Differential proteome and functional analysis of NSCLC cell lines in response to Tualang honey treatment

Honey's therapeutic and nutrition effects have been discovered for centuries. Traditionally, it is applied as a health supplement as well as an alternative treatment for a variety of medical issues ranging from wound healing to anticancer therapy. Tualang honey (TH) is a natural sweet substance produced by Apis dorsata, naturally has a dark brown appearance from its high polyphenolic compounds. TH has been reported to show anticancer effects on various types of cancers including breast, oral, leukemia, cervical and lung cancer through several pathways. The detailed molecular mechanism of anticancer activity of TH as a chemopreventive and therapeutic agent is an interesting endeavor to understand.

Despite the anticancer effects of Tualang honey (TH) on various types of cancer have been widely reported, the exact molecular mechanism underlying its' anticancer action remains unpublished. Thus, this study aimed to investigate changes that occur on the proteome profile and the functional analysis of proteins with differential abundances within non-small cell lung cancer (NSCLC) cells that were treated with TH and discover the plausible molecular mechanism governing its' anticancer action.

NSCLC cell lines (H23 and A549) were treated with 3.6% and 3.1% v/v of TH for 24 h, respectively. Protein extracts were obtained from control NSCLC cells and TH-treated NSCLC cells. Label-free quantitative proteomic analysis was subsequently performed in nanoACQUITY UPLC with quadrupole-time of flight (Q-TOF) Synapt G2 HDMS mass spectrometer system to identify and quantify proteins of TH-treated NSCLC cells. The gene ontology (GO) PANTHER classification system was performed to categorize the identified proteins based on their protein class, biological processes, and pathway. Meanwhile, the STRING functional protein association network database was used to analyze the functional protein-protein interaction and associated pathways of significantly different proteins of NSCLC cells.

A total of 634 and 554 proteins were identified from H23 and A549 cell lines where 88 differential proteins were upregulated and 103 were downregulated in TH-treated H23 cells, whilst 66 differential proteins were upregulated and 61 were downregulated in TH-treated A549 cells. Differently expressed proteins of NSCLC were observed to be associated with the cell cycle, apoptosis, and VEGFA-VEGFR signaling pathway. TH modulated these signaling pathways through downregulation of ELAVL1, H3F3A and PCNA proteins. Three potential protein markers were significantly downregulated in NSCLC cells such as HRAS, HSPB1, and TUBA1C when treated with TH.

Our findings suggested the anticancer activity of TH on NSCLC cells through modulation of pertinent cancer-related proteins that are associated with cell proliferation, apoptosis inhibition, and induction of angiogenesis.