Mary Carmen Zuñiga


Currently a junior at Northern Arizona University and working towards a Bachelor's degree in Biology with a minor in Chemistry, I want to pursue a medical and research career in the oncology field.

Research interests

As a URM scholar, my research deals with depleted uranium and UVB-light cytotoxicity and mutagenics. However, my range of interests includes:

Molecular and chemical mechanisms for cancer induction

  • uranium and UV-light mechanisms of damaging skin    cells in ways that may lead to cancer
  • skin cancer
  • mutagenesis, UV-light induction, and molecular mechanisms

Nanotechnology applied to cancer research

  • self-propelled micro- and nano-scale devices and their biomedical applications
  • photolithography used for creation of micro-scale grippers potential medical applications
  • 3-D cell culture and tissue engineering  
  • diabetes Mellitus
  • genetics and hereditary implications

My research

Cellular damage and DNA-mutations induced by depleted uranium and UVB-light in skin cells

Mentored by Dr. Diane Stearns and supported by the Undergraduate Research Mentoring, I started working with depleted uranium and skin cells during the fall 2010. Our laboratory focuses on how some metals may damage DNA in ways that may lead to cancer. 

What is depleted uranium?

Depleted uranium (DU) is the leftover uranium after 235-U has been collected to be used for nuclear purposes. Because of its composition, it is the least radioactive form of uranium. However, its repercussions in society are highly controversial because this form of uranium is regularly used in the military, especially for tank armor because of its high density and because it is hard to penetrate.

People who work in the military can be exposed to depleted uranium by inhalation of the particles after impact and also by embedding of DU-containing shrapnel within the skin. In addition, civilians are subjects of exposure to DU through contaminated water and soil.

Why depleted uranium?

According to the National Cancer Institute, "at least two thirds of all the cases of cancer in the United States are due to a wide variety of natural and man-made substances in the environment," and some of these carcinogens are metals such as uranium and chromium, which are the metals we study in our lab.

Why UVB-light?

The uranyl ion (UO22+) is known to be photoactivated by UVB-light in the 300-400 nm range. When it is photoactivated, it creates an oxygen-centered radical bound to uranium(V). However, none has studied what this can cause at the DNA level. This research aims to look into the effects of the photoactivated uranyl ion at the molecular level in human skin. It is proposed that its photoactivation by UVB light may contribute to the uranium toxicity in human skin.

My research questions

  • How much cell damage can DU cause in skin cells?
  • How much cell damage can UVB-light cause in skin cells?
  • What mutations are induced by both factors combined (DU + UVB)?

Answering the questions

In order to answer my research questions, I am using cell culture and molecular techniques. My URM prospectus addresses the materials and methods used to answer the questions and any other details about the project.