Insulin and IGF-1 mediated inhibition of apoptosis in CHO cells grown in suspension in a protein-free medium.

摘要: ·When Chinese hamster ovary (CHO) cells were grown in suspension and deprived of serum, 40% them became apoptotic after 72 hours, as determined by flow cytometry analysis TUNEL-labelled cells. Cell viability, assessed erythrocin B staining, decreased correspondingly. An increase the total fraction expressing interleukin converting enzyme (ICE; caspase 1), B-cell lymphoma 2 protein (Bcl-2,) Bcl-2 associated x (Bax) was shown antibody probing subsequent cytometry. The p53 tumour suppressor gene product level remained low within cell population. Insulin-like growth factor-1 (IGF-1) inhibited death a concentration-dependent manner, at 20ng/ml, viability maintained close to 100% no detected. Also, insulin inhibit - 1.0μg/ml, 95%, whereas 10% stained for apoptosis. At highest concentrations IGF-1 insulin, expression ICE, Bax fully suppressed, increased, despite still being detectable minority Under these conditions, may restrain abnormal proliferation. It is concluded that special attention should be paid exposure culture conditions induce acquired susceptibility toxic insult, during development validation cell-based assays.