TCF12 and LncRNA MALAT1 Cooperatively Harness High Cyclin D1 but Low β-Catenin Gene Expression to Exacerbate Colorectal Cancer Prognosis Independently of Metastasis

Metastasis is a well-known factor worsening colorectal cancer (CRC) prognosis, but mortality mechanisms in non-metastatic patients with poor outcomes are less understood. TCF12 is a transcription factor that can be physically associated with the long non-coding RNA MALAT1, creating an alliance with correlated expression levels in CRC patients. This TCF12-MALAT1 alliance is linked to poorer prognosis independently of age and metastasis. To identify the downstream effects responsible for this outcome, we analyzed 2312 common target genes of TCF12 and MALAT1, finding involvement in pathways like Aurora B, ATM, PLK1, and non-canonical WNT. We investigated the impact of WNT downstream genes <i>CTNNB1</i> and <i>CCND1</i>, encoding β-catenin and cyclin D1, respectively, on survival in CRC patients with this alliance. Tumors with higher <i>TCF12</i> and <i>MALAT1</i> gene expressions alongside increased <i>β-catenin</i> gene expressions were classified as having a "Pan-CMS-2 pattern", showing relatively better prognoses. Conversely, tumors with high <i>TCF12</i>, <i>MALAT1</i>, and <i>cyclin D1</i> gene expressions but low <i>β-catenin</i> expression were categorized as "TMBC pattern", associated with poor survival, with survival rates dropping sharply from 60% at one year to 30% at three years. This suggests that targeting cyclin D1-associated CDK4/6 could potentially reduce early mortality risks in TMBC patients, supporting personalized medicine approaches.