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Fulltext A case study of distinctive phenotypes arising from emanuel syndrome in two karyotypically identical patients

Mot Yee Yik, Rabiatul Basria S.M.N. Mydin, Emmanuel Jairaj Moses, Shahrul Hafiz Mohd Zaini, Abdul Rahman Azhari, Narazah Mohd Yusoff

Malaysian Journal of Medicine and Health Sciences, 2020;16(102):78-80.
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Emanuel syndrome, also referred to as supernumerary der(22) or t(11;22) syndrome, is a rare genomic syndrome. Patients are normally presented with multiple congenital anomalies and severe developmental disabilities. Affected newborns usually carry a derivative chromosome 22 inherited from either parent, which stems from a balanced translocation between chromosomes 11 and 22. Unfortunately, identification of Emanuel syndrome carriers is diffi- cult as balanced translocations do not typically present symptoms. We identified two patients diagnosed as Emanuel syndrome with identical chromosomal aberration: 47,XX,+der(22)t(11;22)(q24;q12.1)mat karyotype but presenting variable phenotypic features. Emanuel syndrome patients present variable phenotypes and karyotypes have also been inconsistent albeit the existence of a derivative chromosome 22. Our data suggests that there may exist ac- companying genetic aberrations which influence the outcome of Emanuel syndrome phenotypes but it should be cautioned that more patient observations, diagnostic data and research is required before conclusions can be drawn on definitive karyotypic-phenotypic correlations.
Fulltext The Roles of FOXO3 and c-Myc as key regulatory genes in leukaemia and myelodysplastic syndrome

Mot Yee Yik, Narazah Mohd Yusoff, Adam Azlan, Yaashini Rajasegaran, Lew Sze Yuen, Ong Si Min, et al.

Malaysian Journal of Human Genetics, 2020;1(1):4-17.
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The human leukaemia develops with abnormal increase of blast cells in the bone marrow. Leukaemia is caused by genetic aberrations which activates proto-oncogenes and inactivates tumor-suppressor genes and eventually leads to leukemogenesis. Myelodysplastic syndrome is a preleukemic state which shares similar symptoms and causative factors as leukaemia. FOXO3 and c-Myc have been increasingly recognized as key regulatory genes involved in the initiation and development of leukaemia and myelodysplastic syndromes. Their roles in these diseases is being investigated and findings thus far has indicated that FOXO3 acts as a tumor suppressor while c-Myc has been identified as a proto-oncogene. Currently published literature indicate that there are limited research on the correlation between FOXO3 and c-Myc especially in leukaemia and myelodysplastic syndrome. This review will focus on the key regulatory roles of FOXO3 and c-Myc in leukaemia and myelodysplastic syndrome.
Fulltext Comprehensive cytogenetic analysis of cases referred for suspected chromosomal abnormalities: a five-year study at Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Penang, Malaysia

Mot, Yee Yik, Siti Fatimah Ramli, Nazlina Mohamad Isa, Ruzzieatul Akma Razali, Abdul Rahman Azhari, Abdul Razak Abdul Khalid, et al.

