Expression of steroid receptor coactivator 3 in ovarian epithelial cancer is a poor prognostic factor and a marker for platinum resistance.

BACKGROUND: Steroid receptor coactivator 3 (SRC3) is an important coactivator of a number of transcription factors and is associated with a poor outcome in numerous tumours. Steroid receptor coactivator 3 is amplified in 25% of epithelial ovarian cancers (EOCs) and its expression is higher in EOCs compared with non-malignant tissue. No data is currently available with regard to the expression of SRC-3 in EOC and its influence on outcome or the efficacy of treatment. METHODS: Immunohistochemistry was performed for SRC3, oestrogen receptor-α, HER2, PAX2 and PAR6, and protein expression was quantified using automated quantitative immunofluorescence (AQUA) in 471 EOCs treated between 1991 and 2006 with cytoreductive surgery followed by first-line treatment platinum-based therapy, with or without a taxane. RESULTS: Steroid receptor coactivator 3 expression was significantly associated with advanced stage and was an independent prognostic marker. High expression of SRC3 identified patients who have a significantly poorer survival with single-agent carboplatin chemotherapy, while with carboplatin/paclitaxel treatment such a difference was not seen. CONCLUSION: Steroid receptor coactivator 3 is a poor prognostic factor in EOCs and appears to identify a population of patients who would benefit from the addition of taxanes to their chemotherapy regimen, due to intrinsic resistance to platinum therapy.

KIBRA exhibits MST-independent functional regulation of the Hippo signaling pathway in mammals.

The Salvador/Warts/Hippo (Hippo) signaling pathway defines a novel signaling cascade regulating cell contact inhibition, organ size control, cell growth, proliferation, apoptosis and cancer development in mammals. The upstream regulation of this pathway has been less well defined than the core kinase cassette. KIBRA has been shown to function as an upstream member of the Hippo pathway by influencing the phosphorylation of LATS and YAP, but functional consequences of these biochemical changes have not been previously addressed. We show that in MCF10A cells, loss of KIBRA expression displays epithelial-to-mesenchymal transition (EMT) features, which are concomitant with decreased LATS and YAP phosphorylation, but not MST1/2. In addition, ectopic KIBRA expression antagonizes YAP via the serine 127 phosphorylation site and we show that KIBRA, Willin and Merlin differentially regulate genes controlled by YAP. Finally, reduced KIBRA expression in primary breast cancer specimens correlates with the recently described claudin-low subtype, an aggressive sub-group with EMT features and a poor prognosis.

Defining the molecular response to trastuzumab, pertuzumab and combination therapy in ovarian cancer.

BACKGROUND: Trastuzumab and pertuzumab target the Human Epidermal growth factor Receptor 2 (HER2). Combination therapy has been shown to provide enhanced antitumour activity; however, the downstream signalling to explain how these drugs mediate their response is not clearly understood. METHODS: Transcriptome profiling was performed after 4 days of trastuzumab, pertuzumab and combination treatment in human ovarian cancer in vivo. Signalling pathways identified were validated and investigated in primary ovarian xenografts at the protein level and across a timeseries. RESULTS: A greater number and variety of genes were differentially expressed by the combination of antibody therapies compared with either treatment alone. Protein levels of cyclin-dependent kinase inhibitors p21 and p27 were increased in response to both agents and further by the combination; pERK signalling was inhibited by all treatments; but only pertuzumab inhibited pAkt signalling. The expression of proliferation, apoptosis, cell division and cell-cycle markers was distinct in a panel of primary ovarian cancer xenografts, suggesting the heterogeneity of response in ovarian cancer and a need to establish predictive biomarkers. CONCLUSION: This first comprehensive study of the molecular response to trastuzumab, pertuzumab and combined therapy in vivo highlights both common and distinct downstream effects to agents used alone or in combination, suggesting that complementary pathways may be involved.

