Glioblastoma (GBM) resistance to therapy is the most common cause of tumor recurrence, which is ultimately fatal in 90% of the patients 5 years after initial diagnosis. A sub-population of tumor cells with stem-like properties, glioma stem cells (GSCs), is specifically endowed to resist or adapt to the standard therapies, leading to therapeutic resistance. Several anticancer agents, collectively termed redox therapeutics, act by increasing intracellular levels of reactive oxygen species (ROS). In this study, we investigated mechanisms underlying GSC response and resistance to cannabidiol (CBD), a non-toxic, non-psychoactive cannabinoid and redox modulator. Using primary GSCs, we showed that CBD induced a robust increase in ROS, which led to the inhibition of cell survival, phosphorylated (p)-AKT, self-renewal and a significant increase in the survival of GSC-bearing mice. Inhibition of self-renewal was mediated by the activation of the p-p38 pathway and downregulation of key stem cell regulators Sox2, Id1 and p-STAT3. Following CBD treatment, a subset of GSC successfully adapted, leading to tumor regrowth. Microarray, Taqman and functional assays revealed that therapeutic resistance was mediated by enhanced expression of the antioxidant response system Xc catalytic subunit xCT (SLC7A11 (solute carrier family 7 (anionic amino-acid transporter light chain), member 11)) and ROS-dependent upregulation of mesenchymal (MES) markers with concomitant downregulation of proneural (PN) markers, also known as PN–MES transition. This ‘reprogramming' of GSCs occurred in culture and in vivo and was partially due to activation of the NFE2L2 (NRF2 (nuclear factor, erythroid 2-like)) transcriptional network. Using genetic knockdown and pharmacological inhibitors of SLC7A11, we demonstrated that combining CBD treatment with the inhibition of system Xc resulted in synergistic ROS increase leading to robust antitumor effects, that is, decreased GSC survival, self-renewal, and invasion. Our investigation provides novel mechanistic insights into the antitumor activity of redox therapeutics and suggests that combinatorial approaches using small molecule modulators of ROS offer therapeutic benefits in GBM.

The D2HG product of IDH1 may increase neuronal activity by mimicking the activity of glutamate on the NMDA receptor, and IDH1 gliomas are more likely to cause seizures in patients. This has rapid translational implications for the personalized management of tumor-associated epilepsy, as targeted IDH1 inhibitors may improve antiepileptic therapy in patients with IDH1 gliomas.

BACKGROUND AND PURPOSEThe psychoactive cannabinoid Δ 9 -tetrahydrocannabinol (THC) and the non-psychoactive cannabinoid cannabidiol (CBD) can both reduce cancer progression, each through distinct anti-tumour pathways. Our goal was to discover a compound that could efficiently target both cannabinoid anti-tumour pathways. EXPERIMENTAL APPROACHTo measure breast cancer cell proliferation/viability and invasion, MTT and Boyden chamber assays were used. Modulation of reactive oxygen species (ROS) and apoptosis was measured using dichlorodihydrofluorescein and annexin/propidium iodide, respectively, in combination with cell flow cytometry. Changes in protein levels were evaluated using Western analysis. Orthotopic and i.v. mouse models of breast cancer metastasis were used to test the activity of cannabinoids in vivo. KEY RESULTSCBD reduced breast cancer metastasis in advanced stages of the disease as the direct result of down-regulating the transcriptional regulator Id1. However, this was associated with moderate increases in survival. We therefore screened for analogues that could co-target cannabinoid anti-tumour pathways (CBD-and THC-associated) and discovered the compound O-1663. This analogue inhibited Id1, produced a marked stimulation of ROS, up-regulated autophagy and induced apoptosis. Of all the compounds tested, it was the most potent at inhibiting breast cancer cell proliferation and invasion in culture and metastasis in vivo. CONCLUSIONS AND IMPLICATIONSO-1663 prolonged survival in advanced stages of breast cancer metastasis. Developing compounds that can simultaneously target multiple cannabinoid anti-tumour pathways efficiently may provide a novel approach for the treatment of patients with metastatic breast cancer.

The most common adult primary brain tumor, glioblastoma (GBM), is characterized by fifteen months median patient survival and has no clear etiology. We and others have identified the presence of human cytomegalovirus (HCMV) gene products endogenously expressed in GBM tissue and primary cells, with a subset of viral genes being consistently expressed in most samples. Among these viral genes, several have important oncomodulatory properties, regulating tumor stemness, proliferation, immune evasion, invasion and angiogenesis. These findings lead us to hypothesize that a specific HCMV gene signature may be associated with GBM pathogenesis. To investigate this hypothesis, we used glioma cell lines and primary glioma stem-like cells (GSC) infected with clinical and laboratory HCMV strains and measured relative viral gene expression levels along several time points up to 15 weeks post-infection. While HCMV gene expression was detected in several infected glioma lines through week 5 post-infection, only HCMV-infected GSC expressed viral gene products 15 weeks post-infection. Efficiency of infection across time was higher in GSC compared to cell lines. Importantly, HCMV-infected GSC outlived their uninfected counterparts, and this extended survival was paralleled by increased tumorsphere frequency and upregulation of stemness regulators, such as SOX2, p-STAT3, and BMX (a novel HCMV target identified in this study). Interleukin 6 (IL-6) treatment significantly upregulated HCMV gene expression in long-term infected glioma cultures, suggesting that pro-inflammatory signaling in the tumor milieu may further augment HCMV gene expression and subsequent tumor progression driven by viral-induced cellular signaling. Together, our data support a critical role for long-term, low-level HCMV infection in promoting survival, stemness, and proliferation of GSC that could significantly contribute to GBM pathogenesis.