Journal of Biomedical and Clinical Sciences, 2017;2(1):27-32.
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Chromosomal abnormalities (CA) can affect numerical or structural compositions of chromosomosal DNA leading to a diversity of clinical phenotypic presentations. Awareness of prenatal diagnosis and genetic counselling have improved with advancing medical research but CA remain prevalent as its aetiology is unknown. The objective of this study is to determine the frequencies of various CA in the principle region of north-western Malaysia and compare this data to previous reports to ascertain if statistical differences exist. Karyotype analyses performed at the Genetics Laboratory, Advanced Diagnostic Laboratory (ADL) during the first 5-years of cytogenetic services, totalling 1461 cases, were assessed in this report. Cases suspected of CA were initially diagnosed by clinicians and detailed clinical and family histories were recorded. Peripheral blood lymphocytes of patients were collected and cultured in vitro for acquisition of karyotype by standardized G-banding technique. Fluorescence in situ hybridization (FISH) was conducted in cases suspected of to be DiGeorge, Prader-Willi, Angelman and Williams syndrome. Of the total samples (1805) received and cultured, 1669 (92.46%) successfully yielded results. Abnormal outcomes were observed in 495 cases (29.66%) whereby pronounced majority of cases 299 (68.42%) were Down syndrome. This is followed by Edward, Turner and Patau syndrome, in order of frequency. Numerical CA appears to be prevalent accounting for 85.86% of cases. Structural CA accounted for 14.14% of total positive cases whereby the most common was deletions (34.29%) followed by translocations (20%), ring chromosomes (5.71%), Fragile X syndrome (4.29%), duplications (5.71%) and marker chromosomes (7.14%). The remainder of cases (22.86%) consisted of derivative chromosomes and other complex aberrations. The number of polymorphic variant cases were 27 (1.62%). The number of peripheral blood samples received has significantly increased from 14.3 per month in 2006 to 32.17 per month in 2011. Comparative analysis of our study to previous reports reveal statistical differences in the occurrence of several CA including Edward, Patau, Klinefelter and Fragile-X syndrome. Our experience with peripheral blood samples for cytogenetic analysis demonstrated a success rate of 92.46%. This showed an increase in clinicians validating patients’ diagnoses with karyotyping which is essential in confirming genetic anomalies with the goal to substantiate genetic counselling.
Fulltext Synergistic antibacterial effect of co-administering adipose-derived mesenchymal stromal cells and Ophiophagus hannah L-amino acid oxidase in a mouse model of methicillin-resistant Staphylococcus aureus-infected wounds

Mot YY, Othman I, Sharifah SH

Stem Cell Res Ther, 2017 01 23;8(1):5.
PMID: 28114965 DOI: 10.1186/s13287-016-0457-2

BACKGROUND: Mesenchymal stromal cells (MSCs) and Ophiophagus hannah L-amino acid oxidase (Oh-LAAO) have been reported to exhibit antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). Published data have indicated that synergistic antibacterial effects could be achieved by co-administration of two or more antimicrobial agents. However, this hypothesis has not been proven in a cell- and protein-based combination. In this study, we investigate if co-administration of adipose-derived MSCs and Oh-LAAO into a mouse model of MRSA-infected wounds would be able to result in a synergistic antibacterial effect.
METHODS: MSCs and Oh-LAAO were isolated and characterized by standard methodologies. The effects of the experimental therapies were evaluated in C57/BL6 mice. The animal study groups consisted of full-thickness uninfected and MRSA-infected wound models which received Oh-LAAO, MSCs, or both. Oh-LAAO was administered directly on the wound while MSCs were delivered via intradermal injections. The animals were housed individually with wound measurements taken on days 0, 3, and 7. Histological analyses and bacterial enumeration were performed on wound biopsies to determine the efficacy of each treatment.
RESULTS: Immunophenotyping and differentiation assays conducted on isolated MSCs indicated expression of standard cell surface markers and plasticity which corresponds to published data. Characterization of Oh-LAAO by proteomics, enzymatic, and antibacterial assays confirmed the identity, purity, and functionality of the enzyme prior to use in our subsequent studies. Individual treatments with MSCs and Oh-LAAO in the infected model resulted in reduction of MRSA load by one order of magnitude to the approximate range of 6 log10 colony-forming units (CFU) compared to untreated controls (7.3 log10 CFU). Similar wound healing and improvements in histological parameters were observed between the two groups. Co-administration of MSCs and Oh-LAAO reduced bacterial burden by approximately two orders of magnitude to 5.1 log10 CFU. Wound closure measurements and histology analysis of biopsies obtained from the combinational therapy group indicated significant enhancement in the wound healing process compared to all other groups.
CONCLUSIONS: We demonstrated that co-administration of MSCs and Oh-LAAO into a mouse model of MRSA-infected wounds exhibited a synergistic antibacterial effect which significantly reduced the bacterial count and accelerated the wound healing process.
Mesenchymal Stromal Cells-Derived Exosome and the Roles in the Treatment of Traumatic Brain Injury

