Role of Δ133p53 isoform in NF-κB inhibitor PDTC-mediated growth inhibition of MKN45 gastric cancer cells

Abstract

AIMTo investigate the role of Δ133p53 isoform in nuclear factor-κB (NF-κB) inhibitor pyrrolidine dithiocarbamate (PDTC)-mediated growth inhibition of MKN45 gastric cancer cells.METHODSThe growth rate of MKN45 cells after treatment with different concentrations of only PDTC or PTDC in combination with cisplatin was detected by the CCK-8 assay. mRNA expression levels of Δ133p53, p53β, and the NF-κB p65 subunit and p65 protein levels were detected by reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence, respectively. Growth of MKN45 cells was significantly inhibited by PDTC alone in a dose-dependent manner (P < 0.01). Moreover, the inhibitory effect of cisplatin was remarkably enhanced in a dose-dependent manner by co-treatment with PDTC (P < 0.01).RESULTSRT-PCR analysis revealed that mRNA expression of p65 was curbed significantly in a dose-dependent manner by treatment with only PDTC (P < 0.01), and this suppressive effect was further enhanced when co-treated with cisplatin (P < 0.01). With respect to the other p53 isoforms, mRNA level of Δ133p53 was significantly reduced in a dose-dependent manner by treatment with only PDTC or PTDC in combination with cisplatin (P < 0.01), whereas p53β mRNA expression was not altered by PDTC treatment (P > 0.05). A similar tendency of change in p65 protein expression, as observed for the corresponding mRNA, was detected by immunofluorescence analysis (P < 0.01). Pearson correlation analysis demonstrated that Δ133p53 and p65 mRNA expression levels were positively related, while no significant relationship was observed between those of p65 and p53β (r = 0.076, P > 0.01).CONCLUSIONΔ133p53 isoform (not p53β) is required in PDTC-induced inhibition of MKN45 gastric cancer cells, indicating that disturbance in the cross-talk between p53 and NF-κB pathways is a promising target in pharmaceutical research for the development of treatment strategies for gastric cancer.

QKI‐6 inhibits bladder cancer malignant behaviours through down‐regulating E2F3 and NF‐κB signalling

“…Bladder cancer 5637, T24, 253J, RT4, TCCSUP and J82 cell lines, a normal bladder epithelial cell line SV‐HUC‐1, and a normal kidney cell line HEK‐293T were cultured in Roswell Park Memorial Institute medium‐1640 supplemented with 10% foetal bovine serum (FBS) and 0.1% penicillin‐streptomycin in 25 cm 2 plastic cell culture flasks (all from Invitrogen, Carlsbad, CA) in a humidified incubator with 5% CO 2 at 37°C. Various concentrations (3‐1000 μmol/L) of pyrrolidinedithiocarbamate (PDTC; Targetmol, Boston, MA) or its vehicle (culture medium plus the solvent) were added to the cells for 6 hours prior to additional experimentation …”

The Δ133p53 Isoforms, Tuners of the p53 Pathway

“…Similar upregulation of total Δ133p53 mRNAs has been observed in B-cell precursor acute lymphoblastic leukemia [ 55 ] and in lung carcinomas as compared to adjacent non-cancerous tissue [ 44 ] and is reported to increase cancer cell survival in pathogen-driven cancers such as gastric tumors associated with H. pylori [ 56 ]. In the case of gastric cancer, total Δ133p53 mRNAs expression correlates with the NF-κB p65 subunit expression and may promote gastric cell growth [ 57 ]. Recently, a high total Δ133p53/TAp53 ratio was shown to be a marker of poor overall and progression-free survival in esophageal squamous cell carcinoma [ 45 ].…”

Oxidative Stress at the Crossroads of Aging, Stroke and Depression

“…This pathological process produces excess ROS and RNS, and promotes cerebral vasospasm, cerebrovascular stenosis, and delayed cerebral ischemia [55]. Furthermore, several harmful events occur in SAH survivors, including altered ionic homeostasis, excitotoxicity, destruction of vascular integrity, OS, inflammation, apoptosis, autophagy, and activation of the NOS pathway [56][57][58][59][60][61][62].…”

“…In SAH, free Hb stimulates endothelial cells to express cell adhesion molecules to attract neutrophils. Cells trapped in the subarachnoid space then undergo an oxidative burst, which releases ROS-mediated inflammatory cytokines or other molecules to further damage the brain [56]. During the hemoglobin-heme-iron axis, Hb is released into the extracellular space and is accompanied by an abundance of superoxide generated from the non-enzymatic oxidation of Hb [46].…”

“…In SAH, free Hb stimulates endothelial cells to express cell adhesion molecules to attract neutrophils. Cells trapped in the subarachnoid space then undergo an oxidative burst, which releases ROS-mediated inflammatory cytokines or other molecules to further damage the brain [ 56 ].…”