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PDF - 29K, Differentially expressed Target mRNAs and regulatory miRNAs (showing inverse correlation) from cardiovascular pathways in HCAEC at 24h following SD and MF irradiation were identified by Target Filter Analysis program.

Gene expression of mTOR/AKT related genes after single dose and multifractionated radiation. DU145 human prostate carcinoma cells were irradiated with 10 Gy single dose (SD) or 5 fractions of 2 Gy or 10 fractions of 1 Gy (2 Gy a day) as multifractionated (MF) radiotherapy. At indicated time points after radiation, cells were lysed and RNA was isolated.

PDF - 61K, Legends for Supplementary Tables

PDF - 1331K, Western Blot Analysis.

PDF file - 70K

Radiation schedule for the cell culture and xenograft experiments. Human prostate cancer cells were either plated or injected subcutaneously into the flanks of the right hind legs of athymic nude mice. After 24 h (in vitro) or tumors reached a tumor size of 5 mm x 5 mm (in vivo), tumors were irradiated with different fractionation regimens including a single dose of 10 Gy at day 5, 10 fractions of 1 Gy (2 fractions per day), or 5 fractions of 2 Gy (1 fraction per day). Unirradiated cells or tumors were used as control.

Densitometric analysis of basal protein expression and phosphorylation in DU145 and PC3 cells. Western blots of 3D-grown prostate cancer cell lines were evaluated with ImageJ. Phospho-protein expression was normalized to total protein expression. Results show mean {plus minus} SD (n = 3) (See also Figure 3A).

PDF - 46K, Microarray data depicting gene expression fold changes respective to control group in genes from immune response category following SD and MF radiation exposure at 6h and 24h.

PDF - 42K, miRNAs implicated in several cardiovascular events were also differentially expressed following fractionated irradiation in HCAEC.

PDF file - 734K, Supplementary Figure 1. Heat map top 20 altered genes 24h after radiation.

PDF - 22K, Genes differentially expressed (> 2-fold change, P < 0.05) in response to SD and MF irradiations were classified into functional categories by gene ontology classification. Enrichment of individual functional gene categories was determined by hypergeometric distribution of P values obtained from comparison of the number of the number of genes differentially expressed to the number of annotated genes in each category.

PDF - 56K, Microarray data depicting gene expression fold changes respective to control group in genes from stress response category following SD and MF radiation exposure at 6h and 24h.

PDF file - 69K, Supplementary Table 1. List of top 10 upregulated and downregulated genes 24h after radiation.

Subcellular localization of AKT and mTOR after radiation. Immunofluorescence staining of AKT and mTOR in irradiated and unirradiated DU145 and PC3 cells. Nuclear staining was performed with DAPI.

Implementing targeted drug therapy in radio-oncologic treatment regimens has greatly improved the outcome of cancer patients. However, the efficacy of molecular targeted drugs such as inhibitory antibodies or small molecule inhibitors essentially depends on target expression and activity, which both can change during the course of treatment. Radiotherapy has previously been shown to activate prosurvival pathways, which can help tumor cells to adapt and thereby survive treatment. Therefore, we aimed to identify changes in signaling induced by radiation and evaluate the potential of targeting these changes with small molecules to increase the therapeutic efficacy on cancer cell survival. Analysis of “The Cancer Genome Atlas” database disclosed a significant overexpression of AKT1, AKT2, and MTOR genes in human prostate cancer samples compared with normal prostate gland tissue. Multifractionated radiation of three-dimensional–cultured prostate cancer cell lines with a dose of 2 Gy/day as a clinically relevant schedule resulted in an increased protein phosphorylation and enhanced protein–protein interaction between AKT and mTOR, whereas gene expression of AKT, MTOR, and related kinases was not altered by radiation. Similar results were found in a xenograft model of prostate cancer. Pharmacologic inhibition of mTOR/AKT signaling after activation by multifractionated radiation was more effective than treatment prior to radiotherapy. Taken together, our findings provide a proof-of-concept that targeting signaling molecules after activation by radiotherapy may be a novel and promising treatment strategy for cancers treated with multifractionated radiation regimens such as prostate cancer to increase the sensitivity of tumor cells to molecular targeted drugs. Mol Cancer Ther; 17(2); 355–67. ©2017 AACR.See all articles in this MCT Focus section, “Developmental Therapeutics in Radiation Oncology.”

Oligonucleotides used for CRISPR/Cas9 gene editing

Adaptation of tumor cells to radiotherapy induces changes that are actionable by molecular targeted agents and immunotherapy. This report demonstrates that radiation-induced changes in integrin expression can be targeted 2 months later. Integrins are transmembrane cell adhesion molecules that are essential for cancer cell survival and proliferation. To analyze the short- and long-term effects of radiation on the integrin expression, prostate cancer cells (DU145, PC3, and LNCaP) were cultured in a 3D extracellular matrix and irradiated with either a single dose of radiation (2–10 Gy) or a multifractionated regimen (2–10 fractions of 1 Gy). Whole human genome microarrays, immunoblotting, immunoprecipitation assays, and immunofluorescence staining of integrins were performed. The results were confirmed in a prostate cancer xenograft model system. Interestingly, β1 and β4 integrins (ITGB1 and ITGB4) were upregulated after radiation in vitro and in vivo. This overexpression lasted for more than 2 months and was dose dependent. Moreover, radiation-induced upregulation of β1 and β4 integrin resulted in significantly increased tumor cell death after treatment with inhibitory antibodies. Combined, these findings indicate that long-term tumor adaptation to radiation can result in an increased susceptibility of surviving cancer cells to molecular targeted therapy due to a radiation-induced overexpression of the target.Implications:Radiation induces dose- and schedule-dependent adaptive changes that are targetable for an extended time; thus suggesting radiotherapy as a unique strategy to orchestrate molecular processes, thereby providing new radiation-drug treatment options within precision cancer medicine.

