Conditioning Regimen of 5-Day Decitabine Administration for Allogeneic Stem Cell Transplantation in Patients with Myelodysplastic Syndrome and Myeloproliferative Neoplasms.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for patients with myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN). However, post-HSCT relapse remains a major cause of treatment failure. Here we assessed the efficacy of a new conditioning regimen comprising decitabine (Dec), busulfan (Bu), cyclophosphamide (Cy), fludarabine (Flu), and cytarabine (Ara-c) for allo-HSCT in patients with MDS and MDS/MPN. A total of 48 patients were enrolled, including 44 with MDS and 4 with chronic myelomonocytic leukemia (CMML). Patients received Dec 20 mg/m2/day on days -9 to -5, combined with a Bu/Cy/Flu/Ara-c-modified preparative regimen. At a median follow-up of 522 days (range, 15 to 1313 days), the overall survival (OS) was 86%, relapse incidence was 12%, and nonrelapse mortality was 12%. The incidence of severe acute (grade III-IV) graft-versus-host disease (GVHD) was 23% and that of chronic GVHD was 15%. At 2 years, OS was 74% and 86%, respectively for high-risk and very-high-risk patients with MDS. Survival was promising in patients with poor-risk gene mutations, such as TP53 and ASXL1 (88%), and in those with ≥3 gene mutations (79%). Results of immunomonitoring studies revealed that proper natural killer cells made essential contributions to these favorable clinical outcomes. Overall, this new regimen was associated with a low relapse rate, low incidence and severity of GVHD, and satisfactory survival in allo-HSCT recipients with MDS and MDS/MPN.

The signalling receptor MCAM coordinates apical-basal polarity and planar cell polarity during morphogenesis.

The apical-basal (AB) polarity and planar cell polarity (PCP) provide an animal cell population with different phenotypes during morphogenesis. However, how cells couple these two patterning systems remains unclear. Here we provide in vivo evidence that melanoma cell adhesion molecule (MCAM) coordinates AB polarity-driven lumenogenesis and c-Jun N-terminal kinase (JNK)/PCP-dependent ciliogenesis. We identify that MCAM is an independent receptor of fibroblast growth factor 4 (FGF4), a membrane anchor of phospholipase C-γ (PLC-γ), an immediate upstream receptor of nuclear factor of activated T-cells (NFAT) and a constitutive activator of JNK. We find that MCAM-mediated vesicular trafficking towards FGF4, while generating a priority-grade transcriptional response of NFAT determines lumenogenesis. We demonstrate that MCAM plays indispensable roles in ciliogenesis through activating JNK independently of FGF signals. Furthermore, mcam-deficient zebrafish and Xenopus exhibit a global defect in left-right (LR) asymmetric establishment as a result of morphogenetic failure of their LR organizers. Therefore, MCAM coordination of AB polarity and PCP provides insight into the general mechanisms of morphogenesis.

Macrophagic CD146 promotes foam cell formation and retention during atherosclerosis.

The persistence of cholesterol-engorged macrophages (foam cells) in the artery wall fuels the development of atherosclerosis. However, the mechanism that regulates the formation of macrophage foam cells and impedes their emigration out of inflamed plaques is still elusive. Here, we report that adhesion receptor CD146 controls the formation of macrophage foam cells and their retention within the plaque during atherosclerosis exacerbation. CD146 is expressed on the macrophages in human and mouse atheroma and can be upregulated by oxidized low-density lipoprotein (oxLDL). CD146 triggers macrophage activation by driving the internalization of scavenger receptor CD36 during lipid uptake. In response to oxLDL, macrophages show reduced migratory capacity toward chemokines CCL19 and CCL21; this capacity can be restored by blocking CD146. Genetic deletion of macrophagic CD146 or targeting of CD146 with an antibody result in much less complex plaques in high-fat diet-fed ApoE-/- mice by causing lipid-loaded macrophages to leave plaques. Collectively, our findings identify CD146 as a novel retention signal that traps macrophages within the artery wall, and a promising therapeutic target in atherosclerosis treatment.

A modified busulfan and cyclophosphamide preparative regimen for allogeneic transplantation in myeloid malignancies.

