p53 downregulates the gene expression of mitochondrial aconitase in human prostate carcinoma cells

BACKGROUND

Mitochondrial aconitase (mACON) is regarded as the key enzyme in citrate oxidation in human prostate epithelial cells, and its abnormal expression has been implicated in tumorigenesis of the prostate. Evidence also supports a broad role for the p53 gene in suppressing prostatic tumorigenesis. We investigated whether p53 regulates mACON expression and explore the potential mechanisms responsible for its effect on prostate cancer cells.

METHODS

Camptothecin (CPT) treatments and transient overexpression of p53 were used to investigate p53 regulation of mACON and may effects were assessed using immunoblotting and transient gene expression assays.

RESULTS

In vitro enzymatic activity assays and immunoblot assays showed that CPT treatment induced p53 expression while reducing mACON protein biosynthesis in wild-type p53 expressing LNCaP cells. Immunoblot assays and reporter assays revealed that transient transfection of a p53 expression vector into p53-null PC-3 cells decreased mACON expression. Cyclic pifithrin-α, an inhibitor of p53 transcriptional activity, blocked the decrease in mACON gene expression resulting from CPT treatment in LNCaP cells. Two putative p53 response elements were identified within the mACON promoter; however, mutation of these putative p53 response elements did not abolish the effect of CPT whereby it decreased mACON expression. A similar result was obtained for the effect of these mutants on the promoter activity of the mACON gene after transient overexpression of p53.

CONCLUSIONS

Together these results suggest that p53 downregulation of mACON gene expression in human prostate carcinoma cells may not occur through the putative consensus p53 response elements found within the mACON promoter.

Identification of genetic alterations in upper urinary tract urothelial carcinoma in end-stage renal disease patients

Clinical presentations of end-stage renal disease (ESRD) patients on dialysis with upper urinary tract urothelial carcinoma (UUT-UC) are different from those with normal renal function. The pathogenesis remains unknown. We investigated the pathogenetic influence of chromosomal aberrations in patient on dialysis with UUT-UC. The chromosomal aberrations of UUT-UC specimens from seven dialysis patients were assessed by conventional comparative genomic hybridization (cCGH). Subsequently, we further investigated 20 cases by whole genome and fine-tiling oligonucleotide array-based CGH to demonstrate gains and losses, and compared with the clinicopathologic background. The chromosomal aberrations in UUT-UC specimens from dialysis patients were more complex than in bladder urothelial carcinoma (B-UC). Our data showed that gains at 5p, 7, 19q, and losses at 4q, 9p, and 15q are common in UUT-UC of ESRD patients. Gains in regions associated with DNA repair genes were noted in this study. High-stage and high-grade tumors displayed more copy number variants. In addition, female ESRD patients with UUT-UC had more frequent chromosomal aberrations than their male counterparts. In conclusion, unique chromosomal aberrations were indentified in UUT-UC in ESRD patients.

Discovery of novel bladder cancer biomarkers by comparative urine proteomics using iTRAQ technology

A urine sample preparation workflow for the iTRAQ (isobaric tag for relative and absolute quantitation) technique was established. The reproducibility of this platform was evaluated and applied to discover proteins with differential levels between pooled urine samples from nontumor controls and three bladder cancer patient subgroups with different grades/stages (a total of 14 controls and 23 cancer cases in two multiplex iTRAQ runs). Combining the results of two independent clinical sample sets, a total of 638 urine proteins were identified. Among them, 55 proteins consistently showed >2-fold differences in both sample sets. Western blot analyses of individual urine samples confirmed that the levels of apolipoprotein A-I (APOA1), apolipoprotein A-II, heparin cofactor 2 precursor and peroxiredoxin-2 were significantly elevated in bladder cancer urine specimens (n = 25-74). Finally, we quantified APOA1 in a number of urine samples using a commercial ELISA and confirmed again its potential value for diagnosis (n = 126, 94.6% sensitivity and 92.0% specificity at a cutoff value of 11.16 ng/mL) and early detection (n = 71, 83.8% sensitivity and 94.0% specificity). Collectively, our results provide the first iTRAQ-based quantitative profile of bladder cancer urine proteins and represent a valuable resource for the discovery of bladder cancer markers.