PDF - 34K, Changes in selected differentially expressed genes identified by microarray analysis were confirmed by real-time RT-PCR.

S1. Growth curves of PC3 xenograft tumors after radiation. S2. AIIB2 binds to prostate cancer cells. S3. Integrin expression is elevated after radiation in vitro and in vivo. S4. Cell cycle distribution is unchanged in PC3 long-term survivors (in vitro).

PDF - 64K, Supplementary Materials and Methods

Metabolic data from PC3 cells 6h, 24h, and 48h after SD or MF radiation. Samples were sent to Metabolon for processing. Results indicate decrease in glycolysis intermediates in SD sample at 6h. No significant changes to TCA cycle intermediates. No significant changes to ATP at any time points measured.

Radiotherapy is highly effective due to its ability to physically focus the treatment to target the tumor while sparing normal tissue and its ability to be combined with systemic therapy. This systemic therapy can be utilized before radiotherapy as an adjuvant or induction treatment, during radiotherapy as a radiation “sensitizer,” or following radiotherapy as a part of combined modality therapy. As part of a unique concept of using radiation as “focused biology,” we investigated how tumors and normal tissues adapt to clinically relevant multifraction (MF) and single-dose (SD) radiation to observe whether the adaptations can induce susceptibility to cell killing by available drugs or by immune enhancement. We identified an adaptation occurring after MF (3 × 2 Gy) that induced cell killing when AKT-mTOR inhibitors were delivered following cessation of radiotherapy. In addition, we identified inducible changes in integrin expression 2 months following cessation of radiotherapy that differ between MF (1 Gy × 10) and SD (10 Gy) that remain targetable compared with preradiotherapy. Adaptation is reflected across different “omics” studies, and thus the range of possible molecular targets is not only broad but also time, dose, and schedule dependent. While much remains to be studied about the radiation adaptive response, radiation should be characterized by its molecular perturbations in addition to physical dose. Consideration of the adaptive effects should result in the design of a tailored radiotherapy treatment plan that accounts for specific molecular changes to be targeted as part of precision multimodality cancer treatment.

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.

Adaptation of tumor cells to radiotherapy induces changes that are actionable by molecular targeted agents and immunotherapy. This report demonstrates that radiation-induced changes in integrin expression can be targeted 2 months later. Integrins are transmembrane cell adhesion molecules that are essential for cancer cell survival and proliferation. To analyze the short- and long-term effects of radiation on the integrin expression, prostate cancer cells (DU145, PC3, and LNCaP) were cultured in a 3D extracellular matrix and irradiated with either a single dose of radiation (2–10 Gy) or a multifractionated regimen (2–10 fractions of 1 Gy). Whole human genome microarrays, immunoblotting, immunoprecipitation assays, and immunofluorescence staining of integrins were performed. The results were confirmed in a prostate cancer xenograft model system. Interestingly, β1 and β4 integrins (ITGB1 and ITGB4) were upregulated after radiation in vitro and in vivo. This overexpression lasted for more than 2 months and was dose dependent. Moreover, radiation-induced upregulation of β1 and β4 integrin resulted in significantly increased tumor cell death after treatment with inhibitory antibodies. Combined, these findings indicate that long-term tumor adaptation to radiation can result in an increased susceptibility of surviving cancer cells to molecular targeted therapy due to a radiation-induced overexpression of the target. Implications: Radiation induces dose- and schedule-dependent adaptive changes that are targetable for an extended time; thus suggesting radiotherapy as a unique strategy to orchestrate molecular processes, thereby providing new radiation-drug treatment options within precision cancer medicine.

Radiotherapy is highly effective due to its ability to physically focus the treatment to target the tumor while sparing normal tissue and its ability to be combined with systemic therapy. This systemic therapy can be utilized before radiotherapy as an adjuvant or induction treatment, during radiotherapy as a radiation “sensitizer,” or following radiotherapy as a part of combined modality therapy. As part of a unique concept of using radiation as “focused biology,” we investigated how tumors and normal tissues adapt to clinically relevant multifraction (MF) and single-dose (SD) radiation to observe whether the adaptations can induce susceptibility to cell killing by available drugs or by immune enhancement. We identified an adaptation occurring after MF (3 × 2 Gy) that induced cell killing when AKT-mTOR inhibitors were delivered following cessation of radiotherapy. In addition, we identified inducible changes in integrin expression 2 months following cessation of radiotherapy that differ between MF (1 Gy × 10) and SD (10 Gy) that remain targetable compared with preradiotherapy. Adaptation is reflected across different “omics” studies, and thus the range of possible molecular targets is not only broad but also time, dose, and schedule dependent. While much remains to be studied about the radiation adaptive response, radiation should be characterized by its molecular perturbations in addition to physical dose. Consideration of the adaptive effects should result in the design of a tailored radiotherapy treatment plan that accounts for specific molecular changes to be targeted as part of precision multimodality cancer treatment.

