Cardamonin Suppressed the Migration, Invasion, Epithelial Mesenchymal Transition (EMT) and Lung Metastasis of Colorectal Cancer Cells by Down-regulating ADRB2 Expression

Context: Cardamonin (CDN) can suppress cell growth in colorectal cancer (CRC), a common digestive malignancy.

Objective: We explored the effect and mechanism of CDN on metastatic CRC.

Materials And Methods: Two cell lines (HT29 and HCT116) were initially treated with CDN at different concentrations (5, 10 and 20 μmol/L) or 50 μmol/L propranolol (positive control) for 24 or 48 h. Then, the two cell lines were separately transfected with siADRB2 and ADRB2 overexpression plasmids, and further treated with 10 μmol/L CDN for 24 h. The cell viability, migration and invasion were determined by cell counting kit-8 (CCK-8), wound healing and transwell assays, respectively. The levels of ADRB2, matrix metalloprotease (MMP)-2, MMP-9, E-cadherin and N-cadherin were measured by Western blotting or/and RT-qPCR. A CRC metastasis model was established to evaluate the antimetastatic potential of CDN (25 mg/kg).

Results: ADRB2 (3.2-fold change;  < 0.001) was highly expressed in CRC tissues. CDN at 10 μmol/L suppressed viability (69% and 70%), migration (33% and 66%), invasion (43% and 72%) and ADRB2 expression (2.2- and 2.84-fold change) in HT29 and HCT116 cells ( < 0.001). CDN at 10 μmol/L inhibited MMP-2, MMP-9 and N-cadherin expression but promoted E-cadherin expression in CRC cells ( < 0.001). Importantly, the effect of CDN on CRC cells was impaired by ADRB2 overexpression, but further enhanced by ADRB2 down-regulation ( < 0.01). Additionally, ADRB2 overexpression reversed the inhibitory effect of CDN on metastatic lung nodules ( < 0.05). CDN is a potential candidate for the treatment of metastatic CRC in clinical practice.