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W P Carney

Publications and source records attributed to W P Carney.

At least 19 recordsLinked to original sources
PubMed1998

Molecular epidemiology of p53 protein mutations in workers exposed to vinyl chloride.

The production of mutations in cellular tumor suppressor genes such as p53 is involved in the development of many human cancers. These mutations result in the expression of mutant forms of the encoded p53 protein which can potentially serve as a biomarker for this carcinogenic process. Workers exposed to vinyl chloride who are at risk for the development of the sentinel neoplasm angiosarcoma of the liver represent a model population for the study of such a mutant p53 biomarker, since vinyl chloride is known to cause specific p53 mutations in persons with angiosarcoma of the liver. To determine the relation between vinyl chloride exposure and this p53 biomarker, the authors examined serum samples collected between 1987 and 1992 from a cohort of 225 French vinyl chloride workers and 111 unexposed controls (matched according to age, sex, race, smoking, and alcohol drinking) for the presence of mutant p53 protein, using an enzyme-linked immunosorbent assay. Stratification of the exposed workers by quartile of vinyl chloride exposure (in estimated ppm-years) yielded a statistically significant trend of increasing odds ratios for p53 biomarker seropositivity with increasing exposure. These results suggest that this serum biomarker for mutant p53 protein is related to vinyl chloride exposure and may be an early indicator of carcinogenic risk in exposed individuals.

Adult↗
PubMed1998

ErbB-2 protein in sera and tumors of breast cancer patients.

We compared levels of erbB-2 oncoprotein among three groups: Group I included 60 asymptomatic women; Group II had 51 women with benign breast biopsies; and Group III had 67 women with node-negative breast cancer. Serological levels of erbB-2 protein were measured in all participants; tumor levels were measured for Groups II and III. Forty-three percent of usable tumors (25/58), including three of seven lobular tumors, were erbB-2 positive. Tumor and blood oncoprotein levels were unrelated. Blood levels, however, were positively related to tumor volume, but only when the tumor had both a ductal carcinoma in situ (DCIS) component and an invasive component, suggesting a role for erbB-2 protein in progression of DCIS to invasive carcinoma. In Groups I and II serological levels of erbB-2 protein were directly related to age, and inversely related to having had a live birth. Therefore, a model that determined the threshold levels of serological erbB-2 positivity in Group III included age and nulliparity as independent variables. Only three of the 67 women (4.5%) in Group III were positive for serological erbB-2. In a multivariate model, with serological erbB-2 as the dependent variable, and in which the independent variables included Study Group, there was a statistical trend for younger women, in which Group III had the highest serological levels of erbB-2, followed by Group II, and then Group I. In women who were over the age of 50 years the trend was reversed; i.e., levels of erbB-2 tended to be lowest in Group III, followed by Group II, and finally Group I.

Age Factors↗
PubMed1997

Epitopic characterization of the human wild-type and mutant ras proteins using membrane-bound peptides.

Overlapping octapeptides encompassing the entire sequences of the human oncogene products Ha-ras, K-ras and N-ras protein were synthesized as spots on polypropylene membrane sheets. The binding of anti-ras protein monoclonal antibodies (mAbs) to the membrane-bound peptides was assessed using an enzyme-linked immunosorbent assay. Epitopes of 10 of 18 mAbs to the human ras proteins were mapped and identified by this procedure. The epitopes of nine of the mAbs are within residues 28-39 in the constant domain common to the three ras proteins, whereas the epitope of the tenth (mAb 21) spans residues 136-144 in Ha-ras. The minimal lengths of epitopes of all ten of the mAbs were further precisely mapped using peptides of varying length, and the tolerance for mAb binding of mutated epitopes was determined by systematically replacing each residue in the epitope with each of the 20 common amino acids. The results show that most of these mAbs have essentially the same binding specificity, namely for the sequence YDPT (residues 32-35) or for slightly longer sequences containing these residues. This site is in the switch 1 region (residues 32-38) in the ras effector loop, indicating that some of the same residues important for the interaction of ras with other proteins (GTPase-activating protein, neurofibromin or raf) are highly antigenic. In addition, we investigated epitopes and specificity of five mAbs against the activated human ras proteins by the same procedure. The information gained from this study should be useful both for study of the complicated functions of ras proteins and clinical detection of ras oncogenes in human tumor cells.

