Inhibitory Factor-1 Research Articles

Norcantharidin blocks Wnt/β-catenin signaling via promoter demethylation of WIF-1 in glioma.

Glioma is one of the most common primary intracranial tumors, and the prognosis is poor even though much treatment management is employed. Wnt/β-catenin signaling has been reported to be associated with glioma. Norcantharidin (NCTD) is the demethylated analog of cantharidin isolated from blister beetles, and it is reported to possess anticancer activity but less nephrotoxicity than cantharidin. Accordingly, we aimed to investigate NCTD as an anti-neoplastic drug that inhibits the Wnt/β‑catenin pathway via promoter demethylation of Wnt inhibitory factor-1 (WIF-1) in glioma growth in vitro. In the present study, we report that NCTD inhibited cell proliferation, induced apoptosis and cell cycle arrest, and suppressed cell migration and invasion in vitro. Moreover, we observed that the expression levels of WIF-1 mRNA and protein in the NCTD-treated cells were increased significantly compared with these levels in the negative control (NC) cells. Promoter demethylation was observed in the NCTD‑treated cells. In contrast, aberrant methylation was observed in the NC cells. Additionally, more investigation revealed that NCTD suppressed activity of Wnt/β-catenin signaling and transcription of β-catenin/TCF-4. Furthermore, the expression of apoptosis-related proteins Bcl-2 and cleaved caspase-3 indicated significant cell apoptosis. We provide initial evidence that NCTD reactivates WIF-1 from a methylation state, and downregulates canonical Wnt/β-catenin signaling. Our findings revealed that NCTD is effective for glioma in vitro and may be a new therapeutic option in vivo.

Turn up the cellular power generator with vitamin E analogue formulation.

The down regulation of the cellular power generator, adenosine triphosphate (ATP) synthase, in various cancer cells plays an obstructive role in mitochondria-mediated cell death. Cancer cells up-regulate ATPase inhibitory factor 1 (IF1) and down-regulate β-F1-ATPase of ATP synthase to enhance aerobic glycolysis for tumor growth via inhibiting total ATP synthase activity in the oxidative phosphorylation (OXPHOS) pathway. Alpha-tocopheryl succinate (α-TOS), one of the most bioactive derivatives of vitamin E, can selectively induce apoptosis in numerous cancer cells. The cancer cell selective apoptosis inducing property of α-TOS is correlated to: mitochondrial destabilization, inhibition of anti-apoptotic B cell lymphoma 2 (Bcl2) and protein kinase C (PKC), caspase 3 activation, production of mitochondrial reactive oxygen species (ROS), and inhibition of succinate dehydrogenase activity of mitochondrial complex II, and interaction with complex I to some extent. There is no report which elucidates the effects of α-TOS on the cellular power generator, complex V or ATP synthase. Here, we report the activation of mitochondrial ATP synthase using a suitably designed chemical formulation of α-TOS for the first time. A mitochondria targeted α-TOS nanoparticle formulation demonstrated enhanced cytotoxicity and mitochondrial activities in cancer cells by inhibiting Bcl2 protein and activating ATP synthase. The modulation of ATP synthase in cancer cells by the engineered formulation of α-TOS can be promising for solid cancers with compromised ATP synthase.

F1FO ATP Synthase Is Expressed at the Surface of Embryonic Rat Heart-Derived H9c2 Cells and Is Affected by Cardiac-Like Differentiation.

Taking advantage from the peculiar features of the embryonic rat heart-derived myoblast cell line H9c2, the present study is the first to provide evidence for the expression of F1FO ATP synthase and of ATPase Inhibitory Factor 1 (IF1) on the surface of cells of cardiac origin, together documenting that they were affected through cardiac-like differentiation. Subunits of both the catalytic F1 sector of the complex (ATP synthase-β) and of the peripheral stalk, responsible for the correct F1-FO assembly/coupling, (OSCP, b, F6) were detected by immunofluorescence, together with IF1. The expression of ATP synthase-β, ATP synthase-b and F6 were similar for parental and differentiated H9c2, while the levels of OSCP increased noticeably in differentiated cells, where the results of in situ Proximity Ligation Assay were consistent with OSCP interaction within ecto-F1FO complexes. An opposite trend was shown by IF1 whose ectopic expression appeared greater in the parental H9c2. Here, evidence for the IF1 interaction with ecto-F1FO complexes was provided. Functional analyses corroborate both sets of data. i) An F1FO ATP synthase contribution to the exATP production by differentiated cells suggests an augmented expression of holo-F1FO ATP synthase on plasma membrane, in line with the increase of OSCP expression and interaction considered as a requirement for favoring the F1-FO coupling. ii) The absence of exATP generation by the enzyme, and the finding that exATP hydrolysis was largely oligomycin-insensitive, are in line in parental cells with the deficit of OSCP and suggest the occurrence of sub-assemblies together evoking more regulation by IF1.

