Chinese guideline for the diagnosis and treatment of drug-induced liver injury: an update.

Drug-induced liver injury (DILI) is an important adverse drug reaction that can lead to acute liver failure or even death in severe cases. Currently, the diagnosis of DILI still follows the strategy of exclusion. Therefore, a detailed history taking and a thorough and careful exclusion of other potential causes of liver injury is the key to correct diagnosis. This guideline was developed based on evidence-based medicine provided by the latest research advances and aims to provide professional guidance to clinicians on how to identify suspected DILI timely and standardize the diagnosis and management in clinical practice. Based on the clinical settings in China, the guideline also specifically focused on DILI in chronic liver disease, drug-induced viral hepatitis reactivation, common causing agents of DILI (herbal and dietary supplements, anti-tuberculosis drugs, and antineoplastic drugs), and signal of DILI in clinical trials and its assessment.

Single-cell RNA sequencing to reveal non-parenchymal cell heterogeneity and immune network of acetaminophen-induced liver injury in mice.

The role of non-parenchymal cells (NPCs) in the early phase of acetaminophen (APAP)-induced liver injury (AILI) remains unclear. Therefore, single-cell sequencing (scRNA-seq) was performed to explore the heterogeneity and immune network of NPCs in the livers of mice with AILI. Mice were challenged with saline, 300 mg/kg APAP, or 750 mg/kg APAP (n = 3 for each group). After 3 h, the liver samples were collected, digested, and subjected to scRNA-seq. Immunohistochemistry and immunofluorescence were performed to confirm the expression of Makorin ring finger protein 1 (Mkrn1). We identified 14 distinct cell subtypes among the 120,599 cells. A variety of NPCs were involved, even in the early stages of AILI, indicating highly heterogeneous transcriptome dynamics. Cholangiocyte cluster 3, which had high deleted in malignant brain tumors 1 (Dmbt1) expression, was found to perform drug metabolism and detoxification functions. Liver sinusoidal endothelial cells exhibited fenestrae loss and angiogenesis. Macrophage cluster 1 displayed a M1 polarization phenotype, whereas cluster 3 tended to exhibit M2 polarization. Kupffer cells (KCs) exhibited pro-inflammatory effects due to the high expression of Cxcl2. qRT-PCR and western blotting verified that the LIFR-OSM axis might promote the activation of MAPK signaling pathway in RAW264.7 macrophages. Mkrn1 was highly expressed in the liver macrophages of AILI mice and AILI patients. Interaction patterns between macrophages/KCs and other NPCs were complex and diverse. NPCs were highly heterogeneous and were involved in the immune network during the early phase of AILI. In addition, we propose that Mkrn1 may serve as a potential biomarker of AILI.

Egr1 confers protection against acetaminophen­induced hepatotoxicity via transcriptional upregulating of Acaa2.

Background : Acetaminophen (APAP)-induced liver injury (AILI) is a common cause of drug-induced liver injury (DILI). The mechanism underlying protection in AILI or DILI remains to be elucidated, and the role of early growth response 1 (Egr1) in AILI and potential mechanisms remain to be known. Methods : The role of Egr1 was studied both in vivo and in vitro. Liver-specific Egr1-knockout (Egr1LKO) mice and those overexpressing Egr1 via tail vein injection of Egr1-expressing adenovirus (Ad-Egr1) were utilized with AILI. Chromatin immunoprecipitation-sequencing, RNA-sequencing, seahorse XF analysis, and targeted fatty acid analysis were performed. EGR1 levels were also studied in liver tissues and serum samples from AILI/DILI patients. Results: In this study, we have demonstrated that Egr1 was upregulated in AILI models in vivo and in vitro. liver-specific Egr1 knockout aggravated AILI; however, Ad-Egr1 treatment ameliorated this. Mechanistically, Egr1 deficiency inhibited, whereas overexpression promoted, mitochondrial respiratory function and fatty acid ß-oxidation (FAO) activity in AILI. Egr1 transcriptionally upregulated FAO-related genes in hepatocytes. Notably, the knockdown of acetyl-coenzyme A acyltransferase 2 (Acaa2), a key gene involved in FAO, diminished this protective effect of Egr1. Clinically, EGR1 was markedly increased in liver tissues from AILI patients. Interestingly, EGR1 levels of liver tissues and serum samples were also obviously higher in idiosyncratic DILI patients. Conclusions: Egr1 confers adaptive protection in AILI, mediated via the transcriptional upregulation of Acaa2, which improves mitochondrial FAO, and might be a potential biomarker and novel therapeutic target for AILI.

