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J D Minna

Publications and source records attributed to J D Minna.

At least 73 records · Page 4Linked to original sources
PubMed1999

Expression of DMBT1, a candidate tumor suppressor gene, is frequently lost in lung cancer.

DMBT1 is a candidate tumor suppressor gene located at 10q25.3-26.1. Homozygous deletion of the gene was found in a subset of medulloblastoma and glioblastoma multiforme; lack of expression was noted in the majority of these tumors. In adult tissues, DMBT1 is highly expressed only in lung and small intestine tissues, indicating its important role in these organs. By analyzing lung cancer cell lines and primary lung tumors using reverse transcription-PCR, we found that 100% (20 of 20) of small cell lung cancer (SCLC) cell lines and 43% (6 of 14) of non-small cell lung cancer (NSCLC) cell lines lacked DMBT1 expression. Furthermore, 45% (9 of 20) of the primary NSCLCs exhibited a markedly low level of gene expression compared with corresponding normal lung tissues, indicating that lack of gene expression also occurs in primary lung cancers. To determine the potential mechanisms for lack of DMBT1 expression in lung cancer, we analyzed tumor cell lines for potential intragenic homozygous deletions of the gene and found such homozygous deletions in 10% (4 of 40) of SCLC cell lines but in none of 14 NSCLC cell lines. Moreover, the loss of expression could not be rescued by treatment with a demethylation agent (5-azacytidine) in two NSCLC cell lines lacking DMBT1 expression, suggesting that de novo methylation of the promoter region of the gene is unlikely to play a role in inactivation of the gene. We then sequenced the whole coding region of DMBT1 in 8 NSCLC cell lines that expressed DMBT1 and 20 primary NSCLCs. A potential point mutation at codon 52 was detected in a NSCLC cell line and resulted in an amino acid change from serine to tryptophan. Three common polymorphisms were also detected in tissues analyzed. Our data demonstrate that DMBT1 expression is frequently lost in lung cancer due to gene deletion and to other not yet identified mechanisms, suggesting that inactivation of DMBT1 may play an important role in lung tumorigenesis.

Agglutinins↗
PubMed1999

Allelic losses at chromosome 8p21-23 are early and frequent events in the pathogenesis of lung cancer.

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.

Adult↗
PubMed1999

Sequential molecular abnormalities are involved in the multistage development of squamous cell lung carcinoma.

To understand the molecular pathways involved in the pathogenesis of squamous cell lung carcinoma, we obtained DNA from 94 microdissected foci from 12 archival surgically resected tumors including histologically normal epithelium (n=13), preneoplastic lesions (n=54), carcinoma is situ (CIS) (n=15) and invasive tumors (n=12). We determined loss of heterozygosity (LOH) at 10 chromosomal regions (3p12, 3p14.2, 3p14.1-21.3, 3p21, 3p22-24, 3p25, 5q22, 9p21, 13q14 RB, and 17p13 TP53) frequently deleted in lung cancer, using 31 polymorphic microsatellite markers, including 24 that spanned the entire 3p arm. Our major findings are as follows: (1) Thirty one percent of histologically normal epithelium and 42% of mildly abnormal (hyperplasia/metaplasia) specimens had clones of cells with allelic loss at one or more regions; (2) There was a progressive increase of the overall LOH frequency within clones with increasing severity of histopathological changes; (3) The earliest and most frequent regions of allelic loss occurred at 3p21, 3p22-24, 3p25 and 9p21; (4) The size of the 3p deletions increased with progressive histologic changes; (5) TP53 allelic loss was present in many histologically advanced lesions (dysplasia and CIS); (6) Analyses of 58 normal and non-invasive foci having any molecular abnormality, indicated that 30 probably arose as independent clonal events, while 28 were potentially of the same clonal origin as the corresponding tumor; (7) Nevertheless, when the allelic losses in the 30 clonally independent lesions and their clonally unrelated tumors were compared the same parental allele was lost in 113 of 125 (90%) of comparisons. The mechanism by which this phenomenon (known as allele specific mutations) occurs is unknown; (8) Four patterns of allelic loss in clones were found. Histologically normal or mildly abnormal foci had a negative pattern (no allelic loss) or early pattern of loss while all foci of CIS and invasive tumor had an advanced pattern. However dysplasias demonstrated the entire spectrum of allelic loss patterns, and were the only histologic category having the intermediate pattern. Our findings indicate that multiple, sequentially occurring allele specific molecular changes commence in widely dispersed, apparently clonally independent foci, early in the multistage pathogenesis of squamous cell carcinomas of the lung.

