Ranran Sun

Overexpression of EZH2 is associated with the poor prognosis in osteosarcoma and function analysis indicates a therapeutic potential

Osteosarcoma is a primary malignant bone tumor that has a poor prognosis due to local recurrence, metastasis, and chemotherapy resistance. Therefore, there is an urgent need to develop novel potential therapeutic targets for osteosarcoma. Enhancer of zeste homologue 2 (EZH2) is a member of the polycomb group of proteins, which has important functions in epigenetic silencing and cell cycle regulation. Overexpression of EZH2 has been found in several malignancies, however, its expression and the role of EZH2 in osteosarcoma is largely unknown. In this study, we examined EZH2 expression by immunohistochemistry in a large series of osteosarcoma tissues in association with tumor characteristics and patient outcomes. EZH2 expression was also analyzed in a microarray dataset of osteosarcoma. Results showed that higher expression of EZH2 was significantly associated with more aggressive tumor behavior and poor patient outcomes of osteosarcoma. We subsequently investigated the functional and therapeutic relevance of EZH2 as a target in osteosarcoma. Immunohistochemical analysis indicated that EZH2 expression was significantly associated with more aggressive tumor behavior and poorer patient outcomes of osteosarcoma. EZH2 silencing by siRNA inhibited osteosarcoma cell growth, proliferation, migration, and invasion. Moreover, suppression of EZH2 attenuated cancer stem cell functions. Similar results were observed in osteosarcoma cells treated with EZH2 specific inhibitor 3-deazaneplanocin A (DZNep), which exhausted cellular levels of EZH2. These results suggest that EZH2 is critical for the growth and metastasis of osteosarcoma, and an epigenetic therapy that pharmacologically targets EZH2 via specific inhibitors may constitute a novel approach to the treatment of osteosarcoma.

Ammonium chloride inhibits autophagy of hepatocellular carcinoma cells through SMAD2 signaling.

Autophagy is a cellular degradation process for the clearance of damaged or superfluous proteins and organelles, the recycling of which serves as an alternative energy source during periods of metabolic stress to maintain cell homeostasis and viability. The anti-necrotic function of autophagy is critical for tumorigenesis of many tumor cells, including hepatocellular carcinoma (HCC). However, the underlying mechanism is not clarified yet. Ammonium chloride (NH4Cl) is a well-known autophagy inhibitor, whereas its interaction with SMAD2 signaling pathway has not been reported previously. Here, we show that NH4Cl significantly inhibited rapamycin-induced autophagy in HCC cells through decreasing the levels of Beclin-1, autophagy-related protein 7 (ATG7), p62, and autophagosome marker LC3 and significantly decreased the level of phosphorylated SMAD2 in rapamycin-treated HCC cells. In order to find out whether NH4Cl may inhibit the autophagy in rapamycin-treated HCC cells through inhibition of SMAD2 signaling, we used transforming growth factor β1 (TGFβ1) to induce phosphorylation of SMAD2 in HCC cells. We found that induction of SMAD2 in HCC cells completely abolished the inhibitory effect of NH4Cl on rapamycin-induced autophagy in HCC cells, suggesting that NH4Cl inhibits autophagy of HCC cells through inhibiting SMAD2 signaling.

Gut microbial profile analysis by MiSeq sequencing of pancreatic carcinoma patients in China

Pancreatic carcinoma (PC) is a lethal cancer. Gut microbiota is associated with some risk factors of PC, e.g. obesity and types II diabetes. However, the specific gut microbial profile in clinical PC in China has never been reported. This prospective study collected 85 PC and 57 matched healthy controls (HC) to analyze microbial characteristics by MiSeq sequencing. The results showed that gut microbial diversity was decreased in PC with an unique microbial profile, which partly attributed to its decrease of alpha diversity. Microbial alterations in PC featured by the increase of certain pathogens and lipopolysaccharides-producing bacteria, and the decrease of probiotics and butyrate-producing bacteria. Microbial community in obstruction cases was separated from the un-obstructed cases. Streptococcus was associated with the bile. Furthermore, 23 microbial functions e.g. Leucine and LPS biosynthesis were enriched, while 13 functions were reduced in PC. Importantly, based on 40 genera associated with PC, microbial markers achieves a high classification power with AUC of 0.842. In conclusion, gut microbial profile was unique in PC, providing a microbial marker for non-invasive PC diagnosis.Pancreatic carcinoma (PC) is a lethal cancer. Gut microbiota is associated with some risk factors of PC, e.g. obesity and types II diabetes. However, the specific gut microbial profile in clinical PC in China has never been reported. This prospective study collected 85 PC and 57 matched healthy controls (HC) to analyze microbial characteristics by MiSeq sequencing. The results showed that gut microbial diversity was decreased in PC with an unique microbial profile, which partly attributed to its decrease of alpha diversity. Microbial alterations in PC featured by the increase of certain pathogens and lipopolysaccharides-producing bacteria, and the decrease of probiotics and butyrate-producing bacteria. Microbial community in obstruction cases was separated from the un-obstructed cases. Streptococcus was associated with the bile. Furthermore, 23 microbial functions e.g. Leucine and LPS biosynthesis were enriched, while 13 functions were reduced in PC. Importantly, based on 40 genera associated with PC, microbial markers achieves a high classification power with AUC of 0.842. In conclusion, gut microbial profile was unique in PC, providing a microbial marker for non-invasive PC diagnosis.

