Correction: Systemic Delivery of MicroRNA-101 Potently Inhibits Hepatocellular Carcinoma In Vivo by Repressing Multiple Targets

[This corrects the article DOI: 10.1371/journal.pgen.1004873.].

Ibrutinib inactivates BMX-STAT3 in glioma stem cells to impair malignant growth and radioresistance

Glioblastoma (GBM) is the most lethal primary brain tumor and is highly resistant to current treatments. GBM harbors glioma stem cells (GSCs) that not only initiate and maintain malignant growth but also promote therapeutic resistance including radioresistance. Thus, targeting GSCs is critical for overcoming the resistance to improve GBM treatment. Because the bone marrow and X-linked (BMX) nonreceptor tyrosine kinase is preferentially up-regulated in GSCs relative to nonstem tumor cells and the BMX-mediated activation of the signal transducer and activator of transcription 3 (STAT3) is required for maintaining GSC self-renewal and tumorigenic potential, pharmacological inhibition of BMX may suppress GBM growth and reduce therapeutic resistance. We demonstrate that BMX inhibition by ibrutinib potently disrupts GSCs, suppresses GBM malignant growth, and effectively combines with radiotherapy. Ibrutinib markedly disrupts the BMX-mediated STAT3 activation in GSCs but shows minimal effect on neural progenitor cells (NPCs) lacking BMX expression. Mechanistically, BMX bypasses the suppressor of cytokine signaling 3 (SOCS3)-mediated inhibition of Janus kinase 2 (JAK2), whereas NPCs dampen the JAK2-mediated STAT3 activation via the negative regulation by SOCS3, providing a molecular basis for targeting BMX by ibrutinib to specifically eliminate GSCs while preserving NPCs. Our preclinical data suggest that repurposing ibrutinib for targeting GSCs could effectively control GBM tumor growth both as monotherapy and as adjuvant with conventional therapies.

The antipsychotic agent flupentixol is a new PI3K inhibitor and potential anticancer drug for lung cancer

Background: The phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway is hyperactivated in lung cancer and regulates a broad range of cellular processes, including proliferation, survival, angiogenesis, and metastasis. Thus PI3K is considered a promising target for therapy. To date, PI3K inhibitors have not been approved for lung cancer. Recent studies showed that the antipsychotic agent flupentixol induced apoptosis of lung cancer cell, however the anti-tumor mechanism of flupentixol remains unclear.

Methods: (1) The idock software simulated the molecular docking between the PI3Kα protein and flupentixol. (2) Inhibition of PI3Kα by the flupentixol was examined by in vitro kinase assays. (3) The cytotoxicity of flupentixol on the NSCLC cell lines was tested by MTT assays. (4) We treated A549 and H661 cells with flupentixol and then measured the percentage of apoptotic cells by the Annexin V/PI analysis. (5) We investigated the effect of flupentixol on the expression of critical PI3K/AKT signaling pathway proteins, further analyzed on the cleavage of PARP and caspase-3 by Western blotting. (6) BALB/C nude mice were subcutaneously injected with A549 cells to evaluate the effect of flupentixol on the growth of lung carcinoma.

Results: Structural analysis of the predicted binding conformation suggested that flupentixol docks to the ATP binding pocket of PI3Kα. Kinase assays demonstrate that flupentixol indeed inhibited the PI3Kα kinase activity. Flupentixol exhibited cytotoxicity in lung cancer cell lines A549 and H661 in a dose- and time-dependent manner. Furthermore, flupentixol more strongly inhibited the phosphorylation of AKT (T308 and S473) and the expression of its downstream target gene Bcl-2 than two known PI3K inhibitors (BYL719 and BKM120). Flupentixol induced apoptosis as measured by PARP and caspase-3 cleavage. Finally, flupentixol significantly suppressed A549 xenograft growth in BALB/C nude mice.

Conclusions: Flupentixol could be docked to the PI3Kα protein and specifically inhibit the PI3K/AKT pathway and survival of lung cancer cells in vitro and in vivo. As an old drug, flupentixol is a new PI3K inhibitor that may be used for the treatment of lung cancers.

FMNL1 mediates nasopharyngeal carcinoma cell aggressiveness by epigenetically upregulating MTA1

It has been suggested that formin-like protein 1 (FMNL1) plays an important role in the pathogenic process of several hematopoietic malignancies. In this study, we performed a series of in vivo and in vitro assays to elucidate the biological functions of FMNL1 and underlying mechanisms in human nasopharyngeal carcinoma (NPC) pathogenesis. Herein, we report that high expression of FMNL1 in NPC is positively associated with an aggressive disease and/or poor patient survival. Ectopic overexpression of FMNL1 in NPC cells substantially promoted cell invadopodia formation, epithelial-mesenchymal transition (EMT) and invasiveness, whereas depletion of FMNL1 potently suppressed NPC cells invadopodia formation, EMT, and invasive/metastatic capacities. We further show that FMNL1 could enhance NPC cell aggressiveness by increasing a key downstream target, the metastasis-associated protein 1 (MTA1) gene. Importantly, ectopic overexpression of FMNL1 in NPC cells markedly improved the binding of HDAC1 with Profilin2 in the cytoplasm and suppressed the enrichment of HDAC1 on the promoter of MTA1 and thereby, leading to an increased MTA1 transcription and expression. Furthermore, in addition to the amplification of FMNL1 gene, decreased level of miR-16 in NPCs is another critical mechanism to upregulate FMNL1 expression. These results, collectively, provide first-line of evidences that high expression of FMNL1, resulted from decreased miR-16 and/or MTA1 amplification, has a potent oncogenic role to drive the development and aggressive process of NPC by upregulating MTA1, and FMNL1 might be employed as a new prognostic biomarker and therapeutic target for human NPC.

Novel HDAC5-interacting motifs of Tbx3 are essential for the suppression of E-cadherin expression and for the promotion of metastasis in hepatocellular carcinoma

Tbx3, a transcriptional repressor, is essential in the organogenesis of vertebrates, stem cell self-renewal and differentiation, and the carcinogenesis of multiple tumor types. However, the mechanism by which Tbx3 participates in the metastasis of hepatocellular carcinoma (HCC) remains largely unknown. In this study, we show that Tbx3 was dramatically upregulated in clinical HCC samples and that elevated expression of Tbx3 promoted cancer progression. To determine the underlying mechanism, systematic glycine scan mutagenesis and deletion assays were performed. We identified two critical motifs, ⁵⁸⁵LFSYPYT⁵⁹¹ and ⁶⁰⁴HRH⁶⁰⁶, that contribute to the repression of transcriptional activity. These motifs are also essential for Tbx3 to promote cell migration and metastasis both in vitro and in vivo via the suppression of E-cadherin expression. More importantly, Tbx3 directly interacts with HDAC5 via these motifs, and an HDAC inhibitor blocks Tbx3-mediated cell migration and the downregulation of E-cadherin in HCC. As Tbx3 is involved in the carcinogenesis of multiple types of human cancers, our findings suggest an important target for anti-cancer drug development.

A regulatory protein that represses gene activity interacts with an enzyme involved in chromosome remodeling to promote the migration and metastasis of liver cancer cells. Ming-Liang He from the City University of Hong Kong and colleagues found that levels of the T-box transcription factor Tbx3 were dramatically increased in tissue biopsies of liver tumors. They injected Tbx3-expressing human liver cancer cells into mice and saw a positive correlation between Tbx3 activity and cancer progression. By mutating and deleting parts of Tbx3, the researchers identified two particular stretches of the protein that bind histone deacetylase 5, an enzyme involved in ensuring DNA coils, are wound tight to suppress gene activity. This interaction is needed for Tbx3’s tumor-promoting function and may be targetable with drugs in order to prevent metastasis in patients with aggressive liver cancer.

