Imane Chaib

BRCA1: a novel prognostic factor in resected non-small-cell lung cancer.

Background Although early-stage non-small-cell lung cancer (NSCLC) is considered a potentially curable disease following complete resection, patients have a wide spectrum of survival according to stage (IB, II, IIIA). Within each stage, gene expression profiles can identify patients with a higher risk of recurrence. We hypothesized that altered mRNA expression in nine genes could help to predict disease outcome: excision repair cross-complementing 1 (ERCC1), myeloid zinc finger 1 (MZF1) and Twist1 (which regulate N-cadherin expression), ribonucleotide reductase subunit M1 (RRM1), thioredoxin-1 (TRX1), tyrosyl-DNA phosphodiesterase (Tdp1), nuclear factor of activated T cells (NFAT), BRCA1, and the human homolog of yeast budding uninhibited by benzimidazole (BubR1). Methodology and Principal Findings We performed real-time quantitative polymerase chain reaction (RT-QPCR) in frozen lung cancer tissue specimens from 126 chemonaive NSCLC patients who had undergone surgical resection and evaluated the association between gene expression levels and survival. For validation, we used paraffin-embedded specimens from 58 other NSCLC patients. A strong inter-gene correlation was observed between expression levels of all genes except NFAT. A Cox proportional hazards model indicated that along with disease stage, BRCA1 mRNA expression significantly correlated with overall survival (hazard ratio [HR], 1.98 [95% confidence interval (CI), 1.11-6]; P = 0.02). In the independent cohort of 58 patients, BRCA1 mRNA expression also significantly correlated with survival (HR, 2.4 [95%CI, 1.01-5.92]; P = 0.04). Conclusions Overexpression of BRCA1 mRNA was strongly associated with poor survival in NSCLC patients, and the validation of this finding in an independent data set further strengthened this association. Since BRCA1 mRNA expression has previously been linked to differential sensitivity to cisplatin and antimicrotubule drugs, BRCA1 mRNA expression may provide additional information for customizing adjuvant antimicrotubule-based chemotherapy, especially in stage IB, where the role of adjuvant chemotherapy has not been clearly demonstrated.

Customized Treatment in Non-Small-Cell Lung Cancer Based on EGFR Mutations and BRCA1 mRNA Expression

Background Median survival is 10 months and 2-year survival is 20% in metastatic non-small-cell lung cancer (NSCLC) treated with platinum-based chemotherapy. A small fraction of non-squamous cell lung cancers harbor EGFR mutations, with improved outcome to gefitinib and erlotinib. Experimental evidence suggests that BRCA1 overexpression enhances sensitivity to docetaxel and resistance to cisplatin. RAP80 and Abraxas are interacting proteins that form complexes with BRCA1 and could modulate the effect of BRCA1. In order to further examine the effect of EGFR mutations and BRCA1 mRNA levels on outcome in advanced NSCLC, we performed a prospective non-randomized phase II clinical trial, testing the hypothesis that customized therapy would confer improved outcome over non-customized therapy. In an exploratory analysis, we also examined the effect of RAP80 and Abraxas mRNA levels. Methodology/Principal Findings We treated 123 metastatic non-squamous cell lung carcinoma patients using a customized approach. RNA and DNA were isolated from microdissected specimens from paraffin-embedded tumor tissue. Patients with EGFR mutations received erlotinib, and those without EGFR mutations received chemotherapy with or without cisplatin based on their BRCA1 mRNA levels: low, cisplatin plus gemcitabine; intermediate, cisplatin plus docetaxel; high, docetaxel alone. An exploratory analysis examined RAP80 and Abraxas expression. Median survival exceeded 28 months for 12 patients with EGFR mutations, and was 11 months for 38 patients with low BRCA1, 9 months for 40 patients with intermediate BRCA1, and 11 months for 33 patients with high BRCA1. Two-year survival was 73.3%, 41.2%, 15.6% and 0%, respectively. Median survival was influenced by RAP80 expression in the three BRCA1 groups. For example, for patients with both low BRCA1 and low RAP80, median survival exceeded 26 months. RAP80 was a significant factor for survival in patients treated according to BRCA1 levels (hazard ratio, 1.3 [95% CI, 1–1.7]; P = 0.05). Conclusions/Significance Chemotherapy customized according to BRCA1 expression levels is associated with excellent median and 2-year survival for some subsets of NSCLC patients , and RAP80 could play a crucial modulating effect on this model of customized chemotherapy. Trial Registration ClinicalTrials.gov NCT00883480

