# Instruct tumour cells to make antibodies against their own oncoprotein

Source: https://onco.cc/ideas/idea-bio1-mrna-intrabodies/  
OnCo record `idea-bio1-mrna-intrabodies` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Deliver genetic instructions so the cancer cell itself manufactures a molecule that traps its driver protein inside the cell.

## Summary

Intrabodies (single-domain antibodies or designed binders expressed intracellularly) can sequester or degrade targets that small molecules cannot reach. mRNA-LNP delivery makes transient intracellular expression feasible without viral vectors, and fusion to a degron converts binding into destruction. Delivery specificity and expression level are the open questions rather than the biology.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: An mRNA-encoded degron-fused intrabody reduces its intracellular oncoprotein target by more than 60 percent in tumour tissue and inhibits growth in a xenograft after repeated dosing.
- Rationale: Intrabody function is well established in cell culture; mRNA delivery has solved the manufacturing problem for intracellular proteins in other indications, and antibody-like binders can be raised against surfaces no small molecule can address.
- Proposed test: Mouse study comparing tumour and liver expression, target degradation and growth inhibition for an mRNA intrabody against a validated intracellular driver, with immunogenicity monitoring on repeat dosing.
- Maturity: speculative
- Actor: research

## Sources

- Bottleneck evidence (The undruggable drivers): Dang et al., Drugging the 'undruggable' cancer targets (Nature Reviews Cancer 2017): https://doi.org/10.1038/nrc.2017.36

## Connected records

- technologies: [Personalised neoantigen (mRNA) vaccines](https://onco.cc/technologies/neoantigen-mrna-vaccine/), [PROTACs & molecular glues (targeted protein degradation)](https://onco.cc/technologies/protac-degrader/)
- companies: [Moderna](https://onco.cc/companies/moderna/), [Orna Therapeutics (Eli Lilly)](https://onco.cc/companies/orna-therapeutics/)
- bottlenecks: [The undruggable drivers](https://onco.cc/bottlenecks/b-undruggable-targets/)
- key papers: [Drugging the 'undruggable' cancer targets](https://onco.cc/key-papers/paper-dang-nat-rev-cancer/)

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