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Concordant gene expression profiles in matched primary and recurrent serous ovarian cancers predict platinum response
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ABSTRACTS / Gynecologic Oncology 120 (2011) S2–S133
Results: Comparing clear cell RCC with OCC and ECC, we found a high expression of p-4E BP1 in all three tumor systems. However, OCC and ECC revealed a significantly higher expression of p-S6 (P = 0.04 for OCC and 0.0008 for ECC) and Glut1 (P = 0.006 for OCC and 0.0006 for ECC) than in clear cell RCC, whereas lack of PTEN expression was significantly higher in clear cell RCC than in OCC and ECC (P = 0.0006 for OCC and 0.0008 for ECC). Conclusions: The overexpression of p-4E BP1 mTOR pathway effector in OCC and ECC is similar to that seen in clear cell RCC. These data suggest a potential role for this effector in the oncogenesis of OCC and ECC. They also support a possible therapeutic utility of inhibiting this effector in a strategy similar to that adopted for clear cell RCC.
recurrent tumors. Overall, there was no significant difference between the primary and recurrent tumors when analyzed with hierarchical clustering, ANOVA, and a previously developed platinum sensitivity signature, demonstrating concordance in gene expression between matched primary and recurrent pairs. Conclusions: These data provide evidence that gene expression profiles from primary ovarian cancers are retained in samples obtained at recurrence. Further analyses are needed to determine which specific genomic signatures remain consistent beyond platinum resistance. The ability to base genomic predictive tests on tumor samples from primary surgery would greatly facilitate the development of personalized approaches to the management of women with ovarian cancer.
Immunohistochemical staining results.
p-4E BP1 high expression p-S6 high expression PTEN lack of expression Glut1 high expression
Clear cell RCC
OCC
ECC
71% (n = 38) 54% (n = 37) 82% (n = 39) 49% (n = 39)
76% (n = 17) 78% (n = 32) 42% (n = 33) 82% (n = 33)
79% 93% 37.5% 90%
doi:10.1016/j.ygyno.2010.12.112 (n = 28) (n = 27) (n = 24) (n = 29)
doi:10.1016/j.ygyno.2010.12.111
105 Concordant gene expression profiles in matched primary and recurrent serous ovarian cancers predict platinum response G. Sfakianos1, J. Yan2, R. Whitaker1, S. Murphy1, A. Berchuck1 1 Duke University Medical Center, Durham, NC, 2Cancer Guide Diagnostics, Durham, NC Objective: Primary therapy for ovarian cancer involves debulking surgery and platinum-based chemotherapy. Most patients develop recurrent disease and undergo additional therapy. Our group and others have sought to develop genomic predictors that would guide therapies. These predictors have been developed using frozen tumor samples from primary surgery, because it is more difficult to obtain tumor at the time of recurrence. The objective of this study was to compare gene expression between primary and recurrent ovarian cancers to determine whether samples obtained at primary surgery can guide therapies throughout the course of disease. Gene expression profiles were generated using Affymetrix U133A + 2.0 arrays in 21 pairs of high-grade serous ovarian cancers collected from the same patients at initial surgery and at a second surgery later in the course of disease. Quality controls, raw Q, background, and mean PM intensity, as well as percentage presence, were examined for each chip. Unsupervised clustering and principal component analysis were applied to group samples. Results: All 21 patients had advanced-stage disease. Hierarchical clustering grouped matched tumors from the same patient together. The primary and recurrent tumors were compared using ANOVA. Although none of the genes passed multitest correction by FDR, 37 genes identified at P < 0.005 were able to separate the primary tumors from the recurrent tumors. We tested the primary and recurrent tumor data sets for their response to platinum therapy by applying the top 100 genes from a previously developed platinum sensitivity signature. The sensitivity for this signature was 0.80 in both groups, and specificity was 0.42 for primary tumors and 0.58 for
