Epigenetic actions of environmental factors and promising drugs for cancer therapy.

Carcinogenesis is known to be primarily associated with gene mutations. Recently, increasing evidence has suggested that epigenetic events also serve crucial roles in tumor etiology. Environmental factors, including nutrition, toxicants and ethanol, are involved in carcinogenesis through inducing epigenetic modifications, such as DNA methylation, histone deacetylase and miRNA regulation.

E2F is involved in radioresistance of carbon ion induced apoptosis via Bax/caspase 3 signal pathway in human hepatoma cell.

Deletion of p53, most common genetic alteration, is observed in human tumors and reported to lead to improve in cell radioresistance. Heavy-ion irradiation (IR) could induce p53 cancer cells apoptosis. However, little is known regarding the molecular mechanism in this type of cell apoptosis.

Diallyl disulfide attenuated carbon ion irradiation-induced apoptosis in mouse testis through changing the ratio of Tap73/ΔNp73 via mitochondrial pathway.

Diallyl disulfide (DADS), a major organosulfur compound derived from garlic, has various biological properties, including anti-cancer effects. However, the protective mechanism of DADS against radiation-induced mouse testis cell apoptosis has not been elucidated. In this study, the magnitude of radiation effects evoked by carbon ion irradiation was marked by morphology changes, significant rise in apoptotic cells, activation expression of p53, up regulation the ratio of pro-apoptotic Tap73/anti-apoptotic ΔNp73, as well as alterations of crucial mediator of the mitochondrial pathway.

Disturbance of redox status enhances radiosensitivity of hepatocellular carcinoma.

Aims: High constitutive expression of Nrf2 has been found in many types of cancers, and this high level of Nrf2 also favors resistance to drugs and radiation. Here we investigate how isoliquiritigenin (ISL), a natural antioxidant, inhibits the Nrf2-dependent antioxidant pathway and enhances the radiosensitivity of HepG2 cells and HepG2 xenografts.

Results: Treatment of HepG2 cells with ISL for 6 h selectively enhanced transcription and expression of Keap1.

DNA-PKcs deficiency inhibits glioblastoma cell-derived angiogenesis after ionizing radiation.

DNA-dependent protein kinase catalytic subunit (DNA-PKcs) plays a critical role in non-homologous end-joining repair of DNA double-strand breaks (DSB) induced by ionizing radiation (IR). Little is known, however, regarding the relationship between DNA-PKcs and IR-induced angiogenesis; thus, in this study we aimed to further elucidate this relationship. Our findings revealed that lack of DNA-PKcs expression or activity sensitized glioma cells to radiation due to the defective DNA DSB repairs and inhibition of phosphorylated Akt(Ser473) .

Simulated microgravity conditions and carbon ion irradiation induce spermatogenic cell apoptosis and sperm DNA damage.

Objective: To investigate the effect of simulated microgravity and carbon ion irradiation (CIR) on spermatogenic cell apoptosis and sperm DNA damage to the testis of male Swiss Webster mice, and assess the risk associated with space environment.

Methods: Sperm DNA damage indicated by DNA fragmentation index (DFI) and high DNA stainability (HDS) was measured by sperm chromatin structure assay (SCSA). Apoptosis of spermatogenic cells was detected by annexin V-propidium iodide assay.

Effects of carbon-ion beam or X-ray irradiation on anti-apoptosis ΔNp73 expression in HeLa cells.

ΔNp73 has emerged as an interesting novel factor in cancer research. Here, we report the effect of carbon-ion beams on ΔNp73 expression in human cervix carcinoma HeLa cells in contrast to the effect of X-rays. Cellular sensitivities were determined by colony formation.

Spatial distribution of polygalacturonase-inhibiting proteins in Arabidopsis and their expression induced by Stemphylium solani infection.

Disease-induced polygalacturonase-inhibiting proteins (PGIPs) are the major defense proteins which play an important role in resistance to infection of pathogens. To date, the AtPGIP expression in Arabidopsis induced by Stemphylium solani (S. solani) was not described.