Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Clonal cytogenetic abnormalities found in 30 non-small cell lung carcinomas (NSCLC), including 28 newly diagnosed primary tumor specimens, are summarized. Multiple chromosome alterations were identified in every case, and 19 of 30 tumors had near-triploid or near-tetraploid karyotypes. Polysomy 7 and partial gains of 7p, including 7p11-p13 (site of the EGFR gene), were particularly frequent, occurring alone or in combination in 26 tumors. Recurrent losses involving 1p, 3p, 6q, 9p, 11p, 15p, and 17p (where the TP53 gene is located) were each seen in 16-25 cases. Five tumors exhibited double minutes, which were associated with amplified MYC1 (1 case) and EGFR (1 case), as determined by Southern analysis. The cytogenetic data were compiled from either short term cultures of tumor tissue harvested within 1-9 days (18 cases) or later harvests performed on long term cultures or cell lines (6 cases); in the other 6 cases results were obtained from both short term and long term cultures. Two studies were performed to validate the use of long term culture for cytogenetic analysis of solid lung tumors. First, in order to determine whether cytogenetic results from cultures are representative of the original tumor, the modal chromosome number of 13 specimens placed into culture was compared to the DNA index of the original tumor tissue, as measured by flow cytometry. The DNA indices of the solid tumor biopsies agreed with the degree of aneuploidy observed by cytogenetic analysis in every case. Second, in 6 cases we performed direct comparisons of karyotypes obtained from cells cultured by both methods. Identical chromosome abnormalities were detected in short term cultures and later harvests of the same specimen. Overall, our findings indicate that tumorigenesis in NSCLC is characterized by the accumulation of multiple chromosome alterations. Furthermore, these data demonstrate that recurrent cytogenetic changes can be identified in NSCLC and that detailed karyotypes from long term cultures are relevant to the original tumor. Chromosome abnormalities detected by these techniques may have clinical and biological significance. However, the complex pattern of karyotypic changes seen in newly diagnosed NSCLC emphasizes the need for future investigations of premalignant bronchial lesions in order to identify primary genetic changes important for early detection and intervention in this aggressive neoplasm.
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PMID:Chromosome abnormalities in human non-small cell lung cancer. 131 34

Mutations in the gene coding for the p53 tumor suppressor protein are common in a variety of human cancers. To assess the role of a putative mutated p53 protein in human lung cancer, a monoclonal antibody recognizing it was used in an immunoperoxidase detection system. A total of 114 cases of Stage I and II adenocarcinomas and squamous cell carcinomas were studied. The staining pattern was always intranuclear and heterogeneous. When the median or mean survival time was compared between cases, p53 accumulation had a statistically significant negative prognostic value. This was supported by a Kaplan-Meier survival plot of p53 producers and nonproducers. In 7 of 24 Stage II cases that were negative for p53 in the primary tumor, metastatic regional lymph nodes were p53-positive. These latter cases had greatly reduced survival times. Thus, p53 accumulation in primary tumors (and regional lymph nodes) may identify a subgroup of lung cancer patients with a prognosis of more aggressive disease.
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PMID:Accumulation of p53 protein correlates with a poor prognosis in human lung cancer. 132 96

P53 is a tumor suppressor gene that has been implicated in the molecular genetics of many human malignancies. Nucleotide alterations, most commonly single point mutations, have been shown not only to abrogate the p53 suppressor function but also to contribute to the transformed phenotype. We report the detection of a p53 gene mutation in clinical specimens of a patient with relapsing prostate adenocarcinoma 14 years after definitive external beam radiation. The techniques of single strand conformation polymorphism analysis and direct sequencing of polymerase chain reaction generated products were used for this study. Analysis of tissue from different locations of the primary tumor revealed intratumoral molecular heterogeneity; the mutation was absent in 1 area but present in another. Tumor from a regional lymph node metastasis harbored the identical p53 mutation. Furthermore, an additional genetic alteration, an allelic loss on chromosome 17p but not including the p53 gene, was observed only in the metastatic tissue. These observations in clinical specimens of primary and metastatic sites provide evidence for the association of the p53 gene in the progression of human prostate carcinoma.
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PMID:Alterations of the P53 gene are associated with the progression of a human prostate carcinoma. 134 85

A malignant stromal tumor of the testis with an osteosarcoma component and five of its metastases mainly containing osteosarcoma have been analyzed for RB1 and TP53 abnormalities. Whereas in the primary tumor and in some of the metastases loss of heterozygosity could not be detected for RB1 or for the 17p13 region in which TP53 is located, other metastases showed such losses of heterozygosity. By polymerase chain reaction analysis an 18-base pair deletion from exon 5 of the TP53 gene was found in a small proportion of primary tumor cells and in one of the metastases, but not in the other metastases. Therefore, in this case neither RB1 nor TP53 seems to play an essential role in the initiation of osteosarcoma.
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PMID:Analysis of a metastasizing testicular mixed gonadal stromal tumor with osteosarcoma components suggests that a malignant tumor with the histology of osteosarcoma may develop without primary involvement of RB1 and TP53. 142 18

