220P - Advancing lung adenocarcinoma treatment: Establishing KRAS-driven organoids for drug screening

Background

Lung cancer is the deadliest (18% of the total cancer deaths) and most prevalent type of cancer in the world. Lung adenocarcinoma (LADC) is the most common subtype of lung cancer, accounting for ∼40% of all cases. Approximately 32% of all LADCs are driven by KRAS mutations.

Methods

For the formation of KRAS-driven LADC, we have used transgenic mice harboring mutations of KRAS^G12V, p53-null, and stabilized β-catenin. Dissociated cells were resuspended in BME and submerged airway organoid medium to generate organoids. For characterization, hematoxylin-eosin (H&E) and immunostaining were performed on 4 μm paraffin sections of cultured organoids and parental tumors. We examined the expression of LADC markers, TTF-1 and CK7 as well as CK5 as a control. The mutational profiles of the organoids and their concordance with parental tissues were identified through Sanger sequencing. For drug screening, organoid viability was assessed after 5 days of drug incubation using ATP-based viability assay.

Results

We successfully established a biobank with 21 different organoid lines including KRAS^G12V-driven LADC organoids as well as healthy organoids. The histopathological and mutational features of the parental tumors were highly recapitulated in the organoid lines. All the LADC organoid lines displayed concordant marker expression (TTF-1 and CK7) and mutational (KRAS, p53, and β-catenin) profiles in the corresponding parental tumors. Subsequently, we conducted drug screenings using targeted and epigenetic agents. Our findings reveal that targeted drugs Amuvatinib, Midostaurin, and Selumetinib are selectively active against KRAS^G12V-driven LADC organoids. Notably, a synergistic effect was observed when combining these active targeted agents with the epigenetic drug Decitabine.

Conclusions

Our study demonstrates the successful establishment of a transgenic mouse model with KRAS^G12V- driven LADC and the subsequent derivation of specific organoids. We identified promising compounds and combinations that show potential for effectively combating KRAS^G12V-driven LADC. These findings highlight the significance of our model in targeted drug discovery and advancing personalized therapeutic approaches for patients with this aggressive form of lung cancer.

Legal entity responsible for the study

The author.

Funding

Cancerfonden, Royal Physiographic Society of Lund.

Disclosure

The author has declared no conflicts of interest.