Aged↗
PubMed1999

Molecular pathogenesis of lung cancer.

Lung cancer is the largest cancer killer of men and women in the united states. In addition to the progress made from antismoking primary prevention measures, new tools to help treat patients with lung cancer are emerging from the rapid advances in knowledge of the molecular pathogenesis of lung cancer. These tools include molecular and cellular biology and are starting to provide an insight into how the tumor cell, by altering oncogenes and tumor suppressor genes, achieves growth advantage, uncontrolled proliferation and metastatic behavior via disruption of key cell-cycle regulators and signal transduction cascades. Moreover, new knowledge is being developed in terms of the molecular definition of individual susceptibility to tobacco smoke carcinogens. These tools are being translated into clinical strategies to complement surgery, radiotherapy, and chemotherapy and also to assist in primary and secondary prevention efforts. This review summarizes current knowledge of the molecular pathogenesis of lung cancer. From this we know that respiratory epithelial cells require many genetic alterations to become invasive and metastatic cancer. We can detect cells with a few such changes in current and former smokers, offering the opportunity to intercede with a biomarker-monitored prevention and early detection effort. This will be coupled with new advances in computed tomography-based screening. Finally, because the molecular alterations are known, new mechanism-based therapies are being developed and brought to the clinic, including new drugs, vaccines, and gene therapy, which also must be integrated with standard therapies.

Biomarkers, Tumor↗
PubMed1999

Correlation of abnormal RB, p16ink4a, and p53 expression with 3p loss of heterozygosity, other genetic abnormalities, and clinical features in 103 primary non-small cell lung cancers.

This study was performed to determine the frequency of inactivation and clinical correlates in non-small cell lung cancer (NSCLC) of three known tumor suppressor genes [TSGs; RB, MTS1/CDKN2 (p16), and p53] and various regions of 3p loss of heterozygosity (LOH) as other major potential TSG sites. Paraffin sections from 103 resected NSCLCs were analyzed for expression of pRB, p16, and p53 by immunohistochemistry, whereas DNA from tumor and normal tissue were tested for LOH at 3p25-26, 3p21, and 3p14. Previously published LOH data for 5q, 11p, 17q, and 18q were also available. Loss of pRB or p16 expression and overexpression of p53 were considered abnormal. The immunohistochemical and LOH data were correlated with a variety of clinical parameters including stage, age, sex, smoking history, and survival. With respect to pRB, p16, and p53, the tumors could be grouped into four categories: normal for all three proteins (21%); abnormal for pRB or p16 and normal for p53 (30%); normal for pRB and p16 and abnormal for p53 (20%); and abnormal in both pathways (28%). Aberrant expression of pRB, p16, p53, and 3p LOH, either individually or in combination, was not associated with survival differences or any other clinical parameters, with the exception that pRB/pl6 abnormalities were more common in older patients (P = 0.0005). pRB and p16 expression showed a strong inverse correlation (P = 0.002), whereas there was no correlation between expression of pRB, p16, and p53. Abnormal expression of any of the three genes inversely correlated with K-ras codon 12 mutations (P = 0.004), but not with 3p LOH or LOH at other TSG loci. We conclude that resectable NSCLCs show distinct patterns of TSG inactivation, but that no clear clinical correlates exist either alone or in combination for pRB, p16, p53, and 3p abnormalities.

Adult↗
PubMed1999

Refined mapping of two regions of loss of heterozygosity on chromosome band 11q23 in lung cancer.

11q23-24 chromosome is a region containing frequent allelic loss (loss of heterozygosity; LOH) in human cancers. To examine cancer-related allelic loss in the region between D11S940 and APOC3, we used 17 polymorphic markers and allotyped 28 lung cancer-derived cell lines and their corresponding matched lymphoblastoid cell lines. LOH was found in 71.4% (20/28) of the lung cancer cell lines and was localized to two distinct minimal regions of loss. One region is bracketed by markers D11S1647 and NCAM2 and contains the gene encoding the beta isoform of the A subunit of the human protein phosphatase 2A (PPP2R1B). Recently, mutations in this gene were described in lung and colon cancers, suggesting that PPP2R1B functions as a tumor-suppressor gene. A second minimal region of loss was defined between markers D11S1792 and D11S1885, a region estimated to be less than I Mb. Thus, chromosome 11 likely harbors two sites of suppressor oncogene activity in lung cancer, one defined by the PPP2R1B gene and the second located telomeric to PPP2R1B. This study facilitates the identification and cloning of a second critical tumor-suppressor gene involved in lung cancer, and possibly a variety of other cancers, on human chromosome band 11q23.