Amino Acid Sequence↗
PubMed1995

Detection of p21ras mutations in colorectal adenomas and carcinomas by enzyme-linked immunosorbent assay.

BACKGROUND: Point mutations of the ras protooncogene, primarily within codons 12 and 13, are commonly identified in colorectal carcinomas and large adenomas. Despite data suggesting that ras genotyping may have clinical significance with respect to colorectal cancer screening and prognosis, more widespread use has been limited because of the lack of a suitable assay system. The principal objective of this study was to assess the feasibility and validity of a qualitative enzyme-linked immunosorbent assay (ELISA) for detecting the four most common ras mutations in human colorectal tumors at the protein (p21ras) level. METHODS: Tissue homogenates (11-121 micrograms) from endoscopically or surgically resected colorectal adenomas, carcinomas, and normal mucosae were evaluated by a commercially available ELISA (Oncogene Science, Inc. Cambridge, MA) for mutant p21ras containing arginine position 12 (arg12), valine position 12 (val12), aspartate position 12 (asp12), and aspartate position 13 (asp13) amino acid substitutions. Portions of the same tissue from an initial series of 27 specimens also were subjected to mutant-enriched polymerase chain reaction (PCR) and/or PCR amplification with subsequent DNA sequence analysis to validate the ELISA data. RESULTS: Forty-seven adenomas, 9 carcinomas, and 14 normal mucosae were assayed. Mutations were identified in 16 (34%) of the adenomas (7-asp12, 7-val12, 2-asp13), 3 (33%) of the carcinomas (1-asp12, 1-arg12, 1-asp13), and none of the normal mucosae by ELISA: Polymerase Chain Reaction and DNA sequencing analyses demonstrated identical results for 21 of the 23 (91%) and 14 of 16 (88%) homogenates tested, respectively. The ELISA demonstrated an overall sensitivity of 80-86%, specificity of 90-92%, positive predictive value of 86-100%, and negative predictive value of 86-91%. CONCLUSIONS: The ELISA is a feasible and valid approach for identifying p21ras mutations in human colorectal adenomas and carcinomas.

Adenoma↗
PubMed1995

Levels of p53 antigen in the plasma of patients with adenomas and carcinomas of the colon.

Plasma levels of p53 protein were examined by an enzyme linked immunosorbent assay in 184 patients enrolled in a colonoscopy study. The mean levels among 47 individuals with normal colonoscopic examinations and no prior history of colonic neoplasia (0.12 ng/ml) and among 61 individuals with normal colonoscopic examinations and a prior history of colonic neoplasia (0.09 ng/ml) were similar. However, the mean levels among 54 individuals with newly diagnosed colonic adenomas (0.44 ng/ml) and 22 individuals with newly diagnosed colonic carcinomas (0.55 ng/ml) were statistically significantly elevated compared to the normal controls (P < 0.02). Among these tumor patients, the plasma levels tended to increase with increasing adenoma size and with increasing carcinoma stage, although these trends were not statistically significant. Defining a significant positive plasma level as any value greater than ten times background, the percentage of positive samples increased from 4% in the controls to 20% in the adenoma cases to 32% in the carcinoma cases. These results demonstrate that plasma p53 protein levels are elevated in a subgroup of individuals with colonic neoplasia.

Adenoma↗
PubMed1995

Parasitized erythrocyte membrane antigens of Plasmodium brasilianum: relationships with the ring-infected erythrocyte surface antigen of Plasmodium falciparum.

