microRNA-29a regulates liver tumor-initiating cells expansion via Bcl-2 pathway.

MicroRNAs (miRNAs) participate in tumorigenesis, progression, recurrence and drug resistance of hepatocellular carcinoma (HCC). However, few miRNAs have been identified and entered clinical practice. Herein, we report that miR-29a is downregulated in tumor-initiating cells (T-ICs) and has an important function in liver T-ICs. Functional studies revealed that miR-29a knockdown promotes liver T-ICs self-renewal and tumorigenesis. Conversely, a forced miR-29a expression inhibits liver T-ICs self-renewal and tumorigenesis. Mechanistically, we find that miR-29a downregulates Bcl-2 via binding its mRNA 3'UTR in liver T-ICs. The correlation between miR-29a and Bcl-2 is validated in human HCC tissues. Furthermore, the miR-29a expression determines the responses of hepatoma cells to sorafenib treatment. Analysis of patient-derived xenografts (PDXs) further demonstrated that the miR-29a high patients are more sensitive to sorafenib treatment. In conclusion, our findings revealed the crucial role of the miR-29a in liver T-ICs expansion and sorafenib response, rendering miR-29a as an optimal target for the prevention and intervention of HCC.

Inhibition of allogeneic islet graft rejection by VISTA-conjugated liposome.

The Ig superfamily member V-domain Ig-containing suppressor of T-cell activation (VISTA) is a negative regulator with broad-spectrum activities and has reported that blockade of VISTA or combination with other negative checkpoint receptors sufficiently break tumor tolerance. However, it remains unclear whether VISTA could induce allogeneic T-cell hyporesponsiveness and inhibit allograft rejection. Here we found VISTA treatment significantly inhibited lymphocyte proliferation and activation in allogeneic MLR assay through impairing SYK-VAV pathway. Interestingly, though neither VISTA protein nor VISTA-Fc fusion protein administration exerted satisfactory immunosuppressive effect on allograft survival due to their short half-life in circulation, this problem was solved by conjugating VISTA protein on liposome by biotin-streptavidin system, which markedly prolonged its circulating half-life to 60 h. With islet transplant model, administration of VISTA-conjugated liposome could markedly prolong allograft survival by inhibition of SYK-VAV pathway, thus maintained the normal blood glucose level of recipients during treatment period. The results indicate VISTA is a promising therapeutic target to treat allograft rejection of islet transplantation.

MiR-942-3p Promotes the Proliferation and Invasion of Hepatocellular Carcinoma Cells by Targeting MBL2.

MicroRNAs (miRNAs), a subgroup of small noncoding RNAs, play critical roles in tumor growth and metastasis. Accumulating evidence shows that the dysregulation of miRNAs is associated with the progression of hepatocellular carcinoma (HCC). However, the molecular mechanism by which miR-942-3p contributes to HCC remains undocumented. The association between miR-942-3p expression and the clinicopathological characteristics in HCC patients was analyzed by The Cancer Genome Atlas data set. The targets of miR-942-3p were identified by bioinformatic analysis and dual luciferase report assay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Transwell assays were performed to assess the functional role of miR-942-3p in HCC cells. Consequently, we found that miR-942-3p expression level was elevated in HCC tissues and cell lines as compared with the normal tissues and was associated with the pathological stage and tumor node metastasis (TNM) stage, acting as an independent prognostic factor of poor survival in patients with HCC. Ectopic expression of miR-942-3p enhanced the proliferation and invasive potential of HCC cells, but inhibition of miR-942-3p expression had the opposite effects. Mannose-binding lectin 2 (MBL2) was further identified as a direct target of miR-942-3p and possessed a negative correlation with miR-942-3p expression and unfavorable survival in patients with HCC. Restoration of MBL2 inhibited the progression of HCC cells and attenuated the tumor-promoting effects induced by miR-942-3p. In conclusion, miR-942-3p may act as an oncogenic factor in HCC cells by targeting MBL2 and provide a potential marker for patients with HCC.

lncRNA SNHG8 Promotes the Tumorigenesis and Metastasis by Sponging miR-149-5p and Predicts Tumor Recurrence in Hepatocellular Carcinoma.

