Secretory galectin-3 induced by glucocorticoid stress triggers stemness exhaustion of hepatic progenitor cells.

Adult progenitor cell populations typically exist in a quiescent state within a controlled niche environment. However, various stresses or forms of damage can disrupt this state, which often leads to dysfunction and aging. We built a glucocorticoid (GC)-induced liver damage model of mice, found that GC stress induced liver damage, leading to consequences for progenitor cells expansion. However, the mechanisms by which niche factors cause progenitor cells proliferation are largely unknown. We demonstrate that, within the liver progenitor cells niche, Galectin-3 (Gal-3) is responsible for driving a subset of progenitor cells to break quiescence. We show that GC stress causes aging of the niche, which induces the up-regulation of Gal-3. The increased Gal-3 population increasingly interacts with the progenitor cell marker CD133, which triggers focal adhesion kinase (FAK)/AMP-activated kinase (AMPK) signaling. This results in the loss of quiescence and leads to the eventual stemness exhaustion of progenitor cells. Conversely, blocking Gal-3 with the inhibitor TD139 prevents the loss of stemness and improves liver function. These experiments identify a stress-dependent change in progenitor cell niche that directly influence liver progenitor cell quiescence and function.

CD133 antibody targeted delivery of gold nanostars loading IR820 and docetaxel for multimodal imaging and near-infrared photodynamic/photothermal/chemotherapy against castration resistant prostate cancer.

Due to the lack of effective strategies on the treatment of castration resistant prostate cancer (CRPC), we established a multifunctional nanoplatform (GNS@IR820/DTX-CD133) for the synergistic photothermal therapy (PTT)/photodynamic therapy (PDT)/chemotherapy (CT) under the monitoring of multimodal near-infrared (NIR) fluorescence/photoacoustic (PA) imaging. Benefiting from the guided effect of CD133 antibody, GNS@IR820/DTX-CD133 can targetedly deliver the loaded drug to the tumor tissues, which can further contribute to the combined therapeutic effect. Our experimental results prove that the bio-distribution of GNS@IR820/DTX-CD133 can be monitored with NIR fluorescence and PA imaging. In addition, the application of GNS@IR820/DTX-CD133 for in vitro and in vivo therapy achieves the excellent antitumor effects of the synergistic PTT/PDT/CT strategies under the NIR-light irradiation. Therefore, as a multifunctional nanoplatform integrating the PTT/PDT/CT strategies with tumor multimodal imaging or drug tracing, GNS@IR820/DTX-CD133 has the great potential for clinical applications in the antitumor therapy of CRPC.

Prominins control ciliary length throughout the animal kingdom: New lessons from human prominin-1 and zebrafish prominin-3.

Prominins (proms) are transmembrane glycoproteins conserved throughout the animal kingdom. They are associated with plasma membrane protrusions, such as primary cilia, as well as extracellular vesicles derived thereof. Primary cilia host numerous signaling pathways affected in diseases known as ciliopathies. Human PROM1 (CD133) is detected in both somatic and cancer stem cells and is also expressed in terminally differentiated epithelial and photoreceptor cells. Genetic mutations in the PROM1 gene result in retinal degeneration by impairing the proper formation of the outer segment of photoreceptors, a modified cilium. Here, we investigated the impact of proms on two distinct examples of ciliogenesis. First, we demonstrate that the overexpression of a dominant-negative mutant variant of human PROM1 (i.e. mutation Y819F/Y828F) significantly decreases ciliary length in Madin-Darby canine kidney cells. These results contrast strongly to the previously observed enhancing effect of WT PROM1 on ciliary length. Mechanistically, the mutation impeded the interaction of PROM1 with ADP-ribosylation factor-like protein 13B, a key regulator of ciliary length. Second, we observed that in vivo knockdown of prom3 in zebrafish alters the number and length of monocilia in the Kupffer's vesicle, resulting in molecular and anatomical defects in the left-right asymmetry. These distinct loss-of-function approaches in two biological systems reveal that prom proteins are critical for the integrity and function of cilia. Our data provide new insights into ciliogenesis and might be of particular interest for investigations of the etiologies of ciliopathies.

Delivery Of Curcumin Nanoliposomes Using Surface Modified With CD133 Aptamers For Prostate Cancer.

AIM: The aim of this study was to characterize curcumin (CUR)-loaded CD133 aptamer A15 liposomes for their antitumor activity in vitro and in vivo. METHODS: The modified CUR liposomes were prepared by the thin-film hydration technique. RESULTS: The particles showed spherical shape under electron microscopy with sizes <100 nm. Initial drug burst release was observed within 2 hrs and then the drug was continuously released over 48 hrs. No aggregation or precipitation of liposomes was observed during storage for 3 months. In vitro results showed that blank LPs had lower cellular cytotoxicity. Both liposomes of CUR (with or without A15 modified) exhibited a similar trend of cellular cytotoxicity at the same concentration. With the extension of incubation time, A15-CUR LPs showed a greater inhibitory effect on cells. Cell internalization in DU145 cells was higher for A15-CUR LPs than others. An in vivo study using DU145 prostate carcinoma bearing mice showed that A15-CUR LPs reduced tumor growth more than other forms of CUR. CONCLUSION: These results indicate that A15 modified CUR liposomes are a promising candidate for antitumor drug delivery.