Microvascular fractal dimension predicts prognosis and response to chemotherapy in glioblastoma: an automatic image analysis study

The microvascular profile has been included in the WHO glioma grading criteria. Nevertheless, microvessels in gliomas of the same WHO grade, e.g., WHO IV glioblastoma (GBM), exhibit heterogeneous and polymorphic morphology, whose possible clinical significance remains to be determined. In this study, we employed a fractal geometry-derived parameter, microvascular fractal dimension (mvFD), to quantify microvessel complexity and developed a home-made macro in Image J software to automatically determine mvFD from the microvessel-stained immunohistochemical images of GBM. We found that mvFD effectively quantified the morphological complexity of GBM microvasculature. Furthermore, high mvFD favored the survival of GBM patients as an independent prognostic indicator and predicted a better response to chemotherapy of GBM patients. When investigating the underlying relations between mvFD and tumor growth by deploying Ki67/mvFD as an index for microvasculature-normalized tumor proliferation, we discovered an inverse correlation between mvFD and Ki67/mvFD. Furthermore, mvFD inversely correlated with the expressions of a glycolytic marker, LDHA, which indicated poor prognosis of GBM patients. Conclusively, we developed an automatic approach for mvFD measurement, and demonstrated that mvFD could predict the prognosis and response to chemotherapy of GBM patients.

Discovery of rafoxanide as a dual CDK4/6 inhibitor for the treatment of skin cancer

Since cyclin‑dependent kinases 4/6 (CDK4/6) play pivotal roles in cell cycle regulation and are overexpressed in human skin cancers, CDK4/6 inhibitors are potentially effective drugs for skin cancer. In the present study, we present a mixed computational and experimental study attempting to repurpose approved small‑molecule drugs as dual CDK4/6 inhibitors for skin cancer treatment. We performed structure‑based virtual screening using the docking software idock, targeting an ensemble of CDK4/6 structures. We identified and selected nine compounds with significant predicted scores, and evaluated their cytotoxic effects in vitro in A375 and A431 human skin cancer cell lines. Rafoxanide was found to exhibit the highest cytotoxic effects (IC50: 1.09 µM for A375 and 1.31 µM for A431 cells). Consistent with the expected properties of CDK4/6 inhibitors, rafoxanide significantly increased the G1 phase population. Notably, we revealed that rafoxanide specifically decreased the expression of CDK4/6, cyclin D, retinoblastoma protein (Rb) and the phosphorylation of CDK4/6 and Rb. Furthermore, the anticancer effect of rafoxanide was demonstrated in vivo in BALB/C nude mice subcutaneously xenografted with human skin cancer A375 cells. Rafoxanide (40 mg/kg, i.p.) exhibited significant antitumor activity, comparable to that of oxaliplatin (5 mg/kg, i.p.). The combined administration of rafoxanide and oxaliplatin produced a synergistic therapeutic effect. To the best of our knowledge, the present study is the first to indicate that rafoxanide inhibits CDK4/6 activity and is a potential candidate drug for the treatment of human skin cancer.

Discovery of a novel Nrf2 inhibitor that induces apoptosis of human acute myeloid leukemia cells

Nuclear factor-erythroid 2-related factor 2 (Nrf2) is persistently activated in many human tumors including acute myeloid leukemia (AML). Therefore, inhibition of Nrf2 activity may be a promising target in leukemia therapy. Here, we used an antioxidant response element-luciferase reporter system to identify a novel pyrazolyl hydroxamic acid derivative, 1-(4-(tert-Butyl)benzyl)-3-(4-chlorophenyl)-N-hydroxy-1H pyrazole-5-carboxamide (4f), that inhibited Nrf2 activity. 4f had a profound growth-inhibitory effect on three AML cell lines, THP-1, HL-60 and U937, and a similar anti-growth effect in a chick embryo model. Moreover, flow cytometry of AML cells revealed increased apoptosis with 4f (10 μM) treatment for 48 h. The protein levels of cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase were enhanced in all three AML cell types. Furthermore, Nrf2 protein level was downregulated by 4f. Upregulation of Nrf2 by tert-butylhydroquinone (tBHQ) or Nrf2 overexpression could ameliorate 4f-induced growth inhibition and apoptosis. Treatment with 4f reduced both B-cell lymphoma-2 (Bcl-2) expression and Bcl-2/Bcl-2–associated X protein (Bax) ratio, which indicated that 4f induced apoptosis, at least in part, via mitochondrial-dependent signaling. Therefore, as an Nrf2 inhibitor, the pyrazolyl hydroxamic acid derivative 4f may be a promising agent in AML therapy.

Large Intergenic Non-coding RNA-RoR Inhibits Aerobic Glycolysis of Glioblastoma Cells via Akt Pathway

Reprogramming energy metabolism is a hallmark of malignant tumors, including glioblastoma (GBM). Aerobic glycolysis is often utilized by tumor cells to maintain survival and proliferation. However, the underlying mechanisms of aerobic glycolysis in GBM remain elusive. Herein, we demonstrated that large intergenic non-coding RNA-RoR (LincRNA-RoR) functioned as a critical suppressor to inhibit the aerobic glycolysis and viability of GBM cells. We found that LincRNA-RoR was markedly reduced in GBM tissues compared with adjacent non-tumor tissues from 10 cases of GBM patients. Consistently, LincRNA-RoR expression in GBM cells was significantly lower than that in normal glial cells. The aerobic glycolysis of GBM cells, as determined by the measurement of glucose uptake and lactate production, was impaired by LincRNA-RoR overexpression. Mechanistically, LincRNA-RoR inhibited the expression of Rictor, the key component of mTORC2 (mammalian target of rapamycin complex 2), to suppress the activity of Akt pathway and impair the expression of glycolytic effectors, including Glut1, HK2, PKM2 and LDHA. Finally, enforced expression of LincRNA-RoR reduced the proliferation of GBM cells in vitro, restrained tumor growth in vivo, and repressed the expression of glycolytic molecules in GBM xenografts. Collectively, our results underscore LincRNA-RoR as a new suppressor of GBM aerobic glycolysis with therapeutic potential.

Loss of MYC and E-box3 binding contributes to defective MYC-mediated transcriptional suppression of human MC-let-7a-1~let-7d in glioblastoma

Previously, we reported that MYC oncoprotein down-regulates the transcription of human MC-let-7a-1~let-7d microRNA cluster in hepatocarcinoma (HCC). Surprisingly, in silico analysis indicated that let-7 miRNA expression levels are not reduced in glioblastoma (GBM). Here we investigated the molecular basis of this differential expression. Using human GBM U87 and U251 cells, we first demonstrated that forced over-expression of MYC indeed could not down-regulate the expression of human MC-let-7a-1~let-7d microRNA cluster in GBM. Furthermore, analysis of MC-let-7a-1~let-7d promoter in GBM indicated that MYC failed to inhibit the promoter activity. Pearson's correlation and Linear Regression analysis using the expression data from GSE55092 (HCC) and GSE4290 (GBM) demonstrated a converse relationship of MC-let-7a-1~let-7d and MYC only in HCC but not in GBM. To understand the underlying mechanisms, we examined whether MYC could bind to the non-canonical E-box 3 located in the promoter of MC-let-7a-1~let-7d. Results from both chromatin immune-precipitation (ChIP) and super-shift assays clearly demonstrated the loss of MYC and E-box 3 binding in GBM, suggesting for the first time that a defective MYC and E-box3 binding in GBM is responsible for the differential MYC mediated transcriptional inhibition of MC-let-7a-1~let-7d and potentially other tumor suppressors. MYC and let-7 are key oncoprotein and tumor suppressor, respectively. Understanding the molecular mechanisms of their regulations will provide new insight and have important implications in the therapeutics of GBM as well as other cancers.