Three-Gene Expression Signature Predicts Survival in Early-Stage Squamous Cell Carcinoma of the Lung

Purpose: Adjuvant treatment may improve survival in early-stage squamous cell carcinoma (SCC) of the lung; however, the absolute gain is modest and mainly limited to stage II-IIIA. Current staging methods are imprecise indications of prognosis, but high-risk patients can be identified by gene expression profiling and considered for adjuvant therapy. Experimental Design: The expression of 29 genes was assessed by reverse transcriptase quantitative PCR in frozen primary tumor specimens obtained from 66 SCC patients who had undergone surgical resection. Expression values were dichotomized using the median as a cutoff value. We used a risk score to develop a gene expression model for the prediction of survival. Results: The univariate analysis of gene expression in the training cohort identified 10 genes with significant prognostic value: CSF1, EGFR, CA IX, PH4, KIAA0974, ANLN, VEGFC, NTRK1, FN1, and INR1. In the multivariate Cox model, CSF1 (hazard ratio, 3.5; P = 0.005), EGFR (hazard ratio, 2.7; P = 0.02), CA IX (hazard ratio, 0.2; P < 0.0001), and tumor size >4 cm (hazard ratio, 2.7; P = 0.02) emerged as significant markers for survival. The high prognostic value of a risk score based on the expression of the three genes (CSF1, EGFR, and CA IX) was positively validated in a separate cohort of 26 patients in an independent laboratory (P = 0.05). Conclusions: The three-gene signature is strongly associated with prognosis in early-stage SCC. Positive independent validation suggests its suitability for selecting SCC patients with an increased risk of death who might benefit from adjuvant treatment.

XPG mRNA Expression Levels Modulate Prognosis in Resected Non–Small-Cell Lung Cancer in Conjunction with BRCA1 and ERCC1 Expression

BACKGROUND Molecular markers can help identify patients with early-stage non-small-cell lung cancer (NSCLC) with a high risk of relapse. Excision repair cross-complementing 1 (ERCC1), Xeroderma pigmentosum group G (XPG), and breast cancer 1 (BRCA1) are involved in DNA damage repair, whereas ribonucleotide reductase M1 (RRM1) is implicated in DNA synthesis. Expression levels of these molecules might therefore have a prognostic role in lung cancer. PATIENTS AND METHODS We examined ERCC1, RRM1, XPG, and BRCA1 mRNA levels by real-time quantitative polymerase chain reaction in 54 patients with stage IB-IIB resected NSCLC. A strong correlation was observed between the 4 genes. RESULTS For patients with low BRCA1, regardless of XPG mRNA expression levels, disease-free survival (DFS) was not reached. For patients with intermediate/high BRCA1 and high XPG, DFS was 50.7 months. However, for patients with intermediate/high BRCA1 and low/intermediate XPG, DFS decreased to 16.3 months (P = .002). Similar differences were observed in overall survival, with median survival not reached for patients with low BRCA1, regardless of XPG levels, or for patients with intermediate/high BRCA1 and high XPG. Conversely, for patients with intermediate/high BRCA1 levels and low/intermediate XPG levels, median survival dropped to 25.5 months (P = .007). CONCLUSION BRCA1 and XPG were identified as independent prognostic factors for both median survival and DFS. High BRCA1 mRNA expression confers poor prognosis in early NSCLC, and the combination of high BRCA1 and low XPG expression still further increases the risk of shorter survival. These findings can help optimize the customization of adjuvant chemotherapy.

