The Curcumin Analog C-150, Influencing NF-kappaB, UPR and Akt/Notch Pathways Has Potent Anticancer Activity In Vitro and In Vivo

C-150 a Mannich-type curcumin derivative, exhibited pronounced cytotoxic effects against eight glioma cell lines at micromolar concentrations. Inhibition of cell proliferation by C-150 was mediated by affecting multiple targets as confirmed at transcription and protein level. C-150 effectively reduced the transcription activation of NFkB, inhibited PKC-alpha which are constitutively over-expressed in glioblastoma. The effects of C-150 on the Akt/ Notch signaling were also demonstrated in a Drosophila tumorigenesis model. C-150 reduced the number of tumors in Drosophila with similar efficacy to mitoxantrone. In an in vivo orthotopic glioma model, C-150 significantly increased the median survival of treated nude rats compared to control animals. The multi-target action of C-150, and its preliminary in vivo efficacy would render this curcumin analogue as a potent clinical candidate against glioblastoma

The chemical structure of curcumin and C-150.

<p>Curcumin <b>1</b>: (1<i>E</i>,4<i>Z</i>,6<i>E</i>)-5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one, a related cytotoxic analogue that showed efficacy against glioma <b>2</b>, <i>N</i>,<i>N</i>'-(((1<i>E</i>,3<i>Z</i>,6<i>E</i>)-3-hydroxy-5-oxohepta-1,3,6-triene-1,7-diyl)bis(2-methoxy-4,1-phenylene))diacetamide and C-150 <b>3</b>, <i>N</i>-((<i>E</i>)-5-(3-hydroxyphenyl)-2-((<i>E</i>)-3-(3-hydroxyphenyl)acryloyl)-3-oxo-1-phenylpent-4-en-1-yl)acrylamide.</p

Kinase profiling of C-150.

<p>The effects of C-150 (1μM) on kinase inhibition was examined on a kinase panel of numerous different kinases. Note the significant inhibition of PKC-alpha.</p

Holographic microscopic analysis of C-150 induced cell death.

<p>Tumor cells (U87 MG, U-251 MG, GBM1, GBM2) were treated with 1 μM C-150. Cell volume, area and average thickness data are presented for each cell line 24 h after treatment. Error bars represent the standard error of means (SEM). Statistical significance:* p<0.05 and ** p<0.01 (unpaired, two tailed Student’s t-test).</p

<i>In vivo</i> effects of C-150 in orthotopic glioma xenograft.

<p>Kaplan-Meier survival curves of rats intracerebrally grafted with U87-MG cells and treated with C-150. Time is expressed in days from inoculation. Animals treated with C-150 displayed a significantly longer median survival time compared to control animals (27 vs. 36 days, n = 7 in both groups, p = 0.0181 Log-rank (Mantel-Cox) Test).</p

<i>In vivo</i> effect of C-150 on a <i>Drosophila</i> double Akt/Notch „gain-of-expression” mutant strain.

<p>(<b>a</b>) Malignant transformation occurs in the eye. (<b>b</b>) Tumor incidence is presented for each control and treated group (sample size is indicated for each group overlaid on the columns). Error bars represent standard deviation from 3 independent measurements. All treatments had a p value below 0.01 when compared to their respective controls (Student’s t-test).</p

Cytotoxic effects of curcumin and C-150 on nine different human glioma cell lines determined by MTS assay.

<p>IC₅₀ values (μM) for C-150 and curcumin are indicated in the table.</p

Inhibitory effect of curcumin or C-150 on NF-κB activation.

<p>IC₅₀ values obtained in an <i>in vitro</i> NF-κB activation inhibition assay (C: curcumin, C-150: novel curcumin analog). Error bars represent standard deviation from repeated experiments.</p

The Curcumin Analog C-150, Influencing NF-κB, UPR and Akt/Notch Pathways Has Potent Anticancer Activity <i>In Vitro</i> and <i>In Vivo</i>

<div><p>C-150 a Mannich-type curcumin derivative, exhibited pronounced cytotoxic effects against eight glioma cell lines at micromolar concentrations. Inhibition of cell proliferation by C-150 was mediated by affecting multiple targets as confirmed at transcription and protein level. C-150 effectively reduced the transcription activation of NFkB, inhibited PKC-alpha which are constitutively over-expressed in glioblastoma. The effects of C-150 on the Akt/ Notch signaling were also demonstrated in a <i>Drosophila</i> tumorigenesis model. C-150 reduced the number of tumors in <i>Drosophila</i> with similar efficacy to mitoxantrone. In an <i>in vivo</i> orthotopic glioma model, C-150 significantly increased the median survival of treated nude rats compared to control animals. The multi-target action of C-150, and its preliminary <i>in vivo</i> efficacy would render this curcumin analogue as a potent clinical candidate against glioblastoma.</p></div

Effects of C-150 and curcumin on protein and gene expression.

<p>Effects of C-150 and curcumin on GRP78 and GADD153 protein expression (<b>a</b>). U87 MG glioma cells were treated with compounds at the indicated concentrations for 6 h. Cells were collected and the total lysates isolated and examined by Western blot analysis using an anti-GRP78 or anti-GADD153 specific antibody. Actin is shown as a control for equal loading. (<b>b</b>) Induction of mRNA levels of genes involved in UPR and ER-stress (ATF4, XBP-1, GRP78 and GADD153) as verified by using QRT-PCR method in U87 MG cells. Fold changes are shown for curcumin (10 μM) and C-150 (0.5 μM) treated cells 6 h post-treatment, relative to untreated controls. Statistical significance: * p<0.05 and ** p<0.01</p