Article Impact Level: HIGH Data Quality: STRONG Summary of Cancer Cell https://doi.org/10.1016/j.ccell.2026.04.009 Dr. Salvador Alonso et al.
Points
- Investigators utilized targeted exome sequencing and spatial transcriptomics on patient-matched biopsies to evaluate how advanced colorectal cancer develops resistance to targeted KRAS and EGFR inhibitors.
- Almost half of all colorectal cancer cases harbor a specific KRAS mutation that drives runaway cell division and encourages tumors to form inside the patient tissue.
- The study revealed that resistant tumors exhibit immense intratumoral heterogeneity combining subclonal genetic mutations with distinct non-genetic transcriptional states that resemble fetal and mesenchymal cells.
- Three-dimensional organoid models confirmed that cancer cells autonomously initiate a temporary inflammatory adaptive phase early in the treatment cycle to survive the targeted chemotherapy.
- Combining a specialized TBK1 kinase inhibitor with standard KRAS therapy successfully shut down this internal cell survival program and significantly slowed overall cancer growth in preclinical models.
Summary
This study evaluated the biochemical and transcriptomic mechanisms driving acquired drug resistance in colorectal cancer (CRC) characterized by oncogenic KRAS mutations. The KRAS gene is mutationally activated in approximately 45% to 50% of all CRC cases, promoting uncontrolled cell division and tumor growth. While targeted therapies inactivating these mutated proteins show clinical promise, therapeutic efficacy is severely limited by rapid clinical relapse. Using targeted exome sequencing and spatial transcriptomics on patient-matched colon biopsies before, during, and after combined treatment with KRASG12C and EGFR inhibitors, the researchers sought to characterize the molecular evasion pathways deployed by resistant tumors.
The findings demonstrate that while acquired genetic mutations or target amplification exist at disease progression, these alterations are frequently subclonal and coexist with non-genetic, transcriptional adaptive states. Single-cell spatial analysis revealed significant intratumoral heterogeneity, with mesenchymal, YAP, and fetal-like transcriptional signatures predominating in resistant zones. Notably, an autonomous tumor-specific inflammatory program was induced during the early phase of treatment. Using human and murine three-dimensional organoid models isolated from external immune cells, the investigators confirmed that this inflammatory adaptive signaling is cancer-cell autonomous and directly precedes the emergence of fixed drug resistance.
To disrupt this adaptive survival mechanism, the researchers screened inflammation-related kinase inhibitors and identified TBK1 as a highly viable therapeutic target. Pharmacological inhibition of TBK1 combined with standard KRAS inhibitors in patient-derived tumor models significantly slowed cancer cell growth compared to single-agent regimens. Because the targeted inflammatory signal originates intrinsically within the malignant cells, this dual-targeting strategy abrogates the non-genetic adaptive phase without broadly suppressing systemic patient immune defenses. These results suggest that combined TBK1 and KRAS inhibition may delay or prevent treatment failure, though further clinical trials are necessary to determine long-term patient survival hazard ratios.
Link to the article: https://www.sciencedirect.com/science/article/abs/pii/S1535610826002205?via%3Dihub
References
Alonso, S., Chu, K., Granowsky, E., Rabanales, V. S., Parsons, M. J., Gunasinghe, H., Shia, J., Yaeger, R., & Dow, L. E. (2026). Concurrent genetic and non-genetic resistance mechanisms to KRAS inhibition in colorectal cancer. Cancer Cell, S1535610826002205. https://doi.org/10.1016/j.ccell.2026.04.009
