Discrete single-cell microRNA analysis for phenotyping the heterogeneity of acute myeloid leukemia.

Acute myeloid leukemia (AML) is a highly heterogenous cancer in hematopoiesis, and its subtype specification is greatly important in the clinical practice for AML diagnosis and prognosis. Increasing evidence has shown the association between microRNA (miRNA) phenotype and AML therapeutic outcomes, emphasizing the need for novel techniques for convenient, sensitive, and efficient miRNA profiling in clinical practices. Here, we describe a nanoneedle-based discrete single-cell microRNA profiling technique for multiplexed phenotyping of AML heterogeneity without the requirement of sequencing or polymerase chain reaction (PCR). In virtue of a biochip-based and non-destructive nature of the assay, the expression of nine miRNAs in large number of living AML cells can be simultaneously analyzed with discrete single-cell level information, thus providing a proof-of-concept demonstration of an AML subtype classifier based on the multidimensional miRNA data. We showed successful analysis of subtype-specific cellular composition with over 90% accuracy and identified drug-responsive leukemia subpopulations among a mixed suspension of cells modeling different AML subtypes. The adoption of machine learning algorithms for processing the large-scale nanoneedle-based miRNA data shows the potential for powerful prediction capability in clinical applications to assist therapeutic decisions. We believe that this platform provides an efficient and cost-effective solution to move forward the translational prognostic usage of miRNAs in AML treatment and can be readily and advantageously applied in analyzing rare patient-derived clinical samples.

Colony Stimulating Activities of GM-CSF, G-CSF and IL-3 on Blast Progenitors from Acute Myeloblastic Leukemia.

The colony stimulating activities (CSAs) of recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF), recombinant granulocyte colony-stimulating factor (rG-CSF) and recombinant interleukin-3 (rIL-3) on blast cells from various types of acute myeloblastic leukemia (AML) patients were studied using an in vitro blast colony assay. The stimulatory magnitude of rGM-CSF was highest in type M4 blasts but almost non-existent in type M1 blasts. Some preferential stimulatory action of rG-CSF was observed in type M2, M4 blasts and in overt leukemia in patients with refractory anemia with excess of blasts. On the other hand, the stimulatory activity of rIL-3 did not differ much with the AML subtype. Exposure to rGM-CSF, rG-CSF or rIL-3 did not alter the cellular phenotype or morphology of the leukemic blasts or the self-renewal capacity of blast progenitors. Simultaneous addition of rGM-CSF, rG-CSF and rIL-3, in various combinations, produced variable results and a simple additive effect was seen in 40% of the cases studied and either a significantly larger or smaller value in the remaining cases. Recombinant GM-CSF, rG-CSF and rIL-3 when added together did not reconstitute CSA of phytohemagglutinin-stimulated leukocyte-conditioned medium (PHA-LCM).