The invasive behavior of glioblastoma is essential to its aggressive potential. Here, we show that pleckstrin homology domain interacting protein (PHIP), acting through effects on the force transduction layer of the focal adhesion complex, drives glioblastoma motility and invasion. Immunofluorescence analysis localized PHIP to the leading edge of glioblastoma cells, together with several focal adhesion proteins: vinculin (VCL), talin 1 (TLN1), integrin beta 1 (ITGB1), as well as phosphorylated forms of paxillin (pPXN) and focal adhesion kinase (pFAK). Confocal microscopy specifically localized PHIP to the force transduction layer, together with TLN1 and VCL. Immunoprecipitation revealed a physical interaction between PHIP and VCL. Targeted suppression of PHIP resulted in significant down-regulation of these focal adhesion proteins, along with zyxin (ZYX), and produced profoundly disorganized stress fibers. Live-cell imaging of glioblastoma cells overexpressing a ZYX-GFP construct demonstrated a role for PHIP in regulating focal adhesion dynamics. PHIP silencing significantly suppressed the migratory and invasive capacity of glioblastoma cells, partially restored following TLN1 or ZYX cDNA overexpression. PHIP knockdown produced substantial suppression of tumor growth upon intracranial implantation, as well as significantly reduced microvessel density and secreted VEGF levels. PHIP copy number was elevated in the classical glioblastoma subtype and correlated with elevated EGFR levels. These results demonstrate PHIP’s role in regulating the actin cytoskeleton, focal adhesion dynamics, and tumor cell motility, and identify PHIP as a key driver of glioblastoma migration and invasion.

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The primary objective of this study was to quantify cancer family caregiver (FCG) quality of life (QOL) in a Southern Albanian population and to determine whether differences exist between 4 domains of QOL (physical, psychological, social, and spiritual). This study also sought to compare QOL in our cohort to QOL in historical studies that used the same survey instrument, and to examine correlations between demographic characteristics and QOL to identify any high-risk groups. Methods: A sample of 40 FCGs was recruited at the Mary Potter Palliative Care Clinic in Korçe, Albania. Each participant completed the City of Hope Quality of Life (Family Version), a validated 37-question instrument that measures caregiver wellbeing in 4 domains: physical, psychological, social, and spiritual well-being. Results: There were no significant differences between the composite scores of the 4 QOL domains in our study. However, there were differences when comparing self-reported QOL between domains (''Rate your overall physical/psychological/social/spiritual well-being''). The QOL measured in our study was significantly lower than in 3 studies from the United States that used the same questionnaire. There were no significant correlations between demographic groups and QOL. Conclusions: This study examines the impact that the paucity of palliative services has on the QOL of Albanian cancer FCGs. Although there were no domains of QOL or demographic groups identified in our study that were faring significantly worse than others, the poor overall QOL provides further evidence to support the continued development of palliative services for both patients and family members in Albania.

Background Colorectal cancer (CRC) screening can improve health outcomes, but screening rates remain low across the US. Mailed fecal immunochemical tests (FIT) are an effective way to increase CRC screening rates, but is still underutilized. In particular, cost of FIT has not been explored in relation to practice characteristics, FIT selection, and screening outreach approaches. Methods We administered a cross-sectional survey drawing from prior validated measures to 252 primary care practices to assess characteristics and context that could affect the implementation of direct mail fecal testing programs, including the cost, source of test, and types of FIT used. We analyzed the range of costs for the tests, and identified practice and test procurement factors. We examined the distributions of practice characteristics for FIT use and costs answers using the non-parametric Wilcoxon rank-sum test. We used Pearson’s chi-squared test of association and interpreted a low p-value (e.g. < 0.05) as evidence of association between a given practice characteristic and knowing the cost of FIT or fecal occult blood test (FOBT). Results Among the 84 viable practice survey responses, more than 10 different types of FIT/FOBTs were in use; 76% of practices used one of the five most common FIT types. Only 40 practices (48%) provided information on FIT costs. Thirteen (32%) of these practices received the tests for free while 27 (68%) paid for their tests; median reported cost of a FIT was $3.04, with a range from $0.83 to $6.41 per test. Costs were not statistically significantly different by FIT type. However, practices who received FITs from manufacturer’s vendors were more likely to know the cost (p = 0.0002) and, if known, report a higher cost (p = 0.0002). Conclusions Our findings indicate that most practices without lab or health system supplied FITs are spending more to procure tests. Cost of FIT may impact the willingness of practices to distribute FITs through population outreach strategies, such as mailed FIT. Differences in the ability to obtain FIT tests in a cost-effective manner could have consequences for implementation of outreach programs that address colorectal cancer screening disparities in primary care practices.