Activity and Subunit Composition of Proteasomes in Head and Cervical Squamous Cell Carcinomas

Transcription factors Brn-3α and TRIM16 in cancers, association with hormone reception

Sex hormones, regulating normal physiological processes of most tissues and organs, are considered to be one of the key factors in the development of hormone-dependent cancer and formation of the hormone-resistant tumor phenotype. Recently, the importance of the system for control of hormone receptors expression mediated by nuclear peptides became evident. This system is involved in the regulation of normal physiological processes, in the pathogenesis of many diseases as well as oncogenesis. In the review, we discuss the relationships of the two regulatory peptides – Brn-3α, TRIM16 with hormone receptors. The transcription factor Brn-3α is able to affect the transcription activity of androgen and estrogen receptors. It is observed the participation of TRIM16 protein in the pathogenesis of hormone-dependent tumors due to its "anti-estrogenic effect". Additionally, they are involved in the key intracellular processes, such as proliferation, cell differentiation, and programmed death - apoptosis. Thus, Brn-3α and TRIM16 are associated with cancer development and progression. By understanding these alterations, we can identify potential markers and novel biochemical therapeutic targets. It makes clear the association between classical hormone-dependent tumors and less sensitive ones with the modification in the level of hormone receptors.

Changes in proteasome chymotrypsin-like activity during the development of human mammary and thyroid carcinomas

Changes in the proteasome chymotrypsin-like activity in mammary and thyroid carcinomas in comparison with the adjacent tissue were studied at stages T(1-4)N(0-3)M(0) and T(2-3)N(0-1)M(0), respectively. The activities changed in a wave-like manner over the course of mammary carcinoma growth in cases with and without metastases. The minimum increment of the activity in the tumor was recorded during the T(2)N(0) stage in the absence of local metastases. The increment of the activity reached the peak in N(1) tumors of the same size with metastases. The activities in the tumor and adjacent tissues virtually did not differ during the T(3-4)N(1-3) stages. The time course of proteasome activity changes in thyroid tumors of the studied stages was similar to that in mammary carcinoma. The results can be used for development of methods for evaluating the aggressiveness of mammary and thyroid tumors.