Proteomic profiling revealed the functional networks associated with mitotic catastrophe of HepG2 hepatoma cells induced by 6-bromine-5-hydroxy-4-methoxybenzaldehyde.

Mitotic catastrophe, a form of cell death resulting from abnormal mitosis, is a cytotoxic death pathway as well as an appealing mechanistic strategy for the development of anti-cancer drugs. In this study, 6-bromine-5-hydroxy-4-methoxybenzaldehyde was demonstrated to induce DNA double-strand break, multipolar spindles, sustain mitotic arrest and generate multinucleated cells, all of which indicate mitotic catastrophe, in human hepatoma HepG2 cells. We used proteomic profiling to identify the differentially expressed proteins underlying mitotic catastrophe. A total of 137 differentially expressed proteins (76 upregulated and 61 downregulated proteins) were identified. Some of the changed proteins have previously been associated with mitotic catastrophe, such as DNA-PKcs, FoxM1, RCC1, cyclin E, PLK1-pT210, 14-3-3σ and HSP70. Multiple isoforms of 14-3-3, heat-shock proteins and tubulin were upregulated. Analysis of functional significance revealed that the 14-3-3-mediated signaling network was the most significantly enriched for the differentially expressed proteins. The modulated proteins were found to be involved in macromolecule complex assembly, cell death, cell cycle, chromatin remodeling and DNA repair, tubulin and cytoskeletal organization. These findings revealed the overall molecular events and functional signaling networks associated with spindle disruption and mitotic catastrophe.

[The characteristics of type I, III collagen and LN in pulmonary fibrosis induced by uranium ore dust in rats].

OBJECTIVE: To explore the characteristics of LN and type I, III collagen in pulmonary fibrosis induced by uranium ore dust in rats. METHODS: 60 adult Wistar rats were divided randomly into two groups, control group (30 rats) and uranium ore dust group (30 rats). Non-exposed intratracheal instillation method was used. Uranium ore dust group was exposed 20 mg/ml uranium ore dust suspension 1ml per rat, meanwhile control group was exposed normal saline 1ml per rat. Post-exposed the 7, 14, 21, 30 and 60 d, 6 rats in each group were killed randomly, lung tissue were collected. The pathological changes in lung tissue were observed by microscope using HE staining, the collagen I and III in lungs were observed by polarizing microscope using Biebrich scarlet staining. The expression of LN protein in lung tissue was observed by immunohistochemistry-SP. RESULTS: During lung fibrosis, a large amount of the proliferated I and III collagen in lungs were observed. Post-exposure to uranium ore dust, the characteristics in proliferated collagen in lungs were type I collagen deposited in lung interstitium mainly in the early stage. The area percentage of collagen I and III was increased significantly at 7, 14, 21, 30 and 60d in the experimental group as compared with that in the control group (P < 0.05 or P < 0.01). The over expression of LN in the lung tissue were observed. The expression of LN was distributed in the lung tissue as thickening of the linear or cluster. The integral optical density of LN was increased significantly at 21, 30 and 60 d in the experimental group as compared with that in the control group (P < 0.05 or P < 0.01). CONCLUSIONS: After exposure to uranium ore dust, the characteristics in proliferated collagen in lungs are the type of I collagen deposited in lung interstitium mainly in the early stage, while the type of III collagen increase significantly at the later period. The overexpression of LN exists in the process of pulmonary fibrosis. It suggests that LN has a role effect in the process of pulmonary fibrosis.

Dose-dependent expression changes of early response genes to ionizing radiation in human lymphoblastoid cells.

The sensitivity of cancer cells as well as normal cells in response to ionizing radiation (IR) is believed to be associated with the early inducible expression of specific genes. Using cDNA microarray technology, here we explored and compared the global transcriptional changes in human lymphoblastoid AHH-1 cells irradiated with 0.05-, 0.2-, 0.5-, 2.0- and 10-Gy doses of gamma-rays 4 h after exposure. A dose as low as 0.05 Gy was efficient in inducing a transcriptional response including the up-regulation of 25 genes, some of which are involved in signal transduction pathways, e.g. BMPR2, GPR124, MAPK8IP2 and AGGF1, and the down-regulation of 18 genes. Expression of some genes was altered only at a specific dose. Most importantly, we discovered a number of radiation-response genes, e.g. DNA repair gene XPC, tumor protein p53 inducible protein 3 gene (TP53I3), immediate early response 5 gene, whose transcriptional levels were increased or depressed by IR in a dose-dependent trend within the dose range 0.05-10 Gy. The dose-dependent induced expression of TP53I3 and XPC was confirmed by Northern blot analyses. Using quantitative real-time PCR, we further confirmed that XPC gene induction was dose dependent as well as time dependent, reaching a peak 4 h post-2 Gy and 10 h post-0.05 Gy. The maximum induced expression level of the XPC gene was higher after 2 Gy (3.2-fold) than 0.05 Gy (1.93-fold). The identification of these radiation-inducible genes, especially those exhibiting a dose-dependent response, not only expands our knowledge of the mechanisms underlying the diverse biological effects induced by IR, but provides candidates for developing novel biomarkers of radiation injury.