The influence of TLR4 agonist lipopolysaccharides on hepatocellular carcinoma cells and the feasibility of its application in treating liver cancer

Objective This study was designed to explore the influence of Toll-like receptor 4 (TLR4) agonist lipopolysaccharides (LPS) on liver cancer cell and the feasibility to perform liver cancer adjuvant therapy. Methods Human liver cancer cell lines HepG2, H7402, and PLC/PRF/5 were taken as models, and the expression of TLRs mRNA was detected by real time-polymerase chain reaction method semiquantitatively. WST-1 method was used to detect the influence of LPS on the proliferation ability of liver cancer cells; propidium iodide (PI) single staining and Annexin V/PI double staining were used to test the influence of LPS on the cell cycle and apoptosis, respectively, on human liver cancer cell line H7402. Fluorescent quantitative polymerase chain reaction and Western blot method were used to determine the change of expression of Cyclin D1. Results The results demonstrated that most TLRs were expressed in liver cancer cells; stimulating TLR4 by LPS could upregulate TLR4 mRNA and the protein level, activate NF-κB signaling pathway downstream of TLR4, and mediate the generation of inflammatory factors IL-6, IL-8, and TNF-α; LPS was found to be able to strengthen the proliferation ability of liver cancer cells, especially H7402 cells; the expression of Cyclin D1 rose and H7402 cells were promoted to transit from G1 stage to S stage under the stimulation of LPS, but cell apoptosis was not affected. It was also found that LPS was able to activate signal transducer and activator of transcription -3 (STAT3) signaling pathway in H7402 cells and meanwhile significantly increase the initiation activity of STAT3; proliferation promoting effect of LPS to liver cancer cells remarkably lowered once STAT3 was blocked or inhibited. Conclusion Thus, TLR4 agonist LPS is proved to be able to induce liver cancer cells to express inflammation factors and mediate liver cancer cell proliferation and generation of multidrug resistance by activating the cyclooxygenase-2/prostaglandin signal axis as well as the STAT3 pathway.

Hepatic injury is associated with cell cycle arrest and apoptosis with alteration of cyclin A and D1 in ammonium chloride-induced hyperammonemic rats.

Hyperammonemia is considered to be central to the pathophysiology of hepatic encephalopathy in patients exhibiting hepatic failure (HF). It has previously been determined that hyperammonemia is a serious metabolic disorder commonly observed in patients with HF. However, it is unclear whether hyperammonemia has a direct adverse effect on hepatic cells or serves as a cause and effect of HF. The present study investigated whether hepatic injury is caused by hyperammonemia, and aimed to provide an insight into the causes and mechanisms of HF. Hyperammonemic rats were established via intragastric administration of ammonium chloride solution. Hepatic tissues were assessed using biochemistry, histology, immunohistochemistry, flow cytometry (FCM), semi-quantitative reverse transcription-polymerase chain reaction and western blot analysis. Hyperammonemic rats exhibited significantly increased levels of liver function markers, including alanine transaminase (P<0.01), aspartate aminotransferase (P<0.01), blood ammonia (P<0.01) and direct bilirubin (P<0.05), which indicated hepatic injury. A pathological assessment revealed mild hydropic degeneration, but no necrosis or inflammatory cell infiltration. However, terminal deoxynucleotidyl transferase dUTP nick end-labeling assays confirmed a significant increase in the rate of cellular apoptosis in hyperammonemic rat livers (P<0.01). FCM analysis revealed that there were significantly more cells in the S phase and fewer in the G2/M phase (P<0.01), and the expression levels of cyclin A and D1 mRNA and proteins were significantly increased (P<0.01). In summary, cell cycle arrest, apoptosis and an alteration of cyclin A and D1 levels were all markers of hyperammonemia-induced hepatic injury. These findings provide an insight into the potential mechanisms underlying hyperammonemia-induced hepatic injury, and may be used as potential targets for treating or preventing hepatic damage caused by hyperammonemia, including hepatic encephalopathy.

