Sphingosine 1-phosphate promotes mesenchymal stem cell-mediated cardioprotection against myocardial infarction via ERK1/2-MMP-9 and Akt signaling axis.

AIMS: The sphingolipid metabolite sphingosine 1­phosphate (S1P) has emerged as a potential cardioprotective molecule against ischemic heart disease. Moreover, S1P triggers mobilization and homing of bone marrow-derived stem/progenitor cells into the damaged heart. However, it remains elusive whether S1P promotes mesenchymal stem cells (MSCs)-mediated cardioprotection against ischemic heart diseases. MAIN METHODS: Adipose tissue-derived MSCs (AT-MSCs) were obtained from GFP transgenic mice or C57BL/6J. Myocardial infarction (MI) was induced in C57BL/6J mice by ligation of the left anterior descending coronary artery (LAD). Subsequently, S1P-treated AT-MSCs or vehicle-treated AT-MSCs were intravenously administered for 24 h after induction of MI or sham procedure. KEY FINDINGS: Pre-conditioning with S1P significantly enhanced the migratory and anti-apoptotic efficacies of AT-MSCs. In MI-induced mice, intravenous administration of S1P-treated AT-MSCs significantly augmented their homing and engraftment in ischemic area. Besides, AT-MSCs with S1P pre-treatment exhibited enhanced potencies to inhibit cardiomyocyte apoptosis and fibrosis, and stimulate angiogenesis and preserve cardiac function. Mechanistic studies revealed that S1P promoted AT-MSCs migration through activation of ERK1/2-MMP-9, and protected AT-MSCs against apoptosis via Akt activation. Further, S1P activated the ERK1/2 and Akt via S1P receptor 2 (S1PR2), but not through S1PR1. S1PR2 knockdown by siRNA, however, significantly attenuated S1P-mediated AT-MSCs migration and anti-apoptosis. SIGNIFICANCE: The findings of the present study revealed the protective efficacies of S1P pretreatment on the survival/retention and cardioprotection of engrafted MSCs. Pre-conditioning of donor MSCs with S1P is an effective strategy to promote the therapeutic potential of MSCs for ischemic heart diseases.

[Protective effect of Fuzheng Yanggan Mixture on drug-induced liver injury].

The model of drug-induced liver injury (DILI) induced by acetaminophen (APAP) in mice was established to investigate the anti-oxidation and anti-ferroptosis mechanisms of Fuzheng Yanggan Mixture on DILI. C57BL/6 mice were randomly divided into five groups: control group, model group, positive group, and low and high-dose Fuzheng Yanggan Mixture groups (0.12, 0.24 g·kg⁻¹). Mice were intragastrically administration with Fuzheng Yanggan Mixture (0.12, 0.24 g·kg⁻¹) once per day for 21 consecutive days, and at the same time, mice were weighted every day. The mice were injected intraperitoneally with 600 mg·kg⁻¹ of APAP to establish a mouse model of acute DILI after 16 h from the last administration of Fuzheng Yanggan Mixture. After 6 h from APAP challenge, the experimental animals were weighted and sacrificed to collect blood and liver tissue samples. And then, the effect of Fuzheng Yanggan Mixture on liver weight and the liver weight ratio of mice were examined; the content of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum and the level of malondialdehyde (MDA), glutathione (GSH) and nicotinamide adenine dinucleotide phosphate (NADPH) in the liver tissue were measured. Prostaglandinendoperoxide synthase 2(ptgs2) mRNA level in liver tissues was detected by Q-PCR, and protein expression levels of SLC7A11 and GPX4 in liver tissues were detected by Western blot. Moreover, HE staining, immunohistochemical assay and TUNEL staining were used to observe pathological changes of the liver tissue sections. It is found that Fuzheng Yanggan Mixture could relieve APAP-induced liver enlargement and inhibit hepatic weight ratio increase. Compared with model group, the mice in Fuzheng Yanggan Mixture groups showed decreases in the content of ALT, AST and MDA, and increases in the content of GSH and NADPH. What is more, Fuzheng Yanggan Mixture could down-regulate ptgs2 mRNA level and up-regulate SLC7A11 and GPX4 protein levels. All of the results lead to a conclusion that Fuzheng Yanggan Mixture plays a protective effect on DILI in mice, which may be associated with the inhibition of ferroptosis.

A global burden of gastric cancer: the major impact of China.

