Targeted delivery of vitamin D3-loaded nanoparticles to C6 glioma cell line increased resistance to doxorubicin, epirubicin, and docetaxel in vitro

Multifunctional Targeting Liposomes of Epirubicin Plus Resveratrol Improved Therapeutic Effect on Brain Gliomas

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Anti-tumor effects of vitamin D in glioblastoma: mechanism and therapeutic implications

Glioma is the most prevalent primary brain tumor in adults among which glioblastoma is the most malignant and lethal subtype. Its common resistance to conventional chemotherapeutics calls for the development of alternative or concomitant treatment. Taking advantage of its endocrine function as a neurosteroid, vitamin D has become a target of interest to be used in conjunction with different chemotherapies. In this article, we review the mechanisms through which vitamin D and its analogs induce anti-tumor activity in glioblastoma, and the practical issues relevant to their potential application based on in vitro and in vivo studies. Vitamin D has largely been reported to promote cell cycle arrest and induce cell death to suppress tumor growth in glioblastoma. Glioblastoma cells treated with vitamin D have also shown reduced migratory and invasive phenotypes, and reduced stemness. It is worth noting that vitamin D analogs are able to produce similar inhibitory actions without causing adverse effects such as hypercalcemia in vivo. Upregulation of vitamin D receptors by vitamin D and its analogs may also play a role in enhancing its anti-tumor activity. Based on current findings and taking into consideration its potential cancer-protective effects, the clinical application of vitamin D in glioblastoma treatment and prevention will be discussed. With some study findings subject to controversy, further investigation is warranted to elucidate the mechanism of action of vitamin D and to evaluate relevant issues regarding its treatment efficacy and potential clinical application.

Eldecalcitol (ED-71)-induced exosomal miR-6887-5p suppresses squamous cell carcinoma cell growth by targeting heparin-binding protein 17/fibroblast growth factor-binding protein-1 (HBp17/FGFBP-1)

Heparin-binding protein 17/fibroblast growth factor-binding protein-1 (HBp17/FGFBP-1) was purified from A431 cell-conditioned media based on its capacity to bind to fibroblast growth factor 1 and 2 (FGF-1 and FGF-2). HBp17/FGFBP-1 has been observed to induce the tumorigenic potential of epithelial cells and is highly expressed in oral cancer cell lines and tissues. HBp17/FGFBP-1 is also recognized as a pro-angiogenic molecule as a consequence of its interaction with FGF-2. We have previously reported that Eldecalcitol (ED-71), an analog of 1α,25(OH)₂D₃, downregulated the expression of HBp17/FGFBP-1 and inhibited the proliferation of squamous cell carcinoma (SCC) cells in vitro and in vivo through NF-κb inhibition. To explore the possibility of microRNA (miRNA) control of HBp17/FGFBP-1, we analyzed exosomal miRNAs from medium conditioned by A431 cells treated with ED-71. Microarray analysis revealed that 12 exosomal miRNAs were upregulated in ED-71-treated A431 cells. Among them, miR-6887-5p was identified to have a predicted mRNA target matching the 3' untranslated region (3'-UTR) of HBp17/FGFBP-1. The 3'-UTR of HBp17/FGFBP-1 was confirmed to be a direct target of miR-6887-5p in SCC/OSCC cells, as assessed with a luciferase reporter assay. Functional assessment revealed that overexpression of miR-6887-5p in SCC/OSCC cells inhibited cell proliferation and colony formation in vitro, and inhibited tumor growth in vivo compared with control. In conclusion, our present study supports a novel anti-cancer mechanism involving the regulation of HBp17/FGFBP-1 function by exosomal miR-6887-5p in SCC/OSCC cells, which has potential utility as a miRNA-based cancer therapy.

