Azacytidine induces necrosis of multiple myeloma cells through oxidative stress.

Azacytidine is an inhibitor of DNA methyltransferase and is known to be an anti-leukemic agent to induce cancer cell apoptosis. In the present study, multiple myeloma cells were treated with azacytidine at clinically relevant concentrations to induce necrosis through oxidative stress. Necrotic myeloma cells exhibit unique characteristics, including enrichment of the cell-bound albumin and overexpression of endoplasmic reticulum (ER)- and mitochondrial-specific chaperones, which were not observed in other necrotic cells, including HUH-7, A2780, A549, and Hoc1a. Proteomic analysis shows that HSP60 is the most abundant up-regulated mitochondrial specific chaperone, and azacytidine-induced overexpression of HSP60 is confirmed by western blot analysis. In contrast, expression levels of cytosolic chaperones such as HSP90 and HSP71 were down-regulated in azacytidine-treated myeloma cells, concomitant with an increase of these chaperones in the cell culture medium, suggesting that mitochondrial chaperones and cytosolic chaperones behave differently in necrotic myeloma cells; ER- and mitochondrial-chaperones being retained, and cytosolic chaperones being released into the cell culture medium through the ruptured cell membrane. Our data suggest that HSP60 is potentially a new target for multiple myeloma chemotherapy.

Role of Gd2O3-doped carbon-11-choline-lenvatinib nanoparticles contrast agent PET/CT in the diagnosis of patients with lung cancer.

Positron emission tomography-computed tomography (PET/CT) is an efficient method for the diagnosis of various types of human cancer. Studies have demonstrated that Gd2O3-doped carbon-11-choline (GdCho) can be used as a contrast nanoparticle for PET/CT in the diagnosis of patients with lung cancer. The aim of the present study was to evaluate the effect of GdCho-lenvatinib nanoparticles contrast-PET/CT (GdCho-Len-PET) in the diagnosis and treatment planning of a cohort of patients suspected of having lung cancer. The results of the present study demonstrated that GdCho-Len could be used as an efficient PET/CT contrast agent for the diagnosis of patients with lung cancer. GdCho-Len nanoparticles contrast agent exhibited a significantly improved longitudinal relaxivity compared with GdCho. The outcomes of the present study were that GdCho-Len-PET diagnosed 152 patients with lung cancer, whereas GdCho-PET diagnosed 130 patients with lung cancer among the 172 patients. GdCho-Len-PET presented with higher accuracy and sensitivity compared with GdCho-PET in diagnosing patients with lung cancer. All patients were further confirmed via histological analysis. GdCho-Len-PET contributed to the anticancer treatments in 56 out of 62 (90.3%) patients with lung cancer who were candidates for radiation therapy, 52 out of 57 (91.2%) patients with lung cancer undergoing adjuvant radiotherapy, and 13 out of 17 (76.5%) patients with lung cancer undergoing comprehensive therapy. Patients diagnosed using GdCho-Len-PET improved the survival of patients with lung cancer during a 420-day follow up. In conclusion, GdCho-Len-PET increased the diagnostic efficacy and had a significant effect on survival for patients with lung cancer, and may therefore serve as a reliable method for human cancer diagnosis.

Proteomic analysis for finding serum pathogenic factors and potential biomarkers in multiple myeloma.

BACKGROUND: Multiple myeloma (MM) is a malignant tumor, which takes the second place in malignant blood disease. The clinical symptoms are complicated that make more difficult to diagnose and therapy. Lots of researches focus on the proteins about MM in order to solve those problems. We used proteomic methods to find potential biomarkers in MM patients. METHODS: We applied the peptide ligand library beads (PLLBs) to deplete high abundance proteins in serum for finding potential pathogenic factors and biomarkers of MM. Using 1D-Gel-liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified 789 and 849 unique serum proteins in MM patients and in healthy controls, respectively. RESULTS: Twenty-two proteins were found differentially expressed between the two groups including serum amyloid A protein, vitamin D-binding protein isoform-1 precursor, plasma kallikrein, and apolipoprotein A-I. Changes of integrin alpha-11 and isoform-1 of multimerin-1 were validated with Western blotting. The linkage of the differentially expressed proteins and the pathogenesis pathways of MM were discussed. CONCLUSIONS: PLLB combined with 1D-gel-LC-MS/MS analysis is an efficient method to identify differentially expressed proteins in serum from patients with MM.

