Zbyněk Bortlíček

Combined Proteomics and Transcriptomics Identifies Carboxypeptidase B1 and Nuclear Factor κB (NF-κB) Associated Proteins as Putative Biomarkers of Metastasis in Low Grade Breast Cancer

Current prognostic factors are insufficient for precise risk-discrimination in breast cancer patients with low grade breast tumors, which, in disagreement with theoretical prognosis, occasionally form early lymph node metastasis. To identify markers for this group of patients, we employed iTRAQ-2DLC-MS/MS proteomics to 24 lymph node positive and 24 lymph node negative grade 1 luminal A primary breast tumors. Another group of 48 high-grade tumors (luminal B, triple negative, Her-2 subtypes) was also analyzed to investigate marker specificity for grade 1 luminal A tumors. From the total of 4405 proteins identified (FDR<5%), the top 65 differentially expressed together with 30 previously identified and control markers were analyzed also at transcript level. Increased levels of carboxypeptidase B1 (CPB1), PDZ and LIM domain protein 2 (PDLIM2), and ring finger protein 25 (RNF25) were associated specifically with lymph node positive grade 1 tumors, whereas stathmin 1 (STMN1) and thymosin beta 10 (TMSB10) associated with aggressive tumor phenotype also in high grade tumors at both protein and transcript level. For CPB1, these differences were also observed by immunohistochemical analysis on tissue microarrays. Up-regulation of putative biomarkers in lymph node positive (versus negative) luminal A tumors was validated by gene expression analysis of an independent published data set (n = 343) for CPB1 (p = 0.00155), PDLIM2 (p = 0.02027) and RELA (p = 0.00015). Moreover, statistically significant connections with patient survival were identified in another public data set (n = 1678). Our findings indicate unique pro-metastatic mechanisms in grade 1 tumors that can include up-regulation of CPB1, activation of NF-κB pathway and changes in cell survival and cytoskeleton. These putative biomarkers have potential to identify the specific minor subpopulation of breast cancer patients with low grade tumors who are at higher than expected risk of recurrence and who would benefit from more intensive follow-up and may require more personalized therapy.

LPS structure influences protein secretion in Salmonella enterica

In this study we have compared protein secretion in the wild type of S. Typhimurium and the rfaC mutant. We found out that the rfaC mutant was defective in protein secretion. In addition, the rfaC mutant was defective in its invasion into an IPEC-J2 porcine epithelial cell line and also in motility in semisolid agar. Consistent with this, reduced flagella numbers were observed in the rfaC mutant. In the rfaC mutant, there were no defects in flagellin expression as detected by western blot and immune electron microscopy which demonstrated equal amounts of flagellin in the cytoplasm of both the rfaC mutant and the wild-type S. Typhimurium. However, in the wild-type strain only, the flagellin was assembled to spatially restricted areas on the inner side of cytoplasmic membrane. The oligosaccharide core of LPS is therefore required for the assembly of flagella and T3SS secretion machinery followed by protein secretion.

Weight concerns associated with delay in quit date but not treatment outcomes: A Czech Republic Experience

Background Weight concerns are prevalent in smokers and may reduce the success rate of quitting. This concept has been primarily studied on US populations and it is unknown how weight concerns may differ cross-culturally. This study examined the role of weight concern in European smokers wishing to stop smoking. Methods A sample of 593 smokers (299 men and 294 women, mean age 38 years) utilizing the Centre for Tobacco-Dependent in Prague, Czech Republic, between 2010 and 2013 were studied. Weight concerns were assessed at baseline prior to treatment by evidence-based stop smoking methods. Abstinence was evaluated at 12 months post baseline. Results Approximately 34% of all patients (204/593) were classified as weight concerned (by indicating on the Weight Concern Scale that they would return to smoking after any weight gain) at the time they sought treatment. Among all men, 19.4% (58/299) were weight concerned and among all women, 49.7% (146/294) were weight concerned. Among females, weight-concerned smokers were of similar weight, but younger (p < .001), and had been smoking cigarettes for fewer years (p = .002) compared with those without weight concerns, whereas the male weight-concerned smokers were significantly (p = .030) heavier than those without weight concerns. Although the presence of weight concern was associated with a delay in setting a quit date (log-rank test p = .019), it was not associated with abstinence at one year. Conclusion The quit success rate of weight-concerned smokers in Czech Republic did not differ from those without weight concern when utilizing an individualized smoking cessation treatment program. Individually tailored tobacco dependence treatment could help to prevent weight concern from affecting successful quitting. Implications This study adds the new cross-cultural aspect of post-cessation weight concern. Weight concern has been studied primarily on US populations and our sample consists of European sample of smokers. Additionally, we have found that the presence of weight concern lead to delay in setting a quit date, but the success rate of those weight concerned did not differ from those without weight concern. Thus, it is possible, that this individualized evidence-based tobacco treatment program was able to prevent weight concern impact towards successful quitting.

Czech adolescent smokers: unhappy to smoke but unable to quit.

