We describe the rational design of a novel class of magnetic resonance imaging (MRI) contrast agents with engineered proteins (CAi.CD2, i = 1, 2,..., 9) chelated with gadolinium. The design of protein-based contrast agents involves creating high-coordination Gd(3+) binding sites in a stable host protein using amino acid residues and water molecules as metal coordinating ligands. Designed proteins show strong selectivity for Gd(3+) over physiological metal ions such as Ca(2+), Zn(2+), and Mg(2+). These agents exhibit a 20-fold increase in longitudinal and transverse relaxation rate values over the conventional small-molecule contrast agents, e.g., Gd-DTPA (diethylene triamine pentaacetic acid), used clinically. Furthermore, they exhibit much stronger contrast enhancement and much longer blood retention time than Gd-DTPA in mice. With good biocompatibility and potential functionalities, these protein contrast agents may be used as molecular imaging probes to target disease markers, thereby extending applications of MRI.
These results suggest that serum miR-10b may be a useful biomarker for the identification of bone metastatic breast cancer.
Osteogenesis imperfecta (OI) is a rare hereditary skeletal dysplasia, characterized by recurrent fractures and bone deformity. This study presents a clinical characterization and mutation analysis of 668 patients, aiming to establish the mutation spectrum and to elucidate genotype-phenotype correlations in Chinese OI patients. We identified 274 sequence variants (230 in type I collagen encoding genes and 44 in noncollagen genes), including 102 novel variants, in 340 probands with a detection rate of 90%. Compared with 47 loss-of-function variants detected in COL1A1, neither nonsense nor frameshift variants were found in COL1A2 (p < 0.0001). The major cause of autosomal recessive OI was biallelic variants in WNT1 (56%, 20/36). It is noteworthy that three genomic rearrangements, including one gross deletion and one gross duplication in COL1A1 as well as one gross deletion in FKBP10, were detected in this study. Of ten individuals with glycine substitutions that lie towards the Nterminal end of the triple-helical region of the α1(I) chain, none exhibited hearing loss, suggesting a potential genotype-phenotype correlation. The findings in this study expanded the mutation spectrum and identified novel correlations between genotype and phenotype in Chinese OI patients.
We report that a urine based classifier panel of 4 methylation biomarkers predicts disease progression in patients on active surveillance. Once validated in independent active surveillance cohorts, these promising biomarkers may help establish a less invasive method to monitor patients on active surveillance programs.
Purpose Liquid biopsies that noninvasively detect molecular correlates of aggressive prostate cancer (PCa) could be used to triage patients, reducing the burdens of unnecessary invasive prostate biopsy and enabling early detection of high-risk disease. DNA hypermethylation is among the earliest and most frequent aberrations in PCa. We investigated the accuracy of a six-gene DNA methylation panel (Epigenetic Cancer of the Prostate Test in Urine [epiCaPture]) at detecting PCa, high-grade (Gleason score greater than or equal to 8) and high-risk (D’Amico and Cancer of the Prostate Risk Assessment] PCa from urine. Patients and Methods Prognostic utility of epiCaPture genes was first validated in two independent prostate tissue cohorts. epiCaPture was assessed in a multicenter prospective study of 463 men undergoing prostate biopsy. epiCaPture was performed by quantitative methylation-specific polymerase chain reaction in DNA isolated from prebiopsy urine sediments and evaluated by receiver operating characteristic and decision curves (clinical benefit). The epiCaPture score was developed and validated on a two thirds training set to one third test set. Results Higher methylation of epiCaPture genes was significantly associated with increasing aggressiveness in PCa tissues. In urine, area under the receiver operating characteristic curve was 0.64, 0.86, and 0.83 for detecting PCa, high-grade PCa, and high-risk PCa, respectively. Decision curves revealed a net benefit across relevant threshold probabilities. Independent analysis of two epiCaPture genes in the same clinical cohort provided analytical validation. Parallel epiCaPture analysis in urine and matched biopsy cores showed added value of a liquid biopsy. Conclusion epiCaPture is a urine DNA methylation test for high-risk PCa. Its tumor specificity out-performs that of prostate-specific antigen (greater than 3 ng/mL). Used as an adjunct to prostate-specific antigen, epiCaPture could aid patient stratification to determine need for biopsy.
Bone marrow stromal cells (MSCs) have been shown to differentiate into various lineage cells including neural cells in vitro and in vivo. We therefore examined whether MSCs can differentiate into Schwann cells in injured peripheral nerves, After cultured in vitro, PKH-67-labeled MSCs were injected into the mechanically injured rat sciatic nerves. Three weeks after injection, immunofluorescent examinations were carried out. MSCs had been incorporated around the injured nerves and differentiated into Schwann cells. MSCs had accumulated mainly in the epineurium around the injured nerve. The incorporated cells partially expressed GFAP, S-100, and P75. These results confirmed the possibility that MSCs have the ability to differentiate into Schwann cells, and that injection of MSCs into the injured peripheral nerve would help repair damaged nerve.
Background The development of noninvasive tests for the early detection of aggressive prostate tumors is a major unmet clinical need. miRNAs are promising noninvasive biomarkers: they play essential roles in tumorigenesis, are stable under diverse analytical conditions, and can be detected in body fluids. Methods We measured the longitudinal stability of 673 miRNAs by collecting serial urine samples from 10 patients with localized prostate cancer. We then measured temporally stable miRNAs in an independent training cohort (n = 99) and created a biomarker predictive of Gleason grade using machine-learning techniques. Finally, we validated this biomarker in an independent validation cohort (n = 40). Results We found that each individual has a specific urine miRNA fingerprint. These fingerprints are temporally stable and associated with specific biological functions. We identified seven miRNAs that were stable over time within individual patients and integrated them with machine-learning techniques to create a novel biomarker for prostate cancer that overcomes interindividual variability. Our urine biomarker robustly identified high-risk patients and achieved similar accuracy as tissue-based prognostic markers (area under the receiver operating characteristic = 0.72, 95% confidence interval = 0.69 to 0.76 in the training cohort, and area under the receiver operating characteristic curve = 0.74, 95% confidence interval = 0.55 to 0.92 in the validation cohort). Conclusions These data highlight the importance of quantifying intra- and intertumoral heterogeneity in biomarker development. This noninvasive biomarker may usefully supplement invasive or expensive radiologic- and tissue-based assays.
Nerve regeneration requires not only an autologous, allogenous, or biodegradable scaffolding, but additional interactions with regeneration-promoting Schwann cells. Considering the pluripotency of bone marrow stromal cells into different lineages, the authors compared biodegradable conduits with the application of cultured Schwann cells and bone marrow stromal cells in a rat sciatic injury model. Simple conduit bridging served as controls. Electrophysiologic evaluation and histologic morphometrical analysis were performed after 6 weeks; both groups with cultured cells showed a statistically significantly higher number of axons, more well-shaped remyelinated axons, and an advance in clinical functional recovery (SFI) than the simple conduit-bridging group. Confocal microscopy found that bone marrow stromal cells adopted the Schwann-cell phenotype, expressing S100 protein. Considering the ease of aspiration and greater resource of bone marrow stromal cells, the implantation of a biodegradable conduit with cultured bone marrow stromal cells was capable of presenting an alternative to conduits with Schwann cells for bridging nerve defects.
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