The effect of diet and nutrition on T cell function in cancer.

Cancer can be considered one of the most threatening diseases to human health, and immunotherapy, especially T-cell immunotherapy, is the most promising treatment for cancers. Diet therapy is widely concerned in cancer because of its safety and fewer side effects. Many studies have shown that both the function of T cells and the progression of cancer can be affected by nutrients in the diet. In fact, it is challenging for T cells to infiltrate and eliminate cancer cells in tumor microenvironment, because of the harsh metabolic condition. The intake of different nutrients has a great influence on the proliferation, activation, differentiation and exhaustion of T cells. In this review, we summarize the effects of typical amino acids, lipids, carbohydrates and other nutritional factors on T cell functions and provide future perspectives for dietary treatment of cancer based on modifications of T cell functions.

IL-6-induced cGGNBP2 encodes a protein to promote cell growth and metastasis in intrahepatic cholangiocarcinoma.

BACKGROUND AND AIMS: IL-6-induced tumor progression has been well established through the induction of antiapoptotic and proliferative genes. However, whether other mechanisms such as IL-6 regulation of circular RNAs (circRNAs) may also contribute to tumor development remains unknown. APPROACH AND RESULTS: High-throughput RNA sequencing was used to identify the differentially expressed circRNAs on IL-6 stimulation in intrahepatic cholangiocarcinoma (ICC) cells. CircRNA GGNBP2 (derived from ggnbp2 gene, termed as cGGNBP2) was up-regulated by IL-6 treatment in a time and concentration-dependent manner. The biogenesis of cGGNBP2 was regulated by RNA-binding protein DEx-H Box Helicase 9, which was also mediated by IL-6 exposure. Mass spectrometry and western blotting identified a protein cGGNBP2-184aa encoded by cGGNBP2. cGGNBP2-184aa promoted ICC cell proliferation and metastasis in vitro and in vivo. Mechanistically, cGGNBP2-184aa directly interacted with signal transducers and activators of transduction-3 (STAT3), phosphorylated STAT3Tyr705 , and played a positive regulatory role in modulating IL-6/STAT3 signaling. IL-6/cGGNBP2-184aa/STAT3 formed a positive feedback loop to sustain constitutive activation of IL-6/STAT3 signaling. Elevated cGGNBP2 expression was correlated with poor prognosis of patients with ICC and was identified as an independent risk factor for patient prognosis. CONCLUSIONS: Our study demonstrates that cGGNBP2-184aa, a protein encoded by IL-6-induced cGGNBP2, formed a positive feedback loop to facilitate ICC progression and may serve as an auxiliary target for clinical IL-6/STAT3-targeting treatments in ICC.

Effect of intestinal microbiota on liver disease and its related future prospection: From the perspective of intestinal barrier damage and microbial metabolites.

Liver diseases contribute notably to the global concern of mortality and disease. Emerging evidence has demonstrated that intestinal microbiota can regulate intestinal barrier function and produce bioactive metabolites. Failure of any aspect of this barrier can result in the translocation of microbes into the blood and a sustained inflammatory response that promotes liver injury, fibrosis, and cirrhosis. Here, we review the mechanisms by that intestinal microbiota regulate the intestinal barrier. The multiple underlying mechanisms of intestinal microbiota in liver disease are elaborated in detail, emphasizing them as the bridge linking the liver with gut microbiota. Thus, we highlight the feasibility of targeting the gut-liver axis for treating liver diseases.

Long noncoding RNA TLNC1 promotes the growth and metastasis of liver cancer via inhibition of p53 signaling.

