Philip A. Cornford

Protein Kinase C Isoenzyme Patterns Characteristically Modulated in Early Prostate Cancer

Expression of protein kinase C (PKC) isoenzymes -alpha, -beta, -delta, -epsilon, -gamma, -iota, -lambda, -mu, -theta, and -zeta, and of their common receptor for activated C-kinase (RACK)-1, was determined immunohistochemically using specific antibodies in formalin-fixed and paraffin-embedded specimens of early prostatic adenocarcinomas (n = 23) obtained at radical prostatectomy. Expression of each isoenzyme by malignant tissues was compared with nonneoplastic prostate tissues removed at radical cystectomy (n = 10). The most significant findings were decreased PKC-beta expression in early neoplasia when compared to benign epithelium (P < 0.0001), together with a reciprocal increase in expression of PKC-epsilon (P < 0.0001). Detectable levels of PKC-alpha and PKC-zeta were also significantly increased in the cancers (P = 0.045 and P = 0.015 respectively) but did not correlate with either PKC-beta or PKC-epsilon for individual cases. Alterations in the levels of the four PKC isoenzymes occurred specifically and consistently during the genesis and progression of human prostate cancer. PKC-delta, -gamma, and -theta were not expressed in the epithelium of either the benign prostates or the cancers. Levels of expression for PKC-A, -iota, -mu, and RACK-1 were not significantly different between the benign and malignant groups. Although changes in PKC isoenzyme expression may assist in explaining an altered balance between proliferation and apoptosis, it is likely that changes in activity or concentrations of these isoenzymes exert important modulating influences on particular pathways regulating cellular homeostasis. The findings of this study raise an exciting possibility of novel therapeutic intervention to regulate homeostatic mechanisms controlling proliferation and/or apoptosis, including expression of the p170 drug-resistance glycoprotein, intracellular Ca2+ concentrations, and enhanced cellular mobility resulting in the metastatic dissemination of human prostate cancer cells. Attenuation of PKC-beta expression is currently being assessed as a reliable objective adjunct to morphological appearance for the diagnosis of early progressive neoplasia in human prostatic tissues.

Detailed Tissue Expression of bcl-2, bax, bak and bcl-x in the Normal Human Pancreas and in Chronic Pancreatitis, Ampullary and Pancreatic Ductal Adenocarcinomas

Background: The aim of this study was to evaluate expression of the bcl-2 family of apoptosis regulating proteins in normal and diseased human pancreatic tissues. Method: Expression of bcl-2, bax, bcl-x, bak and p53 was determined in formalin-fixed paraffin wax-embedded archival specimens of normal pancreatic tissue (n = 7), chronic pancreatitis (n = 7), pancreatic ductal adenocarcinoma (n = 23) and ampullary cancer (n = 7) by immunohistochemistry using specific antibodies. Results: In normal pancreas and chronic pancreatitis tissues, bcl-2, bax and bcl-x were predominantly expressed in ductal epithelial cells while p53 was not detected. In pancreatic ductal adenocarcinoma and ampullary cancer, bcl-2 was not detected compared with expression seen in normal acini (p < 0.01), minor (p < 0.001) and major ducts (p < 0.01). bax expression was reduced with respect to minor ducts (p < 0.01) but no different from normal acini or major ducts. bak and bcl-x were more strongly expressed in malignant epithelia compared with acini and major ducts but reduced when compared with minor ducts (p < 0.01). Overexpression of p53 was identified in 11 (48%) of 23 pancreatic adenocarcinomas and 4 (57%) of 7 ampullary cancers. Differential survival of individual patients was predicted by the relative level of bcl-x expression but not bax or bak, such that strong expression of bcl-x was associated with a median post-operative survival of 171 days when compared with 912 days for diminished expression (p < 0.001) of bcl-x. Conclusion: Pancreatic and ampullary cancer are associated with absent bcl-2 expression. bax, bak and bcl-x expression was reduced compared with normal minor ducts whilst bak and bcl-x expression was increased when compared with major ducts. bcl-x expression correlates with survival following resection and may represent a potential prognosis marker.

