The molecular pathology of urological malignancies

Rotating Night Shift Work and Bladder Cancer Risk in Women: Results of Two Prospective Cohort Studies

Bladder cancer is the sixth most common cancer in the United States. Night shift work has previously been linked with cancer risk. Whether there is an association between rotating night shift work and bladder cancer in women has not been studied previously. Eligible participants in the Nurses' Health Study (NHS, n = 82,147, 1988-2016) and Nurses' Health Study II (NHSII, n = 113,630, 1989-2015) were prospectively followed and a total of 620 and 122 incident bladder cancer cases were documented during the follow-up of NHS and NHSII, respectively. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for bladder cancer incidence. We observed a significantly increased risk of bladder cancer among women with >5 years of night shift work history compared with women who never worked rotating night shifts in NHS (HR = 1.24; 95%CI = 1.01-1.54, p for trend = 0.06), but not in the pooled NHS and NHS II (HR = 1.18; 95%CI = 0.97-1.43, p for trend = 0.08). Secondary analyses stratified by smoking status showed no significant interaction (p = 0.89) between the duration of rotating night shift work and smoking status. In conclusion, our results did not provide strong evidence for an association between rotating night shift work and bladder cancer risk.

Gastric and duodenal ulcers, periodontal disease, and risk of bladder cancer in the Health Professionals Follow-up Study

PURPOSE

Studies suggest that peptic ulcer and periodontal disease are positively associated with bladder cancer risk. These two factors are likely to share common biologic mechanisms such as inflammation and dysbiosis. We examined the joint association of peptic ulcer (gastric/duodenal) and periodontal disease on bladder cancer risk.

METHODS

We conducted a prospective analysis among 45,185 men (563 invasive bladder cancer cases) in the Health Professionals Follow-Up Study (follow-up 1986-2016). History of ulcer and periodontal disease was self-reported at baseline and updated during the follow-up. Cox proportional hazards models estimated hazard ratio (HR) and 95% confidence interval (CI) for the joint associations of ulcers (gastric, duodenal) and periodontal disease, adjusting for age and other potential confounders. We tested for interaction using the Wald test for product terms.

RESULTS

Compared with men having no history of ulcer and periodontal disease, men with a history of peptic ulcer only (HR 1.22, 95% CI 0.90-1.66) and men with a history of periodontal disease only (HR 1.19, 95% CI 0.98-1.46) were associated with higher risk of invasive bladder cancer. The highest bladder cancer risk was observed in men with a history of both peptic ulcer and periodontal disease (HR 1.52, 95% CI 1.05-2.20). Similar results were found when we stratified by ulcer types. The interactions between ulcer and periodontal disease were not statistically significant for all ulcer types (p-interaction ≥ 0.59).

CONCLUSION

We did not find sufficient evidence for interaction between gastric/duodenal ulcers and periodontal disease on bladder cancer risk.

DHCR24 predicts poor clinicopathological features of patients with bladder cancer: A STROBE-compliant study

To investigate the prognostic value of DHCR24 for patients with bladder cancer (BC). We used public bladder cancer microarray studies to evaluate the expression of DHCR24 between normal bladder tissues and BC cells, to investigate the relationship between the expression of DHCR24 and the clinical features of BC patients. Survival analysis was performed to investigate the correlation between DHCR24 expression and the survivals of BC patients. Gene set enrichment analysis was conducted to identify relevant mechanisms. The results showed that DHCR24 was up-regulated in BC cells compared with that in normal bladder tissues (P = .0389). Results of chi-square test suggested that BC patients in DHCR24 low expression group were proved to have better clinical characteristics (including tumor grade, disease progression, T staging, and N staging) as compared with those in DHCR24 low expression group (P < .0001, P = .002, P = .005, and P = .002, respectively). BC patients in DHCR24 low expression group were associated with better cancer-specific survival and overall survival (P < .0001 and P = .0008, respectively). DHCR24 might promote the proliferation of BC cells through several oncogenesis-associated biological processes (estrogen response, heme metabolism, P53 pathway, cholesterol homeostasis, mTORC1 signaling, peroxisome, xenobiotic metabolism, glycolysis, and protein secretion). Thus, DHCR24 might be a therapeutic target for patients with BC.

