Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029463 (osteosarcoma)
 16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A patient with bilateral retinoblastoma and subsequent multiple primary osteosarcomas has been described previously. Osteosarcoma cell lines established from this patient were shown to express a shortened RB1 mRNA transcript and no detectable normal Rb protein. We now show that the osteosarcoma cell lines have lost one TP53 allele and contain a mutation in exon 8 codon 286 [GAA to AAA (Glu to Lys)] in the remaining allele. Consequently, the osteosarcoma cell lines have no normal Rb protein and no normal p53 protein. Neither constitutional DNA nor DNA extracted from a retinoblastoma of the left eye of the patient contained the TP53 mutation, suggesting that the TP53 mutation in the osteosarcoma cells may represent a tumor-promoting mutation, which confers a selective growth advantage. If both RB1 and TP53 are involved in the initiation of osteosarcoma, the mechanisms for development of the retinoblastoma and osteosarcoma tumors are different.
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PMID:A TP53 mutation detected in cells established from an osteosarcoma, but not in the retinoblastoma of a patient with bilateral retinoblastoma and multiple primary osteosarcomas. 133 9

The retinoblastoma susceptibility gene (RB) product, the retinoblastoma protein (pRb), functions as a regulator of cell proliferation. Introduction of the RB gene into SAOS-2 osteosarcoma cells, which lack functional pRb, prevents cell cycle progression. Such growth-suppressive functions can be modulated by phosphorylation of pRb, which occurs via cell cycle-regulated kinases. We show that constitutively expressed cyclins A and E can overcome pRb-mediated suppression of proliferation. pRb becomes hyperphosphorylated in cells overexpressing these cyclins, and this phosphorylation is essential for cyclin A- and cyclin E-mediated rescue of pRb-blocked cells. This suggests that G1 and S phase cyclins can act as regulators of pRb function in the cell cycle by promoting pRb phosphorylation.
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PMID:Regulation of retinoblastoma protein functions by ectopic expression of human cyclins. 138 95

Human retinoblastomas can occur both as hereditary and as sporadic cases. Knudson's proposal that they result from two mutational events, of which one is present in the germ line in hereditary cases, has been confirmed by more recent molecular analysis, which has shown both events to involve loss or mutational inactivation of the same gene, RB-1 (ref. 2). RB-1 heterozygosity also predisposes to osteosarcoma, and RB-1 allele losses are seen in sporadic lung, breast, prostate and bladder carcinomas. RB-1 is expressed in most, if not all, tissues and codes for a nuclear phosphoprotein which becomes hypophosphorylated in the G0 growth arrest state and in the G1 phase of the cell cycle. To gain a further insight into the role of RB-1 we and other groups have generated mice carrying an inactivated allele of the homologous gene, Rb-1 (ref. 10), by gene targeting. We report here that young heterozygous mice do not appear abnormal and do not develop retinoblastoma at a detectable frequency. However, homozygous mutant embryos fail to reach term and show a number of abnormalities in neural and haematopoietic development. Broadly similar results are reported by the other groups.
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PMID:Requirement for a functional Rb-1 gene in murine development. 140 28

Functionally equivalent genetic maternal can be labelled by an epigenetic marking process and used differentially depending on whether its origin is maternal or paternal. This phenomenon is known as genomic imprinting and is manifested at either the chromosomal or gene level. Genomic imprinting seems to play an important role in cancer predisposition syndromes, and phenotypic consequences are evident in constitutional deletion syndromes and uniparental disomies. Moreover, there seems to be a preferential retention of paternal alleles in sporadic tumours such as Wilms' tumour, rhabdomyosarcoma, osteosarcoma and retinoblastoma. To investigate whether chromosomes involved in acquired abnormalities of haematologic neoplasms show a similar 'parent of origin' bias, we studied the inheritance of the translocated chromosomes 9 and 22 in cases of Philadelphia-chromosome-positive leukaemia, using unique specific chromosome band polymorphisms. Here we show that the translocated chromosome 9 was of paternal origin, whereas the translocated chromosomes 22 were derived exclusively from the maternal copy, in 11 cases with reliable polymorphisms. Our data therefore provide evidence that imprinting phenomena may play an important role in acquired tumour-specific chromosome rearrangements.
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PMID:Parental origin of chromosomes involved in the translocation t(9;22). 140 53

