5-aza-2'-deoxycytidine induces telomere dysfunction in breast cancer cells

Area of Science:

• Epigenetics
• Cancer Biology
• Molecular Oncology

Background:

• Azacitidine (5-aza) is an epigenetic drug used for hematological malignancies.
• Low-dose 5-aza can demethylate DNA and alter gene expression.
• Previous studies showed 5-aza induces telomere elongation in breast cancer cells.

Purpose of the Study:

• To investigate the mechanisms behind 5-aza-induced telomere length increase.
• To understand how low-dose 5-aza affects breast cancer cells.

Main Methods:

• Breast cancer cell lines were treated with 5-aza in 2D and 3D cultures.
• Analysis included telomere length, DNA damage, telomerase, and ALT activity.
• Gene expression analysis was performed via DNA, RNA, and protein extraction.

Main Results:

• 5-aza treatment induced DNA damage at telomeres.
• Alternative Lengthening of Telomeres (ALT) activity increased 3-fold.
• The gene POLD3 was identified as potentially involved in ALT activity.

Conclusions:

• Low-dose 5-aza can trigger ALT mechanisms in surviving cancer cells.
• This activation may promote cancer cell survival and resistance to 5-aza.
• Understanding these mechanisms is crucial for clinical applications of 5-aza.