The overall research goal of this proposal is to elucidate the mechanisms driving mCRC to better assess the critical need for discovery of biomarkers and targeted therapies. Although early stage colorectal cancer (CRC) is curable with surgery and adjuvant therapy, metastatic CRC (mCRC) is usually lethal. Despite advances in our understanding of primary CRC oncogenesis, the mechanisms by which CRC becomes metastatic and leads to patient death is poorly characterized. In addition, the lack of reliable biomarkers to predict development of mCRC and select patients for further treatment is a critical barrier. To address this critical knowledge gap, our proposal seeks to understand how long non-coding RNAs (lncRNAs) enable primary tumors to invade and metastasize to develop improved diagnostics and therapeutics. Therefore, we performed transcriptome analysis of 37 patient matched normal, primary, and distant metastatic colorectal cancer tissues to discover 148 differentially expressed (DE) RNA Associated with Metastasis (RAMS). Notably, the top up-regulated novel candidate, RAMS11, (i) is associated with poor survival, (ii) induces invasion in vitro and in vivo, (ii) increases resistance to topoisomerase inhibitors, (iii) interacts with chromobox homology 4 (CBX4), and (iv) and can be targeted with locked nucleic acids in vitro. This serves as the rationale for our hypothesis that RAMS11 may serve as a prognostic biomarker associated with poor outcome by interacting with CBX4 to epigenetically regulate genes and can be therapeutically targeted in mCRC. To demonstrate this, Aim 1 will evaluate RAMS11 as a prognostic biomarker associated with poor long-term outcome.
Aim 2 will characterize RAMS11-dependant CBX4 regulation. Lastly, Aim 3 will evaluate RAMS11 therapeutic potential. This proposal will establish the importance of RAMS11 as a master epigenetic regulator to promote colon cancer metastasis. Furthermore, this research is of translational impact by evaluating the prognostic and therapeutic potential of targeting RAMS11 directly with locked nucleic acid antisense oligonucleotides.
Despite advances in our understanding of primary colon cancer (CRC) oncogenesis, the mechanisms of tumor metastases remain poorly characterized. Therefore, this proposal seeks to understand the global regulatory mechanisms of a novel long non-coding RNA, RAMS11, and evaluate its potential as a biomarker and therapeutic target in metastatic CRC. Understanding how lncRNAs enable primary tumors to invade and metastasize and how they can be used as biomarkers is of tremendous clinical impact as it can lead to significant breakthroughs in the development of more specific treatments and better prognosis to improve outcomes in colon cancer.