Lower Urinary Tract Symptoms and Risk of Bladder Cancer in Men: Results From the Health Professionals Follow-up Study

OBJECTIVE

To understand the association between lower urinary tract symptoms (LUTS) and risk of bladder cancer in a large cohort of men.

METHODS

Using data from the Health Professionals Follow-up Study, we examined risk of bladder cancer in relation to severity of LUTS among 30,183 men. During the follow-up period from 1996 until 2010, 476 newly diagnosed cases of bladder cancer occurred. The Cox proportional hazards regression was used to adjust for potential confounders.

RESULTS

Among men with severe LUTS, risk of bladder cancer was 64% higher (relative risk [RR], 1.64; 95% confidence interval [CI], 0.87-3.08) compared with men who reported no LUTS. Subjects with both voiding and storage dysfunction had a significantly higher risk of bladder cancer (RR, 1.60; 95% CI, 1.00-2.56). Among individual urinary symptoms, urinary hesitancy was strongly associated with bladder cancer; those who experienced urinary hesitancy at least 50% of the time had more than twice the risk of bladder cancer (RR, 2.21; 95% CI, 1.29-3.78).

CONCLUSION

Our findings suggest that LUTS, especially urinary hesitancy, are associated with the development of bladder cancer in men.

Fluid intake and risk of bladder cancer in the Nurses' Health Studies

Increase in fluid intake may reduce bladder cancer risk by decreasing the contact time between carcinogens in urine and bladder epithelium. However, this association has not been examined in a large cohort of women. The association between total fluid intake and bladder cancer risk in two large prospective women's cohorts with 427 incident bladder cancer cases was examined. Detailed information on total fluid intake was collected by repeated food frequency questionnaires over time. Multivariable relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated by using Cox proportional hazards regression models. Results from the two cohorts were pooled together using the random-effects model. Using the average values from the earliest two dietary assessments and lowest quartile as reference, a suggestive inverse association was observed between total fluid intake and overall bladder cancer risk (RR: 0.83, 95% CI: 0.61-1.12, p-value for trend: 0.08), and invasive bladder cancer risk (RR: 0.47, 95% CI: 0.23-0.97, p-value for trend: 0.04). Among heavy cigarette smokers, women with the highest quartile of total fluid intake had a 38% decrease in bladder cancer risk (RR: 0.62, 95% CI: 0.41-0.93, p-value for trend: 0.02). The findings suggested that total fluid intake may reduce bladder cancer risk for female smokers, as well as reduce the risk of invasive bladder cancer.

Preclinical Pharmacology of the Pyrrolobenzodiazepine (PBD) Monomer DRH-417 (NSC 709119)

The pyrrolobenzodiazepine monomer DRH-417 is a member of the anthramycin group of anti-tumor antibiotics that bind covalently to the N2 of guanine within the minor groove of DNA. DRH-417 emerged from the EORTC-Drug Discovery Committee and NCI 60 cell line in vitro screening programs as a potent antiproliferative agent with differential sensitivity towards certain cancer types such as melanoma, breast and renal cell carcinoma (mean IC(50) = 3 nM). DRH-417 was therefore tested for in vivo activity. The maximum tolerated dose (MTD) was established as 0.5 mg/kg given i.p. Marked anti-tumor activity was seen in two human renal cell cancers, one breast cancer and a murine colon tumor model (p<0.01). A selective HPLC (LC/MS) analytical method was developed and plasma pharmacokinetics determined. At a dose of 0.5 mg kg(-1), the plasma AUC was 540 nM h (197.1 ng h ml(-1)) and the peak plasma concentration (171 nM [62.4 ng ml(-1)]) occurred at 30 min., reaching doses levels well above those needed for in vitro antiproliferative activity. Genomic profiling of in vivo sensitive tumors revealed that the latter have an activated insulin-like growth factor signaling pathway.

