Quantitative analysis of mutant p53 protein in breast tumor cytosols and study of its association with other biochemical prognostic indicators in breast cancer

Breast tumors are thought to originate, grow, and metastasize in an environment which includes steroid hormone receptors, their cognate steroid ligands, and many gene products which are regulated by steroid hormone receptor-ligand complexes. In this paper we describe highly sensitive and quantitative immunofluorometric procedures for measuring three proteins that are candidate prognostic indicators in breast cancer, namely, the p53 tumor suppressor gene product, carcinoembryonic antigen (CEA), and prostate specific antigen (PSA). These proteins were quantified in over 950 cytosolic tumor extracts along with estrogen and progesterone receptors (ER, PR). Association analysis between all five biochemical parameters revealed strong negative associations between p53 and receptors and strong positive associations between CEA and receptors. Negative associations between p53 and CEA and between CEA and PSA were also found. These associations, not quantitatively studied in previous reports, are related to each other using a hypothetical model. The observed associations may further contribute to the understanding of the biology of breast tumors.     

TA repeat polymorphism of the 5alpha-reductase gene and breast cancer.

There is increasing evidence that androgens play a significant role in the development and progression of breast cancer. 5alpha-Reductase (SRD5A2) is an enzyme that is expressed in androgen-dependent tissues, and it catalyzes the reduction of testosterone to its more bioactive form, dihydrotestosterone, which then transactivates a number of genes. One of these genes encodes for prostate-specific antigen (PSA), a favorable prognostic factor in breast cancer. The 3' untranslated region of the SRD5A2 gene contains either no TA repeats [(TA)0] or 9 [(TA)9] or 18 [(TA)18] repeats. Variations in the length of these dinucleotide repeats have been reported to influence the enzymatic activity of SRD5A2. In this study, we determined the TA genotypes in DNA from 141 well-characterized breast tumors and in DNA from whole blood of 70 women without cancer. The presence of TA genotypes was then associated with tumor cytosolic PSA concentrations and with clinicopathological variables, including disease-free survival and overall survival. Three genotypes, (TA)0 homozygote, (TA)0/(TA)9 heterozygote, and (TA)9 homozygote, were identified. No (TA)18 alleles were detected in any of the two patient groups. A statistically significant association between high PSA concentrations and (TA)0/(TA)9 or (TA)9 genotypes was observed (P = 0.004). (TA)0/(TA)9 or (TA)9 genotypes were found less frequently in patients at stage III or IV disease. TA genotypes were not associated with other clinicopathological variables by contingency table analysis. Patients with (TA)0/(TA)9 or (TA)9 repeats, when compared to those with genotypes homozygous for the (TA)0 allele, showed a significant reduction in the risk for relapse (P = 0.043). Long-term studies are needed to investigate the relevance of this polymorphism to breast cancer susceptibility.     

Maternal serum prostate-specific antigen and Down syndrome in the first and second trimesters of pregnancy. International Prenatal Screening Research Group.

It has been suggested that high levels of maternal serum prostate-specific (PSA) may be associated with fetal Down syndrome. We retrieved stored blood samples from 102 singleton Down syndrome pregnancies at 8-14 weeks' gestation and 99 at 15-22 weeks' gestation, together with samples from five unaffected singleton control pregnancies matched for gestational age. PSA was measured using an ultrasensitive assay. Contrary to earlier reports, PSA levels were similar in affected and unaffected pregnancies in both the first and second trimester of pregnancy; 1.1 and 0.9 multiple of the normal median, respectively, in affected pregnancies. There was no indication that PSA would be a useful screening marker.     

Quebec platelet disorder: features, pathogenesis and treatment.

Quebec platelet disorder (QPD) is a rare, autosomal-dominant, inherited bleeding disorder that is associated with unique abnormalities in fibrinolysis. Its hallmark features are delayed-onset bleeding following hemostatic challenges that responds to fibrinolytic inhibitor therapy and increased expression and storage of the fibrinolytic enzyme urokinase plasminogen activator in platelets, without increased plasma urokinase plasminogen activator or systemic fibrinolysis. The increased urokinase plasminogen activator in QPD platelets is only partially inhibited, and, as a result, there is intraplatelet generation of plasmin, and secondary degradation of many platelet alpha-granule proteins. During clot formation, the urokinase plasminogen activator released by QPD platelets leads to platelet-dependent increased fibrinolysis, and this is postulated to be a major contributor to QPD bleeding. The focus of the present review is to summarize the current state of knowledge on QPD, including the history of this disorder, its clinical and laboratory features, and recommended approaches for its diagnosis and treatment.     

Enhanced prediction of breast cancer prognosis by evaluating expression of p53 and prostate-specific antigen in combination.

