DNA Intercalation and New Targets in Cancer Therapy

What is the mechanism of action of Topoisomerase II (TOP2) inhibitors in cancer chemotherapy?

TOP2 inhibitors trap the covalent TOP2-DNA complex, leading to DNA strand breaks.

Give an example of a Topoisomerase II inhibitor and its mechanism.

Doxorubicin intercalates DNA and inhibits TOP2, leading to double-strand breaks.

What are the side effects associated with the use of anthracyclines like doxorubicin?

Cardiotoxicity limits its use, and drug-induced DNA translocations can lead to secondary malignancies.

What do intercalators do in cancer therapy?

Intercalators insert between DNA base pairs, disrupting transcription and replication.

Name a drug that acts as an intercalator other than doxorubicin.

Mitoxantrone also intercalates DNA, inhibiting replication.

What is the role of G-quadruplexes in cancer therapy?

G-quadruplexes in gene promoters are promising targets for cancer therapy.

What is the function of telomerase in cancer cells?

Telomerase adds repetitive DNA sequences to telomeres, maintaining chromosome integrity.

Name a challenge in targeting telomerase for cancer therapy.

Targeting telomerase without affecting normal stem cells.

What type of DNA repair does base excision repair (BER) address?

BER fixes single-strand breaks.

How can combining DNA-damaging agents with repair inhibitors enhance chemotherapy efficacy?

It counters resistance mechanisms developed by cancer cells through upregulation of DNA repair pathways.

What is the mechanism of action of Telomestatin?

Telomestatin stabilizes telomeric G-quadruplexes, preventing telomerase elongation.

What is a potential strategy to target G-quadruplexes in cancer treatment?

Inhibiting helicases that unwind G-quadruplexes.

What does TMPyP4 do in cancer therapy?

TMPyP4 induces G-quadruplex formation, disrupting telomerase activity.

What is the therapeutic significance of PARP inhibitors?

PARP inhibitors are used for BRCA-mutant cancers, enhancing the effects of chemotherapy by preventing DNA repair.

What are the common DNA repair pathways involved in counteracting chemotherapy-induced damage?

Base excision repair, nucleotide excision repair, homologous recombination, and non-homologous end joining.