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Joseph L Chin

Publications and source records attributed to Joseph L Chin.

At least 19 recordsLinked to original sources
PubMed2006

Clinically significant prostate cancer found incidentally in radical cystoprostatectomy specimens.

OBJECTIVE: To review the incidence, histopathological features and clinical outcomes of patients with incidental prostate cancer found in radical cystoprostatectomy (RCP) specimens excised for bladder cancer, to determine if these cancers affected the follow-up strategy and if prostate-sparing cystectomy would be appropriate for these patients. PATIENTS AND METHODS: We retrospectively reviewed the charts of men who had a RCP for transitional cell carcinoma (TCC) of the bladder, at our institution between 1987 and 2003. Patients with a preoperative diagnosis or clinical suspicion of prostate cancer were excluded from further analysis. We identified those men with incidental prostate cancer in the RCP specimens. The patients' demographic, histopathological and clinical outcome data were collected. RESULTS: In all, 217 men had RCP for TCC between 1987 and 2003; 13 were excluded from the study due to a preoperative diagnosis or clinical suspicion of prostate cancer, and 58 (28%) were found to have incidental prostate cancer. The mean (range) follow-up was 47 (6-157) months. Of these prostate cancers, 20% were of Gleason score > or = 7 and two patients developed local and metastatic prostate cancer recurrences. CONCLUSION: Incidental prostate cancer is a relatively common finding in RCP specimens, with a significant proportion having the characteristics of clinically relevant prostate cancer. The follow-up for prostate cancer should be incorporated with that for TCC and adapted according to the grade and stage of the prostate cancer. Preserving the prostate in an attempt to decrease the morbidity after RCP carries a high risk of significant prostate cancer in the residual prostatic tissue, suggesting that prostate-sparing cystectomy should only be reserved for a highly selected group of patients.

Aged↗
PubMed2006

Prospective evaluation of the prognostic relevance of molecular staging for urothelial carcinoma.

BACKGROUND: Nearly 50% of urothelial carcinoma patients with lymph node-negative invasive cancers recur after radical surgery. In many cases, occult local or lymph node disease may be present but undetectable by current approaches. Reverse-transcriptase polymerase chain reaction (RT-PCR)-detectable mRNA of Uroplakin II (UPII), a urothelial-specific gene mRNA, was evaluated in perivesical and lymph node samples removed at radical surgery as a predictor of clinical recurrence. METHODS: From November 1999 to August 2002, 46 patients with cTa-T4N0M0 urothelial bladder cancer enrolled in a prospective clinical trial and underwent radical cystectomy and pelvic lymphadenectomy. RT-PCR for UPII was performed on biopsies of the external surface of the bladder specimen and lymph nodes. Results were compared with conventional pathology. Patients were followed every 6 months for tumor recurrence. RESULTS: Pathologically node-negative patients had a UPII RT-PCR perivesical positivity of 27% and a lymph node positivity rate of 33%. All 22 UPII RT-PCR node-negative patients were pathologically node-negative and all 13 with pathologically positive nodes had positive UPII RT-PCR lymph node signals. In all, 46% of UPII RT-PCR lymph node-positive patients were pathologically node-negative and 5% of pathologically node-negative/UPII RT-PCR node-negative patients had disease recurrence, whereas 91% of pathologically node-negative/UPII RT-PCR node-positive patients (P < .001) recurred. UPII RT-PCR node positivity was a significant predictor of tumor recurrence in multivariate analysis CONCLUSIONS: Molecular determination of lymph node metastases by UPII RT-PCR node positivity apparently identifies patients with a poor prognosis and may be more predictive of disease recurrence than conventional pathologic analysis.

Adult↗
PubMed2006

Intraoperative laparoscopic renal ultrasonography: use in advanced laparoscopic renal surgery.

