[Non-specific immunotherapy inhibits angiogenesis - results of the monitoring of serum levels of vascular endothelial growth factor and matrix metalloproteinase 8 in patients with malignant melanoma receiving adjuvant high-dose interferon therapy]. / Nespecifická imunoterapie inhibuje angiogenezi - výsledky monitorování sérových hladin vaskulárního endotelového rustového faktoru a matrixmetaloproteinázy 8 v prubehu adjuvantní lécby vysokodávkovaným interferonem u pacientu s maligním melanomem.

OBJECTIVE: Interestingly, evidence is currently emerging that the activation of angiogenesis leads to immunomodulatory/immunosuppressive effects both at the local and systemic levels. These are very complex and interconnected processes. In this study, our aim was to establish interferon alpha-2b as an anti-angiogenic agent and show the complexity of angiogenesis and immunomodulation through the serum levels of vascular endothelial growth factor (VEGF) and matrix metalloproteinase 8 (MMP-8) in high-risk resected malignant melanoma before and after adjuvant therapy with high-dose interferon alpha-2b (HDI). Clinical outcomes of patients were also evaluated. MATERIAL AND METHODS: We prospectively measured the serum levels of VEGF and MMP-8 by ELISA in 29 patients with high-risk resected malignant melanoma receiving adjuvant HDI. Blood samples were collected before and within one week after the treatment. RESULTS: To see the results clearly, we divided our patients into two groups. The first group of patients whose VEGF serum level decreased after HDI (66%) showed long-term complete remission. The mean VEGF serum level in these patients decreased from 779.4 pg/ml to 446.2 pg/ml. This downward trend in VEGF was statistically significant. The second group of patients who did not show a decrease in VEGF serum level after HDI (34%) had no clinical benefit from the treatment. The mean VEGF serum levels in group 2 patients were 408 pg/ml before the treatment and 500 pg/ml after HDI. Results for MMP-8 were ambivalent. CONCLUSIONS: Non-specific immunotherapy with interferons reduces angiogenesis. Our results are in line with the current view of the interconnection and complexity of angiogenesis and immunomodulation/immunosuppression. Non-specific immunotherapy with interferons disrupts the immunosup-pressive effect of the angiogenesis on the development of immune response against tumours and supports anti-tumour response in both direct and indirect way. The interference of HDI with the activation of angiogenesis and tumour progression could explain good clinical outcomes of patients with a decrease in serum VEGF. The outcomes of MMP-8 are inconclusive, its role remain unclear, and MMP-8 does not seem to function as a tumour suppressor.

Low expression of NQO1 predicts pathological complete response to neoadjuvant chemotherapy in breast cancer patients treated with TAC regimen.

The aim of this study was to evaluate preoperative tumour expression of NAD(P)H:quinone oxidoreductase 1 (NQO1) along with other biological markers as potential predictors of pathological complete response (pCR) to neoadjuvant docetaxel, doxorubicin, and cyclophosphamide-containing (TAC) chemotherapy in patients with primary breast cancer. Sixty-one patients who received neoadjuvant chemotherapy (NCT) with TAC regimen were enrolled in this prospective study. The pre- and post- NCT expression of oestrogen receptor (ER), progesterone receptor (PR), epidermal growth factor receptor 1 and 2 (EGFR and HER2), NQO1, Ki-67 proliferation index, multidrug resistance protein 1 (MDR1), p53 and BCL2 were evaluated by immunohistochemistry. The pCR was reached in 14 patients (23 % of the study group). Multivariate analysis demonstrated that patients with ER-, PR-, NQO1- negative, and Ki-67-positive tumours had a significantly higher chance to achieve pCR. Within the biological subtypes, the highest pCR rate (50 %) was seen in triple-negative (i.e. ER-, PR-, HER2-) tumours. Post-operative evaluation showed that in comparison to pre-operative tissue samples, NQO1 expression was significantly increased, while Ki-67 and HER2 decreased, in the residual tissue after NCT. In conclusion, the present data suggests that NQO1 expression may be a novel diagnostic biomarker for the prediction of positive response to NCT in patients with breast cancer.

