- Email: [email protected]
Effects of Fractionation Schedule on Expression Patterns of Clinically Significant Circulating Cytokines During Radiation Therapy for Lung Cancer
Volume 99 Number 2S Supplement 2017
Poster Viewing E587
Purpose/Objective(s): Approximately 15-20% of breast cancers are categorized as triple negative breast cancer (TNBC), which can further be classified as BRCA-associated or non-BRCA associated. The lack of estrogen, progesterone, and HER2 receptors leave few alternative treatments to patients (pts) who become chemo-resistant. PARP inhibitors have shown efficacy in treating TNBC, but this success is limited to BRCA-associated cases. Inducing downregulation of BRCA1/2 in pts without BRCA mutations would present a new treatment option and may portend to improved recurrence free survival rates. This downregulation has been successfully demonstrated with the administration of a PI3K inhibitor. Here we report the co-delivery of a PARP and PI3K inhibitor using the natural, nontoxic polymer alginate as a nanoparticle platform, which is susceptible to degradation in response to ionizing radiation (IR) via cleavage of glycosidic bonds. We hypothesize that externally stimulating release of drugs that work synergistically with IR would effectively reduce the dose of radiation and drug necessary and limit the drug to a more targeted area, resulting in reduced unwanted toxicity thereby improving the therapeutic ratio. Materials/Methods: Breast Cancer Cells (MDA-MB-468) were treated with PI-103 (PI3K inhibitor) and BMN-673 (PARP inhibitor) alone and in combination to determine colony forming ability +/- IR and synergistic or additive effects. These studies were repeated with dual-drug loaded nanoparticles to evaluate the radiolytic release of drugs and impact on colony forming ability. Results: Preliminary data indicates that more DNA double strand breaks accumulate when PI-103 and BMN-673 are delivered in combination. We determined initial IC50 values for each drug, and tested for synergist effects at low doses with IR. MDA-MB-231 and MDA-MB-436 cell lines were also tested. In addition, we have formulated nanosized alginate carriers using cisplatin, as a model drug, and performed physiochemical characterizations.
Materials/Methods: Experiments were performed using different NSCLC (H23, H226, H460, H520, H1299, H1975, A549) and prostate cancer cell lines (DU 145, PC3, LnCAP) growing either under 2D or 3D conditions. SCF was knocked down by siRNA, c-Kit was inhibited by ISCK03 inhibitor and cells were irradiated with 2 Gy or 6 Gy Photons. Cell survival was determined by colony formation assay. Invasion was measured using BioCoatÔ MatrigelÔ invasion chambers. Results: When grown in 3D a 2-3-fold increase in invasion capability was examined in all NSCLC and prostate cancer cell lines except H520. This could be explained by EMT-like changes (enhanced expression of vimentin and N-cadherin and reduction of E-cadherin) when cells were grown in 3D. Just the opposite trends were found for H520 cells. Knock down of SCF was generally found to result in significantly reduced invasion and in only a minor increase of cellular radiosensitivity (2D and 3D). Only in cells characterized by a massive overexpression of SCF (H520) a significant increase of cellular radiosensitivity could be obtained after SCF knock down. The inhibition of c-Kit by a specific inhibitor was also found to result only in minor radiosensitization. Photon irradiation did not modulate cancer cell invasion (2D and 3D). Conclusion: For the regulation of tumor cell motility and invasion the SCF/c-Kit pathway appears to take a key position. Inhibition of this pathway significantly reduces the cell invasion of human NSCLC and prostate cancer cells under 2D and 3D conditions. In addition our data indicate that generally cell survival and radioresponse are not strongly determined by the SCF/c-Kit pathway. As a consequence targeting SCF or c-Kit only results in increased radiosensitivity when SCF is strongly over expressed as found for H520 cells. Author Disclosure: F. Eberle: None. F. Leinberger: None. M. Saulich: None. W. Seeger: None. R. Engenhart-Cabillic: None. E. Dikomey: None. F. Subtil: None.
3398 Abstract 3396 Cell Line
Drug
IC50 (mM)
MDA-MB-468 MDA-MB-468
PI-103 BMN-673
1.770.51 3.423.08
Conclusion: Our findings indicate that co-delivery of these drugs can enhance the efficacy of IR in a difficult to treat subset of breast cancer known as non-BRCA associated TNBC. Future directions include loading PI-103 and BMN-673 into nanocarriers and characterization of drug loading and release, cytotoxicity, and testing in vivo efficacy. Author Disclosure: A.N. DuRoss: None. J. Rosch: None. A. Brown: None. G. Sahay: None. J.J. Jaboin: None. C.R. Thomas: None. C. Sun: None.
