Proteomic analysis of the stroma-related proteins in nasopharyngeal carcinoma and normal nasopharyngeal epithelial tissues

The stroma surrounding cancer cell population is increasingly recognized as playing an important role in cancer proliferation, invasion, and metastasis. To identify the stromal proteins involved in nasopharyngeal carcinoma (NPC) carcinogenesis, differences in protein expression of the stroma from NPC and normal nasopharyngeal epithelium tissues (NNET) were assessed using a comparative proteomic approach combined with laser capture microdissection (LCM). LCM was performed to purify stromal cells from NPC and NNET, respectively. Proteins between the pooled microdissected tumor and normal stroma were separated by two-dimensional electrophoresis (2-DE) and differential proteins were identified by mass spectrometry (MS). Sixty differential proteins between normal stroma (NS) and tumor stroma (TS) were identified, and the expression of CapG protein was further confirmed by western blotting and immunohistochemical analysis. Our results will be helpful to study the role of stroma in the NPC carcinogenesis and may provide helpful clues for pathogenesis, early diagnosis, and progression of NPC.