Epidemiology and risk factors for resistance to treatment of Kawasaki disease in Cyprus

Kawasaki disease (KD) is one of the most common vasculitides of early childhood. There are no previous studies on KD in Cyprus. The aim of this study was to evaluate the epidemiology of KD in Cyprus, risk factors for resistance to treatment and the development of cardiac complications. This is a retrospective multicenter study of pediatric patients with KD hospitalized between January 2000 and-December 2019. The data were collected from medical records. A total of 136 patients with KD were included in the study. 83% of patients were < 5 years of age and 10% were < 6 months. Thirty patients (22%) developed coronary artery lesions. Serum sodium ≤ 133 mmol/L, albumin ≤ 3.2 g/dl, ALT ≥ 80 U/L and neutrophils percentage ≥ 80% at diagnosis, were identified as risk factors for resistance to IVIG. Clinical and epidemiological characteristics of KD in Cyprus population were similar to those reported in the literature. Although the majority of cases received appropriate treatment in time, cardiac complications still occurred

The secret role of microRNAs in cancer stem cell development and potential therapy: A Notch-pathway approach

MicroRNAs (miRNAs) have been implicated in the development of some if not all cancer types and have been identified as attractive targets for prognosis, diagnosis, and therapy of the disease. miRNAs are a class of small non-coding RNAs (20-22 nt in length) that bind imperfectly to the 3'-untranslated region of target mRNA regulating gene expression. Aberrantly expressed miRNAs in cancer, sometimes known as oncomiRNAs, have been shown to play a major role in oncogenesis, metastasis, and drug resistance. Amplification of oncomiRNAs during cancer development correlates with the silencing of tumor suppressor genes; on the other hand, down-regulation of miRNAs has also been observed in cancer and cancer stem cells (CSCs). In both cases, miRNA regulation is inversely correlated with cancer progression. Growing evidence indicates that miRNAs are also involved in the metastatic process by either suppressing or promoting metastasis-related genes leading to the reduction or activation of cancer cell migration and invasion processes. In particular, circulating miRNAs (vesicle-encapsulated or non-encapsulated) have significant effects on tumorigenesis: membrane-particles, apoptotic bodies, and exosomes have been described as providers of a cell-to-cell communication system transporting oncogenic miRNAs from tumors to neighboring cells and distant metastatic sites. It is hypothesized that miRNAs control cancer development in a traditional manner, by regulating signaling pathways and factors. In addition, recent developments indicate a non-conventional mechanism of cancer regulation by stem cell reprograming via a regulatory network consisting of miRNAs and Wnt/ß-catenin, Notch, and Hedgehog signaling pathways, all of which are involved in controlling stem cell functions of CSCs. In this review, we focus on the role of miRNAs in the Notch-pathway and how they regulate CSC self-renewal, differentiation and tumorigenesis by direct/indirect targeting of the Notch-pathway

The secret role of microRNAs in cancer stem cell development and potential therapy: A Notch-pathway approach

MicroRNAs (miRNAs) have been implicated in the development of some if not all cancer types and have been identified as attractive targets for prognosis, diagnosis, and therapy of the disease. miRNAs are a class of small non-coding RNAs (20-22 nt in length) that bind imperfectly to the 3'-untranslated region of target mRNA regulating gene expression. Aberrantly expressed miRNAs in cancer, sometimes known as oncomiRNAs, have been shown to play a major role in oncogenesis, metastasis, and drug resistance. Amplification of oncomiRNAs during cancer development correlates with the silencing of tumor suppressor genes; on the other hand, down-regulation of miRNAs has also been observed in cancer and cancer stem cells (CSCs). In both cases, miRNA regulation is inversely correlated with cancer progression. Growing evidence indicates that miRNAs are also involved in the metastatic process by either suppressing or promoting metastasis-related genes leading to the reduction or activation of cancer cell migration and invasion processes. In particular, circulating miRNAs (vesicle-encapsulated or non-encapsulated) have significant effects on tumorigenesis: membrane-particles, apoptotic bodies, and exosomes have been described as providers of a cell-to-cell communication system transporting oncogenic miRNAs from tumors to neighboring cells and distant metastatic sites. It is hypothesized that miRNAs control cancer development in a traditional manner, by regulating signaling pathways and factors. In addition, recent developments indicate a non-conventional mechanism of cancer regulation by stem cell reprograming via a regulatory network consisting of miRNAs and Wnt/ß-catenin, Notch, and Hedgehog signaling pathways, all of which are involved in controlling stem cell functions of CSCs. In this review, we focus on the role of miRNAs in the Notch-pathway and how they regulate CSC self-renewal, differentiation and tumorigenesis by direct/indirect targeting of the Notch-pathway

