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Our planet, our health: Environment’s effect on cancer, diabetes

To commemorate World Health Day, we are proud to highlight several City of Hope initiatives exploring how the world around us affects our well-being.

“Poverty is a carcinogen”

It is a sobering thought, laid out in stark terms by the National Cancer Institute:
“Exposure to a wide variety of natural and man-made substances in the environment accounts for at least two-thirds of all the cases of cancer in the United States.”
Whether it’s asbestos in building materials, water and air pollution, or even the presence of toxic trash in a dilapidated neighborhood playground, what we breathe, eat, drink or walk through during our day-to-day activities can harm us.
But it’s more than just the presence of dangerous substances. It’s the lack of healthy options as well. And underserved communities are at greater risk, experts say.
“Poverty is a carcinogen,” declared Samuel Broder, former NCI director.
Kimlin Ashing

Kimlin Tam Ashing, Ph.D.

Poor neighborhoods often lack healthful food choices. “One of the keys to better health is eating more fruits and vegetables,” said Kimlin Tam Ashing, Ph.D., professor and director of the Center of Community Alliance for Research & Education (CCARE) at City of Hope. “But how are you going to do that in a food desert? What are you going to do when your primary source of food is a liquor store?”

CCARE was established to improve health care access, disease diagnosis and treatment outcomes for ethnic minorities and others living in lower socioeconomic communities.
“We understand that there are associations between environment and cancer,” said Ashing. “We can clearly see the relationship between poverty and poor health outcomes, for example. And although we don’t always understand the exact mechanism of that relationship, that doesn’t mean we can’t act.”
To create a more healthful community, the so-called “built environment” must be improved, from better education to affordable homes, access to low-cost, high-nutrition foods and safe places to be physically active and play. CCARE works as a community resource, encouraging healthy food retailers to accept EBT cards (California’s version of food stamps) and place healthy food in more visible areas of the store. When large-scale change is necessary, the team teaches community members to lobby on their own behalf.

TRACER Tracks Lung Cancer Among Blacks

It’s a curious paradox.
Although the racial gap in lung cancer cases appears to be closing, likely due to the success of anti-smoking campaigns, Black men still have a higher risk of developing lung cancer compared to white men, even though they tend to smoke less. Black patients are also more likely than white patients to be diagnosed at later stages and to receive no treatment at all for their cancer.
Victoria Seewaldt

Victoria Seewaldt, M.D.

City of Hope is one of three institutions sharing in a $3 million grant from the National Cancer Institute to establish the Translational Research Center in Lung Cancer Disparities, or TRACER. Working with community groups, health departments and other stakeholders in California, Virginia and South Carolina, TRACER seeks to identify cancer risks specific to Black communities.

One potential target is pollution.
“We need to better understand how disparities in exposure to air pollution contributes to lung cancer in Black men and women,” said Victoria Seewaldt, M.D., Ruth Ziegler Chair in Population Sciences at City of Hope and leader of TRACER’s Developmental Research Program. “Now is the time for change. Our goal is to generate the data to drive improvement in air quality, particularly for individuals living near highways and factories.”
Stress may play a role as well.
TRACER will investigate how stress and smoking interact with gene expression to raise lung cancer risk for Black men. Preliminary data shows that Black men tend to express the PRMT6 gene — which drives lung tumor development — at higher levels than white men, and smoking further stimulates PRMT6 expression. This project will look into the role stress plays in the development of lung cancer, and also create early detection tools suitable for use in the Black population.
The three-year study is a first step toward establishing a more permanent research program devoted to ending racial inequities in lung cancer.

Chemicals and Cancer

Much of our modern life would be impossible without the industrial chemicals that go into so many of the products we rely on and take for granted. But those conveniences come with a price: they may elevate our risk of certain cancers.
Shiuan Chen, Ph.D., professor and chair of the Department of Cancer Biology at City of Hope, is investigating two areas in particular: BPA and PBDEs.

Shiuan Chen, Ph.D.

BPA — bisphenol A — is everywhere. It’s used in polycarbonate plastics, epoxy resins, dental sealants and thermal paper used in receipts. BPA is one of the highest volume chemicals produced worldwide and is found pervasively in the environment worldwide. Many people, especially those in lower income communities, come in contact with BPA by handling low-cost food packaging.

PBDE’s — polybrominated diphenyl ethers — number in the hundreds. They are primarily used as flame retardants in foams, textiles, plastics, electronic devices, building materials, furnishings, airplanes, motor vehicles and more.
We’ve known for some time that BPA and PBDEs affect our endocrine systems, acting like the female hormones estrogen and progesterone in the body. Chen’s research is designed to find out whether these chemicals increase the risk of breast cancer, and, if so, to influence public policy.
“We want to produce strong scientific evidence to convince governmental regulatory agencies to stop the use of such environmental chemicals,” he said. “We want to increase awareness among the general population and encourage them to voice their concerns to the government.”

Diabetes: Obesity and Epigenetics

People with diabetes are not born. They’re most often made. Especially in the case of type 2 diabetes, external factors, such as an improper diet leading to obesity, can trigger the disease every bit as much as one’s DNA profile, if not more so.
Rama Natarajan

Rama Natarajan, Ph.D.

“It’s not just about genetics now, but epigenetics as well,” said Rama Natarajan, Ph.D., the National Business Products Industry Professor in Diabetes Research. Epigenetics refers to changes to genes caused by external factors, including nutrients, that don’t change the DNA sequence. These changes can linger even after the patient switches to a healthier diet and loses weight. They can also be passed to the next generation.

Natarajan has spent decades researching diabetes and its complications. Her lab has found that the type of systemic, low-grade inflammation that often occurs in the bodies of obese people is a strong risk factor for developing diabetes and related cardiovascular complications. This inflammation may occur because a previously unknown protective long non-coding RNA called macrophage inflammation-suppressing transcript (MIST) diminishes during obesity in mice and humans, which may contribute to metabolic dysfunction.
“Our goal is to be able to facilitate early interventions that would prevent the progression to severe complications,” Natarajan said.