Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using a combination of polymerase chain reaction and single-strand conformation polymorphism techniques (PCR-SSCP) we have analyzed 78 brain tumor samples (70 primary and 8 metastatic) for the presence of mutations in the conserved regions of the Tp53 (tumor p53) gene. We have found that only two groups, gliomas (exclusively in astrocytomas) and metastases, displayed Tp53 mutations. Three of eight (37.5%) metastases showed a mutant Tp53 allele accompanied by loss of the normal one. In contrast, the frequency of Tp53 mutations in the primary brain tumors examined was lower (5.7%). Although we have examined different types of primary brain tumors, Tp53 mutations were exclusively observed in both, low and high-grade astrocytomas (four of 24). The Tp53 mutations detected in astrocytic tumors appear to be correlated with the malignancy grade. The low-grade astrocytomas were heterozygous for the mutation, whereas the high-grade astrocytomas had affected the two Tp53 alleles, suggesting a two-steps model for inactivation of the p53 gene in astrocytomas. Thus, single p53 mutation seems to occur in initial stages of astrocytoma tumorigenesis; the later lost of the remaining wild-type allele appears associated with the progression towards a more malignant stage.
Hum Mol Genet 1993 Oct
PMID:Timing of p53 mutations during astrocytoma tumorigenesis. 826 22

In 42 human gastric adenocarcinomas of intestinal (n = 25) and diffuse types (n = 17) the expression of CD44v6 splice variants was investigated immunohistochemically and compared with the pattern of lymphogenic tumor spreading. Distinct differences were observed between the two cancer types: 92% of intestinal-type tumors expressed CD44v6 as in the intestinal metaplasia in chronic atrophic gastritis, while v6 expression occurred in only 17% of diffuse-type cancers. The analysis of RNA expression confirmed the immunohistochemical data. Intestinal-type cancers yielded a much more complex pattern of amplification products hybridizing to exon v6 than did normal mucosa, whereas diffuse-type tumors did not express exon v6. Also the pattern of lymphogenic spreading was quite different between the two cancer types: in diffuse-type tumors only a sinus carcinosis without CD44v6 expression was observed in a significantly higher number of lymph nodes than in intestinal-type cancers, which showed in particular infiltrative lymph node metastases always with CD44v6 expression as in the primary tumors. When infiltrative lymph node invasion occurred in v6-negative diffuse-type cancers, v6 neoexpression was also demonstrable in the lymph node metastases. Additionally, the number of infiltrative lymphogenic metastases increased with more extensive v6 expression in primary gastric cancers of both types. These data suggest that the expression of CD44v6 isoform is important for the infiltrative spreading of tumor cells into lymph nodes. Additionally, the phenotypic similarities in v6 expression between intestinal metaplasia and intestinal-type cancers, but not of tumors of diffuse type, may support the Correa hypothesis.
J Mol Med (Berl) 1995 Aug
PMID:Importance of different CD44v6 expression in human gastric intestinal and diffuse type cancers for metastatic lymphogenic spreading. 852 41

The HaCa4 cell line, derived from a mouse skin carcinoma induced by Harvey murine sarcoma virus, is highly tumorigenic when injected into nude mice and produces multiple metastases in the lungs. HaCa4 cells express high levels of viral Ha-ras oncogene products, anomalously synthesize the embryonic/simple epithelial keratin K8, and have lost the expression of the cell-cell adhesion receptor E-cadherin (E-CD). E-CD(+) cell clones (E62 and E24), obtained by transfection of an exogenous E-CD cDNA into HaCa4 cells, had a decreased ability to migrate through type IV collagen matrices. However, the E-CD (+) E62 clone remained as metastatic as the parental cell line, whereas the E24 clone, which does not take up the exogenous cDNA but spontaneously switches on the endogenous E-CD gene, suppressed the metastatic phenotype although it maintained its tumorigenicity. E24 cells had fivefold to sixfold lower levels of viral Ha-ras mRNA and p21 protein than the other cell lines. In addition, they did not synthesize K8 but rather switched on keratin K19. The comparison of E-CD proteins synthesized by E62 and E24 cell lines revealed no structural or functional differences because both localized at cell-cell contacts and associated with alpha-catenin, beta-catenin, and plakoglobin. Furthermore, E-CD was still expressed in metastatic lung nodules produced by E62 cells. These results suggest that suppression of the metastatic phenotype in E24 cells occurs independently of E-CD expression and correlates with decreased levels of the oncogenic ras p21 protein.
Mol Carcinog 1996 Feb
PMID:Suppression of the metastatic phenotype of a mouse skin carcinoma cell line independent of E-cadherin expression and correlated with reduced Ha-ras oncogene products. 859 77

