Detection of DNA methylation in eucaryotic cells

The methods of molecular biology allow for analyzing the methylation pattern in the whole genome and in particular genes. We differentiate methylated sequences from unmethylated ones by means of cutting the genomic template with methylation-sensitive restriction enzymes or by sodium bisulfite DNA modification. Chemical modification precedes most quantitative and qualitative PCR techniques: MS-PCR, MS-nested PCR, Real-Time PCR, QAMA, HeavyMethyl, MSHRM. Restriction enzymes, on the other hand, may be used together with PCR or hybridisation methods (Southern blot and microarrays). PCRs are conducted with primers specific for methylated and unmethylated sequences and sometimes, similarly to hybridisation techniques, with specifically labeled probes or dyes intercalating to double-stranded nucleic acids. The most advanced methylation detection techniques (MALDI-TOF MS and HPLC) significantly reduce the amount of biological material used for tests, but they require specialist equipment.

DNA methylation in states of cell physiology and pathology

DNA methylation is one of epigenetic mechanisms regulating gene expression. The methylation pattern is determined during embryogenesis and passed over to differentiating cells and tissues. In a normal cell, a significant degree of methylation is characteristic for extragenic DNA (cytosine within the CG dinucleotide) while CpG islands located in gene promoters are unmethylated, except for inactive genes of the X chromosome and the genes subjected to genomic imprinting. The changes in the methylation pattern, which may appear as the organism age and in early stages of cancerogenesis, may lead to the silencing of over ninety endogenic genes. It has been found, that these disorders consist not only of the methylation of CpG islands, which are normally unmethylated, but also of the methylation of other dinucleotides, e.g. CpA. Such methylation has been observed in non-small cell lung cancer, in three regions of the exon 5 of the p53 gene (so-called "non-CpG" methylation). The knowledge of a normal methylation process and its aberrations appeared to be useful while searching for new markers enabling an early detection of cancer. With the application of the Real-Time PCR technique (using primers for methylated and unmethylated sequences) five new genes which are potential biomarkers of lung cancer have been presented.

Immunohistochemical markers of cancerogenesis in the lung

Lung cancer is the leading cause of cancer deaths for people of both sexes worldwide. Early diagnosis of precancer lesions may be of crucial significance to lowering lung cancer mortality. The World Health Organization has defined three preneoplastic lesions of the bronchial epithelium: squamous dysplasia and carcinoma in situ, atypical adenomatous hyperplasia and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. These lesions are believed to progress to squamous cell carcinoma, adenocarcinoma and carcinoid tumors, respectively. Apart from WHO classification, two other lesions such as bronchiolization and bronchiolar columnar cell dysplasia (BCCD) can be observed and thought to be preneoplastic lesions leading to adenocarcinoma. In this review we summarize the data of morphological and cell cycle related proteins changes in both central and peripheral compartments of lung. Many molecular changes, which accompany the multistep process of the development of invasive types of cancer, may be observed thanks to the application of immunohistochemical markers. A deeper knowledge of molecular and genetic changes accompanying pre-cancer states may show new directions of early diagnostics of cancer development.

Angiogenesis and Neoangiogenesis—The Role in Lung Cancer and Other Tumors

Nowe naczynia tworzone są w dwóch procesach: waskulogenezy i angiogenezy [...]

Serum Levels of IGF-I and IGFBP-3 in Patients With Lung Cancer During Chemotherapy