Implementing targeted drug therapy in radio-oncologic treatment regimens has greatly improved the outcome of cancer patients. However, the efficacy of molecular targeted drugs such as inhibitory antibodies or small molecule inhibitors essentially depends on target expression and activity, which both can change during the course of treatment. Radiotherapy has previously been shown to activate prosurvival pathways, which can help tumor cells to adapt and thereby survive treatment. Therefore, we aimed to identify changes in signaling induced by radiation and evaluate the potential of targeting these changes with small molecules to increase the therapeutic efficacy on cancer cell survival. Analysis of “The Cancer Genome Atlas” database disclosed a significant overexpression of AKT1, AKT2, and MTOR genes in human prostate cancer samples compared with normal prostate gland tissue. Multifractionated radiation of three-dimensional–cultured prostate cancer cell lines with a dose of 2 Gy/day as a clinically relevant schedule resulted in an increased protein phosphorylation and enhanced protein–protein interaction between AKT and mTOR, whereas gene expression of AKT, MTOR, and related kinases was not altered by radiation. Similar results were found in a xenograft model of prostate cancer. Pharmacologic inhibition of mTOR/AKT signaling after activation by multifractionated radiation was more effective than treatment prior to radiotherapy. Taken together, our findings provide a proof-of-concept that targeting signaling molecules after activation by radiotherapy may be a novel and promising treatment strategy for cancers treated with multifractionated radiation regimens such as prostate cancer to increase the sensitivity of tumor cells to molecular targeted drugs. Mol Cancer Ther; 17(2); 355–67. ©2017 AACR. See all articles in this MCT Focus section, “Developmental Therapeutics in Radiation Oncology.”

Context MF is a life-threatening type of myeloproliferative neoplasm (MPN) with significant morbidity and mortality. Current treatments aim to manage symptoms, improve anemia, and delay progression to acute myeloid leukemia (AML); however, limited real-world data hinder understanding of the safety and effectiveness of emerging therapies and the association between treatment patterns and patient outcomes. Objective To examine the effectiveness and safety of different therapeutics, treatment patterns, clinical outcomes, and patient-reported outcomes (PROs) in patients with MF or MF-related cytopenias. Design The Connect® Myeloid Disease Registry (NCT01688011; formerly Connect® MDS/AML Disease Registry) is a large, US, multicenter, prospective study of patients with newly diagnosed AML or myelodysplastic syndromes (MDS; Steensma et al. BMC Cancer 2016). A new cohort of patients diagnosed with MF began enrollment in February 2021. Patients Eligible patients are ≥18 years of age, must have an MF diagnosis (primary or secondary MF) and have initiated therapy ≤60 days prior to informed consent. 800 patients (n=400 patients receiving first active systemic treatment for MF and n=400 patients receiving treatment for MF-related cytopenias) will be enrolled at 200–250 sites. Patients with MDS/MPN overlap syndromes are also eligible. Patients who have a suspected or proven juvenile myelomonocytic leukemia diagnosis or are currently enrolled in any interventional clinical trial where the investigational product cannot be identified are not eligible. Main Outcome Measures All diagnoses, treatments, and laboratory testing are at the discretion of the treating physician, in accordance with standard clinical practice at each site. Health status, clinical response (by MFSAF, spleen size, transfusion burden, and bone marrow biopsy), overall survival, adverse drug reactions, serious adverse events (AEs), and protocol-defined AEs of interest will be collected. PRO data will be assessed using the MFSAF V.4, FACT-An, and EQ-5D-3L questionnaires. Patients may consent to an optional biomarker tissue sub-study. Patient data will be reported at baseline and quarterly for ≤5 years or until early termination, withdrawal, or death. Conclusions Data collected in the MF cohort of the Registry will increase understanding of the clinical effectiveness, safety, and PRO of current treatment strategies for patients with MF. This is a BMS-sponsored study.

7040 Background: At diagnosis, disease risk and transfusion burden (TB) can impact HRQoL in pts with MDS. The impact of disease status and higher transfusion requirements on HRQoL has not been well studied. We used data from the Connect Myeloid Disease Registry, an ongoing, prospective, observational cohort study that includes adult pts with lower-risk (LR) and higher-risk (HR) MDS, to investigate factors influencing baseline (BL) and subsequent HRQoL. Methods: BL and Month 6 (M6) data from pts enrolled from Dec 12, 2013 to Mar 6, 2020 (data cutoff) were analyzed. Pts were stratified by International Prognostic Scoring System (IPSS) risk (LR, HR), treatment (Tx) within 45 days post-enrollment (no Tx, best supportive care [BSC], active Tx), and TB 16 weeks post-BL (non-transfusion dependent [NTD], low TB [LTB]; 1−3 transfusions, high TB [HTB]: ≥4 transfusions). Pts completed EQ-5D, FACT-An trial outcome index (TOI), and FACT-Fatigue (FACT-F) questionnaires at BL and quarterly thereafter. Clinically meaningful change, based on minimally important differences, was defined as a change of ±0.07 for EQ-5D, ±6 for FACT-An TOI, and ±3 for FACT-F. Results: At data cutoff, 830 (489 LR, 341 HR) pts were enrolled. Median age was 74 years. 278 pts received no initial Tx, 161 BSC, and 378 active Tx. At BL, 470 were NTD, 197 LTB, and 163 HTB. Of 670 pts still on-study at M6, 462 completed the questionnaires at both BL and M6. At BL , clinically meaningful differences were observed in FACT-An TOI and FACT-F scores, but not EQ-5D, between LR- and HR-MDS and the Tx subgroups . From BL to M6, no clinically meaningful changes were observed in mean scores for each questionnaire. For the TB subgroups, meaningful differences were observed at BL in FACT-An TOI and FACT-F scores, but not EQ-5D (Table). From BL to M6, meaningful decreases in scores were reported by 26%, 30%, and 35% of NTD, LTB, and HTB pts in EQ-5D, 41%, 43%, and 48% for FACT-An TOI, and 40%, 42%, and 48% for FACT-F; increases were reported by 19%, 19%, and 20% pts for EQ-5D, 31%, 32%, and 39% for FACT-An TOI, and 30%, 39%, and 40% for FACT-F. Conclusions: This preliminary analysis suggests that pts with HR-MDS, and transfusion-dependent pts, generally had worse HRQoL at BL, providing further support to initiating active Tx in pts with TB. Possible limitations of the analysis are lower completion rates in pts with more severe disease, and EQ-5D may not capture changes in these subgroups at M6. A longer follow-up may help delineate the impact of Tx on HRQoL assessments in pts with MDS. Clinical trial information: NCT01688011. [Table: see text]

