Durability of monumental stones treated with siloxane-based water repellents

The thesis investigates the effect of siloxane-based water repellents on the durability of monumental stones. Laspra, a micritic limestone typical for the Spanish region of Asturias, and Repedea, an oolitic limestone from Moldavia, Romania were selected for the present study, due to their regional / national significance and level of usage. As for the siloxane-based water repellents, three worldwide used products, namely Lotexan-N, Silres® BS 290 and Tegosivin HL 100 and a newly synthesized nanocomposite material, TMSPMA, obtained starting from the 3(trimethoxysilyl)propyl methacrylate as a precursor were investigated. The limestones and the water repellents were thoroughly characterized using specific techniques. The coating of the two monumental stones with the mentioned products and the investigation of coating efficiency yielded to the conclusion that all treatments induce good water repellent properties. The treated limestones were afterwards submitted to different artificially accelerated ageing tests – resistance against UV irradiation, resistance to salt mist action and resistance to SO2 action in the presence of humidity –, the results being analyzed according to standardized evaluation methods. The durability of the treated stones was proved to depend on both stone characteristics and water repellent chemical structure. All four water repellents induced a good protection against UV irradiation, no significant differences among them being noticed. As far as the resistance to salt mist action is concerned, the product that afforded the best results when applied on Laspra was TMSPMA, and on Repedea, Silres® BS 290 or / and TMSPMA showed the highest efficiency. The best resistance to SO2 action in the presence of humidity was conferred by Tegosivin HL 100 and TMSPMA when applied on Laspra, while Silres® BS 290 and TMSPMA afforded better results in the case of Repedea.

The impact of polymorphisms in P-gp, DNA repair and folic acid metabolism genes in newly diagnosed multiple myeloma patients treated with thalidomide plus dexamethasone, with or without bortezomib

The principle aim of this study was to investigate biological predictors of response and resistance to multiple myeloma treatment. Two hypothesis had been proposed as responsible of responsiveness: SNPs in DNA repair and Folate pathway, and P-gp dependent efflux. As a first objective, panel of SNPs in DNA repair and Folate pathway genes, were analyzed. It was a retrospective study in a group of 454, previously untreated, MM patients enrolled in a randomized phase III open-label study. Results show that some SNPs in Folate pathway are correlated with response to MM treatment. MTR genotype was associated with favorable response in the overall population of MM patients. However, this relation, disappear after adjustment for treatment response. When poor responder includes very good partial response, partial response and stable/progressive disease MTFHR rs1801131 genotype was associated with poor response to therapy. This relation - unlike in MTR – was still significant after adjustment for treatment response. Identification of this genetic variant in MM patients could be used as an independent prognostic factor for therapeutic outcome in the clinical practice. In the second objective, basic disposition characteristics of bortezomib was investigated. We demonstrated that bortezomib is a P-gp substrate in a bi-directional transport study. We obtain apparent permeability rate values that together with solubility values can have a crucial implication in better understanding of bortezomib pharmacokinetics with respect to the importance of membrane transporters. Subsequently, in view of the importance of P-gp for bortezomib responsiveness a panel of SNPs in ABCB1 gene - coding for P-gp - were analyzed. In particular we analyzed five SNPs, none of them however correlated with treatment responsiveness. However, we found a significant association between ABCB1 variants and cytogenetic abnormalities. In particular, deletion of chromosome 17 and t(4;14) translocation were present in patients harboring rs60023214 and rs2038502 variants respectively.

