Enhancing the therapeutic effect of receptor radionuclide therapy in neuroendocrine tumors by somatostatin receptor upregulation - Abstract
In this application, I propose a novel precision medicine approach aimed at enhancing the therapeutic effect of
peptide receptor radionuclide therapy (PRRT) in gastroenteropancreatic neuroendocrine carcinomas (GEP-
NET)s. This award will provide protected research time and training in preparation for independent R01 funding.
Over the past decade, there has been a fundamental paradigm shift in the management of GEP-NETs through
use of somatostatin receptor type 2 (SSTR2) targeted PRRT. The FDA has recently approved clinical use of
177Lu-DOTATATE (Lutathera), a somatostatin analog loaded with the therapeutic radionuclide 177Lutetium, for
PRRT of SSTR2-expressing GEP-NETs. Patients with low SSTR2 expressing tumors are often unresponsive to
PRRT, leaving them with limited treatment options. Low SSTR2 expression is mainly mediated through
epigenetic gene silencing. Here we propose to upregulate SSTR2 expression by using short-term pulsed
epigenome-modulating chemotherapy to re-sensitize NETs to PRRT and improve its therapeutic index while
reducing the non-target side effects of PRRT. In preliminary experiments we have shown dose-dependent robust
upregulation of SSTR2 both in vitro and in vivo by targeting a series of ploycomb group proteins (PcG) involved
in gene silencing. We propose to assess this approach in a range of models with the goal of optimizing the dosing
and timing of the de-repression chemotherapy. If successful, this study will pave the way for clinical trials and
near-term translation using clinically approved imaging and PRRT agents to markedly improve the effectiveness
of therapy by increasing the radiation dose delivered to tumors relative to non-target organs.
This proposal will enable me to become an independent investigator in translational precision imaging. My
ultimate goal is to lead an independently-funded research program in the translation of novel theranostics for
improving cancer care. To facilitate my progression to independence, I have designed with my mentors a career
development plan involving tailored didactic coursework, workshops, seminars, and hands-on training that will
provide me with formal education in epigenetics, computational biology, radiochemistry and radiotherapy
dosimetry. The primary mentor for this project is Dr. Umar Mahmood, a renowned expert in translational precision
imaging. Drs. Adam Bass and Ciprian Catana will serve as secondary mentors, lending their expertise in cancer
genetics and epigenetics, and radiation dosimetry modeling, respectively. In addition, I will work with a team of
advisors/consultants from MGH, including Drs. David Ryan, Daniel Chung, Ryan Corcoran, and Peter Caravan
who will provide additional expertise and guidance as part of my scientific advisory committee.
This research will be performed at the Martinos Center, a world-leading institution for translational imaging
research. The project will greatly benefit from the unique resources of the Martinos Center, MGH Cancer Center
and other MGH core facilities. This collaborative framework will help me foster relationships with MGH and Dana-
Farber Cancer Centers and leading experts in NETs to increase the impact and visibility of my research.