DSpace Angular :: Browsing by Author "Wistuba, II"

Browsing by Author "Wistuba, II"

Now showing 1 - 14 of 14

Allelic losses at chromosome 8p21-23 are early and frequent events in the pathogenesis of lung cancer
(AMER ASSOC CANCER RESEARCH, 1999) Wistuba, II; Behrens, C; Virmani, AK; Milchgrub, S; Syed, S; Lam, S; Mackay, B; Minna, JD; Gazdar, AF
Allelic Losses on the short arm of chromosome 8 (8p) have been reported as frequent events in several cancers, including Lung. However, no comprehensive mapping analysis of chromosome 8p in Lung cancer tumors has been performed, and no data are available about the stage at which these abnormalities occur during the multistage development of lung cancer. Using 26 microsatellite markers, we mapped the chromosome 8 regions frequently deleted in lung cancer in 13 small cell carcinoma and 17 non-small cell lung carcinoma cell Lines and in 68 microdissected archival primary lung tumors (22 small cell lung carcinomas, 25 squamous cell carcinomas, and 21 adenocarcinomas), We also studied the role of 8p deletions in lung cancer pathogenesis by examining 95 microdissected normal epithelium and preneoplastic samples from 11 surgically resected squamous cell Lung carcinomas and from 58 bronchoscopy biopsy samples obtained from 31 current and former smokers. High frequencies of deletions at 8p21-23 regions were detected in lung cancer cell lines and in primary lung tumors. Deletions commenced early during the multistage development of lung cancer at the hyperplasia/metaplasia stage in cancer patients and in smokers without cancer. Allelic deletions persisted for up to 48 years after smoking cessation. There was a progressive increase of the overall 8p21-23 loss of heterozygosity frequency and in the size of the deleted region with increasing severity of histopathological preneoplastic changes. In epithelial samples from resected squamous cell Lung carcinomas, we compared the presence of loss of heterozygosity at 8p21-23 with deletions at chromosomes 3p and 9p, Of interest, the pattern of deletions was not random, and 8p21-23 allelic Losses always followed 3p deletions and usually followed 9p deletions. We conclude that 8p21-23 deletions are frequent and early events in the pathogenesis of Lung carcinomas.
Comparison of features of human breast cancer cell lines and their corresponding tumors
(AMER ASSOC CANCER RESEARCH, 1998) Wistuba, II; Behrens, C; Milchgrub, S; Syed, S; Ahmadian, M; Virmani, AK; Kurvari, V; Cunningham, TH; Ashfaq, R; Minna, JD; Gazdar, AF
Although human tumor-derived cell lines play an important role in the investigation of cancer biology and genetics, there is no comprehensive study comparing tumor cell line properties with those of the individual tumors from which they were derived. We compared the properties of a series of 18 human breast cancer cell lines that were cultured for a median period of 25 months (range, 9-60 months) and their corresponding archival tumor tissues. We compared morphological characteristics, ploidy, and immunohistochemical expression of estrogen receptors, progesterone receptors, and HER2/neu and p53 proteins. For 17 of these cases, we also tested for allelic losses at 18 chromosomal regions frequently deleted in breast tumors using 51 polymorphic microsatellite markers, and we determined the TP53 gene mutation status in exons 5 to 10, There was an excellent correlation between the breast tumor cell lines and their corresponding tumor tissues for morphological features (100%); presence of aneuploidy (87%); immunohistochemical expression of estrogen receptors (87%), progesterone receptors (73%), and HER2/neu (93%) and p53 proteins (100%); allelic loss at all of the chromosomal regions analyzed (82-100% concordance); and TP53 gene mutations (75%), The same parental allele was lost in 279 (99%) of 281 of the comparisons of allele losses. The fractional allelic loss indices (a reflection of the total allelic loss) of the cell lines and their corresponding tumor tissues were identical or similar in 15 (88%) of 17 paired comparisons, Although our previous studies (A, Gazdar et at, Int. J, Cancer, in press) indicated that only a subset of primary breast carcinomas that have several features indicative of advanced tumors with poor prognosis can be successfully cultured, the cell lines retain the properties of their parental tumors for lengthy culture periods and, thus, provide suitable model systems for biomedical studies.
