Analyzing normal and disrupted leukemic stem cell adhesion to bone marrow stromal cells by single-molecule tracking nanoscopy

Single Molecule Tracking Nanoscopy Extended to Two Colors with MTT2col for the Analysis of Cell-Cell Interactions in Leukemia

Single molecule tracking (SMT) is a powerful technique to study molecular dynamics, and is particularly adapted to monitor the motion and interactions of cell membrane components. Assessing interactions among two molecular populations is classically performed by several approaches, including dual-color videomicroscopy, which allows monitoring of interactions through colocalization events. Other techniques, such as fluorescence recovery after photobleaching (FRAP), Förster resonance energy transfer (FRET), and fluorescence correlation spectroscopy (FCS), are also utilized to measure molecular dynamics. We developed MTT2col, a set of algorithmic tools extending multi-target tracing (MTT) to dual-color acquisition (https://github.com/arnauldserge1/MTT2col). In this protocol, we used MTT2col to monitor adhesion molecules at the contact between leukemic stem cells and stromal cells, a process involved in cancer resistance to chemotherapy and in relapse. Our dual-color single molecule protocol includes the following steps: (i) labeling molecules of interest with fluorescent probes, (ii) video-acquisition, (iii) analyses using our MTT2col in-house software, to obtain positions and trajectories, followed by (iv) detailed analyses of colocalization, distribution, and dynamic motion modes, according to the issues addressed. MTT2col is a robust and efficient SMT algorithm. Both MTT and MTT2col are open-source software that can be adapted and further developed for specific analyses. Graphical abstract.

Targeting AraC-Resistant Acute Myeloid Leukemia by Dual Inhibition of CDK9 and Bcl-2: A Systematic Review and Meta-Analysis

PURPOSE

This study aims to determine the influence of targeting araC-resistant acute myeloid leukemia by dual inhibition cyclin-dependent protein kinase (CDK9) and B-cell lymphoma-2 （Bcl-2).

METHOD

The c-Myc inhibitor 10058-F4 and the CDK9 inhibitor AZD4573 were used to determine the cell cycle arrest and apoptosis.

RESULTS

10058-F4 reduces c-Myc protein levels and suppresses HepG2 cell proliferation, possibly by upregulating cyclin-dependent kinase (CDK) inhibitors, p21WAF1, and reducing intracellular alpha-fetal protein (AFP) levels.

CONCLUSION

The combination of AZD4573 and 10058-F4 has a synergistic anti-araC-resistant AML activity, providing a solid database for the aforementioned scientific hypothesis.