SOCS3 protein expression predicts the responses of advanced non-small cell lung cancer patients to platinum-based chemotherapy.

Background: This study sought to assess the relationship between suppressor of cytokine signaling 3 (SOCS3) expression, SOCS3 promoter methylation status, and platinum-based chemotherapy responses in advanced non-small cell lung cancer (NSCLC) patients. Methods: A total of 400 advanced NSCLC patients with inoperable disease were enrolled in this study. All the patients underwent platinum-based chemotherapy treatment, and the clinical and prognostic outcomes of these patients were analyzed. The SOCS3 protein expression and SOCS3 promoter methylation status of the tumor tissues in these patients were also tested by immunohistochemistry and polymerase chain reaction (PCR), respectively. In addition, we knocked down SOCS3 expression via small-interfering RNA (siRNA) in the lung cancer cell lines and conducted in vitro analyses to examine cell viability and apoptosis. Results: Patients with higher expression levels of SOCS3 were found to have a lower average tumor stage, higher average tumor differentiation, and higher rates of positive chemotherapy responses than those with lower expression levels of SOCS3. SOCS3 promoter methylation was also found to be correlated with chemotherapy responses in these patients. In the prognostic analyses, only SOCS3 expression, but not SOCS3 promoter methylation, was found to be predictive of outcomes in advanced NSCLC patients. We also found that the pro-apoptotic effects of SOCS3 were mediated by the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathways in the lung cancer cells. Conclusions: Currently, there is a lack of reliable biomarkers for predicting the responses of NSCLC patients to chemotherapy. Our results may aid in clinical evaluations of NSCLC patients.

Effects of nicotine on proliferation and survival in human umbilical cord mesenchymal stem cells.

Cigarette smoking is known to have negative effects on tissue repair and healing. The aim of this study is to investigate the effects of nicotine in human umbilical cord mesenchymal stem cells (MSCs). After nicotine treatment, MSCs became pyknotic, vacuoles appeared in the cytoplasm and nucleus, and the nuclear boundary became fuzzy as observed using atomic force microscopy. Cell proliferation was inhibited in a dose-dependent manner (P < 0.05 for all concentrations). The proportion of apoptotic MSCs was significantly increased in a dose-dependent manner. The mitochondrial membrane potential was significantly decreased (P < 0.05). Nicotine-treated MSCs had a significantly higher G0/G1 ratio (P < 0.05). Peptide mass fingerprinting identified 27 proteins that were differentially expressed between MSCs with and without nicotine treatment. These nicotine exerted toxic effects on MSCs are likely related, at least in part, to the altered expression of multiple proteins that are essential to the health and proliferation of these cells.

[Effects of decitabine on proliferation and apoptosis of NB4 and K562 cells].

This study was aimed to investigate the effects of decitabine (DAC) on proliferation and apoptosis of leukemia NB4 and K562 cells. The proliferation inhibition of DAC on NB4 and K562 cells was detected by Trypan blue staining. After treatment of DAC at different concentrations, the changes of cell cycle and CD11b expression was determined by flow cytometry. The cell morphological changes were observed by Wright's staining. The DNA ladder was used to detect cell apoptosis. The results indicated that DAC significantly inhibited the proliferation of NB4 and K562 cells in dose-and time-dependent manner. The median inhibitory concentration (IC50) of DAC-treated NB4 and K562 cells for 72 h was 0.113 µmol/L and 0.138 µmol/L, respectively. After treating these two cell lines with DAC at different concentration for 72 h, the cell ratio in G0/G1 phase significantly increased, while the cell ratio in S phase obviously decreased in 0.15 µmol/L DAC group (P < 0.05). The expression levels of myeloid differentiation antigen CD11b of both cell lines significantly increased in contrast to the control group (P < 0.05). The cell morphology detected by Wright's staining displayed partial differentiation and apoptosis after treating NB4 and K562 cells with DAC for 48 h. Typical apoptotic DNA ladder was observed in 0.15 µmol/L DAC group at 48 h. It is concluded that DAC can inhibit NB4 and K562 cell proliferation, induce cell differentiation and apoptosis, but more obviously for NB4 cells.

Hypoxia-mimetic agents inhibit proliferation and alter the morphology of human umbilical cord-derived mesenchymal stem cells.