BACKGROUND/AIMS: Long noncoding RNAs (lncRNAs) are aberrantly expressed in multiple malignant tumors involved in tumor growth and metastasis. Accumulating data show that small nucleolar RNA host gene (SNHG) 1/12/20 plays a key role in the progression of hepatocellular carcinoma (HCC). However, the molecular mechanisms by which SNHG8 contributes to HCC remain elusive and merit exploration. METHODS: The association between SNHG8 expression and the clinicopathological characteristics and prognoses in HCC patients was analysed by using qRT-PCR analysis and the data from The Cancer Genome Atlas. Cell growth and metastatic potential were determined by MTT, colony formation, Transwell assays, and the mouse xenograft tumor model and lung metastasis model. Epithelial-mesenchymal transition markers were detected by western blot analysis. The binding capacity of SNHG8 with miRNAs was evidenced by bioinformatic analysis and a luciferase reporter assay. In addition, the rescue experiments were performed based on co-transfection with sh-SNHG8 and a miR-149 inhibitor in HCC cells. RESULTS: The expression levels of lncRNA SNHG8 were dramatically increased in HCC tissues and cell lines as compared with the adjacent normal tissues, and SNHG8 expression was an independent prognostic factor of tumor recurrence in HCC patients. Furthermore, knockdown of SNHG8 inhibited cell proliferation, invasion, and lung metastasis in vitro and in vivo, whereas overexpression of SNHG8 reversed these effects. SNHG8 acted as a sponge of miR-149 and counteracted the tumor suppressive effects of mi R-149 in HCC cells. Expression of phosphatase, Mg2+/Mn2+ dependent 1F, a target of R-149, displayed a negative correlation with miR-149 expression but a positive correlation with SNHG8 expression in HCC specimens. CONCLUSION: As lncRNA SNHG8 may promote HCC tumorigenesis and metastasis by sponging miR-149, it is a potential candidate marker and therapeutic target for HCC.

MicroRNA-500a Promotes the Progression of Hepatocellular Carcinoma by Post-Transcriptionally Targeting BID.

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) is one of the most common human malignant diseases in the world, and the mechanisms underlying HCC carcinogenesis and progression need further investigation. MicroRNAs play important roles in the development of cancer, and miR-500a is suggested to be deregulated in some types of cancer. However, the underlying molecular mechanisms of miR-500a in HCC remain unknown. METHODS: The expression of miR-500a in HCC was analyzed in The Cancer Genome Atlas (TCGA) database and examined in 33 pairs of HCC tissues and matched nontumor tissues. The correlation between miR-500a expression and prognosis of HCC patients was analyzed from the survival data in TCGA. The mechanism of miR-500a upregulation in HCC was detected using chromatin immunoprecipitation-quantitative real-time PCR. The roles of miR-500a in HCC development were examined using a cell counting kit-8 assay in vitro and growth of transplanted tumors in nude mice in vivo. Apoptosis of HCC was detected using Annexin V/propidium iodide staining. The expression of BH3-interacting death agonist (BID) protein was examined using western blot analysis. RESULTS: miR-500a expression was upregulated in HCC tissues, and high miR-500a expression was significantly correlated with the poor prognosis of HCC patients. Histone modifications in the promoter region of miR-500a may be responsible for its increased expression. Inhibition of miR-500a in HCC cell lines significantly promoted apoptosis, as well as inhibiting the proliferation of HCC cells and growth of transplanted tumors in nude mice. miR-500a directly targeted the 3' untranslated region of BID mRNA, and inhibition of miR-500a-promoted apoptosis was almost completely abolished by the administration of ABT-199 via the BID-mitochondria pathway. CONCLUSION: Our results suggest that histone modifications in the promoter region of miR-500a may be responsible for the increased expression of miR-500a in HCC, which promotes cancer progression by targeting BID, indicating that miR-500a may be a potential prognostic predictor and therapeutic target for HCC patients.

