Brief report: no evidence for parvovirus B19 or hepatitis E virus as a cause of acute liver failure.

Viral hepatitis A and B are known to cause acute liver failure. While nearly 20% of acute liver failure cases are of indeterminate etiology, screening for other viruses has not been uniformly performed. We looked for evidence for parvovirus B19 and hepatitis E virus in sera from U.S. acute liver failure patients. For B19, 78 patients' sera, including 34 with indeterminate etiology, were evaluated by DNA dot-blot hybridization, reverse transcription polymerase chain reaction, and enzyme-linked immunosorbent assay for immunoglobin G and M antibodies; none showed evidence for infection.

The effects of sex steroid hormones and interleukin-1-beta on MUC1 expression in endometrial epithelial cell lines.

Oestrogen, progesterone and paracrine signals from the embryo have been associated with the overall control of implantation. Changes in the expression of the heavily glycosylated transmembrane glycoprotein MUC1 mucin on the endometrial epithelium are also thought to be important for embryo attachment. Increased MUC1 expression has been correlated with elevated progesterone levels in the secretory phase of the menstrual cycle. Embryonic control of endometrial receptivity through changes in MUC1 expression could be achieved through the interleukin-1 system. Four endometrial epithelial cell lines (HEC1A, HEC1B, Ishikawa and RL592) were treated with oestrogen and progesterone (with or without interleukin-1-beta) and were subjected to immunocytochemistry and flow cytometric analysis to determine MUC1 production using MUC1 antibodies. HEC1A (oestrogen receptor (ER) and progesterone receptor (PR) positive) and HEC1B (ER positive and PR negative) were transfected with the MUC1 promoter, underwent similar treatment regimes and the activity of the MUC1 promoter relative to their untreated controls was determined using a chloramphenicol acetyltransferase (CAT) enzyme-linked immunoassay. Using the cell lines, we determined that endometrial MUC1 expression is up-regulated by progesterone, consistent with the in vivo increases in MUC1 related to high progesterone levels. We also revealed that neither oestrogen, nor interleukin-1-beta, appear to modulate MUC1. Progesterone-dependent regulation of MUC1 is likely to be an important factor in determining endometrial receptivity.

The expression pattern of MUC1 glycoforms and other biomarkers of endometrial receptivity in fertile and infertile women.

Changes in the surface epithelium of the endometrium, characterized in part by alterations in cell-surface molecules, sex steroid receptors and the appearance of pinopodes, coincide with the window of endometrial receptivity in the menstrual cycle. This study was performed to evaluate the usefulness of hematoxylin and eosin staining, scanning and transmission microscopy, and MUC1 glycoform, sex steroid receptor, and interleukin receptor (type 1) expression as biomarkers of endometrial receptivity using carefully characterized clinical fertile and infertile groups of women. Using a combination of immunohistochemistry and scanning electron microscopy (SEM) called scanning immunoelectron microscopy (SIM), we confirmed that MUC1 mucin was not associated with the endometrial pinopodes, which have been linked with embryo adhesion. We also showed that failure of embryo implantation was associated with an abnormal endometrial expression of MUC1 mucin, and retention of nuclear progesterone receptor (PR) particularly in epithelial cells. Hematoxylin and eosin staining, transmission electron microscopy (TEM), SEM in isolation and immunohistochemistry for interleukin receptor were not shown to be useful markers. Progesterone-dependent regulation of MUC1 appears to be an important factor in determining endometrial receptivity.

Transdermal estradiol improves bone density when used as single agent therapy for prostate cancer.