BACKGROUND: The therapeutic efficacy of human mesenchymal stem cells (hMSCs) for the treatment of hypoxic-ischemic diseases is closely related to level of hypoxia in the damaged tissues. To elucidate the potential therapeutic applications and limitations of hMSCs derived from human umbilical cords, the effects of hypoxia on the morphology and proliferation of hMSCs were analyzed. RESULTS: After treatment with DFO and CoCl2, hMSCs were elongated, and adjacent cells were no longer in close contact. In addition, vacuole-like structures were observed within the cytoplasm; the rough endoplasmic reticulum expanded, and expanded ridges were observed in mitochondria. In addition, DFO and CoCl2 treatments for 48 h significantly inhibited hMSCs proliferation in a concentration-dependent manner (P < 0.05). This treatment also increased the number of cells in G0/G1 phase and decreased those in G2/S/M phase. CONCLUSIONS: The hypoxia-mimetic agents, DFO and CoCl2, alter umbilical cord-derived hMSCs morphology and inhibit their proliferation through influencing the cell cycle.

[Differential proteomic analysis in human umbilical cord mesenchymal stem cells induced by cobalt chloride].

OBJECTIVE: To analyze the differential proteomics in human umbilical cord mesenchymal stem cells (MSC) induced by chemical hypoxia-mimetic agent cobalt chloride (CoCl(2)) by two-dimensional gel electrophoresis (2-DE) and mass-spectrometry. METHODS: 2-DE was performed to separate proteins from treated and untreated human umbilical cord MSC with CoCl(2). 2-DE images were analyzed by ImageMaster 2D Platinum software 6.0. The differential expressed proteins was identified by MALDI-TOF-MS. The differential proteins were classified based on their functions. RESULTS: 2-DE reference patterns of CoCl(2) treated human umbilical cord MSC were established. A total of twenty-six differential proteins were identified, of them eleven proteins were up-regulated and fifteen down-regulated. Their biological functions involved in carbohydrate metabolism, protein metabolism and modification, lipid metabolism, coenzyme and prosthetic group metabolism, cell cycle, immunity and defense, cell structure and motility, signal transduction, protein targeting and localization, neuronal activities, muscle contraction, etc. Peroxiredoxin1 (Prdx) was down-regulated, whereas alpha-enolase (ENO1) and vesicle amine transport protein 1 homolog (VAT1) up-regulated. CONCLUSION: The effects of hypoxia on human umbilical cord MSC were participated by multiple proteins and involved in multiple functional pathways.

[Comparative protein analysis of K562 cell apoptosis induced by 6-gingerol].

OBJECTIVE: To establish two-dimensional electrophoresis (2-DE) pattern for proteome analysis on K562 cells before and after treatment with 6-gingerol, and mass-spectrometry was applied to identify and analyze the differentially expressed proteins. METHODS: K562 cells were treated with 6-gingerol. Cell proliferation was analyzed by CCK-8 assay. Total protein of K562 cells was extracted by 2D-DIGE and then imaged by SDS gel scanning. The differentially expressed proteins were identified using Imagine Master 2D Platinum 6.0 software and functionally classified by MALDI and MALDI-TOF MS. RESULTS: 6-gingerol could significantly inhibit K562 cells proliferation and the efficacy was concentration and dose-dependent. After being treated for 24, 48, 72 h, IC50 was 22.86, 15.75, 11.18 microg/mL, respectively. 42 differentially expressed proteins were identified, including 19 up-regulated expressed proteins and 10 down-regulated expressed proteins. CONCLUSION: Proteomic technique can be used to screen multiple proteins associate with the anti-leukemia effect of 6-gingerol, involving some important proteins related to oxidative stress, cell cycle regulation, apoptosis signal transduction, biosynthesis and glycometabolism.

[Reactive oxygen species and mitochondrial membrane potential changes in leukemia cells during 6-gingerol induced apoptosis].

OBJECTIVE: To observe the effects of 6-gingerol on reactive oxygen species (ROS) and mitochondrial membrane potential(deltapsim) of chronic myeloid leukemia K562 cells and human acute T lymphoblastic leukemia MOLT4 cells, to investigate the role of mitochondrial pathway in the signal transduction of leukemia cell. METHODS: With different concentrations of 6-gingerol treatment, using 2,7-dichloro fluoresceinciactate (DCFH-DA) as ROS probe, rhodamine-123 as deltapsim probe, the levels of ROS and deltapsim of K562 cells and MOLT4 cells were tested by flow cytomentry. RESULTS: After treated with 6-gingerol, the ROS levels of K562 cells were significantly higher than control group (P < 0.01), while the deltapsim were significantly lower than control group (P < 0.01), and the ROS levels of MOLT4 cells were significantly higher than control group (P < 0.05). CONCLUSIONS: 6-gingerol can significantly increase ROS levels of K562 cells and MOLT4 cells, decrease deltapsim of K562 cells,induce apoptosis of leukemia cells by mitochondrial pathway.