Browsing by Subject "Cyclin D1"

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    Aberrant CCND1 copies and cyclin D1 mRNA expression do not result in the production of functional cyclin D1 protein in anaplastic large cell lymphoma
    (Murcia : F. Hernández, 2009) Bobos, Mattheos; Kotoula, Vassiliki; Kaloutsi, Vassiliki; Karayannopoulou, Georgia; Papadimitriou, Constantine S.; Kostopoulos, Ioannis
    Scattered reports in the literature have shown that Cyclin D1 mRNA and protein may be expressed in anaplastic large cell lymphoma (ALCL). ALCLs are characterized by the presence of ALK translocations. Aberrant Cyclin D1 expression seems to promote proliferation in other types of lymphoma, while a growth promoting CCND1/TACSD1(TROP2) fusion product has also been described in tumors. Herein, we investigated 44 ALCL cases for chromosome 11 and CCND1 status (by FISH), cyclin D1 mRNA expression (by in situ hybridization and RT-PCR) and Cyclin D1 protein (by immunohistochemistry with two different monoclonal antibodies), as well as for the expression of Trop-2/GA733-1 (by immunohistochemistry). Polysomy of CCND1 (11q13) and chromosome 11 was found in 15/38 evaluated cases (39.5%). This change was specific for CD30+ neoplastic cells, as shown by double fluorescent staining. Neoplastic cells in the majority of ALCL expressed cyclin D1 mRNA (29/41 [70.7%]), in association with the presence of ALK translocations (p=0.024) and systemic, rather than cutaneous disease (p=0.021). Remarkably, however, Cyclin D1 protein was not detected in neoplastic cells (0/44 cases), neither were these found positive for Trop-2. In conclusion, aberrant copies of CCND1 / chromosome 11 may be observed in ALCL, probably as a consequence of the reported ploidy changes in these tumors. ALCL may often express cyclin D1 mRNA, which, however, does not result in the production of functional Cyclin D1 protein or Trop-2, suggesting that these proteins do not play a role in the pathogenesis of ALCL.
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    Alteration of cell cycle-related genes in hepatocarcinogenesis
    (Murcia : F. Hernández, 1997) Nishida, N.; Fukuda, Y.; Ishizaki, K.; Nakao, K.
    The mammalian cell cycle is controlled by regulators of the G1 to S transition such as tumor suppressor proteins, p53 and retinoblastoma (RB); cyclin D1 and cyclin-dependent kinase 4; and inhibitor of cyclin dependent kinase, Recently, aberrations of these cell cycle-related genes have been reported to contribute to the formation and development of cancer. In human hepatocellular carcinoma (HCC), high frequencies of aberration have been detected in the p53 and RB genes. Loss of heterozygosity (LOH) of chromosome 13q was detected in 35% of HCC and LOH on chromosome 17p was detected in 49%. Mutation of the p53 gene was also detected in 32%. The aberrations of these genes were observed more frequently in poorly differentiated and in advanced HCCs. On the other hand, genetic alterations of the cyclin DI and p161NK4A genes were not so frequent, but appeared to be associated with the aggressive behavior of the tumor, which suggests that disruption of the cell cycle-related genes results in the progression of HCC. Further study with a substantial number of cases is required to determine the actual frequency of the aberrations of the G1 controlling genes in hepatocarcinogenesis.