Clinical Advances in Triple Negative Breast Cancer Treatment: Focus on Poly (L-lactide-coglycolide) Nanoparticles.

Triple negative breast cancer (TNBC) is the most aggressive type of breast cancer and is associated with high probability of metastasis and poor prognosis. Chemotherapeutics and surgery remain the most common options for TNBC patients; however, chemotherapeutic resistance and relapse of tumors limit the progression free survival and patient life span. This review provides an overview of recent chemotherapeutics that are in clinical trial, and the combination of drugs that are being investigated to overcome the drug resistance and to improve patient survival in different molecular subtypes of TNBCs. Nanotherapeutics have emerged as a promising platform for TNBC treatment and aim to improve the selectivity and solubility of drugs, reduce systemic side effects, and overcome multi-drug resistance. The study explores the role of nanoparticles for TNBC treatment and summarizes the types of nanoparticles that are in clinical trials. Poly(L-lactide-co-glycolide) (PLGA) is the most studied polymeric carrier for drug delivery and for TNBC treatment in research and in clinics. This review is about providing recent advancements in PLGA nanotherapeutic formulations and their application to help treat TNBC. Some background on current chemotherapies and pathway inhibitors is provided so that the readers are aware of what is currently considered for TNBC. Some of the pathway inhibitors may also be of importance for nanotherapeutics development. SIGNIFICANCE STATEMENT: This minireview summarizes the progress on chemotherapeutics and nanoparticle delivery for treatment of TNBC and specifically highlights the lead compounds that are in clinical trials.

A tale of two multi-focal therapies for glioblastoma: An antibody targeting ELTD1 and nitrone-based OKN-007.

Glioblastoma (GBM) is the most common primary malignant brain tumour in adults. Despite a multimodal treatment response, survival for GBM patients remains between 12 and 15 months. Anti-ELTD1 antibody therapy is effective in decreasing tumour volumes and increasing animal survival in an orthotopic GBM xenograft. OKN-007 is a promising chemotherapeutic agent that is effective in various GBM animal models and is currently in two clinical trials. In this study, we sought to compare anti-ELTD1 and OKN-007 therapies, as single agents and combined, against bevacizumab, a commonly used therapeutic agent against GBM, in a human G55 xenograft mouse model. MRI was used to monitor tumour growth, and immunohistochemistry (IHC) was used to assess tumour markers for angiogenesis, cell migration and proliferation in the various treatment groups. OKN and anti-ELTD1 treatments significantly increased animal survival, reduced tumour volumes and normalized the vasculature. Additionally, anti-ELTD1 was also shown to significantly affect other pro-angiogenic factors such as Notch1 and VEGFR2. Unlike bevacizumab, anti-ELTD1 and OKN treatments did not induce a pro-migratory phenotype within the tumours. Anti-ELTD1 treatment was shown to be as effective as OKN therapy. Both OKN and anti-ELTD1 therapies show promise as potential single-agent multi-focal therapies for GBM patients.

Optimized monoclonal antibody treatment against ELTD1 for GBM in a G55 xenograft mouse model.

Glioblastoma is an aggressive brain tumour found in adults, and the therapeutic approaches available have not significantly increased patient survival. Recently, we discovered that ELTD1, an angiogenic biomarker, is highly expressed in human gliomas. Polyclonal anti-ELTD1 treatments were effective in glioma pre-clinical models, however, pAb binding is potentially promiscuous. Therefore, the aim of this study was to determine the effects of an optimized monoclonal anti-ELTD1 treatment in G55 xenograft glioma models. MRI was used to assess the effects of the treatments on animal survival, tumour volumes, perfusion rates and binding specificity. Immunohistochemistry and histology were conducted to confirm and characterize microvessel density and Notch1 levels, and to locate the molecular probes. RNA-sequencing was used to analyse the effects of the mAb treatment. Our monoclonal anti-ELTD1 treatment significantly increased animal survival, reduced tumour volumes, normalized the vasculature and showed higher binding specificity within the tumour compared with both control- and polyclonal-treated mice. Notch1 positivity staining and RNA-seq results suggested that ELTD1 has the ability to interact with and interrupt Notch1 signalling. Although little is known about ELTD1, particularly about its ligand and pathways, our data suggest that our monoclonal anti-ELTD1 antibody is a promising anti-angiogenic therapeutic in glioblastomas.