BACKGROUND: Long non-coding RNAs (lncRNAs) have been demonstrated to play vital roles in cancer development and progression. However, their biological roles and function mechanisms in liver cancer remain largely unknown. METHODS: RNA-seq was performed with clinical hepatoma tissues and paired adjacent normal liver tissues to identify differentially expressed lncRNAs. qPCR was utilized to examine the expression levels of lncRNAs. We studied the function of TLNC1 in cell growth and metastasis of hepatoma with both cell and mouse models. RNA-seq, RNA pull-down coupled with mass spectrometry, RNA immunoprecipitation, dual luciferase reporter assay, and surface plasmon resonance analysis were used to analyze the functional mechanism of TLNC1. RESULTS: Based on the intersection of our own RNA-seq, TCGA RNA-seq, and TCGA survival analysis data, TLNC1 was identified as a potential tumorigenic lncRNA of liver cancer. TLNC1 significantly enhanced the growth and metastasis of hepatoma cells both in vitro and in vivo. TLNC1 exerted its tumorigenic function through interaction with TPR and inducing the TPR-mediated transportation of p53 from nucleus to cytoplasm, thus repressing the transcription of p53 target genes and finally contributing to the progression of liver cancer. CONCLUSIONS: TLNC1 is a promising prognostic factor of liver cancer, and the TLNC1-TPR-p53 axis can serve as a potential therapeutic target for hepatoma treatment.

CircNFIB inhibits tumor growth and metastasis through suppressing MEK1/ERK signaling in intrahepatic cholangiocarcinoma.

BACKGROUND: Considerable evidence shows that circular RNAs (circRNAs) play an important role in tumor development. However, their function in intrahepatic cholangiocarcinoma (ICC) metastasis and the underlying mechanisms are incompletely understood. METHODS: circNFIB (hsa_circ_0086376, termed as cNFIB hereafter) was identified in human ICC tissues through circRNAs sequencing. The biological role of cNFIB was determined in vitro and in vivo by gain or loss of functional experiments. Fluorescence in situ hybridization (FISH), RNA immunoprecipitation (RIP) and RNA pull-down assays were conducted to analyze the interaction of cNFIB with dual specificity mitogen-activated protein kinase kinase1 (MEK1). Duolink in situ proximity ligation assay (PLA) and coimmunoprecipitation (co-IP) assay were used to investigate the effects of cNFIB on the interaction between MEK1 and mitogen-activated protein kinase 2 (ERK2). Finally, a series of in vitro and in vivo experiments were performed to explore the influences of cNFIB on the anti-tumor activity of trametinib (a MEK inhibitor). RESULTS: cNFIB was significantly down-regulated in human ICC tissues with postoperative metastases. The loss of cNFIB was highly associated with aggressive characteristics and predicted unfavorable prognosis in ICC patients. Functional studies revealed that cNFIB inhibited the proliferation and metastasis of ICC cells in vitro and in vivo. Mechanistically, cNFIB competitively interacted with MEK1, which induced the dissociation between MEK1 and ERK2, thereby resulting in the suppression of ERK signaling and tumor metastasis. Moreover, we found that ICC cells with high levels of cNFIB held the potential to delay the trametinib resistance. Consistently, in vivo and in vitro studies demonstrated that cotreatment with trametinib and lentivirus vector encoding cNFIB showed greater inhibitory effect than isolated trametinib treatment. CONCLUSIONS: Our findings identified that cNFIB played a key role in ICC growth and metastasis by regulating MEK1/ERK signaling. Given the efficacy of cNFIB modulation on ICC suppression and trametinib sensitivity, cNFIB appears to be a potential therapeutic molecule for ICC treatment.

The role and mechanism of noncoding RNAs in regulation of metabolic reprogramming in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Metabolic reprogramming is considered to be an important hallmark of cancer. Emerging studies have demonstrated that noncoding RNAs (ncRNAs) are closely associated with metabolic reprogramming of HCC. NcRNAs can directly regulate the expressions or functions of metabolic enzymes or indirectly regulate the metabolism of HCC cells through some vital signaling pathways. Until now, the mechanisms of HCC development and progression remain largely unclear, and understanding the regulatory mechanism of ncRNAs on metabolic reprogramming of HCC may provide an important basis for breakthrough progress in the treatment of HCC. In this review, we summarize the ncRNAs involved in regulating metabolic reprogramming of HCC. Specifically, the regulatory roles of ncRNAs in glucose, lipid and amino acid metabolism are elaborated. In addition, we discuss the molecular mechanism of ncRNAs in regulation of metabolic reprogramming and possible therapeutic strategies that target the metabolism of cancer cells by modulating the expressions of specific ncRNAs.

Distribution and density of tertiary lymphoid structures predict clinical outcome in intrahepatic cholangiocarcinoma.

