Gal-300

Tissue invasion is an initiating step of the cancer metastatic cascade. Unraveling the mechanisms underlying intracellular signaling pathway rewiring that activates downstream transcriptional machinery to drive invasiveness could help identify improved strategies to prevent and treat metastasis. Through an unbiased genome-wide CRISPR screen in a mouse model of gastric adenocarcinoma (GAC), an E3 ubiquitin ligase, tripartite motif–containing protein 49 (TRIM49), was identified as a potent suppressor of cancer invasiveness. In two thirds of GAC, TRIM49 expression was downregulated in invading cancer cells, in which TRIM49 deficiency correlated with deeper tumor infiltration and lymph node metastasis and was indicative of shorter overall patient survival. In multiple orthotopic GAC mouse models, TRIM49-deficient cancer cells were highly infiltrative, leading to multiorgan metastasis. Mechanistically, galectin-3, a putative regulator of cancer invasion, was stabilized in TRIM49-deficient cancer, largely because of the failure to undergo TRIM49-mediated polyubiquitination and proteasomal degradation. Consequently, galectin-3 assembled a complex with EGR1, thereby regulating transcriptional activities of a proinvasive gene module. As the galectin-3/EGR1 complex acted as a key node relaying proinvasive signaling, its disruption using GB1107, an oral galectin-3 inhibitor, suppressed tissue infiltration and metastasis of patient-derived xenografts. Taken together, a proinvasive galectin-3/EGR1 transcriptional complex was exploited by TRIM49-deficient GAC to fuel tissue invasion, representing an Achilles’ heel that is potentially targetable to prevent metastasis.

A proinvasion galectin-3/EGR1 transcriptional complex is a therapeutic vulnerability in the highly invasive TRIM49-deficient gastric adenocarcinoma, which can be disrupted by the oral galectin-3 inhibitor GB1107 to prevent cancer spreading.

Clinically, acute kidney injury (AKI) stems from a diverse array of causes including ischemia, exposure to nephrotoxic agents, or sepsis. Renal tubular cells are particularly vulnerable and often sustain the most significant damage during AKI. This raises the question of whether there exists a common pathophysiological mechanism or pathway in renal tubular cells that underlies the development of AKI. We observed that tubular Galectin-3 is significantly up-regulated in four AKI mouse models and its tissue expression shows a positive correlation with tubular injury in human kidneys affected by AKI. The urinary Galectin-3 levels were markedly elevated in a cohort of patients with AKI and these levels correlated with the severity of kidney dysfunction. Based on predictions from bioinformatic analysis and JASPAR database, ChIP-PCR and luciferase-reporter assays demonstrated the direct binding of the transcription factor KLF4 to a specific sequence in the Galectin-3 gene promoter. Furthermore, mice with proximal tubular-specific deletion of KLF4 exhibited reduced kidney injury and inflammation, along with lower Galectin-3 expression in both cisplatin and ischemia-reperfusion-induced AKI. Targeting the KLF4/Galectin-3 axis with Kenpaullone and GB1107 confirmed protective effects against cisplatin-induced cell death and acute kidney injury, respectively. Our study highlights the KLF4/Galectin-3 pathway as a key mediator in the pathogenesis of AKI. Disrupting this signaling pathway may provide a promising therapeutic approach for the treatment of AKI.