Chromosome Instability Drives Metal-Induced Lung Cancer - PROJECT SUMMARY/ABSTRACT
Lung cancer is the leading cause of cancer death with little improvement in survivability over many decades.
Understanding and support for lung cancer have suffered from the stigma that the disease is merely a
consequence of tobacco use, when in fact other agents are a major factor in the disease. Many people with lung
cancer have never used tobacco and only a minority of tobacco users actually get lung cancer. However, while
lung cancer kills more people than colon, breast and prostate cancer combined, it receives less federal funding
than each of these cancers alone. Chromosome instability (CIN) is a hallmark of lung cancer. All established
lung carcinogens cause CIN, yet the mechanisms for how they do have received little attention. Metal exposure
is a worldwide health concern. Metals cause lung cancer, and carcinogenic metals are a component in tobacco.
Metals are poor mutagens but potently induce CIN, yet, how metals cause lung cancer and CIN is poorly
understood. We focus our R35 program on understanding the mechanisms for how metal carcinogens induce
CIN in lung cancer. We use hexavalent chromium [Cr(VI)], a human lung carcinogen of major public health
concern, as our primary metal of interest, although we will compare Cr(VI) outcomes with other metal lung
carcinogens. We will study how Cr(VI) induces structural and numerical CIN, considering human lung fibroblast,
epithelial and induced pluripotent stem cell models. We will progress our studies from individual cell types to
more complex, three-dimensional, mixed cell culture studies. We enhance and deepen our understanding of
these mechanisms with a One Environmental Health approach, which leverages the ability of wildlife to resist
Cr(VI)-induced CIN and provide novel insights into its carcinogenic mechanism. Moreover, we maximize the
impact of these findings by translating our outcomes into animals and into a powerful and unique collection of
human subjects and populations ranging from workers with primarily Cr(VI) exposure, to workers with a mixed
metal exposure including Cr. This combined approach of humans, animals and cell lines with One Environmental
Health tools will give us unprecedented insight into how metals induce structural and numerical CIN. In particular,
we will define: 1) key mechanisms for metal-induced CIN; 2) how these mechanisms persist and are heritable at
the cellular level to cause neoplastic disease; and 3) how they translate to animals and humans. Thus, our
proposed R35 program will revolutionize our understanding of Cr(VI), CIN, metal carcinogenesis, and lung
cancer while also providing important insights for other cancers that involve CIN. Outcomes will include major
scientific breakthroughs in understanding: 1) how metals cause normal human lung cells to become neoplastic;
2) how to detect this neoplastic transformation when it occurs; 3) how to more effectively target lung cells that
have transformed and 4) how to prevent neoplastic change from occurring, leading to improved risk assessment,
treatments, and health outcomes for people exposed to metals.