Nonsteroidal antiinflammatory drug use and risk of bladder cancer in the health professionals follow-up study

Nonsteroidal antiinflammatory drugs (NSAIDs) use, particularly aspirin, may lower the risk of several cancers, including bladder. NSAIDs may reduce development of bladder tumors by decreasing inflammation, inhibiting cycloxygenase-2, inhibiting proliferation and inducing apoptosis of cancer cells. However, acetaminophen, a major metabolite of phenacetin, may be positively associated with bladder cancer risk. Results from case-control studies on NSAIDs and acetaminophen use and bladder cancer risk are inconsistent. We investigated the association between NSAID and acetaminophen use and bladder cancer risk in a large cohort of US males. Among 49,448 men in the Health Professionals Follow-Up Study, 607 bladder cancer cases were confirmed during 18 years of follow-up. Relative risks (RR) and 95% confidence intervals (CI) were calculated by Cox proportional hazards models. Multivariate RR were adjusted for age, current smoking status, pack years, geographic region and fluid intake. No significant associations were observed for regular aspirin (> or =2 tablets per week), (RR = 0.99, 95% CI 0.83-1.18), ibuprofen (RR = 1.11, 95% CI 0.81-1.54), acetaminophen (RR = 0.96, 95% CI 0.67-1.39) or total NSAID use (not including acetaminophen; RR = 1.01, 95% CI 0.85-1.20) and bladder cancer risk compared with nonuse. Consistent use (over 6 years) of aspirin, ibuprofen, acetaminophen and total NSAIDs, compared to nonuse, was not associated with bladder cancer risk. No association was observed between aspirin frequency and dose and bladder cancer risk. We observed no effect-modification by smoking, age or fluid intake. Our results suggest that regular NSAID or acetaminophen use has no substantial impact on bladder cancer risk among men.

Gonorrhoea and male bladder cancer in a prospective study

In a prospective cohort study, a close to two-fold elevated risk of bladder cancer was found among men reporting a history of gonorrhoea (relative risk=1.92, 95% CI=1.10-3.33). Our finding warrants further examination of the role of gonorrhoea in bladder carcinogenesis.

Expression of receptor tyrosine kinases epidermal growth factor receptor and HER-2/neu in synovial sarcoma

BACKGROUND

Synovial sarcomas are high-grade soft tissue neoplasms often characterized by a biphasic spindle and epithelioid cell morphology. The majority of synovial sarcomas harbor a specific chromosomal translocation in which the proximal portion of the SYT gene at chromosome 18q11 is fused to the distal portion of one of several duplicated SSX genes (most notably SSX1 and SSX2) at chromosome Xp11. SYT/SSX1 translocations are seen in nearly three times as many synovial sarcomas as SYT/SSX2 translocations. Although the SYT/SSX2 fusion is usually associated with the monophasic disease pattern, the SYT/SSX1 fusion is present in tumors with biphasic or monophasic patterns. The SYT/SSX1 fusion gene is associated with more aggressive tumor growth and poor outcome. Despite advances in the therapy of local disease, distant metastasis remains the predominant cause of death. Accordingly, there is a need for alternate therapies, such as those recently developed against the receptor tyrosine kinases, such as epidermal growth factor receptor (EGFR) and HER-2/neu.

METHODS

Archival specimens of synovial sarcoma (n=38) representing 30 patients were assessed for EGFR and HER-2/neu protein expression by standard immunohistochemical techniques. To validate the immunohistochemistry results, quantitative real-time polymerase chain reaction (Q-PCR) assays using either fresh and/or archival material was performed. The presence of gene amplification was determined by chromogenic in-situ hybridization.

