Disrupting the MAD2L2-Rev1 Complex Enhances Cell Death upon DNA Damage

Abstract

DNA-damaging chemotherapy agents such as cisplatin have been the first line of treatment for cancer for decades. While chemotherapy can be very effective, its long-term success is often reduced by intrinsic and acquired drug resistance, accompanied by chemotherapy-resistant secondary malignancies. Although the mechanisms causing drug resistance are quite distinct, they are directly connected to mutagenic translesion synthesis (TLS). The TLS pathway promotes DNA damage tolerance by supporting both replication opposite to a lesion and inaccurate single-strand gap filling. Interestingly, inhibiting TLS reduces both cisplatin resistance and secondary tumor formation. Therefore, TLS targeting is a promising strategy for improving chemotherapy. MAD2L2 (i.e., Rev7) is a central protein in TLS. It is an essential component of the TLS polymerase zeta (ζ), and it forms a regulatory complex with Rev1 polymerase. Here we present the discovery of two small molecules, c#2 and c#3, that directly bind both in vitro and in vivo to MAD2L2 and influence its activity. Both molecules sensitize lung cancer cell lines to cisplatin, disrupt the formation of the MAD2L2-Rev1 complex and increase DNA damage, hence underlining their potential as lead compounds for developing novel TLS inhibitors for improving chemotherapy treatments.

REV7 is involved in outcomes of platinum‐based chemotherapy in pancreatic cancer by controlling the DNA damage response

“…The small molecule JH‐RE‐06, which inhibits the REV7–REV1 interaction, enhances sensitivity to cisplatin in vitro and in vivo 47 . The small molecules ZINC97017995 and ZINC25496030, which bind to the REV7 dimer and disrupt the REV7–REV1 interaction, enhance the cell death effect of cisplatin in vitro 48 . These reports indicate that inhibiting REV7 activity is a promising strategy for cancer treatment.…”

“… 47 The small molecules ZINC97017995 and ZINC25496030, which bind to the REV7 dimer and disrupt the REV7–REV1 interaction, enhance the cell death effect of cisplatin in vitro. 48 These reports indicate that inhibiting REV7 activity is a promising strategy for cancer treatment.…”

REV1: A novel biomarker and potential therapeutic target for various cancers

“…Binding of JH-RE-06 induces REV1 dimerization, which blocks the REV1-REV7 interaction and POL ζ recruitment. Recently, Pernicone et al (2022) discovered two small molecules (ZINC97017995 and ZINC25496030) from the ZINC12 subset Library that disrupt the assembly of MAD2L2-Rev1 and the formation of an active TLS complex. The above studies all show that these small molecules combined with cisplatin could enhance the sensitivity of human cancer cells to cisplatin while have minimal toxicity on their own.…”

Developing a peptide to disrupt cohesin head domain interactions

“…The binding kinetics of cohesin-inhibiting peptide 3 (CIP3) to Smc3 were measured by field-effect biosensing (FEB) Agile R100 label-free binding assay (Cardea), following their standard protocol, and as we have done previously,. 65 , 66 , 67 Briefly, 500 nM of CIP3 was immobilized on a graphene sensor chip by functionalizing the amine groups on the sensor surface. To establish the baseline of the current for the experiment, we used phosphate-buffered saline (PBS).…”