Econazole nitrate inhibits PI3K activity and promotes apoptosis in lung cancer cells

The phosphatidylinositol-3-kinase (PI3K)/AKT signaling pathway plays a pivotal role in many cellular processes, including the proliferation, survival and differentiation of lung cancer cells. Thus, PI3K is a promising therapeutic target for lung cancer treatment. In this study, we applied free and open-source protein-ligand docking software, screened 3167 FDA-approved small molecules, and identified putative PI3Kα inhibitors. Among them, econazole nitrate, an antifungal agent, exhibited the highest activity in decreasing cell viability in pathological types of NSCLC cell lines, including H661 (large cell lung cancer) and A549 (adenocarcinoma). Econazole decreased the protein levels of p-AKT and Bcl-2, but had no effect on the phosphorylation level of ERK. It inhibited cell growth and promote apoptosis in a dose-dependent manner. Furthermore, the combination of econazole and cisplatin exhibited additive and synergistic effects in the H661 and A549 lung cancer cell lines, respectively. Finally, we demonstrated that econazole significantly suppressed A549 tumor growth in nude mice. Our findings suggest that econazole is a new PI3K inhibitor and a potential drug that can be used in lung cancer treatment alone or in combination with cisplatin.

The putative tumor activator ARHGEF3 promotes nasopharyngeal carcinoma cell pathogenesis by inhibiting cellular apoptosis

Nasopharyngeal carcinoma (NPC) is one of the most prevalent forms of highly invasive malignancy in Southern China and Southeast Asia. The pathogenesis of NPC is a multistep process driven by the acquisition of numerous genetic abnormalities. We investigated the potential oncogenic role of the Rho-guanine nucleotide exchange factor 3 gene, ARHGEF3, in NPC pathogenesis. Expression levels of ARHGEF3 were frequently up-regulated in NPC cell lines and tissues. In a large cohort of clinical NPC tissues high expression of ARHGEF3 was positively associated with an increased T status, distant metastasis, and a more advanced clinical stage (P < 0.05). Survival analysis revealed that ARHGEF3 expression was a significant and independent prognosis factor for NPC patients. In NPC cell lines, knockdown of ARHGEF3 was sufficient to inhibit cell growth, motility, and invasion in vitro, whereas ectopic overexpression of ARHGEF3 substantially enhanced NPC cells tumorigenesis and metastasis in vivo. Depletion of ARHGEF3 in NPC cells dramatically promoted caspase-3 induced apoptosis and an anti-apoptosis factor, BIRC8, was identified as a critical downstream target of the ARHGEF3. Our findings suggest that increased expression of ARHGEF3 plays a critical oncogenic role in NPC pathogenesis by preventing cell apoptosis through the up-regulation of BIRC8, and ARHGEF3 might be employed as a novel prognostic marker and effective therapeutic target for human NPC.

Stanniocalcin-1 augments stem-like traits of glioblastoma cells through binding and activating NOTCH1

Glioblastoma (GBM) is a fatal tumor and comprises heterogeneous cells in which a subpopulation with stem cell-like properties is included. Cancer cells with stem cell-like properties account for tumor initiation, drug resistance and recurrence. To identify and characterize specific factors in regulating stem-like traits is critical for GBM therapeutic. Here, we showed that Stanniocalcin-1 (STC1), a secretory glycoprotein, functions as a novel stimulator for stem-like traits of GBM cells. We found STC1 was prominently expressed in glioma spheres which are mainly comprised of glioma stem-like cells. The stem-like traits of GBM cells, as determined by the expression of stem cell markers, tumor-sphere formation efficiency and colony-forming ability, were enhanced by STC1 overexpression and inhibited by STC1 knockdown. Furthermore, introduction of STC1 enhanced tumorigenesis in vivo while knockdown of STC1 showed reverse effect. Finally, we demonstrated that STC1 interacted with the extracellular domain of NOTCH1 to activate NOTCH1-SOX2 signaling pathway, by which STC1 augmented the stem-like traits of GBM cells. Taken together, our data herein indicate that STC1 is a novel non-canonical NOTCH ligand and acts as a crucial regulator of stemness in GBM.

Ubiquitin specific peptidase 5 mediates Histidine-rich protein Hpn induced cell apoptosis in hepatocellular carcinoma through P14-P53 signaling

Hpn is a small histidine-rich cytoplasmic protein from Helicobacter pylori and has been recognized as a high-risk factor for several cancers including gastric cancer, colorectal cancer, and MALT lymphoma. However, the relationship between Hpn and cancers remains elusive. In this study, we discovered that Hpn protein effectively suppressed cell growth and induced apoptosis in hepatocellular carcinoma (HCC). A two-dimensional gel electrophoresis and mass spectrometry-based comparative proteomics was performed to find the molecular targets of Hpn in HCC cells. It was identified that twelve proteins were differentially expressed, with USP5 being one of the most significantly downregulated protein. The P14^ARF -P53 signaling was activated by USP5 knockdown in HCC cells. Furthermore, USP5 overexpression significantly rescued the suppressive effect of Hpn on the viability of HCC cells. In conclusion, our study suggests that Hpn plays apoptosis-inducing roles through suppressing USP5 expression and activating the P14^ARF -P53 signaling. Therefore, Hpn may be a potential candidate for developing novel anti-HCC drugs.

Plasma miR-124 Is a Promising Candidate Biomarker for Human Intracerebral Hemorrhage Stroke

Stroke causes death or long-term disabilities and threatens the general health of the population worldwide. Recent studies have suggested that miRNAs are dysregulated and can be used as biomarkers for diagnosis and prognosis in stroke. The intracerebral hemorrhage (ICH) accounts for 15% of all the stroke cases. However, at present, little is known regarding the functions and clinical implications of miRNAs in ICH. In the present study, we established the collagenase-induced rat ICH model to mimic human ICH syndrome. We profiled the expression of 728 rat miRNAs at different time points in rat brain tissues and plasma post-ICH and identified a set human brain-enriched miRNAs that had changed expression level in the plasma of rat ICH. Among them, the expression levels of miR-124 displayed significantly synchronous alterations in rat plasma and brain tissue during ICH progression. They were significantly elevated at the acute injury phase (day 1 and 2), gradually decreased during the delayed recovery phase (day 7, 14 and 30), and finally restored to normal levels at late recovery phase (day 60). We further determined the plasma expression profile of miR-124 from human ICH patients. Similar to the pattern observed in rat ICH model, our results indicated that immediately after patients reached the hospital, the average plasma concentrations of miR-124 increased more than 100-fold in 24 h, then decreased gradually on day 2, 7, 14 and to near normal level on day 30. Taken together, these results strongly suggested that plasma concentration of miR-124 is a promising candidate biomarker for the early detection and predictive prognosis of human ICH.

