Abstract C047: Snail transcription factor promotes neurite outgrowth in prostate and breast cancer cells

Abstract Snail transcription factor has been implicated in prostate cancer (PCa) and breast cancer (BCa) progression and metastasis. Cancer cell interaction with the tumor microenvironment, including the nervous system, contributes to cancer progression, however, the mechanisms are not clearly understood. Cancer cells can promote neurite outgrowth or extensions in nerve cells which can contribute to metastasis and mortality. Microtubule-associated protein 2 (MAP2) is a protein which is found within nerve cells and its function is to support the communication between neurons. This would also help the growth and the development of nerve cells. Previous research in our laboratory showed that LNCaP PCa cells engineered to overexpress Snail (LNCaP Snail) migrated and adhered more towards sNF96 or NS20Y nerve cells compared to LNCaP Neo control. Moreover, conditioned media from C4-2 non-silencing (NS) PCa and MCF-7 Snail BCa cells that express high Snail protein led to higher neurite outgrowth in PC12 nerve cells and Neural Progenitor Cells (NPCs) compared to C4-2 Snail shRNA with stable Snail knockdown (C4-2 E8) and MCF-7 Neo cells that express lower levels of Snail. With the evidence that Snail protein in cancer cells promotes neurite outgrowth in nerve cells, we hypothesize that neurite outgrowth will be associated with higher staining for MAP2. In this study, we investigated using an immunofluorescent (IF) stain to oversee the neurite outgrowth stimulated by Snail-expressing cells in neural progenitor cells (NPCs). IF using the MAP2 antibody marker would allow us to visualize the enhanced neurite outgrowth. To test this, we treated NPCs with conditioned media which has been collected from MCF-7 BCa cells and C4-2 PCa cells which either overexpress Snail protein or display knockdown of Snail protein, respectively. The control groups of our research would be MCF-7 Neo (low Snail) and C4-2 E8 (Snail knockdown) and experimental groups being MCF-7 Snail (high Snail) and C4-2 NS (high Snail). The staining control for the IF is the cells without adding the primary anti-MAP2 antibody. We first used the C4-2 NS and E8 cells with anti-androgen receptor (AR) followed by anti-rabbit conjugated with Oregon green and DAPI staining to practice the IF skills. The results showed the AR protein is localized in the nucleus overlapping with DAPI which specifically stains nucleic acid in the nucleus. Subsequently, we performed the experiment with MCF-7 Neo and MCF-7 Snail with MAP2 antibody followed by anti-rabbit conjugated with Oregon green. The MAP2 was expected to be observed in the cytoplasm and the membrane. However, we detected Oregon green signals were overlapping with DAPI signal in the whole cell including nucleus and cytoplasm. After comparing the emission wavelength of DAPI and Oregon green, they both have emissions between 500-600 nm. This interferes with our quantification of the real MAP2 signals. As a result of this we are currently employing a different secondary antibody of Cy5 which would not have an overlapping emission wavelength with DAPI. Citation Format: Janae M. Ambrose-John, Valerie Odera-Marah, Bor-Jang Hwang. Snail transcription factor promotes neurite outgrowth in prostate and breast cancer cells [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr C047.