Claudin-4 is required for vasculogenic mimicry formation in human breast cancer cells.

Yong-Feng Cui,Qiang Zhang,Ru-Bao Sun,Yun-Xiang Shi,Li-Li Wang,Gui-Lan Pan,An-Heng Liu,Miao Shi,Qiang Wang,Dai-Zhi An,Qiong Feng,Yun Shi

doi:10.18632/oncotarget.3571

Yong-Feng Cui, Qiang Zhang + Show 10 more

Open Access

https://doi.org/10.18632/oncotarget.3571

Copy DOI

Abstract

Vasculogenic mimicry (VM) refers to the unique capability of aggressive tumor cells to mimic the pattern of embryonic vasculogenic networks. Claudins are aberrantly expressed in aggressive breast cancer. However, the relationship between claudins and VM formation is not clear. We examined VM in two human breast cancer cell lines with different aggressive capabilities (MDA-MB-231 and MCF-7 cells) and one human umbilical vein endothelial cell line (HUVEC). Both HUVEC and MDA-MB-231 cells formed vascular channels in Matrigel cultures, while MCF-7 cells did not. Western blot analysis revealed a possible correlation between claudin-4 and -6 expression in breast cancer cell lines and tumor aggressiveness, with protein levels correlating with the ability to form vascular channels. Treatment of MDA-MB-231 and HUVEC cells with claudin-4 monoclonal antibodies completely inhibited the ability of cells to form vascular channels. Moreover, knockdown of claudin-4 by short hairpin RNA completely inhibited tubule formation in MDA-MB-231 cells. Overexpression of claudin-4 in MCF-7 cells induced formation of vascular channels. Immunocytochemistry revealed that membranous claudin-4 protein was significantly associated with vascular channel formation. Collectively, these results indicate that claudin-4 may play a critical role in VM in human breast cancer cells, opening new opportunities to improve aggressive breast cancer therapy.

Highlights

Breast cancer is the most common malignancy in women and is the leading cause of death among women world-wide [1]
To further investigate the matrix-associated vascular channels formed by human umbilical vein endothelial cell line (HUVEC) and MDA-MB-231 cells, we performed Periodic AcidSchiff (PAS) staining, which identifies glycogen and related mucopolysaccharides secreted by these cells to form the extracellular-matrix-rich channels
At 72 h, both HUVEC and MDA-MB-231 cells exhibited strong PAS positivity (Fig. 1b). These results provide direct evidence that aggressive breast cancer cells are more potent in Vasculogenic mimicry (VM) formation than non-aggressive cells

Summary

Introduction

Breast cancer is the most common malignancy in women and is the leading cause of death among women world-wide [1]. Despite many advances in the diagnosis and treatment of breast cancer, metastasis remains an insurmountable challenge. The molecular mechanisms are not completely understood, it is well established that the formation and growth of new blood vessels is critical for sustained tumor growth and metastasis [2]. Studies have found that benign lesions associated with high vascular density are correlated with an increased risk of developing breast cancer. Efforts to reduce the growth and spread of breast cancer focused on the mechanism(s) of angiogenesis by which tumors establish a blood supply for survival, growth, and metastasis [4]

Objectives

Methods

Results

Conclusion