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Ion channels are important regulators in cell proliferation, migration, and apoptosis. The malfunction and/or aberrant expression of ion channels may disrupt these important biological processes and influence cancer progression. In this study, we investigate the expression pattern of ion channel genes in glioma. We designate 18 ion channel genes that are differentially expressed in high-grade glioma as a prognostic molecular signature. This ion channel gene expression based signature predicts glioma outcome in three independent validation cohorts. Interestingly, 16 of these 18 genes were down-regulated in high-grade glioma. This signature is independent of traditional clinical, molecular, and histological factors. Resampling tests indicate that the prognostic power of the signature outperforms random gene sets selected from human genome in all the validation cohorts. More importantly, this signature performs better than the random gene signatures selected from glioma-associated genes in two out of three validation datasets. This study implicates ion channels in brain cancer, thus expanding on knowledge of their roles in other cancers. Individualized profiling of ion channel gene expression serves as a superior and independent prognostic tool for glioma patients. [ABSTRACT FROM AUTHOR]

Purpose: Ferroptosis is a form of regulated cell death that has the potential to be targeted as a cancer therapeutic strategy. But cancer cells have a wide range of sensitivities to ferroptosis, which limits its therapeutic potential. Accumulation of lipid peroxides determines the occurrence of ferroptosis. However, the type of lipid involved in peroxidation and the mechanism of lipid peroxide accumulation are less studied. Methods: The effects of fatty acids (10 μM) with different carbon chain length and unsaturation on ferroptosis were evaluated by MTT and LDH release assay in cell lines derived from prostate cancer (PC3, 22RV1, DU145 and LNCaP), colorectal cancer (HT-29), cervical cancer (HeLa) and liver cancer (HepG2). Inhibitors of apoptosis, necroptosis, autophagy and ferroptosis were used to determine the type of cell death. Then the regulation of reactive oxygen species (ROS) and lipid peroxidation by docosahexaenoic acid (DHA) was measured by HPLC–MS and flow cytometry. The avtive form of DHA was determined by siRNA mediated gene silencing. The role of lipoxygenases was checked by inhibitors and gene silencing. Finally, the effect of DHA on ferroptosis-mediated tumor killing was verified in xenografts. Results: The sensitivity of ferroptosis was positively correlated with the unsaturation of exogenously added fatty acid. DHA (22:6 n-3) sensitized cancer cells to ferroptosis-inducing reagents (FINs) at the highest level in vitro and in vivo. In this process, DHA increased ROS accumulation, lipid peroxidation and protein oxidation independent of its membrane receptor, GPR120. Inhibition of long chain fatty acid-CoA ligases and lysophosphatidylcholine acyltransferases didn't affect the role of DHA. DHA-involved ferroptosis can be induced in both arachidonate lipoxygenase 5 (ALOX5) negative and positive cells. Down regulation of ALOX5 inhibited ferroptosis, while overexpression of ALOX5 promoted ferroptosis. Conclusion: DHA can effectively promote ferroptosis-mediated tumor killing by increasing intracellular lipid peroxidation. Both ALOX5 dependent and independent pathways are involved in DHA-FIN induced ferroptosis. And during this process, free DHA plays an important role. [ABSTRACT FROM AUTHOR]

Acute myocardial infarction (AMI) is the main cause of death in the whole world. This study aimed to investigate whether forkhead box O4 (FoxO4) could negatively modulate ubiquitin specific peptidase 10 (USP10) transcription to aggravate the apoptosis and oxidative stress of hypoxia/reoxygenation (H/R)-induced cardiomyocytes through Hippo/YAP pathway. mRNA expression as well as protein expressions of USP10 and FoxO4 in H9C2 cells after H/R induction or transfection were respectively detected by Reverse transcription-quantitative (RT-q) PCR analysis and Western blot. The viability and apoptosis of H9C2 cells after H/R induction or transfection were respectively detected by CCK-8 and TUNEL assays. The expressions of lactate dehydrogenase (LDH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in H9C2 cells after H/R induction or transfection were analyzed using appropriate kits and intracellular reactive oxygen species (ROS) levels were detected using a ROS Assay Kit. Dual luciferase reporter assay and Chromatin Immunoprecipitation (ChIP) have adopted to confirm the combination of USP10 and FoxO4. Western blot was also used to analyze the expression of apoptosis-related proteins and Hippo/YAP pathway-related proteins. As a result, USP10 expression was decreased in H/R-induced H9C2 cells in a time-dependent manner. USP10 overexpression increased the viability and suppressed the apoptosis and oxidative stress of H/R-induced H9C2 cells. In addition, FoxO4 modulated USP10 transcription. FoxO4 expression was increased in H9C2 cells induced by H/R. FoxO4 overexpression could reverse the protective effects of USP10 overexpression on H/R-induced H9C2 cells by regulating the Hippo/YAP signaling pathway. In conclusion, FoxO4 negatively modulated USP10 transcription to aggravate the apoptosis and oxidative stress of H/R-induced H9C2 cells via blocking Hippo/YAP pathway. [ABSTRACT FROM AUTHOR]

