Stromal cells modulate TCL1 expression, interacting AP-1 components and TCL1-targeting micro-RNAs in chronic...

Area of Science:

• Hematology
• Molecular Biology
• Cancer Research

Background:

• The chronic lymphocytic leukemia (CLL) tissue microenvironment influences disease progression.
• Bone marrow stromal cells (BMSC) promote CLL cell survival via contact-dependent mechanisms.
• The molecular interactions between CLL cells and BMSC are not fully understood.

Purpose of the Study:

• To investigate the molecular mechanisms by which BMSC affect CLL cell survival and activation.
• To identify specific molecular pathways regulated by BMSC in CLL cells.

Main Methods:

• Co-culture of CLL cells with BMSC.
• Gene expression profiling of CLL cells.
• Quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunoblotting, immunoprecipitations, and flow cytometry to validate findings.
• Analysis of micro-RNA levels.

Main Results:

• BMSC significantly upregulated the lymphoid proto-oncogene TCL1 (T-cell leukemia 1) in CLL cells at both mRNA and protein levels.
• TCL1 upregulation by BMSC was associated with decreased levels of TCL1-interacting proteins FOS/JUN.
• BMSC-mediated increases in TCL1 correlated with decreased levels of regulatory micro-RNAs (miR-29b, miR-181b, miR-34b).

Conclusions:

• The BMSC microenvironment plays an active role in regulating TCL1, a known pro-survival molecule in CLL.
• Targeting the cross-talk between CLL cells and BMSC presents a potential therapeutic strategy.