biomolecules Review Targeting Non-Oncogene Addiction for Cancer Therapy Hae Ryung Chang 1,*,†, Eunyoung Jung 1,†, Soobin Cho 1, Young-Jun Jeon 2 and Yonghwan Kim 1,* 1 Department of Biological Sciences and Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Korea;
[email protected] (E.J.);
[email protected] (S.C.) 2 Department of Integrative Biotechnology, Sungkyunkwan University, Suwon 16419, Korea;
[email protected] * Correspondence:
[email protected] (H.R.C.);
[email protected] (Y.K.); Tel.: +82-2-710-9552 (H.R.C.); +82-2-710-9552 (Y.K.) † These authors contributed equally. Abstract: While Next-Generation Sequencing (NGS) and technological advances have been useful in identifying genetic profiles of tumorigenesis, novel target proteins and various clinical biomarkers, cancer continues to be a major global health threat. DNA replication, DNA damage response (DDR) and repair, and cell cycle regulation continue to be essential systems in targeted cancer therapies. Although many genes involved in DDR are known to be tumor suppressor genes, cancer cells are often dependent and addicted to these genes, making them excellent therapeutic targets. In this review, genes implicated in DNA replication, DDR, DNA repair, cell cycle regulation are discussed with reference to peptide or small molecule inhibitors which may prove therapeutic in cancer patients. Additionally, the potential of utilizing novel synthetic lethal genes in these pathways is examined, providing possible new targets for future therapeutics. Specifically, we evaluate the potential of TONSL as a novel gene for targeted therapy. Although it is a scaffold protein with no known enzymatic activity, the strategy used for developing PCNA inhibitors can also be utilized to target TONSL.