ABSTRACT
Current treatments for acute myeloid leukemia (AML) are designed to target rapidly dividing blast populations with limited success in eradicating the functionally distinct leukemia stem cell (LSC) population, which is postulated to be responsible for disease resistance and relapse. We have previously reported high miR-126 expression levels to be associated with a LSC-gene expression profile. Therefore, we hypothesized that miR-126 contributes to 'stemness' and is a viable target for eliminating the LSC in AML. Here we first validate the clinical relevance of miR-126 expression in AML by showing that higher expression of this microRNA (miR) is associated with worse outcome in a large cohort of older (⩾60 years) cytogenetically normal AML patients treated with conventional chemotherapy. We then show that miR-126 overexpression characterizes AML LSC-enriched cell subpopulations and contributes to LSC long-term maintenance and self-renewal. Finally, we demonstrate the feasibility of therapeutic targeting of miR-126 in LSCs with novel targeting nanoparticles containing antagomiR-126 resulting in in vivo reduction of LSCs likely by depletion of the quiescent cell subpopulation. Our findings suggest that by targeting a single miR, that is, miR-126, it is possible to interfere with LSC activity, thereby opening potentially novel therapeutic approaches to treat AML patients.
Subject(s)
Leukemia, Myeloid, Acute/therapy , MicroRNAs/antagonists & inhibitors , Nanoparticles/administration & dosage , Neoplastic Stem Cells/physiology , Animals , DNA Methylation , Humans , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/mortality , Leukocyte Common Antigens/antagonists & inhibitors , Mice , Mice, Inbred C57BL , MicroRNAs/physiology , Neoplastic Stem Cells/drug effectsABSTRACT
BACKGROUND: Although positron emission tomography computed tomography has proven diagnostic and staging value in head and neck carcinoma, it does not have optimal sensitivity or specificity. The positron emission tomography computed tomography fluorodeoxyglucose standardised uptake value has been shown to be associated with carcinoma stage. This study evaluated the impact of major clinicopathological factors on the standardised uptake value at the primary site and at neck lymph node metastases. SUBJECTS AND METHODS: Two hundred and forty-three oral cavity and laryngopharyngeal carcinoma patients who underwent positron emission tomography computed tomography were included. Correlation between the positron emission tomography computed tomography standardised uptake value and various clinicopathological factors was analysed. RESULTS: A positive correlation was found between the standardised uptake value and the size and depth of tumour infiltration, and lymph node positivity. Higher standardised uptake values were seen for more advanced tumour stages. The presence of perineural invasion, lymphatic invasion and extracapsular spread were all associated with increased standardised uptake values. CONCLUSION: Most of the clinicopathological features of head and neck carcinoma which are well known to be poor prognostic factors have a significant impact on positron emission tomography computed tomography fluorodeoxyglucose standardised uptake value.
