Blockade of a Laminin-411-Notch Axis with CRISPR/Cas9 or a Nanobioconjugate Inhibits Glioblastoma Growth through Tumor-Microenvironment Cross-talk.

There is an unmet need for the treatment of glioblastoma multiforme (GBM). The extracellular matrix, including laminins, in the tumor microenvironment is important for tumor invasion and progression. In a panel of 226 patient brain glioma samples, we found a clinical correlation between the expression of tumor vascular laminin-411 (α4ß1γ1) with higher tumor grade and with expression of cancer stem cell (CSC) markers, including Notch pathway members, CD133, Nestin, and c-Myc. Laminin-411 overexpression also correlated with higher recurrence rate and shorter survival of GBM patients. We also showed that depletion of laminin-411 α4 and ß1 chains with CRISPR/Cas9 in human GBM cells led to reduced growth of resultant intracranial tumors in mice and significantly increased survival of host animals compared with mice with untreated cells. Inhibition of laminin-411 suppressed Notch pathway in normal and malignant human brain cell types. A nanobioconjugate potentially suitable for clinical use and capable of crossing blood-brain barrier was designed to block laminin-411 expression. Nanobioconjugate treatment of mice carrying intracranial GBM significantly increased animal survival and inhibited multiple CSC markers, including the Notch axis. This study describes an efficient strategy for GBM treatment via targeting a critical component of the tumor microenvironment largely independent of heterogeneous genetic mutations in glioblastoma.Significance: Laminin-411 expression in the glioma microenvironment correlates with Notch and other cancer stem cell markers and can be targeted by a novel, clinically translatable nanobioconjugate to inhibit glioma growth.

Use of cylindrical coordinates to localize prostate cancers on MRI and prostatectomy pathology.

PURPOSE: To describe and test a quantitative system for designating prostate tumor location on magnetic resonance imaging (MRI) and prostatectomy. A system for describing tumor location will facilitate research correlating MRI and pathology. MATERIALS AND METHODS: The prostate cylindrical coordinate (PCC) system was developed for locating prostate tumors using 3 coordinate values. The 3 coordinate values include the angular location centered on the urethra, the radial distance to the periphery and the long axis from apex to base. To evaluate this system, 26 tumors were identified where the prostate cancer was noted by both the radiologist and the pathologist. PCC values were assigned independently to MRI lesions and corresponding tumors. Intraclass correlation coefficient (ICC) was calculated to assess agreement between PCC assigned using MRI and pathology. The coordinates were used to calculate the average distance between the centers of the same lesion measured by MRI and pathology. RESULTS: Each of the cylindrical coordinates assigned by MRI and pathology were compared and there was no significant difference. The agreement was excellent, and the ICC was 0.70 (P<0.001) for the angular coordinate, 0.81 (P<0.001) for the radial distance, and 0.94 (P<0.001) for the long axis. Compared to pathology, lesions on MRI were significantly larger (1.17 vs. 0.86cm2, P<0.001) but there was strong agreement between the measurements on MRI and pathology (ICC = 0.89, P<0.001). The distance between the centers of the lesions measured on MRI and pathology was small (10.13mm, s.d. = 8.70). CONCLUSIONS: The PCC system quantitatively characterizes lesions seen on MRI and prostatectomy pathology with good agreement.

Covalent nano delivery systems for selective imaging and treatment of brain tumors.

Nanomedicine is a rapidly evolving form of therapy that holds a great promise for superior drug delivery efficiency and therapeutic efficacy than conventional cancer treatment. In this review, we attempt to cover the benefits and the limitations of current nanomedicines with special attention to covalent nano conjugates for imaging and drug delivery in the brain. The improvement in brain tumor treatment remains dismal despite decades of efforts in drug development and patient care. One of the major obstacles in brain cancer treatment is the poor drug delivery efficiency owing to the unique blood-brain barrier (BBB) in the CNS. Although various anti-cancer agents are available to treat tumors outside of the CNS, the majority fails to cross the BBB. In this regard, nanomedicines have increasingly drawn attention due to their multi-functionality and versatility. Nano drugs can penetrate BBB and other biological barriers, and selectively accumulate in tumor cells, while concurrently decreasing systemic toxicity.

