GSPT1 Functions as a Tumor Promoter in Human Liver Cancer.

OBJECTIVE: This study analyzed the role of G1 to S phase transition 1 protein (GSPT1) in promoting progression of liver cancer cells. METHODS: A bioinformatics database was used to analyze the expression levels of GSPT1 in liver cancer tissues and the prognosis of patients. Subsequently, Western blotting and quantitative PCR were used to verify the expression levels of GSPT1 between normal hepatocytes and hepatoma cells. We used a CRISPR/Cas9 system to construct knockouts of GSPT1 in HepG2 and HCCLM9 liver cancer cells. The effect of GSPT1 on liver cancer cell migration and invasion was analyzed using flow cytometry, migration, and tumor formation assays. RESULTS: The Cancer Genome Atlas Liver Hepatocellular Carcinoma dataset indicated that GSPT1 expression was upregulated in liver cancer cell lines, and patients with liver cancer had poor prognosis. Knockout of GSPT1 in cells significantly inhibited tumor proliferation, cell migration, and growth in vivo. CONCLUSION: In this study, we found that GSPT1 promotes the migration and invasion of liver cancer cells.

Bioinformatics Analysis and Identification of Potential Genes Associated with Pathogenesis and Prognosis of Gastric Cancer.

OBJECTIVE: Gastric cancer (GC) is a deadly cancer and a challenging public health problem globally. This study aimed to analyze potential genes associated with pathogenesis and prognosis of gastric cancer. METHODS: This work selected the overlapping differentially expressed genes (DEGs) in GC from four datasets, the GSE29272, GSE29998, GSE54129 and GSE118916 Gene Expression Omnibus databases. These DEGs were used to carry out comprehensive bioinformatic analysis to analyze the related functions and pathways enriched, the relative expression levels and immune infiltrates, the prognostic characteristics and the interaction network. RESULTS: In total, 55 DEGs increased while 98 decreased in their expression levels. For those DEGs with increased expression, they were mostly concentrated on "focal adhesion" and "ECM-receptor interaction", whereas DEGs with decreased expression were mostly associated with "gastric acid secretion" and "drug metabolism cytochrome P450". MCODE and ClueGO results were then integrated to screen 10 hub genes, which were FN1, COL1A1, COL3A1, BGN, TIMP1, COL1A2, LUM, VCAN, COL5A2 and SPP1. Survival analysis revealed that higher expression of the ten hub genes significantly predicted lower overall survival of GC patients. TIMP1 was most significantly related to neutrophils, CD8+ T cells, as well as dendritic cells, while LUM was most significantly related to macrophages. CONCLUSION: Immunohistochemistry results and functional testing showed that the expression of COL5A2 was elevated in GC and that it might be a key gene in GC tumorigenesis.

Overexpression of eRF3a Promotes Cell Proliferation and Migration in Liver Cancer.

OBJECTIVE: The eukaryotic release factor 3a (eRF3a), a member of the eukaryotic peptide chain release factor family, is overexpressed in several types of cancer. This study aims to investigate the biological role and mechanism of eRF3a in the progression of liver cancer. METHODS: Western blotting and RT-qPCR were used to detect the expression level of eRF3a in normal liver cells and liver cancer cells. The cell transfection experiments were performed to overexpress eRF3a levels in liver cancer cells HCCLM9 and Huh7, and then cell cycle and apoptosis experiments, Cell Counting Kit-8 (CCK8), plate cloning, and Transwell experiments were done to evaluate the function of eRF3a in the progression of liver cancer. The Western blotting was done to explore the mechanism of eRF3a promoting the development of liver cancer. Western blotting and RT-qPCR were used to detect the expression level of eRF3a in normal liver cells and liver cancer cells. The cell transfection experiments were performed to overexpress eRF3a levels in liver cancer cells HCCLM9 and Huh7, and then cell cycle and apoptosis experiments, Cell Counting Kit-8 (CCK8), plate cloning, and Transwell experiments were done to evaluate the function of eRF3a in the progression of liver cancer. The Western blotting was done to explore the mechanism of eRF3a promoting the development of liver cancer. RESULTS: eRF3a was significantly highly expressed in liver cancer cells, and its expression level was negatively correlated with the clinical prognosis of patients. In addition, in vitro experiments showed that eRF3a could promote the proliferation and migration of liver cancer cells through the ERK and JNK signaling pathways. CONCLUSION: This study suggests that eRF3a may be a potential prognostic marker for liver cancer and act as an oncogene by activating JNK and ERK signaling; therefore, eRF3a may be a new target for the treatment of liver cancer.