106 Cooperative regulation of hPygo2 biomarker expression in cervical dysplasia and cancer C. Popadiuk, K. Kao, Y. Tzenov Memorial University, St. John's, NL, Canada Objective: We previously demonstrated that the Wnt signaling component hPygo2 is overexpressed and required for cancer cell growth and that Elf-1, which is regulated by the retinoblastoma (Rb) tumor suppressor, activates hPygo2. Because HPV-E7 protein suppresses Rb, we hypothesized that hPygo2 would persist in cervical cells transformed by human papillomavirus (HPV). The purpose of this study was therefore to determine the mechanism of overexpression of hPygo2 in human cervical dysplasia. Expression analyses were performed using immunoblot, immunofluorescence, and immunohistochemistry for protein and quantitative PCR for mRNA. Gene expression assays were performed in vitro using expression and reporter plasmid transfection, and in vivo transcription factor complex binding by chromatin immunoprecipitation (ChIP) assays. Results: Expression of hPygo2 mRNA and protein was significantly higher in HPV-transformed endocervical cells and cervical cancer cell lines relative to primary endocervical cells (HEN). Immunohistochemical analysis of hPygo2 protein expression in a tissue microarray of cervical cancer progression showed weak accumulation of hPygo2 in nuclei of parabasal cells of normal ectocervical epithelium. Cervical intraepithelial neoplasia (CIN) 2 and 3 staged dysplasias showed high levels of expression in cytoplasm, and the highest levels of expression were found in squamous cell carcinomas. HPV antibodies stained nuclei and cytoplasm of nonneoplastic tissues very strongly and, to a lesser extent, CIN 2, CIN 3 and squamous cell carcinomas. Transfection of mutant Rb tumor suppressor repressed Elf-1 activation of hPygo2 in HPV-transformed endo- and ectocervical cells, while Elf-1 itself amplified hPygo2 gene and protein expression. In vivo ChIP assays demonstrated that both Elf-1 and Rb cooperated to regulate hPygo2 expression in HPVtransformed cervical cells. Conclusions: Our findings revealed that hPygo2 protein accumulates in cervical cells as a result of HPV infection and increases with dysplasia leading to frank cancer. Deregulation of Rb protein by HPV resulted in de-repression of the Elf-1 oncogenic transcription factor, which in turn stimulated expression of hPygo2. These findings provide a mechanism to support the hypothesis that increased hPygo2 biomarker expression is a cellular response to HPV infection in cervical dysplasia and cancer.
ABSTRACTS / Gynecologic Oncology 120 (2011) S2–S133
Results: Comparing clear cell RCC with OCC and ECC, we found a high expression of p-4E BP1 in all three tumor systems. However, OCC and ECC revealed a significantly higher expression of p-S6 (P = 0.04 for OCC and 0.0008 for ECC) and Glut1 (P = 0.006 for OCC and 0.0006 for ECC) than in clear cell RCC, whereas lack of PTEN expression was significantly higher in clear cell RCC than in OCC and ECC (P = 0.0006 for OCC and 0.0008 for ECC). Conclusions: The overexpression of p-4E BP1 mTOR pathway effector in OCC and ECC is similar to that seen in clear cell RCC. These data suggest a potential role for this effector in the oncogenesis of OCC and ECC. They also support a possible therapeutic utility of inhibiting this effector in a strategy similar to that adopted for clear cell RCC.
recurrent tumors. Overall, there was no significant difference between the primary and recurrent tumors when analyzed with hierarchical clustering, ANOVA, and a previously developed platinum sensitivity signature, demonstrating concordance in gene expression between matched primary and recurrent pairs. Conclusions: These data provide evidence that gene expression profiles from primary ovarian cancers are retained in samples obtained at recurrence. Further analyses are needed to determine which specific genomic signatures remain consistent beyond platinum resistance. The ability to base genomic predictive tests on tumor samples from primary surgery would greatly facilitate the development of personalized approaches to the management of women with ovarian cancer.