Functional loss of the retinoblastoma (RB) gene has been implicated in the initiation or progression of several human tumor types including cancer of the eye, bone, bladder, and prostate. To examine the consequence of adding one RB allele containing its normal regulatory elements back into representative examples of each of these cancer types, as well as to compare the results to those previously reported using various RB complementary DNA constructs, a neomycin resistant marked 13 chromosome was transferred by microcell fusion. Several attempts to obtain RB positive osteosarcoma cells failed. In addition, only one RB positive retinoblastoma clone was isolated. This clone contained many large cells, could not be maintained in long-term culture, and produced only RB negative tumors. Three RB positive bladder cancer cell clones were obtained, all of which grew slower in culture than their RB negative parental counterpart and did not form colonies in soft agar. Tumorigenicity was markedly suppressed in these clones. One clone yielded no tumors, and the other 2 clones produced only one small tumor each, both of which were RB negative. In contrast, the 2 RB positive prostate cancer cell clones isolated had no differences in their cell culture growth properties, including growth in soft agar compared to the parental cells. One of the clones was nontumorigenic, while the other clone produced 4 small tumors, all of which were RB positive. These results indicate that the transfer of one RB allele by microcell transfer produces different levels of growth inhibition as well as tumor suppression, depending on the cell type examined. In the case of prostate cancer, the function of the RB gene in tumor suppression appears to be independent from its growth regulatory function, since no growth inhibition in cell culture was noted in these cells, although tumor suppression was significant.
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PMID:Changes in growth and tumorigenicity following reconstitution of retinoblastoma gene function in various human cancer cell types by microcell transfer of chromosome 13. 142 76

Proline-directed protein kinase (PDPK) is characterized as a cytoplasmic oncogenic serine/threonine kinase that is activated by growth factor-mediated mechanisms and is proposed to function in mammalian somatic cells as an S phase promoting factor. The present study was undertaken to assess the hypothesis that p34cdc2/p58cyclinA PDPK is a physiologically relevant form of the p34cdc2 protein kinase that phosphorylates and inactivates the product of the retinoblastoma/osteosarcoma tumor susceptibility gene (Rb protein). In the course of these studies it was determined (fortuitously) that the p34cdc2/p58cyclinA PDPK purified from the cytosol of FM3A mouse mammary carcinoma cells was 'contaminated' by several high molecular weight substrate proteins that essentially co-purified with the protein kinase, one of which was identified as the Rb protein itself (p105Rb). High-resolution fast protein liquid chromatography (FPLC) revealed that the Rb protein co-purified with a particular subset of the PDPK heterodimer, i.e. with a single species of the 58 kDa cyclinA doublet. The subset of PDPK associated with the Rb protein exhibited somewhat lower specific enzyme activity, as judged by in vitro kinase assays and comparative Western blotting. Immunoprecipitation studies confirmed that p105Rb is physically associated with the p34cdc2/p58cyclin A PDPK. Further studies confirmed that the underphosphorylated Rb protein (p105Rb) present in G1 lysates of synchronized human MG63 osteosarcoma cells could be readily phosphorylated by purified PDPK in vitro, resulting in the characteristic shift in the apparent molecular mass (SDS-PAGE) of the Rb protein that is reported to accompany the hyperphosphorylation and functional inactivation of this protein. Moreover, the induction of the cyclin A subunit of PDPK in these synchronized MG63 cells was found to be closely correlated with the cell cycle-dependent phosphorylation of the Rb protein. From these studies it is concluded that the growth factor-sensitive PDPK is a physiological Rb kinase, which may function to inactivate the Rb protein in vivo.
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PMID:Co-purification of p34cdc2/p58cyclin A proline-directed protein kinase and the retinoblastoma tumor susceptibility gene product: interaction of an oncogenic serine/threonine protein kinase with a tumor-suppressor protein. 153 45