PURPOSE: Current androgen deprivation therapies for men with prostate cancer cause accelerated osteoporosis and a significant risk of osteoporotic fracture. We have recently shown that transdermal estradiol is an effective alternative for such patients. Here we report the impact of transdermal estradiol therapy on the bone mineral density of men with prostate cancer. MATERIALS AND METHODS: A total of 20 patients with newly diagnosed locally advanced or metastatic prostate cancer were treated with transdermal estradiol patches. Bone mineral density of the lumbar spine and the proximal femur was measured with dual-energy x-ray absorptiometry, and correlated with computerized tomography and isotope bone scan findings at 6-month intervals. RESULTS: In all measured regions bone mineral density increased with time. By 1 year mean bone mineral density +/- SEM had increased by 3.60% +/- 1.6% in the lumbar spine (p = 0.055), 2.19% +/- 1.03% in the femoral neck (p = 0.055), 3.76% +/- 1.35% in the Ward's region (p = 0.008) and 1.90% +/- 0.85% in the total hip (p = 0.031), respectively. Of 12 osteoporotic sites 4 had improvement based on World Health Organization grading. All other sites improved toward a better classification. CONCLUSIONS: Transdermal estradiol protects against bone loss in men with prostate cancer and may improve bone density in those at risk for osteoporotic fracture.

Inverse correlation between high level expression of cyclin E and proliferation index in transitional cell carcinoma of the bladder.

BACKGROUND/AIMS: Overexpression of the G1 cyclins, D1 and E, and/or downregulation of p27(Kip1) allow uncontrolled tumour cell proliferation. This study investigated the relation between these three cell cycle proteins and tumour proliferation in bladder cancer. METHOD: Nuclear expression of cyclin D1, cyclin E, and p27(Kip1) was determined immunohistochemically in 52 primary transitional cell carcinomas, and the Ki-67 proliferation marker was also assessed. For each protein, the percentage of positive tumour cell nuclei was determined and analysed as a continuous variable. RESULTS: Advancing tumour grade and pathological stage were accompanied by increasing proliferation indices, but decreasing p27(Kip1) and cyclin D1 expression, with no significant change in cyclin E expression. Overall, cyclin D1 and E expression did not correlate with proliferation. However, in cyclin D1 overexpressing tumours (> or = 5% nuclei positive), the level of cyclin D1 expression positively correlated with proliferation. The correlation between cyclin E expression and proliferation changed from positive to negative with increasing levels of cyclin E expression, accompanied by a coordinate increase in p27(Kip1) expression. Overall, there was an inverse association between p27(Kip1) expression and proliferation. However, a subset of tumours displayed high proliferation indices despite high p27(Kip1) expression. The G1 cyclin index (sum of the level of expression of cyclins D1 and E) correlated positively with proliferation in superficial but not muscle invasive tumours. This correlation was stronger when the G1 cyclin index was adjusted for p27(Kip1) expression. CONCLUSION: These findings support a role for these proteins in the proliferation, differentiation, and progression of bladder transitional cell carcinomas.

Transdermal estradiol therapy for advanced prostate cancer--forward to the past?

PURPOSE: Current hormonal therapies for prostate cancer are associated with significant morbidities, including symptoms of andropause and osteoporosis. Oral estrogens prevented many of these problems but were abandoned due to cardiovascular toxicity attributed to hepatic effect. In contrast, parenteral estrogens prevent first pass hepatic metabolism and substantially reduce cardiovascular risk, and long-term transdermal estradiol therapy is believed to be cardioprotective. We report preliminary results of a pilot study using transdermal estradiol therapy to treat men with advanced prostate cancer. MATERIALS AND METHODS: A total of 20 patients with advanced prostate cancer were enrolled in a before and after study that examined the impact of estradiol patches on hormones, disease, thrombophilia, vascular flow, osteoporosis and quality of life. RESULTS: Median followup is 15 months. Estradiol levels greater than 1,000 pmol./l. were achieved using 2 patches and higher levels were obtained by increasing the number of patches. All patients achieved castrate levels of testosterone within 3 weeks and had biochemical evidence of disease regression. One patient died of disease at 14 months and 1 cardiovascular complication occurred. Thrombophilic activation was avoided and vascular flow improved. Bone mineral density was significantly increased. Mild or moderate gynecomastia occurred in 80% of patients but no patient had hot flushes. All other functional and symptomatic quality of life domains improved. CONCLUSIONS: Transdermal estradiol therapy produced an effective tumor response. Cardiovascular toxicity was substantially reduced compared with that expected of oral estrogen, and other morbidity (gynecomastia) was negligible. Transdermal estradiol therapy prevented andropause symptoms, improved quality of life scores and increased bone density. Transdermal estradiol costs a tenth of current therapy cost, with the potential for considerable economic savings over conventional hormone therapies.

