Rewiring cancer drivers to activate apoptosis

Area of Science:

• Oncology
• Molecular Biology
• Chemical Biology

Background:

• Cancer cells utilize driver mutations for proliferation and survival.
• Cell death pathways normally eliminate cells for organismal benefit.
• Existing cancer drivers could potentially be rewired to induce cell death.

Purpose of the Study:

• To introduce a new class of molecules, transcriptional/epigenetic chemical inducers of proximity (TCIPs).
• To demonstrate TCIPs' ability to recruit cancer drivers to cell death gene promoters.
• To investigate TCIPs' efficacy in diffuse large B cell lymphoma (DLBCL).

Main Methods:

• Designed TCIPs by linking small molecules targeting B-cell lymphoma 6 (BCL6) and transcriptional activators like BRD4.
• Utilized TCIP1, a potent molecule, to recruit BRD4 to BCL6-binding sites.
• Assessed TCIP1's effect on gene expression and its killing efficacy in DLBCL cell lines.

Main Results:

• TCIP1 enhanced BRD4 binding at target gene promoters, promoting pro-apoptotic gene expression.
• TCIP1 demonstrated potent killing of DLBCL cell lines, including chemotherapy-resistant and TP53-mutant lines (EC50 1-10 nM).
• TCIP1 exhibited cell- and tissue-specific effects, highlighting combinatorial transcriptional specificity.

Conclusions:

• TCIPs represent a novel approach to activate endogenous cell death pathways in cancer.
• TCIP1 shows significant therapeutic potential for DLBCL and other malignancies.
• The TCIP concept may extend to regenerative medicine and developmental disorders.