Hepatic IFIT3 predicts interferon-α therapeutic response in patients of hepatocellular carcinoma.

Adjuvant interferon-α (IFN-α) therapy is used to control certain types of cancer in clinics. For hepatocellular carcinoma (HCC), IFN-α therapy is effective in only a subgroup of patients; therefore, identifying biomarkers to predict the response to IFN-α therapy is of high significance and clinical utility. As the induced IFN-stimulated gene expression following IFN-α treatment plays pivotal roles in IFN-α effects, we screened IFN-stimulated gene expression in HCC tissues and found that several IFN-stimulated genes were significantly decreased in HCC. Interestingly, expression of IFN-induced protein with tetratricopeptide repeats (IFIT) family members, including IFIT1, IFIT2, IFIT3, and IFIT5, was decreased in HCC tissues. We further analyzed the expression of IFIT family members in HCC and their roles in patients' responses to IFN-α therapy in two independent randomized controlled IFN-α therapy clinical trials of HCC patients. We found that higher expression of IFIT3, but not other IFITs, in HCC tissues predicts better response to IFN-α therapy, suggesting that IFIT3 may be a useful predictor of the response to IFN-α therapy in HCC patients. Mechanistically, IFIT3 enhanced the antitumor effects of IFN-α by promoting IFN-α effector responses both in vitro and in vivo. IFIT3 could bind signal transducer and activator of transcription 1 (STAT1) and STAT2 to enhance STAT1-STAT2 heterodimerization and nuclear translocation upon IFN-α treatment, thus promoting IFN-α effector signaling. CONCLUSION: Higher IFIT3 expression in HCC tissues predicts better response to IFN-α therapy in HCC patients; IFIT3 promotes IFN-α effector responses and therapeutic effects by strengthening IFN-α effector signaling in HCC. (Hepatology 2017;66:152-166).

Excessive intraoperative blood loss independently predicts recurrence of hepatocellular carcinoma after liver transplantation.

BACKGROUND: Several studies have investigated the effect of intraoperative blood loss (IBL) on recurrence of tumors. However, the independent effect of IBL on oncological outcome after liver transplantation (LT) for hepatocellular carcinoma (HCC) is unclear. METHODS: A total of 479 patients who underwent LT for HCC from January 2001 to December 2012 at our institution were enrolled in this retrospective study. Kaplan-Meier and Cox regression methods were used to assess the recurrence rate, as well as its risk factors. Stratified analysis was performed to further examine the effect of IBL on HCC recurrence according to different characteristics of tumors. We also investigated the independent risk factors for excessive IBL using logistic regression analysis. RESULTS: The median follow-up was 28 months (range, 1-131 months). Kaplan-Meier analysis with the log-rank test according to IBL at per liter intervals showed that IBL > 4 L was significantly associated with a higher recurrence rate (P < 0.001). Multivariate analysis identified that IBL > 4 L (P < 0.001; hazard ratio [HR] = 2.32, 95 % confidence interval [CI] = 1.60-3.36) was an independent risk factor for post-LT HCC recurrence, as well as age < 60 years, exceeding Milan criteria, α-fetoprotein levels > 400 ng/mL, and micro- and macrovascular invasion. IBL > 4 L (P < 0.001; HR = 2.45, 95 % CI = 1.64-3.66) was also independently associated with early (within 1 year) recurrence after LT. Furthermore, a significant correlation between IBL > 4 L and vascular invasion (P = 0.019) was found. IBL > 4 L was independently associated with HCC recurrence for patients with vascular invasion, but not for patients without vascular invasion. Finally, we found that the presence of ascites, model for end-stage liver disease score, and operation time were independent risk factors for IBL > 4 L. CONCLUSIONS: Excessive IBL is an independent predictor of HCC recurrence after LT, especially in patients with vascular invasion.