Arginine reverses ethanol-induced inflammatory and fibrotic changes in liver despite continued ethanol administration.

We investigated the potential of arginine to reverse pathological changes in alcohol-induced liver injury. Four groups (six rats/group) of male Wistar rats were fed a fish oil-ethanol diet for 6 (group 2) or 8 (group 1) weeks. Rats in group 3 were fed fish oil-ethanol for 6 weeks, after which they were administered arginine with fish oil-ethanol for an additional 2 weeks. Rats in group 4 were fed fish oil-dextrose for 8 weeks. Liver samples were analyzed for histopathology, lipid peroxidation, cytochrome P4502E1 activity, nuclear factor-kappaB, and levels of messenger RNA for tumor necrosis factor-alpha, cyclooxygenase-2, and inducible nitric oxide synthase. Concentrations of endotoxin were measured in plasma. The most severe inflammation and fibrosis was detected in groups 1 and 2, as were the highest levels of endotoxin, lipid peroxidation, cytochrome P450 2E1 activity, activation of nuclear factor-kappaB, and mRNA levels for tumor necrosis factor-alpha, cyclooxygenase-2, and inducible nitric oxide synthase. Plasma nitric oxide was also increased as was nitrotyrosine in liver. After arginine was administered, there was marked improvement in the pathological changes accompanied by decreased levels of endotoxin, lipid peroxidation, activation of nuclear factor-kappaB, tumor necrosis factor-alpha, cyclooxygenase-2, inducible nitric oxide, and nitrotyrosine staining. The therapeutic effects of arginine are probably secondary to increased levels of nitric oxide but other effects of arginine cannot be excluded.

Human MUC1 mucin: a potent glandular morphogen.

Human MUC1 mucin is a high-molecular-weight transmembrane glycoprotein, which is apically expressed in the majority of glandular epithelia. During embryonic development, changes in the pattern of MUC1 mucin expression coincide with the onset of glandular differentiation. This mucin is also frequently overexpressed and aberrantly glycosylated in carcinomas. To investigate the potential role of MUC1 mucin in morphogenesis, a full length MUC1 cDNA was transfected into murine mammary adenocarcinoma (410.4) and Madin-Darby canine kidney (MDCK) cells. This generated four clonal cell lines. Western blotting, FACS analysis, and immunohistochemistry confirmed expression of MUC1. All four MUC1-expressing clones demonstrated altered morphogenesis when cultured in three-dimensional type I collagen gels. While parental and vector control 410.4 cells formed compact spherical structures, the MUC1-expressing clones formed complex branching structures. Similarly, while parental and vector control MDCK cells formed small circumscribed colonies with a central lumen, the MUC1-expressing clones formed elongated tubules. MUC1 expression was also associated with reduced cellular cohesion and enhanced migration on type I collagen-coated surfaces for all except one of the clones, which expressed only low levels of MUC1 on the cell surface. These results show that MUC1 expression stimulates morphogenetic changes in two distinct epithelial cell lines. Taken together with previous observations on MUC1 expression in embryonic development and carcinomas, this finding suggests that MUC1 may induce changes in tissue architecture in both normal development and cancer.

MUC1 in normal and impaired spermatogenesis.

