[show abstract][hide abstract] ABSTRACT: Title 6-alkyl-, 6-aryl- and 6-hetaryl-7-deazapurine ribonucleosides previously known as nanomolar cytostatics were found to be potent inhibitors of either human or mycobacterial (MTB) adenosine kinase (ADK). Several new derivatives bearing bulky substituents at position 6 were non-cytotoxic but selectively inhibited MTB ADK. However, most of the nucleosides (ADK inhibitors) as well as their octadecylphosphate prodrugs were inactive in the whole cell assay of inhibition of Mycobacterium bovis growth. 6-Methyl-7-deazapurine ribonucleoside was found to be a potent antimycobacterial agent.
Medicinal Chemistry Communication 11/2013; 4(11):1497-1500. · 2.72 Impact Factor
[show abstract][hide abstract] ABSTRACT: Circulating tumor cells present an important marker of the progress of several cancer diseases including breast and colorectal cancer, and enables an interesting prognosis and diagnostic options that can complement convenient diagnostic techniques based on several imaging methods. Based on its relevance, the analysis of such kinds of cells is within the scope of many research and clinical institutes; however, it still presents a difficult task. Here we used a state-of-the-art micro-Raman microscopic technique to enhance possibilities in the study of circulating tumor cells and their further differentiation. As cytospins present a convenient form of sample collection and preparation, we used this form of sampling as the initial point. Raman presents a non-destructive form of sample analysis and thus the samples can be further used for a method validation. We have considered the influence of fixation methods of the cells, where we found out that the ability of Raman spectroscopy to differentiate between three cell lines strictly depends upon the sample preparation method used. Namely breast (BT 549) and colorectal (HCT 116) circulating tumor cell lines and human mononuclear cells were compared. Methanol and paraformaldehyde methods of fixation were compared to simple drying out of the sample. It has been shown that drying out of the cells enables the best performance to be obtained in cell differentiation and this is demonstrated by the use of principal component analysis, where all three given cell lines were differentiated with a high level of confidence. Next, the cells were also scanned using 1 μm spatial resolution. The acquired data were visualized using both chemigrams and hierarchical clustering analysis.
[show abstract][hide abstract] ABSTRACT: BACKGROUND: Non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancer that is the leading cause of cancer-related mortality worldwide. Several predictive markers have been found in NSCLC patients to date but only a few are currently used for tailored therapy. METHODS AND RESULTS: PubMed and Web of Science online databases were used to search review and original articles on the most important predictive markers in NSCLC. CONCLUSION: EGFR activating mutations (exons 18 to 21) and EML4-ALK rearrangement are clinically important markers able to select NSCLC patients which benefit from EGFR or ALK tyrosine kinase inhibitors (gefitinib, erlotinib, crizotinib). Other markers, such as KRAS mutation, EGFR T790M mutation and C-MET amplification, are responsible for resistance to these inhibitors. Overcoming of this resistance as well as discovery of new potential markers and inhibitors is the main goal of ongoing research and clinical trials in NSCLC.
Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia 05/2013; · 0.99 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: Even after successful radical treatment of lung cancer, patients in stages I and II of the TNM system very frequently suffer recurrence, which end lethally. Detection of subclinical residual disease after surgery is thus one of the most important emerging diagnostic methods. Minimal residual disease (MRD) is defined as the presence of isolated tumor cells or circulating cells in a patient after curative primary tumor removal and at the same time, no clinical signs of cancer. Conventional methods cannot detect minimal residual disease and hence there is a need for detection using new molecular biological methods. METHODS: We searched the PubMed database for original and review articles on minimal residual disease in lung cancer. Search words were "lung cancer", "minimal residual disease" and "detection of minimal residual disease". The publications we found were compared with the results of our own studies on the detection of minimal residual disease in lung cancer and the personal experiences are described. Examination of blood samples from 98 healthy volunteers and bone marrow from 12 patients with non inflammatory and non tumour illness, were used to determine cut-off values for specific markers in the compartments. Subsequently, expression of selected markers in tumor tissue was analysed in a pilot sample of 50 patients with lung cancer and the presence of MRD was measured as expression of values of the tested markers correlated with clinico-pathological characteristics. CONCLUSIONS: Recent studies on other malignancies apart from lung cancer have shown the importance of MRD detection in the determination of disease progression and prognosis. The methods of MRD diagnostics are based on detection of specific tumor markers. Of these, the most specific for lung cancer, appears to be the LunX protein. The best method for determining MRD is probably RT-PCR. Further studies should expand knowledge in this area: to refine understanding of the importance of tumor markers for prognosis, as well as to confirm the significance of these findings in clinical practice.
Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia 04/2013; · 0.99 Impact Factor
[show abstract][hide abstract] ABSTRACT: AIMS: Male infertility has been associated with imbalance in the polyunsaturated fatty acids arachidonic acid/docosahexaenoic acid (AA/DHA) ratio. This study aimed to assess whether use of the potent antioxidant, lycopene, would affect this imbalance in seminal plasma and to test whether modulation of the AA/DHA ratio correlates with male fertility. METHODS: The study included 44 males from infertile couples who were treated with lycopene for three months before scheduled IVF treatment. The control group was 13 fertile males who were also treated with lycopene for three months. AA and DHA levels were measured in seminal plasma before and after treatment. The outcome of IVF treatment after lycopene use in of males from infertile couples was recorded. RESULTS: The subjects were subdivided into 21 normozoospermic males from couples with idiopathic infertility and 23 males with semen abnormalities. Prior to the treatment with lycopene, the AA/DHA ratios in both subgroups of patients were significantly higher than in fertile controls and improved following treatment with lycopene. Improvement was more marked in the normospermic males. Seven spontaneous pregnancies (16%) occurred before the scheduled IVF treatment and 15 couples (42%) achieved pregnancy after IVF. CONCLUSIONS: Three months of treatment with lycopene led to a significant improvement in the AA/DHA ratio in seminal plasma of males from infertile couples and facilitated the spontaneous as well as IVF conception.
Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia 02/2013; · 0.99 Impact Factor
[show abstract][hide abstract] ABSTRACT: Meningiomas represent one of the most common types of primary intracranial tumours. However, the specific molecular mechanisms underlying their pathogenesis remain uncertain. Loss of chromosomes 22q, 1p, and 14q have been implicated in most meningiomas. Inactivation of the NF2 gene at 22q12 has been identified as an early event in their pathogenesis, whereas abnormalities of chromosome 14 have been reported in higher-grade as well as recurrent tumours. It has long been supposed that chromosome 14q32 contains a tumour suppressor gene. However, the identity of the potential 14q32 tumour suppressor remained elusive until the Maternally Expressed Gene 3 (MEG3) was recently suggested as an ideal candidate. MEG3 is an imprinted gene located at 14q32 that encodes a non-coding RNA (ncRNA). In meningiomas, loss of MEG3 expression, its genomic DNA deletion and degree of promoter methylation have been found to be associated with aggressive tumour growth. These findings indicate that MEG3 may have a significant role as a novel long noncoding RNA tumour suppressor in meningiomas.
Journal of Neuro-Oncology 01/2013; · 3.12 Impact Factor
[show abstract][hide abstract] ABSTRACT: There were synthesized new types of ribbon type steroidal dimers derived from three types of steroidal skeletons (cholic acid, etienic acid, estrone) using Cu(I) catalyzed 1,3-dipolar cycloaddition reaction. Steroid parts of the molecular "ribbons" are linked by heterocyclic moiety, namely by 2,6-bis((1H-1,2,3-triazol-1-yl)-methyl)pyridine. Compounds synthesized possess different cytotoxic and hormone receptor modulating activities.
