Surf4 collaborates with derlin-2 and derlin-1 to mediate cyclooxygenase-2 translocation to the cytosol for degradation.

Derlin family members participate in the retrotranslocation of endoplasmic reticulum (ER) lumen proteins to the cytosol for ER-associated degradation (ERAD); however, the proteins facilitating this retrotranslocation remain to be explored. Using CRISPR library screening, we have found that derlin-2 and surfeit locus protein 4 (Surf4) are candidates to facilitate degradation of cyclooxygenase-2 (COX-2, also known as PTGS2). Our results show that derlin-2 acts upstream of derlin-1 and that Surf4 acts downstream of derlin-2 and derlin-1 to facilitate COX-2 degradation. Knockdown of derlin-2 or Surf4 impedes the ubiquitylation of COX-2 and the interaction of COX-2 with caveolin-1 (Cav-1) and p97 (also known as VCP) in the cytosol. Additionally, COX-2 degradation is N-glycosylation dependent. Although derlin-2 facilitates degradation of N-glycosylated COX-2, the interaction between derlin-2 and COX-2 is independent of COX-2 N-glycosylation. Derlin-1, Surf4 and p97 preferentially interact with non-glycosylated COX-2, whereas Cav-1 preferentially interacts with N-glycosylated COX-2, regardless of the N-glycosylation pattern. Collectively, our results reveal that Surf4 collaborates with derlin-2 and derlin-1 to mediate COX-2 translocation from the ER lumen to the cytosol. The derlin-2-derlin-1-Surf4-Cav-1 machinery might represent a unique pathway to accelerate COX-2 degradation in ERAD.

Association of Tumor Hydroxyindole O-Methyltransferase and Serum 5-Methoxytryptophan with Long-Term Survival of Hepatocellular Carcinoma.

5-methoxytryptophan (5-MTP) is a recently discovered tryptophan (Trp) metabolite with anti-inflammatory and tumor-suppressing actions. Its synthesis is catalyzed by hydroxyindole O-methyltransferase (HIOMT). HIOMT levels were reported to be decreased in some patients with colorectal, pancreatic and breast cancer. It is unclear whether tissue HIOMT levels is altered in hepatocellular carcinoma (HCC). It is also unclear whether serum 5-MTP concentration is influenced by HCC. In this study, 150 HCC and adjacent normal liver tissues and serum samples were obtained from the HCC biobank established by a prospective multicenter study. Serum samples from 47 healthy subjects were included as a reference. HIOMT mRNA was measured by real time PCR. Serum 5-MTP and selected Trp metabolites were analyzed by quantitative LC-MS. HCC tissue HIOMT mRNA levels adjusted for adjacent normal tissue HIOMT mRNA levels was associated with overall and relapse-free (RF) survival. Combined serum 5-MTP or tissue HIOMT mRNA and serum kynurenine (Kyn) analysis predicted prolonged overall and RF survival following liver resection. A high serum 5-MTP or tissue HIOMT mRNA and low serum Kyn is associated with long-term survival. In conclusion, tumor tissue HIOMT mRNA and serum 5-MTP are potential biomarkers of HCC, especially when analyzed in combination with serum Kyn.

Reduced Expression of Metallothionein-I/II in Renal Proximal Tubules Is Associated with Advanced Chronic Kidney Disease.

Chronic kidney disease (CKD) is a commonly occurring complex renal syndrome that causes overall mortality in many diseases. The clinical manifestations of CKD include renal tubulointerstitial fibrosis and loss of renal function. Metallothionein-I/II (MT-I/II) is potentially expressed in the liver and kidney, and possesses antioxidant and metal detoxification properties. However, whether MT-I/II expression is associated with the prognosis of nephropathy remains unknown. In this study, we investigated the MT-I/II level in human CKD, using immunohistochemistry. MT-I/II is located on the proximal tubules and is notably reduced in patients with CKD. MT-I/II expression was significantly correlated with the functional and histological grades of CKD. In an aristolochic acid (AAI)-induced nephropathy mouse model, MT-I/II was abundantly increased after AAI injection for 7 days, but decreased subsequently compared to that induced in the acute phase when injected with AAI for 28 days. Furthermore, we found that ammonium pyrrolidinedithiocarbamate (PDTC) restored AAI-induced MT-I/II reduction in HK2 cells. The injection of PDTC ameliorated AAI-induced renal tubulointerstitial fibrosis and reduced the concentrations of blood urea nitrogen and creatinine in mouse sera. Taken together, our results indicate that MT-I/II reduction is associated with advanced CKD, and the retention of renal MT-I/II is a potential therapeutic strategy for CKD.