Monitoring circulating cancer cells by multichannel in vivo flow cytometry

We report a new approach for potential monitoring of tumor burden in experimental animals using multichannel in vivo flow cytometry, a novel optical technique that enables the realtime, continuous detection and quantification of fluorescently labeled cells in the circulation without the need for blood extraction. The ability to non-invasively track circulating cells in real time and in their native environment, opens up enormous possibilities for new investigations into the mechanisms that govern the complex trafficking and tissue interactions of these cells in a wide range of clinical and biological fields such as cancer, stem cell biology and immunology. We have developed the in vivo flow cytometer in order to track circulating cancer cells in a mouse model and provide a new, non-invasive method for the monitoring of cancer disease progression as well as the response to therapeutic intervention

Cancer Stem Cells, MicroRNAs & Therapeutic strategies including Stem Cell Microparticles

Introduction: In recent years, the cancer stem cell (CSC) model has been suggested to explain the functional heterogeneity and the carcinogenesis process of cancer. CSCs have the ability to initiate and sustain tumor growth, metastasis and resistance to therapy. MicroRNAs (miRNAs) are small non-coding RNA molecules, which function in transcriptional and post-transcriptional regulation of gene expression. Aberrant expression of miRNAs has been implicated in numerous diseases including some if not all cancer types. Recent findings suggest that miRNAs could be involved in maintaining and regulating the stemness of CSCs. Therefore, miRNAs have been proposed as attractive targets for therapy and miRNA-related therapeutic strategies are under investigation. However, systemic delivery of miRNAs faces its own set of limitations because miRNAs may be degraded in the blood by enzymes such as RNases and excreted by the kidneys. In this work we propose a novel system for therapeutic miRNA delivery applicable for both local and systemic administration with the use of umbilical cord mesenchymal stem cell (MSC) microparticles (MPs). Methodology: MSCs were isolated from the Wharton’s jelly of human umbilical cords. The MSC cultures were subjected to stress conditions, leading to the formation of MPs (secreted membrane vehicles <1μm) which were harvested and characterized by SEM, PCR, FACS and Fluorescence Microscopy. Breast (MDA-MB231 & MCF-7), colon (RKO & HT-29) and ovarian adenocarcinoma (SKOV3) cell lines were then exposed to MPs. The response to treatment was evaluated by cell morphology, proliferation, migration, gene expression and apoptosis. Furthermore, the therapeutic potential of MPs was tested in vivo in xenograft tumor mouse models. Innovative imaging modalities such as in vivo flow cytometry and whole body fluorescence-bioluminescence were employed to dynamically investigate the biodistribution and homing kinetics of MPs in mice. Results: In vitro experiments confirmed that MSC-derived MPs can be internalised by the various cancer cell lines and induce a biological effect as evidenced by membrane damage, cell shrinkage and blebbing in the recipient cell. Significantly, there was evidence that MPs induce apoptosis, inhibit cell proliferation and mediate tumor growth attenuation in a dose/time-dependent manner. The proapoptotic and anti-migrating effects of MPs in cancer cells were almost completely abrogated by RNase treatment before administration to cultures. Preliminary in vivo studies demonstrated that we were able to monitor and quantify fluorescently labelled MPs in circulation and to detect and image the biodistribution and incorporation in cells and organs in healthy and tumor-bearing mice. Conclusion: MSC-derived MPs containing miRNAs possess tumor inhibitory properties both in vitro and in vivo. Administration of MPs after RNase treatment induces the loss of anti-cancer properties suggesting a horizontal transfer of small RNAs from MPs to cancer cells. MPs formulated to contain specific miRNAs, could affect the action of genes associated with carcinogenesis, neovascularization, metastasis and other cancer characteristics leading to therapeutic benefit

Therapeutic miRNAs targeted selectively to tumors by mesenchymal stem cell derived microparticles

Presented at 105th Annual Meeting of the American Association for Cancer Research, 2014, 5-9 April, San Diego, CA, US

Cancer Stem Cells, MicroRNAs & Therapeutic strategies including Stem Cell Microparticles

