Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0242379 (lung cancer)
 71,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent developments in the molecular genetics of human cancers shows the importance of multiple genetic alterations in the pathogenesis of these lesions. DNA diagnostic techniques are being introduced rapidly into the clinical laboratory setting. 1) In lung cancer, several oncogenes and tumor suppressor genes, such as ras, myc, p53, RB, allelic loss of chromosomes, play very important roles. These genetic changes are being applied to cancer diagnosis, prediction of prognosis or disease metastasis, or response to treatment. 2) Drug resistance is one of the major problems of current lung cancer chemotherapy. Identification of the molecular marker for drug resistance, like DNA topoisomerase gene mutation, in clinical samples will be of great help for choosing chemotherapy regimens. 3) Interindividual differences in susceptibility to lung cancer may be screened using genotyping of the P450IA1 and GSTmu genes. To develop newer diagnostic and therapeutic approaches, detailed investigation of the molecular pathogenesis of lung cancer using clinical samples is essential. I review the present status on these applications of genetic markers to lung cancer diagnosis in this article.
 ...
PMID:[Application of molecular diagnosis to human lung cancer]. 747 38

Inactivation of the p53 tumor suppressor gene has been reported to be a prognostic factor in several human cancer types. Normal function of the gene is affected by deletion in one allele; dysfunction of the other allele is often caused by a mutation. In tumors of heterozygous individuals, deletion of one allele can be detected as loss of heterozygosity (LOH). A recently found variable number of tandem repeats (VNTR) segment in intron 1 of the p53 gene seems to be highly polymorphic and, therefore, a very useful marker in detecting LOH in various types of tumor samples. We in vitro amplified the VNTR segment from genomic DNA samples of 101 lung cancer patients and run conventional agarose gel electrophoreses in order to detect the alleles of various length, differing by the number of repeats. The usefulness of the method was studied using DNA from white blood cell samples and from fresh and formalin-fixed, paraffin-embedded tumor samples. Of the patients, 56% were found to have two different alleles, i.e. were informative in this assay. In 18% of the lung tumors from the informative cases, LOH in the p53 suppressor gene was detected.
 ...
PMID:Detection of loss of heterozygosity in the p53 tumor suppressor gene using a PCR-based assay. 747 57

Antibodies specific for human p53 were analysed in sera of lung cancer patients. We detected p53 antibodies in the sera of 24% (10/42) of patients with lung carcinoma. The distribution was as follows: 4/9 small-cell lung carcinomas (SCLCs), 2/18 squamous cell lung carcinomas (SCCs), 2/10 adenocarcinomas (ADCs) and 2/5 large-cell lung carcinomas (LCCs). p53 antibodies were always present at the time of diagnosis and did not appear during progression of the disease. Using an original peptide-mapping procedure, we precisely localised the p53 epitopes recognised by p53 antibodies. Immunodominant epitopes reacting with antibodies were localised in the amino and carboxy termini of the protein, similar to those found in breast carcinoma patients or in animals immunised with p53. In light of these data, we suggest that p53 antibodies occur via a self-immunisation process that is the consequence of p53 accumulation in tumour cells. p53 antibodies were also detected in two patients without detected malignant disease. One of these patients died 6 months later of lung carcinoma, suggesting that p53 antibodies may be a precocious marker of p53 alteration.
 ...
PMID:Analyses of p53 antibodies in sera of patients with lung carcinoma define immunodominant regions in the p53 protein. 751 26

