Comparison of the miRNA profiles in HPV-positive and HPV-negative tonsillar tumors and a model system of human keratinocyte clones

BACKGROUND

Better insights into the molecular changes involved in virus-associated and -independent head and neck cancer may advance our knowledge of HNC carcinogenesis and identify critical disease biomarkers. Here we aimed to characterize the expression profiles in a matched set of well-characterized HPV-dependent and HPV-independent tonsillar tumors and equivalent immortalized keratinocyte clones to define potential and clinically relevant biomarkers of HNC of different etiology.

METHODS

Fresh frozen tonsillar cancer tissues were analyzed together with non-malignant tonsillar tissues and compared with cervical tumors and normal cervical tissues. Furthermore, relative miRNAs abundance levels of primary and immortalized human keratinocyte clones were evaluated. The global quantitation of miRNA gene abundance was performed using a TaqMan Low Density Array system. The confirmation of differentially expressed miRNAs was performed on a set of formalin-fixed paraffin-embedded tumor samples enriched for the tumor cell fraction by macrodissection.

RESULTS

We defined 46 upregulated and 31 downregulated miRNAs characteristic for the HPV-positive tonsillar tumors and 42 upregulated miRNAs and 42 downregulated miRNAs characteristic for HPV-independent tumors. In comparison with the expression profiles in cervical tumors, we defined miR-141-3p, miR-15b-5p, miR-200a-3p, miR-302c-3p, and miR-9-5p as specific for HPV induced malignancies. MiR-335-5p, miR-579-3p, and miR-126-5p were shared by the expression profiles of HPV-positive tonsillar tumors and of the HPV immortalized keratinocyte clones, whereas miR-328-3p, miR-34c-3p, and miR-885-5p were shared by the miRNA profiles of HPV-negative tonsillar tumors and the HPV-negative keratinocytes.

CONCLUSIONS

We identified the miRNAs characteristic for HPV-induced tumors and tonsillar tumors of different etiology, and the results were compared with those of the model system. Our report presents the basis for further investigations leading to the identification of clinically relevant diagnostic and/or therapeutic biomarkers for tumors of viral and non-viral etiology.

The Hans algorithm failed to predict outcome in patients with diffuse large B-cell lymphoma treated with rituximab

Diffuse large B-cell lymphoma (DLBCL) consists of at least two biologically and pathogenetically different subtypes, the germinal centre B-cell (GCB) and the activated B cell type (ABC). It has been suggested that immunohistochemistry can discriminate these subtypes as well. The aim of this study was to verify the validity of the most commonly used Hans algorithm in patients with DLBCL treated with anthracycline- based chemotherapy with rituximab. Immunohistochemical staining using standard protocols was performed on formalin fixed paraffin-embedded tissues. CD20, CD5, CD23, BCL2, CD10, BCL6, MUM1 and Ki67 antibodies were applied. Out of 120 examined cases 52 patients were evaluated as GCB type and 68 patients as having non-GCB, out of a set of 99 patients treated with immunochemotherapy 45 patients with GCB and 54 patients with non-GCB DLBCL were identified. In this set of patients, there was no statistically significant difference neither in overall survival (OS) (HR 1.47 95% CI 0.51-2.63; p=0.45) nor in progression free survival (PFS) (HR 1.57, 95 % CI 0.76-3.22; p=0.731) between both groups.

Genetic variability of cytomegalovirus glycoprotein O in hematopoietic stem cell transplant recipients

Genetic variation of cytomegalovirus (CMV) strains can correlate with their pathogenicity for immunocompromised patients. Glycoprotein O (gO), together with glycoprotein L and glycoprotein H, mediate the fusion of the viral envelope with the cell membrane and promotes virus penetration, envelopment, and release. The variability of gO might play a role in CMV cell tropism. The goal was a retrospective analysis of gO variability in a cohort of hematopoietic stem cell transplant (HSCT) recipients to determine the distribution of gO genotypes and to investigate their impact on clinical outcome and manifestation of CMV infection.

