Stable Coronary Artery Disease / Atividade da Calicreína Tecidual Humana na Doença Coronariana Crônica Estável Angiograficamente Documentada

AbstractBackground:Human tissue kallikrein (hK1) is a key enzyme in the kallikrein–kinin system (KKS). hK1-specific amidase activity is reduced in urine samples from hypertensive and heart failure (HF) patients. The pathophysiologic role of hK1 in coronary artery disease (CAD) remains unclear.Objective:To evaluate hK1-specific amidase activity in the urine of CAD patientsMethods:Sixty-five individuals (18–75 years) who underwent cardiac catheterism (CATH) were included. Random midstream urine samples were collected immediately before CATH. Patients were classified in two groups according to the presence of coronary lesions: CAD (43 patients) and non-CAD (22 patients). hK1 amidase activity was estimated using the chromogenic substrate D-Val-Leu-Arg-Nan. Creatinine was determined using Jaffé’s method. Urinary hK1-specific amidase activity was expressed as µM/(min · mg creatinine) to correct for differences in urine flow rates.Results:Urinary hK1-specific amidase activity levels were similar between CAD [0.146 µM/(min ·mg creatinine)] and non-CAD [0.189 µM/(min . mg creatinine)] patients (p = 0.803) and remained similar to values previously reported for hypertensive patients [0.210 µM/(min . mg creatinine)] and HF patients [0.104 µM/(min . mg creatinine)]. CAD severity and hypertension were not observed to significantly affect urinary hK1-specific amidase activity.Conclusion:CAD patients had low levels of urinary hK1-specific amidase activity, suggesting that renal KKS activity may be reduced in patients with this disease.

ResumoFundamento:A calicreína tecidual humana (hK1) é enzima-chave do sistema calicreína-cinina (SCC). A atividade amidásica da hK1 está reduzida na urina de pacientes com hipertensão e insuficiência cardíaca (IC); seu papel na doença arterial (DAC) coronariana ainda não está esclarecido.Objetivo:Avaliar a atividade amidásica da hK1 na urina de pacientes com DAC.Métodos:Sessenta e cinco indivíduos (18 a 75 anos) que se submeteram ao cateterismo cardíaco (CAT) coletaram amostra do jato médio de urina imediatamente antes do CAT. Baseando-se na presença de lesões coronarianas, os pacientes eram classificados em dois grupos: DAC (43 pacientes) e sem DAC (22 indivíduos). A atividade amidásica da hK1 foi estimada com o substrato cromogênico D-Val-Leu-Arg-Nan. Creatinina foi determinada pelo método de Jaffé. A atividade amidásica específica da hK1 urinária foi expressa em µM/(min . mg de creatinina) para corrigir diferenças no fluxo urinário.Resultados:A atividade amidásica da hK1 urinária foi semelhante entre os pacientes com DAC [0,146 µM/(min . mg de creatinina)] e aqueles sem DAC [0,189 µM/(min . mg de creatinina)] (p = 0,803), e permaneceu entre os baixos valores previamente publicados para pacientes com hipertensão primária [0,210 µM/(min . mg de creatinina)] e para aqueles com IC [0,104 µM/(min . mg de creatinina)], respectivamente. Nenhum efeito estatisticamente significativo da gravidade da DAC e da hipertensão sobre a atividade amidásica da hK1 urinária foi observado.Conclusão:A atividade amidásica da hK1 na urina estava reduzida nos pacientes com DAC, o que pode sugerir que a atividade do SCC renal esteja reduzida nessa doença.

Cancer prostate; treatment response on the level of prostate specific antigen [PSA]

