Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0006826 (cancer)
 1,092,456 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The epidermal growth factor (EGF) receptor (EGFR) can efficiently couple with mitogenic signaling pathways when it is transfected into interleukin-3 (IL-3)-dependent 32D hematopoietic cells. When expression vectors for erbB-2, which is structurally related to EGFR, or its truncated counterpart, delta NerbB-2, were introduced into 32D cells, neither was capable of inducing proliferation. This was despite overexpression and constitutive tyrosine kinase activity of their products at levels associated with potent transformation of fibroblast target cells. Thus, EGFR and erbB-2 couple with distinct mitogenic signaling pathways. The region responsible for the specificity of intracellular signal transduction was localized to a 270-amino acid stretch encompassing their respective tyrosine kinase domains. Thus, tissue- or cell-specific regulation of growth factor receptor signaling can occur at a point after the initial interaction of growth factor with receptor. Such specificity in signal transduction may account for the selection of certain oncogenes in some malignancies.
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PMID:EGF receptor and erbB-2 tyrosine kinase domains confer cell specificity for mitogenic signaling. 218 68

CML has provided a model for the genetic basis of human neoplasia. Since 1960 with the discovery of the Ph chromosome, study of this disease has provided a conceptual basis for viewing cancer as a clonal disorder occurring at the stem cell level and associated with intrinsic genetic defects which contribute to abnormal growth regulation. Although several oncogenes have been identified through the study of tumor-producing retroviruses in animals, discovery of the BCR/ABL translocation, the altered 8.5 kb BCR/ABL transcript, and the hybrid BCR/ABL P210 protein with enhanced tyrosine kinase activity has provided one of the first examples of a human neoplasm in which structural alterations in a normal cellular gene might lead to malignant transformation. However, it is likely that P210 is necessary but not sufficient for the full spectrum of malignant behavior observed in this disease. Investigation of the molecular events that are associated with the additional cytogenetic abnormalities of blast phase will most likely reveal alterations of other important growth regulatory genes which contribute to the multistep nature of malignant transformation in CML.
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PMID:Chronic myelogenous leukemia as a model for the genetic basis of cancer. 218 95

Overexpression of oncogenes has been associated with the pathogenesis of some human cancers. The ros oncogene, which encodes a putative receptor with tyrosine kinase activity, has been recently shown to be specifically expressed in high levels in human astrocytoma and glioblastoma cell lines. Using transcription mapping analysis, we surveyed 25 primary astrocytomas of all histological grades, including glioblastomas, and failed to demonstrate elevated expression of ros in these tumors. This difference between the cell lines and the primary tumors may be due to dilution of the ros-positive clones by larger populations of ros-negative cells in the primary tumors or to induction of ros oncogene when the tumors are adapted to tissue culture.
Cancer Res 1990 May 15
PMID:Differential expression of ros oncogene in primary human astrocytomas and astrocytoma cell lines. 218 78

We have isolated the human homolog (hltk) of the murine tyrosine kinase gene ltk from a K-562 human leukemia cDNA library. The deduced protein sequence of hltk is 17 amino acids longer in the juxtamembrane domain and 28 amino acids shorter in the carboxy terminus than that of murine ltk. The partially identical splicing points of hltk to those of c-ros showed a close genetic linkage between the two. In Northern blot analysis of 35 human malignancies, hltk is preferentially expressed in leukemias (10 out of 18 cases) with no cell lineage specificity, but none of 17 nonleukemic neoplasms expressed hltk gene.
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PMID:Human ltk: gene structure and preferential expression in human leukemic cells. 232 Mar 75

A number of protooncogenes have been implicated in human tumorigenesis. The ABL oncogene is consistently rearranged and activated as a consequence of the translocation t(9;22) that gives rise to the Philadelphia chromosome in chronic myeloid leukemia and in some cases of acute lymphoblastic leukemia. Here we describe rearrangement of ABL in a different type of malignancy. The glioblastoma cell line A172 lacks germline alleles of ABL. A recombination event, presumably followed by a duplication, has created two ABL alleles in which exon 11 is joined to chromosome 16 sequences. Although the main body of ABL exons was still present, two considerably shortened ABL mRNAs of 3.8 and 2.8 kilobases were detected; the 3.8-kilobase mRNA hybridized exclusively to an exon IB probe. Neither mRNA hybridized to an ABL probe encompassing part of the tyrosine kinase domain. Thus, the cell line A172 is able to survive in the absence of a functional ABL gene product, indicating that the role of ABL is unlikely to be "housekeeping."
Cancer Res 1990 Jun 01
PMID:Rearrangement of the human ABL oncogene in a glioblastoma. 233 39

