Application of laser capture microdissection and differential display technique for screening of pathogenic genes involved in endometrial carcinoma

The objective is to eliminate the interference from other cell types; gene fragments involved in endometrial carcinoma (EC) are screened and cloned. Human normal endometrial glandular epithelia and EC cells were harvested with laser capture microdissection (LCM). The purification and concentration of minimal RNA were used to screen differential expressed gene fragments involved in EC by fluoro differential display polymerase chain reaction (FDD‐PCR). The differential gene fragments were cloned, sequenced, and then identified by reverse Northern blot hybridization. Positive fragments were analyzed with basic local alignment search tool (BLAST). Cyclin‐dependent kinase 7 (CDK7) expressions in EC and normal endometrial tissue were tested by immunohistochemical staining. Of 38 differential bands, 3 bands were of high expression in normal endometrium and 35 in EC. Six positive differential gene fragments were obtained and BLAST analysis for them suggested that L1.1 was homologous (99% identical) to the CDK7; L1.9 had a 99% homology with protein phosphatase 1 regulatory (inhibitor) subunit 12 A (PPP1R12A); L1.21 and L1.22 showed a 100% homology with cellular repressor of E1A‐stimulated genes 1 (CREG); and L1.25 and L1.26 indicated more than 98% homology with solute carrier family 39 (zinc transporter), member 10 (SLC39A10). Immunohistochemistry revealed that CDK7 expression was higher in EC than in normal endometrium. We conclude that pathogenic genes involved in EC are obtained with LCM and FDD‐PCR. It has been first found that CDK7, PPP1R12A, CREG, and SLC39A10 are correlative with EC from gene level. CDK7 is strongly associated with EC and can be used as potential molecular marker of EC for further studies.