Probes for INS

As tumour protein 53 (p53) isoforms have tumour promoting, migration and inflammatory properties, this study investigated whether p53 isoforms contributed to glioblastoma progression. The expression levels of full-length TP53α (TAp53α) and six TP53 isoforms were quantitated by RT-qPCR in 89 glioblastomas and correlated with TP53 mutation status, tumour-associated macrophage content and various immune cell markers. Elevated levels of Δ133p53β mRNA characterised glioblastomas with increased CD163-positive macrophages and wild-type TP53. In situ based analyses found Δ133p53β expression localised to malignant cells in areas with increased hypoxia, and in cells with the monocyte chemoattractant protein C-C motif chemokine ligand 2 (CCL2) expressed. Tumours with increased Δ133p53β had increased numbers of cell positive for macrophage colony stimulating factor 1 receptor (CSF1R) and programmed death ligand 1 (PDL1). In addition, cells expressing a murine 'mimic' of Δ133p53 (Δ122p53) were resistant to temozolomide treatment and oxidative stress. Our findings suggest elevated Δ133p53β is an alternative pathway to TP53 mutation in glioblastoma that aids tumour progression by promoting an immunosuppressive and chemoresistant environment. Adding Δ133p53β to a TP53 signature along with TP53 mutation status will better predict treatment resistance in glioblastoma.

Although hundreds of cytosolic or transmembrane molecules form the primary cilium, few secreted molecules are known to contribute to ciliogenesis. Here, homologous secreted metalloproteases ADAMTS9 and ADAMTS20 are identified as ciliogenesis regulators that act intracellularly. Secreted and furin-processed ADAMTS9 bound heparan sulfate and was internalized by LRP1, LRP2 and clathrin-mediated endocytosis to be gathered in Rab11 vesicles with a unique periciliary localization defined by super-resolution microscopy. CRISPR-Cas9 inactivation of ADAMTS9 impaired ciliogenesis in RPE-1 cells, which was restored by catalytically active ADAMTS9 or ADAMTS20 acting in trans, but not by their proteolytically inactive mutants. Their mutagenesis in mice impaired neural and yolk sac ciliogenesis, leading to morphogenetic anomalies resulting from impaired hedgehog signaling, which is transduced by primary cilia. In addition to their cognate extracellular proteolytic activity, ADAMTS9 and ADAMTS20 thus have an additional proteolytic role intracellularly, revealing an unexpected regulatory dimension in ciliogenesis.

Cleidocranial dysplasia (CCD) is an autosomal dominant human disorder characterized by abnormal bone development that is mainly due to defective intramembranous bone formation by osteoblasts. Here, we describe a mouse strain lacking the E3 ubiquitin ligase RNF146 that shows phenotypic similarities to CCD. Loss of RNF146 stabilized its substrate AXIN1, leading to impairment of WNT3a-induced β-catenin activation and reduced Fgf18 expression in osteoblasts. We show that FGF18 induces transcriptional coactivator with PDZ-binding motif (TAZ) expression, which is required for osteoblast proliferation and differentiation through transcriptional enhancer associate domain (TEAD) and runt-related transcription factor 2 (RUNX2) transcription factors, respectively. Finally, we demonstrate that adipogenesis is enhanced in Rnf146-/- mouse embryonic fibroblasts. Moreover, mice with loss of RNF146 within the osteoblast lineage had increased fat stores and were glucose intolerant with severe osteopenia because of defective osteoblastogenesis and subsequent impaired osteocalcin production. These findings indicate that RNF146 is required to coordinate β-catenin signaling within the osteoblast lineage during embryonic and postnatal bone development.

The contributions of the innate immune system to the development of pancreatic cancer are still ill defined. Inflammatory macrophages can initiate metaplasia of pancreatic acinar cells to a duct-like phenotype (acinar-to-ductal metaplasia [ADM]), which then gives rise to pancreatic intraepithelial neoplasia (PanIN) when oncogenic KRas is present. However, it remains unclear when and how this inflammatory macrophage population is replaced by tumor-promoting macrophages. Here, we demonstrate the presence of interleukin-13 (IL-13), which can convert inflammatory into Ym1+ alternatively activated macrophages, at ADM/PanIN lesions. We further show that Ym1+ macrophages release factors, such as IL-1ra and CCL2, to drive pancreatic fibrogenesis and tumorigenesis. Treatment of mice expressing oncogenic KRas under an acinar cell-specific promoter with a neutralizing antibody for IL-13 significantly decreased the accumulation of alternatively activated macrophages at these lesions, resulting in decreased fibrosis and lesion growth.