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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2010-10-27
pubmed:abstractText
Activation of Janus kinases (JAKs) and Signal Transducers and Activators of Transcription (STATs) plays a crucial role in cell survival and proliferation. The JAK/STAT signaling pathway has received a great deal of attention as a therapeutic target for the treatment of cancer. Thus, the identification of a compound that blocks this pathway would contribute significantly to growth inhibition and apoptosis of tumor cells. The antitumor alkaloid camptothecin (CPT) may be useful in the treatment of certain cancer, but the effects of this drug on colon cancer cells remain largely undefined. The purpose of the present study was to characterize the effects of CPT on human colon cancer cells and to determine the cellular mechanisms involved in CPT-mediated cell inhibition. The cellular determinants for CPT activity were studied in six colon cancer cell lines; these cell lines exhibited natural differences in sensitivity to CPT and could be ranked according to increasing resistance levels in the order Lovo < SW48 < HCT116 < HCT8 < HT29 < WiDr. Our findings suggest that JAK2 is necessary for induction of apoptosis following CPT treatment. Inhibition of JAK2 and STAT3 Tyr705 phosphorylation decreased the expression of STAT3 downstream target genes such as Bcl-2, Bcl-x(L) and Mcl-1. Finally, we show that JAK2 mRNA expression to be a better determination for CPT sensitivity than the topoisomerase-I activity or mRNA expression.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1555-8576
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
354-61
pubmed:meshHeading
pubmed-meshheading:20534983-Antineoplastic Agents, Phytogenic, pubmed-meshheading:20534983-Apoptosis, pubmed-meshheading:20534983-Blotting, Western, pubmed-meshheading:20534983-Camptothecin, pubmed-meshheading:20534983-Cell Cycle, pubmed-meshheading:20534983-Cell Line, Tumor, pubmed-meshheading:20534983-Cell Survival, pubmed-meshheading:20534983-Colonic Neoplasms, pubmed-meshheading:20534983-DNA Repair, pubmed-meshheading:20534983-DNA Topoisomerases, Type I, pubmed-meshheading:20534983-Drug Resistance, Neoplasm, pubmed-meshheading:20534983-Fluorescent Antibody Technique, pubmed-meshheading:20534983-Gene Expression, pubmed-meshheading:20534983-Humans, pubmed-meshheading:20534983-Janus Kinase 2, pubmed-meshheading:20534983-Phosphorylation, pubmed-meshheading:20534983-RNA, Messenger, pubmed-meshheading:20534983-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:20534983-STAT Transcription Factors, pubmed-meshheading:20534983-Signal Transduction
pubmed:year
2010
pubmed:articleTitle
Janus-activated kinases and signal transducer and activator of transcription control tumor growth response to camptothecin in human colon cancer cells.
pubmed:affiliation
Korea Institute of Radiological & Medical Sciences, Seoul, Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't