Deepak Kamnasaran

Laval University, Quebec City, Quebec, Canada

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Publications (54)195.28 Total impact

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    Norbert F Ajeawung · Harish C Joshi · Deepak Kamnasaran
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    ABSTRACT: Pediatric gliomas, the most common solid childhood neoplasm, manifest unique molecular signatures that distinguish them from adult gliomas. Unfortunately, most studies have focused on adult gliomas and extrapolate the findings to treat pediatric gliomas. In this study, we assessed the efficacy of Targetin, a folate conjugated analogue of Noscapine, on the treatment of pediatric low and high grade gliomas. An assortment of standard cancer assays were used with different drug doses and experimental durations. We found that pediatric glioma cells are more susceptible to lower doses of Targetin than parental Noscapine. Targetin functions by disrupting the microtubule network, and can likewise perturb DNA synthesis, delay the cellular transition within the S and G2M cell cycle phases, diminish anchorage independent growth and the migratory/invasiveness of pediatric glioma cells. Moreover, Targetin impairs the expression of several regulators of cancer progression belonging to prominent signalling pathways in pediatric gliomas; including Platelet Derived Growth Factor alpha and some members of the Mitogen Activated Protein Kinase cascade. Targetin has an excellent anti-neoplastic profile and functions to modulate the expression of several genes belonging to key cancer progression pathways in pediatric gliomas. Collectively, findings from this study highlight the usefulness of Targetin for the treatment of pediatric high and low grade gliomas.
    Preview · Article · Dec 2013
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    ABSTRACT: Intervention aimed at disrupting or inhibiting newly formed vascular network is highly desired to attenuate the progression of angiogenesis-dependent diseases. In cancer, this is tightly associated with the generation of VEGF by hypoxia inducible factor-1α following its activation by hypoxia. In light of the multiple cellular roles played by microtubules and their involvement in the processing of the hypoxia inducible factor-1α transcript, modulation of microtubule dynamics is emerging as a logical approach to suppress tumor reliance on angiogenesis. Targetin is a novel noscapinoid that interferes with microtubule dynamicity and inhibits the growth of cell lines from many types of cancers. Utilizing in-vitro and ex-vivo angiogenic models, we discovered the vascular disrupting and anti-angiogenic properties of Targetin. Targetin disrupted pre-assembled capillary-like networks of human endothelial cells by severing cell-cell junctions, inhibiting endothelial cell proliferation and metabolic activity in the presence and absence of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Furthermore, we show that Targetin significantly inhibits the formation of neovasculature network sprouting from rat aortic explants stimulated with proangiogenic stimuli, namely VEGF or bFGF. We conclude that Targetin is a potential clinically promising anti-angiogenic agent for the treatment of many diseases including cancers.
    Full-text · Article · Dec 2013
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    Georgi Konstantinov Maximov · Deepak Kamnasaran
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    ABSTRACT: Hiccup (Singultus) is a sudden and involuntary contraction of the diaphragm followed by a sharp closure of the epiglottis which results in the production of a specific "hic" sound. Normally, hiccups are treated without intervention. Intractable hiccups occur rarely but are a disturbing symptom underlying other health related disorders. We report the clinical case of a 67-year-old male patient with myocardial infarction accompanied by intractable hiccups during the course of 8 months, and who was non-responsive to chlorpromazine or metoclopramide, and baclofen; drugs routinely used to treat this condition. This sustained hiccup had severely restricted the patient's ability to intake food and sleep. To explore alternative treatments, we investigated the adjuvant administration of lansoprazole, dimenhydrinate and clonazepam in this patient. We discovered that this drug combination was capable of successfully terminating his intractable hiccups, with no further evidence of recurrence. No similar treatment is previously reported for intractable hiccups. We further suggest a hypothesis concerning a potential mechanism on the anti-hiccup effect of dimenhydrinate. We identified that the adjuvant use of lansoprazole, clonazepam and dimenhydrinate was capable of attenuating the symptoms of our patient with intractable hiccups.
    Full-text · Article · Aug 2013 · BMC Research Notes
  • Norbert Ajeawung · Faure R · Jones C · Kamnasaran D.

