title: C1 Domain-targeted isophthalate derivatives induce cell elongation and cell cycle arrest in HeLa cells.
abstract: Diacylglycerol (DAG)-mediated signaling pathways, such as those mediated by protein kinase C (PKC), are central in regulating cell proliferation and apoptosis. DAG-responsive C1 domains are therefore considered attractive drug targets. Our group has designed a novel class of compounds targeted to the DAG binding site within the C1 domain of PKC. We have previously shown that these 5-(hydroxymethyl)isophthalates modulate PKC activation in living cells. In this study we investigated their effects on HeLa human cervical cancer cell viability and proliferation by using standard cytotoxicity tests and an automated imaging platform with machine vision technology. Cellular effects and their mechanisms were further characterized with the most potent compound, HMI-1a3. Isophthalate derivatives with high affinity to the PKC C1 domain exhibited antiproliferative and non-necrotic cytotoxic effects on HeLa cells. The anti-proliferative effect was irreversible and accompanied by cell elongation. HMI-1a3 induced down-regulation of retinoblastoma protein and cyclins A, B1, D1, and E. Effects of isophthalates on cell morphology, cell proliferation and expression of cell cycle-related proteins were different from those induced by phorbol 12-myristate-13-acetate (PMA) or bryostatin 1, but correlated closely to binding affinities. Therefore, the results strongly indicate that the effect is C1 domain-mediated.
authors.affiliation: Division of Pharmacology and Toxicology, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland. virpi.talman@helsinki.fi
authors.forename: Virpi
authors.initials: V
authors.lastname: Talman
authors.forename: Raimo K
authors.initials: RK
authors.lastname: Tuominen
authors.forename: Gustav
authors.initials: G
authors.lastname: Boije af Gennäs
authors.forename: Gustav Boije Af
authors.initials: GB
authors.lastname: Gennäs
authors.forename: Jari
authors.initials: J
authors.lastname: Yli-Kauhaluoma
authors.forename: Elina
authors.initials: E
authors.lastname: Ekokoski
mesh_terms: D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D019925:Cyclin A / Q000378:metabolism; D056744:Cyclin B1 / Q000378:metabolism; D019938:Cyclin D1 / Q000378:metabolism; D004075:Diglycerides / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D010795:Phthalic Acids / Q000737:chemistry / Q000494:pharmacology*; D011493:Protein Kinase C / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016160:Retinoblastoma Protein / Q000378:metabolism
chemical_list: D019925:Cyclin A; D056744:Cyclin B1; D004075:Diglycerides; D010795:Phthalic Acids; D016160:Retinoblastoma Protein; C000592883:bis(3-trifluoromethylbenzyl) 5-(hydroxymethyl)isophthalate; C059768:isophthalate; D019938:Cyclin D1; D011493:Protein Kinase C