p53 gene mutation is the most common genetic alteration in neoplastic diseases, including breast cancer, for which p53 alteration may indicate poor prognosis. Recent clinical evidence suggests that prostate-specific antigen (PSA) expression may identify breast cancer patients with favourable outcome. Assessment of p53 and PSA in combination, potentially offering improved prediction, has not yet been performed. Extracts from 952 primary breast carcinomas were assayed for PSA and p53 by quantitative enzyme-linked immunosorbent assays (ELISAs) developed by the authors. Concentrations of each marker were classified as negative or positive on the basis of median and 30th percentile cut-off points for p53 and PSA respectively. Patients followed for a median of 6 years having different combinations of negative or positive status for PSA and p53 were compared with respect to the relative risks (RRs) for relapse and death by Cox proportional hazards regression analysis, in which an interaction term was also evaluated, and with respect to disease-free survival (DFS) and overall survival (OS) probabilities by Kaplan-Meier plots and log-rank tests. Multivariate models were adjusted for oestrogen and progesterone receptor status, nodal status, patient age, tumour size, DNA ploidy, S phase fraction and receipt of chemotherapy. Interactions were not found between the status of PSA and p53 in the Cox models, in which PSA-negativity (RR = 1.47, P = 0.020 for DFS, and RR = 1.49, P = 0.023 for OS) and p53-positivity (RR = 1.46, P = 0.017 for DFS, and RR = 1.41, P = 0.033 for OS) were individually associated with prognosis. Evaluation of a combined three-level variable revealed that PSA(-)/p53(+) patients had significantly higher risks for relapse (RR = 2.13, P < 0.001) and death (RR = 2.08, P = 0.001) than PSA(+)/p53(-) patients, and that patients positive or negative for both markers had intermediate risks for the outcome events in the same multivariate analysis (RR = 1.45 for both DFS and OS). The results of our study demonstrate that the assessment of combined PSA and p53 expression status by ELISAs, easily applicable to breast tumour extracts prepared for steroid hormone receptor analyses, may stratify breast cancer patients into groups differing by relapse and death risks of greater magnitude than offered by the assessment of either p53 or PSA alone.     

Nidogen-2: A new serum biomarker for ovarian cancer

Objectives:New ovarian cancer biomarkers suitable for early disease diagnosis, prognosis or monitoring could improve patient management and outcomes.Design and Methods:Nidogen-2 was measured by immunoassay in serum of 100 healthy women, 100 women with benign gynecological conditions and 100 women with ovarian carcinoma.Results:Serum nidogen-2 concentration between normal and benign disease patients was not different (median, 13.2 and 12.1 mg/L, respectively). However, nidogen-2 concentration in serum of ovarian cancer patients was elevated (median, 18.6 mg/L; p < 0.0001). Both nidogen-2 and CA125 were elevated more in serous histotypes of ovarian cancer and late state disease. Nidogen-2 and CA125 concentrations were strongly correlated. ROC curve analysis for nidogen-2 had an area under the curve (AUC) ranging from 0.73 to 0.83 but CA125 was superior (AUC ranging from 0.87 to 0.99). There was no complementarity between the two markers.Conclusions:Nidogen-2 is a new biomarker for ovarian cancer which correlates closely with CA125.     

Human tissue kallikrein expression in the stratum corneum and serum of atopic dermatitis patients

Human tissue kallikreins are a family of 15 trypsin- or chymotrypsin-like secreted serine proteases (KLK1-KLK15). Many KLKs have been identified in normal stratum corneum (SC) and sweat, and are candidate desquamation-related proteases. We report quantification by enzyme-linked immunosorbent assay (ELISA) of KLK5, KLK6, KLK7, KLK8, KLK10, KLK11, KLK13 and KLK14 in the SC and serum of atopic dermatitis (AD) patients by ELISA, and examine their variation with clinical phenotype, correlation with blood levels of eosinophils, lactate dehydrogenase (LDH) and immunoglobulin E. The overall SC serine protease activities were also measured. In the SC of AD, all KLKs, except KLK11, were significantly elevated. The elevation of chymotrypsin-like KLK7 was predominant, compared with trypsin-like KLKs. The SC overall plasmin- and furin-like activities were significantly elevated, while trypsin- and chymotrypsin-like activities did not differ significantly. In the serum of AD patients, KLK8 was significantly elevated and KLK5 and KLK11 were significantly decreased. However, their serum levels were not modified by corticosteroid topical agents. The alterations of KLK levels in the SC of AD were more pronounced than those in the serum. KLK7 in the serum was significantly correlated with eosinophil counts in the blood of AD patients, while KLK5, KLK8 and KLK11 were significantly correlated with LDH in the serum. In conclusion, we report abnormal kallikrein levels in the SC and the serum of AD patients. KLKs might be involved in skin manifestation and/or focal/systemic inflammatory reactions in AD. Our data may contribute to a better understanding of the pathogenesis of AD.     

Co-expression of KLK6 and KLK10 as prognostic factors for survival in pancreatic ductal adenocarcinoma

Kallikreins play an important role in tumour microenvironment and as cancer biomarkers in different cancer entities. Previous studies suggested an upregulation of KLK10 and KLK6 in pancreatic ductal adenocarcinoma (PDAC). Therefore, we evaluated the clinicopathological role of these kallikreins and their value as biomarkers in PDAC.Differential expression was validated by DNA-microarrays and immunohistochemistry in normal and malignant pancreatic tissues. Sera concentrations of both kallikreins were evaluated using ELISA. In silico analysis of possible protein interactions and gene silencing of KLK10 in vitro using siRNAs gave further insights in the pathomechanisms.Gene expression analysis and immunohistochemistry demonstrated a strong expression for KLK10 and KLK6 in PDAC. Statistical analysis showed that co-expression of these kallikreins correlated with an R1-resection status (P=0.017) and worse outcome for overall survival (P=0.031). Multivariate analysis proofed that co-expression is an independent prognostic factor for survival (P=0.043). Importantly, KLK10 knockdown in AsPC-1 cells significantly reduced cell migration, whereas computational analysis suggested interaction of KLK6 with angiogenetic factors as an important mechanism.Co-expression of KLK10 and KLK6 plays an unfavourable role in PDAC. Our results suggest that this effect is likely mediated by an interaction with the factors of the extracellular matrix and enhancement of cancer cell motility.