[show abstract][hide abstract] ABSTRACT: Objective: To describe the possibility of detection of HPV DNA in cervical cancer.Design: Review.Setting: Institute of Molecular and Translational Medicine, Laboratory of Experimental Medicine, Palacky University and University Hospital Olomouc.Methods: Human papillomavirus (HPV) is the cause of many cancers, especially cervical cancer. Current cervical cancer screening is based on cytological examination, which is followed by HPV DNA diagnostics only in cases with abnormal results of uncertain significance. Methods used for HPV detection are often based on PCR reaction followed by genotyping (complete or partial). HPV DNA diagnostics isn´t currently included into the primary cervical cancer screening in the Czech Republic although it has higher sensitivity than cytology.Conclusion: Inclusion of HPV DNA testing into the primary cervical cancer screening would significantly increase its sensitivity and thus would help to reduce the morbidity and mortality of this disease in Czech population. Keywords: human papillomavirus - HPV - cervical carcinoma - cervical cancer screening - cytology - LBC - PCR.
[show abstract][hide abstract] ABSTRACT: Drug resistance is the major obstacle to successful cancer therapy. Our study focuses on resistance to Aurora kinase inhibitors tested as anti-cancer drugs in clinical trials. We have used 2-D electrophoresis in pH range of 4-7 and 6-11 followed by protein identification using MALDI-TOF/TOF to compare protein composition of HCT116 colon cancer cells either sensitive to CYC116 and ZM447439 inhibitors or resistant towards these drugs. The analysis also included p53+/+ and p53-/- phenotypes of HCT116 cells. Our findings demonstrate that platelet-activating factor acetylhydrolase and GTP-binding nuclear protein Ran contribute to the development of resistance to ZM447439 only where resistance is related to p53. On the other hand, serine hydroxymethyltransferase was found to promote the tumor growth in cells resistant to CYC116 without the influence of p53. Computer modelling of interaction networks highlighted a direct link of p53-independent mechanism of resistance to CYC116 with autophagy. Importantly, serine hydroxymethyltransferase, serpin B5 and calretinin represent the target proteins which may help overcome resistance in combination therapies. In addition, serpin B5 and calretinin appear to be candidate biomarkers which may be accessible in patients for monitoring of cancer therapy with ease.
Journal of Proteome Research 11/2012; · 5.06 Impact Factor
[show abstract][hide abstract] ABSTRACT: AIMS: The aim of this study was to test the hypothesis that occult tumour cells in peritoneal lavage are a negative prognostic factor in pancreatic adenocarcinoma. METHODS: Real-time RT-PCR analysis of CEA, EGFR and hTERT transcript levels was used to identify occult tumour cells in peritoneal lavage samples from 96 pancreatic cancer patients. RESULTS: We found significant association between CEA expression levels in peritoneal lavage and clinical stage. We also found that EGFR transcript levels were higher in peritoneal lavage samples from patients with high grade tumours than in samples from patients with low grade tumours. Detection of CEA and/or EGFR occult tumour cell markers in the peritoneal lavage was associated with significantly shorter overall survival and increased hazard ratio for disease recurrence. CONCLUSIONS: The results show that the presence of occult tumour cells in peritoneal lavage is a negative prognostic factor for survival in pancreatic cancer patients, and that detection of occult tumour cells using PCR-based methods can identify patients with advanced disease for whom radical surgery is likely to have little benefit.
Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia 10/2012; · 0.99 Impact Factor
[show abstract][hide abstract] ABSTRACT: INTRODUCTION: Glucocorticoids, particularly prednisone/ prednisolone and dexamethasone, play a prominent role in the treatment of pediatric patients with acute lymphoblastic leukemia due to their ability to induce apoptosis in susceptible cells. Current therapeutic protocols use prednisone for both the prophase and the induction phase of the therapy because the greater antileukemic activity of dexamethasone is compromised by its high frequency of serious adverse reactions. AIM: To compare, for the first time, the in vitro antileukemic activity of prednisolone alone to that of a combination of prednisolone and dexamethasone using dexamethasone at a very low and presumably safe dosage (1/50 w/w). METHODS: Lymphoblasts were isolated from bone marrow and/or blood samples from children with newly diagnosed acute lymphoblastic leukemia. The cytotoxic activity of prednisolone, dexamethasone and the prednisolone/dexamethasone combination against isolated leukemia cells was analyzed using the MTT cytotoxicity assay. RESULTS: We observed differences in the in vitro antileukemic activity of prednisolone and dexamethasone in 21% of the tested patients. 3% of the children were prednisolone sensitive but dexamethasone resistant, while 18% were prednisolone resistant and dexamethasone sensitive. 32% were sensitive to both glucocorticoids and 18% were resistant to both. Cells from patients with good in vivo responses to prednisone monotherapy were more responsive to prednisolone in vitro than were cells from patients with poor prednisone responses (P<0.07). Importantly, we demonstrated that the use of even a minimal dose (1/50 w/w) of dexamethasone with prednisolone dramatically increases the in vitro anti-leukemic activity of prednisolone (P<0.0006). CONCLUSION: The high inter-individual variability of acute lymphoblastic leukemia responses to glucocorticoids suggest that either patients should be selected for prednisone or dexamethasone treatment on the basis of predictive biomarkers or that prednisone should be used directly in combination with a very low and safe dose of dexamethasone to potentiate its antileukemic activity. The latter option is likely to be cheaper and more efficient, and therefore warrants further clinical investigation to assess its efficacy and safety in treating childhood acute lymphoblastic leukemia.
Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia 10/2012; · 0.99 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: It is mandatory to confirm the absence of mutations in the KRAS gene before treating metastatic colorectal cancers with epidermal growth factor receptor inhibitors, and similar regulations are being considered for non-small cell lung carcinomas (NSCLC) and other tumor types. Routine diagnosis of KRAS mutations in NSCLC is challenging because of compromised quantity and quality of biological material. Although there are several methods available for detecting mutations in KRAS, there is little comparative data regarding their analytical performance, economic merits, and workflow parameters. METHODS: We compared the specificity, sensitivity, cost, and working time of five methods using 131 frozen NSCLC tissue samples. We extracted genomic DNA from the samples and compared the performance of Sanger cycle sequencing, Pyrosequencing, High-resolution melting analysis (HRM), and the Conformite Europeenne (CE)-marked TheraScreen DxS and K-ras StripAssay kits.Results and conclusionsOur results demonstrate that TheraScreen DxS and the StripAssay, in that order, were most effective at diagnosing mutations in KRAS. However, there were still unsatisfactory disagreements between them for 6.1% of all samples tested. Despite this, our findings are likely to assist molecular biologists in making rational decisions when selecting a reliable, efficient, and cost-effective method for detecting KRAS mutations in heterogeneous clinical tumor samples.
Journal of Experimental & Clinical Cancer Research 09/2012; 31(1):79. · 3.07 Impact Factor
[show abstract][hide abstract] ABSTRACT: Two sets of new conjugates obtained from d-mannose derivatives and o-, m-, and p-substituted benzoic acid esters interconnected through a triazole ring were synthesized by Cu(I) catalyzed azide-alkyne cycloaddition. All synthesized compounds were tested for their in vitro cytotoxic activity against seven cancer cell lines with/without multidrug resistance phenotype as well as non-tumor MRC-5 and BJ fibroblasts. Butyl ester of 4-aminobenzoic acid 6c showed the highest activity among all tested compounds, however, it was active only against K562 myeloid leukemia cells. N-Glycosyltriazole conjugates, both acetylated and nonacetylated at mannose moiety, were almost completely inactive. In contrast, some of the acetylated O-glycosyl conjugates showed cytotoxic activity which was cell line dependent and strongly affected by position of benzoic acid substitution as well as a length of its ester alkyl chain; the most potent compound was acetylated mannoside conjugated with octyl ester of m-substituted benzoic acid. However, deacetylation resulting in hydrophilicity increase of the glycosides almost completely abolished their cytotoxic potency.