Prominin-1 Modulates Rho/ROCK-Mediated Membrane Morphology and Calcium-Dependent Intracellular Chloride Flux.

Membrane morphology is an important structural determinant as it reflects cellular functions. The pentaspan membrane protein Prominin-1 (Prom1/CD133) is known to be localised to protrusions and plays a pivotal role in migration and the determination of cellular morphology; however, the underlying mechanism of its action have been elusive. Here, we performed molecular characterisation of Prom1, focussing primarily on its effects on cell morphology. Overexpression of Prom1 in RPE-1 cells triggers multiple, long, cholesterol-enriched fibres, independently of actin and microtubule polymerisation. A five amino acid stretch located at the carboxyl cytosolic region is essential for fibre formation. The small GTPase Rho and its downstream Rho-associated coiled-coil-containing protein kinase (ROCK) are also essential for this process, and active Rho colocalises with Prom1 at the site of initialisation of fibre formation. In mouse embryonic fibroblast (MEF) cells we show that Prom1 is required for chloride ion efflux induced by calcium ion uptake, and demonstrate that fibre formation is closely associated with chloride efflux activity. Collectively, these findings suggest that Prom1 affects cell morphology and contributes to chloride conductance.

CD133 receptor mediated delivery of STAT3 inhibitor for simultaneous elimination of cancer cells and cancer stem cells in oral squamous cell carcinoma.

Oral Squamous Cell Carcinoma (OSCC) is one of the major causes of cancer related deaths worldwide. Presence of chemoresistant cancer stem cells is the major reason behind metastasis, tumor relapse and treatment resistance in OSCC. STAT 3 signalling plays a key role in survival of cancer stem cells (CSC's), Epithelial Mesenchymal Transition (EMT) mediated metastasis in OSCC. CD 133 is the surface marker for identification of cancer stem cells. In the present study we hypothesise the selective targeting of CSC's using CD 133 mediated delivery of STAT 3 inhibitor, Niclosamide to specifically target CSC's and Non CSC's.

The sustained and targeted treatment of hemangiomas by propranolol-loaded CD133 aptamers conjugated liposomes-in-microspheres.

We previously developed propranolol-encapsulated liposomes-in-microspheres (PLIM) to realize the sustained propranolol release for the treatment of hemangiomas. However, the liposomes released from the microspheres still lacked specificity for CD133-positive hemangioma-derived stem cells (HemSCs) which are considered to be the seeds of hemangiomas. Therefore, we hereby encapsulated propranolol-loaded CD133 aptamers conjugated liposomes in poly(lactic-co-glycolic acid (PLGA) microspheres to develop propranolol-loaded CD133 aptamers conjugated liposomes-in-microspheres (PCLIM), to realize the aim of the sustained and targeted therapy of hemangiomas. The evaluation of the release of propranolol from PCLIM was carried out, and the cytotoxic effect and angiogenic growth factor expression inhibitory ability of PCLIM were performed in HemSCs. The in vivo hemangioma inhibitory ability of PCLIM was also investigated in nude mice with subcutaneous human hemangiomas. PCLIM possessed a desired size of 29.2 µm, drug encapsulation efficiency (25.3%), and a prolonged drug release for 40 days. Importantly, PCLIM could inhibit HemSCs proliferation and the protein expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor-A (VEGF) in HemSCs to a greater extent compared with PLIM. In nude mice bearing hemangioma xenograft, PCLIM showed the best therapeutic efficacy towards hemangiomas, as reflected by remarkably decreased hemangioma volume, weight and microvessel density (MVD). Thus, our results demonstrated that PCLIM realized the sustained and targeted treatment of hemangiomas, resulting in remarkable inhibition of hemangiomas.

Prominin-1 (CD133) modulates the architecture and dynamics of microvilli.