Identification of Prognostic Genes for Colon Cancer through Gene Co-expression Network Analysis.

OBJECTIVE: The present study was aimed to identify novel key genes, prognostic biomarkers and molecular pathways implicated in tumorigenesis of colon cancer. METHODS: The microarray data GSE41328 containing 10 colon cancer samples and 10 adjacent normal tissues was analyzed to identify 4763 differentially expressed genes. Meanwhile, another microarray data GSE17536 was performed for weighted gene co-expression network analysis (WGCNA). RESULTS: In present study, 12 co-expressed gene modules associated with tumor progression were identified for further studies. The red module showed the highest association with pathological stage by Pearson's correlation analysis. Functional enrichment analysis revealed that genes in red module focused on cell division, cell proliferation, cell cycle and metabolic related pathway. Then, a total of 26 key hub genes were identified, and GEPIA database was subsequently selected for validation. Holliday junction-recognizing protein (HJURP) and cell division cycle 25 homolog C (CDC25C) were identified as effective prognosis biomarkers, which were all detrimental to prognosis. Gene set enrichment analyses (GSEA) found the two hub genes were enriched in "oocyte meiosis", "oocyte maturation that are progesterone-mediated", "p53 signaling pathway", and "cell cycle". Furthermore, the immunohistochemistry and western blotting showed that HJURP was highly expressed in colon cancer tissue. CONCLUSION: HJURP was identified as a key gene associated with colon cancer progression and prognosis by WGCNA, which might influence the prognosis by regulating cell cycle pathways.

Characterization of novel lncRNAs in upper thoracic spinal cords of rats with myocardial ischemia-reperfusion injuries.

Myocardial ischemia-reperfusion injury (MIRI) is a significant problem in clinical cardiology, and refers to a more serious myocardial injury caused by blood recanalization after a period of myocardial ischemia, as compared with injury caused by vascular occlusion. The spinal cord, as the primary afferent and efferent center of cardiac sensory and sympathetic nerve fibres, has received increased attention in recent years with regards to the regulation of MIRIs. Previous studies have revealed that MIRI has a strong correlation with the abnormal expression of long non-coding (lnc)RNAs in the myocardium; however, there are limited reports on the effects of the altered expression of lncRNAs in the spinal cord following MIRI. To investigate the expression patterns of lncRNAs in the spinal cord after MIRI and their potential role in the early stage of reperfusion, a MIRI model was established in rats. After 30 min of myocardial ischemia and 2 h of reperfusion, the upper thoracic spinal cord tissues were immediately dissected and isolated. lncRNAs and mRNAs in spinal cord tissues were screened using transcriptome sequencing technology, and the expression of several highly deregulated mRNAs, including Frs3, Zfp52, Dnajc6, Nedd4l, Tep1, Myef2, Tgfbr1, Fgf12, Mef2c, Tfdp1 and lncRNA, including ENSRNOT00000080713, ENSRNOT00000090564, ENSRNOT00000082588, ENSRNOT00000091080, ENSRNOT00000091570, ENSRNOT00000087777, ENSRNOT00000082061, ENSRNOT00000091108, ENSRNOT00000087028, ENSRNOT00000086475, were further validated via reverse transcription-quantitative PCR. The number of altered expressed lncRNAs was 126, among which there were 41 upregulated probe sets and 85 downregulated sets. A total of 470 mRNAs were differentially expressed, in which 231 probe sets were upregulated and 239 were downregulated. Gene Ontology analysis indicated that dysregulated transcripts related to biological processes were mainly associated with 'cell-cell signaling'. Moreover, pathway analysis demonstrated significant changes in the 'PI3K/Akt signaling pathway' and the 'p53 signaling pathway'. Thus, the altered expression of lncRNAs in the spinal cord may be of considerable importance in the process of MIRI. The present results could provide an insight into the potential roles and mechanism of lncRNAs during the early stage of reperfusion.