5-methoxytryptophan: an arsenal against vascular injury and inflammation.

5-methoxytryptophan (5-MTP) is an endothelial factor with anti-inflammatory properties. It is synthesized from L-tryptophan via two enzymatic steps: tryptophan hydroxylase-1 (TPH-1) and hydroxyindole O-methyltransferase. Lipopolysaccharide (LPS) and pro-inflammatory cytokines suppress endothelial 5-MTP production by inhibiting TPH-1 expression. 5-MTP protects endothelial barrier function and promotes endothelial repair, while it blocks vascular smooth muscle cell migration and proliferation by inhibiting p38 MAPK activation. 5-MTP controls macrophage transmigration and activation by inhibiting p38 MAPK and NF-κB activation. 5-MTP administration attenuates arterial intimal hyperplasia, defends against systemic inflammation and prevents renal fibrosis in relevant murine models. Serum 5-MTP level is depressed in human sepsis as well as in mice with sepsis-like disorder. It is reduced in chronic kidney disease and acute myocardial infarction in humans. The reported data suggest that serum 5-MTP may be a theranostic biomarker. In summary, 5-MTP represents a new class of tryptophan metabolite which defends against inflammation and inflammation-mediated tissue damage and fibrosis. It may be a valuable lead compound for developing new drugs to treat complex human inflammatory disorders.

Expression of Nik-related kinase in smooth muscle cells attenuates vascular inflammation and intimal hyperplasia.

Inflammation of the vascular microenvironment modulates distinct types of vascular cells, and plays important roles in promoting atherosclerosis, stenosis/restenosis, and vascular-related diseases. Nik-related kinase (Nrk), a member of the Ste20-type kinase family, has been reported to be selectively expressed in embryonic skeletal muscle. However, whether Nrk is expressed in adult vascular smooth muscle, and if it influences intimal hyperplasia is unclear. Here, we found that Nrk is abundantly expressed in cultured vascular smooth muscle cells (VSMC) and mouse arterial intima. Treatment of mouse VSMCs with lipopolysaccharide (LPS) or platelet-derived growth factor significantly reduced Nrk expression. In addition, expression of Nrk was significantly reduced in regions of neointimal formation caused by guide-wire carotid artery injuries in mice, as well as in human atherosclerotic tissues, when compared to normal vessels. We identified that expression of matrix metalloproteinases (MMP3, MMP8 and MMP12) and inflammatory cytokines/chemokines (CCL6, CCL8, CCL11, CXCL1, CXCL3, CXCL5 and CXCL9) are synergistically induced by Nrk siRNA in LPS-treated mouse VSMCs. Moreover, we found that resveratrol significantly impaired LPS- and Nrk siRNA-induced expression of MMP3, CCL8, CCL11, CXCL3 and CXCL5. These results suggested that Nrk may play important roles in regulating pathological progression of atherosclerosis or neointimal- hyperplasia-related vascular diseases.

Oral Charcoal Adsorbents Attenuate Neointima Formation of Arteriovenous Fistulas.

Chronic kidney disease (CKD) accelerates the development of neointima formation at the anastomosis site of arteriovenous (AV) fistulas. Accumulation of certain uremic toxins has a deleterious effect on the cardiovascular system. The oral charcoal adsorbent, AST-120, reduces circulating and tissue uremic toxins, but its effect on neointima formation at an AV fistula is unknown. To understand the effect of CKD and AST-120 on neointima formation, we created AV fistulas (common carotid artery to the external jugular vein in an end-to-side anastomosis) in mice with and without CKD. AST-120 was administered in chow before and after AV fistula creation. Administration of AST-120 significantly decreased serum indoxyl sulfate levels in CKD mice. CKD mice had a larger neointima area than non-CKD mice, and administration of AST-120 in CKD mice attenuated neointima formation. Both smooth muscle cell and fibrin components were increased in CKD mice, and AST-120 decreased both. RNA expression of MMP-2, MMP-9, TNFα, and TGFß was increased in neointima tissue of CKD mice, and AST-120 administration neutralized the expression. Our results provided in vivo evidence to support the role of uremic toxin-binding therapy on the prevention of neointima formation. Peri-operative AST-120 administration deserves further investigation as a potential therapy to improve AV fistula patency.

