Dr. James Hoerter is inter­ested in find­ing out what causes the early stages of melanoma by study­ing zebrafish.

Hoerter and his Biology 103 lab recently started using zebrafish as a model to inves­ti­gate the early stages that lead to melanoma.

Hoerter, a pro­fes­sor in the Biological Sciences Department, spent a semes­ter in Ireland while on a U.S. Fulbright Fellowship trip. While on the trip, he worked with the radi­a­tion and envi­ron­men­tal sci­ence group on the cel­lu­lar and sub­cel­lu­lar responses to radi­a­tion. After encoun­ter­ing sev­eral labs in Ireland using fish for research, he was impressed with how zebrafish were being stud­ied to indi­cate the main cause of melanoma.

“What we don’t know is how melanoma really begins,” said Hoerter.

He explained that melanocytes, which are stem cells in the skin, might be involved in UV-induced melanoma.

Hoerter said he received sev­eral grants to begin the research project, adding that Ferris pur­chased the cham­ber
for the zebrafish.

“To test our hypoth­e­sis, we have to irra­di­ate melanocyte stem cells. The zebrafish are treated with a non-toxic chem­i­cal solu­tion that elim­i­nates all adult melanocytes,” said Hoerter. “Afterwards, we irra­di­ate them and observe the fish to see if they develop melanoma.”

The stripes that appear on the zebrafish van­ish after they are irra­di­ated. However, when the fish are removed from the non-toxic chem­i­cal solu­tion and placed in fresh water, the melanocytes grow back and the stripes reap­pear on the zebrafish.

“Zebrafish have genes that are very sim­i­lar to humans,” said Hoerter.

Hoerter explained the process that plays a role in the cause of early stage melanoma. He said that when a melanocyte is killed, a stem cell receives the mes­sage and pro­duces new stem cells.

“We think UVA (ultra­vi­o­let rays) dam­ages melanocyte stem cells,” said Hoerter. He said new melanocytes are needed to pro­duce new stem cells. If the melanocytes are dam­aged, a per­son is likely to get melanoma.

UVA rays might be con­tribut­ing to melanoma, said Hoerter. The zebrafish model is being used for research to dis­cover if UVA rays are the main cause, rather than UVB rays, “which can cause other forms of skin can­cer and melanoma as well,” said Hoerter.

Hoerter cred­its Richard Marble, the direc­tor of the Animal Care Facility, for help­ing out with the project and stu­dents Ryan Freye and Kristen Eischens, who are inter­ested in help­ing him out. Some of Hoerter’s stu­dents are coau­thors of his research papers on the experiment.

“I really depend a lot on my stu­dents,” said Hoerter.

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Editor’s Note: be sure to check out the fea­ture pho­tos.