CNOT7 Blood Level and Correlation to LAIR-1 in Metastatic vs Non-metastatic Breast Cancer Egyptian Patient's Cohort; a Case-Controlled Mechanistic Study

1. Introduction 1.1. Research Problem. Breast cancer (BC) is the primary cause of cancer deaths in women (1,2). The main cause of this mortality is the metastatic spread to other organs (3). Metastasis occurs when tumor cells acquire invasive features (4) and the ability to escape from antitumor immunity; innate and adaptive immune responses important for tumor control (5,6). Major impairment of peripheral blood natural killer (NK) cell maturation and cytotoxic functions was reported to accompany BC progression (7). Several gene expression profiling studies have shown that a better outcome is associated with a strong cytotoxic infiltrate containing NK cells (8,9). These data suggest that BC progression is linked to the antitumor immune efficiency of NK cells, T-cells, and B-cells. However, how BC progression affects peripheral NK cells phenotype is not abundantly investigated.

The activity of NK cells is determined by activating and inhibitory receptors present on NK cells that are triggered during target cell (herein, tumor cell) recognition, inducing a positive or a negative cell signaling pathway, respectively. The integration of these opposite signals determines NK cell activation weight (10). Recent studies have shown that several molecules, notably inhibitory factors, often found in the tumor microenvironment (TME) can sharply impair NK cells' phenotype and functions (11,12) resulting in a decreased expression of activating NK cell receptors and an increased expression of the inhibitory receptors (like LAIR-1 that was detected previously in HCC clinical blood samples T-cytotoxic cells (13). These may promote BC progression and would correlate with the decreased immune cell cytotoxic function encountered by NK cells and T-cells or B-cells (14).

1.2. Aim and Objectives. To explore CNOT7 role related to immune cells resistance in BC metastasis, the investigators attempted to measure the serum levels of CNOT7 in Egyptian female BC patients' cohort in relation to the clinicopathological parameters. CNOT7 tissue expression in BC tissue samples categorized as metastatic vs non-metastatic tumor alongside with adjacent non-tumor tissue margin were measured. Further, quantified the inhibitory receptor on NK cells namely; LAIR-1 serum levels, whose overexpression would be linked to the aggressive BC features and adverse clinical outcome(s) (22) manifested as TNM. The correlation of CNOT7 with LAIR-1 blood levels to be assessed clinically and to be confirmed or rolled-out via bioinformatics databases search and in silico analysis. Per the investigators are looking for BC metastasis mechanism, not just exploring CNOT7 or LAIR1 blood levels, therefore, finding more therapeutic options, via CNOT7 molecular docking or through blocking its down-stream pathways or effector gene-gene networks interaction, either as potential promising treatment options. Where, these pathways and interactions will be retrieved from KEGG pathways search, further addressed through text-mined interactions or search into curated in silico bioinformatics DBs.

2.1. Study Participants 2.1.1. Ethical Approval and Informed Consent to participate. Ethical approval was obtained from Ain Shams University, Faculty of Pharmacy's review board Research Ethical Committee (REC ID# 48, October 20th, 2021).

2.1.2. The study was carried out according to guidelines by the World Medical Association (WMA) fulfilling the Declaration of Helsinki ethical principles for medical research involving human subjects, the revised July 2018 version, where all participating individuals signed the ethically approved informed consent (IC).