Radosław Mlak

The VEGF receptor, neuropilin-1, represents a promising novel target for chronic lymphocytic leukemia patients

Angiogenesis has been shown to substantially contribute to the progression of chronic lymphocytic leukemia (CLL). Neuropilin‐1 (NRP1) represents a receptor for vascular endothelial growth factor (VEGF), which has been reported to be overexpressed in several malignancies. In our study, we characterized mRNA levels of VEGF receptors including NRP1 in a large cohort of CLL patients (n = 114), additionally we performed a detailed characterization of NRP1 expression on B cells, plasmacytoid dendritic cells (PDCs) and regulatory T cells (Tregs). The expression of NRP1 was significantly higher on leukemic lymphocytes compared to control B lymphocytes on mRNA and protein levels (22.72% vs. 0.2%, p = 0.0003, respectively), Tregs (42.6% vs. 16.05%, p = 0.0003) and PDCs (100% vs. 98% p < 0.0001). In functional studies, we found higher NRP1 expression on CLL cells after stimulation with VEGF. The correlation between expression of VEGF receptors: FLT1, NRP1 and FOXP3 expression (r2 = 0.53, p < 0.0001 and r2 = 0.49, p < 0.0001, respectively) was observed. Earlier we described the specific Treg reduction during the therapy with thalidomide in vivo. Now we observe the reduction of the NRP1 expression on Tregs in vitro, thereby suggesting a possible target of thalidomide action. In conclusion, NRP1 might represent an interesting link between angiogenesis and tolerance mechanisms and represents interesting target for therapy.

Predictive value of ERCC1 single-nucleotide polymorphism in patients receiving platinum-based chemotherapy for locally-advanced and advanced non-small cell lung cancer — a pilot study

Platinum-based chemotherapy is the main type of I-line treatment of advanced and non-operative NSCLC patients without EGFR gene mutation. The excision repair cross-complementation group 1 (ERCC1) is an enzyme that executes the incision of the damaged DNA strand and removes platinum-induced DNA adducts. We investigated whether ERCC1 gene polymorphism has an effect on the response to chemotherapy and survival in 43 patients with NSCLC treated with platinum-based chemotherapy. ERCC1 19007 T>C SNPs were assessed using a PCR-RFLP methods in DNA isolated from peripheral blood lymphocytes. Disease control occurred significantly (p = 0.045) more frequently in patients with CC or CT genotype compared to patients with TT genotype. Median PFS and OS for CC homozygous were 4 and 10.5 months, 4 and 12.5 months for CT heterozygous, but only 0.3 and 1.5 months for TT homozygous patients, respectively. The probability of PFS was significantly higher (HR = 0.438, 95% CI: 0.084–0.881, p = 0.03) and probability of OS was insignificantly higher (HR = 0.503, 95% CI: 0.129–1.137, p = 0.084) in patients with CC or CT genotype than in patients with TT genotype. Uncommon TT genotype of ERCC1 19007 T>C polymorphism could predict poor response and shortening of progression free survival in NSCLC patients treated with platinum-based I-line chemotherapy. The analysis of this polymorphism may serve as a promising tool in the qualification of advanced NSCLC patients for appropriate chemotherapy.

The Qualification of Docetaxel or Erlotinib for Second-Line Therapy Should Be Based on Clinical and Molecular Predictive Factors

Background: We evaluated the effectiveness of docetaxel or erlotinib in second-line treatment of non-small cell lung cancer (NSCLC) and focused on the impact of predictive factors on the outcome of therapy. Methods: 204 patients with progressive disease after platinum-based therapy were enrolled: 102 received an infusion of 75 mg/m2 of docetaxel and 102 received 150 mg of erlotinib orally. Results: Response rate (RR) was 6.9 and 8.8% for docetaxel and erlotinib, respectively. Progression-free survival (PFS) was 1.2 months for docetaxel and 1.6 months for erlotinib (hazard ratio, HR = 1.2, p = 0.17). Overall survival was 5.5 versus 7 months for docetaxel and erlotinib, respectively (HR = 1.35, p = 0.06). Using Cox regression, we found clinical factors (performance status and weight loss) with predictive values for RR and PFS in second-line-treated patients. Prior radiotherapy, smoking status and EGFR mutation might help to predict outcome of erlotinib treatment and βIII-tubulin mRNA expression that of docetaxel, but histopathological diagnosis did not have any predictive value. Conclusions: Erlotinib and docetaxel show similar efficacy in the treatment of NSCLC. The application of predictive factors may facilitate qualification for second-line treatment with both drugs.