The MUC1 mucin [also known as episialin, epithelial membrane antigen (EMA) or polymorphic epithelial mucin (PEM)] is a component of the mucosal glycocalyx, contributing to anti-adhesive and protective cell functions. MUC1 has been shown in a variety of epithelial cell types in the reproductive tracts of males and females, but this is the first report of its expression in human testis and non-epithelial cells of the germ cell lineage. Analysing 65 testes with normal or impaired spermatogenesis, we identified MUC1 protein in maturing germ cells by immunohistochemistry using the monoclonal antibodies HMFG1, HMFG2 and SM3 binding to different glycosylation variants. MUC1 expression was confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis on tissue extracts of human testis, and RT-PCR of selected germ cells after UV laser-assisted cell picking. MUC1 glycosylation variants were selectively distributed during normal spermatogenesis. Whereas HMFG1 labelled certain groups of pachytene spermatocytes, HMFG2 labelled only spermatids. Low glycosylated forms of MUC1 mucin, recognized by SM3, were not found. In contrast to its weak expression during normal spermatogenesis, the HMFG1 glycosylation variant accumulated markedly in all spermatocytes showing abnormal or arrested maturation. These results suggest a variable glycosylation of MUC1 mucin in differentiating germ cells, which is aberrant in pathological conditions.

MUC 1: a genetic susceptibility to infertility?

In man and some animals regulation of embryo implantation by endometrial expression of the highly polymorphic MUC 1 mucin has been suggested. We assessed the polymorphism of MUC 1 in women known to be fertile and those with infertility due to suspected failure of embryo implantation. The median of the lower allele size in the infertile group was only 2.5 kb compared with 3.4 kb in the fertile group (p=0.0029, difference 0.9, [95% CI 0.1-1.3]). Women with unexplained infertility might have a genetic susceptibility to failure of embryo implantation due to small MUC 1 allele size.

Differential expression of cell death regulators in response to thapsigargin and adriamycin in Bcl-2 transfected DU145 prostatic cancer cells.

Functional overexpression of Bcl-2 has been reported to confer an anti-apoptotic potential in a variety of cell types. The role of Bcl-2 in epithelial cell-cycle control and in interactions with other cell-cycle regulators is not clearly understood. Its expression has been correlated with the hormono- and chemo-resistant phenotype in advanced prostate cancer. The aim of this study was to investigate the mechanisms through which Bcl-2 mediates increased cytotoxic chemoresistance by assessing alterations in the expression of cell death regulatory molecules. The DU145 human prostatic adenocarcinoma cell line was stably transfected with a Bcl-2 encoding expression plasmid. Two Bcl-2 transfectants, DKC9 and DKC11, were expanded for further study. The effects of Bcl-2 expression on cellular proliferation, cell death (+/- adriamycin or thapsigargin), and expression of cell-cycle/death regulators (p53, PCNA, Bax, Bak, Bcl-X(L)) were evaluated. Compared with controls, Bcl-2 transfectants showed no difference in the rate of proliferation, a decrease in p53 (approximately two-fold), an increase in Bax (approximately two-fold) and PCNA (approximately three-fold), and no change in the levels of Bcl-X(L) and Bak proteins. DKC9 and DKC11 also exhibited a significantly increased chemoresistance to adriamycin (0.0025-5 microM) and thapsigargin (0.0025-5 microM) compared with controls. In the presence of thapsigargin or adriamycin, levels of Bcl-2 and its heterodimeric partner Bax were elevated approximately two-fold with no change in Bak in Bcl-2 transfectants in contrast to controls, where Bak was increased (two-fold). This is the first study to demonstrate that Bcl-2 transfection modulates the expression of mutant p53, Bax, and PCNA in prostate cancer cells. Moreover, Bcl-2 overexpression conferred a significant cytotoxic chemoresistance and altered the balance of expression of death promoters (from Bak, a dominant death promoter in controls, to Bax) in response to thapsigargin and adriamycin.

Cyclooxygenase-2: a possible target in schistosoma-associated bladder cancer.

