Purpose Cyclin E1 (CCNE1) amplification is associated with primary treatment resistance and poor outcome in high grade serous ovarian cancer (HGSC). Here, we explore approaches to target CCNE1 amplified cancers and potential strategies to overcome resistance to targeted agents. Experiment Design To examine dependency on CDK2 in CCNE1 amplified HGSC, we utilised siRNA and conditional shRNA gene suppression, and chemical inhibition using dinaciclib, a small molecule CDK2 inhibitor. High throughput compound screening was used to identify selective synergistic drug combinations, as well as combinations that may overcome drug resistance. An observed relationship between CCNE1 and the AKT pathway was further explored in genomic data from primary tumors, and functional studies in fallopian tube secretory cells. Results We validate CDK2 as a therapeutic target by demonstrating selective sensitivity to gene suppression. However, we found that dinaciclib did not trigger amplicon-dependent sensitivity in a panel of HGSC cell lines. A high throughput compound screen identified synergistic combinations in CCNE1 amplified HGSC, including dinaciclib and AKT inhibitors. Analysis of genomic data from TCGA demonstrated co-amplification of CCNE1 and AKT2. Over-expression of Cyclin E1 and AKT isoforms, in addition to mutant TP53, imparted malignant characteristics in untransformed fallopian tube secretory cells, the dominant site of origin of HGSC. Conclusions These findings suggest a specific dependency of CCNE1 amplified tumors for AKT activity, and point to a novel combination of dinaciclib and AKT inhibitors that may selectively target patients with CCNE1 amplified HGSC.

BackgroundEndometrioid adenocarcinoma of the uterus and ovarian endometrioid carcinoma share many morphological and molecular features. Differentiation between simultaneous primary carcinomas and ovarian metastases of an endometrial cancer may be very challenging but is essential for prognostic and therapeutic considerations.Case PresentationIn the present case study of a 33 year-old patient we used targeted amplicon next-generation re-sequencing for clarifying the origin of synchronous endometrioid cancer of the corpus uteri and the left ovary. The patient developed a metachronous lung metastasis of an endometrioid adenocarcinoma four years after hyster- and adnexectomy, vaginal brachytherapy and treatment with the synthetic steroid tibolone. Removal of the metastasis and megestrol treatment for seven years led to a complete remission.A total of 409 genes from the Ampliseq Comprehensive Cancer Panel (Ion Torrent, Thermo Fisher) were analysed by next generation sequencing and mutations in 10 genes, including ARID1A, CTNNB1, PIK3CA and PTEN were identified and confirmed by Sanger sequencing. Primary endometrial as well as ovarian cancer showed an identical mutational profile, suggesting the presence of an ovarian metastasis of the endometrial cancer, rather than a simultaneous endometrial and ovarian cancer. The metachronous lung metastasis showed a different mutational profile compared to the primary cancer. Immunohistochemical staining of the corresponding proteins suggested that the tumour development was driven by alterations in the protein function rather than by changes of the protein abundance in the cell.ConclusionsOur results have demonstrated next generation sequencing as a valuable tool in the differentiation of synchronous primary tumours and metastases, which has an important impact on the clinical decision making process. Similar to breast cancer, targeted therapies based on mutational tumour profiling will become increasingly important in endometrial and ovarian cancer. In summary, our results support the usage of next generation sequencing as a supplementary diagnostic tool, assisting in personalized precision medicine.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-017-3054-6) contains supplementary material, which is available to authorized users.

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