Chromosome 17q23-25 amplification,
expression, and PTEN protein expression in CCC. CGH array was performed to evaluate chromosomal alterations in 28 primary CCC tumors. Nine out of 28 patients (32%) showed chromosomal amplification in the 17q23-25 region that contains miR-21. Seven of 9 tumors (77.7%) with 17q23-25 amplification showed miR-21 overexpression. 17q23-25 amplification with both miR-21 overexpression and PTEN protein loss was detected in 4/28 cases (14.2%).