Co-activation of STAT3 and YES-Associated Protein 1 (YAP1) Pathway in EGFR-Mutant NSCLC.

Background: The efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC) is limited by adaptive activation of cell survival signals. We hypothesized that both signal transducer and activator of transcription 3 (STAT3) and Src-YES-associated protein 1 (YAP1) signaling are dually activated during EGFR TKI treatment to limit therapeutic response. Methods: We used MTT and clonogenic assays, immunoblotting, and quantitative polymerase chain reaction to evaluate the efficacy of EGFR TKI alone and in combination with STAT3 and Src inhibition in three EGFR-mutant NSCLC cell lines. The Chou-Talalay method was used for the quantitative determination of drug interaction. We examined tumor growth inhibition in one EGFR-mutant NSCLC xenograft model (n = 4 mice per group). STAT3 and YAP1 expression was evaluated in tumors from 119 EGFR-mutant NSCLC patients (64 in an initial cohort and 55 in a validation cohort) by quantitative polymerase chain reaction. Kaplan-Meier and Cox regression analyses were used to assess the correlation between survival and gene expression. All statistical tests were two-sided. Results: We discovered that lung cancer cells survive initial EGFR inhibitor treatment through activation of not only STAT3 but also Src-YAP1 signaling. Cotargeting EGFR, STAT3, and Src was synergistic in two EGFR-mutant NSCLC cell lines with a combination index of 0.59 (95% confidence interval [CI] = 0.54 to 0.63) for the PC-9 and 0.59 (95% CI = 0.54 to 0.63) for the H1975 cell line. High expression of STAT3 or YAP1 predicted worse progression-free survival (hazard ratio [HR] = 3.02, 95% CI = 1.54 to 5.93, P = .001, and HR = 2.57, 95% CI = 1.30 to 5.09, P = .007, respectively) in an initial cohort of 64 EGFR-mutant NSCLC patients treated with firstline EGFR TKIs. Similar results were observed in a validation cohort. Conclusions: Our study uncovers a coordinated signaling network centered on both STAT3 and Src-YAP signaling that limits targeted therapy response in lung cancer and identifies an unforeseen rational upfront polytherapy strategy to minimize residual disease and enhance clinical outcomes.

Estrogen receptor 1 gene expression and its combination with estrogen receptor 2 or aromatase expression predicts survival in non-small cell lung cancer.

The biological roles of estrogen receptor 1 (ERS1), estrogen receptor 2 (ERS2), and aromatase (CYP19A1) genes in the development of non-small cell lung cancer (NSCLC) is unclear, as is the use of their expression as a prognostic factor. The aim of this study was to investigate the prognostic value of estrogen receptors and aromatase mRNA expression, along with aromatase protein concentration, in resected NSCLC patients. Tumor and non-tumor lung tissue samples were analyzed for the mRNA expression of ERS1, ERS2 and CYP19A1 by RT-PCR. Aromatase concentration was measured with an ELISA. A total of 96 patients were included. ERS1 expression was significantly higher in non-tumor tissue than in tumor samples. Two gene expression categories were created for each gene (and protein): high and low. ERS1 high category showed increased overall survival (OS) when compared to the low expression category. Aromatase protein concentration was significantly higher in tumor samples. Higher ERS1 expression in tumor tissues was related to longer overall survival. The analysis of gene expression combinations provides evidence for longer OS when both ERS1 and ERS2 are highly expressed. ESR1, alone or in combination with ERS2 or CYP19A1, is the most determining prognostic factor within the analyzed 3 genes. It seems that ERS1 can play a role in NSCLC prognosis, alone or in combination with other genes such as ERS2 or Cyp19a1. ERS2 in combination with aromatase concentration could have a similar function.

Cisplatin-based three drugs combination (NIP) as induction and adjuvant treatment in locally advanced non-small cell lung cancer: final results.

INTRODUCTION: This phase III trial was conducted in non-small cell lung cancer patients with locally advanced stage II B (only T3N0) III A and III B (only T4 N0). Primary endpoint was 2-year survival; secondary were toxicity, disease-free survival, and overall survival. METHODS: After three cycles of vinorelbine (N) 25 mg/m2 on days 1 and 5, ifosfamide/mesna (I) 3 g/m2 on day 1, cisplatin (P) (NIP), patients were treated by surgery and within 45 days were randomized to two additional cycles of NIP versus observation. RESULTS: Median tumor diameter was 5.5 cm (1.2-10.6). Overall, 155 of 156 patients received chemotherapy: 133 (85%) men, median age: 59 years (35-75). Sixty-five percentage of patients were stage III A, 28% II B, and 7% III B. The study has been closed prematurely because of the low inclusion rate. After three cycles of induction in 143 assessable patients, 82 reported an objective response (57.3%) (95% CI: 48.8-65.6), with 3.5% complete response and 53.8% partial response. Relative dose intensity during neoadjuvant NIP (%) was 97, 98, and 98.5 for vinorelbine, ifosfamide/mesna, and cisplatin, respectively. Tolerance: G3 to 4 neutropenia in 3% of patients and G3 to 4 anemia in 4%; nonhematological toxicities included G3 nausea/vomiting in 11%, G3 anorexia and G3 to 4 infection in 6.5%, G3 asthenia in 10% and G3 to 4 alopecia in 25.5%. After a median of 32 days after NIP, 107 patients (69%) underwent operation with complete resection (R0) in 74% (79 of 107 patients). Downstaging (N2 to N0) after surgery was 29%. Operative mortality rate was 2.8%. Twenty-one days (median) after surgery, 79 patients were randomized to adjuvant NIP (47%) or control (53%). Tolerance of adjuvant NIP: 12.5% G3 to 4 nausea/vomiting, 19% G3 alopecia, 6% G3 infection, and G3 asthenia. Overall median survival 32.3 versus 31.8 months in the observation and NIP arms, respectively. CONCLUSIONS: NIP allows 74% of R0 with no surgery delay. The few number of randomized patients did not allow to conclude on the efficacy of adjuvant chemotherapy.