Transcriptionomic Study on Apoptosis of SKOV-3 Cells Induced by Phycoerythrin from Gracilaria lemaneiformis.

OBJECTIVE To investigate the effects of phycoerythrin (PE) on the human ovarian cancer cell line SKOV-3 and its antitumor mechanisms from a transcriptional point of view. METHODS SKOV-3 cells were exposed to different concentrations of phycoerythrin. The efficiency of this treatment was evaluated through cell growth inhibition, changes in cell morphology, apoptosis and intracellular ROS levels. High throughput sequencing (RNA-seq) was performed to screen differentially expressed genes (DEGs), which was verified using RT-PCR and Western blotting. RESULTS PE showed a significant inhibitory effect on the growth of SKOV-3 cells in a time- and dose-dependent manner. H&E staining, electron microscopy and flow cytometry revealed that PE induced apoptosis in SKOV-3 cells. Transcriptome analysis showed that 2963 genes were differentially expressed between untreated or PE-treated cells. GO and KEGG pathway analyses identified 16 classical pathways that were enriched. We verified 8 DEGs including, JNK, GADD45A, EDEM2, RAD23, UBQLN, CAPN1, XBP1, and OS9. These results were consistent with results from transcriptional sequences. CONCLUSION The inhibitory effect of PE on SKOV-3 cells was a result of interaction with multiple pathways and signaling molecules. Among these, the ROS/JNK/Bcl-2 signaling pathway, upregulation of JNK, GADD45A and RAD23 as well as downregulation of XBP1 and OS9 played a critical role in the PE -induced apoptosis in human ovarian cancer cells.