calebin-a and Colorectal-Neoplasms

The majority of chemotherapeutic agents stimulate NF-κB signaling that mediates cell survival, proliferation and metastasis. The natural turmeric non-curcuminoid derivate Calebin A has been shown to suppress cell growth, invasion and colony formation in colorectal cancer cells (CRC) by suppression of NF-κB signaling. Therefore, we hypothesized here that Calebin A might chemosensitize the TNF-β-treated tumor cells and potentiates the effect of 5-Fluorouracil (5-FU) in advanced CRC.. CRC cells (HCT116) and their clonogenic 5-FU chemoresistant counterparts (HCT116R) were cultured in monolayer or alginate-based 3D tumor environment culture and were treated with/without Calebin A, TNF-β, 5-FU, BMS-345541 and DTT (dithiothreitol).. The results showed that TNF-β increased proliferation, invasion and resistance to apoptosis in chemoresistant CRC cells. Pretreatment with Calebin A significantly chemosensitized HCT116R to 5-FU and inhibited the TNF-β-induced enhanced efforts for survival, invasion and anti-apoptotic effects. We found further that Calebin A significantly suppressed TNF-β-induced phosphorylation and nuclear translocation of p65-NF-κB, similar to BMS-345541 (specific IKK inhibitor) and NF-κB-induced tumor-promoting biomarkers (NF-κB, β1-Integrin, MMP-9, CXCR4, Ki67). This was associated with increased apoptosis in HCT116 and HCT116R cells. Furthermore, blocking of p65-NF-κB stimulation by Calebin A was imparted through the downmodulation of p65-NF-κB binding to the DNA and this suppression was turned by DTT.. Our findings indicate, for the first time, that Calebin A chemosensitizes human CRC cells to chemotherapy by targeting of the p65-NF-κB signaling pathway.

Topics: Antineoplastic Agents; Apoptosis; Biomarkers, Tumor; Cell Line; Cell Proliferation; Cell Survival; Cinnamates; Colonic Neoplasms; Colorectal Neoplasms; Fluorouracil; Humans; Lymphotoxin-alpha; Monoterpenes; NF-kappa B; Phosphorylation; Signal Transduction; Transcription Factor RelA

Natural polyphenol Calebin A has been recently discovered as a novel derivate from turmeric with anti-cancer potential. Pro-inflammatory cytokine TNF-β (lymphotoxin α) is a stimulant for cancer cell malignity via activation of NF-B pathway, also in colorectal cancer (CRC). Here, we investigated the potential of Calebin A to suppress TNF-β-induced NF-B signalling in CRC.. Three distinct CRC cell lines (HCT116, RKO, SW480) were treated in monolayer or 3-dimensional alginate culture with TNF-β, Calebin A, curcumin, BMS-345541, dithiothreitol (DTT) or antisense oligonucleotides-(ASO) against NF-B.. Calebin A suppressed dose-dependent TNF-β-induced CRC cell vitality and proliferation in monolayer culture. Further, in alginate culture, Calebin A significantly suppressed TNF-β-enhanced colonosphere development, as well as invasion and colony formation of all three CRC cell lines investigated. Calebin A specifically blocked TNF-β-induced activation and nuclear translocation of p65-NF-B, similar to curcumin (natural NF-B inhibitor), BMS-345541 (specific IKK inhibitor) and ASO-NF-B. Moreover, Immunofluorescence and Immunoblotting showed that Calebin A, similar to curcumin or BMS-345541 suppressed TNF-β-induced activation and nuclear translocation of p65-NF-B and the transcription of NF-B-promoted biomarkers associated with proliferation, migration and apoptosis, in a dose- and time-dependent manner. Those findings were potentiated by the specific treatment of extracted nuclei with DTT, which abrogated Calebin A-mediated nuclear p65-NF-B-inhibition and restored p65-NF-B-activity in the nucleus.. Overall, these results demonstrate, for the first time, that multitargeted Calebin A has an anti-cancer capability on TNF-β-induced malignities through inhibitory targeting of NF-B activation in the cytoplasm, as well as by suppressing the binding of p65-NF-B to DNA.

Topics: Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cinnamates; Colorectal Neoplasms; Curcuma; Curcumin; Humans; Imidazoles; Lymphotoxin-alpha; Monoterpenes; Neoplasm Invasiveness; Neoplasm Metastasis; Quinoxalines; Signal Transduction; Transcription Factor RelA