BACKGROUND & AIMS: The prognostic value and clinical relevance of tertiary lymphoid structures (TLSs) in intrahepatic cholangiocarcinoma (iCCA) remain unclear. Thus, we aimed to investigate the prognostic value and functional involvement of TLSs in iCCA. METHODS: We retrospectively included 962 patients from 3 cancer centers across China. The TLSs at different anatomic subregions were quantified and correlated with overall survival (OS) by Cox regression and Kaplan-Meier analyses. Multiplex immunohistochemistry (mIHC) was applied to characterize the composition of TLSs in 39 iCCA samples. RESULTS: A quaternary TLS scoring system was established for the intra-tumor region (T score) and peri-tumor region (P score) respectively. T scores positively correlated with favorable prognosis (p <0.001), whereas a high P score signified worse survival (p <0.001). mIHC demonstrated that both T follicular helper and regulatory T cells were significantly increased in intra-tumoral TLSs compared to peri-tumoral counterparts (p <0.05), and regulatory T cell frequencies within intra-tumoral TLSs were positively associated with P score (p <0.05) rather than T score. Collectively, the combination of T and P scores stratified iCCAs into 4 immune classes with distinct prognoses (p <0.001) that differed in the abundance and distribution pattern of TLSs. Patients displaying an immune-active pattern had the lowest risk, with 5-year OS rates of 68.8%, whereas only 3.4% of patients with an immune-excluded pattern survived at 5 years (p <0.001). The C-index of the immune class was statistically higher than the TNM staging system (0.73 vs. 0.63, p <0.001). These results were validated in an internal and 2 external cohorts. CONCLUSIONS: The spatial distribution and abundance of TLSs significantly correlated with prognosis and provided a useful immune classification for iCCA. T follicular helper and regulatory T cells may play a critical role in determining the functional orientation of spatially different TLSs. LAY SUMMARY: Tertiary lymphoid structures (TLSs) are associated with favorable prognosis in a number of cancers. However, their role in intrahepatic cholangiocarcinoma (iCCA) remains unclear. Herein, we comprehensively evaluated the spatial distribution, abundance, and cellular composition of TLSs in iCCA, and revealed the opposite prognostic impacts of TLSs located within or outside the tumor. This difference could be mediated by the different immune cell subsets present within the spatially distinct TLSs. Based on our analysis, we were able to stratify iCCAs into 4 immune subclasses associated with varying prognoses.

Predicting Genomic Alterations of Phosphatidylinositol-3 Kinase Signaling in Hepatocellular Carcinoma: A Radiogenomics Study Based on Next-Generation Sequencing and Contrast-Enhanced CT.

BACKGROUND: Exploring the genomic landscape of hepatocellular carcinoma (HCC) provides clues for therapeutic decision-making. Phosphatidylinositol-3 kinase (PI3K) signaling is one of the key pathways regulating HCC aggressiveness, and its genomic alterations have been correlated with sorafenib response. In this study, we aimed to predict somatic mutations of the PI3K signaling pathway in HCC samples through machine-learning-based radiomic analysis. METHODS: HCC patients who underwent next-generation sequencing and preoperative contrast-enhanced CT were recruited from West China Hospital and The Cancer Genome Atlas for model training and validation, respectively. Radiomic features were extracted from volumes of interest (VOIs) covering the tumor (VOItumor) and peritumoral areas (5 mm [VOI5mm], 10 mm [VOI10mm], and 20 mm [VOI20mm] from tumor margin). Factor analysis, logistic regression analysis, least absolute shrinkage and selection operator, and random forest analysis were applied for feature selection and model construction. Model performance was characterized based on the area under the receiver operating characteristic curve (AUC). RESULTS: A total of 132 HCC patients (mean age: 61.1 ± 14.7 years; 108 men) were enrolled. In the training set, the AUCs of radiomic signatures based on single CT phases were moderate (AUC 0.694-0.771). In the external validation set, the radiomic signature based on VOI10mm in arterial phase demonstrated the highest AUC (0.733) among all models. No improvement in model performance was achieved after adding the tumor radiomic features or manually assessed qualitative features. CONCLUSIONS: Machine-learning-based radiomic analysis had potential for characterizing alterations of PI3K signaling in HCC and could help identify potential candidates for sorafenib treatment.

[Lipid Metabolic Reprogramming and Metabolic Stress in Liver Cancer].