Progression of human melanoma toward increasing malignant behavior is associated with several nonrandom chromosomal aberrations, most commonly involving chromosomes 1, 6, 7, 9, and 10. We previously showed that introduction of human chromosome 6 into the highly metastatic human malignant melanoma cell line C8161 completely suppressed metastasis without altering tumorigenicity (Welch DR, Chen P, Miele ME, et al., Oncogene 9:255-262, 1994). Alterations of chromosome 1 are the most frequent chromosome abnormality observed in melanomas, and they frequently arise late in tumor progression. The purpose of the study presented here was to compare the effects of chromosomes 1 and 6 on malignant melanoma metastasis. By using microcell-mediated chromosome transfer, single copies of neo-tagged human chromosomes 1 or 6 were introduced into the human melanoma cell line MelJuSo. The presence of the added chromosome was verified by G banding of karyotypes, fluorescence in situ hybridization, and screening for polymorphic markers on each chromosome. The incidence and number of metastases per lung after intravenous or intradermal injection of parental MelJuSo cells was significantly (P<0.01) greater than those of hybrids containing either chromosome 1 or chromosome 6, although chromosome 1 was a less potent inhibitor of metastasis than chromosome 6. Cultures established from primary tumors and metastases remained neomycin resistant, suggesting that portions of the added chromosomes were retained. These results strengthen the evidence for the presence of a melanoma metastasis suppressor gene on chromosome 6. neo6/MelJuSo hybrids expressed 2.4- to 3.4-fold more of the melanoma differentiation-associated gene mda-6 (previously shown to be identical to WAF1/CIP1/Sdi1/CAP20) than parental metastatic cells. mda-6/WAF1 is among the candidate genes on chromosome 6. These results also demonstrate, for the first time, the existence of metastasis suppressor genes on human chromosome 1, although these genes appear to be less potent than the one encoded on chromosome 6.
Mol Carcinog 1996 Apr
PMID:Metastasis suppressed, but tumorigenicity and local invasiveness unaffected, in the human melanoma cell line MelJuSo after introduction of human chromosomes 1 or 6. 863 87

Breast cancer metastasis to bone is a multistep process requiring attachment of tumor cells to the bone and bone marrow environment. The precise adhesion molecules involved in skeletal homing of breast cancer to bone are unknown but likely include integrins. We investigated the expression of vitronectin receptor (alpha V beta 3) by breast cancer cells residing in bone because this heterodimer mediates osteoclast-bone recognition. We used immunohistochemistry and in situ hybridization in a systematic study of 22 bone biopsies containing breast cancer metastases and available samples of corresponding primary tumors and normal breast and compared alpha V beta 3, alpha 2 beta 1, and alpha B beta 5 integrin expression. The results showed that alpha V beta 3 was strongly expressed by normal breast epithelium and was decreased in some and strongly expressed in other primary invasive breast carcinomas. In contrast, this integrin heterodimer was abundant in all breast cancer cells metastatic to bone. In situ hybridization revealed high levels of steady-state mRNA corresponding to sites of protein expression; alpha 2 beta 1 was weakly expressed in both primary and metastatic tumors, and alpha V beta 5 was not detected. Our results showed an overexpression of alpha V beta 3 by bone-residing breast cancer cells and suggest either subclonal selection of alpha V beta 3-expressing tumor cell populations or upregulation of alpha V beta 3 in the bone microenvironment.
Diagn Mol Pathol 1996 Jun
PMID:Integrin alpha V beta 3 expression by bone-residing breast cancer metastases. 872

Changes in the expression and function of adhesion molecules on the surface of cancer cells are important characteristics in the development of gastrointestinal malignancies and might be used in the future as prognostic factors or as new targets for diagnostic and therapeutic approaches. In esophageal cancer a down-regulation of the E-cadherin receptor and the cytoplasmic protein alpha-catenin is associated with tumor dedifferentiation, infiltrative growth and lymph-node metastasis. In gastric cancer a reduction of E-cadherin expression due to gene mutations is restricted to diffuse-type tumors while the occurrence of the CD44-standard and the CD44-9v isoform is significantly related to a higher tumor-induced mortality and a shorter survival time. The CD44-6v isoform is predominantly expressed by intestinal-type gastric carcinomas, giving these tumor cells the ability to perform lymph-node metastasis. In pancreatic cancer the expression of integrin adhesion receptors is significantly altered during the malignant transformation while a loss of the E-cadherin receptor can generate dedifferentiation and invasiveness of pancreas carcinoma cells. There is increasing evidence that integrin receptors as well as different isoforms of the CD44 receptor are altered following the malignant transformation of colonic mucosa into adenomas and invasive carcinomas. The expression of the CD44-6v isoform seems to be associated with an adverse prognosis in colorectal cancer due to the development of tumor metastases. A strong correlation has been observed between the expression of the 67-kDa laminin receptor and the degree of differentiation, the invasive phenotype and the metastatic abilities af colorectal cancer cells. Analyzing the expression of the E-cadherin receptor showed that this receptor may serve as an independent prognostic marker in Dukes' stage B colorectal cancer to identify patients with poor prognosis and designate them for intensive adjuvant therapy and clinical observation after curative surgical tumor treatment.
J Mol Med (Berl) 1996 May
PMID:Adhesion receptors in malignant transformation and dissemination of gastrointestinal tumors. 877 62