The dramatic changes in the technological delivery of radiation therapy, the repertoire of molecular targets for which pathway inhibitors are available, and the cellular and immunologic responses that can alter long-term clinical outcome provide a potentially unique role for using the radiation-inducible changes as therapeutic targets. Various mathematical models of dose and fractionation are extraordinarily useful in guiding treatment regimens. However, although the model may fit the clinical outcome, a deeper understanding of the molecular and cellular effect of the individual dose size and the adaptation to repeated exposure, called multifraction (MF) adaptation, may provide new therapeutic targets for use in combined modality treatments using radiochemotherapy and radioimmunotherapy. We discuss the potential of using different radiation doses and MF adaptation for targeting transcription factors, immune and inflammatory response, and cell “stemness.” Given the complex genetic composition of tumors before treatment and their adaptation to drug treatment, innovative combinations using both the pretreatment molecular data and also the MF-adaptive response to radiation may provide an important role for focused radiation therapy as an integral part of precision medicine and immunotherapy.

CONTEXT: Accidental exposure to life-threatening radiation in a nuclear event is a major concern; there is an enormous need for identifying biomarkers for radiation biodosimetry to triage populations and treat critically exposed individuals. OBJECTIVE: To identify dose differentiating miRNA signatures from whole blood samples of whole body irradiated mice. METHODS: Mice were whole body irradiated with X-rays (2 Gy −15 Gy); blood was collected at various time-points post exposure; total RNA was isolated; miRNA microarrays were performed; miRNAs differentially expressed in irradiated vs. unirradiated controls were identified; feature extraction and classification models were applied to predict dose-differentiating miRNA signature. RESULTS: We observed a time and dose responsive alteration in the expression levels of miRNAs. Maximum number of miRNAs were altered at 24 h and 48 h time-points post-irradiation. A 23-miRNA signature was identified using feature selection algorithms and classifier models. An inverse correlation in the expression level changes of miR-17 members and their targets was observed in whole body irradiated mice and non-human primates. CONCLUSION: Whole blood-based miRNA expression signatures might be used for predicting radiation exposures in a mass casualty nuclear incident.

Aryankalayil, M. J., Chopra, S., Levin, J., Eke, I., Makinde, A., Das, S., Shankavaram, U., Vanpouille-Box, C., Demaria, S. and Coleman, C. N. Radiation-Induced Long Noncoding RNAs in a Mouse Model after Whole-Body Irradiation. Radiat. Res. 189, 251–263 (2018). Long noncoding RNAs (lncRNAs) are emerging as key molecules in regulating many biological processes and have been implicated in development and disease pathogenesis. Biomarkers of cancer and normal tissue response to treatment are of great interest in precision medicine, as well as in public health and medical management, such as for assessment of radiation injury after an accidental or intentional exposure. Circulating and functional RNAs, including microRNAs (miRNAs) and lncRNAs, in whole blood and other body fluids are potential valuable candidates as biomarkers. Early prediction of possible acute, intermediate and delayed effects of radiation exposure enables timely therapeutic interventions. To address whether long noncoding RNAs (lncRNAs) could serve as biomarkers for radiation biodosimetry we performed whole genome transcriptome analysis in a mouse model after whole-body irradiation. Differential lncRNA expression patterns were evaluated at 16, 24 and 48 h postirradiation in total RNA isolated from whole blood of mice exposed to 1, 2, 4,8 and 12 Gy of X rays. Sham-irradiated animals served as controls. Significant alterations in the expression patterns of lncRNAs were observed after different radiation doses at the various time points. We identified several radiation-induced lncRNAs known for DNA damage response as well as immune response. Long noncoding RNA targets of tumor protein 53 (P53), Trp53cor1, Dino, Pvt1 and Tug1 and an upstream regulator of p53, Meg3, were altered in response to radiation. Gm14005 (Morrbid) and Tmevpg1 were regulated by radiation across all time points and doses. These two lncRNAs have important potential as blood-based radiation biomarkers; Gm14005 (Morrbid) has recently been shown to play a key role in inflammatory response, while Tmevpg1 has been implicated in the regulation of interferon gamma. Precise molecular biomarkers, likely involving a diverse group of inducible molecules, will not only enable the development and effective use of medical countermeasures but may also be used to detect and circumvent or mitigate normal tissue injury in cancer radiotherapy.

