Survivin is a member of the inhibitor of apoptosis protein (IAP) family, that has been implicated in both control of cell division and inhibition of apoptosis. Specifically, its anti-apoptotic function seems to be related to the ability to directly or indirectly inhibit caspases. Survivin is selectively expressed in the most common human neoplasms and appears to be involved in tumor cell resistance to some anticancer agents and ionizing radiation. On the basis of these findings survivin has been proposed as an attractive target for new anticancer interventions. Several preclinical studies have demonstrated that down-regulation of survivin expression/function, accomplished through the use of antisense oligonucleotides, dominant negative mutants, ribozymes, small interfering RNAs and cyclin-dependent kinase inhibitors, increased the apoptotic rate, reduced tumor-growth potential and sensitized tumor cells to chemotherapeutic drugs with different action mechanisms and γ-irradiation in in vitro and in vivo models of different human tumor types.
Mesenchymal sem cells (MSCs) are multipotent progenitors with the ability to differentiate along multiple cell lineages and are today considered a useful tool for cell therapy and tissue engineering approaches. Concerns that adult human MSCs may undergo malignant transformation have been recently raised. In fact, human adipose tissue-derived MSCs have been shown to spontaneously transform after long-term in vitro culture. Aim of this study was to investigate the susceptibility to transformation of human bone marrow (BM)-derived MSCs at different time points of in vitro culture. MSCs were isolated from BM of 10 healthy donors and propagated continuously in vitro until reaching a senescence phase or passage (P) 25. MSCs in the senescence phase were closely monitored for 8–12 weeks, to look for the appearance of a crisis phase. MSCs were characterized by morphology, differentiation capacity and immunophenotype at different time-points in culture. The genetic characterization of MSCs was investigated through array comparative genomic hybridization (array-CGH), classical cytogenetics and subtelomeric FISH analysis both before and after prolonged in vitro culture. MSCs were tested for the expression of telomerase activity (TA), hTERT transcripts and alternative mechanisms of telomere lengthening (ALT) at different time-points in culture. MSCs from 5 donors were also analyzed for telomere length at P3 and P15. p53 gene status was also analyzed in MSCs from donors #1 and #2 that rapidly reached senescence in culture. A huge variability between donors was noted in terms of proliferative capacity and in vitro life-span of MSCs. All MSCs maintained the typical spindle-shaped morphology, phenotype and ability to differentiate into osteoblasts and adipocytes throughout the culture period. All MSCs displayed a progressive decrease in the proliferative capacity until reaching senescence, not followed by any further growth. Array-CGH, karyotype and subtelomeric FISH analyses demonstrated that MSCs expanded in vitro did not show chromosomal rearrangements, also after long term culture. TA was not evidenced in the samples tested, including a post-senescence culture. hTERT transcripts (full-length and the additional splice variants a−, b−, a−b−) were found not to be expressed in any of the examined cultures. Telomeres shortened during the culture period. ALT were not evidenced in the MSCs tested, as indicated by the lack of ALT-associated promyelocytic leukemia bodies. Direct DNA sequencing of exons 2–11 in pre-senescence cultures from donors #1 and #2 did not evidence the presence of mutation in the p53 gene. Human BM-derived MSCs do not display an aptitude for spontaneous transformation and can be safely expanded in vitro without any sign of immortalization or development of chromosomal abnormalities. Our results provide support to the concept that the biological properties of human BM-derived MSCs after ex vivo expansion remain suitable for use in cell-therapy approaches; however, it is strongly recommended that phenotype, functional and genetic characteristics of MSCs after in vitro culture and before in vivo infusion are tested, to further guarantee safety for the patient.
