Synthesis, crystal structures, and antiglioma activity evaluation of two novel Ho(III) metal-organic complexes

Abstract

Two new 3-D metal-organic frameworks, {[Ho(H₂O)((CO₂)₃C₂₄H₁₅)]· 7H₂O}_n (1) and {[Ho₃(H₂O)₃((CO₂)₃C₁₈H₁₂N)₃]·7H₂O}_n (2), have been prepared under solvothermal or hydrothermal conditions by using two C₃-symmetrical organic ligands 4,4′,4″-benzene-1,3,5-triyl-tri-benzoic acid (H₃BTB) and 4,4′,4″-nitrilotribenzoic acid (H₃NTB). The in vitro anticancer activities of 1 and 2 were detected on human glioma cell line U251. The MTT assay and the IC₅₀ values indicated that, even though both of these two compounds have anticancer ability, 1 shows a stronger inhibitory effect on cancer proliferation. The Annexin V-FITC/PI assay confirmed that 1 inhibits U251 cells proliferation via apoptosis. This apoptotic effect was mediated by increased ROS and activation of caspase-3 and caspase-8, which is determined by flow cytometer and western blot. We then verified that the anticancer effect of the two new synthesized compounds could be abolished by ROS inhibitor NAC.

Graphical Abstract

Keywords:

• 3-D
• anti-cancer
• glioma
• apoptosis
• ROS
• caspase-3

Disclosure statement

No potential conflict of interest was reported by the authors.