| 초록 |
We have previously reported the role of miR-326-HDAC3 loop in anti-cancer drug-resistance. CAGE, a cancer/testis antigen, regulates the response to anti-cancer drug-resistance by forming a negative feedback loop with miR-200b. Studies investigating the relationship between CAGE and HDAC3 revealed that HDAC3 negatively regulated the expression of CAGE. ChIP assays demonstrated the binding of HDAC3 to the promoter sequences of CAGE. However, CAGE did not affect the expression of HDAC3. We also found that EGFR signaling regulated the expressions of HDAC3 and CAGE. Anti-cancer drug-resistant cancer cell lines show an increased expression of $pEGFR^{Y845}$ . HDAC3 was found to negatively regulate the expression of $pEGFR^{Y845}$ . CAGE showed an interaction and co-localization with EGFR. It was seen that miR-326, a negative regulator of HDAC3, regulated the expression of CAGE, $pEGFR^{Y845}$ , and the interaction between CAGE and EGFR. miR-326 inhibitor induced the binding of HDAC3 to the promoter sequences in anti-cancer drug-resistant $Malme3M^R$ cells, decreasing the tumorigenic potential of $Malme3M^R$ cells in a manner associated with its effect on the expression of HDAC3, CAGE and $pEGFR^{Y845}$ . The down-regulation of HDAC3 enhanced the tumorigenic, angiogenic and invasion potential of the anti-cancer drug-sensitive Malme3M cells in CAGE-dependent manner. Studies revealed that $PKC{ delta}$ was responsible for the increased expression of $pEGFR^{Y845}$ and CAGE in $Malme3M^R$ cells. CAGE showed an interaction with $PKC{ delta}$ in $Malme3M^R$ cells. Our results show that HDAC3-CAGE axis can be employed as a target for overcoming resistance to EGFR inhibitors. |