Down-regulation of oxidative phosphorylation in the liver by expression of the ATPase inhibitory factor 1 induces a tumor-promoter metabolic state.

The ATPase Inhibitory Factor 1 (IF1) is an inhibitor of the mitochondrial H+-ATP synthase that regulates the activity of both oxidative phosphorylation (OXPHOS) and cell death. Here, we have developed transgenic Tet-On and Tet-Off mice that express a mutant active form of hIF1 in the hepatocytes to restrain OXPHOS in the liver to investigate the relevance of mitochondrial activity in hepatocarcinogenesis. The expression of hIF1 promotes the inhibition of OXPHOS in both Tet-On and Tet-Off mouse models and induces a state of metabolic preconditioning guided by the activation of the stress kinases AMPK and p38 MAPK. Expression of the transgene significantly augmented proliferation and apoptotic resistance of carcinoma cells, which contributed to an enhanced diethylnitrosamine-induced liver carcinogenesis. Moreover, the expression of hIF1 also diminished acetaminophen-induced apoptosis, which is unrelated to differences in permeability transition pore opening. Mechanistically, cell survival in hIF1-preconditioned hepatocytes results from a nuclear factor-erythroid 2-related factor (Nrf2)-guided antioxidant response. The results emphasize in vivo that a metabolic phenotype with a restrained OXPHOS in the liver is prone to the development of cancer.

Silencing of ATPase Inhibitory Factor 1 Inhibits Cell Growth via Cell Cycle Arrest in Bladder Cancer

Objective: The role of the ATPase inhibitory factor 1 (IF1) is inhibit the hydrolase activity of F₁F_o-ATPase when oxidative phosphorylation is impaired. It has been demonstrated that IF1 is overexpressed in various carcinomas and mediates tumor cell activities, but the detailed mechanisms of IF1-mediated tumor progression and the link between IF1 and cell cycle progression remain unclear. Herein, we aimed to investigate the potential role of IF1 in cell cycle progression of human bladder cancer (BCa). Methods: The expression of IF1 was analyzed by immunohistochemistry in tumor tissues. Western blot was used to detect protein expression in the cells. Cell proliferation was determined by MTT and colony formation assays. The cell cycle was analyzed using flow cytometry. Results: We firstly showed IF1 was overexpressed in BCa. Silencing of IF1 by small interfering RNA led to a significant decrease in cell proliferation and migration in T24 and UM-UC-3 cells. Importantly, IF1 knockdown caused cell cycle arrest at G₀/G₁ stage and decreased the protein level of cyclin E/cyclin-dependent kinases (cdk) 2 and/or cyclin D/cdk4/cdk6. Conclusion: These results suggest the inhibitory effect of IF1 knockdown on BCa cell proliferation is via the suppression of cyclins and cdks related to G₁/S transition and then induction of G₀/G₁ arrest, and firstly indicate IF1 mediates the tumor cell cycle. We concluded that IF1 may be a novel therapeutic target for BCa.

Expression and promoter methylation of Wnt inhibitory factor-1 in the development of oral submucous fibrosis.