Mot YY, Moses EJ, Mohd Yusoff N, Ling KH, Yong YK, Tan JJ

Cell Mol Neurobiol, 2023 Mar;43(2):469-489.
PMID: 35103872 DOI: 10.1007/s10571-022-01201-y

Traumatic brain injury (TBI) could result in life-long disabilities and death. Though the mechanical insult causes primary injury, the secondary injury due to dysregulated responses following neuronal apoptosis and inflammation is often the cause for more detrimental consequences. Mesenchymal stromal cell (MSC) has been extensively investigated as the emerging therapeutic for TBI, and the functional properties are chiefly attributed to their secretome, especially the exosomes. Delivering these nanosize exosomes have shown to ameliorate post-traumatic injury and restore brain functions. Recent technology advances also allow engineering MSC-derived exosomes to carry specific biomolecules of interest to augment their therapeutic outcome. In this review, we discuss the pathophysiology of TBI and summarize the recent progress in the applications of MSCs-derived exosomes, the roles and the signalling mechanisms underlying the protective effects in the treatment of the TBI.
Cytogenetics analysis as the central point of genetic testing in acute myeloid leukemia (AML): a laboratory perspective for clinical applications

Rosli AA, Azlan A, Rajasegaran Y, Mot YY, Heidenreich O, Yusoff NM, et al.

Clin Exp Med, 2023 Aug;23(4):1137-1159.
PMID: 36229751 DOI: 10.1007/s10238-022-00913-1

Chromosomal abnormalities in acute myeloid leukemia (AML) have significantly contributed to scientific understanding of its molecular pathogenesis, which has aided in the development of therapeutic strategies and enhanced management of AML patients. The diagnosis, prognosis and treatment of AML have also rapidly transformed in recent years, improving initial response to treatment, remission rates, risk stratification and overall survival. Hundreds of rare chromosomal abnormalities in AML have been discovered thus far using chromosomal analysis and next-generation sequencing. As a result, the World Health Organization (WHO) has categorized AML into subgroups based on genetic, genomic and molecular characteristics, to complement the existing French-American classification which is solely based on morphology. In this review, we aim to highlight the most clinically relevant chromosomal aberrations in AML together with the technologies employed to detect these aberrations in laboratory settings.
A RUNX1/ETO-SKP2-CDKN1B axis regulates expression of telomerase in t (8;21) acute myeloid leukemia

Moses EJ, Azlan A, Khor KZ, Mot YY, Mohamed S, Seeni A, et al.

Cell Mol Life Sci, 2023 Feb 23;80(3):70.
PMID: 36820913 DOI: 10.1007/s00018-023-04713-y

The fusion oncoprotein RUNX1/ETO which results from the chromosomal translocation t (8;21) in acute myeloid leukemia (AML) is an essential driver of leukemic maintenance. We have previously shown that RUNX1/ETO knockdown impairs expression of the protein component of telomerase, TERT. However, the underlying molecular mechanism of how RUNX1/ETO controls TERT expression has not been fully elucidated. Here we show that RUNX1/ETO binds to an intergenic region 18 kb upstream of the TERT transcriptional start site and to a site located in intron 6 of TERT. Loss of RUNX1/ETO binding precedes inhibition of TERT expression. Repression of TERT expression is also dependent on the destabilization of the E3 ubiquitin ligase SKP2 and the resultant accumulation of the cell cycle inhibitor CDKN1B, that are both associated with RUNX1/ETO knockdown. Increased CDKN1B protein levels ultimately diminished TERT transcription with E2F1/Rb involvement. Collectively, our results show that RUNX1/ETO controls TERT expression directly by binding to its locus and indirectly via a SKP2-CDKN1B-E2F1/Rb axis.