Aberrant glucose metabolism is one of the hallmarks of cancer that facilitates cancer cell survival and proliferation. Here, we demonstrate that MUC1, a large, type I transmembrane protein that is overexpressed in several carcinomas including pancreatic adenocarcinoma, modulates cancer cell metabolism to facilitate growth properties of cancer cells. MUC1 occupies the promoter elements of multiple genes directly involved in glucose metabolism and regulates their expression. Furthermore, MUC1 expression enhances glycolytic activity in pancreatic cancer cells. We also demonstrate that MUC1 expression enhances in vivo glucose uptake and expression of genes involved in glucose uptake and metabolism in orthotopic implantation models of pancreatic cancer. The MUC1 cytoplasmic tail is known to activate multiple signaling pathways through its interactions with several transcription factors/coregulators at the promoter elements of various genes. Our results indicate that MUC1 acts as a modulator of the hypoxic response in pancreatic cancer cells by regulating the expression/stability and activity of hypoxia-inducible factor-1α (HIF-1α). MUC1 physically interacts with HIF-1α and p300 and stabilizes the former at the protein level. By using a ChIP assay, we demonstrate that MUC1 facilitates recruitment of HIF-1α and p300 on glycolytic gene promoters in a hypoxia-dependent manner. Also, by metabolomic studies, we demonstrate that MUC1 regulates multiple metabolite intermediates in the glucose and amino acid metabolic pathways. Thus, our studies indicate that MUC1 acts as a master regulator of the metabolic program and facilitates metabolic alterations in the hypoxic environments that help tumor cells survive and proliferate under such conditions. cancer metabolism | glutamine accumulation | pentose phosphate pathway | 2-ketoglutarate M UC1, a type I transmembrane protein, plays a significant role in the progression of cancer, particularly pancreatic adenocarcinoma (1-4). Although expressed in the normal pancreas, its expression is elevated in pancreatic adenocarcinoma and its expression pattern changes from a strictly apical localization on normal polarized epithelial cells to a broad distribution across the cell surface membrane of nonpolarized tumor cells (2). This results in aberrant signaling that enhances tumor progression and metastasis. MUC1 protein is expressed in >90% of pancreatic tumors (5), and MUC1 expression in tumors and its serum levels are associated with a poor prognosis and recurrence in patients with resected tumors (6). Much of the oncogenic role of MUC1 can be attributed to the participation of the small, cytoplasmic tail of MUC1 (MUC1.CT) in signal transduction and transcriptional events (2). ChIP-chip analyses have demonstrated that MUC1 occupies a plethora of promoter elements in which MUC1 modulates the recruitment and activity of transcription factors, thus regulating transcription of the corresponding genes (7).Several studies have established a role for MUC1 in tumor growth, invasion and metastas...

RNA-sequencing (RNA-seq) has become the standard method for unbiased analysis of gene expression but also provides access to more complex transcriptome features, including alternative RNA splicing, RNA editing, and even detection of fusion transcripts formed through chromosomal translocations. However, differences in library methods can adversely affect the ability to recover these different types of transcriptome data. For example, some methods have bias for one end of transcripts or rely on low-efficiency steps that limit the complexity of the resulting library, making detection of rare transcripts less likely. We tested several commonly used methods of RNA-seq library preparation and found vast differences in the detection of advanced transcriptome features, such as alternatively spliced isoforms and RNA editing sites. By comparing several different protocols available for the Ion Proton sequencer and by utilizing detailed bioinformatics analysis tools, we were able to develop an optimized random primer based RNA-seq technique that is reliable at uncovering rare transcript isoforms and RNA editing features, as well as fusion reads from oncogenic chromosome rearrangements. The combination of optimized libraries and rapid Ion Proton sequencing provides a powerful platform for the transcriptome analysis of research and clinical samples.

Activating mutations in cytokine receptors and transcriptional regulators govern aberrant signal transduction in T‐cell lineage acute lymphoblastic leukemia (T‐ ALL ). However, the roles played by suppressors of cytokine signaling remain incompletely understood. We examined the regulatory roles of suppressor of cytokine signaling 5 ( SOCS 5) in T‐ ALL cellular signaling networks and leukemia progression. We found that SOCS 5 was differentially expressed in primary T‐ ALL and its expression levels were lowered in HOXA ‐deregulated leukemia harboring KMT 2A gene rearrangements. Here, we report that SOCS 5 expression is epigenetically regulated by DNA methyltransferase‐3A‐mediated DNA methylation and methyl CpG binding protein‐2‐mediated histone deacetylation. We show that SOCS 5 negatively regulates T‐ ALL cell growth and cell cycle progression but has no effect on apoptotic cell death. Mechanistically, SOCS 5 silencing induces activation of JAK‐STAT signaling, and negatively regulates interleukin‐7 and interleukin‐4 receptors. Using a human T‐ ALL murine xenograft model, we show that genetic inactivation of SOCS 5 accelerates leukemia engraftment and progression, and leukemia burden. We postulate that SOCS 5 is epigenetically deregulated in T‐ ALL and serves as an important regulator of T‐ ALL cell proliferation and leukemic progression. Our results link aberrant downregulation of SOCS 5 expression to the enhanced activation of the JAK ‐ STAT and cytokine receptor‐signaling cascade in T‐ ALL .

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