Interferon/STAT1 and neuregulin signaling pathways are exploratory biomarkers of cetuximab (Erbitux®) efficacy in KRAS wild-type squamous carcinomas: a pathway-based analysis of whole human-genome microarray data from cetuximab-adapted tumor cell-line models

Int J Oncol. 2011 Dec;39(6):1455-79. doi: 10.3892/ijo.2011.1155. Epub 2011 Aug 9.


KRAS mutation status is being used as the sole biomarker to predict therapeutic efficacy of cetuximab in metastatic colorectal cancer (mCRC). A significant number of mCRC patients with KRAS wild-type (WT) tumors, however, do not benefit from cetuximab. We are also lacking efficacy predictors in head and neck squamous cell carcinomas with an intact KRAS signaling and in non-small cell lung cancer in which KRAS mutations do not predict cetuximab efficacy. We recently established pre-clinical models of EGFR gene-amplified KRAS WT A431 squamous carcinoma cells chronically adapted to grow in the presence of cetuximab. We employed the ingenuity pathway analysis software to functionally interpret data from Agilent's whole human genome arrays in the context of biological processes, networks, and pathways. Cetuximab-induced activation of the interferon (IFN)/STAT1 appeared to switch from 'growth inhibitory' in acutely-treated cells to 'pro-survival' in chronically-adapted cells. Cetuximab treatment appeared to negatively select initially dominant IFN-sensitive clones and promoted selection of IFN- and cetuximab-refractory tumor clones constitutively bearing an up-regulated IFN/STAT1 signaling. High-levels of mRNAs coding for the EGFR ligands amphiregulin (AREG), epiregulin (EREG), and neuregulin-1/heregulin (NRG1) predicted for acute cetuximab's functioning. Chronic cetuximab, however, appeared to negatively select initially dominant AREG/EREG/NRG1-positive clones to promote selection of cetuximab-refractory clones exhibiting a knocked-down neuregulin signaling. Our current evolutionary mapping of the transcriptomic changes that occur during cetuximab-induced chronic blockade of EGFR/KRAS WT signaling strongly suggests that mRNAs coding for IFN/STAT1- and EGFR ligands-related genes can be evaluated as novel predictors of efficacy in KRAS WT squamous cancer patients being treated with cetuximab.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / pharmacology
  • Antibodies, Monoclonal / therapeutic use*
  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents / therapeutic use*
  • Biomarkers / metabolism
  • Carcinoma, Squamous Cell / drug therapy*
  • Carcinoma, Squamous Cell / genetics
  • Carcinoma, Squamous Cell / metabolism
  • Cell Line, Tumor
  • Cetuximab
  • ErbB Receptors / antagonists & inhibitors
  • Gene Expression Profiling
  • Gene Expression Regulation, Neoplastic
  • Gene Regulatory Networks
  • Genome, Human
  • Genome-Wide Association Study
  • Humans
  • Interferons / pharmacology*
  • Models, Biological
  • Neuregulins / metabolism*
  • Oligonucleotide Array Sequence Analysis
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins p21(ras)
  • STAT1 Transcription Factor / metabolism*
  • Signal Transduction / drug effects
  • ras Proteins / genetics*


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents
  • Biomarkers
  • KRAS protein, human
  • Neuregulins
  • Proto-Oncogene Proteins
  • STAT1 Transcription Factor
  • STAT1 protein, human
  • Interferons
  • ErbB Receptors
  • Proto-Oncogene Proteins p21(ras)
  • ras Proteins
  • Cetuximab