# Feedback Modulation between Human IN080 Chromatin Remodeling Complex and miR-372 in HCT116 Cells
## 3 Discussion
Our findings are directly in line with previous findings reported by [PERSON] and his colleagues [37], that the upstream region of the miR-372 contains two YY1 consensus binding sites (\(-\)1331 and \(-\)159 sites), suggesting that YY1 may directly control _miR-372_ transcriptional regulation. YY1 is a member of the INO80 complex and a DNA-binding protein. YY1 can initiate, activate, or repress cell gene transcription by recruiting different transcriptional cofactors to its activation or repression domain [43]. For example, YY1 transactivates _CDC6_ and _GRP78_ by recruiting the INO80 complex to the DNA binding sites on their promoters [44]. INO80 complex is well-known for its capability to regulate many target genes via recruitment at specific genome sites and remodeling the chromatin structure. Our previous study has also revealed the direct influence of INO80 on the p53/p21 pathway by prompting the removal of H2A.Z at the p53-binding site of the p21 gene in response to doxorubicin [45]. Therefore, we speculate that the INO80 complex may regulate the transcription _miR-372_ by binding to its promoter through YY1 and regulating the local chromatin structure, as we have previously revealed in the INO80- p21 regulatory axis. However, further studies are needed to elucidate the association between INO80-mediated chromatin remodeling and miR-372 expression in cancer cells. On the other hand, our results strongly suggest that miR-372 post-transcriptionally regulates the expression of the INO80 complex. According to the Target Scan Human ([[https://www.targetscan.org](https://www.targetscan.org)]([https://www.targetscan.org](https://www.targetscan.org)), accessed on 5 March 2021) website analysis, complementary sequences of miR-372 in the 3\({}^{\prime}\)-UTR of multi-subunits of INO80 complex, including _INO80_, _Arp8_, _YY1_, _INO80D_, and _MCRS1_, were predicted. In our experiments, _miR-372 mimics reduced the expression levels of INO80 and Arp8 in both mRNA and protein. Moreover, mimic _miR-372_ expression significantly suppressed the luciferase activities of pMIR-luc/INO80-3\({}^{\prime}\)-UTR and pMIR-luc/Arp8-3\({}^{\prime}\)-UTR in HCT116 cells, suggesting that miR-372 modulates the expression of _INO80_ and _Arp8_ by directly targeting their 3\({}^{\prime}\)-UTR. Based on the published literature, miR-372 can act as a tumor suppressor or an oncogenic factor depending on the gene targeted in different tumor cells. For instance, overexpression of _miR-372_ promotes the proliferation and migration of colorectal cancer cells by inhibiting the tumor suppressor gene _LATS2_[30]. In our experiments, either _miR-372_ mimics or _INO80_ silencing markedly suppressed the clonogenic ability of HCT116 cells, supposing that the miR-372 inhibiting colony formation is at least partially caused by inhibition of the INO80 complex. Through this, _INO80_ silencing selectively inhibits melanoma cell proliferation, tumorigenesis, and tumor maintenance in mouse xenografts [46], indicating that miR-372-INO80 complex regulatory axis may function as a tumor suppressor in cells. Combined with our experimental results and previously reported data, the INO80 complex not only occupies p53-binding sites of the _p2_ promoter but also negatively regulates p21 expression in a p53-dependent manner, further affecting the cell cycle process and maintenance of chromosome stability [35]. In HCT116 cells, mimicking _miR-372_ expression or knockdown of _INO80_ could upregulate p53 and p21 protein levels. Moreover, in Dox-induced INO80 knockdown HCT116 cells, _miR-372_ mimics significantly upregulated the p21 and p53 protein levels compared to INO80 knockdown only group, suggesting that the INO80 complex and miR-372 may be involved in the p21/p53 pathway in a coordinated regulation mode.