Joanna Chorostowska-Wynimko

Lipoxygenases - A Challenging Problem in Enzyme Inhibition and Drug Development

Lipoxygenases (LOXs), cytochromes P450 (CYPs) and cyclooxygenases (COXs) catalyze peroxidation of unsaturated fatty acids. In humans they convert arachidonic acid into a variety of eicosanoids, which play a role in all inflammatory responses, cardiovascular and kidney diseases, Alzheimers, cancer and other ailments. Blocking one pathway can prompt the body to switch to the available alternatives. In contrast to CYP and COX, LOX has a non-heme iron co-factor. Several LOXs are produced or stress-induce d in the human body. They share the same mechanism, but differ in sequence causing catalysis on the same substrate to be regio- and stereospecific. The action of 15-LOXs could be pro- or anti-inflamma tory, and pro- or anti - carcinogenic. Depending on the dose, LOXs inhibitors can induce or inhibit other oxygenases. Inhibition of these enzymes presents a great challenge in solving the problem of how to control their action and treat diseases, without causing severe side effects and maintaining/restoring a delicate equilibrium between them. Research on CYPs and COXs is more advanced, while studies of LOXs are lagging behind. This article presents a brief review about LOX structures and inhibition, their involvement in human diseases, and their interplay with other oxidoreductases.

Quantitative analysis of free- circulating DNA in plasma of patients with resectable NSCLC

Objective: Minute amounts of free-circulating DNA are present in plasma of healthy individuals, whereas its increased concentration was observed in patients with malignant tumors including non-small cell lung cancer (NSCLC). This study aimed at demonstrating the potential usefulness of plasma DNA concentration monitoring in NSCLC patients for therapy effectiveness assessment throughout the treatment and follow-up period. Methods: Plasma DNA concentration was assessed in 50 NSCLC patients (stage I – IIIA) prior and following the radical treatment using real-time quantitative PCR method. 10 orthopedic patient undergoing hip joint surgery and 40 healthy volunteers comprised control groups. Results: NSCLC patients (8.02 ng/ml) demonstrated significantly higher mean plasma DNA concentration with respect to healthy controls (2.27 ng/ml; p < 0.0000). Drastic increase in plasma DNA levels up to mean 68.74 ng/ml was detected a week after primary tumor resection. Still, similar phenomenon was observed in patients subjected to orthopedic surgical treatment (from 3.00 to 28.38 ng/ml, p < 0.0015). Most resected NSCLC patients with no disease recurrence during 3- to 6-month follow-up demonstrated reduced plasma DNA levels (mean 2.77 ng/ml) with respect to their presurgical values, whereas in relapsed subjects plasma DNA levels were significant higher. Conclusion: Free-circulating DNA concentration in plasma was significantly higher in NSCLC patients versus healthy controls. Its drastic increase following radical NSCLC treatment was most likely due to the surgical trauma. Importantly, the kinetics of plasma free-circulating DNA seems to be a promising marker of long-term effects of radical surgery in NSCLC.

miRNAs as Biomarkers and Therapeutic Targets in Non-Small Cell Lung Cancer: Current Perspectives

