Correction: Transforming growth factor ß-induced epithelial-to-mesenchymal signature predicts metastasis-free survival in non-small cell lung cancer.

[This corrects the article DOI: 10.18632/oncotarget.26574.].

Transforming growth factor ß-induced epithelial-to-mesenchymal signature predicts metastasis-free survival in non-small cell lung cancer.

Transforming growth factor beta (TGFß) plays a key role in regulating epithelial-to-mesenchymal transition (EMT). A gene expression signature (TGFß-EMT) associated with TGFß-induced EMT activities was developed using human Non-Small Cell Lung Carcinoma (NSCLC) cells treated with TGFß-1 and subjected to Affymetrix microarray analysis. The final 105-probeset TGFß-EMT signature covers 77 genes, and a NanoString assay utilized a subset of 60 of these genes (TGFß-EMTN signature). We found that the TGFß-EMT and TGFß-EMTN gene signatures predicted overall survival (OS) and metastasis-free survival (MFS). The TGFß-EMT signature was validated as prognostic of 5-year MFS in 3 cohorts: a 133 NSCLC tumor dataset (P = 0.0002), a NanoString assays of RNA isolated from formalin-fixed paraffin-embedded samples from these same tumors (P = 0.0015), and a previously published NSCLC MFS dataset (P = 0.0015). The separation between high and low metastasis signature scores was higher at 3 years (ΔMFS TGFß-EMT = -28.6%; ΔMFS TGFß-EMTN = -25.2%) than at 5 years (ΔMFS TGFß-EMT = -18.6%; ΔMFS TGFß-EMTN = -11.8%). In addition, the TGFß-EMT signature correlated with whether the cancer had already metastasized or not at time of surgery in a colon cancer cohort. The results show that the TGFß-EMT signature successfully discriminated lung cancer cell lines capable of undergoing EMT in response to TGFß-1 and predicts MFS in lung adenocarcinomas. Thus, the TGFß-EMT signature has the potential to be developed as a clinically relevant predictive biomarker, for example to identify those patients with resected early stage lung cancer who may benefit from adjuvant therapy.

Characterization of epidermal growth factor receptor (EGFR) P848L, an unusual EGFR variant present in lung cancer patients, in a murine Ba/F3 model.

Lung cancer patients with mutations in epidermal growth factor receptor (EGFR) benefit from treatments targeting tyrosine kinase inhibitors (TKIs). However, both intrinsic and acquired resistance of tumors to TKIs are common, and EGFR variants have been identified that are resistant to multiple TKIs. In the present study, we characterized selected EGFR variants previously observed in lung cancer patients and expressed in a murine bone marrow pro-B Ba/F3 cell model. Among these EGFR variants, we report that an exon 20 deletion/insertion mutation S768insVGH is resistant to erlotinib (a first-generation TKI), but sensitive to osimertinib (a third-generation TKI). We also characterized a rare exon 21 germline variant, EGFR P848L, which transformed Ba/F3 cells and conferred resistance to multiple EGFR-targeting TKIs. Our analysis revealed that P848L (a) does not bind erlotinib; (b) is turned over less rapidly than L858R (a common tumor-derived EGFR mutation); (c) is not autophosphorylated at Tyr 1045 [the major docking site for Cbl proto-oncogene (c-Cbl) binding]; and (d) does not bind c-Cbl. Using viability assays including 300 clinically relevant targeted compounds, we observed that Ba/F3 cells transduced with EGFR P848L, S768insVGH, or L858R have very different drug-sensitivity profiles. In particular, EGFR P848L, but not L858R or S768insVGH, was sensitive to multiple Janus kinase 1/2 inhibitors. In contrast, cells driven by L858R, but not by P848L, were sensitive to multikinase MAPK/extracellular-signal-regulated kinase (ERK) kinase and ERK inhibitors including EGFR-specific TKIs. These observations suggest that continued investigation of rare TKI-resistant EGFR variants is warranted to identify optimal treatments for cancer.