HNF1α inhibition triggers epithelial-mesenchymal transition in human liver cancer cell lines

Freeze-Dried Mesenchymal Stem Cells: From Bench to Bedside. Review

This review describes the freeze-dried mesenchymal stem cells (MSCs) and their ability to restore damaged tissues and organs. An analysis of the literature shows that after the lyophilization MSCs retain >80% of paracrine factors and that the mechanism of their action on the restoration of damaged tissues and organs is similar to the mechanism of action of paracrine factors in fresh and cryopreserved mesenchymal stem cells. Based on the own materials, the use of paracrine factors of freeze-dried MSCs in vivo and in vitro for the treatment of various diseases of organs and tissues has shown to be effective. The study also discusses about the advantages and disadvantages of freeze-dried MSCs versus cryopreserved MSCs. However, for the effective use of freeze-dried MSCs in clinical practice, a more detailed study of the mechanism of interaction of paracrine factors of freeze-dried MSCs with target cells and tissues is required. It is also necessary to identify possible other specific paracrine factors of freeze-dried MSCs. In addition, develop new therapeutic strategies for the use of freeze-dried MSCs in regenerative medicine and tissue bioengineering.

Protective role of Decylubiquinone against secondary melanoma at lung in B16F10 induced mice by reducing E-cadherin expression and ameliorating ROCKII-Limk1/2-Cofiliin mediated metastasis

Melanoma is one of the most consequential skin cancer with a rising death incidences. Silent but belligerent nature of metastatic sprouting is the leading cause of melanoma related mortality. Invasion of metastatic cells and re-expression of E-Cadherin play the crucial role in the establishment of secondary tumor at distal sites. Thus, manipulation of tumor cell invasion in parallel to regulation of E-Cadherin expression can be considered as potential anti-metastatic strategy. Evidences suggested key role of reactive oxygen species associated ROCK activities in the modulation of metastatic invasion via F-actin stabilization. Here, we first-time report Decylubiquinone, a dietary Coenzyme Q₁₀ analog, as an effective attenuator of pulmonary metastatic melanoma in C57BL/6 mice. Current study depicted detailed molecular interplay associated with Decylubiquinone mediated phosphorylation of ROCKII at Tyr722 along with reduced phosphorylation of ROCKII Ser1366 leading to suppression of Limk1/2-Cofilin-F-actin stabilization axis that finally restricted B16F10 melanoma cell invasion at metastatic site. Analysis further deciphered the role of HNF4α as its nuclear translocation modulated E-Cadherin expression, the effect of reactive oxygen species dependent ROCKII activity in secondarily colonized B16F10 melanoma cells at lungs. Thus unbosoming of related signal orchestra represented Decylubiquinone as a potential remedial agent against secondary lung melanoma.

Tentatively Identified (UPLC/T-TOF-MS/MS) Compounds in the Extract of Saussurea costus Roots Exhibit In Vivo Hepatoprotection via Modulation of HNF-1α, Sirtuin-1, C/ebpα, miRNA-34a and miRNA-223

Saussurea costus is a plant traditionally used for the treatment of several ailments. Our study accomplished the UPLC/T-TOF-MS/MS analysis of a methanol extract of Saussurea costus roots (MESC), in addition to lipoidal matter determination and assessment of its in vivo hepatoprotective activity. In this study, we were able to identify the major metabolites in MESC rather than the previously known isolated compounds, improving our knowledge of its chemical constituents. The flavones apigenin, acacetin, baicalein, luteolin, and diosmetin, and the flavonol aglycones quercetin, kaempferol, isorhamnetin, gossypetin, and myricetin and/or their glycosides and glucuronic derivatives were the major identified compounds. The hepatoprotective activity of MESC was evaluated by measuring catalase activity using UV spectrophotometry, inflammatory cytokines and apoptotic markers using ELISA techniques, and genetic markers using PCR. Paracetamol toxicity caused a significant increase in plasma caspase 2, cytokeratin 18 (CK18), liver tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), miRNA-34a, and miRNA-223, as well as a significant decrease in liver catalase (CAT) activity and in the levels of liver nuclear factor 1α (HNF-1α), sirtuin-1, and C/ebpα. Oral pretreatment with MESC (200 mg/kg) showed a significant decrease in caspase 2, CK18, TNF-α, IL-6 and a significant increase in liver CAT activity. MESC decreased the levels of liver miRNA-34a and miRNA-223 and induced HNF-1α, sirtuin-1, and C/ebpα gene expression. The histological examination showed a significant normalization in rats pretreated with MESC. Our findings showed that Saussurea costus may exert a potent hepatoprotective activity through the modulation of the expression of cellular cytokines, miRNA-34a, and miRNA-223.