BACKGROUND: Busulfan/cyclophosphamide (Bu/Cy) is commonly used as a standard conditioning regimen without total body irradiation for patients with hematological myeloid malignancies undergoing hematopoietic stem cell transplantation (HSCT). OBJECTIVE: To develop a new myeloablative conditioning regimen incorporating fludarabine (Flu) and cytarabine (Ara-c). SETTING: A tertiary blood disease hospital in Tianjin, China. METHODS: A Bu/Cy preparative regimen was used, modified by Flu 90 mg/m(2) and Ara-c 6 g/m(2) in 57 unselected patients (median age 37 years) with hematological myeloid malignancies. The patients were to receive allogeneic hematopoietic stem cell transplantation (allo-HSCT). Thirteen patients had high-risk leukemia, fifty patients had HLA matched sibling donors while seven patients had HLA mismatched sibling donors. Cy was given 50 mg/kg/day for 2 days while Bu was given 3.2 mg/kg/day intravenously for 3 days. MAIN OUTCOME MEASURE: Post-transplant donor chimerism, relapse tendency and minimal residual disease. RESULTS: Extramedullar toxicity was relatively limited; the incidence of treatment-related mortality (TRM) within 100 days was 3.5 %. The incidence of grade II-IV, grade III-IV acute graft versus host disease (GVHD) and chronic GVHD of the evaluable patients were 21.1, 8.8 and 36.4 %, respectively. With a median follow up of 59 (13-96.5) months, TRM and relapse rate (RR) at eight years were 24.1 ± 5.8 and 14.7 ± 4.8 %, respectively. Disease free survival at eight years was 67.9 ± 6.2 % for the entire group, 60.0 ± 8.9 % for patients with AML, 77.3 ± 8.9 % for patients with CML, 70.0 ± 6.5 and 42.9 ± 18.7 % or matched sibling and mismatched sibling HSCT respectively. CONCLUSION: The new regimen was associated with a low relapse rate, low incidence and severity of graft versus host disease and satisfactory survival for patients with myeloid malignancies.

H-ferritin-nanocaged doxorubicin nanoparticles specifically target and kill tumors with a single-dose injection.

An ideal nanocarrier for efficient drug delivery must be able to target specific cells and carry high doses of therapeutic drugs and should also exhibit optimized physicochemical properties and biocompatibility. However, it is a tremendous challenge to engineer all of the above characteristics into a single carrier particle. Here, we show that natural H-ferritin (HFn) nanocages can carry high doses of doxorubicin (Dox) for tumor-specific targeting and killing without any targeting ligand functionalization or property modulation. Dox-loaded HFn (HFn-Dox) specifically bound and subsequently internalized into tumor cells via interaction with overexpressed transferrin receptor 1 and released Dox in the lysosomes. In vivo in the mouse, HFn-Dox exhibited more than 10-fold higher intratumoral drug concentration than free Dox and significantly inhibited tumor growth after a single-dose injection. Importantly, HFn-Dox displayed an excellent safety profile that significantly reduced healthy organ drug exposure and improved the maximum tolerated dose by fourfold compared with free Dox. Moreover, because the HFn nanocarrier has well-defined morphology and does not need any ligand modification or property modulation it can be easily produced with high purity and yield, which are requirements for drugs used in clinical trials. Thus, these unique properties make the HFn nanocage an ideal vehicle for efficient anticancer drug delivery.

Impaired tumor angiogenesis and VEGF-induced pathway in endothelial CD146 knockout mice.

CD146 is a newly identified endothelial biomarker that has been implicated in angiogenesis. Though in vitro angiogenic function of CD146 has been extensively reported, in vivo evidence is still lacking. To address this issue, we generated endothelial-specific CD146 knockout (CD146(EC-KO)) mice using the Tg(Tek-cre) system. Surprisingly, these mice did not exhibit any apparent morphological defects in the development of normal retinal vasculature. To evaluate the role of CD146 in pathological angiogenesis, a xenograft tumor model was used. We found that both tumor volume and vascular density were significantly lower in CD146(EC-KO) mice when compared to WT littermates. Additionally, the ability for sprouting, migration and tube formation in response to VEGF treatment was impaired in endothelial cells (ECs) of CD146(EC-KO) mice. Mechanistic studies further confirmed that VEGF-induced VEGFR-2 phosphorylation and AKT/p38 MAPKs/NF-κB activation were inhibited in these CD146-null ECs, which might present the underlying cause for the observed inhibition of tumor angiogenesis in CD146(EC-KO) mice. These results suggest that CD146 plays a redundant role in physiological angiogenic processes, but becomes essential during pathological angiogenesis as observed in tumorigenesis.