CYP17A1 polymorphisms and clinical outcome of patients with metastatic castration-resistant prostate cancer treated with abiraterone

Background. Abiraterone acetate is a potent inhibitor of cytochrome P450 17 α-hydrolase (CYP17A1) that causes a reduction in the synthesis of testosterone in the adrenal glands, testes and tumor microenvironment. Blocking androgen production, abiraterone has been shown to prolong progression-free survival (PFS) and overall survival (OS) in patients with metastatic castration-resistant prostate cancer (CRPC) previously submitted to chemotherapy. The aim of our study was to verify the role of single nucleotide polymorphisms (SNPs) in predicting clinical outcome in CRPC patients treated with abiraterone after chemotherapy. Methods. We analyzed 48 CRPC consecutive patients treated with abiraterone after at least one chemotherapeutic regimen with docetaxel. DNA was extracted from peripheral blood and genotyped for four polymorphisms in the CYP17A1 gene (rs743572, rs10883783, rs17115100, rs284849). PFS and OS survival curves were used to identify statistical associations between haplotypes and clinical outcome. Results. Forty-eight Caucasian patients with metastatic CRPC treated with abiraterone were genotyped for polymorphisms in the CYP17A1 gene. All samples were evaluable for both sequencing and TaqMan Genotyping assay. The CRPC patients treated with abiraterone had a median PFS and OS of 7.6 months (95% CI: 4.3-10.5) and 17.6 months (95% CI: 10.5-19.0), respectively Statistical analyses highlighted a difference approaching statistical significance (log-rank test p = 0.0534) between rs10883783 and PFS. Other polymorphisms were not associated with a benefit from treatment with abiraterone. Conclusions. In our case series of 48 treated patients, rs10883783 only was identified as a possible predictive marker, results showing a trend toward statistical significance. Further analysis of this polymorphism is needed in larger series of patients to confirm our findings.

Next-Generation Sequencing-Based Mutations Scanning Strategy of the BCR-ABL Kinase Domain in Patients with PhiladelPhia-Chromosome Positive Leukemias Treated with Tyrosine Kinase Inhibitors

In chronic myeloid leukemia and Philadelphia-positive acute lymphoblastic leukemia patients resistant to tyrosine kinase inhibitors (TKIs), BCR-ABL kinase domain mutation status is an essential component of the therapeutic decision algorithm. The recent development of Ultra-Deep Sequencing approach (UDS) has opened the way to a more accurate characterization of the mutant clones surviving TKIs conjugating assay sensitivity and throughput. We decided to set-up and validated an UDS-based for BCR-ABL KD mutation screening in order to i) resolve qualitatively and quantitatively the complexity and the clonal structure of mutated populations surviving TKIs, ii) study the dynamic of expansion of mutated clones in relation to TKIs therapy, iii) assess whether UDS may allow more sensitive detection of emerging clones, harboring critical 2GTKIs-resistant mutations predicting for an impending relapse, earlier than SS. UDS was performed on a Roche GS Junior instrument, according to an amplicon sequencing design and protocol set up and validated in the framework of the IRON-II (Interlaboratory Robustness of Next-Generation Sequencing) International consortium.Samples from CML and Ph+ ALL patients who had developed resistance to one or multiple TKIs and collected at regular time-points during treatment were selected for this study. Our results indicate the technical feasibility, accuracy and robustness of our UDS-based BCR-ABL KD mutation screening approach. UDS was found to provide a more accurate picture of BCR-ABL KD mutation status, both in terms of presence/absence of mutations and in terms of clonal complexity and showed that BCR-ABL KD mutations detected by SS are only the “tip of iceberg”. In addition UDS may reliably pick 2GTKIs-resistant mutations earlier than SS in a significantly greater proportion of patients.The enhanced sensitivity as well as the possibility to identify low level mutations point the UDS-based approach as an ideal alternative to conventional sequencing for BCR-ABL KD mutation screening in TKIs-resistant Ph+ leukemia patients

Clinical outcome and biological characteristics of Chronic Myeloid Leukemia patients treated with nilotinib front-line

The present work reports the outcome of the GIMEMA CML WP study CML0811, an independent trial investigating nilotinib as front-line treatment in chronic phase chronic myeloid leukemia (CML). Moreover, the results of the proteomic analysis of the CD34+ cells collected at CML diagnosis, compared to the counterpart from healthy donors, are reported. Our study confirmed that nilotinib is highly effective in the prevention of the progression to accelerated/blast phase, a condition that today is still associated with high mortality rates. Despite the relatively short follow-up, cardiovascular issues, particularly atherosclerotic adverse events (AE), have emerged, and the frequency of these AEs may counterbalance the anti-leukemic efficacy. The deep molecular response rates in our study compare favorably to those obtained with imatinib, in historic cohorts, and confirm the findings of the Company-sponsored ENESTnd study. Considering the increasing rates of deep MR over time we observed, a significant proportion of patients will be candidate to treatment discontinuation in the next years, with higher probability of remaining disease-free in the long term. The presence of the additional and complex changes we found at the proteomic level in CML CD34+ cells should be taken into account for the investigation on novel targeted therapies, aimed at the eradication of the disease.