Simultaneous blockade of interacting CK2 and EGFR pathways by tumor-targeting nanobioconjugates increases therapeutic efficacy against glioblastoma multiforme.

Glioblastoma multiforme (GBM) remains the deadliest brain tumor in adults. GBM tumors are also notorious for drug and radiation resistance. To inhibit GBMs more effectively, polymalic acid-based blood-brain barrier crossing nanobioconjugates were synthesized that are delivered to the cytoplasm of cancer cells and specifically inhibit the master regulator serine/threonine protein kinase CK2 and the wild-type/mutated epidermal growth factor receptor (EGFR/EGFRvIII), which are overexpressed in gliomas according to The Cancer Genome Atlas (TCGA) GBM database. Two xenogeneic mouse models bearing intracranial human GBMs from cell lines LN229 and U87MG that expressed both CK2 and EGFR at different levels were used. Simultaneous knockdown of CK2α and EGFR/EGFRvIII suppressed their downstream prosurvival signaling. Treatment also markedly reduced the expression of programmed death-ligand 1 (PD-L1), a negative regulator of cytotoxic lymphocytes. Downregulation of CK2 and EGFR also caused deactivation of heat shock protein 90 (Hsp90) co-chaperone Cdc37, which may suppress the activity of key cellular kinases. Inhibition of either target was associated with downregulation of the other target as well, which may underlie the increased efficacy of the dual nanobioconjugate that is directed against both CK2 and EGFR. Importantly, the single nanodrugs, and especially the dual nanodrug, markedly suppressed the expression of the cancer stem cell markers c-Myc, CD133, and nestin, which could contribute to the efficacy of the treatments. In both tumor models, the nanobioconjugates significantly increased (up to 2-fold) animal survival compared with the PBS-treated control group. The versatile nanobioconjugates developed in this study, with the abilities of anti-cancer drug delivery across biobarriers and the inhibition of key tumor regulators, offer a promising nanotherapeutic approach to treat GBMs, and to potentially prevent drug resistance and retard the recurrence of brain tumors.

Rosiglitazone-activated PPARγ induces neurotrophic factor-α1 transcription contributing to neuroprotection.

Brain peroxisome proliferator-activated receptor gamma (PPARγ), a member of the nuclear receptor superfamily of ligand-dependent transcription factors, is involved in neuroprotection. It is activated by the drug rosiglitazone, which then can increase the pro-survival protein B-cell lymphoma 2 (BCL-2), to mediate neuroprotection. However, the mechanism underlying this molecular cascade remains unknown. Here, we show that the neuroprotective protein neurotrophic factor-α1 (NF-α1), which also induces the expression of BCL-2, has a promoter that contains PPARγ-binding sites that are activated by rosiglitazone. Treatment of Neuro2a cells and primary hippocampal neurons with rosiglitazone increased endogenous NF-α1 expression and prevented H2 O2 -induced cytotoxicity. Concomitant with the increase in NF-α1, BCL-2 was also increased in these cells. When siRNA against NF-α1 was used, the induction of BCL-2 by rosiglitazone was prevented, and the neuroprotective effect of rosiglitazone was reduced. These results demonstrate that rosiglitazone-activated PPARγ directly induces the transcription of NF-α1, contributing to neuroprotection in neurons. We proposed the following cascade for neuroprotection against oxidative stress by rosiglitazone: Rosiglitazone enters the neuron and binds to peroxisome proliferator-activated receptor gamma (PPARγ) in the nucleus. The PPARγ-rosiglitazone complex binds to the neurotrophic factor-α1 (NF-α1) promoter and activates the transcription of NF-α1 mRNA which is then translated to the protein. NF-α1 is the secreted, binds to a cognate receptor and activates the extracellular signal-regulated kinases (ERK) pathway. This in turn enhances the expression of the pro-survival protein, B-cell lymphoma 2 (BCL-2) and inhibition of caspase 3 (Csp-3) to mediate neuroprotection under oxidative stress. Akt, protein kinase B (PKB).