Recent studies have shown that tumor microenvironment plays an important regulatory role in the growth and metastasis of liver cancer. Metabolic reprogramming represents a series of adaptive metabolic alterations that liver cancer cells undertake when they are under metabolic stress caused by glucose deficiency and hypoxia microenvironment, and lipid reprogramming is an important part of it. Previous studies have revealed a variety of lipid types with altered metabolic patterns in liver cancer cells, and have, to a certain extent, investigated the biological functions and regulatory mechanisms of these lipid metabolic reprogramming processes. However, there are still many lipid metabolic reprogramming processes that have not received thorough investigation, and little is known about their roles and mechanisms in the pathogenesis and development of liver cancer. In addition, how to accomplish the goal of treating liver cancer by targeting key regulatory factors in lipid metabolic reprogramming still remains a major challenge in translational medical research. This paper introduced the sources of lipids and the main functions and driving factors of lipid metabolic reprogramming in liver cancer cells, attempting to provide a theoretical basis and potential therapeutic targets for the treatment of liver cancer through regulating or restricting lipid metabolic reprogramming.

[A Review of Progress of the Relation Between Stress Response and Diabetes Mellitus].

Stress response is an adaptive process of the organism to confront environmental perturbation. Moderate stress response induces the organism to establish effective adaptive strategies for survival, while excessive stress response results in stress injury, which is a major cause of a variety of physical or psychological diseases, including diabetes mellitus. Diabetes mellitus is a typical stress-related disease, with numerous evidence indicating that the development and progression of diabetes mellitus are closely related to stress response, such as metabolic stress, oxidative stress and endoplasmic reticulum stress. However, the detailed mechanisms of stress response mediated regulation of diabetes mellitus and how to prevent or treat diabetes mellitus via modification of stress response remain to be further investigated. Here, we will introduce the definition and regulatory mechanisms of stress response, as well as discuss the biological functions and mechanisms of various stress responses during the pathogenesis of diabetes mellitus. This review highlights recent advances of stress medicine associated with diabetes mellitus, in order to provide theoretical basis and reference for prevention and treatment of diabetes mellitus. Future studies should focus on elucidating the clinical application potential of the key factors of stress response that mediate the pathogenesis of diabetes mellitus, as well as boosting the related translational medicine studies.

Classification and Prognosis Prediction from Histopathological Images of Hepatocellular Carcinoma by a Fully Automated Pipeline Based on Machine Learning.

OBJECTIVE: The aim of this study was to develop quantitative feature-based models from histopathological images to distinguish hepatocellular carcinoma (HCC) from adjacent normal tissue and predict the prognosis of HCC patients after surgical resection. METHODS: A fully automated pipeline was constructed using computational approaches to analyze the quantitative features of histopathological slides of HCC patients, in which the features were extracted from the hematoxylin and eosin (H&E)-stained whole-slide images of HCC patients from The Cancer Genome Atlas and tissue microarray images from West China Hospital. The extracted features were used to train the statistical models that classify tissue slides and predict patients' survival outcomes by machine-learning methods. RESULTS: A total of 1733 quantitative image features were extracted from each histopathological slide. The diagnostic classifier based on 31 features was able to successfully distinguish HCC from adjacent normal tissues in both the test [area under the receiver operating characteristic curve (AUC) 0.988] and external validation sets (AUC 0.886). The random-forest prognostic model using 46 features was able to significantly stratify patients in each set into longer- or shorter-term survival groups according to their assigned risk scores. Moreover, the prognostic model we constructed showed comparable predicting accuracy as TNM staging systems in predicting patients' survival at different time points after surgery. CONCLUSIONS: Our findings suggest that machine-learning models derived from image features can assist clinicians in HCC diagnosis and its prognosis prediction after hepatectomy.

KIAA1429 contributes to liver cancer progression through N6-methyladenosine-dependent post-transcriptional modification of GATA3.