Introduction: In recent years, the cancer stem cell (CSC) model has been suggested to explain the functional heterogeneity and the carcinogenesis process of cancer. CSCs have the ability to initiate and sustain tumor growth, metastasis and resistance to therapy. MicroRNAs (miRNAs) are small non-coding RNA molecules, which function in transcriptional and post-transcriptional regulation of gene expression. Aberrant expression of miRNAs has been implicated in numerous diseases including some if not all cancer types. Recent findings suggest that miRNAs could be involved in maintaining and regulating the stemness of CSCs. Therefore, miRNAs have been proposed as attractive targets for therapy and miRNA-related therapeutic strategies are under investigation. However, systemic delivery of miRNAs faces its own set of limitations because miRNAs may be degraded in the blood by enzymes such as RNases and excreted by the kidneys. In this work we propose a novel system for therapeutic miRNA delivery applicable for both local and systemic administration with the use of umbilical cord mesenchymal stem cell (MSC) microparticles (MPs). Methodology: MSCs were isolated from the Wharton’s jelly of human umbilical cords. The MSC cultures were subjected to stress conditions, leading to the formation of MPs (secreted membrane vehicles <1μm) which were harvested and characterized by SEM, PCR, FACS and Fluorescence Microscopy. Breast (MDA-MB231 & MCF-7), colon (RKO & HT-29) and ovarian adenocarcinoma (SKOV3) cell lines were then exposed to MPs. The response to treatment was evaluated by cell morphology, proliferation, migration, gene expression and apoptosis. Furthermore, the therapeutic potential of MPs was tested in vivo in xenograft tumor mouse models. Innovative imaging modalities such as in vivo flow cytometry and whole body fluorescence-bioluminescence were employed to dynamically investigate the biodistribution and homing kinetics of MPs in mice. Results: In vitro experiments confirmed that MSC-derived MPs can be internalised by the various cancer cell lines and induce a biological effect as evidenced by membrane damage, cell shrinkage and blebbing in the recipient cell. Significantly, there was evidence that MPs induce apoptosis, inhibit cell proliferation and mediate tumor growth attenuation in a dose/time-dependent manner. The proapoptotic and anti-migrating effects of MPs in cancer cells were almost completely abrogated by RNase treatment before administration to cultures. Preliminary in vivo studies demonstrated that we were able to monitor and quantify fluorescently labelled MPs in circulation and to detect and image the biodistribution and incorporation in cells and organs in healthy and tumor-bearing mice. Conclusion: MSC-derived MPs containing miRNAs possess tumor inhibitory properties both in vitro and in vivo. Administration of MPs after RNase treatment induces the loss of anti-cancer properties suggesting a horizontal transfer of small RNAs from MPs to cancer cells. MPs formulated to contain specific miRNAs, could affect the action of genes associated with carcinogenesis, neovascularization, metastasis and other cancer characteristics leading to therapeutic benefit

Creation of miRNA-loaded, mesenchymal stem cell derived microparticles as targeted cancer therapy

The project describes a new class of therapeutic agents, based on microparticles (MPs) derived from mesenchymal stem cells (MSCs) that can selectively target tumours in vivo.containing and delivering miRNAs that affect the action of genes associated with cancer growth, neovascularisation and metastasis applicable for both local and systemic administration. MSCs isolated from the Wharton’s jelly of human umbilical cords were used to generate MPs from the membrane of MSCs as intact vesicles. The MSC-derived MPs were harvested and characterized by SEM, PCR, FACS and Fluorescence Microscopy. Different cancer cell lines (breast, colon, ovarian adenocarcinoma) were exposed to MPs and the response to treatment was evaluated by cell morphology, proliferation, migration, gene expression and apoptosis. The therapeutic potential of MPs was tested in vivo in orthotopic tumor mouse models using in vivo flow cytometry and whole body fluorescence-bioluminescence to dynamically investigate the biodistribution and homing kinetics of MPs in mice. In vitro experiments confirmed that MSC-derived MPs can be internalised by cancer cells and induce a biological effect as evidenced by damage/shrinkage of the recipient cell, induction of apoptosis, inhibition of cell proliferation and tumor growth attenuation in a dose-dependent manner. In vivo studies monitored and quantified fluorescently labelled MPs in circulation and detected the biodistribution and incorporation in cells and organs in healthy and tumor-bearing mice. MSC-MPs containing miRNAs possess tumor inhibitory properties, transfer miRNAs and affect the action of cancer genes