Browsing by Author "Dobrolecki, Lacey E."

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    Human C6orf211 Encodes Armt1, a Protein Carboxyl Methyltransferase that Targets PCNA and Is Linked to the DNA Damage Response
    (ScienceDirect, 2015-03) Perry, J. Jefferson P.; Ballard, Gregory D.; Albert, Alexandra E.; Dobrolecki, Lacey E.; Malkas, Linda H.; Hoelz, Derek J.; Department of Hematology and Oncology, IU School of Medicine
    Recent evidence supports the presence of an L-glutamyl methyltransferase(s) in eukaryotic cells, but this enzyme class has been defined only in certain prokaryotic species. Here, we characterize the human C6orf211 gene product as “acidic residue methyltransferase-1” (Armt1), an enzyme that specifically targets proliferating cell nuclear antigen (PCNA) in breast cancer cells, predominately methylating glutamate side chains. Armt1 homologs share structural similarities with the SAM-dependent methyltransferases, and negative regulation of activity by automethylation indicates a means for cellular control. Notably, shRNA-based knockdown of Armt1 expression in two breast cancer cell lines altered survival in response to genotoxic stress. Increased sensitivity to UV, adriamycin, and MMS was observed in SK-Br-3 cells, while in contrast, increased resistance to these agents was observed in MCF7 cells. Together, these results lay the foundation for defining the mechanism by which this post-translational modification operates in the DNA damage response (DDR).
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    Quantitative Serum Glycomics of Esophageal Adenocarcinoma, and Other Esophageal Disease Onsets
    (American Chemical Society, 2009-06) Mechref, Yehia; Hussein, Ahmed; Bekesova, Slavka; Pungpapong, Vitara; Zhang, Min; Dobrolecki, Lacey E.; Hickey, Robert J.; Hammoud, Zane T.; Novotny, Milos V.; Department of Medicine, IU School of Medicine
    Aberrant glycosylation has been implicated in various types of cancers and changes in glycosylation may be associated with signaling pathways during malignant transformation. Glycomic profiling of blood serum, in which cancer cell proteins or their fragments with altered glycosylation patterns are shed, could reveal the altered glycosylation. We performed glycomic profiling of serum from patients with no known disease (N=18), patients with high grade dysplasia (HGD, N=11) and Barrett’s (N=5), and patients with esophageal adenocarcinoma (EAC, N=50) in an attempt to delineate distinct differences in glycosylation between these groups. The relative intensities of 98 features were significantly different among the disease onsets; 26 of these correspond to known glycan structures. The changes in the relative intensities of three of the known glycan structures predicted esophageal adenocarcinoma with 94% sensitivity and better than 60% specificity as determined by receiver operating characteristic (ROC) analysis. We have demonstrated that comparative glycomic profiling of EAC reveals a subset of glycans that can be selected as candidate biomarkers. These markers can differentiate disease-free from HGD, disease-free from EAC, and HGD from EAC. The clinical utility of these glycan biomarkers requires further validation.