OBJECTIVES: To highlight the use of intraoperative laparoscopic ultrasonography (ILUS) in complex renal surgery, as well its impact on management. ILUS has been used to facilitate advanced laparoscopic surgery, but only limited descriptions of the indications for its use have been published. METHODS: All patients undergoing laparoscopic renal procedures requiring ILUS from October 2001 to March 2005 were reviewed. A total of 50 cases, including 35 partial nephrectomies, cryoablation of 6 renal tumors, 6 radical nephrectomies, 2 perinephric explorations, and 1 resection of a renal artery aneurysm were assessed by ILUS. RESULTS: The average tumor size in the patients undergoing laparoscopic partial nephrectomy was 3.1 cm (range 1.4 to 8.0), and all margins were negative. Also, a previously unidentified satellite lesion was found in 1 patient. ILUS was essential in assessing iceball formation during laparoscopic renal cryotherapy. ILUS also proved useful in defining the anatomy during laparoscopic perinephric exploration, assessing renal vein thrombi during laparoscopic nephrectomy, and evaluating renal perfusion during laparoscopic renal artery aneurysm repair. CONCLUSIONS: ILUS can be extremely useful in advanced laparoscopic renal surgery. In a number of situations, it is an essential surgical tool. With expanding indications for laparoscopic surgery, the indications for ILUS continue to grow.

Adult↗
PubMed2006

Location of a positive biopsy as a predictor of surgical margin status and extraprostatic disease in radical prostatectomy.

OBJECTIVE: To investigate whether the location of preoperative biopsy positive cores can identify patients at higher risk of a positive surgical margin (SM) and extraprostatic extension (EPE) at radical retropubic prostatectomy (RRP). PATIENTS AND METHODS: We retrospectively reviewed the clinical and pathological data of 371 patients who had a RRP for biopsy confirmed prostate cancer between January 2000 and October 2003. RESULTS: A positive biopsy at the apex was not predictive of a positive apical SM or EPE. However, a positive biopsy at the base was predictive of a positive basal SM and EPE. A positive SM, in turn, correlated with EPE on final pathology. Positive basal SM correlated with EPE in 75% of cases whereas positive apical SM showed EPE in only 33% (P < 0.02). CONCLUSION: A positive biopsy core at the base appears to correlate with a positive basal SM and EPE. A positive basal SM correlates with EPE at a higher rate than apical SMs.

Adult↗
PubMed2006

Bub1 up-regulation and hyperphosphorylation promote malignant transformation in SV40 tag-induced transgenic mouse models.

Rodents do not naturally develop prostate cancer. Currently, most widely used genetically engineered mouse prostate cancer models use SV40 T/tag oncogene. To understand the mechanism underlying prostate cancer development in transgenic and knock-in SV40 Tag mouse models, we did cDNA microarray analyses, comparing gene expression profiles of prostate cancer tissues from early-, late-, and advance-stage androgen-independent prostate cancers. Of the 67 genes that were up-regulated by > or = 10-fold, 40 are known to be required for chromosome stability. In particular, the spindle checkpoint component Bub1 was persistently up-regulated from early to advanced androgen-independent prostate cancer lesions. Significantly, Bub1, which is required for accurate chromosome segregation during mitosis, has recently been reported to bind SV40 Tag. Consistent with a spindle checkpoint defect, flow cytometry experiments indicate that advanced androgen-independent prostate cancer tumors exhibit aneuploidy, along with up-regulation of levels of both Bub1 mRNA and Bub1 protein or hyperphosphorylation. Importantly, up-regulation and hyperphosphorylation of Bub1 were also observed in established human prostate cancer cell lines and in clinical studies. Furthermore, analysis of human prostate cancer lines showed impaired spindle checkpoint function and endoreduplication following exposure to spindle toxins. Small interfering RNA-mediated repression of Bub1 in the human prostate cancer line PC-3 restrained cell proliferation, an effect mimicked by inhibition of mitogen-activated protein kinase, an upstream activator of Bub1. Thus, by perturbing Bub1 function, our observations suggest a new mechanism whereby the SV40 Tag oncoprotein promotes chromosomal instability and aneuploidy in transgenic mouse prostate cancer models. Whereas the exact details of this mechanism remain unclear, our novel findings raise the possibility of exploiting Bub1 as a new therapeutic target in the treatment of prostate cancer, the most common cancer in adult men in North America.

Animals↗
PubMed2006

Treatment of radiation failure in prostate cancer.

Radiotherapy, both external beam and more recently, interstitial, have been therapeutic options for localized prostate cancer. Management of patients who have failed of local radiotherapy remains a challenge. Herein the current therapeutic options are reviewed.

Humans↗
PubMed2006

Timing cystectomy and perioperative chemotherapy in the treatment of muscle invasive bladder cancer.