Prominin-1 is a cell surface biomarker that allows the identification of stem and cancer stem cells from different organs. It is also expressed in several differentiated epithelial and non-epithelial cells. Irrespective of the cell type, prominin-1 is associated with plasma membrane protrusions. Here, we investigate its impact on the architecture of membrane protrusions using microvilli of Madin-Darby canine kidney cells as the main model. Our high-resolution analysis revealed that upon the overexpression of prominin-1 the number of microvilli and clusters of them increased. Microvilli with branched and/or knob-like morphologies were observed and stimulated by mutations in the ganglioside-binding site of prominin-1. The altered phenotypes were caused by the interaction of prominin-1 with phosphoinositide 3-kinase and Arp2/3 complex. Mutation of tyrosine 828 of prominin-1 impaired its phosphorylation and thereby inhibited the aforementioned interactions abolishing altered microvilli. This suggests that the interplay of prominin-1-ganglioside membrane complexes, phosphoinositide 3-kinase and cytoskeleton components regulates microvillar architecture. Lastly, the expression of prominin-1 and its mutants modified the structure of filopodia emerging from fibroblast-like cells and silencing human prominin-1 in primary hematopoietic stem cells resulted in the loss of uropod-associated microvilli. Altogether, these findings strengthen the role of prominin-1 as an organizer of cellular protrusions.

Targeted salinomycin delivery with EGFR and CD133 aptamers based dual-ligand lipid-polymer nanoparticles to both osteosarcoma cells and cancer stem cells.

We previously developed salinomycin (sali)-entrapped nanoparticles labeled with CD133 aptamers which could efficiently eliminate CD133+ osteosarcoma cancer stem cells (CSCs). However, sufficient evidences suggest that the simultaneous targeting both CSCs and cancer cells is pivotal in achieving preferable cancer therapeutic efficacy, due to the spontaneous conversion between cancer cells and CSCs. We hereby constructed sali-entrapped lipid-polymer nanoparticles labeled with CD133 and EGFR aptamers (CESP) to target both osteosarcoma cells and CSCs. The cytotoxicity of CESP in osteosarcoma cells and CSCs was superior to that of single targeting or nontargeted sali-loaded nanoparticles. Administration of CESP in vivo showed the best efficacy in inhibiting tumor growth than other controls in osteosarcoma-bearing mice. Thus, CESP was demonstrated to be capable of efficiently targeting both osteosarcoma CSCs and cancer cells, and it represents an effective potential approach to treat osteosarcoma.

Monoubiquitination of Cancer Stem Cell Marker CD133 at Lysine 848 Regulates Its Secretion and Promotes Cell Migration.

CD133, a widely known marker of cancer stem cells, was recently found in extracellular vesicles. However, the mechanisms underlying CD133 translocation to the extracellular space remain largely unknown. Here we report that CD133 is monoubiquitinated. Ubiquitination occurs primarily on complex glycosylated CD133. The lysine 848 residue at the intracellular carboxyl terminus is one of the sites for CD133 ubiquitination. The K848R mutation does not affect CD133 degradation by the lysosomal pathway but significantly reduces CD133 secretion by inhibiting the interaction between CD133 and tumor susceptibility gene 101 (Tsg101). Furthermore, knockdown of the E3 ubiquitin protein ligase Nedd4 largely impairs CD133 ubiquitination and vesicle secretion. Importantly, CD133-containing vesicles are taken up by recipient cells, consequently promoting cell migration. The K848R mutation reduces cell migration induced by CD133. Taken together, our findings show that monoubiquitination contributes to CD133 vesicle secretion and promotes recipient cell migration. These findings provide a clue to the mechanisms of CD133 secretion and cancer stem cell microenvironment interactional effects.

Evaluation of METase-pemetrexed-loaded PEG-PLGA nanoparticles modified with anti-CD133-scFV for treatment of gastric carcinoma.

PEG-PLGA nanoparticles (NPs) modified with anti-CD133 and tumor-targeting single-chain antibody fragment (scFV-NPs) for systemic delivery of methioninase (METase) and pemetrexed for gastric carcinoma were successfully formulated. The structure characterization and biological functions of METase-pemetrexed-loaded scFV-PEG-PLGA NPs (scFV-METase/pemetrexed-NPs) in vitro were investigated. Functional scFV-PEG-PLGA NPs or PEG-PLGA NPs present low cell cytoxicity in CD133+ SGC7901 cells. scFV-METase/pemetrexed-NPs (scFv-M/P-NP) was more effective in inhibiting tumor growth (including cell growth and migration ability) in CD133 positive expressed gastric cancer cells than METase/pemetrexed-NPs (M/P-NP). Moreover, METase enhanced the inhibitory effect of pemetrexed on thymidylate synthase (TS) synthesis and cell apoptosis. We have demonstrated the application of scFV-targeted PEG-PLGA NPs as a new potential strategy to enhance treatment benefits for gastric carcinoma.

Development of docetaxel liposome surface modified with CD133 aptamers for lung cancer targeting.