Carbohydrate research 08/2012; 361C:1-6. · 2.03 Impact Factor
[show abstract][hide abstract] ABSTRACT: Trastuzumab is effective in about half of HER2-positive breast cancer patients. The PI3K/Akt signalling pathway plays an important role in the process of primary and secondary resistance to anti-HER2 targeted therapy. We evaluated the relationship between expression, activation and subcellular localization of selected Akt isoforms and response to trastuzumab-based anti-HER2 targeted therapy in patients with HER2-positive metastatic breast cancer. Seventy-four women with verified HER2-positive breast cancer were treated with trastuzumab for metastatic disease. Immunohistochemistry was used to evaluate Akt1, Akt2, pAkt Thr308 and pAkt Ser473 expression. For pAkt, cytoplasmic and nuclear fractions were assessed separately. Even though Akt isoforms were expressed in the majority of tumours, activated Akt (pAkt) was present in the cytoplasm only and not in the nucleus in >20% of tumours, and there was no pAkt at all in another 7-13% of tumours. Patients whose tumours showed strong Akt2 expression and had pAkt (pAkt-Thr308 and/or pAkt-Ser473) detectable in the cytoplasm as well as nucleus (n+c), exhibited improved time to progression (TTP) and overall survival from the initiation of trastuzumab therapy (OSt). Patients with tumours with strong Akt2 and pAkt Thr308 (n+c) had superior TTP (17.0 vs. 7.6 months, P=0.024; HR 0.52) and OSt (51.8 vs. 16.8 months, P=0.0009; HR 0.34) compared to other tumours. Similar results were found for strong Akt2 and pAkt Ser473 (n+c): TTP 13.1 vs. 7.2 months (P=0.085, HR 0.62) and OSt 50.8 vs. 17.0 months (P=0.009; HR 0.45). This study is the first to prove the significance of Akt kinase isoform, activity and compartmentalization for the prediction of response to trastuzumab-based therapy in patients with HER2-positive metastatic breast cancer.
International Journal of Oncology 07/2012; · 2.66 Impact Factor
[show abstract][hide abstract] ABSTRACT: Epidermal growth factor receptor (EGFR) is an important therapeutic target and a poor prognosis factor in head and neck squamous cell carcinoma (HNSCC). The aim of the study was to analyze EGFR expression and KRAS and EGFR mutational status and to correlate it with treatment response to anti-EGFR therapy combined with radiotherapy in 29 patients with advanced head and neck squamous cell carcinomas (HNSCC).EGFR gene expression normalized to GAPDH and EGFR variant type III (EGFRvIII) was detected in tumor tissue using real time reverse transcription -PCR. The mutational status of the EGFR and KRAS genes was investigated by real time PCR with sequence specific primers.Gene expression median values were 3.1x10(8) GAPDH gene copies per µg of RNA, and 8x10(6) EGFR gene copies per µg of RNA. The median EGFR/GADPH ratio reached 0.14. Patients, who achieved complete response after Cetuximab combined with radiotherapy, had significantly higher expression of the EGFR gene in tumors than patients with partial remission or patient without treatment response. An EGFRvIII mutation was found in 20.7 % of patients and no association was found between this mutation and treatment response. 27 patients (93.1 %) had an EGFR gene wild type tumor, and deletion in exon 19 was found in two patients with a poor clinical outcome. Most of the patients (82.8%) had a KRAS wild type tumor; a p.Gly12Cys was found in three patients and a p.Gly12Val mutation in one. Presence of a p.Gly12Val mutation in the KRAS gene was associated with an absence of response to treatment. CONCLUSION: Our data suggest that KRAS mutation (p.Gly12Val) and somatic EGFR mutation located in exon 19 may contribute to the limited clinical response to therapy with cetuximab + radiotherapy. Higher EGFR gene expression serves as an independent indicator of good clinical response to EGFR-targeted therapy + radiotherapy.
[show abstract][hide abstract] ABSTRACT: a b s t r a c t The aim of this work was to synthesize a set of heterocyclic derivatives of lupane, lup-20(29)-ene, and 18a-oleanane, and to investigate their cytotoxic activities. Some of those heterocycles were previously known in the oleanane (allobetulin) group; however, to our knowledge the syntheses and biological activities of lupane heterocycles have not been reported before. Starting from betulin (1) and betulinic acid (2), we prepared 3-oxo compounds and 2-bromo-3-oxo compounds 3–10, 2-hydroxymethylene-3-oxo compounds 11–13 and b-oxo esters 14–16. Condensation of these intermediates with hydrazine, phenylhydrazine, hydroxylamine, or thiourea yielded the pyrazole and phenylpyrazole derivatives 17– 22, pyrazolones 23–25, isoxazoles 26 and 27, and thiazoles 28–31. Fifteen compounds (14–16, 18–25, and 29–32) have not been reported before. The cytotoxicity was measured using panel of seven cancer cell lines with/without MDR phenotype and non tumor MRC-5 and BJ fibroblasts. The preferential cyto-toxicity to cancer cell lines, particularly to hematological tumors was observed, the bromo acids 5, 6 showed highest activity and selectivity against tumor cells.