3397 Possibilities of Radiosensitization and Reduced Invasion After Targeting the SCF/c-Kit Pathway in Human Cancer Cells F. Eberle,1 F. Leinberger,1 M. Saulich,1 W. Seeger,2 R. EngenhartCabillic,3 E. Dikomey,4 and F. Subtil1; 1Department of Radiotherapy and Radiooncology, Philipps University, Marburg, Germany, 2Universities of Giessen & Marburg Lung Center (UGMLC), Giessen, Germany, 3 Department of Radiation Oncology, University Marburg, Marburg, Germany, 4Laboratory of Radiobiology & Experimental Radiooncology, University Medical Center Hamburg-Eppendorf, Germany, Hamburg, Germany Purpose/Objective(s): The SCF/c-Kit pathway is often overexpressed in human tumors leading to an enhanced proliferation and invasion. Resulting therapy resistance and metastasis often are limiting factors of a successfull radiotherapy. It was now tested for NSCLC and prostate cancer cells growing in 2D and 3D whether the inhibition of this pathway can be used to achieve a reduced cancer cell invasion and whether a significant increased radiosensitivity could be achieved.
Effects of Fractionation Schedule on Expression Patterns of Clinically Significant Circulating Cytokines During Radiation Therapy for Lung Cancer S. Ellsworth,1 J. Chen,2 W. Wang,3 M.M. Matuszak,4 R. K. Ten Haken,5 S. Jolly,6 and F.M. Kong3; 1Indiana University Department of Radiation Oncology, Indianapolis, IN, 2Medical College of Georgia, Augusta, GA, 3 Department of Radiation Oncology, Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN, 4Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, 5University of Michigan, Department of Radiation Oncology, Ann Arbor, MI, 6University of Michigan, Ann Arbor, MI Purpose/Objective(s): Radiation therapy (RT) is associated with acute and late effects on the immune system. However, the effects of RT on immunomodulatory cytokines (CK) are not been described. This study prospectively analyzed levels of 30 CKs in patients treated with different regimens for non-small cell lung cancer (NSCLC). The primary goal was to determine whether fractionation schedule or chemotherapy was associated with differences in the levels of clinically significant CKs. Materials/Methods: Patients were treated on 3 separate prospective clinical trials of conventionally fractionated radiation (CFRT; 60-87.9 Gy in 30-36 fractions, nZ18), chemoradiation (ChRT; 60-85.5 Gy in 30-37 fractions, nZ114), and stereotactic body radiation (SBRT; 50-55 Gy in 5 fractions, nZ16). CK levels were determined from platelet-poor plasma specimens with ELISA at baseline and midway through treatment. Principal component analysis (PCA) was used to identify CKs of interest for further study, which included IP10 and sCD40l. IL2, TGF-B1, IL7, IL8, IL10, and IL15 were also included in the analysis as these are known to be immunologically significant CKs and/or have been previously identified as potentially significant circulating factors in NSCLC. Results: This report includes 148 patients. Median age was 66 yrs (range 40-92 yrs), 24.3% of patients were female, and median follow-up was 46 months. CK expression patterns differed significantly among the 3 groups. In SBRT and ChRT patients, IL-8 decreased significantly during treatment
E588
International Journal of Radiation Oncology Biology Physics
(pZ0.03 and 0.01 respectively) but did not change significantly in CFRT patients. IL-15 increased significantly during treatment in the CFRT (p Z 0.01) and ChRT (p<0.001) patients but not in the SBRT group. ChRT patients exhibited the most dynamic changes in CK expression, with significant decreases in IP-10 (p < 0.001), sCD40l (pZ0.003), and IL-2 (pZ0.04) as well as the previously noted changes in IL-8 and IL-15. Median TGF-B1 values increased in the SBRT and CFRT groups but decreased in the ChRT group, although these changes were not statistically significant. Conclusion: Treatment scheme appeared to be significantly associated with differing cytokine expression patterns in patients undergoing radiation for NSCLC. Combined ChRT patients appeared to have the greatest variability in multiple CKs including IP-10, sCD40l, IL-2, IL-8, and IL-15. Differences were also seen among the treatment groups in IL-8 and IL-15. Further study is needed to determine whether CK expression patterns can serve as an immune biomarker for outcomes in NSCLC. Author Disclosure: S. Ellsworth: None. J. Chen: None. W. Wang: None. M.M. Matuszak: Employee; William Beaumont Hospital. R.K. Ten Haken: Research Grant; NIH-NCI. Travel Expenses; Varian Medical Systems Inc. S. Jolly: None. F.M. Kong: Research Grant; NCI/NIH, Varian. Sino-American Network for Therapeutic Radiology, American Association of Women Radiologists (AAWR), Association for Chinese Professors, Chinese-American Network for Hematology and Oncolo, SinoAmerican Network for Therapeutic Radiation On.
