P53/miR-34a/SIRT1 positive feedback loop regulates the termination of liver regeneration.

BACKGROUND: The capacity of the liver to restore its architecture and function assures good prognoses of patients who suffer serious hepatic injury, cancer resection, or living donor liver transplantation. Only a few studies have shed light on the mechanisms involved in the termination stage of LR. Here, we attempt to further verify the role of the p53/miR-34a/SIRT1 positive feedback loop in the termination of liver regeneration and its possible relationship with liver cancer. METHOD: We performed partial hepatectomy (PH) in mice transfected with adenovirus (Ade) overexpressing P53 and adenovirus-associated virus (AAV) overexpressing miR-34a. LR was analyzed by liver weight/body weight, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and cell proliferation, and the related cellular signals were investigated. Bile acid (BA) levels during LR were analyzed by metabolomics of bile acids. RESULTS: We found that the P53/miR-34a/SIRT1 positive feedback loop was activated in the late phase of LR. Overexpression of P53 or miR-34a terminated LR early and enhanced P53/miR-34a/SIRT1 positive feedback loop expression and its proapoptotic effect. T-ß-MCA increased gradually during LR and peaked at 7 days after PH. T-ß-MCA inhibited cell proliferation and promoted cell apoptosis via facilitating the P53/miR-34a/SIRT1 positive feedback loop during LR by suppressing FXR/SHP. The P53/miR-34a/SIRT1 positive feedback loop was abolished in HCC patients with P53 mutations. CONCLUSIONS: The P53/miR-34a/SIRT1 positive feedback loop plays an important role in the termination of LR. Our findings showed the molecular and metabolic mechanisms of LR termination and provide a potential therapeutic alternative for treating P53-wild-type HCC patients.

Hepatic stellate cell exosome-derived circWDR25 promotes the progression of hepatocellular carcinoma via the miRNA-4474-3P-ALOX-15 and EMT axes.

Recently, the emerging role of circular RNAs (circRNAs) in tumor development and progression has been a topic of great interest. Nevertheless, the effects of hepatic stellate cell (HSC)-derived exosomes in hepatocellular carcinoma (HCC) remain unclear. Here, we aim to explore the potential effect of HSC exosome-derived circWDR25 on the aggressiveness of HCC. Firstly, a microarray analysis of circRNAs was performed to profile and identify the differentially expressed circRNAs derived from HSC exosomes activated by HCC cells. Subsequently, the roles of circWDR25 in HCC tumor growth and aggressiveness were confirmed through in vitro and in vivo functional experiments. Moreover, RNA pull-down, dual-luciferase reporter assays, and fluorescent in situ hybridization (FISH) were performed to determine interactions in the circWDR25-miR-4474-3p-ALOX15 loop. Immunohistochemical analysis was also performed on a microarray of HCC tissues and peritumoral tissues. We found that overexpressed peritumoral circWDR25 was associated with survival and recurrence in patients with HCC and promoted the progression of HCC cells both in vitro and in vivo. Mechanistically, both exogenous and HSC exosomal-derived circWDR25 regulated the expression of ALOX15 by sponging miR-4474-3p and ultimately inducing an epithelial-to-mesenchymal transition (EMT) in HCC cells. Moreover, exogenous and HSC exosomal-derived circWDR25 promoted the expression of CTLA-4 in HSCs and PD-L1 in HCC cells. In conclusion, circWDR25 facilitated HCC cell proliferation and invasion via the circWDR25/miR-4474-3p/ALOX15 and EMT axes and it promoted the expression of CTLA-4 in HSCs and PD-L1 in HCC cells, thus providing insights into the mechanism of tumor aggressiveness mediated by HSC-derived exosomal circWDR25.

Effect of TRAF1 on Phenotypic Changes Of Kupffer Cells In Liver Transplantation Ischemic-Reperfusion.

OBJECTIVE: The purpose of this study was to explore the effect of TRAF1 on phenotypic changes of KCs in I/R in liver transplantation. METHODS: SD rats were randomly divided into sham group and liver transplantation I/R group. KCs were extracted from rat livers in each group. KCs were transfected by lentivirus of si-TRAF1 or si-HOIP, and induced by Lipopolysaccharide (LPS). Flow cytometry was used to detect cell apoptosis. Western blot and RT-PCR were used to detect the protein and mRNA expression levels. RESULTS: Compared with the sham group, the expression levels of TRAF1, TNF-α and IL-1ß were significantly increased in the I/R group (P<0.05). In addition, compared with the control group, the expression levels of NF-κB (P65 and p-P65) and M1 phenotype (TNF-α and IL-1ß) were notably increased in si-TRAF1 and si-HOIP group (all P<0.05). Furthermore, the levels of Linear Ubiquitin Complex (LUBAC) were markedly increased in LPS-induced KCs in comparison with the control group (P<0.05). Moreover, compared with the control group, the expression levels of P65, p-P65, TNF-α and IL-1ß were notably decreased in the si-TRAF1 and si-HOIP group (P<0.05). The expression levels of P65, p-P65, TNF-α and IL-1ß were significantly increased in si-TRAF1 and si-HOIP group when compared to the control group (P<0.05). CONCLUSION: TRAF1 was an important negative regulator of liver transplantation I/R by inhibiting the activation of NF-κB in KCs and preventing its M1 phenotype transformation.

