Tissue transglutaminase expression in human astroglial tumours

Transglutaminase 2 (TG2) is involved in the physiological regulation of cell growth, but has also been associated with a number of cancer-associated features, such as cell adhesion, metastasis and extracellular matrix modulation. Several studies undertaken with primary tumours suggest that TG2 expression and activity in the tumour body and surrounding matrix generally decreases with tumour progression, favoring matrix destabilization, but supporting angiogenesis and tumour invasion. Elevated expression and alternative splicing, resulting in a short isoform of TG2, TG2-S, with more active crosslinking activity, are associated with increased neuronal loss in affected regions in the demented brain and more neurodegenerative disorders. TG2 full-length protein and TG2-S isoform seem to be involved in two different and opposite ways to determine cellular fate. Astrocytomas are the most common glioma, accounting for about half of all primary brain tumours. Astrocytoma is graded as pilocytic (WHO grade I), diffuse (WHO grade II), anaplastic (WHO grade III), and glioblastoma multiforme (WHO grade IV). The progression from low- to high-grade astrocytoma is associated with distinct molecular changes that vary with other patient status (age, side), yet the prognosis of high-grade tumours remain dismal. We investigated TG2 and TG2-S role in different grade of human astroglial brain tumours.