The aim of this study was to assess serum levels of insulin-like growth factors (IGF-I and IGFBP-3) in patients with lung cancer during chemotherapy. The study included 38 patients (33 males and 5 females; mean age 59.8) diagnosed histologically with lung cancer. Twenty-five patients (65%) had non-small cell lung cancer (NSCLC) and 13 patients (35%) had small cell lung cancer (SCLC). Squamous cell carcinoma was established in 30% (11 patients) of all patients with NSCLC, adenocarcinoma in 13% (5 patients), and non-small cell cancer in 36% (9 patients). The control group consisted of 10 healthy volunteers. Peripheral blood samples were taken before and after four cycles of chemotherapy. IGF-I and IGFBP-3 levels were assessed by ELISA method. Serum levels of IGF-I measured before chemotherapy were significantly higher in both NSCLC and SCLC groups in comparison with controls. No significant differences were observed in serum IGF-I levels before and after four cycles of chemotherapy. The levels were still high after chemotherapy in patients with NSCLC and SCLC. Serum levels of IGFBP-3 were markedly lower in patients with NSCLC both before and after treatment compared to controls. No significant differences were found in patients with NSCLC before and after cytoreduction treatment. Prior to treatment, serum IGFBP-3 levels were significantly lower in patients with SCLC in comparison with controls. After cytoreduction treatment, the levels were decreased when compared to controls but without statistical significance. In conclusion, both before and after chemotherapy serum levels of IGF-I were significantly higher, whereas IGFBP-3 levels were lower in patients with NSCLC and SCLC compared to controls. Chemotherapy had no influence on the serum levels of IGF-I and IGFBP-3. Neither a histological type of NSCLC nor clinical staging had any effect on the serum levels of IGF-I and IGFBP-3.

Serum endostatin levels in patients with lung carcinoma

The purpose of our study was to evaluate the clinical usefulness of serum endostatin levels during chemotherapy of lung cancer in relation to the histopathological type of the tumor, clinical stage and response to therapy.

MATERIALS AND METHODS

Serum concentrations of endostatin were determined in 37 patients (24 with non-small cell lung cancer and 13 with small cell lung cancer), 10 healthy subjects constituted controls. To determine endostatin levels (ELISA), venous blood samples were collected from each patient before treatment and after 4-6 courses of chemotherapy.

RESULTS

The serum concentrations of endostatin were found significantly higher in patients in comparison with controls (p=0.003). No statistically significant differences were established between the concentrations of endostatin with regard to such clinical features, as: performance status, clinical stage (III and IV) and histopathological type (non-small cell lung cancer and small cell lung cancer). The concentrations of endostatin did not change after chemotherapy. There was no change of endostatin concentration caused by the response to treatment.

CONCLUSIONS

The serum endostatin concentrations were elevated in lung cancer patients.

[Evaluation of some functions of polymorphonuclear granulocytes in lung cancer patients during chemotherapy]

Lung cancer (NSCLC and SCLC) is one of most frequent carcinoma. Lung cancer is at the top of the list of cancers causing mortality in males. Many patients are qualified to chemotherapy which causes neutropenia. The aim of this work was to evaluate the number and function of (phagocytosis, test of NBT reduction and MPO activity) of leukocytes in patients with lung cancer before chemotherapy, during leukopenia and after stimulation with granulocyte colony stimulating factor (G-CSF). Patients with lung cancer have increased number of leukocytes before the treatment. After chemotherapy the number of leukocytes decreases. Treatment with G-CSF increases the number of leukocytes but it doesn't increase their ability to phagocytosis and to NBT reduction.

Serum levels of IGF-I and IGF-II in patients with lung cancer during chemotherapy

The AIM of this study was to assess the influence of chemotherapy on the serum levels of IGF-I and IGF-II in patients with lung cancer.

METHODS

The study included 38 patients (33 males and 5 females) at mean age of 59.8, diagnosed histologically with lung cancer. Twenty five patients had non-small cell lung cancer (NSCLC) including 11 patients with squamous cell carcinoma (SCC), 5 patients with adenocarcinoma and 9 patients without an essential histological type of NSCLC. A total of 13 patients had small cell lung cancer (SCLC). The control group consisted of 10 healthy volunteers. The peripheral blood samples were taken before and after 4 cycles of chemotherapy. IGF-I and IGF-II levels were assessed by ELISA method.

RESULTS

Serum levels of IGF-I and IGF-II measured before chemotherapy were significantly higher in both NSCLC and SCLC groups in comparison with controls. There were no significant differences of serum levels of both growth factors before and after 4 cycles of chemotherapy. Serum levels of IGF-I and IGF-II were still high after chemotherapy in patients with NSCLC and SCLC. Patients with SCC and adenocarcinoma had similar serum levels of IGF-I and IGF-II without statistical differences.