INTRODUCTION: The ability of cystectomy to cure patients with muscle-invasive transitional carcinoma of the bladder (TCC) is diminished by the presence of occult micrometatases. Chemotherapy contributes to cure to the extent that it may eradicate these micrometastases. In the absence of methods to preoperatively stage TCC precisely or assess tumor biology, we review the current literature regarding the timing of cystectomy and use of perioperative chemotherapy. Based on this data, we suggest optimal and feasible strategies for treating TCC in a resource-constrained environment. MATERIALS AND METHODS: Systematic reviews of TCC were sought using electronic databases to obtain optimal information about: 1) the relationship between TNM stage and survival, 2) the effect of surgical waiting times on tumor stage and survival outcomes, 3) the benefits of neoadjuvant and adjuvant chemotherapy, and 4) the patients who benefit most from perioperative chemotherapy. RESULTS: Prospective data from the largest contemporary series of patients treated with cystectomy confirmed long-term survival in patients with extravesical and/or lymph node disease of 25%-47% at 5 years and 17%-27% at 10 years. Lymph node involvement was more common in patients with extravesical tumors. Retrospective studies of the effect of delay to cystectomy on outcomes showed higher tumor stage and reduced survival with delay of cystectomy beyond 12 weeks. Two individual patient data meta-analyses, including all currently available randomized controlled trials (RCTs), comparing neoadjuvant and adjuvant chemotherapy to local therapy alone confirmed that overall survival is modestly improved by cisplatin-based combination neoadjuvant chemotherapy. None of these RCTs showed a detrimental effect of delaying cystectomy for this treatment. Tumor status at cystectomy appears to correlate with overall survival. CONCLUSIONS: We propose immediate use of neoadjuvant chemotherapy in patients suspected of having extravesical TCC. As most have micrometatastases, immediate surgery is less critical. For patients suspected of having organ-confined TCC, immediate cystectomy is recommended with adjuvant chemotherapy recommendations based on pathological staging. If surgery within 12 weeks is not possible for these patients, neoadjuvant chemotherapy with monitoring of response can be used. Improved preoperative staging and understanding of tumor biology are required to optimize the multimodality treatment of TCC.

Carcinoma, Transitional Cell↗
PubMed2005

Establishment of a serum tumor marker for preclinical trials of mouse prostate cancer models.

Current prostate cancer research in both basic and preclinical trial studies employ genetically engineered mouse models. However, unlike in human prostate cancer patients, rodents have no counterpart of prostatic-specific antigen (PSA) for monitoring prostate cancer initiation and progression. In this study, we established a mouse serum tumor marker from a mouse homologue of human prostate secretory protein of 94 amino acids (PSP94). Immunohistochemistry studies on different histologic grades from both transgenic and knock-in mouse prostate cancer models showed the down-regulation of tissue PSP94 expression (P < 0.001), the same as for PSA and PSP94 in humans. The presence of mouse serum PSP94 was shown by affinity column and immunoprecipitation purification using a polyclonal mouse PSP94 antibody. A competitive ELISA protocol was established to quantify serum PSP94 levels with a sensitivity of 1 ng/mL. Quantified serum levels of mouse PSP94 ranged from 49.84 ng/mL in wild-type mice to 113.86, 400.45, and 930.90 ng/mL in mouse prostatic intraepithelial neoplasia with microinvasion, well differentiated, moderately differentiated, and poorly differentiated prostate cancer genetically engineered prostate cancer mice, respectively (P < 0.01, n = 68). This increase in serum PSP94 is also well correlated with age and tumor weight. Through longitudinal monitoring of serum PSP94 levels of castrated mice (androgen ablation therapy), we found a correlation between responsiveness/refractory prostate tissues and serum PSP94 levels. The utility of mouse serum PSP94 as a marker in hormone therapy was further confirmed by three-dimensional ultrasound imaging. The establishment of the first rodent prostate cancer serum biomarker will greatly facilitate both basic and preclinical research on human prostate cancer.

Animals↗
PubMed2005

Increased intratumoral expression of prostate secretory protein of 94 amino acids predicts for worse disease recurrence and progression after radical prostatectomy in patients with prostate cancer.

OBJECTIVES: To examine the impact of prostate secretory protein of 94 amino acids (PSP94) expression within the primary tumor on disease recurrence and progression using radical prostatectomy specimens from patients with adenocarcinoma of the prostate. METHODS: PSP94 immunohistochemistry was performed on 59 radical prostatectomy specimens. The degree of PSP94 expression was reported as either present (group 1) or absent (group 2). Clinical data, including survival outcome measures, were correlated with PSP94 expression. RESULTS: The time to disease progression for group 1 was shorter compared with that for group 2 (P = 0.042). Disease-free survival was also less in group 1 than in group 2 (P = 0.033). Multivariate analyses demonstrated that PSP94 expression was an independent prognostic factor for a shorter interval to disease progression (P = 0.046) and disease-free survival (P = 0.049). CONCLUSIONS: PSP94 expression in radical prostatectomy tumor specimens appears to be associated with worsened survival outcomes and may provide additional prognostic information.