[show abstract][hide abstract] ABSTRACT: AbstractThe deregulation of cell cycle components in cancer cells has provided a rationale for the development of small molecule inhibitors
of cyclin-dependent kinases as novel anticancer drugs. A series of 1,5-diaryl-3-(3,4,5-trihydroxyphenyl)-1H-pyrazolo[4,3-e][1,2,4]triazines was synthesized and their kinase inhibitory activity and cytotoxicity against several cancer cell lines
has been evaluated. Some of the compounds of the series exhibited induction of caspase-dependent cell death and inhibition
of cyclin-dependent kinase 2 (CDK2).
[show abstract][hide abstract] ABSTRACT: The aim of this work was to synthesize a set of heterocyclic derivatives of lupane, lup-20(29)-ene, and 18α-oleanane, and to investigate their cytotoxic activities. Some of those heterocycles were previously known in the oleanane (allobetulin) group; however, to our knowledge the syntheses and biological activities of lupane heterocycles have not been reported before. Starting from betulin (1) and betulinic acid (2), we prepared 3-oxo compounds and 2-bromo-3-oxo compounds 3-10, 2-hydroxymethylene-3-oxo compounds 11-13 and β-oxo esters 14-16. Condensation of these intermediates with hydrazine, phenylhydrazine, hydroxylamine, or thiourea yielded the pyrazole and phenylpyrazole derivatives 17-22, pyrazolones 23-25, isoxazoles 26 and 27, and thiazoles 28-31. Fifteen compounds (14-16, 18-25, and 29-32) have not been reported before. The cytotoxicity was measured using panel of seven cancer cell lines with/without MDR phenotype and non tumor MRC-5 and BJ fibroblasts. The preferential cytotoxicity to cancer cell lines, particularly to hematological tumors was observed, the bromo acids 5, 6 showed highest activity and selectivity against tumor cells.
[show abstract][hide abstract] ABSTRACT: Minimal systemic disease (MSD) means the presence of circulating or disseminated tumour cells in mesenchymal compartments of a patientts' body (lymphatic nodes, blood or bone marrow). The aim of our pilot study was to identify sensitive and specific markers for MSD detection in 50 lung cancer patients, who underwent curative surgery in the I. Department of Surgery, Faculty of Medicine and Dentistry, Palacky University and Faculty Hospital Olomouc in 2009 and 2010.
Absolute gene expression of carcinoembryonic antigen (CEA), epidermal growth factor receptor (EGFR1), lung-specific X protein (LUNX) and hepatocyte growth factor receptor (c-met) was determined in peripheral blood, bone marrow and pulmonary blood of 50 lung cancer patients using real-time reverse transcriptase-polymerase chain reaction (real-time RT-PCR).
(1) The LUNX marker is specific and sensitive for MSD detection in lung cancer patients. (2) The CEA positivity for MSD in the bone marrow correlated significantly with histopathological grading (GI-GIII). (3) Higher expression of CEA and c-met was found in pulmonary blood of patients with hilar or mediastinal lymphadenopathy. (4) Higher expression of MSD markers (CEA in bone marrow, c-met in peripheral blood and LUNX in pulmonary blood) correlated with higher pTNM classification.
Minimal systemic disease detection in lung cancer patients is technically feasible using sufficiently sensitive and specific markers for RT-PCR. Minimal systemic disease detection can be used to guide further systemic treatment. This theory must be validated in a larger group of patients and correlated with clinical data, especially with survival data.
Rozhledy v chirurgii: měsíčník Československé chirurgické společnosti 04/2012; 91(4):209-15.