CONCLUSION

Serum levels of IGF-I and IGF-II were significantly higher in patients with NSCLC and SCLC before chemotherapy than in controls. Chemotherapy had no influence on the serum levels of insulin-like growth factors (IGFs). Serum levels of IGF-I and IGF-II did not depend on a histological type of NSCLC either.

The epidemiology of asbestos-related diseases

Asbestos has been recognised as a potential health hazard since the 1940s. Of the two major species of asbestos; white asbestos (chrysotile) and blue asbestos (crocidolite), both of which are hazardous. The workers at extraction facilities are at the greatest risk of exposure to asbestos and, therefore, the development of asbestos-related diseases, commonly mesothelioma. However, other individuals at a high risk of exposure include asbestos-cement workers, insulation workers and ship-yard workers. Environmental exposure to asbestos can occur as a result of living in areas either characterised by natural outcrops of asbestos or asbestos-related materials, or those close to asbestos-producing or -using plants. Unfortunately, man-made fibre alternatives to asbestos, such as rock and slag-wool and glass wool, have also been shown to have a detrimental effect on human health. A characteristic of mesothelioma is that there is a long latency period (20-30 years) before the signs and symptoms of the disease become apparent. In addition, diagnosis of the disease can be difficult. The use of biological markers, such as tissue polypeptide antigen, may play a useful role in the early detection of the disease in individuals at risk.

[Circulating VEGF and its soluble receptor sVEGFR-1 in patients with lung cancer]

Angiogenesis plays an important role in the pathogenesis of lung cancer. This process is caused by the imbalance between stimulating and inhibiting agents. VEGF is a key stimulator having a biologic effect via two different receptors of tyrosine kinase: VEGF-R1 and VEGF-R2. A soluble form of sVEGF-R1 is a negative regulator of VEGF activity. The serum concentrations of VEGF, sVEGF-R1 were assayed in 24 patients with NSCLC and 13 patients with SCLC and 10 healthy volunteers by means of ELISA method. The serum concentrations of VEGF were significantly higher in patients than in controls (p=0.016). The concentration of sVEGF-R1 was not significantly different in patients and controls. No statistically significant differences were established between the concentrations of VEGF, and sVEGF-R1 with regard to such clinical features, as: performance staging, clinical staging (stage III vs. stage IV) and histological pattern (NSCLC vs. SCLC). The significantly higher VEGF concentrations were reported in patients with the tumor of more than 7.5 cm in the diameter (p=0.027). Analyzing the influence of the response to treatment on the concentrations of parameters examined, a significant increase in VEGF concentration was demonstrated in the case of disease progression (p=0.034). The concentrations of sVEGF-R1 did not change after treatment. No correlation was found between parameters examined.

Serum levels of interleukin-18 (IL-18) and soluble interleukin-2 receptor (sIL-2R) in lung cancer

PURPOSE

We evaluated the clinical usefulness of interleukin-18 (IL-18) and soluble interleukin-2 receptor (sIL-2R) during chemotherapy of lung cancer in relation to the histological type of the tumor, clinical stage, response to therapy and time survival.

MATERIAL AND METHODS

Serum levels of IL-18 and sIL-2R were determined in 73 patients (62 males; mean age 64 years; 41 with non-small cell lung cancer-NSCLC, 32 with small cell lung cancer-SCLC); 12 healthy subjects served as controls. To determine IL-18 serum concentrations (Elisa), venous blood samples were collected from each patient before and after chemotherapy.

RESULTS

The mean serum IL-18 level in all patients with lung cancer was significantly higher compared with healthy volunteers (p = 0.0001; NSCLC vs control p = 0.0001; SCLC vs control p = 0.004). In NSCLC group with stage IV the mean IL-18 level was significantly higher than those with stage IIIB (p = 0.04). Regarding tumor stage and response to therapy, no significant differences in IL-18 were observed. Using cut-off serum IL-18 concentration of 319.6 pg/ml, the prognoses of the two groups were different, but it was not statistically significant. The serum levels of sIL-2R in NSCLC patients were significantly higher than in controls (p = 0.018). There were no significant differences in serum sIL-2R levels in relation to clinical stage of lung cancer and response to therapy. The cut-off value between high and low serum sIL-2R concentration was defined as 582.27 U/ml. The difference in survival rate between the high and low sIL-2R groups was not significant.

