Telomere-specific reverse transcriptase (hTERT) and cell-free RNA in plasma as predictors of pathologic tumor response in rectal cancer patients receiving neoadjuvant chemoradiotherapy.

PURPOSE: To investigate whether the plasma levels of cell-free RNA (cfRNA) and telomere-specific reverse transcriptase mRNA (hTERT) are associated with tumor response in rectal cancer patients who received preoperative chemoradiotherapy (pCRT). METHODS: Patients who underwent pCRT for rectal cancer and for whom baseline and paired post-pCRT blood samples were available were studied. On the basis of tumor regression score, patients were classified as having response or having no response. Clinical variables and plasma levels of cfRNA and hTERT before and after the pCRT were evaluated. The association between each predictor and tumor response was assessed by univariate and multivariate analyses. RESULTS: Of 98 eligible patients, 45 were determined to respond to therapy, and 53 did not respond to therapy. In univariate analysis, gender (P = 0.040), baseline levels of cfRNA (P = 0.026), post-pCRT levels of both hTERT and cfRNA (P < 0.0001 and P = 0.001, respectively), and the difference between the post- and pre-pCRT levels of both hTERT and cfRNA (P = 0.009 and P = 0.001, respectively) were found to be significant predictors of tumor response. In multivariate analysis, using variables that were available before pCRT, cfRNA levels and gender independently predicted the tumor response, while in multivariate analysis, which used all of the variables available before the surgical procedure, the post-pCRT levels of cfRNA and the difference between the post- and pre-pCRT levels of cfRNA independently predicted tumor response. CONCLUSIONS: Plasma levels of cfRNA and hTERT are promising markers of tumor response to pCRT for rectal cancer.

Telomere length and telomerase levels delineate subgroups of B-cell chronic lymphocytic leukemia with different biological characteristics and clinical outcomes.

BACKGROUND: B-cell chronic lymphocytic leukemia is a clinically heterogeneous disease; some patients rapidly progress and die within a few years of diagnosis, whereas others have a long life expectancy with minimal or no treatment. Telomere length and telomerase levels have been proposed as prognostic factors; however, very few cases have been characterized for both parameters and no study has analyzed the prognostic value of the telomere/telomerase profile. DESIGN AND METHODS: One hundred and seventy-three cases of chronic lymphocytic leukemia were characterized for telomere lengths and telomerase levels by real-time polymerase chain reaction. Data were correlated with established prognostic markers, IGVH mutational status and chromosomal aberrations, and clinical outcome. RESULTS: Telomere lengths were inversely correlated with telomerase levels (r(s) = -0.213; P = 0.012), and most of the cases of chronic lymphocytic leukemia with high levels (above median) of telomerase had short (below median) telomeres (P = 0.0001). Telomerase levels were higher and telomeres were shorter in unmutated IGVH cases than in mutated IGVH ones (P<0.0001). Chronic lymphocytic leukemias with 11q, 17p deletion or 12 trisomy had significantly higher levels of telomerase and shorter telomeres than those with no chromosomal aberration or the sole 13q deletion (P < 0.001). Telomere length/telomerase level profiles identified subgroups of patients with different clinical outcomes (P < 0.0001), even within the subsets of chronic lymphocytic leukemia defined by IGVH mutational status or chromosomal aberrations. Short telomere/high telomerase profile was independently associated with more rapid disease progression. CONCLUSIONS: Comprehensive analyses of telomeres, telomerase, chromosomal aberrations, and IGVH mutational status delineate groups of chronic lymphocytic leukemias with distinct biological characteristics and clinical outcomes. The telomere/telomerase profile may be particularly useful in refining the prognosis of chronic lymphocytic leukemia patients with mutated IGVH and no high-risk chromosomal aberrations.

hTERT inhibition triggers Epstein-Barr virus lytic cycle and apoptosis in immortalized and transformed B cells: a basis for new therapies.

PURPOSE: Induction of viral lytic cycle, which induces death of host cells, may constitute a useful adjunct to current therapeutic regimens for Epstein-Barr virus (EBV)-driven malignancies. Human telomerase reverse transcriptase (hTERT), essential for the oncogenic process, may modulate the switch from latent to lytic infection. The possible therapeutic role of hTERT inhibition combined with antiviral drugs was investigated. EXPERIMENTAL DESIGN: EBV-negative BL41 and convertant EBV-positive BL41/B95.8 Burkitt's lymphoma cell lines and lymphoblastoid cell lines (LCL) were infected with retroviral vector encoding short hairpin RNA (shRNA) anti-hTERT and cultured with or without the prodrug ganciclovir. The effects on EBV lytic replication, cell proliferation, and apoptosis were characterized. RESULTS: hTERT silencing by shRNA induced the expression of BZLF1, EA-D, and gp350 EBV lytic proteins and triggered a complete lytic cycle. This effect was associated with downregulation of BATF, a negative regulator of BZLF1 transcription. hTERT silencing also resulted in antiproliferative and proapoptotic effects. In particular, hTERT inhibition induced an accumulation of cells in the S-phase, an effect likely due to the dephosphorylation of 4E-BP1, an AKT1-dependent substrate, which results in a decreased availability of proteins needed for cell-cycle progression. Besides inducing cell death through activation of complete EBV lytic replication, hTERT inhibition triggered AKT1/FOXO3/NOXA-dependent apoptosis in EBV-positive and -negative Burkitt's lymphoma cells. Finally, ganciclovir enhanced the apoptotic effect induced by hTERT inhibition in EBV-positive Burkitt's lymphomas and LCLs. CONCLUSIONS: These results suggest that combination of antiviral drugs with strategies able to inhibit hTERT expression may result in therapeutically relevant effects in patients with EBV-related malignancies.

Immune senescence and cancer in elderly patients: results from an exploratory study.

BACKGROUND: The challenge of immune senescence has never been addressed in elderly cancer patients. This study compares the thymic output and peripheral blood telomere length in ≥70year old cancer patients. PATIENTS AND METHODS: Fifty-two elderly cancer patients and 39 age-matched controls without personal history of cancer were enrolled. All patients underwent a Comprehensive Geriatric Assessment (CGA), from which a multidimensional prognostic index (MPI) score was calculated. Peripheral blood samples were studied for naïve and recent thymic emigrant (RTE) CD4(+) and CD8(+) cells by flow cytometry. T-cell receptor rearrangement excision circle (TREC) levels, telomere length and telomerase activity in peripheral blood cells were quantified by real-time PCR. RESULTS: The percentages of CD8(+) naïve and CD8(+) RTE cells and TREC levels were significantly lower in cancer patients than in controls (p=0.003, p=0.004, p=0.031, respectively). Telomere lengths in peripheral blood cells were significantly shorter in cancer patients than in controls (p=0.046) and did not correlate with age in patients, whereas it did in controls (r=-0.354, p=0.031). Short telomere (≤median)/low TREC (≤median) profile was associated with higher risk of cancer (OR=3.68 [95% CI 1.22-11.11]; p=0.021). Neither unfitness on CGA nor MPI score were significantly related to thymic output or telomere length in either group. CONCLUSIONS: Immune senescence is significantly worse in elderly cancer patients than in age-matched controls. The low thymic output and the shorter telomeres in peripheral blood cells of cancer patients may reflect a pre-existing condition which facilitates the onset of malignancies in elderly people.