Identifying Resistance Mechanisms against Five Tyrosine Kinase Inhibitors Targeting the ERBB/RAS Pathway in 45 Cancer Cell Lines

Zsófia Pénzváltó,Reinhold Schäfer,A Marcell Szász,Zsófia Sztupinszki,István Likó,Bálint Tegze,Balázs Győrffy,Attila Szendrői,Stefan Wölfl

doi:10.1371/journal.pone.0059503

Abstract

Because of the low overall response rates of 10–47% to targeted cancer therapeutics, there is an increasing need for predictive biomarkers. We aimed to identify genes predicting response to five already approved tyrosine kinase inhibitors. We tested 45 cancer cell lines for sensitivity to sunitinib, erlotinib, lapatinib, sorafenib and gefitinib at the clinically administered doses. A resistance matrix was determined, and gene expression profiles of the subsets of resistant vs. sensitive cell lines were compared. Triplicate gene expression signatures were obtained from the caArray project. Significance analysis of microarrays and rank products were applied for feature selection. Ninety-five genes were also measured by RT-PCR. In case of four sunitinib resistance associated genes, the results were validated in clinical samples by immunohistochemistry. A list of 63 top genes associated with resistance against the five tyrosine kinase inhibitors was identified. Quantitative RT-PCR analysis confirmed 45 of 63 genes identified by microarray analysis. Only two genes (ANXA3 and RAB25) were related to sensitivity against more than three inhibitors. The immunohistochemical analysis of sunitinib-treated metastatic renal cell carcinomas confirmed the correlation between RAB17, LGALS8, and EPCAM and overall survival. In summary, we determined predictive biomarkers for five tyrosine kinase inhibitors, and validated sunitinib resistance biomarkers by immunohistochemistry in an independent patient cohort.

Highlights

Targeted therapy in cancer treatment refers to the application of special agents acting on specific molecular features of signal transduction pathways involved in the development of the cancerous phenotype
Sunitinib is a small-molecule multi-targeted receptor tyrosine kinase (RTK) inhibitor that was approved by the FDA for the treatment of renal cell carcinoma (RCC) and imatinib-resistant gastrointestinal stromal tumor (GIST)
Targeted therapy agents acting via the ERBB/RAS pathway entered the mainstream cancer therapy guidelines

Summary

Introduction

Targeted therapy in cancer treatment refers to the application of special agents acting on specific molecular features of signal transduction pathways involved in the development of the cancerous phenotype. Gefitinib, sorafenib, sunitinib and lapatinib are all clinically used tyrosine kinase inhibitors (TKIs) targeting receptors and downstream members of the ERBB/RAS pathway [1]. Erlotinib and gefitinib are reversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors used in the treatment of non-small cell lung cancer. Lapatinib inhibits the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2). It is approved for the treatment of breast cancer, where the overall response rate to this treatment is 24% [3]. Sunitinib is a small-molecule multi-targeted receptor tyrosine kinase (RTK) inhibitor that was approved by the FDA for the treatment of renal cell carcinoma (RCC) and imatinib-resistant gastrointestinal stromal tumor (GIST). Because of the low overall response rates of 10– 47% [6,7,8,9,10], there is an increasing need for biomarkers predicting response to targeted therapy treatment

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