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Updated: Sep 6, 2025
Creating Matched In vivo/In vitro Patient-Derived Model Pairs of PDX and PDX-Derived Organoids for Cancer Pharmacology Research
Published on: May 5, 2021
BRAFV600E;K601Q metastatic melanoma patient-derived organoids and docking analysis to predict the response to
Letizia Porcelli1, Roberta Di Fonte1, Ciro L Pierri2
1IRCCS Istituto Tumori Giovanni Paolo II, V.le O. Flacco, 65, 70124 Bari, Italy.
Abstract:
The V600E mutation in BRAF is associated with increased phosphorylation of Erk1/2 and high sensitivity to BRAFi/MEKi combination in metastatic melanoma. In very few patients, a tandem mutation in BRAF, V600 and K601, causes a different response to BRAFi/MEKi combination. BRAFV600E;K601Q patient-derived organoids (PDOs) were generated to investigate targeted therapy efficacy and docking analysis was used to assess BRAFV600E;K601Q interactions with Vemurafenib. PDOs were not sensitive to Vemurafenib and Cobimetinib given alone and sensitive to their combination, although not as responsive as BRAFV600E PDOs. The docking analysis justified such a result showing that the tandem mutation in BRAF reduced the affinity for Vemurafenib. Tumor analysis showed that BRAFV600E;K601Q displayed both increased phosphorylation of Erk1/2 at cytoplasmic level and activation of Notch resistance signaling. This prompted us to inhibit Notch signaling with Nirogacestat, achieving a greater antitumor response and providing PDOs-based evaluation of treatment efficacy in such rare metastatic melanoma.
Insights
Metastatic melanoma with rare BRAF tandem mutations (V600E;K601Q) show reduced sensitivity to BRAF/MEK inhibitors. Combining BRAF/MEK inhibitors with Notch inhibitors like Nirogacestat improves treatment efficacy.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- The BRAF V600E mutation is a key driver in metastatic melanoma, conferring sensitivity to BRAF/MEK inhibitor (BRAFi/MEKi) combinations.
- Rare tandem mutations, such as BRAF V600E;K601Q, present unique challenges in targeted therapy response.
Purpose of the Study:
- To investigate the efficacy of targeted therapies in metastatic melanoma harboring the BRAF V600E;K601Q tandem mutation.
- To explore the underlying mechanisms of resistance and identify potential combination strategies.
Main Methods:
- Generation of BRAF V600E;K601Q patient-derived organoids (PDOs) for drug sensitivity testing.
- In silico docking analysis to evaluate drug-target interactions.
- Analysis of signaling pathways, including Erk1/2 phosphorylation and Notch signaling activation.
Main Results:
- BRAF V600E;K601Q PDOs demonstrated limited sensitivity to single-agent Vemurafenib or Cobimetinib but responded to the combination.
- The tandem mutation reduced BRAF V600E;K601Q affinity for Vemurafenib, as predicted by docking analysis.
- Tumors exhibited increased Erk1/2 phosphorylation and activated Notch resistance signaling, which was partially overcome by Nirogacestat.
Conclusions:
- The BRAF V600E;K601Q mutation confers distinct drug resistance patterns in metastatic melanoma.
- Combination therapy targeting both BRAF/MEK and Notch pathways offers a promising strategy for this rare patient subgroup.
- PDOs serve as a valuable platform for evaluating treatment efficacy in rare melanoma mutations.