The impact of intraclonal heterogeneity on the outcomes of Multiple Myeloma patients treated with new drugs

Understanding the biology of Multiple Myeloma (MM) is of primary importance in the struggle to achieve a cure for this yet incurable neoplasm. A better knowledge of the mechanism underlying the development of MM can guide us in the development of new treatment strategies. Studies both on solid and haematological tumours have shown that cancer comprises a collection of related but subtly different clones, a feature that has been termed “intra-clonal heterogeneity”. This intra-clonal heterogeneity is likely, from a “Darwinian” natural selection perspective, to be the essential substrate for cancer evolution, disease progression and relapse. In this context the critical mechanism for tumour progression is competition between individual clones (and cancer stem cells) for the same microenvironmental “niche”, combined with the process of adaptation and natural selection. The Darwinian behavioural characteristics of cancer stem cells are applicable to MM. The knowledge that intra-clonal heterogeneity is an important feature of tumours’ biology has changed our way to addressing cancer, now considered as a composite mixture of clones and not as a linear evolving disease. In this variable therapeutic landscape it is important for clinicians and researchers to consider the impact that evolutionary biology and intra-clonal heterogeneity have on the treatment of myeloma and the emergence of treatment resistance. It is clear that if we want to effectively cure myeloma it is of primarily importance to understand disease biology and evolution. Only by doing so will we be able to effectively use all of the new tools we have at our disposal to cure myeloma and to use treatment in the most effective way possible. The aim of the present research project was to investigate at different levels the presence of intra-clonal heterogeneity in MM patients, and to evaluate the impact of treatment on clonal evolution and on patients’ outcomes.

Serum anti-interferon alpha antibodies in chronic hepatitis C patients treated with pegylated interferon alpha containing therapy

The development of anti-IFNα antibodies is an occurrence described in chronic hepatitis C patients during treatment with Interferonα/PEG-Interferonα. However, its relevance, especially in difficult-to treat patients, has not been defined. Methods: We retrospectively measured the serum levels of anti-IFNα antibodies (baseline and week 12) and IFNα levels (week 12) by ELISA in 76 previous non-responders, and in 14 naive patients treated with Pegylated-IFNα and Ribavirin. A group of 57 healthy donors (HD) was also assessed as control. Positivity to anti-IFNα antibodies was established on the values of HD. Results: Baseline anti-IFNα antibodies were detected in 15.5% of patients and in 7% of HD, with significantly higher concentrations in patients than HD (181.5±389.9 vs 95.9±143.0 ng mL−1, p=0.0023). All positive patients were IFNα-experienced. At week 12, the prevalence of positivity increased to 22.3 and 28.5% in experienced and naïve patients, respectively, and the levels of anti-IFNα antibodies did not differ between the two groups (391±792.3 vs 384.7±662.6 ng mL−1, respectively). IFNα concentrations were significantly lower in antibody-positive patients than in antibody-negatives (988.2±1402 vs 3462±830.8 pg mL−1, p≤0.0001) and the levels of antibodies and IFNα were inversely correlated (r=-0.405, p=0.0001). The antibody-positive population clustered in null responders (67%) and 19/21 patients (90%) did not achieve SVR. Conclusions: The development of anti-IFNα antibodies is a non-negligible occurrence in patients treated with PEG-IFNα, is stable over time, and has a relevant clinical impact when associated with low levels of circulating PEG-IFNα. It should be considered in patients undergoing treatments including PEG-IFNα.