Efficacy and safety of bicyclol for treating patients with idiosyncratic acute drug-induced liver injury: A multicenter, randomized, phase II trial.

BACKGROUND AND AIMS: Evidence for using bicyclol in drug-induced liver injury (DILI) is limited. This study aimed to explore the efficacy and safety of bicyclol in acute DILI. METHODS: This was a multicenter, randomized, double-blinded, double-dummy, active-controlled, superiority and phase II trial. Patients with idiosyncratic acute DILI were randomized 1: 1:1 to low-dose bicyclol (25 mg times a day [TID]), high-dose bicyclol (50 mg TID) and polyene phosphatidylcholine (control) groups. The primary endpoint was the decrease from baseline in serum alanine aminotransferase (ALT) levels at post-treatment for 4 weeks. RESULTS: Overall, 241 patients were included in the full analysis set, with 81, 82 and 78 patients in the low-dose bicyclol, high-dose bicyclol, and control groups respectively. ALT levels decreased across groups (-249.2 ± 151.1, -273.6 ± 203.1, and -180.8 ± 218.2 U/L in the low-dose bicyclol, high-dose bicyclol and control groups, respectively; both p < .001, the bicyclol-dependent groups vs. control group). The ALT normalization rates at weeks 1, 2, 4, 6 and 8 were higher in the bicyclol-dependent groups than in the control group (p = .002 at week 1 and all p < .001 at weeks 2, 4, 6 and 8 respectively). The median times to ALT normalization in the low-dose bicyclol, high-dose bicyclol and control groups were 29, 16 and 43 days respectively. Adverse events, serious adverse events and adverse drug reactions were similar across groups. CONCLUSIONS: Bicyclol (25 and 50 mg TID) appeared efficacious and safe for treating idiosyncratic acute DILI, while bicyclol 50 mg TID showed higher efficacy. TRIAL REGISTRATION NUMBER: www. CLINICALTRIALS: gov (registration no. NCT02944552).

Incidence and risk factors of drug-induced liver injury.

The epidemiology and aetiology of drug-induced liver injury (DILI) vary across different countries and populations. Overall, DILI is rare in the general population but has become more prevalent in hospitalized patients, especially among patients with unexplained liver conditions. In addition, drugs implicated in DILI differ between Western and Eastern countries. Antibiotics are the leading drugs implicated in DILI in the West, whereas traditional Chinese medicine is the primary cause implicated in DILI in the East. The incidence of herbal and dietary supplements-induced hepatotoxicity is increasing globally. Several genetic and nongenetic risk factors associated with DILI have been described in the literature; however, there are no confirmed risk factors for all-cause DILI. Some factors may contribute to the risk of DILI in a drug-specific manner.

Exploring the efficacy and safety of polyene phosphatidylcholine for treatment of drug-induced liver injury using the Roussel Uclaf causality assessment method: a propensity score matching comparison.