Quantitative proteomics reveals ER-α involvement in CD146-induced epithelial-mesenchymal transition in breast cancer cells.

The cell adhesion molecule CD146 is a novel inducer of epithelial-mesenchymal transition (EMT), which was associated with triple-negative breast cancer (TNBC). To gain insights into the complex networks that mediate CD146-induced EMT in breast cancers, we conducted a triple Stable Isotope Labeling with Amino Acids in Cell Culture (SILAC), to analyze whole cell protein profiles of MCF-7 cells that had undergone gradual EMT upon CD146 expression from moderate to high levels. In this study, we identified 2293 proteins in total, of which 103 exhibited changes in protein abundance that correlated with CD146 expression levels, revealing extensive morphological and biochemical changes associated with EMT. Ingenuity Pathway Analysis (IPA) showed that estrogen receptor (ER) was the most significantly inhibited transcription regulator during CD146-induced EMT. Functional assays further revealed that ER-α expression was repressed in cells undergoing CD146-induced EMT, whereas re-expression of ER-α abolished their migratory and invasive behavior. Lastly, we found that ER-α mediated its effects on CD146-induced EMT via repression of the key EMT transcriptional factor Slug. Our study revealed the molecular details of the complex signaling networks during CD146-induced EMT, and provided important clues for future exploration of the mechanisms underlying the association between CD146 and TNBC as observed in the clinic. BIOLOGICAL SIGNIFICANCE: This study used a proteomics screen to reveal molecular changes mediated by CD146-induced epithelial-mesenchymal transition (EMT) in breast cancer cells. Estrogen receptor (ER) was found to be the most significantly inhibited transcription regulator, which mediated its effects on CD146-induced EMT via repression of the transcriptional factor Slug. Elucidation of protein interaction networks and signal networks generated from 103 significantly changed proteins would facilitate future investigation into the mechanisms underlying CD146 induced-EMT in breast cancers.

Targeting endothelial CD146 attenuates colitis and prevents colitis-associated carcinogenesis.

Recently, enhanced CD146 expression was reported on endothelial cells in intestinal biopsies from patients with inflammatory bowel disease. However, the underlying mechanism remains unknown. Here, we found that overexpressed endothelial CD146 promoted the inflammatory responses in inflammatory bowel disease, which further potentiated the occurrence of colitis-associated colorectal carcinogenesis. Eliminating endothelial CD146 by conditional knockout significantly ameliorated the severity of inflammation in two different murine models of colitis, and decreased tumor incidence and tumor progression in a murine model of colitis-associated colorectal carcinogenesis. Mechanistic study showed that cytokine tumor necrosis factor-α (TNF-α) up-regulated the expression of endothelial CD146 through NF-κB transactivation. In turn, the enhanced endothelial CD146 expression promoted both angiogenesis and proinflammatory leukocyte extravasations, contributing to inflammation. Using an anti-CD146 antibody, AA98, alone or together with an anti-TNF-α antibody significantly attenuated colitis and prevented colitis-associated colorectal carcinogenesis in mice. Our study provides the first evidence that CD146 plays a dual role on endothelium, facilitating leukocyte extravasations and angiogenesis, thus promoting inflammation. This finding not only reveals the function and regulating mechanism of CD146 in inflammatory bowel disease, but also provides a promising therapeutic strategy for treating inflammatory bowel disease and preventing colitis-associated colorectal carcinogenesis.

FXYD6: a novel therapeutic target toward hepatocellular carcinoma.

FXYD6, FXYD domain containing ion transport regulator 6, has been reported to affect the activity of Na(+)/K(+)-ATPase and be associated with mental diseases. Here, we demonstrate that FXYD6 is up-regulated in hepatocellular carcinoma (HCC) and enhances the migration and proliferation of HCC cells. Up-regulation of FXYD6 not only positively correlates with the increase of Na(+)/K(+)-ATPase but also coordinates with the activation of its downstream Src-ERK signaling pathway. More importantly, blocking FXYD6 by its functional antibody significantly inhibits the growth potential of the xenografted HCC tumors in mice, indicating that FXYD6 represents a potential therapeutic target toward HCC. Altogether, our results establish a critical role of FXYD6 in HCC progression and suggest that the therapy targeting FXYD6 can benefit the clinical treatment toward HCC patients.