The Potential for Natural Products to Overcome Cancer Drug Resistance by Modulation of Epithelial-Mesenchymal Transition

The acquisition of resistance and ultimately disease relapse after initial response to chemotherapy put obstacles in the way of cancer therapy. Epithelial-mesenchymal transition (EMT) is a biologic process that epithelial cells alter to mesenchymal cells and acquire fibroblast-like properties. EMT plays a significant role in cancer metastasis, motility, and survival. Recently, emerging evidence suggested that EMT pathways are very important in making drug-resistant involved in cancer. Natural products are gradually emerging as a valuable source of safe and effective anticancer compounds. Natural products could interfere with the different processes implicated in cancer drug resistance by reversing the EMT process. In this review, we illustrate the molecular mechanisms of EMT in the emergence of cancer metastasis. We then present the role of natural compounds in the suppression of EMT pathways in different cancers to overcome cancer cell drug resistance and improve tumor chemotherapy. HighlightsDrug-resistance is one of the obstacles to cancer treatment.EMT signaling pathways have been correlated to tumor invasion, metastasis, and drug-resistance.Various studies on the relationship between EMT and resistance to chemotherapy agents were reviewed.Different anticancer natural products with EMT inhibitory properties and drug resistance reversal effects were compared.

Disruption of Tumor Suppressors HNF4α/HNF1α Causes Tumorigenesis in Liver

The hepatocyte nuclear factor-4α (HNF4α) and hepatocyte nuclear factor-1α (HNF1α) are transcription factors that influence the development and maintenance of homeostasis in a variety of tissues, including the liver. As such, disruptions in their transcriptional networks can herald a number of pathologies, such as tumorigenesis. Largely considered tumor suppressants in liver cancer, these transcription factors regulate key events of inflammation, epithelial-mesenchymal transition, metabolic reprogramming, and the differentiation status of the cell. High-throughput analysis of cancer cell genomes has identified a number of hotspot mutations in HNF1α and HNF4α in liver cancer. Such results also showcase HNF1α and HNF4α as important therapeutic targets helping us step into the era of personalized medicine. In this review, we update current findings on the roles of HNF1α and HNF4α in liver cancer development and progression. It covers the molecular mechanisms of HNF1α and HNF4α dysregulation and also highlights the potential of HNF4α as a therapeutic target in liver cancer.

Liraglutide blocks the proliferation, migration and phenotypic switching of Homocysteine (Hcy)-induced vascular smooth muscle cells (VSMCs) by suppressing proprotein convertase subtilisin kexin9 (PCSK9)/ low-density lipoprotein receptor (LDLR)

Liraglutide, a glucagon-like peptide 1 (GLP1) receptor agonist, is known to inhibit the atherosclerosis of apoE mice and suppress the cellular behaviors of VSMCs induced by AngII. This study aimed to explore whether liraglutide can reduce the proliferation, invasion and phenotypic transformation of VSMCs induced by Hcy and the underlying mechanism. Hcy was used to induce the proliferation of VSMCs, and liraglutide was then used to expose the cells for assessing cell proliferation. Afterward, the cell migration and phenotypic switch were evaluated to observe the effects of liraglutide. Meanwhile, the expression of PCSK9 and LDLR was detected. After overexpressing PCSK9, the changes in proliferation, cell migration and phenotypic switch were estimated again. Hcy promoted cell proliferation of VSMCs, whereas liraglutide blocked the proliferation, migration and phenotypic switch of Hcy-induced VSMCs. Furthermore, the expression of PCSK9 was downregulated and LDLR expression was upregulated after liraglutide administration in Hcy-induced VSMCs. After overexpressing PCSK9, the proliferation, migration and phenotypic switch of Hcy-induced VSMCs were enhanced. Liraglutide blocked the proliferation, migration and phenotypic switching of Hcy-induced VSMCs by suppressing PCSK9/LDLR. This finding provided the basis for the future application of liraglutide as an effective drug for therapeutic strategy in targeting AS.

Bile and urine peptide marker profiles: access keys to molecular pathways and biological processes in cholangiocarcinoma

Background

Detection of cholangiocarcinoma (CCA) remains a diagnostic challenge. We established diagnostic peptide biomarkers in bile and urine based on capillary electrophoresis coupled to mass spectrometry (CE-MS) to detect both local and systemic changes during CCA progression. In a prospective cohort study we recently demonstrated that combined bile and urine proteome analysis could further improve diagnostic accuracy of CCA diagnosis in patients with unknown biliary strictures. As a continuation of these investigations, the aim of the present study was to investigate the pathophysiological mechanisms behind the molecular determinants reflected by bile and urine peptide biomarkers.

Methods

Protease mapping and gene ontology cluster analysis were performed for the previously defined CE-MS based biomarkers in bile and urine. For that purpose, bile and urine peptide profiles (from samples both collected at the date of endoscopy) were investigated from a representative cohort of patients with benign (n = 76) or CCA-associated (n = 52) biliary strictures (verified during clinical follow-up). This was supplemented with a literature search for the association of the individual biomarkers included in the proteomic patterns with CCA or cancer progression.