High-mobility group box 1 released by autophagic cancer-associated fibroblasts maintains the stemness of luminal breast cancer cells

Cancer stem cells/cancer-initiating cells (CICs) and their microenvironmental niche play a vital role in malignant tumour recurrence and metastasis. Cancer-associated fibroblasts (CAFs) are major components of the niche of breast cancer-initiating cells (BCICs), and their interactions may profoundly affect breast cancer progression. Autophagy has been considered to be a critical process for CIC maintenance, but whether it is involved in the cross-talk between CAFs and CICs to affect tumourigenesis and pathological significance has not been determined. In this study, we found that the presence of CAFs containing high levels of microtubule-associated protein 1 light chain 3 (LC3II), a marker of autophagosomes, was associated with more aggressive luminal human breast cancer. CAFs in human luminal breast cancer tissues with high autophagy activity enriched BCICs with increased tumourigenicity. Mechanistically, autophagic CAFs released high-mobility group box 1 (HMGB1), which activated its receptor, Toll-like receptor (TLR) 4, expressed by luminal breast cancer cells, to enhance their stemness and tumourigenicity. Furthermore, immunohistochemistry of 180 luminal breast cancers revealed that high LC3II/TLR4 levels predicted an increased relapse rate and a poorer prognosis. Our findings demonstrate that autophagic CAFs play a critical role in promoting the progression of luminal breast cancer through an HMGB1-TLR4 axis, and that both autophagy in CAFs and TLR4 on breast cancer cells constitute potential therapeutic targets. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Nucleophosmin Interacts with PIN2/TERF1-interacting Telomerase Inhibitor 1 (PinX1) and Attenuates the PinX1 Inhibition on Telomerase Activity

Telomerase activation and telomere maintenance are critical for cellular immortalization and transformation. PIN2/TERF1-interacting telomerase inhibitor 1 (PinX1) is a telomerase regulator and the aberrant expression of PinX1 causes telomere shortening. Identifying PinX1-interacting proteins is important for understanding telomere maintenance. We found that PinX1 directly interacts with nucleophosmin (NPM), a protein that has been shown to positively correlate with telomerase activity. We further showed that PinX1 acts as a linker in the association between NPM and hTERT, the catalytic subunit of telomerase. Additionally, the recruitment of NPM by PinX1 to the telomerase complex could partially attenuate the PinX1-mediated inhibition on telomerase activity. Taken together, our data reveal a novel mechanism that regulates telomerase activation through the interaction between NPM, PinX1 and the telomerase complex.

Oblongifolin M, an active compound isolated from a Chinese medical herb Garcinia oblongifolia, potently inhibits enterovirus 71 reproduction through downregulation of ERp57

There is no effective drug to treat EV71 infection yet. Traditional Chinese herbs are great resources for novel antiviral compounds. Here we showed that Oblongifolin M (OM), an active compound isolated from Garcinia oblongifolia, potently inhibited EV71 infection in a dose dependent manner. To identify its potential effectors in the host cells, we successfully identified 18 proteins from 52 differentially expressed spots by comparative proteomics studies. Further studies showed that knockdown of ERp57 inhibited viral replication through downregulating viral IRES (internal ribosome entry site) activities, whereas ectopic expression of ERp57 increased IRES activity and partly rescued the inhibitory effects of OM on viral replication. We demonstrated that OM is an effective antiviral agent; and that ERp57 is one of its cellular effectors against EV71 infection.

MiR-34a modulates ErbB2 in breast cancer

Breast cancer is the second highest cause of carcinoma-related death caused by distant metastasis in women. Estrogen receptor (ER), human epidermal growth factor receptor 2, (HER2) and progesterone receptor (PR) are three classified makers of breast cancer, which are defined as ER+, HER2+, and the most serious ER-PR-HER2- (triple-negative). It is well known that ErbB2 (V-Erb-B2 avian erythroblastic leukemia viral oncogene homolog 2) plays an important part in breast cancer. However, the molecular mechanisms underlying ErbB2 action needs to be well studied. In this report, we discovered that the decreased expression levels of miR-34a were inversely correlated with the increased ErbB2 levels in breast cancer. A luciferase reporter assay was done to understand the potential correlation between ErbB2 and miR-34a. Over-expression of miR-34a reduces ErbB2 expression and suppresses breast cancer cell invasion and growth in vitro. What's more, reduced expression of ErbB2 inhibits breast Cancer cell proliferation and re-expression of ErbB2 reversed miR-34a-dependent tumor suppression. Meanwhile, miR-34a levels were correlated inversely with breast cancer malignancy. Our study demonstrates that miR-34a, like ErbB2, might be a diagnostic target in breast cancer.

Comparison of Iron-Binding Ability Between Thr70-NapA and Ser70-NapA of Helicobacter pylori

BACKGROUND

The neutrophil-activating protein (NapA) of Helicobacter pylori (H. pylori), with DNA-binding and iron seizing properties, is a fundamental virulence factor involved in H. pylori-related diseases. Compared with Ser70-NapA strain, Thr70-NapA strain is more intimately correlated with iron-deficiency anemia.

METHODS

To investigate whether two types of proteins differ in iron-binding ability, mutated Thr70-NapA and Ser70-NapA strains were established. Isothermal titration calorimetry (ITC) method was conducted to measure the binding between the NapA protein and Fe(2+) . The structural changes of NapA protein were also tested during iron interaction by fast protein liquid chromatography (FPLC) and circular dichroism (CD) methods. DNA-binding assay was performed for evaluate the affinity of both mutated and wild types of NapA with DNA.

RESULTS

Mutated Thr70-NapA had higher iron-binding ability than wild Ser70-NapA. The structural stability of Thr70-NapA was disrupted and became more active along with the rising concentration of Fe(2+) , whereas no similar association was observed between Ser70-NapA and Fe(2+) level. When the iron/protein molar ratio ranged from 10 to 20, both Ser70-NapA and Thr70-NapA displayed weaker DNA-binding ability.

CONCLUSIONS

Thr70-NapA has much stronger ability to sequester ferrous ion compared with Ser70-NapA in H. pylori. In addition, the DNA-binding property of NapA is dependent upon the Fe(2+) concentration.

Lower MGMT expression predicts better prognosis in proneural-like glioblastoma

OBJECTIVE

To investigate the expression and significance of MGMT in different molecular subtypes of glioblastoma (GBM), and to evaluate the important role of MGMT and P53 in predicting the prognosis of GBM patients.

METHODS

MGMT expression was detected by immunohistochemical staining in 72 cases of GBM which had been classified as three molecular subtypes. The relationship between MGMT and P53, an important molecule for identification of proneural-like GBM, were further analyzed. The association between MGMT and patients' prognosis was analyzed with Kaplan-Meier method, which was further validated by the data from 513 cases of GBM in the TCGA database.

RESULTS

MGMT expression was lower in proneural-like subtype in 72 GBM cases (p < 0.001), and was negatively correlated with P53 (r=-0. 6203, p < 0.001). This results was also verified by a validation group of 87 GBM cases (r=-0. 2950, p < 0.001). Interestingly, low expression of MGMT predicted a better outcome in proneurallike subtype or P53 high-expression group (p < 0.05) but not in non-proneural-like subtype and P53 low-expression group. All of these results were verified by the data from TCGA database.

CONCLUSION

MGMT can be used as an independent prognostic factor and plays an important role in molecular typing and diagnosis of GBM by combination with proneural-like subtype marker P53.

Hotair mediates hepatocarcinogenesis through suppressing miRNA-218 expression and activating P14 and P16 signaling

BACKGROUND & AIMS

Long non-coding RNA Hotair has been considered as a pro-oncogene in multiple cancers. Although there is emerging evidence that reveals its biological function and the association with clinical prognosis, the precise mechanism remains largely elusive.

METHODS

We investigated the function and mechanism of Hotair in hepatocellular carcinoma (HCC) cell models and a xenograft mouse model. The regulatory network between miR-218 and Hotair was elucidated by RNA immunoprecipitation and luciferase reporter assays. Finally, the correlation between Hotair, miR-218 and the target gene Bmi-1 were evaluated in 52 paired HCC specimens.

RESULTS

In this study, we reported that Hotair negatively regulated miR-218 expression in HCC, which might be mediated through an EZH2-targeting-miR-218-2 promoter regulatory axis. Further investigation revealed that Hotair knockdown dramatically inhibited cell viability and induced G1-phase arrest in vitro and suppressed tumorigenicity in vivo by promoting miR-218 expression. Oncogene Bmi-1 was shown to be a functional target of miR-218, and the main downstream targets signaling, P16(Ink4a) and P14(ARF), were activated in Hotair-suppressed tumorigenesis. In primary human HCC specimens, Hotair and Bmi-1 were concordantly upregulated whereas miR-218 was downregulated in these tissues. Furthermore, Hotair was inversely associated with miR-218 expression and positively correlated with Bmi-1 expression in these clinical tissues.