Immunohistochemical staining results.
p-4E BP1 high expression p-S6 high expression PTEN lack of expression Glut1 high expression
Clear cell RCC
OCC
ECC
71% (n = 38) 54% (n = 37) 82% (n = 39) 49% (n = 39)
76% (n = 17) 78% (n = 32) 42% (n = 33) 82% (n = 33)
79% 93% 37.5% 90%
doi:10.1016/j.ygyno.2010.12.112 (n = 28) (n = 27) (n = 24) (n = 29)
doi:10.1016/j.ygyno.2010.12.111
105 Concordant gene expression profiles in matched primary and recurrent serous ovarian cancers predict platinum response G. Sfakianos1, J. Yan2, R. Whitaker1, S. Murphy1, A. Berchuck1 1 Duke University Medical Center, Durham, NC, 2Cancer Guide Diagnostics, Durham, NC Objective: Primary therapy for ovarian cancer involves debulking surgery and platinum-based chemotherapy. Most patients develop recurrent disease and undergo additional therapy. Our group and others have sought to develop genomic predictors that would guide therapies. These predictors have been developed using frozen tumor samples from primary surgery, because it is more difficult to obtain tumor at the time of recurrence. The objective of this study was to compare gene expression between primary and recurrent ovarian cancers to determine whether samples obtained at primary surgery can guide therapies throughout the course of disease. Gene expression profiles were generated using Affymetrix U133A + 2.0 arrays in 21 pairs of high-grade serous ovarian cancers collected from the same patients at initial surgery and at a second surgery later in the course of disease. Quality controls, raw Q, background, and mean PM intensity, as well as percentage presence, were examined for each chip. Unsupervised clustering and principal component analysis were applied to group samples. Results: All 21 patients had advanced-stage disease. Hierarchical clustering grouped matched tumors from the same patient together. The primary and recurrent tumors were compared using ANOVA. Although none of the genes passed multitest correction by FDR, 37 genes identified at P < 0.005 were able to separate the primary tumors from the recurrent tumors. We tested the primary and recurrent tumor data sets for their response to platinum therapy by applying the top 100 genes from a previously developed platinum sensitivity signature. The sensitivity for this signature was 0.80 in both groups, and specificity was 0.42 for primary tumors and 0.58 for
106 Cooperative regulation of hPygo2 biomarker expression in cervical dysplasia and cancer C. Popadiuk, K. Kao, Y. Tzenov Memorial University, St. John's, NL, Canada Objective: We previously demonstrated that the Wnt signaling component hPygo2 is overexpressed and required for cancer cell growth and that Elf-1, which is regulated by the retinoblastoma (Rb) tumor suppressor, activates hPygo2. Because HPV-E7 protein suppresses Rb, we hypothesized that hPygo2 would persist in cervical cells transformed by human papillomavirus (HPV). The purpose of this study was therefore to determine the mechanism of overexpression of hPygo2 in human cervical dysplasia. Expression analyses were performed using immunoblot, immunofluorescence, and immunohistochemistry for protein and quantitative PCR for mRNA. Gene expression assays were performed in vitro using expression and reporter plasmid transfection, and in vivo transcription factor complex binding by chromatin immunoprecipitation (ChIP) assays. Results: Expression of hPygo2 mRNA and protein was significantly higher in HPV-transformed endocervical cells and cervical cancer cell lines relative to primary endocervical cells (HEN). Immunohistochemical analysis of hPygo2 protein expression in a tissue microarray of cervical cancer progression showed weak accumulation of hPygo2 in nuclei of parabasal cells of normal ectocervical epithelium. Cervical intraepithelial neoplasia (CIN) 2 and 3 staged dysplasias showed high levels of expression in cytoplasm, and the highest levels of expression were found in squamous cell carcinomas. HPV antibodies stained nuclei and cytoplasm of nonneoplastic tissues very strongly and, to a lesser extent, CIN 2, CIN 3 and squamous cell carcinomas. Transfection of mutant Rb tumor suppressor repressed Elf-1 activation of hPygo2 in HPV-transformed endo- and ectocervical cells, while Elf-1 itself amplified hPygo2 gene and protein expression. In vivo ChIP assays demonstrated that both Elf-1 and Rb cooperated to regulate hPygo2 expression in HPVtransformed cervical cells. Conclusions: Our findings revealed that hPygo2 protein accumulates in cervical cells as a result of HPV infection and increases with dysplasia leading to frank cancer. Deregulation of Rb protein by HPV resulted in de-repression of the Elf-1 oncogenic transcription factor, which in turn stimulated expression of hPygo2. These findings provide a mechanism to support the hypothesis that increased hPygo2 biomarker expression is a cellular response to HPV infection in cervical dysplasia and cancer.