Evaluation of annexin A1 expression in lung, breast, colon, and prostatic adenocarcinomas and in tumor microenvironment

Annexin A1 (ANXA1) which plays a role in tumor development and metastasis has been reported to be an effective regulator for tumor stroma and interacts with different components in the tumor microenvironment. The role of ANXA1 in tumorigenesis has not been fully understood. One of the main reasons for this is the great variability of ANXA1 expression in malignant tumors across different tumor types. Archived hematoxylin-eosin stained preparations of lung adenocarcinoma, breast invasive ductal carcinoma, colonic adenocarcinoma, and prostatic acinar carcinoma were re-evaluated and tumor regions to be analyzed with the tissue microarray method were determined. The ANXA1 expressions between the tumors and tumor microenvironment were evaluated immunohistochemically. ANXA1 expression was decreased in the lung, breast, colon, and prostate adenocarcinomas. The most prominent staining was seen in lung adenocarcinoma cases. There was no statistically significant difference between the tumors in terms of ANXA1 staining (P > 0.05). ANXA1 was shown to be a more stained tumor microenvironment than in the tumor. Statistically significant staining with ANXA1 between within tumor and tumor microenvironment was observed in breast adenocarcinomas (P < 0.05). Our study showed differences between ANXA1 expression in different cancers, in tumor cells, and tumor microenvironment. Considering the effects of ANXA1 on tumor development and metastasis, a potential use as a biomarker may be suggested. Particularly, in breast adenocarcinomas, the high expression of ANXA1 in the tumor microenvironment supports the notion that it could induce the tumor stroma response.