Radiotherapy alters expression of molecular targets in prostate cancer in a fractionation- and time-dependent manner

Abstract

The efficacy of molecular targeted therapy depends on expression and enzymatic activity of the target molecules. As radiotherapy modulates gene expression and protein phosphorylation dependent on dose and fractionation, we analyzed the long-term effects of irradiation on the post-radiation efficacy of molecular targeted drugs. We irradiated prostate cancer cells either with a single dose (SD) of 10 Gy x-ray or a multifractionated (MF) regimen with 10 fractions of 1 Gy. Whole genome arrays and reverse phase protein microarrays were used to determine gene expression and protein phosphorylation. Additionally, we evaluated radiation-induced pathway activation with the Ingenuity Pathway Analysis software. To measure cell survival and sensitivity to clinically used molecular targeted drugs, we performed colony formation assays. We found increased activation of several pathways regulating important cell functions such as cell migration and cell survival at 24 h after MF irradiation or at 2 months after SD irradiation. Further, cells which survived a SD of 10 Gy showed a long-term upregulation and increased activity of multiple molecular targets including AKT, IGF-1R, VEGFR2, or MET, while HDAC expression was decreased. In line with this, 10 Gy SD cells were more sensitive to target inhibition with Capivasertib or Ipatasertib (AKTi), BMS-754807 (IGF-1Ri), or Foretinib (VEGFR2/METi), but less sensitive to Panobinostat or Vorinostat (HDACi). In summary, understanding the molecular short- and long-term changes after irradiation can aid in optimizing the efficacy of multimodal radiation oncology in combination with post-irradiation molecularly-targeted drug treatment and improving the outcome of prostate cancer patients.

Multiomic-Based Molecular Landscape of FaDu Xenograft Tumors in Mice after a Combinatorial Treatment with Radiation and an HSP90 Inhibitor Identifies Adaptation-Induced Targets of Resistance and Therapeutic Intervention

“…S5 and S6. We have previously demonstrated the utility of phosphoproteomic expression in determining treatment targets ( 22 ). Briefly, we present protein heat maps that were normalized to intensity, but due to the low sample number ( n = 2), we do not claim significance (Supplementary Fig.…”

“…Reverse phase protein microarray was performed as recently described ( 22 ). Collected tissue samples were immediately frozen in Tissue-Tek O.C.T.…”

“…Both core and comparison analyses were performed in IPA (Qiagen Inc., https://digitalinsights.qiagen.com/products-overview/discovery-insights-portfolio/analysis-and-visualization/qiagen-ipa/?cmpid=QDI_GA_DISC_IPA&gad_source=1&gclid=CjwKCAjwkuqvBhAQEiwA65XxQMiHSmK6tW1iTNhn-SaSqHcapyY_vptMCG0pn_cUqpS0aSwzpPtcBBoCSjcQAvD_BwE , RRID:SCR_008653) as published previously ( 22 ). Pathways and function terms that satisfied an absolute z-score > ( 2 ) and P value < 0.01 for at least one condition were predicted to be altered based on the gene-expression data.…”

Radioresistance Mechanisms in Prostate Cancer Cell Lines Surviving Ultra-Hypo-Fractionated EBRT: Implications and Possible Clinical Applications

“…However, it remains to be investigated why PC3RR cells and DU-145RR cells show different sensitivity to taxanes. Interestingly, it has recently been that there is biological heterogeneity of the radiation-surviving cell subpopulations in PCa, including their phenotypic plasticity, stem-like cell properties and tumorigenic abilities [ 87 ]. On the basis of these findings, we can speculate that radiation-resistant prostate cancer cells may include various subpopulations of cells displaying different traits of chemo/radiosensitivity or resistance, such as mesenchymal markers, invasion/migration ability, low basal ROS levels, CSC markers and ER-stress defence machinery.…”

From Omics to Multi-Omics Approaches for In-Depth Analysis of the Molecular Mechanisms of Prostate Cancer

“…A dedicated phosphoproteomic study led to the discovery of definite kinase pathways involved in the formation of prostate cancer metastasis [ 211 ]. Irradiation of PC-3 cells rapidly induces changes in the phosphoproteome and increased AKT and MET phosphorylation is detected [ 212 ]. Numerous kinases and phosphatases interact with the AR and a shift in the phosphoproteome during tumor progression is observed in clinical samples [ 213 ].…”