Abstract 5408: SERPINB3 impact on cervical cancer cell mobility and migration
Authors: Guerrero Marlene L. Campos , Chen Li-Yun , Markovina Stephanie 
Published: March 2024

Abstract
Cervical cancer is the fourth most common cancer in women, with 311,000 deaths worldwide in 2018. About two thirds of patients with cervical cancer exhibit elevated serum levels of squamous cell carcinoma antigen (SCCA), also known as SERPINB3. SERPINB3 is associated with advanced stage and lymph node metastasis and we have previously shown it has a protective role against radiation treatment and chemotherapy induced cell death. We have also shown that SERPINB3 promotes tumor growth in both immunocompromised and immune competent murine models, yet the molecular mechanism is unknown. We have recently shown that SERPINB3 expression results in activation of signal transducer of transcription 3 (STAT3) and extracellular signal regulated kinase (ERK) in cervical cancer cells. These signaling cascades promote cell proliferation, survival, invasion, and metastasis. Proximity labeling using biotin-ligase fused to SERPINB3 revealed STAT3 and ERK as potential interacting partners. We aim to identify the molecular mechanism by which SERPINB3 promotes tumor progression, and determine if SERPINB3 drives invasion and metastasis in-vivo. We hypothesized that SERPINB3 directly interacts with and activates STAT3 and ERK leading to downstream signaling promoting invasion and metastasis. To test this hypothesis, we used cervical tumor cell lines engineered with SERPINB3 or empty vector control and determined migration by wound healing assay and downstream activation of STAT3 and ERK. Co-immunoprecipitation (co-IP) with western blot was performed to determine an interaction between SERPINB3 and STAT3 and ERK. E6/E7-expressing TC-1, and Lewis Lung Carcinoma cells, LL2, to develop a method for injecting the cervix of immunocompetent c57BL/6 albino mice (no available murine cervical carcinoma line). Wound healing assays revealed that knocking out SERPINB3 shows a decrease in wound closure in both SW756 and HT3 cervical cancer cells compared to control cells, respectively. Co-IP of STAT3 in HT3 cells revealed the presence of SERPINB3, providing further evidence for an interaction between STAT3 and SERPINB3. We were able to grow tumors in the cervix of the C57/BL6 mice and identified potential metastatic deposits in the lung. Moving forward, we plan to identify the minimal functional domain of the interaction between SERPINB3 and STAT3/ERK using a step-wise genetic approach for protein domain deletion. To determine the role of SERPINB3 on metastasis in vivo, we will use, LL2 and TC-1 engineered with the mouse orthologue mSERPINB3a to determine effect of SERPINB3 on invasion and metastasis. Conducting this study will provide insights as to how SERPINB3 may function in a pro-tumor role in cervical cancer and allow the development of SERPINB3-targeted drugs.
Citation Format: Marlene L. Campos Guerrero, Li-Yun Chen, Stephanie Markovina. SERPINB3 impact on cervical cancer cell mobility and migration [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5408.