Although modern radiotherapy technologies can precisely deliver higher doses of radiation to tumors, thus, reducing overall radiation exposure to normal tissues, moderate dose, and normal tissue toxicity still remains a significant limitation. The present study profiled the global effects on transcript and miR expression in human coronary artery endothelial cells using single-dose irradiation (SD, 10 Gy) or multifractionated irradiation (MF, 2 Gy × 5) regimens. Longitudinal time points were collected after an SD or final dose of MF irradiation for analysis using Agilent Human Gene Expression and miRNA microarray platforms. Compared with SD, the exposure to MF resulted in robust transcript and miR expression changes in terms of the number and magnitude. For data analysis, statistically significant mRNAs (2-fold) and miRs (1.5-fold) were processed by Ingenuity Pathway Analysis to uncover miRs associated with target transcripts from several cellular pathways after irradiation. Interestingly, MF radiation induced a cohort of mRNAs and miRs that coordinate the induction of immune response pathway under tight regulation. In addition, mRNAs and miRs associated with DNA replication, recombination and repair, apoptosis, cardiovascular events, and angiogenesis were revealed. Implications: Radiation-induced alterations in stress and immune response genes in endothelial cells contribute to changes in normal tissue and tumor microenvironment, and affect the outcome of radiotherapy. Mol Cancer Res; 12(7); 1002–15. ©2014 AACR.

New technologies enabling the analysis of various molecules, including DNA, RNA, proteins and small metabolites, can aid in understanding the complex molecular processes in cancer cells. In particular, for the use of novel targeted therapeutics, elucidation of the mechanisms leading to cell death or survival is crucial to eliminate tumor resistance and optimize therapeutic efficacy. While some techniques, such as genomic analysis for identifying specific gene mutations or epigenetic testing of promoter methylation, are already in clinical use, other "omics-based" assays are still evolving. Here, we provide an overview of the current status of molecular profiling methods, including promising research strategies, as well as possible challenges, and their emerging role in radiation oncology.

The major goal was to evaluate effects of various radiation regimens on leukocyte populations relatively long-term after whole-body irradiation.C57BL/6 mice were exposed to-low-dose/low-dose rate (LDR) (57)Co γ-rays (0.01 Gy, 0.03 cGy/h), with and without acute 2 Gy proton (1 Gy/min) or γ-ray (0.9 Gy/min) irradiation; analyses were done on days 21 and 56 post-exposure.Numerous radiation-induced changes were noted at one or both time points. Among the most striking differences (P 0.05) were: (i) High percentage of CD4(+)CD25(+)Foxp3(+) T cells in spleens from the Proton vs. LDR, Gamma and LDR + Proton groups (day 56); (ii) high interleukin-2 (IL-2) in spleen supernatants from the LDR and LDR + Proton groups vs. 0 Gy (day 56), whereas IL-10 was high in the LDR + Gamma group vs. 0 Gy (day 56); (iii) difference in transforming growth factor-β1 (TGF-β1) in spleen supernatants from Proton and LDR + Proton groups vs. Gamma and LDR + Gamma groups (both days); (iv) low TGF-β1 in blood from LDR + Proton vs. LDR + Gamma group (day 21); and (v) high level of activated cJun N-terminal kinase (JNK) in CD4(+) T cells from LDR + Proton vs. LDR + Gamma group (day 21).The findings demonstrate that at least some immune responses to acute 2 Gy radiation were dependent on radiation quality time of assessment, and pre-exposure to LDR γ-rays.

To determine whether differences exist between proton and electron radiations on biological responses after total-body exposure.ICR mice (n=45) were irradiated to 2 Gray (Gy) using fully modulated 70 MeV protons (0.5 Gy/min) and 21 MeV electrons (3 Gy/min). At 36 h post-irradiation liver gene expression, white blood cell (WBC), natural killer (NK) cell and other analyses were performed.Oxidative stress-related gene expression patterns were strikingly different for irradiated groups compared to 0 Gy (P0.05). Proton radiation up-regulated 15 genes (Ctsb, Dnm2, Gpx5, Il19, Il22, Kif9, Lpo, Nox4, Park7, Prdx4, Prdx6, Rag2, Sod3, Srxn1, Xpa) and down-regulated 2 genes (Apoe, Prdx1). After electron irradiation, 20 genes were up-regulated (Aass, Ctsb, Dnm2, Gpx1, Gpx4, Gpx5, Gpx6, Gstk1, Il22, Kif9, Lpo, Nox4, Park7, Prdx3, Prdx4, Prdx5, Rag2, Sod1, Txnrd3, Xpa) and 1 was down-regulated (Mpp4). Of the modified genes, only 11 were common to both forms of radiation. Comparison between the two irradiated groups showed that electrons significantly up-regulated three genes (Gstk1, Prdx3, Scd1). Numbers of WBC and major leukocyte types were low in the irradiated groups (P0.001 vs. 0 Gy). Hemoglobin and platelet counts were low in the electron-irradiated group (P0.05 vs. 0 Gy). However, spleens from electron-irradiated mice had higher WBC and lymphocyte counts, as well as enhanced NK cell cytotoxicity, compared to animals exposed to protons (P0.05). There were no differences between the two irradiated groups in body mass, organ masses, and other assessed parameters, although some differences were noted compared to 0 Gy.Collectively, the data demonstrate that at least some biological effects induced by electrons may not be directly extrapolated to protons.

