Adenovirus-Mediated Wild-Type p53 Transfer Radiosensitizes H1299 Cells to Subclinical-Dose Carbon-Ion Irradiation Through the Restoration of p53 Function

Abstract

To determine whether adenovirus-mediated wild-type p53 transfer after radiotherapy could radiosensitize non-small-cell lung cancer (NSCLC) cells to subclinical-dose carbon-ion beam (C-beam), H1299 cells were exposed to a C-beam or gamma-ray and then infected with 5 MOI of AdCMV-p53 or GFP (C-beam or gamma-ray with p53 or GFP). Cell cycle was detected by flow cytometric analysis. The apoptosis was examined by a fluorescent microscope with DAPI staining. DNA fragmentation was monitored by the TUNEL assay. P53 mRNA was detected by reverse-transcriptase polymerase chain reaction. The expression of p53, MDM(2), and p21 was monitored by Western blot. Survival fractions were determined by colony-forming assay. The percentages of G(1)-phase cells in C-beam with p53 increased by 8.2%-16.0%, 5.2%-7.0%, and 5.8%-18.9%, respectively, compared with C-beam only, gamma-ray with p53, or p53 only. The accumulation of G(2)-phase cells in C-beam with p53 increased by 5.7%-8.9% and 8.8%-14.8%, compared with those in gamma-ray with p53 or p53 only, respectively. The percentage of apoptosis for C-beam with p53 increased by 7.4%-19.1%, 5.8%-11.7%, and 5.2 %-19.2%, respectively, compared with C-beam only, gamma-ray with p53, or p53 only. The level of p53 mRNA in C-beam with p53 was significantly higher than that in p53 only. The expression level of p53 and p21 in C-beam with p53 was significantly higher than that in both C-beam with GFP and p53 only. The survival fractions for C-beam with p53 were significantly less than those for the other groups (p < 0.05). The data suggested that AdCMV-p53 transfer could more efficiently radiosensitize H1299 cells to subclinical-dose C-beam irradiation through the restoration of p53 function.

MEK–ERK-dependent multiple caspase activation by mitochondrial proapoptotic Bcl-2 family proteins is essential for heavy ion irradiation-induced glioma cell death

“…Among these proapoptotic ERK mechanisms, the relationship with reactive oxygen species (ROS)-mediated cell death induction, which is explained by ROS-induced ERK activation after cell death, has been most frequently mentioned. 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29, 30, 31 However, in the present model, neither ROS production (Supplementary Figure 5a) nor the inhibitory effect of antioxidants in CB irradiation-induced glioma cell death was confirmed (Supplementary Figure 5b). Thus, unlike cell death induced by other high-dose DNA damage stresses, which induce ROS-dependent cell death, it was suggested that gliomas do not produce ROS even after a maximum clinical dose of CB irradiation, which may be related to the refractory nature against standard radiotherapy.…”

“…20, 21 However, tumor cells with wild-type p53 could have the potential to be treated effectively by conventional radiation. Furthermore, radioresistant gliomas have been reported to have a tendency for mutations in the p53 gene.…”

The Tumor Suppressor, p53, Contributes to Radiosensitivity of Lung Cancer Cells by Regulating Autophagy and Apoptosis

“…Liu et al reported that H1299 cells treated with C-beam with AdCMV-p53 or C-beam only underwent changes typical of apoptosis. 16 Other than apoptosis, autophagy is a dynamic process of protein degradation characterized by the formation of prominent double-membrane cytoplasmic vesicles called autophagosomes. 17 The specific markers of autophagy include the expression and the relocalization of MAPLC3, the autophagy regulatory gene, and so on.…”

Regulation of miRNAs Affects Radiobiological Response of Lung Cancer Stem Cells

“…In recent researches, many molecules and signaling pathways are found to function in self-renewal and radioresistance of LCSCs, including p53 mutation [ 67 ], Kras mutation [ 43 ], NF- κ B1 activation [ 45 ], and senescence inhibition [ 46 ]. Studies reveal that miRNAs are usually involved in these signaling pathways.…”