Objective In China, polyene phosphatidylcholine (PPC) is widely used to treat alanine aminotransferase (ALT) elevation associated with various liver diseases. Here, we assessed the efficacy and safety of PPC in treating drug-induced liver injury (DILI).Methods Data from a multicenter retrospective cohort study (DILI-R) were analyzed to compare PPC and magnesium isoglycyrrhizinate (MgIG) for treatment of DILI. We used the Roussel Uclaf causality assessment method (RUCAM) to evaluate patients with DILI. Patients with RUCAM scores ≥6 were included in the study, while those with RUCAM scores <6 were further evaluated by a panel of hepatologists. The primary outcome was the proportion of patients with ALT normalization at discharge. Propensity score matching was used to identify 183 matched pairs of patients (366 patients in total) from 25,927 patients with DILI.Results Among the DILI patients, 64 of 183 (34.97%) achieved normal ALT levels after treatment in both the PPC and the MgIG groups.Conclusion There were no significant differences in safety biomarkers including serum creatinine, blood urea nitrogen, white blood cells, platelets, hemoglobin, and albumin between patients treated with PPC or MgIG. The safety and efficacy of these two agents for treatment of DILI were comparable.

Bicyclol for the treatment of drug-induced liver injury: a propensity score matching analysis using a nationwide inpatient database.

OBJECTIVE: To evaluate the efficacy and safety of bicyclol in patients with drug-induced liver injury (DILI) using a nationwide database. METHODS: We retrospectively analyzed the clinical data of DILI patients in the DILI-R database. Propensity score matching was performed to balance the bicyclol and control groups, and alanine aminotransferase (ALT) recovery was compared between the two groups. Factors associated with ALT recovery and safety were identified. RESULTS: The analysis included the data of 25,927 patients. Eighty-seven cases were included in the bicyclol group, with 932 cases in the control group. One-to-one propensity score matching created 86 matched pairs. The ALT normalization rate in the bicyclol group was significantly higher than that in the control group (50.00% vs. 24.42%), and statistical significance was found in the superiority test. After adjustment of baseline ALT levels, baseline total bilirubin levels, sex, age, acute or chronic liver diseases, and suspected drugs in the multivariate logic regression analysis, the major influencing factors for ALT recovery included the time interval between ALT tests (days) and the group factor (bicyclol treatment). There were no differences in the proportion of renal function impairment or blood abnormalities between the two groups. CONCLUSIONS: Bicyclol is a potential candidate for DILI.

Tolvaptan therapy of Chinese cirrhotic patients with ascites after insufficient diuretic routine medication responses: a phase III clinical trial.

BACKGROUND: To determine the safety and efficacy of different doses of tolvaptan for treating Chinese cirrhotic patients with or without hyponatraemia who still had ascites after routine therapy with diuretics. METHODS: In the present placebo-controlled, randomized, double-blinded, multicentre clinical trial, patients with cirrhotic ascites who failed to adequately respond to a combination of an aldosterone antagonist plus an orally administered loop diuretic were randomly placed at a 4:2:1 ratio into 3 groups [the 15 mg/day tolvaptan group (N = 301), 7.5 mg/day tolvaptan group (N = 153) and placebo group (N = 76)] for 7 days of treatment. The effects and safety were evaluated on days 4 and 7. A change in body weight from baseline on day 7 of treatment was the primary endpoint. RESULTS: The administration of 7.5 or 15 mg/day tolvaptan significantly decreased body weight from baseline on day 7 of treatment compared to that with placebo treatment (P = 0.026; P = 0.001). For the secondary endpoints, changes in abdominal circumference from baseline and improvements in ascites were markedly different in the treatment groups and the placebo group on day 7 (P7.5 = 0.05, P15.0 = 0.002 and P7.5 = 0.037, P15.0 = 0.003), but there was no difference between the 7.5 mg/day and 15 mg/day dosage groups. The 24-h cumulative urine volume was higher in the 7.5 mg/day and 15 mg/day tolvaptan groups than the placebo group (P = 0.002, P < 0.001) and was greater in the 15 mg/day tolvaptan group than the 7.5 mg/day tolvaptan group (P = 0.004). Sodium serum concentrations were higher in patients with hyponatraemia after tolvaptan treatment, with no significant difference between the two dosage groups. The incidence of serious adverse drug reactions was not different between the groups (P = 0.543). CONCLUSIONS: Tolvaptan treatment at 7.5 mg per day might be a good therapeutic choice for Chinese cirrhotic patients with ascites who did not achieve satisfactory clinical responses to previous treatment regimens with combination therapy with an aldosterone antagonist and an orally administered loop diuretic. TRIAL REGISTRATION: NCT01349348. Retrospectively registered May 2011.

