Features of LIMCH1 Protein Localization in Tumor Cells in Breast Cancer.

The LIMCH1 protein reduces cell motility by regulating the activity of NM-IIA, which may be critical for tumor cell invasion. At present, the role of the LIMCH1 protein in cancer is not well understood. This work is devoted to the study of the localization of LIMCH1 protein domains in different tumor-cell compartments of patients with nonspecific invasive breast carcinoma (NSBC) and the involvement of LIMCH1 protein domains in the collective or individual migration of tumor cells. The phenomenon of tumor morphological heterogeneity was used as a model system in the work. The LIM domain of the LIMCH1 protein most often had nuclear and submembrane localization, while another domain of the LIMCH1 protein, calponin, most often had submembrane and cytoplasmic localization. The nuclear localization of the LIMCH1 protein in tumor cells suggests that the functions of the LIMCH1 protein in tumor cells are not limited to the effect on cell motility. Much more often, the LIMCH1 protein was found in the cytoplasm of single tumor cells compared to multicellular structures, which can be regarded as an indicator of the amoeboid type of movement, given the association of single tumor cells with hematogenous metastasis. It can be supposed that the main function of the LIMCH1 protein in multicellular structures is to provide intercellular adhesion. [ABSTRACT FROM AUTHOR]