CONCLUSION

Hotair silence activates P16(Ink4a) and P14(ARF) signaling by enhancing miR-218 expression and suppressing Bmi-1 expression, resulting in the suppression of tumorigenesis in HCC.

Macrophage migration inhibitory factor as a potential prognostic factor in gastric cancer

AIM: To investigate macrophage migration inhibitory factor (MIF) expression and its clinical relevance in gastric cancer, and effects of MIF knockdown on proliferation of gastric cancer cells.

METHODS: Tissue microarray containing 117 samples of gastric cancer and adjacent non-cancer normal tissues was studied for MIF expression by immunohistochemistry (IHC) semiquantitatively, and the association of MIF expression with clinical parameters was analyzed. MIF expression in gastric cancer cell lines was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Two pairs of siRNA targeting the MIF gene (MIF si-1 and MIF si-2) and one pair of scrambled siRNA as a negative control (NC) were designed and chemically synthesized. All siRNAs were transiently transfected in AGS cells with Oligofectamine^TM to knock down the MIF expression, with the NC group and mock group (Oligofectamine^TM alone) as controls. At 24, 48, and 72 h after transfection, MIF mRNA was analyzed by RT-PCR, and MIF and proliferating cell nuclear antigen (PCNA) proteins were detected by Western blot. The proliferative rate of AGS cells was assessed by methylthiazolyl tetrazolium (MTT) assay and colony forming assay.

RESULTS: The tissue microarray was informative for IHC staining, in which the MIF expression in gastric cancer tissues was higher than that in adjacent non-cancer normal tissues (P < 0.001), and high level of MIF was related to poor tumor differentiation, advanced T stage, advanced tumor stage, lymph node metastasis, and poor patient survival (P < 0.05 for all). After siRNA transfection, MIF mRNA was measured by real-time PCR, and MIF protein and PCNA were assessed by Western blot analysis. We found that compared to the NC group and mock group, MIF expression was knocked down successfully in gastric cancer cells, and PCNA expression was downregulated with MIF knockdown as well. The cell counts and the doubling times were assayed by MTT 4 d after transfection, and colonies formed were assayed by colony forming assay 10 d after transfection; all these showed significant changes in gastric cancer cells transfected with specific siRNA compared with the control siRNA and mock groups (P < 0.001 for all).

CONCLUSION: MIF could be of prognostic value in gastric cancer and might be a potential target for small-molecule therapy.

Adapalene inhibits the activity of cyclin-dependent kinase 2 in colorectal carcinoma

Cyclin-dependent kinase 2 (CDK2) has been reported to be overexpressed in human colorectal cancer; it is responsible for the G1-to-S-phase transition in the cell cycle and its deregulation is a hallmark of cancer. The present study was the first to use idock, a free and open-source protein-ligand docking software developed by our group, to identify potential CDK2 inhibitors from 4,311 US Food and Drug Administration-approved small molecular drugs with a re-purposing strategy. Among the top compounds identified by idock score, nine were selected for further study. Among them, adapalene (ADA; CD271,6-[3-(1-adamantyl)-4-methoxyphenyl]-2-naphtoic acid) exhibited the highest anti-proliferative effects in LoVo and DLD1 human colon cancer cell lines. Consistent with the expected properties of CDK2 inhibitors, the present study demonstrated that ADA significantly increased the G1-phase population and decreased the expression of CDK2, cyclin E and retinoblastoma protein (Rb), as well as the phosphorylation of CDK2 (on Thr-160) and Rb (on Ser-795). Furthermore, the anti-cancer effects of ADA were examined in vivo on xenograft tumors derived from DLD1 human colorectal cancer cells subcutaneously inoculated in BALB/C nude mice. ADA (20 mg/kg orally) exhibited marked anti-tumor activity, comparable to that of oxaliplatin (40 mg/kg), and dose-dependently inhibited tumor growth (P<0.05), while combined administration of ADA and oxaliplatin produced the highest therapeutic effect. To the best of our knowledge, the present study was the first to indicate that ADA inhibits CDK2 and is a potential candidate drug for the treatment of human colorectal cancer.

Ornithine-δ-Aminotransferase Inhibits Neurogenesis During Xenopus Embryonic Development

PURPOSE

In humans, deficiency of ornithine-δ-aminotransferase (OAT) results in progressive degeneration of the neural retina (gyrate atrophy) with blindness in the fourth decade. In this study, we used the Xenopus embryonic developmental model to study functions of the OAT gene on embryonic development.

METHODS

We cloned and sequenced full-length OAT cDNA from Xenopus oocytes (X-OAT) and determined X-OAT expression in various developmental stages of Xenopus embryos and in a variety of adult tissues. The phenotype, gene expression of neural developmental markers, and enzymatic activity were detected by gain-of-function and loss-of-function manipulations.

RESULTS

We showed that X-OAT is essential for Xenopus embryonic development, and overexpression of X-OAT produces a ventralized phenotype characterized by a small head, lack of axial structure, and defective expression of neural developmental markers. Using X-OAT mutants based on mutations identified in humans, we found that substitution of both Arg 180 and Leu 402 abrogated both X-OAT enzymatic activity and ability to modulate the developmental phenotype. Neurogenesis is inhibited by X-OAT during Xenopus embryonic development.

CONCLUSIONS

Neurogenesis is inhibited by X-OAT during Xenopus embryonic development, but it is essential for Xenopus embryonic development. The Arg 180 and Leu 402 are crucial for these effects of the OAT molecule in development.

MiR-218-targeting-Bmi-1 mediates the suppressive effect of 1,6,7-trihydroxyxanthone on liver cancer cells

Traditional Chinese medicine is recently emerged as anti-cancer therapy or adjuvant with reduced side-effects and improved quality of life. In the present study, an active ingredient, 1,6,7-trihydroxyxanthone (THA), derived from Goodyera oblongifolia was found to strongly suppress cell growth and induce apoptosis in liver cancer cells. MicroRNAs are a group of small non-coding RNAs that regulate gene expression at post-transcriptional levels. Our results demonstrated that miR-218 was up-regulated and oncogene Bmi-1 was down-regulated by THA treatment. Further investigation showed that THA-induced-miR-218 up-regulation could lead to activation of tumor suppressor P16(Ink4a) and P14(ARF), the main down-stream targets of Bmi-1. In conclusion, THA might be a potential anti-cancer drug candidate, at least in part, through the activation of miR-218 and suppression of Bmi-1 expression.

Identification of a novel MTOR activator and discovery of a competing endogenous RNA regulating autophagy in vascular endothelial cells

MTOR, a central regulator of autophagy, is involved in cancer and cardiovascular and neurological diseases. Modulating the MTOR signaling balance could be of great significance for numerous diseases. No chemical activators of MTOR have been found, and the urgent challenge is to find novel MTOR downstream components. In previous studies, we found a chemical small molecule, 3-benzyl-5-((2-nitrophenoxy) methyl)-dihydrofuran-2(3H)-one (3BDO), that inhibited autophagy in human umbilical vein endothelial cells (HUVECs) and neuronal cells. Here, we found that 3BDO activated MTOR by targeting FKBP1A (FK506-binding protein 1A, 12 kDa). We next used 3BDO to detect novel factors downstream of the MTOR signaling pathway. Activation of MTOR by 3BDO increased the phosphorylation of TIA1 (TIA1 cytotoxic granule-associated RNA binding protein/T-cell-restricted intracellular antigen-1). Finally, we used gene microarray, RNA interference, RNA-ChIP assay, bioinformatics, luciferase reporter assay, and other assays and found that 3BDO greatly decreased the level of a long noncoding RNA (lncRNA) derived from the 3' untranslated region (3'UTR) of TGFB2, known as FLJ11812. TIA1 was responsible for processing FLJ11812. Further experiments results showed that FLJ11812 could bind with MIR4459 targeting ATG13 (autophagy-related 13), and ATG13 protein level was decreased along with 3BDO-decreased FLJ11812 level. Here, we provide a new activator of MTOR, and our findings highlight the role of the lncRNA in autophagy.