completely healed at all times. At days 14 and 20, the healing in the 0 Gy + wound was so minimal that we did not measure the other groups until day 28. At 28 days, the mice in the 8.0 Gy + wound group still showed a significantly decreased tensile strength (1.1 0.1 newtons) compared to 1.4 0.1 newtons for the 0 Gy + wound (p Z 0.0013). Conclusion: This murine combined injury model of TBI irradiation + wound revealed a clear decreased survival compared to mice receiving TBI only. While longer observation times are needed to monitor the rates of wound healing, mice receiving 8.0 Gy + wound had decreased wound healing compared to 0 Gy + wound. Author Disclosure: M. Epperly: None. A. Bellare: None. J.S. Greenberger: None. R. Fisher: None. P. Wipf: None. G. Julie: None.
3399 A Murine Combined Injury Model of Total Body Irradiation and Skin Wound M. Epperly,1 A. Bellare,2 J.S. Greenberger,3 R. Fisher,4 P. Wipf,4 and G. Julie2; 1University of Pittsburgh Cancer Institute, Pittsburgh, PA, 2 Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, Boston, MA, 3UPMC-Shadyside Hospital, Pittsburgh, PA, 4University of Pittsburgh, Pittsburgh, PA Purpose/Objective(s): In the radiation terrorism scenario there will be combined injuries; we have developed a mouse model of combined injury (total body irradiation (TBI) plus defined skin wound). We measured the effect of TBI doses from 7.0 to 9.25 Gy irradiation on survival and healing of the skin wound. Materials/Methods: C57BL/6NTac female mice (8 weeks of age) were irradiated to doses of 0 Gy, 7.0 Gy, 8.0 Gy, 8.5 Gy, 9.0 Gy and 9.25 Gy TBI. Twenty-four hours before irradiation, the lower backs were shaved followed by depilation with NAIR. One hour after TBI, mice were anesthetized and a 25 mm length, 5 mm deep scalpel incision/wound was made in the skin. The wound was closed using staples. Control mice received no irradiation and no skin wound. Numbers of surviving mice were recorded daily. At 14, or 20 days after irradiation, groups of control and 0 Gy + wounded mice were sacrificed and wound healing was determined by measuring the tensile strength of each of ten 2 mm strips of skin per mouse across the wound using a 45N capacity tensile tester. On day 28 following irradiation, all remaining mice were tested. Results: The LD50/30 for C57BL/6NTac mice was 9.25 Gy. In the combined injury model the LD50/30 was 8.5 Gy with significantly increased lethality with wounding at 8.5 Gy and 9.0 Gy. Mice irradiated to 9.0 Gy + wound and 8.5 Gy + wound had a statistically significant decrease in survival compared to those receiving 9.0 Gy or 8.5 Gy alone (p Z 0.0073 and 0.0115, respectively). The number of deaths in the 8.5 Gy, 9.0 Gy and 9.25 Gy + wound groups was high. We tested the tensile strength in wounds from mice receiving 0 Gy + wound, 7.0 Gy + wound and 8.0 Gy + wound. Compared to the control (non-irradiated, non-wounded) mice tensile strength, the wounds in the combined injury mice were less
3400 The Expression of BDNF and PDGF Predict Curative Effect in Patients with Esophageal Squamous Cell Carcinoma Treated By Radiation Therapy P. Er1 and Q. Dong2; 1Tianjin Medical University Cancer Institute and hospital Tianjin, China, 2Tianjin Medical University Cancer Institute and Hospital, Tianjin, China Purpose/Objective(s): Radiotherapy plays a standard role and is well tolerated in the treatment of esophageal squamous cell carcinoma (ESCC). However, no effective biological markers have been identified for radiation sensitivity and curative effect prediction of patients with ESCC. Therefore, the present study was to explore the relationship between the expression of brain-derived neurotrophic factor (BDNF) or platelet-derived growth factor (PDGF) and prognosis of patients with ESCC who receive radiotherapy, and to evaluate the clinical utility of these biomarkers. Materials/Methods: This pilot study recruited patients who received neoadjuvant chemoradiotherapy (neo-CRT) or definitive chemoradiotherapy (CRT) of total doses ranging from 40 to 60Gy (2.0Gy/fraction per day). Each patient underwent blood samples collection before treatment and at the time of administration of total doses of 40Gy. Cytokines expression analyses were preformed in pretreated serum compared to that at the doses of 40Gy from 8 ESCCs. 