ZNF479 downregulates metallothionein-1 expression by regulating ASH2L and DNMT1 in hepatocellular carcinoma.

Decreased expression of metallothionein-1 (MT-1) is associated with a poor prognosis in hepatocellular carcinoma (HCC). Here, we found that MT-1 expression was suppressed by 14-3-3ε, and MT-1 overexpression abolished 14-3-3ε-induced cell proliferation and tumor growth. We identified that 14-3-3ε induced expression of ZNF479, a novel potential transcriptional regulator by gene expression profiling and ZNF479 contributed to 14-3-3ε-suppressed MT-1 expression. ZNF479 induced the expression of DNMT1, UHRF1, and mixed-lineage leukemia (MLL) complex proteins (ASH2L and Menin), and increased tri-methylated histone H3 (H3K4me3) levels, but suppressed H3K4 (H3K4me2) di-methylation. ZNF479-suppressed MT-1 expression was restored by silencing of ASH2L and DNMT1. Furthermore, ZNF479 expression was higher in HCC tissues than that in the non-cancerous tissues. Expression analyses revealed a positive correlation between the expression of ZNF479 and DNMT1, UHRF1, ASH2L, and Menin, and an inverse correlation with that of ZNF479, ASH2L, Menin, and MT-1 isoforms. Moreover, correlations between the expression of ZNF479 and its downstream factors were more pronounced in HCC patients with hepatitis B. Here, we found that ZNF479 regulates MT-1 expression by modulating ASH2L in HCC. Approaches that target ZNF479/MLL complex/MT-1 or related epigenetic regulatory factors are potential therapeutic strategies for HCC.

Cordycepin Suppresses Endothelial Cell Proliferation, Migration, Angiogenesis, and Tumor Growth by Regulating Focal Adhesion Kinase and p53.

Focal adhesion kinase (FAK) plays an important role in vascular development, including the regulation of endothelial cell (EC) adhesion, migration, proliferation, and survival. 3'-deoxyadenosine (cordycepin) is known to suppress FAK expression, cell migration, and the epithelial⁻mesenchymal transition in hepatocellular carcinoma (HCC). However, whether cordycepin affects FAK expression and cellular functions in ECs and the specific molecular mechanism remain unclear. In this study, we found that cordycepin suppressed FAK expression and the phosphorylation of FAK (p-FAK) at Tyr397 in ECs. Cordycepin inhibited the proliferation, wound healing, transwell migration, and tube formation of ECs. Confocal microscopy revealed that cordycepin significantly reduced FAK expression and decreased focal adhesion number of ECs. The suppressed expression of FAK was accompanied by induced p53 and p21 expression in ECs. Finally, we demonstrated that cordycepin suppressed angiogenesis in an in vivo angiogenesis assay and reduced HCC tumor growth in a xenograft nude mice model. Our study indicated that cordycepin could attenuate cell proliferation and migration and may result in the impairment of the angiogenesis process and tumor growth via downregulation of FAK and induction of p53 and p21 in ECs. Therefore, cordycepin may be used as a potential adjuvant for cancer therapy.

Prognostic Significance of 14-3-3ε, Aldo-keto Reductase Family 1 B10 and Metallothionein-1 in Hepatocellular Carcinoma.

BACKGROUND/AIM: Expression of 14-3-3ε is associated with prognostic outcomes of hepatocellular carcinoma (HCC) patients. Metallothionein-1 (MT-1) proteins and aldo-keto-reductase family 1 B10 (AKR1B10) are considered potential tumor regulators of HCC. The aim of this study, was to examine the prognostic value of 14-3-3ε, MT-1 and AKR1B10 expression in HCC. MATERIALS AND METHODS: The expression levels of 14-3-3ε, MT-1 and AKR1B10 in HCC cell lines and paraffin-embedded tissues were examined by western blotting and immunohistochemical analysis. RESULTS: 14-3-3ε positivity was significantly associated with decreased MT-1 expression in HCC. Patients with decreased MT-1 expression had worse survival rates and a higher risk of metastasis than 14-3-3ε-positive HCC patients with unchanged MT-1 expression. Distinct expression patterns of 14-3-3ε/MT-1/AKR1B10 were significantly associated with the metastatic incidence and survival rates of HCC patients. Patients with negative 14-3-3ε staining in primary tumors had better prognostic outcomes. In contrast, patients with positive 14-3-3ε staining, decreased MT-1 expression and no increase in AKR1B10 expression in primary tumors had the worst overall and disease-free survival rates and the highest metastatic risk. CONCLUSION: 14-3-3ε, AKR1B10, and MT-1 act as potential prognostic biomarkers of HCC.