Lung cancer is the most common cancer worldwide. Up to 85% of lung cancer cases are diagnosed as non-small cell lung cancer (NSCLC). The effectiveness of NSCLC treatment is expected to be improved through the implementation of robust and specific biomarkers. MicroRNAs (miRNAs) are small, non-coding molecules that play a key role in the regulation of basic cellular processes, including differentiation, proliferation and apoptosis, by controlling gene expression at the post-transcriptional level. Deregulation of miRNA activity results in the loss of homeostasis and the development of a number of pathologies, including lung cancer. During lung carcinogenesis, miRNAs exhibit dual regulatory function: they act as oncogenes to promote cancer development or as tumour suppressors. Unique miRNA sequences have been detected in malignant tissues and corresponding healthy tissues. Furthermore, stable forms of tumour-related miRNAs are detectable in the peripheral blood of patients with NSCLC. The potential benefits of using extracellular miRNAs present in body fluids as part of the diagnostic evaluation of cancer include low invasiveness (compared with tumour cell/tissue sampling), and the repeatability and ease of obtaining the specimens. Apart from the diagnostic applications of altered miRNA expression profiles, the dual regulatory role of miRNA in cancer might drive the further development of personalised therapies in NSCLC. The clinical usefulness of miRNA expression analysis to predict the efficacy of various treatment strategies including surgery, radio- and chemotherapy, and targeted therapies has been evaluated in NSCLC. Also, the capacity of a single miRNA to regulate the expression of multiple genes simultaneously presents an opportunity to use these small molecules in personalised therapy as individualised therapeutic tools.

Plasma cell-free DNA levels and integrity in patients with chest radiological findings: NSCLC versus benign lung nodules

Effective discrimination between lung cancer and benign tumours is a common clinical problem in the differential diagnosis of solitary pulmonary nodules. The analysis of cell-free DNA (cfDNA) in blood may greatly aid the early detection of lung cancer by evaluating cancer-related alterations. The plasma cfDNA levels and integrity were analysed in 65 non-small cell lung cancer (NSCLC) patients, 28 subjects with benign lung tumours, and 16 healthy controls using real-time PCR. The NSCLC patients demonstrated significantly higher mean plasma cfDNA levels compared with those with benign tumours (P = 0.0009) and healthy controls (P < 0.0001). The plasma cfDNA integrity in healthy individuals was significantly different than that found in patients with NSCLC or benign lung tumours (P < 0.0003). In ROC curve analysis, plasma cfDNA levels >2.8 ng/ml provided 86.4% sensitivity and 61.4% specificity in discriminating NSCLC from benign lung pathologies and healthy controls. cfDNA integrity showed better discriminatory power (91% sensitivity, 68.2% specificity). These data demonstrate that plasma cfDNA concentration and integrity analyses can significantly differentiate between NSCLC and benign lung tumours. The diagnostic capacity of the quantitative cfDNA assay is comparable to the values presented by conventional imaging modalities used in clinical practice.

Correlation of serum vascular endothelial growth factor-D concentration with clinical presentation and course of lymphangioleiomyomatosis

BACKGROUND Increased serum vascular endothelial growth factor D (VEGF-D) concentration has been accepted as a diagnostic marker in lymphangioleiomyomatosis (LAM). The study was performed to evaluate the correlation of VEGF-D with clinical presentation and course of LAM. MATERIAL The study group comprised of 48 women with LAM (27 with sLAM, 9 with sLAM and lymphangioma (sLAM-LYM) and 12 patients with TSC/LAM). Patients were assessed at the time of VEGF-D examination, and pulmonary function parameters were compared with those, obtained one year before. VEGF-D serum concentration was measured by ELISA method. RESULTS Patients with TSC/LAM and sLAM-LYM displayed higher concentrations of VEGF-D than patients with sLAM (2682 ± 1347 pg/mL and 2223 ± 1184 pg/mL vs.1281 ± 791 pg/mL; p = 0.0002, p = 0.009) respectively. Patients with sLAM and VEGF-D concentration <800 pg/mL (sLAM-L) had better lung function as assessed by FEV1 (2.38 ± 0.88 L vs. 1.75 ± 0.8 L; p < 0.015) and DL,CO (5.8 ± 2.25 vs. 3.93 ± 1.74 mL/min/mmHg; p < 0.028), had higher blood oxygenation, then those with VEGF-D >800 pg/mL (sLAM-H). Significant yearly increase of TLC (390 ± 700 mL; p < 0.021) and RV (340 ± 790 mL; p < 0.03), and decrease of distance in 6MWT (-30 ± 50 m; p = 0.04) were observed in sLAM-H group. Lung function parameters remained constant in sLAM-L patients. Patients with sLAM-H displayed higher yearly decline of FVC (120 vs. 50 mL; p = 0.035) and increase of TLC (390 vs. -80 mL; p = 0.038) and RV (340 vs. 90 mL; p = 0.045) than sLAM-L patients. Negative correlations between VEGF-D concentration and DL,CO, PaO2, PaCO2, and positive with HRCT grading, and desaturation in 6MWT were noticed in sLAM patients without lymphangioma. CONCLUSIONS Serum VEGF-D is the useful biomarker of LAM extension, and might also prove predictive towards therapeutic decision.