Adenocarcinoma↗
PubMed2005

Long-term results of microwave thermotherapy for symptomatic benign prostatic hyperplasia.

PURPOSE: To study the long-term outcomes of men with moderately severe symptomatic benign prostatic hyperplasia (BPH) who were treated with transurethral microwave thermotherapy (TUMT) with the Dornier Urowave machine. PATIENTS AND METHODS: A total of 220 patients (mean age 66.2 years) with clinical BPH, an American Urological Association (AUA) Symptom Score of >or=13, and a peak urinary flow rate (Qmax) of <or=12 mL/sec were enrolled in a multicenter randomized, double-blind, sham-controlled trial. Sham and active treatments were conducted under local anesthesia as an outpatient procedure. Patients were followed up at 1 week and at 1, 3, and 6 months. Patients in the sham-treatment arm who still met the initial enrollment criteria were then offered active treatment. The 6-month interim analysis of the safety and efficacy of this treatment has been previously reported (Urology 1998;51:19). Patients were then followed at 6-month intervals out to 60 months after treatment. At our center, 34 men (mean age 64+/-6 years) continued on the recommended long-term follow-up protocol. RESULTS: Among the 34 men from our center initially entered in the study, 15 completed the entire 5-year follow-up. Four of the men available for follow-up at the 5-year mark were on alpha-blocker medication, and six men had required transurethral surgery for symptom relief. At 5 years, this cohort of patients maintained improvement in AUA Score (from 20.5+/-6.2 to 11.5+/-5.0; P<0.001) and Quality of Life score (from 3.7+/-1.3 to 1.9+/-1.0; P<0.001) but showed no significant improvement in Qmax (8.2+/-1.9 mL/sec to 8.4+/-4.3 mL/sec). At 5 years, 11 of the 15 patients available for review had not required additional therapy. CONCLUSIONS: While improvement in voiding symptoms and Quality of Life scores were maintained without the need for adjuvant treatment in approximately one third of men 5 years after TUMT, a significant number had required salvage therapies for symptom relief.

Aged↗
PubMed2005

Current status of local salvage therapies following radiation failure for prostate cancer.

PURPOSE: We reviewed the curative options available to patients with local failure after radical radiotherapy for prostate cancer and identified the patients best suited for such salvage therapies. MATERIALS AND METHODS: A literature search of English language publications was done using the key terms salvage, prostatectomy, cryosurgery, brachytherapy and radiation failure. RESULTS: Salvage radical prostatectomy offers 5-year biochemical relapse-free rates between 55 and 69%. Higher complication rates are reported with salvage compared to primary radical prostatectomy, including rectal injuries, bladder neck contracture and urinary incontinence. Cryosurgery biochemical response rates vary according to the definition of failure but they are generally lower than those of salvage radical prostatectomy. The local control rates of cryosurgery are acceptable. Major complications related to cryotherapy are urinary incontinence, impotence, pelvic pain and urinary retention. Experience with salvage brachytherapy has been limited but some success has been reported in terms of biochemical control. CONCLUSIONS: Salvage prostatectomy for localized radiation failure is a good option in the patient with a life expectancy of at least 10 years, preradiation and preoperative prostate specific antigen less than 10 ng/ml, and localized preoperative stage with the understanding that complication risks are higher. Salvage cryotherapy is a valid option in patients with preoperative prostate specific antigen less than 10 ng/ml and Gleason score less than 8, clinical stage less than T3 who are hormonally naive. Salvage cryotherapy is especially suited for older patients with some comorbidities who are still considered to be at reasonable anesthetic risk. The study of brachytherapy remains in its infancy and the efficacy of this modality remains to be determined.

Cryosurgery↗
PubMed2005

Do all patients with high-grade prostatic intraepithelial neoplasia on initial prostatic biopsy eventually progress to clinical prostate cancer?