Efficacy and safety of magnesium isoglycyrrhizinate injection in patients with acute drug-induced liver injury: A phase II trial.

BACKGROUND: Drug-induced liver injury (DILI) is the most common reason for a drug to be withdrawn from the market. Apart from stopping the offending drug, no regimens are available for treating idiosyncratic DILI in clinical practice. METHODS: We carried out a randomized, double-blind, multidoses, active drug controlled, multicentre phase II trial to assess the safety and efficacy of the study drug, magnesium isoglycyrrhizinate (MgIG), as compared to tiopronin, a standard therapy for DILI in China. The primary outcome was the proportion of alanine aminotransferase (ALT) normalization at week 4 after study drug administration. Logistic regression was used to examine the odds of ALT normalization between low dose (Group A) and high dose (Group B) vs active control (Group C). RESULTS: One hundred and seventy-four eligible subjects were randomized and enrolled into three groups: 59 in group A, 56 in group B and 59 in group C. It was shown that group A and group B lowered ALT level even at early stage of study drug administration; when compared with Group C (61.02%), the proportions of ALT normalization at week 4 were significantly greater in Group A (84.75%, P = .0029) and Group B (85.71%, P = .0037) respectively. The results from the univariate logistic model showed that the odds of ALT normalized among subjects in Group A were about 3.6 times greater (OR = 3.55, 95% CI: 1.47-8.57, P = .0049) than subjects in Group C. Similar effect was observed among subjects in Group B (OR = 3.83, 95% CI: 1.54-9.55, P = .0039). CONCLUSIONS: This trial provided preliminary evidence that MgIG is an effective and safe treatment for patients with acute DILI.

Correction to: Case report of cryptogenic multifocal ulcerous stenosing enteritis (CMUSE): a rare isease may contribute to endoscopy-capsule retention in the small intestine.

Following publication of the original article [1], the author reported the wrong version of Table 1 has been published. The word of 'Capsule' was mistakenly written as 'Capusle'.

Case report of cryptogenic multifocal ulcerous stenosing enteritis (CMUSE): a rare disease may contribute to endoscopy-capsule retention in the small intestine.

BACKGROUND: CMUSE is a rare disease whose diagnosis remains difficult because the lesion is confined to the small bowel. CASE PRESENTATION: Here, we present a case of 43-year-old female patient suffered chronic abdominal pain for 20 years, and finally diagnosed with CMUSE. Capsule endoscopy was performed when general endoscopic investigation failed to find the lesion, but the capsule was stranded in the small intestine. Moreover, capsule retention results in acute intestinal obstruction. Thus, surgery was performed and CMUSE was confirmed. The patient was recovered after partial small intestine resection. CONCLUSIONS: Capsule retention occurred in nearly 60% of patients with CMUSE. Capsule endoscopy should be avoided when the patient is suspected of CMUSE, especially with severe anemia and radiologic finding in the ileum.

DEAD-box helicase 27 promotes colorectal cancer growth and metastasis and predicts poor survival in CRC patients.