Oral squamous cell carcinoma (OSCC) is a type of head and neck malignancy with a high mortality rate. Oral submucous fibrosis (OSF) is the pre-cancerous lesion of OSCC, whose molecular mechanisms in OSCC tumorigenesis remain largely unclear. Activation of the Wnt/β-catenin signaling pathway plays an important role in oral mucous carcinogenesis, although rare mutations of Wnt signaling molecules are found in OSCC, suggesting an epigenetic mechanism mediating aberrant Wnt/β‑catenin signaling in OSCC. Wnt inhibitory factor-1 (WIF1) is an Wnt antagonist, and its downregulation and methylation have been reported in a number of malignancies. However, the expression and methylation of WIF1 in the development of OSF have yet to be reported. In the present study, we investigated the WIF1 expression level by immuno-histochemical staining and semi‑quantitative RT-PCR in normal oral, OSF and OSCC tissues, as well as the methylation status by methylation-specific PCR and bisulfite genomic sequencing. The results showed that WIF1 was readily expressed in normal oral mucous tissues, but decreased gradually in OSF early, moderately advanced and advanced tissues, and was less expressed in OSCC tissues. Moreover, WIF1 was able to translocate from the nuclear to cytoplasm in OSF and OSCC tissues. Furthermore, WIF1 was frequently methylated in OSCC cases with betel quid chewing habit, but not in normal oral mucous and different stages of OSF tissues, suggesting WIF1 methylation is tumor-specific in the development of OSF. Thus, the results demonstrated that WIF1 is frequently downregulated or silenced by promoter methylation in the carcinogenesis of OSF, which serves as a potential epigenetic biomarker for the early detection of OSCC.

PKA Phosphorylates the ATPase Inhibitory Factor 1 and Inactivates Its Capacity to Bind and Inhibit the Mitochondrial H(+)-ATP Synthase.

The mitochondrial H(+)-ATP synthase synthesizes most of cellular ATP requirements by oxidative phosphorylation (OXPHOS). The ATPase Inhibitory Factor 1 (IF1) is known to inhibit the hydrolase activity of the H(+)-ATP synthase insituations that compromise OXPHOS. Herein, we demonstrate that phosphorylation of S39 in IF1 by mitochondrial protein kinase A abolishes its capacity to bind the H(+)-ATP synthase. Only dephosphorylated IF1 binds and inhibits both the hydrolase and synthase activities of the enzyme. The phosphorylation status of IF1 regulates the flux of aerobic glycolysis and ATP production through OXPHOS in hypoxia and during the cell cycle. Dephosphorylated IF1 is present in human carcinomas. Remarkably, mouse heart contains a large fraction of dephosphorylated IF1 that becomes phosphorylated and inactivated upon invivo β-adrenergic stimulation. Overall, we demonstrate the essential function of the phosphorylation of IF1 in regulating energy metabolism and speculate that dephosho-IF1 might play a role in signaling mitohormesis.

The shrimp mitochondrial FoF1-ATPase inhibitory factor 1 (IF1)

The whiteleg shrimp species Litopenaeus vannamei is exposed to cyclic changes of the dissolved oxygen concentration of seawater and must neutralize the adverse effects of hypoxia by using ATP as energy source. In crustaceans, the mitochondrial FOF1-ATP synthase is pivotal to the homeostasis of ATP and function prevalently as a FOF1-ATPase. Hitherto, it is unknown whether these marine invertebrates are equipped with molecules able to control the FOF1-ATPase inhibiting the ATP consumption. In this study, we report two variants of the mitochondrial FOF1-ATPase Inhibitory Factor 1 (IF1) ubiquitously expressed across tissues of the Litopenaeus vannamei transcriptome: the IF1_Lv1 and the IF1_Lv2. The IF1_Lv1, with a full-length sequence of 550 bp, encodes a 104 aa long protein and its mRNA amounts are significantly affected by hypoxia and re-oxygenation. The IF1_Lv2, with a sequence of 654 bp, encodes instead for a protein of 85 aa. Both proteins share a 69 % homology and contain a conserved minimal inhibitory sequence (IATP domain) along with a G-rich region on their N-terminus typical of the invertebrate. In light of this characterization IF1 is here discussed as an adaptive mechanism evolved by this marine species to inhibit the FOF1-ATPase activity and avoid ATP dissipation to thrive in spite of the changes in oxygen tension.

ATPase inhibitory factor 1 is a potential prognostic marker for the migration and invasion of glioma.