We report a method for large-scale absolute protein expression measurements (APEX) and apply it to estimate the relative contributions of transcriptional- and translational-level gene regulation in the yeast and Escherichia coli proteomes. APEX relies upon correcting each protein's mass spectrometry sampling depth (observed peptide count) by learned probabilities for identifying the peptides. APEX abundances agree with measurements from controls, western blotting, flow cytometry and two-dimensional gels, as well as known correlations with mRNA abundances and codon bias, providing absolute protein concentrations across approximately three to four orders of magnitude. Using APEX, we demonstrate that 73% of the variance in yeast protein abundance (47% in E. coli) is explained by mRNA abundance, with the number of proteins per mRNA log-normally distributed about ∼5,600 (∼540 in E. coli) protein molecules/mRNA. Therefore, levels of both eukaryotic and prokaryotic proteins are set per mRNA molecule and independently of overall protein concentration, with >70% of yeast gene expression regulation occurring through mRNA-directed mechanisms. [ABSTRACT FROM AUTHOR]

Background: T-cell immunoglobulin domain and mucin domain 4 (TIM-4) is exclusively expressed in antigen-presenting cells and involved in immune regulation. However, the role of TIM-4 expressed in tumour cells remains completely unknown.Methods: Immunohistochemistry staining was used to examine TIM-4 or Ki-67 expression in tumour tissues. Real-time PCR or RT-PCR was performed to detect TIM-4 mRNA expression. Lung cancer cell growth and proliferation were conducted by CCK-8 assay and EdU staining. Cell cycle progression was analysed by flow cytometry. The PCNA and cell cycle-related proteins were verified by western blot. Co-IP assay was used to identify the interaction of TIM-4 and integrin αvβ3. The efficacy of TIM-4 in vivo was evaluated using xenograft tumour model.Results: The expression of TIM-4 in non-small-cell lung cancer (NSCLC) tissues was significantly higher than that of the adjacent tissues. Enhanced TIM-4 expression was negatively correlated with histological differentiation of lung carcinoma and lifespan of patients. Overexpression of TIM-4 promoted lung cancer cell growth and proliferation, and upregulated the expression of PCNA, cyclin A, cyclin B1 and cyclin D1, accompanied by accumulation of lung cancer cells in S phase. Interestingly, Arg-Gly-Asp (RGD) motif mutation abolished the effect of TIM-4 on lung cancer cells, which was further verified by tumour xenografts in mice. Furthermore, we found that TIM-4 interacted with αvβ3 integrin through RGD motif.Conclusions: This finding suggests that TIM-4 might be a potential biomarker for NSCLC that promotes lung cancer progression by RGD motif. [ABSTRACT FROM AUTHOR]

Purpose: Downregulation of miRNA expression has been identified as a novel feature of renal cell carcinoma (RCC). Recently, miR-129-2 is well known to be frequently reduced by DNA methylation and has anti-tumor effects in various tumors but so far not in RCC. The aim of this study was to investigate the clinical significance and the role of it in RCC. Methods: The expression levels of miR-129-3p and miR-129-5p, two mature products of miR-129-2, were determined by real-time quantitative reverse transcription PCR in 69 cases of paired different kidney tumors and normal tissues and clear cell RCC (ccRCC) cell lines. The roles of them in RCC cells were assessed by functional analyses. Protein expression was detected by Western blot. Results: miR-129-3p, but not miR-129-5p, was widely attenuated in human ccRCC, and chromophobe RCC. miR-129-3p could yield 73.5 % accuracy in discriminating ccRCCs from normal tissues. The relative miR-129-3p expression significantly differed between malignant and benign kidney tumors. Importantly, low miR-129-3p levels were associated with short disease-free and overall survival. Ectopic expression of miR-129-3p robustly impaired RCC cell migratory and invasive properties, but had no impact on cell viability and cell cycle distribution. Finally, miR-129-3p decreased multiple metastasis-related genes in RCC cells, including SOX4, phosphorylation of focal adhesion kinase and MMP-2/9 expression. Conclusions: miR-129-3p may act as a promising diagnostic biomarker for discriminating ccRCC from benign tumors and normal tissues and an independent prognostic biomarker in ccRCC. miR-129-3p may exert its anti-metastatic function through modulating multiple targets. [ABSTRACT FROM AUTHOR]

