FGFR1-4 RNA-Based Gene Alteration and Expression Analysis in Squamous Non-Small Cell Lung Cancer

While fibroblast growth factor receptors (FGFRs) are involved in several biological pathways and FGFR inhibitors may be useful in the treatment of squamous non-small cell lung cancer (Sq-NSCLC), FGFR aberrations are not well characterized in Sq-NSCLC. We comprehensively evaluated FGFR expression, fusions, and variants in 40 fresh-frozen primary Sq-NSCLC (stage IA3−IV) samples and tumor-adjacent normal tissues using real-time PCR and next-generation sequencing (NGS). Protein expression of FGFR1−3 and amplification of FGFR1 were also analyzed. FGFR1 and FGFR4 median gene expression was significantly (p < 0.001) decreased in tumors compared with normal tissue. Increased FGFR3 expression enhanced the recurrence risk (hazard ratio 4.72, p = 0.029), while high FGFR4 expression was associated with lymph node metastasis (p = 0.036). Enhanced FGFR1 gene expression was correlated with FGFR1 protein overexpression (r = 0.75, p = 0.0003), but not with FGFR1 amplification. NGS revealed known pathogenic FGFR2,3 variants, an FGFR3::TACC3 fusion, and a novel TACC1::FGFR1 fusion together with FGFR1,2 variants of uncertain significance not previously reported in Sq-NSCLC. These findings expand our knowledge of the Sq-NSCLC molecular background and show that combining different methods increases the rate of FGFR aberrations detection, which may improve patient selection for FGFRi treatment.

p38 Mediates Resistance to FGFR Inhibition in Non-Small Cell Lung Cancer

FGFR signalling is one of the most prominent pathways involved in cell growth and development as well as cancer progression. FGFR1 amplification occurs in approximately 20% of all squamous cell lung carcinomas (SCC), a predominant subtype of non-small cell lung carcinoma (NSCLC), indicating FGFR as a potential target for the new anti-cancer treatment. However, acquired resistance to this type of therapies remains a serious clinical challenge. Here, we investigated the NSCLC cell lines response and potential mechanism of acquired resistance to novel selective FGFR inhibitor CPL304110. We found that despite significant genomic differences between CPL304110-sensitive cell lines, their resistant variants were characterised by upregulated p38 expression/phosphorylation, as well as enhanced expression of genes involved in MAPK signalling. We revealed that p38 inhibition restored sensitivity to CPL304110 in these cells. Moreover, the overexpression of this kinase in parental cells led to impaired response to FGFR inhibition, thus confirming that p38 MAPK is a driver of resistance to a novel FGFR inhibitor. Taken together, our results provide an insight into the potential direction for NSCLC targeted therapy.

MET-Pyk2 Axis Mediates Acquired Resistance to FGFR Inhibition in Cancer Cells

Deregulation of fibroblast growth factor receptors (FGFRs) signaling, as a result of FGFR amplification, chromosomal translocation, or mutations, is involved in both initiation and progression of a wide range of human cancers. Clinical data demonstrating the dependence of cancer cells on FGFRs signaling clearly indicate these receptors as the molecular targets of anti-cancer therapies. Despite the increasing number of tyrosine kinase inhibitors (TKIs) being investigated in clinical trials, acquired resistance to these drugs poses a serious therapeutic problem. In this study, we focused on a novel pan-FGFR inhibitor-CPL304110, currently being investigated in phase I clinical trials in adults with advanced solid malignancies. We analyzed the sensitivity of 17 cell lines derived from cancers with aberrant FGFR signaling, i.e. non-small cell lung cancer, gastric and bladder cancer to CPL304110. In order to explore the mechanism of acquired resistance to this FGFR inhibitor, we developed from sensitive cell lines their variants resistant to CPL304110. Herein, for the first time we revealed that the process of acquired resistance to the novel FGFR inhibitor was associated with increased expression of MET in lung, gastric, and bladder cancer cells. Overexpression of MET in NCI-H1703, SNU-16, RT-112 cells as well as treatment with HGF resulted in the impaired response to inhibition of FGFR activity. Moreover, we demonstrated that cells with acquired resistance to FGFR inhibitor as well as cells overexpressing MET displayed enhanced migratory abilities what was accompanied with increased levels of Pyk2 expression. Importantly, inhibition of both MET and Pyk2 activity restored sensitivity to FGFR inhibition in these cells. Our results demonstrate that the HGF/MET-Pyk2 signaling axis confers resistance to the novel FGFR inhibitor, and this mechanism is common for lung, gastric, and bladder cancer cells. Our study suggests that targeting of MET/Pyk2 could be an approach to overcome resistance to FGFR inhibition.

Cell-based assay for low- and high-scale screening of the Wnt/β-catenin signaling modulators

Deregulation of the Wnt/β-catenin signaling pathway is associated with many serious disorders, including cancer and Alzheimer's disease. The pivotal player is β-catenin, which avoids degradation after activation of the pathway and is translocated to the nucleus, where it interacts with TCF/LEF transcription factors and induces expression of genes involved in cell cycle and apoptosis regulation. The identification of small molecules that may affect Wnt/β-catenin signaling remains an important target during the development of novel therapies. We used the TCF/LEF lentiviral vector and the Wnt-independent H1703 cell line to develop a luciferase reporter-based cell assay for screening of the Wnt/β-catenin pathway modulators. Following the optimization of cell density, concentration of activator, and stimulation time, the reporter system was validated by demonstrating its specific and dose-dependent response to several established modulators of Wnt/β-catenin signaling such as Wnt3a, small interfering RNA (siRNA) against β-catenin, glycogen synthase kinase 3 (GSK-3), and β-catenin/TCF transcription complex inhibitors. Two pilot screens of inhibitors and activators of Wnt/β-catenin signaling identified potential novel modulators of this pathway. Our findings suggest that the H1703-7TFP assay constitutes a suitable model of low background and high sensitivity for the low- and high-scale screening of the Wnt/β-catenin pathway modulators.