Wnt5a uses CD146 as a receptor to regulate cell motility and convergent extension.

Dysregulation of Wnt signalling leads to developmental defects and diseases. Non-canonical Wnt signalling via planar cell polarity proteins regulates cell migration and convergent extension; however, the underlying mechanisms are poorly understood. Here we report that Wnt5a uses CD146 as a receptor to regulate cell migration and zebrafish embryonic convergent extension. CD146 binds to Wnt5a with the high affinity required for Wnt5a-induced activation of Dishevelled (Dvl) and c-jun amino-terminal kinase (JNK). The interaction between CD146 and Dvl2 is enhanced on Wnt5a treatment. Mutation of the Dvl2-binding region impairs its ability to activate JNK, promote cell migration and facilitate the formation of cell protrusions. Knockdown of Dvls impairs CD146-induced cell migration. Interestingly, CD146 inhibits canonical Wnt signalling by promoting ß-catenin degradation. Our results suggest a model in which CD146 acts as a functional Wnt5a receptor in regulating cell migration and convergent extension, turning off the canonical Wnt signalling branch.

CD146 deletion in the nervous system impairs appetite, locomotor activity and spatial learning in mice.

Cell adhesion molecules (CAMs) are crucial effectors for the development and maintenance of the nervous system. Mutations in human CAM genes are linked to brain disorders and psychological diseases, and CAM knockout mice always exhibit similar behavioral abnormalities. CD146 is a CAM of the immunoglobulin superfamily that interacts with Neurite Outgrowth Factor and involved in neurite extension in vitro. However, little is known about its in vivo function in the nervous system. In this study, we used a murine CD146 nervous system knockout (CD146(ns-ko)) model. We found that the brains of some CD146(ns-ko) mice were malformed with small olfactory bulbs. CD146(ns-ko) mice exhibited lower body weights and smaller food intake when compared with wild type littermates. Importantly, behavior tests revealed that CD146(ns-ko) mice exhibited significant decreased locomotor activity and impaired capacity for spatial learning and memory. Our results demonstrate that CD146 is important for mammalian nervous system development and proper behavior patterns.

MicroRNA 329 suppresses angiogenesis by targeting CD146.

CD146, an endothelial biomarker, has been shown to be aberrantly upregulated during pathological angiogenesis and functions as a coreceptor for vascular endothelial growth factor receptor 2 (VEGFR-2) to promote disease progression. However, the regulatory mechanisms of CD146 expression during angiogenesis remain unclear. Using a microRNA screening approach, we identified a novel negative regulator of angiogenesis, microRNA 329 (miR-329), that directly targeted CD146 and inhibited CD146-mediated angiogenesis in vitro and in vivo. Endogenous miR-329 expression was downregulated by VEGF and tumor necrosis factor alpha (TNF-α), resulting in the elevation of CD146 in endothelial cells. Upregulation of CD146 facilitated an endothelial response to VEGF-induced SRC kinase family (SKF)/p38 mitogen-activated protein kinase (MAPK)/NF-κB activation and consequently promoted endothelial cell migration and tube formation. Our animal experiments showed that treatment with miR-329 repressed excessive CD146 expression on blood vessels and significantly attenuated neovascularization in a mouse model of pathological angiogenesis. Our findings provide the first evidence that CD146 expression in angiogenesis is regulated by miR-329 and suggest that miR-329 could present a potential therapeutic tool for the treatment of angiogenic diseases.

A novel 'pipeline' system for downstream preparation of therapeutic monoclonal antibodies.

A novel 'pipeline' system for the preparation of therapeutic monoclonal antibodies (mAb) in a non-GMP compliant environment has been developed. We used sterile silica-gel pipes to connect individual process units, in order to form a fully-enclosed and seamlessly connected system. This 'pipeline' system was used to implement downstream preparation processes for a humanized anti-CD146 mAb, huAA98, which is a therapeutic mAb generated to inhibit cancer-related angiogenesis. The quality assessment of the huAA98 end-product indicated that endotoxin levels were 0.016 EU/ml, protein A levels were 1.08 ng/ml and host cell protein (HCP) was undetectable. Thus, all measures were below the clinical criteria set by the Chinese Pharmacopoeia (Edition 2010). Having passed our proof-of-concept test, this 'pipeline' system can be used as a universal platform for the preparation of mAbs suitable for pre-clinical studies, in a non-GMP compliant laboratory environment.