    No preview · Article · Aug 2013 · Future Oncology
  • Norbert Fonya Ajeawung · Robert Faure · Chris Jones · Deepak Kamnasaran
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    ABSTRACT: Aim: The treatment of pediatric low-grade gliomas with current treatment modalities still remains ineffective among a subset of patients; hence, justifying the need to further investigate more effective therapies. Dipotassium bisperoxo (picolinato) oxovanadate V (Bpv[pic]), is a derivative of the trace metal vanadium and a potent inhibitor of protein tyrosine phosphatases, which are important mediators of oncogenic and tumor suppressive activities in cancers. In this study, we undertook a preclinical evaluation of the antineoplastic functions of Bpv(pic) in the treatment of pediatric low-grade gliomas. Materials & methods: We utilized pediatric low-grade glioma cell lines (Res186, Res259 and R286) in a wide variety of cancer assays to determine whether Bpv(pic) can abrogate the neoplastic properties of these cells. Results: Our preclinical evaluation of the antineoplastic properties of Bpv(pic) in pediatric low-grade gliomas reveals a significant dose-dependent decrease in cell viability as a consequence of decreased proliferation and sustained induction of growth arrest and apoptosis. Bpv(pic) significantly decreases cell migration/invasion and anchorage-independent growth in soft agarose. Within cells, Bpv(pic) functions by attenuating CDC25A activity, and by decreasing the expression of multiple protein tyrosine phosphatases, DNA repair genes, microtubule-associated genes, such as PLK1, AURKA and HDAC6, and conversely augmenting the expression of proapoptotic mediators such as BAK, AIFM and CTSL1. Conclusion: Collectively, our data strongly suggest novel evidence of Bpv(pic) being a potent antineoplastic drug and a suitable alternative for the treatment of pediatric low-grade gliomas.
    No preview · Article · Aug 2013 · Future Oncology
  • M Broome · Y Vial · S Jacquemont · C Sergi · D Kamnasaran · E Giannoni
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    ABSTRACT: Syngnathia is an extremely rare condition involving congenital fusion of the maxilla with the mandible. Clinical presentations vary from simple mucosal bands (synechiae) to complete bony fusion (synostosis). Most cases are unilateral incomplete fusions. We report the case of a severely growth-retarded newborn infant with complete synostosis of the mandible with the maxilla and the zygoma associated with cleft palate, choanal atresia, deafness, delayed cerebral white matter development, and genital and limb malformations. Extensive genetic analysis did not reveal any mutations. This association of multiple congenital malformations may represent an entity distinct from previously described syndromes associated with syngnathia.
    No preview · Article · Jun 2013 · Pediatrics & Neonatology
  • Majed Dasouki · Brian Andrews · Prabhu Parimi · Deepak Kamnasaran
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    ABSTRACT: Agnathia-otocephaly is a rare craniofacial malformation complex that is caused by de novo heterozygous and biallelic mutations in PRRX1 in two unrelated babies, respectively. We studied the PRRX1 gene in a non-consanguineous Indonesian female infant who was diagnosed prenatally with severe retrognathia (bilateral Pruzansky type III). Her older affected brother died shortly after birth and had agnathia-otocephaly. A c.266_269dupAAAA frameshift mutation in the poly A tract in PRRX1 was identified in the proband while her father only had an inframe duplication (c.267_269dupAAA) of the adenosine trinucleotide residue. Expression of both mutations in COS7 cells showed loss of function of the frame shift mutation only. Results of SNP genotyping coupled with recurrence of this novel mutation in this family are consistent with a paternally derived germline mosaicism rather than autosomal recessive inheritance as predicted by the family history. Severe retrognathia (bilateral Pruzansky III) and agnathia-otocephaly represent a spectrum of craniofacial malformations in this family. © 2013 Wiley Periodicals, Inc.
    No preview · Article · Apr 2013 · American Journal of Medical Genetics Part A
  • Norbert F Ajeawung · Harish C Joshi · Deepak Kamnasaran
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    ABSTRACT: Low grade gliomas are a heterogeneous group of tumours representing the most common form of neoplasms in the central nervous system among children. Although gross total resection remains the principal treatment, it is often impractical especially for the resection of tumours within eloquent regions of the brain. Instead Radiotherapy is utilised in such cases, but because of its associated toxicities, it is refrained from use among younger children. These limitations coupled with hypersensitivity and toxicities associated with some commonly used chemotherapeutic agents, have ignited the need to search for safer and more effective treatments for paediatric low grade gliomas. In this study, we investigated the EM011 drug on the growth of two pilocytic and one diffuse paediatric astrocytoma cell lines, using an assortment of cancer assays. We discovered that treatments of low grade gliomas with EM011 abrogated cell viability by inducing a decrease in cell proliferation and an arrest in the S and G2M cell cycle phases, followed by a converse increase in apoptosis in a dose and time dependent manner. The cell migratory and invasion indices, as well as anchorage independent growth in soft agarose, were significantly attenuated. These findings were mechanistically associated with a transient release of AIF, a disruption of microtubule architecture, and a decline in the expression of key genes which drive cancer progression including EGFR, mTORC1, JUN and multiple MMPs. In fact, the activity of MMP2 was also perturbed by EM011. These findings, in conjunction with the insignificant adverse side effects established from other studies, make EM011 an appealing chemotherapeutic agent for the treatment of paediatric low grade gliomas.
