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Ovarian Cancer Dataset

ABSTRACT: Background. Genome-wide expression changes are associated with development of chemoresistance in patients with ovarian cancer (OVCA); the BCL2 antagonist of cell death (BAD) apoptosis pathway may play a role in clinical outcome. Methods. We analyzed specimens and/or genomic data from 1,406 patients and 116 cancer cell lines. Genome-wide expression changes and cisplatin-resistance were evaluated in OVCA cell lines subjected to a total of 144 (cisplatin)-treatment/recovery cycles. Pathway analysis was performed on genes associated with increasing cisplatin-resistance. BAD protein phosphorylation was studied in patient samples and cell lines, and small interfering RNAs (siRNA) used to explore the pathway as a therapeutic target. We evaluated the influence of BAD-pathway expression on chemosensitivity and/or clinical outcome using genomic data from 60 human cancer cell lines and ovarian, breast, colon, and brain cancers from 1,258 patients. Results. The BAD pathway was associated with evolution of OVCA cell line cisplatin-resistance (P<0.001) and resistance of 7 human cancer cell types to 8 cytotoxic agents (P<0.05). OVCA chemoresistance was associated with BAD protein phosphorylation, and targeted siRNA modulation produced corresponding changes in chemosensitivity. Expression of a 47-gene BAD-pathway signature was associated with survival of 1,258 patients with ovarian, breast, colon, and brain cancer. The OVCA BAD-pathway signature survival advantage was independent of surgical cytoreductive status. Conclusions. The BAD apoptosis pathway influences the sensitivity of human cancers to a variety of chemotherapies, likely via modulation of BAD-phosphorylation. The pathway has clinical relevance as a potential biomarker of therapeutic response, patient survival, and as a promising therapeutic target.

ORGANISM(S): Homo sapiens

PROVIDER: GSE23554 | GEO | 2011/10/03

SECONDARY ACCESSION(S): PRJNA133365

REPOSITORIES: GEO

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Project description:Background. Genome-wide expression changes are associated with development of chemoresistance in patients with ovarian cancer (OVCA); the BCL2 antagonist of cell death (BAD) apoptosis pathway may play a role in clinical outcome. Methods. We analyzed specimens and/or genomic data from 1,406 patients and 116 cancer cell lines. Genome-wide expression changes and cisplatin-resistance were evaluated in OVCA cell lines subjected to a total of 144 (cisplatin)-treatment/recovery cycles. Pathway analysis was performed on genes associated with increasing cisplatin-resistance. BAD protein phosphorylation was studied in patient samples and cell lines, and small interfering RNAs (siRNA) used to explore the pathway as a therapeutic target. We evaluated the influence of BAD-pathway expression on chemosensitivity and/or clinical outcome using genomic data from 60 human cancer cell lines and ovarian, breast, colon, and brain cancers from 1,258 patients. Results. The BAD pathway was associated with evolution of OVCA cell line cisplatin-resistance (P<0.001) and resistance of 7 human cancer cell types to 8 cytotoxic agents (P<0.05). OVCA chemoresistance was associated with BAD protein phosphorylation, and targeted siRNA modulation produced corresponding changes in chemosensitivity. Expression of a 47-gene BAD-pathway signature was associated with survival of 1,258 patients with ovarian, breast, colon, and brain cancer. The OVCA BAD-pathway signature survival advantage was independent of surgical cytoreductive status. Conclusions. The BAD apoptosis pathway influences the sensitivity of human cancers to a variety of chemotherapies, likely via modulation of BAD-phosphorylation. The pathway has clinical relevance as a potential biomarker of therapeutic response, patient survival, and as a promising therapeutic target. Twenty-eight (28) advanced-stage serous epithelial ovarian cancers were resected at the time of primary surgery from patients who would receive platinum-based therapy. The tumors were arrayed on Affymetrix HG-U133A GeneChips. The samples were analyzed with respect to the BAD pathway for correlation to overall survival and cisplatin response.

Project description:Understanding the mechanism of resistance in platinum-based regimens for the treatment of high-grade serous ovarian cancer (HGSOC) is important for identifying new therapeutic targets to improve the clinical outcome of ovarian cancer patients. Mass spectrometry-based proteomic strategy was applied to spheroidal cisplatin sensitive and resistant HGSOC generated cell lines in the absence and presence of cisplatin drug. A complete expressed HGSOC proteome and phosphoproteome was characterized in cisplatin sensitive and resistant HGSOC cell lines providing insight into the mechanism of resistance development. PCA analysis showed that phosphorylation of a few proteins provides better classification than the whole proteome of the cellular subtypes. Specifically, a distinctive phosphoproteomic signature between cisplatin sensitive and resistant cell lines in the absence of drug was observed. This same phosphoproteomic signature was observed in our cisplatin sensitive cell line in the absence and presence of drug, indicating a vital role for phosphorylation of proteins in resistance development to cisplatin. The most phosphorylated protein was sequestosome (p62/SQSTM1). Differential expressions of apoptosis by the prognostic factor ratio of Bcl-2/Bax and autophagy, known to be regulated by p62/SQSTM1, was validated in the proteome data and by western blot analysis. A significant increase in apoptosis in the presence of cisplatin was observed in only the sensitive cell line while autophagy revealed increased expression in the resistant relative to sensitive cell line. Furthermore, site specific phosphorylation on 20 modified residues of sequestosome was characterized. Elevated expression of phosphorylation of sequestosome in resistant HGSOC cell lines was validated with western blot analysis. Here, we propose phosphorylation of sequestosome to be a marker and key in cisplatin resistance development in HGOSC ovarian cancers by shuttling ubiquitinated proteins to the autophagy pathway and influencing down-regulation of apoptosis.

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Ovarian Cancer Dataset

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