Prostate specific antigen was identified and characterized first time in 1977. There is no doubt that the PSA has significant role in prostate cancer diagnosis with help of Digital' Rectal Examination and biopsy. This study was designed to assess the level of PSA in prostate cancer patients before and after the treatment given to patients. To determine the specific and precise finding regarding the tumors stages, the cancer biomarkers are handy and helpful. For this purpose researchers monitor changes in the cell on chromosomal level by comparing primary tumor with secondary tumor. The prostate-specific gene kallikrein 3 [KLK3], encodes PSA located on chromosome 19q13.4. KLK2 and KLK4 genes are also present here which are present in a family of fifteen closely related serine proteases. Allied Hospital, Faisalabad. Jan 2014 to Dec 2014. We use the PSA [Human] CLIA Kit which is a solid phase two site immunoassay. One antibody was coated on the surface of the microtiter wells and another antibody [used as a tracer] was labeled with horseradish peroxidase. The PSA molecules present in the standard solution or serum were [sandwiched] between the two antibodies. All prostate cancer patients had highly variable serum PSA values ranging from 12.90 ng/mL to 193.5 ng/mL The post treatment PSA analysis revealed that the increase level of PSA [15%] which showed that the PSA level increased after the treatment. Whereas in all other 17 patients the PSA level was found to decreased. Our study also shows that sometime PSA level is increased by non-cancer associated benign prostatic hyperplasia [BPH], prostatitis, medications and environment and diet alterations. This study indicated that PSA serum level has a useful role in diagnosis of prostate cancer

Stroke Update 2012: Etiology and Mechanism of Stroke / 대한뇌졸중학회지

In 2011, a number of studies shed further light on the understanding of stroke etiologies and mechanism. Regarding eating habit and a risk of stroke, three studies from Swedish cohort showed independent relations of chocolate, red meat, and coffee consumption with a risk of stroke. In relation to biomarkers, plasma tissue Kallikrein and resistin levels have been shown to be associated with a risk of stroke. In addition, with regard to infection and stroke, one study reported an increasing incidence of HIV infection in stroke patients and another study demonstrated that new-onset atrial fibrillation among patients with severe sepsis is associated with an increased risk of stroke. Finally, European consortium of cervical artery dissection reported risk factors for cervical artery dissection and differences between carotid and verterbral artery dissections.

Combined panel of serum human tissue kallikreins and CA-125 for the detection of epithelial ovarian cancer / 부인종양

OBJECTIVE: To determine the predictive accuracy of the combined panels of serum human tissue kallikreins (hKs) and CA-125 for the detection of epithelial ovarian cancer. METHODS: Serum specimens collected from 5 Indonesian centers and 1 Vietnamese center were analyzed for CA-125, hK6, and hK10 levels. A total of 375 specimens from patients presenting with ovarian tumors, which include 156 benign cysts, 172 epithelial ovarian cancers (stage I/II, n=72; stage III/IV, n=100), 36 germ cell tumors and 11 borderline tumors, were included in the study analysis. Receiver operating characteristic analysis were performed to determine the cutoffs for age, CA-125, hK6, and hK10. Sensitivity, specificity, negative, and positive predictive values were determined for various combinations of the biomarkers. RESULTS: The levels of hK6 and hK10 were significantly elevated in ovarian cancer cases compared to benign cysts. Combination of 3 markers, age/CA-125/hk6 or CA-125/hk6/hk10, showed improved specificity (100%) and positive predictive value (100%) for prediction of ovarian cancer, when compared to the performance of single markers having 80-92% specificity and 74-87% positive predictive value. Four-marker combination, age/CA-125/hK6/hK10 also showed 100% specificity and 100% positive predictive value, although it demonstrated low sensitivity (11.9%) and negative predictive value (52.8%). CONCLUSION: The combination of human tissue kallikreins and CA-125 showed potential for improving prediction of epithelial ovarian cancer in patients presenting with ovarian tumors.

Optimization of polyethylenimine-mediated transient transfection using response surface methodology design

Response surface methodology was undertaken to optimize the polyethylenimine-mediated transient transfection of suspension cultured HEK 293-F cells. A total of 15 combinations were designed according to Box-Behnken design to identify the effects of DNA concentration, polyethylenimine concentration and incubation time on transient transfection efficiency. The highest integral optic density of green fluorescent protein presenting r-protein yield was accessed using a DNA concentration of 1.75 ug/mL, a polyethylenimine concentration of 10.5 ug/mL, and an incubation time of 11.8 min. Analysis of variance demonstrated that the experimental values fit well with a quadratic model. The RSM-optimized transient transfection resulted in greater production of human tissue prokallikrein (TproK) than non-RSM-optimized conditions: protein yield was 32.0 mg/L and the maximum viable cell density reached 3.57 x 10(6) cells/mL in a 5 L stirred-tank bioreactor culture.