Results

For most of the peptide markers, association to CCA has been described in literature. Protease mapping revealed ADAMTS4 activity in cleavage of both bile and urine CCA peptide biomarkers. Furthermore, increased chymase activity in bile points to mast cell activation at the tumor site. Gene ontology cluster analysis indicates cellular response to chemical stimuli and stress response as local and extracellular matrix reorganization by tissue destruction and repair as systemic events. The analysis further supports that the mapped proteases are drivers of local and systemic events.

Conclusions

The study supports connection of the CCA-associated peptide biomarkers to the molecular pathophysiology and indicates an involvement in epithelial-to-mesenchymal transition, generation of cancer-associated fibroblasts and activation of residual immune cells. Proteases, extracellular matrix components, inflammatory cytokines, proangiogenic, growth and vasoactive factors released from the tumor microenvironment are drivers of systemic early events during CCA progression.

Hepatic Nuclear Factor 1 Alpha (HNF-1α) In Human Physiology and Molecular Medicine

The transcription factors (TFs) play a crucial role in the modulation of specific gene transcription networks. One of the hepatocyte nuclear factors (HNFs) family's member, hepatocyte nuclear factor-1α (HNF-1α) has continuously become a principal TF to control the expression of genes. It is involved in the regulation of a variety of functions in various human organs including liver, pancreas, intestine, and kidney. It regulates the expression of enzymes involved in endocrine and xenobiotic activity through various metabolite transporters located in the above organs. Its expression is also required for organ-specific cell fate determination. Despite two decades of its first identification in hepatocytes, a review of its significance was not comprehended. Here, the role of HNF-1α in the above organs at the molecular level to intimate molecular mechanisms for regulating certain gene expression whose malfunctions are attributed to the disease conditions has been specifically encouraged. Moreover, the epigenetic effects of HNF-1α have been discussed here, which could help in advanced technologies for molecular pharmacological intervention and potential clinical implications for targeted therapies. HNF-1α plays an indispensable role in several physiological mechanisms in the liver, pancreas, intestine, and kidney. Loss of its operations leads to the non-functional or abnormal functional state of each organ. Specific molecular agents or epigenetic modifying drugs that reactivate HNF-1α are the current requirements for the medications of the diseases.

TGFβ Impairs HNF1α Functional Activity in Epithelial-to-Mesenchymal Transition Interfering With the Recruitment of CBP/p300 Acetyltransferases

The cytokine transforming growth factor β (TGFβ) plays a crucial role in the induction of both epithelial-to-mesenchymal transition (EMT) program and fibro-cirrhotic process in the liver, where it contributes also to organ inflammation following several chronic injuries. All these pathological situations greatly increase the risk of hepatocellular carcinoma (HCC) and contribute to tumor progression. In particular, late-stage HCCs are characterized by constitutive activation of TGFβ pathway and by an EMT molecular signature leading to the acquisition of invasive and metastatic properties. In these pathological conditions, the cytokine has been shown to induce the transcriptional downregulation of HNF1α, a master regulator of the epithelial/hepatocyte differentiation and of the EMT reverse process, the mesenchymal-to-epithelial transition (MET). Therefore, the restoration of HNF1α expression/activity has been proposed as targeted therapeutic strategy for liver fibro-cirrhosis and late-stage HCCs. In this study, TGFβ is found to trigger an early functional inactivation of HNF1α during EMT process that anticipates the effects of the transcriptional downregulation of its own gene. Mechanistically, the cytokine, while not affecting the HNF1α DNA-binding capacity, impaired its ability to recruit CBP/p300 acetyltransferases on target gene promoters and, consequently, its transactivating function. The loss of HNF1α capacity to bind to CBP/p300 and HNF1α functional inactivation have been found to correlate with a change of its posttranslational modification profile. Collectively, the results obtained in this work unveil a new level of HNF1α functional inactivation by TGFβ and contribute to shed light on the early events triggering EMT in hepatocytes. Moreover, these data suggest that the use of HNF1α as anti-EMT tool in a TGFβ-containing microenvironment may require the design of new therapeutic strategies overcoming the TGFβ-induced HNF1α inactivation.

Evolocumab, a proprotein convertase subtilisin/kexin type 9 inhibitor, promotes angiogenesis in vitro

The proprotein convertases family is involved in several physiological processes such as cell growth, migration, and angiogenesis, and also in different pathological conditions. Evolocumab, an inhibitor of proprotein convertase subtilisin/kexin type 9 (PCSK9), has recently been approved for treatment of hypercholesterolemia. This study aimed to investigate the effect of evolocumab on angiogenesis in human umbilical vein endothelial cells (HUVECs). Cell proliferation and migration were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Transwell methods. In vitro angiogenesis was assessed by tube formation assay. Vascular endothelial growth factor (VEGF) secretion by HUVECs was also determined using an enzyme-linked immunosorbent assay kit. Evolocumab significantly increased HUVECs viability at 100 μg/mL. Significant enhancement in cell migration, and mean tubules length and size was observed at the concentrations of 10 and 100 μg/mL and also in mean number of junctions at the concentration of 100 μg/mL. Administration of evolocumab at the concentration of 10 μg/mL increased VEGF release into supernatants of HUVECs. Findings of this investigation provided in vitro evidence for pro-angiogenic activity of evolocumab through promoting cell proliferation, migration, tubulogenesis, and VEGF secretion in HUVECs.

