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Gene Expression Response to Ionizing Radiation in Luminal and Basal Breast Cancer Cell Lines
S710
International Journal of Radiation Oncology Biology Physics
default parameters. Genes expressed either in normal or cancer tissues or in both tissues were grouped based on Reads Per Kilobase of exon model per Million mapped reads (RPKM) values. Validation of the results was carried out by RT qPCR of selected transcripts. The differential expression between normal and cancerous tissue was derived using the RPKM values of the corresponding transcripts. Enrichment of the genes belonging to specific biological pathways were analysed. To increase the reproducibility, genes were selected with RPKM values 5 in at least one of the samples and the genes which were detected in both the samples were further selected with fold change 3. Results: Four hundred fifty-four sequencing platforms, identified a total of 1,797 and 2,655 genes uniquely expressed in normal and cancer tissues, respectively with 2,466 genes expressed in both tissues. Among the genes expressed in both tissues, 1,842 were up-regulated whereas 624 were down-regulated in cancer tissue. The RT qPCR of selected transcripts demonstrated reproducibility of differential expression profiling by RNASeq analysis. Further analysis of the deregulated transcripts by KEGG pathway and gene ontology revealed significant enrichment of genes in pathways commonly found to be altered in cancer with gene ontology suggesting suppression of genes involved in the actin mediated cell contraction process in cancer. Conclusion: Besides transcripts known to be involved in cancer, this study led to identification of novel transcripts, with significantly altered expression in buccal cancer, providing potential targets for cancer therapeutics. Author Disclosure: C. G.Joshi: None. V. Shankar: None. C. Haritha: None. S. Shah: None. M.R. Sajnani: None. A.K. Patel: None. V.D. Bhatt: None. A.K. Tripathi: None. S.J. Jakhesara: None. V.B. Ahir: None.
stimulating antibody (CH11) resulted in radiosensitization (dose modifying factor Z 2.5). Conclusion: These data link patterns of gene expression response to radiation response and identify potential subtype-specific targets that can enhance radiation effect. Induction of the Fas pathway, in particular, was found to enhance the radiation sensitivity of resistant breast tumors. The successful in vivo confirmation of these findings will greatly enhance our ability to predict and modulate the response of breast tumors to ionizing radiation. Author Disclosure: J.K. Horton: None. D.R. Fels: None. H. Kung: None. K. Ashcraft: None. M.W. Dewhirst: G. Consultant; Actium Corporation. K. Stock; Celsion. J.A. Chi: None.
3310 Gene Expression Response to Ionizing Radiation in Luminal and Basal Breast Cancer Cell Lines J.K. Horton, D.R. Fels, H. Kung, K. Ashcraft, M.W. Dewhirst, and J.A. Chi; Duke University Medical Center, Durham, NC Purpose/Objective(s): There are significant clinical differences in how breast tumors respond to ionizing radiation. Understanding the molecular determinants of this variation may enable individualized treatment strategies to maximize therapeutic benefit and reduce toxicity. A growing body of data suggests that the intrinsic (luminal, basal) subtypes of breast cancer contribute significantly to the probability of locoregional control in women receiving radiation as a component of their treatment. We hypothesized that this may be, in part, due to distinct patterns of gene expression among diverse breast tumors and tumor cells. Understanding the molecular underpinnings of these differences could identify biologically-based targets for radiosensitization. Materials/Methods: Six commercially available human breast cancer cell lines known to display gene expression patterns of distinct breast subtypes (luminal - ZR751, T47D, MCF7; basal - SUM159, SUM149, MDA-MB231) were selected to study their gene expression and phenotypic responses to ionizing radiation. Cell lines were maintained in appropriate media and grown in triplicate to account for individual sample variability. After reaching confluence, RNA was harvested before and 24 hours after a single dose of 5Gy. Clonogenic cell survival assays were performed to assess the varying degrees of radiosensitivity and compared with gene expression to identify markers of radiation response. Clonogenic assays were also utilized to assess the impact of pharmacologic modulation on targets identified by the genomic assay. Results: Resistance to ionizing radiation was significantly associated, but not in perfect agreement with, the basal type breast cells. Similarly, preand post-radiation gene expression mostly tracked with basal versus luminal cell types, but distinct patterns of gene expression seen between the two cell types were tightly associated with varying degrees of radiosensitivity. Among the genes that were strongly induced in the radiosensitive cell lines was Fas, which encodes a critical modulator of programmed cell death and is linked with radiation response in other cell types. Treatment of a resistant basal cell line, SUM159, with Fas