Effects of human tissue kallikrein 1 gene delivery on carotid artery neointima formation after balloon angioplasty in spontaneously hypertensive rats / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effects of human tissue kallikrein 1(Ad-hKLK1) gene delivery on the neointima formation in carotid arteries of spontaneously hypertensive rats (SHRs).</p><p><b>METHODS</b>Carotid artery restenosis was induced in male SHR rats by balloon-injury. Rats were randomly assigned into 4 groups: Sham-operated (n = 6); Angioplasty (phosphate buffered solution 50 microl, n = 8); Vector virus (control virus, 1 x 10(9) IU in 50 microl, n = 8) and Ad-hKLK1(Ad-hKLK1, 1 x 10(9) IU in 50 microl, n = 8). Rats were sacrificed 4 weeks later. The wall-to-lumen area ratio and intima/media ratio in carotid artery were assessed by image analysis in HE stained sections. The mRNA bradykinin receptor (B1R and B2R) expressions were detected by RT-PCR. The protein expression of the cycle-independent kinase inhibitors p27Kip1 and p2lCip1 were determined by Western blot analysis.</p><p><b>RESULTS</b>Wall-to-lumen area ratio reduced 35.6% and intima/media ratio reduced 38.8%in Ad-hKLK1 treated SHRs compared to angioplasty group (all P < 0.001). The expression of p27Kip1 and p2lCip1 increased significantly in Ad-hKLK1 treated SHRs compared with angioplasty rats (all P < 0.001). The mRNA expression of B2R was significantly upregulated in angioplasty rats compared with sham-operated rats (P < 0.05) while mRNA expression of B1R was similar between the 2 groups.</p><p><b>CONCLUSION</b>hKLK1 gene delivery may effectively reduce neointimal formation via downregulating bradykinin B2R and up-regulating the expressions of p27Kip1, p2lCip1 signaling pathways in carotid arteries of SHRs after balloon injury.</p>

Association of single nucleotide polymorphisms of kallikrein 1 gene with cerebral hemorrhage in Changsha Han Chinese / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the association between single nucleotide polymorphisms (SNPs) of KLK1 gene and cerebral hemorrhage in Changsha Han Chinese.</p><p><b>METHODS</b>Two hundred and seventy-three cerebral hemorrhage (CH) patients and 140 healthy controls were collected. The SNPs of rs5516 and rs5517 loci of KLK1 gene were analyzed by SNaPshot methods and direct sequencing.</p><p><b>RESULTS</b>(1)Genotype and allele frequencies in rs5516 locus had no difference between the CH patients and controls (P> 0.05). However, the A allele frequency of the rs5517 locus in CH patients was higher than that in the control group (0.419, 0.321 respectively, P< 0.05). (2)In the control group,the levels of diastolic blood pressure (DBP) of the GA and AA genotype carriers of the rs5517 locus were significantly higher than those of the GG genotype (P< 0.05), while the levels of blood pressure were not significantly different among different genotypes of the rs5516 polymorphism in both CH patients and the control group(P> 0.05).</p><p><b>CONCLUSION</b>Author's preliminary results suggested that the rs5517 polymorphism was associated with cerebral hemorrhage, while the rs5516 polymorphism was not in Changsha Han Chinese.</p>

Effects of human tissue kallikrein gene transfer on the migration of vascular smooth muscule cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of adenovirus-mediated human tissue kallikrein (Ad-hKLK1) gene transfer on platelet-derived growth factor-BB (PDGF-BB)-induced migration of vascular smooth muscle cells from spontaneously hypertensive rats (VSMC(SHR)).</p><p><b>METHODS</b>A bicistronic recombinant adenovirus vector (Ad-hKLK1) carrying the target hKLK1 gene and the reporter gene EGFP was constructed. VSMCs isolated from the thoracic aorta of male SHR were passaged, and the quiescent VSMC(SHR) in passages 3-6 seeded in 6-well plates were treated with Ad-hKLK1 and control virus. Human PDGF-BB or icatibant Hoe140, a BK B2 antagonistat, was used as the chemoattractant and placed in the bottom chamber of the Boyden chamber. The mRNA expressions of bradykinin B1 receptor and B2 receptor were detected by RT-PCR in VSMC(SHR).</p><p><b>RESULTS</b>hKLK1 gene transfer significantly inhibited PDGF-BB-induced migration of VSMC(SHR), with the peak inhibition rate of 34.6% (P<0.001). PDGF-BB significantly increased the mRNA expression of B2 receptor but not B1 receptor in VSMC(SHR).</p><p><b>CONCLUSIONS</b>hKLK1 gene transfer can inhibit the migration of VSMC(SHR) induced by PDGF-BB, and the inhibitory effects may be not mediated by bradykinin B2 receptor.</p>

