Normal and Tumour Tissue mRNA Expressions of Telomerase Complex Genes in Several Types of Cancer.

AIMS: To investigate the changes in mRNA expression levels of telomerase-related significant proteins in several types of cancer. METHODS: Human telomerase reverse transcriptase, pontin, reptin and dyskerin expressions were measured in normal and tumour tissues obtained from 26 patients with colorectal, breast and gastric cancers, using the real-time reverse transcriptase-polymerase chain reaction method. RESULTS: For all patients, no significant difference was found in mRNA expressions of human telomerase reverse transcriptase and dyskerin (p>0.05), although their levels in tumour tissues were found to be higher than in normal tissues. However, pontin and reptin mRNA expressions were significantly higher in tumour tissues than in normal tissues (p<0.01). While human telomerase reverse transcriptase showed a high correlation with only pontin (p<0.001) in normal tissues, high positive correlations were observed between human telomerase reverse transcriptase with pontin (p<0.005), reptin (p<0.01) and dyskerin (p<0.01) in tumour tissues. CONCLUSION: The increased mRNA expressions of all four genes in tumour tissues may suggest a role in cancer development. Correlations of pontin, reptin and dyskerin with human telomerase reverse transcriptase support the hypotheses describing their roles in telomerase complexes.

Influence of gender on C-reactive protein, fibrinogen, and erythrocyte sedimentation rate in obstructive sleep apnea.

Inflammation is one of the pathophysiological pathways suggested for the development of cardiovascular disease in obstructive sleep apnea (OSA). The recurrent nocturnal episodes of hypoxia/reoxygenation observed in patients with OSA appear to be partly responsible for the systemic inflammatory response. The aim of this study was to investigate the role of inflammation by measuring the C-reactive protein (CRP) and fibrinogen levels, and erythrocyte sedimentation rate (ESR) in the OSA according to gender. This study included 139 apparently healthy subjects with newly diagnosed OSA and 27 control subjects who underwent overnight polysomnography and routine blood tests. Levels of inflammatory markers (CRP, fibrinogen, and ESR) were determined from the blood samples taken in the morning. The levels of CRP and fibrinogen were significantly higher in patients than in controls (p<0.0001 and p=0.001, respectively). Fibrinogen and ESR were significantly higher in the female patients than in the male patients (p<0.0001). In female patients, CRP and ESR correlated with time spent at oxygen saturation (T%SaO2)<90 (R=0.327, p=0.029 and R=0.301, p=0.05, respectively), T%SaO2<85 (R=0.482, p=0.001 and R=0.409, p=0.006, respectively), oxygen desaturation index (ODI) (R=0.298, p=0.047 and R=0.340, p=0.026, respectively), lowest oxygen saturation (SaO2) (R=-0.293, p=0.051 and R=-0.374, p=0.013, respectively), mean SaO2 (R=-0.408, p=0.005 and R=-0.385, p=0.011, respectively). In male patients, CRP correlated with T%SaO2<90 (R=0.267, p=0.009), T%SaO2<85 (R=0.279, p=0.006), mean SaO2 (R=-0.284, p=0.006) and fibrinogen correlated with T%SaO2<90 (R=0.282, p=0.028), and mean SaO2 (R=-0.252, p=0.05). In conclusion, increased values of systemic inflammatory markers and their correlations with sleep data observed in our study support other studies suggesting the possible involvement of inflammation in OSA. As this correlation is more apparent in female patients then the males, it suggests that there may be a stronger relation between OSA development and inflammation in females. Higher levels of CRP, fibrinogen, and ESR may result from the combined interactions of obesity, metabolic syndrome (MetS) and nocturnal hypoxia.

Increased levels of 8-hydroxydeoxyguanosine and its relationship with lipid peroxidation and antioxidant vitamins in lung cancer.

BACKGROUND: Reactive oxygen species produced either endogenously or exogenously can attack lipids, proteins and DNA in human cells and cause potentially deleterious consequences. In recent years, their role in the pathogenesis of lung cancer and the preventive effect of antioxidants have been studied extensively. In this study, our aim was to investigate the levels of 8-hydroxy-2'-deoxyguanosine (8OHdG) and malondialdehyde as a marker for the effects of reactive oxygen species on DNA and lipids, the levels of antioxidant vitamins and the correlations between these oxidative stress markers and antioxidants in lung cancer. METHODS: Serum malondialdehyde, beta-carotene, retinol, and vitamins C and E were measured by high-performance liquid chromatography methods in fasting blood samples and 8OHdG was measured by gas chromatography-mass spectrometry in 24-h urine samples of patients with lung cancer (n=39) and healthy controls (n=31). RESULTS: The levels of 8OHdG and malondialdehyde were significantly higher (p<0.05 and p<0.005, respectively) and beta-carotene, retinol, and vitamins C and E (p<0.0001, p<0.0001, p<0.0001, and p<0.05, respectively) were significantly lower in patients than in controls. There was a significantly positive correlation between 8OHdG and malondialdehyde (r=0.463, p=0.01) and a negative correlation between the levels of 8OHdG and retinol (r=-0.419, p=0.021) in the patient group. CONCLUSIONS: Our results demonstrate that the oxidant/antioxidant balance was spoiled in favor of lipid peroxidation and DNA damage in lung cancer patients. Significant increases in the levels of malondialdehyde and 8OHdG and decreases in the levels of antioxidants suggest the possible involvement of oxidative stress in lung cancer.

Usefulness of homocysteine as a cancer marker: total thiol compounds and folate levels in untreated lung cancer patients.

BACKGROUND: Apart from being a risk factor for atherosclerotic cardiovascular diseases, the latest research suggests homocysteine as a marker for cancer. We aimed to explore the clinical utility of plasma homocysteine levels as a marker in lung cancer. PATIENTS AND METHODS: Changes in serum total thiols and folate levels were investigated in newly diagnosed untreated lung cancer patients (n = 37) and compared with healthy controls (n = 26). Fluorometric HPLC methods were used for the determination of thiols. Other parameters were determined with commercial diagnostic kits. RESULTS: Increased total homocysteine (t-Hcy), decreased total glutathione (t-GSH) and folate levels were observed in lung cancer patients compared with healthy controls. Total levels of thiols and folate did not show any significant difference between SCLC and NSCLC patients. However, there were significantly higher t-Hcy, lower t-GSH and folate levels in the advanced-stage group compared with controls. Prevalence of hyperhomocysteinemia was 65% in lung cancer patients when 12 micromol/l were taken as a cut-off value for t-Hcy levels. CONCLUSION: Homocysteine is suggested as a marker for several types of cancer, but our result did not support this hypothesis for lung cancer. Although higher homocysteine levels were observed in the present study, further investigation in the larger cancer population would clarify the importance of homocysteine as a cancer marker.