Allelic loss of chromosome 17p with a mutated p53 gene on the remaining allele has been observed in various kinds of human cancers. To examine the significance of allelic loss of chromosome 17p in human urothelial cancer with special attention to the clinicopathological features, 49 tumors with various stages and grades from 43 cases (35 bladder cancers and 8 renal pelvic or ureteral cancers) were examined for loss of heterozygosity using 5 polymorphic probes on chromosome 17p. Thirty-seven cases were informative, and allelic loss of chromosome 17p was observed in 15 (41%) of them. In bladder cancers, the loss of 17p was observed with significantly higher frequency (p < 0.01) in cases with invasive (> or = pT2) tumors (7/10, 70%) than in cases with superficial (pTa or pT1) tumors (4/21, 19%). In renal pelvic or ureteral cancers, none of 2 superficial tumors and all of 4 invasive tumors showed the allelic loss. As to tumor grade, the allelic loss was observed in 1/9 (11%) for grade 1 cases, 6/18 (33%) for grade 2 cases, and 8/10 (80%) grade 3 cases (grade 1 versus 3, p < 0.01; grade 2 versus 3, p < 0.05). On the other hand, examination of clinical features, such as primary tumor site, tumor multiplicity or previous history of urothelial cancer did not significantly influence the frequency of the allelic loss. Our results suggest that the allelic loss of chromosome 17p is strongly associated with invasive phenotype in urothelial cancer. The results further indicate that the 17p deletion may represent a new genetic marker of malignant potentials in urothelial cancers.
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PMID:Allelic loss of chromosome 17p in urothelial cancer: strong association with invasive phenotype. 143 75

The molecular genetics of colorectal carcinoma are among the best understood of any common human cancer. Reported molecular genetic abnormalities involve tumor-suppressor genes that undergo inactivation (e.g., apc, mcc, dcc, p53, and possibly genes on chromosomes 8p, 1p, and 22q) and dominant-acting oncogenes (e.g., ras, src, and myc). Multiple clonal genetic abnormalities accumulate during the development of colorectal carcinoma in adenomas. Altered DNA methylation is an early event, and the specific genetic alterations occur in a preferential order. However, the clinical application of molecular genetics in patients who are at risk for or have colorectal carcinoma is in its infancy. Patients with a predisposition to colorectal carcinoma caused by inheritance of familial adenomatous polyposis can be identified by genetic analysis of the apc gene on chromosome 5q21. In patients who undergo curative resection of colorectal cancer, deletion of the p53 gene on chromosome 17p, deletion of the dcc gene on 18q, and high fractional allelic loss (fraction of nonacrocentric autosomal arms with deletion) in the primary tumor appear to indicate an increased likelihood of occult disseminated disease and thus a poor prognosis. Additional studies are needed to establish the role of the molecular genetics of colorectal carcinoma in the management of patients who are at risk for or already have neoplasia of the large bowel.
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PMID:Molecular genetics of colorectal carcinoma. 151 69

There are reports of p53 gene mutations in various human cancers but not in rat tumor cell lines or rat primary tumor tissue. We found a p53 gene mutation in a cell line of a spontaneous squamous cell carcinoma of the rat Zymbal gland, SCC131, at codon 171 by direct sequencing of cDNA fragments amplified by PCR. We tested for p53 gene mutations in 15 primary Zymbal gland tumors induced by 2-amino-3-methylimidazo[4,5-f]quinoline by single-strand conformation polymorphism analysis of the PCR-amplified cDNA products. Samples of four tumors showed mobility shifts. Direct sequencing revealed that all these tumors had mutations in conserved regions or in scattered conserved residues. Single-strand conformation polymorphism analysis of cDNA suggested that mRNA from the wild-type allele of the p53 gene was not present in tumor cells of three of four positive cases, although genomic DNA analysis indicated that the wild-type allele was retained in all the cases. All mutations were found at a guanine base: three mutations were guanine----pyrimidine transversions and one was a deletion of a guanine base within a G+C-rich sequence. These findings indicate that 2-amino-3-methylimidazo[4,5-f]quinoline may be directly involved in induction of these mutations by forming DNA adducts at various sites in the p53 gene.
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PMID:Rat p53 gene mutations in primary Zymbal gland tumors induced by 2-amino-3-methylimidazo[4,5-f]quinoline, a food mutagen. 159 84