A better understanding of low dose radiation effects is needed to accurately estimate health risks. In this study, C57BL/6 mice were gamma-irradiated to total doses of 0, 0.01, 0.05, and 0.1 Gy ((57)Co; ~0.02 cGy/h). Subsets per group were euthanized at the end of irradiation (day 0) and on days 4 and 21 thereafter. Relative spleen mass and splenic white blood cell (WBC) counts, major leukocyte populations, and spontaneous DNA synthesis were consistently higher in the irradiated groups on day 0 compared to 0 Gy controls, although significance was not always obtained. In the spleen, all three major leukocyte types were significantly elevated on day 0 (P < 0.05). By day 21 post-irradiation the T, B, and natural killer (NK) cell counts, as well as CD4(+) T cells and CD4:CD8 T cell ratio, were low especially in the 0.01 Gy group. Although blood analyses showed no significant differences in leukocyte counts or red blood cell and platelet characteristics, the total T cells, CD4(+) T cells, and NK cells were increased by day 21 after 0.01 Gy (P < 0.05). Gene analysis of CD4(+) T cells negatively isolated from spleens on day 0 after 0.1 Gy showed significantly enhanced expression of Il27 and Tcfcp2, whereas Inha and Socs5 were down-regulated by 0.01 Gy and 0.1 Gy, respectively (P < 0.05). A trend for enhancement was noted in two additional genes (Il1r1 and Tbx21) in the 0.1 Gy group (P < 0.1). The data show that protracted low dose photons had dose- and time-dependent effects on CD4(+) T cells after whole-body exposure.

The health consequences of exposure to low-dose radiation combined with a solar particle event during space travel remain unresolved. The goal of this study was to determine whether protracted radiation exposure alters gene expression and oxidative burst capacity in the liver, an organ vital in many biological processes. C57BL/6 mice were whole-body irradiated with 2 Gy simulated solar particle event (SPE) protons over 36 h, both with and without pre-exposure to low-dose/low-dose-rate photons ((57)Co, 0.049 Gy total at 0.024 cGy/h). Livers were excised immediately after irradiation (day 0) or on day 21 thereafter for analysis of 84 oxidative stress-related genes using RT-PCR; genes up or down-regulated by more than twofold were noted. On day 0, genes with increased expression were: photons, none; simulated SPE, Id1; photons + simulated SPE, Bax, Id1, Snrp70. Down-regulated genes at this same time were: photons, Igfbp1; simulated SPE, Arnt2, Igfbp1, Il6, Lct, Mybl2, Ptx3. By day 21, a much greater effect was noted than on day 0. Exposure to photons + simulated SPE up-regulated completely different genes than those up-regulated after either photons or the simulated SPE alone (photons, Cstb; simulated SPE, Dctn2, Khsrp, Man2b1, Snrp70; photons + simulated SPE, Casp1, Col1a1, Hspcb, Il6st, Rpl28, Spnb2). There were many down-regulated genes in all irradiated groups on day 21 (photons, 13; simulated SPE, 16; photons + simulated SPE, 16), with very little overlap among groups. Oxygen radical production by liver phagocytes was significantly enhanced by photons on day 21. The results demonstrate that whole-body irradiation with low-dose-rate photons, as well as time after exposure, had a great impact on liver response to a simulated solar particle event.

To understand the impact of clinically relevant radiation therapy (RT) on tumor immune gene expression and to utilize the changes that occur during treatment to improve cancer treatment outcome, we examined how immune response genes are modulated in prostate cancer cells of varying p53 status. LNCaP (p53 wild-type), PC3 (p53 null) and DU145 (p53 mutant) cells received a 10 Gy single dose or 1 Gy × 10 multifractionated radiation dose to simulate hypofractionated and conventionally fractionated prostate radiotherapy. Total RNA was isolated 24 h after multi-fractionated radiation treatment and single-dose treatments and subjected to microarray analysis and later validated by RT-PCR. RT-PCR was utilized to identify total-dose inflection points for significantly upregulated genes in response to multifractionated radiation therapy. Radiation-induced damage-associated molecular pattern molecules (DAMPs) and cytokine analyses were performed using bioluminescence and ELISA. Multifractionated doses activated immune response genes more robustly than single-dose treatment, with a relatively larger number of immune genes upregulated in PC3 compared to DU145 and LNCaP cells. The inflection point of multifractionated radiation-induced immune genes in PC3 cells was observed in the range of 8–10 Gy total radiation dose. Although both multifractionated and single-dose radiation-induced proinflammatory DAMPs and positively modulated the cytokine environment, the changes were of higher magnitude with multifractionated therapy. The findings of this study together with the gene expression data suggest that cells subjected to multifractionated radiation treatment would promote productive immune cell–tumor cell interactions.