The mammalian target of rapamycin inhibitor everolimus (RAD001) in early breast cancer: results of a pre-operative study.

mTOR plays a key role in tumor cell cycle control, proliferation, and survival. RAD001 (everolimus) is a novel macrolide that inhibits mTOR and thus downstream signaling pathways. 31 post-menopausal women with early breast cancer were given 5 mg RAD001 once daily for 14 days prior to surgery. Biopsies were taken at diagnosis and at surgery (post 14 days of treatment) and assessed for immunohistochemical changes in proliferation (Ki67), apoptosis (active caspase-3), p-AKT (s473), p-S6 (s235/236 and s240/244), p-mTOR (s2448), ER, and PR. Five patients did not complete the 2-week treatment period due to adverse events. All adverse events were grade 1 or 2 (NCIC-CTC scale). RAD001 treatment significantly decreased proliferation (geometric mean reduction 74% from baseline (p = 0.019)), particularly in HER-2 positive tumors. High Ki67 pre-treatment correlated with reduction in Ki67, an increase in apoptosis, a reduction in p-AKT (cytoplasmic) and reduction in p-mTOR following treatment. Nuclear expression of p-AKT was significantly reduced with treatment. Tumors that had a reduction in Ki67 with treatment exhibited a significant reduction in cytoplasmic p-AKT. p-S6 staining was significantly reduced independently of Ki67 (p < 0.001 for two sites of phosphorylation). RAD001 5 mg/daily is safe and tolerable in postmenopausal early breast cancer patients and inhibits the mTOR pathway and its downstream effectors, significantly reducing tumor cell proliferation. Tumors with high Ki67, high p-AKT, and HER-2 positivity may be more responsive to mTOR inhibition with RAD001. This is the first study to report results of RAD001 5 mg as a single agent in early breast cancer.

A gene on the HER2 amplicon, C35, is an oncogene in breast cancer whose actions are prevented by inhibition of Syk.

BACKGROUND: C35 is a 12 kDa membrane-anchored protein endogenously over-expressed in many invasive breast cancers. C35 (C17orf37) is located on the HER2 amplicon, between HER2 and GRB7. The function of over-expressed C35 in invasive breast cancer is unknown. METHODS: Tissue microarrays containing 122 primary human breast cancer specimens were used to examine the association of C35 with HER2 expression. Cell lines over-expressing C35 were generated and tested for evidence of cell transformation in vitro. RESULTS: In primary breast cancers high levels of C35 mRNA expression were associated with HER2 gene amplification. High levels of C35 protein expression were associated with hallmarks of transformation, such as, colony growth in soft agar, invasion into collagen matrix and formation of large acinar structures in three-dimensional (3D) cell cultures. The transformed phenotype was also associated with characteristics of epithelial to mesenchymal transition, such as adoption of spindle cell morphology and down-regulation of epithelial markers, such as E-cadherin and keratin-8. Furthermore, C35-induced transformation in 3D cell cultures was dependent on Syk kinase, a downstream mediator of signalling from the immunoreceptor tyrosine-based activation motif, which is present in C35. CONCLUSION: C35 functions as an oncogene in breast cancer cell lines. Drug targeting of C35 or Syk kinase might be helpful in treating a subset of patients with HER2-amplified breast cancers.

Quantitative analysis of changes in ER, PR and HER2 expression in primary breast cancer and paired nodal metastases.

BACKGROUND: Assessment of receptors [estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2)] is routinely carried out on primary tumour in order to select appropriate adjuvant therapy; the same analysis is not carried out on nodal metastases. Since de novo resistance to therapy is common, we quantified differences in receptor expression between primary and nodal disease in order to assess whether this might contribute to therapeutic resistance. PATIENTS AND METHODS: A total of 385 patients with invasive primary breast carcinomas and paired lymph nodes (n = 211) were assessed for ER, PR and HER2 expression using quantitative immunofluorescence. Cut-points were defined by comparison with tumours scored by immunohistochemistry (IHC) and FISH. Differences in expression for each of the markers and molecular phenotype were analysed. RESULTS: Quantitative receptor expression shows a wide dynamic range compared with IHC. Overall, 46.9% cases had disparate breast/node receptor status of at least one receptor. Many of the differences in expression between primary tumour and node are large magnitude (greater than fivefold) changes. Triple-negative phenotype changes in 23.1% of cases. CONCLUSIONS: A significant number of patients show discordant quantitative expression of molecular markers between primary and nodal disease. Appropriately measured, lymph node receptor status could be a more accurate measurement for guiding adjuvant therapy, which requires testing in a clinical trial.

Tissue microarray technology in the routine assessment of HER-2 status in invasive breast cancer: a prospective study of the use of immunohistochemistry and fluorescence in situ hybridization.

