CDKN2 (MTS1) tumor suppressor gene mutations in human tumor cell lines.
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Base Sequence↗
Biomedical subjects
M McClure
Publications and source records attributed to M McClure.
CDKN2 (MTS1) tumor suppressor gene mutations in human tumor cell lines.
Tumor suppressor gene CDKN2 (also called MTS1, CDK4I and p16INK4) is located in 9p21 and deleted homozygously in a high percentage of tumor cell lines. We have examined the sequence of CDKN2 in 154 tumor cell lines that are not homozygously deleted for CDKN2. Overall, 18% (27/154) of the cell lines carried mutations in CDKN2. These mutations were found in cell lines derived from melanoma, bladder, lung and prostate cancers, as well as sarcomas of various origin. The spectrum of the CDKN2 mutations found in melanoma cell lines indicated a major role for ultraviolet light in generating the mutations, suggesting the mutations occurred in vivo. The frequency of loss of heterozygosity in 9p21 in this set of lines is only slightly higher than the background rate of aneuploidy, suggesting that a second 9p21 tumor suppressor gene, if it exists, must lie near CDKN2.
Amino Acid Sequence↗
A collaborative survey of 80 mutations in the BRCA1 breast and ovarian cancer susceptibility gene. Implications for presymptomatic testing and screening.
OBJECTIVES: To report the initial experience of an international group of investigators in identifying mutations in the BRCA1 breast and ovarian cancer susceptibility gene, to assess the spectrum of such mutations in samples from patients with different family histories of cancer, and to determine the frequency of recurrent mutations. DESIGN: Nine laboratories in North America and the United Kingdom tested for BRCA1 mutations in DNA samples obtained from a total of 372 unrelated patients with breast or ovarian cancer largely chosen from high-risk families. Three of these laboratories also analyzed a total of 714 additional samples from breast or ovarian cancer cases, including 557 unselected for family history, for two specific mutations that had been found to recur in familial samples. PARTICIPANTS: A total of 1086 women with either breast or ovarian cancer. MAIN OUTCOME MEASURE: The detection of sequence variation in patients' DNA samples that is not found in sets of control samples. RESULTS: BRCA1 mutations have now been identified in a total of 80 patient samples. Thirty-eight distinct mutations were found among 63 mutations identified through a complete screen of the BRCA1 gene. Three specific mutations appeared relatively common, occurring eight, seven, and five times, respectively. When specific tests for the two most common mutations were performed in larger sets of samples, they were found in 17 additional patients. Mutations predicted to result in a truncated protein accounted for 86% of the mutations detected by complete screening. CONCLUSIONS: The high frequency of protein-terminating mutations and the observation of many recurrent mutations found in a diverse set of samples could lead to a relatively simple diagnostic test for BRCA1 mutations. More data must be accumulated to address specifically the sensitivity and specificity of such a diagnostic testing procedure and to better estimate the age-specific risk for breast and ovarian cancer associated with such mutations.
Adult↗
MTS-1 (CDKN2) tumor suppressor gene deletions are a frequent event in esophagus squamous cancer and pancreatic adenocarcinoma cell lines.
MTS-1 is a candidate tumor suppressor gene on chromosome 9p21-22, a region frequently observed to have loss of heterozygosity in esophagus squamous cell carcinomas and pancreatic ductal adenocarcinomas. In order to determine whether MTS-1 sequences are deleted or mutated in cell lines derived from these cancers, we performed PCR amplification of MTS-1 exons 1 and 2. In this fashion, we found that 67% of esophagus squamous cancer cell lines have deletions of both exons 1 and 2, and 50% of pancreatic cancer cell lines have similar deletions. Furthermore, an additional 30% of pancreatic cancer cell lines harbored point mutations or microdeletions based on DNA sequencing. MTS-1 encodes p16, an inhibitor of cyclin-dependent kinase 4 (cdk4) which complexes with cyclin D1. Our data suggest that MTS-1 deletions and mutations may play an important role in the molecular pathogenesis of esophagus squamous cell and pancreatic cancers.
Adenocarcinoma↗
Direct mutation analysis of 495 patients for fragile X carrier status/proband diagnosis.
With the cloning of the FMR-1 gene, direct mutation analysis is possible for fragile X syndrome. We have analyzed 495 patients using the StB12.3 probe/EcoRI/EagI system of Rousseau et al. [N Engl J Med 325:1673-1681, 1991] and 167 of these also with PCR analysis according to Brown et al. [JAMA 270:1569-1575, 1993]. For 28 patients requesting carrier status due to a family history of fragile X, 10 were shown to have either premutations or full mutations; for the remainder with varied backgrounds, 1 in 182 was shown to carry a premutation. For proband diagnosis, 7 of 14 with a fragile X family history carried a full mutation; 11 of 271 with other family histories carried the full mutation.
