Therapeutic potential of matrine and osthole against copper-promoted lung cancer cell malignancy

Non-small cell lung cancer (NSCLC) is the major type of malignant tumor in the lungs. Emerging epidemiological evidence implicates environmental copper exposure as a potential risk modulator for NSCLC progression. This study investigated the effects of low-dose Copper (Cu) exposure on A549 cells and evaluated the therapeutic potential of two natural compounds, osthole and matrine. The results demonstrated that Cu exposure (5 μg/mL, 12 h) significantly promoted the migration, invasion and colony formation of A549 cells (P < 0.05), accompanied by a reduction in cell apoptosis, a decrease in ROS levels and an increase in mitochondrial membrane potential. Meanwhile, osthole and matrine treatment could reverse these phenotypes and arrest the cell cycle of A549 in the G1 phase. Transmission electron microscopy results revealed that Cu exposure induced slightly swollen mitochondria and as well as the increase in the number of mitochondria, while osthole and matrine treatments resulted in severe degenerative changes in mitochondria. Both qPCR and Western blot examinations indicated that Cu exposure promoted the expression of PGC-1α but inhibited the expressions of STAT1, TNF-α and IL-2. Osthole treatment could down-regulate the expression of PGC-1α and up-regulate the expressions of STAT1, TNF-α and IL-2, while matrine treatments could up-regulate the expressions of STAT1 and TNF-α and down-regulate the expressions of PGC-1α and IL-2. Taken together, these findings indicate that low-dose Cu exposure can promote the proliferation, migration, invasion and mitochondrial damage of A549 cells, while osthole and matrine treatments inhibit Cu effects by regulating the STAT1, BGC-1 α, TNF-α and IL-2.