Sarabia-Estrada, Rachel

Abstract Glioblastoma (GBM) is the most common form of malignant primary brain cancer in adults with a median survival of only 15 months. Therefore, new therapies to suppress malignant brain cancer are needed. Brain Tumor Initiating Cells (BTICs) are a GBM subpopulation of cells with a highly glycolytic profile that are thought to be responsible of the resistance of GBM to treatments. Metabolic reprogramming allows tumor cells to survive in unsupportive microenvironments. Manipulating tumor metabolism to counteract GBM resistance arises as a powerful approach with minimum effects in normal counterparts. At pharmacological concentrations, melatonin displays oncostatic properties. This is thought to be due to an increase in mitochondrial oxidative phosphorylation through the effects of melatonin in mitochondria, key organelle in metabolic homeostasis. We hypothesize that melatonin could alter BTIC metabolism, by inducing an anti-Warburg effect and as consequence, melatonin will decrease the viability of GBM cells and tumor growth. We found that treatment of GBM cell lines with 3mM melatonin significantly altered tumor cell metabolism. We observed that melatonin downregulated the lactate symporter MCT4 (p<0.002), inducing a significant intracellular accumulation of lactate (p<0.002) while decreasing it in the extracellular media (p<0.001). This was followed by a decrease in the internal pH (p<0.002). These effects were compensated by an increase in the oxygen consumption rate (OCR) followed by decay that leaded to an increase in ROS production (p<0.001). All these changes result in a depletion of cellular ATP (p<0.001) and eventually drove to a decrease in the proliferation (p<0.001) and cell death (p<0.001). When applied in vivo we observed a significant reduction in the tumor growth (p<0.001), volume (p<0.002) and weight (p<0.002), as well as a drop in the proliferation marker ki67 (p<0.001) and a fibrosis increase in treated tumors. These results position melatonin as a strong therapeutic candidate for GBM therapy.

Objetivo: Evaluar una serie de biomarcadores que permiten medir el proceso de cicatrización de las heridas e identificar los materiales que fueron utilizados para realizar dicha medición, teniendo en cuenta su incorporación en apósitos inteligentes. Método: Se realizó una revisión sistemática a partir de PubMed, Medline, CINAHL y Embase, sobre estudios que evaluaran el uso de materiales sensibles a biomarcadores. Se incluyeron estudios en inglés, sin tomar en cuenta el estado o fecha de publicación. No se incluyeron artículos de revisión ni sinopsis de conferencias. Resultados: La búsqueda mostró 296 estudios. Un investigador seleccionó 19 artículos para su inclusión. Todos los estudios fueron experimentales. Se encontraron artículos que evaluaron pH, tensión de oxígeno, temperatura, presión, ácido úrico, y glucosa. Los materiales utilizados fueron hidrogeles, fibras y tintas conductivas. Conclusión: El biomarcador más estudiado fue el pH. Los materiales que evalúan biomarcadores por medio de métodos colorimétricos podrían ser los más adecuados para su incorporación en apósitos inteligentes. Conflicto de interés: Este estudio fue respaldado, en parte, por el centro de Medicina Individualizada de Mayo Clinic, y por la Fundación de Cirugía Plástica (Plastic Surgery Foundation).

A dual-function microneedle for rapid, high-resolution, and quantitative 3D deep-brain imaging and power-efficient tissue ablation.