Valproic acid decreases the reparation capacity of irradiated MOLT-4 cells.

The aim of our work was to evaluate mechanisms leading to radiosensitization of MOLT-4 leukemia cells following valproic acid (VA) treatment. Cells were pretreated with 2 mM VA for 24 h followed by irradiation with a dose of 0.5 or 1 Gy. The effect of both noxae, alone and combined, was detected 1 and 24 hours after the irradiation. Induction of apoptosis was evaluated by a flow cytometry. The extent of DNA damage was further determined by phosphorylation of histone H2AX using confocal microscopy. Changes in protein expression were identified by SDS-PAGE/immunoblotting. Two-millimolar VA increased apoptosis induction after irradiation as well as phosphorylation of H2AX and provokes an increase in the level of p53 and its phosphorylation at Ser392 in 4 h post-irradiation. Likewise, p21 protein reached its maximal expression in 4 h after the irradiation of VA-treated cells. Twenty four hours later, only the p53 phosphorylated at Ser15 was detected. At the same time, the protein mdm2 (negative regulator of p53) was maximally activated. The 24-hour treatment of MOLT-4 leukemia cells with 2 mM VA results in radiosensitizing, increases apoptosis induction, H2AX phosphorylation, and also p53 and p21 activation.

CD8+ natural killer cells have a potential of a sensitive and reliable biodosimetric marker in vitro.

The aim of our work was to evaluate peripheral blood lymphocyte subsets as in vitro indicators of the received dose of ionizing radiation (biodosimetric markers) in the range of 3-20 Gy and to determine the appropriate time interval, during which a dose-dependent induction of apoptosis occurs upon gamma irradiation. In lymphocyte subsets characterized by double color surface immunophenotyping, four-color flow cytometry was used for visualizing cell death-associated increase in superficial phosphatidylserine exposure and cytoplasmic membrane permeability by fluorinated Annexin V and propidium iodide, respectively. No differences between sham-treated and lethal dose (7 Gy)-irradiated samples were observed upon 6 h cultivation in vitro. Ten and 18 h later, about 50 % of lymphocytes were apoptotic, but only the minority of them was in the late apoptotic phase. The only difference in radioresistance of the CD4(+)CD8(-) and CD4(-)CD8(+) lymphocyte subsets was seen upon 2-day cultivation when huge depletion of intact cells and prevalence of the late apoptotic population became obvious. A dose-dependence study in 16 and 48 h cultures confirmed the effectiveness of major T cell subsets as biodosimetric indicators. On the other hand, the minor CD8(+) subset of natural killer (NK) cells has been identified as a radiosensitive lymphocyte population the disappearance of which correlated with the received dose. We demonstrated that the CD3(-)CD8(+)NK subset can be used as a lethal/sublethal dose discriminator to 16 h cultivation. In addition, our data indicate that two-day cultivation followed by CD3/CD8 expression analysis in an intact lymphocyte population may provide a clue for low dosage biodosimetry.

[Contribution to neglecting of power analysis in experimental medicine studies]. / Prîspevek k nápravé opomíjení významu síly testu ve studiích z experimentální medicíny.

The work provides basic information about what is being understood under the term "statistical analysis of power of test" from the viewpoint of correct use of mathematical statistics in medicine. The detail rules of statistical decision-making are described. Furthermore, the work contains an illustration of power analysis of test application when using unpaired t-test.

Proteome study of colorectal carcinogenesis.

Development of cancer is a complex process involving multiple changes in gene expression. To unravel these alterations, a proteome approach aimed at the identification of qualitative and quantitative changes in protein composition, including their post-translational modifications, attracts great attention. Our study was focused on the identification of proteins whose amount is altered in the course of malignant transformation of colon mucosa. Proteins extracted from tissue specimens or cell lysates were separated by two-dimensional gel electrophoresis (2-DE). Comparative analyses of 2-DE protein patterns were done using computerized image analysis. Selected proteins exhibiting statistically significant abundance alterations comparing healthy and diseased tissues were identified by mass spectrometry. Globally, we have found 57 proteins that exhibited either a significant decrease or increase in amount in pathological tissues, and 18 of these were annotated by mass spectrometry. The alterations in the expression of nine proteins were common for both precancerous and neoplastic tissues suggesting their role in colon tumorigenesis. The epithelial origin of all identified spots was checked in two cell lines Caco-2 and DLD-1 originating from well-differentiated and poorly differentiated colon carcinoma, respectively.