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.

BIM and mTOR expression levels predict outcome to erlotinib in EGFR-mutant non-small-cell lung cancer

BIM is a proapoptotic protein that initiates apoptosis triggered by EGFR tyrosine kinase inhibitors (TKI). mTOR negatively regulates apoptosis and may influence response to EGFR TKI. We examined mRNA expression of BIM and MTOR in 57 patients with EGFR-mutant NSCLC from the EURTAC trial. Risk of mortality and disease progression was lower in patients with high BIM compared with low/intermediate BIM mRNA levels. Analysis of MTOR further divided patients with high BIM expression into two groups, with those having both high BIM and MTOR experiencing shorter overall and progression-free survival to erlotinib. Validation of our results was performed in an independent cohort of 19 patients with EGFR-mutant NSCLC treated with EGFR TKIs. In EGFR-mutant lung adenocarcinoma cell lines with high BIM expression, concomitant high mTOR expression increased IC50 of gefitinib for cell proliferation. We next sought to analyse the signalling pattern in cell lines with strong activation of mTOR and its substrate P-S6. We showed that mTOR and phosphodiesterase 4D (PDE4D) strongly correlate in resistant EGFR-mutant cancer cell lines. These data suggest that the combination of EGFR TKI with mTOR or PDE4 inhibitors could be adequate therapy for EGFR-mutant NSCLC patients with high pretreatment levels of BIM and mTOR.

Activation of signal transducer and activator of transcription 3 (STAT3) signaling in EGFR mutant non-small-cell lung cancer (NSCLC)

Gefitinib, erlotinib or afatinib are the current treatment for non-small-cell lung cancer (NSCLC) harboring an activating mutation of the epidermal growth factor receptor (EGFR), but less than 5% of patients achieve a complete response and the median progression-free survival is no longer than 12 months. Early adaptive resistance can occur as soon as two hours after starting treatment by activating signal transducer and activation of transcription 3 (STAT3) signaling. We investigated the activation of STAT3 in a panel of gefitinib-sensitive EGFR mutant cell lines, and gefitinib-resistant PC9 cell lines developed in our laboratory. Afatinib has great activity in gefitinib-sensitive as well as in gefitinib-resistant EGFR mutant NSCLC cell lines. However, afatinib therapy causes phosphorylation of STAT3 tyrosine 705 (pSTAT3Tyr705) and elevation of STAT3 and RANTES mRNA levels. The combination of afatinib with TPCA-1 (a STAT3 inhibitor) ablated pSTAT3Tyr705 and down-regulated STAT3 and RANTES mRNA levels with significant growth inhibitory effect in both gefitinib-sensitive and gefitinib-resistant EGFR mutant NSCLC cell lines. Aldehyde dehydrogenase positive (ALDH+) cells were still observed with the combination at the time that Hairy and Enhancer of Split 1 (HES1) mRNA expression was elevated following therapy. Although the combination of afatinib with STAT3 inhibition cannot eliminate the potential problem of a remnant cancer stem cell population, it represents a substantial advantage and opportunity to further prolong progression free survival and probably could increase the response rate in comparison to the current standard of single therapy.

Melanoma: oncogenic drivers and the immune system.

Advances and in-depth understanding of the biology of melanoma over the past 30 years have contributed to a change in the consideration of melanoma as one of the most therapy-resistant malignancies. The finding that oncogenic BRAF mutations drive tumor growth in up to 50% of melanomas led to a molecular therapy revolution for unresectable and metastatic disease. Moving beyond BRAF, inactivation of immune regulatory checkpoints that limit T cell responses to melanoma has provided targets for cancer immunotherapy. In this review, we discuss the molecular biology of melanoma and we focus on the recent advances of molecularly targeted and immunotherapeutic approaches.