RESULTS

EGFR and HER-2/neu protein were detected by immunohistochemistry in 21 of 38 (55.3%) and 20 of 38 (52.6%) synovial specimens, respectively. EGFR immunoreactivity showed a granular and membranous pattern, whereas HER-2/neu immunoreactivity demonstrated only a membrane pattern. Coexpression was observed in 13 of 38 specimens (34.2%). HER-2/neu expression by immunohistochemistry in synovial sarcomas was restricted to tumors with the SYT/SSX1 translocations. Of 6 specimens with SSX2 translocation, none (0%) showed HER-2/neu immunoreactivity and 1 (17%) demonstrated EGFR expression. Q-PCR demonstrated the presence of mRNA for EGFR and HER-2/neu in 19 of 30 specimens (63.3%) and 22 of 30 specimens (73.3%), respectively. EGFR and HER-2/neu were expressed at low concentrations compared with the expression of glyceraldehyde 3-phosphate dehydrogenase (GAPDH). No evidence of gene amplification was observed.

CONCLUSIONS

EGFR and HER-2/neu are expressed in the majority of patients with SYT/SSX1 synovial sarcomas, albeit at low levels. Treatment with tyrosine kinase inhibitors may represent appropriate alternate therapy for these patients.

Peptic ulcer disease and the risk of bladder cancer in a prospective study of male health professionals

Helicobacter pylori is a risk factor for gastric and duodenal ulcers, but gastric ulcers generally occur in individuals who have low acid production and diffuse gastritis, whereas duodenal ulcers are more likely to occur with high acid output and antrum-predominant gastritis. Low acid production, gastritis, and ulcer healing each contribute to poor antioxidant absorption, oxidative stress, and elevated nitrite levels in the stomach. N-Nitrosamines are known carcinogens, and nitrate ingestion has been related to bladder cancer risk. Consequently, we hypothesized that the gastric conditions associated with gastric ulcers may contribute to elevated bladder cancer risk. We thus examined the association between self-reported history of peptic ulcer disease and the risk of bladder cancer (414 cases) over 14 years of follow-up in the Health Professional Follow-Up Study. Cox proportional hazards models were performed to adjust for known risk factors of bladder cancer. Men who reported a gastric ulcer before 1986 had a significantly higher risk of bladder cancer compared with those with no history of gastric ulcer (relative risk = 1.55, 95% confidence interval = 1.03-2.33, controlling for smoking and other potential confounders). No association was observed for duodenal ulcers (multivariate relative risk = 0.97, 95% confidence interval = 0.68-1.38). The ulcers in this study were based solely on self-report and not medical records; consequently, misclassification of ulcers may have occurred. Although intriguing, these findings need to be replicated.

Hereditary renal cancers

Hereditary renal cancer syndromes can lead to multiple bilateral kidney tumors that occur at a younger age than do nonhereditary renal cancers. Imaging plays an important role in the diagnosis and management of these syndromes. During the past decade, several new hereditary renal syndromes have been discovered but are not yet widely known. Whereas previously, the list of hereditary renal cancers in adults included von Hippel-Lindau disease and a rare form of chromosomal translocation, the list now includes the following syndromes: tuberous sclerosis, hereditary papillary renal cancer, Birt-Hogg-Dubé syndrome, hereditary leiomyoma renal cell carcinoma, familial renal oncocytoma, hereditary nonpolyposis colon cancer, and medullary carcinoma of the kidney. In addition, a number of newly described but poorly understood syndromes are under investigation. Even at this early stage, it is clear that elucidation of the underlying genetic mutations that cause hereditary renal cancer syndromes will have profound implications for understanding the origins of nonhereditary renal tumors. These studies will likely culminate in a better understanding of the causes of renal cancer, its prevention, and, ultimately, its cure.