BACKGROUND: N6-methyladenosine (m6A) modification, the most abundant internal methylation of eukaryotic RNA transcripts, is critically implicated in RNA processing. As the largest known component in the m6A methyltransferase complex, KIAA1429 plays a vital role in m6A methylation. However, its function and mechanism in hepatocellular carcinoma (HCC) remain poorly defined. METHODS: Quantitative PCR, western blot and immunohistochemistry were used to measure the expression of KIAA1429 in HCC. The effects of KIAA1429 on the malignant phenotypes of hepatoma cells were examined in vitro and in vivo. MeRIP-seq, RIP-seq and RNA-seq were performed to identify the target genes of KIAA1429. RESULTS: KIAA1429 was considerably upregulated in HCC tissues. High expression of KIAA1429 was associated with poor prognosis among HCC patients. Silencing KIAA1429 suppressed cell proliferation and metastasis in vitro and in vivo. GATA3 was identified as the direct downstream target of KIAA1429-mediated m6A modification. KIAA1429 induced m6A methylation on the 3' UTR of GATA3 pre-mRNA, leading to the separation of the RNA-binding protein HuR and the degradation of GATA3 pre-mRNA. Strikingly, a long noncoding RNA (lncRNA) GATA3-AS, transcribed from the antisense strand of the GATA3 gene, functioned as a cis-acting element for the preferential interaction of KIAA1429 with GATA3 pre-mRNA. Accordingly, we found that the tumor growth and metastasis driven by KIAA1429 or GATA3-AS were mediated by GATA3. CONCLUSION: Our study proposed a complex KIAA1429-GATA3 regulatory model based on m6A modification and provided insights into the epi-transcriptomic dysregulation in hepatocarcinogenesis and metastasis.

Preoperative Radiomic Approach to Evaluate Tumor-Infiltrating CD8+ T Cells in Hepatocellular Carcinoma Patients Using Contrast-Enhanced Computed Tomography.

BACKGROUND: To help identify potential hepatocellular carcinoma (HCC) candidates for immunotherapies, we aimed to develop and validate a radiomics-based biomarker (Rad score) to predict the infiltration of tumor-infiltrating CD8+ T cells in HCC patients, and to evaluate the correlation of Rad score with tumor immune characteristics. METHODS: Overall, 142 HCC patients (n = 100 and n = 42 in the training and validation sets, respectively) were subjected to radiomic feature extraction. Imaging features and immunochemistry data of patients in the training set were subjected to elastic-net regularized regression analysis to predict the level of CD8+ T cell infiltration. RESULTS: A Rad score for CD8+ T-cell infiltration, which contained seven variables, was developed and was validated in the validation set (area under the curve [AUC]: training set 0.751, 95% confidence interval [CI] 0.656-0.846; validation set 0.705, 95% CI 0.547-0.863). The decision curve indicated the clinical usefulness of the Rad score. A higher Rad score correlated with superior overall and disease-free survival outcomes (p = 0.012 and 0.0088, respectively). Using the pathological slides, we found that the Rad score positively correlated with the percentage of tumor-infiltrating lymphocytes (TILs; Spearman rho = 0.51, p < 0.0001). Moreover, the Rad score could also discriminate inflamed tumors from immune-desert and immune-excluded tumors (Kruskal-Wallis, p < 0.0001), and higher Rad scores could be found in patients with positive programmed cell death ligand 1 expression in tumor/immune cells, as well as those with positive programmed cell death protein 1 expression. CONCLUSION: The newly developed Rad score was a powerful predictor of CD8+ T-cell infiltration, which could be useful in identifying potential HCC patients who can benefit from immunotherapies when validated in large-scale prospective cohorts.

SETD3 is regulated by a couple of microRNAs and plays opposing roles in proliferation and metastasis of hepatocellular carcinoma.