CONCLUSIONS

Serum IL-18 and sIL-2R levels can be useful in clinical practice, but their practical significance needs further studies.

Serum levels of osteoprotegerin (OPG) and pro gastrin releasing peptide (ProGRP) during chemotherapy of lung cancer

The aim of our study was to evaluate the usefulness of serum OPG and ProGRP during chemotherapy of lung cancer in relation to the histological type of the tumour, its clinical stage and the response to therapy. The levels of OPG and ProGRP were determined in 39 patients (20 NSCLC, 19 SCLC) and 10 healthy subjects. Blood samples were collected from each patient before and after chemotherapy. OPG and ProGRP levels in all the patients with lung cancer were higher than those in the controls. ProGRP were higher in SCLC group than in those NSCLC. In NSCLC group (after chemotherapy), OPG level in patients with Stage IV tumour was higher than in those with Stage IIIB (p=0.03). OPG in ED SCLC were higher than those in LD SCLC (p=0.04). In SCLC group, ProGRP were higher in LD patients than those with ED (p=0.04). Concluding, the measuring of OPG and ProGRP in lung cancer patients may be useful in clinical practice.

K-ras codon 12 mutations may be detected in serum of patients suffering from adeno- and large cell lung carcinoma. A preliminary report

We investigated the presence of K-ras mutations in the serum of 40 patients with respectable stages of adeno- and large cell lung carcinomas. Mutations in codon 12 of the K-ras gene were examined by enriched PCR method in DNA extracts from surgical specimens and serum samples. K-ras mutations were detected in 20 (51%) of 39 analyzed tumours, and in 7 (35%) of 20 patients with K-ras gene mutation positive tumours, a mutation was found in the serum DNA. We also found K-ras mutation in two (10.5%) of 19 serum samples obtained from patients whose tumours were not found to harbor mutation and in one serum sample from patient without tumour sample available for investigation. All of the 14 control healthy persons were negative for serum DNA K-ras mutation assay. Although our results are preliminary they show that K-ras mutation may be detected in serum of patients suffering from adeno- and large cell lung carcinomas and confirm the suggestion that at least a part of a free-cell extracellular blood DNA in cancer patients has neoplastic origin and may become a noninvasive target for genetic investigations of lung cancer patients.

The clinical significance of serum soluble interleukin 2 receptor (sIL-2R) concentration in lung cancer

The activated mononuclear cells can release a soluble form of interleukin 2 receptor (sIL-2R) in the blood. Serum sIL-2R level is a sensitive and quantitative marker of circulating peripheral blood mononuclear cell activation. This molecule acts as an antagonist of IL-2-mediated responses. The present study was carried out to analyze the circulating levels of sIL-2R in lung cancer in relation to the histological type of the tumour, clinical stage, response to therapy, time survival for patients. The study included 62 patients (30 SCLC, 32 NSCLC) and 10 healthy subjects as controls. SIL-2R serum levels were measured with a sandwich enzyme immunoassay using commercial kits (ENDOGEN). The mean serum values of sIL-2R were significantly higher in cancer patients than in controls (p=0.01). There was no significant difference in relation to tumour histological type. Within the NSCLC chemotherapy group, sIL-2R mean levels observed at the end of chemotherapy were higher in the progressing patients than in the responding patients. The metastatic patients had higher levels of sIL-2R than those with locally limited disease. In the case of SCLC classified to extensive disease mean levels of sIL-2R were higher than SCLC classified to limited disease. The mean serum values of sIL-2R were significantly higher in weight loss patients than no weight ones (p=0.03). Within NSCLC group there was a correlation between sIL-2R mean levels and the age of patients (p=0.04). In SCLC group there was a correlation between levels of sIL-2R and time survival for patients (p=0.009).