Bikunin loss in urine as useful marker for bladder carcinoma

PURPOSE

We searched for bladder tumor markers by analyzing urine samples from patients with bladder cancer and normal individuals.

MATERIALS AND METHODS

Proteins in urine samples of patients with cancer and normal subjects were systematically examined by 2-dimensional electrophoresis combined with matrix assisted laser desorption ionization time-of-flight mass spectrometry. Of the proteins bikunin expression was confirmed by Western blot analysis and further evaluated. To correlate urinary bikunin levels with clinical significance we examined urine samples from patients with bladder cancer and normal controls for bikunin expression in parallel with pro-urolinase-plasminogen activator, which was previously shown to be associated with advanced bladder carcinoma.

RESULTS

A significant relationship was established between the low level and absence of bikunin, and pro-urolinase-plasminogen activator in urine samples from patients with bladder tumors.

CONCLUSIONS

Analysis of urinary proteomes may be a feasible, noninvasive and efficient strategy for searching for potential bladder tumor biomarkers. We identified bikunin loss in urine as a potential bladder carcinoma marker.

Risk factors associated with transrectal ultrasound guided prostate needle biopsy in patients with prostate cancer

BACKGROUND

Transrectal ultrasound (TRUS) guided prostate needle biopsy is a commonly used diagnostic procedure. We determined associated risk factors for patients who suffered major complications and required hospitalization after TRUS-guided prostate biopsy.

METHODS

A total of 1,529 patients, 27 to 92 years old (mean 67.6 years) were included in this study conducted between January 2003 and July 2006. Each patient underwent sextant prostate biopsy under transrectal ultrasound guidance. Six-core transrectal biopsies were performed by urologists, consultant urologists and residents in training.

RESULTS

The mean prostate-specific antigen (PSA) level and prostate volume were 113.2 ng/ml and 46.2 grams, respectively. One hundred forty-seven patients had complications. Some patients may have had more than one complication, but no major sequelae were seen immediately after biopsy. Sixty-two (4.1%) of these patients had gross hematuria, while 26 (1.7%) had acute urinary retention, 21 (1.4%) had urinary tract infection, 17 (1.1%) had hematospermia,14 (0.9%) had anal bleeding and 7 (0.5%) had anal pain. Urinary tract infection and rectal preparation were found significantly associated with complications.

CONCLUSIONS

The results of our study demonstrate that minor complications occur without sequelae. Thus, TRUS-guided prostate needle biopsy is a safe and effective diagnostic tool. Urinary tract infection and rectal preparation might affect the complication rate.

Enterovesical fistula caused by a bladder squamous cell carcinoma

Enterovesical fistulas are not uncommon in patients with inflammatory or malignant colonic disease, however, fistulas secondary to primary bladder carcinomas are extremely rare. We herein reported a patient presenting with intractable urinary tract infection due to enterovesical fistula formation caused by a squamous cell carcinoma of the urinary bladder. This patient underwent en bloc resection of the bladder dome and involved ileum, and recovered uneventfully without urinary complaint. To the best of our knowledge, this is the first case reported in the literature.

LOUPE-ASSISTED MODIFIED ONE-LAYER VASOVASOSTOMY

Several studies indicate that microsurgical modified one-layer vasovasostomy is comparable to the two-layer anastomosis with respect to patency and pregnancy rates. The objective of this study was to determine the feasibility and result of modified one-layer vasovasostomy under loupe magnification only. Thirty-two patients aged 28 to 64 years (mean 41.3 +/- 6 years) underwent vasovasostomy at CGMH from July 1997 to June 2002, with all operations being a modified on-layer anastomosis created with the aid of a 3 x loupe. The estimated duration of vasectomy ranged from 4 months to 27 years, with a mean of 9.2 +/- 4.8 years. Postoperative semen analysis and pregnancy were examined. Each patient was followed up at 1,4, and 12 weeks postoperatively. The total operation time ranged from 118 to 228 minutes (average 150 +/- 35 minutes). There was no operation-related complication such as hematoma or wound infection. The patency rate was 89% (25/28), and the pregnancy rate at 2 years or more of follow-up was 39% (11/28). The patency and pregnancy rates were similar to those obtained in most studies of microsurgical vasovasostomy. For uncomplicated vasectomy reversal, this simple loupe-assisted modified one-lyer vasovasostomy seems to provide an adequate anastomosis.

