Abstract 3264
Background
A subgroup of MEK1 mutations in human tumors were recently described as RAF- and phosphorylation independent and as insensitive to currently clinically used allosteric MEK inhibitors. We established a novel cell line that carries a MEK1 mutation of this class (pGlu102_Lys104delinsGln) and tested a novel ATP competitive MEK inhibitor (MAP855) in this model. According to our knowledge this is the first patient derived cell line with this type of MEK mutation and the first spitzoid melanoma cell model.
Methods
PF130 cell line was established from the pleural effusion sample of a 37-year-old male patient with spitzoid melanoma. NGS was used for mutational analysis. Cells were treated either with allosteric MEK inhibitor selumetinib or with newly developed ATP competitive MEK inhibitor MAP855. We analyzed changes in cell number, cell cycle distribution and ERK activation after treatment in vitro. Furthermore, the in vivo tumorigenicity was tested by injecting the cells subcutaneously, intrapleurally or intravenously into female SCID mice.
Results
We found that ATP competitive MEK inhibitor MAP855 strongly decreased the viability of PF130 cells, while allosteric inhibitor selumetinib did not. Cell cycle analysis showed that MAP588 treatment could induce cell death in PF130 cells in a concentration dependent manner and slightly reduced the amount of cells in the S and the G2M phases. Furthermore, MAP855 was able to reduce ERK protein activation in PF130 cells effectively while selumetinib treatment had no effect. In vivo, intrapleurally injected cells established macroscopic tumors in the chest cavity after two months while intravenously and subcutaneously delivered cells showed limited growth.
Conclusions
We established a new cellular model of tumors with RAF- and phosphorylation independent MEK mutation. We found that recently developed ATP-competitive MEK inhibitor MAP855 is a potent inhibitor of these cells in vitro. The in vivo efficacy is currently under investigation. Furthermore, we describe here to the best of our knowledge the first patient derived spitzoid melanoma cell model to test both in vitro and in vivo novel therapeutic modalities.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Balazs Hegedus.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5368 - Durvalumab and Paclitaxel Combination for treatment of metastatic triple negative breast cancer is safe with very promising efficacy
Presenter: Hazem Ghebeh
Session: Poster Display session 3
Resources:
Abstract
1520 - A prospective cohort study on the pharmacokinetics of nivolumab in metastatic non-small cell lung cancer, melanoma, and renal cell cancer patients
Presenter: Daan Hurkmans
Session: Poster Display session 3
Resources:
Abstract
1603 - Safety and clinical activity of subcutaneously (SC) administered anti-PD-1 antibody PF-06801591 in phase I dose-expansion cohorts of locally advanced or metastatic non-small-cell lung cancer (NSCLC) and urothelial carcinoma (UC)
Presenter: Byoung Cho
Session: Poster Display session 3
Resources:
Abstract
3922 - Development of the Functional Assessment of Cancer Therapy-Immune Checkpoint Modulator (FACT-ICM): A scale to measure quality of life in cancer patients treated with ICMs
Presenter: Aaron Hansen
Session: Poster Display session 3
Resources:
Abstract
2408 - Immune checkpoint inhibitors (ICIs) as “chemotherapy (Ctx) sensitization” strategy in advanced solid tumors
Presenter: Francisco Javier Ros Montana
Session: Poster Display session 3
Resources:
Abstract
3612 - Validation of progression-free survival (PFS) as surrogate endpoint in randomised trials of immune checkpoint inhibitors in advanced solid cancers
Presenter: Peey Sei Kok
Session: Poster Display session 3
Resources:
Abstract
3827 - Pharmacokinetic (PK) analysis of weight-based and fixed dose cemiplimab in patients (pts) with advanced malignancies
Presenter: Michael Migden
Session: Poster Display session 3
Resources:
Abstract
2120 - A burst of highly differentiated CD4 TL identifies a subset of fast progressors, and correlates with hyperprogressive disease in NSCLC patients treated with ICI
Presenter: Hugo Arasanz
Session: Poster Display session 3
Resources:
Abstract
4254 - Nivolumab treatment in advanced non-small cell lung cancer (aNSCLC): a French nationwide retrospective cohort (UNIVOC Study)
Presenter: Christos Chouaid
Session: Poster Display session 3
Resources:
Abstract
1084 - Dissociated responses in patients with metastatic solid tumors treated with immunotherapy
Presenter: Pauline Vaflard
Session: Poster Display session 3
Resources:
Abstract