Monitoring of blood serum amyloid (SAA) to predict outcome of first-line pembrolizumab (P) in patients (pts) with advanced non-small cell lung cancer (ANSCLC).

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Biological and clinical effects of abiraterone on anti-resorptive and anabolic activity in bone microenvironment

Abiraterone acetate (ABI) is associated not only with a significant survival advantage in both chemotherapy-naive and -treated patients with metastatic castration-resistant prostate cancer (mCRPC), but also with a delay in time to development of Skeletal Related Events and in radiological skeletal progression. These bone benefits may be related to a direct effect on prostate cancer cells in bone or to a specific mechanism directed to bone microenvironment. To test this hypothesis we designed an in vitro study aimed to evaluate a potential direct effect of ABI on human primary osteoclasts/osteoblasts (OCLs/OBLs). We also assessed changes in bone turnover markers, serum carboxy-terminal collagen crosslinks (CTX) and alkaline phosphatase (ALP), in 49 mCRPC patients treated with ABI.Our results showed that non-cytotoxic doses of ABI have a statistically significant inhibitory effect on OCL differentiation and activity inducing a down-modulation of OCL marker genes TRAP, cathepsin K and metalloproteinase-9. Furthermore ABI promoted OBL differentiation and bone matrix deposition up-regulating OBL specific genes, ALP and osteocalcin. Finally, we observed a significant decrease of serum CTX values and an increase of ALP in ABI-treated patients.These findings suggest a novel biological mechanism of action of ABI consisting in a direct bone anabolic and anti-resorptive activity

Blood serum amyloid A as potential biomarker of pembrolizumab efficacy for patients affected by advanced non-small cell lung cancer overexpressing PD-L1: results of the exploratory "FoRECATT" study

Background: Identifying the patients who may benefit the most from immune checkpoints inhibitors remains a great challenge for clinicians. Here we investigate on blood serum amyloid A (SAA) as biomarker of response to upfront pembrolizumab in patients with advanced non-small-cell lung cancer (NSCLC). Methods: Patients with PD-L1 ≥ 50% receiving upfront pembrolizumab (P cohort) and with PD-L1 0-49% treated with chemotherapy (CT cohort) were evaluated for blood SAA and radiological response at baseline and every 9 weeks. Endpoints were response rate (RR) according to RECIST1.1, progression-free (PFS) and overall survival (OS). The most accurate SAA cut-off to predict response was established with ROC analysis in the P cohort. Results: In the P Cohort (n = 42), the overall RR was 38%. After a median follow-up of 18.5 months (mo), baseline SAA ≤ the ROC-derived cut-off (29.9 mg/L; n = 28/42.67%) was significantly associated with higher RR (53.6 versus 7.1%; OR15, 95% CI 1.72-130.7, p = 0.009), longer PFS (17.4 versus 2.1 mo; p < 0.0001) and OS (not reached versus 7.2mo; p < 0.0001) compared with SAA > 29.9 mg/L. In multivariate analysis, low SAA positively affects PFS (p = 0.001) and OS (p = 0.048) irrespective of ECOG PS, number of metastatic sites and pleural effusion. SAA monitoring (n = 40) was also significantly associated with survival endpoints: median PFS 17.4 versus 2.1 mo and median OS not reached versus 7.2 mo when SAA remained low (n = 14) and high (n = 12), respectively. In the CT Cohort (n = 30), RR was not affected by SAA level (p > 0.05) while low SAA at baseline (n = 17) was associated with better PFS (HR 0.38, 95% CI 0.16-0.90, p = 0.006) and OS (HR 0.25, 95% CI 0.09-0.67, p < 0.001). Conclusion: Low SAA predicts good survival outcomes irrespective of treatment for advanced NSCLC patients and higher likelihood of response to upfront pembrolizumab only. The strong prognostic value might be exploited to easily identify patients most likely to benefit from immunotherapy. A further study (FoRECATT-2) is ongoing to confirm results in a larger sample size and to investigate the effect of SAA on immune response in vitro assays

Clinical, Pathological and Prognostic Features of Rare BRAF Mutations in Metastatic Colorectal Cancer (mCRC): A Bi-Institutional Retrospective Analysis (REBUS Study)