HIGH INGUINAL LOUPE-ASSISTED VARICOCELECTOMY FOR SUBFERTILE MEN WITH VARICOCOCELES: TECHNICAL FEASIBILITY, CLINICAL OUTCOMES AND COMPLICATIONS

254 consecutive patients underwent high inguinal loupe-assisted varicocelectomy. All patients had at least a one year history of infertility with abnormal semen parameters and physical examination and/or color Doppler ultrasound proven varicocele. To facilitate the procedure, an x 3.0 loupe was used during spermatic cord dissection near or at level of internal inguinal ring. Semen analysis and physical examination were performed at 3 monthly intervals. No intra-operative complications occurred. The most common post-operative complications were transient scrotal pain and stitch reaction, occurring in 12% and 4% of men, respectively. Only one permanent and two transient hydroceles were observed. Recurrent or persistent varicocele was identified by physical examination and color Doppler in 5 varicocelectomies (1.4%), and by color Doppler only in 6 varicocelectomies (1.7%). Sperm motility increased from 30 +/- 8% to 46 +/- 20%, and sperm concentration. (10(6)/cc) increased from 24 +/- 18 to 41 +/- 28. The one-year pregnancy rate was 37%. High inguinal loupe-assisted varicocelectomy is a safe, simple, and effective treatment for varicocele.

SNP ID-info: SNP ID searching and visualization platform

Many association studies provide the relationship between single nucleotide polymorphisms (SNPs), diseases and cancers, without giving a SNP ID, however. Here, we developed the SNP ID-info freeware to provide the SNP IDs within inputting genetic and physical information of genomes. The program provides an "SNP-ePCR" function to generate the full-sequence using primers and template inputs. In "SNPosition," sequence from SNP-ePCR or direct input is fed to match the SNP IDs from SNP fasta-sequence. In "SNP search" and "SNP fasta" function, information of SNPs within the cytogenetic band, contig position, and keyword input are acceptable. Finally, the SNP ID neighboring environment for inputs is completely visualized in the order of contig position and marked with SNP and flanking hits. The SNP identification problems inherent in NCBI SNP BLAST are also avoided. In conclusion, the SNP ID-info provides a visualized SNP ID environment for multiple inputs and assists systematic SNP association studies. The server and user manual are available at http://bio.kuas.edu.tw/snpid-info.

Web-based clinical pathway for reducing practice variations in radical prostatectomy

BACKGROUND

A clinical pathway support system on the Internet (CPSSI) has been designed for creating and implementing a web-based clinical pathway for radical prostatectomy. This investigation assessed the effects of the web-based clinical pathway for radical prostatectomy on practice variations.

METHODS

From June 2002 to Jun 2003, 22 consecutive patients with localized prostate cancer who underwent radical prostatectomy were treated according to the web-based clinical pathway. The treatment results were compared with an identically sized sample of patients treated during the year before implementing the web-based clinical pathway. Variations before and following the implementation of the web-based clinical pathway for radical prostatectomy were also assessed. The CPSSI automatically measured pathway variations and length of hospital stay.

RESULTS

After implementing the web-based clinical pathway, the average hospital stay was reduced significantly (p=0.0001). The mean number of variations also differed markedly (p=0.0002).

CONCLUSION

This study concludes that the CPSSI-based clinical pathway support system may provide a good tool for creating and implementing a web-based clinical pathway. After implementing the web-based clinical pathway for radical prostatectomy, practice variations and length of stay were reduced considerably. Moreover, automatically assessing the effects of web-based clinical pathway implementation can enhance the quality of patient care.

Curcumin blocks the activation of androgen and interlukin-6 on prostate-specific antigen expression in human prostatic carcinoma cells