Adenosine triphosphatase inhibitory factor 1 (IF1) has previously been considered to be a driving oncogene in human cancers. Several studies have revealed that IF1 overexpression is present in a variety of tumor types and promotes tumor growth and metastasis. The present study aimed to investigate the clinical significance of IF1 in glioma and the role of IF1 in cell migration and invasion. The mRNA and protein expression of IF1 in glioma tissues was found to be significantly increased compared with the expression in normal brain tissues (P<0.05). The presence of IF1 expression was significantly associated with an advanced clinical stage in glioma (P<0.05). Furthermore, the presence of IF1 expression was found to be associated with a reduced overall survival rate of glioma patients (P<0.05). Multivariate Cox regression analysis indicated that IF1 was an independent factor for predicting the overall survival rate of patients with glioma (P<0.05). IF1 knockdown also significantly reduced the number of migratory and invasive U251 and U87 cells (P<0.05). In addition, IF1 knockdown inhibited the expression of nuclear factor-κB (NF-κB) and Snai1, and led to increased E-cadherin expression and reduced vimentin expression. In conclusion, the presence of IF1 expression is associated with poor clinicopathological features in glioma. IF1 expression is an independent prognostic marker for predicting the overall survival rate of patients with glioma. Mechanistically, IF1 may promote glioma cell migration and invasion through the NF-κB/Snai1 axis.

Role of Wnt Inhibitory Factor-1 in Inhibition of Bisdemethoxycurcumin Mediated Epithelial-to-Mesenchymal Transition in Highly Metastatic Lung Cancer 95D Cells.

Background:Bisdemethoxycurcumin (BDMC) is an active component of curcumin and a chemotherapeutic agent, which has been suggested to inhibit tumor growth, invasion and metastasis in multiple cancers. But its contribution and mechanism of action in invasion and metastasis of non-small cell lung cancer (NSCLC) are not very clear. Therefore, we tried to study the effects of BDMC on regulation of epithelial-to-mesenchymal transition (EMT), which is closely linked to tumor cell invasion and metastasis.Methods:In this study, we first induced transforming growth factor-β1 (TGF-β1) mediated EMT in highly metastatic lung cancer 95D cells. Thereafter, we studied the effects of BDMC on invasion and migration of 95D cells. In addition, EMT markers expressions were also analyzed by western blot and immunofluorescence assays. The contribution of Wnt inhibitory factor-1 (WIF-1) in regulating BDMC effects on TGF-β1 induced EMT were further analyzed by its overexpression and small interfering RNA knockdown studies.Results:It was observed that BDMC inhibited the TGF-β1 induced EMT in 95D cells. Furthermore, it also inhibited the Wnt signaling pathway by upregulating WIF-1 protein expression. In addition, WIF-1 manipulation studies further revealed that WIF-1 is a central molecule mediating BDMC response towards TGF-β1 induced EMT by regulating cell invasion and migration.Conclusions:Our study concluded that BDMC effects on TGF-β1 induced EMT in NSCLC are mediated through WIF-1 and elucidated a novel mechanism of EMT regulation by BDMC.

Norcantharidin inhibits Wnt signal pathway via promoter demethylation of WIF-1 in human non-small cell lung cancer.

Wingless-type (Wnt) family of secreted glycoproteins is a group of signal molecules implicated in oncogenesis. Abnormal activation of Wnt signal pathway is associated with a variety of human cancers, including non-small cell lung cancer (NSCLC). Wnt antagonists, such as the secreted frizzled-related protein (SFRP) family, Wnt inhibitory factor-1 (WIF-1) and cerberus, inhibit Wnt signal pathway by directly binding to Wnt molecules. Norcantharidin (NCTD) is known to possess anticancer activity but less nephrotoxicity than cantharidin. In this study, we found that NCTD inhibited cell proliferation, induced apoptosis, arrested cell cycle and suppressed cell invasion/migration in vitro. Additionally, Wnt signal pathway transcription was also suppressed. NCTD treatment blocked cytoplasmic translocation of beta-catenin into the nucleus. Alterations of apoptosis-related proteins, such as Bax, cleaved caspase-3 (pro-apoptotic) and Bcl-2 (anti-apoptotic), had been detected. Furthermore, the expression levels of WIF-1 and SFRP1 were significantly increased in NCTD-treated groups compared with negative control (NC) groups. Abnormal methylation was observed in NC groups, while NCTD treatment promoted WIF-1 demethylation. The present study revealed that NCTD activated WIF-1 via promoter demethylation, inhibiting the canonical Wnt signal pathway in NSCLC, which may present a new therapeutic target in vivo.