OKlahoma Nitrone-007: novel treatment for diffuse intrinsic pontine glioma.

BACKGROUND: Diffuse intrinsic pontine glioma (DIPG) is the most common brainstem cancer in childhood. This rapidly progressing brainstem glioma holds a very dismal prognosis with median survival of less than 1 year. Despite extensive research, no significant therapeutic advancements have been made to improve overall survival in DIPG patients. METHODS: Here, we used an orthotopic xenograft pediatric DIPG (HSJD-DIPG-007) mouse model to monitor the effects of anti-cancer agent, OKlahoma Nitrone-007 (OKN-007), as an inhibitor of tumor growth after 28 days of treatment. Using magnetic resonance imaging (MRI), we confirmed the previously described efficacy of LDN-193189, a known activin A receptor, type I (ACVR1) inhibitor, in decreasing tumor burden and found that OKN-007 was equally efficacious. RESULTS: After 28 days of treatment, the tumor volumes were significantly decreased in OKN-007 treated mice (p < 0.01). The apparent diffusion coefficient (ADC), as a measure of tissue structural alterations, was significantly decreased in OKN-007 treated tumor-bearing mice (p < 0.0001). Histological analysis also showed a significant decrease in CD34 expression, essential for angiogenesis, of OKN-007 treated mice (p < 0.05) compared to LDN-193189 treated mice. OKN-007-treated mice also significantly decreased protein expression of the human nuclear antigen (HNA) (p < 0.001), ACVR1 (p < 0.0001), and c-MET (p < 0.05), as well as significantly increased expression of cleaved caspase 3 (p < 0.001) and histone H3 K27-trimethylation (p < 0.01), compared to untreated mouse tumors. CONCLUSIONS: With the dismal prognosis and limited effective chemotherapy available for DIPG, there is significant room for continued research studies, and OKN-007 merits further exploration as a therapeutic agent.

Analysis of retention of gadolinium by brain, bone, and blood following linear gadolinium-based contrast agent administration in rats with experimental sepsis.

PURPOSE: It is important to identify populations that may be vulnerable to the brain deposition of gadolinium (Gd) from MRI contrast agents. At intervals from 24 hours to 6 weeks following injection of a linear Gd contrast agent, the brain, blood and bone content of Gd were compared between control rats and those with experimental endotoxin-induced sepsis that results in neuroinflammation and blood-brain barrier disruption. METHODS: Male rats were injected intraperitoneally with 10 mg/kg lipopolysaccharide. Control animals received no injection. Twenty-four hours later, 0.2 mmol/kg of gadobenate dimeglumine was injected intravenously. Brain, blood, and bone Gd levels were measured at 24 hours, 1 week, 3 weeks, and 6 weeks by inductively coupled plasma mass spectroscopy. RESULTS: Blood Gd decreased rapidly between 24 hours and 1 week, and thereafter was undetectable, with no significant difference between lipopolysaccharide and control rats. Brain levels of Gd were significantly higher (4.29-2.36-fold) and bone levels slightly higher (1.35-1.11-fold) in lipopolysaccharide than control rats at all time points with significant retention at 6 weeks. CONCLUSION: Experimental sepsis results in significantly higher deposition of Gd in the brain and bone in rats. While blood Gd clears rapidly, brain and bone retained substantial Gd even at 6 weeks following contrast injection.

Immunologically modified MnFe2O4 nanoparticles to synergize photothermal therapy and immunotherapy for cancer treatment.