Novel recurrently mutated genes and a prognostic mutation signature in colorectal cancer

BACKGROUND

Characterisation of colorectal cancer (CRC) genomes by next-generation sequencing has led to the discovery of novel recurrently mutated genes. Nevertheless, genomic data has not yet been used for CRC prognostication.

OBJECTIVE

To identify recurrent somatic mutations with prognostic significance in patients with CRC.

METHOD

Exome sequencing was performed to identify somatic mutations in tumour tissues of 22 patients with CRC, followed by validation of 187 recurrent and pathway-related genes using targeted capture sequencing in additional 160 cases.

RESULTS

Seven significantly mutated genes, including four reported (APC, TP53, KRAS and SMAD4) and three novel recurrently mutated genes (CDH10, FAT4 and DOCK2), exhibited high mutation prevalence (6-14% for novel cancer genes) and higher-than-expected number of non-silent mutations in our CRC cohort. For prognostication, a five-gene-signature (CDH10, COL6A3, SMAD4, TMEM132D, VCAN) was devised, in which mutation(s) in one or more of these genes was significantly associated with better overall survival independent of tumor-node-metastasis (TNM) staging. The median survival time was 80.4 months in the mutant group versus 42.4 months in the wild type group (p=0.0051). The prognostic significance of this signature was successfully verified using the data set from the Cancer Genome Atlas study.

CONCLUSIONS

The application of next-generation sequencing has led to the identification of three novel significantly mutated genes in CRC and a mutation signature that predicts survival outcomes for stratifying patients with CRC independent of TNM staging.

Aldehyde dehydrogenase 1A1 circumscribes high invasive glioma cells and predicts poor prognosis

Glioma is the most aggressive brain tumor with high invasiveness and poor prognosis. More reliable, sensitive and practical biomarkers to reveal glioma high invasiveness remain to be explored for the guidance of therapy. We herein evaluated the diagnostic and prognostic value of aldehyde dehydrogenase 1A1 (ALDH1A1) in the glioma specimens from 237 patients, and found that ADLH1A1 was frequently overexpressed in the high-grade glioma (WHO grade III-IV) as compared to the low-grade glioma (WHO grade I-II) patients. The tumor cells with ALDH1A1 expression were more abundant in the region between tumor and the borderline of adjacent tissue as compared to the central part of the tumor. ALDH1A1 overexpression was associated with poor differentiation and dismal prognosis. Notably, the overall and disease-free survivals of the patients who had ALDH1A1(+) tumor cells sparsely located in the adjacent tissue were much worse. Furthermore, ALDH1A1 expression was correlated with the "classical-like" (CL) subtype as we examined GBM specimens from 72 patients. Multivariate Cox regression analysis revealed that ALDH1A1 was an independent marker for glioma patients' outcome. Mechanistically, both in vitro and in vivo studies revealed that ALDH1A1(+) cells isolated from either a glioblastoma cell line U251 or primary glioblastoma cells displayed significant invasiveness, clonogenicity, and proliferation as compared to ALDH1A1(-) cells, due to increased levels of mRNA and protein for matrix metalloproteinase 2, 7 and 9 (MMP2, MMP7 and MMP9). These results indicate that ALDH1A1(+) cells contribute to the progression of glioma including invasion, proliferation and poor prognosis, and suggest that targeting ALDH1A1 may have important implications for the treatment of highly invasive glioma.

Systemic delivery of microRNA-101 potently inhibits hepatocellular carcinoma in vivo by repressing multiple targets

Targeted therapy based on adjustment of microRNA (miRNA)s activity takes great promise due to the ability of these small RNAs to modulate cellular behavior. However, the efficacy of miR-101 replacement therapy to hepatocellular carcinoma (HCC) remains unclear. In the current study, we first observed that plasma levels of miR-101 were significantly lower in distant metastatic HCC patients than in HCCs without distant metastasis, and down-regulation of plasma miR-101 predicted a worse disease-free survival (DFS, P<0.05). In an animal model of HCC, we demonstrated that systemic delivery of lentivirus-mediated miR-101 abrogated HCC growth in the liver, intrahepatic metastasis and distant metastasis to the lung and to the mediastinum, resulting in a dramatic suppression of HCC development and metastasis in mice without toxicity and extending life expectancy. Furthermore, enforced overexpression of miR-101 in HCC cells not only decreased EZH2, COX2 and STMN1, but also directly down-regulated a novel target ROCK2, inhibited Rho/Rac GTPase activation, and blocked HCC cells epithelial-mesenchymal transition (EMT) and angiogenesis, inducing a strong abrogation of HCC tumorigenesis and aggressiveness both in vitro and in vivo. These results provide proof-of-concept support for systemic delivery of lentivirus-mediated miR-101 as a powerful anti-HCC therapeutic modality by repressing multiple molecular targets.

Overexpression of NKX6.1 is closely associated with progressive features and predicts unfavorable prognosis in human primary hepatocellular carcinoma

The homeobox gene NKX6.1 was recently identified in cervical tumors. This study was designed to explore the clinical and prognostic significance of NKX6.1 further in patients with primary hepatocellular carcinoma (HCC). The expression levels of NKX6.1 were examined using real-time PCR, Western blotting, and immunohistochemistry in HCC cell lines and HCC tissues. The invasion capability of cell lines following silencing or overexpression of NKX6.1 was investigated by Transwell assay. Cells proliferation was tested by MTT assays. Epithelial-mesenchymal transition (EMT) marker expression levels were detected in relation to NKX6.1 expression. Correlation between NKX6.1 immunohistochemical staining, clinicopathologic parameters, and follow-up data of HCC patients was analyzed statistically. NKX6.1 expression was higher in HCC tissues compared to the adjacent noncancerous tissue. NKX6.1 overexpression was significantly correlated with tumor size, tumor differentiation, clinical stage, metastasis, and relapse. Kaplan-Meier analysis revealed that NKX6.1 overexpression was related to unfavorable 5-year disease-free survival and overall survival. Importantly, multivariate analysis indicated that NKX6.1 overexpression was an independent unfavorable marker for overall survival. Moreover, a significant relationship was observed between NKX6.1 and EMT marker expression levels, and NKX6.1 knockdown inhibited cell invasion, and overexpression of NKX6.1 promotes cell proliferation in vitro. NKX6.1 is upregulated in HCC and is a reliable prognostic marker for patients with HCC.

MiR-29c mediates epithelial-to-mesenchymal transition in human colorectal carcinoma metastasis via PTP4A and GNA13 regulation of β-catenin signaling

BACKGROUND

Distant metastasis is the major cause of cancer-related death, and epithelial-to-mesenchymal transition (EMT) has a critical role in this process. Accumulating evidence indicates that EMT can be regulated by microRNAs (miRNAs). miR-29c has been implicated as a tumor suppressor in several human cancers. However, the role of miR-29c in the progression of colorectal cancer (CRC) metastasis remains largely unknown.

PATIENTS AND METHODS

The expression of miR-29c was examined by qRT-PCR in a cohort of primary CRC (PC) and distant liver metastasis (LM) tissues. A series of in vivo and in vitro assays were carried out in order to elucidate the functions of miR-29c and the molecular mechanisms underlying the pathogenesis of metastatic CRC.