N-Glycomic and Transcriptomic Changes Associated with CDX1 mRNA Expression in Colorectal Cancer Cell Lines

The caudal-related homeobox protein 1 (CDX1) is a transcription factor, which is important in the development, differentiation, and homeostasis of the gut. Although the involvement of CDX genes in the regulation of the expression levels of a few glycosyltransferases has been shown, associations between glycosylation phenotypes and CDX1 mRNA expression have hitherto not been well studied. Triggered by our previous study, we here characterized the N-glycomic phenotype of 16 colon cancer cell lines, selected for their differential CDX1 mRNA expression levels. We found that high CDX1 mRNA expression associated with a higher degree of multi-fucosylation on N-glycans, which is in line with our previous results and was supported by up-regulated gene expression of fucosyltransferases involved in antenna fucosylation. Interestingly, hepatocyte nuclear factors (HNF)4A and HNF1A were, among others, positively associated with high CDX1 mRNA expression and have been previously proven to regulate antenna fucosylation. Besides fucosylation, we found that high CDX1 mRNA expression in cancer cell lines also associated with low levels of sialylation and galactosylation and high levels of bisection on N-glycans. Altogether, our data highlight a possible role of CDX1 in altering the N-glycosylation of colorectal cancer cells, which is a hallmark of tumor development.

HNF1α Controls Liver Lipid Metabolism and Insulin Resistance via Negatively Regulating the SOCS-3-STAT3 Signaling Pathway

This study is aimed at evaluating the effects, functions, and mechanism of HNF1α on hepatic glycolipid metabolism. In this study, free fatty acid- (FFA-) induced steatosis of hepatocyte liver cell LO2 was used as an in vitro model. The methods of Oil Red O staining, RT-qPCR, western blot, and immunofluorescence staining were used to detect LO2-regulated HNF1α expression and its effects on FFA-induced LO2 cell steatosis, the insulin signaling and SOCS-3-STAT3 signaling pathways, the expression of lipid metabolism-related regulators, and phosphorylation. With increased FFA induction time, the expression of HNF1α in the LO2 fatty degeneration hepatic cells gradually decreased. Downregulation of HNF1α expression aggravated FFA-induced steatosis of LO2 hepatocytes. HNF1α promotes activation of the insulin pathway and oxidative breakdown of fat and inhibits lipid anabolism. Inhibitors of STAT3 can reverse the regulation of decreased HNF1α expression on the insulin signaling pathway and fat metabolism. We also confirmed this pathway using HNF1α-/- mice combining treatment with STAT3 inhibitor NSC 74859 in vivo. HNF1α regulates hepatic lipid metabolism by promoting the expression of SOCS-3 and negatively regulating the STAT3 signaling pathway.

Hepatocyte nuclear factor 1A deficiency causes hemolytic anemia in mice by altering erythrocyte sphingolipid homeostasis

The hepatocyte nuclear factor (HNF) family regulates complex networks of metabolism and organ development. Human mutations in its prototypical member HNF1A cause maturity-onset diabetes of the young (MODY) type 3. In this study, we identified an important role for HNF1A in the preservation of erythrocyte membrane integrity, calcium homeostasis, and osmotic resistance through an as-yet unrecognized link of HNF1A to sphingolipid homeostasis. HNF1A^-/- mice displayed microcytic hypochromic anemia with reticulocytosis that was partially compensated by avid extramedullary erythropoiesis at all erythroid stages in the spleen thereby excluding erythroid differentiation defects. Morphologically, HNF1A^-/- erythrocytes resembled acanthocytes and displayed increased phosphatidylserine exposure, high intracellular calcium, and elevated osmotic fragility. Sphingolipidome analysis by mass spectrometry revealed substantial and tissue-specific sphingolipid disturbances in several tissues including erythrocytes with the accumulation of sphingosine as the most prominent common feature. All HNF1A^-/- erythrocyte defects could be simulated by exposure of wild-type (WT) erythrocytes to sphingosine in vitro and attributed in part to sphingosine-induced suppression of the plasma-membrane Ca²⁺-ATPase activity. Bone marrow transplantation rescued the anemia phenotype in vivo, whereas incubation with HNF1A^-/- plasma increased the osmotic fragility of WT erythrocytes in vitro. Our data suggest a non-cell-autonomous erythrocyte defect secondary to the sphingolipid changes caused by HNF1A deficiency. Transcriptional analysis revealed 4 important genes involved in sphingolipid metabolism to be deregulated in HNF1A deficiency: Ormdl1, sphingosine kinase-2, neutral ceramidase, and ceramide synthase-5. The considerable erythrocyte defects in murine HNF1A deficiency encourage clinical studies to explore the hematological consequences of HNF1A deficiency in human MODY3 patients.