Comparison of features of human lung cancer cell lines and their corresponding tumors
(AMER ASSOC CANCER RESEARCH, 1999) Wistuba, II; Bryant, D; Behrens, C; Milchgrub, S; Virmani, AK; Ashfaq, R; Minna, JD; Gazdar, AF
Although human lung tumor-derived cell lines play an important role in the investigation of lung cancer biology and genetics, there is no comprehensive study comparing the genotypic and phenotypic properties of lung cancer cell lines with those of the individual tumors from which they were derived, We compared a variety of properties of 12 human non-small cell lung carcinoma (NSCLC) cell lines (cultured for a median period of 39 months; range, 12-69) and their corresponding archival tumor tissues. There was, in general, an excellent concordance between the lung tumor cell lines and their corresponding tumor tissues for morphology (100%), the presence of aneuploidy (100%), immunohistochemical expression of HER2/neu (100%) and p53 proteins (100%), loss of heterozygosity at 13 chromosomal regions analyzed (97%) using 37 microsatellite markers, microsatellite alterations (MAs, 75%), TP53 (67%), and K-ras (100%) gene mutations, In addition, there was 100% concordance for the parental allele lost in all 115 comparisons of allelic losses. Some discrepancies were found; more aneuploid subpopulations of cells were detected in the cell lines as well as higher incidences of TP53 mutations (4 of 10 mutations not found in the tumors) and microsatellite alterations (two cell lines with MAs not detected in the tumors). Similar loss of heterozygosity frequencies by chromosomal regions and mean fractional allelic loss index were detected between successfully cultured and 40 uncultured lung tumors (0.45 and 0.49, respectively), indicating that both groups were similar. Our findings indicate that the NSCLC cell lines in the large majority of instances retain the properties of their parental tumors for lengthy culture periods. NSCLC cell lines appear very representative of the lung cancer tumor from which they were derived and thus provide suitable model systems for biomedical studies of this important neoplasm.
Comparison of molecular changes in cervical intraepithelial neoplasia in HIV-positive and HIV-indeterminate subjects
(ACADEMIC PRESS INC ELSEVIER SCIENCE, 1999) Wistuba, II; Syed, S; Behrens, C; Duong, M; Milchgrub, S; Muller, CY; Jagirdar, J; Gazdar, AF
Objective. HIV infection is associated with an increased incidence of cervical malignancy and its precursor lesions (CIN, cervical intraepithelial neoplasia) compared with the general population. We studied the molecular abnormalities in the development of HIV-associated CIN and compared them with those present in CINs arising in HIV-indeterminate subjects ("sporadic CIN").
Comparison of molecular changes in lung cancers in HIV-positive and HIV-indeterminate subjects
(AMER MEDICAL ASSOC, 1998) Wistuba, II; Behrens, C; Milchgrub, S; Virmani, AK; Jagirdar, J; Thomas, B; Ioachim, HL; Litzky, LA; Brambilla, EM; Minna, JD; Gazdar, AF
Context.-Human immunodeficiency virus (HIV) infection has been associated with an increasing incidence of malignancy, and HIV-infected persons have an increased incidence of primary lung carcinoma compared with the general population,
Deletions of chromosome 3p are frequent and early events in the pathogenesis of uterine cervical carcinoma
(AMER ASSOC CANCER RESEARCH, 1997) Wistuba, II; Montellano, FD; Milchgrub, S; Virmani, AK; Behrens, C; Chen, HL; Ahmadian, M; Nowak, JA; Muller, C; Minna, JD; Gazdar, AF
To study the molecular abnormalities involved in the multistage development of cervical carcinoma (CC), we investigated the presence of oncogenic human papillomavirus (HPV) sequences, loss of heterozygosity (LOH), and microsatellite alterations at several genes/loci at 3p (3p14.2 at the FHIT gene, 3p14.3-21.1, 3p21, and 3p22-24.2), 9p21, RB and P53, and P53 gene point mutations in precisely microdissected archival tissues from 20 CCs and their accompanying precursor lesions (cervical intraepithelial neoplasia, CIN; n = 40) and normal epithelia (n = 20). In all HPV-positive cases (90% of CCs), HPV sequences were detected as the earliest appearing molecular change or simultaneously with other changes. LOH at any 3p region was found in 70% of CCs, and 3p14.2 (FHIT gene/FRA3B fragile site) (56%) and 3p21 (57%) were the most frequent 3p sites of loss. LOH at some 3p region was in the CIN I stage, and the 3p deletions in precursor CIN lesions were smaller than the 3p losses found in the associated invasive CC. LOH at the other regions studied and P53 gene mutations were less frequent and later events. Microsatellite alterations were detected in 35% of CCs, and identical abnormalities were detected in the associated precursor lesions. Although infection with oncogenic HPV strains is the earliest and most frequent molecular event, progressive deletions at one or more 3p regions (particularly at 3p14.2, and 3p21) are also frequent events occurring early in the pathogenesis of CC.