Simple SummarySomatic BRAF mutations occur in approximately 10% of metastatic colorectal cancers (mCRCs) and, according to the involved codon, are classified as V600E and in non-V600, accounting for 80% and 20%, respectively. Being the most frequent mutation, the BRAF V600E mutation has been extensively investigated and up to now its clinical, pathological and molecular phenotype and its prognostic impact have been clearly described. On the contrary, evidence concerning BRAF non-V600 is weaker. We retrospectively evaluated 537 mCRC patients treated at two Italian Institutions. This study corroborates and strengthens available evidence concerning phenotype and prognostic performance of BRAF non-V600 compared to BRAF V600E and BRAF wild-type mCRCs. This deeper insight on rare BRAF non-V600 mutated mCRC is a primary issue in the precision oncology era, since the wider application of NGS is expected to increase the identification of those aberrations.Recently, retrospective analysis began to shed light on metastatic colorectal cancers (mCRCs) harboring rare BRAF non-V600 mutations, documenting a distinct phenotype and a favorable prognosis. This study aimed to confirm features and prognosis of rare BRAF non-V600 mCRCs compared to BRAF V600E and BRAF wild-type mCRCs treated at two Italian Institutions. Overall, 537 cases were retrospectively evaluated: 221 RAS/BRAF wild-type, 261 RAS mutated, 46 BRAF V600E and 9 BRAF non-V600. Compared to BRAF V600E mCRC, BRAF non-V600 mCRC were more frequently left-sided, had a lower tumor burden and displayed a lower grade and an MMR proficient/MSS status. In addition, non-V600 mCRC patients underwent more frequently to resection of metastases with radical intent. Median overall survival (mOS) was significantly longer in the non-V600 compared to the V600E group. At multivariate analysis, only age < 65 years and ECOG PS 0 were identified as independent predictors of better OS. BRAF V600E mCRCs showed a statistically significant worse mOS when compared to BRAF wild-type mCRCs, whereas no significant difference was observed between BRAF non-V600 and BRAF wild-type mCRCs. Our study corroborates available evidence concerning incidence, clinicopathologic characteristics and prognosis of BRAF-mutated mCRCs

PTEN Loss as a Predictor of Tumor Heterogeneity and Poor Prognosis in Patients With EGFR-mutant Advanced Non-small-cell Lung Cancer Receiving Tyrosine Kinase Inhibitors

Background: Rapid disease progression of patients with advanced epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer (NSCLC) has been recently associated with tumor heterogeneity, which may be mirrored by coexisting concomitant alterations. The aim of this analysis was to investigate the correlation between loss of function of PTEN and the efficacy of tyrosine kinase inhibitors in this population. Materials and Methods: Archival tumor blocks from patients with EGFR-mutant NSCLC who were administered upfront tyrosine kinase inhibitors were retrospectively collected. The status of 4 genes (PTEN, TP53, c-MET, IGFR) was evaluated by immunohistochemistry, and it was correlated with overall response rate, overall survival (OS), and progression-free survival (PFS). Results: Fifty-one patients were included. In multivariate analysis, PTEN loss (hazard ratio [HR], 3.46; 95% confidence interval [CI], 1.56-7.66; P = .002), IGFR overexpression (HR, 2.22; 95% CI, 1.03-4.77; P = .04), liver metastases (HR, 3.55; 95% CI, 1.46-8.65; P = .005), and Eastern Cooperative Oncology Group performance status (ECOG PS) > 1 (HR, 2.57; 95% CI, 1.04-6.34; P = .04) were significantly associated with shorter PFS. Patients with PTEN loss had a median PFS of 6 months (2-year PFS, 11.6%), whereas patients without PTEN loss had a median PFS of 18 months (2-year PFS, 43.6%) (log-rank P < .005). In the multivariate analysis, PTEN loss (HR, 5.92; 95% CI, 2.37-14.81; P < .005), liver metastases (HR, 2.63; 95% CI, 1.06-6.51; P = .037), and ECOG PS > 1 (HR, 2.80; 95% CI, 1.15-6.81; P = .024) were significantly associated with shorter OS. Patients with PTEN loss had a median OS of 6 months (2-year OS, 12.2%), whereas in patients without PTEN loss, OS was not reached (2-year OS, 63.9%) (log-rank P < .0005).Conclusions: A low-cost and reproducible immunohistochemistry assay for PTEN loss analysis represents a potential tool for identifying tumor heterogeneity in patients with advanced EGFR-mutant NSCLC

