The content of soluble forms of galectins -1, -3, -4, -7, -9 in patients with renal cell cancer of various morphological types

Background: Galectins are a family of β-galactoside binding proteins that regulate the vast majority of cellular functions, including proliferation, migration, adhesion, and phagocytosis in both health and disease. More and more experimental and clinical evidence indicates that galectins are involved in many stages of carcinogenesis, including patients with renal cell carcinoma (RCC). Aim: To analyze the clinical significance of soluble forms of galectins -1, -3, -4, -7, -9 in patients with various histological RCC types. Materials and methods: We performed a retrospective analysis of the clinical significance of galectins -1, -3, -4, -7, -9 in the serum of 140 RCC patients (84 with clear cell RCC (ccRCC), 38 with papillary (papRCC), 18 with chromophobe (chrRCC)) and in 73 healthy donors (control group), who were examined and treated from 2019 to 2023 in the N. N. Blokhin National Medical Research Center of Oncology. Galectin levels were measured in serum (obtained according to standard methods before the initiation of specific treatment) with an enzyme-linked immunosorbent assay. Results: There was a significant increase in serum galectin -1, -3, -9 levels in the whole RCC patient group, compared to the healthy donor control group; no increase was found for galectins -4 and -7. Serum galectin-1 levels in the ccRCC and papRCC patients were significantly higher than those in the controls (p = 0.0003 and p = 0.0135, respectively). No association between the serum galectins -1 and -7 and the clinical and morphological characteristics of RCC was found; however, serum galectin-7 levels in the papRCC patients correlated with the grade of tumor differentiation (r = -0.592; p = 0.001). The area under the ROC curve (AUC) for galectin-1 in ccRCC was 0.721 (p 0.0001), in papRCC 0.673 (p = 0.0086), and in chrRCC 0.576 (p = 0.355). For galectin-7, the ROC AUC values were 0.527 (p = 0.634) in ccRCC, 0.513 (p = 0.845) in papRCC, and 0.566 (p = 0.425) in chrRCC. In all histological types of RCC, there was a significant increase in serum galectin-3 compared to the controls (ccRCC, p = 0.0208; papRCC, p = 0.0014; chrRCC, p = 0.0041). The ROC analysis for galectin-3 in patients with RCC of various histological types showed AUC = 0.721 (p 0.0001) for ccRCC, 0.673 (p = 0.0086) for papRCC, and 0.576 (p = 0.355) for chrRCC. Galectin-9 levels was directly and significantly associated with the tumor size, as well as with regional metastases (r = 0.251, p = 0.021; r = 0.239, p = 0.028, respectively). The AUC values for galectin-4 were 0.619 (p = 0.021) in ccRCC, 0.577 (p = 0.214) in papRCC, and 0.534 (p = 0.666) for chrRCC. For galectin-9, they were 0.649 (p = 0.0075), 0.613 (p = 0.087), and 0.539 (p = 0.637), respectively. Conclusion: The study has demonstrated a certain association between serum galectin -1, -3, -4, -7, and -9 in the patients with RCC of various histological types. Although the results of the ROC analysis indicated average quality of the model, which does not allow for the use of the obtained data for diagnostic purposes, it is necessary to continue the research for better understanding of the mechanisms of galectin functioning, before galectin-based therapeutic agents would be introduced into clinical practice for the treatment of RCC.