Overexpression of mature insulin-like growth factor (IGF)-II leads to growth arrest in Caco-2 human colon cancer cells.

摘要: Abstract Caco-2 cells produce both mature 7500 M r and higher forms of IGF-II (pro – pIGF-II) pIGF-II production is much than that (mIGF-II). The present study was performed to determine whether overexpression mIGF-II or stimulates cell growth. A cDNA construct expresses including the E-domain prepared by cloning a 1250 bp Bam H I– Apa I human prepro fragment downstream CMV promoter in pcDNA3. To create which does not express E-domain, two stop codons were inserted right after glutamine residue D-peptide site directed mutagenesis utilizing expression as template. stably transfected with construct. Secretion into serum-free medium clones constructs compared vector controls. Both clonal lines grew faster control until six days culture. However, at day 12 final density expressing clones. Western blot analysis lysates 8 through anti-IGF-I receptor (IGF-IR) β subunit antibody revealed IGF-IR levels lower overexpressing clone. Furthermore, it shown significantly These results indicate more effective down-regulating pIGF-II. We propose causes down-regulation IGF-IR, leading growth arrest cells.