Synthesis of decasubstituted pillar[5]arene derivatives containing L-alanine fragments: self-assembly, cytotoxicity, clonogenic assay and gene expression

Pillar[5]arenes are a new class of molecular receptors that have proven to be an effective drug delivery system overcoming drug resistance.
Cytotoxicity studies on MCF7, HUH7, and BEAS-2B cell lines "using MTT-test" revealed that the ester derivative of pillar[5]arene exhibited cytotoxic activity at concentrations ranging from 2.3 to 3.2 μM, whereas the betaine derivative showed activity at significantly higher concentrations (25.1 to 175.6 μM).
Real-time PCR established that pillar[5]arenes with ester moieties were found to significantly downregulate p21 gene expression in both MCF7 and BEAS-2B cell lines. Additionally, this compound upregulated MDM2 expression in MCF7 cells.
Despite eliciting a robust cellular response, the pillar[5]arenes demonstrated no clearly quantifiable antitumor activity. However, biological properties correlated with the spatial packing of macrocycles, which opens opportunities for 3D macrocyclic systems.