An antigen, designated here as the parasitized erythrocyte membrane antigen (PEMA), is present in the erythrocyte membrane surrounding all intraerythrocytic stages of Plasmodium brasilianum. An antibody specific for PEMA appeared in 21 (50%) of 42 antisera from Saimiri sciureus monkeys naturally infected with P. brasilianum. Of these 42 sera, nine (21.4%) contained antibody to the ring-infected erythrocyte membrane antigen (RESA); of these nine sera, six did not react with PEMA. Sera of humans infected with P. malariae reacted with PEMA and RESA in a similar pattern; i.e., of 83 antisera, 71 (85.5%) reacted with PEMA and 30 (36%) reacted with RESA. Only one of these latter 30 sera were not reactive with PEMA. Of 167 sera from humans infected with P. falciparum but not P. malariae, 133 (79.6%) reacted with RESA; of these, 43 (25.7% of the total) reacted with PEMA but not RESA. Although PEMA was demonstrated with P. brasilianum and RESA with P. falciparum, neither PEMA or RESA could be demonstrated with P. malariae. Interactions of PEMA and RESA and the corresponding antibodies offer a method whereby the two morphologically similar quartan species, P. malariae and P. brasilianum, can be readily distinguished from each other and may furnish clues to genetic separation of the two and the mechanisms of interaction of quartan malaria and P. falciparum where they are coendemic.

Animals↗
PubMed1994

Correlations of chronic hepatitis B virus infection and cigarette smoking with elevated expression of neu oncoprotein in the development of hepatocellular carcinoma.

To investigate the potential role of neu oncogene expression in hepatocarcinogenesis, a nested case-control study was conducted within a cohort of 9691 male adults in Taiwan. Blood samples of study subjects were collected during 1984-1986 and frozen at -30 degrees C until subsequent analysis. The neu oncoprotein level in the stored serum was measured by an enzyme-linked immunosorbent assay for 27 cases of newly developed hepatocellular carcinoma (HCC), 12 liver cirrhosis cases, and 40 healthy controls. The mean level of neu oncoprotein was significantly higher in HCC and liver cirrhosis cases than in controls. The risk of HCC increased significantly with increasing serum level of neu oncoprotein (trend test, P = 0.02). The proportion of subjects having an elevated serum level of neu oncoprotein, defined as a level greater than the mean level of all controls, was significantly higher among asymptomatic HBsAg carriers than noncarriers (P = 0.05), showing a multivariate-adjusted odds ratio of 4.0. Among HCC cases, a strong association was observed between cigarette smoking and elevated prediagnostic serum level of neu oncoprotein. The association remained highly significant (P = 0.017) even when adjustment was made for potential confounders. The multivariate-adjusted odds ratio of having an elevated serum level of neu oncoprotein, defined as a level greater than the mean plus 1 SD of control levels, for HCC cases who smoked more than 10 cigarettes a day was as high as 386.5 compared with the cases who smoked less than 10 cigarettes a day or nonsmoking cases. The results suggest that both HBsAg carrier status and cigarette smoking are related to the increased expression of neu oncogene, and cigarette smoking seems to play a significant role in the latter stages of hepatocarcinogenesis. There was no association between alcohol drinking and serum neu oncoprotein level.

Adult↗
PubMed1994

Detection of increased amounts of the extracellular domain of the c-erbB-2 oncoprotein in serum during pulmonary carcinogenesis in humans.

Over-expression of the c-erbB-2 oncogene-encoded p185 protein product has been implicated in the pathogenesis of a wide variety of human malignancies, including lung cancer. Over-expression of p185 can be detected immunologically by quantification of the extracellular domain of p185 (c-erbB-2 oncopeptide) in extracellular fluid in vitro and in serum in vivo. An enzyme-linked immunosorbent assay (ELISA) for the c-erbB-2 oncopeptide was used to examine banked serum samples of 11 pneumoconiosis patients who subsequently developed lung cancer and serum samples from 11 hospital controls matched for age, sex, ethnic group and smoking as well as 55 unmatched general population controls. The mean serum level for the c-erbB-2 oncopeptide in human neu units/ml in the lung cancer cases (1,756 +/- 549 HNU/ml) was statistically significantly elevated (p < 0.001) in comparison to the mean level in the matched controls (976 +/- 488 HNU/ml) or the general population controls (888 +/- 655 HNU/ml). Defining a positive elevation of the serum c-erbB-2 oncopeptide as any value more than 2 standard deviations above the mean of the matched controls, 64% (7 of 11) of the lung cancer cases were positive compared to 0% (0 of 11) matched controls and 5% (3 of 55) of the unmatched controls. In addition, 4 of the 7 c-erbB-2 oncopeptide-positive cancer cases had positive serum samples prior to the time of disease diagnosis (average = 35 months). These results suggest that serum c-erbB-2 oncopeptide may be elevated at an early stage of pulmonary carcinogenesis and that further prospective study of the utility of this biomarker is warranted.