INTRODUCTION: Gastric cancer (GC) is a highly aggressive cancer and a major cause of cancer-related deaths worldwide. Approximately half of the world's GC cases and deaths occur in china. GC presents challenges in early diagnosis and effective therapy due to a lack of understanding of the underlying molecular biology. The primary goals of this review are to outline current GC research in china and describe future trends in this field. Areas covered: This review mainly focuses on a series of GC-related advances China has achieved. Considerable progress has been made in understanding the role of H. pylori in GC by a series of population-based studies in well-established high-risk areas; A few germline and somatic alterations have been identified by 'omics' studies; Studies on the mechanisms of malignant phenotypes have helped us to form an in-depth understanding of GC and advance drug discovery. Moreover, identification of potential biomarkers and targeted therapies have facilitated the diagnosis and treatment of GC. However, many challenges remain. Expert commentary: To combat GC, sufficient funding is important. More attention should be paid on early diagnosis and the discovery of novel efficient biomarkers and the development of biomarker-based or targeted therapeutics in GC.

Berberine inhibits EGFR signaling and enhances the antitumor effects of EGFR inhibitors in gastric cancer.

Cetuximab plus chemotherapy for advanced gastric cancer (GC) shows an active result in phase 2 trials. Unfortunately, Combination of cetuximab does not provide enough benefit to chemotherapy alone in phase 3 trials. Studies have demonstrated that berberine can suppress the activation of EGFR in tumors. In this study, we evaluated whether berberine could enhance the effects of EGFR-TKIs in GC cell lines and xenograft models. Our data suggest that berberine could effectively enhance the activity of erlotinib and cetuximab in vitro and in vivo. Berberine was found to inhibit growth in GC cell lines and to induce apoptosis. These effects were linked to inhibition of EGFR signaling activation, including the phosphorylation of STAT3. The expressions of Bcl-xL and Cyclind1 proteins were decreased, whereas the levels of cleavage of poly-ADP ribose polymerase (PARP) were considerably increased in the cell lines in response to berberine treatment. These results suggest a potential role for berberine in the treatment of GC, particularly in combination with EGFR-TKIs therapy. Berberine may be a competent therapeutic agent in GC where it can enhance the effects of EGFR inhibitors.

Elevated O-GlcNAcylation promotes gastric cancer cells proliferation by modulating cell cycle related proteins and ERK 1/2 signaling.

O-GlcNAc transferase (OGT) is the only enzyme in mammals that catalyzes the attachment of ß-D-N-acetylglucosamine (GlcNAc) to serine or threonine residues of target proteins. Hyper-O-GlcNAcylation is becoming increasingly realized as a general feature of cancer and contributes to rapid proliferation of cancer cells. In this study, we demonstrated that O-GlcNAc and OGT levels were increased in all six gastric cancer (GC) cell lines as compared with immortal gastric epithelial cells. Downregulation of the O-GlcNAcylation level by silencing OGT inhibited cell viability and growth rate via the cdk-2, cyclin D1 and ERK 1/2 pathways. In vivo xenograft assays also demonstrated that the hyper-O-GlcNAc level markedly promoted the proliferation of tumors. Moreover, compared with noncancerous tissues, the O-GlcNAcylation level was increased in cancerous tissues. GC patients with higher levels of O-GlcNAcylation exhibited large tumor sizes (≥5 cm), deep tumor invasion (T3 and T4), high AJCC stages (stage III and IV), more lymph node metastases and lower overall survival. Notably, the phosphorylation level of ERK 1/2 was increased progressively with the increase of O-GlcNAcylation in both SGC 7901 and AGS cells. Consistently, human GC tissue arrays also revealed that ERK 1/2 signaling was positively correlated to O-GlcNAcylation (r = 0.348; P = 0.015). Taken together, here we reported that hyper-O-GlcNAcylation significantly promotes GC cells proliferation by modulating cell cycle related proteins and ERK 1/2 signaling, suggesting that inhibition of OGT may be a potential novel therapeutic target of GC.

Biased random walk model for the prioritization of drug resistance associated proteins.

Multi-drug resistance is the main cause of treatment failure in cancer patients. How to identify molecules underlying drug resistance from multi-omics data remains a great challenge. Here, we introduce a data biased strategy, ProteinRank, to prioritize drug-resistance associated proteins in cancer cells. First, we identified differentially expressed proteins in Adriamycin and Vincristine resistant gastric cancer cells compared to their parental cells using iTRAQ combined with LC-MS/MS experiments, and then mapped them to human protein-protein interaction network; second, we applied ProteinRank to analyze the whole network and rank proteins similar to known drug resistance related proteins. Cross validations demonstrated a better performance of ProteinRank compared to the method without usage of MS data. Further validations confirmed the altered expressions or activities of several top ranked proteins. Functional study showed PIM3 or CAV1 silencing was sufficient to reverse the drug resistance phenotype. These results indicated ProteinRank could prioritize key proteins related to drug resistance in gastric cancer and provided important clues for cancer research.

Genistein suppresses FLT4 and inhibits human colorectal cancer metastasis.

