BACKGROUND: Glioblastoma (GBM) is an aggressive brain tumor. Integrins have been implicated in the malignancy of GBM. A recent study demonstrated that integrin α3 (ITGA3) promoted the invasion of breast cancer cells by regulating transcriptional factor POU3F2. However, whether this also happened in GBM remained unknown.
METHODS: Therefore, we explored the relationship between ITGA3 and POU3F2 in GBM. We measured the expression of ITGA3 and POU3F2 in GBM tissues. We generated ITGA3 knockdown and POU3F2 knockdown GBM U87MG cells and the proliferation, migration and invasion, the expression of stemness markers and epithelial to mesenchymal transition (EMT) markers were measured. We transplanted ITGA3 knockdown and POU3F2 knockdown GBM U87MG cells into mice. The mice were treated with anti-ITGA3 antibody. The tumor sizes, the expression of stemness markers and epithelial-to-mesenchymal transition (EMT) markers were measured.
RESULTS: Both ITGA3 and POU3F2 were upregulated in GBM tissues. Knocking down ITGA3 resulted in reduced expression of POU3F2. Knocking down ITGA3 and POU3F2 suppressed U87MG cells proliferation, migration and invasion, inhibited the expression of stemness markers and prevented epithelial- to-mesenchymal transition. The transplantation of ITGA3 knockdown and POU3F2 knockdown U87MG cells decreased tumor size.
CONCLUSIONS: Anti-ITGA3 antibody treatment reduced the tumor size. ITGA3 regulates stemness and invasion of glioblastoma through POU3F2.

Three adhesion complexes span the sarcolemma and facilitate critical connections between the extracellular matrix and the actin cytoskeleton: the dystrophin- and utrophin-glycoprotein complexes and α7β1 integrin. Loss of individual protein components results in a loss of the entire protein complex and muscular dystrophy. Muscular dystrophy is a progressive, lethal wasting disease characterized by repetitive cycles of myofiber degeneration and regeneration. Protein-replacement therapy offers a promising approach for the treatment of muscular dystrophy. Recently, we demonstrated that sarcospan facilitates protein-protein interactions amongst the adhesion complexes and is an important potential therapeutic target. Here, we review current protein-replacement strategies, discuss the potential benefits of sarcospan expression, and identify important experiments that must be addressed for sarcospan to move to the clinic.

Streptococcus pyogenes (group A streptococcus, GAS) is a human bacterial pathogen of global significance, causing severe invasive diseases associated with serious morbidity and mortality. To survive within the host and establish an infection, GAS requires essential nutrients, including iron. The streptococcal hemoprotein receptor (Shr) is a surface-localized GAS protein that binds heme-containing proteins and extracellular matrix components. In this study, we employ targeted allelic exchange mutagenesis to investigate the role of Shr in the pathogenesis of the globally disseminated serotype M1T1 GAS. The shr mutant exhibited a growth defect in iron-restricted medium supplemented with ferric chloride, but no significant differences were observed in neutrophil survival, antimicrobial peptide resistance, cell surface charge, fibronectin-binding or adherence to human epithelial cells and keratinocytes, compared with wild-type. However, the shr mutant displayed a reduction in human blood proliferation, laminin-binding capacity and was attenuated for virulence in in vivo models of skin and systemic infection. We conclude that Shr augments GAS adherence to laminin, an important extracellular matrix attachment component. Furthermore, Shr-mediated iron uptake contributes to GAS growth in human blood, and is required for full virulence of serotype M1T1 GAS in mouse models of invasive disease.