Correction: Regulation of Aldo-keto-reductase family 1 B10 by 14-3-3ε and their prognostic impact of hepatocellular carcinoma.

[This corrects the article DOI: 10.18632/oncotarget.5734.].

Deletion of caveolin-1 attenuates LPS/GalN-induced acute liver injury in mice.

Acute hepatic injury caused by inflammatory liver disease is associated with high mortality. This study examined the role of caveolin-1 (Cav-1) in lipopolysaccharide (LPS) and D-galactosamine (GalN)-induced fulminant hepatic injury in wild type and Cav-1-null (Cav-1-/- ) mice. Hepatic Cav-1 expression was induced post-LPS/GalN treatment in wild-type mice. LPS/GalN-treated Cav-1-/- mice showed reduced lethality and markedly attenuated liver damage, neutrophil infiltration and hepatocyte apoptosis as compared to wild-type mice. Cav-1 deletion significantly reduced LPS/GalN-induced caspase-3, caspase-8 and caspase-9 activation and pro-inflammatory cytokine and chemokine expression. Additionally, Cav-1-/- mice showed suppressed expression of Toll-like receptor 4 (TLR4) and CD14 in Kupffer cells and reduced expression of vascular cell adhesion molecule 1 and intercellular adhesion molecule 1 in liver cells. Cav-1 deletion impeded LPS/GalN-induced inducible nitric oxide synthase expression and nitric oxide production and hindered nuclear factor-κB (NF-κB) activation. Taken together, Cav-1 regulated the expression of mediators that govern LPS-induced inflammatory signalling in mouse liver. Thus, deletion of Cav-1 suppressed the inflammatory response mediated by the LPS-CD14-TLR4-NF-κb pathway and alleviated acute liver injury in mice.

Intrahepatic hepatitis B virus large surface antigen induces hepatocyte hyperploidy via failure of cytokinesis.

Hepatitis B virus (HBV) is an aetiological factor for liver cirrhosis and hepatocellular carcinoma (HCC). Despite current antiviral therapies that successfully reduce the viral load in patients with chronic hepatitis B, persistent hepatitis B surface antigen (HBsAg) remains a risk factor for HCC. To explore whether intrahepatic viral antigens contribute directly to hepatocarcinogenesis, we monitored the mitotic progression of HBV-positive cells. Cytokinesis failure was increased in HBV-positive HepG2.2.15 and 1.3ES2 cells, as well as in HuH-7 cells transfected with a wild-type or X-deficient HBV construct, but not in cells transfected with an HBsAg-deficient construct. We show that expression of viral large surface antigen (LHBS) was sufficient to induce cytokinesis failure of immortalized hepatocytes. Premitotic defects with DNA damage and G2 /M checkpoint attenuation preceded cytokinesis in LHBS-positive cells, and ultimately resulted in hyperploidy. Inhibition of polo-like kinase-1 (Plk1) not only restored the G2 /M checkpoint in these cells, but also suppressed LHBS-mediated in vivo tumourigenesis. Finally, a positive correlation between intrahepatic LHBS expression and hepatocyte hyperploidy was detected in >70% of patients with chronic hepatitis B. We conclude that HBV LHBS provokes hyperploidy by inducing DNA damage and upregulation of Plk1; the former results in atypical chromatin structures, and the latter attenuates the function of the G2 /M DNA damage checkpoint. Our data uncover a mechanism by which genomic integrity of hepatocytes is disrupted by viral LHBS. These findings highlight the role of intrahepatic surface antigen as an oncogenic risk factor in the development of HCC. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

An Efficient Transfection Method for Differentiation and Cell Proliferation of Mouse Embryonic Stem Cells.