    No preview · Article · Feb 2013 · Cancer letters
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    Consolato Sergi · Jean Gekas · Deepak Kamnasaran
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    ABSTRACT: We report a new and rare case of recurrent anencephaly in a family with no other apparent abnormalities. The karyotypes of the family and all affected subjects were normal. Thorough mutational analyses of VANGL1 of chromosome 1p13.1 and FOXN1 of chromosome 17q11-q12, genes that are associated with phenotypes of the anencephaly spectrum, unfortunately did not disclose any DNA variations in an affected fetus of this family. The etiology of recurrent anencephaly in this family is therefore due to mutations in genes yet to be discovered, perhaps of the planar cell polarity pathway, or to possible environmental gestational factors during development.
    Full-text · Article · Jan 2013 · Fetal and pediatric pathology
  • Norbert Fonya Ajeawung · Hao Yang Wang · Deepak Kamnasaran
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    ABSTRACT: Medulloblastomas are highly aggressive tumors of the cerebellum with an embryonal origin. Despite current treatment modalities which include a combination of surgery, chemotherapy and/or radiation, challenges still exist to effectively treat some patients, especially those within the younger age group. In an effort to find improved therapies, ongoing research led by world-wide teams have explored non-conventional therapeutic strategies, as well as examined the efficacy of several drugs in Clinical trials among patients with Medulloblastomas. We outline in this article, recent advances on the efficacy and toxicity of numerous therapeutic agents including those that are DNA damaging agents, microtubules binding compounds, and those that are inhibitors of Topoisomerase and of the Notch and Hedgehog signalling pathway, which were assessed in recent Phase I and II clinical trials. Among these clinical trials, it is unfortunate that the outcomes were dismal with the majority of the patients with Medulloblastomas still succumbing to relapse after conventional therapies. Furthermore, it is yet to be established clearly the clinical efficacy of non-conventional therapies such as immunotherapy and gene therapy. Moreover, there is growing interest in proton therapy as a potential replacement for photon therapy, while high dose chemotherapy and autologous stem cell rescue may improve therapeutic efficacies. However, further research is needed to resolve the inherent toxicity from these novel therapeutic methods. In conclusion, novel therapies based on a better understanding of the biology of Medulloblastomas are pivotal in improving non-conventional therapies in the treatment of this deadly disease.
    No preview · Article · Dec 2012 · Cancer letters
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    ABSTRACT: Pediatric low grade gliomas are the most common central nervous system tumors and are still incurable among a subset of patients despite current treatment modalities. Steroid biosynthesis occurs in a wide variety of organs including the brain, to mediate an assortment of functions, including a proposed role in the growth of gliomas. Hence, targeting steroid biosynthesis and/or their signalling pathways, is anticipated as an effective approach for treating gliomas. In this study, we investigated whether our chemical library of steroid inhibitors can modulate the growth of pediatric low grade glioma cell lines (Res186, Res259, R286), and subsequently identified a potent inhibitor of 17beta-hydroxysteroid dehydrogenase type 3, referred to as DK16, which functions by attenuating cell viability, proliferation, migration/invasion and anchorage independent growth and conversely induces apoptosis and cell cycle arrest in a dose and duration dependent manner. Further investigations into the mechanisms of how DK16 functions showed that this drug increased the BAX/BCL2 expression ratio, induced phosphatidylserine externalization, and mitochondrial membrane depolarisations culminating to the release and nuclear translocation of AIF. In addition, treatments of low grade glioma cell lines with DK16 increased the expression of pro-apoptotic mediators including CDK2 and CTSL1, and with the converse diminished expression of pro-survival and migratory/invasion genes like PRKCA, TERT, MAPK8, MMP1 and MMP2. Our findings collectively demonstrate the potent anti-neoplastic properties of DK16, a steroid biosynthesis inhibitor, on the growth of pediatric low grade gliomas.
    No preview · Article · Nov 2012 · Cancer letters
  • D.Poirier · N.Ajeawung · R.Maltais · D. Kamnasaran

