THE EFFECT OF NATURAL AND SYNTHETIC COMPOUNDS ON COLORECTAL CANCER: IN VITRO AND IN VIVO STUDIES

Abstract

Colorectal cancer (CRC) is one of the deadliest malignancies in the world. Despite improved treatment, CRC incidence and mortality rates have been increasing lately. Current conventional therapies are associated with severe side effects that affect patients' quality of life. Drug resistance, severe pain, hair loss, and blood abnormalities are the most common side effects. Therefore, novel, and safe alternatives are required to control metastasis and prevent CRC with minimum or no side effects. Recently, natural products became an attractive target as a safe resource for anticancer agents. Flavonoids are a group of biologically active compounds naturally found in a wide range of human dietary. Additionally, flavonoids from natural and synthetic sources, showed significant therapeutic effects against CRC. Elaeagnus Angustifolia (EA) is a natural resource for flavonoids traditionally used to treat different illnesses. Another resource for flavonoids is synthetic chalcone analogs. Previous work from our team explored the effect of EA and chalcone compounds against various types of cancer. In this study, we sought to particularly illustrate the impact of the EA flower’s aqueous extract and the nitrogen-based-synthetically designed chalcone analogs (DK13 and DK14) and their underlying mechanisms of action on CRC using in vitro (the human CRC cell lines [𝐻𝐶𝑇-116 and LoVo]) and in vivo (the Drosophila melanogaster Ras mutant fly lines) model systems. Our results showed that EA extract inhibits cell proliferation and alters cell cycle progression of both CRC cell lines as compared to the control group. Moreover, EA extract significantly reduces colony formation and cell invasive ability of HCT-116 and LoVo cell lines; a phenotype accompanied by a significant upregulation of E-cadherin and a downregulation of vimentin and β-catenin, which are important epithelialmesenchymal transition (EMT) biomarkers. Also, and as detected in our in vivo model, EA-treated Ras85D mutant fly lines exhibited a significantly increased survival rate as compared to their control. Furthermore, molecular pathway analysis in vitro revealed a significant suppression in total and phosphorylated EGFR and AKT expression in EAtreated cells as compared to controls, suggesting the EGFR-RAS and PI3K-AKT pathways as key molecular pathway targeted by EA to control ongoing oncogenic events. Along this, our data related to DK13 and DK14 also revealed that these compounds inhibit cell proliferation and deregulate cell-cycle progression in both cell lines. Additionally, DK13 and DK14 significantly reduce cell invasion and colony formation of both cell lines compared to the action of conventional anticancer 5'fluorouracil (5-FU) and DMSO-treated control. This was translated into a significant increase in the survival rates of D. melanogaster Ras85D mutant fly lines as compared to their controls. Moreover, the molecular pathway analysis of chalcone- treated cells revealed an inhibitory effect of DK13 and DK14 on the expression patterns of both AKT and mTOR, highlighting RAS/MAPK and PI3K/AKT/mTOR pathways as key molecular pathway targeted by DK13 and DK14 to control ongoing oncogenic events. Collectively, our study findings demonstrate an apparent anticancer effect of EA extract and chalcone compounds on CRC, presenting EA, Dk13, and Dk14 as promising chemotherapeutic agents.