OBJECTIVE: To assess the clinical outcome of patients with a diagnosis of high-grade prostatic intraepithelial neoplasia (PIN) on initial prostatic biopsy, with a minimum of 5 years of follow-up, as such patients are at greater risk of having prostate cancer on subsequent biopsy. PATIENTS AND METHODS: Between November 1992 and October 1998, 21 patients were identified as having PIN on their initial transrectal ultrasonography-guided prostate biopsy. None of these patients had a focus of cancer on the initial biopsy. Their medical data were reviewed retrospectively to determine the natural history of PIN in these patients. Patients who were not identified as having cancer were followed every 6-12 months with prostate-specific antigen (PSA) testing and digital rectal examinations (DRE). RESULTS: A mean (range) of 7 (2-8) cores were taken at initial biopsy; the mean age of the patients was 63 (53-77) years and mean PSA level 9.1 (4.9-17.6) ng/mL. Six patients had an abnormal DRE at presentation. A mean of 8 (7-10) cores were obtained on the second biopsy; six patients were diagnosed with cancer, with a mean Gleason score of 6 (5-7), while three were diagnosed with persistent PIN. These three patients had a third prostate biopsy which showed cancer of Gleason score 6 in one and benign prostatic hyperplasia in two. After a mean follow-up of 72.2 (60-84) months, none of the remaining 12 patients was diagnosed with clinically significant cancer. Five of these patients went on to a third prostate biopsy, with no evidence of cancer. One patient died from unrelated causes during this period. CONCLUSION: This study affirms our current practice of following patients with PIN conservatively if a second or third subsequent prostate biopsy is negative. Whether PIN is a premalignant lesion or merely a lesion associated with cancer needs to be addressed in multicentre studies with a follow-up of > 10 years.

Aged↗
PubMed2005

Current status of salvage cryoablation for prostate cancer following radiation failure.

The role of salvage cryoablation of the prostate for patients with clinically localized prostate cancer that have failed radiotherapy to the prostate is reviewed with reference to alternatives including salvage radical prostatectomy and brachytherapy. The diagnosis and work-up of local recurrence/persistence of cancer in the prostate are reviewed and the patient selection criteria for salvage cryoablation is discussed. Technical aspects of the cryoablation procedure along with the outcome in terms of cancer control and treatment-related complications are detailed. The five-year biochemical disease-free rate is approximately 40%. The complication rate is acceptable. Salvage cryoablation definitely has a role in the management of localized prostate cancer treatment failure following radiotherapy, especially in older patients and those with some comorbidities.

Cryosurgery↗
PubMed2004

Long-term efficacy of zoledronic acid for the prevention of skeletal complications in patients with metastatic hormone-refractory prostate cancer.

In a placebo-controlled randomized clinical trial, zoledronic acid (4 mg via a 15-minute infusion every 3 weeks for 15 months) reduced the incidence of skeletal-related events (SREs) in men with hormone-refractory metastatic prostate cancer. Among 122 patients who completed a total of 24 months on study, fewer patients in the 4-mg zoledronic acid group than in the placebo group had at least one SRE (38% versus 49%, difference = -11.0%, 95% confidence interval [CI] = -20.2% to -1.3%; P =.028), and the annual incidence of SREs was 0.77 for the 4-mg zoledronic acid group versus 1.47 for the placebo group (P=.005). The median time to the first SRE was 488 days for the 4-mg zoledronic acid group versus 321 days for the placebo group (P =.009). Compared with placebo, 4 mg of zoledronic acid reduced the ongoing risk of SREs by 36% (risk ratio = 0.64, 95% CI = 0.485 to 0.845; P =.002). Patients in the 4-mg zoledronic acid group had a lower incidence of SREs than did patients in the placebo group, regardless of whether they had an SRE prior to entry in the study. Long-term treatment with 4 mg of zoledronic acid is safe and provides sustained clinical benefits for men with metastatic hormone-refractory prostate cancer.

Aged↗
PubMed2004

Laparoscopic versus open partial nephrectomy.