Galectin-1 Modulates the Survival and Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) Sensitivity in Human Hepatocellular Carcinoma Cells

Galectin-1 is a member of carbohydrate-binding proteins and plays critical roles in tumor growth and progression. It has been reported that galectin-1 is upregulated in human hepatocellular carcinoma (HCC) and facilitates HCC cell migration and invasion. In this study, the authors aimed to explore the effects of the knockdown of galectin-1 on HCC cell survival and sensitivity to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Human HCC cells were transfected with galectin-1-targeting small interfering RNA (siRNA) with or without 100 ng/mL TRAIL treatment and tested for apoptosis and gene expression changes. Cotransfection of Bcl-2- and survivin-expressing plasmids with galectin-1 siRNA was done, before TRAIL exposure, cell viability, and apoptosis were assessed. The authors found that siRNA-mediated downregulation of galectin-1 caused apoptosis in HCC cells, which was coupled with reduced Bcl-2 and survivin and increased Bax expression. Overexpression of Bcl-2 and survivin significantly blocked galectin-1 silencing-induced apoptosis of HCC cells. Knockdown of galectin-1 significantly enhanced TRAIL cytotoxicity against HCC cells, as determined by the MTT assay. Moreover, galectin-1 downregulation significantly induced apoptosis in TRAIL-treated HCC cells. Such effects were almost completely counteracted by the enforced expression of Bcl-2 and survivin. Taken together, these data first show that galectin-1 downregulation induces apoptosis in and augments TRAIL cytotoxicity to HCC cells largely through regulation of Bcl-2 and survivin expression. These findings provide a rationale for preclinical and clinical evaluation of targeting galectin-1 for improving TRAIL-based therapy against HCC.

LDHA is a direct target of miR‐30d‐5p and contributes to aggressive progression of gallbladder carcinoma

Gallbladder cancer (GBC) is the most general biliary tract malignancy, with poor prognosis due to rapid tumor progression and lack of specific symptoms. Lactate dehydrogenase‐A (LDHA) can promote Warburg effect to produce lactate and Adenosine Triphosphate (ATP) in aerobic condition, which contributes to oncogenesis metastasis and drug resistance in various cancers. However, the expression and functional role of LDHA in GBC are largely unknown. We determined that LDHA was over‐expressed in GBC tumor tissues compared with normal tissues, which was also an independent prognostic factor for the overall survival of GBC patients by tissue microarrays analysis. In addition, RNAi‐mediated LDHA silencing could suppress the GBC cell proliferation, invasion, colony formation and glycolysis while promoting cell apoptosis in vitro. Similar results were observed in GBC cells treated with LDHA specific inhibitor FX11. Moreover, we confirmed that knockdown of LDHA could inhibit tumor growth in vivo. Additionally, we found that the 3′‐untranslated region (3′‐UTR) of LDHA mRNA was the direct target of microRNA‐30d‐5p (miR‐30d‐5p), which was low expressed in GBC tissues and associated with poor prognosis of GBC patients. Our findings disclose a novel role for miR‐30d‐5p/LDHA axis contribute to aggressive progression by reprogramming the metabolic process in GBC cells, and suggest a potential application of miR‐30d‐5p/LDHA axis in prognosis prediction and GBC treatment.

Upregulation of ALDH1B1 promotes tumor progression in osteosarcoma

Osteosarcoma (OS) is the most common primary malignant bone tumor in childhood and adolescence with poor prognosis. The mechanism underlying tumorigenesis and development of OS is largely unknown. ALDH1B1 has been reported to involve in many kinds of human cancers and functions as an oncogene, but the role of ALDH1B1 in OS has not been investigated comprehensively. In the present study, we aimed to examine clinical value and biological function of ALDH1B1 in OS. Firstly, we investigated the roles of ALDH1B1 on an OS tissue microarray (TMA) as well as two OS cohorts from GEO database. We found that ALDH1B1 was significantly up-regulated in OS tissues and was independently associated with poor prognosis. Moreover, ALDH1B1 silencing could suppress the proliferation, migration, invasion in vitro and inhibit the growth of xenograft tumor and of OS cells in vivo. Additional, ALDH1B1 knockdown increased the apoptosis rate and lead to cell cycle arrest in G1 stage of OS cell in vitro. More importantly, the inhibition of ALDH1B1 expression could increase the sensitivity of OS cells to chemotherapy, which suggested that ALDH1B1 might be served as a therapeutic target to reverse drug resistance in chemotherapy in OS patients. Taken together, our founding suggested that ALDH1B1 contributes to OS tumor progression and drug resistance, which may represent a novel prognostic marker and potential therapeutic target for OS patients.

