*2.6. Gene Expression Analyses*

We investigated the gene expression involved in the formation of cell junctions, in cell migration, and in DNA repair, as well as whether this gene expression is associated with the metastatic potential of cells (*MMP2*, *MMP9*, *OCLN*, *CTNNB1*, and *ERCC1*). Gene expression levels in the treated A549 cells were compared with those measured in the untreated, control cells grown only in the nutrient medium (Figure 4).

**Figure 4.** Effects of DOX IC20, MAE (20 μg/mL), MAW (20 μg/mL), or their combinations on gene expression.

DOX treatment was shown to decrease *MMP2* expression, while both the applied extracts and DOX/extract combinations slightly increased the expression of this gene (Figure 4). In contrast to this, *MMP9* expression was considerably lower after treatment with combination of the cytostatic and the investigated plant extracts (Figure 4), but it increased after treatment with DOX alone, in contrast to the control. Furthermore, DOX treatment was shown to inhibit the expression of *OCLN* and induce

*CTNNB1* expression. Both the investigated extracts alone and the DOX/MAE combination treatment induced expression of *OCLN* (Figure 4) as opposed to the control cells, while its expression in cells treated with the DOX/MAW combination was higher than in cells treated with DOX alone. There were no alterations in *CTNNB1* expression after treatment with the DOX/MAW combination, while its expression was shown to be slightly lower after treatment of cells with the DOX/MAE combination than in the untreated cells (Figure 4).

Cells treated with MAE alone showed a slight increase in *ERCC1* expression levels, while inhibition of this gene expression was observed in samples treated with DOX, in those treated with MAW, as well as in those treated with the DOX/plant extract combination (Figure 4).
