Anti-SLC44A1 (aa 74-183) polyclonal antibody

The recently discovered MCPIP1 (monocyte chemoattractant protein-induced protein 1), a multidomain protein encoded by the MCPIP1 (ZC3H12A) gene, has been described as a new differentiation factor, a ribonuclease, and a deubiquitination-supporting factor. However, its role in cancer is poorly recognized. Our recent analysis of microarrays data showed a lack of expression of the MCPIP1 transcript in primary neuroblastoma, the most common extracranial solid tumor in children. Additionally, enforced expression of the MCPIP1 gene in BE(2)-C cells caused a significant decrease in neuroblastoma proliferation and viability. Aim of the present study was to further investigate the role of MCPIP1 in neuroblastoma, using expression DNA microarrays and microRNA microarrays. Transient transfections of BE(2)-C cells were used for overexpression of either wild type of MCPIP1 (MCPIP1-wt) or its RN-ase defective mutant (MCPIP1-DPIN). We have analyzed changes of transcriptome and next, we have used qRT-PCR to verify mRNA levels of selected genes responding to MCPIP1 overexpression. Additionally, protein levels were determined for some of the selected genes. The choline transporter, CTL1, encoded by the SLC44A1 gene, was significantly repressed at the specific mRNA and protein levels and most importantly this translated into a decreased choline transport in MCPIP1-overexpressing cells. Then, we have found microRNA-3613-3p as the mostly altered in the pools of cells overexpressing the wild type MCPIP1. Next, we analyzed the predicted targets of the miR-3613-3p and validated them using qRT-PCR and western blot. These results indicate that the expression of miR-3613-3p might be regulated by MCPIP1 by cleavage of its precursor form. J. Cell. Biochem. 117: 694-707, 2016. (C) 2015 Wiley Periodicals, Inc.

Histone deacetylase (HDAC) inhibitors have emerged as effective antineoplastic agents in the clinic. Studies from our lab and others have reported that magnetic resonance spectroscopy (MRS)-detectable phosphocholine (PC) is elevated following SAHA treatment, providing a potential noninvasive biomarker of response. Typically, elevated PC is associated with cancer while a decrease in PC accompanies response to antineoplastic treatment. The goal of this study was therefore to elucidate the underlying biochemical mechanism by which HDAC inhibition leads to elevated PC. We investigated the effect of SAHA on MCF-7 breast cancer cells using C-13 MRS to monitor [1,2-C-13] choline uptake and phosphorylation to PC. We found that PC synthesis was significantly higher in treated cells, representing 154 +/- 19% of control. This was within standard deviation of the increase in total PC levels detected by P-31 MRS (129 +/- 7% of control). Furthermore, cellular choline kinase activity was elevated (177 +/- 31%), while cytidylyltransferase activity was unchanged. Expression of the intermediate-affinity choline transporter SLC44A1 and choline kinase a increased (144% and 161%, respectively) relative to control, as determined by mRNA microarray analysis with protein-level confirmation by Western blotting. Taken together, our findings indicate that the increase in PC levels following SAHA treatment results from its elevated synthesis. Additionally, the concentration of glycerophosphocholine (GPC) increased significantly with treatment to 210 +/- 45%. This is likely due to the upregulated expression of several phospholipase A2 (PLA(2)) isoforms, resulting in increased PLA(2) activity (162 +/- 18%) in SAHA-treated cells. Importantly, the levels of total choline (tCho)-containing metabolites, comprised of choline, PC and GPC, are readily detectable clinically using H-1 MRS. Our findings thus provide an important step in validating clinically translatable non-invasive imaging methods for follow-up diagnostics of HDAC inhibitor treatment.