| 1. |
- Ahnström, Marie, et al.
(författare)
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Altered expression of cyclin E and the retinoblastoma protein influences the effect of adjuvant therapy in breast cancer
- 2009
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Ingår i: International Journal of Oncology. - : Spandidos Publications. - 1019-6439 .- 1791-2423. ; 34:2, s. 441-448
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Tidskriftsartikel (refereegranskat)abstract
- Cyclin E and the retinoblastoma protein (Rb) are both important regulators of the G(1) phase in the cell cycle. Overexpression of cyclin E and lost expression of Rb has previously been observed in breast tumours at frequencies of 10-50% and 20-30%, respectively. We explored the prognostic role of cyclin E and Rb in breast cancer patients randomised for tamoxifen (TAM), CMF (cyclophosphamide, metotrexate, 5-fluorouracil) chemotherapy and radiotherapy (RT) and how their expression affects the patients response to treatment. Protein expression was assessed with immunohistochemistry. We found overexpression of cyclin E in 32.1% (71/221) of the tumours and loss of Rb expression in 25.0% (59/236). Increased expression of cyclin E correlated to dysfunctional p53 (P=0.003) while loss of Rb correlated to normal p53 status (P=0.001). Our results suggest that patients with high cyclin E tumours have less benefit from tamoxifen (ER+, TAM vs. no TAM; RR=0.97; 95% CI, 0.36-2.60) than patients whose tumours show low expression (ER+, TAM vs. no TAM; RR =0.41; 95% CI, 0.24-0.72). Cyclin E also tended to predict the benefit from radiotherapy with a local recurrence rate of 0.31 (RT vs. CMF; 95% CI, 0.12-0.93) for patients with low expression and 0.68 (RT vs. CMF; 95% CI, 0.2-2.32) for patients with high expression of cyclin E. When the p53 status was taken in consideration the results showed that patients with both normal p53 and normal Rb expression had considerably lower locoregional recurrence rate when treated with radiotherapy instead of CMF (RR=0.17; 95% CI, 0.052-0.58) as compared to patients with either altered Rb or p53 or both (RR=0.70; 95% CI, 0.28-1.73).
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| 2. |
- Ahnström Waltersson, Marie, 1976-, et al.
(författare)
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Role of cyclin D1 in ErbB2-positive breast cancer and tamoxifen resistance.
- 2005
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 0167-6806 .- 1573-7217. ; 91:2, s. 145-151
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Tidskriftsartikel (refereegranskat)abstract
- Cyclin D1 plays an important role in the regulation of the G1 phase in the cell cycle. In mammary epithelial cells the expression of cyclin D1 is regulated through the oestrogen receptor and via ErbB2 signalling. Here we investigated the prognostic significance of cyclin D1 among 230 breast cancer patients randomised for tamoxifen, CMF chemotherapy and radiotherapy. The importance of combined cyclin D1 and ErbB2 overexpression was also analysed. Immunohistochemical analysis of the cyclin D1 expression resulted in 69 (29.8%) weakly positive, 107 (46.5%) moderately positive and 54 (23.7%) strongly positive cases. The prognostic importance of ErbB2 was significantly greater for patients whose tumours overexpressed cyclin D1 than for other patients (p = 0.026). In the former group, ErbB2 overexpression was strongly associated with increased risk of recurrence (RR = 4.7; 95% CI, 2.1-10.4) and breast cancer death (RR = 5.4; 95% CI, 2.3-12.6). This result is in accordance with experimental studies demonstrating a link between cyclin D1 and ErbB2 in oncogenesis. Among oestrogen receptor positive patients, those with moderate cyclin D1 expression significantly did benefit from tamoxifen treatment (RR = 0.42; 95% CI, 0.21-0.82) whereas those with weak or strong expression did not. Therefore cyclin D1 might be a predictive marker for tamoxifen resistance.
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| 3. |
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| 4. |
- Fischer, Hubertus, et al.