Copy number alterations (CNAs) are crucial for colorectal cancer (CRC) development. In this study, DEAD box polypeptide 27 (DDX27) was identified to be highly amplified in both TCGA CRC (474/615) and primary CRC (47/103), which was positively correlated with its mRNA overexpression. High DDX27 mRNA (N = 199) and protein expression (N = 260) predicted poor survival in CRC patients. Ectopic expression of DDX27 increased CRC cells proliferation, migration and invasion, but suppressed apoptosis. Conversely, silencing of DDX27 exerted opposite effects in vitro and significantly inhibited murine xenograft tumor growth and lung metastasis in vivo. Up-regulation of DDX27 enhanced and prolonged TNF-α-mediated NF-κB signaling. Nucleophosmin (NPM1) was identified as a binding partner of DDX27. DDX27 increased nuclear NPM1 and NF-κB-p65 interaction to enhance DNA binding activity of NF-κB. Silencing NPM1 abrogated DDX27-activating NF-κB signaling and its tumor-promoting function. Together, DDX27 is overexpressed and plays a pivotal oncogenic role in CRC.

Assessing the potential value of long interspersed element-1 hypomethylation in colorectal cancer: evidence from retrospective studies.

BACKGROUND AND AIMS: Long interspersed element-1 (LINE-1) hypomethylation may play an important role in colorectal cancer (CRC). Studies were identified that investigated LINE-1 methylation levels in CRC compared with normal controls. METHODS: The random-effects model was used to estimate standardized mean difference with 95% confidence intervals according to the heterogeneity between the studies. We explored the relationship between LINE-1 hypomethylation and microsatellite instability (MSI) status, clinical features, and molecular features in CRC patients using a fixed-effects model. RESULTS: A total of 7396 CRC patients were included in the meta-analysis. LINE-1 methylation was significantly lower in CRC patients than in controls (P=0.000). Mean LINE-1 methylation was significantly lower in non-MSI-high than in MSI-high tumors (P=0.000). LINE-1 hypomethylation was found more frequently in patients with a family history compared with those without family history (P=0.002). Patients with left colon cancer had lower LINE-1 methylation than those with right colon cancer (P=0.001). LINE-1 methylation was not associated with body mass index or patient sex. LINE-1 hypomethylation was found in p21 lost tumors (P=0.000). LINE-1 methylation levels were not associated with KRAS or PIK3CA-mutation status. CONCLUSION: LINE-1 hypomethylation is a potential biomarker for risk of CRC and associated with various clinical and molecular features of CRC.

Long noncoding RNA GAPLINC regulates CD44-dependent cell invasiveness and associates with poor prognosis of gastric cancer.

It is increasingly evident that long noncoding RNAs (lncRNA) have causative roles in carcinogenesis. In this study, we report findings implicating a novel lncRNA in gastric cancer, termed GAPLINC (gastric adenocarcinoma predictive long intergenic noncoding RNA), based on the use of global microarray and in situ hybridization (ISH) analyses to identify aberrantly expressed lncRNA in human gastric cancer specimens. GAPLINC is a 924-bp-long lncRNA that is highly expressed in gastric cancer tissues. GAPLINC suppression and with gene expression profiling in gastric cancer cells revealed alterations in cell migration pathways, with CD44 expression the most highly correlated. Manipulating GAPLINC expression altered CD44 mRNA abundance and the effects of GAPLINC on cell migration and proliferation were neutralized by suppressing CD44 expression. Mechanistic investigations revealed that GAPLINC regulates CD44 as a molecular decoy for miR211-3p, a microRNA that targets both CD44 and GAPLINC. Tissue ISH analysis suggested that GAPLINC overexpression defines a subgroup of patients with gastric cancer with very poor survival. Taken together, our results identify a noncoding regulatory pathway for the CD44 oncogene, shedding new light on the basis for gastric cancer cell invasiveness.

Folic acid prevents the initial occurrence of sporadic colorectal adenoma in Chinese older than 50 years of age: a randomized clinical trial.

