TERC telomerase subunit gene copy number in different disease stages of non-hodgkin lymphoma and in hepatitis C.

ABSTRACT Focal amplification of specific regions of the genome creates high copy number and expression of oncogenes in tumors. By applying fluorescence in situ hybridization (FISH) to leukocytes of hepatitis C (HCV) patients and non-Hodgkin lymphoma (NHL) patients, we estimated gene dosage of the TERC gene at 3q26.3. Higher TERC copy numbers were found in NHL at diagnosis compared to HCV patient groups. Higher TERC copy numbers were also observed in NHL patient at diagnosis and relapse compared to patients in remission. We believe that the TERC gene amplification is involved in the process of genetic instability leading to tumor genesis such as in NHL.

Telomere aggregates in hepatitis C patients.

Telomeres of tumor nuclei tend to form aggregates (TA). The aim of this study was to estimate the TA formation in leukocytes of patients with chronic hepatitis C (HCV) which is considered to be premalignant disease, in patients of HCV who eradicated the virus. PNA Telomere kit (Dako) was used to evaluate the TA formation with the utilization of 2D fluorescence microscopy. A higher rate of TA was found in both HCV groups as compared to controls. Our results indicate that HCV patients have some of the components that create the cascade of events leading to malignancies.

Telomere length in Hepatitis C.

Telomeres are nucleoprotein structures located at the termini of chromosomes that protect the chromosomes from fusion and degradation. Hepatocyte cell-cycle turnover may be a primary mechanism of telomere shortening in hepatitis C virus (HCV) infection, inducing fibrosis and cellular senescence. HCV infection has been recognized as potential cause of B-cell lymphoma and hepatocellular carcinoma. The present study sought to assess relative telomere length in leukocytes from patients with chronic HCV infection, patients after eradication of HCV infection (in remission), and healthy controls. A novel method of manual evaluation was applied. Leukocytes derived from 22 patients with chronic HCV infection and age- and sex-matched patients in remission and healthy control subjects were subjected to a fluorescence-in-situ protocol (DAKO) to determine telomere fluorescence intensity and number. The relative, manual, analysis of telomere length was validated against findings on applied spectral imaging (ASI) in a random sample of study and control subjects. Leukocytes from patients with chronic HCV infection had shorter telomeres than leukocytes from patients in remission and healthy controls. On statistical analysis, more cells with low signal intensity on telomere FISH had shorter telomeres whereas more cells with high signal intensity had longer telomeres. The findings were corroborated by the ASI telomere software. Telomere shortening in leukocytes from patients with active HCV infection is probably due to the lower overall telomere level rather than higher cell cycle turnover. Manual evaluation is an accurate and valid method of assessing relative telomere length between patients with chronic HCV infection and healthy subjects.

Telomere aggregates in non-Hodgkin lymphoma patients at different disease stages.

Telomeres of tumor nuclei tend to form aggregates (TA). The same phenomenon was also observed in premalignant states. The aim of this study was to estimate TA formation in leukocytes of patients with non-Hodgkin lymphoma (NHL) at different disease stages (diagnosis, treatment, relapse, and remission). The peptide nucleic acid Telomere Kit was used to evaluate TA formation, using two-dimensional fluorescence microscopy. A higher rate of TA was found in all the NHL stages (including remission) than in the control group. Significantly higher TA formation was also observed in the relapse group, compared to the diagnosis group. It may be possible that patients with higher TA numbers are prone to relapse. From our previous results involving replication pattern, random aneuploidy rate, and (recently) TA formation, it can be concluded that the patients in remission are at higher risk of developing relapse than the normal population throughout their life span. The genetic instability parameters remain in the cells of these patients, who must continue to be monitored throughout their life.