Multiple roles of mitochondria in aging processes.

Aging is a multifactorial process influenced by genetic factors, nutrition, and lifestyle. According to mitochondrial theory of aging, mitochondrial dysfunction is widely considered a major contributor to age-related processes. Mitochondria are both the main source and targets of detrimental reactions initiated in association with age-dependent deterioration of the cellular functions. Reactions leading to increased reactive oxygen species generation, mtDNA mutations, and oxidation of mitochondrial proteins result in subsequent induction of apoptotic events, impaired oxidative phosphorylation capacity, mitochondrial dynamics, biogenesis and autophagy. This review summarizes the major changes of mitochondria related to aging, with emphasis on mitochondrial DNA mutations, the role of the reactive oxygen species, and structural and functional changes of mitochondria.

Molecular profile of 5-fluorouracil pathway genes in colorectal carcinoma.

BACKGROUND: This study addresses involvement of major 5-fluorouracil (5-FU) pathway genes in the prognosis of colorectal carcinoma patients. METHODS: Testing set and two validation sets comprising paired tumor and adjacent mucosa tissue samples from 151 patients were used for transcript profiling of 15 5-FU pathway genes by quantitative real-time PCR and DNA methylation profiling by high resolution melting analysis. Intratumoral molecular profiles were correlated with clinical data of patients. Protein levels of two most relevant candidate markers were assessed by immunoblotting. RESULTS: Downregulation of DPYD and upregulation of PPAT, UMPS, RRM2, and SLC29A1 transcripts were found in tumors compared to adjacent mucosa in testing and validation sets of patients. Low RRM2 transcript level significantly associated with poor response to the first-line palliative 5-FU-based chemotherapy in the testing set and with poor disease-free interval of patients in the validation set irrespective of 5-FU treatment. UPP2 was strongly methylated while its transcript absent in both tumors and adjacent mucosa. DPYS methylation level was significantly higher in tumor tissues compared to adjacent mucosa samples. Low intratumoral level of UPB1 methylation was prognostic for poor disease-free interval of the patients (P = 0.0002). The rest of the studied 5-FU genes were not methylated in tumors or adjacent mucosa. CONCLUSIONS: The observed overexpression of several 5-FU activating genes and DPYD downregulation deduce that chemotherapy naïve colorectal tumors share favorable gene expression profile for 5-FU therapy. Low RRM2 transcript and UPB1 methylation levels present separate poor prognosis factors for colorectal carcinoma patients and should be further investigated.

Isocitrate dehydrogenase-1 mutations as prognostic biomarker in glioblastoma multiforme patients in West Bohemia.

INTRODUCTION: Glioblastoma multiforme (GBM) is the most malignant primary brain tumor in adults. Recent whole-genome studies revealed novel GBM prognostic biomarkers such as mutations in metabolic enzyme IDH-isocitrate dehydrogenases (IDH1 and IDH2). The distinctive mutation IDH1 R132H was uncovered to be a strong prognostic biomarker for glioma patients. We investigated the prognostic role of IDH1 R132H mutation in GBM patients in West Bohemia. METHODS: The IDH1 R132H mutation was assessed by the RT-PCR in the tumor samples from 45 GBM patients treated in the Faculty Hospital in Pilsen and was correlated with the progression free and overall survival. RESULTS: The IDH1 R132H mutation was identified in 20 from 44 GBM tumor samples (45.4%). The majority of mutated tumors were secondary GBMs (16 in 18, 89.9%). Low frequency of IDH1 mutations was observed in primary GBMs (4 in 26, 15.3%). Patients with IDH R132H mutation had longer PFS, 136 versus 51 days (P < 0.021, Wilcoxon), and OS, 270 versus 130 days (P < 0.024, Wilcoxon test). SUMMARY: The prognostic value of IDH1 R132H mutation in GBM patients was verified. Patients with mutation had significantly longer PFS and OS than patients with wild-type IDH1 and suffered more likely from secondary GBMs.

Immediately preoperative use of biological therapy does not influence liver regeneration after large resection--porcine experimental model with monoclonal antibody against epidermal growth factor.