Interim analysis of the Spanish Lung Cancer Group (SLCG) BRCA1-RAP80 Expression Customization (BREC) randomized phase III trial of customized therapy in advanced non-small cell lung cancer (NSCLC) patients (p) (NCT00617656/GECP-BREC).

LBA8002 Background: Findings from the SLCG phase II customized chemotherapy trial (NCT00883480) showed that RAP80, a component of the BRCA1 complex, influenced outcome both in p with low BRCA1 expression treated with cisplatin (cis)/gemcitabine (gem) and in p with intermediate/high BRCA1 levels treated with cis/docetaxel (doc) or with doc alone. Together with the French Lung Cancer Group, the SLCG has performed a prospective, randomized phase III trial comparing noncustomized cis/doc with customized therapy in metastatic NSCLC p. A parallel phase II study (ChiCTR-TRC-12001860) is being carried out in China under the auspices of the SLCG. METHODS Since 6 March 2008, 391 p with wild-type EGFR have been randomized 1:1 to the control or experimental arm. p in the control arm receive cis/doc; p in the experimental arm receive treatment according to their BRCA1 and RAP80 levels: p with low RAP80, regardless of BRCA1 levels, cis/gem; p with intermediate/high RAP80 and low/intermediate BRCA1, cis/doc; p with intermediate/high RAP80 and high BRCA1, doc alone. The primary endpoint is progression-free survival (PFS). RESULTS At the planned interim analysis (cut-off, 15 October 2012; N=279), PFS was 5.49 months (m) in the control and 4.38 m in the experimental arm (P=0.07). Overall survival (OS) was 12.66 m in the control and 8.52 m in the experimental arm (P=0.006). Response rate (RR) was 37.3% in the control and 27% in the experimental arm (P=0.07). In the multivariate analysis including PS, treatment arm, BRCA1, RAP80, histology, smoking status, and metastatic site, only extrathoracic metastases were associated with an increased risk of progression (HR, 1.78; P=0.02). CONCLUSIONS Based on the negative results for PFS at the interim analysis, accrual has been closed on this study. Negative results may be due to the poor predictive capacity of RAP80 and the inclusion of doc alone as a treatment in the experimental arm. In addition, doc/cis may not be the ideal combination for the control arm. CLINICAL TRIAL INFORMATION NCT00617656.

Common Co-activation of AXL and CDCP1 in EGFR-mutation-positive Non-Small Cell Lung Cancer Associated With Poor Prognosis

Epidermal growth factor receptor (EGFR)-mutation-positive non-small cell lung cancer (NSCLC) is incurable, despite high rates of response to EGFR tyrosine kinase inhibitors (TKIs). We investigated receptor tyrosine kinases (RTKs), Src family kinases and focal adhesion kinase (FAK) as genetic modifiers of innate resistance in EGFR-mutation-positive NSCLC. We performed gene expression analysis in two cohorts (Cohort 1 and Cohort 2) of EGFR-mutation-positive NSCLC patients treated with EGFR TKI. We evaluated the efficacy of gefitinib or osimertinib with the Src/FAK/Janus kinase 2 (JAK2) inhibitor, TPX0005 in vitro and in vivo. In Cohort 1, CUB domain-containing protein-1 (CDCP1) was an independent negative prognostic factor for progression-free survival (hazard ratio of 1.79, p = 0.0407) and overall survival (hazard ratio of 2.23, p = 0.0192). A two-gene model based on AXL and CDCP1 expression was strongly associated with the clinical outcome to EGFR TKIs, in both cohorts of patients. Our preclinical experiments revealed that several RTKs and non-RTKs, were up-regulated at baseline or after treatment with gefitinib or osimertinib. TPX-0005 plus EGFR TKI suppressed expression and activation of RTKs and downstream signaling intermediates. Co-expression of CDCP1 and AXL is often observed in EGFR-mutation-positive tumors, limiting the efficacy of EGFR TKIs. Co-treatment with EGFR TKI and TPX-0005 warrants testing.