TY - JOUR
T1 - Functional genomics identifies predictive markers and clinically actionable resistance mechanisms to CDK4/6 inhibition in bladder cancer
AU - Tong, Zhichao
AU - Sathe, Anuja
AU - Ebner, Benedikt
AU - Qi, Pan
AU - Veltkamp, Christian
AU - Gschwend, Juergen E.
AU - Holm, Per Sonne
AU - Nawroth, Roman
N1 - Publisher Copyright:
© 2019 The Author(s).
PY - 2019/7/22
Y1 - 2019/7/22
N2 - Background: CDK4/6 inhibitors are a promising treatment strategy in tumor therapy but are hampered by resistance mechanisms. This study was performed to reveal predictive markers, mechanisms of resistance and to develop rational combination therapies for a personalized therapy approach in bladder cancer. Methods: A genome-scale CRISPR-dCas9 activation screen for resistance to the CDK4/6 inhibitor Palbociclib was performed in the bladder cancer derived cell line T24. sgRNA counts were analyzed using next generation sequencing and MAGeCK-VISPR. Significantly enriched sgRNAs were cloned and validated on a molecular and functional level for mediating resistance to Palbociclib treatment. Analysis was done in vitro and in vivo in the chorioallantois membrane model of the chicken embryo. Comparison of screen hits to signaling pathways and clinically relevant molecular alterations was performed using DAVID, Reactome, DGIdb and cBioPortal. Results: In the screen, 1024 sgRNAs encoding for 995 genes were significantly enriched indicative of mediators of resistance. 8 random sgRNAs were validated, revealing partial rescue to Palbociclib treatment. Within this gene panel, members of Receptor-Tyrosine Kinases, PI3K-Akt, Ras/MAPK, JAK/STAT or Wnt signaling pathways were identified. Combination of Palbociclib with inhibitors against these signaling pathways revealed beneficial effects in vitro and in in vivo xenografts. Conclusions: Identification of potential predictive markers, resistance mechanisms and rational combination therapies could be achieved by applying a CRISPR-dCas9 screening approach in bladder cancer.
AB - Background: CDK4/6 inhibitors are a promising treatment strategy in tumor therapy but are hampered by resistance mechanisms. This study was performed to reveal predictive markers, mechanisms of resistance and to develop rational combination therapies for a personalized therapy approach in bladder cancer. Methods: A genome-scale CRISPR-dCas9 activation screen for resistance to the CDK4/6 inhibitor Palbociclib was performed in the bladder cancer derived cell line T24. sgRNA counts were analyzed using next generation sequencing and MAGeCK-VISPR. Significantly enriched sgRNAs were cloned and validated on a molecular and functional level for mediating resistance to Palbociclib treatment. Analysis was done in vitro and in vivo in the chorioallantois membrane model of the chicken embryo. Comparison of screen hits to signaling pathways and clinically relevant molecular alterations was performed using DAVID, Reactome, DGIdb and cBioPortal. Results: In the screen, 1024 sgRNAs encoding for 995 genes were significantly enriched indicative of mediators of resistance. 8 random sgRNAs were validated, revealing partial rescue to Palbociclib treatment. Within this gene panel, members of Receptor-Tyrosine Kinases, PI3K-Akt, Ras/MAPK, JAK/STAT or Wnt signaling pathways were identified. Combination of Palbociclib with inhibitors against these signaling pathways revealed beneficial effects in vitro and in in vivo xenografts. Conclusions: Identification of potential predictive markers, resistance mechanisms and rational combination therapies could be achieved by applying a CRISPR-dCas9 screening approach in bladder cancer.
KW - Bladder cancer
KW - CDK4/6 inhibition
KW - CRISPR
KW - Combination therapies
KW - Resistance
UR - http://www.scopus.com/inward/record.url?scp=85069755692&partnerID=8YFLogxK
U2 - 10.1186/s13046-019-1322-9
DO - 10.1186/s13046-019-1322-9
M3 - Article
C2 - 31331377
AN - SCOPUS:85069755692
SN - 0392-9078
VL - 38
JO - Journal of Experimental and Clinical Cancer Research
JF - Journal of Experimental and Clinical Cancer Research
IS - 1
M1 - 322
ER -