Biochemistry and Structural Biology  http://www.gbs.uab.edu  http://www.uab.edu/graduate

Faculty Detail   
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Graduate Biomedical Sciences Affiliations
Biochemistry and Molecular Genetics Program 
Biochemistry and Structural Biology 
Cancer Biology 
Genetics, Genomics and Bioinformatics 
Integrative Genetics Graduate Program 
Medical Scientist Training Program 

Biographical Sketch 
Scott Blume received his bachelor's degree in Biochemistry from the University of Alabama in 1982. His undergraduate research dealt with the kinetics of tryptophan synthetase and was performed under the direction of Dr. John K. Hardman. He received his doctorate degree from the University of Alabama in 1986, and performed post-doctoral research on DNA-binding drugs and gene amplification from 1987-91 under the direction of Dr. Donald M. Miller. He is an Associate Scientist in the Comprehensive Cancer Center, and a member of the faculty of the Graduate School. His research has been funded by the American Cancer Society, the Department of Defense Breast Cancer Research Program, the National Heart, Lung, and Blood Institute, and the National Cancer Institute.

Society Memberships
Organization Name Position Held Org Link
American Association for Cancer Research  Member   
 

Research/Clinical Interest
Title
Specific regulation of gene expression at the translational level - through sequence-specific RNA-binding proteins and complex 5'-untranslated RNA sequences; dysregulation of gene-specific translational control mechanisms in cancer.
Description
Translation initiation is generally accomplished via ribosomal scanning from the beginning (5'-end) of the mRNA, and for many genes this a relatively efficient process which is not subject to specific regulatory controls. However, the genes most critical to the control of cellular proliferation and survival (e.g. protooncogenes, growth factor receptors, and apoptotic regulators) are associated with very long, highly structured 5'-untranslated leader sequences which present significant obstacles to 40S ribosomal scanning and translation initiation. These complex 5'-UTRs serve essentially as "RNA promoters", with structural features and regulatory protein binding sites which provide the opportunity for specific regulation of gene expression at the translational level. Such features include upstream open reading frames (uORFs), which may derail the scanning ribosome, or in some cases encode a functional peptide or small protein, and internal ribosomal entry sites (IRESs), which recruit the 40S ribosomal subunit into the vicinity of the authentic translation initiation codon. Importantly, these do not appear to be static structural features, rather they are regulated through dynamic interactions with sequence-specific RNA-binding proteins. Roughly 8% of all human genes encode RNA-binding proteins, yet we are just beginning to profile the spectrum of RNA-binding proteins and their functions in regulating gene expression. In fact, we are just now beginning to realize that these RNA-binding translation-regulatory proteins are capable of a degree of sequence specificity rivaling that of the much more thoroughly studied DNA-binding transcription factors, whose roles in gene expression and in tumorigenesis have been well-established over the past 20 years. Our research has focused on two genes, the protooncogene c-myc and the potent anti-apoptotic factor IGF1R, both of which are directly implicated in human breast cancer pathogenesis, and both of which are regulated at the translational level. In particular, we are investigating the IGF1R IRES, the c-myc uORF, and the RNA-binding proteins interacting with each of these complex 5'-untranslated sequences. We hypothesized that the dynamic, competitive interactions between these RNA-binding proteins and the IGF1R and c-myc 5'-UTRs may determine the functional state of the mRNA (whether it is actively translated, temporarily repressed, or permanently sequestered to facilitate the induction of apoptosis; molecular triage), and have accumulated data which support this hypothesis. Perhaps most importantly, our data indicate that pathological alterations in the activities of these RNA-binding translation-regulatory proteins may be responsible for dysregulation of gene expression in human breast cancer cells, and may contribute significantly to the molecular pathogenesis of this disease. Ultimately, this work is intended to establish gene-specific translational control mechanisms as targets for development of molecular therapeutic interventions.

Selected Publications 
Ji, M.H., Kim, S.K., Kim, C.Y., Phi, J.H., Jun, H.J., Blume, S.W., Choi, H.S. (2015) Physiological expression and accumulation of the products of two upstream open reading frames mrtl and MycHex1 along with p64 and p67 Myc from the human c-myc locus. J. Cell. Biochem. in press.  26552949 
Vaklavas, C., Meng, Z., Choi, H., Grizzle, W.E., Zinn, K.R., & Blume, S.W. (2015) Small molecule inhibitors of IRES-mediated translation. Cancer Biol. Ther. 16:1471-85.
 