Modification, expression and bioactivity analysis of hK-Fc fusion protein / 生物工程学报

To prolong serum half-life of human kallikrein (hK) and enhance its secretion rate, we modified hK gene and constructed a new form of recombinant hK protein (hK'-Fc). We amplified hK gene and Fc sequence, replaced the signal peptide of hK gene with murine signal peptide, constructed native expression plasmid of pcDNA-hK-Fc and modified expression plasmid of pcDNA-hK'-Fc, then transfected to CHO cells respectively. After the stable cell lines were screened, we compared the secretion rate between native fusion protein and modified fusion protein, purified fusion protein through Protein A+G affinity chromatography column and investigated the bioactivity of fusion protein. The results showed that recombinant vectors encoding fusion protein hK-Fc and hK'-Fc were constructed successfully; CHO cell lines stably secreting fusion protein were obtained, the yield is higher than 11 mg/L; Secretion rate was enhanced by 5-10 times after the signal peptide of fusion protein was modified; Fusion protein has enzymatic activity in vitro. The above results could promote the following researches on serum half-life of the fusion protein and develop a new stroke medicine with better clinical efficacy.

Effects of human urinary tissue kallikreins on vasodilation of basilar artery in rabbits with symptomatic cerebral vasospasm / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the effects of urinary kallidinogenase on subarachnoid hemorrhage (SAH) in rabbits.</p><p><b>METHODS</b>Rabbits symptomatic cerebral vasospasm model was built though Endo method, among the 40 rabbits, 8 died or had severe nervous system syndrome, the other 32 were randomly divided into 4 groups:group A, control group, injection of normal saline to the cisterna magna;group B, subarachnoid hemorrhage;group C, injection of human urinary tissue kallikreins;group D, treated with Nimodipine. The behavior scores, neurological scores and cerebral angiography changes were observed.</p><p><b>RESULTS</b>Food intake obviously decreased and neurological deficit were seen in group B, while which were attenuated in group C and group D, and group A was normal. Comparing the diameter of basilar artery was (1.9 +/- 0.3) mm before SAH, the diameter of group B 4 d later was (1.5 +/- 0.3) mm, 7 d later (1.4 +/- 0.3) mm, the difference was significant (P < 0.05). Comparing with group C on the day 4th and 7th, the diameters of basilar artery were significantly different (P < 0.001). Comparing with group D on the day 4th, 7th and 14th, there was no obvious improvement.</p><p><b>CONCLUSION</b>Urinary kallidinogenase and Nimodipine can obviously alleviate symptomatic cerebral vasospasm in rabbits remarkably, but the former's effect of attenuating vasospasm is better than that of Nimodipine.</p>

The regulatory effect of the first intron and 3'-regulatory region of ovalbumin gene on transgene expression / 生物工程学报

We studied the influence of the first intron and 3'-regulatory region of ovalbumin gene (ov) on oviduct-specific transgene expression. The 3'-regulatory region in the oviduct-specific expression vector containing human tissue kallikrein (hK1) cDNA was replaced with bovine growth hormone (BGH) poly A, and the first intron was deleted by restriction enzyme digestion, resulting in five new vectors pOV2K, pOV3K, pOV4K, pOV5K and pOV6K. After mixing with polyethylenimine, we injected same copies of the five vectors via wing vein route into laying hens and compared their expression levels by quantitative assay for enzymatic activities in the egg whites. Among the five vectors tested, the pOV2K containing both the 5'- and 3'-regulatory regions expressed highest level of rhK1 activity, followed by pOV3K with the 3'-regulatory region replaced with BGH poly A, and then by the first intron-shortened vectors pOV4K, pOV5K and pOV6K. These data suggest that both the first intron and 3'-regulatory region of ov gene have enhancing effect on transgene expression in oviduct cells, which should be included in oviduct-specific expression vectors.

