Abstract 6211: Clinical and prognostic assessment of the lncRNA ZFAS1-related gene signature in colorectal cancer

Abstract Colorectal cancer (CRC) is one of the leading causes of cancer death with a rapidly rising incidence rate in younger adults. It is projected to be the leading cause of death in adults under 50 years old by 2030. Although progress over the last couple of decades has improved the clinical management of patients affected by CRC, there is a lack of accurate biomarkers to stratify CRC patients. Among several other biomolecules, lncRNAs (long non-coding RNAs) are non-coding transcripts under 200 nucleotides that can regulate gene expression. Furthermore, lncRNAs are important players in oncogenesis and cancer progression and have the potential to be used as reliable biomarkers. Through this study, we explored the clinical relevance of lncRNAs in colorectal cancer. To analyze the distribution of lncRNAs, we utilized de-identified FFPE (formalin-fixed paraffin-embedded) blocks from Augusta University (n = 88). FFPE blocks were sectioned to extract tissue segments and were subsequently stained using H&E (hematoxylin and eosin dyes) to identify the tumor and adjacent normal regions. The quantification of the gene expression was performed using a medium-throughput NanoString platform. Further analyses were performed using clinicopathological features of the institutional cohort and an independent Cancer Genome Atlas (TCGA) dataset. TCGA contains genomic data along with clinical and molecular characterization of over 11,000 samples of various lineages. In the institutional cohort, ZFAS1 showed higher gene expression in the low survival group for stage II and III colorectal cancer patients, while no significant difference was observed in stage I and IV patients. ZFAS1 expression did not significantly correlate with other clinicopathological parameters, including race, alcohol consumption, tobacco consumption, age, grade, and family history of cancer. In an orthogonal TCGA analysis, higher ZFAS1 expression was associated with genomic perturbations, including significantly altered tumor mutational burden (TMB), aneuploidy, fractional genome alteration, and microsatellite instability. Further, a 21-gene signature was developed for prognostication using gene co-expression network analysis. The gene signature was significantly associated with overall and disease-free survival in the TCGA-CRC cohort. Immune deconvolution analysis of the RNA sequencing data revealed that higher expression of the 21-gene signature was associated with increased infiltration of regulatory T cells while being inversely correlated with the overall level of T cells. In conclusion, our study identified the clinicopathological role of ZFAS1 lncRNA and its interaction genes with prognostic significance in colorectal cancer. Further investigation into the therapeutic relevance of the ZFAS1-related gene signature may prove invaluable in improving the clinical outcomes of colorectal cancer patients. Citation Format: Pankaj Kumar Ahluwalia, Tiffanie Leeman, Ashis Mondal, Ashutosh Vashisht, Harmanpreet Singh, Nivin Omar, Kimya Jones, Ravindra Kolhe. Clinical and prognostic assessment of the lncRNA ZFAS1-related gene signature in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6211.