Carcinoma, Small Cell↗
PubMed1999

Comparison of features of human lung cancer cell lines and their corresponding tumors.

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.

Adult↗
PubMed1999

Deletions of chromosome 4 at multiple sites are frequent in malignant mesothelioma and small cell lung carcinoma.

Recent allelotyping studies suggest that allelic losses at one or both arms of chromosome 4 are frequent in several tumor types. Cytogenetic studies of malignant mesothelioma (MM) and comparative genomic hybridization analyses of small cell lung carcinoma (SCLC) suggest that chromosome 4 deletions may also play a role in these tumor types, although these results have not been confirmed by allelotyping. In an effort to more precisely identify and map the locations of putative tumor suppressor gene(s) on chromosome 4 involved in the pathogenesis of these tumors, we performed loss of heterozygosity studies using 16 polymorphic microsatellite markers. After precise microdissection of archival surgical cases, we studied DNA obtained from 20 MMs, 21 SCLCs, and 20 non-SCLCs (NSCLCs). In addition, DNA from 14 SCLC and 17 NSCLC cell lines and corresponding B lymphoblastoid lines were studied. In MM and SCLC, we observed frequent losses at three nonoverlapping regions: (a) 4q33-34 (region R1; >80%); (b) 4q25-26 (region R2; >60%); and (c) 4p15.1-15.3 (region R3; >50%). Losses at these sites occurred at lower frequencies in NSCLC (>20-30%). Data from tumors and cell lines were similar. In MM and SCLC, the most frequently observed pattern was loss at all three regions. However, in NSCLC, the most frequent pattern was loss at R3 alone. Our study has delineated three nonoverlapping regions of frequent deletions on chromosome 4 in MM and SCLC, suggesting that there may be three putative suppressor genes on chromosome 4, the inactivation of which may be important in the pathogenesis of these tumor types.

Carcinoma, Non-Small-Cell Lung↗
PubMed1998

Characterization of paired tumor and non-tumor cell lines established from patients with breast cancer.

The goal of our study was to develop a panel of tumor cell lines along with paired non-malignant cell lines or strains collected from breast cancers, predominantly primary tumors. From a total of 189 breast tumor samples consisting of 177 primary tumors and 12 metastatic tissues, we established 21 human breast tumor cell lines that included 18 cell lines derived from primary tumors and 3 derived from metastatic lesions. Cell lines included those from patients with germline BRCA1 and FHIT gene mutations and others with possible genetic predisposition. For 19 tumor cell lines, we also established one or more corresponding non-malignant cell strains or B lymphoblastoid (BL) lines, which included 16 BL lines and 7 breast epithelial (2) or stromal (5) cell strains. The present report describes clinical, pathological and molecular information regarding the normal and tumor tissue sources along with relevant personal information and familial medical history. Analysis of the breast tumor cell lines indicated that most of the cell lines had the following features: they were derived from large tumors with or without axillary node metastases; were aneuploid and exhibited a moderate to poorly differentiated phenotype; were estrogen receptor (ER)- and progesterone receptor (PR)-negative; and overexpressed p53 and HER2/neu proteins. Of 13 patients with primary breast cancers receiving curative intent mastectomies, 7 were dead after a mean period of 10 months. Our panel of paired tumor and non-malignant cell lines should provide important new reagents for breast cancer research.

Adult↗
PubMed1998

Mutation analysis of the PTEN/MMAC1 gene in lung cancer.

