Neoplastic cells transformation

Propylene oxide is mutagenic in several microorganisms and in Drosophila. It induces sister chromatid exchanges and chromosomal aberrations, as well as DNA damage (single- and double-strand breaks) in human cells. Propylene oxide induces neoplastic cell transformation in mouse embryo cells. 

Lee KM, Lee DE, Seo SK, Hwang MK, Heo YS, Lee KW, Lee HI (2010) Phosphatidy-linositol 3-kinase, a novel target molecule for the inhibitray effects of kacunpferol on neoplastic cell transformation. Carcinogenesis 31 1338-1343... 

Cancer results from the multistep accumulation of somatic, and occasionally inherited, mutations that lead to clonal neoplastic cell transformation [1]. The associated genetic lesions include the activation of dominant oncogenes and the inactivation of tumor suppressor genes through mutation and loss of heterozygosity. Some 191 cancer genes have been reported, 90% of them exhibiting somatic mutations [2]. 

The process, once initiated, is self-sustaining and may become more accelerated with time because the atrophy and intestinal metaplasia are progressive lesions and lead to further loss of parietal cells and incrased bacterial colonization of the mucosa. The initial mutations transform gastric cells into mature intestinal-type cells. Further superimposed mutations transform metaplastic cells into progressively dysplastic cells and eventually into neoplastic cells. This is a process of loss of differentiation which implies a multihit phenomenon which could be explained on the basis of continued formation of minute amounts of nitroso compounds over many years. 

The SHE cell transformation assay at pH 6.7 is conducted to determine the ability of a test article to induce morphological transformation in cultured SHE cells. The SHE cell transformation assay is one of the most widely used cell transformation assays. The endpoints of this assay are related to the conversion of normal cells into preneoplastic or neoplastic cells. The assay provides a valuable tool in the process of assessment and evaluation of the carcinogenic potential of a test article.2 28... 

Transformation the conversion of normal cells into neoplastic cells. 

Cancer is a disease present in people and animals in which the stracture and normal function of body tissues are disrupted. The exact etiology of most types of cancer is unknown. However, it is well known that infections, environmental factors (chemical substances, foreign particles, radiation), and genetic factors can induce transformation of normal cells to neoplastic cells, i.e. those that multiply and function abnormally. 

As so many physiological compounds regulating cell growth and metabolism appear to interact with gangliosides as components of cellular receptors, it has been suggested that the loss of growth control in certain transformed cells may partially be based on the altered gaug-lioside composition observed in neoplastic cells.541... 

Neoplastic transformation in ceU culture is a multistage process, and the mechanisms of the different steps in this process may vary. For example, some aneuploid ceU lines, which are nontumorigenic, have some properties of neoplastic ceUs and progress to neoplastic cells more... 

Butyrate appears to have its most profound effects on neoplastic cells such as HeLa in addition to morphological and biochemical differentiation, the fatty acid inhibits cell growth (2). Previous studies have established a correlation between decreased ganglioside synthesis and malignant transformation (43-46). Transformed baby hamster kidney and newborn rat kidney cells exhibited a loss of GM3 and sialyl transferase activity (43,44). 

This usually means that the system should detect three major classes of mutation—genic, chromosomal, and genomic. Only with additional justification would other end points, such as chemical damage to DMA and mammalian cell transformation (neoplastic transformation), be recommended as part of a mutagenicity test battery. Such systems can be validated by demonstrating that they predict mutation. 

HeLa cells (Gey, 1955) were derived originally from tumour tissues and appear to have been transformed in vivo. Although not all neoplastic cell populations will grow indefinitely in vitro many of the human cell lines in common use have such an origin (e.g. HEP2, KB, Detroit 6). 

Syrian hamster embryo (SHE) cell transformation assay (In vitro) (SHE cells are used to evaluate the potential of a wide range of agents to induce morphological transformations. Following carcinogen exposure (1-7 days), SHE cells display a multistage pattern of neoplastic progression similar to that observed in vivo)... 

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