The Effects of Apigenin on Cell Proliferation and Apoptosis in Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is a WHO grade IV brain tumor. These tumors are highly proliferative, infiltrative, necrotic, angiogenic, and resistant to apoptosis. One major characteristic of GBM is the overexpression of epidermal growth factor receptor (EGFR), which leads to cell growth and proliferation when activated. GBM is very difficult to treat due to its location, heterogeneity, and invasiveness; an effective treatment is therefore needed. The use of flavonoids, which are natural compounds found in many fruits and vegetables, has been studied in the treatment of many different tumor types. Apigenin is a specific flavonoid that has previously been shown to have antitumor activity in a number of cancer cells. Our study set out to investigate the molecular effects of apigenin treatment on glioblastoma cell proliferation and viability using the trypan blue exclusion assay, MTT assay, and an LDH assay. In addition, Western blot analyses were utilized out to determine the signaling pathways through which apigenin treatment exerts its effects on cell proliferation and apoptosis. Finally, hoechst-propidium iodide staining and flow cytometry were used to examine the extent of apoptosis and the cell cycle context of these effects. Our results show that apigenin reduces cell viability and proliferation in a dose and time dependent manner while increasing cytotoxicity in GBM cells. Additionally, apigenin inhibits the EGFR mediated phosphorylation in the presence of EGF treatment of AKT, mTOR, and s6k resulting in decreased cell survival, growth and proliferation. It also inhibits the MAPK pathways in one cell line thereby reducing cell growth and proliferation. It also inhibits the anti-apoptotic effects of BCL-XL and increases PARP cleavage, which leads to increased apoptosis. Finally, apigenin induced cycle arrest at the G2M checkpoint, meaning that apoptosis primarily occurred at the DNA repair checkpoint in the cell cycle. In conclusion, apigenin has demonstrated some in vitro biological effects on glioblastoma cell lines that show promises in limiting the growth, proliferation and survival of these cell lines. Future research should look to identify means through which apigenin can be administered in clinically significant concentrations to the brain

Natural Products as Therapeutic Agents in Cancer Treatment

Cancer accounts for 25% of deaths in the United States, and brain tumors greatly contribute to this percentage. However, relative to other types of cancers, brain tumors prove difficult to treat because they are heterogeneous, highly proliferative, highly invasive, and resistant to the traditional cancer treatments of chemotherapy and radiotherapy. Past studies have shown that flavonoids and curcuminoids, two classes of compounds derived from natural sources, are effective in inhibiting the development and metastasis of breast and lung cancer cells. Research has also indicated that these compounds have potential for treating brain tumors. The purpose of this research is to further explore the potential of flavonoids as therapeutic options for the treatment of brain tumors. Specifically, flavonoids’ effect on cell proliferation, cell death, and tumor invasion will be studied. Another objective of this study is to identify the signaling mechanism by which flavonoids mediate their therapeutic effects on brain tumor cell lines. Three human brain tumor cell lines (U-1242, U-251, and U-87) will be studied. They will be treated with various flavonoids at increasing concentrations (10, 20, 40, and 80 µM). Cells will be counted following the trypan blue staining protocol. MTT assays and Western blot analyses will be used to assess cell proliferation. Cell death will be assessed with flow analyses and Western blot analyses. Unpaired t-tests will be run to compare treated and control cells at a 95% confidence interval. If necessary, one-way ANOVA with multiple comparisons will be used to compare multiple treatment groups and a control at a 95% confidence interval, and the Tukey post-hoc test will be utilized if appropriate. All statistical tests will be run in IBM SPSS 21®

Natural Products as Therapeutic Agents in Cancer Treatment

Cancer accounts for 25% of deaths in the United States, and brain tumors greatly contribute to this percentage. However, relative to other types of cancers, brain tumors prove difficult to treat because they are heterogeneous, highly proliferative, highly invasive, and resistant to the traditional cancer treatments of chemotherapy and radiotherapy. Past studies have shown that flavonoids and curcuminoids, two classes of compounds derived from natural sources, are effective in inhibiting the development and metastasis of breast and lung cancer cells. Research has also indicated that these compounds have potential for treating brain tumors. The purpose of this research is to further explore the potential of flavonoids as therapeutic options for the treatment of brain tumors. Specifically, flavonoids’ effect on cell proliferation, cell death, and tumor invasion will be studied. Another objective of this study is to identify the signaling mechanism by which flavonoids mediate their therapeutic effects on brain tumor cell lines. Three human brain tumor cell lines (U-1242, U-251, and U-87) will be studied. They will be treated with various flavonoids at increasing concentrations (10, 20, 40, and 80 µM). Cells will be counted following the trypan blue staining protocol. MTT assays and Western blot analyses will be used to assess cell proliferation. Cell death will be assessed with flow analyses and Western blot analyses. Unpaired t-tests will be run to compare treated and control cells at a 95% confidence interval. If necessary, one-way ANOVA with multiple comparisons will be used to compare multiple treatment groups and a control at a 95% confidence interval, and the Tukey post-hoc test will be utilized if appropriate. All statistical tests will be run in IBM SPSS 21®