Mutations in the VHL gene from potassium bromate-induced rat clear cell renal tumors

Potassium bromate (KBrO(3)) is a rat renal carcinogen and a major drinking water disinfection by-product in water disinfected with ozone. Clear cell renal tumors, the most common form of human renal epithelial neoplasm, are rare in animals but are inducible by KBrO(3) in F344 rats. Detection of cytoplasmic periodic acid-Schiff-positive granules in clear cell tumors, indicative of glycogen accumulation, provides evidence of their biochemical similarity to human counterparts. Mutation in the coding region of the von Hippel-Lindau (VHL) gene is frequently detected in human clear cell renal carcinomas. Detection of VHL mutations in KBrO(3)-induced rat renal tumors could enhance the relevancy of these rat renal tumors for human health risk assessment. Formalin-fixed paraffin-embedded control tissues and renal tumors from male F344 rats exposed to KBrO(3) in the drinking water for 2 years were examined microscopically and were microdissected for DNA extraction. The coding sequence and a promoter region of the VHL gene were examined by polymerase chain reaction-single strand conformation polymorphism and/or DNA sequencing. Two of nine clear cell renal tumors carried the same C to T mutation at the core region of the Sp1 transcription factor binding motif in the VHL promoter and one of four untreated animals had C to T mutation outside the highly conserved core region. Mutation in the VHL coding sequence was only detected in one tumor. No VHL mutations were observed in three chromophilic tumors. KBrO(3)-induced rat renal tumors are morphologically similar to their human counterpart but the genetic basis of tumorigenesis is different.

Identification and characterization of ART-27, a novel coactivator for the androgen receptor N terminus

The androgen receptor (AR) is a ligand-regulated transcription factor that stimulates cell growth and differentiation in androgen-responsive tissues. The AR N terminus contains two activation functions (AF-1a and AF-1b) that are necessary for maximal transcriptional enhancement by the receptor; however, the mechanisms and components regulating AR transcriptional activation are not fully understood. We sought to identify novel factors that interact with the AR N terminus from an androgen-stimulated human prostate cancer cell library using a yeast two-hybrid approach designed to identify proteins that interact with transcriptional activation domains. A 157-amino acid protein termed ART-27 was cloned and shown to interact predominantly with the AR(153-336), containing AF-1a and a part of AF-1b, localize to the nucleus and increase the transcriptional activity of AR when overexpressed in cultured mammalian cells. ART-27 also enhanced the transcriptional activation by AR(153-336) fused to the LexA DNA-binding domain but not other AR N-terminal subdomains, suggesting that ART-27 exerts its effect via an interaction with a defined region of the AR N terminus. ART-27 interacts with AR in nuclear extracts from LNCaP cells in a ligand-independent manner. Interestingly, velocity gradient sedimentation of HeLa nuclear extracts suggests that native ART-27 is part of a multiprotein complex. ART-27 is expressed in a variety of human tissues, including sites of androgen action such as prostate and skeletal muscle, and is conserved throughout evolution. Thus, ART-27 is a novel cofactor that interacts with the AR N terminus and plays a role in facilitating receptor-induced transcriptional activation.

Risk of bladder cancer by geographic region in a U.S. cohort of male health professionals

Large regional variations in bladder cancer rates have been observed for numerous decades in the United States and persist to date. We examined the incidence rates of bladder cancer by geographic region among U.S. male health professionals to determine whether diet or other lifestyle factors can account for variations observed. During 12 years of follow-up, 328 cases of bladder cancer were diagnosed in the Health Professionals Follow-up Study cohort. We inquired about diet, lifetime history of smoking, race, marital status, and other nondietary factors using mailed questionnaires. An elevated risk of bladder cancer was observed in the Northeast compared with the West [relative risk (RR) = 1.71, 95% confidence interval (CI) = 1.23-2.39], which was slightly attenuated after controlling for smoking (RR = 1.65, 95% CI = 1.18-2.30). Smoking patterns, diet, and other lifestyle factors could not account for all of the elevated bladder cancer risk in the Northeast. Bladder cancer risk was highest among men who had a long residency in the Northeast compared with a long residency in the West (RR = 1.77, 95% CI = 1.15-2.71, adjusted for smoking). Diet and other known characteristics do not appear to be responsible for the regional variations in bladder cancer rates in the United States.

