Detecting Pin1 MRNA Of Circulating Tumor Cells In Non-small Cell Lung Cancer Patients During Perioperative Period By Real-time Fluorescent Quantitative PCR

BACKGROUD:Phosphorylation of proteins on serine or threonine residues preceding proline (Ser/Thr-Pro) is a major regulatory mechanism in cell proliferation and transformation. Interestingly, the Ser/Thr-Pro motifs in proteins exist in two distinct cis and trans conformations, whose conversion rate is normally reduced on phosphorylation, but is catalyzed specifically by the prolyl isomerase Pin1(Protein interaction with NMA1). And the catalytic reaction of pin1 is a new signal pathway of changing phosphorylation protein function. Pin1 is over expressed in several different human cancers, and it is called the catalytic molecule in the tumor vegetation. This is the first report about the overexpression of pin1 mRNA in the circulation of NSCLC.METHOD:26 consecutive patients with NSCLC who underwent surgical resection with curative intention were randomly assigned PA-first ligation group and PV-first ligation group . The blood samples were collected just before the operation and 7 days later. During the lobectomy, blood samples of the proximal part and distal part of the pulmonary vein when it's ligated were collected.Additionally, 10 patients with benign lung disease served as control subjects undergoing surgical resection ;10 healthy-person served as negative control. All the blood samples were subjected to real-time PCR with Pin1 as marker.RESULTS:(1) Compared to the benign lung disease and healthy-person, the Pin1 mRNA in NSCLC is overexpressed; and correlated with lymph node positive disease and tumor stage(p < 0.05).(2) The expression of Pin1 mRNA in the distal part of the pulmonary vein is significant higher than the proximal part(p=0.019); And the expression of proximal part in PV-first group is lower than the PA-first group (p=0.106), by contrast to diatal part. (p=0.082)(3) The expression after 7 days of the operation was significant lower than the preoperation.CONCLUSION:(1) Pin1 is overexpressed in circulation of NSCLC, and may possibly be used as a tumor marker or as a target for cancer therapy.(2) Surgical manipulation could promote the release of tumour cells into the bloodstream, but the ligation of pulmonary vein before the ligation of the pulmonary artery may partly prevent such release during surgery.