Diagnostic strategies and the incidence of prostate cancer： reasons for the low reported incidence of prostate cancer in China

We have analysed the reasons for the low reported incidence of prostate cancer in China and argue for early diagnosis and treatment of this disease. According to the 2002 database of the International Agency for Research on Cancer （IARC）, the age-standardized incidence of prostate cancer in China is 1.6/105 person years （PY）, with a mortality rate of 1.0/105 PY and mortality-to-incidence rate ratio （MR/IR） = 0.63. The MR/IR ratio of prostate cancer in China was found to be higher than the average in Asia （MR/IR = 0.57） and much higher than that in North America （MR/IR = 0.13）. These data indicate that in China most prostate cancers were in the advanced stages at the time of diagnosis, and that patients had a short survival time thereafter. In 2004, Stamey et al. reported a retrospective American study of prostate cancer for the years 1983-2003. It was shown that most cases of prostate cancer detected by prostate-specific antigen （PSA） screening were in the advanced stage at the start of this 20-year period. These early follow-up data are quite similar to the results obtained from mass PSA screening of elderly men in Changchun, China. However, after the American programmes for early diagnosis and treatment of prostate cancer were accepted, tumours were diagnosed at earlier stages. On the basis of these findings, mass screening should be performed in the whole of China using serum PSA to facilitate early diagnosis and treatment of prostate cancer.

;~lasmid-based Survivin shRNA and GRIM-19 carried by attenuated Salmonella suppresses tumor cell growth

Persistent activation of Survivin and its overexpression contribute to the formation, progression and metastasis of several different tumor types. Therefore, Survivin is an ideal target for RNA interference mediated-growth inhibition. Blockade of Survivin using specific short hairpin RNAs （shRNA） can significantly reduce prostate tumor growth. RNA interference does not fully ablate target gene expression, owing to the idiosyncrasies associated with shRNAs and their targets. To enhance the therapeutic efficacy of Survivin-specific shRNA, we employed a combinatorial expression of Survivin-specific shRNA and gene associated with retinoid-interferon-induced mortality-19 （GRIM-19）. Then, the GRIM-19 coding sequences and Survivin-specific shRNAs were used to create a dual expression plasmid vector and were carried by an attenuated strain of Salmonella enteric serovar typhimurium （S. typhimurium） to treat prostate cancer in vitro and in vivo. We found that the co-expressed Survivin-specific shRNA and GRIM-19 synergistically and more effectively inhibited prostate tumor proliferation and survival, when compared with treatment with either single agent alone in vitroand in vivo. This study has provided a novel cancer gene therapeutic approach for prostate cancer.

Plasmid-based Stat3 siRNA delivered by hydroxyapatite nanoparticles suppresses mouse prostate tumour growth in vivo

DNA vector-based Stat3-specific RNA interference （si-Stat3） blocks Stat3 signalling and inhibits prostate tumour growth. However, the antitumour activity depends on the efficient delivery of si-Stat3. The effects on the growth of mouse prostate cancer cells of si-Stat3 delivered by hydroxyapatite were determined in this study. RM-1 tumour blocks were transplanted into C57BIJ6 mice. CaCl2-modified hydroxyapatite carrying si-Stat3 plasmids were injected into tumours, and tumour growth and histology were determined. The expression levels of Star3, pTyr-Stat3, Bcl-2, Bax, Caspase3, VEGFand cyclin D1 were measured by western blot analysis. Amounts of apoptosis in cancer cells were analysed with immunohistochemistry and the terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling （TUNEL） assay. The results showed that hydroxyapatite-delivered si-Stat3 significantly suppressed tumour growth up to 74% （P〈0.01）. Stat3 expression was dramatically downregulated in the tumours. The immunohistochemistry and TUNEL results showed that si-Stat3-induced apoptosis （up to 42%, P〈0.01）. The Stat3 downstream genes Bcl-2, VEGFand cyclin DI were also strongly downregulated in the tumour tissues that also displayed significant increases in Bax expression and Caspase3 activity. These results suggest that hydroxyapatite can be used for the in vivo delivery of plasmid-based siRNAs into tumours.