Dietary consumption of genistein, found in soy, has been associated with a potentially protective role in colorectal cancer (CRC) development and progression. Herein we demonstrate that genistein will inhibit human CRC cell invasion and migration, that it does so at non-cytotoxic concentrations and we demonstrate this in multiple human CRC cell lines. After orthotopic implantation of human CRC tumors into mice, oral genistein did not inhibit tumor growth, but did inhibit distant metastasis formation, and was non-toxic to mice. Using a qPCR array, we screened for genistein-induced changes in gene expression, followed by Western blot confirmation, demonstrating that genistein downregulated matrix metalloproteinase 2 and Fms-Related Tyrosine Kinase 4 (FLT4; vascular endothelial growth factor receptor 3). After demonstrating that genistein suppressed neo-angiogenesis in mouse tumors, we examined FLT4 expression in primary CRC and adjacent normal colonic tissue from 60 human subjects, demonstrating that increased FLT4 significantly correlates with increased stage and decreased survival. In summary, we demonstrate for the first time that genistein inhibits human CRC metastasis at dietary, non-toxic, doses. FLT4 is identified as a marker of metastatic disease, and as a response marker for small molecule therapeutics that inhibit CRC metastasis.

Decreased expression of FOXJ1 is a potential prognostic predictor for progression and poor survival of gastric cancer.

BACKGROUND: FOXJ1 is a member of the forkhead transcription factor family, which has been mostly studied for its role in the development of ciliated epithelium and immunology. However, the role of FOXJ1 in tumorigenesis remains largely unknown or even conflicting. We thus investigated FOXJ1 expression in gastric cancer and analyzed its correlations with tumor progression and prognosis. METHODS: The expression of FOXJ1 was detected by immunohistochemistry in 105 gastric cancer samples and adjacent noncancerous tissues. Staining evaluation was conducted to assess clinicopathological parameters and the survival rate. In addition, the relation between FOXJ1 and metastasis was investigated in another 40 pairs of primary lesions and corresponding lymph node metastases. Furthermore, cell proliferation, migration, and invasion were confirmed in vitro. RESULTS: Decreased FOXJ1 expression was significantly correlated with clinic stage, lymph node metastasis, and distant metastasis, and lower FOXJ1 expression independently predicted shorter survival time in gastric carcinoma. Moreover, the positive incidence of FOXJ1 decreased significantly in metastatic lymph nodes compared with that in the primary lesions. Consistently, FOXJ1 overexpression significantly weakened cell proliferation, motility, migration, and invasion, while FOXJ1 knockdown induced the opposite effects. CONCLUSIONS: Decreased expression of FOXJ1 is an independent prognostic predictor for gastric cancer and is critical to disease progression. FOXJ1 may be an attractive therapeutic target for the treatment of gastric cancer.

Roles of epithelial-mesenchymal transition in cancer drug resistance.

Overcoming intrinsic and acquired drug resistance is a major challenge in treating cancer. Poor responses to drug treatment can result in metastasis, cancer dissemination and death. Recently, the epithelial-mesenchymal transition (EMT) has been found to play a critical role in cancer drug resistance, but the nature of this intrinsic link remains unclear. This review summarizes recent advances in the understanding of drug resistance and focuses especially on the association between EMT and drug resistance. We discuss the roles of EMT in regulating drug resistance across different types of cancer, focusing simultaneously on the molecular mechanisms and potential pathways involved in the regulation of drug resistance by EMT. In addition, we discuss potential therapeutic strategies to target EMT to reverse drug resistance.

Meta-analysis: the relationship between TNF-alpha polymorphisms and susceptibility to primary biliary cirrhosis.

BACKGROUND/AIMS: To investigate the possible influence of TNF-α gene promoter polymorphisms in conferring a predisposition to PBC patients. METHODOLOGY: We performed a meta-analysis of nine articles searched from PubMed up to July 2010 that investigated the association between two TNF-α polymorphisms (-308 and -238) and PBC. RESULTS: The data showed no significant association between TNF-α-308, -238 gene polymorphisms and the susceptibility to PBC in the global group (OR=0.95, 95%CI=0.80-1.13, p=0.55; OR=1.00, 95%CI=0.65-1.55, p=0.99, respectively). Stratified by sub-groups (European, American, Asian), TNF -308 minor allele, but not -238, was found to be a protective factor in the European population (OR= 0.81, 95%CI=0.67-0.99, p=0.04; OR=0.99, 95%CI=0.55-1.77, p=0.97, respectively). Moreover, no significant difference was observed between TNF-α-308 alleles and PBC when stratified by histological stages (stages I-II, OR=0.68, 95%CI=0.32-1.48, p=0.33; stages III-IV, OR=0.69, 95%CI=0.41-1.15, p=0.15). CONCLUSIONS: TNF-α promoter polymorphisms might not be associated with PBC risk. However, studies with larger population of varying ethnicity and stratified by clinical and laboratory characteristics are needed to validate our findings.