The Antiproliferative and Apoptotic Effects of Apigenin on Glioblastoma Cells

OBJECTIVES: Glioblastoma (GBM) is highly proliferative, infiltrative, malignant and the most deadly form of brain tumour. The epidermal growth factor receptor (EGFR) is overexpressed, amplified and mutated in GBM and has been shown to play key and important roles in the proliferation, growth and survival of this tumour. The goal of our study was to investigate the antiproliferative, apoptotic and molecular effects of apigenin in GBM. METHODS: Proliferation and viability tests were carried out using the trypan blue exclusion, MTT and lactate dehydrogenase (LDH) assays. Flow cytometry was used to examine the effects of apigenin on the cell cycle check-points. In addition, we determined the effects of apigenin on EGFR-mediated signalling pathways by Western blot analyses. KEY FINDINGS: Our results showed that apigenin reduced cell viability and proliferation in a dose- and time-dependent manner while increasing cytotoxicity in GBM cells. Treatment with apigenin-induced is poly ADP-ribose polymerase (PARP) cleavage and caused cell cycle arrest at the G2M checkpoint. Furthermore, our data revealed that apigenin inhibited EGFR-mediated phosphorylation of mitogen-activated protein kinase (MAPK), AKT and mammalian target of rapamycin (mTOR) signalling pathways and attenuated the expression of Bcl-xL. CONCLUSION: Our results demonstrated that apigenin has potent inhibitory effects on pathways involved in GBM proliferation and survival and could potentially be used as a therapeutic agent for GBM

Building Community Consensus for Scientific Metadata with YAMZ

ABSTRACTThis paper reports on a demonstration of YAMZ (Yet Another Metadata Zoo) as a mechanism for building community consensus around metadata terms. The demonstration is motivated by the complexity of the metadata standards environment and the need for more user-friendly approaches for researchers to achieve vocabulary consensus. The paper reviews a series of metadata standardization challenges, explores crowdsourcing factors that offer possible solutions, and introduces the YAMZ system. A YAMZ demonstration is presented with members of the Toberer materials science laboratory at the Colorado School of Mines, where there is a need to confirm and maintain a shared understanding for the vocabulary supporting research documentation, data management, and their larger metadata infrastructure. The demonstration involves three key steps: 1) Sampling terms for the demonstration, 2) Engaging graduate student researchers in the demonstration, and 3) Reflecting on the demonstration. The results of these steps, including examples of the dialog provenance among lab members and voting, show the ease with YAMZ can facilitate building metadata vocabulary consensus. The conclusion discusses implications and highlights next steps

A TREM2-activating antibody with a blood-brain barrier transport vehicle enhances microglial metabolism in Alzheimer's disease models

van Lengerich et al. developed a human TREM2 antibody with a transport vehicle (ATV) that improves brain exposure and biodistribution in mouse models. ATV:TREM2 promotes microglial energetic capacity and metabolism via mitochondrial pathways. Loss-of-function variants of TREM2 are associated with increased risk of Alzheimer's disease (AD), suggesting that activation of this innate immune receptor may be a useful therapeutic strategy. Here we describe a high-affinity human TREM2-activating antibody engineered with a monovalent transferrin receptor (TfR) binding site, termed antibody transport vehicle (ATV), to facilitate blood-brain barrier transcytosis. Upon peripheral delivery in mice, ATV:TREM2 showed improved brain biodistribution and enhanced signaling compared to a standard anti-TREM2 antibody. In human induced pluripotent stem cell (iPSC)-derived microglia, ATV:TREM2 induced proliferation and improved mitochondrial metabolism. Single-cell RNA sequencing and morphometry revealed that ATV:TREM2 shifted microglia to metabolically responsive states, which were distinct from those induced by amyloid pathology. In an AD mouse model, ATV:TREM2 boosted brain microglial activity and glucose metabolism. Thus, ATV:TREM2 represents a promising approach to improve microglial function and treat brain hypometabolism found in patients with AD

Identification of regulatory variants associated with genetic susceptibility to meningococcal disease.

Non-coding genetic variants play an important role in driving susceptibility to complex diseases but their characterization remains challenging. Here, we employed a novel approach to interrogate the genetic risk of such polymorphisms in a more systematic way by targeting specific regulatory regions relevant for the phenotype studied. We applied this method to meningococcal disease susceptibility, using the DNA binding pattern of RELA - a NF-kB subunit, master regulator of the response to infection - under bacterial stimuli in nasopharyngeal epithelial cells. We designed a custom panel to cover these RELA binding sites and used it for targeted sequencing in cases and controls. Variant calling and association analysis were performed followed by validation of candidate polymorphisms by genotyping in three independent cohorts. We identified two new polymorphisms, rs4823231 and rs11913168, showing signs of association with meningococcal disease susceptibility. In addition, using our genomic data as well as publicly available resources, we found evidences for these SNPs to have potential regulatory effects on ATXN10 and LIF genes respectively. The variants and related candidate genes are relevant for infectious diseases and may have important contribution for meningococcal disease pathology. Finally, we described a novel genetic association approach that could be applied to other phenotypes

Rachel Kunze

https://digitalcommons.cedarville.edu/white_coat_ceremony_gallery_2013/1038/thumbnail.jp