Effects of acrous gramineus and its component, alpha-asarone, on apoptosis of hippocampal neurons after seizure in immature rats

BACKGROUND： α-asarone and acrous gramineus have been shown to play a necessary function in enhancing the reactivity and convulsant threshold to electric stimulation of immature rats. They have also been shown to effectively suppress epileptic seizures induced by pentylenetetrazol in young rats. However, the mechanisms for these roles have been still unclear. OBJECTIVE： To observe the effects in immature rats of acrous gramineus and α -asarone on apoptosis of hippocampal neurons after epileptic seizure at the protein level, and to analyze the mechanism for these effects. DESIGN： A randomized controlled animal experiment. SETTINGS： Department of Pediatrics, First Hospital of Jilin University; Department of Histology and Embryology, Norman Bethune Medical School of Jilin University; Department of Internal Medicine, Children＇s Hospital of Changchun City; Department of Neurology, First Clinical Hospital affiliated to Harbin Medical University. MATERIALS： Fifty 3-week old Wistar rats, 34-40 g, irrespective of gender, were provided by Gaoxin Research Center of Medical Animal Experiment, Changchun. The animals were treated according to the animal ethical standards. The following chemicals were used for this study： acrous gramineus powders or infusion （Batch No, 0307113, Tianjiang Medicine Company Limited, Jiangyin）, α-asarone tablets （Batch No. 030219, Tianwei Pharmaceutical Factory, Shenyang）, and phenobarbital sodium tablets （Batch No. 020608, Xinya Medicine Company Limited, Shanghai）. The animals were divided into five groups randomly. First, ten rats were chosen as the normal controls. The remaining rats were treated with i.p. injections of pentylenetetrazol to stimulate an epileptic model. METHODS： The experiments were performed at the Neurological Laboratory of the First Hospital of Jilin University between October and December 2004. The rats were treated with i.p. injections of pentylenetetrazol （60 mg/kg） to establish an epileptic model. According to Racine＇ s standard, animals that reached stage 4 and 5 were chosen and randomly divided into 4 groups： model group, phenobarbital sodium, acrous gramineus, and a-asarone group. The normal control group was treated with an i.p. injection of physiological saline （0.5 mL）. After modeling, the model groups were intragastrically administrated 0.5 mL saline. The phenobarbital sodium, acrous gramineus, and α-asarone groups were intragastrically administrated 18 mg/kg/d phenobarbital sodium, 2 350 mg/kg/d acrous gramineus and 29 mg/kg/d α-asarone, respectively. The course of treatment was twice a day for 7 days. The normal group received intragastric administration of 0.5 mL saline at the same time. The rats were sacrificed and brain sections were prepared for light microscopy and electron microscopy. MAIN OUTCOME MEASURES： （1） Pathological changes of CA1 and CA3 hippocampal region neurons were observed by light microscopy and electronic microscopy. （2） Neuronal apoptosis in the CA1 and CA3 region was measured by TUNEL staining. （3） Bcl-2 and Bax expression in CA1 and CA3 region neurons was detected by immunohistochemistry and a ratio of Bcl-2/Bax was calculated. RESULTS： All 50 immature rats were included in the final analysis. （1） Pathological changes of CA1 and CA3 region hippocampal neurons： there were different pathological changes in all groups other than the normal control group. The number of damaged neurons in the model group was highest. The phenobarbital sodium, acrous gramineus, and α -asarone group exhibited different degrees of improvement. （2） Neuronal apoptosis in the CA1 and CA3 regions： there were less TUNEL-positive cells in the CA1 and CA3 regions in the normal control group. One week after PTZ-induced seizure, numerous TUNEL-positive cells were detected in the CA1 and CA3 regions in the remaining four groups. There was a significant difference between the normal control group and the remaining four groups （t = 12.089-19.162, P 〈 0.0 1）. The number of TUNEL-positive cells was less in the phenobarbital sodium, acrous gramineus, and α-asarone groups compared to the model group （t = 4.707-5.268, P 〈 0.01）. （3）Bcl-2 and Bax expression of neurons in the CA1 and CA3 regions： The number of Bcl-2- and Bax-positive cells was less in the normal control group. The Bax-positive cells exhibited a normal shape and had large round nuclei that were predominant. One week after PTZ-induced epilepsy, the number of Bcl-2- and Bax-positive cells in the CA1 and CA2 regions was significantly increased in the remaining four groups compared to the normal control group （t = 11.606-27.042, P 〈 0.01）. The Bax-positive cells exhibited a reduced size and nuclear pyknosis was predominant. However, there was no significant difference among the four groups （P 〉 0.05）. The number of Bcl-2-positive cells in the phenobarbital sodium, acrous gramineus, and a-asarone groups were significantly increased compared to the model group （t = 4.051-6.404, P 〈 0.01）. However, the number of Bax-positive cells was not significantly different among the four groups. The ratio of Bcl-2 to Bax expression was approximately 6.0 in the normal controls, 0.7 in the model group, and 1.0 in the remaining three groups. CONCLUSION： Acrous gramineus and a-asarone increased Bcl-2 expression and decreased Bax expression, and also reduced the number of apoptotic hippocampal neurons during PTZ-induced epileptic seizures in immature rats.

