Tumor suppressor miR-218 directly targets epidermal growth factor receptor (EGFR) expression in triple-negative breast cancer, sensitizing cells to irradiation

Abstract

Purpose MicroRNA-218 (miR-218) is a key regulator of numerous processes relevant to tumor progression. In the present study, we aimed to characterize the relationship between miR-218 and the Epidermal Growth Factor Receptor (EGFR) as well as to understand downstream effects in triple-negative breast cancer (TNBC). Methods We assessed miR-218 and EGFR expression in cell lines and publicly available primary breast cancer gene expression data. We then overexpressed miR-218 in two TNBC cell lines and investigated effects on EGFR and downstream mitogen-activated protein (MAP) kinase signaling. Luciferase reporter assay was used to characterize a direct binding interaction between miR-218 and EGFR mRNA. Digital holographic microscopy helped investigate cell migration and dry mass after miR-218 overexpression. Cell division and invasion were assessed microscopically, while radiation response after miR-218 overexpression alone or combined with additional EGFR knockdown was investigated via clonogenic assays. Results We found an inverse correlation between EGFR expression and miR-218 levels in cell lines and primary breast cancer tissues. MiR-218 overexpression resulted in a downregulation of EGFR via direct binding of the mRNA. Activation of EGFR and downstream p44/42 MAPK signaling were reduced after pre-miR-218 transfection. Cell proliferation, motility and invasiveness were inhibited whereas cell death and mitotic catastrophe were upregulated in miR-218 overexpressing cells compared to controls. MiR-218 overexpressing and EGFR siRNA-treated cells were sensitized to irradiation, more than miR-218 overexpressing cells alone. Conclusion This study characterizes the antagonistic relationship between miR-218 and EGFR. It also demonstrates downstream functional effects of miR-218 overexpression, leading to anti-tumorigenic cellular changes.

Genetic association of CCL18 and EGF genes elevate the risk of breast cancer

“…A 53-amino acid polypeptide known as epidermal growth factor (EGF), has the ability to affect the differentiation and proliferation of a wide range of cells. Numerous breast cancer cell lines, particularly ER-negative tumor cells, as well as primary tumors and metastases in humans, have been shown to express EGF receptors [11]. Both healthy and cancerous mammary epithelial cells coexpress a variety of related peptides to epidermal growth factor (EGF), including transforming growth factor c (TGFc), amphiregulin (AR), heregulin (HRG), and cripto-1 (CR-1).…”

Yttrium Functionalized Reduced Graphene Oxide Nanocomposite-Based Aptasensor for Ultrasensitive Detection of a Breast Cancer Biomarker

“…2,3 In this context, a noteworthy biomarker over cancer tumorigenic cells is the epidermal growth factor receptor (EGFR) for which altered expression and downstream signaling cascades have been reported to be associated with the worsening of the cancerous condition. 4,5 Overexpression of EGFR receptors and excessive levels of EGFR antigen have been associated with cancer; therefore increasing research studies have been conducted to detect EGFR in cancer patients' serum samples. 6,7 Enzymelinked immunosorbent assay, 8 PCR, 9 electron paramagnetic resonance spectrometry, 10 hydrophilic interaction liquid chromatography/mass spectrometry, 11 surface plasmon reso-nance, 12,13 and electrochemical voltammetry methods 6 are some of the analytical techniques currently used to detect EGFR.…”

“…Due to the associated risk and improved means of ensuring a humane healthcare system, cancer biomarker detection has recently had a noteworthy impact on cancer research. Several biomarkers, EGFR, carcinoembryonic antigen, HER-2, CA-125, CD44, etc., have been categorized as valid biomarkers associated with breast cancer. , In this context, a noteworthy biomarker over cancer tumorigenic cells is the epidermal growth factor receptor (EGFR) for which altered expression and downstream signaling cascades have been reported to be associated with the worsening of the cancerous condition. , Overexpression of EGFR receptors and excessive levels of EGFR antigen have been associated with cancer; therefore increasing research studies have been conducted to detect EGFR in cancer patients’ serum samples. , Enzyme-linked immunosorbent assay, PCR, electron paramagnetic resonance spectrometry, hydrophilic interaction liquid chromatography/mass spectrometry, surface plasmon resonance, , and electrochemical voltammetry methods are some of the analytical techniques currently used to detect EGFR. However, these techniques have limited specificity and selectivity; therefore the development of trustworthy and affordable analytical approaches for EGFR biomarker identification is of utmost importance.…”