Colorectal adenoma (CRA) is the precursor lesion of colorectal cancer (CRC). Several agents have been shown to be effective in the chemoprevention of CRA recurrence, but there has been little research on its primary prevention. Participants older than 50 years with no adenomas were recruited for our study and randomized to receive either 1 mg/day folic acid supplement or treatment without folic acid. After 3 years of follow-up, plasma folate and colonoscopy were evaluated. Seven hundred ninety-one participants (91.98%) completed the study. CRA occurred in 64 (14.88%) participants in the folic acid group and 132 (30.70%) in the control group [unadjusted risk ratio (RR), 0.49; 95% confidence interval (CI), 0.37-0.63; P < 0.01]; left-sided adenoma (unadjusted RR, 0.54; 95% CI, 0.38-0.76; P = 0.001) and advanced CRA (unadjusted RR, 0.36; 95% CI, 0.16-0.81; P = 0.01) were most common. There was no significance difference in the occurrence of three or more adenomas (unadjusted RR, 0.70; 95% CI, 0.36-1.77; P = 0.38) or right-sided adenoma (unadjusted RR, 0.55; 95% CI, 0.30-1.00; P = 0.07) between the two groups. Participants with low plasma folate may have a high risk of CRA. In conclusion, primary prevention with 1 mg/day folic acid supplementation could reduce the incidence of CRA, especially left-sided and advanced disease in those with no previous adenomas. People with differing baseline plasma folate levels should be given individualized treatment. Those with low plasma folate should be encouraged to take adequate supplements; plasma folate should be elevated to an effective therapeutic level, which may reduce the incidence of CRA.

Constitutive activation of STAT3 is predictive of poor prognosis in human gastric cancer.

Abnormalities in signal transducer and activator of transcription (STAT) signaling, especially STAT3 and STAT5, are involved in the oncogenesis of several human cancers, including gastric cancer (GC). However, the downstream targets of STAT3 and STAT5 are not fully identified, and the precise roles and the prognostic value of STAT3 and STAT5 in GC have not been fully characterized. In this study, we used ChIP-on-chip to identify STAT3 and STAT5 target genes on a whole genome scale in AGS cells, a human GC cell line. A total of 2,514 and 1,314 genes were identified as STAT3 and STAT5 target genes, which were mainly related to cell growth, metabolism, differentiation, adhesion, immune response, and stress response. Furthermore, we depleted STAT3 and STAT5 with a small interfering RNA, respectively. Our results demonstrate that STAT3, but not STAT5, is involved in GC cell growth and cell cycle progression through regulation of gene expression, such as Bcl-2, p16(ink4a) and p21(waf1/cip1). Moreover, expression of pSTAT3(Tyr705) correlates with TNM stage, differentiation and survival, and is a significant prognostic factor in GC. Therefore, our findings provide novel evidence that STAT3 may be a potential therapeutic target for GC treatment and pSTAT3(Tyr705) expression can predict prognosis in GC.

Trichostatin A, a histone deacetylase inhibitor, suppresses JAK2/STAT3 signaling via inducing the promoter-associated histone acetylation of SOCS1 and SOCS3 in human colorectal cancer cells.

Aberrant janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling is involved in the oncogenesis of several cancers. Suppressors of cytokine signaling (SOCS) genes and SH2-containing protein tyrosine phosphatase 1 (SHP1) proteins, which are negative regulators of JAK/STAT signaling, have been reported to have tumor suppressor functions. However, in colorectal cancer (CRC) cells, the mechanisms that regulate SOCS and SHP1 genes, and the cause of abnormalities in the JAK/STAT signaling pathway, remain largely unknown. The present study shows that trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, leads to the hyperacetylation of histones associated with the SOCS1 and SOCS3 promoters, but not the SHP1 promoter in CRC cells. This indicates that histone modifications are involved in the regulation of SOCS1 and SOCS3. Moreover, upregulation of SOCS1 and SOCS3 expression was achieved using TSA, which also significantly downregulated JAK2/STAT3 signaling in CRC cells. We also demonstrate that TSA suppresses the growth of CRC cells, and induces G1 cell cycle arrest and apoptosis through the regulation of downstream targets of JAK2/STAT3 signaling, including Bcl-2, survivin and p16(ink4a) . Therefore, our data demonstrate that TSA may induce SOCS1 and SOCS3 expression by inducing histone modifications and consequently inhibits JAK2/STAT3 signaling in CRC cells. These results also establish a mechanistic link between the inhibition of JAK2/STAT3 signaling and the anticancer action of TSA in CRC cells.