Effects of Hydroxyapatite Nanoparticles on Apoptosis and Invasion of Human Renal Cell Carcinoma 786-0 Cells

Renal cell carcinoma is the most common cancer of the kidney, and resistant to traditional therapies. The aim of this study is to investigate the effects of hydroxyapatite nanoparticles on human renal cell carcinoma 786-0 cells. Cell proliferation was assessed with an 3-（4,5-dimethylthiazol-2-yl） 2,5-diphenyltetrazolium bromide（MTT） staining kit. The apoptosis assay was assessed with an FITC Annexin V Apoptosis Detection Kit. Caspase-3 and caspase-12 were detected by immunocytochemical staining and semi-quantitative RT-PCR. Cell wound healing assay was used to ensure cell motility. Matrigel invasion assay was analysed via transwell chambers. Our results showed that hydroxyapatite nanoparticles significantly reduced cell proliferation, invasion and induced apoptosis of 786-0 cells. The inhibiting action may have relation with up-regulated caspase-12, leading the cells to apoptosis. This study suggests that hydroxyapatite nanoparticles may be an effective and delivery system for renal cell carcinoma therapy.

Proteasome alteration and delayed neuronal death in hippocampal CA1 and dentate gyrus regions following transient cerebral ischemia

BACKGROUND： Proteasome dysfunction has been reported to induce abnormal protein aggregation and cell death. OBJECTIVE： To investigate the effect of proteasome changes on delayed neuronal death in CA1 and dentate gyrus （DG） regions of the rat hippocampus following transient cerebral ischemia. DESIGN, TIME AND SETTING： A randomized, controlled animal experiment. The study was performed at the Department of Biochemistry and Molecular Biology, Norman Bethune Medical College of Jilin University, from September 2006 to May 2008. MATERIALS： Rabbit anti-19S S10B polyclonal antibody was purchased from Bioreagents, USA; propidium iodide and fluorescently-labeled goat anti-rabbit IgG were purchased from Jackson Immunoresearch, USA; hematoxylin and eosin staining solution was purchased from Sigma, USA; LSM 510 confocal microscope was purchased from Zeiss, Germany. METHODS： A total of 40 healthy Wistar rats, male, 4 months old, were randomly divided into sham surgery group （n = 8） and model group （n = 32）. Ischemic models were established in the model group by transient clamping of the bilateral carotid arteries and decreased blood pressure. After 20 minutes of global ischemia, the clamp was removed to allow blood flow for 30 minutes, 4, 24 and 72 hours, respectively, with 8 rats at each time point. The bilateral carotid arteries were not ligated in the sham surgery group. MAIN OUTCOME MEASURES： Neuronal death in the CA1 and DG regions was observed by hematoxylin-eosin staining. Proteasome expression in CA1 and DG region neurons was detected by immunohistochemistry. RESULTS： Hematoxylin-eosin staining showed neuronal death in the CA1 region alone at 72 hours of reperfusion following ischemia. In comparison to the sham surgery group, a significant decrease in proteasome expression was observed, by immunohistochemistry, in the CA1 and DG regions in the model group, following 30 minutes, 4, 24, and 72 hours of reperfusion （P 〈 0.01）. After 72 hours of reperfusion following ischemia, proteasome expression had almost completely disappeared in the CA1 region. In contrast, neurons of the DG region showed minimized proteasome expression at 24 hours, with a slight increase at 72 hours （P 〈 0.01）. CONCLUSION： The alteration of proteasome following ischemia/reperfusion in the neurons of hippocampal CA1 and DG regions reduces the ability of cells to degrade abnormal protein, which may be an important factor resulting in delayed neuronal death following transient cerebral ischemia.