p.Q511L mutation of HNF1α in hepatocellular carcinoma suppresses the transcriptional activity and the anti-tumor effect of HNF1α

Hepatocyte nuclear factor 1α (HNF1α) is a liver-enriched transcription factor that regulates many aspects of hepatocyte functions. Our previous studies have demonstrated that HNF1α has potent therapeutic effects on hepatocellular carcinoma (HCC). Mutations in HNF1α gene are frequently associated with maturity-onset diabetes of the young type 3 (MODY3) and hepatocellular adenomas. However, the association of HNF1α mutation and HCC remains elusive. In this study, the point mutation of HNF1α gene with c.A1532 > T/p.Q511L was identified in an HCC patient by exon-capture high-throughput sequencing. Mutation of c.A1532 > T/p.Q511L in HNF1α gene was only detected in the tumor tissue but not in the adjacent non-tumorous liver tissue of the patient. Luciferase reporter assay and real-time PCR revealed that mutation of p.Q511L reduced the transcriptional activity of HNF1α. Immunofluorescence staining and subcellular fraction analysis revealed that mutation of p.Q511L disturbed the intracellular localization of HNF1α in HCC cells. Moreover, the inhibitory effect of HNF1α on the proliferation, migration and invasion in HCC cells was also partially abolished by the mutation of p.Q511L. Our data suggested that the missense mutation of HNF1α (p.Q511L) may associate with the progression of HCC.

Peroxisome Proliferator-Activated Receptor Gamma in Obesity and Colorectal Cancer: the Role of Epigenetics

Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear receptor that is deregulated in obesity. PPARγ exerts diverse antineoplastic effects. Attempting to determine the clinical relevance of the epigenetic mechanisms controlling the expression PPARγ and susceptibility to colorectal cancer (CRC) in obese subjects, this study investigated the role of some microRNAs and DNA methylation on the deregulation of PPARγ. Seventy CRC patients (34 obese and 36 lean), 22 obese and 24 lean healthy controls were included. MicroRNA levels were measured in serum. PPARγ promoter methylation was evaluated in peripheral blood mononuclear cells (PBMC). PPARγ level was evaluated by measuring mRNA level in PBMC and protein level in serum. The tested microRNAs (miR-27b, 130b and 138) were significantly upregulated in obese and CRC patients. Obese and CRC patients had significantly low levels of PPARγ. A significant negative correlation was found between PPARγ levels and the studied microRNAs. There was a significant PPARγ promoter hypermethylation in CRC patients that correlated to low PPARγ levels. Our results suggest that upregulation of microRNAs 27b, 130b and 138 is associated with susceptibility to CRC in obese subjects through PPARγ downregulation. Hypermethylation of PPARγ gene promoter is associated with CRC through suppression of PPARγ regardless of BMI.

Plumbagin Enhances Tamoxifen Sensitivity and Inhibits Tumor Invasion in Endocrine Resistant Breast Cancer through EMT Regulation

Tamoxifen is widely used as the first line drug for estrogen receptor-positive subtype which is expressed in 70% of overall breast cancer patients. However, approximately 50% of these patients develop acquired resistance after 5 years of treatment, which is characterized by tumor recurrence and metastasis. The epithelial mesenchymal transition (EMT) is an important process in breast cancer invasion. Fundamentally, targeting the EMT represents a crucial therapeutic strategy for preventing or treating breast cancer metastasis. Plumbagin (PLB) is a natural naphthoquinone with significant anticancer effects against several types of tumor cells including breast cancer. In this study, we investigated the effect of PLB on human endocrine-resistant breast cancer cell growth, invasion and the possible mechanisms underlying such actions. PLB exhibited potent cytotoxic activity at a micromolar concentration against endocrine-resistant breast cancer cells. Interestingly, a fixed low concentration of PLB and tamoxifen combination resulted in an increase in growth inhibition in endocrine-resistant cells. In addition, PLB also significantly suppressed mesenchymal biomarker expressions that govern the EMT process, resulting in attenuated metastatic capabilities. In conclusion, PLB should be developed as a pharmacological agent for the use as a single treatment or in combination for endocrine-resistant breast cancer. Copyright © 2016 John Wiley & Sons, Ltd.