Immunohistochemical demonstration of cyclin D1 in bladder cancers as an inverse indicator of invasiveness but not an independent prognostic factor

BACKGROUND

Cyclin D1 is essential for G1 progression through the cell cycle phase. It is a possible proto-oncogene whose aberrant expression may be responsible for the occurrence of some types of human neoplasms. The objective of the present study was to demonstrate immunohistochemically cyclin D1 expression in bladder cancer tissues and establish any relationship with the histologic findings and the clinical course.

METHODS

Tissue from 102 patients with bladder cancers and bladder tissue from five normal subjects were used for an immunohistochemical study of cyclin D1 using the avidin-biotin complex method.

RESULTS

Nuclear staining of cyclin D1 was found in 79 (77%) out of the 102 cases of bladder cancer. The five cases of normal epithelium had no immunostaining for cyclin D1. All grade 1 tumors were positive for cyclin D1. With the advance of tumor grade the incidence of cyclin D1 decreased. All pTa tumors stained positively for cyclin D1, whereas the positive staining rates of invasive tumors were 47% in pT1, 73% in pT2, 31% in pT3 and 0% in pT4 tumors. Although a univariate analysis revealed patients with lesions positive to cyclin D1 had more favorable survival rates than those with negative findings, a multivariate analysis showed that positivity for cyclin D1 is not an independent prognostic factor. No relationship was discovered between positivity for cyclin D1 and tumor recurrence in patients with superficial bladder cancers.

CONCLUSIONS

These findings suggest that cyclin D1 demonstrated immunohistochemically could be used as an inverse indicator for the level of invasiveness of bladder cancer, but not as an independent prognostic factor.

The E-cadherin-catenin complex in tumour metastasis: structure, function and regulation

E-cadherin and the associated catenin complex have been recognised as performing a key role in cell adhesion. Loss of cell adhesion is seen as a key step in the cascade leading to tumour metastasis. The ability of both extra- and intracellular factors to regulate E-cadherin-mediated cell adhesion in physiological processes has provided insight into both the interactions of the E-cadherin-catenin complex, and possible mechanisms utilised by tumours in the process of metastasis. The interaction of the E-cadherin-catenin complex with various regulating factors, their effect on cell signalling pathways, and the relationship with the metastatic potential of tumours are reviewed.

Relationship between expression of the KAI1 metastasis suppressor and other markers of advanced bladder cancer

Expression of a newly described inhibitor of tumour metastasis, KAI1, was examined in bladder cancer progression and compared with the expression of p53 and pRb, which are markers of advanced disease. KAI1 mRNA (by in situ hybridization) and protein levels (by immunohistochemistry) were examined in 135 paraffin-embedded bladder tissue sections. Significant decreases in KAI1 mRNA and protein levels were detected between normal and tumour tissue (p<0.001 and p=0.026, respectively), and between non-invasive and invasive tumours (p=0.046 and p<0.001, respectively). Loss of KAI1 protein expression was accompanied by a shift in staining pattern from a uniform distribution to a weaker, membranous or heterogeneous pattern. Normal tissue and low-grade tumours showed little p53 protein staining. High level staining (indicative of mutant p53) was associated with increased grade in non-invasive tumours (p=0.031) but was not significantly higher in invasive tumours. Whilst p53 protein staining increased with malignant progression and KAI1 mRNA expression decreased, there was no significant correlation between the two patterns (p=0.33, adjusted for group, p=0.18) or when only cancer samples were analysed (p=0.065, adjusted for group, p=0.26), even when taking into account overexpression of MDM-2 protein as a pathway for inactivation of p53. There was no correlation between loss of KAI1 mRNA expression and gain of abnormal pRb staining (p=0. 30, or adjusted for tumour samples only, p=0.59). These results suggest that loss of KAI1 expression is associated with invasive bladder cancer, but is not related to mutation of p53 or to loss of normal pRb expression.

