Dysregulation of members of the epidermal growth factor (EGF) receptor (EGFR) family is associated with oncogenesis and tumor growth. Due to its relevance in cancer development, EGFR is an important target in cancer drug discovery, and several EGFR targeted therapies have already been developed. Their clinical success has, however, often been modest, reinforcing the need for a more complete understanding of the EGFR signaling pathway. This proposal focuses on the insufficiently understood role of large-scale EGFR associates (clusters) in signaling initiation and transduction, in particular. While i has long been known that ligand induced dimerization plays a critical role in receptor signaling, there is growing evidence that this textbook model needs to be augmented to account for the heterogenous lateral distribution of the receptor in the plasma membrane. The local enrichment of the receptors in ''micro-domains or ''nanoclusters'' could strongly affect cooperative receptor interactions and shift the local EGFR association equilibria through a local concentration effect. The experimental investigation of the fundamental mechanisms underlying the large-scale receptor organization with conventional fluorescence microscopy remains challenging, due to the method's limitation with regard to throughput, spatial and temporal resolution, and maximum observation time. Plasmon Coupling Microscopy (PCM) is a novel non-fluorescence based approach that uses electromagnetic interactions between noble metal nanoparticles (NPs) to investigate receptor clustering on subdiffraction limit distances (but beyond the spatial barrier o Fluorescence Resonance Energy Transfer, FRET). NP's do not blink or bleach, are very bright, and can be imaged in a conventional widefield microscope. Consequently, PCM facilitates the monitoring of EGFR clustering without limitations in observation time in many individual cells simultaneously. This competitive renewal builds upon the plasmon coupling based tools developed in the previous funding cycle and outlines a vigorous research plan to elucidate the structural origin of dynamic EGFR clustering. PCM will then be applied to test the hypothesis that receptor clustering regulates the mode and strength of signaling and to elucidate the mechanisms underlying a spatial regulation of signaling intensity and outcome. The obtained insight will improve the understanding of spatial regulation mechanisms for a broad range of receptors. Noble metal NPs are not only superb optical labels for characterizing EGFR clustering in the plasma membrane, but they also represent potential therapeutic tools to restore and enhance negative EGFR signaling after covalent attachment to EGF. This hypothesis is experimentally tested in this proposal. If successful, this strategy would provide a new approach for overcoming apoptosis evasion in cancer.

Public Health Relevance

EGFR signaling is involved in regulating normal cell proliferation and tissue development. Abnormal EGFR signaling is a cause of uncontrolled cell growth in cancer. The proposed research will provide novel nanotechnologies that will make it possible to utilize the large-scale association of EGFR as a quantitative biomarker for the optical detection of dysregulated EGFR signaling on the single cell level. This project will improve patient outcomes and quality of life by advancing the molecular understanding of cancer and by enhancing early cancer detection and screening modalities.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA138509-08
Application #
9036944
Study Section
Nanotechnology Study Section (NANO)
Program Officer
Knowlton, John R
Project Start
2009-06-01
Project End
2019-04-30
Budget Start
2016-05-01
Budget End
2017-04-30
Support Year
8
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Boston University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
049435266
City
Boston
State
MA
Country
United States
Zip Code
Khanehzar, Ali; Fraire, Juan C; Xi, Min et al. (2018) Nanoparticle-cell interactions induced apoptosis: a case study with nanoconjugated epidermal growth factor. Nanoscale 10:6712-6723
Xu, Fangda; Bandara, Asanga; Akiyama, Hisashi et al. (2018) Membrane-wrapped nanoparticles probe divergent roles of GM3 and phosphatidylserine in lipid-mediated viral entry pathways. Proc Natl Acad Sci U S A 115:E9041-E9050
Zhang, Qianyun; Reinhard, Björn M (2018) Ligand Density and Nanoparticle Clustering Cooperate in the Multivalent Amplification of Epidermal Growth Factor Receptor Activation. ACS Nano 12:10473-10485
Xi, Min; Reinhard, Björn M (2018) Localized Surface Plasmon Coupling between Mid-IR-Resonant ITO Nanocrystals. J Phys Chem C Nanomater Interfaces 122:5698-5704
Lerch, Sarah; Reinhard, Björn M (2017) Spectral signatures of charge transfer in assemblies of molecularly-linked plasmonic nanoparticles. Int J Mod Phys B 31:
Chen, Tianhong; Wang, Xiao; Alizadeh, Mohammad Hossein et al. (2017) Monitoring transient nanoparticle interactions with liposome-confined plasmonic transducers. Microsyst Nanoeng 3:
Ferreira, Mário F S; Castro-Camus, Enrique; Ottaway, David J et al. (2017) Roadmap on optical sensors. J Opt 19:
Feizpour, Amin; Stelter, David; Wong, Crystal et al. (2017) Membrane Fluidity Sensing on the Single Virus Particle Level with Plasmonic Nanoparticle Transducers. ACS Sens 2:1415-1423
Lerch, Sarah; Reinhard, Björn M (2016) Quantum Plasmonics: Optical Monitoring of DNA-Mediated Charge Transfer in Plasmon Rulers. Adv Mater 28:2030-6
Kijewski, Suzanne D G; Akiyama, Hisashi; Feizpour, Amin et al. (2016) Access of HIV-2 to CD169-dependent dendritic cell-mediated trans infection pathway is attenuated. Virology 497:328-336

Showing the most recent 10 out of 42 publications