3311 The Role of Biochemical Markers in Prediction of Radiation Therapy Failure for Patients With Head-and-Neck Cancer T. Rutkowski, J. Mrochem-Kwarciak, B. Masłyk, A. Hajduk, A. Wygoda, B. Lukaszczyk-Wideł, B. Hejduk, M. Hutnik, M. Golen, and K. Składowski; Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice, Poland Purpose/Objective(s): There is lack of effective diagnostic tools for early assessment of radiation therapy (RT) outcome in patients with head and neck cancer. Timely diagnose of treatment failure may allow to carry out salvage procedures to prevent disease progression. Complex assessment of SCC-Ag (SCC), CYFRA 21.1(CYFRA), osteopontin (OPN) and C-reactive protein (CRP) as early markers of radiation therapy failure in patients with pharyngeal or laryngeal carcinoma has done. Materials/Methods: Between 01/2008 and 06/2010 137 patients in the mean age of 55 years with squamous cell carcinoma of nasopharynx (8%), oropharynx (39%), hypopharynx (13%) or larynx (40%) were treated with curative intent with RT alone or combined with chemotherapy. Male: female ratio was 3:1. There were 9%, 25%, 13% and 53% patients with I, II, III and IV stage of the disease respectively. Biomarkers were marked in serum three times: before RT, immediately after RT completion and during 6-24 months follow-up. Wilcoxon signed rank test was used to compare marker concentrations in these time points in two groups of patients: complete remissioned (CR) and not completely remissioned (NCR). Results: Median of follow-up was 10 months (range 6- 24 months). There were 69% CR, and 31% NCR. Comparing CR and NCR there were no significant differences between markers concentration obtained before RT. After RT SCC (p Z 0,01) and CYFRA (p Z 0,02) were significantly elevated in NCR group. For all patients there was a significant increase of OPN (p Z 0,0001) and CRP (p Z 0,0001) concentration during RT. During follow up significant decrease in OPN concentration (p Z 0,0001) and CRP concentration (p Z 0,0001) appeared only in CR group. Conclusions: High concentration of SCC and CYFRA shortly after RT predict treatment failure. High level of OPN and CRP at that moment should not worry unless remain increased during follow-up. More data is however needed to confirm these preliminary results. Author Disclosure: T. Rutkowski: None. J. Mrochem-Kwarciak: None. B. Masłyk: None. A. Hajduk: None. A. Wygoda: None. B. LukaszczykWideł: None. B. Hejduk: None. M. Hutnik: None. M. Golen: None. K. Składowski: None.
3312 C-Reactive Protein (CRP): Initial Exploratory Study of an Inflammatory Biomarker for Prostate Cancer Radiation Therapy W.A. Hall,1 P.J. Rossi,1 S. Cooper,1 V.A. Master,2 and A.B. Jani1; 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 2Department of Urology and Winship Cancer Institute, Atlanta, GA Purpose/Objective(s): The inflammatory biomarker C-Reactive Protein (CRP) has been demonstrated to have a pivotal role for several malignancies, particular renal cell cancer. Although CRP has been correlated with PSA in the setting of metastatic and castrate-resistant prostate cancer
International Journal of Radiation Oncology Biology Physics
default parameters. Genes expressed either in normal or cancer tissues or in both tissues were grouped based on Reads Per Kilobase of exon model per Million mapped reads (RPKM) values. Validation of the results was carried out by RT qPCR of selected transcripts. The differential expression between normal and cancerous tissue was derived using the RPKM values of the corresponding transcripts. Enrichment of the genes belonging to specific biological pathways were analysed. To increase the reproducibility, genes were selected with RPKM values 5 in at least one of the samples and the genes which were detected in both the samples were further selected with fold change 3. Results: Four hundred fifty-four sequencing platforms, identified a total of 1,797 and 2,655 genes uniquely expressed in normal and cancer tissues, respectively with 2,466 genes expressed in both tissues. Among the genes expressed in both tissues, 1,842 were up-regulated whereas 624 were down-regulated in cancer tissue. The RT qPCR of selected transcripts demonstrated reproducibility of differential expression profiling by RNASeq analysis. Further analysis of the deregulated transcripts by KEGG pathway and gene ontology revealed significant enrichment of genes in pathways commonly found to be altered in cancer with gene ontology suggesting suppression of genes involved in the actin mediated cell contraction process in cancer. Conclusion: Besides transcripts known to be involved in cancer, this study led to identification of novel transcripts, with significantly altered expression in buccal cancer, providing potential targets for cancer therapeutics. Author Disclosure: C. G.Joshi: None. V. Shankar: None. C. Haritha: None. S. Shah: None. M.R. Sajnani: None. A.K. Patel: None. V.D. Bhatt: None. A.K. Tripathi: None. S.J. Jakhesara: None. V.B. Ahir: None.
stimulating antibody (CH11) resulted in radiosensitization (dose modifying factor Z 2.5). Conclusion: These data link patterns of gene expression response to radiation response and identify potential subtype-specific targets that can enhance radiation effect. Induction of the Fas pathway, in particular, was found to enhance the radiation sensitivity of resistant breast tumors. The successful in vivo confirmation of these findings will greatly enhance our ability to predict and modulate the response of breast tumors to ionizing radiation. Author Disclosure: J.K. Horton: None. D.R. Fels: None. H. Kung: None. K. Ashcraft: None. M.W. Dewhirst: G. Consultant; Actium Corporation. K. Stock; Celsion. J.A. Chi: None.