Curcumin, a naturally occurring compound, exhibits anticancer chemopreventive effects. We evaluated the effects and mechanisms of curcumin on the gene expression of prostate-specific antigen (PSA) in human androgen-sensitive prostatic carcinoma cells. LNCaP cells were used to determine the effect of curcumin on PSA expression. Quantitative PSA expression was assessed by reverse transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and immunoblot assay. The modulation of androgen, interlukin-6 (IL-6), and prostate-derived Ets factor (PDEF) on the PSA gene was identified by transient gene expression assay with the use of a PSA reporter vector. The effect of curcumin on the activity of androgen receptors was evaluated by electrophoretic mobility shift assay (EMSA). Immunoblot assays, RT-PCR, and ELISA indicated that curcumin treatments blocked the stimulation of methyltrienolone (R1881) and IL-6 on PSA gene expression in LNCaP cells. The effects of curcumin appear to be mediated via the androgen response element of PSA gene. Results from immunoblot assay and EMSA revealed the modulation of curcumin on the expression of androgen receptor and androgen receptor binding activity on androgen response element of PSA gene. Although overexpression of PDEF dramatically enhanced PSA gene expression, the results of immunoblot assays and transient reporter assays indicated that curcumin treatments did not affect the gene expression of PDEF. Curcumin inhibits R1881- and IL-6-mediated PSA gene expression in LNCaP cells through down-regulation of the expression and activity of androgen receptors.

Evaluating the function of matriptase and N-acetylglucosaminyltransferase V in prostate cancer metastasis

Previous studies have identified a subclone cell line (PC-J) which was isolated from a metastatic human prostate cell line, PC-3. In vitro matrigel invasion assays and xenograft animal studies suggested that matriptase was a putative metastatic gene in human prostate carcinoma cells. Although low metastatic prostate tumor cells, LNCaP, also expressed high levels of matriptase mRNA, gelatin zymography indicated that LNCaP cells had extremely low matriptase activity. Further studies using RT-PCR and lectin blotting assays revealed that the expression of N-acetylglucosaminyltransferase V (MGAT5), a glycoprotein that stabilizes matriptase, was low in LNCaP cells compared to PC-3 and PC-J cells. The transient overexpression of MGAT5 significantly enhanced the activity of matriptase and the invasion ability in the LNCaP cells. Knock-down of MGAT5 in PC-3 cells attenuated the metastatic ability of the cells, as determined by the in vitro invasion assay and the xenograft animal studies. Matriptase and MGAT5 may play important role in the metastasis of prostate cancer.

Down-regulation of matriptase by overexpression of bikunin attenuates cell invasion in prostate carcinoma cells

The precise mechanisms of metastasis in prostatic cancer are still unknown. A subculture cell line (PC-J) was isolated from the metastasis human prostate cell line PC-3. In vitro cell proliferation, wound healing and invasion assays revealed that tumorigenesis and metastasis differed between PC-3 and PC-J cells. Eight weeks after nude mice were prostate-injected with PC-J and PC-3 cells, the PC-3 group had low tumor volume and exhibited metastasis whereas the PC-J group had high tumor volume and no metastasis. Subsequent RT-PCR and immunoblot assays indicated that matriptase was the putative metastatic gene. Overexpression of bikunin significantly reduced the gene expression of matriptase, which attenuated in vitro cell invasion in the PC-3 cells. In vitro and xenograft animal models indicated different metastatic characteristics between PC-3 and PC-J cells, suggesting that matriptase plays an important role in the metastasis of prostate cancer.

Prostate specific antigen gene expression in androgen insensitive prostate carcinoma subculture cell line

A novel prostate cancer cell line (PC-J) was isolated from an androgen independent non-prostate specific antigen (non-PSA) producing carcinoma cell line. The homologous correlation between PC-J and PC-3 was determined by short tandem repeat analysis. The PSA promoter activity was detected by transient expression assay in the PC-J and LNCaP cells but not in androgen insensitive PC-3 cells. When the PC-J cells were cotransfected with androgen receptor, androgen receptor coactivators and PSA reporter vector cells, the reporter assays indicated that nuclear receptor coactivator 4 (NCOA4) but not androgen receptor activator 24 (ARA24) increased the sensitivity and maximum stimulation of dihydrotestosterone (DHT)-inducing PSA promoter activity. The RT-PCR assays revealed that the expression of several tumor markers, including interleukin-6, prostate stem cell antigen (PSCA), prostate epithelium-specific Ets transcription factor (PDEF) and matriptase, was lower in the PC-J cells than in the PC-3 cells. This cell model elucidated the regulation of PSA expression and enabled comparison of the gene profile at different stages of metastasis in prostatic carcinoma.