    No preview · Article · Nov 2012 · European Journal of Cancer
  • R. Faure · N. Ajeawung · D. Kamnasaran

    No preview · Article · Nov 2012 · European Journal of Cancer
  • N. Ajeawung · H. Joshi · D. Kamnasaran

    No preview · Article · Nov 2012 · European Journal of Cancer
  • D. Poirier · N. Ajeawung · R. Maltais · D. Kamnasaran

    No preview · Article · Nov 2012 · European Journal of Cancer
  • Norbert F Ajeawung · Hao Y Wang · Peter Gould · Deepak Kamnasaran
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    ABSTRACT: Purpose: To present an assortment of molecular targets evident from a variety of signal transduction pathways and downstream effectors, which may have clinical relevance for the treatment of medulloblastomas. Source: Data were archived from MEDLINE, using Boolean-formatted queries on the keywords including: medulloblastoma, pathology, prognosis, classification, tumor regression, inhibition, therapy, clinical trial, therapeutic agent, drug, molecular inhibitor, and signalling pathway. Only the most reputable articles were selected for critical analyses based on the qualitative assessment of the citation index, novelty of the findings and relevance to prospective novel ways of targeted therapies for medulloblastomas. Principal findings: Medulloblastomas are highly aggressive embryonal tumors of the cerebellum, akin to primitive neuroectodermal tumors elsewhere in the brain. Current treatments for medulloblastomas which include a combination of surgery, chemotherapy and radiation, remain challenging especially, for younger patients; however, advances in understanding regulatory pathways in medulloblastomas are crucial to develop more effective therapeutic targets. Evidence showing several molecular and pharmacological targets within key signalling pathways, such as HEDGEHOG, WNT, NOTCH, Receptor Tyrosine Kinase (ERB, IGF-IR, c-MET, PDGF, Estrogen, p75NTR) , their downstream effectors like PI3K/AKT, c-MYC and STAT3, and as well as other targets such as telomerase and cytoskeletal elements, is summarized. All molecular and pharmacological targets have pivotal roles in the pathogenesis of medulloblastomas. Most importantly, these pathways can be effectively pharmacologically targeted to regress the growth of medulloblastomas. Pre-clinical studies were routinely undertaken with a variety of human and murine cell lines and as well as murine models of medulloblastomas. Thus far, two drugs which target the NOTCH and HEDGEHOG signalling have completed Phase I clinical trials, but with evidence of low efficacies; hence, reinforcing the importance of continuing investigations in search of new therapeutic agents and targets. Conclusion: Novel therapies, based on better understanding key biological pathways in medulloblastomas, hold promise for improved treatments in due course among patients with medulloblastomas.
    No preview · Article · Oct 2012 · Clinical and investigative medicine. Medecine clinique et experimentale
  • Source
    Jean Gekas · Consolato Sergi · Deepak Kamnasaran
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    ABSTRACT: holoprosencephaly is the most common forebrain malformation syndrome with a multifactorial etiology. Currently, mutations are identified in 5-10% of non syndromic, non-chromosomal cases in at least 12 genes. We report the molecular prenatal diagnosis of a fetus with alobar holoprosencephaly. CTG band karyotyping and array CGH genome-wide cytogenetic screenings were done, in conjunction with DNA sequence analyses of the SHH, ZIC2, SIX3 and TGIF genes in search of a molecular etiology and with comparison of findings to prior cases. standard CTG band karyotyping and array CGH genome-wide screening failed to identify plausible chromosome imbalances or structural anomalies. However, extensive sequencing of the genomic DNA from the fetus and both parents on all exon and exon-intron boundaries of the four most commonly mutated genes: SHH, ZIC2, SIX3 and TGIF, identified codon 100 of the sonic hedgehog (SHH) gene having a hotspot for loss-of-function mutations in our case and others. mutations in codon 100 of SHH were discovered in both sporadic and autosomal dominant inherited cases with evidence of variable expressivity and penetrance. Collectively, this study reinforces the complexity of genotype-phenotype correlations in the prenatal diagnosis of holoprosencephalic fetuses.
    Full-text · Article · Jul 2012

  • No preview · Article · Jun 2012 · Prenatal Diagnosis
  • Consolato Sergi · Jean Gekas · Deepak Kamnasaran
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    ABSTRACT: We report a new case of a fetus with holoprosencephaly-polydactyly syndrome, also known as pseudo-trisomy 13 syndrome, and no other apparent abnormalities except for septal agenesis of the left lung. The fetal karyotype was normal. Mutational analysis of five genes (SHH, SIX3, TGIF, ZIC2, and GLI3), which are major genes associated with holoprosencephaly, did not disclose any mutational findings. We therefore propose that the abnormalities of our fetus support the demarcation of this syndrome as an autonomous phenotype. Specific diagnostic criteria for holoprosencephaly-polydactyly syndrome need to be complemented by the absence of mutations in the major holoprosencephaly genes.
    No preview · Article · Mar 2012 · Fetal and pediatric pathology

  • No preview · Article · Dec 2011 · Clinical Genetics

Publication Stats

451 Citations
195.28 Total Impact Points


  • 2010-2013
    • Laval University
      • Department of Pediatrics
      Quebec City, Quebec, Canada
  • 2005-2009
    • University of Toronto
      Toronto, Ontario, Canada
  • 2004-2005
    • SickKids
      • Arthur and Sonia Labatt Brain Tumour Research Centre (BTRC)
      Toronto, Ontario, Canada
  • 2000-2005
    • University of Alberta
      • Department of Medical Genetics
      Edmonton, Alberta, Canada