Aged↗
PubMed1994

Mutant c-Ki-ras p21 protein in chemical carcinogenesis in humans exposed to vinyl chloride.

Mutations in ras oncogenes and expression of their encoded p21 protein products are believed to play an important role in carcinogenesis in humans. Detection of mutant p21 proteins in serum may be a useful molecular epidemiologic biomarker with which to study this process, and workers with heavy exposure to vinyl chloride (VC) represent a model population for such study. We studied the occurrence of a specific ras mutation (Asp 13 c-Ki-ras) by oligonucleotide hybridization and the expression of the corresponding p21 protein in tumor tissue and serum by immunohistochemistry and immunoblotting with monoclonal antibodies in five individuals with heavy exposure to VC and resultant angiosarcomas of the liver (ASL). Four of five (80 percent) of the cases of ASL were found to contain the mutation and to express the corresponding mutant protein in their tumor tissue and serum. Serum expression of the mutant protein also was examined in nine VC-exposed workers with liver angiomas and 45 VC-exposed workers with no evidence of liver neoplasia; eight of nine (89 percent) of the former and 22 of 45 (49 percent) of the latter were also positive for the mutant p21 in their serum. However, serum immunoblotting results for 28 age-gender-race matched, unexposed controls were all negative. Stratification by years of VC exposure showed a significant linear trend (P < 10(-5)) for the occurrence of the serum mutant p21 protein with increasing duration of exposure. These results suggest that detection of serum mutant p21 protein can be a valid surrogate for ras gene expression at the tissue level.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

The detection of increased amounts of the extracellular domain of the epidermal growth factor receptor in serum during carcinogenesis in asbestosis patients.

Overexpression of the epidermal growth factor receptor (EGFr) has been implicated in the pathogenesis of a wide variety of human malignancies and may be related to asbestos-induced carcinogenesis. Overexpression of the EGFr can be detected immunologically by quantitation of the extracellular domain (ECD) in the extracellular fluid in vitro and in serum in vivo. An enzyme-linked immunosorbent assay (ELISA) for the EGFr ECD was used to examine banked serum samples of 38 asbestosis patients who subsequently developed cancer, 72 age-sex-race-smoking-asbestos exposure matched asbestosis controls without cancer, and 20 age-sex-race-smoking matched nonasbestosis noncancer controls. The mean serum level for the EGFr ECD in the cancer cases (636 +/- 299 fmol/ml) was statistically significantly elevated (P < 0.05) in comparison to the mean level in the asbestosis controls (546 +/- 147 fmol/ml) or the nonasbestosis controls (336 +/- 228 fmol/ml). Defining a positive elevation of the serum EGFr ECD as any value more than 2 standard deviations above the nonasbestosis control mean, 7 (18%) of the cancer cases were positive compared to 4 (6%) of the asbestosis controls and one (5%) of the nonasbestosis controls. In addition, all of these cancer cases had positive serum samples prior to the time of disease diagnosis (average = 5.1 years). These results suggest that serum EGFr ECD may be elevated at an early stage of carcinogenesis in some asbestosis patients and that further prospective study of the utility of this biomarker is warranted.

Adult↗
PubMed1994

The c-erbB-2 protein in oncogenesis: molecular structure to molecular epidemiology.