7 differentially expressed cytokines identified by cytokine antibody arrays were validated by enzyme-linked immunosorbant assay. Of these, up-regulation of BDNF and PDGF in serum at the doses of 40Gy was found in radiation-resistant patients. The predictive value of BDNF and PDGF were further assessed in a second set of 48 ESCCs. All 48 patients were recruited in clinical trial (NCT02959385). Results: Significant decrease in the levels of the two cytokines at 40Gy compared with that in pretreated serum were observed[BDNF (PZ0.017); PGDF (PZ0.034)]. The median follow-up time of these patients was 10.24 months (range: 3.75e19.42 months). In ultivariate analysis, patients with lower levels of BDNF in serum at the total dose of 40Gy, compared to that of pretreatment, were associated with superior outcome (NZ24 vs 23, median survival time: 12.61 vs 10.37months, PZ0.035).Besides, patients with decreased levels in either BDNF or PDGF at the total doses of 40Gy have significantly favorable outcome in comparison to others (NZ27 vs 20, median survival time: 13.23 vs 10.27months, PZ0.018). Conclusion: We found that the levels of BDNF and PDGF in serum are reliable and predictive biomarkers for CRT response and progression-free survival in patients with ESCC. It can be used as a prognostic indicator in patients with ESCC treated by chemoradiotherapy, which will facilitate the individualization of ESCC treatment. Additional clinical researches with quantities of cases are accordingly desired to fully assess its predictive power. Author Disclosure: P. Er: None. Q. Dong: None.
Poster Viewing E587
Purpose/Objective(s): Approximately 15-20% of breast cancers are categorized as triple negative breast cancer (TNBC), which can further be classified as BRCA-associated or non-BRCA associated. The lack of estrogen, progesterone, and HER2 receptors leave few alternative treatments to patients (pts) who become chemo-resistant. PARP inhibitors have shown efficacy in treating TNBC, but this success is limited to BRCA-associated cases. Inducing downregulation of BRCA1/2 in pts without BRCA mutations would present a new treatment option and may portend to improved recurrence free survival rates. This downregulation has been successfully demonstrated with the administration of a PI3K inhibitor. Here we report the co-delivery of a PARP and PI3K inhibitor using the natural, nontoxic polymer alginate as a nanoparticle platform, which is susceptible to degradation in response to ionizing radiation (IR) via cleavage of glycosidic bonds. We hypothesize that externally stimulating release of drugs that work synergistically with IR would effectively reduce the dose of radiation and drug necessary and limit the drug to a more targeted area, resulting in reduced unwanted toxicity thereby improving the therapeutic ratio. Materials/Methods: Breast Cancer Cells (MDA-MB-468) were treated with PI-103 (PI3K inhibitor) and BMN-673 (PARP inhibitor) alone and in combination to determine colony forming ability +/- IR and synergistic or additive effects. These studies were repeated with dual-drug loaded nanoparticles to evaluate the radiolytic release of drugs and impact on colony forming ability. Results: Preliminary data indicates that more DNA double strand breaks accumulate when PI-103 and BMN-673 are delivered in combination. We determined initial IC50 values for each drug, and tested for synergist effects at low doses with IR. MDA-MB-231 and MDA-MB-436 cell lines were also tested. In addition, we have formulated nanosized alginate carriers using cisplatin, as a model drug, and performed physiochemical characterizations.
