Proteomic features of potential tumor suppressor NESG1 in nasopharyngeal carcinoma

We previously defined the recently revised NESG1 gene as a potential tumor suppressor in nasopharyngeal carcinoma (NPC). Here, we further used proteomics technology to globally examine NESG1‐controlled proteins in NPC cells. Twenty‐six proteins were found to be deregulated by NESG1 using proteomics analysis while enolase 1 (alpha) (ENO1), heat shock protein 90 kDa beta (Grp94), member 1 (HSP90B1), and cathepsin D (CTSD) proteins were differentially expressed by Western blot. Interestingly, a‐enolase (ENO1), an overexpressed gene in NPC, was confirmed as a NESG1‐regulated protein in NPC cells. Overexpressed ENO1 not only restored cell proliferation and cell‐cycle progression, but also antagonized the regulation of NESG1 to cell‐cycle regulators p21 and CCNA1 expression as well as induced the expression of C‐Myc, pRB, and E2F1 in NESG1‐ovexpressed NPC cells. Real‐time PCR and immunohistochemistry analysis showed that NESG1 expression is negatively correlated with ENO1 expression in NPC tissues. Our observations suggest that ENO1 downregulation plays an important role in NESG1‐induced growth inhibition of NPC cancer cells.