Squamous, large cell, and adenocarcinoma, collectively termed non-small cell lung cancer (NSCLC), are diagnosed in approximately 75% of patients with lung cancer in the United States. The treatment of these three tumor cell types is approached in virtually identical fashion because, in contrast to small cell carcinoma of the lung, NSCLC more frequently presents with localized disease at the time of diagnosis and is thus more often amenable to surgical resection but less frequently responds to chemotherapy and irradiation. Cigarette smoking is etiologically related to the development of NSCLC in the great majority of cases. Genetic mutations in dominant oncogenes such as K-ras, loss of genetic material on chromosomes 3p, 11p, and 17p, and deletions or mutations in tumor suppressor genes such as rb and p53 have been documented in NSCLC tumors and tumor cell lines. NSCLC is diagnosed because of symptoms related to the primary tumor or regional or distant metastases, as an incidental finding on chest radiograph, or rarely because of a paraneoplastic syndrome such as hypercalcemia or hypertrophic pulmonary osteoarthropathy. Screening smokers with periodic chest radiographs and sputum cytologic examination has not been shown to reduce mortality. The diagnosis of NSCLC is usually established by fiberoptic bronchoscopy or percutaneous fine-needle aspiration, by biopsy of a regional or distant metastatic site, or at the time of thoracotomy. Pathologically, NSCLC arises in a setting of bronchial mucosal metaplasia and dysplasia that progressively increase over time. Squamous carcinoma more often presents as a central endobronchial lesion, while large cell and adenocarcinoma have a tendency to arise in the lung periphery and invade the pleura. Once the diagnosis is made, the extent of tumor dissemination is determined. Since most NSCLC patients who survive 5 years or longer have undergone surgical resection of their cancers, the focus of the staging process is to determine whether the patient is a candidate for thoracotomy with curative intent. The dominant prognostic factors in NSCLC are extent of tumor dissemination, ambulatory or performance status, and degree of weight loss. Stages I and II NSCLC, which are confined within the pleural reflection, are managed by surgical resection whenever possible, with approximate 5-year survival of 45% and 25%, respectively. Patients with stage IIIa cancers, in which the primary tumor has extended through the pleura or metastasized to ipsilateral or subcarinal lymph nodes, can occasionally be surgically resected but are often managed with definitive thoracic irradiation and have 5-year survival of approximately 15%.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Non-small cell lung cancer. Part I: Biology, diagnosis, and staging. 164 34

Squamous, large cell, and adenocarcinoma, collectively termed non-small cell lung cancer (NSCLC), are diagnosed in approximately 75% of patients with lung cancer in the United States. The treatment of these three tumor cell types is approached in virtually identical fashion because, in contrast to small cell carcinoma of the lung, NSCLC more frequently presents with localized disease at the time of diagnosis and is thus more often amenable to surgical resection but less frequently responds to chemotherapy and irradiation. Cigarette smoking is etiologically related to the development of NSCLC in the great majority of cases. Genetic mutations in dominant oncogenes such as K-ras, loss of genetic material on chromosomes 3p, 11p, and 17p, and deletions or mutations in tumor suppressor genes such as rb and p53 have been documented in NSCLC tumors and tumor cell lines. NSCLC is diagnosed because of symptoms related to the primary tumor or regional or distant metastases, as an incidental finding on chest radiograph, or rarely because of a paraneoplastic syndrome such as hypercalcemia or hypertrophic pulmonary osteoarthropathy. Screening smokers with periodic chest radiographs and sputum cytologic examination has not been shown to reduce mortality. The diagnosis of NSCLC is usually established by fiberoptic bronchoscopy or percutaneous fine-needle aspiration, by biopsy of a regional or distant metastatic site, or at the time of thoracotomy. Pathologically, NSCLC arises in a setting of bronchial mucosal metaplasia and dysplasia that progressively increase over time. Squamous carcinoma more often presents as a central endobronchial lesion, while large cell and adenocarcinoma have a tendency to arise in the lung periphery and invade the pleura. Once the diagnosis is made, the extent of tumor dissemination is determined. Since most NSCLC patients who survive 5 years or longer have undergone surgical resection of their cancers, the focus of the staging process is to determine whether the patient is a candidate for thoracotomy with curative intent. The dominant prognostic factors in NSCLC are extent of tumor dissemination, ambulatory or performance status, and degree of weight loss. Stages I and II NSCLC, which are confined within the pleural reflection, are managed by surgical resection whenever possible, with approximate 5-year survival of 45% and 25%, respectively. Patients with stage IIIa cancers, in which the primary tumor has extended through the pleura or metastasized to ipsilateral or subcarinal lymph nodes, can occasionally be surgically resected but are often managed with definitive thoracic irradiation and have 5-year survival of approximately 15%.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Non-small cell lung cancer. Part II: Treatment. 171 39

Functional alterations or loss of tumor-suppressor genes are an important feature of neoplastic progression in humans. The employment of suitable animal model systems would greatly facilitate the detection and manipulation of such genes. We describe here an experimental approach to this problem based on the analysis of skin tumors induced in F1 hybrids between Mus musculus and Mus spretus mice. The results show that loss of heterozygosity on chromosome 11 occurred in 4/13 mouse skin carcinomas, but not in premalignant papillomas. Since the murine p53 gene is located on this chromosome, immunoprecipitation and DNA-sequencing studies were carried out on tumorigenic cell lines and primary tumor DNA respectively to determine the status of p53 alleles. These studies revealed the presence of p53 mutations, both frameshifts and missense, some of which are identical to those found in human tumors. Loss of normal p53 function is found in well-differentiated squamous-cell carcinomas and thus does not appear to be directly responsible for further progression to an undifferentiated spindle cell phenotype.
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PMID:Loss of heterozygosity and mutational alterations of the p53 gene in skin tumours of interspecific hybrid mice. 176 80


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