Low CPNE3 expression is associated with risk of acute myocardial infarction: A feasible genetic marker of acute myocardial infarction in patients with stable coronary artery disease.

Background: Gene COPINE III may be related to a phosphoprotein with intrinsic kinase activity and belongs to an unconventional kinase family. The CPNE3 gene may be used as a biomarker for assessment of occurrence and prognosis of various tumors. Methods: Peripheral blood was collected from 87 stable coronary artery disease (CAD) patients and 91 acute myocardial infarction (AMI) patients. Real-time quantitative polymerase chain reaction test and the western blot method were adopted to measure expression quantity of CPNE3 gene at the mRNA level and the protein level. Results: The expression of the CPNE3 gene in peripheral blood of AMI patients was significantly lower than those in peripheral blood of stable CAD patients. Low expression of CPNE3 gene was found to be unrelated to level of fasting blood glucose and serum blood lipid of patients, quantity of cardiac troponin and time of onset but was found to be correlated to the Gemini score for coronary artery. When the expression of CPNE3 gene at the mRNA level in peripheral blood was used as the criterion for diagnosing AMI, its sensitivity, specificity, positive predictive value and negative predictive value were 69%, 64.8%, 68.6% and 65.2%, respectively. Conclusions: Compared to stable CAD patients, AMI patients have a lower expression of CPNE3 gene in their peripheral blood. Patients who have low CPNE3 expression in peripheral blood are more likely to suffer from AMI than those with stable CAD. Low expression of CPNE3 gene serves as an potential independent risk factor of AMI.