BACKGROUND: The aim of this work was to study the influence of isolated biological therapy administered immediately before extended liver resection on liver function and regenerative capacity of future liver remnant (FLR) in a large-animal experiment. MATERIALS AND METHODS: Nineteen piglets were included in this study (10 in the control group and 9 in the experimental group). A port-a-cath was introduced into the superior caval vein. On days 11 and 4 before liver resection, cetuximab was administered via this port at 400 mg/m2 of piglet body surface. Physiological solution was applied to the control group. Resection of the left lateral, left medial and right medial hepatic lobes was followingly performed (reduction of 50-60% of liver parenchyma). Blood samples were collected at different times before the operation and after liver resection. Serum levels of bilirubin, urea, creatinine, alkaline phosphatase, gamma glutamyltransferase, cholinesterase, aspartate aminotransferase, alanine aminotransferase, albumin, C-reactive protein and transforming growth factor-ß1 were assessed. The ultrasonographic examinations at different time points were performed pre-operatively and after liver resection in order to assess the liver volume. The biopsies from the liver parenchyma were examined for proliferative activity, binocluated hepatocytes, size of hepatocytes, and the length of the lobuli. The comparison of distribution of the studied parameters between the groups was carried out using the Wilcoxon test. The Spearman rank correlation co-efficient was used because of the non-Gaussian distribution of the parameter values. The whole development of the studied parameters over time was compared between the groups using ANOVA. RESULTS: There were no important complications of administration of biologic therapy during the operation or throughout the peri-operative period. There was no statistically significant difference in the regeneration of FLR nor were any differences in biochemical, immunoanalytical and histological parameters detected. CONCLUSION: The achieved results of comparable liver regeneration in both the experimental and control groups confirms the use of biological treatment with cetuximab in the pre-operative period for minimizing the recovery period.

The role of ABC transporters in progression and clinical outcome of colorectal cancer.

Worldwide, colorectal cancer (CRC) is the third most common cancer, with the highest mortality rates occurring in Central Europe. The use of chemotherapy to treat CRC is limited by the inter-individual variability in drug response and the development of cancer cell resistance. ATP-binding cassette (ABC) transporters play a crucial role in the development of resistance by the efflux of anticancer agents outside of cancer cells. The aim of this study was to explore transcript levels of all human ABCs in tumours and non-neoplastic control tissues from CRC patients collected before the first line of treatment by 5-fluorouracil (5-FU)-containing regimen. The prognostic potential of ABCs was evaluated by the correlation of transcript levels with clinical factors. Relations between transcript levels of ABCs in tumours and chemotherapy efficacy were also addressed. The transcript profile of all known human ABCs was assessed using real-time polymerase chain reaction with a relative standard curve. The majority of the studied ABCs were down-regulated or unchanged between tumours and control tissues. ABCA12, ABCA13, ABCB6, ABCC1, ABCC2 and ABCE1 were up-regulated in tumours versus control tissues. Transcript levels of ABCA12, ABCC7 and ABCC8 increased in direction from colon to rectum. Additionally, transcript levels of ABCB9, ABCB11, ABCG5 and ABCG8 followed the reverse significant trend, i.e. a decrease in direction from colon to rectum. The transcript level of ABCC10 in tumours correlated with the grade (P = 0.01). Transcript levels of ABCC6, ABCC11, ABCF1 and ABCF2 were significantly lower in non-responders to palliative chemotherapy in comparison with responders. The disease-free interval of patients treated by adjuvant chemotherapy was significantly shorter in patients with low transcript levels of ABCA7, ABCA13, ABCB4, ABCC11 and ABCD4. In conclusion, ABCC11 may be a promising candidate marker for a validation study on 5-FU therapy outcome.

[Contribution of molecular biology to the diagnosis and therapy of colorectal carcinoma--the present and future]. / Prínos molekulární biologie v diagnostice a lécbe kolorektálního karcinomu--soucasnost a budoucnost.

Colorectal cancer is one of the most frequent malignant disease and despite of the development of modern surgical and oncological treatment, it is still a very severe diagnosis for the patient. The survival of the patient after the radical surgery is mostly affected by the time of detection of the disease and by the selection of the appropriate oncological treatment. The effectivity of the oncological treatment depends mainly on the features of the malignant tissue. During the last decade, the importance of the molecular biology and it's methodology have been growing for both detection of the disease and the selection of the best treatment for the individual patient. Genetic and epigenetic characteristics of the tumours helps to predict the prognosis of the disease and also select the best treatment, which extends the disease-free and overall survival of the patient. The presented review describes the most important molecular-biological characteristics with the prognostic or predictive function, which are used in the clinical practice or are in the later phase of clinical study.