Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In human fibroblasts, the expression of SV40 large T antigen is known to cause a variety of chromosomal aberrations and especially dicentric chromosomes. In some cases, the later aberrations have been reported to be reversible telomeric associations. We report here aberration and chromosome number studies of twenty-nine T antigen positive lineages, studied from their initiation by transfection of T antigen sequences into human diploid fibroblasts, until crisis or immortalization occurred or, in some cases until the lines became tumorigenic in nude mice. The data show that T antigen consistently produced chromosomal instability of both number and structure by an active process that began before transformation indicators were positive and continued throughout neoplastic progression. The most frequently observed aberrations were dicentric chromosomes, which were shown to be true dicentrics by examination by in situ hybridization with telomeric sequences. These data are consistent with the hypothesis that T antigen causes human fibroblasts to become neoplastically transformed by successive rounds of chromosomal mutation and lineage evolution.
 ...
PMID:SV40 T antigen induced chromosomal changes reflect a process that is both clastogenic and aneuploidogenic and is ongoing throughout neoplastic progression of human fibroblasts. 128 Dec 78

Ribonuclease/angiogenin inhibitor (RAI) is a tight-binding inhibitor of ribonucleolytic and angiogenic activities involved in tumor progression. It is translated from various mRNAs differing in their 5 regions and originating from a single gene locus. Recently, this gene (RNH) has been assigned to 11p15.5, the terminal part of the short arm of chromosome 11. The regional chromosomal localization was confirmed by somatic cell and in situ hybridization and further refined by long-range restriction mapping. The data place RNH within 90 kb of the Harvey-ras protooncogene (HRAS), so far the most telomeric gene on 11p, in a region involved in growth regulation and tumor development.
 ...
PMID:The human ribonuclease/angiogenin inhibitor is encoded by a gene mapped to chromosome 11p15.5, within 90 kb of the HRAS protooncogene. 154 20

Cytogenetic evidence of clonal evolution was detected in five uterine leiomyomas. In two tumors, two clones were found, the third tumor had four, the fourth had nine, and the fifth had 12 clones. The first tumor had trisomy 12 as the primary anomaly and a sideline that also contained a del(7)(q21q31). Both clones of the second tumor had three structural changes in common but differed by the presence in the more advanced clone of an inv(7)(q31q34). Two cytogenetically unrelated pairs of clones were seen in the third tumor. One clone had a stemline of 46 and an r(1); a sideline had developed through duplication of this clone. The other pair had a del(7)(q21q31) in common. The last two tumors both had t(12;14)(q14-15;q23-24) as the primary abnormality. They also had a high frequency of telomeric associations that involved certain chromosome arms only. One of the secondary changes in the fourth tumor was a del(7)(q21q31); the principal secondary change in the fifth case was a ring chromosome 1 of variable size in the different clones. The analysis of these five uterine leiomyomas and the collation of the results with previously obtained data lead us to conclude that del(7)(q21q31) is secondary to t(12;14) and + 12 in this tumor type, and that ring formation involving chromosome 1 material, often with duplication of segments, is a common phenomenon during clonal evolution. The fact that the tumors were classified as cellular and had an increased mitotic rate indicates a parallel development between histologically detectable tumor progression and cytogenetically recognizable clonal evolution in uterine leiomyomas.
 ...
PMID:Parallel karyotypic evolution and tumor progression in uterine leiomyoma. 226 79

