LINC02257 regulates malignant phenotypes of colorectal cancer via interacting with miR-1273g-3p and YB1

Colorectal cancer (CRC) is the third most common cancer diagnosed and the second leading cause of cancer-related deaths. Emerging evidence has indicated that long non-coding RNAs (lncRNAs) are involved in the progression of various types of cancer. In this study, we aimed to identify potential causal lncRNAs in CRC through comprehensive multilevel bioinformatics analyses, coupled with functional validation. Our bioinformatics analyses identified LINC02257 as being highly expressed in CRC, and associated with poor survival and advanced tumor stages among patients with CRC. Genome-wide association analysis revealed significant associations between variants near LINC02257 and CRC, suggesting a causal role for LINC02257 in CRC. Network analysis identified LINC02257 as playing a key role in the epithelial-mesenchymal transition pathway. Single-cell RNA sequencing showed that elevated expression of LINC02257 was associated with a reduced proportion of epithelial cells. In vitro experiments showed that LINC02257 positively regulated the metastatic and proliferative potential of CRC cells. Mechanistically, LINC02257 affected CRC malignancy by functioning as a competitive endogenous RNA of microRNAs and RNA-binding proteins. LINC02257 upregulated SERPINE1 by sequestering tumor suppressive miR-1273g-3p, thereby increasing metastatic and proliferative abilities of CRC cells. Additionally, LINC02257 directly interacted with YB1 and induced its phosphorylation, thereby facilitating YB1 nuclear translocation. The transcriptional activation of YB1 target genes was associated with the oncogenic functions of LINC02257. Taken together, our results demonstrate LINC02257 as a promising therapeutic target for CRC treatment.