Using whole exome sequencing to identify genetic candidates for carboplatin and gemcitabine induced toxicities
(English)Article in journal (Other academic) Submitted
Chemotherapies are associated with significant inter-individual variability in therapeutic effect and adverse drug reactions. In lung cancer the use of gemcitabine and carboplatin induces grade 3-4 myelosuppression in about ¼ of the patients while an equal fraction of patients are basically unaffected in terms of myelosuppressive side effects. We therefore set out to try to identify genetic markers for gemcitabine / carboplatin induced myelosuppression. We selected 32 patients that suffered extremely high neutropenia and thrombocytopenia (grade 3 or 4 after first chemotherapy cycle) or were virtually unaffected (grade 0-1 after the first chemotherapy cycle) by the chemotherapy out of 243 lung cancer patients treated with gemcitabine / carboplatin. These patients were exome sequenced and their genetic differences compared using six different bioinformatic strategies; whole exome non-synonymous SNV association analysis, deviation from Hardy-Weinberg equilibrium, analysis of genes selected by a priori biological knowledge, analysis of genes selected from gene expression meta-analysis of toxicity data sets, Ingenuity pathway analysis and FunCoup network enrichment analysis. All patients were successfully sequenced and 5000-7000 non-synonymous single nucleotide variants were identified in each patient. PI3 (elastase specific inhibitor in neutrophils) showed the strongest association in the single SNV analysis (nominal p=0.0005). Further, variants within IL37, an inhibitor of the innate immune system, and CSAG1, a tumor antigen, differed among the two patient groups and appeared among the top hits in several of the performed analysis, indicating that the approach identifies genetic variants associated with the immune system and tumor differentiation, which might be important for the sensitivity to chemotherapeutic agents. However, the associations reported here are in a need of replication before clinical interpretations can be made.
Exome sequencing, Gemcitabine, Carboplatin, Thrombocytopenia, Neutropenia, Toxicity
IdentifiersURN: urn:nbn:se:kth:diva-104474OAI: oai:DiVA.org:kth-104474DiVA: diva2:564871
QS 20122012-11-052012-11-052012-11-05Bibliographically approved