P16INK4a point mutations and promoter hypermetylation in bronchial preneoplastic lesions

The aim of this study was to determine p16INK4a point mutations and promoter hypermethylation in tumour cells and bronchial preneoplastic lesions in 32 surgically resected lungs due to primary squamous cell carcinoma. P16 point mutations were detected in 1 (3%) and promoter hypermethylation in 12 (31%) of 32 squamous cell carcinomas. The status of p16 was further characterized in 38 premalignant lesions including squamous metaplasias without dysplasia, squamous metaplasias with mild, moderate and severe dysplasias and 4 carcinomas in situ. No p16 point mutations have been found in premalignant or CIS lesions. Methylation of p16 was detected in 1 of 8 (12.5%) cases of squamous metaplasias without dysplasia, in 1 of 10 (10%) cases of squamous metaplasias with mild dysplasia, in 1 of 9 (11%) cases of squamous metaplasia with moderate dysplasia and in 2 of 7 (28.5%) cases of severe dysplasias, as well as in 1 of 4 (25%) carcinomas in situ. This investigation indicates that P16INK4a supressor gene point mutations are rather late event and inactivation of this gene by promoter hypermethylation is early and likely critical in bronchial cancerogenesis.

K-ras codon 12 mutations detected with enriched PCR method in operable non-small cell lung cancer

Activated point mutations of the K-ras gene are one of the most common genetic alterations found in human malignancies, including lung cancer, and are largely limited to adenocarcinomas. Using a highly sensitive assay for codon 12 K-ras mutation detection, called enriched PCR, we investigated 130 radically resected stage I-IIIa non-small cell lung cancer (NSCLC). There were statistically less positive results for squamous cell carcinoma (1.3%) than for adenocarcinoma (42.4%) and large cell carcinoma (27.8%). No statistically significant association between results of K-ras mutations and TNM stage of disease was found. In stage I of adenocarcinoma patients the incidence of K-ras mutations was similar to that in stage II or IIIa (40%, 42.9% and 42.9%, respectively). The results of our study showed that K-ras mutations might play an important role in pathogenesis of pulmonary adenocarcinoma due to its high prevalence in the operable tumours.

Endothelial cells and angiogenesis intensity in lung cancer

We focused our studies on single endothelial cells (ECs) scattered in extracellular matrix in lung cancer tumors. Neovascularization was evaluated in 100 tumors obtained from patients operated for lung cancer, in relation to histological type, tumor differentiation and clinical stage of the disease. Angiogenic objects (single endothelial cells and microvessels) were identified by immunohistochemistry using monoclonal antibodies against von Willebrand factor. The count of angiogenic objects per 1 mm2 in each section was determined in a "hot spot" located at the margin of the tumor. We used an arbitrary scale of angiogenesis intensity: 1 - 0-200, 2 - 201-400, 3 - >400 angiogenic objects/mm2. A majority (57%) of the examined cases belonged to the group 2. The angiogenesis intensity measured by the single EC numbers/mm2 correlates with the histological type and the differentiation of the tumors. There was no such a correlation when the angiogenesis intensity was measured by counting total angiogenic objects (microvessels + EC) number/mm2. Single EC number/mm2 in different histological types of cancer were as follows: 162+/-121 in squamous cell (SqCC), 194+/-71 in adenocarcinoma (AdC), 225+/-145 in large cell (LCC), 264+/-52 in small cell (SCC), 279+/-173 in combined cancer. The differences between the EC counts in the different histological types of lung cancers were statistically significant in the following pairs: SqCC vs SCC (p=0.0233) and AdC vs SCC (p=0.0409). The correlation between EC count in the "hot spot" and the grade of tumor differentiation was statistically significant for G1 vs G4 (p=0.0007) and G1 vs G2 (p=0.0411). Our results suggest that higher numbers of EC/mm2 may confirm rapid development of angioneogenesis. These relations should be examined in larger series of cases.