RESULTS

miR-29c was markedly downregulated in PCs with distant metastasis and determined to be an independent predictor of shortened patient survival. But LM tissues showed higher levels of miR-29c than that in PC tissues. In CRC cells, miR-29c dramatically suppressed cell migration and invasion abilities in vitro and cancer metastasis in vivo. In addition, miR-29c inhibited EMT and negatively regulated Wnt/β-catenin signaling pathway. Guanine nucleotide binding protein alpha13 (GNA13) and protein tyrosine phosphatase type IVA (PTP4A) were identified as direct targets of miR-29c, which acted through ERK/GSK3β/β-catenin and AKT/GSK3β/β-catenin pathways, respectively, to regulate EMT. Furthermore, significant associations between miR-29c, its target genes (GNA13 and PTP4A) and EMT markers were validated in both PC and LM tissues.

CONCLUSION

Our findings highlight the important role of miR-29c in regulating CRC EMT via GSK-3β/β-catenin signaling by targeting GNA13 and PTP4A and provide new insights into the metastatic basis of CRC.

Ablation of EIF5A2 induces tumor vasculature remodeling and improves tumor response to chemotherapy via regulation of matrix metalloproteinase 2 expression

Hepatocellular carcinoma (HCC) is a highly vascularized tumor with poor clinical outcome. Our previous work has shown that eukaryotic initiation factor 5A2 (EIF5A2) over-expression enhances HCC cell metastasis. In this study, EIF5A2 was identified to be an independent risk factor for poor disease-specific survival among HCC patients. Both in vitro and in vivo assays indicated that ablation of endogenous EIF5A2 inhibited tumor angiogenesis by reducing matrix metalloproteinase 2 (MMP-2) expression. Given that MMP-2 degrades collagen IV, a main component of the vascular basement membrane (BM), we subsequently investigated the effect of EIF5A2 on tumor vasculature remodeling using complementary approaches, including fluorescent immunostaining, transmission electron microscopy, tumor perfusion assays and tumor hypoxia assays. Taken together, our results indicate that EIF5A2 silencing increases tumor vessel wall continuity, increases blood perfusion and improves tumor oxygenation. Additionally, we found that ablation of EIF5A2 enhanced the chemosensitivity of HCC cells to 5-Fluorouracil (5-FU). Finally, we demonstrated that EIF5A2 might exert these functions by enhancing MMP-2 activity via activation of p38 MAPK and JNK/c-Jun pathways.

CONCLUSION

This study highlights an important role of EIF5A2 in HCC tumor vessel remodeling and indicates that EIF5A2 represents a potential therapeutic target in the treatment of HCC.

Distinct patterns of ALDH1A1 expression predict metastasis and poor outcome of colorectal carcinoma

PURPOSE

Aldehyde dehydrogenase 1A1 (ALDH1A1) has been proposed as a candidate biomarker for colorectal carcinoma (CRC). However, the heterogeneity of its expression makes it difficult to predict the outcome of CRC. The aim of this study was to evaluate the diagnostic and prognostic value of this molecule in CRC.

METHODS AND RESULTS

In this study, we examined ALDH1A1 expression by immunohistochemistry including 406 cases of primary CRC with corresponding adjacent mucosa, with confirmation of real-time PCR and Western blotting. We found that the expression patterns of ALDH1A1 were heterogeneous in the CRC and corresponding adjacent tissues. We defined the ratio of ALDH1A1 level in adjacent mucosa to that in tumor tissues as RA/C and found that the capabilities of tumor invasion and metastasis in the tumors with RA/C < 1 were significantly higher than those with RA/C ≥ 1. Follow-up data showed the worse prognoses in the CRC patients with RA/C < 1. For understanding the underlying mechanism, the localization of β-catenin was detected in the CRC tissues with different patterns of ALDH1A1 expression from 221 patients and β-catenin was found preferentially expressed in cell nuclei of the tumors with RA/C < 1 and ALDH1A1(high) expression of HT29 cell line, indicating that nuclear translocation of β-catenin might contribute to the increased potentials of invasion and metastasis.

CONCLUSION

Our results indicate that RA/C is a novel biomarker to reflect the distinct expression patterns of ALDH1A1 for predicting metastasis and prognosis of CRC.

Interleukin-27 is differentially associated with HIV viral load and CD4+ T cell counts in therapy-naïve HIV-mono-infected and HIV/HCV-co-infected Chinese

Human Immunodeficiency Virus (HIV) infection and the resultant Acquired Immunodeficiency Syndrome (AIDS) epidemic are major global health challenges; hepatitis C virus (HCV) co-infection has made the HIV/AIDS epidemic even worse. Interleukin-27 (IL-27), a cytokine which inhibits HIV and HCV replication in vitro, associates with HIV infection and HIV/HCV co-infection in clinical settings. However, the impact of HIV and HCV viral loads on plasma IL-27 expression levels has not been well characterized. In this study, 155 antiretroviral therapy-naïve Chinese were recruited. Among them 80 were HIV- and HCV-negative healthy controls, 45 were HIV-mono-infected and 30 were HIV/HCV-co-infected. Plasma level HIV, HCV, IL-27 and CD4+ number were counted and their correlation, regression relationships were explored. We show that: plasma IL-27 level was significantly upregulated in HIV-mono-infected and HIV/HCV-co-infected Chinese; HIV viral load was negatively correlated with IL-27 titer in HIV-mono-infected subjects whereas the relationship was opposite in HIV/HCV-co-infected subjects; and the relationships between HIV viral loads, IL-27 titers and CD4+ T cell counts in the HIV mono-infection and HIV/HCV co-infection groups were dramatically different. Overall, our results suggest that IL-27 differs in treatment-naïve groups with HIV mono-infections and HIV/HCV co-infections, thereby providing critical information to be considered when caring and treating those with HIV mono-infection and HIV/HCV co-infection.

De-oncogenic HPV E6/E7 vaccine gets enhanced antigenicity and promotes tumoricidal synergy with cisplatin

In order to develop more effective therapeutic vaccines against cancers with high-risk human papillomavirus (HPV) infection, it is crucial to enhance the immunogenicity, eliminate the oncogenicity of oncoproteins, and take a combination of E7- and E6-containing vaccines. It has been shown recently that PE(ΔIII)-E7-KDEL3 (E7), a fusion protein containing the HPV16 oncoprotein E7 and the translocation domain of Pseudomonas aeruginosa exotoxin A, is effective against TC-1 tumor cells inoculated in mice, therefore, we engineered PE(ΔIII)-E6-CRL-KDEL3 (E6), the de-oncogenic versions of the E7 and E6 fusion proteins [i.e. PE(ΔIII)-E7(d)-KDEL3, E7(d), and PE(ΔIII)-E6(d)-CRL-KDEL3, E6(d)] and tested the immunoefficacies of these fusion proteins as mono- and bivalent vaccines. Results indicated that the E7(d) get higher immunogenicity than its wild type and the E6 fusion proteins augmented the immunogenicity and antitumor effects of their E7 counterparts. Furthermore, the bivalent vaccine system E7(d) plus E6(d), in the presence of cisplatin, showed the best tumoristatic and tumoricidal effects against established tumors in vivo. Therefore, it can be concluded that this novel therapeutic vaccine system, upon further optimization, may shed new light on clinical management of HPV-related carcinomas.

PinX1 suppresses bladder urothelial carcinoma cell proliferation via the inhibition of telomerase activity and p16/cyclin D1 pathway

BACKGROUND

PIN2/TRF1-interacting telomerase inhibitor1 (PinX1) was recently suggested as a putative tumor suppressor in several types of human cancer, based on its binding to and inhibition of telomerase. Moreover, loss of PinX1 has been detected in many human malignancies. However, the possible involvement of PinX1 and its clinical/prognostic significance in urothelial carcinoma of the bladder (UCB) are unclear.