Restriction enzyme mining for SNPs in genomes

Many different single nucleotide polymorphisms (SNPs) genotyping methods have been developed recently. However, most of them are expensive. Using restriction enzymes for SNP genotyping is a cost-effective method. However, restriction enzyme mining for SNPs in a genome sequence is still challenging for researchers who do not have a background in genomics and bioinformatics. In this review, the basic bioinformatics tools used for restriction enzyme mining for SNP genotyping are summarized and described. The objectives of this paper include: i) the introduction of SNPs, genotyping and PCR-restriction fragment length polymorphism (RFLP); ii) a review of components for genotyping software, including tools for primer design only or restriction enzyme mining only; iii) a review of software providing the flanking sequence for primer design; iv) recent advances in PCR-RFLP tools and natural and mutagenic PCR-RFLP; v) highlighting the strategy for restriction enzyme mining for SNP genotyping; vi) a discussion of potential problems for multiple PCR-RFLP. The different implications for restriction enzymes on sense and antisense strands are also discussed. Our PCR-RFLP freeware, SNP-RFLPing, is included in this review to illustrate many characteristics of PCR-RFLP software design. Future developments will include further sophistication of PCR-RFLP software in order to provide better visualization and a more interactive environment for SNP genotyping and to integrate the software with other tools used in association studies.

Odds ratio-based genetic algorithms for generating SNP barcodes of genotypes to predict disease susceptibility

Genome-wide association analysis involving many single nucleotide polymorphisms (SNPs) data is challenging mathematically and computationally. It is time consuming to classify the combination of multilocus genotypes into high- and low-risk groups without false positive and negative errors. Hence, we propose the odds ratio-based genetic algorithms (OR-GA) method that uses the odds ratio as a new quantitative measure of disease risk among many SNP combinations. Genetic algorithms (GA) are applied to generate SNP "barcodes" of genotypes, which propose the maximal difference of occurrence between the case and control groups, to predict disease susceptibility (e.g., osteoporosis). When individuals are grouped into a low and high bone mass density (BMD) range, different SNP barcode patterns may occur several times in each of these two groups. Our results showed that a GA can effectively identify a specific SNP barcode with an optimized fitness value. SNP barcodes with a low fitness value will naturally be discarded from the population. A representative SNP barcode with a variable number of SNPs is processed by odds ratio analysis to determine the maximum difference between the low and high BMD groups in a statistical manner. Therefore, this paper introduces a powerful procedure for analysis of disease-associated SNP barcode in genome-wide genes.

Triiodothyronine modulates cell proliferation of human prostatic carcinoma cells by downregulation of the B-cell translocation gene 2

BACKGROUND

Studies suggest that triiodothyronine (T3) and cognate nuclear receptors (hTR) are involved in regulation of prostatic cell growth and differentiation. To probe mechanisms for T3 effects, we studied prostate carcinoma cells, investigating the effect of T3 on expression of the B-cell translocation gene 2 (BTG2), which regulates the G1/S transition of the cell cycle.

METHODS

Effects of T3 on cell proliferation were determined by (3)H-thymidine incorporation. T3 modulation of BTG2 expression was investigated using immunoblots, Northern blots, and transient gene expression assays. The putative T3 response element was determined by electrophoretic mobility shift assay.

RESULTS

T3 (0.1-1,000 nM) enhanced threefold the proliferation of prostate carcinoma cells and human androgen-dependent prostate carcinoma cells (LNCaP), but not PC-3 cells. T3 also inhibited BTG2 gene expression in LNCaP cells. Reporter assays showed that T3 downregulates by 50% promoter activity of the BTG2 gene in LNCaP cells but not PC-3 cells or thyroid-hormone receptor (TRbeta1)-overexpression PC-3 cells. Deleting the putative thyroid hormone response element (TRE; AGCGATGACCTCAGCG) blocked the inhibitory effect of T3 on BTG2 promoter activity. Electrophoretic mobility shift assays with purified TRbeta1 from in vitro translation, or with nuclear extracts from LNCaP cells and PC-3 cells, demonstrated the presence of T3 receptor binding sites in the TRE region.

CONCLUSIONS

These results suggested that the T3 upregulates proliferation of LNCaP cells by downregulating BTG2 gene expression through the consensus TRE pathway.