Embryonic stem (ES) cells are an important source of stem cells in tissue engineering and regenerative medicine because of their high self-renewal capacities and differentiation potentials. However, the detailed molecular mechanisms controlling the differentiation and renewal programs in ES cells remained unclear. One of the difficulties in understanding these mechanisms substantially results from the low efficacies of gene manipulation by delivering exogenous gene expression or knockdown of endogenous gene expression with small interfering RNA (siRNA) in ES cells. Here we describe an optimized protocol for efficiently transfecting mouse ES cells by Effectene, a liposome-based method. The high transfection efficiency in mouse ES cells is demonstrated in this chapter by (1) achieving a percentage of enhanced green fluorescence protein (EGFP) expression in >98% embryoid bodies after introducing plasmids encoding the protein; (2) decreased SOX-2 and Oct-3/4 expression and subsequent morphological evidences of cell differentiation after introducing siRNA expression for suppressing SOX-2 and Oct-3/4, which are known to be essential for maintenance of stem cell properties in mouse ES cells; and (3) overexpression or attenuated expression of 14-3-3σ to regulate cell proliferation of mouse ES cells.

Cordycepin disrupts leukemia association with mesenchymal stromal cells and eliminates leukemia stem cell activity.

Maintaining stemness of leukemic stem cells (LSCs) and reciprocal interactions between leukemia and stromal cells support leukemic progression and resistance to chemotherapy. Targeting the niche-based microenvironment is thus a new approach for leukemia therapy. Cordycepin is an analogue of adenosine and has been suggested to possess anti-leukemia properties. However, whether cordycepin influences association of leukemia and mesenchymal stromal cells has never been investigated. Here we show that cordycepin reduces CD34+CD38- cells in U937 and K562 cells and induces Dkk1 expression via autocrine and paracrine regulation in leukemia and mesenchymal stromal/stem cells (MSCs). Cordycepin suppresses cell attachment of leukemia with MSCs and downregulates N-cadherin in leukemia and VCAM-1 in MSCs. Moreover, incubation with leukemic conditioned media (CM) significantly induces IL-8 and IL-6 expression in MSCs, which is abrogated by cordycepin. Suppression of leukemic CM-induced VCAM-1 and IL-8 by cordycepin in MSCs is mediated by impairing NFκB signaling. Finally, cordycepin combined with an adenosine deaminase inhibitor prolongs survival in a leukemic mouse model. Our results indicate that cordycepin is a potential anti-leukemia therapeutic adjuvant via eliminating LSCs and disrupting leukemia-stromal association.

Human pluripotent stem cell (PSC)-derived mesenchymal stem cells (MSCs) show potent neurogenic capacity which is enhanced with cytoskeletal rearrangement.

Mesenchymal stem cells (MSCs) are paraxial mesodermal progenitors with potent immunomodulatory properties. Reports also indicate that MSCs can undergo neural-like differentiation, offering hope for use in neurodegenerative diseases. However, ex vivo expansion of these rare somatic stem cells for clinical use leads to cellular senescence. A newer source of MSCs derived from human pluripotent stem cells (PSC) can offer the 'best-of-both-worlds' scenario, abrogating the concern of teratoma formation while preserving PSC proliferative capacity. PSC-derived MSCs (PSC-MSCs) also represent MSCs at the earliest developmental stage, and we found that these MSCs harbor stronger neuro-differentiation capacity than post-natal MSCs. PSC-MSCs express higher levels of neural stem cell (NSC)-related genes and transcription factors than adult bone marrow MSCs at baseline, and rapidly differentiate into neural-like cells when cultured in either standard neurogenic differentiation medium (NDM) or when the cytoskeletal modulator RhoA kinase (ROCK) is inhibited. Interestingly, when NDM is combined with ROCK inhibition, PSC-MSCs undergo further commitment, acquiring characteristics of post-mitotic neurons including nuclear condensation, extensive dendritic growth, and neuron-restricted marker expression including NeuN, ß-III-tubulin and Doublecortin. Our data demonstrates that PSC-MSCs have potent capacity to undergo neural differentiation and also implicate the important role of the cytoskeleton in neural lineage commitment.

Paracrine regulation of matrix metalloproteinases contributes to cancer cell invasion by hepatocellular carcinoma-secreted 14-3-3σ.