Upon inactivation of both alleles of the retinoblastoma gene (RB), individuals develop the intraocular eye tumor, retinoblastoma. The gene encodes a Mr 110,000 phosphorylated nuclear protein that may be involved in regulation of the cell cycle. Besides retinoblastoma, mutations of the gene have been detected in several other types of tumors, including bladder carcinoma. Up to one-third of bladder carcinomas may contain mutations of the RB gene. Introducing the retinoblastoma gene into single retinoblastoma, osteosarcoma, or prostate carcinoma cell lines suppresses their tumorigenicity as assayed in nude mice. We have sought to extend these results by introducing the retinoblastoma gene into multiple bladder carcinoma lines, and analyzing several of the resulting, cloned lines. We have found that inhibition of tumorigenicity, as assayed by tumor growth in nude mice or growth of cells in soft agar, is the only consistent phenotype observed upon re-expression of RB in all bladder carcinoma cells examined. The effect of RB expression on growth and cellular morphology varied depending on the particular parental cell line. We conclude that RB expression generally correlates with reduced tumorigenicity, but not reduced growth rate, in bladder carcinoma cells.
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PMID:Expression of the retinoblastoma gene product in bladder carcinoma cells associates with a low frequency of tumor formation. 155 Nov 25

The pattern of malignancies among indigenous Zambian children is described. The study, based upon an analysis of histopathology, autopsy and haematology records for a 10-year period (1980-1989), reveals a total of 525 neoplasms with a peak prevalence in the 5-9 year age group. Non-Hodgkin's lymphoma (17.5%) was the most common disorder followed by Burkitt's lymphoma (13.9%), retinoblastoma (11.4%), Kaposi's sarcoma (8.8%), Hodgkin's disease (5.9%), Wilms' tumour (5.9%), acute lymphocytic leukaemia (4%), rhabdomyosarcoma (3.4%), nasopharyngeal carcinoma (2.7%) and osteogenic sarcoma (2.1%). Kaposi's sarcoma and Hodgkin's disease revealed a significant male dominance; the former presented mainly in nodal form. Compared to an earlier report from Zambia (1968-1972), a significant increase in the incidence of Kaposi's sarcoma and nasopharyngeal carcinoma was noted in the present series.
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PMID:The pattern of paediatric malignancy in Zambia (1980-1989): a hospital-based histopathological study. 156 Apr 80

We have investigated the involvement of tumor suppressor genes in the genesis of osteosarcoma by analyzing allele losses at polymorphic loci in tumor tissues. Genotypes of DNA from primary osteosarcoma tissue and corresponding normal cells from 37 patients were analyzed at 58 polymorphic loci representing each autosomal chromosome arm except 5p and 20q. Allele losses were found at polymorphic loci on 36 of 37 chromosome arms analyzed. In particular, four of them showed frequencies of allele loss higher than 60%: 3q (75%); 13q (68%); 17p (72%); and 18q (64%). This result suggests that, in addition to the RB (retinoblastoma) gene on 13q and the p53 gene on 17p, at least two more tumor suppressor genes located on 3q and 18q are frequently involved in the development of osteosarcoma. The extent of allele losses as defined by fractional allelic loss among 36 tumors was diverse, from 0 to 0.64. The median fractional allelic loss value of 0.32 was much higher than those previously reported in colorectal carcinoma and breast carcinoma. Although no definite association of fractional allelic loss value to clinical prognosis of each case was found in osteosarcoma, tumors with 17p loss were more prone to the early onset of lung metastasis than tumors without 17p loss, indicating that allele loss on chromosome 17p can be a useful measure of prognosis.
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PMID:Allelotype analysis in osteosarcomas: frequent allele loss on 3q, 13q, 17p, and 18q. 156 11

153 patients suffering from retinoblastoma and treated between 1960 and 1980 were analysed retrospectively. Median follow-up was 11.2 years. 13 patients (8.5%) died from retinoblastoma. 3 patients died from a secondary osteosarcoma. The survival rates from patients with differentiated retinoblastomas did not differ from those with undifferentiated tumor cells. Optic nerve invasion decreased significantly the survival rate and involvement of the sectional line led to a survival rate after 5 years of only 22.2%. Due to 3 cases of death from secondary osteosarcoma, the survival rate of 91.14% after 5 years deteriorated to 87.64% after 10 to 14 years.
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PMID:[Effect of histological criteria (TpNM classification, degree of differentiation) on mortality of patients with retinoblastoma]. 161 90


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