Telomeres, the extreme ends of chromosomes, play an important role in chromosome structure and function. The shortening of telomeres is one of the supposed mechanisms of cellular aging and death. Because of end replication problems the length of telomeres decreases with every cell cycle. This may lead to chromosome instability and additional genetic alterations possibly responsible of significant tumor development. In many cancer cells the length of telomeres depends on a balance between the loss of telomeric repeats, at each replication cycle, and the telomere lengthening, by the enzyme telomerase, which is repressed in most normal somatic cells. Many tumor cells demonstrate shortened telomeres in comparison to the corresponding normal tissue. In some types of human cancers the reduction of telomeric repeats was correlated with increasing disease severity. We analyzed Southern blots of HINF1-digested DNA of a large number of renal cell carcinomas (RCC) including different tumor areas, secondary tumors and metastases (76 cases with 142 tumor samples) for changes in the length of telomeric repeats using the oligonucleotide probe (TTAGGG)3 and found telomere shortening in 54%, suggesting that a reduction of the telomeric repeat length is not a general characteristic in RCC. Intratumor heterogeneity was demonstrated in seven cases. But also two RCC, with elongated telomeres in the tumor tissue, were observed. Shortened telomeres do not seem to be associated with advanced stages of tumor development or specific histopathological subtypes of RCC.
Cell Mol Biol (Noisy-le-grand) 1996 Jun
PMID:Changes in telomere lengths in renal cell carcinomas. 882 3

The metastatic process is characterized by a complex series of sequential steps involving constant interactions (mutual "cross-talks") of metastasized tumor cells with their microenvironment (lymphocyte, macrophages, endothelial cells, etc.) in target organs. These interactions determine the outcome of metastasis (either the eradication of metastatic cells or their increased proliferation and invasion). Recently developed methods of tumor and host cell analysis at the molecular level allow better elucidation of molecular mechanisms of metastasis and of immune mechanisms involved in antitumor responses. Direct modulation of these processes will probably increase the success of clinical cancer treatment. Here we review data (a) on the expression of some costimulatory (MHC class II, CD80, sialoadhesin) and adhesion (LFA-1, ICAM-1, VLA-4) molecules on both metastasized tumor cells and host cells and (b) on the production of a cytotoxic molecule, nitric oxide, by in situ activated Kupffer and endothelial cells in the process of liver metastasis. This study was performed with well-characterized murine ESbL T lymphoma cells transduced with the bacterial lacZ gene, which allows detection and quantification of metastases at the single cell level throughout lymphoma growth and metastasis. Experimental results are discussed in the context of recent literature.
J Mol Med (Berl) 1996 Jul
PMID:New insights into tumor-host interactions in lymphoma metastasis. 884 48

A supportive or causal role for human herpesvirus 6 (HHV-6) in lymphoproliferative disorders is still controversial. Different results were obtained in both tissue-based and serological investigations. We investigated 243 lymph node and salivary gland tissue biopsies for the presence of viral DNA by using a newly developed, highly sensitive nested polymerase chain reaction method. HHV-6 was detected in 39% of the non-Hodgkin's lymphomas, in 52% of Hodgkin's diseases, 64% of non-neoplastic lymph nodes, 23% of tumor metastases, and 50% of salivary gland biopsies. When correlating the patients' ages with the occurrence of HHV-6, we found a significantly higher percentage of positive samples in patients younger than 60 years of age (54%) than in older patients (35%). This age-related difference was found in all the lymphoproliferative disorders studied as well as in salivary gland biopsies. Taking patient's ages into account, we found no significant difference between the various groups of disorders concerning the percentage of HHV-6-positive samples.
Diagn Mol Pathol 1996 Sep
PMID:Presence of human herpesvirus type 6 in sporadic lymphoproliferative disorders. A comparative study. 886 29

We have developed a reverse transcriptase-polymerase chain reaction (RT-PCR) assay to identify breast carcinoma cells in bone marrow aspirates with high sensitivity and specificity. This assay relies on the detection of cytokeratin 19 (K19) RNA by nested primer PCR followed by annealing to a (32P)-labeled internal sequence probe and autoradiography. In reconstitution experiments, this assay is capable of detecting 10 fg of admixed mammary tumor RNA in 1 microgram of normal marrow RNA (a dilution of 1:10(7)). Thirty of 30 primary breast tumor specimens, 19 of 19 cytologically positive bone marrow aspirate specimens, and three of 11 aspirate negative/biopsy positive specimens showed detectable K19 transcript. This assay shows high specificity, with 50 of 52 negative control aspirates showing no detectable amplification product. False-positive amplification was noted in two of 18 aspirates obtained from patients with active chronic myelogenous leukemia. Of stage II and III postsurgical breast carcinoma patients with histologically negative bone marrows and no radiographic bone disease, 14 of 30 were K19 positive by PCR. RT-PCR analysis of K19 transcript is a highly sensitive and specific method of detecting and monitoring low-level metastatic disease in patients with primary carcinoma of the breast. The presence of K19 RNA in histologically negative bone marrows suggests that this assay may prove a powerful monitor for patients undergoing curative therapy as well as a novel prognostic indicator.
Diagn Mol Pathol 1996 Sep
PMID:High-sensitivity detection of minimal residual breast carcinoma using the polymerase chain reaction and primers for cytokeratin 19. 886 30


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