Challenges and Prospects for Alpha-1 Antitrypsin Deficiency Gene Therapy

Alpha-1 antitrypsin (AAT) is a protease inhibitor belonging to the serpin family. A number of identified mutations in the SERPINA1 gene encoding this protein result in alpha-1 antitrypsin deficiency (AATD). A decrease in AAT serum concentration or reduced biological activity causes considerable risk of chronic respiratory and liver disorders. As a monogenic disease, AATD appears to be an attractive target for gene therapy, particularly for patients with pulmonary dysfunction, where augmentation of functional AAT levels in plasma might slow down respiratory disease development. The short AAT coding sequence and its activity in the extracellular matrix would enable an increase in systemic serum AAT production by cellular secretion. In vitro and in vivo experimental AAT gene transfer with gamma-retroviral, lentiviral, adenoviral, and adeno-associated viral (AAV) vectors has resulted in enhanced AAT serum levels and a promising safety profile. Human clinical trials using intramuscular viral transfer with AAV1 and AAV2 vectors of the AAT gene demonstrated its safety, but did not achieve a protective level of AAT >11 μM in serum. This review provides an in-depth critical analysis of current progress in AATD gene therapy based on viral gene transfer. The factors affecting transgene expression levels, such as site of administration, dose and type of vector, and activity of the immune system, are discussed further as crucial variables for optimizing the clinical effectiveness of gene therapy in AATD subjects.

Coexistence of Borrelia burgdorferi s.l. genospecies within Ixodes ricinus ticks from central and eastern Poland

The purpose of the study was to assess the prevalence and coinfection rates of Borrelia burgdorferi sensu lato genotypes in Ixodes ricinus (L.) ticks sampled from diverse localities in central and eastern regions of Poland. In years 2009–2011, questing nymphs and adults of I. ricinus were collected using a flagging method at 18 localities representing distinct ecosystem types: urban green areas, suburban forests and rural woodlands. Molecular detection of B. burgdorferi s.l. genospecies was based on amplification of a fla gene using nested PCR technique, subsequent PCR-RFLP analysis and bidirectional sequencing. It was revealed that 45 samples (2.1%) harboured two different B. burgdorferi s.l. genospecies, whereas triple infections with various spirochetes was found in 11 (0.5%) individuals. Generally, the highest average coinfection rates were evidenced in arachnids gathered at rural woodlands, intermediate at suburban forests, while the lowest were recorded at urban green areas. Overall, single spirochete infections were noted in 16.3% (n = 352/2,153) ticks. Importantly, it is the first report evidencing the occurrence of Borrelia miyamotoi (0.3%, n = 7/2153) in I. ricinus populations within central Poland. Circumstantial variability of B. burgdorferi s.l. genospecies in the common tick individuals sampled at various habitat types in central and eastern Poland was displayed. The coexistence of two or three different spirochete genospecies in single adult ticks, as well as the presence of B. miyamotoi were demonstrated. Therefore, further studies uncovering the co-circulation of the tested bacteria and other human pathogens in I. ricinus ticks are required.