Proteomic analysis of gossypol induces necrosis in multiple myeloma cells.

Gossypol is a phenolic aldehyde extracted from plants and is known to be an antitumor agent to induce cancer cell apoptosis. In the present study, multiple myeloma cells were treated with gossypol, which resulted in an increase of cellular reactive oxygen species (ROS) and cell necrosis. Quantitative proteomic analysis was carried out to identify differentially expressed proteins between untreated and gossypol-treated cells. Proteomic analysis identified 4330 proteins, in which 202 proteins are upregulated and 383 proteins are downregulated in gossypol-treated cells as compared to the untreated cells. Importantly, proteomic and western blot analysis showed that apoptosis regulators BAK and Bax were upregulated in gossypol-treated cells, indicating that Bcl-2 associated death pathway was activated. Similarly, gossypol also induced upregulations of DNA mismatch repair proteins and DNA replication licensing factor, suggesting that gossypol caused significant DNA damage. Furthermore, upregulations of HLA class I and class II histocompatibility antigens and beta-2-microglobulin were observed in gossypol-treated cells, indicating that gossypol has a novel function to activate cellular immune responses. Our data demonstrate that the execution of necrosis is a complex process involving ROS, DNA damage, and Bcl-2 family proteins. Gossypol-activated immune responses are a potential new approach for multiple myeloma chemotherapy.

Oxidative stress induces monocyte necrosis with enrichment of cell-bound albumin and overexpression of endoplasmic reticulum and mitochondrial chaperones.

In the present study, monocytes were treated with 5-azacytidine (azacytidine), gossypol or hydrogen peroxide to induce cell death through oxidative stress. A shift from apoptotic to necrotic cell death occurred when monocytes were treated with 100 µM azacytidine for more than 12 hours. Necrotic monocytes exhibited characteristics, including enrichment of cell-bound albumin and up-regulation of endoplasmic reticulum (ER)- and mitochondrial-specific chaperones to protect mitochondrial integrity, which were not observed in other necrotic cells, including HUH-7, A2780, A549 and HOC1a. Our results show that the cell-bound albumin originates in the culture medium rather than from monocyte-derived hepatocytes, and that HSP60 is a potential binding partner of the cell-bound albumin. Proteomic analysis shows that HSP60 and protein disulfide isomerase are the most abundant up-regulated mitochondrial and ER-chaperones, and that both HSP60 and calreticulin are ubiquitinated in necrotic monocytes. In contrast, expression levels of the cytosolic chaperones HSP90 and HSP71 were down-regulated in the azacytidine-treated monocytes, concomitant with an increase in the levels of these chaperones in the cell culture medium. Collectively, our results demonstrates that chaperones from different organelles behave differently in necrotic monocytes, ER- and mitochondrial chaperones being retained and cytosolic and nuclear chaperones being released into the cell culture medium through the ruptured cell membrane. HSP60 may serve as a new target for development of myeloid leukemia treatment.

Development of the Fc-III tagged protein expression system for protein purification and detection.

In the present work, we developed the Fc-III tagged protein expression system for protein purification and detection. The Fc-III sequence encodes for a 13 residue peptide and this peptide is cyclized by disulfide bond formation when the fusion protein is expressed. The Fc-III-fusion proteins selectively bind to immunoglobulin Fc domains (IgG-Fc) expressed from E. coli. We showed the efficient purification of Fc-III tagged proteins by immobilized non-native IgG-Fc and the detection of the cellular locations of fusion proteins by fluorescent-conjugated IgG-Fc. Our results prove that Fc-III tagged protein expression system is a simple and efficient tool for protein purification and detection and is a useful addition to the biochemistry and proteomics toolbox.