[Analysis of differential proteins in laryngeal carcinoma cell line Hep-2 with transfection of LCRG1].

Background & Objective: Laryngeal carcinoma-related gene 1 (LCRG1), a novel laryngeal carcinoma-related tumor suppressor gene, was cloned with mRNA differential display method. Previous researches showed LCRG1 might inhibit cell growth, proliferation, colony formation in soft agar, and tumorigenesis of laryngeal carcinoma cell line Hep-2. This study was to screen the proteins associated with the tumor suppressive function of LCRG1 by comparative proteomics method.
Methods: The whole cellular proteins of Hep-2/LCRG1 and Hep-2/pcDNA3.1(+) cells were extracted and separated by two-dimensional gel electrophoresis (2-DE) technology. After electrophoresis, the gels were stained by Coomassie Brilliant Blue G-250, and analyzed using PDQuest software. The differentially expressed proteins were cut from the gels, analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), or electrospray ionization-quadrupole time-of-flight MS/MS (ESI-Q-TOF MS/MS), and identified through searching database with Mascot software.
Results: The well-resolved, reproducible 2-DE patterns of Hep-2/LCRG1 and Hep-2/pcDNA3.1(+) cells were established. The total protein spots were 1,075+/-43 in Hep-2/LCRG1 cells and 1,027+/-23 in Hep-2/pcDNA3.1(+) cells, with an average matching rate of 91%. Using mass spectrometry technology, 20 differential protein spots between the 2 cell lines were identified. Among them, 16 were identified by MALDI-TOF-MS, and 4 were identified by ESI-Q-TOF MS/MS. Some of the identified proteins were characterized as members of cellular transcription and metabolism enzymes.
Conclusions: In this study, 2-DE gels of Hep-2/LCRG1 cell line with high expression of LCRG1 mRNA and vector control Hep-2/pcDNA3.1(+) cell line were established; some differential proteins related to LCRG1 were identified by mass spectrometry. These data will help to illustrate the molecular mechanism of LCRG1.