Expression Patterns of Protein Kinase C Isoenzymes Are Characteristically Modulated in Chronic Pancreatitis and Pancreatic Cancer

We immunohistochemically identified protein kinase C (PKC) isoenzymes and the receptor for activated C-kinase (RACK-1) in normal, chronically inflamed, and malignant pancreas specimens. Expression patterns were specific and consistent for each microanatomic structure. In chronic pancreatitis, the expression patterns by epithelial cells were indistinguishable from those in normal pancreas. In the stroma, there was a gain of PKC-delta (P < .05) and loss of PKC-mu (P < .0001). Expression in pancreatic duct carcinomas, compared with control normal minor ductular epithelial cells, revealed relative loss of PKC-epsilon (P < .0001), PKC-iota (P = .005), and PKC-theta (P < .0001) but no gain in any isoenzyme. Compared with control normal major duct epithelial cells, the principal differences were a relative loss in PKC-gamma (P < .05) and a relative gain in PKC-beta (P < .05), PKC-iota (P < .05), and PKC-zeta (P < .005). The stroma adjacent to ductal carcinomas was characterized by prominent expression of PKC-mu and a gain in PKC-delta (P < .0001) and PKC-zeta (P > .005). Ampullary carcinomas revealed a relative gain of PKC-iota (P < .05) and RACK-1 (P < .05). In the adjacent stroma was enhanced expression of PKC-delta (P < .005) and PKC-gamma (P < .001) and loss of PKC-mu (P < .05). Specific changes in isoenzyme expression in stroma of chronic pancreatitis and in epithelial cells and stroma of ductal and ampullary pancreatic adenocarcinomas reflect specific modulation of intracellular signaling pathways that control critical homeostatic mechanisms.

Prostate-specific antigen: An evolving role in diagnosis, monitoring, and treatment evaluation in prostate cancer

Prostate specific antigen (PSA) was introduced as a prostate cancer screening tool more than 20 years ago. However, there is continuing debate regarding its utility in screening for prostate cancer. Mass screening is costly, may result in the diagnosis and treatment of prostate cancers that never become clinically significant, and the evidence of a subsequent reduction in mortality is inconclusive. In addition to its role in screening, PSA is also used to monitor the progression of the disease, both localized and metastatic. Although the evidence is contradictory, PSA is still an important tool for monitoring patient progression following treatment of definitive localized prostate cancer. However, its use in monitoring castrate-resistant prostate cancer (CRPC) is more controversial, particularly in the context of novel targeted treatments, which may have little impact on PSA levels. These issues highlight the urgent need to identify prostate cancer biomarkers that will improve early disease detection, increase accuracy of diagnosis, determine the aggressiveness of disease, and monitor treatment efficacy, particularly in late-stage disease. This review discusses the key issues associated with the use of PSA as an early screening tool for prostate cancer, as a prognostic marker to measure disease progression in both early- and late-stage prostate cancer, and as a surrogate endpoint in clinical trials with new agents.

A pilot randomized double-blind placebo-controlled trial on the use of antibiotics on urinary catheter removal to reduce the rate of urinary tract infection: the pitfalls of ciprofloxacin

To assess if a short course of antibiotics starting at the time of the removing a short‐term urethral catheter decreases the incidence of subsequent urinary tract infection (UTI).

Surveillance of testicular microlithiasis?: Results of an UK based national questionnaire survey

BackgroundThe association of testicular microlithiasis with testicular tumour and the need for follow-up remain largely unclear.MethodsWe conducted a national questionnaire survey involving consultant BAUS members (BAUS is the official national organisation (like the AUA in USA) of the practising urologists in the UK and Ireland), to provide a snapshot of current attitudes towards investigation and surveillance of patients with testicular microlithiasis.ResultsOf the 464 questionnaires sent to the BAUS membership, 263(57%) were returned. 251 returns (12 were incomplete) were analysed, of whom 173(69%) do and 78(31%) do not follow-up testicular microlithiasis. Of the 173 who do follow-up, 119(69%) follow-up all patients while 54(31%) follow-up only a selected group of patients. 172 of 173 use ultra sound scan while 27(16%) check tumour makers. 10(6%) arrange ultrasound scan every six months, 151(88%) annually while 10(6%) at longer intervals. 66(38%) intend to follow-up these patients for life while, 80(47%) until 55 years of age and 26(15%) for up to 5 years. 173(68.9%) believe testicular microlithiasis is associated with CIS in < 1%, 53(21%) think it is between 1&10% while 7(3%) believe it is > 10%. 109(43%) believe those patients who develop a tumour, will have survival benefit with follow-up while 142(57%) do not. Interestingly, 66(38%) who follow-up these patients do not think there is a survival benefit.ConclusionThere is significant variability in how patients with testicular microlithiasis are followed-up. However a majority of consultant urologists nationally, believe surveillance of this patient group confers no survival benefit. There is a clear need to clarify this issue in order to recommend a coherent surveillance policy.

Potentiation of chemotherapeutics by the Hsp90 antagonist geldanamycin requires a steady serum condition.

