Abstract

To gain insight into the mechanism of cancer progression, we examined the isoform-specific roles of actin capping protein (CPβ1 and CPβ2) related to actin cytoskeletal dynamics and metastatic progression in human uterine epithelial cells (HeLa). We employed qPCR to determine the relative expression levels of CPβ1 and CPβ2 in actively growing HeLa cells. Our findings confirmed that CPβ1 and CPβ2 are differentially expressed, with CPβ2 being the predominant isoform, two-fold higher, consistent with its expression in other non-muscle tissues. To extend our expression studies, the localization and spatial distribution of the isoforms were visualized via immunolocalization studies using isoform-specific monoclonal antibodies in HeLa cells. Immunochemistry staining revealed distinct and overlapping subcellular localization patterns for CPβ1 and CPβ2. CPβ1 was broadly distributed, with enrichment in the perinuclear region and punctate cytoplasm distribution, while CPβ2 was localized at the cell periphery, particularly in structures like lamellipodia, filopodia, and stress fibers.

Finally, we transiently overexpressed GFP-CPβ1 and GFP-CPβ2 to evaluate isoform-specific effects on actin organization and cell morphology. Our results showed isoform-specific changes in actin organization, cell morphology, and membrane dynamics. CPβ1 and CPβ2 overexpression induced distinct phenotypes, indicating non-redundant roles in actin cytoskeleton remodeling and metastatic behavior. Overexpression of CPβ2 led to a reduction in circularity and increased surface area compared to CPβ1. Our findings show that CPβ1 and CPβ2 play distinct roles in regulating actin dynamics, leading to the formation of metastatic phenotypes in uterine epithelial cells. The isoform-specific functions of CPβ1 and CPβ2 may provide new insight into the mechanism of cancer migration and may offer a potential target for antimetastatic therapies.

Advisor

Marilyn Hart

Committee Member

David Sharlin

Committee Member

Allison Land

Date of Degree

2025

Language

english

Document Type

Thesis

Degree

Master of Science (MS)

Program of Study

Biology

Department

Biological Sciences

College

Science, Engineering and Technology

Recommended Citation

Osamudiamen, E. (2025). Characterization of actin capping protein beta isoform specific dynamics in metastatic cells [Master’s thesis, Minnesota State University, Mankato]. Cornerstone: A Collection of Scholarly and Creative Works for Minnesota State University, Mankato. https://cornerstone.lib.mnsu.edu/etds/1549/