MicroRNA-149 inhibits proliferation and cell cycle progression through the targeting of ZBTB2 in human gastric cancer.

An increasing body of evidence indicates that miR-149 can both suppress and promote tumor growth depending on the tumor type. However, the role of miR-149 in the progression of gastric cancer (GC) remains unknown. Here we report that miR-149 is a tumor suppressor in human gastric cancer. miR-149 expression is decreased in GC cell lines and clinical specimens in comparison to normal gastric epithelial cell and tissues, respectively. The expression levels of miR-149 also correlate with the differentiation degree of GC cells and tissues. Moreover, ectopic expression of miR-149 in gastric cancer cells inhibits proliferation and cell cycle progression by down-regulating ZBTB2, a potent repressor of the ARF-HDM2-p53-p21 pathway, with a potential binding site for miR-149 in its mRNA's 3'UTR. It is also found that ZBTB2 expression increases in GC cells and tissues compared to normal gastric epithelial cell and tissues, respectively. Silencing of ZBTB2 leads to suppression of cell growth and cell cycle arrest in G0/G1 phase, indicating that ZBTB2 may act as an oncogene in GC. Furthermore, transfection of miR-149 mimics into gastric cancer cells induces down-regulation of ZBTB2 and HDM2, and up-regulation of ARF, p53, and p21 compared to the controls. In summary, our data suggest that miR-149 functions as a tumor suppressor in human gastric cancer by, at least partially through, targeting ZBTB2.

Osteopontin contributes to TGF-ß1 mediated hepatic stellate cell activation.

BACKGROUND AND PURPOSE: Liver fibrosis is characterized by accumulation of extracellular matrix. Our previous study found that osteopontin (OPN) increased in plasma of cirrhotic patients and indicative of cirrhosis staging. The present study was designed to investigate the expression of OPN in liver tissues and plasma of cirrhotic patients and further explore the role of OPN in human hepatic stellate cell (HSC) activation. METHODS: We used immunohistochemical staining and enzyme-linked immunosorbent assay to evaluate the expression level of OPN in liver tissues and plasma from cirrhotic patients, respectively. We produced lentivirus particles and infected target cell to manipulate OPN expression. Infection efficiency was determined by real-time RT-PCR and western blot. Cell proliferation was determined using CCK8 assay, and phenotypes of HSC activation were determined by real-time RT-PCR. OPN promoter activity was determined by dual luciferase reporter assay. RESULTS: We found that OPN expression in human cirrhotic liver tissues was upregulated compared to normal controls. In addition, its expression correlated with Child-Pugh classification, MELD score and the occurrence of complications. We further explored OPN level in patients' plasma and showed that its level correlated with transforming growth factor-ß1 (TGF-ß1). In human HSC cell line LX-2, we found that change of OPN expression level could not only affect the proliferation of cells but also the TGF-ß1 mediated HSC activation. Moreover, OPN was increased by TGF-ß1 stimulation and regulated by TGF-ß1 at transcription level. CONCLUSIONS: OPN is upregulated in liver tissues and plasma of cirrhotic patients and promotes TGF-ß1 mediated HSC activation.

Identification of cancer stem cells in vincristine preconditioned SGC7901 gastric cancer cell line.

Cancer stem cells (CSCs), or tumor initiating cells, are a subpopulation of cancer cells with self-renewal and differentiation properties. However, there has been no direct observation of the properties of gastric CSCs in vitro. Here we describe a vincristine (VCR)-preconditioning approach to obtain cancer stem-like cells (CSLCs) from the gastric cancer cell line SGC7901. The CSLCs displayed mesenchymal characteristics, including the up-regulated mesenchymal markers Snail, Twist, and vimentin, and the down-regulated epithelial marker E-cadherin. Using a Matrigel-based differentiation assay, CSLCs formed 2D tube-like and 3D complex lumen-like structures, which resembled differentiated gastric crypts. The characteristic of cellular differentiation was also found by transmission electron microscopy and up-regulation of gastrointestinal genes CDX2 and SOX2. We further showed that CSLCs could self-renew through significant asymmetric division compared with parent cells by tracing PKH-26, BrdU, and EDU label-retaining cells. In addition, these CSLCs also increased expression of CD44, CD90, and CXCR4 at the mRNA level, which was identified as novel targets. Furthermore, drug sensitivity assays and xenograft experiments demonstrated that the cells developed multi-drug resistance (MDR) and significant tumorigenicity in vivo. In summary, gastric CSCs were identified from VCR-preconditioned SGC7901 cell line, characterized by high tumorigenicity and the capacity for self-renewal and differentiation.