Neurochemical alterations of different cerebral regions in rats with myocardial ischemia-reperfusion injury based on proton nuclear magnetic spectroscopy analysis.

BACKGROUND: Recent studies have demonstrated a complex and dynamic neural crosstalk between the heart and brain. A heart-brain interaction has been described regarding cardiac ischemia, but the cerebral metabolic mechanisms involved are unknown. METHODS: Male Sprague Dawley rats were randomly allocated into 2 groups: those receiving myocardial ischemia-reperfusion surgery (IR group, n =10) and surgical controls (Con group, n=10). These patterns of metabolic abnormalities in different brain regions were assessed using proton magnetic resonance spectroscopy (PMRS). RESULTS: Results assessed by echocardiography showed resultant cardiac dysfunction following heart ischemia-reperfusion. Compared with the control group, the altered metabolites in the IR group were taurine and choline, and differences mainly occurred in the thalamus and brainstem. CONCLUSIONS: Alterations in cerebral taurine and choline are important findings offering new avenues to explore neuroprotective strategies for myocardial ischemia-reperfusion injury. These results provide preliminary evidence for understanding the cerebral metabolic process underlying myocardial ischemia-reperfusion injury in rats.

The miR-370/UQCRC2 axis facilitates tumorigenesis by regulating epithelial-mesenchymal transition in Gastric Cancer.

Ubiquinol-cytochrome c reductase core protein 2 (UQCRC2) is an important mitochondrial complex III subunit. This study investigated the role of UQCRC2 in gastric cancer (GC) and its upstream regulatory microRNAs (miRNAs). UQCRC2 expression levels were lower in GC tissues than non-carcinoma tissues. Furthermore, UQCRC2 levels were negatively correlated with lymph node metastasis, relapse, and tumor grade. Bioinformatics analysis predicted UQCRC2 as the target gene for miR-370, and this was verified in luciferase reporter assays. MiR-370 levels were inversely correlated with UQCRC2 levels in GC. UQCRC2 overexpression suppressed GC cell migration and invasion in vitro and in vivo, whereas up-regulating miR-370 reversed these effects. Western blotting analysis showed that miR-370 targeted UQCRC2 and positively regulated the epithelial-mesenchymal transition (EMT) signaling pathway in GC cells. Therefore, the miR-370/UQCRC2 axis may regulate EMT signaling pathways to affect tumor proliferation and metastasis and is, thus, a potential target for GC treatment.

Quantitative proteomics identified 3 oxidative phosphorylation genes with clinical prognostic significance in gastric cancer.

The aim of the present study was to explore the underlying mechanisms involved in gastric cancer (GC) formation using data-independent acquisition (DIA) quantitative proteomics analysis. We identified the differences in protein expression and related functions involved in biological metabolic processes in GC. Totally, 745 differentially expressed proteins (DEPs) were found in GC tissues vs. gastric normal tissues. Despite enormous complexity in the details of the underlying regulatory network, we find that clusters of proteins from the DEPs were mainly involved in 38 pathways. All of the identified DEPs involved in oxidative phosphorylation were down-regulated. Moreover, GC possesses significantly altered biological metabolic processes, such as NADH dehydrogenase complex assembly and tricarboxylic acid cycle, which is mostly consistent with that in KEGG analysis. Furthermore the higher expression of UQCRQ, NDUFB7 and UQCRC2 were positively correlated with a better prognosis, implicating these proteins may as novel candidate diagnostic and prognostic biomarkers.

Expression of Stanniocalcin 2 in Breast Cancer and Its Clinical Significance.