Immunotherapy has been a promising candidate for cancer treatment. The combination of photothermal therapy (PTT) and immunotherapy have shown to cause tumor ablation and induce host immune response. However, this strategy is often hampered by a limited immune response and undesirable immunosuppression. In this work, we developed an immunologically modified nanoplatform, using ovalbumin (OVA)-coated PEGylated MnFe2O4 nanoparticles (NPs) loaded with R837 immunoadjuvant (R837-OVA-PEG-MnFe2O4 NPs) to synergize PTT and immunotherapy for the treatment of breast cancer. The designed R837-OVA-PEG-MnFe2O4 NPs are able to elicit significant immune responses in vitro and in vivo. MnFe2O4 NPs also allowed for a reduction of systemic immunosuppression through downregulation of M2-associated cytokines. More importantly, the R837-OVA-PEG-MnFe2O4 NPs under laser irradiation effectively inhibited tumor growth and prevented lung metastases, leading to a prolonged survival time and improved survival rate. In addition, the designed multitasking MnFe2O4 NPs showed as a good contrast agent for magnetic resonance (MR) imaging to detect orthotopic breast tumor in vivo. Our work provides a novel strategy for combined PTT and improved immunotherapy in the treatment of breast and other metastatic cancers.

A Feasibility Study to Determine Whether Clinical Contrast Enhanced Magnetic Resonance Imaging can Detect Increased Bladder Permeability in Patients with Interstitial Cystitis.

PURPOSE: Interstitial cystitis/bladder pain syndrome is a bladder pain disorder associated with voiding symptomatology and other systemic chronic pain disorders. Currently diagnosing interstitial cystitis/bladder pain syndrome is complicated as patients present with a wide range of symptoms, physical examination findings and clinical test responses. One hypothesis is that interstitial cystitis symptoms arise from increased bladder permeability to urine solutes. This study establishes the feasibility of using contrast enhanced magnetic resonance imaging to quantify bladder permeability in patients with interstitial cystitis. MATERIALS AND METHODS: Permeability alterations in bladder urothelium were assessed by intravesical administration of the magnetic resonance imaging contrast agent Gd-DTPA (Gd-diethylenetriaminepentaacetic acid) in a small cohort of patients. Magnetic resonance imaging signal intensity in patient and control bladders was compared regionally and for entire bladders. RESULTS: Quantitative assessment of magnetic resonance imaging signal intensity indicated a significant increase in signal intensity in anterior bladder regions compared to posterior regions in patients with interstitial cystitis (p <0.01) and significant increases in signal intensity in anterior bladder regions (p <0.001). Kurtosis (shape of probability distribution) and skewness (measure of probability distribution asymmetry) were associated with contrast enhancement in total bladders in patients with interstitial cystitis vs controls (p <0.05). Regarding symptomatology interstitial cystitis cases differed significantly from controls on the SF-36®, PUF (Pelvic Pain and Urgency/Frequency) and ICPI (Interstitial Cystitis Problem Index) questionnaires with no overlap in the score range in each group. ICSI (Interstitial Cystitis Symptom Index) differed significantly but with a slight overlap in the range of scores. CONCLUSIONS: Data suggest that contrast enhanced magnetic resonance imaging provides an objective, quantifiable measurement of bladder permeability that could be used to stratify bladder pain patients and monitor therapy.

Immuno-spin trapping from biochemistry to medicine: advances, challenges, and pitfalls. Focus on protein-centered radicals.

BACKGROUND: Immuno-spin trapping (IST) is based on the reaction of a spin trap with a free radical to form a stable nitrone adduct, followed by the use of antibodies, rather than traditional electron paramagnetic resonance spectroscopy, to detect the nitrone adduct. IST has been successfully applied to mechanistic in vitro studies, and recently, macromolecule-centered radicals have been detected in models of drug-induced agranulocytosis, hepatotoxicity, cardiotoxicity, and ischemia/reperfusion, as well as in models of neurological, metabolic and immunological diseases. SCOPE OF THE REVIEW: To critically evaluate advances, challenges, and pitfalls as well as the scientific opportunities of IST as applied to the study of protein-centered free radicals generated in stressed organelles, cells, tissues and animal models of disease and exposure. MAJOR CONCLUSIONS: Because the spin trap has to be present at high enough concentrations in the microenvironment where the radical is formed, the possible effects of the spin trap on gene expression, metabolism and cell physiology have to be considered in the use of IST and in the interpretation of results. These factors have not yet been thoroughly dealt with in the literature. GENERAL SIGNIFICANCE: The identification of radicalized proteins during cell/tissue response to stressors will help define their role in the complex cellular response to stressors and pathogenesis; however, the fidelity of spin trapping/immuno-detection and the effects of the spin trap on the biological system should be considered. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn.