We studied PTEN/MMAC1, a newly discovered candidate tumor suppressor gene at 10q23.3, for mutations in lung cancer. One hundred and thirty-six lung cancer cell line DNAs (66 small cell lung cancers, SCLC, 61 non-small cell lung cancers, NSCLC, four mesotheliomas, five extrapulmonary small cell cancers) were analysed for PTEN/MMAC1 homozygous deletions and five (8%) SCLC lines showed homozygous deletions interrupting the PTEN/MMAC1 gene. Using single stranded conformation polymorphism (SSCP) analysis, we screened the PTEN/MMAC1 open reading frame of 53 lung cancer cell line cDNAs for point mutations and found that 3/35 SCLCs and 3/18 NSCLCs contained homozygous amino acid sequence altering mutations. Northern blot analysis revealed that expression of the PTEN/MMAC1 gene was considerably lower in all the tumor cell lines with point mutations while no expression was detected for cell lines with PTEN/MMAC1 homozygous deletions. Mutation analysis of 22 uncultured, microdissected, primary SCLC tumors and metastases showed two silent mutations, and two apparent homozygous deletions. We also discovered a processed pseudogene (PTEN2) which has 98.5% nt identity to PTEN/MMAC1, that needs to be accounted for in cDNA mutation analysis. Our findings suggest that genetic abnormalities of the PTEN/MMAC1 gene are only involved in a relatively small subset of lung cancers.

Carcinoma, Small Cell↗
PubMed1998

TSG101 is not mutated in lung cancer but a shortened transcript is frequently expressed in small cell lung cancer.

TSG101 is a candidate tumor suppressor gene whose deletion in NIH3T3 cells leads to spontaneous lung metastases in nude mice. Aberrant transcripts of TSG101 have been identified in 47% of primary breast carcinomas, without evidence of intragenic deletions at the TSG101 locus on 11p15. To investigate the possible role of TSG101 in lung cancer, which often shows 11p allele loss, we performed transcript analysis and mutational analysis of TSG101 in lung cancer cell lines. Reverse transcriptase RT-PCR and Northern analysis detected a common TSG101 transcript, shortened because of an internal deletion, which was expressed simultaneously with the wild-type transcript in 89% of small cell lung cancer (SCLC) lines. In contrast, the wild-type transcript was expressed alone in normal tissues, primary non-small cell lung cancer (NSCLC) specimens, and the majority of NSCLC cell lines. Sequence of the shortened SCLC transcript was identical to that of the most common aberrant transcript identified in breast cancer, consisting of a deletion of exons 2-4 and part of 1 and 5. Southern analysis of SCLC lines expressing the shortened transcript did not detect any intragenic deletions. Single strand conformational polymorphism (SSCP) analysis and direct sequencing of TSG101 cDNAs also identified no mutations or deletions. These results suggest that TSG101 is not mutated in lung cancer but that aberrant splicing of TSG101 occurs in SCLC.

Blotting, Northern↗
PubMed1998

Progress in understanding the molecular pathogenesis of human lung cancer.

We review the molecular pathogenesis of lung cancer including alterations in dominant oncogenes, recessive oncogenes/tumor suppressor genes, alterations in growth regulatory signaling pathways, abnormalities in other pathways, such as apoptosis, autocrine and paracrine growth stimulatory loops, angiogenesis, and host immune responses, other mechanisms of genetic changes, such as microsatellite and methylation alterations, and the potential for inherited predisposition to lung cancer. These changes are related to multistage carcinogenesis involving preneoplastic lesions, and lung development and differentiation. The translational applications of these findings for developing new ways of early detection, prevention, treatment, and prognosis of lung cancer are discussed.

Apoptosis↗
PubMed1998

Characterization of a breast cancer cell line derived from a germ-line BRCA1 mutation carrier.

A tumor cell line, HCC1937, was established from a primary breast carcinoma from a 24-year-old patient with a germ-line BRCA1 mutation. A corresponding B-lymphoblastoid cell line was established from the patient's peripheral blood lymphocytes. BRCA1 analysis revealed that the tumor cell line is homozygous for the BRCA1 5382insC mutation, whereas the patient's lymphocyte DNA is heterozygous for the same mutation, as are at least two other family members' lymphocyte DNA. The tumor cell line is marked by multiple additional genetic changes including a high degree of aneuploidy, an acquired mutation of TP53 with wild-type allele loss, an acquired homozygous deletion of the PTEN gene, and loss of heterozygosity at multiple loci known to be involved in the pathogenesis of breast cancer. Comparison of the primary tumor with the cell line revealed the same BRCA1 mutation and an identical pattern of allele loss at multiple loci, indicating that the cell line had maintained many of the properties of the original tumor. This breast tumor-derived cell line may provide a useful model system for the study of familial breast cancer pathogenesis and for elucidating BRCA1 function and localization.