This study aims to explore the expression of stanniocalcin 2 (STC2) gene in breast cancer and its clinical significance. Female patients with breast cancer from Zhongnan Hospital of Wuhan University admitted during March 2014 to October 2014 were enrolled in this study. All the tissues used in this experiment included 50 cases of breast cancer tissues and corresponding 50 cases of paracancer normal breast tissues with complete patients' information. The real-time quantitative polymerase chain reaction (qPCR) was applied to detect the expression of STC2 gene in 50 cases of breast cancer and paracancer normal breast tissues. The results showed that the expression level of STC2 gene in 50 cases of breast cancer tissues was significantly higher than that in paracancer normal breast tissues (P<0.001). The expression of STC2 gene was correlated with lymph node metastasis, distant metastasis, TNM stage and histological grade (P<0.001). The expression level of STC2 gene was significantly higher in breast cancer tissues with higher expression of Ki-67 (P<0.001). The expression level of STC2 gene was significantly higher in estrogen receptor (ER) positive breast cancer tissues than in ER negative ones (P<0.001). However, different groups of age, pathological type, tumor size, PR expression and human epidermal growth factor receptor-2 (HER2) expression did not show significant differences in STC2 expression (P>0.05). In conclusion, the abnormal overexpression of STC2 gene may play a role in the development and progression of breast cancer, and it can be used as an independent metastasis and prognostic factor of breast cancer. In addition, STC2 gene probably promotes the development and metastasis of breast cancer by interacting with estrogen and ER, and it may become a new direction for breast cancer endocrine therapy.

TRPM7 deficiency suppresses cell proliferation, migration, and invasion in human colorectal cancer via regulation of epithelial-mesenchymal transition.

BACKGROUND: It has been documented that transient receptor potential melastatin 7 (TRPM7) plays a pivotal role in the development of multiple cancers. However, the role of TRPM7 in human colorectal cancer (CRC) is poorly understood. Therefore, the aim of this study was to investigate the expression and significance of TRPM7 in CRC. METHODS: In this study, TRPM7 expression was first investigated in Gene Expression Omnibus (GEO), and then validated it with the data from our medical center. CCK-8, colony survival, transwell, and flow cytometry assays were employed to evaluate the effects of TRPM7 knockdown on the CRC cell proliferation, migration, and invasion, as well as cell cycle and apoptosis. RESULTS: We observed markedly increased TRPM7 expression in CRC tissues. CRC patients with high expression of TRPM7 suggested deeper tumor infiltration, positive lymph node metastasis, distant metastasis, and advanced clinical stage. In addition, TRPM7 was also overexpressed in CRC cell lines. Downregulated TRPM7 in vitro suppressed CRC cell proliferation, migration, and invasion, as well as triggered cell cycle arrest at the G0/G1 phase, reduced the S phase, and promoted apoptosis. Importantly, decreased TRPM7 in CRC cells reversed the epithelial-mesenchymal transition (EMT) status, accompanied by downregulation of N-cadherin and upregulation of E-cadherin. CONCLUSION: Our study indicated that the expression of TRPM7 was positively correlated with tumor infiltration, lymph node metastasis, distant metastasis and clinical stage of CRC. Besides, decreased TRPM7 in vitro inhibited CRC cell proliferation, migration and invasion by modulating EMT.

Alterations in amino acid levels and metabolite ratio of spinal cord in rat with myocardial ischemia-reperfusion injury by proton magnetic resonance spectroscopy.