Hepatocyte Nuclear Factor 1A Is a Cell-Intrinsic Transcription Factor Required for B Cell Differentiation and Development in Mice

The hepatocyte NF (HNF) family of transcription factors regulates the complex gene networks involved in lipid, carbohydrate, and protein metabolism. In humans, HNF1A mutations cause maturity onset of diabetes in the young type 3, whereas murine HNF6 participates in fetal liver B lymphopoiesis. In this study, we have identified a crucial role for the prototypical member of the family HNF1A in adult bone marrow B lymphopoiesis. HNF1A(-/-) mice exhibited a clear reduction in total blood and splenic B cells and a further pronounced one in transitional B cells. In HNF1A(-/-) bone marrow, all B cell progenitors-from pre-pro-/early pro-B cells to immature B cells-were dramatically reduced and their proliferation rate suppressed. IL-7 administration in vivo failed to boost B cell development in HNF1A(-/-) mice, whereas IL-7 stimulation of HNF1A(-/-) B cell progenitors in vitro revealed a marked impairment in STAT5 phosphorylation. The B cell differentiation potential of HNF1A(-/-) common lymphoid progenitors was severely impaired in vitro, and the expression of the B lymphopoiesis-promoting transcription factors E2A, EBF1, Pax5, and Bach2 was reduced in B cell progenitors in vivo. HNF1A(-/-) bone marrow chimera featured a dramatic defect in B lymphopoiesis recapitulating that of global HNF1A deficiency. The HNF1A(-/-) lymphopoiesis defect was confined to B cells as T lymphopoiesis was unaffected, and bone marrow common lymphoid progenitors and hematopoietic stem cells were even increased. Our data demonstrate that HNF1A is an important cell-intrinsic transcription factor in adult B lymphopoiesis and suggest the IL-7R/STAT5 module to be causally involved in mediating its function.

Expression of liver fatty acid binding protein in hepatocellular carcinoma

Loss of expression of liver fatty acid binding protein (LFABP) by immunohistochemistry has been shown to be characteristic of a subset of hepatocellular adenomas (HCAs) in which HNF1A is inactivated. Transformation to hepatocellular carcinoma is thought to be a very rare phenomenon in the HNF1A-inactivated variant of HCA. However, we recently observed 2 cases at our institution, 1 definite hepatocellular carcinoma and 1 possible hepatocellular carcinoma, with loss of LFABP staining, raising the possibility that LFABP down-regulation may be associated with hepatocellular carcinogenesis. Our aim was to evaluate hepatocellular carcinomas arising in various backgrounds and with varying degrees of differentiation for loss of LFABP staining. Twenty total cases of hepatocellular carcinoma were examined. Thirteen cases arose in a background of cirrhosis due to hepatitis C (n = 8) or steatohepatitis (n = 5); 7 cases arose in a noncirrhotic background, with 2 cases arising within HNF1A-inactivated variant HCA and 2 cases arising within inflammatory variant HCA. Complete loss of expression of LFABP was seen in 6 of 20 cases, including 2 cases of hepatocellular carcinoma arising within HNF1A-inactivated variant HCA. Thus, loss of staining for LFABP appears to be common in hepatocellular carcinoma and may be seen in well-differentiated hepatocellular carcinoma. Therefore, LFABP loss should not be interpreted as evidence for hepatocellular adenoma over carcinoma, when other features support a diagnosis of hepatocellular carcinoma. The findings raise consideration for a role of HNF1A inactivation in hepatocellular carcinogenesis, particularly in less differentiated tumors.

New Tools for Molecular Therapy of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common type of liver cancer, arising from neoplastic transformation of hepatocytes or liver precursor/stem cells. HCC is often associated with pre-existing chronic liver pathologies of different origin (mainly subsequent to HBV and HCV infections), such as fibrosis or cirrhosis. Current therapies are essentially still ineffective, due both to the tumor heterogeneity and the frequent late diagnosis, making necessary the creation of new therapeutic strategies to inhibit tumor onset and progression and improve the survival of patients. A promising strategy for treatment of HCC is the targeted molecular therapy based on the restoration of tumor suppressor proteins lost during neoplastic transformation. In particular, the delivery of master genes of epithelial/hepatocyte differentiation, able to trigger an extensive reprogramming of gene expression, could allow the induction of an efficient antitumor response through the simultaneous adjustment of multiple genetic/epigenetic alterations contributing to tumor development. Here, we report recent literature data supporting the use of members of the liver enriched transcription factor (LETF) family, in particular HNF4α, as tools for gene therapy of HCC.