Contrast enhanced magnetic resonance imaging as a diagnostic tool to assess bladder permeability and associated colon cross talk: preclinical studies in a rat model.

PURPOSE: Interstitial cystitis/painful bladder syndrome is a devastating disease associated with multiple symptoms. It is usually diagnosed based on pain, urgency and frequency in the absence of other known causes. To our knowledge there is no diagnostic test to date. MATERIALS AND METHODS: In a model of rats intravesically exposed to protamine sulfate we performed in vivo diagnostic contrast enhanced magnetic resonance imaging with intravesical administration of Gd-diethylenetriamine pentaacetic acid contrast medium via a catheter to visualize increased bladder urothelium permeability. Gd-diethylenetriamine pentaacetic acid was administered intravenously to visualize secondary tissue effects in the colon. RESULTS: Bladder urothelium and colon mucosa were assessed 24 hours after bladder protamine sulfate exposure. Enhanced contrast magnetic resonance imaging established bladder urothelium leakage of Gd-diethylenetriamine pentaacetic acid according to the change in magnetic resonance imaging signal intensity in rats exposed to protamine sulfate vs controls (mean ± SD 399.7% ± 68.7% vs 39.2% ± 12.2%, p < 0.0001) as well as colon related uptake of contrast agent (mean 65.2% ± 17.1% vs 20.8% ± 9.8%, p < 0.01) after bladder protamine sulfate exposure. The kinetics of Gd-diethylenetriamine pentaacetic acid uptake and excretion were also assessed during 20 minutes of bladder and 30 minutes of colon exposure with increased signal intensity at 7 and 12 minutes, respectively. CONCLUSIONS: These preliminary studies indicate that contrast enhanced magnetic resonance imaging can be used to monitor primary bladder urothelium loss of permeability and secondary enhanced contrast medium in the colon mucosa. It can be considered a potential clinical diagnostic method for interstitial cystitis/painful bladder syndrome that involves loss of the permeability barrier. It can also be used to assess visceral organ cross talk.

A new anti-glioma therapy, AG119: pre-clinical assessment in a mouse GL261 glioma model.

BACKGROUND: High grade gliomas (HGGs; grades III and IV) are the most common primary brain tumors in adults, and their malignant nature ranks them fourth in incidence of cancer death. Standard treatment for glioblastomas (GBM), involving surgical resection followed by radiation and chemotherapy with temozolomide (TMZ) and the anti-angiogenic therapy bevacizumab, have not substantially improved overall survival. New therapeutic agents are desperately needed for this devastating disease. Here we study the potential therapeutic agent AG119 in a pre-clinical model for gliomas. AG119 possesses both anti-angiogenic (RTK inhibition) and antimicrotubule cytotoxic activity in a single molecule. METHODS: GL261 glioma-bearing mice were either treated with AG119, anti-VEGF (vascular endothelial growth factor) antibody, anti c-Met antibody or TMZ, and compared to untreated tumor-bearing mice. Animal survival was assessed, and tumor volumes and vascular alterations were monitored with morphological magnetic resonance imaging (MRI) and perfusion-weighted imaging, respectively. RESULTS: Percent survival of GL261 HGG-bearing mice treated with AG119 was significantly higher (p < 0.001) compared to untreated tumors. Tumor volumes (21-31 days following intracerebral implantation of GL261 cells) were found to be significantly lower for AG119 (p < 0.001), anti-VEGF (p < 0.05) and anti-c-Met (p < 0.001) antibody treatments, and TMZ-treated (p < 0.05) mice, compared to untreated controls. Perfusion data indicated that both AG119 and TMZ were able to reduce the effect of decreasing perfusion rates significantly (p < 0.05 for both), when compared to untreated tumors. It was also found that IC50 values for AG119 were much lower than those for TMZ in T98G and U251 cells. CONCLUSIONS: These data support further exploration of the anticancer activity AG119 in HGG, as this compound was able to increase animal survival and decrease tumor volumes in a mouse GL261 glioma model, and that AG119 is also not subject to methyl guanine transferase (MGMT) mediated resistance, as is the case with TMZ, indicating that AG119 may be potentially useful in treating resistant gliomas.

