Receptor Protein Tyrosine Phosphatases, cell-cell adhesion and signal transduction: We are studying the role of receptor protein tyrosine phosphatases (RPTPs) in signals transduced upon cell-cell contact. Some RPTPs such as PTPµ have cell adhesion molecule-like extracellular segments and are involved in adhesion-dependent signaling. PTPµ mediates adhesion by binding homophilically, i.e., PTPµ on the surface of one cell binds to PTPµ on an apposing cell. Interestingly, we found that PTPµ associates with another family of cell adhesion molecules called cadherins. Cadherins are adhesion molecules that play a role in cytoskeletal organization and cell junction formation. We are investigating the role of RPTPs and tyrosine phosphorylation in assembly and signal transduction at sites of cell-cell adhesion.
RPTPs and cancer: We are investigating the role of RPTPs in cell growth and malignancy in cancer. Protein tyrosine kinases can cause uncontrolled cell growth by disrupting the balance of cellular phosphotyrosine levels suggesting that PTPs may play an important role in negative growth regulation or could function as tumor suppressors. In this regard, we have recently found that certain cancer cells have lost PTPµ expression. Therefore, we are determining whether restoration of PTPµ expression in cancer cells results in changes in adhesion, growth, tumorigenicity or metastasis.
Gu Y, Wang CY, Anderson CE, Liu Y, Hu H, Johansen ML, Ma D, Jiang Y, Ramos-Estebanez C, Brady-Kalnay S, Griswold MA, Flask CA, Yu X. Fast magnetic resonance fingerprinting for dynamic contrast-enhanced studies in mice. Magn Reson Med. 2018 May 9. doi: 10.1002/mrm.27345. [Epub ahead of print]. PubMed PMID: 29744935. [PubMed]
Anderson CE, Donnola SB, Jiang Y, Batesole J, Darrah R, Drumm ML, Brady-Kalnay SM, Steinmetz N, Yu X, Griswold MA, Flask CA. Dual Contrast - Magnetic Resonance Fingerprinting (DC-MRF): A Platform for Simultaneous Quantification of Multiple MRI Contrast Agents. Scientific Reports. 2017. Aug 16;7(1):8431. PubMed PMID: 28814732; PubMed Central PMCID: PMC5559598. [PubMed]
Perera VS, Covarrubias G, Lorkowski M, Atukorale P, Rao A, Raghunathan S, Gopalakrishnan R, Erokwu BO, Liu Y, Dixit D, Brady-Kalnay SM, Wilson D, Flask C, Rich J, Peiris PM, Karathanasis E. One-pot synthesis of nanochain particles for targeting brain tumors. Nanoscale. 2017 Jul 13;9(27):9659-9667. doi: 10.1039/c7nr02370g. PubMed PMID: 28675230; PubMed Central PMCID: PMC5557407. [PubMed]
Johansen ML, Gao Y, Hutnick MA, Craig SEL, Pokorski JK, Flask CA, Brady-Kalnay SM. Quantitative Molecular Imaging with a Single Gd-Based Contrast Agent Reveals Specific Tumor Binding and Retention in Vivo. Anal Chem. 2017 Jun 6;89(11):5932-5939. doi: 10.1021/acs.analchem.7b00384. Epub 2017 May 22. PubMed PMID: 28481080; PubMed Central PMCID: PMC5603198. [PubMed]
Herrmann K, Erokwu BO, Johansen ML, Basilion JP, Gulani V, Griswold MA, Flask CA, Brady-Kalnay SM. Dynamic Quantitative T1 Mapping in Orthotopic Brain Tumor Xenografts. Transl Oncol. 2016 Apr;9(2):147-54. doi: 10.1016/j.tranon.2016.02.004. PubMed PMID: 27084431; PubMed Central PMCID: PMC4833967. [PubMed]
Craig SEL, Wright J, Sloan AE, Brady-Kalnay SM. Fluorescent-Guided Surgical Resection of Glioma with Targeted Molecular Imaging Agents: A Literature Review. World Neurosurg. 2016 Jun;90:154-163. doi: 10.1016/j.wneu.2016.02.060. Epub 2016 Feb 23. Review. PubMed PMID: 26915698; PubMed Central PMCID: PMC4915969. [PubMed]