# Evolution of transmissible cancers and genetics of host resistance

> **NIH NIH K22** · PACIFIC NORTHWEST RESEARCH INSTITUTE · 2020 · $193,017

## Abstract

SUMMARY:
Cancer is not a single event. It continues to evolve as is multiplies, spreads through its host, and evades its
host’s basic mechanisms of recognition. We identified a retrotransposon, Steamer, amplified in a leukemia-like
disease in soft-shell clams. Through investigation of integration sites of the Steamer retrotransposon, mtDNA
SNPs, and polymorphic microsatellites, I discovered that the disease is spread by horizontal transmission of
leukemic cells themselves, acting as a contagious cancer, and we have found that this is a widespread
phenomenon in multiple bivalves. Based on my preliminary investigations while under the mentorship of Dr.
Stephen Goff at Columbia University, I propose to investigate the evolution of transmissible cancers and the
role of the retroelement, Steamer, in development of the disease as well as the mechanism of transmission of M.
arenaria leukemia and the development of host resistance. This research will build on my previous training in
retrovirology and cancer biology as I transition into independent academic research position where I will
develop this cancer system as a unique model of leukemia. This will be done in three independent, but
interconnected aims: (1) Investigate the mutations and selective pressures which drive cancer evolution
including the role of the Steamer retrotransposon, (2) determine the route and mechanism of cancer cell
transmission, and (3) identify the host genetic determinants of cancer cell engraftment/rejection. This unique
invertebrate cancer model will allow us to learn more about cancer evolution and the role of retroelements in
cancer, and to investigate leukemia acquisition and fundamental mechanisms of self/nonself recognition.

## Key facts

- **NIH application ID:** 9899956
- **Project number:** 5K22CA226047-03
- **Recipient organization:** PACIFIC NORTHWEST RESEARCH INSTITUTE
- **Principal Investigator:** Michael Jeffrey Metzger
- **Activity code:** K22 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $193,017
- **Award type:** 5
- **Project period:** 2018-05-01 → 2021-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9899956

## Citation

> US National Institutes of Health, RePORTER application 9899956, Evolution of transmissible cancers and genetics of host resistance (5K22CA226047-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9899956. Licensed CC0.

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