45 research outputs found
Tailored treatment including radical prostatectomy and radiation therapy + androgen deprivation therapy versus exclusive radical prostatectomy in high-risk prostate cancer patients: results from a prospective study
Purpose To evaluate outcomes of patients with high risk prostate cancer (PCa) who underwent radical prostatectomy (RP) in a context of a multidisciplinary approach including adjuvant radiation (RT) + androgen deprivation therapy (ADT). Matherials and Methods 244 consecutive patients with high risk localized PCa underwent RP and bilateral extended pelvic lymph node dissection at our institution. Adjuvant RT + 24 months ADT was carried out in subjects with pathological stage ≥ T3N0 and/or positive surgical margins or in patients with local relapse. Results After a median follow-up was 54.17 months (range 5.4-117.16), 13 (5.3%) subjects had biochemical progression, 21 (8.6%) had clinical progression, 7 (2.9%) died due to prostate cancer and 15 (6.1%) died due to other causes. 136 (55.7%) patients did not receive any adjuvant treatment while 108 (44.3%) received respectively adjuvant or salvage RT+ADT. Multivariate Cox proportional hazard analysis showed that pre-operative PSA value at diagnosis is a significant predictive factor for BCR (HR: 1.04, p < 0.05) and that Gleason Score 8-10 (HR: 2.4; p<0.05) and PSMs (HR: 2.01; p < 0.01) were significant predictors for clinical progression. Radical prostatectomy group was associated with BPFS, CPFS, CSS and OS at 5-years of 97%, 90%, 95% and 86% respectively, while adjuvant radiation + androgen deprivation therapy group was associated with a BPFS, CPFS and CSS at 5-years of 91%, 83%, 95% and 88%, without any statistical difference. Conclusions Multimodality tailored treatment based on RP and adjuvant therapy with RT+ADT achieve similar results in terms of OS after 5-years of follow-up
Mechanisms of human telomerase reverse transcriptase (hTERT) regulation: clinical impacts in cancer
Background
Limitless self-renewal is one of the hallmarks of cancer and is attained by telomere maintenance, essentially through telomerase (hTERT) activation. Transcriptional regulation of hTERT is believed to play a major role in telomerase activation in human cancers.
Main body
The dominant interest in telomerase results from its role in cancer. The role of telomeres and telomere maintenance mechanisms is well established as a major driving force in generating chromosomal and genomic instability. Cancer cells have acquired the ability to overcome their fate of senescence via telomere length maintenance mechanisms, mainly by telomerase activation.
hTERT expression is up-regulated in tumors via multiple genetic and epigenetic mechanisms including hTERT amplifications, hTERT structural variants, hTERT promoter mutations and epigenetic modifications through hTERT promoter methylation. Genetic (hTERT promoter mutations) and epigenetic (hTERT promoter methylation and miRNAs) events were shown to have clinical implications in cancers that depend on hTERT activation. Knowing that telomeres are crucial for cellular self-renewal, the mechanisms responsible for telomere maintenance have a crucial role in cancer diseases and might be important oncological biomarkers. Thus, rather than quantifying TERT expression and its correlation with telomerase activation, the discovery and the assessment of the mechanisms responsible for TERT upregulation offers important information that may be used for diagnosis, prognosis, and treatment monitoring in oncology. Furthermore, a better understanding of these mechanisms may promote their translation into effective targeted cancer therapies.
Conclusion
Herein, we reviewed the underlying mechanisms of hTERT regulation, their role in oncogenesis, and the potential clinical applications in telomerase-dependent cancers.info:eu-repo/semantics/publishedVersio
Tumor cells fail to trans-induce telomerase in human umbilical vein endothelial cell cultures
The shortening of the telomeres that occurs in most somatic cells and untransformed cell cultures is considered a hallmark of cellular senescence. Re-activation of telomerase, which is usually present in immortal cells, avoids telomere shortening and considerably extends the culture life span. Normal human endothelial cells are characterized by an accelerated rate of telomere shortening and reach replicative senescence after a limited number of cell divisions. It has recently been reported that human telomerase reverse transcriptase expression may be strongly up-regulated in human endothelial cells cocultivated with tumor cells. Due to the important implications of this finding on tumor progression, we have extensively analyzed for the presence of telomerase in primary human endothelial cells either cocultivated with tumor cells or grown with tumorconditioned medium. We found modest, but readily detectable, amounts of telomerase in all human endothelial cell cultures analyzed that disappeared as the cultures approached senescence. Quantitative reverse transcription-PCR also showed a direct correlation between human telomerase reverse transcriptase expression and the proliferative index of the cultures. Nevertheless, we did not find any evidence of induction of telomerase activity by tumor cells in any of the tested conditions. All data indicate that telomerase in human endothelial cells follows an activation program that is strictly associated to the culture growth rate
MicroRNA-dependent Regulation of Telomere Maintenance Mechanisms: A Field as Much Unexplored as Potentially Promising
The activation of telomere maintenance mechanisms, which rely on telomerase reactivation or on a recombination-based process known as alternative lengthening of telomeres, guarantees a limitless proliferative potential to human tumor cells. To date, the molecular underpinnings that drive the activation of telomere maintenance mechanisms during tumorigenesis are poorly understood, but there are indications that complex signaling networks might be involved. Since telomerase activity has been mainly detected in tumors of epithelial origin and the alternative lengthening of telomere mechanisms is more frequently expressed in mesenchymal and neuroepithelial cancers, it could be hypothesized that cell-type specific mechanisms can favor their activation during tumor development. In this context, microRNAs - small non coding RNAs that regulate gene expression at post-transcriptional level - have emerged as key players in the development and progression of human cancers, being involved in the control of all the typical features of cancer cells, including the limitless replicative potential. In the present review, we will summarize the recent findings concerning the identification and biological validation of microRNAs which may play a role in the regulation of telomere biology as well as of the mechanisms that govern telomere maintenance