uPA/PAI-1 ratios distinguish benign prostatic hyperplasia and prostate cancer

Purpose

Urokinase plasminogen activator (uPA) and its inhibitor type 1 (PAI-1) are associated with tumour metabolism and are widely considered to be informative for the identification of cancer. We have analysed prostate tissue resections from patients with prostate cancer (PCa) and with benign prostatic hyperplasia (BPH) for protein levels of uPA and PAI-1, and searched for distinctions between these two clinical manifestations.

Methods

Prostate tissue was deep frozen in liquid N2 and homogenized in a stainless steel punch homogenizer. The tissue powder was extracted with a pH 8.5 TRIS/Triton X-100 buffer, and the extract analysed by FEMTELLE assay to generate uPA and PAI-1 readings in ng/mg protein. The uPA/PAI-1 ratio was calculated for each sample, and the mean ratios for the two diagnostic groups were compared.

Results

The concentration of uPA (mean ± SD) was found to be 0.19 ± 0.04 ng/mg protein (range 0.05–0.72 ng/mg) and 0.15 ± 0.02 ng/mg protein (range 0.03–0.78 ng/mg) in PCa and BPH samples, respectively. The concentration of PAI-1 was found to be 4.93 ± 0.90 ng/mg (range 1.10–11.80 ng/mg) and 5.87 ± 0.70 ng/mg (range 0.2–25.0 ng/mg) in PCa and BPH samples, respectively. A consistent finding being that PAI-1 concentrations exceed uPA concentrations by far giving rise to characteristic uPA/PAI-1 ratios. In BPH samples, there was a trend of PAI-1 to increase with uPA content, while in PCa samples, PAI-1 remained fairly constant. The mean uPA/PAI-1 ratio in PCa samples was found to be 0.06 ± 0.01 and was significantly higher than in BPH samples where the mean uPA/PAI-1 ratio was 0.03 ± 0.003 (p = 0.0028). R ² = 0.1389.

Conclusion

Using a contingent of 62 patients of which 46 were BPH and 16 were PCa, we report definitive concentrations of uPA and PAI-1 in tumour tissue extracts and show that the uPA/PAI-1 ratio emerges as a candidate marker to distinguish between BPH and PCa.     

Immunohistochemical cathepsin-D expression in breast cancer: correlation with established pathological parameters and survival

Breast cancer is an increasingly important cause of illness and death among women. In recent years, several novel prognostic determinants of breast cancer have been identified, including Cathepsin-D (CD) protein. CD protein expression was analyzed immunohistochemically (IHC) in tumor specimens (315 patients) of infiltrating ductal breast carcinoma. These patients also had axillary lymph node sampling. Overexpression of CD was observed in 39% of the tumors. IHC results were compared with the histological grade. Seventy nine percent (n = 95; 79%) tumor positivity was seen in grade II tumors, followed by grade I (n = 13; 11%) and grade III tumors (n = 12; 10%). Axillary lymph node metastasis had no significant correlation with CD positivity (p > 0.05). Bone metastases were significantly correlated with CD positivity (p < 0.05). CD positivity showed no significant correlation with disease-free and overall survival (p > 0.05). At a median follow-up of 48 (4 years) months in CD-positive patients, overall survival was 3.17 years, and disease-free survival 2.67 years. The overall survival of CD-negative tumor patients was 3.50 years, and disease-free survival was 2.93 years. We conclude that in comparison with cytosol-based quantitative studies, CD expression is not a good prognostic marker when, as in all ICH studies, only the expression in the tumor is considered.     

Concordant CpG island methylation in hyperplastic polyposis

The CpG island methylator phenotype (CIMP) is a newly described mechanism for carcinogenesis in colorectal carcinomas and adenomas characterized by methylation of multiple CpG islands. The causes of CIMP are unknown. We studied CIMP in hyperplastic polyps (HPs), with emphasis on patients with multiple HPs (5 to 10 HPs), large HPs (one HP >1 cm) or hyperplastic polyposis (>20 HPs). Methylation of p16, MINT1, MINT2, MINT31, and hMLH1 was analyzed by methylation-specific polymerase chain reaction in 102 HPs, 8 serrated adenomas, 19 tubular adenomas, and 9 adenocarcinomas from 17 patients, with multiple/large HPs or hyperplastic polyposis and in 16 sporadic HPs from 14 additional patients. Sporadic HPs were CIMP-negative (not methylated at any locus), but 43% of HPs from multiple/large HPs, or hyperplastic polyposis were CIMP-high (two or more methylated loci, P = 0.00001). Methylation among the four loci was correlated within HPs (odds ratio, 3.41; P = 0.002), and the methylation status of HPs within the same patient was also correlated (odds ratio, 5.92; P = 0.0001). CIMP-high HPs were present primarily in patients with a predominance of HPs in the right colon and/or serrated adenomas (P = 0.0009) and were associated with the absence of K-ras proto-oncogene mutations (odds ratio, 5.08; P = 0.03). Our findings of concordant CpG island methylation of HPs in multiple/large HPs or hyperplastic polyposis supports the concept that some patients have a hypermethylator phenotype characterized by methylation of multiple HPs and other colorectal lesions. The hypermethylator phenotype is related to patient-specific factors, such as carcinogenic exposure or genetic predisposition.     