OKN-007 decreases tumor necrosis and tumor cell proliferation and increases apoptosis in a preclinical F98 rat glioma model.

BACKGROUND: Glioblastoma is a malignant World Health Organization (WHO) grade IV glioma with a poor prognosis in humans. New therapeutics are desperately required. The nitrone OKN-007 (2,4-disulfophenyl-PBN) has demonstrated effective anti-glioma properties in several rodent models and is currently being used as a clinical investigational drug for recurrent gliomas. We assessed the regional effects of OKN-007 in the tumor necrotic core and non-necrotic tumor parenchyma. METHODS: An F98 rat glioma model was evaluated using proton magnetic resonance spectroscopy ((1) H-MRS), diffusion-weighted imaging (DWI), morphological T2-weighted imaging (T2W) at 7 Tesla (30 cm-bore MRI), as well as immunohistochemistry and microarray assessments, at maximum tumor volumes (15-23 days following cell implantation in untreated (UT) tumors, and 18-35 days in OKN-007-treated tumors). RESULTS: (1) H-MRS data indicates that Lip0.9/Cho, Lip0.9/Cr, Lip1.3/Cho, and Lip1.3/Cr ratios are significantly decreased (all P < 0.05) in the OKN-007-treated group compared with UT F98 gliomas. The Cho/Cr ratio is also significantly decreased in the OKN-007-treated group compared with UT gliomas. In addition, the OKN-007-treated group demonstrates significantly lower ADC values in the necrotic tumor core and the nonnecrotic tumor parenchyma (both P < 0.05) compared with the UT group. There was also an increase in apoptosis following OKN-007 treatment (P < 0.01) compared with UT. CONCLUSION: OKN-007 reduces both necrosis and tumor cell proliferation, as well as seems to mediate multiple effects in different tumor regions (tumor necrotic core and nonnecrotic tumor parenchyma) in F98 gliomas, indicating the efficacy of OKN-007 as an anti-cancer agent and its potential clinical use.

Combined molecular MRI and immuno-spin-trapping for in vivo detection of free radicals in orthotopic mouse GL261 gliomas.

Free radicals play a major role in gliomas. By combining immuno-spin-trapping (IST) and molecular magnetic resonance imaging (mMRI), in vivo levels of free radicals were detected within mice bearing orthotopic GL261 gliomas. The nitrone spin trap DMPO (5,5-dimethyl pyrroline N-oxide) was administered prior to injection of an anti-DMPO probe (anti-DMPO antibody covalently bound to a bovine serum albumin (BSA)-Gd (gadolinium)-DTPA (diethylene triamine penta acetic acid)-biotin MRI contrast agent) to trap tumor-associated free radicals. mMRI detected the presence of anti-DMPO adducts by either a significant sustained increase (p<0.001) in MR signal intensity or a significant decrease (p<0.001) in T1 relaxation, measured as %T1 change. In vitro assessment of the anti-DMPO probe indicated a significant decrease (p<0.0001) in T1 relaxation in GL261 cells that were oxidatively stressed with hydrogen peroxide, compared to controls. The biotin moiety of the anti-DMPO probe was targeted with fluorescently-labeled streptavidin to locate the anti-DMPO probe in excised brain tissues. As a negative control a non-specific IgG antibody covalently bound to the albumin-Gd-DTPA-biotin construct was used. DMPO adducts were also confirmed in tumor tissue from animals administered DMPO, compared to non-tumor brain tissue. GL261 gliomas were found to have significantly increased malondialdehyde (MDA) protein adducts (p<0.001) and 3-nitrotyrosine (3-NT) (p<0.05) compared to normal mouse brain tissue, indicating increased oxidized lipids and proteins, respectively. Co-localization of the anti-DMPO probe with either 3-NT or 4-hydroxynonenal was also observed. This is the first report regarding the detection of in vivo levels of free radicals from a glioma model.