[Allergic broncho-pulmonary tuberculosis--a case without bronchial asthma]

Aspergillus fumigatus can cause a number of lung diseases. One of them is allergic bronchopulmonary aspergillosis (ABPA) characterized by pulmonary eozynophilia, asthma, an allergic type of immune response in the bronchi and proximal bronchiectases. ABPA was recognised in 28-years old man (round shadows in the lung, obturated bronchus with mucoid impaction, positive skin tests with aspergillin and presence of precipitins to Aspergillus fumigatus, elevated serum IgE level). Patient was treated for 6 months with corticosteroids. After 2 years of regression there was an exacerbation of ABPA was recognised. The steroid therapy was repeated.

Morphological aspects of carcinogenesis in the lung

The origins of the various histological types of primary lung cancer are not well understood. Numerous recent studies have indicated that lung cancer is not a result of a sudden transforming event in the bronchial and alveolar epithelium and in the neuroendocrine cells, but a multistep process in which a sequence of morphological and genetic changes is occurring. New modern technical approaches like fluorescence bronchoscopy techniques and microdissection, provide facilities to obtain valuable specimens for morphological and genetic verification of the sequentional changes in lung cancerogenesis. With their help, cells with morphologically recognized changes thought to be preneoplastic, may be removed and prepared for molecular and genetic studies. Therefore, the knowledge of the morphological aspects of lung preneoplastic lesions is crucial to make progress in molecular studies of lung carcinogenesis. Presently the knowledge about the sequence of molecular events in the lung carcinogenesis and their relationship to morphology is not perfect. In this review we will describe morphological aspects of various preneoplastic lesions occurring in the bronchial and bronchiolo-alveolar compartments including neuroendocrine cells.

Morphological and molecular aspects of cancerogenesis in the lung

Morphology and some molecular aspects of hyperplastic (bronchial basal cell hyperplasia and alveolar cell hyperplasia), metaplastic (squamous metaplasia), preneoplastic and early neoplastic (dysplasia in squamous metaplasia, cancer in situ and atypical alveolar cell hyperplasia) changes were studied in 180 lungs resected due to non-small cell lung cancer: 106 cases (58.9%) of squamous cell carcinoma, 42 (23.3%) of adenocarcinoma and 32 (17.8%) of large cell carcinoma. P53 protein and PCNA expressions were detected immunohistochemically (using formalin-fixed, paraffin-embedded sections). DNA extracted from the microdissected P53-positive cells was analysed for point mutations in the P53 gene. No P53 immunostaining was observed in normal mucosa, hyperplasia of basal cells, squamous metaplasia without and with minor and moderate dysplasia of bronchial mucosa as well as alveolar cell hyperplasia. Overexpression of P53 protein occurred in 3 out of 12 (25%) cases of severe bronchial dysplasia, 5 out of 11 (45.5%) cases of intraepithelial carcinoma and 6 out of 45 (13.3%) cases of alveolar cell hyperplasia. Using direct sequencing, mutations in the P53 gene were detected in 11 out of 14 (87%) P53-immunopositive samples, including all severe dysplasias, all carcinomas in situ and 3 of 6 alveolar cell hyperplasias. A significant association was observed between PCNA expression and preinvasive as well as invasive lesions. The data clearly show that lung resected due to primary cancer ought to be treated as "field cancerization" in which one can find early morphologic events of multi-step cancerogenesis. P53 protein alterations and P53 gene mutations can occur before invasion and its frequency depends on the degree of dysplasia.

Detection of human papillomavirus in non-small cell lung carcinoma by polymerase chain reaction

Human papillomavirus (HPV) infection is one of the risk factors contributing to the pathogenesis of lung cancer. The aim of the study was to determine the presence of HPV in non-small cell carcinomas of the lung. The study included 40 tumors: 22 squamous cell carcinomas, 13 adenocarcinomas and 5 large cell carcinomas. HPV was found in 4 cases (10%). High risk HPV was present in 3 tumors: in one squamous cell carcinoma, one large cell carcinoma and one adenocarcinoma, while low risk HPV was detected in one adenocarcinoma.