Cholinergic interactions between donepezil and prucalopride in human colon: potential to treat severe intestinal dysmotility

BACKGROUND AND PURPOSE

Cholinesterase inhibitors such as neostigmine are used for acute colonic pseudo-obstruction, but cardio-bronchial side-effects limit use. To minimize side-effects, lower doses could be combined with a 5-HT₄ receptor agonist, which also facilitates intestinal cholinergic activity. However, safety concerns, especially in the elderly, require drugs with good selectivity of action. These include the AChE inhibitor donepezil (used for Alzheimer''s disease, with reduced cardio-bronchial liability) and prucalopride, the first selective, clinically available 5-HT₄ receptor agonist. This study examined their individual and potential synergistic activities in human colon.

EXPERIMENTAL APPROACH

Neuronally mediated muscle contractions and relaxations of human colon were evoked by electrical field stimulation (EFS) and defined phenotypically as cholinergic, nitrergic or tachykinergic using pharmacological tools; the effects of drugs were determined as changes in ‘area under the curve’.

KEY RESULTS

Prucalopride increased cholinergically mediated contractions (EC₅₀ 855 nM; 33% maximum increase), consistent with its ability to stimulate intestinal motility; donepezil (477%) and neostigmine (2326%) had greater efficacy. Concentrations of donepezil (30–100 nM) found in venous plasma after therapeutic doses had minimal ability to enhance cholinergic activity. However, donepezil (30 nM) together with prucalopride (3, 10 μM) markedly increased EFS-evoked contractions compared with prucalopride alone (P = 0.04). For example, the increases observed with donepezil and prucalopride 10 μM together or alone were, respectively, 105 ± 35%, 4 ± 6% and 35 ± 21% (n = 3–7, each concentration).

CONCLUSIONS AND IMPLICATIONS

Potential synergy between prucalopride and donepezil activity calls for exploration of this combination as a safer, more effective treatment of colonic pseudo-obstruction.     

Quinolone derivatives as antitubercular drugs

New chemotherapeutic drugs are the need to improve tuberculosis (TB) control particularly due to the emergence of multidrug-resistant strains and extensively drug-resistant strains of TB. These antitubercular compounds have different chemical moieties in their structure. Quinolones are generally used against many Gram-positive and Gram-negative bacteria. They are also active against atypical mycobacteria. Some quinolones (ciprofloxacin, levofloxacin, etc.) inhibit strains of Mycobacterium tuberculosis at concentrations <2.0 μg/mL. Fluoroquinolones are an important recent addition to the drugs available for TB, especially for strains that are resistant to first-line agents. The present review provides an overview of the drugs that are being used have quinolone moieties in TB treatment.     

Prognostic Impact of Deficient DNA Mismatch Repair and KRAS and BRAF V600E Mutations in Patients with Lymph-Node-Positive Colon Cancer

Although tumor stage remains the key determinant of colorectal cancer prognosis and treatment, there is considerable stage-independent variability in clinical outcome. Molecular markers hold promise for explaining variations in clinical behavior, and may identify patient subsets with differential efficacy and survival after adjuvant chemotherapy, which is the standard of care for patients with lymph-node-positive, i.e., stage III, colon cancer. An increased understanding of the molecular evolution and progression of colorectal cancer has identified two major pathways of tumorigenesis that are characterized by chromosomal instability and by microsatellite instability. Microsatellite instability is a consequence of deficient DNA mismatch repair that is generally due to epigenetic inactivation of MLH1 in tumors that often carry mutations (V600E) in oncogenic BRAF. Activating BRAF ^V600E and KRAS mutations are mutually exclusive, and in this article, we review the current status of these mutations and the mismatch repair status as prognostic biomarkers in stage III colon cancers.