Differential expression of FEZ1/LZTS1 gene in lung cancers and their cell cultures
(AMER ASSOC CANCER RESEARCH, 2002) Toyooka, S; Fukuyama, Y; Wistuba, II; Tockman, MS; Minna, JD; Gazdar, AF
Purpose: The FEZ1/LZTS1 (FEZ1) gene, located on chromosome 8p22 (8p22), was identified recently as a candidate tumor suppressor gene. Because loss of heterozygosity at 8p21-22 is a frequent event in lung cancers, we studied FEZ1 alteration in short-term cultures of resected lung cancer tumors and cell lines.
Distinct K-ras mutation pattern characterizes signet ring cell colorectal carcinoma
(AMER ASSOC CANCER RESEARCH, 2003) Wistuba, II; Behrens, C; Albores Saavedra, J; Delgado, R; Lopez, F; Gazdar, AF
Purpose: Signet ring cell colorectal carcinoma (SRCCC) represents a unique, infrequent, and highly malignant variant of colorectal cancer. To understand the pathogenesis of SRCCC, we investigated its molecular abnormalities and compared them with those of the usual type of colorectal adenocarcinoma.
Expression and regulation of scavenger receptor class B type I (SR-BI) in gall bladder epithelium
(BMJ PUBLISHING GROUP, 2003) Miquel, JF; Moreno, M; Amigo, L; Molina, H; Mardones, P; Wistuba, II; Rigotti, A
Background and aims: Biliary lipid absorption by the gall bladder mucosa and the cholesterol content of the gall bladder wall appear to play a role in cholesterol gall stone formation. As the scavenger receptor class B type I (SR-BI) regulates cellular cholesterol uptake, we studied its expression in human and murine gall bladders, its regulation by increased biliary lipid content, and its role in gall stone formation.
Genome-wide allelotyping analysis reveals multiple sites of allelic loss in gallbladder carcinoma
(AMER ASSOC CANCER RESEARCH, 2001) Wistuba, II; Tang, MY; Maitra, A; Alvarez, H; Troncoso, P; Pimental, F; Gazdar, AF
Although gallbladder carcinoma (GBC) is a highly malignant neoplasm, there is very limited information about the molecular changes involved in its pathogenesis. To identify the chromosomal locations of putative tumor suppressor gene loci Involved in the pathogenesis of GBC, we conducted a genome-wide allelotyping or loss of heterozygosity (LOH) analysis of GBCs. Microdissected tissue from 24 archival GBCs and their matched control DNAs were analyzed for PCR-based LOH using 169 microsatellite markers spanning all nonacrocentric autosomal arms and the X chromosome. The chromosomal arms with the greatest frequencies of LOH (greater than or equal to 60%) were 3p, 6q, 7q, 8p, 9p, 9q, 11q, 12q, 17p, 18q, 19p, 22q, and Xq. The average fractional allele loss index in GBC cases was high (0.43) and frequent breakpoints were detected in gallbladder tumors. Of interest, 21 different regions of frequent LOH (hot spots) defined as greater than or equal to 50% for individual GBC samples were detected in this neoplasm, nearly half of them confined to one microsatellite marker. We conclude that in GBC at least 21 chromosomal regions with frequent allele losses are involved, suggesting that several putative tumor suppressor genes are inactivated in its pathogenesis. Overall, these data provide global estimates of the extent of genetic changes leading to GBC and will be useful for the identification of new tumor suppressor genes and for multiple new markers for translational research.
Microsatellite instability and loss of heterozygosity have distinct prognostic value for testicular germ cell tumor recurrence
(TAYLOR & FRANCIS INC, 2004) Velasco, A; Riquelme, E; Schultz, M; Wistuba, II; Villarroel, L; Koh, MS; Leach, FS
Germ cell tumor (GCT) is the most common genitourinary malignancy of men between the ages of 18 and 35 years. Therapy is ultimately successful in over 90% of patients, however significant morbidity and mortality can be associated with adjuvant treatment and relapse. Molecular markers that predict treatment response and/or poor outcome would have immediate clinical benefit since adjuvant treatment could be selectively reserved for patients at higher risk for relapse and those patients most likely to respond to treatment. In order to identify potential prognostic molecular markers, we evaluated 118 GCT for microsatellite instability (MSI), loss of heterozygosity (LOH) and MSH2 immunostaining to identify tumors associated with relapse and/or poor outcome following initial surgical, medical and/or radiation therapy.
