Serum Beta-Secretase 1 Activity Is a Potential Marker for the Differential Diagnosis between Alzheimer's Disease and Frontotemporal Dementia: A Pilot Study.

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the two major neurodegenerative diseases causing dementia. Due to similar clinical phenotypes, differential diagnosis is challenging without specific biomarkers. Beta-site Amyloid Precursor Protein cleaving enzyme 1 (BACE1) is a ß-secretase pivotal in AD pathogenesis. In AD and mild cognitive impairment subjects, BACE1 activity is increased in brain/cerebrospinal fluid, and plasma levels appear to reflect those in the brain. In this study, we aim to evaluate serum BACE1 activity in FTD, since, to date, there is no evidence about its role. The serum of 30 FTD patients and 30 controls was analyzed to evaluate (i) BACE1 activity, using a fluorescent assay, and (ii) Glial Fibrillary Acid Protein (GFAP) and Neurofilament Light chain (NfL) levels, using a Simoa kit. As expected, a significant increase in GFAP and NfL levels was observed in FTD patients compared to controls. Serum BACE1 activity was not altered in FTD patients. A significant increase in serum BACE1 activity was shown in AD vs. FTD and controls. Our results support the hypothesis that serum BACE1 activity is a potential biomarker for the differential diagnosis between AD and FTD.

Imbalance of Essential Metals in Traumatic Brain Injury and Its Possible Link with Disorders of Consciousness.

Dysfunction of the complex cerebral networks underlying wakefulness and awareness is responsible for Disorders of Consciousness (DoC). Traumatic Brain Injury (TBI) is a common cause of DoC, and it is responsible for a multi-dimensional pathological cascade that affects the proper functioning of the brainstem and brain consciousness pathways. Iron (Fe), Zinc (Zn), and Copper (Cu) have a role in the neurophysiology of both the ascending reticular activating system, a multi-neurotransmitter network located in the brainstem that is crucial for consciousness, and several brain regions. We aimed to summarize the role of these essential metals in TBI and its possible link with consciousness alterations. We found that TBI alters many neuronal molecular mechanisms involving essential metals, causing neurodegeneration, neural apoptosis, synaptic dysfunction, oxidative stress, and inflammation. This final pattern resembles that described for Alzheimer's disease (AD) and other neurological and psychiatric diseases. Furthermore, we found that amantadine, zolpidem, and transcranial direct current stimulation (tDCS)-the most used treatments for DoC recovery-seem to have an effect on essential metals-related pathways and that Zn might be a promising new therapeutic approach. This review summarizes the neurophysiology of essential metals in the brain structures of consciousness and focuses on the mechanisms underlying their imbalance following TBI, suggesting their possible role in DoC. The scenario supports further studies aimed at getting a deeper insight into metals' role in DoC, in order to evaluate metal-based drugs, such as metal complexes and metal chelating agents, as potential therapeutic options.

Inhibition of SIRT1 deacetylase and p53 activation uncouples the anti-inflammatory and chemopreventive actions of NSAIDs.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) have been proposed as chemopreventive agents for many tumours; however, the mechanism responsible for their anti-neoplastic activity remains elusive and the side effects due to cyclooxygenase (COX) inhibition prevent this clinical application. METHODS: Molecular biology, in silico, cellular and in vivo tools, including innovative in vivo imaging and classical biochemical assays, were applied to identify and characterise the COX-independent anti-cancer mechanism of NSAIDs. RESULTS: Here, we show that tumour-protective functions of NSAIDs and exisulind (a sulindac metabolite lacking anti-inflammatory activity) occur through a COX-independent mechanism. We demonstrate these NSAIDs counteract carcinogen-induced proliferation by inhibiting the sirtuin 1 (SIRT1) deacetylase activity, augmenting acetylation and activity of the tumour suppressor p53 and increasing the expression of the antiproliferative gene p21. These properties are shared by all NSAIDs except for ketoprofen lacking anti-cancer properties. The clinical interest of the mechanism identified is underlined by our finding that p53 is activated in mastectomy patients undergoing intraoperative ketorolac, a treatment associated with decreased relapse risk and increased survival. CONCLUSION: Our study, for the first-time, links NSAID chemopreventive activity with direct SIRT1 inhibition and activation of the p53/p21 anti-oncogenic pathway, suggesting a novel strategy for the design of tumour-protective drugs.

Increased Sensitivity of Computed Tomography Scan for Neoplastic Tissues Using the Extracellular Vesicle Formulation of the Contrast Agent Iohexol.

Computed tomography (CT) is a diagnostic medical imaging modality commonly used to detect disease and injury. Contrast agents containing iodine, such as iohexol, are frequently used in CT examinations to more clearly differentiate anatomic structures and to detect and characterize abnormalities, including tumors. However, these contrast agents do not have a specific tropism for cancer cells, so the ability to detect tumors is severely limited by the degree of vascularization of the tumor itself. Identifying delivery systems allowing enrichment of contrast agents at the tumor site would increase the sensitivity of detection of tumors and metastases, potentially in organs that are normally inaccessible to contrast agents, such as the CNS. Recent work from our laboratory has identified cancer patient-derived extracellular vesicles (PDEVs) as effective delivery vehicles for targeting diagnostic drugs to patients' tumors. Based on this premise, we explored the possibility of introducing iohexol into PDEVs for targeted delivery to neoplastic tissue. Here, we provide preclinical proof-of-principle for the tumor-targeting ability of iohexol-loaded PDEVs, which resulted in an impressive accumulation of the contrast agent selectively into the neoplastic tissue, significantly improving the ability of the contrast agent to delineate tumor boundaries.

