Different activities of the adenovirus types 5 and 12 E1A regions in transformation with the EJ Ha-ras oncogene (original) (raw)
Related papers
Journal of Virology, 1994
Chimeric adenovirus type 5 (Ad5)/Ad12 early region 1A (E1A) genes were used to transform primary baby rat kidney cells in cooperation with Ad12 E1B, and the resulting cell lines were assayed for tumorigenicity in syngeneic rats. It was found that lines were nontumorigenic when transformed by hybrid E1A genes consisting of the amino-terminal 80 amino acids from Ad12 including conserved region 1 (CR1), with the remaining portion from Ad5. In contrast, cell lines transformed by hybrids containing Ad12 E1A sequences from the amino terminus to the leftmost border of CR3 or beyond were tumorigenic. To extend these results, sequences spanning CR2 and CR3 of Ad5 E1A were replaced with the homologous regions of Ad12 E1A and additional transformed cell lines were established. These lines were weakly-to-moderately tumorigenic, suggesting that Ad12 E1A sequences between CR2 and CR3 may be involved in tumorigenicity but are not the sole factors influencing it. Interestingly, examination of an E1...
Adenovirus type 12 E1B 19-kilodalton protein is not required for oncogenic transformation in rats
Journal of Virology, 1988
The adenovirus type 12 mutants in700 and pm700 carry site-specific mutations within the reading frame encoding the E1B 19-kilodalton protein (19K protein) which prevent the production of the intact 19K protein. In cultures of human A549 cells, these mutants grow just as well as the wild-type virus does, but they display a large-plaque (lp), cytocidal (cyt) phenotype. DNA in these infected cells is not degraded, but at late times in human KB cells infected by the mutants, the mutants display a DNA degradation (deg) phenotype. The transformation phenotype of these mutants is also host range. Although the mutants are defective for transformation of the 3Y1 rat cell line, they transform rat and mouse primary kidney cells in vitro at wild-type efficiency and are capable of inducing tumors in rats. These results support the view that the type 12 E1B 19K protein is not obligatory for oncogenic transformation.
Cancer research, 1985
In this paper, we describe for the first time the transformation of normal rat cells by DNA equivalent to adenovirus type 12 Early Region 1 (E1A). This DNA was 30-fold less efficient at transformation than DNA encoding the entire E1 region. Those established lines expressing a full complement of adenovirus type 12 E1 proteins were phenotypically indistinguishable from adenovirus type 12 virus-transformed cell lines. However, cell lines produced by plasmids carrying subgenomic fragments of E1 DNA and therefore not expressing E1B Mr 52,000 protein took longer to establish and produced tumors only after a protracted latent period. A Giemsa-banding study showed that adenovirus transformation can occur without disruption of the normal rat karyotype.
Cell, 1977
Six independently isolated adenovirus P-transformed rat cell lines and one adenovirus 54ransformed human cell line have been examined in vitro for serum growth requirements, saturation density, anchorage-independent growth, proteolytic enzyme activity and the presence of LETS glycoprotein and T antigen. This series of adenovirus-transformed cell lines exhibits an oncogenic spectrum ranging from being tumorigenic in immunocompetent rats through to nontumorigenic in adult nude mice. The relevance of the in vitro findings to growth potential in vivo is discussed.
Adenovirus Type 12-Rat Embryo Transformation System
Journal of Virology, 1967
Adenovirus type 12 (Huie) inoculated into cultures of primary whole rat embryo produced foci of morphologically altered cells. The number and identification of these transformed areas was dependent upon the calcium concentration of the medium; more foci appeared in 0.1 m m than in 1.8 m m calcium. Cell lines derived from these inoculated cultures did not yield infectious virus, and also were similar to cell lines derived from adenovirus type 12-induced tumors with respect to morphology, presence of virus-specific tumor antigen, and oncogenicity. Dose-response curves revealed that transformation of rat embryo cells by adenovirus type 12 followed one-hit kinetics, and that approximately 7 × 10 5 infectious virus particles were required for one transformation event. Our results indicate that the transformation system described for adenovirus type 12 is reproducible, and that previous difficulties experienced in developing such a system may well be explained by the higher calcium concen...
