RESUMO
Objective To search for lymph node metastasis-associated proteins in human lung squamous carcinoma (hLSC).Methods Laser capture microdissection (LCM) was used to purify the target cells from lung primary tumor and matched lymph node metastatic tumor in hLSC. Two-dimensional gel electrophoresis (2-DE) was performed to separate the total proteins of microdissected tumor cells from lung primary tumor and matched lymph node metastatic tumor. PDQuest software was applied to analyze 2-DE images. Differential protein spots between the two types of tissues were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). The expression of Rho-GDIα, one of the differential proteins, in the microdissected lung primary tumor cells (LPTC) and matched lymph node metastatic tumor cells (LNMTC) was detected by Western blot. Results In the present study, 2-DE patterns of microdissected LPTC and LNMTC were established, and 22 differential proteins in the above two tissues were identified, of which 14 were down-regulated in LNMTC and 8 were up-regulated in LNMTC.Conclusion The 22 differential proteins may play some roles in the process of lymph node metastasis in hLSC, and the data provide new clues for metastasis-associated biomarker screen and mechanism of hLSC.