AIMS: To compare tissue microarray (TMA) and whole-section (WS) techniques in the routine assessment of HER-2 status in invasive breast cancer by immunohistochemistry and fluorescence in situ hybridization (FISH). METHODS AND RESULTS: HER-2 status was assessed prospectively in 106 consecutive cases of excised high-grade and/or node-positive breast carcinoma using both WS- and TMA-based techniques. Whole sections were assessed by immunohistochemistry with FISH being performed on equivocal cases (scoring 2+ on HercepTest) and randomly selected 3+ cases included for quality assurance. Five 0.6-mm cores from each tumour allowed accurate immunohistochemical and FISH testing in >95% of cases. Ninety-seven per cent concordance was achieved between WS and TMA approaches to FISH analysis, the only discrepancies being in cases that were borderline or near borderline by both techniques. TMA and WS approaches were comparable in terms of time for preparation and scoring. CONCLUSIONS: TMA technology is a robust method of assessing HER-2 status in invasive breast cancer. This is directly comparable to the current standard methodology using whole sections. The use of TMA technology offers several advantages over existing full-section methods in terms of cost, quality control, facilitation of future research and the facility to provide a high-throughput testing methodology.

Predictive markers in breast cancer--the future.

The published literature is awash with examples of new tissue biomarkers promising to predict responses to therapy in breast cancer patients. However, few, if any, of these progress from the laboratory to the clinic. In this review we discuss some of the reasons for this, illustrating our discussion with a selection of biomarkers which are in development and which may be candidates for clinical application within the next few years (topoisomerase II alpha, epidermal growth factor receptor, AKT, phosphatase and tensin homologue). In particular, we explore how our ever increasing knowledge of molecular and pathway biology is facilitating hypothesis-driven biomarker discovery, and the statistical considerations which need to be addressed in order to validate new candidate biomarkers adequately.

Effects of fulvestrant 750mg in premenopausal women with oestrogen-receptor-positive primary breast cancer.

Fulvestrant (Faslodex) is a pure anti-oestrogen that reduces markers of hormone sensitivity and proliferation in postmenopausal women with oestrogen-receptor (ER)-positive breast cancer. This randomised trial compared the effects on the tumours of a single dose of 750mg fulvestrant to those of daily tamoxifen (20mg) taken 14-16 days prior to surgery in 60 premenopausal women with ER-positive primary breast cancer. There were statistically significant falls in the expression of ER and Ki67 levels compared to the baseline with both drugs. Both drugs caused a decrease in PgR expression from baseline but this was only statistically significant with fulvestrant. No statistically significant differences were seen between the two treatment groups. Fulvestrant caused an increase in circulating levels of oestradiol, irrespective of the stage of the menstrual cycle at which patients commenced treatment. No major changes were seen in LH, FSH and progesterone levels with either drug. The most common adverse events with fulvestrant were headaches, hot flushes, nausea and disturbance of menses. Contrary to previous studies with fulvestrant 250mg, these findings suggest that at a dose of 750mg fulvestrant is effective at reducing the effects of oestrogen on ER-positive breast cancer in premenopausal women.

A review of the pathology and management of uterine papillary serous carcinoma and correlation with outcome.

Uterine papillary serous carcinoma (UPSC) accounts for 10% of endometrial carcinomas but a higher proportion of deaths due to its aggressive nature and poor response to chemotherapy and radiotherapy. In order to add to the knowledge of UPSC in the literature and to review our local practices, we examined the pathology, medical records, and management of all cases of UPSC (67 patients) treated in South East Scotland over a 10-year period and also evaluated the prognostic significance of the percentage of UPSC in endometrial pipelle and hysterectomy specimens. Although only 63% of initial diagnostic biopsies were reported to contain UPSC, rereview of the cases revealed UPSC in 98.5% of the preoperative biopsies. The percentage of UPSC in the tumors did not affect the outcome. Stage, positive omentum, and treatment with external-beam +/- intracavitary radiotherapy were significantly correlated with overall survival and progression-free survival by univariate analysis, but only stage (P < 0.01) was correlated with outcome on multivariate analysis. Chemotherapy did not affect outcome. UPSC may be difficult to diagnose in preoperative biopsies, particularly when present as part of a mixed tumor. Even a small percentage of UPSC in a diagnostic biopsy or hysterectomy specimen is correlated with a poor prognosis. This study emphasizes the need of a cooperative, prospective study on this distinct uterine carcinoma.