Inhibition of Hsp90 potentiates diverse chemotherapeutics, but it is not clear if this applies only to specific agents, tumor types or conditions. The aim of this report is to determine the effect of serum starvation (SS) on potentiation. SUIT2 cells were cultured with and without the presence of serum and 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide (MTT) assays were carried out at time intervals. Cytotoxic agents were added individually or in combination. Immunohistochemistry of tumor samples and immunofluorescence of cultured cells were used to examine Hsp90 localization. In the presence of serum an at least additive effect of combining the Hsp90 inhibitor geldanamycin (GA) with 5‐fluorouracil (5FU) was demonstrated. Following pretreatment with GA, 5FU and GA were synergistic. However, during SS GA was protective against 5FU. Geldanamycin also protected cells from 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) during SS. Protection of cells is transitory, as after 24 h of SS GA again has an at least additive negative effect on vitality with 5FU or TPA. Serum starvation of pancreatic cancer cell lines causes normally largely cytoplasmic Hsp90 to become predominantly nuclear localized. Hsp90 nuclear localization was observed in pancreatic and prostate tumors. Hsp90 binding to a pro‐apoptotic client could explain the transitory protection of cells by Hsp90 inhibition during SS. Although potentiation of chemotherapeutics by Hsp90 inhibition is probably a general phenomenon, design of clinical trials should take into account that continuous co‐administration may be ineffective because of a balance of synergy of the drugs in some cells and mutual inhibition of the two drug activities in other cells.

Evolution of Docetaxel-Based Therapy for Metastatic Castrate-Resistant Prostate Cancer

Until the publication of the SWOG 99–16 [1] and TAX 327 [2] trials in 2004, urologists understood that only purely palliative treatment was available for men with prostate cancer that was progressive despite androgen deprivation. However, following the establishment of docetaxel-based chemotherapy as an active treatment option for most men with metastatic disease, researchers have focused their questions on the optimal timing of treatment. Should docetaxel be considered after one or two lines of hormone manipulation? Is it necessary to wait until the patient has bone pain? In latter years, the research focus has widened to embrace second-line and even third-line chemotherapy for this patient group, raising the possibility of advanced prostate cancer being managed as a chronic condition. This article looks at the evolution of docetaxel-based chemotherapy in advanced prostate cancer, and considers the next likely developments.

The increased expression of fatty acid-binding protein 9 in prostate cancer and its prognostic significance

In contrast to numerous studies conducted to investigate the crucial role of fatty acid binding protein 5 (FABP5) in prostate cancer, investigations on the possible involvement of other FABPs are rare. Here we first measured the mRNA levels of 10 FABPs in benign and malignant prostate cell lines and identified the differentially expressed FABP6 and FABP9 mRNAs whose levels in all malignant cell lines were higher than those in the benign cells. Thereafter we assessed the expression status of FABP6 and FABP9 in both prostate cell lines and in human tissues. FABP6 protein was overexpressed only in 1 of the 5 malignant cell lines and its immunostaining intensities were not significantly different between benign and malignant prostate tissues. In contrast, FABP9 protein was highly expressed in highly malignant cell lines PC-3 and PC3-M, but its level in the benign PNT-2 and other malignant cell lines was not detectable. When analysed in an archival set of human prostate tissues, immunohistochemical staining intensity for FABP9 was significantly higher in carcinomas than in benign cases and the increase in FABP9 was significantly correlated with reduced patient survival times. Moreover, the increased level of staining for FABP9 was significantly associated with the increased joint Gleason scores (GS) and androgen receptor index (AR). Suppression of FABP9 expression in highly malignant PC3-M cells inhibited their invasive potential. Our results suggest that FABP9 is a valuable prognostic marker to predict the outcomes of prostate cancer patients, perhaps by playing an important role in prostate cancer cell invasion.

Inhibitor SBFI26 suppresses the malignant progression of castration-resistant PC3-M cells by competitively binding to oncogenic FABP5.

Castration resistant-prostate cancer is largely impervious to feather hormonal therapy and hence the outlook for patients is grim. Here we use an approach to attach the recently discovered Achilles heel. The experimental treatment established in this study is based on the recent discovery that it is the FABP5-PPARγ-VEGF signalling axis, rather than the androgen receptor pathway, played a dominant role in promoting the malignant progression of castration resistant prostate cancer cells. Treatments have been established in mice by suppressing the biological activity of FABP5 using a chemical inhibitor SBFI26. The inhibitor significantly suppressed the proliferation, migration, invasiveness and colony formation of PC3-M cells in vitro. It also produced a highly significant suppression of both the metastases and the primary tumours developed from cancer cells implanted orthotopically into the prostate glands of the mice. The inhibitor SBFI26 interferes with the FABP5-PPARγ- signalling pathway at the initial stage of the signal transduction by binding competitively to FABP5 to inhibit cellular fatty acid uptake. This avoids the fatty-acid stimulation of PPARγ and prevents it activating the down-stream regulated cancer-promoting genes. This entirely novel experimental approach to treating castration- resistant prostate cancer is completely different from current treatments that are based on androgen-blockade therapy.