Comparisons of voided urine cytology, nuclear matrix protein-22 and bladder tumor associated antigen tests for bladder cancer of geriatric male patients in Taiwan, China

AIM

To compare the results of bladder tumor associated antigen (BTA TRAK), nuclear matrix protein 22 (NMP 22) and voided urine cytology (VUC) in detecting bladder cancer.

METHODS

A total of 135 elderly male and 50 healthy volunteers enrolled in this study were classified into three groups: (i) 93 patients with bladder cancer; (ii) 42 patients with urinary benign conditions; and (iii) 50 healthy volunteers. BTA TRAK and NMP 22 kits were used to detect bladder cancer. Voided urine cytology was used to compare the sensitivity and specificity of the screening tests.

RESULTS

The sensitivity and specificity of cytology, BTA TRAK and NMP 22 were 24% and 97%, 51% and 73%, 78% and 73%, respectively. The level of NMP 22 increased with tumor grading. The BTA TRAK kit has the lowest sensitivity among the screening tests. The NMP 22 with the best sensitivity can be an adjunct to cytology for evaluating bladder cancer.

CONCLUSION

The NMP 22 test has a better correlation with the grading of the bladder cancer than BTA TRAK. As cytology units are typically not available in hospitals or in outpatient clinics, NMP 22 might be a promising tool for screening bladder cancer.

Arterial bleeding in patients with intractable hematospermia and concomitant hematuria: A preliminary report

OBJECTIVES

To assess the presence of arterial bleeding and its outcome after transcatheter arterial embolization (TAE) in patients with intractable hematospermia and concomitant hematuria.

METHODS

In a 32-month period, 5 patients with hematospermia and concomitant hematuria who were unresponsive to medical treatment were enrolled in this study to undergo pelvic angiography. When angiography revealed arterial bleeding, TAE was done whenever possible to stop the bleeding. All patients were then followed up at the outpatient clinics by the referring urologists for the result of TAE on hematospermia and the presence of impotence.

RESULTS

Arterial bleeding mainly from the internal pudendal artery was revealed by angiography in all 5 patients. The cessation of bleeding by TAE was successfully achieved in all patients. Hematospermia was improved in 3 patients. In the other 2 patients, hematospermia subsided after TAE but recurred at 12 and 23 months. Subsequent angiography of the 2 patients showed recurrent arterial bleeding, fed by blood flow from the opposite side. One of the 2 patients agreed to undergo a second TAE, after which the hematospermia disappeared. None of the 5 patients had impotence at follow-up.

CONCLUSIONS

Patients with intractable hematospermia and concomitant hematuria may have arterial bleeding that can be detected by angiography. The cessation of the bleeding could be achieved by TAE without complication of impotence. However, long-term follow-up is necessary for possible reconstitution of blood flow from the opposite side.

Absence of Epstein-Barr virus infection in squamous cell carcinoma of upper urinary tract and urinary bladder

OBJECTIVES

To address whether Epstein-Barr virus (EBV) infection may be involved in the carcinogenesis of squamous cell carcinoma of the upper urinary tract and urinary bladder (SCC-UB). EBV has been implicated in the genesis of a variety of human cancers, including urothelial carcinoma of the urinary bladder.

METHODS

Whether EBV infection is related to SCC-UB carcinogenesis was investigated by in situ hybridization for EBV-encoded RNA and immunohistochemistry for latent membrane protein-1 in 26 cases of SCC-UB.

RESULTS

EBV-encoded RNA and latent membrane protein-1 were identified in the control case of nasopharyngeal carcinoma. None of the SCC-UB cases had a nuclear signal of EBV-encoded RNA, and the cancer cells, normal urothelial cells, and inflammatory cells were all negative for latent membrane protein-1, irrespective of the site of SCC-UB.

CONCLUSIONS

This study is the first to explore the role of EBV infection in SCC-UB. Our results suggest that EBV infection is not involved in the carcinogenesis of SCC of the renal pelvis, ureter, and urinary bladder.

Manganese antagonizes iron blocking mitochondrial aconitase expression in human prostate carcinoma cells

AIM

To investigate the possible role of manganese in the regulation of mitochondrial aconitase (mACON) activity human prostate carcinoma cell line PC-3 cells.