High level expression, purification and characterization of human kallikrein-1 in Pichia pastoris / 生物工程学报

Human kallikrein-1 (hK1) gene was cloned from kidney tissues cDNA, it was inserted into the plasmid pPICZalphaA, then the yeast expression vector pPICZalpha-hK1 was constructed. After transformed into Pichia pastoris host X33, high-level expression transformants were screened by escalating the concentration of Zeocin (from 500 to 700 microg/mL) of YPD plate and medium. When temperature was 30 degrees C, pH 6.0 with induction duration of 64 hours in the 30 L fermenter, the highest yield can reach about 6500 u/L (1.25 g/L). The variation of glycosylation resulted in two kinds of molecules, i.e. rhK1-H with a heavy molecular weight and rhK1-L with a light one. rhK1 was purified from the supernatant through Phenyl hydrophobic interaction, Cu(2+)-charged Chelating and Anion-exchange chromatography. 0.28 g rhK1-H and 0.62 g rhK1-L can be purified from one liter supernatant. The yield recovery was 72% with a purity of > 96%. So far our yield of rhK1 is superior than known recombinant expression method reported by other researchers.

Differential expression of the KLK2 and KLK3 genes in peripheral blood and tissues of patients with prostate cancer

We used the multiplex semi-quantitative reverse-transcriptase PCR (RT-PCR) to investigate kallikrein 2 and 3 (KLK2 and KLK3) mRNA levels in prostate tissue from 42 prostate cancer patients, 33 of whom were also assessed for peripheral blood KLK2 expression by qualitative semi-nested RT-PCR. We found that KLK2 was an important tissue biomarker for distinguishing between prostate cancer patients and those with benign prostatic hyperplasia, particularly when KLK2 expression was > 60 percent of that of the beta2-microglobulin constitutive gene. Patients with an average relative expression value > 0.6 (cutoff value) had an eleven-fold higher chance of having prostate cancer. When one or two tissues samples were evaluated for KLK2 expression using the cutoff value the estimated chance of having prostate cancer was increased by seven times for one positive sample and 45 times for two positive samples. There was no significant correlation between KLK3 gene expression and prostate cancer diagnosis. Logistic regression for blood and tissue KLK2 expression successfully detected 92 percent of the prostate cancer cases. The detection of KLK2 in blood showed a sensitivity of 59 percent and a specificity of 82 percent. This study indicates that the KLK2 gene may be a useful molecular marker for the diagnosis of prostate cancer and that analysis of KLK2 expression in blood and tissues could provide a novel approach for the clinical investigation of this type of cancer.

Estudo da especificidade da calicreína 6 humana(hK6) / Study of specificity of human kallikrein 6(hK6)

Calicreína 6 humana (hK6) é uma serino-protease tripsina-símile expressa em altos níveis no sistema nervoso central que está envolvida em doenças neurodegenerativas como mal de Alzheimer e esclerose múltipla. Este trabalho fornece dados a respeito da especificidade da enzima e sua ativação por glicosaminoglicanos e sais cosmotrópicos da série de Hofmeister. A utilização de peptídeos FRET possibilitou identificar a sequência Abz-AFRFSQ-Eddnp como o melhor substrato sintético descrito para hK6 (kcatlKm = 38,667 mM.sr1 até o momento. Análises de blast demonstraram que a sequência AFRFS está presente no domínio amino-terminal dos receptores ionotrópicos de glutamato, semaforinas e acetilcolinesterase. Foi observado também que hK6 cliva substratos derivados de APP (proteína precursora amilóide), centro reativo do loop da a1-antiquimotripsina, proteína básica de mielina humana (M8P), plasminogênio e sítios de clivagem da pró-hK6, todos previamente descritos como prováveis substratos naturais da hK6. Além disto, peptídeos FRET derivados de seqüências dos receptores ativados por proteases (PARs) 1-4 foram ensaiados com a enzima, sendo hidrolisado somente o substrato com a sequência do PAR-2. Os resultados sugerem que hK6 desempenhe um papel importante em processos neurodegenerativos modulando a atividade de receptores ionotrópicos de glutamato e ativando PAR-2.