Cancer-derived EVs show tropism for tissues at early stage of neoplastic transformation.

From the past decade, extracellular vesicles (EVs) have attracted considerable attention as tools for the selective delivery of anti-neoplastic drugs to cancer tissues. Compared to other nanoparticles, EVs display interesting unique features including immune compatibility, low toxicity and the ability to encapsulate a large variety of small- and macro-molecules. However, in virtually all studies, investigations on EVs have been focused on fully transformed cancers: the possibility to apply EV technology also to early-stage tumors has never been explored. Methods: Herein, we studied the ability of cancer-derived EVs to recognize and deliver their cargo also to incipient cancers. To this purpose, EV biodistribution was studied in MMTV-NeuT genetically modified mice during early mammary transformation, in fully developed breast tumors and in the normal gland of wild type syngeneic mice. EVs were loaded with indocyanine green (ICG), a near-infrared (NIR) dye together with oncolytic viruses and i.v. injected in mice. The nanoparticle biodistribution was assayed by in vivo and ex vivo optical imaging (detecting the ICG) and semiquantitative real-time PCR (measuring the adenoviral genome) in different tissues. Results: Our results demonstrate the ability of cancer-derived EVs to recognize early-stage neoplastic tissues opening the possibility to selectively deliver theranostics also for tumor prevention. Conclusions: Taken together our study demonstrates the ability of EVs to recognize and deliver diagnostic and therapeutic agents not only to fully transformed tissues but also to early stage tumors. These findings pave the way for the synthesis of "universal" EVs-based formulation for targeted cancer therapy.

Transplantation of autologous extracellular vesicles for cancer-specific targeting.

Nano- and microsized extracellular vesicles (EVs) are naturally occurring cargo-bearing packages of regulatory macromolecules, and recent studies are increasingly showing that EVs are responsible for physiological intercellular communication. Nanoparticles encapsulating anti-tumor theranostics represent an attractive "exosome-interfering" strategy for cancer therapy. Methods: Herein, by labeling plasma-derived EVs with indocyanine green (ICG) and following their biodistribution by in vivo and ex vivo imaging, we demonstrate the existence of nanoparticles with a highly selective cancer tropism in the blood of colorectal cancer (CRC) patients but not in that of healthy volunteers. Results: In CRC patient-derived xenograft (PDX) mouse models, we show that transplanted EVs recognize tumors from the cognate nanoparticle-generating individual, suggesting the theranostic potential of autologous EVs encapsulating tumor-interfering molecules. In large canine breeds bearing spontaneous malignant skin and breast tumors, the same autologous EV transplantation protocol shows comparable safety and efficacy profiles. Conclusions: Our data show the existence of an untapped resource of intercellular communication present in the blood of cancer patients, which represents an efficient and highly biocompatible way to deliver molecules directly to the tumor with great precision. The novel EV-interfering approach proposed by our study may become a new research direction in the complex interplay of modern personalized cancer therapy.

Heterologous and cross-species tropism of cancer-derived extracellular vesicles.

Extracellular vesicles (EVs) are naturally occurring cargo delivery vesicles that have recently received considerable attention for their roles in intercellular communication in many physiological and pathological processes, including tumourigenesis. EVs generated by different tissues demonstrated specific homing: in particular, cancer-derived EVs showed a selective tropism for the tumor tissue from which the vesicles originated. For this property, EVs have been proposed as drug delivery tools for anti-cancer therapies, although the limited knowledge about their in vivo tropism hinders their therapeutic applications. The current study aimed to characterize the targeting properties of cancer-derived EVs in vitro and their biodistribution in vivo, by using an imaging approach. Methods: EVs were generated from: i) murine lung (LL/2) and colon (MC-38) cancer lines, ii) human lung cancer cell line (A549) and iii) human liver biopsy samples from healthy individuals. EVs were loaded with fluorescent dyes alone or in combination with a biopharmaceutical agent, the oncolytic adenovirus (OV), characterized for charge and size and tested for their activity in cancer cell lines. Finally, optical imaging was extensively applied to study in vivo and ex vivo the biodistribution of EVs originated from different sources in different mouse models of cancer, including xenograft, syngeneic graft and the MMTV-NeuT genetically modified animal. Results: We initially demonstrated that even loading EVs even with a large biopharmaceutical oncolytic viruses (OVs) did not significantly change their charge and dimension properties, while increasing their anti-neoplastic activity compared to the virus or EVs alone. Interestingly, this activity was observed even if the EVs derived from lung cancer were applied to colon carcinoma cell lines and vice versa, suggesting that the EV uptake occurred in vitro without any specificity for the cancer cells from which the vesicles originated. When administered i.v (intravenously) to the mouse models of cancer, the tumour-derived EVs, but not the EVs derived from a healthy tissue, demonstrated a selective accumulation of the fluorescence at the tumour site 24 h after injection; adding OVs to the formulation did not change the tumour-specific tropism of the EVs also in vivo. Most interestingly, the in vivo experiments confirmed the in vitro observation of the generalized tropism of tumour-derived EVs for any neoplastic tissue, independent of the tumour type or even the species originating the vesicles. Conclusions: Taken together, our in vitro and in vivo data demonstrate for the first time a heterologous, cross-species tumour-tropism for cancer-derived EVs. This finding challenges our current view on the homing properties of EVs and opens new avenues for the selective delivery of diagnostic/therapeutic agents to solid tumours.