胶质母细胞瘤（GBM）是最恶性的脑肿瘤，其特征是细胞异质性，包括负责侵袭性的干细胞（GSC）。钙蛋白酶/钙蛋白酶抑制剂（calp/cast）蛋白水解系统参与关键的生理过程和癌症进展。在这项工作中，我们展示了 hcast 3-25（一种缺乏抑制单位的 III 型钙蛋白酶抑制剂变体）的表达谱以及几个患者来源的 GSC 中的系统成员，探索 hcast 3-25 与钙蛋白酶激活/活性之间的关系。每个 GSC 都显示出独特的 calp/cast mRNA 和蛋白质表达模式，hcast 3-25 表达最少。分化促进除 hcast 3-25 mRNA 之外的所有 calp/cast 系统组件的上调，hcast 3-25 mRNA 的增加或减少取决于个体 GSC 培养物。将 hcast 3-25-V5 转染到两个选定的 GSC 中表明 hcast 3-25 有效地与钙蛋白酶结合，支持选定钙蛋白酶靶标的消化。 Hcast 3-25 可能会影响茎状态，促进分化、攻击性较小的表型。版权所有 © 2024 Spinelli、Barbieri、Averna、Florio、Pedrazzi、Tremonti、Capraro 和 De Tullio。

Glioblastoma (GBM) is the most malignant brain tumor, characterized by cell heterogeneity comprising stem cells (GSCs) responsible for aggressiveness. The calpain/calpastatin (calp/cast) proteolytic system is involved in critical physiological processes and cancer progression. In this work we showed the expression profile of hcast 3-25 (a Type III calpastatin variant devoid of inhibitory units) and the members of the system in several patient-derived GSCs exploring the relationship between hcast 3-25 and activation/activity of calpains. Each GSC shows a peculiar calp/cast mRNA and protein expression pattern, and hcast 3-25 is the least expressed. Differentiation promotes upregulation of all the calp/cast system components except hcast 3-25 mRNA, which increased or decreased depending on individual GSC culture. Transfection of hcast 3-25-V5 into two selected GSCs indicated that hcast 3-25 effectively associates with calpains, supporting the digestion of selected calpain targets. Hcast 3-25 possibly affects the stem state promoting a differentiated, less aggressive phenotype.Copyright © 2024 Spinelli, Barbieri, Averna, Florio, Pedrazzi, Tremonti, Capraro and De Tullio.