OBJECTIVES: The mechanism behind spinal metabolites and myocardial ischemia-reperfusion (IR) injury is not well understood. Proton magnetic resonance spectroscopic analysis of spinal cord extracts provides a quick evaluation of the specific metabolic activity in rats with myocardial IR injury. We investigated the relationship between the IR-related variables and the changes in spinal metabolites. METHODS: Proton magnetic resonance spectroscopy (1H-MRS) was used to assess the spinal metabolites of adult rats with and without myocardial IR injury (n = 6 per group). Myocardial IR injury was reproduced using intermittent occlusion of the left anterior descending coronary artery. We studied the relationship between the metabolite ratio measurement and IR-related variables. All rats underwent 1H-MRS, with the ratio of interest placed in different spinal cord segments to measure levels of twelve metabolites including N-acetylaspartate (NAA), taurine (Tau), glutamate (Glu), gamma amino acid butyric acid (GABA), creatine (Cr), and myoinositol (MI), etc. Results: Rats with myocardial IR injury had higher concentration of Tau in the upper thoracic spinal cord (P < 0.05), and lower concentration of Gly and Glu in the cervical segment of the spinal cord (P < 0.05), when compared to the Control group. The ratios of glutamate/taurine (Glu/Tau), Glu/(GABA + Tau) and Glu/Total were significantly different between the IR group and the Control group in the upper thoracic spinal cord (P < 0.05). So were the ratios of Glu/(GABA + Tau) in the cervical segment (P < 0.05), and Glu/Tau and Glu/(GABA + Tau) in the lower thoracic spinal cord (P < 0.05). CONCLUSIONS: These findings suggest that myocardial IR injury may be related to spinal biochemical alterations. It is speculated that these observed changes in the levels of spinal metabolites may be involved in the pathogenesis and regulation of myocardial IR injury.

Identification of lncRNA and mRNA expression profiles in rat spinal cords at various time­points following cardiac ischemia/reperfusion.

The identification of the expression patterns of long non­coding RNAs (lncRNAs) and mRNAs in the spinal cord under normal and cardiac ischemia/reperfusion (I/R) conditions is essential for understanding the genetic mechanisms underlying the pathogenesis of cardiac I/R injury. The present study used high­throughput RNA sequencing to investigate differential gene and lncRNA expression patterns in the spinal cords of rats during I/R­induced cardiac injury. Male Sprague Dawley rats were assigned to the following groups: i) Control; ii) 2 h (2 h post­reperfusion); and iii)v0.5 h (0.5 h post­reperfusion). Further mRNA/lncRNA microarray analysis revealed that the expression profiles of lncRNA and mRNA in the spinal cords differed markedly between the control and 2 h groups, and in total 7,980 differentially expressed (>2­fold) lncRNAs (234 upregulated, 7,746 downregulated) and 3,428 mRNAs (767 upregulated, 2,661 downregulated) were identified. Reverse transcription­quantitative polymerase chain reaction analysis was performed to determine the expression patterns of several lncRNAs. The results indicated that the expression levels of lncRNA NONRATT025386 were significantly upregulated in the 2 and 0.5 h groups when compared with those in the control group, whereas the expression levels of NONRATT016113, NONRATT018298 and NONRATT018300 were elevated in the 2 h group compared with those in the control group; however, there was no statistically significant difference between the 0.5 h and control groups. Furthermore, the expression of lncRNA NONRATT002188 was significantly downregulated in the 0.5 and 2 h groups when compared with the control group. The present study determined the expression pattern of lncRNAs and mRNAs in rat spinal cords during cardiac I/R. It was suggested that lncRNAs and mRNAs from spinal cords may be novel therapeutic targets for the treatment of I/R­induced cardiac injury.

DJ-1 Alters Epirubicin-induced Apoptosis via Modulating Epirubicinactivated Autophagy in Human Gastric Cancer Cells.

Epirubicin, which is a conventional chemotherapeutic drug for gastric cancer, has innate and adaptive chemoresistance. Recent studies revealed that epirubicin could induce autophagy as a defensive mechanism in drug resistance of mammary carcinoma. Another study implied that DJ-1 may be a chemoresistance-related gene. But the association between DJ-1 and drug resistance of epirubicin in gastric cancer is still ambiguous. In the present report, we explored whether and how DJ-1 conduced to epirubicin-induced apoptosis in gastric cancer. Epirubicin dose-dependently increased the expression of DJ-1 and induced autophagy. Knockdown of DJ-1 notably enhanced epirubicin-induced cell apoptosis, whereas overexpression of DJ-1 attenuated epirubicin-induced cell apoptosis. Further studies revealed that down-regulation of DJ-1 modulated epirubicinactivated autophagy which augmented epirubicin-induced apoptosis. In conclusion, our results validated that DJ-1 reduced epirubicin-induced apoptosis in gastric cancer cells via modulating epirubicin-activated autophagy.

Application of animal and human PET in cardiac research.