Targeting endothelial CD146 attenuates neuroinflammation by limiting lymphocyte extravasation to the CNS.

The ability to selectively block the entry of leukocytes into the central nervous system (CNS) without compromising the immune system is an attractive therapeutic approach for treating multiple sclerosis (MS). Using endothelial CD146-deficienct mice as a MS model, we found that endothelial CD146 plays an active role in the CNS-directed extravasation of encephalitogenic T cells, including CD146(+) TH1 and TH17 lymphocytes. Moreover, treating both active and passive MS models with the anti-CD146 antibody AA98 significantly decreased the infiltrated lymphocytes in the CNS and decreased neuroinflammation. Interestingly, the ability of AA98 to inhibit the migration of CD146(+) lymphocytes was dependent on targeting endothelial CD146, but not lymphocytic CD146. These results suggest a key molecular target located on the blood-brain barrier endothelium that mediates the extravasation of inflammatory cells into the CNS. In addition, our data suggest that the AA98 is a promising candidate for treating MS and other CNS autoimmune diseases.

CD146 is a potential marker for the diagnosis of malignancy in cervical and endometrial cancer.

Cluster of differentiation 146 (CD146) is an endothelial cell adhesion molecule which is overexpressed in various types of malignant cancer, including ovarian cancer. However, whether CD146 is overexpressed in another two types of gynecological cancer, cervical cancer and endometrial cancer, remains unclear. In the present study, we showed that CD146 expression levels were higher in cells from cervical cancer and endometrial cancer compared with their corresponding normal tissues, using anti-CD146 mouse antibody AA4 (mAb AA4) and that mAb AA4 exhibited a high performance for specificity, sensitivity and positive predictive value in the detection of these two types of cancer. CD146 expression was positively and significantly correlated with the pathological subtype of cervical cancer and with the histological grade and depth of myometrial invasion in endometrial cancer. In addition, we confirmed that CD146 is present in the majority of blood vessels in cervical and endometrial cancer, suggesting that CD146 may be actively implicated in the metastasis of cervical and endometrial cancer via the vascular system. Thus, this study provides insights for further development of CD146 mAb in the detection of gynecological malignant cancer types and implies that a combined treatment strategy of anti-CD146 immunotherapy with other traditional chemo- or radiotherapy treatments may be a promising approach against cervical and endometrial cancer.

A novel anti-sTn monoclonal antibody 3P9 Inhibits human xenografted colorectal carcinomas.

The aim of this study is to raise tumor-suppressing monoclonal antibodies (mAbs) against colorectal carcinomas. Here, we generated a novel mAb 3P9, targeted a cancer-associated carbohydrate antigen sialyl-Tn (sTn), which showed significant inhibitory effect on proliferation and migration of sTn cells and tumor growth by inducing apoptosis. We also demonstrated that mAb 3P9 showed higher sensitivity and specificity in immunohistochemistry assay on colonic adenocarcinoma than the broadly used commercial anti-sTn antibody B72.3. These results provide the first evidence that mAb 3P9 has potential applications, not only for diagnosis but also for antibody-based tumor therapy.

Magnetoferritin nanoparticles for targeting and visualizing tumour tissues.

Engineered nanoparticles have been used to provide diagnostic, therapeutic and prognostic information about the status of disease. Nanoparticles developed for these purposes are typically modified with targeting ligands (such as antibodies, peptides or small molecules) or contrast agents using complicated processes and expensive reagents. Moreover, this approach can lead to an excess of ligands on the nanoparticle surface, and this causes non-specific binding and aggregation of nanoparticles, which decreases detection sensitivity. Here, we show that magnetoferritin nanoparticles (M-HFn) can be used to target and visualize tumour tissues without the use of any targeting ligands or contrast agents. Iron oxide nanoparticles are encapsulated inside a recombinant human heavy-chain ferritin (HFn) protein shell, which binds to tumour cells that overexpress transferrin receptor 1 (TfR1). The iron oxide core catalyses the oxidation of peroxidase substrates in the presence of hydrogen peroxide to produce a colour reaction that is used to visualize tumour tissues. We examined 474 clinical specimens from patients with nine types of cancer and verified that these nanoparticles can distinguish cancerous cells from normal cells with a sensitivity of 98% and specificity of 95%.

