Identification of modulators of the ALT pathway through a native FISH-based optical screen

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Alternative lengthening of telomeres (ALT) is a key mechanism for telomere maintenance in a significant fraction of human cancers.
• Understanding the genetic regulation of ALT is crucial for developing targeted cancer therapies.

Purpose of the Study:

• To identify novel genes that modulate the alternative lengthening of telomeres (ALT) pathway using a high-throughput screen.
• To validate identified ALT modulators and explore their therapeutic potential.

Main Methods:

• Development and application of TAILS (telomeric ALT in situ localization screen), a high-throughput imaging-based screen.
• Screening of over 1,000 genes involved in DNA transactions.
• Validation of candidate genes using molecular and cellular assays.

Main Results:

• Identification of both promoters (e.g., CHD4, SGF29) and suppressors (e.g., DDX39A/B, TIMELESS, CAF1) of ALT.
• Demonstration that defects in histone deposition are linked to ALT-associated phenotypes.
• Confirmation that pharmacological agents can modulate ALT activity.

Conclusions:

• The TAILS screen successfully identified key regulators of the ALT pathway.
• Targeting histone deposition and identified ALT modulators offers potential therapeutic strategies for ALT-positive cancers.
• Pharmacological interventions can be used to manipulate ALT activity for cancer treatment.