14-3-3σ overexpression results in enhanced hepatocellular carcinoma (HCC) cell migration and HCC tumor vascular-invasion is significantly associated with 14-3-3σ expression. However, increased expression of 14-3-3σ paradoxically suppresses in vitro cell invasion of HCC. We hypothesize that surrounding tumor-associated stromal cells play a crucial role in 14-3-3σ-regulated HCC cell invasion. In this study, H68 fibroblasts, THP-1 and phorbol-12-myristate-13-acetate (PMA)-treated THP-1 (PMA-THP-1) cells were incubated with conditioned media of control (control-CM) and 14-3-3σ-overepxressing cells (14-3-3σ-CM), followed by co-culture with HCC cells. Invasiveness of HCC cells was examined by a Boyden chamber assay. HCC cells co-cultured with 14-3-3σ-CM treated cells significantly enhanced their invasive ability compared with control-CM treated cells. Moreover, incubation with 14-3-3σ-CM induced differential expression profiles of matrix metalloproteinases (MMPs) in fibroblasts (MMP-1, MMP-2, MMP-9, MMP-12 and MMP-14), THP-1 (MMP-1 and MMP-12) and PMA-THP-1 cells (MMP-2, MMP-12 and MMP-14). In contrast, silencing of 14-3-3σ by siRNA significantly abolished 14-3-3σ-CM induced MMPs. In addition, treatment with recombinant 14-3-3σ (r14-3-3σ) protein exhibits a similar expression profile of MMPs induced by 14-3-3σ-CM in fibroblasts, THP-1 and PMA-THP-1 cells. Finally, knockdown of aminopeptidase N (APN) significantly abrogated r14-3-3σ induced expression of MMPs in HS68 fibroblasts. These results suggest that HCC-secreted 14-3-3σ promotes expression of MMPs in cancerous surrounding cells via an APN dependent mechanism. 14-3-3σ has a paracrine effect in educating stromal cells in tumor-associated microenvironment.

An EGFR/Src-dependent ß4 integrin/FAK complex contributes to malignancy of breast cancer.

ß4 integrin and focal adhesion kinase (FAK) are often associated with a poor prognosis in cancer patients, and their signaling events have recently been linked to malignant outcomes. Here, we demonstrate, for the first time, physical and functional interactions between ß4 integrin and FAK that influence breast cancer malignancy. An amino-terminal linker within FAK is essential for its binding with the cytodomain of ß4 integrin. Moreover, EGFR/Src-signaling triggers the tyrosine phosphorylation of ß4 integrin, which, in turn, recruits FAK to ß4 integrin and leads to FAK activation and signaling. Upon disruption of the ß4 integrin/FAK complex, tumorigenesis and metastasis in triple-negative breast cancer were markedly reduced. Importantly, the concomitant overexpression of ß4 integrin and FAK significantly correlates with malignant potential in patients with triple-negative breast cancer. This study describes a pro-metastatic EGFR/Src-dependent ß4 integrin/FAK complex that is involved in breast cancer malignancy and is a novel therapeutic target for triple-negative breast cancer.

Regulation of aldo-keto-reductase family 1 B10 by 14-3-3ε and their prognostic impact of hepatocellular carcinoma.

14-3-3ε is overexpressed in hepatocellular carcinoma (HCC) and its expression significantly associates with a poor prognostic outcome. To uncover how 14-3-3ε contributes to the tumor progression of HCC, we investigated the potential downstream targets regulated by 14-3-3ε. We found that 14-3-3ε increases expression and nuclear translocation of ß-catenin and that 14-3-3ε-induced cell proliferation is attenuated by ß-catenin silencing in HCC cells. Moreover, 14-3-3ε induces aldo-keto reductase family 1 member B10 (AKR1B10) expression through the activation of ß-catenin signaling. Knockdown of AKR1B10 by siRNAs abolished 14-3-3ε-induced in vitro cell proliferation, anchorage-independent growth as well as in vivo tumor growth. Furthermore, AKR1B10 silencing increased retinoic acid (RA) levels in the serum of tumor-bearing mice and RA treatment attenuated 14-3-3ε-induced HCC cell proliferation. We further examined 14-3-3ε and AKR1B10 expression and clinicopathological characteristics of HCC tumors. Although the expression of AKR1B10 was significantly correlated with 14-3-3ε, an increase of AKR1B10 expression in 14-3-3ε positive patients paradoxically had better overall survival and disease-free survival rates as well as lower metastatic incidence than those without an AKR1B10 increase. Finally, we found a loss of AKR1B10 expression in cells exhibiting a high capacity of invasiveness. Silencing of AKR1B10 resulted in inducing snail and vimentin expression in HCC cells. These results indicate that AKR1B10 may play a dual role during HCC tumor progression. Our results also indicate that 14-3-3ε regulates AKR1B10 expression by activating ß-catenin signaling. A combination of 14-3-3ε with AKR1B10 is a potential therapeutic target and novel prognostic biomarker of HCC.

