Di‐2‐picolylamine triggers caspase‐independent apoptosis by inducing oxidative stress in human liver hepatocellular carcinoma cells

Abstract

Di‐2‐picolylamine (DPA) is an organic compound that has been shown to possess antioxidant properties when conjugated to form a metal complex. The basis of this study was to determine the effects of DPA on the proliferation and apoptosis of human hepatocellular carcinoma cells and elucidate the possible mechanisms. The methylthiazol tetrazolium assay served to measure cell viability and generated an IC50 of 1591 µM. Luminometry was used to investigate caspase activity and ATP concentration. It was observed that the decreased cell viability was associated with reduced ATP levels. Despite increased Bax and caspase 9 activity, cell death was caspase independent as indicated by the reduction in caspase 3/7 activity. This was associated with the downregulation poly(ADP‐ribose) polymerase cleavage (Western blotting). However, the Hoescht assay depicted nuclear condensation and apoptotic body formation with elevated DPA levels suggesting DNA damage in HepG2 cells. DNA damage assessed by the comet assay confirmed an increased comet tail formation. The presence of oxidative stress was investigated by quantifying reactive species (malondialdehyde and nitrates concentration) and Western blotting to confirm the expression of antioxidant proteins. The DPA increased lipid peroxidation (RNS), a marker of oxidative stress, consequently causing cell death. The accompanying upregulation of stress‐associated proteins superoxide dismutase (SOD2), nuclear factor (erythroid‐derived 2)‐like 2 (Nrf2), and Hsp70 verifies oxidative stress.

CLASRP oncogene as a novel target for colorectal cancer

“…The activation of caspase-3 is a central event in the process of apoptosis (Budihardjo et al 1999 ; Thornberry and Lazebnik 1998 ; Wolf and Green 1999 ). This cysteine protease, which is proteolytically activated by the cleavage of pro-caspase-3 by caspase-8, cleaves several intracellular proteins (Madide et al 2021 ; Thornberry et al 1997 ). Therefore, the results confirmed that the Clk inhibitor could more severely induce apoptosis of CRC cells overexpressing CLASRP.…”

The toxicogenic effect of Terminalia phanerophlebia Engl. & Diels leaf extract on oxidative stress parameters in an in vitro Hek293 model

“…Thereafter, the buffer was discarded followed by blocking the membrane with 5% BSA for 2 h. HRP-conjugated house-keeping antibody β-actin (abd1214) (1:5000 dilution in 5% BSA/TTBS 1 h) was then added. After successive washes in TTBS, the membrane was viewed as described previously (Madide et al, 2020).…”

DPA‐Substituted Carbazole Derivative as a Fluorescent Ligand for G4 DNA

“…Di‐2‐picolylamine (DPA) is an organic compound that consists of 2 picolyl groups substituted with amine groups on each side. The nitrogen atoms on the picolyl groups are the atoms that have been proven to have anticancer activities [30] . Thus, DPA and N ‐substituted DPA derivatives have been investigated for their anticancer activities against malignant cells [31] .…”

“…The nitrogen atoms on the picolyl groups are the atoms that have been proven to have anticancer activities. [30] Thus, DPA and N-substituted DPA derivatives have been investigated for their anticancer activities against malignant cells. [31] With respect to the literatures, structural design of carbazole probes with substituents at the 9 th position and their molecular interactions with G4 DNAs have been rarely discussed.…”