Disease Modification in Emphysema Related to Alpha-1 Antitrypsin Deficiency

ABSTRACT Alpha-1 antitrypsin deficiency (AATD) is associated with premature onset of emphysema resulting from low serum A1-PI levels. The only available pharmacological treatment affecting the underlying cause of AATD is A1-PI therapy. AATD-related emphysema is considered a good model to study disease-modifying effects of treatment as the causative process has been identified. Disease modification is a sustained improvement in disease state following therapeutic intervention that persists when therapy is discontinued. Appropriate trial design and the use of valid study endpoints are key to illustrating disease modification, particularly in clinical trials of rare diseases where it can be difficult to recruit sufficient numbers of patients. Delayed-start trials are advantageous ethically as all patients ultimately receive active treatment and imaging techniques have proven promising as valid study endpoints. Specifically, computed tomography (CT) measured lung density has been used to monitor emphysema and is considered a more sensitive outcome than pulmonary function tests to monitor disease progression. This review will discuss the importance of clinical endpoints and trial design to determine disease modification and will review the evidence for disease modification in AATD-related emphysema. Until recently, clinical studies have not shown a significant effect of A1-PI therapy, possibly due to insufficient numbers of patients, short duration of clinical trials and lack of appropriate trial design. A recently completed randomised trial and open-label extension study followed a larger study population for a longer duration and incorporated a delayed-start design. The results demonstrated clinical efficacy of A1-PI therapy and indicate that treatment is disease-modifying.

The National Alpha-1 Antitrypsin Deficiency Registry in Poland

Abstract The alpha-1 antitrypsin deficiency (AATD) targeted screening program, together with the National Registry, were established in Poland in 2010 soon after the AATD diagnostics became available. Between 2010 and 2014 a total of 2525 samples were collected from respiratory patients countrywide; 55 patients with severe AAT deficiency or rare mutations were identified and registered, including 36 PiZZ subjects (65%). The majority of AATD patients were diagnosed with COPD (40%) or emphysema (7%), but also with bronchial asthma (16%) and bronchiectasis (13%). Therefore, the registry has proved instrumental in setting-up the AATD-dedicated network of respiratory medical centres in Poland. Since augmentation therapy is not reimbursed in our country, the smoking cessation guidance, optimal pharmacotherapy of respiratory symptoms as well the early detection, and effective treatment of exacerbations is absolutely essential.

Reliable Detection of Rare Mutations in EGFR Gene Codon L858 by PNA-LNA PCR Clamp in Non-small Cell Lung Cancer

PNA-LNA PCR clamp real-time PCR method represents allele-specific approach to mutation analysis of EGFR gene in NSCLC. Due to its unique design, it is characterized by exceptionally high specificity and sensitivity but also allows detection of rare or not specifically-targeted EGFR mutations within examined exons, otherwise undetectable by other mutation-specific fluorescent probes. We herein present two cases of rare mutations revealed by PNA-LNA PCR clamping of NSCLC samples referred for routine EGFR gene molecular diagnostics. In one, the EGFR gene L858 codon mutation was detected by standard PNA-LNA PCR clamping, subsequently reconfirmed and characterized by direct sequencing of allele specific amplification products as the missense mutation c.2572C>A (p.L858M) paired with L861Q mutation on the same allele (in cis). In the second sample, low quality FFPE material from pleural biopsy, c.2573C>T missense mutation (p.L858P) was revealed. Still, repeated DNA analysis by PNA-LNA PCR clamp and direct sequencing demonstrated low level of mutant allele existing in a total allele pool suggesting rather artifactual c.2572C>T transition, a phenomenon quite frequent in low-volume FFPE samples upon fixation procedures. In conclusion, superior sensitivity and unique design of PNA-LNA PCR clamping are crucial for its excellent diagnostic effectiveness. As we demonstrated, the method allows detecting rare EGFR mutations, although it increases the risk of detection of a very low signal, e.g., generated by a small pool of mutated allele. Therefore, applicability of PNA-LNA PCR clamp product for the direct sequencing reevaluation is of key importance enabling reliable validation of results.