Despite the steadily increasing number of patients suffering from squamous cell carcinomas of the oropharyngeal region, little is known about the molecular steps involved in the induction of these neoplasms. The aim of this study was to determine the incidence and type of p53 mutations in oropharyngeal squamous cell carcinomas. Five of 38 patients had lymph node metastases, three patients had multiple primary carcinomas and two patients presented with multiple primary tumours and lymph node metastases. Exons 5 through 8 of the p53 gene were screened by single-strand conformation polymorphism analysis followed by direct DNA sequencing. A total of 16 tumours (42%) contained point mutations scattered throughout exons 5 to 8. Most mutations (56%) were transitions, predominantly G-->A. G-->T mutations prevailed among the transversions that have also been found in smoking-related lung cancer. One carcinoma of the soft palate showed a mutation which was retained in a lymph node metastasis. The status of p53 differed in primary carcinomas of patients with multiple tumours indicating an independent generation of these neoplasms. The frequent occurrence of p53 mutations in oropharyngeal carcinomas supports the view that this gene plays a role in initiation or progression of the malignant phenotype.
 ...
PMID:p53 mutations in oropharyngeal carcinomas: a comparison of solitary and multiple primary tumours and lymph node metastases. 753 94

Within the past few years, the measurement of serum and tissue markers has had an increasing influence on clinical decisions about initial treatment and follow-up. Lung cancer illustrates the types and importance of these various markers. This review presents data concerning the most studied and interesting markers in non-small cell (NSCLC) and small cell lung cancer (SCLC). CEA, TPA, SCC-Ag, CYFRA 21-1, ferritin, CA19-9, CA50, CA242, H-K-N-ras mutations and p53 mutation seem to be the most prolific in NSCLC, while NSE, BN/GRP, CK-BB, NCAM, IL-2R, IGF-I, transferrin, ANP, mAb (cluster 5), Le-y and c-N-L-myc mutation are markers in SCLC patients. Some of these serum markers might be useful adjuncts for monitoring response to therapy, including early detection of tumour reactivation to allow curative therapy and rapid detection of treatment failure to allow change of the regimen. The study of these markers also may lead to a better understanding of the biological characteristics of lung cancer. The information derived from these biological studies represents the most promising avenue towards new treatment strategies, as well as attempts at secondary prevention.
 ...
PMID:Clinical tumour markers in lung cancer. 753 17

Technological developments have made possible extension of polymerase chain reaction (PCR) analysis to individual cells to localize DNA/RNA with non-radioactive labels at the light microscopic level. This approach, in situ PCR, is particularly useful in resolving low-frequency message expression in mixed populations of cells and tissues. We have established a working protocol for direct in situ PCR and have utilized several controls to validate our results. In this report we outline the procedures for detecting either DNA or RNA in a rapid and reproducible manner. We evaluate the sequential steps required for this analysis, such as protease hydrolysis, DNAse digestion, "hot start" capabilities, and detection methods. We have applied these methods in several applications, including detection of the p53 gene in human tumor samples, localization of insulin-like growth factor-IA mRNA in cell lines with low levels of expression, and distribution of transferrin mRNA in lung cancer cell lines and tumors. We demonstrate from this study that the in situ PCR technique is an investigative approach capable of detecting specific DNA/RNA sequences at the cellular level and of identifying cells with low levels of mRNA expression.
 ...
PMID:Non-radioactive localization of nucleic acids by direct in situ PCR and in situ RT-PCR in paraffin-embedded sections. 754 78

Beryllium (Be) metal and several of its analogues have been shown to be carcinogenic in rats. In addition, workers employed at Be processing plants have been shown to have a slight excess of lung cancer. In this study, a single inhalation exposure to Be metal produced a 64% incidence of lung tumors in the F344/N rat. The most frequent tumor type observed was adenocarcinoma. These Be metal-induced lung carcinomas were examined for genetic alterations in the K-ras, p53, and c-raf-1 genes. DNA isolated from lung neoplasms was analyzed by PCR amplification and direct DNA sequence analysis, immunohistochemical analysis and Southern blot analysis. No K-ras codon 12, 13 or 61 mutations were detected in 24 lung tumors by direct sequencing. Using a more sensitive K-ras codon 12 mutation selection assay, K-ras codon 12 GGT-GTT transversions were detected in two of 12 adenocarcinomas. These results suggest that activation of the K-ras protooncogene is both a rare and late event, possibly stemming from genomic instability during the progression of some Be-induced rat adenocarcinomas of the lung. No mutant p53 nuclear immunoreactivity was observed in any Be-induced tumor. Because immunohistochemical analysis of the p53 protein only detects missense mutations, exons 5-8 of this gene were also analyzed by direct DNA sequencing. In order to perform the p53 sequence analysis, it was necessary to first characterize and sequence the p53 intron sequences flanking exons 5-8 and their splice sites. Details of this expanded intron DNA sequence information are given here. No mutations were detected within exons 5-8 of the p53 gene. No rearrangement of the c-raf-1 protooncogene was detected by Southern blot analysis. These results indicate that the mechanisms underlying the development of Be-induced lung cancer in rats do not involve gene dysfunctions commonly associated with human non-small-cell lung cancer.
 ...
PMID:Analysis of K-ras, p53 and c-raf-1 mutations in beryllium-induced rat lung tumors. 754 9