CD146 is a coreceptor for VEGFR-2 in tumor angiogenesis.

CD146 is a novel endothelial biomarker and plays an essential role in angiogenesis; however, its role in the molecular mechanism underlying angiogenesis remains poorly understood. In the present study, we show that CD146 interacts directly with VEGFR-2 on endothelial cells and at the molecular level and identify the structural basis of CD146 binding to VEGFR-2. In addition, we show that CD146 is required in VEGF-induced VEGFR-2 phosphorylation, AKT/p38 MAPKs/NF-κB activation, and thus promotion of endothelial cell migration and microvascular formation. Furthermore, we show that anti-CD146 AA98 or CD146 siRNA abrogates all VEGFR-2 activation induced by VEGF. An in vivo angiogenesis assay showed that VEGF-promoted microvascular formation was impaired in the endothelial conditional knockout of CD146 (CD146(EC-KO)). Our animal experiments demonstrated that anti-CD146 (AA98) and anti-VEGF (bevacizumab) have an additive inhibitory effect on xenografted human pancreatic and melanoma tumors. The results of the present study suggest that CD146 is a new coreceptor for VEGFR-2 and is therefore a promising target for blocking tumor-related angiogenesis.

Ex vivo detection of iron oxide magnetic nanoparticles in mice using their intrinsic peroxidase-mimicking activity.

Iron oxide magnetic nanoparticles (MNPs) are widely used as diagnostic and therapeutic agents for biomedical applications. Quantitatively analyzing biodistribution, pharmacokinetics and organ clearance of MNPs in mouse models is important for understanding their in vivo behavior. In this study, we developed a novel histochemical method for visualizing unlabeled MNPs in mouse tissues by employing their intrinsic peroxidase-mimicking activity, regarding which we reported previously that MNPs could catalyze the oxidation of peroxidase substrates to produce a color reaction at the site of MNPs (Gao et al. Nat. Nanotechnol.2007, 2, 577-583). Based on this MNPs-peroxidase approach, we determined the biodistribution and organ clearance of MNPs by visualizing and quantifying the localization of MNPs within the main organs. Compared to traditional Prussian blue assay, this novel MNPs-peroxidase approach has higher sensitivity. In conclusion, the developed MNPs-peroxidase approach based on intrinsic peroxidase activity of iron oxide nanoparticles was used effectively for quantitative detection of MNPs in mice by histochemical staining. Presumably, other nanoparticles having intrinsic peroxidase activity could also be considered.

CD146, an epithelial-mesenchymal transition inducer, is associated with triple-negative breast cancer.

The epithelial-mesenchymal transition (EMT) plays an important role in breast cancer metastasis, especially in the most aggressive and lethal subtype, "triple-negative breast cancer" (TNBC). Here, we report that CD146 is a unique activator of EMTs and significantly correlates with TNBC. In epithelial breast cancer cells, overexpression of CD146 down-regulated epithelial markers and up-regulated mesenchymal markers, significantly promoted cell migration and invasion, and induced cancer stem cell-like properties. We further found that RhoA pathways positively regulated CD146-induced EMTs via the key EMT transcriptional factor Slug. An orthotopic breast tumor model demonstrated that CD146-overexpressing breast tumors showed a poorly differentiated phenotype and displayed increased tumor invasion and metastasis. We confirmed these findings by conducting an immunohistochemical analysis of 505 human primary breast tumor tissues and found that CD146 expression was significantly associated with high tumor stage, poor prognosis, and TNBC. CD146 was expressed at abnormally high levels (68.9%), and was strongly associated with E-cadherin down-regulation in TNBC samples. Taken together, these findings provide unique evidence that CD146 promotes breast cancer progression by induction of EMTs via the activation of RhoA and up-regulation of Slug. Thus, CD146 could be a therapeutic target for breast cancer, especially for TNBC.