Role of Wnt/β-catenin and RANKL/OPG in bone healing of diabetic Charcot arthropathy patients

Background and purpose — Charcot neuropathy is characterized by bone destruction in a foot leading to deformity, instability, and risk of amputation. Little is known about the pathogenic mechanisms. We hypothesized that the bone-regulating Wnt/β-catenin and RANKL/OPG pathways have a role in Charcot arthropathy.Patients and methods — 24 consecutive Charcot patients were treated by off-loading, and monitored for 2 years by repeated foot radiography, MRI, and circulating levels of sclerostin, dickkopf-1, Wnt inhibitory factor-1, Wnt ligand-1, OPG, and RANKL. 20 neuropathic diabetic controls and 20 healthy controls served as the reference.Results — Levels of sclerostin, Dkk-1 and Wnt-1, but not of Wif-1, were significantly lower in Charcot patients than in the diabetic controls at inclusion. Dkk-1 and Wnt-1 levels responded to off-loading by increasing. Sclerostin levels were significantly higher in the diabetic controls than in the other groups whereas Wif-1 levels were significantly higher in the healthy controls than in the other groups. OPG and RANKL levels were significantly higher in the Charcot patients than in the other groups at inclusion, but decreased to the levels in healthy controls at 2 years. OPG/RANKL ratio was balanced in all groups at inclusion, and it remained balanced in Charcot patients on repeated measurement throughout the study.Interpretation — High plasma RANKL and OPG levels at diagnosis of Charcot suggest that there is high bone remodeling activity before gradually normalizing after off-loading treatment. The consistently balanced OPG/RANKL ratio in Charcot patients suggests that there is low-key net bone building activity by this pathway following diagnosis and treatment. Inter-group differences at diagnosis and changes in Wnt signaling following off-loading treatment were sufficiently large to be reflected by systemic levels, indicating that this pathway has a role in bone remodeling and bone repair activity in Charcot patients. This is of particular clinical relevance considering the recent emergence of promising drugs that target this system.

Bisdemethoxycurcumin Induces Apoptosis in Activated Hepatic Stellate Cells via Cannabinoid Receptor 2

Activated Hepatic Stellate Cells (HSCs), major fibrogenic cells in the liver, undergo apoptosis when liver injuries cease, which may contribute to the resolution of fibrosis. Bisdemethoxycurcumin (BDMC) is a natural derivative of curcumin with anti-inflammatory and anti-cancer activities. The therapeutic potential of BDMC in hepatic fibrosis has not been studied thus far in the context of the apoptosis in activated HSCs. In the current study, we compared the activities of BDMC and curcumin in the HSC-T6 cell line and demonstrated that BDMC relatively induced a potent apoptosis. BDMC-induced apoptosis was mediated by a combinatory inhibition of cytoprotective proteins, such as Bcl2 and heme oxygenase-1 and increased generation of reactive oxygen species. Intriguingly, BDMC-induced apoptosis was reversed with co-treatment of sr144528, a cannabinoid receptor (CBR) 2 antagonist, which was confirmed with genetic downregulation of the receptor using siCBR2. Additionally, incubation with BDMC increased the formation of death-induced signaling complex in HSC-T6 cells. Treatment with BDMC significantly diminished total intracellular ATP levels and upregulated ATP inhibitory factor-1. Collectively, the results demonstrate that BDMC induces apoptosis in activated HSCs, but not in hepatocytes, by impairing cellular energetics and causing a downregulation of cytoprotective proteins, likely through a mechanism that involves CBR2.

RETRACTED: ATPase inhibitory factor 1 is a prognostic marker and contributes to proliferation and invasion of human gastric cancer cells

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the authors, who have informed the Editor-in-Chief that the regulatory effect of IF1 on apoptosis reported in the paper cannot be repeated. In subsequent experiments, two independent shRNAs designed to knockdown IF1 were unable to induce apoptosis in SGC-7901 or MGC-803 cells. The authors cannot explain why the results are not reproducible, but speculate that the original findings may reflect an off-target effect of IF1 shRNA knockdown. The authors no longer have confidence in the reliability of the results and would like to apologize for any inconvenience caused. The Editor-in-Chief agreed to retract the article.