Abnormalities of the p53 oncogene in lung cancer have recently been reported to be more frequent in small cell lung cancer (SCLC) than in non-small cell lung cancer (non-SCLC), but their status in combined type SCLC is as yet unknown. In this study, immunohistochemical analysis using a polyclonal antibody against p53 protein was performed in 12 surgically resected specimens of combined type SCLC. Immunoreactivity of the p53 protein was found in 5 (42%) of the 12 cases, and the immunostaining pattern of the p53 protein in areas of the non-small cell carcinoma type was the same as in those of the small cell carcinoma type. Thus, it seems that the incidence of p53 abnormalities in combined type SCLC is slightly lower than in ordinary type SCLC. It is also suggested that abnormalities of the p53 oncogene in this histological type may not be a specific event related to the morphological difference between small cell carcinoma and non-small cell carcinoma.
 ...
PMID:p53 immunostaining in combined type small cell lung cancer. Brief report. 754 52

It has been proposed that the patterns of mutations in the p53 tumor suppressor gene will provide clues to the mechanisms of cancer occurrence. Cigarette smoking is known to be the greatest risk factor for lung cancer. Epidemiological evidence has also implicated radon and asbestos as exposures that significantly increase this disease risk; asbestos exposure synergistically enhances the lung cancer risk of smokers. Previous studies of the mutational spectra of the p53 gene in lung cancer have shown cigarette smoke and radon exposure to be associated with the induction of particular lesions or classes of lesions. We have investigated the p53 gene in surgically resectable lung cancers in 85 patients from the Massachusetts General Hospital. We found 25 (29%) patients to have somatic p53 mutations in their tumors. The patients with p53 mutations who were current smokers were significantly older (75.1 versus 59.8 years; P < 0.01 and had smoked for significantly more years (56.8 versus 41.2 years; P < 0.01) than had those without p53 changes. Consistent with other reports, we observed a large number (40%) of G:C to T:A transversion mutations, noting that their occurrence increased with increasing cumulative exposure to cigarette smoke. Interestingly, we also found that p53 mutations occurred significantly more frequently in patients with a history of occupational exposure to asbestos [3 of 60 (5%) for patients without p53 mutations versus 5 of 25 (20%) of those with p53 mutations; P < 0.05].(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Mutations in the p53 gene in lung cancer are associated with cigarette smoking and asbestos exposure. 754 12

The results of conventional treatments for lung cancer remain poor and long-term survival rates have changed little over the last 10 years. In the same period of time there has been an explosion in the knowledge on the processes of cellular transformation, tumour progression, invasion and metastasis. The major categories of biological events implicated in non-small cell lung cancer include growth factor receptors expression (epidermal growth receptor, p185c-neu), autocrine growth factor production (transforming growth factor alpha), dominant oncogenes activation (ras genes) and deletion of tumour suppressor genes (p53 gene, retinoblastoma gene) and these are some of the abnormalities associated with specific histological types and with poor prognosis. Additional prognostic information can be obtained from the evaluation of the ploidy and proliferative activity of the tumours, carbohydrate antigens expression, presence of neuroendocrine differentiation and the evaluation of markers of the sequential steps involved in the process of tumour dissemination.
Lung Cancer 1995 Apr
PMID:Biological prognostic factors in non-small cell lung cancer. 755 21


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>