Predictive value of ERCC1 and RRM1 gene single-nucleotide polymorphisms for first-line platinum- and gemcitabine-based chemotherapy in non-small cell lung cancer patients

Platinum-based chemotherapy with third generation drugs (such as gemcitabine) is an efficacious regimen of first-line treatment of patients with advanced, unresectable non-small cell lung cancer (NSCLC), without activating EGFR mutations. Mechanism of action of cytostatics are distortions in the DNA. ERCC1 and RRM1 are key proteins involved in the repair of DNA, thus, they may be responsible for the ineffectiveness of therapy. We investigated whether ERCC1 (19007C>T) and RRM1 (-37C>A) polymorphisms impact response to chemotherapy and survival in 62 patients with NSCLC treated with platinum and gemcitabine. Single nucleotide polymorphisms (SNPs) were assessed using a PCR-RFLP method in DNA isolated from PBLs. There were no statistically significant relationships between ERCC1 genotypes and response to therapy (p=0.581, χ2=1.09) as well as patient overall survival (OS). Carriers of the RRM1 AC genotype showed disease progression significantly more frequently (p=0.019, χ2=5.473) compared to carriers of the AA or CC genotypes. Carriers of the ERCC1/RRM1TT/CC genotype combination showed disease control significantly more frequently (p=0.047, χ2=3.95) compared to carriers of other genotype combinations. Patients with AA or CC genotypes of RRM1 showed significantly higher progression-free survival probability (p=0.0001, HR=0.39, 95% CI, 0.22-0.70) and OS probability (p=0.0104, HR=0.39, 95% CI, 0.18-0.82) compared to those with the AC genotype. In Cox regression model, poor performance status (p=0.0016, HR=4.78, 95% CI, 1.82-12.56), AC genotype of RRM1 gene (p=0.0414, HR=2.47, 95% CI, 1.04-5.87), lack of prior surgical treatment (p=0.0425, HR=4.71, 95% CI, 1.06-20.92) and lack of subsequent lines of treatment (p=0.0127, HR=3.23, 95% CI, 1.29-8.11) were significantly associated with shortening of patient survival. The analysis of RRM1 (-37C>A) more than ERCC1 (19007C>T) polymorphism may be a promising tool in the qualification of NSCLC patients for chemotherapy containing platinum compounds and gemcitabine.

The polymorphism of the CHRNA5 gene and the strength of nicotine addiction in lung cancer and COPD patients.

A rare variant of chromosomal region 15q25.1, marked by rs16969968 (substitution 1354G>A in CHRNA5), was found to be associated with increased lung cancer and nicotine-dependence risk. We attempted to confirm the relationship of the polymorphism of the CHRNA5 gene and nicotine-dependence strength measured by the Fagerström test with the serum cotinine level in lung cancer and chronic obstructive pulmonary disease (COPD) patients and healthy individuals. Polymorphism of the CHRNA5 gene was analyzed using the PCR-based restriction fragment length polymorphism method in 97 lung cancer patients, 99 COPD patients, and 98 healthy individuals. The Fagerström test was used as an instrument for assessing the intensity of physical addiction. Cotinine serum level was measured using an enzyme-linked immunosorbent assay. The frequencies of AA, AG, and GG genotypes were 10.5, 47.3, and 42.2%, respectively. The polymorphism of CHRNA5 did not have a significant influence on the elevated risk of lung cancer and COPD. The percentage of smokers did not differ between groups of study participants with different genotypes. However, the presence of the GG genotype decreased the risk of nicotine addiction strength (hazard ratio=0.238; 95% confidence interval 0.066–0.857; P<0.05). Moreover, allele A was presented more frequently in participants with a high level of nicotine dependence and in participants with early addiction onset (P<0.05). Serum cotinine level was significantly correlated with the results of the Fagerström test (P<0.001). The carriers of allele A expressed significantly higher levels of cotinine when compared with the carriers of the GG genotype (P=0.05). We report for the first time the relationship between the polymorphism of the CHRNA5 gene and the strength of nicotine addiction measured by multiple factors including the Fagerström test score.

