👤 Krzysztof Kurek

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are widely used for type 2 diabetes and obesity, delivering robust metabolic and cardiovascular benefits. However, their potential impact on tumorigenesis remains debated. Preclinical findings in rodents have suggested that GLP-1R activation may influence thyroid C-cells and pancreatic ducts, while human studies have yielded inconsistent cancer risk signals. This review synthesizes current evidence on GLP-1R and glucose-dependent insulinotropic polypeptide receptor (GIPR) signaling in cancer biology, emphasizing the role of biased agonism and context-dependent effects. GLP-1R activation, predominantly via cAMP/PKA signaling, has shown antiproliferative effects in gastrointestinal adenocarcinomas and pancreatic ductal adenocarcinoma models, whereas GIPR activation frequently engages PI3K/Akt (PI3K, phosphoinositide 3-kinase; Akt, protein kinase B) and ERK/MAPK cascades (ERK, extracellular signal-regulated kinase; MAPK, mitogen-activated protein kinase), enhancing proliferation in colorectal and neuroendocrine tumors. Conversely, GLP-1R stimulation can promote growth in GLP-1R-high neuroendocrine tumors, reflecting ligand- and tissue-specific signaling biases. Beyond direct tumor cell effects, GLP-1RAs modulate the tumor microenvironment by reducing NF-κB-driven inflammation, altering stromal activity, and potentially enhancing immune surveillance. Current clinical evidence does not support a generalized increase in cancer risk with GLP-1RA therapy; benefits in metabolic control may even reduce obesity-related cancer incidence. Nonetheless, caution is advised in patients with medullary thyroid carcinoma, MEN2, or GLP-1R-high neuroendocrine tumors. The emerging paradigm suggests precision approaches, integrating receptor profiling, biased agonist design, and risk stratification, will be key to safely leveraging incretin-based therapies in oncology. Show less

Metachondromatosis (MC) is a rare, autosomal dominant, incompletely penetrant combined exostosis and enchondromatosis tumor syndrome. MC is clinically distinct from other multiple exostosis or multiple enchondromatosis syndromes and is unlinked to EXT1 and EXT2, the genes responsible for autosomal dominant multiple osteochondromas (MO). To identify a gene for MC, we performed linkage analysis with high-density SNP arrays in a single family, used a targeted array to capture exons and promoter sequences from the linked interval in 16 participants from 11 MC families, and sequenced the captured DNA using high-throughput parallel sequencing technologies. DNA capture and parallel sequencing identified heterozygous putative loss-of-function mutations in PTPN11 in 4 of the 11 families. Sanger sequence analysis of PTPN11 coding regions in a total of 17 MC families identified mutations in 10 of them (5 frameshift, 2 nonsense, and 3 splice-site mutations). Copy number analysis of sequencing reads from a second targeted capture that included the entire PTPN11 gene identified an additional family with a 15 kb deletion spanning exon 7 of PTPN11. Microdissected MC lesions from two patients with PTPN11 mutations demonstrated loss-of-heterozygosity for the wild-type allele. We next sequenced PTPN11 in DNA samples from 54 patients with the multiple enchondromatosis disorders Ollier disease or Maffucci syndrome, but found no coding sequence PTPN11 mutations. We conclude that heterozygous loss-of-function mutations in PTPN11 are a frequent cause of MC, that lesions in patients with MC appear to arise following a "second hit," that MC may be locus heterogeneous since 1 familial and 5 sporadically occurring cases lacked obvious disease-causing PTPN11 mutations, and that PTPN11 mutations are not a common cause of Ollier disease or Maffucci syndrome. Show less