Neuroprotective treatment with the nitrone compound OKN-007 mitigates age-related muscle weakness in aging mice.

Despite the universal impact of sarcopenia on compromised health and quality of life in the elderly, promising pharmaceutical approaches that can effectively mitigate loss of muscle and function during aging have been limited. Our group and others have reported impairments in peripheral motor neurons and loss of muscle innervation as initiating factors in sarcopenia, contributing to mitochondrial dysfunction and elevated oxidative stress in muscle. We recently reported a reduction in α motor neuron loss in aging mice in response to the compound OKN-007, a proposed antioxidant and anti-inflammatory agent. In the current study, we asked whether OKN-007 treatment in wildtype male mice for 8-9 months beginning at 16 months of age can also protect muscle mass and function. At 25 months of age, we observed a reduction in the loss of whole-body lean mass, a reduced loss of innervation at the neuromuscular junction and well-preserved neuromuscular junction morphology in OKN-007 treated mice versus age matched wildtype untreated mice. The loss in muscle force generation in aging mice (~ 25%) is significantly improved with OKN-007 treatment. In contrast, OKN-007 treatment provided no protection in loss of muscle mass in aging mice. Mitochondrial function was improved by OKN-007 treatment, consistent with its potential antioxidative properties. Together, these exciting findings are the first to demonstrate that interventions through neuroprotection can be an effective therapy to counter aging-related muscle dysfunction.

In vivo characterization of several rodent glioma models by 1H MRS.

The assessment of metabolites by (1)H MRS can provide information regarding glioma growth, and may be able to distinguish between different glioma models. Rat C6, 9 L/LacZ, F98 and RG2, and mouse GL261, cells were intracerebrally implanted into the respective rodents, and human U87 MG cells were implanted into athymic rats. Ethyl-nitrosourea induction was also used. Glioma metabolites [e.g. total choline (tCho), total creatine (tCr), N-acetylaspartate (NAA), lactate (Lac), glutamine (Gln), glutamate (Glu), aspartate (Asp), guanosine (Gua), mobile lipids and macromolecules (MMs)] were assessed from (1)H MRS using point-resolved spectroscopy (PRESS) [TE = 24 ms; TR = 2500 ms; variable pulse power and optimized relaxation delay (VAPOR) water suppression; 27-µL and 8-µL voxels in rats and mice, respectively] at 7 T. Alterations in metabolites (Totally Automatic Robust Quantitation in NMR, TARQUIN) in tumors were characterized by increases in lipids (Lip1.3: 8.8-54.5 mM for C6 and GL261) and decreases in NAA (1.3-2.0 mM for RG2, GL261 and C6) and tCr (0.8-4.0 mM for F98, RG2, GL261 and C6) in some models. F98, RG2, GL261 and C6 models all showed significantly decreased (p < 0.05) tCr, and RG2, GL261 and C6 models all exhibited significantly decreased (p < 0.05) NAA. The RG2 model showed significantly decreased (p < 0.05) Gln and Glu, the C6 model significantly decreased (p < 0.05) Asp, and the F98 and U87 models significantly decreased (p < 0.05) Gua, compared with controls. The GL261 model showed the greatest alterations in metabolites. (1)H MRS was able to differentiate the metabolic profiles in many of the seven rodent glioma models assessed. These models are considered to resemble certain characteristics of human glioblastomas, and this study may be helpful in selecting appropriate models.

OKN-007 Alters Protein Expression Profiles in High-Grade Gliomas: Mass Spectral Analysis of Blood Sera.