The Applicability of a Predictive Index for Second- and Third-Line Treatment of Unselected Non-Small-Cell Lung Cancer Patients

Background: Tyrosine kinase inhibitors of EGFR (TKI-EGFR) induced response in only 10% of Caucasian non-small-cell lung cancer patients in second- or third-line treatment. Independent predictive factors for qualification to TKI-EGFR treatment have not been assessed. In 2008, a prognostic index was reported for patients treated with erlotinib in the BR.21 trial, but its application for real, unselected patients is limited. Objectives: Based on clinical and molecular factors of patients treated with erlotinib, we tried to create a predictive index which could be applied in real treatment practice. Methods: In a Cox regression model, we established 6 factors which affected overall survival for erlotinib treatment: performance status, erlotinib-induced rash, time from diagnosis to treatment, gender, weight loss and LDH level. We analyzed the risk factors of early progression and survival shorter than 6 months. In addition we included: time from first-line chemotherapy to erlotinib treatment, smoking status, mutation status in EGFR and anemia. Results: Our model consisted of 10 factors that were assigned points according to HR or χ2 and p value. The score was used to separate patients into 4 risk categories of unfavorable disease course based on 10th, 50th and 90th percentiles: low risk (I), intermediate low risk (II), intermediate high risk (III) and high risk (IV). Survival probability was significantly higher for group I, intermediate for groups II and III, and significantly lower for group IV (χ2 = 49.5, p < 0.0001). Based on the previously reported index we could not qualify our patients for the low risk group. Conclusions: Our model could be useful for qualification for erlotinib treatment of patients with numerous adverse factors and limited access to genetic examination.

Mechanisms of resistance to reversible inhibitors of EGFR tyrosine kinase in non-small cell lung cancer

Abnormalities of epidermal growth factor receptor (EGFR) in non-small-cell lung cancer (NSCLC) patients consist of EGFR overexpression and EGFR (HER1) gene mutations. Structural dysfunction of the tyrosine kinase domain of EGFR is associated with the clinical response to tyrosine kinase inhibitors (TKI) in patients with NSCLC. The most common EGFR gene mutations occur as either deletions in exon 19 or as substitution L858R in exon 21 and cause a clinically beneficial response to gefinitib or erlotinib treatment. Unfortunately, the majority of patients finally develop resistance to these drugs. Acquired resistance is linked to secondary mutations localised in the EGFR gene, mainly substitution T790M in exon 20. Through intense research a few different mechanisms of resistance to reversible tyrosine kinase inhibitors have been identified: amplification of MET or IGF-1R genes, abnormalities of PTEN and mTOR proteins as well as rare mutations in EGFR and HER2 genes. Extensively investigated new drugs could be of significant efficiency in NSCLC patients with secondary resistance to reversible EGFR TKI.

The diagnostic role of plasma circulating precursors of miRNA-944 and miRNA-3662 for non-small cell lung cancer detection