OBJECTIVE: To analyse and compare the expression of cyclooxygenase (COX) enzymes in schistosoma-associated bladder cancer, and to determine any association with tumour grade or stage. MATERIALS AND METHODS: Sixty paired samples of tumour and adjacent nonmalignant urothelium were identified. There were 25 squamous and 28 transitional cell carcinomas, and seven adenocarcinomas. Serial sections were obtained and a standard three-layer immunohistochemistry protocol, using COX-1- and COX-2-specific mouse monoclonal antibodies, applied. RESULTS: COX-1 was expressed mostly in nonvascular smooth muscle with weak reactivity in malignant and nonmalignant urothelium. Nonmalignant urothelium expressed COX-2 weakly, notably in areas of dysplasia and squamous metaplasia whereas there was a significant increase in COX-2 (P < 0.001) with moderate to strong granular cytoplasmic expression in all three malignant histological types. The COX-2 reactivity was higher in transitional and adenocarcinomas than in squamous cell carcinoma (P < 0.001). Areas of carcinoma in situ showed COX-2 reactivity comparable with that in invasive areas and more intense than that detected in dysplastic or metaplastic urothelium (P < 0.001). There was a statistically significant positive correlation between COX-2 expression and tumour grade (P = 0.0052). CONCLUSION: COX-2 is over-expressed in schistosoma-associated bladder cancer, consistent with a potential role for COX-2 inhibitors in the prevention and management of this disease.

Cytoplasmic induction and over-expression of cyclooxygenase-2 in human prostate cancer: implications for prevention and treatment.

OBJECTIVE: To assess the level and morphological distribution of cyclooxygenase (COX)-1 and -2 in human prostates and to determine any association with the Gleason grade of prostate cancer. Materials and methods The study comprised 30 samples from patients with benign prostatic hyperplasia (BPH) and 82 with prostate cancer. Immunohistochemistry was used to assess the expression of COX-1 and -2, and 13 samples were also assessed using immunoblotting (six BPH and seven cancers). RESULTS: For both BPH and prostate cancer, COX-1 expression was primarily in the fibromuscular stroma, with variable weak cytoplasmic expression in glandular/neoplastic epithelial cells. In contrast, COX-2 expression differed markedly between BPH and cancer. In BPH there was membranous expression of COX-2 in luminal glandular cells and no stromal expression. In cancer the stromal expression of COX-2 was unaltered, but expression by tumour cells was significantly greater (P = 0.008), with a change in the staining pattern from membranous to cytoplasmic (P < 0.001). COX-2 expression was significantly higher in poorly differentiated than in well differentiated tumours (P < 0.001). These results were supported by immunoblotting, which showed similar levels of COX-1 in both BPH and cancer, but four times greater expression of COX-2 in cancer than in BPH. CONCLUSION: This is the first study to assess the co-expression of COX-1 and COX-2 proteins in benign and malignant human prostates, and showed the induction and significantly greater expression of COX-2 in cancer, which was also associated with tumour grade. The regular use of nonsteroidal anti-inflammatory drugs is associated with a reduced incidence of cancers. The present results provide the basis for a potential role for COX-2 inhibitors in the prevention and treatment of prostate cancer.

Disruption of the developmentally regulated Rev3l gene causes embryonic lethality.

The REV3 gene encodes the catalytic subunit of DNA polymerase (pol) zeta, which can replicate past certain types of DNA lesions [1]. Saccharomyces cerevisiae rev3 mutants are viable and have lower rates of spontaneous and DNA-damage-induced mutagenesis [2]. Reduction in the level of Rev31, the presumed catalytic subunit of mammalian pol zeta, decreased damage-induced mutagenesis in human cell lines [3]. To study the function of mammalian Rev31, we inactivated the gene in mice. Two exons containing conserved DNA polymerase motifs were replaced by a cassette encoding G418 resistance and beta-galactosidase, under the control of the Rev3l promoter. Surprisingly, disruption of Rev3l caused mid-gestation embryonic lethality, with the frequency of Rev3l(-/-) embryos declining markedly between 9.5 and 12.5 days post coitum (dpc). Rev3l(-/-) embryos were smaller than their heterozygous littermates and showed retarded development. Tissues in many areas were disorganised, with significantly reduced cell density. Rev3l expression, traced by beta-galactosidase staining, was first detected during early somitogenesis and gradually expanded to other tissues of mesodermal origin, including extraembryonic membranes. Embryonic death coincided with the period of more widely distributed Rev3l expression. The data demonstrate an essential function for murine Rev31 and suggest that bypass of specific types of DNAlesions by pol zeta is essential for cell viability during embryonic development in mammals.

