Direct targeting of amplified gene loci for proapoptotic anticancer therapy

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Gene amplification is a key driver of oncogenesis across many cancer types.
• Targeting amplified driver genes with drugs faces challenges due to acquired drug resistance.
• Existing therapies may be limited in efficacy against cancers with specific genetic alterations.

Purpose of the Study:

• To develop a novel therapeutic strategy for targeting cancer-associated gene amplifications.
• To investigate the efficacy of triplex-forming oligonucleotides (TFOs) in inducing cancer cell apoptosis.
• To explore a TFO-based approach as an alternative to overcome drug resistance in amplified cancers.

Main Methods:

• Utilized triplex-forming oligonucleotides (TFOs) to activate the DNA damage response in cancer cells.
• Focused on HER2-amplified cancers, employing TFOs designed to target the HER2 gene.
• Assessed DNA double-strand breaks (DSBs), apoptosis induction, and in vivo efficacy in tumor xenografts.

Main Results:

• TFOs targeting HER2 induced copy number-dependent DNA double-strand breaks (DSBs).
• Apoptosis was activated in HER2-positive cancer cells and xenografts independently of HER2 cellular function.
• The TFO strategy demonstrated in vivo efficacy comparable to current precision medicines.

Conclusions:

• Triplex-forming oligonucleotides offer a viable strategy for targeting tumors with amplified genomic loci.
• This approach provides a feasible alternative to combat drug resistance in HER2-positive breast and ovarian cancers.
• The TFO-mediated DNA damage response activation presents a generalizable therapeutic modality for amplified cancers.