An updated review of melasma pathogenesis

Melasma is a pigmentation disorder characterized by common clinical findings. However, the pathogenic mechanisms involved are heterogeneous in different individuals and ethnic groups. We have reviewed the pathophysiological mechanisms involved in melasma. Although the pathogenesis has not entirely been elucidated thus far, new findings are being identified by research groups. Epidemiologic studies may provide clues on the involvement of genetic factor(s), UV irradiation, or hormones in melasma. Some of the mechanisms of altered skin pigmentation, such as UV-induced pigmentation, may also be applicable to the pathogenesis of melasma. In fact, an increase in similar keratinocyte-derived melanogenic factors and their receptors occur in both UV-induced melanogenesis and melasma. Increased expression of female sex hormone receptors and the identification of the PDZ domain containing 1 (PDZK1) signaling mechanism provide insights to further our understanding of melasma. In addition to keratinocyte-derived paracrine factors, the role of paracrine factors from dermal fibroblasts, such as stem cell factor (SCF) and Wnt inhibitory factor-1 (WIF-1), is elucidated in melasma. Furthermore, the involvement of ion exchangers and microRNAs (miRNAs), such as H19 miRNA (miR-675), are also suggested.

Reciprocal activation between ATPase inhibitory factor 1 and NF-κB drives hepatocellular carcinoma angiogenesis and metastasis.

Hepatocellular carcinoma (HCC) is a highly vascularized tumor with frequent extrahepatic metastasis. Active angiogenesis and metastasis are responsible for rapid recurrence and poor survival of HCC. However, the mechanisms that contribute to tumor metastasis remain unclear. Here we evaluate the effects of ATPase inhibitory factor 1 (IF1), an inhibitor of the mitochondrial H(+)-adenosine triphosphate (ATP) synthase, on HCC angiogenesis and metastasis. We found that increased expression of IF1 in human HCC predicts poor survival and disease recurrence after surgery. Patients with HCC who have large tumors, with vascular invasion and metastasis, expressed high levels of IF1. Invasive tumors overexpressing IF1 were featured by active epithelial-mesenchymal transition (EMT) and increased angiogenesis, whereas silencing IF1 expression attenuated EMT and invasion of HCC cells. Mechanistically, IF1 promoted Snai1 and vascular endothelial growth factor (VEGF) expression by way of activating nuclear factor kappa B (NF-κB) signaling, which depended on the binding of tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1) to NF-κB-inducing kinase (NIK) and the disruption of NIK association with the TRAF2-cIAP2 complex. Suppression of the NF-κB pathway interfered with IF1-mediated EMT and invasion. Chromatin immunoprecipitation assay showed that NF-κB can bind to the Snai1 promoter and trigger its transcription. IF1 was directly transcribed by NF-κB, thus forming a positive feedback signaling loop. There was a significant correlation between IF1 expression and pp65 levels in a cohort of HCC biopsies, and the combination of these two parameters was a more powerful predictor of poor prognosis. IF1 promotes HCC angiogenesis and metastasis by up-regulation of Snai1 and VEGF transcription, thereby providing new insight into HCC progression and IF1 function. (Hepatology 2014;60:1659-1673).

Role of Colonic Expression of Wnt Inhibitory Factor-1 in Ulcerative Colitis

Introduction: Wnt proteins constitute a family of molecules that are considered to have paramount importance in embryonic development. Recent data suggests that Wnt pathways play a significant role in inflammation, carcinogenesis, and bone development. Wnt inhibitor factor-1 (WIF-1) is a secreted protein that binds to Wnt proteins and inhibits their activity. Our aim was to investigate the colonic expression of WIF-1 in ulcerative colitis (UC). Methods: A total of 24 UC patients were enrolled. Four colon biopsies were obtained during routine surveillance colonoscopy from each patient--2 biopsies from normal-looking areas of colon; and 2 were sampled from inflamed colon. The degree of inflammation in multiple sections of the colon biopsies was graded as I, II, and III by an experienced pathologist. By immunohistochemistry, WIF-1 staining in the glandular region and lamina propria of the colon was graded as I, II, and III based on the percentage of positively stained cells and intensity of staining. The association between inflammation and WIF-1 staining in the multiple colon biopsy sections of UC was studied using Pearson correlation. Results: Of the 24 patients, 70% were males. Mean age was 55.2 years (26-83). WIF-1 staining significantly increased in the lamina propria (p=0.01) and glandular region (p=0.005) with increasing inflammation in UC patients (Figures). On stratification of UC colon biopsy sections in those obtained from normal-looking areas and inflamed-looking areas during colonoscopy, WIF-1 staining was significantly increased in both lamina propria (p= 0.013) and glandular region (p=0.01) in inflamed-looking areas of colon. Conclusion: WIF-1 is increasingly expressed in the inflamed areas of colon in UC patients. WIF-1 may have a crucial role in the pathogenesis of UC; and a potential novel therapeutic strategy may be identified for UC by blocking the WIF-1 in Wnt pathway.Figure 1Figure 2

Inhibition of hepatocellular carcinoma by fulvestrant involves the estrogen receptor α and Wnt pathways in vitro and in patients.