Phenotypic and genotypic characterization of commonly used human prostatic cell lines.

OBJECTIVE: To investigate and catalogue systematically the phenotypic and genotypic characteristics of the commonly used prostatic cell lines using immunocytochemistry and polymerase chain reaction (PCR) of hypervariable sequences within the genome to provide a 'fingerprint' characteristic of each cell line. Materials and methods Malignant (LNCaP, LNCaP-r, PC-3, DU-145) and benign immortalized prostatic cell lines (PNT-1A, PNT-1B, BPH-1) were grown on four-well slides, fixed and subjected to indirect streptavidin-biotin immunocytochemistry. Twenty-three antibodies were used in the following groups: cytoskeletal elements: cytokeratins (CK)-5, -7, -8, -14 (two), -16, -18, -19 (three), -20, vimentin and desmin; MUC1 (three); cell adhesion molecules (E-cadherin, alpha-beta-and gamma-catenin); and prostatic associated proteins: prostate specific antigen (PSA), prostatic acid phosphatase (PAP) and androgen receptor (AR). For the PCR, genomic DNA was extracted from the cell lines and from SKOV3 and MCF7 (positive controls). PCR was performed on three variable regions which were then sequenced: AR exon 1 (CAG repeat polymorphism), and two areas of microsatellite instability (MSI): AR exon 8 and hypoxanthine-guanine phosphoribosyl transferase (HPRT) exon 3. RESULTS: All cell lines were CK-8/18 positive and most also expressed CK-7 and -19. Heterogeneous CK-20 expression was detected for the first time in prostatic cell lines. All lines were positive for vimentin and negative for desmin. MUC1 was expressed in one malignant (DU-145) and all immortalized cell lines. E-cadherin expression was low or absent in three lines: PNT1A, 1B and PC-3. Only PC-3 failed to express alpha-catenin; beta- and gamma-catenin were expressed by all lines. PSA, PAP and AR were only expressed by LNCaP and LNCaP-r. On PCR, the CAG repeat lengths in exon 1 of the AR ranged from 19 to 27. Three pairs of cell lines had the same exon 1 CAG repeat length: LNCaP/PC-3 (26 repeats), BPH-1/DU-145 (19 repeats) and PNT1 A/1B (20 repeats). Exon 8 sequences were identical except for LNCaP, which showed a single base mutation, and HPRT exon 3 sequences were all identical. There was no evidence of generalized MSI in any of the cell lines examined. CONCLUSIONS: The cell lines studied fell into three broad groups according to their phenotypic characteristics: (i) prostatic marker positive (LNCaP and LNCaP-r); (ii) high expression of most antigens (DU-145, PC-3 and BPH-1); and (iii) low or absent expression of most antigens (PNT1 A and 1B). Each of the cell lines derived from PC could be identified on the basis of exon 1 and 8 AR sequence variability. DU145 and BPH-1 had identical profiles of the three areas studied, but these cell lines are easily distinguished by their different phenotypic characteristics. PNT1A and 1B had identical genetic and similar phenotypic profiles, which is unsurprising given that they are subclones derived from the same parental line. Even so, these were separable on the basis of CK-19 immunostaining. Using a combination of geno- and phenotypic markers it was possible to derive a 'fingerprint' for each of the cell lines assessed, which will allow meaningful comparison between similar cell lines held in other laboratories.

