Malignant cell culture, loss

Although efforts are underway to identify markers in serum and prostate tissue, the question arose as to whether metastatic prostate cancer cell lines accurately represent in vivo disease. It was found that in vitro cell cultures (LnCaP and PC3) shared less than 20% of proteins when compared to in vivo LCM procured malignant prostate cancer. 2D-PAGE protein profiles were used to compare normal and malignant cells to immortalized cells from the same patient. Protein expression patterns were dramatically altered when cells were grown in culture and immortalized most notably, a loss of prostate specific antigen expression was observed [18]. Thus, caution must be used when working with immortalized cell lines to discover potential disease markers. 

Many vimses, both DNA and RNA containing, will cause cancer in animals. This so-called oncogenic achvity of a vims can be demonstrated by the observahon of tumour formahon in inoculated experimental animals and by the ability of the vims to transform normal tissue culture cells into cells with malignant characteristics. These transformed cells are easily recognizable as they exhibit such properties as rapid growth and frequent mitosis, or loss of normal cell contact inhibition, so that they pile up on top of each other instead of remaining in a well-organized layer. 

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