Current therapies for high-grade gliomas, particularly glioblastomas (GBM), do not extend patient survival beyond 16-22 months. OKN-007 (OKlahoma Nitrone 007), which is currently in phase II (multi-institutional) clinical trials for GBM patients, and has demonstrated efficacy in several rodent and human xenograft glioma models, shows some promise as an anti-glioma therapeutic, as it affects most aspects of tumorigenesis (tumor cell proliferation, angiogenesis, migration, and apoptosis). Combined with the chemotherapeutic agent temozolomide (TMZ), OKN-007 is even more effective by affecting chemo-resistant tumor cells. In this study, mass spectrometry (MS) methodology ESI-MS, mass peak analysis (Leave One Out Cross Validation (LOOCV) and tandem MS peptide sequence analyses), and bioinformatics analyses (Ingenuity® Pathway Analysis (IPA®)), were used to identify up- or down-regulated proteins in the blood sera of F98 glioma-bearing rats, that were either untreated or treated with OKN-007. Proteins of interest identified by tandem MS-MS that were decreased in sera from tumor-bearing rats that were either OKN-007-treated or untreated included ABCA2, ATP5B, CNTN2, ITGA3, KMT2D, MYCBP2, NOTCH3, and VCAN. Conversely, proteins of interest in tumor-bearing rats that were elevated following OKN-007 treatment included ABCA6, ADAMTS18, VWA8, MACF1, and LAMA5. These findings, in general, support our previous gene analysis, indicating that OKN-007 may be effective against the ECM. These findings also surmise that OKN-007 may be more effective against oligodendrogliomas, other brain tumors such as medulloblastoma, and possibly other types of cancers.

Pharmacologic treatment with OKN-007 reduces alpha-motor neuron loss in spinal cord of aging mice.

Aging is associated with molecular and functional declines in multiple physiologic systems. We have previously reported age-related changes in spinal cord that included a decline in α-motor neuron numbers, axonal loss, and demyelination associated with increased inflammation and blood-spinal cord barrier (BSCB) permeability. These changes may influence other pathologies associated with aging, in particular loss of muscle mass and function (sarcopenia), which we and others have shown is accompanied by neuromuscular junction disruption and loss of innervation. Interventions to protect and maintain motor neuron viability and function in aging are currently lacking and could have a significant impact on improving healthspan. Here we tested a promising compound, OKN-007, that has known antioxidant, anti-inflammatory and neuroprotective properties, as a potential intervention in age-related changes in the spinal cord. OKN-007 is a low molecular weight disulfonyl derivative of (N-tert Butyl-α-phenylnitrone) (PBN) that can easily cross the blood-brain barrier. We treated middle age (16 month) wild-type male mice with OKN-007 in drinking water at a dose of 150 mg/kg/day until 25 months of age. OKN-007 treatment exerted a number of beneficial effects in the aging spinal cord, including a 35% increase in the number of lumbar α-motor neurons in OKN-treated old mice compared to age-matched controls. Brain spinal cord barrier permeability, which is increased in aging spinal cord, was also blunted by OKN-007 treatment. Age-related changes in microglia proliferation and activation are blunted by OKN-007, while we found no effect on astrocyte proliferation. Transcriptome analysis identified expression changes in a number of genes that are involved in neuronal structure and function and revealed a subset of genes whose changes in response to aging are reversed by OKN-007 treatment. Overall, our findings suggest that OKN-007 exerts neuroprotective and anti-inflammatory effects on the aging spinal cord and support OKN-007 as a potential therapeutic to improve α-motor neuron health.

XRN2 Is Required for Cell Motility and Invasion in Glioblastomas.

One of the major obstacles in treating brain cancers, particularly glioblastoma multiforme, is the occurrence of secondary tumor lesions that arise in areas of the brain and are inoperable while obtaining resistance to current therapeutic agents. Thus, gaining a better understanding of the cellular factors that regulate glioblastoma multiforme cellular movement is imperative. In our study, we demonstrate that the 5'-3' exoribonuclease XRN2 is important to the invasive nature of glioblastoma. A loss of XRN2 decreases cellular speed, displacement, and movement through a matrix of established glioblastoma multiforme cell lines. Additionally, a loss of XRN2 abolishes tumor formation in orthotopic mouse xenograft implanted with G55 glioblastoma multiforme cells. One reason for these observations is that loss of XRN2 disrupts the expression profile of several cellular factors that are important for tumor invasion in glioblastoma multiforme cells. Importantly, XRN2 mRNA and protein levels are elevated in glioblastoma multiforme patient samples. Elevation in XRN2 mRNA also correlates with poor overall patient survival. These data demonstrate that XRN2 is an important cellular factor regulating one of the major obstacles in treating glioblastomas and is a potential molecular target that can greatly enhance patient survival.

