Interstitial chemotherapy plays a pivotal role in the treatment of glioblastoma multiforme (GBM), an aggressive form of primary brain cancer, by enhancing drug biodistribution to the tumor and avoiding systemic toxicities. The use of new polymer structures that extend the release of cytotoxic agents may therefore increase survival and prevent recurrence. A novel core-sheath fiber loaded with the drug carmustine (BCNU) was evaluated in an in vivo brain tumor model. Three-dimensional discs were formed from coaxially electrospun fiber membranes and in vitro BCNU release kinetics were measured. In vivo survival was assessed following implantation of discs made of compressed core-sheath fibers (NanoMesh) either concurrently with or five days after intracranial implantation of 9L gliosarcoma. Co-implantation of NanoMesh and 9L gliosarcoma resulted in statistically significant long-term survival (>150 days). Empty control NanoMesh confirmed the safety of these novel implants. Similarly, Day 5 studies showed significant median, overall, and long-term survival rates, suggesting optimal control of tumor growth, confirmed with histological and immunohistochemical analyses. Local chemotherapy by means of biodegradable NanoMesh implants is a new treatment paradigm for the treatment for brain tumors. Drug delivery with coaxial core-sheath structures benefits from high drug loading, controlled long-term release kinetics, and slow polymer degradation. This represents a promising evolution for the current treatment of GBM.

Retrobulbar fat deposits surround the posterior retina and optic nerve head, but their function and origin are obscure. We report that mouse retrobulbar fat is a neural crest-derived tissue histologically and transcriptionally resembles interscapular brown fat. In contrast, human retrobulbar fat closely resembles white adipose tissue. Retrobulbar fat is also brown in other rodents, which are typically housed at temperatures below thermoneutrality, but is white in larger animals. We show that retrobulbar fat in mice housed at thermoneutral temperature show reduced expression of the brown fat marker Ucp1, and histological properties intermediate between white and brown fat. We conclude that retrobulbar fat can potentially serve as a site of active thermogenesis, that this capability is both temperature and species-dependent, and that this may facilitate regulation of intraocular temperature.

Keratoconus is a highly prevalent (1 in 2000), genetically complex and multifactorial, degenerative disease of the cornea whose pathogenesis and underlying transcriptomic changes are poorly understood. To identify disease-specific changes and gene expression networks, we performed next generation RNA sequencing from individual corneas of two distinct patient populations - one from the Middle East, as keratoconus is particularly severe in this group, and the second from an African American population in the United States. We conducted a case: control RNA sequencing study of 7 African American, 12 Middle Eastern subjects, and 7 controls. A Principal Component Analysis of all expressed genes was used to ascertain differences between samples. Differentially expressed genes were identified using Cuffdiff and DESeq2 analyses, and identification of over-represented signaling pathways by Ingenuity Pathway Analysis. Although separated by geography and ancestry, key commonalities in the two patient transcriptomes speak of disease - intrinsic gene expression networks. We identified an overwhelming decrease in the expression of anti-oxidant genes regulated by NRF2 and those of the acute phase and tissue injury response pathways, in both patient groups. Concordantly, NRF2 immunofluorescence staining was decreased in patient corneas, while KEAP1, which helps to degrade NRF2, was increased. Diminished NRF2 signaling raises the possibility of NRF2 activators as future treatment strategies in keratoconus. The African American patient group showed increases in extracellular matrix transcripts that may be due to underlying profibrogenic changes in this group. Transcripts increased across all patient samples include Thrombospondin 2 (THBS2), encoding a matricellular protein, and cellular proteins, GAS1, CASR and OTOP2, and are promising biomarker candidates. Our approach of analyzing transcriptomic data from different populations and patient groups will help to develop signatures and biomarkers for keratoconus subtypes. Further, RNA sequence data on individual patients obtained from multiple studies may lead to a core keratoconus signature of deregulated genes and a better understanding of its pathogenesis.

Members of the miR-125 family are strongly expressed in several tissues, particularly brain, but may be dysregulated in cancer including adult and pediatric glioma. In this study, miR-125 members were downregulated in pilocytic astrocytoma (PA) as a group compared to non-neoplastic brain in the Agilent platform. In the Nanostring platform, miR-125 members were downregulated primarily in pleomorphic xanthoastrocytomas and gangliogliomas. Using CISH for miR-125b, highest levels of expression were present in grade II tumors (11/33, 33% grade II tumors with 3+ expression compared to 3/70, 4% grade I tumors) (p < 0.001). When focusing on the two histologic subgroups with the largest number of samples, PA and diffuse astrocytoma (DA), the highest expression levels were present in DA, in comparison with the PA group (p = 0.01). Overexpression of miR-125b in pediatric low grade glioma (PLGG) derived cell lines (Res186, Res259, and BT66) resulted in decreased growth and invasion, as well as apoptosis. Additionally, miR-125b overexpression in BT66 resulted in senescence. These findings suggest that miR-125 is frequently underexpressed in PLGG, and overexpression results in a decrease in cell growth and induction of apoptosis, findings that deserve further investigation given its potential as a novel therapeutic strategy for PLGG.

Tumor progression, limited efficacy of current standard treatments, and the rise in patient mortality are associated with gene expression caused by the synergistic action of intratumoral hypoxia and HIF-1α activation. For this reason, recent investigations have focused on HIF-targeting therapeutic agents, with encouraging preclinical and clinical results in solid tumors. Here we describe the efficacy of a HIF-1α inhibitor, Acriflavine, and demonstrate its potency against brain cancer. This safe antibacterial dye induces cell death and apoptosis in several glioma cell lines, targets HIF-1α-mediated pathways, and decreases the level of PGK1, VEGF and HIF-1α in vitro and in vivo. Administered locally via biodegradable polymers, Acriflavine provides significant benefits in survival resulting in nearly 100% long term survival, confirmed by MRI and histological analyses. This study reports preclinical evidence that this safe, small molecule can contribute to brain tumor therapy and highlights the significance of HIF-1α-targeting molecules.