A previous study reported that histone methyltransferase SETD3 is up-regulated in tumor tissues of hepatocellular carcinoma (HCC) and is associated with the growth of HCC. However, the clinical significance and the effect of SETD3 on HCC metastasis remain unclear. In the present study, both the protein and mRNA expression levels of SETD3 were measured in a larger cohort of HCC patients. The results showed that the protein level of SETD3 in HCC tissues was significantly higher than that in non-tumorous tissues, which was inconsistent with the mRNA expression level of SETD3. The high protein level of SETD3 in HCC tissues was significantly associated with male gender, poor pathological differentiation, liver cirrhosis and unfavorable prognosis of HCC patients. Subsequently, we demonstrated that SETD3 could be regulated at post-transcriptional step by a couple of miRNAs (miR-16, miR-195 and miR-497). Additionally, in vitro and in vivo experiments revealed that SETD3 played opposing roles in proliferation and metastasis of HCC: promoting proliferation but inhibiting metastasis. Mechanistic experiments revealed that doublecortin-like kinase 1 (DCLK1) was a downstream target of SETD3. SETD3 could increase the DNA methylation level of DCLK1 promoter to inhibit the transcription of DCLK1. Further study revealed that DCLK1/PI3K/matrix metalloproteinase (MMP) 2 (MMP-2) was an important pathway that mediated the effect of SETD3 on HCC metastasis. In conclusion, the present study revealed that SETD3 is associated with tumorigenesis and is a promising biomarker for predicting the prognosis of HCC patients after surgical resection. In addition, SETD3 plays inhibitory role in HCC metastasis partly through DCLK1/PI3K/MMP-2 pathway.

Laparoscopic versus open mesohepatectomy for patients with centrally located hepatocellular carcinoma: a propensity score matched analysis.

BACKGROUND: Although laparoscopic mesohepatectomy (LM) has been performed for patients with centrally located hepatocellular carcinoma (CL-HCC), its short- and long-term benefits compared with traditional open surgery remain unclear. The aim of the present study was to explore the independent role of LM in the prognosis of patients with CL-HCC. METHODS: A retrospective analysis was undertaken of 348 patients who underwent mesohepatectomy for CL-HCC between January 2012 and October 2017 in our hospital. The impact of the surgical methods on long-term prognosis was evaluated by multivariable regression analysis. In addition, patients in the LM group were matched in a 1:3 ratio with open mesohepatectomy (OM) group. RESULTS: Some 307 patients underwent OM and 41 had LM. In both adjusted and non-adjusted models, patients in LM group had similar overall survival (OS, both P > 0.05) and disease-free survival (DFS, both P > 0.05) compared to OM patients. The mean (s.d.) OS in LM and OM groups was 41.6 (7.2) and 46.4 (1.4) months, respectively. The mean (s.d.) DFS in LM and OM groups was 37.7 (5.9) and 33.4 (1.5) months, respectively. After propensity score-matched (PSM) analysis, 96 patients remained in OM group and 32 patients in LM group. In the PSM subset, patients in LM group still had comparable OS (P = 0.120) and DFS (P = 0.757) compared to patients in the OM group. After PSM, patients receiving LM had longer vascular exclusion time (P = 0.006) and shorter hospital stay (P = 0.004). In addition, LM was associated with reduced postoperative morbidity after PSM adjustment (P = 0.026). CONCLUSIONS: LM is associated with fewer complications and does not compromise survival compared with OM. LM can be recommended as a safe and reasonable surgical option in selected patients with CL-HCC.

Transarterial chemoembolization plus iodine-125 implantation for hepatocellular carcinoma: a systematic review and meta-analysis.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common malignancy in liver. Transarterial chemoembolization (TACE) is recommended as an effective treatment in advanced HCC patients. Recent studies showed iodine-125 seed (a low-energy radionuclide) can provide long-term local control and increase survival for HCC patients. The aim of the study was to evaluate the outcome of TACE plus iodine-125 seed in comparison with TACE alone for HCC. METHODS: A comprehensive search of studies among PubMed, Embase, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews was conducted with published date from the earliest to January 10th, 2018. No language restrictions were applied, while only prospective randomized controlled trials (RCTs) or non-randomized controlled trials (non-RCTs) were eligible for a full-text review. The primary outcome was overall survival (OS), response rate (the rate of partial atrophy or complete clearance of the tumor lesion) and adverse events (AEs). The odds ratios (ORs) were combined using either fixed-effects model or random-effects model. All statistical analyses were performed using the Stata 12.0 software. RESULTS: 9 studies were included, involving 894 patients. Among them, 473 patients received combined therapy of TACE plus iodine-125 implantation, compared with 421 patients with TACE alone. Patients receiving combined therapy of TACE plus iodine-125 showed significantly improvement in 1-year OS (OR = 4.47, 95% confidence intervals (CI): 2.97-6.73; P < 0.001), 2-year OS (OR = 4.72, 95% CI: 2.63-8.47; P < 0.001). No significant publication bias was observed in any of the measured outcomes. CONCLUSIONS: Based on these findings, TACE plus iodine-125 implantation achieves better clinical efficacy compared with TACE alone in the treatment of HCC.