Expression of the kallikreins-kinins system in the corpus cavernosum of rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the expression of the kallikreins-kinins system in the corpus cavernosum of rats.</p><p><b>METHODS</b>The expression of tissue kallikrein I and kinin B2 receptor gene in the corpus cavernosum and heart of adult rats was detected by reverse transcription polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>The tissue kallikrein I and kinin B2 receptor were detected in the corpus cavernosum as well as in the heart of the rats and the contents were similar.</p><p><b>CONCLUSION</b>A kallikreins-kinins system exists in the corpus cavernosum of rats, and the content is rich, almost similar to that in the heart.</p>

Prolonged hypotensive effect of human tissue kallikrein gene delivery and recombinant enzyme administration in spontaneous hypertension rats

To evaluate the feasibility of treating hypertension by human tissue kallikrein gene (KLK1) delivery and by enzyme (rK1) administration, two recombinant vectors expressing KLK1 cDNA were constructed for gene delivery (pcDNA-KLK1) and recombinant enzyme preparation (pOV-KLK1). Expression of the pcDNA-KLK1 vector in COS-1 cells was confirmed by immunofluorescence and in spontaneous hypertension rats (SHR) by enzymatic detection. Following intramuscular or intravenous injection with the pcDNA-KLK1 vector, systolic pressure of SHR was significantly decreased, which lasted for 20 d to two months depending on dose, route and/or time of injection. Egg white containing recombinant hK1 was prepared by injection of egg-laying hens with the oviduct-specific expression vector pOV-KLK1 and administered into SHR via oral gavage. Following administration, systolic pressure of the SHR was decreased to that of normal rats, which lasted for 3-5 d depending on the dosage used. These data suggest that both hKLK1 gene delivery and recombinant enzyme administration can be used as alternative strategies for treating human hypertension.

Clinical significance of expression of PSA, hK2, PSMA in the peripheral blood of patients with prostate cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To find sensitive and specific micro-metastic markers for prostate cancer.</p><p><b>METHODS</b>Using nested reverse transcription-PCR, we examined the expression of PSA, hK2 and PSMA mRNA in peripheral blood mononuclear cells of 51 patients with prostate cancer, 33 patients with benign prostate hyperplasia (BPH) and 32 normal young people.</p><p><b>RESULTS</b>The expression rates of PSA, hK2 and PSMA mRNA were 52.9%, 43.1% and 64.7%, respectively in prostate cancer group, and 6.2%, 7.7% and 4.6%, respectively in control group (BPH patients and normal young people) with statistical significance (P < 0.01). Although the expression rate of PSA and hK2 mRNA increased with cancer progression, there was no statistical significance among patients in different stages. The expression rate of PSMA mRNA was higher than that of PSA and hK2 mRNA in each clinical stage.</p><p><b>CONCLUSION</b>PSMA mRNA expression detected by nested RT-PCR is of greater value for the diagnosis, therapy choice and prognostic evaluation of prostate cancer patients.</p>

Linear competitive inhibition of human tissue kallikrein by 4-aminobenzamidine and benzamidine and linear mixed inhibition by 4-nitroaniline and aniline

Hydrolysis of D-valyl-L-leucyl-L-arginine p-nitroanilide (7.5-90.0 `M) by human tissue kallikrein (hK1) (4.58-5.27 nM) at pH 9.0 and 37ºC was studied in the absence and in the presence of increasing concentrations of 4-aminobenzamidine (96-576 `M), benzamidine (1.27-7.62 mM), 4-nitroaniline (16.5-66 `M) and aniline (20-50 mM). The kinetic parameters determined in the absence of inhibitors were: Km = 12.0 + or - 0.8 `M and k cat = 48.4 + or - 1.0 min-1. The data indicate that the inhibition of hK1 by 4-aminobenzamidine and benzamidine is linear competitive, while the inhibition by 4-nitroaniline and aniline is linear mixed, with the inhibitor being able to bind both to the free enzyme with a dissociation constant Ki yielding an EI complex, and to the ES complex with a dissociation constant Ki', yielding an ESI complex. The calculated Ki values for 4-aminobenzamidine, benzamidine, 4-nitroaniline and aniline were 146 + or - 10, 1,098 + or - 91, 38.6 + or - 5.2 and 37,340 + or - 5,400 `M, respectively. The calculated Ki' values for 4-nitroaniline and aniline were 289.3 + or - 92.8 and 310,500 + or - 38,600 `M, respectively. The fact that Ki'>Ki indicates that 4-nitroaniline and aniline bind to a second binding site in the enzyme with lower affinity than they bind to the active site. The data about the inhibition of hK1 by 4-aminobenzamidine and benzamidine help to explain previous observations that esters, anilides or chloromethyl ketone derivatives of Nalpha-substituted arginine are more sensitive substrates or inhibitors of hK1 than the corresponding lysine compounds