Adult↗
PubMed1998

Computerized polymorphic marker identification: experimental validation and a predicted human polymorphism catalog.

A computational system for the prediction of polymorphic loci directly and efficiently from human genomic sequence was developed and verified. A suite of programs, collectively called POMPOUS (polymorphic marker prediction of ubiquitous simple sequences) detects tandem repeats ranging from dinucleotides up to 250 mers, scores them according to predicted level of polymorphism, and designs appropriate flanking primers for PCR amplification. This approach was validated on an approximately 750-kilobase region of human chromosome 3p21.3, involved in lung and breast carcinoma homozygous deletions. Target DNA from 36 paired B lymphoblastoid and lung cancer lines was amplified and allelotyped for 33 loci predicted by POMPOUS to be variable in repeat size. We found that among those 36 predominately Caucasian individuals 22 of the 33 (67%) predicted loci were polymorphic with an average heterozygosity of 0.42. Allele loss in this region was found in 27/36 (75%) of the tumor lines using these markers. POMPOUS provides the genetic researcher with an additional tool for the rapid and efficient identification of polymorphic markers, and through a World Wide Web site, investigators can use POMPOUS to identify polymorphic markers for their research. A catalog of 13,261 potential polymorphic markers and associated primer sets has been created from the analysis of 141,779,504 base pairs of human genomic sequence in GenBank. This data is available on our Web site (pompous.swmed.edu) and will be updated periodically as GenBank is expanded and algorithm accuracy is improved.

Computer Communication Networks↗
PubMed1998

Cloning of a breast cancer homozygous deletion junction narrows the region of search for a 3p21.3 tumor suppressor gene.

Chromosome 3p abnormalities and allele loss are frequent in lung and breast cancers, and several lung cancer cell lines exhibit homozygous deletions of 3p indicating potential sites of tumor suppressor genes at regions 3p21.3, 3p14.2 and 3p12. We have identified and characterized a new 3p21.3 homozygous deletion in a breast cancer cell line and the primary tumor that overlaps those previously described in small cell lung cancer (SCLC). This homozygous deletion is approximately 220 kb in length and represents a somatically acquired change in the primary breast cancer. Cloning and sequencing of the breakpoint demonstrated that this resulted from an interstitial deletion and precisely pinpoints this deletion within the three SCLC homozygous deletions previously reported. This deletion significantly narrows the minimum common deleted region to 120 kb and is distinct from the previously reported region that suppresses tumor formation of the murine A9 fibrosarcoma cells. These findings suggest that a common homozygous deletion region on 3p21.3 is important in both lung and breast cancers. It is likely that this very well characterized region either contains one tumor suppressor gene common to both tumor types or two closely linked tumor suppressor genes specific for each tumor.

Adult↗
PubMed1998

Comparison of molecular changes in lung cancers in HIV-positive and HIV-indeterminate subjects.

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. OBJECTIVE: To investigate the molecular changes present in HIV-associated lung tumors and compare them with those present in lung carcinomas arising in HIV-indeterminate subjects ("sporadic tumors"). DESIGN: Convenience sample. SUBJECTS: Archival tissues from 11 HIV-positive persons and from 35 persons of indeterminate HIV status. SETTING: University-based medical centers and affiliated hospitals. MAIN OUTCOME MEASURES: Analysis of frequency of loss of heterozygosity (LOH) and microsatellite alteration (MA) using polymerase chain reaction and 16 polymorphic microsatellite markers at 8 chromosomal regions frequently deleted in lung cancer. Presence of HIV and human papillomavirus (HPV) sequences. RESULTS: The overall frequency of LOH at all chromosomal regions tested and the frequencies at most of the individual regions were similar in the 2 groups. Frequency of MA present in the HIV-associated tumors (0.18) was 6-fold higher than in sporadic tumors (0.03) (P<.001). At least 1 MA was present in 10 (91%) of 11 HIV-associated tumors vs 17 (48%) of 35 sporadic tumors (P=.02). Molecular changes were independent of tumor stage and gender. HIV and HPV sequences were not detected in the HIV-associated lung carcinomas. CONCLUSIONS: Microsatellite alterations, which reflect widespread genomic instability, occur at greatly increased frequency in HIV-associated lung carcinomas. Although the mechanism underlying the development of increased MAs is unknown, it may play a crucial role in the development of many HIV-associated tumors.

Adult↗