Pectolinarigenin (PEC), a natural
flavonoid that is present in citrus fruits, has been reported to exhibit antitumor effects in several
cancers. Though the mechanism of PEC-induced cytotoxicity effects has been documented, the proteomic changes that are associated with the cellular response to this
flavonoid are poorly understood in
gastric cancer cells. In this study, a comparative proteomic analysis was performed to identify
proteins associated with PEC-induced cell death in two human
gastric cancer cell lines: AGS and MKN-28. Two-dimensional gel electrophoresis (2-DE) revealed a total of 29 and 56
protein spots with significant alteration were screened in AGS and MKN-28 cells respectively. In total, 13 (AGS) and 39 (MKN28)
proteins were successfully identified by mass spectrometry from the differential spots and they are known to be involved in signal transduction, apoptosis, transcription and translation, cell structural organization, and metabolism, as is consistent with multiple effects of PEC on
tumor cells. Notably, novel target
proteins like Probable
ATP-dependent
RNA helicase DDX4 (DDX4) and E3
ubiquitin-protein ligase LRSAM1 (LRSAM1) along with the commonly differential expressed
proteins on both the cell lines that are treated with PEC were confirmed by immunoblotting. The DDX4 accelerates cell cycle progression by abrogating the G2 checkpoint when overexpressed in
cancer cells, while the aberrant expression of LRSAM1 may be involved in the
cancer pathology. Thus, proteomic analysis provides vital information about target
proteins that are important for PEC-induced cell death in
gastric cancer cells.