Materials/Methods: Experiments were performed using different NSCLC (H23, H226, H460, H520, H1299, H1975, A549) and prostate cancer cell lines (DU 145, PC3, LnCAP) growing either under 2D or 3D conditions. SCF was knocked down by siRNA, c-Kit was inhibited by ISCK03 inhibitor and cells were irradiated with 2 Gy or 6 Gy Photons. Cell survival was determined by colony formation assay. Invasion was measured using BioCoatÔ MatrigelÔ invasion chambers. Results: When grown in 3D a 2-3-fold increase in invasion capability was examined in all NSCLC and prostate cancer cell lines except H520. This could be explained by EMT-like changes (enhanced expression of vimentin and N-cadherin and reduction of E-cadherin) when cells were grown in 3D. Just the opposite trends were found for H520 cells. Knock down of SCF was generally found to result in significantly reduced invasion and in only a minor increase of cellular radiosensitivity (2D and 3D). Only in cells characterized by a massive overexpression of SCF (H520) a significant increase of cellular radiosensitivity could be obtained after SCF knock down. The inhibition of c-Kit by a specific inhibitor was also found to result only in minor radiosensitization. Photon irradiation did not modulate cancer cell invasion (2D and 3D). Conclusion: For the regulation of tumor cell motility and invasion the SCF/c-Kit pathway appears to take a key position. Inhibition of this pathway significantly reduces the cell invasion of human NSCLC and prostate cancer cells under 2D and 3D conditions. In addition our data indicate that generally cell survival and radioresponse are not strongly determined by the SCF/c-Kit pathway. As a consequence targeting SCF or c-Kit only results in increased radiosensitivity when SCF is strongly over expressed as found for H520 cells. Author Disclosure: F. Eberle: None. F. Leinberger: None. M. Saulich: None. W. Seeger: None. R. Engenhart-Cabillic: None. E. Dikomey: None. F. Subtil: None.
3398 Abstract 3396 Cell Line
Drug
IC50 (mM)
MDA-MB-468 MDA-MB-468
PI-103 BMN-673
1.770.51 3.423.08
Conclusion: Our findings indicate that co-delivery of these drugs can enhance the efficacy of IR in a difficult to treat subset of breast cancer known as non-BRCA associated TNBC. Future directions include loading PI-103 and BMN-673 into nanocarriers and characterization of drug loading and release, cytotoxicity, and testing in vivo efficacy. Author Disclosure: A.N. DuRoss: None. J. Rosch: None. A. Brown: None. G. Sahay: None. J.J. Jaboin: None. C.R. Thomas: None. C. Sun: None.
3397 Possibilities of Radiosensitization and Reduced Invasion After Targeting the SCF/c-Kit Pathway in Human Cancer Cells F. Eberle,1 F. Leinberger,1 M. Saulich,1 W. Seeger,2 R. EngenhartCabillic,3 E. Dikomey,4 and F. Subtil1; 1Department of Radiotherapy and Radiooncology, Philipps University, Marburg, Germany, 2Universities of Giessen & Marburg Lung Center (UGMLC), Giessen, Germany, 3 Department of Radiation Oncology, University Marburg, Marburg, Germany, 4Laboratory of Radiobiology & Experimental Radiooncology, University Medical Center Hamburg-Eppendorf, Germany, Hamburg, Germany Purpose/Objective(s): The SCF/c-Kit pathway is often overexpressed in human tumors leading to an enhanced proliferation and invasion. Resulting therapy resistance and metastasis often are limiting factors of a successfull radiotherapy. It was now tested for NSCLC and prostate cancer cells growing in 2D and 3D whether the inhibition of this pathway can be used to achieve a reduced cancer cell invasion and whether a significant increased radiosensitivity could be achieved.