OBJECTIVES: To compare, retrospectively, the results of laparoscopic partial nephrectomy (LPN) to open partial nephrectomy (OPN) using a tumor size-matched cohort of patients. Limited data are available comparing LPN to OPN in the treatment of small renal tumors. METHODS: Between September 2000 and September 2003, 27 LPNs and 22 OPNs were performed to treat renal masses less than 4 cm. Patient demographics and tumor location and size (2.4 +/- 1.0 cm versus 2.9 +/- 0.9 cm, respectively; P = not statistically significant) were similar between the LPN and OPN groups. RESULTS: Although the mean operative time was longer in the LPN than in the OPN group (210 +/- 76 minutes versus 144 +/- 24 minutes; P <0.001), the blood loss was comparable between the two groups (250 +/- 250 mL versus 334 +/- 343 mL; P = not statistically significant). No blood transfusions were performed in either group. The hospital stay was significantly reduced after LPN compared with after OPN (2.9 +/- 1.5 days versus 6.4 +/- 1.8 days; P <0.0002), and the postoperative parenteral narcotic requirements were lower in the LPN group (mean morphine equivalent 43 +/- 62 mg versus 187 +/- 71 mg; P <0.02). Three complications occurred in each group. With LPN, no patient had positive margins or tumor recurrence. Also, direct financial analysis demonstrated lower total hospital costs after LPN (4839 dollars+/- 1551 dollars versus 6297 dollars+/- 2972 dollars; P <0.05). CONCLUSIONS: LPN confers several benefits over OPN concerning patient convalescence and costs, despite prolonged resection times at our current phase of the learning curve. Long-term results on cancer control in patients treated with LPN continue to be assessed.

Adult↗
PubMed2004

Characterization of initiation of angiogenesis in early stages of prostate adenocarcinoma development and progression in a transgenic murine model.

OBJECTIVES: A novel prostate-specific protein of 94 amino acids (PSP94) promoter/enhancer-directed transgenic murine model of prostate cancer (CaP) was examined to determine the temporal relationship of angiogenesis with the development and progression of CaP. METHODS: Immunohistochemistry and in situ hybridization were performed to determine the protein and mRNA expression of basic fibroblast growth factor, vascular endothelial growth factor, and microvessel formation at different stages of CaP development and progression. RESULTS: Differential expression of basic fibroblast growth factor and vascular endothelial growth factor protein was found with the development and progression of CaP (P <0.0001 and P <0.0001, respectively). Angiogenesis was identified in CaP. mRNA expression of basic fibroblast growth factor and vascular endothelial growth factor was present from high-grade prostatic intraepithelial neoplasia to poorly differentiated CaP. CONCLUSIONS: The PSP94 gene is conserved in humans and rodents; therefore, the PSP94 transgenic murine model of CaP provides a preclinical model to test such antiangiogenic or other chemopreventive therapies that may be predictive of human CaP.

Adenocarcinoma↗
PubMed2003

Mouse PSP94 expression is prostate tissue-specific as demonstrated by a comparison of multiple antibodies against recombinant proteins.

Prostate tissue-specific gene expression is crucial for driving potentially therapeutic genes to target specifically to the prostate. Prostate secretory protein of 94 amino acids (PSP94), also known as beta-MSP (microseminoprotein), is one of the three most abundant secretory proteins of the prostate gland, and is generally considered to be prostate tissue-specific. We have previously demonstrated that the expression of the rat PSP94 gene is strictly prostate tissue-specific by an antibody against a recombinant rat PSP94. In order to study prostate targeting utilizing the PSP94 gene in a mouse pre-clinical experimental model, we need to establish antibodies against mouse PSP94 to confirm if it is prostate tissue-specific as well. In this study, firstly we raised a polyclonal antibody against a recombinant glutathione-S-transferase- (GST-) mouse mature form of PSP94. However, it showed very poor immunoreactivity against prostate tissue PSP94 as tested in Western blotting experiments. Neither antibodies against rat PSP94 nor mouse PSP94 showed significant cross-reactivity. Thus a second antibody was established against a recombinant mouse mature PSP94 containing N-terminal polyhistidines, and stronger immunoreactivity against mouse prostate tissue PSP94 was identified in Western blotting experiments. Both of these antibodies showed immunohistochemical reactivity, while the latter showed stronger reactivity in IHC when tested with different fixatives. By studying tissue distribution, we demonstrated that, as with rat PSP94, mouse PSP94 is strictly prostate tissue-specific in experiments of both Western blotting and immunohistochemistry (IHC). This conclusion was also derived from a comparison among antibodies against human, rat, and mouse PSP94, showing very different immunoreactivities in Western blotting and IHC. Finally, a competitive assay between different species was performed. We demonstrated that antibodies against PSP94 from different species (human, primate, rodents) have poor cross-reactivities. These observations also indicate that the PSP94 gene is a rapidly evolving gene in all species. Results from this study have led to the possibility of utilizing PSP94 as a targeting agent specifically to the prostate in a mouse experimental model.

Animals↗