Analysis of prognostic significance of merkel cell polyomavirus in chronic lymphocytic leukemia.

BACKGROUND: Merkel cell polyomavirus (MCPyV), a ubiquitous DNA tumor virus, has been found to be associated with Merkel cell carcinoma and chronic lymphocytic leukemia (CLL). Previous studies have reported conflicting results on the frequency and potential pathogenetic role of MCPyV in CLL. The aim of this study was to evaluate MCPyV's association with CLL and its prognostic significance. PATIENTS AND METHODS: Between 2006 and 2013, DNA samples obtained from CLL patients (n = 119) before treatment were tested for MCPyV using quantitative real-time polymerase chain reaction analysis and verified by gel electrophoresis. Only samples testing positive by both methods were considered valid. RESULTS: We found that 13 (11%) of 119 CLL cases were positive for MCPyV. Between the groups of MCPyV-positive and -negative patients, there was no significant difference in the sex, age, cytogenetics, presence of p53 defect, or immunoglobulin heavy chain (IGHV) mutational status. In the subset of MCPyV-negative patients, advanced Rai stage (III to IV) was found more frequently, and therapy was initiated more often. There was no difference in overall response rate, median progression-free survival, and overall survival between both groups. We did not observe any new positivity after treatment in initially MCPyV-negative patients. CONCLUSION: This study provides the first analysis of the prognostic role of MCPyV in CLL. MCPyV occurrence seems to be a relatively rare event during the course of CLL. MCPyV is also unlikely to influence the outcome of CLL patients.

Detection of minimal residual disease in lung cancer.

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.

Different effect of sodium butyrate on cancer and normal prostate cells.

Sodium butyrate, as a naturally occurring inhibitor of histone deacetylases (HDACI), is a non-toxic agent, with an ability to change histone acetylation and expression of large number genes. This study shows different effects of sodium butyrate on expression and transcription activity of the androgen receptor in cancer (LNCaP, C4-2) and normal (RWPE-1) prostate cells. Moreover, we studied the coregulator expressions and histone acetylation alteration in cancer and normal cells. Coregulators, coactivators as well as corepressors, play an important role in AR-mediated growth and progression of prostate cancer. There is a competition between coactivators and corepressors for binding on the AR and therefore the changes in coregulators expression and ratio could be important for prostate cancer survival. Our study was focused on two coregulators, SMRT and p300, which interact with AR in multiprotein complex and affect the AR transcription activity. Our data indicate that sodium butyrate has an effect on AR coregulators expression, transcription activity and histone acetylation in cancer cells, but there is only minimal effect in normal cells. In addition, the results of changes in acetylation level on lysine residues of histone H4 after sodium butyrate treatment confirm its epigenetic effect on prostate cancer cells.

Occult tumour cells in peritoneal lavage are a negative prognostic factor in pancreatic cancer.

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.

[Possibility of using the determination of minimal residual disease in pancreatic adenocarcinoma using real-time RT-PCR--a pilot study]. / Moznosti vyuzití stanovení minimální reziduální choroby u adenokarcinomu pankeatu pomocí metodiky real-tim RT-PCR--pilotní studie.

BACKGROUND: Minimal residual disease in patients with pancreatic cancer is defined as the presence of isolated tumor cells in the patient's body, in which the primary tumor was removed and is currently without clinical signs of disease. These isolated tumor cells may be described as precursors of micrometastases. Assessment of MRD in patients with this highly malignant disease could eliminate burdensome implementation of surgery in patients with systematic dissemination of molecular disease and provide a more precise prognosis. METHODS AND RESULTS; The study to date included 70 patients operated on with curative intent for carcinoma of the pancreas. Samples of peripheral and portal blood, bone marrow, peritoneal lavage and of the tumor itself were analyzed by real-time PCR which measured the expression of hTERT (telomerase), EGFR1 (receptor for epidermal growth factor) and CEA (carcinoembryonic antigen). The expression of these markers was correlated with clinicopathological characteristics and survival parameters. We found a statistically significant association between EGFR expression levels in the portal blood and clinical stage--patients with advanced disease have a higher expression of EGFR in the portal stream and peritoneal lavage in contrast to patients without the presence of metastases. CONCLUSIONS: The results of this pilot study demonstrated a high sensitivity and specificity of the RT-PCR method for detecting circulating tumor cells in patients with pancreatic cancer. By utilizing this methodology, we are able to provide prognostic value of minimal residual disease and its significance for the indication of radical surgery for pancreatic cancer.