The aim of the present study was to investigate the effect of anti-estrogen treatment (fulvestrant) on the biological activity of hepatocellular carcinoma (HCC), involving the estrogen receptor α (ERα) and Wnt pathways, and to evaluate whether ERα and Wnt inhibitory factor-1 (WIF1) could be biomarkers for anti-estrogen clinical therapy. H22 and HepG2 cells were treated with 0.04 to 625 nM fulvestrant and the WST-8 method was used to assess the inhibition rate after 72 h. Furthermore, prolactin (PRL) secretion by HepG2 cells was assessed at 24 h using an enzyme immunoassay. Quantitative polymerase chain reaction and western blot analysis were used to analyze the mRNA and protein expression levels of ERα, β-catenin and WIF1, respectively, in HepG2 cells. For clinical patient analysis, the tumor volume was analyzed by magnetic resonance imaging methods, and PRL in the blood was detected by an enzyme immunoassay. In HepG2 cells, the mRNA and protein expression levels of ERα were downregulated (P<0.01), while β-catenin expression remained unchanged and WIF1 expression was upregulated (P<0.01). Analysis of samples from clinical patients demonstrated that there was a positive correlation between PRL levels and tumor volume. In addition, as compared with non-cancerous tissues, the ERα mRNA levels in tumor tissue were upregulated (P<0.05), particularly in that of male patients, while WIF1 expression was significantly downregulated (P<0.01). In conclusion, fulvestrant inhibited the proliferation of HepG2 cells, involving the ERα and non-canonical Wnt pathways, and it may be a promising therapeutic for HCC.

WIF1 can effectively co-regulate pro-apoptotic activity through the combination with DKK1

Wnt inhibitory factor-1 (WIF1) is a conserved lipid-binding protein that interrupts Wnt ligands by interacting with their Frizzled receptors. Thus, they may suppress the activation of the Wnt/β-catenin triggered signaling cascade. Recently, we found that WIF1 can effectively co-regulate pro-apoptotic activity through the combination with Dickkopf-1 (DKK1). The tumor suppressor p53 protein expression was remarkably increased in the WIF1- and DKK1-transfected cells, along with p21. In contrast, expressions of the anti-apoptotic proteins, c-Myc and Bcl-2, were noticeably reduced. In addition, WIF1 and/or DKK1 significantly activated the transcription of p21 and p53, whereas c-Myc and Bcl-2 activities were remarkably reduced. The tumor suppressor WIF1 was also found to be capable of suppressing tumor growth through the inhibition of tumor angiogenesis in the cellular biological/physiological condition through the targeting of the PI3K/Akt/mTOR signaling pathway, while also being recognized as a Wnt antagonist factor in the Wnt cascade. Consistently, WIF1 conspicuously decreased the VEGF-induced phosphorylation of the PI3K/Akt signaling cascade components, including PDK1, mTOR, TSC-2, GSK-3β, and the p70S6K protein. Collectively, our results indicate for the first time that the tumor suppressor WIF1 is involved in angiogenesis and supplies a possible molecular target for the treatment of distinct malignant cancers, as well as several other associated diseases.

Androgenetic alopecia-associated cytokines

It is widely accepted that the occurrence of androgenetic alopecia (AGA) is closely related to androgen,androgen receptor and androgen-metabolizing enzymes.However,how they work in AGA remains unclear.Recent studies have shown that androgen exerts their roles by regulating various cytokines secreted by dermal papilla cells.At present,it is considered that insulin-like growth factor,vascular endothelial growth factor,transforming growth factor-β and Wnt inhibitory factor-1 are the most important and well-studied cytokines in the pathogenesis of AA,which may modulate hair growth via accelerating or deccelarating the growth of hair follicles. Key words: Alopecia; Androgen; Cytokines