Value of immunohistochemical Ki-67 and p53 determinations as predictive factors of outcome in renal cell carcinoma

OBJECTIVES

Nuclear grade and tumor stage are important prognostic factors in renal cell carcinoma, but tumors of similar stage and grade can exhibit a wide variation in biologic behavior and clinical outcome. In this retrospective study, we evaluated the immunologic markers, Ki-67 (MIB1) and p53, in 73 cases of conventional (clear cell) renal cell carcinoma and compared these markers with the accepted prognostic features of grade, stage, and tumor size in predicting outcome.

METHODS

Specimens of 73 renal cell carcinomas of different nuclear grade (20 Furhman I/II, 32 Fuhrman III, and 21 Fuhrman IV) and different stage (10 pT1, 23 pT2, 36 pT3, and 4 pT4) were immunostained with monoclonal antibodies against Ki-67 and p53.

RESULTS

Univariate statistical analysis showed that tumor size (P <0. 001), nuclear grade (P <0.01), tumor stage (P <0.01), Ki-67 index (P <0.001), and p53 immunostaining (P <0.03) correlated significantly with a poor prognosis. A Ki-67 index of 20% was a powerful predictor of survival in all patients (P <0.00001), with strong predictive values. On multivariate analysis, the Ki-67 index and metastases were significant independent prognostic factors (P <0.02 and <0.01, respectively).

CONCLUSIONS

Ki-67 immunostaining appeared to be an additional prognostic indicator of biologic aggressiveness in renal cell carcinoma. Immunohistochemical assessment of tumor antigens could be used to identify patients at high risk of tumor progression in addition to conventional prognostic factors.

Differential RNA expression of the pS2 gene in the human benign and malignant prostatic tissue

PURPOSE

The pS2 trefoil protein has been detected in close association with neuro-endocrine differentiation in prostate cancer and prostatic intraepithelial neoplasia. These preliminary results have suggested that pS2 is a candidate as a specific marker for prostate cancer tissue. To ascertain the specificity of pS2 in prostate cancer tissue, we have used an RT-PCR method from prostate biopsies provided from human malignant and benign prostatic hyperplasia (BPH) tissue.

MATERIALS AND METHODS

Prostate biopsies were obtained from transrectal biopsies from 153 patients with an abnormal DRE or a PSA more than 4 ng./ml. or symptoms of BPH and a PSA more than 4 ng./ml. Total RNA was extracted from fresh frozen specimens of tissue samples. Detection of pS2 transcript compared with GADPH transcripts was done using RT-PCR.

RESULTS

Biopsy results showed that 108 patients had prostate cancer (average Gleason score 6.39+/-0.74) and 45 patients had BPH. PS2 RT-PCR results showed that PS2 RNA expression was negative in 83% of the BPH cases. Conversely, 92% of prostate cancer specimens were positive (Chi-square: 86.09, p<0.001). There was no correlation with tumor stage or the Gleason score. Comparing the expression of pS2 in BPH and localized prostate cancer, we found a sensitivity of 92% and a specificity of 82%.

CONCLUSIONS

On this large sample of prostate biopsies from patients at risk of having prostate cancer, pS2 was demonstrated as an interesting marker significantly associated with prostate cancer. Further work on the expression of pS2 according to differentiation and hormonal status is in progress.

Regulation of E-cadherin: does hypoxia initiate the metastatic cascade?

The ability of tumours to metastasis is regarded as one of the hallmarks of malignancy. The process through which tumours evolve to achieve this has been termed the metastatic cascade. This cascade has been the subject of much investigation over many years. One of the vital events identified by these investigations is the reduction of adhesion between tumour cells facilitating invasion of the surrounding tissues and vascular channels, ultimately leading to the development of a distant metastasis. E-cadherin and its associated catenin complex have been identified as key molecules in cell adhesion. This review looks at the structure and interaction of the E-cadherin-catenin complex and the factors that appear to regulate E-cadherin expression and thus cell adhesion. From the data gathered, it has become possible to propose the hypothesis that the development of tumour hypoxia is the initiating factor that sets the tumour on the road to metastasis.