NFκB p65 ELISA Kit

Background: Gene and protein expression of the glucose transporter GLUT6 are elevated in multiple cancers, including endometrial cancer. However, the extrinsic and intrinsic mechanisms that regulate GLUT6 expression in this malignancy are unknown. Herein we investigate the potential mechanisms regulating GLUT6 expression in endometrial cancer. Methods: Data mining of the GLUT6 gene (SLC2A6) in The Cancer Genome Atlas (TCGA) PanCan datasets was performed in cBioPortal. A transcriptome PCR array was used to identify regulators of GLUT6 expression. The role of RELA in regulating GLUT6 gene and protein expression was investigated by overexpressing constitutively active and dominant-negative RELA in endometrial cells. Endometrial cells were treated with the pro-inflammatory cytokine TNF alpha and the expression of RELA, I kappa B alpha, TNF alpha, and GLUT6 were examined by Western blotting and RT-qPCR. Results: GLUT6 is altered in 1% of all cancer samples (157 of 10, 967 samples) within TCGA datasets including 4.7% of uterine (endometrial) cancers. GLUT6 expression was positively co-expressed with multiple members of the NF-kappa B signalling pathway including NFKB2, RELB, NFKBIE, and TNF in endometrial cancer samples. A transcriptome PCR array identified RELA as the top potential transcriptional regulator of GLUT6 expression. Overexpression of constitutively active RELA increased GLUT6 gene expression in normal endometrial epithelial cells (hUE-Ts), while overexpression of dominant-negative RELA decreased GLUT6 expression in cancerous RL95-2 endometrial cells. TNF alpha treatment activated canonical NF-kappa B signalling and increased the expression of GLUT6, but not that of other glucose transporters (GLUTs 1, 3, 4, 8, 10, or 12) in endometrial cells. Conclusions: TNF alpha is a cytokine that is commonly increased in obesity-related endometrial cancer and the findings herein support a potential mechanism whereby TNF alpha may contribute to endometrial cancer initiation or progression by increasing GLUT6 expression. Furthermore, we identified RELA, an important downstream mediator of the TNF alpha signalling cascade, as a regulator of GLUT6 expression in endometrial cells. Future studies are warranted to determine how GLUT6 expression affects endometrial tumourigenesis or cancer progression.

Metastatic cancer cells cross endothelial barriers and travel through the blood or lymphatic fluid to pre-metastatic niches, leading to their colonisation. 'S' stereoisomer 12S-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid [12(S)-HETE] is secreted by a variety of cancer cell types and has been indicated to open up these barriers. In the present study, another aspect of the endothelial unlocking mechanism was elucidated. This was achieved by investigating 12(S)-HETE-treated lymph endothelial cells (LECs) with regard to their expression and mutual interaction with v-rel avian reticuloendotheliosis viral oncogene homolog A (RELA), intercellular adhesion molecule 1, SRY-box transcription factor 18 (SOX18), prospero homeobox 1 (PROX1) and focal adhesion kinase (FAK). These key players of LEC retraction, which is a prerequisite for cancer cell transit into vasculature, were analysed using western blot analysis, reverse transcription-quantitative PCR and transfection with small interfering (si)RNA. The silencing of a combination of these signalling and executing molecules using siRNA, or pharmacological inhibition with defactinib and Bay11-7082, extended the mono-culture experiments to co-culture settings using HCT116 colon cancer cell spheroids that were placed on top of LEC monolayers to measure their retraction using the validated 'circular chemorepel-lent-induced defect' assay. 12(S)-HETE was indicated to induce the upregulation of the RELA/SOX18 feedback loop causing the subsequent phosphorylation of FAK, which fed back to RELA/SOX18. Therefore, 12(S)-HETE was demonstrated to be associated with circuits involving RELA, SOX18 and FAK, which transduced signals causing the retraction of LECs. The FAK-inhibitor defactinib and the NF-kappa B inhibitor Bay11-7082 attenuated LEC retraction additively, which was similar to the suppression of FAK and PROX1 (the target of SOX18) by the transfection of respective siRNAs. FAK is an effector molecule at the distal end of a pro-metastatic signalling cascade. Therefore, targeting the endothelial-specific activity of FAK through the pathway demonstrated herein may provide a potential therapeutic method to combat cancer dissemination via vascular routes.