title: A fine-needle aspirate-based vulnerability assay identifies polo-like kinase 1 as a mediator of gemcitabine resistance in pancreatic cancer.
abstract: This work aimed to discover targets for combination treatment with gemcitabine in pancreatic cancer. We selected 11 tumors from our live collection of freshly generated pancreatic cancer xenografts with known degrees of varying gemcitabine sensitivity. We briefly (6 h) exposed fine-needle aspiration material to control vehicle or gemcitabine (1 mumol/L) and compared the gene expression of the treated and untreated samples using a reverse transcription-PCR-based, customized low-density array with 45 target genes of therapeutic interest. The gene expression of the untreated sample (which can be considered a baseline/static readout) was not predictive of gemcitabine efficacy in these tumors. Altogether, the only gene that differentiated sensitive versus resistant cases was polo-like kinase 1 (Plk1), showing >50% downregulation in sensitive cases and no change in the resistant cases. Inhibition of Plk1 by either small interfering RNA gene knockdown or with the Plk1 pathway modulator (ON 01910.Na) synergized with gemcitabine in gemcitabine-refractory in vitro models providing mechanistic proof of concept. In vivo experiments in gemcitabine-resistant xenografts showed synergistic activity decreasing cell proliferation and tumor regressions. A quantitative gene expression-based vulnerability assay identified Plk1 as a relevant target dictating the susceptibility of pancreatic cancer to gemcitabine. Dynamic interrogation of cancer has the potential to provide key information about mechanisms of resistance and to enhance individualization of treatment.
authors.affiliation: Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland 21231, USA.
authors.forename: Antonio
authors.initials: A
authors.lastname: Jimeno
authors.forename: Belen
authors.initials: B
authors.lastname: Rubio-Viqueira
authors.forename: N V
authors.initials: NV
authors.lastname: Rajeshkumar
authors.forename: Audrey
authors.initials: A
authors.lastname: Chan
authors.forename: Anna
authors.initials: A
authors.lastname: Solomon
authors.forename: Manuel
authors.initials: M
authors.lastname: Hidalgo
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D044963:Biopsy, Fine-Needle / Q000379:methods*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D016896:Treatment Outcome; D000093542:Gemcitabine; D000097869:Polo-Like Kinase 1
chemical_list: D000970:Antineoplastic Agents; D018797:Cell Cycle Proteins; D003841:Deoxycytidine; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D000093542:Gemcitabine; D000097869:Polo-Like Kinase 1