Effects of Fractionation Schedule on Expression Patterns of Clinically Significant Circulating Cytokines During Radiation Therapy for Lung Cancer S. Ellsworth,1 J. Chen,2 W. Wang,3 M.M. Matuszak,4 R. K. Ten Haken,5 S. Jolly,6 and F.M. Kong3; 1Indiana University Department of Radiation Oncology, Indianapolis, IN, 2Medical College of Georgia, Augusta, GA, 3 Department of Radiation Oncology, Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN, 4Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, 5University of Michigan, Department of Radiation Oncology, Ann Arbor, MI, 6University of Michigan, Ann Arbor, MI Purpose/Objective(s): Radiation therapy (RT) is associated with acute and late effects on the immune system. However, the effects of RT on immunomodulatory cytokines (CK) are not been described. This study prospectively analyzed levels of 30 CKs in patients treated with different regimens for non-small cell lung cancer (NSCLC). The primary goal was to determine whether fractionation schedule or chemotherapy was associated with differences in the levels of clinically significant CKs. Materials/Methods: Patients were treated on 3 separate prospective clinical trials of conventionally fractionated radiation (CFRT; 60-87.9 Gy in 30-36 fractions, nZ18), chemoradiation (ChRT; 60-85.5 Gy in 30-37 fractions, nZ114), and stereotactic body radiation (SBRT; 50-55 Gy in 5 fractions, nZ16). CK levels were determined from platelet-poor plasma specimens with ELISA at baseline and midway through treatment. Principal component analysis (PCA) was used to identify CKs of interest for further study, which included IP10 and sCD40l. IL2, TGF-B1, IL7, IL8, IL10, and IL15 were also included in the analysis as these are known to be immunologically significant CKs and/or have been previously identified as potentially significant circulating factors in NSCLC. Results: This report includes 148 patients. Median age was 66 yrs (range 40-92 yrs), 24.3% of patients were female, and median follow-up was 46 months. CK expression patterns differed significantly among the 3 groups. In SBRT and ChRT patients, IL-8 decreased significantly during treatment
E588
International Journal of Radiation Oncology Biology Physics
(pZ0.03 and 0.01 respectively) but did not change significantly in CFRT patients. IL-15 increased significantly during treatment in the CFRT (p Z 0.01) and ChRT (p<0.001) patients but not in the SBRT group. ChRT patients exhibited the most dynamic changes in CK expression, with significant decreases in IP-10 (p < 0.001), sCD40l (pZ0.003), and IL-2 (pZ0.04) as well as the previously noted changes in IL-8 and IL-15. Median TGF-B1 values increased in the SBRT and CFRT groups but decreased in the ChRT group, although these changes were not statistically significant. Conclusion: Treatment scheme appeared to be significantly associated with differing cytokine expression patterns in patients undergoing radiation for NSCLC. Combined ChRT patients appeared to have the greatest variability in multiple CKs including IP-10, sCD40l, IL-2, IL-8, and IL-15. Differences were also seen among the treatment groups in IL-8 and IL-15. Further study is needed to determine whether CK expression patterns can serve as an immune biomarker for outcomes in NSCLC. Author Disclosure: S. Ellsworth: None. J. Chen: None. W. Wang: None. M.M. Matuszak: Employee; William Beaumont Hospital. R.K. Ten Haken: Research Grant; NIH-NCI. Travel Expenses; Varian Medical Systems Inc. S. Jolly: None. F.M. Kong: Research Grant; NCI/NIH, Varian. Sino-American Network for Therapeutic Radiology, American Association of Women Radiologists (AAWR), Association for Chinese Professors, Chinese-American Network for Hematology and Oncolo, SinoAmerican Network for Therapeutic Radiation On.
completely healed at all times. At days 14 and 20, the healing in the 0 Gy + wound was so minimal that we did not measure the other groups until day 28. At 28 days, the mice in the 8.0 Gy + wound group still showed a significantly decreased tensile strength (1.1 0.1 newtons) compared to 1.4 0.1 newtons for the 0 Gy + wound (p Z 0.0013). Conclusion: This murine combined injury model of TBI irradiation + wound revealed a clear decreased survival compared to mice receiving TBI only. While longer observation times are needed to monitor the rates of wound healing, mice receiving 8.0 Gy + wound had decreased wound healing compared to 0 Gy + wound. Author Disclosure: M. Epperly: None. A. Bellare: None. J.S. Greenberger: None. R. Fisher: None. P. Wipf: None. G. Julie: None.