Keratin 17 Suppresses Cell Proliferation and Epithelial-Mesenchymal Transition in Pancreatic Cancer.

Keratin 17 (K17), a member of type I acidic epithelial keratin family, has been reported to be upregulated in many malignant tumors and to be involved in promoting the development of tumors. However, the precise role of K17 in progression of pancreatic cancer is still unknown. In this study, we found that K17 expression was highly expressed in pancreatic cancer tissues and cell lines and that upregulated expression was associated with the pathological grade and poor prognosis. K17 expression served as an independent predictor of pancreatic cancer survival. Meanwhile, we showed that knocking down K17 induced pancreatic cancer cell proliferation, colony formation and tumor growth in xenografts in mice. However, K17 upregulation inhibited pancreatic cancer cell proliferation and colony formation. Further mechanistic study revealed that K17 knockdown promoted cell cycle progression by upregulating CyclinD1 expression and repressed cell apoptosis. However, K17 upregulation suppressed cell cycle progression by decreasing CyclinD1 expression, and induced apoptosis by increasing the levels of cleaved Caspase3. In addition, K17 knockdown promoted pancreatic cancer cell migration and invasion, but K17 upregulation suppressed cell migration and invasion. Moreover, knocking down K17 promoted epithelial-mesenchymal transition (EMT) in pancreatic cancer cell by inhibiting E-cadherin expression and inducing Vimentin expression, and the effects of K17 upregulation were opposite to that of K17downregulation. Taken together, our findings suggest that K17 functions as a potential tumor suppressor, even though it is upregulated in pancreatic cancer.

Anti-CD206 antibody-conjugated Fe3O4-based PLGA nanoparticles selectively promote tumor-associated macrophages to polarize to the pro-inflammatory subtype.

M2 macrophages serve roles in inhibiting inflammation and promoting tumor development. Reversing tumor-associated macrophages (TAMs) from M2- to M1-type polarization may provide an important strategy for tumor immunotherapy. The present study aimed to enhance antitumor immunity by targeting the concentration of iron in macrophages. Fe3O4-based poly(lactic-co-glycolic) acid (PLGA) nanoparticles surface-modified with an anti-CD206 monoclonal antibody were prepared using the oil in water single-emulsion technique. Particle size was measured using a particle size analyzer, the ζ potential was determined using a ζ potential analyzer and the carrier rate of Fe3O4 was measured using an iron assay kit. The conjugation of anti-CD206, and the ability to target M2 macrophages were studied via immunofluorescence. Polarization indexes of the macrophages were detected using both western blotting and reverse transcription-quantitative PCR (RT-qPCR), and a mouse model with subcutaneous tumors was established to verify the antitumor effects of the nanoparticles in vivo. Nanoparticles had a mean diameter in the range of 260-295 nm, and the ζ potential values were between -19 and -33 mV. The Fe3O4 association efficiency ranged from 65-75%, whereas the anti-CD206 conjunction efficiency ranged from 65-70%. The immunofluorescence experiments were able to demonstrate the successful targeting of the M2 macrophages. The western blotting and RT-qPCR experiments identified that CD206-Fe3O4-PLGA and Fe3O4-PLGA promoted the expression of TNF-α, inducible nitric oxide synthase (iNOS) and IL-1ß in the macrophages. The in vivo studies indicated that CD206-Fe3O4-PLGA nanoparticles were able to promote CD86 expression in TAMs, with CD86 being a specific marker of the M1 subtype. In summary, nanoparticles were characterized in the present study by their mean particle size, polydispersity index, ζ potential and morphology, as well as by their association with Fe3O4 and conjugation with the anti-CD206 monoclonal antibody. Collectively, the present results suggested that the nanoparticles were able to both target M2 macrophages and reverse the M2 polarization of the macrophages to the M1 phenotype via the release of coated iron-oxide particles.

[Anti-CD206 antibody-conjugated Fe3O4-based PLGA nanoparticles selectively promotes M1 polarization of tumorassociated macrophages in mice].

