Female breast Cancer (BRCA) is one of the most common forms of cancer and the fifth leading cause of cancer mortality worldwide. BRCA has now exceeded lung cancer as the leading cause of cancer incidence in 2020 with an estimated 2,261,419 (11.7% of all sites) new cases and 684,966 (6.9% of all sites) deaths globally. It accounts for 1 in 4 cancer cases and 1 in 6 cancer deaths, ranking first for incidence in the vast majority of countries (159 of 185 countries) and mortality in 110 countries among females [1]. Incidence rates are 88% higher in developed countries than in developing countries (55.9 and 29.7 per 100,000, respectively), with the highest incidence rates (> 80 per 100,000) in Australia/New Zealand, Western Europe (Belgium has the world's highest incidence), Northern America, and Northern Europe and the lowest rates (< 40 per 100,000) in Central America, Eastern and Middle Africa, and South Central Asia. However, women living in developing countries have 17% higher mortality rates compared with women in developed countries (15.0 and 12.8 per 100,000, respectively) because of high fatality rates, with the highest mortality rates found in Melanesia, Western Africa, Micronesia/Polynesia, and the Caribbean (Barbados has the world's highest mortality) [1, 2].
According to the WHO, a proper definition of biomarkers encompasses "seemingly any data indicating a connection between a biological system and a possible danger, which may be chemical, physical, or biological". It is a biological molecule that can be discovered in blood, other bodily fluids, or tissues and is a marker of a healthy or unhealthy process. The observed reaction can be physiological, functional, or cellular biological [3]. Particularly, the term "cancer biomarker" refers to a biological compound produced by a tumor cell or by human tissues in response to cancer. Cancer biomarkers (CBs) might be proteins, peptides, DNA (germline or somatic), RNA, metabolites, hormones, or even in biological processes like apoptosis, proliferation, or angiogenesis, depending on their biochemical composition. It can be found in secretions such as urine, feces, sputum, or nipple discharge as well as in the circulation (whole blood, plasma, or serum). In addition, CBs are primarily employed in three different capacities in cancer research and treatment: diagnostic, prognostic, and predictive [4].
The CC chemokine family includes the small cytokine known as chemokine (C-C motif) ligand 18 (CCL18) which is predominantly produced by monocyte-derived cells with M2 phenotype [5]. Its production can be upregulated by interleukins (IL-4, IL-10, and IL-13 cells), which are cytokines that favor a 2 type response. Besides other consequences, higher concentrations of CCL18 in the serum or the tumor are linked to a worse prognosis for cancer patients[6]. Abundant CCL18 production in M2 macrophages has been observed in a variety of chronic inflammations and fibrotic illnesses, such as Gaucher's disease and rheumatoid arthritis [7]. Furthermore, CCL18 was found to be expressed constitutively in macrophages infiltrating ovarian cancer, gastric cancer, breast cancer, and glioma [8]. In particular, breast cancer is the condition in which CCL18 is most evidently involved. CCL18 may function as an immunosuppressive cytokine in breast cancers by generating immunosuppressive dendritic cells, macrophages, and T-regulatory cells, as well as driving effector T-cells to abolish their anti-cancer capabilities and immune system [9]. Several studies have shown that breast TAMs (tumor-associated macrophages) release CCL18, which reduces the expression of miR98 and miR27b but promotes angiogenesis, adherence, and migration of breast cancer cells to the extracellular matrix. By triggering the epithelial-mesenchymal transition (EMT) via the PI3K/Akt/GSK3/Snail signaling pathway in breast cancer cells, CCL18 binds to its receptor and promotes tumor growth and metastasis. It is known that when carcinoma-associated fibroblasts and breast cancer cells are co-cultured, CCL18 production increases, promoting the invasion and metastasis of breast cancer cells [10].
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). Among these, the EGF-related peptides may be crucial in the etiology of breast cancer. Generally, malignant breast epithelial cells express TGFc, AR, and CR-1 more frequently and at a higher level than normal mammary epithelium [12]. It has been demonstrated that activating this receptor promotes the migration, proliferation, and protection against apoptosis of breast cancer cells. Metaplastic breast cancer has been linked to the EGFR gene in 25% of patients. Activating mutations of EGFR, which have been shown in lung cancer and central nervous system tumors but are uncommon in breast cancer, are another method of EGFR overexpression [13].
Several in vitro and in vivo studies have revealed that the release of cytokines and chemokines under the control of EGF and CCL18 or the protease-dependent remodeling of the extracellular matrix are two ways that macrophages promote chemoattractant bioavailability, invasion, and migration [14, 15]. In addition, a study by Li et al., 2018 suggests that after being stimulated for 1 hour with tumor-associated macrophages produced by cytokines such as CCL18, CXCL12, IL-beta, IL-6, and EGF, only CCL18 significantly increased the phosphorylation of AMAP1 at Tyr782 in MCF-7 cells, whereas EGF only marginally increased it [16].
There is no such type of research concerning the CCL18 and EGF correlation with breast cancer carried. Here we investigated the expression, correlation, and survival analysis of both CCL18 and EGF with BRCA risks using publicly available computational biology tools. Therefore, this study aims to disclose the risk of breast cancer associated with CCL18 and EGF.