Abstract Background Chronic tenosynovitis of the upper extremities caused by Mycobacterium kansasii (M. kansasii) is uncommon, but symptoms may overlap with other more common diseases. Late diagnosis and treatment can lead to disfiguration of structures and rupture of tendons, resulting in worse cosmetic outcomes after reconstruction. Methods We present a clinical case and literature review of M. kansasii in patients with chronic tenosynovitis of upper extremities. PubMed was queried for cases of upper extremities tenosynovitis caused by M. kansasii. The keywords “M. kansasii,” “tenosynovitis” and synonyms were used for search in different combinations. Manuscripts, with no specific data or another condition, where the infection was not located in the upper extremities, were reviews, or not in English, were excluded from the study. Results We described 23 reported cases of tenosynovitis of the upper extremity caused by M. kansasii. An immunosuppressed state was present in eight (34.8%) cases, and 12 (52.2%) patients received immunosuppressive treatment. A long-time period between the first appearance of symptoms and the definitive diagnosis was identified (median: 7 months, interquartile range: 9). The most frequent symptoms were local swelling (65.2%), pain (56.5%), mass effect (26%), and stiffness (13%). Tendon rupture was found in three (13%) patients as a complication of the disease. Moreover, seven (30.4%) patients underwent previous surgeries to try to relieve the symptoms before definitive diagnosis was achieved. Conclusion M. kansasii is an important differential causal pathogen for tenosynovitis of the upper extremities. Although rare, raising awareness about this infectious disease is imperative to avoid inadequate management and hazardous aesthetic sequelae.

Abstract Around fifteen to thirty percent of stage IV breast cancer metastasizes to the brain, severely decreasing the quality of life of these patients by causing neurological decline and eventually death. In metastatic cancers there is a small subset of cells in the primary tumor bulk called Metastatic Tumor Initiating Cells (MTICs) which are able to escape and produce a niche establishment at distal sites where they can quickly become resistant to surgery and radiation. Melatonin has shown an inhibitory role in the viability and invasiveness of breast cancer and in modulating the expression of proteins related to Breast Cancer Stem Cells (BCSCs). These findings suggest its potential anti-metastatic role in different breast cancer cell lines. In this study we aimed to evaluate the effects of melatonin treatment in vitro for breast cancer brain metastasis. The cell line MDA-BT was originally obtained from MDA-MB-231, passed through the rat’s heart and then isolated once engrafted as a tumor in the brain. After a dose response assay, cells were treated with melatonin at doses of 1500 and 3000 µM for 48hrs. Clonogenic assay, MTT, as well as a stem cell signature through RT-qPCR, including CD44, CD24 and ALDH1 markers, were performed to evaluate the malignancy of the MTICs. The results showed that melatonin at high doses impacts morphology, declines viability, reduces colony formation ability, and decreases stemness in MDA-BT cells. Therefore, our findings highlight melatonin as a relevant therapeutic candidate to target breast cancer brain metastases.

Abstract Patients with primary cancers often develop delayed brain metastases. One of the most common cancer types and sources of brain metastasis is lung cancer. For metastasis from lung cancer the 3-year survival is < 5%. Cancer cells in circulation are responsible for metastatic spread. The mechanical microenvironment plays an important role in cancer cells behavior. When cancer cells reach the bloodstream they are exposed to hemodynamic shear stress. It has been shown that most of the circulating tumor cells die once they reach the bloodstream, but the biology of the survival cells is poorly understood. We designed a microfluidics system that simulated the mechanical stress in the human circulating system such as turbulence, change in pressure (0.4-15dyn/cm2) and flow rate (1.06–106.1mm/s). Lung adenocarcinoma cells (A549) were put into circulation and collected after 72 hours. It was found that, 1.4±0.3% of the cells survived, and viability was evaluated by LDH and calcein. CD133, SOX2, and NANOG were downregulated and EMT genes were upregulated in the circulating cancer cells (CCCs) compared with cells in static-suspension or 2D. After re-seeding in 2D, CCCs overexpressed CD133. Female athymic nude rats (6-8weeks,n=16) received intracardiac injections of CCCs or 2D cells (GFP-LUC lentivirus traduced). Bioluminescence imaging was performed every week; the survival in of the CCCs group was lower than the 2D group. One-way ANOVA test was used to analyze survival and gene expression. Survival data was plotted on a Kaplan-Meier curve and compared using the Mantel-Cox logrank test, p=< 0.05. We have isolated a cellular subpopulation of lung adenocarcinoma with high resistance to hemodynamic shear stress that shows a higher metastatic capacity and genetic plasticity compared with cells growing in suspension or 2D. Targeting these cells would potentially allow us to develop personalized treatments to help to stop metastatic spread and improve actual therapeutical strategies.