Bone-Specific Drug Delivery for Osteoporosis and Rare Skeletal Disorders.

PURPOSE OF REVIEW: The skeletal system provides an important role to support body structure and protect organs. The complexity of its architecture and components makes it challenging to deliver the right amount of the drug into bone regions, particularly avascular cartilage lesions. In this review, we describe the recent advance of bone-targeting methods using bisphosphonates, polymeric oligopeptides, and nanoparticles on osteoporosis and rare skeletal diseases. RECENT FINDINGS: Hydroxyapatite (HA), a calcium phosphate with the formula Ca10(PO4)6(OH)2, is a primary matrix of bone mineral that includes a high concentration of positively charged calcium ion and is found only in the bone. This unique feature makes HA a general targeting moiety to the entire skeletal system. We have applied bone-targeting strategy using acidic amino acid oligopeptides into lysosomal enzymes, demonstrating the effects of bone-targeting enzyme replacement therapy and gene therapy on bone and cartilage lesions in inherited skeletal disorders. Virus or no-virus gene therapy using techniques of engineered capsid or nanomedicine has been studied preclinically for skeletal diseases. Efficient drug delivery into bone lesions remains an unmet challenge in clinical practice. Bone-targeting therapies based on gene transfer can be potential as new candidates for skeletal diseases.

Phenotypic Characteristics and Copy Number Variants in a Cohort of Colombian Patients with VACTERL Association.

VACTERL association (OMIM 192350) is a heterogeneous clinical condition characterized by congenital structural defects that include at least 3 of the following features: vertebral abnormalities, anal atresia, heart defects, tracheoesophageal fistula, renal malformations, and limb defects. The nonrandom occurrence of these malformations and some familial cases suggest a possible association with genetic factors such as chromosomal alterations, gene mutations, and inherited syndromes such as Fanconi anemia (FA). In this study, the clinical phenotype and its relationship with the presence of chromosomal abnormalities and FA were evaluated in 18 patients with VACTERL association. For this, a G-banded karyotype, array-comparative genomic hybridization, and chromosomal fragility test for FA were performed. All patients (10 female and 8 male) showed a broad clinical spectrum: 13 (72.2%) had vertebral abnormalities, 8 (44.4%) had anal atresia, 14 (77.8%) had heart defects, 8 (44.4%) had esophageal atresia, 10 (55.6%) had renal abnormalities, and 10 (55.6%) had limb defects. Chromosomal abnormalities and FA were ruled out. In 2 cases, the finding of microalterations, namely del(15)(q11.2) and dup(17)(q12), explained the phenotype; in 8 cases, copy number variations were classified as variants of unknown significance and as not yet described in VACTERL. These variants comprise genes related to important cellular functions and embryonic development.

Role of RUNX2 transcription factor in epithelial mesenchymal transition in non-small cell lung cancer lung cancer: Epigenetic control of the RUNX2 P1 promoter.

Lung cancer has a high mortality rate in men and women worldwide. Approximately 15% of diagnosed patients with this type of cancer do not exceed the 5-year survival rate. Unfortunately, diagnosis is established in advanced stages, where other tissues or organs can be affected. In recent years, lineage-specific transcription factors have been associated with a variety of cancers. One such transcription factor possibly regulating cancer is RUNX2, the master gene of early and late osteogenesis. In thyroid and prostate cancer, it has been reported that RUNX2 regulates expression of genes important in tumor cell migration and invasion. In this study, we report on RUNX2/ p57 overexpression in 16 patients with primary non-small cell lung cancer and/or metastatic lung cancer associated with H3K27Ac at P1 gene promoter region. In some patients, H3K4Me3 enrichment was also detected, in addition to WDR5, MLL2, MLL4, and UTX enzyme recruitment, members of the COMPASS-LIKE complex. Moreover, transforming growth factor-ß induced RUNX2/ p57 overexpression and specific RUNX2 knockdown supported a role for RUNX2 in epithelial mesenchymal transition, which was demonstrated through loss of function assays in adenocarcinoma A549 lung cancer cell line. Furthermore, RUNX2 increased expression of epithelial mesenchymal transition genes VIMENTIN, TWIST1, and SNAIL1, which reflected increased migratory capacity in lung adenocarcinoma cells.

Transición epitelio mesénquima: de lo molecular a lo fisiológico / Epitelial Mesenchymal Transition: From the Molecular to Physiologic

La transición epitelio mesénquima (EMT) es un proceso compuesto de diferentes fases, donde una célula epitelial adquiere un fenotipo mesenquimal. Dentro de los cambios involucrados se encuentran: pérdida de la polaridad celular, adquisición de una capacidad migratoria, capacidad invasora, resistencia a la apoptosis y aumento en la producción de componentes de la matriz extracelular. Todos estos cambios ocurren como una consecuencia de la activación y represión de genes involucrados con rutas de señalización específicas relacionadas con este evento. La EMT está relacionada con procesos fisiológicos y patológicos como el cáncer. Consta de tres fases: una de células no migratorias, células premigratorias y células migratorias; cada una de ellas producto de diferentes señales intra o extracelulares, factores de transcripción (TGF-B, Snail, TWIST, Sox, Slug, ZEB1, entre otras) y proteínas involucradas (E-cadherina, integrina, vimentina, ocludinas y claudinas).

Transition mesenchymal epithelium (EMT) is a process composed of different phases where an epithelial cell acquires a mesenchymal phenotype. Among the changes involved are: loss of cellular polarity, acquisition of a migratory capacity, invasive capacity, resistance to apoptosis, and increase in the production of components of the extracellular matrix. All these changes occur as a consequence of the activation and repression of genes involved with specific signaling pathways related to this event. EMT is related to physiological and pathological processes such as cancer. It consists of three phases: A phase of non-migratory cells, pre-migratory cells and migratory cells; (TGF-B, Snail, TWIST, Sox, Slug, ZEB1 among others), and proteins involved (E-cadherin, integrin, vimentin, occludins and claudins).

Systems biology study of mucopolysaccharidosis using a human metabolic reconstruction network.

Mucopolysaccharidosis (MPS) is a group of lysosomal storage diseases (LSD), characterized by the deficiency of a lysosomal enzyme responsible for the degradation of glycosaminoglycans (GAG). This deficiency leads to the lysosomal accumulation of partially degraded GAG. Nevertheless, deficiency of a single lysosomal enzyme has been associated with impairment in other cell mechanism, such as apoptosis and redox balance. Although GAG analysis represents the main biomarker for MPS diagnosis, it has several limitations that can lead to a misdiagnosis, whereby the identification of new biomarkers represents an important issue for MPS. In this study, we used a system biology approach, through the use of a genome-scale human metabolic reconstruction to understand the effect of metabolism alterations in cell homeostasis and to identify potential new biomarkers in MPS. In-silico MPS models were generated by silencing of MPS-related enzymes, and were analyzed through a flux balance and variability analysis. We found that MPS models used approximately 2286 reactions to satisfy the objective function. Impaired reactions were mainly involved in cellular respiration, mitochondrial process, amino acid and lipid metabolism, and ion exchange. Metabolic changes were similar for MPS I and II, and MPS III A to C; while the remaining MPS showed unique metabolic profiles. Eight and thirteen potential high-confidence biomarkers were identified for MPS IVB and VII, respectively, which were associated with the secondary pathologic process of LSD. In vivo evaluation of predicted intermediate confidence biomarkers (ß-hexosaminidase and ß-glucoronidase) for MPS IVA and VI correlated with the in-silico prediction. These results show the potential of a computational human metabolic reconstruction to understand the molecular mechanisms this group of diseases, which can be used to identify new biomarkers for MPS.