Integrin alpha5 in human breast cancer is a mediator of bone metastasis and a therapeutic target for the treatment of osteolytic lesions

Bone metastasis remains a major cause of mortality and morbidity in breast cancer. Therefore, there is an urgent need to better select high-risk patients in order to adapt patient’s treatment and prevent bone recurrence. Here, we found that integrin alpha5 (ITGA5) was highly expressed in bone metastases, compared to lung, liver, or brain metastases. High ITGA5 expression in primary tumors correlated with the presence of disseminated tumor cells in bone marrow aspirates from early stage breast cancer patients (n = 268; p = 0.039). ITGA5 was also predictive of poor bone metastasis-free survival in two separate clinical data sets (n = 855, HR = 1.36, p = 0.018 and n = 427, HR = 1.62, p = 0.024). This prognostic value remained significant in multivariate analysis (p = 0.028). Experimentally, ITGA5 silencing impaired tumor cell adhesion to fibronectin, migration, and survival. ITGA5 silencing also reduced tumor cell colonization of the bone marrow and formation of osteolytic lesions in vivo. Conversely, ITGA5 overexpression promoted bone metastasis. Pharmacological inhibition of ITGA5 with humanized monoclonal antibody M200 (volociximab) recapitulated inhibitory effects of ITGA5 silencing on tumor cell functions in vitro and tumor cell colonization of the bone marrow in vivo. M200 also markedly reduced tumor outgrowth in experimental models of bone metastasis or tumorigenesis, and blunted cancer-associated bone destruction. ITGA5 was not only expressed by tumor cells but also osteoclasts. In this respect, M200 decreased human osteoclast-mediated bone resorption in vitro. Overall, this study identifies ITGA5 as a mediator of breast-to-bone metastasis and raises the possibility that volociximab/M200 could be repurposed for the treatment of ITGA5-positive breast cancer patients with bone metastases

Биологическое и клиническое действие абиратерона на антирезорбтивную и анаболическую активность микроокружения костной ткани

