Abstract C017: Detection of wild-type and truncated HMGA2 in prostate cancer tissues using RNA in situ hybridization

Abstract High mobility group A2 (HMGA2), a non-histone protein, is known to promote epithelial-mesenchymal transition (EMT), which plays a critical role in prostate cancer progression and metastasis. Both full-length HMGA2 (WT-HMGA2) and truncated (lacking the 3’UTR) HMGA2 (TR-HMGA2) isoforms are overexpressed in several cancers such as lung carcinomas, ovarian cancer, breast cancer, and gastric cancer. However, there is no study investigating the expression and differential roles of WT vs truncated HMGA2 isoforms in prostate cancer. Our previous results indicated that the overexpression of HMGA2 in LNCaP cells increased cell viability and migration for both wild-type and truncated HMGA2. Promotion of EMT was observed in wild-type, but not truncated HMGA2. Reactive oxygen species (ROS) levels were increased with truncated HMGA2 more than wild-type HMGA2. Therefore, wild-type and truncated HMGA2 may play different roles on cancer progression and metastasis. The goal of this study is to examine the expression of wild-type vs. truncated HMGA2 in prostate cancer patient tissue. We have developed a way to detect location and expression of wild-type and truncated HMGA2 using RNA in situ hybridization (RISH). The specific probes’ hybridization followed by a serial signal amplification process allows us to locate and quantify the HMGA2 isoforms in Formalin-Fixed Paraffin-Embedded (FFPE) tissue specimens from cancer patients. Several prostate tissue samples and a prostate cancer tissue microarray that includes 35 patients from different races, stages of cancer, and metastasis status was analyzed. Our results showed increased HMGA2 expression (both wild-type and truncated) in several prostate cancer samples with higher stage cancer. We also observed that most wild-type and truncated HMGA2 is located within the nucleus, while some wild-type isoforms were detected within the cytoplasm. We will further quantify the expression levels to examine whether they are associated with tumor stage and/or race. These studies are the first to examine HMGA2 isoform expression and localization in prostate patient tissue and may offer novel therapeutic intervention strategies based on HMGA2 isoform expression. Citation Format: Bor-Jang Hwang, Mojisoluwa Awolowo, Taaliah Campbell, Ohuod Hawsawi, Sharon Harrison, Denise Gibbs, Camille Ragin, Valerie Odero-Marah. Detection of wild-type and truncated HMGA2 in prostate cancer tissues using RNA in situ hybridization [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C017.