Ex Vivo Detection of Circulating Tumor Cells from Whole Blood by Direct Nanoparticle Visualization
ACS NANO
Authors: Sobral-Filho, Regivaldo G.; DeVorkin, Lindsay; Macpherson, Sarah; Jirasek, Andrew; Lum, Julian J.; Brolo, Alexandre G.
Abstract
The detection of circulating tumor cells (CTCs) from blood samples can predict prognosis, response to systemic chemotherapy, and metastatic spread of carcinoma. Therefore, approaches for CTC identification is an important aspect of current cancer research. Here, a method for the direct visualization of nanoparticle-coated CTCs under dark field illumination is presented. A metastatic breast cancer cell line (4T1) was transduced with a non-native target protein (Thy1.1). Positive 4T1-Thy1.1 cells incubated with antibody-coated metallic nanoshells appeared overly bright at low magnification, allowing a quick screening of samples and easy visual detection of even single isolated CTCs. The use of a nontransduced cell line as control creates the ideal scenario to evaluate nonspecific binding. A murine metastatic tumor model with the 4T1-Thyl.1 cell line was also implemented. Blood was drawn from mice over the course of one month, and CTCs were successfully detected in all positive subjects. This work validates the use of metallic nanoshells as labels for direct visualization of CTCs while providing guidelines to a systematic development of nanotechnology-based detection systems for CTCs.
Beneficial effects of cysteamine in Thy1-alpha-Syn mice and induced pluripotent stem cells with a SNCA gene triplication
NEUROBIOLOGY OF DISEASE
Authors: Siddu, Alberto; David, Linda Suzanne; Lauinger, Nadine; Chen, Xiuqing; Saint-Pierre, Martine; Alpaugh, Melanie; Durcan, Thomas; Cicchetti, Francesca
Abstract
A number of publications have reported that cysteamine has significant therapeutic effects on several aspects of Parkinson's disease (PD)-related pathology but none of these studies have evaluated its impact on pathological forms of alpha-Synuclein (alpha-Syn), one of the main hallmarks of PD. We therefore tested the efficacy of cysteamine on the Thy1-alpha-Syn mouse model which over-expresses full-length human wild-type alpha-Syn. Two-month (early stage disease) and 6-month old (late stage disease) mice and littermate controls were treated daily with cysteamine (20 mg/kg, i.p.) to assess the protective and restorative properties of this compound. After 6 weeks of treatment, animals were tested using a battery of motor tests. Cysteamine-treated transgenic mice displayed significant improvements in motor performance as compared to saline-treated transgenic littermates. Post-mortem readouts revealed a reduction in fibrillation, phosphorylation and total levels of overexpresed human alpha-Syn. To determine if such outcomes extended to human cells, the benefits of cysteamine were additionally tested using 6-hydroxydopamine (6-OHDA) treated neurons differentiated from induced pluripotent stem cells (iPSCs) derived from a PD patient harbouring a triplication of the SNCA gene. SNCA neurons treated with cysteamine exhibited significantly more intact/healthy neurites than cells treated with 6-OHDA alone. Additionally, SNCA neurons treated with cysteamine in the absence of 6-OHDA showed a trend towards lower total alpha-Syn levels. Overall, our in vivo and in vitro findings suggest that cysteamine can act as a disease-modifying molecule by enhancing -the survival of dopaminergic neurons and reducing pathological forms of alpha-Syn.