Применение абиратерона ацетата (АА) сопровождается не только значимым увеличением выживаемости пациентов с метастатическим кастрационно-резистентным раком предстательной железы (мКРРПЖ), но также отдалением времени до развития рентгенологического прогрессирования заболевания. Эти преимущества относительно костных метастатических очагов могут быть связаны с непосредственным воздействием на метастатические клетки рака предстательной железы в костях или со специфическими механизмами, направленными на костное микроокружение. Чтобы проверить эти гипотезы, мы прове- ли исследование in vitro, направленное на оценку потенциального действия AA на первичные остеокласты (ОКЛ) / остеобласты (ОБЛ); in vivo оценивали изменения уровней маркеров костного метаболизма, С-концевых телопептидов коллагена 1-го типа (CTX, маркер костной резорбции) и щелочной фосфатазы (ЩФ) у 49 пациентов с мКРРПЖ, получавших AA.Наши результаты показали, что AA оказывает статистически значимое ингибирующее действие на дифференцировку и активность ОКЛ, уменьшая экспрессию ОКЛ-маркерных генов TRAP (тартратрезистентная кислая фосфатаза), образование катепсина К и матриксной металлопротеиназы-9. Кроме того, AA способствовал дифференцировке ОБЛ и отложению костной матрицы, увеличивая экспрессию специфичных для ОБЛ генов RUNX2 (фактор транскрипции-2, содержащий домен Runt), образование ЩФ и остеокальцина. Также мы наблюдали in vivo значимое снижение уровня CTX в сыворотке и повышение уровня ЩФ у пациентов, получавших AA.Эти данные позволяют предполагать новый биологический механизм действия AA, состоящий в прямом анаболическом и антирезорбтивном влиянии на костную ткань.Применение абиратерона ацетата (АА) сопровождается не только значимым увеличением выживаемости пациентов с метастатическим кастрационно-резистентным раком предстательной железы (мКРРПЖ), но также отдалением времени до развития рентгенологического прогрессирования заболевания. Эти преимущества относительно костных метастатических очагов могут быть связаны с непосредственным воздействием на метастатические клетки рака предстательной железы в костях или со специфическими механизмами, направленными на костное микроокружение. Чтобы проверить эти гипотезы, мы провели исследование in vitro, направленное на оценку потенциального действия AA на первичные остеокласты (ОКЛ) / остеобласты (ОБЛ); in vivo оценивали изменения уровней маркеров костного метаболизма, С-концевых телопептидов коллагена 1-го типа (CTX, маркер костной резорбции) и щелочной фосфатазы (ЩФ) у 49 пациентов с мКРРПЖ, получавших AA.Наши результаты показали, что AA оказывает статистически значимое ингибирующее действие на дифференцировку и активность ОКЛ, уменьшая экспрессию ОКЛ-маркерных генов TRAP (тартратрезистентная кислая фосфатаза), образование катепсина К и матриксной металлопротеиназы-9. Кроме того, AA способствовал дифференцировке ОБЛ и отложению костной матрицы, увеличивая экспрессию специфичных для ОБЛ генов RUNX2 (фактор транскрипции-2, содержащий домен Runt), образование ЩФ и остеокальцина. Также мы наблюдали in vivo значимое снижение уровня CTX в сыворотке и повышение уровня ЩФ у пациентов, получавших AA.Эти данные позволяют предполагать новый биологический механизм действия AA, состоящий в прямом анаболическом и антирезорбтивном влиянии на костную ткань

Development of Highly Active and Selective Copper Catalysts for New ATRP Initiating Systems