METHODS

In archived blood samples from 51 adult allogeneic HSCT recipients with active CMV infection, gO was analyzed by sequencing the N-terminal domain of the UL74 gene using the dye deoxy termination method.

RESULTS

The gO1 and gO2 clades were most common (39% and 20%, respectively, and gO3 was associated with higher risk of symptomatic infection (P = 0.026 in multivariant analysis). Despite being associated with higher antigenemia levels (P = 0.02), gO4 had the best survival and lower rate of CMV recurrence. No significant differences were found in clinical manifestation and outcome of CMV disease between patients with various gO clades. Because CMV strains sharing an identical gO sequence differed in glycoprotein B genotypes, sequencing the N-terminal part of the gO gene does not seem to be optimal for the identification of strains.

CONCLUSIONS

gO genotyping may contribute to the biological characterization of CMV strains in HSCT recipients.

Distinguishing of primary mediastinal B-cell lymphoma and diffuse large B-cell lymphoma using real-time quantitative polymerase chain reaction

Primary mediastinal B-cell lymphoma (PMBL) seems to be reliably distinguished from diffuse large B-cell lymphoma (DLBCL) with microarray technology. We measured expression of Fcer2, Pdl2 and Blk genes using real-time quantitative polymerase chain reaction (RTqPCR) on formalin fixed, paraffin embedded material (FFPE) and suggested a formula to discriminate PMBL from DLBCL. For 39/82 included patients the diagnosis of PMBL was expected clinico-pathologically. Diagnosis of 10/39 and 2/43 of clinically considered PMBLs and DLBCLs, respectively, was not genetically confirmed. Compared to confirmed PMBLs, unconfirmed ones showed clinical features similar to DLBCLs, e.g. spleen infiltration (p=0,028) and decreased invasiveness in pericardium (p=0,045). They tended to have more common infradiaphragmatic involvement, less often tumor sclerosis or fluidothorax. There were no immunohistochemical differences between genetically confirmed and unconfirmed PMBLs. New approach of distinguishing PMBL and DLBCL is presented. It is based on expression of three genes in routinely available FFPE material using RTqPCR.

Clonal distribution of invasive pneumococci, Czech Republic, 1996-2003

We conducted surveillance on invasive pneumococci isolated from adults in the Czech Republic during 1996-2003. The 7 most prevalent serotypes were characterized. Coverage with the 7-valent pneumococcal conjugate vaccine was low. Our observations confirm that detection methods may have modified the expected effect of this vaccine.

A study of excess mortality during influenza epidemics in the Czech Republic, 1982–2000

Influenza related mortality rates have been established in many countries; nevertheless, studies focusing on the Central European population have been rare to date. We assess mortality attributable to influenza by comparing all cause mortality and mortality due to diseases of the circulatory system during influenza epidemic and non-epidemic periods, as defined by acute respiratory infection surveillance data. Data on total mortality, mortality due to diseases of the circulatory system and surveillance data for influenza and other respiratory infections were used in a general linear model with a logarithmic link for dependence of left censored mortality data over time, and week as a categorical factor. Results of the analysis show statistically significant (p <0.001) differences in excess mortality rates between influenza epidemic and non-epidemic periods in the Czech Republic between 1982 and 2000. We estimate that 2.17% of all cause mortality, and 2.57% of mortality due to diseases of the circulatory system throughout the study period was attributable to influenza, with an estimated annual average of 2661 and 1752 deaths respectively. The highest numbers of deaths were reported during seasons when influenza A/H3N2 was the predominant circulating strain. Improving vaccination coverage against influenza is considered to be the primary strategy for prevention of influenza associated mortality.