Fifty-one randomly selected primary squamous cell carcinomas of the head and neck, derived from the larynx (n = 18) and pharynx (oropharynx, n = 18, and hypopharynx, n = 15) were analyzed with centromeric probes for chromosomes 1, 7, 9, 11, 17, and 18 to study numerical aberrations, chromosome imbalances, and aneuploidy by fluorescence in situ hybridization. The tumors were grouped into nonmetastasizing (N0) tumors (from patients clinically free of lymph node metastases for at least 18 months after surgery, n = 25) and metastasizing (N1-3) tumors (n = 26). We found a significant association between the tumor ploidy and the nodal status; in the N0 group, diploidy prevailed, and the most common aberration was loss to monosomy for chromosome 9 (44%), whereas in the N1-3 group, aneuploidy predominated (P = 0.002). Specifically, these genomic changes associated with progression to metastasis were: (a) tetrasomic or polysomic chromosomes were detected in 17 of 26 N1-3 tumors but in none of the 25 N0 tumors (P < 0.0001); (b) heterogeneous chromosomal copy numbers (i.e., extensive chromosomal imbalances) were also much more frequent in the N1-3 tumors (69.2% versus 24.0% in the N0 group; P = 0.018); and (c) loss of chromosome 9 (73%) and gains of chromosomes 7 (35%) and 17 (31%) persisted, but in addition, loss of chromosome 18 occurred in 31%. Overexpression of the p53 protein correlated with an increased incidence of chromosomal imbalances and aneuploidy (P < 0.001) and, hence, constituted an additional risk factor. The lower metastatic potential of larynx tumors as compared with tumors from the pharynx was reflected by a lower incidence of these genomic changes. These specific patterns of chromosomal aberrations can characterize and distinguish different stages of tumor progression of squamous cell carcinomas of the head and neck and should be valuable diagnostic and prognostic markers.
 ...
PMID:Distinct nonrandom patterns of chromosomal aberrations in the progression of squamous cell carcinomas of the head and neck. 758 47

To examine the significance of Y chromosome losses in bladder cancer, fluorescence in situ hybridization (FISH) was used to determine its prevalence and associations with known parameters of malignancy. Cells were dissociated from formalin-fixed paraffin-embedded bladder tumors from 68 male patients and from 11 post-mortem bladder washes of male patients with a negative bladder cancer history, and were examined by FISH using centromeric probes for chromosomes X, Y, 7, 9, and 17. Nullisomy for chromosome Y was seen in 23 of 68 tumors (34%), monosomy in 28 of 68 tumors (41%), and polysomy in 17 of 68 tumors (25%). There was no association between chromosome Y loss and tumor grade, stage, tumor growth fraction (Ki67 LI), p53 immunostaining, and presence of p53 deletions. Patient age was higher for tumors with a Y loss (73.5 +/- 12.0 years) than for tumors without Y loss (66.6 +/- 10.8 years; p = 0.0207). In one normal bladder wash, a distinct subpopulation (38% of cells) with Y nullisomy was seen. These data suggest that Y loss is a frequent event that can occur early in bladder cancer, although there is no evidence for a role of Y loss in tumor progression.
 ...
PMID:Y chromosome loss detected by FISH in bladder cancer. 766 48

To investigate the possibility of collaboration between telomeric deletion on the short arm of chromosome 1 and genetic amplification similar to that described in human neuroblastoma, 122 human primary breast tumors were examined by restriction fragment length polymorphism analysis for loss of heterozygosity on 1p32-pter and for the three most frequently amplified genetic regions in breast carcinomas (MYC and ERBB2 protooncogenes and the chromosomal region 11q13). Allelic losses at one or more loci on the telomeric part of the short arm of chromosome 1 was observed in 57 (47%) of 122 informative tumors. MYC, ERBB2, and the 11q13 region were amplified in 23, 20, and 21% of breast tumors, respectively. A correlation was found between loss of heterozygosity on chromosome 1p32-pter and amplification of the MYC (formerly c-myc) protooncogene (P = 0.003), suggesting that these two genetic events may collaborate during tumor progression in human breast cancer. These results, together with those obtained in human neuroblastoma, suggest that the distal part of the short arm of chromosome 1 harbors an unidentified tumor suppressor gene(s), whose inactivation may be involved in MYC family gene amplification (an example of genetic instability) in tumors of various cellular origins.
 ...
PMID:A tumor suppressor gene on chromosome 1p32-pter controls the amplification of MYC family genes in breast cancer. 791 73