The c-erbB-2 (HER-2, neu) oncogene has been implicated frequently in many human tumors. This oncogene codes for a 185-kDa protein that functions as a transmembrane growth factor receptor. Overexpression of the normal protein or point mutations in the transmembrane domain of the protein have been shown to have a transforming effect. Molecular structure studies of the transmembrane domain provide a plausible explanation for this transforming effect in both cases and relate this to the process of receptor dimerization in the membrane, degradation of the protein with release of the extracellular domain (ECD) into the extracellular environment, and aberrant signal transduction. The release of the ECD into the extracellular environment provides a potential biomarker for the study of signal transduction at the molecular level in vivo. The ECD can be quantitated immunologically in the serum of individuals with cancers associated with p185 overexpression and in individuals at risk for the development of such cancers and can be used to distinguish these individuals from normal, healthy controls. Identification of such individuals by their serum ECD levels combined with specific chemotherapeutic/chemoprophylactic interventions could allow for improvement treatment and prevention of c-erbB-2-related cancers.

Amino Acid Sequence↗
PubMed1993

Detection of c-erbB-2 oncoprotein expression in breast tissue by multiparameter flow cytometry.

A novel technique in multiparameter flow cytometry (FCM) using dual laser excitation of three fluorescent dyes has been developed to differentiate breast epithelial cells from stromal components. This technique has been applied to determine the expression of the oncoprotein c-erbB-2 in breast epithelial tumors. SK-BR-3, a breast cancer cell line with c-erbB-2 overexpression, can be identified by FCM from a mixed cell suspension using a monoclonal anti-human cytokeratin antibody conjugated with fluorescein isothiocyanate. Using the mouse monoclonal anti-c-erbB-2 antibody, TA-1 (4.8 +/- 1.0 x isotype control), the c-erbB-2 oncoprotein overexpression in breast epithelial cells can be detected as an increase in indirect blue fluorescence by aminomethyl coumarin. MCF-7, a breast cancer cell line with normal c-erbB-2 expression, has baseline blue fluorescence (1.0 +/- 0.5 x isotope control). Twenty-one fresh breast specimens have been examined by FCM. Overexpression of c-erbB-2, defined by blue fluorescence ratio of TA-1/isotype control > or = 1.5 (> 3 SD from baseline), is detected in 0 of 3 patients with Stage I cancer, 5 of 14 patients with Stage II and III cancer, and 3 of 4 patients with proliferative disease. Patients with elevation of oncoprotein detected by FCM have corresponding RNA overexpression detected by Northern blot hybridization and increased gene amplification detected by Southern blot hybridization. FCM allows for the simultaneous identification of breast epithelial cells and the selective examination of these cells for the expression of c-erbB-2 oncoprotein, thus minimizing stromal contamination. This represents a novel application of FCM with potential for wide clinical applicability.

Biomarkers, Tumor↗
PubMed1992

The pathobiology of salivary gland. II. Morphological evaluation of acinic cell carcinomas in the parotid gland of male transgenic (MMTV/v-Ha-ras) mice as a model for human tumours.

In the transgenic TG.SH (mouse mammary tumour virus/v-Ha-ras) mouse, designed to develop mammary tumours, occasional spontaneous salivary gland tumours have been reported, predominantly in males. The incidence and histomorphology of salivary gland tumours in 73 TG.SH mice were surveyed and in total, 21.9% developed both overt and microscopic parotid tumours. The majority developed between 73 and 150 days of age. In 31.5% of the TG.SH mice, occasional unilateral, but more frequently bilateral exophthalmos due to hyperplasia of the intraorbital (Harderian) lacrimal gland was observed. In 70% of these animals, parotid tumours developed later. Since Harderian gland hyperplasia, occurring as early as 5 weeks of age, preceded the development of palpable salivary gland lesions, this stigma is useful for the early selection of animals likely to progress to tumour formation. Before tumour-bearing transgenic mice are considered to be suitable models of human neoplastic disease, morphological characterization is necessary to ensure that the tumours are histologically representative of the human lesions for which they are potential models. In this study, all parotid tumours consisted of acinar-like glandular structures with central lumina discernible by electron microscopy. Ultrastructurally, secretory granules evident in the apical cytoplasm of the tumour cells resembled the zymogen granules of the normal parotid acinar cell, and some cells had a prominent complement of rough endoplasmic reticulum. These features, along with focal amylase expression detected immunohistochemically in some parotid tumours, identified these neoplasms as acinic cell carcinomas that mimic the human salivary gland acinic cell carcinoma faithfully.