Iron oxide nanoparticles as a drug carrier reduce host immunosuppression for enhanced chemotherapy.

Chemotherapy is still regarded as the main modality for cancer treatment. However, it often suppresses the host immune system, resulting in limited therapeutic effects. It is desirable to design a novel chemotherapeutic agent to reduce the level of immunosuppression. Herein, we designed bovine serum albumin (BSA)-bioinspired iron oxide nanoparticles (IONPs) as a nanocarrier to load anticancer drug mitoxantrone (MTX) for enhanced chemotherapy of orthotopic breast cancer. The treatment with IONPs@BSA-MTX complexes increased CD3+CD4+ and CD3+CD8+ T lymphocytes more than free MTX. The complexes effectively restored the host immune system and exhibited a better anticancer efficacy than free MTX. It was worth noting that the BSA-inspired IONPs were a satisfactory contrast agent for magnetic resonance imaging of tumors and lymph nodes. Our work provides a novel strategy for enhanced chemotherapy with low levels of immunosuppression in the treatment of breast cancer and other cancers.

Synergistic interventional photothermal therapy and immunotherapy using an iron oxide nanoplatform for the treatment of pancreatic cancer.

Pancreatic cancer (PC) is the most lethal malignancy due to its high metastatic ability and poor drug permeability. Here, a synergized interventional photothermal-immunotherapy strategy was developed with imaging guidance and temperature monitoring by magnetic resonance imaging (MRI) technique, for the local treatment of metastatic PC. A tumor microenvironment (TME)-responsive nanoplatform was fabricated via coating of DSPE-PEG and indocyanine green (ICG) onto imiquimod (IMQ) loaded amorphous iron oxide nanoparticles (IONs). This unique nanoplatform, IMQ@IONs/ICG, served as a contrast agent for MRI, a drug delivery vehicle for IMQ and ICG, and a catalyst for TME modulation. The biodegradable IMQ@IONs/ICG was also non-toxic, and improved the penetration of the loaded drugs in PC to maximize thermal ablation of the tumor and minimize damage to the surrounding healthy tissue. For the treatment of aggressive, metastatic Panc02-H7 pancreatic tumors in mice, ION-assisted MRI was employed to guide the administration of interventional photothermal therapy (IPTT) and monitor the temperature distribution in target tumor and surrounding tissue during treatment. The local IPTT treatment induced in situ immunogenic cell death (ICD), and, in combination with released IMQ, triggered a strong antitumor immunity, leading to decreased metastases and increased CD8+ in spleen and tumors. With precise local treatment and monitoring, treated primary tumors were completely eradicated, mesentery metastases were dramatically reduced, and the survival time was significantly prolonged, without damage to normal tissue and systemic autoimmunity. Overall, this synergistic strategy represents a promising approach to treat PC with significant potential for clinical applications. STATEMENT OF SIGNIFICANCE: Pancreatic cancer (PC) is one of the most lethal malignancies because it is non-permeable to drugs and highly metastatic. In this study, we designed a tumor microenvironment-responsive amorphous iron oxide nanoplatform (ION) to co-deliver photothermal agent (ICG) and toll-like-receptor-7 agonist (IMQ). This biodegradable nanoplatform IMQ@IONs/ICG improved the penetration of the loaded drugs in pancreatic tumor. With MR imaging guidance and temperature monitoring, the precise interventional photothermal therapy on mouse Panc02-H7 orthotopic tumors releases tumor antigens to initiate tumor-special immune responses, amplified by the released IMQ. Our results demonstrate that IMQ@IONs/ICG overcomes the obstacle of drug delivery to pancreatic tumors, and when combined with photothermal therapy, induces a systemic antitumor immunity to control metastatic tumors.