Cytogenetic analysis has been carried out on 17 parallel short-term cultures from four malignant testicular teratomas of intermediate differentiation (MTI), two of them combined with seminomas. Clonal development was seen in three tumors, with most of the variation involving different rearrangements of chromosome 1. Two copies of the i(12p), characteristic of testicular germ-cell tumors, were present in the two tumors with yolk sac elements, a single i(12p) and a 12q- were found in an MTI that had metastasized, and a rearrangement of chromosome 12 containing centromeric chromatin from chromosome 18 was found instead of the i(12p) in a mixed tumor. A 13p+ marker containing Q-negative material was seen in two of the tumors, with a der(7)t(Y;7) in one. Chromosomes 1, 3, 6, 7, 8, 12, 17, and X were invariably overrepresented either as complete or partial trisomies, and chromosomes 4, 5, 13, and 18 were underrepresented in all four tumors, strengthening the idea that tumor suppressor genes on the latter four chromosomes, all of which show some loss of heterozygosity with DNA markers, may be important in tumor progression.
 ...
PMID:Chromosome analysis of parallel short-term cultures from four testicular germ-cell tumors. 805 86

Our recent allelic analysis of head and neck squamous cell carcinomas identified a high incidence of chromosomal loss on 13q. To further define an area of minimal loss, we tested 60 primary head and neck squamous cell carcinomas in 59 patients for loss of heterozygosity (LOH) by using 10 polymorphic microsatellite markers spanning the long arm of chromosome 13. We examined the same primary tumors for inactivation of the retinoblastoma (Rb) gene by immunohistochemical analysis of paraffin-embedded specimens. Thirty-one of 60 (52%) tumors demonstrated LOH in at least one 13q marker. Twenty-nine of 31 (94%) lost a portion of 13q that included D13s133, which lies just telomeric to the Rb gene at 13q14.3. However, immunohistochemical staining revealed absence of Rb protein in only 6 of these 31 tumors (19.4%) with LOH. All but one tumor without LOH on 13q displayed normal Rb protein staining. Although Rb may be inactivated by an unusual mechanism in some head and neck squamous cell carcinomas, our data suggest that another tumor suppressor gene locus at 13q14 is likely to be involved in head and neck tumor progression.
 ...
PMID:Infrequent inactivation of the retinoblastoma gene despite frequent loss of chromosome 13q in head and neck squamous cell carcinoma. 806 50

Alterations of the p53 gene are among the most frequent genetic lesions in a variety of human malignancies. Their role in prostate cancer is, however, unclear. We have analyzed 10 primary and two metastatic human prostate carcinomas as well as 3 prostate cancer cell lines for mutations of the p53-gene. Using single strand conformational polymorphism analysis (SSCP) and direct sequencing of the polymerase chain reaction (PCR) products, p53 mutations were detected in 1 of 10 primary prostate cancers. By contrast, 1 of 2 metastatic tumors and all 3 prostate cancer cell lines (derived from metastases) were found to contain a mutant p53 gene. Thus, our data suggest that alterations of the p53 gene at the mutational "hot spots" appear to occur infrequently in primary human prostate cancer, but may emerge in later stages of tumor progression. Furthermore, we confirm that loss of heterozygosity at a locus telomeric to p53, but not including p53, is associated with metastatic progression in 1 case.
 ...
PMID:p53 gene alterations in human prostate carcinoma. 851 Feb 67

There is increasing evidence supporting the hypothesis that telomere shortening both in vitro and in vivo, is the clock that counts cell divisions and determines the onset of cellular senescence. Cells that overcome the normal senescence mechanisms do so by stabilizing telomere length, probably due to the activity of telomerase, a ribonucleoprotein enzyme that synthesizes telomeric repeats. Most human primary tumors contain telomerase, while the cells of most normal tissues lack this activity. A hypothesis gaining prominence is that the activation of telomerase is necessary for the sustained growth of most solid tumors. Since normal hematopoietic stem cells and some of their progeny already express telomerase activity, it is important to consider whether or not telomere shortening and telomerase activity play any role in cancer progression in various forms of leukemia. This review includes a discussion of the utility of telomere length and/or telomerase activity measurements in the diagnosis and prognosis of leukemia as well as the potential value of antitelomerase therapy for the leukemias.
 ...
PMID:Telomeres and telomerase in human leukemias. 870 28


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