Is XMRV a causal virus for prostate cancer？

The potential association between xenotropic murine leukaemia virus-related gammaretrovirus （XMRV） and prostate cancer （PCa） has been documented since 2006, It is important for furthering our understanding of the biological mechanisms of PCa to ascertain whether this association is causal. To summarize the available information on the epidemiological and laboratory findings of the association, we conducted a literature search of the PubMed electronic database （from March 2006 to February 2011） to identify relevant published studies that examined the association between XMRV and PCa, Although several studies showed the positive association between XMRV and PCa, more recent studies did not support this conclusion, The positive findings might be due to contamination of human samples, Further studies are needed to clarify this association,

Inhibitory Effects of Phenylacetic Acid on Proliferation of Human Pancreatic Carcinoma BXPC-3 Cells by the Regulation of Adenosine Deaminases Acting on RNA

The effect and mechanism of phenylacetic acid on the proliferation of pancreatic carcinoma cells were investigated in cultured pancreatic carcinoma BXPC-3 cells by means of 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide assay and flow cytometry assay.The results show that the treatment of pancreatic carcinoma cells with phenylacetic acid significantly inhibited the cell proliferation in time-dependent and dose-dependent manners.The proliferation of BXPC-3 cells was inhibited at the stage of S phase,the cells at the end stage of S phase were accumulated abundantly,and thus DNA synthesis could not be accomplished entirely.In addition,the expression of adenosine deaminases acting on RNA（ADARs） mRNA in BXPC-3 cells and pancreatic carcinoma specimen were detected by RT-PCR.Having been treated with phenylacetic acid,ADAR2 mRNA in BXPC-3 cells was significantly decreased,the differences were of statistical significance（P0.01）.Taken together,these results suggest that phenylacetic acid may likely regulate the proliferation of pancreatic carcinoma cells through the regulation of ADAR2 mRNA expression.

Three-dimensional reconstruction method for measuring the knee valgus angle of the femur in northern Chinese adults

The purpose of this study was to establish a method for measuring the knee valgus angle from the ana- tomical and mechanical axes on three-dimensional reconstruction imaging models, and to use this method for estimating an average knee valgus angle value for northern Chinese adults. Computed tomographic angiography data in DICOM format for 128 normal femurs from 64 adult subjects were chosen for analysis. After the femur images were subjected to three-dimensional reconstruction, the deepest point in the intercondylar notch （point A）, the midpoint of the medullary cavity 20 cm above the knee-joint line （point B）, and the landmark of the femoral head rotation center （point C） were identified on each three-dimensional model. The knee valgus angle was defined as the angle enclosed by the distal femoral anatomical axis （line AB） and the femoral mechanical axis （line AC）. The average （mean＋SD） of knee valgus angle for the 128 femurs was 6.20°±1.20° （range, 3.05° to 10.64°）. Significant positive correlations were found between the knee valgus angles of the right and left sides and between the knee valgus angle and age. During total knee arthroplasty, choosing a valgus cut angle of approximately 6° may achieve a good result in reestablishing the natural mechanical alignment of the lower extremity for patients of northern Chinese ethnicity. Larger valgus cut angles should be chosen for older patients.