Thiol-based redox proteomics in cancer research.

Cancer cells maintain their intracellular ROS concentrations at required levels for their survival. Changes in ROS concentrations can regulate biochemical signaling mechanisms that control cell function. It has been demonstrated that ROS regulate the cellular events through redox regulation of redox-sensitive proteins (redox sensors). Upon oxidative stress, redox sensors undergo redox modifications that cause the allosteric changes of these proteins and endow them with different functions. Understanding the altered functions of redox sensors and the underlying mechanisms is critical for the development of novel cancer therapeutics. Recently, a series of high-throughput proteomics approaches have been developed for screening redox processes. In this manuscript, we review these methodologies and discuss the important redox sensors recently identified that are related to cancer.

Autophagy plays an essential role in the clearance of Pseudomonas aeruginosa by alveolar macrophages.

Intracellular bacteria have been shown to cause autophagy, which impacts infectious outcomes, whereas extracellular bacteria have not been reported to activate autophagy. Here, we demonstrate that Pseudomonas aeruginosa, a Gram-negative extracellular bacterium, activates autophagy with considerably increased LC3 punctation in both an alveolar macrophage cell line (MH-S) and primary alveolar macrophages. Using the LC3 Gly120 mutant, we successfully demonstrated a hallmark of autophagy, conjugation of LC3 to phosphatidylethanolamine (PE). The accumulation of typical autophagosomes with double membranes was identified morphologically by transmission electron microscopy (TEM). Furthermore, the increase of PE-conjugated LC3 was indeed induced by infection rather than inhibition of lysosome degradation. P. aeruginosa induced autophagy through the classical beclin-1-Atg7-Atg5 pathway as determined by specific siRNA analysis. Rapamycin and IFN-γ (autophagy inducers) augmented bacterial clearance, whereas beclin-1 and Atg5 knockdown reduced intracellular bacteria. Thus, P. aeruginosa-induced autophagy represents a host protective mechanism, providing new insight into the pathogenesis of this infection.

Decreased levels of miR-224 and the passenger strand of miR-221 increase MBD2, suppressing maspin and promoting colorectal tumor growth and metastasis in mice.

BACKGROUND & AIMS: Little is known about functions of microRNA (miR) passenger strands (miR*) or their roles in tumor development or progression. We screened for miRs and miR* with levels that were altered in metastatic colorectal cancer (CRC) cells and human tumor samples and investigated their targets and effects on cell function and tumor progression in mice. METHODS: We performed array-based profile analysis to identify miRs with levels that were increased more than 2-fold in metastatic (SW620) CRC cells compared with nonmetastatic (SW480) cells. Quantitative polymerase chain reaction and in situ hybridization analyses were used to measure miRNA levels in CRC cell lines and human tumor samples. We used miRNA duplex mimics or inhibitors to increase and decrease levels of miRNA in CRC cells and assessed their activities and ability to form metastatic xenograft tumors in nude mice. RESULTS: Levels of miR-221* and miR-224 were reduced in metastatic compared with nonmetastatic CRC cells; levels in human tumor samples correlated inversely with tumor stage and metastasis to lymph nodes as well as patient survival times. SW480 cells transfected with miR-221* or miR-224 inhibitors had increased motility in vitro compared with SW480 control cells and formed larger, more metastatic tumors when injected into mice. SW620 cells transfected with miR-221* or miR-224 mimics had reduced migration and motility in vitro and formed smaller tumors with fewer metastases in mice compared with control SW620 cells. We identified the 3' untranslated region of MBD2 messenger RNA as a target of miR-221* and miR-224. MBD2 silences the gene encoding maspin, a suppressor of metastasis. In CRC cells, we found that miR-221* and miR-224 increase the expression of maspin through MBD2 down-regulation. CONCLUSIONS: In metastatic CRC cells, reduced levels of miR-221* and miR-224 increase levels of MBD2, thereby decreasing expression of the metastasis suppressor maspin. Increased activities of miR-221* and miR-224 reduce growth and metastasis of CRC xenograft tumors in mice; these miRs might be developed as therapeutic reagents or biomarkers of CRC progression.