TRAPPC4-ERK2 interaction activates ERK1/2, modulates its nuclear localization and regulates proliferation and apoptosis of colorectal cancer cells.

The trafficking protein particle complex 4 (TRAPPC4) is implicated in vesicle-mediated transport, but its association with disease has rarely been reported. We explored its potential interaction with ERK2, part of the ERK1/2 complex in the Extracellular Signal-regulated Kinase/ Mitogen-activated Protein Kinase (ERK-MAPK) pathway, by a yeast two-hybrid screen and confirmed by co-immunoprecipitation (Co-IP) and glutathione S-transferase (GST) pull-down. Further investigation found that when TRAPPC4 was depleted, activated ERK1/2 specifically decreased in the nucleus, which was accompanied with cell growth suppression and apoptosis in colorectal cancer (CRC) cells. Overexpression of TRAPPC4 promoted cell viability and caused activated ERK1/2 to increase overall, but especially in the nucleus. TRAPPC4 was expressed more highly in the nucleus of CRC cells than in normal colonic epithelium or adenoma which corresponded with nuclear staining of pERK1/2. We demonstrate here that TRAPPC4 may regulate cell proliferation and apoptosis in CRC by interaction with ERK2 and subsequently phosphorylating ERK1/2 as well as modulating the subcellular location of pERK1/2 to activate the relevant signaling pathway.

MicroRNA 345, a methylation-sensitive microRNA is involved in cell proliferation and invasion in human colorectal cancer.

Aberrant methylation has been shown to trigger the inactivation of tumor suppressor genes during tumorigenesis. MicroRNAs (miRNAs) have been found deregulated in human colorectal cancer (CRC), and some of them may function as tumor suppressor genes. Here, we investigated CpG island promoter hypermethylation as a potential mechanism underlying miRNA disruption and identifed methylation-sensitive miRNAs that might repress CRC development. We compared differential expression of miRNAs after 5-aza-2'-deoxycitidine (5-aza-dC) treatment using microarrays. DNA methylation status of the candidate miRNA was analyzed. The candidate miRNA was transfected into CRC cells and growth-suppressive mechanisms were explored. Luciferase reporter assay and western blot were used to identify the target genes of the candidate miRNA. The expression of mir-345 was significantly increased after 5-aza-dC treatment. DNA methylation analyses of mir-345 showed high methylation levels in tumor versus normal tissues. Expression of mir-345 was significantly down-regulated in 51.6% of CRC tissues compared with corresponding non-cancerous tissues. Low expression of mir-345 was associated with lymph node metastasis and worse histological type. Increased mir-345 function was sufficient to suppress colon cancer cell proliferation and invasiveness in vitro. Furthermore, we identified BCL2-associated athanogene 3 (BAG3), an anti-apoptosis protein, to be a target of mir-345. These results suggested as a methylation-sensitive miRNA in CRC, mir-345 may play an important role of antineoplastic as a growth inhibitor in the development of CRC.

MicroRNA regulatory network in human colorectal cancer.

Epigenetic modifications include DNA methylation, histone modifications, and noncoding RNAs containing microRNAs (miRNA). miRNAs are small noncoding RNAs that are 21 to 25 nt in length; they downregulate gene expression during cell development, cell proliferation, cell differentiation, and apoptosis. They play a critical role in human carcinogenesis. Presently, evidences show that miRNAs participate as oncogenic miRNAs or tumor suppressors in the developmental and physiological processes of human colorectal cancer (CRC). Disturbed miRNA expression may be attributable to a mechanism involving multiple factors. In this review, we focus on the colorectal miRNA expression profile and further discuss the miRNA regulatory network involved in the tumorigenesis of human CRC. We, thus, hope to open up new avenues for anticancer therapy based on the epigenetic regulation of miRNA.