AKT3 promotes prostate cancer proliferation cells through regulation of Akt, B-Raf, and TSC1/TSC2.

The qRT-PCR analysis of 139 clinical samples and analysis of 150 on-line database clinical samples indicated that AKT3 mRNA expression level was elevated in primary prostate tumors. Immunohistochemical staining of 65 clinical samples revealed that AKT3 protein expression was higher in prostate tumors of stage I, II, III as compared to nearby normal tissues. Plasmid overexpression of AKT3 promoted cell proliferation of LNCaP, PC-3, DU-145, and CA-HPV-10 human prostate cancer (PCa) cells, while knockdown of AKT3 by siRNA reduced cell proliferation. Overexpression of AKT3 increased the protein expression of total AKT, phospho-AKT S473, phospho-AKT T308, B-Raf, c-Myc, Skp2, cyclin E, GSK3ß, phospho-GSK3ß S9, phospho-mTOR S2448, and phospho-p70S6K T421/S424, but decreased TSC1 (tuberous sclerosis 1) and TSC2 (tuberous Sclerosis Complex 2) proteins in PC-3 PCa cells. Overexpression of AKT3 also increased protein abundance of phospho-AKT S473, phospho-AKT T308, and B-Raf but decreased expression of TSC1 and TSC2 proteins in LNCaP, DU-145, and CA-HPV-10 PCa cells. Oncomine datasets analysis suggested that AKT3 mRNA level was positively correlated to BRAF. Knockdown of AKT3 in DU-145 cells with siRNA increased the sensitivity of DU-145 cells to B-Raf inhibitor treatment. Knockdown of TSC1 or TSC2 promoted the proliferation of PCa cells. Our observations implied that AKT3 may be a potential therapeutic target for PCa treatment.

Rho-associated kinase inhibitors promote the cardiac differentiation of embryonic and induced pluripotent stem cells.

BACKGROUND: Rho-associated kinase (ROCK) plays an important role in maintaining embryonic stem (ES) cell pluripotency. To determine whether ROCK is involved in ES cell differentiation into cardiac and hematopoietic lineages, we evaluated the effect of ROCK inhibitors, Y-27632 and fasudil on murine ES and induced pluripotent stem (iPS) cell differentiation. METHODS: Gene expression levels were determined by real-time PCR, Western blot analysis and immunofluorescent confocal microscopy. Cell transplantation of induced differentiated cells were assessed in vivo in a mouse model (three groups, n=8/group) of acute myocardial infarction (MI). The cell engraftment was examined by immunohistochemical staining and the outcome was analyzed by echocardiography. RESULTS: Cells were cultured in hematopoietic differentiation medium in the presence or absence of ROCK inhibitor and colony formation as well as markers of ES, hematopoietic stem cells (HSC) and cells of cardiac lineages were analyzed. ROCK inhibition resulted in a drastic change in colony morphology accompanied by loss of hematopoietic markers (GATA-1, CD41 and ß-Major) and expressed markers of cardiac lineages (GATA-4, Isl-1, Tbx-5, Tbx-20, MLC-2a, MLC-2v, α-MHC, cTnI and cTnT) in murine ES and iPS cells. Fasudil-induced cardiac progenitor (Mesp-1 expressing) cells were infused into a murine MI model. They engrafted into the peri-infarct and infarct regions and preserved left ventricular function. CONCLUSIONS: These findings provide new insights into the signaling required for ES cell differentiation into hematopoietic as well as cardiac lineages and suggest that ROCK inhibitors are useful in directing iPS cell differentiation into cardiac progenitor cells for cell therapy of cardiovascular diseases.