OBJECTIVE To assess the prevalence of tobacco dependence among adolescents in the Czech Republic in 2010, their willingness to quit and knowledge about quitting options. METHODS Primary, intermediate and secondary school students completed an anonymous questionnaire on tobacco use during a smoking prevention class, with a response rate of 100%. RESULTS Of 1420 anonymous questionnaires analysed, 66.8% (n = 949) of respondents had ever tried smoking. More were from smoking (50.4%) than non-smoking (49.6%) families; there were no differences in sex. Most student smokers had experimented with cigarettes (94.6%), cigars (8%), marihuana cigarettes (4.6%) and water pipes (1.9%). At the time of the survey, 52.9% (520/949) of those who had ever tried smoking were current smokers, 30.3% smoked daily, 18.3% weekly and 4.2% less frequently. Only 20.5% of smokers had not considered quitting, and 66.9% had tried unsuccessfully to quit. Withdrawal symptoms were experienced by 24.5% (123/502) of the current smokers, indicating a high level of nicotine dependence in this age group. The majority (346/467, 74.1%) of the current smokers said they would stop smoking immediately on their own. Only a few would seek help at a pharmacy (4.9%), 3.4% would ask their doctor and 1.7% their parents. CONCLUSIONS Tobacco dependence is prevalent among Czech adolescents. The majority of smokers wanted to stop, but knowledge about smoking cessation and quitting assistance offered to smokers was low.

Comparison of EGFR-TKI and chemotherapy in the first-line treatment of advanced EGFR mutation-positive NSCLC.

Molecular targeted therapy based on EGFR tyrosine kinase inhibitors (EGFR-TKI) is currently astate of the art option for management of advanced stage NSCLC. Activating EGFR mutations are preferable for a good treatment response to EGFR-TKI. The presented retrospective study evaluated a clinical observation of EGFR-TKI aiming at its efficacy and safety in comparison to a standard chemotherapy in the first-line treatment of advanced stage NSCLC. Total number of patients with advanced stage (IIIB, IV) EGFR mutation-positive NSCLC was 54 of which 23 were treated with EGFR-TKI and 31 patients with various chemotherapy regimens in the first line. The treatment efficacy was characterized in terms of disease control rate (DCR), progression-free survival (PFS) and overall survival (OS). The comparison of DCR was performed using Fishers exact test and the differences in survival were tested using log-rank test. DCR for EGFR-TKI treatment was 95.6% vs. 70.9% for chemotherapy (p=0.032). Median of PFS in patients treated with EGFR-TKI was 7.2 months vs. 2.5 months in patients treated with chemotherapy (p<0.001). Median of OS was 14.5 months vs. 21.4 months (p=0.729). EGFR-TKI was associated with higher incidence of skin rash and diarrhoea; chemotherapy was associated with higher incidence of haematologic adverse events and nausea or vomiting. The analysis results showed a favourable DCR and PFS in patients treated with EGFR-TKI in the first line. The non-significant difference in OS could be attributed to a cross-over during the patient follow-up as well as the differences in performance status and age between both groups. EGFR-TKI is the optimal choice for the first-line treatment of EGFR mutation-positive NSCLC.

Bevacizumab with chemotherapy in patients with KRAS wild-type metastatic colorectal cancer: Czech registry data

AIM This retrospective analysis investigated the effectiveness of combination therapy with bevacizumab and chemotherapy in the first-line treatment of patients with KRAS wild-type metastatic colorectal cancer. PATIENTS & METHODS Patients with KRAS wild-type metastatic colorectal cancer in the CORECT registry who initiated treatment with bevacizumab between 2008 and 2012 were enrolled. Overall survival and progression-free survival were the main effectiveness end points. RESULTS A total of 981 patients were enrolled. Median progression-free survival was 11.3 months (95% CI: 10.7-11.8) and median overall survival was 28.4 months (95% CI: 26.2-30.6). The most common adverse events were thromboembolic disease (4%) and hypertension (3.5%). CONCLUSION This retrospective analysis shows the effectiveness of bevacizumab with chemotherapy in patients with KRAS wild-type metastatic colorectal cancer.

Long term experience of patients with unresectable or metastatic KIT positive gastrointestinal stromal tumours.

A retrospective analysis of consecutive patients (183 in total, of which 105 were males and 78 females) with gastrointestinal stromal tumour (GIST) was performed. The mean age was 61 years, median age 64 years. The most frequent localization of the tumour was stomach in 74 patients (40.4 %) and the small intestine in 46 patients (25.1 %). Two or more different synchronous or metachronous cancers occurred in 34 (18.6 %) patients with histologically confirmed GIST. Ninety-six patients were treated with imatinib mesylate in palliative setting during the course of their disease. The therapy was finished in 60 patients and 36 patients have been treated so far. The median progression-free survival reached 32.9 months in the group of 96 patients treated with imatinib. The median overall survival in the group of 96 patients treated for metastatic disease reached 77 months. Two-year and 5-year survival was 85.2 % and 63.1 %, respectively. The second-line therapy with sunitinib malate was administered in 37 patients, of which 31 finished and 6 continued in the therapy. The median progression free survival and median survival since the sunitinib therapy initiation reached 8.4 and 22.1 months, respectively (Tab. 2, Fig. 2, Ref. 16).