METHODS

The PinX1 expression profile was examined by quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemistry (IHC) in UCB tissues and adjacent normal urothelial bladder epithelial tissues. PinX1 was overexpressed and silenced in UCB cell lines to determine its role in tumorigenesis, development of UCB, and the possible mechanism.

RESULTS

PinX1 expression in UCB was significantly down-regulated at both mRNA and protein level as compared with that in normal urothelial bladder epithelial tissues. PinX1 levels were inversely correlated with tumor multiplicity, advanced N classification, high proliferation index (Ki-67), and poor survival (P < 0.05). Moreover, overexpression of PinX1 in UCB cells significantly inhibited cell proliferation in vitro and in vivo, whereas silencing PinX1 dramatically enhanced cell proliferation. Overexpression of PinX1 resulted in G1/S phase arrest and cell growth/proliferation inhibition, while silencing PinX1 led to acceleration of G1/S transition, and cell growth/proliferation promotion by inhibiting/enhancing telomerase activity and via the p16/cyclin D1 pathway.

CONCLUSIONS

These findings suggest that down-regulation of PinX1 play an important role in the tumorigenesis and development of UCB and that the expression of PinX1 as detected by IHC is an independent molecular marker in patients with UCB.

1,3,5-Trihydroxy-13,13-dimethyl-2H-pyran [7,6-b] xanthone directly targets heat shock protein 27 in hepatocellular carcinoma

We previously showed that the small molecule 1,3,5-trihydroxy-13,13-dimethyl-2H-pyran [7,6-b] xanthone (TDP) induces apoptosis in hepatocellular carcinoma (HCC) by suppressing Hsp27 expression, although the mechanism is not fully understood. To investigate the functional association between TDP and Hsp27 protein in HCC, recombinant Hsp27 protein was incubated with TDP at room temperature, and assayed by mass spectrum (MS) and natural electrophoresis. TDP effectively stimulated Hsp27 to form aggregates ex vitro, leading to suppression of its chaperone activity. The aggregates were degraded by the ubiquitin-proteasome (UPS) pathway. TDP directly interacted with Asp17 and Phe55 in chain C of Hsp27 on the basis of bioinformatic prediction. In conclusion, Hsp27 is a direct target of TDP in its anti-cancer activity, which provides strong support for a clinical application.

The interaction between human enteroviruses and type I IFN signaling pathway

Human enteroviruses (HEV), very common and important human pathogens, cause infections in diverse ways. Recently, the large epidemic of HFMD caused by HEV infection became a growing threat to public health in China. As the first line of immune response, the type I interferon (IFN-α/β) pathway plays an essential role in antiviral infection, particularly in limiting both the early and late stages of infection. Because of co-evolution with the host, the viruses have evolved multiple strategies to evade or subvert the host immunity to ensure their survival. In this paper, we systematically reviewed and summarized the interaction between HEV infections and host type I IFN responses. We firstly described the recent findings of HEV recognition and IFN induction, specifically on host pattern-recognition receptors (PRRs) in HEV infection. Then we discussed the antiviral effect of IFN in HEV infection. Finally, we timely summarized the mechanisms of HEV to circumvent the IFN responses. Clarification of the complexity in this battle may provide us new strategies for prevention and antiviral treatment.

Overexpression of YAP 1 contributes to progressive features and poor prognosis of human urothelial carcinoma of the bladder

Background

Yes-associated protein 1 (YAP 1), the nuclear effector of the Hippo pathway, is a key regulator of organ size and a candidate human oncogene in multiple tumors. However, the expression dynamics of YAP 1 in urothelial carcinoma of the bladder (UCB) and its clinical/prognostic significance are unclear.

Methods

In this study, the methods of quantitative real-time polymerase chain reaction (qRT-PCR), Western blotting and immunohistochemistry (IHC) were utilized to investigate mRNA/ protein expression of YAP 1 in UCBs. Spearman’s rank correlation, Kaplan-Meier plots and Cox proportional hazards regression model were used to analyze the data.

Results

Up-regulated expression of YAP 1 mRNA and protein was observed in the majority of UCBs by qRT-PCR and Western blotting, when compared with their paired normal bladder tissues. By IHC, positive expression of YAP 1 was examined in 113/213 (53.1%) of UCBs and in 6/86 (7.0%) of normal bladder specimens tissues. Positive expression of YAP 1 was correlated with poorer differentiation, higher T classification and higher N classification (P < 0.05). In univariate survival analysis, a significant association between positive expression of YAP 1 and shortened patients’ survival was found (P < 0.001). In different subsets of UCB patients, YAP 1 expression was also a prognostic indicator in patients with grade 2 (P = 0.005) or grade 3 (P = 0.046) UCB, and in patients in pT1 (P = 0.013), pT2-4 (P = 0.002), pN- (P < 0.001) or pT2-4/pN- (P = 0.004) stage. Importantly, YAP 1 expression (P = 0.003) together with pT and pN status (P< 0.05) provided significant independent prognostic parameters in multivariate analysis.

Conclusions

Our findings provide evidences that positive expression of YAP 1 in UCB may be important in the acquisition of an aggressive phenotype, and it is an independent biomarker for poor prognosis of patients with UCB.

Inhibition of hepatocellular carcinoma growth by adenovirus-mediated expression of human telomerase reverse transcriptase COOH-27 terminal polypeptide in mice

A 27-kDa C-terminal fragment of human telomerase reverse transcriptase, hTERTC27, has previously been reported to inhibit the growth and tumorigenicity of HeLa human cervical cancer cells and U87-MG human glioblastoma multiforme cells. However, the antitumor effects of hTERTC27 in hepatoma and its underlying mechanisms are unclear. In the current study, the therapeutic effect of hTERTC27, mediated by recombinant adenovirus, in hepatocellular carcinoma (HCC) was explored in vitro and in vivo to investigate the possible mechanisms. The results indicated that recombinant adenovirus carrying hTERTC27 (rAdv-hTERTC27) effectively inhibited the growth and induced apoptosis of the Hepa 1–6 HCC cells. Dendritic cells transduced with rAdv-hTERTC27 were highly effective at inducing antigen-specific T cell proliferation and increasing the activated cytotoxicity of T cells against Hepa 1–6 cells. HCC was inhibited significantly when a single dose of 5×10⁷ pfu rAdv-hTERTC27 was administered intravenously. In summary, the results of this study demonstrated that rAdv-hTERTC27 may serve as a reagent for intravenous administration when combined with telomerase-based gene therapy and immunotherapy for cancer.

MicroRNA-128 promotes cell-cell adhesion in U87 glioma cells via regulation of EphB2

MicroRNAs (miRNAs) are small, non-coding RNAs which regulate gene expression at the post-transcriptional level. Abnormal expression of miRNAs occurs frequently in human tumors. Despite the fact that reduced expression of miR-128 has been observed in glioma tissues and cells, the role of miR-128 in tumors has not been fully characterized. In the present study, cell adhesion assays indicated that overexpression of miR-128 can promote cell-cell adhesion. Target site prediction algorithms indicated that miR-128 binds the 3'-untranslated regions of erythropoietin-producing hepatocellular receptor (Eph)B1 and EphB2 mRNAs. Luciferase reporter assays confirmed that miR-128 binds and regulates EphB1 and EphB2 mRNAs. Overexpression of EphB2 reduced the ability of miR-128 to promote cell-cell adhesion. The wound-healing assay indicated that miR-128 significantly inhibited cell migration via EphB2. This study revealed the novel functions of miR-128 in cell-cell adhesion and cell migration in glioma cells through the regulation of EphB2, and identified EphB1 and EphB2 as novel miR-128 targets.