Changes in Proteasome Chymotrypsin-Like Activity during the Development of Human Mammary and Thyroid Carcinomas

Abstract

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.

Diagnostics of thyroid cancer: Limitations of the existing methods and perspectives for future developments

“…These modifications lead to a sharp increase in the chymotrypsin like proteasome activity. The mini mal difference from this activity in the conditionally normal adjacent tissue was shown to make up 150% (Shashova et al, 2013). The succession of changes in the proteasome pool of the thyroid papillary carci noma is shown in Fig.…”

“…We studied in detail the characteristics of protea somes of different types of tumors of experimental ani mals and humans (Astakhova and Sharova, 2006;Astakhova et al, 2010;Zakharova et al, 2011;Spirina et al, 2012;Shashova et al, 2013). It was found that each type of tumor was characterized by a unique protea some pool.…”

Estrogen Receptors and Ubiquitin Proteasome System: Mutual Regulation

“…A study of breast cancer tissue revealed the positive correlation between the expression of proteasome activator REGγ and ERα status [121]. On the whole, the development of estrogen-dependent malignant tumors is accompanied by an increase in the chymotrypsin-like activity of the proteasomes and a change in their subunit composition [122][123][124]. The use of proteasome inhibitors, together with antiestrogens, against the ER-positive culture of breast cancer leads to a significantly increased antitumor effect, compared to the action of these drugs in a single mode [125].…”

The Activity of Circulating Proteasomes in Tumor and Precancerous Diseases of the Head and Neck Organs

“…Proteasomes are involved in the pathogenesis of many cancers including breast, endometrial, and thyroid cancers [12,13]. We previously showed that the the ChTL and CL levels were higher in patients with HNSCC than in patients with chronic laryngeal hyperplasia associated with epithelial dysplasia.…”