OBJECTIVE: To enhance the anti-tumor immunity of macrophages by increasing iron concentration in the macrophages using nanospheres. METHODS: Anti-CD206 antibody-conjugated Fe3O4-based polylactic acid glycolic acid (CD206- Fe3O4-PLGA) nanoparticles were prepared with the W/O/W method. The particle diameter was measured using Malvern particle size detector, the Zeta potential was determined using Zeta potentiometry, and the encapsulation efficiency of Fe3O4 was determined using an iron determination kit. The macrophage-binding and targeting abilities of the conjugated nanoparticles were evaluated using immunofluorescence assay, and the polarization index of macrophages was determined with Western blotting and qRT-PCR. BALB/C-57 mouse models bearing subcutaneous tumors were used to verify the efficacy of the nanoparticles to promote polarization of the tumor-associated macrophages (TAMs). RESULTS: The conjugated nanoparticles had a mean diameter of 260-295 nm with Zeta potential values ranging from -19 mV to -33 mV, encapsulation efficiency of Fe3O4 ranging from 65% to 75%, and anti-CD206 conjunction efficiency of 65%-70%. Immunofluorescence assay verified the targeted binding ability of the nanoparticles with M2 macrophages. Western blotting and qRT-PCR confirmed that both CD206-Fe3O4-PLGA and Fe3O4-PLGA nanoparticles promoted the expression of TNF-α, iNOS and IL-1ß (P < 0.05). In the tumor-bearing mouse models, CD206-Fe3O4-PLGA nanoparticles were confirmed to promote CD86 expression in the TAMs. CONCLUSIONS: CD206-Fe3O4-PLGA nanoparticles are capable of targeted binding to M2 macrophages and reversing the M2 macrophages to M1 phenotype by releasing coated iron oxide particles.

Nogo-B fosters HCC progression by enhancing Yap/Taz-mediated tumor-associated macrophages M2 polarization.

Tumor-associated macrophages (TAMs) and their M2-type extremely promote tumor angiogenesis, invasion and metastasis, including hepatocellular carcinoma (HCC). Nogo-B is expressed in most tissues and participates in macrophage polarization. However, whether Nogo-B is involved in the polarization and the effects of TAMs has been unclear. The expression of Nogo-B in TAMs of HCC patients is significantly increased, which correlated with the poor prognosis of the patients with HCC. Coincidentally, HCC conditioned medium (HCM) facilitated Nogo-B expression and the M2 phenotype of macrophages. Nogo-B knockdown Nogo-B significantly suppressed the M2-type polarization of macrophages and inhibited HCC cells proliferation both in vivo and in vitro. Furthermore, interference of Nogo-B facilitates macrophage-mediated apoptosis of tumor cells. Nogo-B meaningfully enhanced IL4-stimulated the alternative activation of macrophages as well as expression of the transcriptional regulators Yes-associated protein (Yap)/transcriptional coactivator with PDZ-binding motif (Taz). An inhibitor of Yap, Verteporfin, could block Nogo-B-Yap/Taz-mediated macrophages M2 polarization. Nogo-B expression in macrophages facilitates tumor-associated macrophages M2 polarization and protumoral effects of TAMs in HCC. Targeting Nogo-B/Yap/Taz in macrophages could provide a new therapeutic strategy in HCC therapy.

Retraction Note: MicroRNA-31-5p regulates chemosensitivity by preventing the nuclear location of PARP1 in hepatocellular carcinoma.

The authors are retracting this article [1] because it overlaps significantly with a previously published article by Moody et al. [2] without proper citation. All authors agree with this retraction.

MicroRNA-31-5p regulates chemosensitivity by preventing the nuclear location of PARP1 in hepatocellular carcinoma.

