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Pheno-SELEX: Engineering Anti-Metastatic Aptamers through Targeting the Invasive Phenotype Using Systemic Evolution
Greg Shelley1, Jinlu Dai1, Jill M Keller2
1Department of Urology, University of Michigan, Ann Arbor, MI 48109, USA.
Abstract:
Multiple methods (e.g., small molecules and antibodies) have been engineered to target specific proteins and signaling pathways in cancer. However, many mediators of the cancer phenotype are unknown and the ability to target these phenotypes would help mitigate cancer. Aptamers are small DNA or RNA molecules that are designed for therapeutic use. The design of aptamers to target cancers can be challenging. Accordingly, to engineer functionally anti-metastatic aptamers we used a modification of systemic evolution of ligands by exponential enrichment (SELEX) we call Pheno-SELEX to target a known phenotype of cancer metastasis, i.e., invasion. A highly invasive prostate cancer (PCa) cell line was established and used to identify aptamers that bound to it with high affinity as opposed to a less invasive variant to the cell line. The anti-invasive aptamer (AIA1) was found to inhibit in vitro invasion of the original highly invasive PCa cell line, as well as an additional PCa cell line and an osteosarcoma cell line. AIA1 also inhibited in vivo development of metastasis in both a PCa and osteosarcoma model of metastasis. These results indicate that Pheno-SELEX can be successfully used to identify aptamers without knowledge of underlying molecular targets. This study establishes a new paradigm for the identification of functional aptamers.
Insights
Researchers developed Pheno-SELEX to create aptamers targeting cancer metastasis. This new method identified an anti-invasive aptamer (AIA1) that successfully inhibited cancer invasion and metastasis in preclinical models.
Area of Science:
- Biotechnology
- Molecular Biology
- Cancer Research
Background:
- Targeting cancer phenotypes is crucial for treatment, but many molecular mediators remain unknown.
- Aptamers, therapeutic nucleic acid molecules, offer potential but designing cancer-targeting aptamers is challenging.
- Current methods often require knowledge of specific molecular targets, limiting their application.
Purpose of the Study:
- To engineer functional anti-metastatic aptamers using a novel phenotypic selection method.
- To identify aptamers that inhibit cancer cell invasion and metastasis without prior knowledge of molecular targets.
- To establish a new paradigm for aptamer discovery based on cellular phenotypes.
Main Methods:
- Developed Pheno-SELEX, a modification of systemic evolution of ligands by exponential enrichment (SELEX), to select aptamers based on a specific cancer phenotype (invasion).
- Utilized highly invasive and less invasive prostate cancer (PCa) cell lines to identify high-affinity aptamers against the invasive phenotype.
- Tested the identified anti-invasive aptamer (AIA1) for its efficacy in inhibiting cancer cell invasion and metastasis in vitro and in vivo.
Main Results:
- Identified a novel anti-invasive aptamer (AIA1) using Pheno-SELEX.
- AIA1 demonstrated significant inhibition of in vitro invasion in multiple prostate cancer and osteosarcoma cell lines.
- AIA1 effectively suppressed in vivo metastasis in both prostate cancer and osteosarcoma models.
Conclusions:
- Pheno-SELEX is a successful strategy for identifying functional aptamers targeting specific cellular phenotypes like metastasis, even without knowing the molecular targets.
- The anti-invasive aptamer AIA1 shows therapeutic potential for inhibiting cancer metastasis.
- This study introduces a new paradigm for aptamer discovery, broadening therapeutic applications in oncology.