Decreased HLA-A expression in prostate cancer is associated with normal allele dosage in the majority of cases.

A comparison has been made of the phenotypic expression of MHC class I antigens with the corresponding HLA-A genotype in 15 cases of benign prostatic hyperplasia (BPH) and 34 cases of primary locally invasive prostatic carcinoma. Expression of class 1 protein, detected by immunocytochemistry, was partially or completely lost in approximately 90% of the tumours examined. Comparative genomic analysis of the beta2 microglobulin (beta2m) gene and 15 individual HLA-A haplotypes using a polymerase chain reaction (PCR)-based method demonstrated abnormal gene dosage in the minority of cases: homozygous deletion of the beta2m locus was detected in one case and HLA-A allele in two cases (HLA-A1 and HLA-A2, respectively), representing approximately 8% of the population studied. This first comparative study of gene dosage and expression of class 1 protein reported for prostate cancer reveals that deletion is not the cause of the partial or complete loss seen in the majority of cases. This raises the possibility, in the future, for novel selective immunomodulatory therapeutic strategies which stimulate a clinically significant re-expression of class 1 protein and associated cytotoxic T-cell response.

Correlation between androgen receptor expression and FGF8 mRNA levels in patients with prostate cancer and benign prostatic hypertrophy.

AIM: To investigate the correlation between androgen receptor expression and fibroblast growth factor 8 (FGF8) mRNA levels. METHODS: 39 human prostate cancers and 14 benign prostatic hypertrophy specimens were examined immunohistochemically for androgen receptor expression and by in situ hybridisation and reverse transcription polymerase chain reaction for FGF8 expression. RESULTS: In 39 tumours there was a statistically significant negative correlation between tumour grade and FGF8 expression and a positive correlation between FGF8 and androgen receptor expression. All 14 benign hypertrophy specimens expressed moderate to high levels of FGF8 and androgen receptor. CONCLUSIONS: Loss of FGF8 may be a factor involved in the development of prostatic cancer.

Role of the Bcl-2 gene family in prostate cancer progression and its implications for therapeutic intervention.

Prostate cancer (PC) is an escalating health burden in the western world. A large number of patients still present with extraprostatic (i.e., T3/T4, N0, M0/M1 or any T category and M1 disease or involved lymph nodes) and therefore incurable disease. Since the work of Huggins in 1940, there have been no major therapeutic advances and androgen ablation remains the best treatment option for extraprostatic androgen-responsive PC. Eighty to ninety percent of PC patients respond well to this form of treatment initially. After a median time of approximately 2 years, however, relapse to an androgen-independent (AI) state occurs, followed by death after a further median 6 months. Androgen ablation is rarely curative. The major molecular defect in extraprostatic and AI PC is the inability of PC cells to initiate apoptosis in response to a variety of stimuli, including different forms of androgen ablation and cytotoxic agents. The balance between cellular proliferation and cell death is regulated by multiple genes or families of genes through the cell cycle. The exact mechanisms governing this intricate and complex process are as yet not fully understood. One family of genes involved in cell survival/death control is the Bcl-2 gene family, which consists of homologous proteins that function to regulate distal and crucial commitment steps of the apoptotic pathway. The Bcl-2 family constitutes both agonists and antagonists of apoptosis that function at least in part through protein-protein interactions between various members of the family. The final outcome depends on the relative ratio of death agonists and antagonists. Bcl-2 expression has been closely associated with the AI phenotype of PC. Cytotoxic chemotherapy may be used as palliative therapy in AI PC but has not been found effective. Most chemotherapeutic cytotoxic agents induce apoptosis in cancer cells by direct and indirect action on the cell cycle. In vitro and in vivo studies have established that Bcl-2 expression confers an antiapoptotic activity against androgen withdrawal and cytotoxic chemotherapy. It thus offers a tempting potential target for therapeutic manipulations of PC.