Peripheral progenitor cells (PBPC) in supportive care after high-dose chemotherapy in breast cancer.

Hemopoietic growth factors (HGF) and leukapheresed peripheral progenitor cells (PBPC) are increasingly used for supportive care in high-dose chemotherapy (HDC) of solid tumors. Presently, therapeutic protocols with cyclic HDC plus PBPC support are successfuly used in breast cancer patients. Administration of PBPC significantly influences hemopoietic recovery in terms of shortening the pancytopenia period which reduces the risk of dangerous complications, especially the risk of infection. As a certain controversy exists about efficacy of this therapy, large randomized studies are conducted to find more accurate conclusions. In 1998 National Cancer Institute (NCI) gave top priority to four randomized studies of HDC with PBPC support. In recent years, rising yields of PBPC are obtained. The use of new combinations and dosages of hemopoietic growth factors leads to a significant increase of progenitor cells circulating in peripheral blood. Effective mobilization regimens combinations of chemotherapy and cytokines - enable to increase the numbers of circulating progenitors as much as 100-fold. Another aspect, how to minimize the risks is to reduce the transplant volume and so reduce the amount of cryoprotective agent DMSO (dimethyl sulfoxide) and hemolysed erythrocytes. This led to the idea to use only whole blood enriched for PBPC. At present it has been used also in our patients. The results show that enriched whole blood can be used as sufficient substitution for support in intensive cyclic chemotherapy in breast cancer patients.

The alveolar septal thickness and type II pneumocytes number in irradiated lungs, time expression and the effect of pentoxifylline.

PURPOSE: We studied the relationship between type II pneumocytes number and alveolar septal thickness during different time after sublethal whole-thorax irradiation of rats and we investigated the influence of pentoxifylline (TNF-alpha inhibitor). MATERIALS AND METHODS: Wistar rats were exposed to 15 Gy thoracic irradiation and pentoxifylline (35 mg/kg) twice a week. Lungs were examined histologically and immunohistochemically at intervals ranging from 1-12 weeks and alveolar septal thickness, number of type II pneumocytes (identified by immunoreactivity for cytokeratin 18), and neutrophile granulocytes were counted. RESULTS: Significant increase of alveolar septal thickness and type II pneumocytes depletion 3 weeks after irradiation were found. Correlation of these markers was r = -0.759. Pentoxifylline significantly inhibits increased alveolar septal thickness without the influence on type II pneumocytes number. Neutrophil penetration started 5 weeks after irradiation in non-treated animals, 8 weeks after irradiation in PTX-treated rats. CONCLUSIONS: We suggest that pneumocytes depletion is linked to increased vascular permeability, and pentoxifylline therapy does not influence on pneumocytes kinetics after irradiation.

Apoptosis and bcl-2 expression in irradiated lungs and the effect of pentoxifylline.

We measured number of bcl-2, apoptotic, neutrophil, and surfactant apoprotein D (SP-D) positive cells in irradiated rat lungs during different time points after the sublethal whole-thorax irradiation of rats. We also investigated the influence of pentoxifylline (PTX) therapy on these markers. Wistar rats were given 15 Gy thoracic irradiation and PTX (35 mg/kg) twice a week. Animals were examined histologically and imunohistochemically at intervals from 1-12 weeks. In non-treated rats compared with treated rats, bcl-2 expression was significantly inhibited from 4 weeks after irradiation. A higher apoptosis presence in non-treated rats from 4 weeks was found and apoptosis development in PTX-treated animals was delayed and started 8 weeks after irradiation. Similar differences were measured during neutrophil granulocytes examination. Neutrophil penetration in non-treated rats was found 5 weeks after irradiation in contrast to the RP onset of PTX-treated animals 8 weeks after irradiation. The number of SP-D positive cells in non-treated rats observed until 5 weeks after irradiation was higher than in the control group. PTX-treated animals expressed higher number of SP-D positive cells during the whole experiment than the control group. We suggest that apoptosis is linked to neutrophil granulocyte actions during the RP onset and that PTX-therapy causes diminished inflammation development.

