Eblin, K. E., Jensen, T. J., Wnek, S. M., Buffington, S. E., Futscher, B. W., & Gandolfi, A. J. (2009). Reactive oxygen species regulate properties of transformation in UROtsa cells exposed to monomethylarsonous acid by modulating MAPK signaling. Toxicology, 255(1-2), 107-114.
PMID: 19014992;PMCID: PMC2665711;Abstract:
UROtsa cells exposed to 50 nM monomethylarsonous acid [MMA(III)] for 52 wk (MSC52) achieved hyperproliferation, anchorage independent growth, and enhanced tumorgenicity. MMA(III) has been shown to induce reactive oxygen species (ROS), which can lead to activation of signaling cascades causing stress-related proliferation of cells and even cellular transformation. Previous research established the acute activation of MAPK signaling cascade by ROS produced by MMA(III) as well as chronic up regulation of COX-2 and EGFR in MSC52 cells. To determine if ROS played a role in the chronic pathway perturbations by acting as secondary messengers, activation of Ras was determined in UROtsa cells [exposed to MMA(III) for 0-52 wk] and found to be increased through 52 wk most dramatically after 20 wk of exposure. Ras has been shown to cause an increase in O2- and be activated by increases in O2-, making ROS important to study in the transformation process. COX-2 upregulation in MSC52 cells was confirmed by real time RT-PCR. By utilizing both antioxidants or specific COX inhibitors, it was shown that COX-2 upregulation was dependent on ROS, specifically, O2-. In addition, because previous research established the importance of MAPK activation in phenotypic changes associated with transformation in MSC52 cells, it was hypothesized that ROS play a role in maintaining phenotypic characteristics of the malignant transformation of MSC52 cells. Several studies have demonstrated that cancer cells have lowered superoxide dismutase (MnSOD) activity and protein levels. Increasing levels of MnSOD have been shown to suppress the malignant phenotype of cells. SOD was added to MSC52 cells resulting in slower proliferation rates (doubling time = 42 h vs. 31 h). ROS scavengers of {radical dot}OH also slowed proliferation rates of MSC52 cells. To further substantiate the importance of ROS in these properties of transformation in MSC52 cells, anchorage independent growth was assessed after the addition of antioxidants, both enzymatic and non-enzymatic. Scavengers of {radical dot}OH, and O2- blocked the colony formation of MSC52 cells. These data support the role for the involvement of ROS in properties of transformation of UROtsa cells exposed to MMA(III). © 2008 Elsevier Ireland Ltd. All rights reserved.
Futscher, B. W. (2015). Semaphorin 7a exerts pleiotropic effects to promote breast tumor progression. Oncogene.
Futscher, B., Novak, P., Jensen, T., Oshiro, M. M., Wozniak, R. J., Nouzova, M., Watts, G. S., Klimecki, W. T., Kim, C., & Futscher, B. W. (2006). Epigenetic inactivation of the HOXA gene cluster in breast cancer. Cancer research, 66(22).
BIO5 Collaborators
Bernard W Futscher, Walter Klimecki
Using an integrated approach of epigenomic scanning and gene expression profiling, we found aberrant methylation and epigenetic silencing of a small neighborhood of contiguous genes-the HOXA gene cluster in human breast cancer. The observed transcriptional repression was localized to approximately 100 kb of the HOXA gene cluster and did not extend to genes located upstream or downstream of the cluster. Bisulfite sequencing, chromatin immunoprecipitation, and quantitative reverse transcription-PCR analysis confirmed that the loss of expression of the HOXA gene cluster in human breast cancer is closely linked to aberrant DNA methylation and loss of permissive histone modifications in the region. Pharmacologic manipulations showed the importance of these aberrant epigenetic changes in gene silencing and support the hypothesis that aberrant DNA methylation is dominant to histone hypoacetylation. Overall, these data suggest that inactivation of the HOXA gene cluster in breast cancer may represent a new type of genomic lesion-epigenetic microdeletion. We predict that epigenetic microdeletions are common in human cancer and that they functionally resemble genetic microdeletions but are defined by epigenetic inactivation and transcriptional silencing of a relatively small set of contiguous genes along a chromosome, and that this type of genomic lesion is metastable and reversible in a classic epigenetic fashion.
Zhao, F., Severson, P., Pacheco, S., Futscher, B. W., & Klimecki, W. T. (2013). Arsenic exposure induces the warburg effect in cultured human cells. Toxicology and Applied Pharmacology, 271(1), 72-77.
BIO5 Collaborators
Bernard W Futscher, Walter Klimecki
PMID: 23648393;PMCID: PMC3714307;Abstract:
Understanding how arsenic exacts its diverse, global disease burden is hampered by a limited understanding of the particular biological pathways that are disrupted by arsenic and underlie pathogenesis. A reductionist view would predict that a small number of basic pathways are generally perturbed by arsenic, and manifest as diverse diseases. Following an initial observation that arsenite-exposed cells in culture acidify their media more rapidly than control cells, the report here shows that low level exposure to arsenite (75. ppb) is sufficient to induce aerobic glycolysis (the Warburg effect) as a generalized phenomenon in cultured human primary cells and cell lines. Expanded studies in one such cell line, the non-malignant pulmonary epithelial line, BEAS-2B, established that the arsenite-induced Warburg effect was associated with increased accumulation of intracellular and extracellular lactate, an increased rate of extracellular acidification, and inhibition by the non-metabolized glucose analog, 2-deoxy-D-glucose. Associated with the induction of aerobic glycolysis was a pathway-wide induction of glycolysis gene expression, as well as protein accumulation of an established glycolysis master-regulator, hypoxia-inducible factor 1A. Arsenite-induced alteration of energy production in human cells represents the type of fundamental perturbation that could extend to many tissue targets and diseases. © 2013 Elsevier Inc.
Futscher, B. W. (2018). Epigenetic silencing of lncRNA MORT in 16 TCGA cancer types. F1000Research.