26177060 
Meng, Z., Jackson, N.L., Shcherbakov, O.D., Choi, H., Blume, S.W. (2010) The human IGF1R IRES likely operates through a Shine-Dalgarno-like interaction with the G961 loop (E-site) of the 18S rRNA and is kinetically modulated by a naturally-polymorphic polyU loop. J. Cell. Biochem. 110: 531-44.  20432247 
Blume, S.W., Jackson, N.L., Frost, A.R., Grizzle, W.E., Shcherbakov, O.D, Choi, H., Meng, Z. (2010) Northwestern profiling of potential translation-regulatory proteins in human breast epithelial cells and malignant breast tissues: evidence for pathological activation of the IGF1R IRES. Exp. Mol. Pathol. 88(3):341-52.  20233590 
Choi, H., Jackson, N.L., Shaw, D.R., Emanuel, P.D., Liu, Y. L., Tousson, A., Meng, Z., & Blume, S.W. (2008)
mrtl – A translation / localization regulatory protein encoded within the human c-myc locus and distributed throughout the endoplasmic and nucleoplasmic reticular network.
J. Cell. Biochem. 105: 1092-1108. 
18816594 
Meng, Z., Jackson, N.L., Choi, H., King, P.H., Emanuel, P.D., & Blume, S.W. (2008) Alterations in RNA-binding activities of IRES-regulatory proteins as a mechanism for physiological variability and pathological dysregulation of IGF-IR translational control in human breast tumor cells. J. Cell Physiol. 217: 172-83.  18452152 
Meng, Z., King, P.H., Nabors, L.B., Jackson, N.L., Chen, C-Y., Emanuel, P.D., &
Blume, S.W. (2005) The ELAV RNA-stability factor HuR binds the 5’-untranslated region of the human IGF1R transcript and differentially represses cap-dependent and IRES-mediated translation. Nucleic Acids Res. 33: 2962-2979.
 
15914670 
Blume, S.W., Miller, D.M., Guarcello, V., Shrestha, K., Meng, Z., Snyder, R.C., Grizzle, W.E., Ruppert, J.M., Gartland, G.L., Stockard, C.R., Jones, D.E., & Emanuel, P.D. (2003) Inhibition of tumorigenicity by the 5’-untranslated RNA of the human c-myc P0 transcript. Exp. Cell Res. 288: 131-142.  12878165 
Meng, Z., Snyder, R.C., Shrestha, K., Miller, D.M., Emanuel, P.D., & Blume, S.W. (2003) Evidence for Differential Ribonucleoprotein Complex Assembly In Vitro on the 5'-Untranslated Region of the Human IGF-IR Transcript.
Mol. Cell. Endocrinol. 200: 127-140.
 
12644306 
Blume, S.W., Meng, Z., Shrestha, K., Snyder, R.C., & Emanuel, P.D. (2003) The 5'-untranslated RNA of the human dhfr minor transcript alters transcription pre-initiation complex assembly at the major (core) promoter.
J. Cell. Biochem. 88: 165-180.
 
12461786  
Kar, S.R., Lebowitz, J., Blume, S., Taylor, K.B., & Hall, L.M. (2001) SmtB-DNA and protein-protein interactions in the formation of the Cyanobacterial Metallothionein repression complex: Zn2+ does not dissociate the protein-DNA complex in vitro. Biochemistry 40: 13378-89.
 
11683648  
Blume, S.W., Lebowitz, J., Zacharias, W., Guarcello, V., Mayfield, C.A., Ebbinghaus, S.W., Bates, P., Jones, D.E. Jr., Trent, J., Vigneswaran, N., & Miller, D.M. (1999) The integral divalent cation within the intermolecular purine*purine.pyrimidine structure: A variable determinant of the potential for, and characteristics of the triple helical association. Nucleic Acids Res. 27: 695-702.
 
9862999 
Blume, S.W., Guarcello, V., Zacharias, W. & Miller, D.M. (1997) Divalent transition metal cations counteract potassium-induced quadruplex assembly of oligo(dG) sequences. Nucleic Acids Res. 25: 617-625.  9016604 
Blume, S.W., Snyder, R.C., Ray, R., Thomas, S., Koller, C.A., & Miller, D.M. (1991) Mithramycin inhibits Sp1 binding and selectively inhibits transcriptional activity of the dihydrofolate reductase gene in vitro and in vivo. J. Clin. Invest. 88:1613-1621.  1834700 
Snyder, R.C., Ray, R., Blume, S.W., & Miller, D.M. (1991) Mithramycin blocks transcriptional initiation of the c-myc P1 and P2 promoters. Biochemistry 30: 4290-4297.  1827033 
Gee, J.E., Blume, S., Snyder, R.C., Ray, R., & Miller, D.M. (1992) Triplex formation prevents Sp1 binding to the dihydrofolate reductase promoter. J. Biol. Chem. 267: 11163-11167.  1597451 
Blume, S.W., Gee, J.E., Shrestha, K., & Miller, D.M. (1992) Triple helix formation by purine-rich oligonucleotides targeted to the human dihydrofolate reductase promoter. Nucleic Acids Res. 20: 1777-1784.  1579471  
Vaklavas, C., Grizzle, W.E., Choi, H., Meng, Z., Zinn, K.R., Shrestha, K., and Blume, S.W. (2016) IRES inhibition induces terminal differentiation and synchronized death in triple-negative breast cancer and glioblastoma cells. Tumor Biol. (in press)   
 

Keywords
RNA-binding proteins, gene-specific translational regulation, breast cancer, c-myc, IGF1R, internal ribosomal entry site (IRES).