Blotting, Southern↗
Complete detection of mutations in cystic fibrosis patients of Native American origin.
An increased incidence of cystic fibrosis (CF) has been reported in some populations of Native Americans of the Southwest such as the Pueblo, which is a genetic isolate. As the most common mutation found in Caucasians (delta F508) was absent and only one chromosome carried the G542X mutation, we decided to analyze the entire coding sequence of the CFTR gene in eight Pueblo CF patients. We have identified four different mutations: G542X, R1162X, 3849+10kbC-->T, and D648V that account for these 16 haplotypes. The R1162X was found on 11 chromosomes. Using intragenic microsatellites, we have compared the haplotypes of those chromosomes to those of Italian origin where the R1162X mutation was initially reported. These haplotypes turned out to be identical, suggesting a common origin and an admixture with Italian or Spanish settlers, followed by typical founder effect. In contrast the 3849+10kbC-->T mutation, which was found on three chromosomes, is associated with different haplotypes than those on chromosomes carrying the same mutation in Caucasians. A novel mutation, D648V, observed on one chromosome has not been found outside the Pueblo population.
Base Sequence↗
HIV quiet but not silent.
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HIV Infections↗
Cystic fibrosis genotyping by direct PCR analysis of Guthrie blood spots.
In the United States the most common cystic fibrosis (CF) alleles known are F508, G551D, G542X, R553X, and N1303K. These mutations comprise approximately 85% of U.S. CF alleles, and their detection along with analysis of XV-2C and KM-19 restriction fragment length polymorphisms (RFLPs) can enable the determination of CF status. To facilitate studies for determining CF carrier status, we developed methods to detect each of these mutations and RFLPs by direct PCR amplification of dried blood spots collected on newborn screening (Guthrie) cards. Following collection, samples were protected from contamination by individual plastic bags. One-mm2 segments of filter paper were added directly to 100-microliters PCR reactions containing 1/16 mM spermidine. Three initial cycles at 96 degrees C, then 55 degrees C, for 3 min were performed to free DNA and minimize inhibition by other related materials. Next, 1 unit of Taq polymerase was added and a 2-min extension was carried out at 72 degrees C, followed by 33 amplification cycles using denaturing, annealing, and extension temperatures and times optimal for each primer set. Then, 35 microliters of each reaction was run on 8% acrylamide gels directly or 1% agarose gels following digestion; genotypes were inferred by ethidium bromide staining of gels. Guthrie blood spots of 250 CF probands and their parents were screened and the frequencies of all five mutations as well as the XV-2C KM-19 RFLP haplotypes were determined.(ABSTRACT TRUNCATED AT 250 WORDS)
Alleles↗
Utility of internal markers to improve the accuracy of cystic fibrosis genotype analysis.
DNA diagnostic tests often utilize restriction endonuclease digestion of PCR-amplified portions of genes under analysis. When partial digestion occurs, the resulting patterns may lead to error in diagnosis. To overcome such potential errors in cystic fibrosis testing, we have developed internal markers that can increase the precision and reliability of genotype assignments.
Cystic Fibrosis↗
Mutation analysis of the cystic fibrosis transmembrane regulator gene in Native American populations of the southwest.
We report DNA and clinical analyses of cystic fibrosis (CF) in two previously unstudied, genetically isolated populations: Pueblo and Navajo Native Americans. Direct mutation analysis of six mutations of the CFTR gene--namely, delta F508, G542X, G551D, R553X, N1303K, and W1282X--was performed on PCR-amplified genomic DNA extracted from blood samples. Haplotype analyses with marker/enzyme pairs XV2c/TaqI and KM19/PstI were performed as well. Of the 12 affected individuals studied, no delta F508 mutation was detected; only one G542X mutation was found. None of the other mutations was detected. All affected individuals have either an AA, AC, or CC haplotype, except for the one carrying the G542X mutation, who has the haplotype AB. Clinically, six of the affected individuals examined exhibit growth deficiency, and five (all from the Zuni Pueblo) have a severe CF phenotype. Four of the six Zunis with CF are also microcephalic, a finding not previously noted in CF patients. Our DNA data have serious implications for risk assessment of CF carrier status for these people.
Adolescent↗
Management of epithelial ovarian neoplasms using a platinum-based regimen: a 10-year experience.
