# Understanding the Relationship of Repeat Expression and Metastasis

> **NIH NIH R01** · MASSACHUSETTS GENERAL HOSPITAL · 2021 · $137,750

## Abstract

PROJECT SUMMARY
Metastasis is the cause of mortality in the majority of solid cancers including colorectal cancer. Understanding
the metastatic process will open the door to developing new therapeutic and diagnostic modalities for the care
of cancer patients. Analysis of circulating tumor cells (CTCs) in cancer mouse models has revealed the abundant
expression of repetitive element RNAs implicating their role in the metastatic cascade. Many of these repeat
RNAs are capable of retrotransposition through reverse transcription (RT), which leads to alterations in the
cancer genome. Our preclinical cell line and mouse models have demonstrated the ability of these endogenous
RT to be blocked by nucleoside reverse transcriptase inhibitors (NRTIs) commonly used for viral infections.
Interestingly, we have found anti-cancer effects of NRTIs in multiple colorectal cancer (CRC) preclinical models
that led to a Phase II clinical trial of the NRTI 3TC in metastatic CRC patients. In this proposal, we plan to:
1) Understand the effects of 3TC on in vitro and in vivo metastatic capability in CRC
2) Compare the expression of repeat RNAs in paired primary tumor and liver metastases resected from patients
with CRC
3) Characterize the dynamics of CTCs in patients treated with 3TC in the phase II clinical trial

## Key facts

- **NIH application ID:** 10380304
- **Project number:** 3R01CA240924-03S1
- **Recipient organization:** MASSACHUSETTS GENERAL HOSPITAL
- **Principal Investigator:** Benjamin Greenbaum
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $137,750
- **Award type:** 3
- **Project period:** 2019-07-01 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10380304

## Citation

> US National Institutes of Health, RePORTER application 10380304, Understanding the Relationship of Repeat Expression and Metastasis (3R01CA240924-03S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10380304. Licensed CC0.

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