Animals↗
PubMed1992

Neu oncogene expression in ovarian tumors: a quantitative study.

We studied neu mRNA expression by slot blot analysis and protein product expression by capture ELISA and immunohistochemistry in 57 primary and metastatic ovarian neoplasms, two paraovarian leiomyosarcomas, and eight normal ovaries. Some 61% of ovarian tumors but none of the paraovarian neoplasms or normal ovaries overexpressed neu mRNA. A total of 96% of the ovarian tumors that overexpressed neu were of epithelial type. Epithelial ovarian tumors had significantly higher amounts of the neu oncogene product as determined by capture ELISA than either germ cell and stromal tumors or normal ovaries (p less than 0.025). Different subtypes of ovarian carcinomas had significantly different amounts of neu oncogene product as measured by capture ELISA; endometrioid tumors had the highest, and poorly differentiated carcinomas not otherwise specified had the lowest (p less than 0.025). ELISA values, mRNA overexpression, and immunohistochemical staining intensity did not correlate with stage at diagnosis or architectural or nuclear grade in ovarian tumors. We conclude that capture ELISA is a simple, effective way to measure the neu oncogene protein product and that there is a good correlation between ELISA levels and immunohistochemical staining intensity. However, ELISA values did not correlate with stage or histologic prognostic factors in ovarian neoplasms.

Carcinoma↗
PubMed1991

Production and characterization of monoclonal antibodies to Ha-ras and N-ras p21.

The mammalian ras family consists of the Ha, Ki and N-ras genes that encode a series of 21,000 dalton proteins (p21). The three ras proteins participate in normal cell physiology and have been implicated in cellular transformation by either overexpression of the normal p21 or by mutation at positions 12, 13, or 61. To help understand the biological roles of the different ras proteins, we have generated monoclonal antibodies (Mabs) to the Ha-ras and N-ras p21. Mab Ha-770, raised to a Ha-specific synthetic peptide, reacts with Ha-ras recombinant p21 (r-p21) as well as cellular Ha-ras p21 by immunoprecipitation. Western blot and sandwich ELISA assays. Mab N-838, raised to an N-ras specific synthetic peptide, reacts with the N-ras recombinant p21 by immunoprecipitation, Western blot and sandwich ELISA assays. Mabs to the Ha-ras and N-ras p21 should be valuable reagents in assessing the individual roles of ras proteins in normal and neoplastic cells.

Amino Acid Sequence↗
PubMed1991

Generation of monoclonal antibodies specific for ras p21 Glu-12 oncoproteins: detection in carcinogen-induced mammary carcinomas.

ras genes have been shown to become oncogenes by single point mutations which result in amino acid substitutions that affect either their GTPase activity (positions 12, 13, 59, 61) or their affinity for GTP and GDP. Ras oncogenes and their corresponding proteins have been described in a variety of human cancers as well as in animal tumors induced by physical and chemical carcinogens. One of these animal tumor systems involves the induction of mammary carcinomas in rats by a single dose of N-nitroso-N-methylurea (NMU), a methylating carcinogen. These NMU-induced mammary carcinomas contain transforming H-ras genes activated by G----A transitions in the second nucleotide of their 12th codon, presumably a consequence of the pre-mutagenic lesions induced by NMU. These G----A mutations result in the replacement of the normal glycine in the 12th position of the ras p21 protein by a glutamic acid residue. In this study, we report the generation of monoclonal antibodies (Mab) reactive with oncogenic ras p21 proteins containing glutamic acid at position 12 (p21 Glu-12). Mab designated E184 specifically recognized activated ras p21 Glu-12 proteins but not normal p21 (Gly-12) or p21 proteins activated by other position 12 substitutions including arginine, aspartic acid, cysteine, valine or serine residues. Western blot analysis of NMU-induced mammary carcinomas demonstrated that Mab E184 recognized p21 proteins expressed in these rat tumors but not p21 present in normal tissues nor in other carcinogen-induced tumors known to carry H-ras oncogenes activated by mutations at position 61.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