The hallmarks of chronic myelogenous leukemia (CML) include the Philadelphia chromosome (Ph) translocation [t (9;22)(q34;q11)] and consistent molecular genetic aberrations: a break within a restricted 5.8 kb DNA segment, bcr, on chromosome 22q11; transposition of the c-abl protooncogene from chromosome 9q34 to 22q11; and formation of a hybrid bar-abl gene encoding an abnormal 210 Kd bcr-abl protein with augmented tyrosine kinase enzymatic activity. These molecular phenomena may occur even in the absence of cytogenetic evidence of the Ph translocation. They are highly specific and sensitive markers for CML, and are presumed to play a significant role in the pathogenesis of this malignancy. Surprisingly, we have encountered 11 patients who lacked the Ph translocation, bcr rearrangement, and (in the four patients with available mRNA) a bcr-abl message, and yet had a disease phenotype at diagnosis that was a morphologic facsimile of classic chronic phase CML. These patients presented with high white blood cell counts, neutrophilia, occasional basophilia, splenomegaly, and a hypercellular bone marrow with granulocytic hyperplasia and a left shift in myeloid maturation. Despite the striking resemblance between the early stages of bcr-negative and bcr-positive CML, disease progression manifests distinctly in these two disorders. In contrast to the blastic transformation that inevitably complicates bcr-positive CML, the natural history of our 11 Ph-negative, bcr-negative CML patients was characterized by increasing leukemia burden with leukocytosis, pronounced organomegaly, extramedullary infiltrates, and eventual bone marrow failure (anemia and thrombocytopenia) without marked increases in blast cells. Our current observations suggest that a chronic myeloid leukemia process can develop without associated changes in the bcr or c-abl genes. Although the initial phase of this disease is indistinguishable from CML, the presence or absence of molecular markers may aid in the prediction of the clinical course of Ph-negative CML.
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PMID:Philadelphia chromosome-negative chronic myelogenous leukemia without breakpoint cluster region rearrangement: a chronic myeloid leukemia with a distinct clinical course. 240 27

The FMS gene encodes the functional cell surface receptor for colony-stimulating factor 1, the macrophage- and monocyte-specific growth factor. Codons 969 and 301 have been identified as potentially involved in promoting the transforming activity of FMS. Mutations at codon 301 are believed to lead to neoplastic transformation by ligand independence and constitutive tyrosine kinase activity of the receptor. The tyrosine residue at codon 969 has been shown to be involved in a negative regulatory activity, which is disrupted by amino acid substitutions. This study reports on the frequency of point mutations at these codons, in vivo, in human myeloid malignancies and in normal subjects. We studied 110 patients [67 with myelodysplasia (MDS) and 48 with acute myeloblastic leukemia (AML)], 5 patients being studied at the MDS and the later AML stage of the disease. There was a total incidence of 12.7% (14/110) with mutations in codon 969 and 1.8% (2/110) with mutations in codon 301. Two patients had mutations in the AML stage of the disease but not in the preceding MDS and one had a mutation in the MDS stage but not upon transformation of AML. This is consistent with the somatic origin of these mutations. FMS mutations were most prevalent (20%) in chronic myelomonocytic leukemia and AML type M4 (23%), both of which are characterized by monocytic differentiation. One of 51 normal subjects had a constitutional codon 969 mutation, which may represent a marker for predisposition to myeloid malignancy.
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PMID:FMS mutations in myelodysplastic, leukemic, and normal subjects. 240 20