(författare)
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Reconstruction of millennial changes in dust emission, transport and regional sea ice coverage using the deep EPICA ice cores from the Atlantic and Indian Ocean sector of Antarctica
- 2007
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Ingår i: Earth and Planetary Science Letters. - : Elsevier BV. - 0012-821X. ; 260, s. 340-354
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Tidskriftsartikel (refereegranskat)abstract
- Continuous sea salt and mineral dust aerosol records have been studied on the two EPICA (European Project for Ice Coring inAntarctica) deep ice cores. The joint use of these records from opposite sides of the East Antarctic plateau allows for an estimate ofchanges in dust transport and emission intensity as well as for the identification of regional differences in the sea salt aerosolsource. The mineral dust flux records at both sites show a strong coherency over the last 150 kyr related to dust emission changes inthe glacial Patagonian dust source with three times higher dust fluxes in the Atlantic compared to the Indian Ocean sector of theSouthern Ocean (SO). Using a simple conceptual transport model this indicates that transport can explain only 40% of theatmospheric dust concentration changes in Antarctica, while factor 5–10 changes occurred. Accordingly, the main cause for the strong glacial dust flux changes in Antarctica must lie in environmental changes in Patagonia. Dust emissions, hence environmentalconditions in Patagonia, were very similar during the last two glacials and interglacials, respectively, despite 2–4 °C warmertemperatures recorded in Antarctica during the penultimate interglacial than today. 2–3 times higher sea salt fluxes found in bothice cores in the glacial compared to the Holocene are difficult to reconcile with a largely unchanged transport intensity and thedistant open ocean source. The substantial glacial enhancements in sea salt aerosol fluxes can be readily explained assuming sea iceformation as the main sea salt aerosol source with a significantly larger expansion of (summer) sea ice in the Weddell Sea than inthe Indian Ocean sector. During the penultimate interglacial, our sea salt records point to a 50% reduction of winter sea icecoverage compared to the Holocene both in the Indian and Atlantic Ocean sector of the SO. However, from 20 to 80 ka beforepresent sea salt fluxes show only very subdued millennial changes despite pronounced temperature fluctuations, likely due to thelarge distance of the sea ice salt source to our drill sites.
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| 5. |
- Perez-Tenorio, Gizeh, 1971-, et al.
(författare)
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Clinical Value of RPS6KB1 and RPS6KB2 Gene Amplification in Postmenopausal Breast Cancer
- 2008
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Tidskriftsartikel (refereegranskat)abstract
- The mammalian target of rapamycin (mTOR) and its substrates the ribosomal S6 kinases (S6K)1 and 2 integrate nutrient and hormonal/growth factor mediated signals and are implicated indiabetes, obesity and cancer. The genes encoding S6K1 (RPS6KB1) and S6K2 (RPS6KB2) aresituated close to well known amplicons but information regarding its expression and clinicalvalue is scarce. In this study we quantified RPS6KB1/2 gene copy number, establishedassociations with other clinical factors and explored their clinical value in breast cancer. RPS6KB1/2 copy number was determined by fast real-time PCR in 207 breast tumors.RPS6KB1 was amplified (≥ 4 copies) in 10.7% (22/206) and RPS6KB2 in 4.3% (9/207) of thetumors. Amplification of RPS6KB1 was associated with HER2 gene amplification (P=0.025)and protein expression (P=0.014) while RPS6KB2 correlated with ER+ status (P=0.046) and CCND1 amplification (P<0.00001). In a multivariate analysis, both genes were independentprognostic factors indicating higher risk to develop recurrences. In terms of loco regionalcontrol, amplification of the RPS6KB1 gene predicted less response to radiotherapy (P=0.035) while RPS6KB2 gene copy gain (≥ 3 copies) indicated increased benefit from tamoxifen (P=0.03) among ER+ patients. S6K1/2 gene amplification could be used as an indicator oftherapy response among postmenopausal breast cancer patients.
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| 6. |
- Pérez-Tenorio, Gizeh, 1971-, et al.
