University of Vermont

College of Medicine

Department of Pathology and Laboratory Medicine


Evans Lab Research


The Experimental Pathology Laboratory (EPL) was established in 2000 as a facility allowing pathology attendings, residents and medical students to pursue academic research pursuits.

The EPL conducts short, medium and long term projects addressing focused research questions on a wide variety of pathological conditions. All types of pathology specimens are investigated including formalin-fixed, paraffin-embedded (FFPE), fine need aspiration (FNA) and other cytology preparations, fresh-frozen tissues, and blood samples. The EPL technical repertoire includes: immunohistochemistry; chromogenic, fluorescence and silver-enhanced in situ hybridization (CISH, FISH and SISH) for DNA or RNA targets; nucleic acid extraction from pathology samples; end-point and real-time quantitative PCR; and, dot blot and Southern blot hybridization. Additionally, the EPL prepares tissue microarrays (TMAs) using archival FFPE specimens; TMAs represent a convenient resource for the rapid and economic analysis of multiple tissue specimens and can be used for IHC and ISH applications. EPL research activities have yielded more than 30 peer-reviewed publications and more than 40 published conference abstracts in the past 10 years. Human papillomavirus (HPV) infections in cervical and head and neck tumors are an area of particular interest to EPL researchers.

More recently, the EPL has interacted increasingly with the wider clinical research community at the University of Vermont (UVM)/Fletcher Allen Health Care (FAHC), sharing its experience in the handling and analysis of pathology specimens and playing a part in multi-center grant funded projects.

Education: EPL personnel contribute to teaching on molecular diagnostic and other laboratory techniques to pathology residents and medical students, and to undergraduate and postgraduate students.

Service: The EPL has a primary role in the newly established Vermont Cancer Center (VCC) Translational Tissue Core Facility. The purpose of the facility is to collect and bank freshly-frozen tissue specimens from excess surgical material and maintain a tissue database with links to clinicopathological data whilst assuring regulatory compliance. Activities may extend to acquiring blood samples complementary to the surgical specimens, providing fresh tissues for primary cell culture, and collecting autopsy samples, and might eventually encompass the extraction and banking of DNA and/or RNA and/or protein from surgical specimens. A repository of banked TMAs may also be established. The Tissue Core Facility aims to represent a centralized shared resource, providing a professional, efficient, and standarized service, facilitating the availability of human tissue specimens for translational research activities and the timely completion of such activities.

Clinical: The EPL is CLIA registered for clinical diagnostic tests including HPV screening by PCR and in situ hybridization, and confirmation of patient specimen identity by genotyping.

In Alliance with: Khon Kaen University, Thailand; Sri Aurobindu Institute of Medical Sciences, India; University of Witwatersrand, South Africa

Selected current EPL projects:
  • Amplification of TOP2A and HER2 in small cell lung carcinoma (SCLC). This study is using fluorescence in situ hybridization (FISH) to investigate the amplification of TOP2A and HER2 genes on chromosome 17 in fine needle aspiration samples prepared from SCLC. SCLC may be treatable by anthracyclines that inhibit TOP2A. In tumors from other organ sites, both TOP2A and HER2 are potential markers of candidate patients for anthracyclines therapy.
  • Prognostic markers of glioblastoma multiforme (GBM). This brain tumor has a poor prognosis. The study is examining a panel of seven antibody markers to assess their utility in distinguishing the most/least aggressive forms of GBM.
  • The use of tissue microarrays (TMAs) in the assay of MLH1, MLH2, MSH6, and PMS2 protein expression in colorectal carcinoma. Microsatellite instability characterizes ~15% of colorectal cancers. Immunohistochemical assay of MLH1, MLH2, MSH6, and PMS2 is commonly used to determine whether a tumor has an intact or deficient mismatch repair system. This study is examining whether TMAs (versus whole tissue sections) can be used to accurately gauge mismatch repair status.
  • Vitamin D Receptor (VDR) and Ki-67 expression in benign breast lesions. As part of study on breast cancer prevention, this study is examining VDR and Ki-67 protein expression in fine needle aspiration samples of benign breast lesion from patients with diets supplemented with vitamin D versus patients not receiving the supplement.
  • HPV chromogenic in situ hybridization (CISH) and p16INK4a immunohistochemical (IHC) staining patterns and the diagnosis of cervical lesion grade. This study is comparing HPV CISH and p16INK4a IHC staining patterns with histological diagnosis and patient outcomes in several hundred preinvasive cervical lesions to assess CISH and IHC utility in lesion diagnosis.
  • HPV prevalence in normal cervical smear samples from high-school and college age females. HPV is the established cause of invasive cervical carcinoma. This study is examining the range and prevalence of HPV types in young women with normal cervical cytology to obtain baseline data about this common infection.
  • HPV in rare cervical carcinomas. Although HPV is the accepted cause of squamous and adenosquamous cervical carcinoma, it is less certain that rare forms of cervical cancer are also caused by HPV. This study is examining HPV in rare tumors by PCR, CISH and IHC.
  • HPV genotype distribution in cervical carcinomas from India. In collaboration with the Sri Aurobindu Institute of Medical Sciences, Indore, India, this study is examining the range and prevalence of HPV types in several hundred Indian cervical carcinomas by PCR, ISH and IHC. These data are important for supporting HPV vaccination and health education programs in India.
  • HPV genotype distribution in head and neck tumors from black and white South Africans. HPV is established as the cause of a subset of head and neck tumors. Recent US data has indicated that HPV is more common in Caucasian than African Americans. This study, in collaboration with the University of Witwatersrand, South Africa, is examining whether HPV is racially distributed in head and neck tumors from South Africa.



HER2 non-amplification (A) and amplification (B) in tumor cells demonstrated by fluorescence in situ hybridization (FISH). Green signals represent chromosome 17 centromerers and red signals the HER2 locus at 17q12.


Low (A) and high-grade (B) cervical lesions stained by immunohistochemistry for p16INK4a.

HPV chromogenic in situ hybridization

HPV chromogenic in situ hybridization (CISH) signals in low-grade (A) and high-grade (B) preinvasive cervical lesions and invasive cervical carcinoma (C). diffuse signals (episomal HPV) are indicated by blue arrows and punctuate signals (integrated HPV) are shown by red arrows.

Last modified January 08 2012 06:42 PM