PURPOSE OF REVIEW: After a warm-up period of imaging research, several modalities of positron emission tomography (PET) are under development for evaluating ischemic heart disease. RECENT FINDINGS: Several types of well-documented stem/progenitor PET imaging have been utilized for changes in myocardial blood flow and carbohydrate metabolism. Some recent experimental and human studies reported that these data may have beneficial effects on cardiac research. SUMMARY: Although the role of PET in the pathology of ischemic heart disease has not been sufficiently elucidated, many studies attempting imaging research of myocardial metabolism and neural regulation have been reported. Further studies are needed to better evaluate the potential of PET in evaluating ischemic heart disease.

Knockdown of GRHL3 inhibits activities and induces cell cycle arrest and apoptosis of human colorectal cancer cells.

The Grainyhead-like 3 (GRHL3) is involved in epidermal barrier formation, neural tube closure and wound repair. Previous studies have suggested that GRHL3 has been linked to many different types of cancers. However, to date, its effects on human colorectal cancer (CRC) has not been clarified yet. Our microarray analysis has indicated predominant GRHL3 expression in CRC. The purpose of this study was to investigate the expression and significance of GRHL3 in CRC tumorigenesis using CRC tissues and paired paracancerous tissues, as well as using distinct CRC cell lines (HT29 and DLD1). We observed increased GRHL3 expression at both mRNA and protein levels in CRC tissues and CRC cell lines using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Moreover, silencing GRHL3 with siRNA could suppress CRC cell proliferation, viability and migration in vitro. We also found that knockdown of GRHL3 could promote cell cycle arrest at G0/G1 phase in HT29 cells and DLD1 cells, and induce cell apoptosis in HT29 cells. Together, our study revealed the down-regulation of GRHL3 in vitro could inhibit CRC cell activity and trigger cell cycle arrest at G0/G1 phase and apoptosis.

Inhibition of adhesion and metastasis of HepG2 hepatocellular carcinoma cells in vitro by DNA aptamer against sialyl Lewis X.

The sialyl Lewis X (SLex) antigen encoded by the FUT7 gene is the ligand of endotheliam-selectin (E-selectin). The combination of SLex antigen and E-selectin represents an important way for malignant tumor metastasis. In the present study, the effect of the SLex-binding DNA aptamer on the adhesion and metastasis of hepatocellular carcinoma HepG2 cells in vitro was investigated. Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence staining were conducted to detect the expression of FUT7 at both transcriptional and translational levels. The SLex expression in HepG2 cells treated with different concentrations of SLex-binding DNA aptamer was detected by flow cytometry. Besides, the adhesion, migration, and invasion of HepG2 cells were measured by cell adhesion assay, and the Transwell migration and invasion assay. The results showed that the FUT7 expression was up-regulated at both mRNA and protein levels in HepG2 cells. SLex-binding DNA aptamer could significantly decrease the expression of SLex in HepG2 cells. The cell adhesion assay revealed that the SLex-binding DNA aptamer could effectively inhibit the interactions between E-selectin and SLex in the HepG2 cells. Additionally, SLex-binding DNA aptamers at 20 nmol/L were found to have the similar effect to the monoclonal antibody CSLEX-1. The Transwell migration and invasion assay revealed that the number of penetrating cells on the down-side of Transwell membrane was significantly less in cells treated with 5, 10, 20 nmol/L SLex-binding DNA aptamer than those in the negative control group (P<0.01). Our study demonstrated that the SLex-binding DNA aptamer could significantly inhibit the in vitro adhesion, migration, and invasion of HepG2 cells, suggesting that the SLex-binding DNA aptamer may be used as a potential molecular targeted drug against metastatic hepatocellular carcinoma.

Neuroanatomical circuitry between kidney and rostral elements of brain: a virally mediated transsynaptic tracing study in mice.