BACKGROUND: MicroRNAs (miRNAs) posttranscriptionally regulate gene expression and thereby contribute to the modulation of numerous complex and disease-relevant cellular processes, including cell proliferation, cell motility, apoptosis and stress response. miRNA-31-5p is encoded on a genomic fragile site, 9p21.3, which is reportedly lost in many hepatocellular carcinoma (HCC) tumors. Based on previous findings, we hypothesized that miR-31-5p alters chemosensitivity and that miR-31-5p mimics may influence sensitivity to chemotherapeutics in HCC as well as in a variety of other cancers. METHODS: MiR-31-5p and PARP1 in HCC tissues were tested by RT-PCR and histological analysis, respectively. Next, clonogenic assay and western blot were used to detect miR-31-5p and PARP1 to modulate sensitivity to OXA-based chemotherapy. The distribution of OXA in the nuclear and intracellular was detected by ICP-MS. Coimmunoprecipitation was used to characterize the protein-protein interaction between PARP1 and ABCB9. A xenograft nude mouse model was used to examine the in vivo effects of miR-31-5p. RESULTS: Reintroduction of miR-31-5p into miR-31-5p-null Hep3B cells significantly enhanced clonogenic resistance to oxaliplatin. Although miR-31-5p re-expression increased chemoresistance, it paradoxically increased the relative intracellular accumulation of oxaliplatin. This effect was coupled with a significantly decreased intranuclear concentration of oxaliplatin by ICP-MS. miR-31-5p prevents the nuclear location of PARP1 detected by immunofluorescence, histological analysis and Western blotting analysis. We subsequently identified an indirect miR-31-5p-mediated upregulation of ABCB9, which is a transporter associated with drug accumulation in lysosomes, along with an increased uptake of oxaliplatin to lysosomes; these phenomena were associated with a downregulation of PARP1, a bipotential transcriptional regulator with multiple miR-31-5p binding sites. However, the indirect overexpression of ABCB9 promoted cellular chemosensitivity, suggesting that miR-31-5p promotes chemoresistance largely via an ABCB9-independent mechanism. CONCLUSIONS: Overall, our data suggest that the loss of miR-31-5p from HCC tumors promotes chemosensitivity, and this knowledge may be prognostically beneficial in the context of therapeutic sensitivity.

MicroRNA-766-3p Inhibits Tumour Progression by Targeting Wnt3a in Hepatocellular Carcinoma.

Recent studies have indicated that microRNAs (miRNAs) play an important role in hepatocellular carcinoma (HCC) progression. In this study, we showed that miR-766-3p was decreased in approximately 72% of HCC tissues and cell lines, and its low expression level was significantly correlated with tumour size, TNM stage, metastasis, and poor prognosis in HCC. Ectopic miR-766-3p expression inhibited HCC cell proliferation, colony formation, migration and invasion. In addition, we showed that miR-766-3p repressed Wnt3a expression. A luciferase reporter assay revealed that Wnt3a was a direct target of miR-766-3p, and an inverse correlation between miR-766-3p and Wnt3a expression was observed. Moreover, Wnt3a up-regulation reversed the effects of miR-766-3p on HCC progression. In addition, our study showed that miR-766-3p up-regulation decreased the nuclear ß-catenin level and expression of Wnt targets (TCF1 and Survivin) and reduced the level of MAP protein regulator of cytokinesis 1 (PRC1). However, these effects of miR-766-3p were reversed by Wnt3a up-regulation. In addition, PRC1 up-regulation increased the nuclear ß-catenin level and protein expression of TCF1 and Survivin. iCRT3, which disrupts the ß-catenin-TCF4 interaction, repressed the TCF1, Survivin and PRC1 protein levels. Taken together, our results suggest that miR-766-3p down-regulation promotes HCC cell progression, probably by targeting the Wnt3a/PRC1 pathway, and miR-766-3p may serve as a potential therapeutic target in HCC.

Iron overloaded polarizes macrophage to proinflammation phenotype through ROS/acetyl-p53 pathway.

PURPOSE: Macrophages play critical roles in inflammation and wound healing and can be divided into two subtypes: classically activated (M1) and alternatively activated (M2) macrophages. Macrophages also play important roles in regulating iron homeostasis, and intracellular iron accumulation induces M1-type macrophage polarization which provides a potential approach to tumor immunotherapy through M2 tumor-associated macrophage repolarization. However, the mechanisms underlying iron-induced M1 polarization remain unclear. METHODS: Western blotting, qRT-PCR, and flow cytometry were used to detect the polarization indexes in RAW 264.7 murine macrophages treated with iron, and Western bloting and qRT-PCR were used to detect p21 expression. The compound 2,7-dichlorofluorescein diacetate was used to measure reactive oxygen species (ROS) levels in macrophages after iron or N-acetyl-l-cysteine (NAC) treatment. The p300/CREB-binding protein (CBP) inhibitor C646 was used to inhibit p53 acetylation, and Western bloting, qRT-PCR, and immunofluorescence were used to detect p53 expression and acetylation. BALB/c mice were subcutaneously injected with H22 hepatoma cells, and macrophage polarization status was investigated after tail intravenous injection of iron. Immunohistochemical staining was used to evaluate the protein expression of cluster of differentiation 86 (CD86) and EGF-like module-containing mucin-like hormone receptor-like 1 (F4/80) in the subcutaneous tumors. RESULTS: Iron overload induced M1 polarization by increasing ROS production and inducing p53 acetylation in RAW cells, and reduction in ROS levels by NAC repressed M1 polarization and p53 acetylation. Inhibition of acetyl-p53 by a p300/CBP inhibitor prevented M1 polarization and inhibited p21 expression. These results showed that high ROS levels induced by iron overload polarized macrophages to the M1 subtype by enhancing p300/CBP acetyltransferase activity and promoting p53 acetylation.