Mechanistic insights into the dual role of CCAR2/DBC1 in cancer

Cell cycle and apoptosis regulator 2 (CCAR2), also known as deleted in breast cancer 1 (DBC1), has been recently identified as a master regulator of transcriptional processes and plays diverse roles in physiology and pathophysiology, including as a regulator of apoptosis, DNA repair, metabolism, and tumorigenesis. CCAR2 functions as a coregulator of various transcription factors and a critical regulator of numerous epigenetic modifiers. Based on its ability to stimulate apoptosis by activating and stabilizing p53, CCAR2 was initially considered to be a tumor suppressor. However, an increasing number of studies have shown that CCAR2 also functions as a tumor-promoting coregulator by activating oncogenic transcription factors and regulating the enzymatic activity of epigenetic modifiers, indicating that CCAR2 may play a dual role in cancer progression by acting as a tumor suppressor and tumor promoter. Here, we review recent progress in understanding the dual tumor-suppressing and oncogenic roles of CCAR2 in cancer. We discuss CCAR2 domain structures, its interaction partners, and the molecular mechanisms by which it regulates the activities of transcription factors and epigenetic modifiers. Cancer: nuclear protein both an off- and on-switch for tumorsA nuclear protein, originally identified by its tumor-suppressing activity, has been shown to also be a tumor promoter. CCAR2 promotes programmed cell death, suppressing tumors by triggering the removal of damaged cells. However, recent research, reviewed by Jeong Hoon Kim at Sungkyunkwan University, Seoul, South Korea, and co-workers, shows that CCAR2's role in cancer is more complex than first thought. CCAR2 has a complicated shape that allows it to perform many functions, including regulating proteins that reorganize DNA architecture to expose or hide genes, activating or deactivating them, and thereby suppressing or promoting cancer depending on the genes involved. Increased levels of CCAR2 are associated with poor prognosis, indicating its potential for use as a prognostic marker. Understanding CCAR2's dual nature may help in developing new treatments for various cancers.

Automated summary

A recent study has found that CCAR2, also known as DBC1, acts as both a tumor suppressor and a tumor promoter. Initially considered a tumor suppressor due to its ability to stimulate apoptosis, CCAR2 has been found to also activate oncogenic transcription factors and regulate the enzymatic activity of epigenetic modifiers. Its dual role in cancer progression makes it a potential prognostic marker and understanding its mechanisms may lead to new treatments for various cancers.