Wnt/β-catenin pathway as a potential prognostic and predictive marker in patients with advanced ovarian cancer

Background

β-catenin is the key protein in the WNT signalling pathway and it forms adherent junctions together with E-cadherin. In ovarian carcinoma, abnormal expression of β-catenin, E-cadherin and WNT-1 was observed, but their prognostic and predictive role is unclear. The aim of this study was to clarify the prognostic and predictive role of E-cadherin, β-catenin and WNT-1 in advanced epithelial ovarian carcinoma (AEOC).

Methods

The expression of E-cadherin, β-catenin and WNT-1 was determined by immunohistochemistry in AEOC. The correlation between expression of these proteins and progression-free survival (PFS) and overall survival (OS) was evaluated. Statistical analyses included Kaplan-Meier estimation, log-rank test, Spearman correlation and Cox proportional-hazards model.

Results

In ovarian cancer, intense expression of E-cadherin, β-catenin and WNT-1 was found. In multivariate analysis, strong membrane β-catenin expression was an independent unfavourable predictor for PFS (HR 2.19, 95% CI 1.09-4.39; p = 0.028), while in univariate analysis, strong membrane β-catenin expression was a prognostic factor for OS in patients with AOC (p = 0.039). In multivariate analysis, only resistance to first-line chemotherapy was an adverse independent prognostic factor for OS (HR 16.84; 95% CI 5.07-55.98; p < 0.0001). Additionally, strong membranous β-catenin expression was associated with resistance to platinum-based chemotherapy (p = 0.027).

Conclusions

These findings support that WNT/β-catenin pathway and E-cadherin are important factors in advanced epithelial ovarian cancer.

Abstract B33: Prognostic role of Wnt/beta-catenin pathway in colorectal carcinoma

Introduction: Beta-catenin is a member of a cadherin-catenin complex mediating cell adhesion. It is also a key protein of Wnt/Beta-catenin pathway responsible for cell cycle and proliferation. This is important for initiation and progression of colorectal cancer. The aim of this study was to determine expression and localization of E-cadherin, Beta-catenin and Wnt-1 proteins in colorectal tumors.

Description: Forty-four unrelated patients with advanced colorectal carcinoma (CRC) were enrolled consecutively from CRC patients attending palliative care. Expression of Beta-catenin, E-cadherin and Wnt-1 was determined by immunohistochemistry on formalin-fixed, paraffin-embedded primary colorectal tissue. The expression was scored by two independent observers who had no knowledge of the clinical data. Correlation was measured with Spearman test, overall survival were analyzed with Kaplan-Meier method. Log-rank test was used for univariate analysis, while Cox regression model for multivariate analysis. A value of p &lt; 0,05 was considered significant.

Results: Decreased expression of membrane E-cadherin and Beta-catenin was observed in 34% and 27% of patients, respectively. Abnormal cytoplasmic E-cadherin was detected in 32% of cases and abnormal cytoplasmic and nuclear Beta-catenin was detected in 50% and 25% of patients, respectively. 60% of patients had decreased cytoplasmic Wnt-1 expression. Correlation was seen between cytoplasmic E-cadherin and cytoplasmic Beta-catenin (R 0,35; p=0,019). Nuclear localization of Betacatenin was correlated with localization of primary tumor (the highest expression in rectum) (R 0,48; p=0,001) and tumor size (R 0,32; p=0,035). Lower Wnt-1 expression was correlated with higher nodal stage (R -0,31; p=0,047). Nuclear Beta-catenin was an adverse prognostic factor in univariate analysis (log-rank test p=0,034) which was confirmed in multivariate analysis (HR 4,27 95% CI 1,70–10,72; p=0,002). Higher CEA serum level before treatment (HR 4,30 95% CI 1,35–13,66; p=0,013) and female sex (HR 2,75 95% CI 1,24–6,10; p=0,013) were also independent prognostic factors.

Conclusions: This finding supports that Beta-catenin is an independent prognostic factor for colorectal carcinoma.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B33.

[Clinical analysis of patients surgically treated for cancer in the body of the uterus]

107 patients, aged 40 to 87, after surgical intervention with diagnosis of uterine corpus cancer were clinically examined. 68.1 percent of them were 51 to 70 year old women. 20.5 percent had been never pregnant, and 22.47 been pregnant for one time. In 93.2 percent, corpus cancer was revealed after menopause. Among risk factors, there was observed: diabetes mellitus in 7.4%, hypertension in 35.5%, and obesity in 78% of cases. It was stated interdependence between the depth of uterine infiltration, parametrium metaplastic focuses, adnexa metaplastic focuses, cervix infiltration and decrease of adenocarcinoma maturity. The concord between biopsy and clinical stage I degree was stated in 86 percent of cases.