Faculty Member – Randy Haun

Randy S. Haun, Ph.D. Randy Haun

Associate Professor

Office: WRCI, Room 427
Phone: 501-686-8594
FAX: 501-686-6517
E-mail: HaunRandyS@uams.edu

Pancreatic adenocarcinomas

Currently, there is a lack of any specific or sensitive diagnostic test for early stages of pancreatic cancer. Although a wide variety of tumor-associated antigens have been evaluated as markers for screening and diagnosing pancreatic cancer, most have proven ineffective due to their low sensitivity and cross reactivity with other tumors. To identify potential tumor markers for the early detection of pancreatic cancer, we have used both genomic and proteomic technologies to identify differentially genes and proteins, respectively, from tissue samples obtained from pancreatic cancer patients compared with unaffected individuals.

In particular, from studies aimed at identifying proteases that selectively expressed in pancreatic tumors compared with normal pancreatic tissues, we found two proteases that are overexpressed in pancreatic cancer: kallikrein 7, previously known as stratum corneum chymotryptic enzyme (SCCE) and meprin beta, an astacin-family metalloproteinase that are normally only expressed at high levels in mammalian renal and intestinal brush-border membranes. We are currently trying to determine the role of these proteases in the development and spread of this devastating disease.

Oncoproteomics is rapidly emerging as a powerful tool for detection of cancer-derived gene products from biologic fluids to aid in early diagnosis of cancer. A number of proteomics approaches have emerged which can be used to provide a powerful tool for biomarker discovery. Previously, we have successfully used surface-enhanced laser desorption/ionization (SELDI) mass spectrometry (MS) to develop classification models from patient serum that could distinguish PaC patient serum from control serum samples with high sensitivity and specificity. Currently, we are using a complementary proteomic approach that facilitates the identification of intact proteins identified in serum protein profiles and expands the size range of peptides/proteins that can be detected. Using the state-of-the-art proteomic technique of two-dimensional liquid chromatography followed by tandem mass spectrometry (2-D LC/MS/MS), we may be able to identify a panel of biomarkers that can be used for the early detection of pancreatic cancer.