The dialysis of Ochratoxin A (OTA).

Standard dialysis did not result in a decrease of the OTA level in the blood serum of patients regularly treated by dialysis. Therefore, we examined the effect of dialysis on both OTA bound to the blood plasma proteins and free OTA. We carried out an in vivo experiment to determine OTA levels in the serum of patients in the terminal stage of chronic renal insufficiency (CHRI) before and after dialysis and also in the dialysate in which we did not find OTA. OTA bound to blood plasma proteins did not penetrate the dialysis membrane. In contrast, free OTA during an in vitro experiment with the identical dialyzer (as during the in vivo experiment), easily penetrated the same dialysis membrane.

Differential expression of the Ca2+ binding S100A6 protein in normal, preneoplastic and neoplastic colon mucosa.

The expression of calcium-binding protein S100A6 was investigated in normal colon tissue, in colon adenomas and in colorectal carcinomas. Using an immunoblotting approach we detected four S100A6 variants with Mwt of 10 kDa and pI of 5.05 (isoform I), 5.15 (isoform II), 5.23 (isoform III) and 5.32 (isoform IV) that were differentially expressed in the analysed samples. The quantitative examination of S100A6 variant expression in 25 pairs of colorectal carcinoma and matched control mucosa proved a statistically significant increased abundance of S100A6 isoforms I (P = 0.004) and III (P = 0.025) in malignant tissue, and conversely, an increased level of S100A6 isoform IV in healthy tissue (P = 0.022). The expression of isoforms I and III and the loss of isoform IV were also observed in colon cancer cell lines. In addition, the immunohistochemical study of 16 primary colorectal carcinomas revealed both in the non-paired Student t-test and in the Mann Whitney test the statistically significant accumulation of S100A6 protein (P < 0.001) in the invasive margin of the tumour. The immunohistochemical analysis of S100A6 protein in polyps differing in clinical severity gave a strong staining that was maximal in dysplastic lesions. Thus, our results indicate a possible, statistically significant correlation (non-paired Student t-test P = 0.036) between S100A6 expression and colon carcinoma progression.

Protein abundance alterations in matched sets of macroscopically normal colon mucosa and colorectal carcinoma.

Our current results, aimed at the detection of protein abundance alterations that could be associated with the process of colon tumorigenesis, are summarized. The matched sets of macroscopically normal colon mucosa and colorectal carcinoma were examined by a one- or two-dimensional electrophoretic approach and proteins were identified using immunoblotting or mass spectrometry. The following results were observed: The levels of liver fatty acid-binding protein, actin-binding protein/smooth muscle protein 22-alpha and cyclooxygenase 2 were downregulated in colorectal carcinoma compared to normal colon mucosa. Conversely, the expression of a novel variant of heat shock protein70 and several members of the S100 protein family of calcium-binding proteins (two isoforms of S100A9, S100A8, S100A11 and S100A6) were upregulated in transformed colon mucosa. Despite the variations of the levels of expression of given protein among analyzed samples, all quantitative changes were found to be statistically significant (Mann-Whitney test assuming p < or = 0.05). We conclude that the proteomic approach is useful for the study of complex biological events underlying the process of colorectal tumorigenesis.

Radiation pneumonitis: the model of interstitial edema.

We used the measurement of the thickness of alveolar septa in the lungs in (C57BI/6xDBA/2)F1 mice irradiated locally in the area of the thorax with absorbed doses of 14, 16 and 18 Gy of gamma rays. The thickness of alveolar septa of the pulmonary tissue was measured using a computer image analysis. 24 weeks after irradiation we found a significant increase in the thickness of alveolar septa in direct relation to the dose within a range of 14 to 18 Gy. This indicator can be used for observation of the radioprotective and remedial interventions against the inception and the development of radiation pneumonitis.