3310 Gene Expression Response to Ionizing Radiation in Luminal and Basal Breast Cancer Cell Lines J.K. Horton, D.R. Fels, H. Kung, K. Ashcraft, M.W. Dewhirst, and J.A. Chi; Duke University Medical Center, Durham, NC Purpose/Objective(s): There are significant clinical differences in how breast tumors respond to ionizing radiation. Understanding the molecular determinants of this variation may enable individualized treatment strategies to maximize therapeutic benefit and reduce toxicity. A growing body of data suggests that the intrinsic (luminal, basal) subtypes of breast cancer contribute significantly to the probability of locoregional control in women receiving radiation as a component of their treatment. We hypothesized that this may be, in part, due to distinct patterns of gene expression among diverse breast tumors and tumor cells. Understanding the molecular underpinnings of these differences could identify biologically-based targets for radiosensitization. Materials/Methods: Six commercially available human breast cancer cell lines known to display gene expression patterns of distinct breast subtypes (luminal - ZR751, T47D, MCF7; basal - SUM159, SUM149, MDA-MB231) were selected to study their gene expression and phenotypic responses to ionizing radiation. Cell lines were maintained in appropriate media and grown in triplicate to account for individual sample variability. After reaching confluence, RNA was harvested before and 24 hours after a single dose of 5Gy. Clonogenic cell survival assays were performed to assess the varying degrees of radiosensitivity and compared with gene expression to identify markers of radiation response. Clonogenic assays were also utilized to assess the impact of pharmacologic modulation on targets identified by the genomic assay. Results: Resistance to ionizing radiation was significantly associated, but not in perfect agreement with, the basal type breast cells. Similarly, preand post-radiation gene expression mostly tracked with basal versus luminal cell types, but distinct patterns of gene expression seen between the two cell types were tightly associated with varying degrees of radiosensitivity. Among the genes that were strongly induced in the radiosensitive cell lines was Fas, which encodes a critical modulator of programmed cell death and is linked with radiation response in other cell types. Treatment of a resistant basal cell line, SUM159, with Fas
3311 The Role of Biochemical Markers in Prediction of Radiation Therapy Failure for Patients With Head-and-Neck Cancer T. Rutkowski, J. Mrochem-Kwarciak, B. Masłyk, A. Hajduk, A. Wygoda, B. Lukaszczyk-Wideł, B. Hejduk, M. Hutnik, M. Golen, and K. Składowski; Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice, Poland Purpose/Objective(s): There is lack of effective diagnostic tools for early assessment of radiation therapy (RT) outcome in patients with head and neck cancer. Timely diagnose of treatment failure may allow to carry out salvage procedures to prevent disease progression. Complex assessment of SCC-Ag (SCC), CYFRA 21.1(CYFRA), osteopontin (OPN) and C-reactive protein (CRP) as early markers of radiation therapy failure in patients with pharyngeal or laryngeal carcinoma has done. Materials/Methods: Between 01/2008 and 06/2010 137 patients in the mean age of 55 years with squamous cell carcinoma of nasopharynx (8%), oropharynx (39%), hypopharynx (13%) or larynx (40%) were treated with curative intent with RT alone or combined with chemotherapy. Male: female ratio was 3:1. There were 9%, 25%, 13% and 53% patients with I, II, III and IV stage of the disease respectively. Biomarkers were marked in serum three times: before RT, immediately after RT completion and during 6-24 months follow-up. Wilcoxon signed rank test was used to compare marker concentrations in these time points in two groups of patients: complete remissioned (CR) and not completely remissioned (NCR). Results: Median of follow-up was 10 months (range 6- 24 months). There were 69% CR, and 31% NCR. Comparing CR and NCR there were no significant differences between markers concentration obtained before RT. After RT SCC (p Z 0,01) and CYFRA (p Z 0,02) were significantly elevated in NCR group. For all patients there was a significant increase of OPN (p Z 0,0001) and CRP (p Z 0,0001) concentration during RT. During follow up significant decrease in OPN concentration (p Z 0,0001) and CRP concentration (p Z 0,0001) appeared only in CR group. Conclusions: High concentration of SCC and CYFRA shortly after RT predict treatment failure. High level of OPN and CRP at that moment should not worry unless remain increased during follow-up. More data is however needed to confirm these preliminary results. Author Disclosure: T. Rutkowski: None. J. Mrochem-Kwarciak: None. B. Masłyk: None. A. Hajduk: None. A. Wygoda: None. B. LukaszczykWideł: None. B. Hejduk: None. M. Hutnik: None. M. Golen: None. K. Składowski: None.
3312 C-Reactive Protein (CRP): Initial Exploratory Study of an Inflammatory Biomarker for Prostate Cancer Radiation Therapy W.A. Hall,1 P.J. Rossi,1 S. Cooper,1 V.A. Master,2 and A.B. Jani1; 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 2Department of Urology and Winship Cancer Institute, Atlanta, GA Purpose/Objective(s): The inflammatory biomarker C-Reactive Protein (CRP) has been demonstrated to have a pivotal role for several malignancies, particular renal cell cancer. Although CRP has been correlated with PSA in the setting of metastatic and castrate-resistant prostate cancer