Reversible deactivation radical polymerization (RDRP) techniques have revolutionized polymer chemistry for the controlled synthesis of functional polymers with predefinedmolecular weights, narrow molecular weight distributions and with high chain-end functionality. One of these techniques, atom transfer radical polymerization (ATRP), makes use of a catalytic system, most commonly copper complexed by a nitrogen-based ligand, in which the L/CuI activator species cleaves a (macro)alkyl halide bond generating a carbon-centered radical and the oxidized L/CuII-X deactivator species. The radical propagates by adding to a few monomer units before being quickly deactivated by the L/CuII-X complex. As with any radicalprocess, irreversible termination reactions are unavoidable and thus a gradual buildup of L/CuIIX is observed according to the persistent radical effect (PRE), leading to a suppressed rate of polymerization. Various systems with activator regeneration, also known as “low ppm CuATRP,” have been developed to overcome the PRE, but these require the use of highly active catalysts. At the forefront of ATRP research has been the development of new externally regulated systems as well as mechanistic understanding of the processes in order to select thebest catalytic system. My contribution to the field was primarily focused on: (1) the development and understanding of new initiating systems for low ppm ATRP using light andzero-valent metals such as Ag0 and Cu0, (2) the synthesis and characterization the highly active catalysts based on ligand design and (3) quantification and mechanistic understanding of radical termination processes in both conventional free radical polymerization and ATRP with highly active catalysts. Chapter 1 overviews the progressive development of catalytic systems in ATRP. Since ATRP’s discovery in 1995, various kinetic and thermodynamic parameters have been quantified in order to better understand this system. The first catalysts involved the use of relatively simple bidentate bipyridine (bpy)-based ligand and required catalyst loadings of greater than 10,000 ppm. Through rational ligand design, structure vs. reactivity relationships between activity and N-atom donor type, denticity, geometry were understood. This allowed thesynthesis of more complex and robust ligands which greatly increased the efficiency of ATRP. The activity of catalysts in ATRP has now increased over 1,000,000,000 times compared to seminal bpy-based catalysts and allow for ATRP to be conducted using catalyst loadings as lowas 5 ppm. This chapter encompasses almost 25 years of ATRP catalytic systems and discusses potential opportunities for future development. Chapter 2 discusses mechanistic studies for the newly developed photochemically mediated ATRP. Photochemical control over ATRP with ppm amounts of copper was firstachieved in 2012, however, there was significant mechanistic debate over how the polymerization operated, namely the mechanism of photochemical reduction of L/CuII-X. Usingboth experimental and simulation techniques, the mechanism of photoATRP was elucidated. It was found that the main method of radical (re)generation occurs via a reductive quenching process between excited state deactivator complex, [L/CuII-X]* and excess amines acting as electron donors. By using model studies and kinetic simulations, other photochemical processes were studied and quantified. The effect of light irradiation on other methods of low ppm ATRP such as initiators for continuous activator regeneration (ICAR) ATRP was also quantified.Chapter 3 discusses ATRP in the presence of zero-valent metals. This is an attractive method because the reactions are easy to operate and it opens up the possibility for catalyst recycling. ATRP was first conducted in the presence of Cu0 in 1997, however, a vigorous mechanistic debate was ongoing for over a decade. Specifically, two mechanisms, supplemental activator and reducing agent (SARA) ATRP and single electron transfer livingradical polymerization (SET-LRP), both using the same species, were debated. It was found that the SARA mechanism holds true in both aqueous and organic media. Both activation of alkyl halides by Cu0, ka0, and comproportionation between Cu0 and L/CuII, kcomp, were quantified in a variety of solvents for different ligands and alkyl halides. In-depth mechanistic studies attempted to elucidate the surface reactions occurring in SARA ATRP. Finally, a new system employing the use of Ag0 wire as a reducing agent for L/CuII-X was used in ATRP and exhibitedone of the highest degrees of “living” control in any ATRP system reported thus far. Chapter 4 overviews in-depth kinetics of both normal and low ppm ATRP systems suchas ICAR ATRP and SARA ATRP. Recent reports have made inaccurate claims about reaction mechanisms due to the misunderstanding that the rate of polymerization in ATRP is not directly related to the rate of alkyl halide activation. This chapter aims to rectify the claims made by others and to present a much clearer and accurate picture of the kinetics of ATRP. Chapter 5 discusses the recent advancements in catalytic design in ATRP. Specifically, the tetradentate tripodal ligand tris(2-pyridylmethyl)amine (TPMA) was systematically modified to include methyl (-Me) and methoxy (-OMe) electron donating groups to decrease the redox potential, E1/2, of the L/CuI/II couple. Substitution of each pyridine arm lead to a catalyst that was 10, 100 and 1000 times more active than the unsubstituted ligand. Structural studies of both the L/CuI and L/CuII-X species were also conducted. The catalysts were characterized insolution using UV-Vis, electrochemistry and low-temperature 1H NMR spectroscopy and also used as catalysts in activators regenerated by electron transfer (ARGET) ATRP. In order to increase the activity further, the TPMA scaffold was substituted with even more electron donating dimethylamino (-NMe2) groups. Characterization of this complex, [CuII(TPMANMe2)Br][Br], revealed the most active ATRP catalyst to date with rates of activation approaching diffusion controlled-limits (ka > 106 M-1s-1) and KATRP values approaching unity for ethyl α-bromoisobutyrate (EBiB) in acetonitrile (MeCN) at ambient temperatures. ICAR and Ag0-mediated ARGET ATRP exhibited a well-controlled polymerization with >99% chain-endfunctionality using as little as 10 ppm of catalyst.Chapter 6 discusses the recent research efforts to understand how acrylate radicals terminate in both conventional radical polymerization (RP) and ATRP. It is known that active L/CuI catalysts can catalyze the termination of acrylate radicals, the mechanism, however,remains elusive. It has been concluded that un-catalyzed radical termination of acrylatesnoccurs predominately via combination while CRT gives saturated chain-ends. We aimed tondetermine the effects that ligand geometry and electronics has on this reaction as well as elucidate the mechanism of non-catalyzed radical termination. The intimate mechanism of the CRT reaction is currently being studied. Throughout the process, a novel reaction betweenorganotellanyl radicals (TeR) and propagating carbon-based radicals was discovered. Finally, Chapter 7 provides a summary with an emphasis on future directions. <br