3399 A Murine Combined Injury Model of Total Body Irradiation and Skin Wound M. Epperly,1 A. Bellare,2 J.S. Greenberger,3 R. Fisher,4 P. Wipf,4 and G. Julie2; 1University of Pittsburgh Cancer Institute, Pittsburgh, PA, 2 Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, Boston, MA, 3UPMC-Shadyside Hospital, Pittsburgh, PA, 4University of Pittsburgh, Pittsburgh, PA Purpose/Objective(s): In the radiation terrorism scenario there will be combined injuries; we have developed a mouse model of combined injury (total body irradiation (TBI) plus defined skin wound). We measured the effect of TBI doses from 7.0 to 9.25 Gy irradiation on survival and healing of the skin wound. Materials/Methods: C57BL/6NTac female mice (8 weeks of age) were irradiated to doses of 0 Gy, 7.0 Gy, 8.0 Gy, 8.5 Gy, 9.0 Gy and 9.25 Gy TBI. Twenty-four hours before irradiation, the lower backs were shaved followed by depilation with NAIR. One hour after TBI, mice were anesthetized and a 25 mm length, 5 mm deep scalpel incision/wound was made in the skin. The wound was closed using staples. Control mice received no irradiation and no skin wound. Numbers of surviving mice were recorded daily. At 14, or 20 days after irradiation, groups of control and 0 Gy + wounded mice were sacrificed and wound healing was determined by measuring the tensile strength of each of ten 2 mm strips of skin per mouse across the wound using a 45N capacity tensile tester. On day 28 following irradiation, all remaining mice were tested. Results: The LD50/30 for C57BL/6NTac mice was 9.25 Gy. In the combined injury model the LD50/30 was 8.5 Gy with significantly increased lethality with wounding at 8.5 Gy and 9.0 Gy. Mice irradiated to 9.0 Gy + wound and 8.5 Gy + wound had a statistically significant decrease in survival compared to those receiving 9.0 Gy or 8.5 Gy alone (p Z 0.0073 and 0.0115, respectively). The number of deaths in the 8.5 Gy, 9.0 Gy and 9.25 Gy + wound groups was high. We tested the tensile strength in wounds from mice receiving 0 Gy + wound, 7.0 Gy + wound and 8.0 Gy + wound. Compared to the control (non-irradiated, non-wounded) mice tensile strength, the wounds in the combined injury mice were less
3400 The Expression of BDNF and PDGF Predict Curative Effect in Patients with Esophageal Squamous Cell Carcinoma Treated By Radiation Therapy P. Er1 and Q. Dong2; 1Tianjin Medical University Cancer Institute and hospital Tianjin, China, 2Tianjin Medical University Cancer Institute and Hospital, Tianjin, China Purpose/Objective(s): Radiotherapy plays a standard role and is well tolerated in the treatment of esophageal squamous cell carcinoma (ESCC). However, no effective biological markers have been identified for radiation sensitivity and curative effect prediction of patients with ESCC. Therefore, the present study was to explore the relationship between the expression of brain-derived neurotrophic factor (BDNF) or platelet-derived growth factor (PDGF) and prognosis of patients with ESCC who receive radiotherapy, and to evaluate the clinical utility of these biomarkers. Materials/Methods: This pilot study recruited patients who received neoadjuvant chemoradiotherapy (neo-CRT) or definitive chemoradiotherapy (CRT) of total doses ranging from 40 to 60Gy (2.0Gy/fraction per day). Each patient underwent blood samples collection before treatment and at the time of administration of total doses of 40Gy. Cytokines expression analyses were preformed in pretreated serum compared to that at the doses of 40Gy from 8 ESCCs. 7 differentially expressed cytokines identified by cytokine antibody arrays were validated by enzyme-linked immunosorbant assay. Of these, up-regulation of BDNF and PDGF in serum at the doses of 40Gy was found in radiation-resistant patients. The predictive value of BDNF and PDGF were further assessed in a second set of 48 ESCCs. All 48 patients were recruited in clinical trial (NCT02959385). Results: Significant decrease in the levels of the two cytokines at 40Gy compared with that in pretreated serum were observed[BDNF (PZ0.017); PGDF (PZ0.034)]. The median follow-up time of these patients was 10.24 months (range: 3.75e19.42 months). In ultivariate analysis, patients with lower levels of BDNF in serum at the total dose of 40Gy, compared to that of pretreatment, were associated with superior outcome (NZ24 vs 23, median survival time: 12.61 vs 10.37months, PZ0.035).Besides, patients with decreased levels in either BDNF or PDGF at the total doses of 40Gy have significantly favorable outcome in comparison to others (NZ27 vs 20, median survival time: 13.23 vs 10.27months, PZ0.018). Conclusion: We found that the levels of BDNF and PDGF in serum are reliable and predictive biomarkers for CRT response and progression-free survival in patients with ESCC. It can be used as a prognostic indicator in patients with ESCC treated by chemoradiotherapy, which will facilitate the individualization of ESCC treatment. Additional clinical researches with quantities of cases are accordingly desired to fully assess its predictive power. Author Disclosure: P. Er: None. Q. Dong: None.