The identity of higher-order neurons and circuits playing an associative role to control renal function is not well understood. We identified specific neural populations of rostral elements of brain regions that project multisynaptically to the kidneys in 3-6 days after injecting a retrograde tracer pseudorabies virus (PRV)-614 into kidney of 13 adult male C57BL/6J strain mice. PRV-614 infected neurons were detected in a number of mesencephalic (e.g. central amygdala nucleus), telencephalic regions and motor cortex. These divisions included the preoptic area (POA), dorsomedial hypothalamus (DMH), lateral hypothalamus, arcuate nucleus (Arc), suprachiasmatic nucleus (SCN), periventricular hypothalamus (PeH), and rostral and caudal subdivision of the paraventricular nucleus of the hypothalamus (PVN). PRV-614/Tyrosine hydroxylase (TH) double-labeled cells were found within DMH, Arc, SCN, PeH, PVN, the anterodorsal and medial POA. A subset of neurons in PVN that participated in regulating sympathetic outflow to kidney was catecholaminergic or serotonergic. PRV-614 infected neurons within the PVN also contained arginine vasopressin or oxytocin. These data demonstrate the rostral elements of brain innervate the kidney by the neuroanatomical circuitry.

SLC38A1 promotes proliferation and migration of human colorectal cancer cells.

Current studies have demonstrated that SLC38A1 proteins play a causal role in neoplastic cell transformation. The twofold aim of this study was to provide insight into whether a variance in the expression of SLC38A1 exists between human colorectal cancer and healthy human tissues and to determine how silencing or overexpressing the SLC38A1 gene could affect the proliferation, viability and migration of colorectal cancer cells. Immunohistochemical staining was used to analyze the expression of SLC38A1 in colorectal cancer tissues and adjacent normal mucosa in 77 patients who underwent surgical resection. The expression of SLC38A1 in colorectal cancer tissues and cell lines was detected using RT-PCR and Western blotting. Two colorectal cancer cell lines SW480 and HCT116 were used to examine whether silencing SLC38A1 with siRNA and overexpressing SLC38A1 with shRNA could affect cell viability and migration. As a result, the SLC38A1 protein was very low or undetectable in the normal colon mucosa. In contrast, strong staining of SLC38A1 protein was found in the cytoplasm in 79.2% colorectal cancer samples. More pronounced SLC38A1 expression in colorectal cancer tissues was significantly associated with tumor node metastasis (TNM) stage. Inhibition of SLC38A1 reduced tumour growth and suppressed proliferation and migration of SW480 cells. In contrast, overexpression of SLC38A1 had the opposite effects on HCT116 cells. SLC38A1 is overexpressed in colorectal cancer, which suggests that it is associated with tumour progression. These results encourage the exploration of SLC38A1 as a target for intervention in colorectal cancer.

Foxp3 expression in CD4+CD25+Foxp3+ regulatory T cells promotes development of colorectal cancer by inhibiting tumor immunity.

The mechanism underlying CD4+CD25+Foxp3+ regulatory T cells (Tregs) promoting the development of colorectal cancer (CRC) was elucidated in the present study. Forty-eight cases of colorectal carcinomas, 22 cases of colon polyps and 21 cases of normal colorectal tissues were collected. The correlation among Foxp3, IL-10 and Stat3, and the clinical relevance of these three indexes were analyzed. The results showed that the levels of Foxp3 expressed in infiltrating CD4+CD25+Foxp3+Tregs, and IL-10 and Stat3 in CRC tissues were all significantly higher than those in polypus tissues and normal colon tissues (P< 0.01). Pearson correlation analysis indicated that the expression level of Foxp3 was positively correlated with Stat3 at mRNA level (r=0.526, P=0.036), and was positively correlated with IL-10 at protein level (r=0.314, P=0.030). The Foxp3 expressed in CD4+CD25+Foxp3+Tregs was correlated with the histological grade, lymph node metastasis and TNM stage of CRC (P<0.05 for all). The IL-10 expression was correlated with the histological grade and TNM stage (both P<0.05). The Stat3 expression was correlated with the lymph node metastasis and TNM stage (both P<0.05). It was concluded that CD4+CD25+Foxp3+Tregs can inhibit tumor immunity in combination with some other related inhibitory cytokines and that Foxp3 expression in CD4+CD25+Foxp3+Tregs correlates with CRC progression.