A Novel Role of the LINC01270/miR-326/LDOC1 Axis in Proinflammatory Response Regulation via STAT1 Modulation in THP-1 Cells

LINC01270 is a long intergenic noncoding RNA implicated in the progression of various cancers. In our previous study, we demonstrated that LINC01270 plays a role in regulating the pro-inflammatory response in the THP-1 monocytic cell line, partly through modulation of NF-κB activation. Given the multifaceted nature of inflammation and the ability of noncoding RNAs to influence this process at multiple levels, we further investigated the potential role of LINC01270 in modulating additional inflammatory signaling pathways in lipopolysaccharide (LPS)-stimulated THP-1 cells. We found that attenuation of LINC01270 levels led to increased transcription and phosphorylation of STAT1, accompanied by elevated expression of the genes under STAT1 regulation. Further investigation revealed that LINC01270 regulates <i>STAT1</i> expression via the miR-326/leucine zipper downregulated in cancer 1 (LDOC1) axis. Notably, inhibition of the interaction between LINC01270 and miR-326 effectively reversed the effects of LINC01270 knockdown on <i>STAT1</i> expression and its downstream targets. Interestingly, both gain- and loss-of-function experiments with LDOC1 resulted in a consistent upregulation of <i>STAT1</i> transcription. Taken together, our findings highlight a pleiotropic role of the LINC01270 in regulating the pro-inflammatory response through modulation of STAT1 signaling, in addition to its previously established role in NF-κB regulation. Furthermore, this study uncovers a novel function of the LDOC1 in inflammation through its regulation of STAT1. These findings provide new mechanistic insights into lncRNA-microRNA-protein interactions in inflammatory signaling and may open avenues for developing novel therapeutic strategies targeting chronic inflammatory diseases.