One-hundred and twenty-four patients with primary advanced (n = 103) and recurrent (n = 21) ovarian carcinoma completed a course of platinum-based chemotherapy (cyclophosphamide/doxorubicin/cisplatin or cyclophosphamide/cisplatin) or developed progressive disease while on therapy and were evaluated. All patients were treated between August 1, 1977 and December 31, 1987. The 5-year survival for patients with primary disease was 27% for stage III (n = 73) and 7% for stage IV (n = 30). The 5-year survival based on residual disease was 91% for microscopic disease (n = 13), 24% for disease less than 2 cm (n = 27), and 8% for disease greater than or equal to 2 cm (n = 64). The 5-year survival for the patients treated with recurrent disease was 5% (n = 21). Borderline tumors have been excluded. Long-term toxicity, including cardiac toxicity, renal toxicity, and a 5% incidence of second primary tumors, is evaluated.
Adult↗
Serum albumin: its relationship to marrow and renal toxicity from platinum-based combination chemotherapy.
One hundred and three patients treated with CAP chemotherapy were evaluated to determine the relationship between low prechemotherapy serum albumin (less than 3 g/dl) and low WBC nadir (less than 2000 cells/mm3). Additionally, the relationship of serum albumin to renal toxicity (delta serum creatinine) was examined. Low prechemotherapy serum albumin appears to be a marker for advanced disease, but does not appear to predict marrow or renal toxicity.
Antineoplastic Combined Chemotherapy Protocols↗
The CD4 receptor for the AIDS virus.
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Acquired Immunodeficiency Syndrome↗
Child psychiatry in Japan.
Japanese society strongly influences the mode of presentation of child mental health problems, both in terms of protective factors and pressures inherent in Japanese child-rearing practices. Recent changes in society associated with Japan's rapid economic development are affecting the mental health of children and families. Currently there is concern about levels of school refusal, bullying, suicidal behavior, and delinquency.
Child↗
Randomized trial of megestrol acetate vs. megestrol acetate/tamoxifen for the management of progressive or recurrent epithelial ovarian carcinoma.
Thirty-three patients were randomly treated with either megestrol acetate (Mg) or megestrol acetate/tamoxifen (Mg/Tx) from November, 1983, to December, 1985. Thirty-two of 33 were previously treated with platinum-based combination chemotherapy. Ten of 32 were also treated with hexamethylmelamine-based second line therapy. Doses were 160 mg/day of Mg and 20 mg/day of Tx. All patients had measurable disease. The two groups did not differ as to progression-free interval. There were no patients who demonstrated tumor regression. Overall, 39% showed stabilization of disease from 4 to 16+ months (median 8.0 months and mean 9.0 months).
Adult↗
In vitro effect of a microfibrillar collagen hemostat on platelets.
Microscopic particles of microfibrillar collagen hemostat (MCH) have been shown to pass through a 40-micron blood transfusion filter. This study indicates that MCH passing through the filter retains a significant portion of its ability to aggregate platelets in vitro and the aggregating ability is dose related. The extent of platelet aggregation in the presence of the MCH filtrate or an ADP standard was measured photometrically and log dose-response curves constructed from the data. An ED50 of 3.6 micrograms protein/ml platelet-rich plasma (PRP) was calculated at a protein concentration of 7.6 mg/ml in the MCH filtrate and an ED50 of 5.9 micrograms protein/ml PRP at 12 mg/ml protein in the MCH filtrate. The platelet aggregating ability of the MCH filtrates corresponded to 18.8 and 39.6% of the maximum response produced by adenosine-5'-diphosphate. These findings support the view that blood contaminated with MCH should not be returned to a patient's circulation.
Adenosine Diphosphate↗
Phosphonoformate (foscarnet): a pilot study in AIDS and AIDS related complex.
Phosphonoformate (PFA; a pyrophosphate analogue) is an effective inhibitor of the reverse transcriptase enzyme in many animal retroviruses. In vitro studies have shown that PFA is also an effective inhibitor of HIV (HTLV III/LAV) at doses readily attainable in vitro. A pilot study was therefore performed with a 3-week intravenous infusion of PFA in 11 patients with AIDS and AIDS-related complex (ARC). Viral isolations were performed before and at regular intervals up to 3 months post-infusion on treated patients, as well as on four untreated control patients. Virus isolation was negative after therapy in eight patients, six of whom were negative throughout the follow-up period. Virus was isolated on 70% of attempts from the four control subjects and on 20% of attempts from treated subjects. Three patients showed an improvement in delayed hypersensitivity responses. No obvious improvement was seen in patients' OKT4 positive lymphocyte counts. Treatment was not limited by side-effects with the exception of one patient who developed an axillary vein thrombosis within 4 days of treatment via a subclavian line. Treatment was therefore discontinued following administration of only one dose and the patient was excluded from further study. A further patient had reversible renal dysfunction. Other side-effects were minor, consisting of headache or thrombophlebitis at the site of infusion. These results suggest that a further trial with PFA administered over a longer period and with a longer follow-up period in AIDS and ARC patients may be warranted, particularly if an oral preparation becomes available.(ABSTRACT TRUNCATED AT 250 WORDS)
AIDS-Related Complex↗