For direct identification of phosphotyrosine-containing proteins in lysates of various cells, phosphotyrosine (P-Tyr) was coupled to carrier proteins and anti-P-Tyr antibodies were raised in rabbits and mice. The antibodies were highly specific for P-Tyr and did not cross-react with phosphoserine or phosphothreonine. The mean association constant of rabbit anti-P-Tyr antibody to N-acetyl-P-Tyr was about four times that of rabbit anti-azobenzene phosphonate antibody. In addition, anti-P-Tyr antibody scarcely cross-reacted with the 5'-monophosphate of ribosyladenine or the 5'-monophosphate of ribosylinosine, whereas anti-azobenzene phosphonate antibody cross-reacted appreciably with these compounds. Anti-P-Tyr antibody immunoprecipitated three oncogenic gene products from cells transformed with Rous sarcoma virus, Fujinami sarcoma virus, and Abelson murine leukemia virus, respectively. The immunoprecipitates with anti-P-Tyr antibody from cells transformed with these three retroviruses all manifested tyrosine kinase activity including activity for phosphorylations of oncogene products. In addition to the proteins reported previously, the following new phosphotyrosine-containing proteins were immunoprecipitated from the respective retrovirus-transformed cells by anti-P-Tyr antibody: Mr 230,000, 74,000, and 24,000 proteins (Rous sarcoma virus); Mr 230,000, 69,000, and 24,000 proteins (Fujinami sarcoma virus); and Mr 230,000, 62,000, and 54,000 proteins (Abelson murine leukemia virus).
Cancer Res 1986 Feb
PMID:Direct identification of phosphotyrosine-containing proteins in some retrovirus-transformed cells by use of anti-phosphotyrosine antibody. 241 36

We previously derived, from a nonmalignant clonal line of rat myogenic cells (L6 alpha 1), two sublines which have lost the capacity to differentiate, the M4 cell of low malignancy and the RMS4 cell of high malignancy. In the present study it is shown that 14 of 15 protooncogenes analyzed exhibit detectable levels of transcripts during L6 alpha 1 cell proliferation. When L6 alpha 1 cells from myotubes, the levels of c-abl, c-myb, and c-Ha-ras transcripts remain unchanged, the level of c-N-ras RNA is augmented, the level of c-erbB RNA is markedly reduced, and all other c-onc transcripts (c-erbA, c-sis, c-src, c-fes, c-fms, c-fos, c-myc, c-Ki-ras, and the putative tyrosine kinase transcript of the c-fgr gene) become hardly, if at all, detectable. Surprisingly, when the three cell types are growing at similar rates only, one protooncogene (c-mos) is not expressed at detectable levels in L6 alpha 1, two others (c-fos, c-erbA) are not expressed in M4 or in RMS4, and three additional ones (c-erbB, c-sis, c-src) are expressed in M4 but not in RMS4. Moreover the level of c-fes RNAs is markedly lower in RMS4 than in M4 or L6 alpha 1. By contrast, the level of two c-Ki-ras 5.4- and 2.2-kilobase transcripts is lower in M4 and L6 alpha 1 than in RMS4, and the latter contains another abundant c-Ki-ras 3.8-kilobase transcript which is hardly detectable in M4 and not at all in L6 alpha 1. These data suggest an activation of the c-Ki-ras gene in the malignant myoblasts and some relationship between the progression of malignancy and inactivation of certain other c-onc genes.
Cancer Res 1986 Aug
PMID:Differential expression of protooncogenes related to transformation and cancer progression in rat myoblasts. 242 41

Previous work has shown that proteins phosphorylated on tyrosine are selectively detectable by antibodies against phosphotyrosine (P-Tyr) in cells transformed by retroviral class-1 oncogene-encoded kinases endowed with non-regulated activity (Di Renzo et al., 1986). In this work P-Tyr antibodies were used to investigate the existence of human tumors expressing abnormal levels of tyrosine phosphoproteins and tyrosine kinases. Among 18 cell lines examined, the antibodies identified a number of tumors with a detectable level of proteins phosphorylated on tyrosine. Among these were a major protein with an approximate Mr of 150,000 in a gastric carcinoma; 2 proteins, with Mr of 130,000 and 110,000 in a colon carcinoma; a major protein with Mr of 170,000, tyrosine phosphorylated in both a urinary bladder and an epidermoid carcinoma; a 100,000 Mr protein phosphorylated in lung and breast carcinomas. An 80,000 Mr tyrosine phosphorylated protein was found in a fibrosarcoma and in a rhabdomyosarcoma. Among the hemopoietic malignancies screened, in 2 Philadelphia-positive chronic myelogenous leukemias P-Tyr antibodies recognized the chimeric bcr-abl 210,000 Mr protein and its substrates. Two tyrosine phosphorylated proteins, one of Mr 70,000 and one of Mr 60,000, were detected in a Burkitt lymphoma line. These phosphoproteins were not found in samples harvested from normal gastro-intestinal or urinary bladder epithelium, nor in control fibroblasts and lymphocytes. Two of the above proteins have associated tyrosine kinase activity: the 170,000 Mr protein of bladder carcinoma cells was found to be a constitutively phosphorylated EGF receptor.
Int J Cancer 1987 Apr 15
PMID:Proteins phosphorylated on tyrosine as markers of human tumor cell lines. 243 63


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