METHODS

The mACON enzymatic activities of human prostate carcinoma cell line PC-3 cells were determined using a reduced nicotinamide adenine dinucleotide-coupled assay. Immunoblot and transient gene expression assays were used to study gene expression of the mACON. The putative response element for gene expression was identified using reporter assays with site-directed mutagenesis and electrophoretic mobility-shift assays.

RESULTS

In vitro study revealed that manganese chloride (MnCl2) treatment for 16 h inhibited the enzymatic activity of mACON, which induced the inhibition of citrate utility and cell proliferation of PC-3 cells. Although results from transient gene expression assays showed that MnCl2 treatment upregulated gene translation by approximately 5-fold through the iron response element pathway, immunoblot and reporter assays showed that MnCl2 treatments inhibited protein and gene expression of mACON. This effect was reversed by co-treatment with ferric ammonium citrate. Additional reporter assays with site-directed mutagenesis and electrophoretic mobility-shift assays suggested that a putative metal response element in the promoter of the mACON gene was involved in the regulation of MnCl2 on the gene expression of mACON.

CONCLUSION

These findings suggest that manganese acts as an antagonist of iron, disrupting the enzymatic activity and gene expression of mACON and citrate metabolism in the prostate.

V-MitoSNP: visualization of human mitochondrial SNPs

BACKGROUND

Mitochondrial single nucleotide polymorphisms (mtSNPs) constitute important data when trying to shed some light on human diseases and cancers. Unfortunately, providing relevant mtSNP genotyping information in mtDNA databases in a neatly organized and transparent visual manner still remains a challenge. Amongst the many methods reported for SNP genotyping, determining the restriction fragment length polymorphisms (RFLPs) is still one of the most convenient and cost-saving methods. In this study, we prepared the visualization of the mtDNA genome in a way, which integrates the RFLP genotyping information with mitochondria related cancers and diseases in a user-friendly, intuitive and interactive manner. The inherent problem associated with mtDNA sequences in BLAST of the NCBI database was also solved.

DESCRIPTION

V-MitoSNP provides complete mtSNP information for four different kinds of inputs: (1) color-coded visual input by selecting genes of interest on the genome graph, (2) keyword search by locus, disease and mtSNP rs# ID, (3) visualized input of nucleotide range by clicking the selected region of the mtDNA sequence, and (4) sequences mtBLAST. The V-MitoSNP output provides 500 bp (base pairs) flanking sequences for each SNP coupled with the RFLP enzyme and the corresponding natural or mismatched primer sets. The output format enables users to see the SNP genotype pattern of the RFLP by virtual electrophoresis of each mtSNP. The rate of successful design of enzymes and primers for RFLPs in all mtSNPs was 99.1%. The RFLP information was validated by actual agarose electrophoresis and showed successful results for all mtSNPs tested. The mtBLAST function in V-MitoSNP provides the gene information within the input sequence rather than providing the complete mitochondrial chromosome as in the NCBI BLAST database. All mtSNPs with rs number entries in NCBI are integrated in the corresponding SNP in V-MitoSNP.

CONCLUSION

V-MitoSNP is a web-based software platform that provides a user-friendly and interactive interface for mtSNP information, especially with regard to RFLP genotyping. Visual input and output coupled with integrated mtSNP information from MITOMAP and NCBI make V-MitoSNP an ideal and complete visualization interface for human mtSNPs association studies.

Searching cell-secreted proteomes for potential urinary bladder tumor markers

To search for biomarkers critical for bladder carcinoma diagnosis and prognosis, secreted proteomes of highly malignant U1 and pre-malignant U4 cell lines were initially analyzed. Proteins in the culture media of the U1 and U4 cell lines were systematically examined by SDS-PAGE combined with MALDI-TOF MS. Among them, expression of pro-u-plasminogen activator (pro-u-PA) was confirmed by Western blot analysis and further evaluated. In analyzing urine samples from bladder cancer patients and normal subjects, we established a statistically significant relationship between the low level and absence of pro-u-PA in urine with high stages and grades of the tumor samples. Constitutive expression of Ras dominant negative protein led to increased expression of pro-u-PA in culture media, indicating that the loss of pro-u-PA is associated with oncogenic transformation. Analysis of cancer-secreted proteomes can be a feasible, non-invasive and efficient strategy for searching potential bladder tumor biomarkers. Our work also has identified the loss of pro-u-PA in urine as potential marker of more advanced bladder carcinoma.