Tumorigenicity of cells transformed by adenovirus type 12 by evasion of T-cell immunity
1983
Evidence is presented that cells transformed by adenovirus type 12 are oncogenic because they escape from T-cell immunity. This effect is brought about by reducing the expression of class I transplantation antigens and is a function of the protein translated from the 13S mRNA, transcribed from early region la. These findings establish a novel mechanism by which transformed cells can acquire an oncogenic phenotype. ADENOvIRUS-transformed rodent cells exhibit variable degrees of oncogenicity, depending on the adenovirus species used for transformation: rat cells transformed by the highly oncogenic adenovirus 12 (Ad12) are highly oncogenic in the syngeneic host', whereas rat cells transformed by the nononcogenic adenoviruses, for example Ad2 and Ad5, are rarely tumorigenic in immunocompetent syngeneic rats2. It has been proposed that cells transformed by the non-oncogenic adenoviruses fail to form tumours because they are more antigenic than are cells transformed by oncogenic adenoviruses and
Bmc Genomics, 2009
Background: Cells transformed by human adenoviruses (Ad) exhibit differential capacities to induce tumours in immunocompetent rodents; for example, Ad12-transformed rodent cells are oncogenic whereas Ad5-transformed cells are not. The E1A gene determines oncogenic phenotype, is a transcriptional regulator and dysregulates host cell gene expression, a key factor in both cellular transformation and oncogenesis. To reveal differences in gene expression between cells transformed with oncogenic and non-oncogenic adenoviruses we have performed comparative analysis of transcript profiles with the aim of identifying candidate genes involved in the process of neoplastic transformation.
Proceedings of the National Academy of Sciences, 1986
Inbred hamster and mouse cells transformed by the nononcogenic adenovirus (Ad) serotypes, Ad2 and Ad5, are nontumorigenic in syngeneic adult animals, while cells from these species transformed by the highly oncogenic Ad12 are tumorigenic in such rodents. By immunoprecipitation and flow cytometry, cells from four of six Ad2- and Ad5-transformed hamster and mouse lines expressed high levels of cell-surface class I major histocompatibility complex (MHC) antigens, while cells from two of these six lines expressed low levels of cell-surface class I MHC antigens. The levels of class I MHC proteins expressed by cells from these latter two lines were comparable to the levels of cell-surface class I MHC proteins expressed by cells from Ad12-transformed hamster and mouse lines. Moreover, an Ad2-transformed line that had become highly oncogenic after in vivo adaptation showed the same high level of MHC expression as the nononcogenic parent. The amounts of class I mRNA, analyzed by RNA blotting...
Isolation and characterization of four adenovirus type 12-transformed human embryo kidney cell lines
Molecular and Cellular Biology, 1984
Four transformed cell lines were established from cultures of human embryo kidney (HEK) cells microinjected or transfected with cloned adenovirus 12 (Ad12) EcoRI-C DNA (0 through 16.5 map units of the left-hand end of the viral genome). Each cell line showed a different growth pattern. Southern blotting demonstrated that all of the cell lines contained Ad12-specific DNA sequences, but in the microinjected isolates these were at a much lower copy number than in the transfected isolate. Two cell lines (Ad12 HEK 1 and 3) appeared to contain tandemly repeated Ad12 EcoRI-C DNA fragments. Immunoprecipitation and Western blotting confirmed that Ad12 early region 1 (E1) proteins were being expressed by all four of the transformed cell lines, but indicated that E1A polypeptide expression was considerably less than E1B polypeptide expression. All of the Ad12-transformed HEK cell lines were tumorigenic when inoculated intracranially into athymic nude mice.
Transformation of rat cells by DNA of human adenovirus 5
Virology, 1973
Primary rat embryo and baby rat kidney cells have been transformed by human adenovirus 5 DNA. Transforming activity was resistant to heating (1 hr at 56 °C), and to pronase, but was sensitive to DNase. The efficiency of transformation was approximately 1 transformed focus/μg DNA.