Radiation oncology modalities such as intensity-modulated and image-guided radiation therapy can reduce the high dose to normal tissue and deliver a heterogeneous dose to tumors, focusing on areas deemed at highest risk for tumor persistence. Clinical radiation oncology produces daily doses ranging from 1 to 20 Gy, with tissues being exposed to 30 or more daily fractions. Hypothesizing the cells that survive fractionated radiation therapy have a substantially different phenotype than the untreated cells, which might be exploitable for targeting with molecular therapeutics or immunotherapy, three prostate cancer cell lines (PC3, DU145, and LNCaP) and normal endothelial cells were studied to understand the biology of differential effects of multifraction (MF) radiation of 0.5, 1, and/or 2 Gy fraction to 10 Gy total dose, and a single dose of 5 and 10 Gy. The resulting changes in mRNA, miRNA, and phosphoproteome were analyzed. Significant differences were observed in the MF radiation exposures including those from the 0.5 Gy MF that produces little cell killing. As expected, p53 function played a major role in response. Pathways modified by MF include immune response, DNA damage, cell-cycle arrest, TGF-β, survival, and apoptotic signal transduction. The radiation-induced stress response will set forth a unique platform for exploiting the effects of radiation therapy as “focused biology” for cancer treatment in conjunction with molecular targeted or immunologically directed therapy. Given that more normal tissue is treated, albeit to lower doses with these newer techniques, the response of the normal tissue may also influence long-term treatment outcome. Mol Cancer Res; 11(1); 5–12. ©2012 AACR.

Nonsteroidal anti-inflammatory drugs (NSAIDs) have come under scrutiny because of the gastrointestinal, renal, and cardiovascular toxicity associated with prolonged use of these drugs. The purpose of this study was to identify molecular targets for NSAIDs related to cellular toxicity with a view to optimize drug efficacy in the clinic. Coronary artery smooth muscle cells and endothelial cells were treated with low (clinically achievable) and high (typically used in preclinical studies) concentrations of celecoxib, NS398, and ibuprofen for 24 hours. NSAIDs-induced gene expression changes were evaluated by microarray analysis and validated by real-time reverse-transcription polymerase chain reaction and western blotting. The functional significance of differentially expressed genes was evaluated by Ingenuity Pathway Analysis. At high concentrations, NSAIDs altered the expression of genes regulating cell proliferation and cell death. NSAIDs also altered genes associated with cardiovascular functions including inflammation, thrombosis, fibrinolysis, coronary artery disease, and hypertension. The gene expression was most impacted by ibuprofen, celecoxib, and NS398, in that order. This study revealed that NSAIDs altered expression of an array of genes associated with cardiovascular events and emphasizes the potential for fingerprinting drugs in preclinical studies to assess the potential drug toxicity and to optimize the drug efficacy in clinical settings.

Background: In order to understand the changes induced in tumor cells following multi-fraction (MF) radiation therapy, we have previously studied molecular changes using prostate cancer cells and endothelial cells treated in vitro with MF doses of 0.5 Gy/1 Gy x 10 and 2 Gy x 5 and single-dose (SD) of 5 Gy and 10 Gy. The hypothesis being tested is that the response and adaptation to radiation-induced stress will produce a druggable phenotype. This might increase the utility of molecularly targeted therapeutics and also help address tumor cell heterogeneity. The data indicate more genes and pathways are induced by MF compared to SD and that the change in phenotype is more stable following MF. In this report, the focus is on new data from PC-3 cells irradiated in vivo and comparing it to MF and SD in vitro using MF 1 Gy x 10 and SD 10 Gy. Methods: PC-3 prostate cancer cells were implanted subcutaneously into the lateral aspect of rear leg of nude mice. Mice were divided into three groups (n = 3), based on radiation dose/schedule- control, SD, and MF. SD and MF employed similar dose/schedule as used for the in vitro studies, 10 Gy x 1 and 1 Gy x 10 respectively. RNA was isolated 24 h after radiation treatment. mRNA microarray analysis was performed using Agilent Technologies Human Gene Expression 4 × 44 K V2 microarrays. The data was generated and analyzed with GeneSpring® software (Agilent Technologies, Santa Clara, CA) and IPA software (IPA, QIAGEN, Redwood City, CA). Results: 6,374 genes were significantly altered by MF, with a cohort of genes, based on the > 250 gene ontology categories, involved in DNA response to stimulus, DNA repair, mitosis, cell cycle, and metabolism. In contrast, only 453 genes were significantly altered by SD, with ontological categories associated with cell morphology, assembly and organization such as actin filament-based process, extracellular matrix organization and biogenesis, fibril organization and biogenesis and collagen catabolism. Further bioinformatics analysis of the gene expression data with IPA, identified multiple pathways with functions correlated with the ontological categories. Significantly altered MF-induced genes are members of pathways which play a central role in DNA replication, recombination, and repair, cell proliferation and metabolism such as HIPPO Signaling, Protein Ubiquitination Pathway, JNK/SAPK Signaling, ERK/MAPK Signaling, G2/M DNA Damage Checkpoint Regulation, ATM Signaling, PI3K/AKT Signaling and Oxidative Phosphorylation. These pathways were uniquely up-regulated by MF treatment, as none of these changes were identified with SD radiation exposure. Conclusion: Our result show the differential expression pattern between SD and MF, with MF inducing changes in “targetable” molecular pathways. Ongoing studies: Currently we are in the process of evaluating radiation-induced targets in ATM signaling, DNA damage and repair, and multiple metabolic targets, and their potential for using radiation to prime cells for molecular-targeted drug therapy. Citation Format: Adeola Y. Makinde, Iris Eke, Molykutty J. Aryankalayil, Mansoor Ahmed, C. Norman Coleman. Radiation-inducible molecular targets in a human prostate cancer mouse model. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C146.