Head and neck squamous cell carcinoma (HNSCC) is a disease with heterogeneous clinical behavior and response to therapies. Despite the introduction of multimodality treatment, 40–50% of patients with advanced disease recur. Therefore, there is an urgent need to improve the classification beyond the current parameters in clinical use to better stratify patients and the therapeutic approaches. Following a meta-analysis approach we built a large training set to whom we applied a Disease-Specific Genomic Analysis (DSGA) to identify the disease component embedded into the tumor data. Eleven independent microarray datasets were used as validation sets.Six different HNSCC subtypes that summarize the aberrant alterations occurring during tumor progression were identified. Based on their main biological characteristics and de-regulated signaling pathways, the subtypes were designed as immunoreactive, inflammatory, human papilloma virus (HPV)-like, classical, hypoxia associated, and mesenchymal. Our findings highlighted a more aggressive behavior for mesenchymal and hypoxia-associated subtypes. The Genomics Drug Sensitivity Project was used to identify potential associations with drug sensitivity and significant differences were observed among the six subtypes.To conclude, we report a robust molecularly defined subtype classification in HNSCC that can improve patient selection and pave the way to the development of appropriate therapeutic strategies.
p53 expression appears to be indicative of clinical outcome in postmenopausal patients treated with tamoxifen. Whether p53 overexpression and weak bcl-2 expression are indicators of biologic aggressiveness, regardless of treatment, or of hormone resistance remains to be defined.
Survivin is an antiapoptotic gene, which is overexpressed in most human tumors and involved in mitotic checkpoint control. Recent evidence points to an essential role for heat shock protein 90 (Hsp90) in survivin function regulation. Although the survivin-Hsp90 association may promote tumor cell proliferation, it may also suggest new opportunities for the design of novel anticancer approaches. We evaluated the effect of small interfering RNA (siRNA) -mediated inhibition of survivin on the proliferative potential of prostate cancer cells and their sensitivity to the Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG). Human androgenindependent prostate cancer cell lines (DU145 and PC-3) were transfected with four 21-mer double-stranded siRNAs (100 nmol/L) directed against different portions of survivin mRNA. After transfection, cells were collected and analyzed for survivin mRNA and protein expression, cell proliferation rate, ability to undergo apoptosis, and sensitivity to 17-AAG. Transfection of prostate cancer cells with siRNAs induced a variable extent of inhibition of survivin mRNA expression (39 -60% compared with controls), which was paralleled by a 38% to 75% reduction in survivin protein abundance. The three siRNAs able to induce the greatest inhibition of survivin expression also significantly reduced cell proliferation and enhanced the rate of apoptosis, with a concomitant increase in caspase-9 activity. Sequential treatment with siRNA and 17-AAG induced supra-additive antiproliferative effects in all cell lines, with an enhanced caspase-9-dependent apoptotic response. These findings suggest that combined strategies aimed at interfering with the survivin-Hsp90 connection may provide novel approaches for treatment of androgen-independent prostate cancer. [Mol Cancer Ther 2006;5(1):179 -86]
Our study provides indirect evidence of a benefit from radiation therapy in preventing local breast cancer relapse, particularly among node-negative patients with tumors that express elevated levels of the p53 or GST-pi proteins or that express little or no Bcl-2 protein.
The term “biobanking” is often misapplied to any collection of human biological materials (biospecimens) regardless of requirements related to ethical and legal issues or the standardization of different processes involved in tissue collection. A proper definition of biobanks is large collections of biospecimens linked to relevant personal and health information (health records, family history, lifestyle, genetic information) that are held predominantly for use in health and medical research. In addition, the International Organization for Standardization, in illustrating the requirements for biobanking (ISO 20387:2018), stresses the concept of biobanks being legal entities driving the process of acquisition and storage together with some or all of the activities related to collection, preparation, preservation, testing, analysing and distributing defined biological material as well as related information and data. In this review article, we aim to discuss the basic principles of biobanking, spanning from definitions to classification systems, standardization processes and documents, sustainability and ethical and legal requirements. We also deal with emerging specimens that are currently being generated and shaping the so-called next-generation biobanking, and we provide pragmatic examples of cancer-associated biobanking by discussing the process behind the construction of a biobank and the infrastructures supporting the implementation of biobanking in scientific research.
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