Berry Phenolic Compounds Increase Expression of Hepatocyte Nuclear Factor-1α (HNF-1α) in Caco-2 and Normal Colon Cells Due to High Affinities with Transcription and Dimerization Domains of HNF-1α

Hepatocyte nuclear factor-1α (HNF-1α) is found in the kidneys, spleen, thymus, testis, skin, and throughout the digestive organs. It has been found to promote the transcription of various proteins involved in the management of type II diabetes, including dipeptidyl peptidase-IV (DPP-IV). Phenolic compounds from berries and citrus fruits are known to inhibit DPP-IV, but have not been tested for their interactions with wild-type HNF-1α. By studying the interactions of compounds from berries and citrus fruits have with HNF-1α, pre-transcriptional mechanisms that inhibit the expression of proteins such as DPP-IV may be elucidated. In this study, the interactions of berry phenolic compounds and citrus flavonoids with the dimerization and transcriptional domains of HNF-1α were characterized using the molecular docking program AutoDock Vina. The anthocyanin delphinidin-3-O-arabinoside had the highest binding affinity for the dimerization domain as a homodimer (-7.2 kcal/mol) and transcription domain (-8.3 kcal/mol) of HNF-1α. Anthocyanins and anthocyanidins had relatively higher affinities than resveratrol and citrus flavonoids for both, the transcription domain and the dimerization domain as a homodimer. The flavonoid flavone had the highest affinity for a single unit of the dimerization domain (-6.5 kcal/mol). Nuclear expression of HNF-1α was measured in Caco-2 and human normal colon cells treated with blueberry and blackberry anthocyanin extracts. All extracts tested increased significantly (P < 0.05) the nuclear expression of HNF-1α in Caco-2 cells by 85.2 to 260% compared to a control. The extracts tested increased significantly (P < 0.02) the nuclear expression of HNF-1α in normal colon cells by 48.6 to 243%. It was confirmed that delphinidin-3-O-glucoside increased by 3-fold nuclear HNF-1α expression in Caco-2 cells (P < 0.05). Anthocyanins significantly increased nuclear HNF-1α expression, suggesting that these compounds might regulate the genes HNF-1α promotes.

Molecular mechanisms controlling the phenotype and the EMT/MET dynamics of hepatocyte

The complex spatial and paracrine relationships between the various liver histotypes are essential for proper functioning of the hepatic parenchymal cells. Only within a correct tissue organization, in fact, they stably maintain their identity and differentiated phenotype. The loss of histotype identity, which invariably occurs in the primary hepatocytes in culture, or in vivo in particular pathological conditions (fibrosis and tumours), is mainly because of the phenomenon of epithelial-to-mesenchymal transition (EMT). The EMT process, that occurs in the many epithelial cells, appears to be driven by a number of general, non-tissue-specific, master transcriptional regulators. The reverse process, the mesenchymal-to-epithelial transition (MET), as yet much less characterized at a molecular level, restores specific epithelial identities, and thus must include tissue-specific master elements. In this review, we will summarize the so far unveiled events of EMT/MET occurring in liver cells. In particular, we will focus on hepatocyte and describe the pivotal role in the control of EMT/MET dynamics exerted by a tissue-specific molecular mini-circuitry. Recent evidence, indeed, highlighted as two transcriptional factors, the master gene of EMT Snail, and the master gene of hepatocyte differentiation HNF4α, exhorting a direct reciprocal repression, act as pivotal elements in determining opposite cellular outcomes. The different balances between these two master regulators, further integrated by specific microRNAs, in fact, were found responsible for the EMT/METs dynamics as well as for the preservation of both hepatocyte and stem/precursor cells identity and differentiation. Overall, these findings impact the maintenance of stem cells and differentiated cells both in in vivo EMT/MET physio-pathological processes as well as in culture.

Transcriptome analysis of pancreatic cancer reveals a tumor suppressor function for HNF1A

Pancreatic ductal adenocarcinoma (PDAC) is driven by the accumulation of somatic mutations, epigenetic modifications and changes in the micro-environment. New approaches to investigating disruptions of gene expression networks promise to uncover key regulators and pathways in carcinogenesis. We performed messenger RNA-sequencing in pancreatic normal (n = 10) and tumor (n = 8) derived tissue samples, as well as in pancreatic cancer cell lines (n = 9), to determine differential gene expression (DE) patterns. Sub-network enrichment analyses identified HNF1A as the regulator of the most significantly and consistently dysregulated expression sub-network in pancreatic tumor tissues and cells (median P = 7.56×10(-7), median rank = 1, range = 1-25). To explore the effects of HNF1A expression in pancreatic tumor-derived cells, we generated stable HNF1A-inducible clones in two pancreatic cancer cell lines (PANC-1 and MIA PaCa-2) and observed growth inhibition (5.3-fold, P = 4.5×10(-5) for MIA PaCa-2 clones; 7.2-fold, P = 2.2×10(-5) for PANC-1 clones), and a G0/G1 cell cycle arrest and apoptosis upon induction. These effects correlated with HNF1A-induced down-regulation of 51 of 84 cell cycle genes (e.g. E2F1, CDK2, CDK4, MCM2/3/4/5, SKP2 and CCND1), decreased expression of anti-apoptotic genes (e.g. BIRC2/5/6 and AKT) and increased expression of pro-apoptotic genes (e.g. CASP4/9/10 and APAF1). In light of the established role of HNF1A in the regulation of pancreatic development and homeostasis, our data suggest that it also functions as an important tumor suppressor in the pancreas.