Background and aims: To date, the association between special AT-rich sequence-binding protein 1 (SATB1) and colorectal cancer (CRC) has not been reported. This study was aimed at investigating the expression and potential role of SATB1 in human rectal cancers. Methods: Ninety-three paired samples of rectal cancer and distant normal rectal tissue were analyzed by quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC), and the correlations between SATB1 expression and clinicopathological parameters were evaluated. The expression profiles of SATB1 were also investigated in a panel of five human colon carcinoma cell lines. Results: The general level of SATB1 mRNA in rectal cancer tissues was statistically significantly higher than that in normal mucosa ( P = 0.043). The rate of positive SATB1 protein expression in rectal cancers (44.1%) was significantly higher than that in normal tissues (25.8%) by IHC analysis ( P = 0.009). Overexpression of SATB1 mRNA was more predominant in patients with earlier onset of rectal cancer ( P = 0.033). SATB1 expression correlated with invasive depth and tumor node metastasis (TNM) stage at both protein and mRNA levels ( P < 0.05). Furthermore, SATB1 expression in the poorly metastatic KM12C cells was significantly lower than the highly metastatic KM12SM and KM12L4A cells and higher than the HCT116 and SW480 cells ( P = 0.001). These results were further confirmed by Western blotting. Conclusion: Our results indicate that SATB1 may play an important role in the progression of human rectal cancer, which represents a possible new mechanism underlying CRC. [ABSTRACT FROM AUTHOR]

Purpose: Dysregulation of microRNA (miRNA) metabolism has been observed in a variety of human cancers, but the expression patterns of the enzymes responsible for generating miRNAs remain largely unexplored. In this study, we investigated the expression profiles of the two most important enzymes of the miRNA machinery, Drosha and Dicer, which were closely correlated with nasopharyngeal carcinoma (NPC) and patient survival. Methods: Dicer and Drosha mRNA levels were detected by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) using 24 NPC tissues, 7 normal nasopharyngeal epithelium samples (NPE) and NPC cell lines. In addition, protein levels were detected by immunohistochemistry (IHC) using an NPC tissue microarray (TMA), which include 251 NPC and 105 NPE cases. For some NPC patients can not be contacted, the survival data were available only for 146 patients. Kaplan-Meier analysis was performed, and the chi-square and log-rank tests were used to detect significance levels using SPSS 15.0 software. Results: The mean level of Dicer and Drosha mRNA were significantly down-regulated in NPC tissue specimens and cell lines when compared with controls. The low levels of Dicer and Drosha protein were frequently seen in NPC, and the low expression of Dicer and Drosha protein was significantly correlated with shorter progression-free survival (PFS) and overall survival (OS) of NPC patients. Conclusions: We observed that Drosha and Dicer expression was dysregulation in NPC compared with healthy control samples and was significantly correlated with shorter PFS and OS of NPC patients. Therefore, we hypothesise that the expression levels of Dicer and Drosha could be used as potential prognostic biomarkers for NPC. [ABSTRACT FROM AUTHOR]

Increased nigral iron levels and intracytoplasmic Lewy bodies (LBs) in the degenerating neurons are found in Parkinson's disease (PD). Whether LBs formation is involved in the toxicity of iron is largely unknown. In the present study, we observed that the toxicity of ferric iron was enhanced when SK-N-SH cells were overexpressed with wild-type alpha-synuclein. The mitochondrial transmembrane potential (Δ ψ) and cell viability were decreased in these cells, while the intracellular reactive oxygen species (ROS) were increased, compared with that of control. More aggregated alpha-synuclein was observed in these cells. However, while silencing the expression of alpha-synuclein in SK-N-SH cells with siRNA, iron-induced toxicity could be partially alleviated, indicated by the returned Δ ψ and cell viability and reduced ROS formation compared with that of control. No alpha-synuclein aggregation could be observed in these cells. The results suggest that alpha-synuclein aggregation was involved in the toxicity of iron to SK-N-SH neuroblastoma cells. Targeting the aggregation of alpha-synuclein might provide a therapeutic strategy for PD in the future. [ABSTRACT FROM AUTHOR]