Abstract:

Cellular secretion is a fundamental process that, while essential for normal physiology, also contributes to cancer progression. Among its key regulators, proprotein convertases activate signaling molecules that promote tumor development. Specifically, convertase PCSK6, also known as PACE4, has been implicated in various cancers, promoting processes like invasion and metastasis. However, its role in testicular germ cell tumor (TGCT), a common malignancy in young men, remains unexplored. This study investigates PCSK6 expression in healthy cell lines and in seminomatous, and non-seminomatous testicular tumor tissues and its secretion by healthy (Hs1.Tes) cell-lines and non-seminomatous (NTERA-2) tumor cell lines using immunohistochemistry and the CellStudio platform. The results showed the presence of PCSK6 in healthy germ cells and tumor tissues, with differentiated expression patterns. Firstly, the immunohistochemistry images demonstrated the protein in seminiferous tubules and in the different cancer types, following a characteristic pattern in each case, with higher intensity observed in non-seminomatous cancer. Secondly, analyses using the CellStudio platform revealed that healthy Hs1.Tes cells secreted higher extracellular PCSK6 compared to the NTERA-2 cancer cell line, which showed greater intracellular retention. These findings suggest a complex, context-dependent role of PCSK6 in TGCT biology. The study highlights PCSK6 as a promising molecular marker and underscores the utility of microfluidic platforms for studying tumor protein dynamics, paving the way for improved diagnosis and personalized therapies in testicular cancer.