Hepatocyte nuclear factor 1 regulates the expression of the organic cation transporter 1 via binding to an evolutionary conserved region in intron 1 of the OCT1 gene

The organic cation transporter 1 (OCT1), also known as solute carrier family 22 member 1, is strongly and specifically expressed in the human liver. Here we show that the hepatocyte nuclear factor 1 (HNF1) regulates OCT1 transcription and contributes to the strong, liver-specific expression of OCT1. Bioinformatic analyses revealed strong conservation of HNF1 binding motifs in an evolutionary conserved region (ECR) in intron 1 of the OCT1 gene. Electrophoretic mobility shift and chromatin immunoprecipitation assays confirmed the specific binding of HNF1 to the intron 1 ECR. In reporter gene assays performed in HepG2 cells, the intron 1 ECR increased SV40 promoter activity by 22-fold and OCT1 promoter activity by 13-fold. The increase was reversed when the HNF1 binding sites in the intron 1 ECR were mutated or the endogenous HNF1α expression was downregulated with small interfering RNA. Following HNF1α overexpression in Huh7 cells, the intron 1 ECR increased SV40 promoter activity by 11-fold and OCT1 promoter activity by 6-fold. Without HNF1α overexpression, the increases were only 3- and 2-fold, respectively. Finally, in human liver samples, high HNF1 expression was significantly correlated with high OCT1 expression (r = 0.48, P = 0.002, n = 40). In conclusion, HNF1 is a strong regulator of OCT1 expression. It remains to be determined whether genetic variants, disease conditions, or drugs that affect HNF1 activity may affect the pharmacokinetics and efficacy of OCT1-transported drugs such as morphine, tropisetron, ondansetron, tramadol, and metformin. Beyond OCT1, this study demonstrates the validity and usefulness of interspecies comparisons in the discovery of functionally relevant genomic sequences.

Hepatocellular benign tumors-from molecular classification to personalized clinical care

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are benign hepatocellular tumors that develop most frequently in women without cirrhosis. Genomic approaches have identified signaling pathways related to these benign hepatocyte proliferations. FNH, a polyclonal lesion, is characterized by local vascular abnormalities and heterogeneous activation of Wnt/β-catenin and transforming growth factor β signaling. Four major subgroups of HCAs have been identified based on mutations in specific oncogenes and tumor suppressor genes. Each molecular subtype of HCA has been associated with specific pathways, providing new information about benign tumorigenesis. Key features include metabolic alterations (induced by defects in HNF1A), oncogene-induced inflammation (activation of JAK-STAT signaling in inflammatory adenomas), and an association between activation of Wnt/β-catenin signaling and progression of HCAs in hepatocellular carcinomas. Benign hepatocellular tumors can be classified using immunohistochemical analyses. Studies of genotypes and phenotypes of FNH and HCAs have led to the identification of risk factors and improved invasive and noninvasive diagnostic techniques, evaluation of prognosis, and treatment. We review the molecular pathways involved in benign hepatocyte proliferation and discuss how this basic knowledge has been progressively translated into personalized clinical care.

Molecular classification of hepatocellular adenomas

Hepatocellular adenomas (HCAs) are benign tumors developed in normal liver most frequently in women before menopause. HCAs lead to diagnostic pitfalls and several difficulties to assess the risk of malignant transformation in these young patients. Recent advances in basic knowledge have revealed a molecular classification related to risk factors, pathological features, and risk of transformation in hepatocellular carcinoma. Three major molecular pathways have been identified altered in specific HCA subgroups that are defined by either (1) inactivation of hepatocyte nuclear factor 1A (HNF1A) transcription factor, (2) activation of the WNT/β-catenin by CTNNB1 mutations, or (3) activation of the IL6/STAT3 pathway by somatic mutation of IL6ST, GNAS, or STAT3. Here, we will review the different molecular classes of HCA.

PPARG Epigenetic Deregulation and Its Role in Colorectal Tumorigenesis

Peroxisome proliferator-activated receptor gamma (PPARγ) plays critical roles in lipid storage, glucose metabolism, energy homeostasis, adipocyte differentiation, inflammation, and cancer. Its function in colon carcinogenesis has largely been debated; accumulating evidence, however, supports a role as tumor suppressor through modulation of crucial pathways in cell differentiation, apoptosis, and metastatic dissemination. Epigenetics adds a further layer of complexity to gene regulation in several biological processes. In cancer, the relationship with epigenetic modifications has provided important insights into the underlying molecular mechanisms. These studies have highlighted how epigenetic modifications influence PPARG gene expression in colorectal tumorigenesis. In this paper, we take a comprehensive look at the current understanding of the relationship between PPARγ and cancer development. The role that epigenetic mechanisms play is also addressed disclosing novel crosstalks between PPARG signaling and the epigenetic machinery and suggesting how this dysregulation may contribute to colon cancer development.