Radiation is a major factor in the spaceflight environment that has carcinogenic potential. Astronauts on missions are continuously exposed to low-dose/low-dose-rate (LDR) radiation and may receive relatively high doses during a solar particle event (SPE) that consists primarily of protons. However, there are very few reports in which LDR photons were combined with protons. In this study, C57BL/6 mice were exposed to 1.7 Gy simulated SPE (sSPE) protons over 36 h, both with and without pre-exposure to 0.01 Gray (Gy) LDR γ-rays at 0.018 cGy/h. Apoptosis in skin samples was determined by immunohistochemistry immediately post-irradiation (day 0). Spleen mass relative to body mass, white blood cells (WBC), major leukocyte populations, lymphocyte subsets (T, Th, Tc, B, NK), and CD4+ CD25+ Foxp3+ T regulatory (Treg) cells were analyzed on days 4 and 21. Apoptosis in skin samples was evident in all irradiated groups; the LDR+sSPE mice had the greatest expression of activated caspase-3. On day 4 post-irradiation, the sSPE and LDR+sSPE groups had significantly lower WBC counts in blood and spleen compared to non-irradiated controls ( p < 0.05 vs. 0 Gy). CD4+ CD25+ Foxp3+ Treg cell numbers in spleen were decreased at day 4, but proportions were increased in the sSPE and LDR+sSPE groups ( p < 0.05 vs. 0 Gy). By day 21, lymphocyte counts were still low in blood from the LDR+sSPE mice, especially due to reductions in B, NK, and CD8+ T cytotoxic cells. The data demonstrate, for the first time, that pre-exposure to LDR photons did not protect against the adverse effects of radiation mimicking a large solar storm. The increased proportion of immunosuppressive CD4+ CD25+ Foxp3+ Treg and persistent reduction in circulating lymphocytes may adversely impact immune defenses that include removal of sub-lethally damaged cells with carcinogenic potential, at least for a period of time post-irradiation.

The goal of this study was to evaluate cytokine secretion capacity in a mouse model of prostate cancer, both with and without metalloporphyrin antioxidant and radiation treatment. C57BL/6 mice with subcutaneous RM-9 tumors were treated daily for 12 days with MnTE-2-PyP(5+) [Mn (III) tetrakis (N-ethylpyridinium-2-yl) porphyrin], beginning 1 day after injection of RM-9 cells; a 10-Gy tumor-localized dose of (60)Co gamma rays was administered in a single fraction on day 7. Spleen, tumors and plasma were collected on day 12. T cells in the spleen were activated with anti-CD3 antibody and supernatants were collected. Twenty-two cytokines were quantified in spleen supernatants, five in tumor homogenates, and three in plasma using multiplex bead array technology and ELISA. The presence of a tumor had significant effects on many of the cytokines quantified (P0.05). Tumor-induced depression was evident for eight spleen cytokines (TNF-alpha, G-CSF, GM-CSF, IFN-gamma, IL10, IP-10, MIP-1alpha and mKC), whereas only three were enhanced (IL1beta, IL6 and MCP-1). Radiotherapy resulted in enhanced splenocyte capacity to produce IL4 and IL13 and increased IL4, MCP-1 and VEGF in tumors (P0.05). Addition of MnTE-2-PyP(5+) to radiation decreased the concentrations of IL4, IL13 and TGF-beta1 in spleen supernatants and IL4 and VEGF in tumors (P0.05 compared to radiation alone). Some differences were also noted in plasma cytokines. Overall, the findings suggest that administration of MnTE-2-PyP(5+) together with radiotherapy may enhance anti-tumor immune responsiveness and decrease the risk for radiation-induced normal tissue toxicities.

Metalloporphyrin antioxidants can protect tissues against radiation-induced damage. However, for effective use in radiotherapy as normal tissue radioprotectants, they must not protect the cancer. The major objectives were to evaluate the effects of Mn (III) tetrakis (N-ethylpyridinium-2-yl) porphyrin (MnTE-2-PyP) on tumor response to radiation and to explore mechanisms responsible for the observed effects.C57BL/6 mice were subcutaneously (s.c.) injected with RM-9 prostate tumor cells on day 0 and grouped according to treatment with MnTE-2-PyP (s.c. 6 mg/kg/day beginning on day 1 for 16 maximum days), 10 Gray (Gy) single fraction radiation on day 7, a combination of both or neither. Subsets per group and non-tumor bearing controls were evaluated for leukocyte populations, red blood cell (RBC) and platelet characteristics and cytokines on day 12; the remaining mice were followed for tumor growth.Although radiation alone significantly slowed tumor growth and the addition of MnTE-2-PyP resulted in slightly slower tumor progression, the difference between radiation and radiation plus drug was not statistically significant. However, the treatment with drug alone significantly elevated T (helper, Th and cyotoxic, Tc) and natural killer (NK) cells in the spleen, B-cells in the blood and spleen, and the capacity to produce interleukin-2. The addition of the drug to radiation did not ameliorate the depression seen in all the major leukocyte types, but did protect against radiation-induced decreases in RBC counts, hemoglobin and hematocrit. Vascular endothelial growth factor (VEGF) increased in the plasma from both the irradiated groups and a trend for increased transforming growth factor-beta1 (TGF-beta1) was noted with radiation alone.MnTE-2-PyP did not protect RM-9 prostate tumors against radiation damage and was not toxic under the conditions used. The drug-induced enhancement of certain immune parameters suggests that MnTE-2-PyP may be beneficial not only as a normal tissue radioprotectant, but also as a facilitator of antitumor immunity.