INTRODUCTION microRNA (miRNA) seem to be most attractive cancer markers due their crucial role in tumor development and possibility of their analysis using liquid biopsy. To date there is little known about role of miRNA precursors (pri-miRNA) in carcinogenesis and their utility as tumor markers. MATERIAL AND METHODS miRNA-944 and miRNA-3662 precursors as potential non-small cell lung cancer (NSCLC) markers were analyzed in plasma samples of 56 patients in an early stage of NSCLC and 100 healthy individuals. RESULTS Diagnostic test based on two studied markers for stage I-IIIA of the disease allowed to distinguish NSCLC from healthy individuals with 75.7% sensitivity and 82.3% specificity (AUC=0.898). pri-miRNA-944 distinguished SCC from AC with sensitivity of 78.6% and specificity of 91.7% (AUC=0.771), and pri-miRNA-3662 distinguished AC from SCC with 57.1% sensitivity and 90% specificity (AUC=0.845). CONCLUSION Circulating pri-miRNA-944 and 3662 can improve non-invasive NSCLC detection of operable stages of SCC and AC. miRNA precursors could be considered as novel potential lung cancer biomarkers.

Impact of I/D polymorphism of ACE gene on risk of development and course of chronic obstructive pulmonary disease

Introduction Chronic obstructive pulmonary disease (COPD) affects more than 10% of the worlds population over 40 years of age. The main exogenous risk factor is cigarette smoking; however, only 20% of smokers develop COPD, indicating that some other factors, e.g. genetic, may play an important role in the disease pathogenesis. Recent research indicates that ACE (angiotensin-converting enzyme) may be a susceptibility gene for asthma or COPD. The aim of our study was to determine the influence of I/D (insertion/deletion) polymorphism of the ACE gene (AluYa5, rs4646994) on the risk and course of COPD. Material and methods We investigated ACE I/D polymorphism in 206 COPD and 165 healthy Caucasian subjects. Results In the generalized linear model (GLZ) analysis of the influence of selected factors on presence of COPD we found a significant independent effect for male sex (repeatedly increases the risk of COPD, OR = 7.7, p = 0.049), as well as smoking or lower body mass index, but only in combination with older age (OR = 0.96, p = 0.003 and OR = 1.005, p = 0.04 respectively). Interestingly, analysis of factors which may influence the risk of a higher number of exacerbations demonstrated that occurrence of DD genotype, but only in men, is associated with a lower risk (OR = 0.7, p = 0.03) of this complication. Conclusions We suggest that ACE may not be a susceptibility gene for the origin of COPD but a disease-modifying gene. Since the impact of I/D polymorphism of the ACE gene on COPD risk is moderate or negligible, other molecular changes, that will help predict the development of this disease, should still be sought.

Predictive and prognostic factors in second- and third-line erlotinib treatment in NSCLC patients with known status of the EGFR gene

Erlotinib is a reversible tyrosine kinase inhibitor of epidermal growth factor receptor (TKI EGFR). In Poland, as of July 2012, it is used in the treatment only of patients with non-small cell lung cancer (NSCLC) and with EGFR mutation gene after standard chemotherapy failure. The effectiveness of erlotinib in second- or third-line treatment of NSCLC patients without EGFR activating mutation gene remains debatable. Clinical trial results indicated that TKI EGFR showed an efficacy of 70‑80% in patients with EGFR mutations, while the clinical response to treatment among unselected Caucasian patients is only 10%. The present study was conducted in a group of 71 patients with inoperable, locally advanced or metastatic NSCLC treated with erlotinib as the second- or third-line therapy. Molecular tests (examination of EGFR mutation and gene amplification) were carried out retrospectively. Objective response rate, overall survival (OS) and progression-free survival (PFS) were calculated. Effects of clinical and molecular factors including the presence of EGFR mutations, EGFR gene amplification, patient performance status, rash, smoking status, time from diagnosis to start of therapy, weight loss and the serum LDH levels were analyzed. An objective response in the form of partial response occurred in only 5 patients (7%), who carried EGFR gene mutation. Median time to PFS for the entire group of patients was 1.5 months and median OS was 10 months. The strongest factors increasing the risk of progression in patients treated with erlotinib were the absence of activating mutations in the EGFR gene (6‑fold increased risk) and no treatment‑related rash (4.5‑fold increased risk). The most important factors affecting the risk of early mortality were poor performance status (HR 37.344; P>0.0001), no treatment-related rash (HR 14.9348; P=0.0002) and a short response time on the first-line chemotherapy (HR 9.519; P=0.0445).