Low microRNA-139 expression associates with poor prognosis in patients with tumors: A meta-analysis

BACKGROUND microRNA-139 (miR-139) is dysregulated in various types of tumors and plays a key role in carcinogenesis. miR-139 may be used as a diagnostic and prognostic biomarker of cancers. However, the data from the literature are not consistent. The present study aimed to verify the prognostic and diagnostic values of miR-139 in solid tumors. DATA SOURCES PubMed, Web of Science and Embase databases were searched and publications from January 2011 to August 2017 were included. We used Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) database to further validate this meta-analysis. RESULTS Eight individual studies from seven articles were included. Pooled analyses showed that low miR-139 expression was related to worse overall survival (OS) [hazard ratio (HR) = 2.27; 95% confidence intervals (CI): 1.74-2.95; P < 0.001] in solid tumors, including hepatocellular carcinoma (HCC) and glioblastoma multiforme (GBM), consisting with the results of TCGA. However, our results of CRC showed that low miR-139 expression was associated with poor OS which was contradictory with the results in TCGA database and need larger samples to validate the phenomenon; whereas for CRC patients, high miR-139 expression predicted poor RFS, which was in good accordance with TCGA results. The results of 27 microarrays from GEO database showed that miR-139 expression levels were lower in tumor tissues compared to adjacent non-tumor tissues or healthy tissues. Decreased miR-139 expression was also significantly correlated with poor differentiation grade (OR = 3.57; 95% CI: 1.44-8.85; P = 0.006). However, the combined data indicated that no associations between miR-139 expression and the following parameters such as age (pooled OR = 1.50; 95% CI: 0.69-3.24; P = 0.304), gender (pooled OR = 0.92; 95% CI: 0.56-1.51; P = 0.738), tumor size (pooled OR = 1.51; 95% CI: 0.69-3.31; P = 0.298), late tumor-node-metastasis stage (pooled OR = 1.63; 95% CI: 0.99-2.68; P = 0.057) and lymph-node-metastasis (pooled OR = 0.66; 95% CI: 0.34-1.28; P = 0.222). CONCLUSIONS Low miR-139 expression was related to poor prognosis in HCC and GBM, which could be regarded as a potential prognostic biomarker. However, its precise functional role in CRC still need to be further investigated through larger samples and multicenter studies.

Gut microbiome analysis as a tool towards targeted non-invasive biomarkers for early hepatocellular carcinoma

Objective To characterise gut microbiome in patients with hepatocellular carcinoma (HCC) and evaluate the potential of microbiome as non-invasive biomarkers for HCC. Design We collected 486 faecal samples from East China, Central China and Northwest China prospectively and finally 419 samples completed Miseq sequencing. We characterised gut microbiome, identified microbial markers and constructed HCC classifier in 75 early HCC, 40 cirrhosis and 75 healthy controls. We validated the results in 56 controls, 30 early HCC and 45 advanced HCC. We further verified diagnosis potential in 18 HCC from Xinjiang and 80 HCC from Zhengzhou. Results Faecal microbial diversity was increased from cirrhosis to early HCC with cirrhosis. Phylum Actinobacteria was increased in early HCC versus cirrhosis. Correspondingly, 13 genera including Gemmiger and Parabacteroides were enriched in early HCC versus cirrhosis. Butyrate-producing genera were decreased, while genera producing-lipopolysaccharide were increased in early HCC versus controls. The optimal 30 microbial markers were identified through a fivefold cross-validation on a random forest model and achieved an area under the curve of 80.64% between 75 early HCC and 105 non-HCC samples. Notably, gut microbial markers validated strong diagnosis potential for early HCC and even advanced HCC. Importantly, microbial markers successfully achieved a cross-region validation of HCC from Northwest China and Central China. Conclusions This study is the first to characterise gut microbiome in patients with HCC and to report the successful diagnosis model establishment and cross-region validation of microbial markers for HCC. Gut microbiota-targeted biomarkers represent potential non-invasive tools for early diagnosis of HCC.