Bone marrow microenvironment modulation of acute lymphoblastic leukemia phenotype

Area of Science:

• Hematology
• Cancer Biology
• Cellular Biology

Background:

• Acute lymphoblastic leukemia (ALL) survival has improved, but chemoresistant minimal residual disease (MRD) causes relapse.
• The bone marrow microenvironment (BMM) protects ALL cells, contributing to drug resistance.
• Existing models inadequately represent BMM-protected leukemic cell resistance.

Purpose of the Study:

• To develop an improved in vitro model for studying ALL-BMM interactions.
• To characterize a chemoresistant ALL subpopulation within the BMM.
• To inform preclinical strategies for targeting MRD and relapse.

Main Methods:

• An innovative 2-D coculture model was developed using ALL cells and bone marrow-derived stromal cells.
• Leukemic cells were observed to bury beneath stromal cells, forming a "phase dim" subpopulation.
• Phenotypic analysis included metabolism, protein expression, and quiescence assessment.

Main Results:

• The "phase dim" ALL subpopulation displayed altered metabolism and distinct protein expression.
• These cells exhibited increased quiescence and pronounced chemotherapy resistance.
• This model effectively recapitulates drug-resistant ALL within the BMM sanctuary.

Conclusions:

• The "phase dim" ALL subpopulation represents a critical target for overcoming treatment resistance.
• This model provides a more accurate platform for studying MRD and relapse mechanisms.
• Further investigation of "phase dim" ALL can optimize preclinical drug development for ALL.