Molecular abnormalities associated with endocrine tumors of the uterine cervix
(ACADEMIC PRESS INC ELSEVIER SCIENCE, 1999) Wistuba, II; Thomas, B; Behrens, C; Onuki, N; Lindberg, G; Albores Saavedra, J; Gazdar, AF
Objective. We studied the molecular abnormalities involved in the pathogenesis of endocrine tumors of the uterine cervix.
Molecular changes in the bronchial epithelium of patients with small cell lung cancer
(AMER ASSOC CANCER RESEARCH, 2000) Wistuba, II; Berry, J; Behrens, C; Maitra, A; Shivapurkar, N; Milchgrub, S; Mackay, B; Minna, JD; Gazdar, AF
To better understand the pathways involved in the pathogenesis of small cell lung carcinoma (SCLC), we compared the patterns of molecular changes present in these tumors and their accompanying bronchial epithelium with those present in the other two major types of lung cancer [squamous cell carcinoma (SQC) and adenocarcinoma (ADC)I, We obtained DNA from 68 microdissected invasive lung tumors (22 SCLCs, 21 ADCs, and, 25 SQCs) and 119 noncontiguous foci of histologically normal or hyperplastic epithelia from 10 tumors of each histological type. We determined loss of heterozygosity and microsatellite alterations at 12 chromosomal regions frequently deleted in lung cancers using 19 polymorphic microsatellite markers. Our major findings are as follows: (a) the mean index of allelic loss in SCLC (0.85) and SQC (0.71) tumors was higher than that in ADC (0.39) tumors; (b) although there was considerable overlap, each tumor type had a characteristic pattern of allelic loss; (c) most samples of bronchial epithelium accompanying SCLC (90%) had allelic loss at one or more loci compared with samples accompanying SQC (54%) or ADC (10%); (d) the mean index of allelic loss was much higher in bronchial epithelial samples from SCLC (0.27) than in those from SQC (0.08) or ADC (0.01); and (e) although the mean indices of microsatellite alterations in the tumor types were similar, the bronchial epithelial samples accompanying SCLC had a 10-fold higher mean index (0.063) than those accompanying SQC (0.006) or ADC (0,006), Our findings indicate that extensive genetic damage in the accompanying normal and hyperplastic bronchial epithelium is characteristic of SCLC tumors and suggest major differences in the pathogenesis of the three major lung cancer types.
Two identical triplet sisters carrying a germline BRCAI gene mutation acquire very similar breast cancer somatic mutations at multiple other sites throughout the genome
(WILEY, 2000) Wistuba, II; Tomlinson, GE; Behrens, C; Virmani, A; Geradts, J; Blum, JL; Minna, JD; Gazdar, AF
Monozygotic twins, each of whom has breast cancer, offer a natural study population for gene-environmental interactions as causation of cancer, because they are genetically identical. If heritable factors play a large role in the origin of a neoplasm, disease concordance should be significant in monozygotic twins. Two monozygotic triplet sisters carrying a germline BRCA1 gene mutation (5382insC) who both developed breast cancer at early ages were studied for loss of heterozygosity (LOH) in their microdissected, paraffin-embedded tumors along with control blood and stromal breast tissue at 19 chromosomal arms using 161 microsatellite markers. Microdissected areas of normal lobular and ductal epithelium and ductal in situ carcinoma were also studied for LOH using a subset of microsatellite markers. The mother's DNA (extracted from peripheral blood lymphocytes) was analyzed to determine the parental allele under LOH in each case. Both tumors demonstrated similar histologic features suggestive of a secretory variant of ductal carcinoma. The tumors from both sisters had similar overall LOH frequency expressed by the fractional allelic loss (FAL) indices (0.56 vs, 0.60) and demonstrated concordance for loss or retention at 82 of 97 informative markers (85% correlation). In addition, detailed mapping analysis of several chromosomal arms revealed that identical breakpoints were detected in both tumors at several chromosome regions. Finally, in both sisters' tumors, when a chromosome exhibited allelic loss, all of the markers exhibited LOH of the same parental allele even when there were intervening regions of retention of heterozygosity, In contrast, 17 archival sporadic breast carcinomas demonstrated a wide range of FAL indexes and highly individual patterns of LOH. Our findings support the hypothesis that inherited factors play a role in the development of the multiple somatic deletions occurring in breast carcinomas. Whether one of these factors is the mutant BRCA1 allele or some other gene(s) remains to be determined. (C) 2000 Wiley-Liss, Inc.

Browsing by Author "Wistuba, II"

Results Per Page

Sort Options