Disturbances of anticoagulation and fibrinolytic systems in monoclonal gammopathies-another mechanism of M-protein interference with hemostasis

Monoclonal gammopathies (MG) may be associated with unique monoclonal immunoglobulin (MIg)-induced disturbances of either primary hemostasis or plasma coagulation. We have investigated the possible interference of MIg with antithrombotic systems in 49 patients with MG. Although an increase of tissue-type plasminogen activator (t-PA) activity was the most frequent abnormality in our group, defect of anticoagulation factors was found in 26.5% of patients. The relationship between MIg type and concentration and frequency of antithrombotic factor abnormalities was not found. The risk of venous thrombosis was higher in patients with the defect in comparison with the unaffected group (46% vs. 22%), but the difference was not statistically significant. Bleeding complications were markedly less frequent in the group of patients with defect of anticoagulation mechanisms (0% vs. 17%). In conclusion, we have found abnormalities in anticoagulation and/or fibrinolytic system, analogous to well-known disturbances of hemostatic mechanisms, in more than a quarter of patients with MG. The interference of M-protein with antithrombotic pathways is supposed to be another mechanism of secondary deficiencies of antithrombin III (AT III), protein C (PC), protein S (PS), plasminogen and APC resistance. Together with other factors, it could contribute to higher risk of thromboembolism in myeloma patients.

Vibratory perception threshold in the lower extremities. Normative values

Objective was to obtain normative values for the vibratory perception threshold (VPT) in the lower extremities and study the dependence of VPT on various physiological factors. Thirty healthy volunteers: 10 men and 20 women entered in the study. The VPT for 8, 16, 31.5, 63, 125, and 500 Hz were estimated on the right and left external malleolus using the B&K vibration threshold meter, modified type 1800, and the threshold tracking method. The applied static force could not be controlled. The measurements were repeated twice. VPTs expressed as mean +/- SD were as follows: 8 Hz 109 +/- 3.4 dB, 16 Hz 112 +/- 4.1 dB, 31.5 Hz 116 +/- 6.2 dB, 63 Hz 116 +/- 8.4 dB, 125 Hz 117 +/- 8 dB, 250 Hz 125 +/- 9.3 dB, and 500 Hz 136 +/- 13.1 dB. A nomogram was constructed with reference ranges of VPTs for individual frequencies, from which the profile of vibratory perception thresholds can be seen. Moreover, a global index was calculated as a sum of VPTs for individual frequencies. Its reference value was 840 +/- 52 dB and it varied in repeated measurements by up to 9%. No statistically significant difference of VPTs between the right and left side and between the 1st and 2nd examination was found. A tendency to the increase of VPTs with age was observed, which in males reached statistical significance for frequencies 16, 31.5, 63, and 125 Hz.

The serum activity of glucose-6phosphatase and 5'-nucleotidase during human pregnancy

An attempt has been made to show that the increase in enzyme activities in sera of pregnant women found with glucose-6-phosphate and adenosine 5'-monophosphate as substrates (described as glucose-6-phosphatase and 5'-nucleotidase) was due to the increase in alkaline phosphatase. The three enzyme activities has pH optima and heat stability characteristics of alkaline phosphatase. The response to the action of inhibitors and activators was typical for alkaline phosphatase. There was an identical increase in all three enzyme activities during pregnancy. As a control similar investigations were made with liver and placental tissue extracts.

Source of the pregnancy serum N-acetyl-beta-glucosaminidase isoenzyme during human pregnancy

The antisera to the A and B isoenzymes found in placenta and fetal liver were raised in rabbits. No antigenic difference was found between the fetal liver and adult tissue isoenzymes. Antisera to the placental isoenzymes did not react with the isoenzymes of adult tissues. The antibody raised against the placental B and fetal B liver isoenzyme decreased the N-acetyl-beta-glucosaminidase activity in maternal serum at 38 weeks gestation to the value found in normal human serum. Immunological evidence has been presented that the isoenzyme of N-acetyl-beta-glucosaminidase found only in pregnancy serum was of placental origin.