The aim of the present study was to prepare a novel CD133 aptamer modified DTX liposome system and investigate its characteristics in vitro and in vivo studies. In this study, the CD133-DTX LP was prepared by the thin-film hydration method and with the particle size of 100-120 nm. The TEM photomicrographs were smooth, sub-spherical in shape and aggregated to form small clusters. In vitro, a relatively slower DTX release profile was observed in CD133-DTX LP due to the presence of CD133 aptamers on the outer surface which might hinder the drug release. The drug release mechanism fit well with the Higuchi equation better. In cytotoxicity study, CD133 aptamers modified DTX LP significantly decreased cell proliferation and improved the therapeutic efficiency. In vivo imaging result indicated that CD133-DTX LP had very good tumour targeting ability. In vivo antitumour activity indicated that the CD133-DTX LP showed a significant antitumour activity in A549 tumour mice, with a very low systemic toxicity.

PLGA nanoparticles with CD133 aptamers for targeted delivery and sustained release of propranolol to hemangioma.

AIM: To develop propranolol-loaded poly(lactic-co-glycolic acid) nanoparticle with CD133 aptamers (PPN-CD133) to treat infantile hemangioma. MATERIALS & METHODS: The antihemangioma activity and mechanism of PPN-CD133 were evaluated. RESULTS & CONCLUSION: PPN-CD133 are of desired size (143.7 nm), drug encapsulation efficiency (51.8%) and sustained drug release for 8 days. PPN-CD133 could effectively bind to CD133+ hemangioma stem cells, resulting in enhanced cytotoxic effect and reduced expression of angiogenesis factors in hemangioma stem cells. The therapeutic effect of PPN-CD133 in hemangioma was superior to that of untargeted PPN and propranolol in vivo, as reflected by reduced hemangioma volume, weight and microvessel density. PPN-CD133 represents a very promising approach to locally and efficiently deliver propranolol leading to significant inhibition of infantile hemangioma.

Acoustic and hybrid 3D-printed electrochemical biosensors for the real-time immunodetection of liver cancer cells (HepG2).

This study presents an efficient acoustic and hybrid three-dimensional (3D)-printed electrochemical biosensors for the detection of liver cancer cells. The biosensors function by recognizing the highly expressed tumor marker CD133, which is located on the surface of liver cancer cells. Detection was achieved by recrystallizing a recombinant S-layer fusion protein (rSbpA/ZZ) on the surface of the sensors. The fused ZZ-domain enables immobilization of the anti-CD133 antibody in a defined manner. These highly accessible anti-CD133 antibodies were employed as a sensing layer, thereby enabling the efficient detection of liver cancer cells (HepG2). The recognition of HepG2 cells was investigated in situ using a quartz crystal microbalance with dissipation monitoring (QCM-D), which enabled the label-free, real-time detection of living cells on the modified sensor surface under controlled conditions. Furthermore, the hybrid 3D additive printing strategy for biosensors facilitates both rapid development and small-scale manufacturing. The hybrid strategy of combining 3D-printed parts and more traditionally fabricated parts enables the use of optimal materials: a ceramic substrate with noble metals for the sensing element and 3D-printed capillary channels to guide and constrain the clinical sample. Cyclic voltammetry (CV) measurements confirmed the efficiency of the fabricated sensors. Most importantly, these sensors offer low-cost and disposable detection platforms for real-world applications. Thus, as demonstrated in this study, both fabricated acoustic and electrochemical sensing platforms can detect cancer cells and therefore may have further potential in other clinical applications and drug-screening studies.

Imatinib Inhibits the Renewal and Tumorigenicity of CT-26 Colon Cancer Cells after Cytoreductive Treatment with Doxorubicin.

Conventional anti-cancer drugs preferentially eliminate differentiated cancer cells but those cells that are spared (i.e. cancer stem cells: CSC), initiate recurrence. We tested whether drugs that target receptor tyrosine kinases (RTKs) involved in developmental signaling cascades and activated in CSC, could be used to silence and/or to eliminate colorectal cancer cells refractory to conventional treatment with cytoreductive drugs. A sequential treatment model was thereby developed with doxorubicin (DOX) and imatinib. CT-26 mouse colon carcinoma cells were pre-treated with DOX to select DOX-refractory cells with CSC properties, which were then subsequently treated with RTK inhibitor imatinib, where their regrowth was found to be inhibited. Under both normoxic and hypoxic conditions, imatinib potently inhibited clonogenicity of DOX-refractory CT-26 cells. Treatment with DOX did not eliminate tumorigenic CT-26 cells, since CT-26 cells pre-exposed to DOX in vitro, when inoculated subcutaneously, induced tumors in 90 % of mice, as opposed to a 100 % rate in the case of chemonaive CT-26 cells. In mice inoculated with chemonaive CT-26 cells, tumor formation was not prevented by imatinib. However, imatinib prevented tumor formation in 50 % of mice inoculated with CT-26 cells pre-exposed to DOX in vitro, with the remaining 50 % mice showing delayed tumor formation. These results suggest that the sequential use of the drug imatinib, as a drug targeting cancer cells expressing stem cell features after conventional cytoreductive treatment, is a promising future strategy for preventing tumor recurrence.