Drug Delivery Systems for Vitamin D Supplementation and Therapy

Vitamin D (VD) is a fat-soluble prohormone well known for its role in regulating calcium and phosphate metabolism. It has been clinically used for many years to prevent rickets in children, osteomalacia, and osteoporosis in adults. VD insufficiency is a common medical condition, and many supplements are available in the market in order to increase serum 25-hydroxy VD levels to recommended amounts. Over the course of the last decades, it has become increasingly clear that calcitriol, an active form of VD, regulates multiple cellular processes with effects on normal and malignant cell growth and differentiation, and on the immune and cardiovascular function. Increasing evidence supports the role of the VD system in cancer prevention and therapy. Due to many pleiotropic and beneficial effects in extra-skeletal disorders, VD has gained potential and become an interesting active for encapsulation into drug delivery systems. The purpose of this review is to present the diversity of drug delivery systems that have been reported for VD or VD derivatives in an orderly manner across the following categories: Oral administration, application on the skin, cancer prevention/therapy, and other diseases or routes of administration.

From epidemiology and neurometabolism to treatment: Vitamin D in pathogenesis of glioblastoma Multiforme (GBM) and a proposal for Vitamin D + all-trans retinoic acid + Temozolomide combination in treatment of GBM

Here we review tumoricidal efficacy of Vitamin D analogues in glioblastoma multiforme (GBM) and potential synergisms with retinoic acid and temozolomide based on epidemiological and cellular studies. Epidemiological data suggest that winter birth is associated with higher risk of GBM, and GBM debulking in the winter enhanced mortality, which may relate with lower exposure to sunlight essential to convert cholecalciferol to Vitamin D. Comparative studies on blood bank specimens revealed that higher prediagnosis levels of calcidiol are associated with lower risk of GBM in elderly men. Supplemental Vitamin D reduced mortality in GBM patients in comparison to nonusers. Expression of Vitamin D Receptor is associated with a good prognosis in GBM. Conversely, Vitamin D increases glial tumor synthesis of neutrophins NGF and NT-3, the low affinity neurotrophin receptor p75NTR, IL-6 and VEGF, which may enhance glioma growth. Antitumor synergisms between temozolomide and Vitamin D and Vitamin D with Vitamin A derivatives were observed. Hence, we hypothesize that Calcitriol + ATRA (All-Trans Retinoic Acid) + Temozolomide - CAT combination might be a safer approach to benefit from Vitamin D in the management of high-grade glial tumors. Adding acetazolomide to this protocol may reduce the risk of pseudotumor cerebri, as both Vitamin D and Vitamin A excess may cause intracranial hypertension; this approach may provide further benefit as acetazolomide also exhibits anticancer activity.

Glycosylation Changes in Brain Cancer

Protein glycosylation is a posttranslational modification that affects more than half of all known proteins. Glycans covalently bound to biomolecules modulate their functions by both direct interactions, such as the recognition of glycan structures by binding partners, and indirect mechanisms that contribute to the control of protein conformation, stability, and turnover. The focus of this Review is the discussion of aberrant glycosylation related to brain cancer. Altered sialylation and fucosylation of N- and O-glycans play a role in the development and progression of brain cancer. Additionally, aberrant O-glycan expression has been implicated in brain cancer. This Review also addresses the clinical potential and applications of aberrant glycosylation for the detection and treatment of brain cancer. The viable roles glycans may play in the development of brain cancer therapeutics are addressed as well as cancer-glycoproteomics and personalized medicine. Glycoprotein alterations are considered as a hallmark of cancer while high expression in body fluids represents an opportunity for cancer assessment.

Molecular imaging and cancer gene therapy

Gene therapy is known as one of the most advanced approaches for therapeutic prospects ranging from tackling genetic diseases to combating cancer. In this approach, different viral and nonviral vector systems such as retrovirus, lentivirus, plasmid and transposon have been designed and employed. These vector systems are designed to target different therapeutic genes in various tissues and cells such as tumor cells. Therefore, detection of the vectors containing therapeutic genes and monitoring of response to the treatment are the main issues that are commonly faced by researchers. Imaging techniques have been critical in guiding physicians in the more accurate and precise diagnosis and monitoring of cancer patients in different phases of malignancies. Imaging techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are non-invasive and powerful tools for monitoring of the distribution of transgene expression over time and assessing patients who have received therapeutic genes. Here, we discuss most recent advances in cancer gene therapy and molecular approaches as well as imaging techniques that are utilized to detect cancer gene therapeutics and to monitor the patients' response to these therapies worldwide, particularly in Iranian Academic Medical Centers and Hospitals.Cancer Gene Therapy advance online publication, 18 November 2016; doi:10.1038/cgt.2016.62.