(författare)
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PIK3CA mutations and PTEN loss correlate with similar prognostic factors and are not mutually exclusive in breast cancer
- 2007
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 13:12, s. 3577-3584
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The phosphatidylinositol 3'-kinase/Akt pathway is frequently altered in breast cancer. PTEN, a phosphatase that opposes the effect of phosphatidylinositol 3'-kinase, can be mutated or lost, whereas the PIK3CA gene is mutated. These have been proposed as alternative mechanisms, and their clinicalpathology significance is under discussion. In this study, we aimed to explore whether PIK3CA mutations and PTEN loss are mutually exclusive mechanisms, correlate with other known clinicopathologic markers, or have clinical implication in breast cancer. Experimental Design: Exons 9 and 20 of the PIK3CA gene were analyzed in 270 breast tumors, and mutations were detected by single-stranded conformational analysis followed by sequencing. The expression of PTEN was evaluated by immunohistochemistry in 201 tumors. Results: PIK3CA mutations were found in 24% of the tumors and associated with estrogen receptor(+) status, small size, negative HER2 status, high Akt1, and high cyclin D1 protein expression. PTEN was negative in 37% of the cases and PTEN loss was associated with PIK3CA mutations (P = 0.0024). Tumors presenting PTEN loss or both alterations were often estrogen receptor(+), small in size, and HER2(-). PIK3CA mutations predicted for longer local recurrence-free survival. Moreover, PTEN loss by itself or combined with mutated PIK3CA tended to confer radiosensitivity. In addition, the patients with high S-phase fraction had longer recurrence-free survival if they carried mutations in the PIK3CA gene and/or had lost PTEN, whereas the same alterations were associated with shorter recurrence-free survival among patients with low S-phase fraction. Conclusions: PIK3CA mutations and PTEN loss were not mutually exclusive events and associated with similar prognostic factors.
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| 7. |
- Söderlund, Karin, 1979-, et al.
(författare)
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The BRCA1/BRCA2/Rad51 complex is a prognostic and predictive factor in early breast cancer
- 2007
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 84:3, s. 242-251
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: The breast cancer susceptibility genes BRCA1 and BRCA2 interact with Rad51, one of the central components in the homologous recombination repair pathway. This study evaluates the prognostic and predictive role of BRCA1, BRCA2 and Rad51, individually and as a complex, in breast cancer.Material and Methods: Expression of BRCA1, BRCA2 and Rad51 was investigated using immunohistochemistry in tumours from 224 women with early breast cancer, who were randomised to receive postoperative radiotherapy or adjuvant chemotherapy (CMF).Results: 53% (112/212) of the tumours had reduced expression of the BRCA1/BRCA2/Rad51 complex. Low expression correlated to high histologic grade (p=0.05). Patients with low expression of the complex developed significantly more local recurrences as compared to patients with high expression (RR=3.20, 95% C.I. 1.48-6.88, p=0.003). Expression of the BRCA1/BRCA2/Rad51 complex was an independent prognostic factor in multivariate analysis (p=0.03). Patients with low expression of the complex responded well to radiotherapy (RR=0.31, 95% C.I. 0.14-0.70, p=0.005), whereas patients with high expression had few local recurrences and no additional benefit from radiotherapy (RR=1.08, 95% C.I. 0.40-2.90, p=0.88).Conclusions: Low expression of the BRCA1/BRCA2/Rad51 complex is a marker of poor prognosis, but predicts good effect of radiotherapy in patients with early breast cancer.
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| 8. |
- Söderlund Leifler, Karin, 1979-, et al.
(författare)
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Intact Mre11/Rad50/Nbs1 complex predicts good response to radiotherapy in early breast cancer
- 2007
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier BV. - 0360-3016 .- 1879-355X. ; 68:1, s. 50-58
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Post-operative radiotherapy is offered to a majority of breast cancer patients, since it significantly reduces the risk of local recurrence. However, some patients still develop recurrences. Owing to their vital roles in the repair of radiation-induced double-strand breaks, the Mre11/Rad50/Nbs1 (MRN) complex and the ATM protein might be implicated in tumour cell resistance to radiotherapy. The aim of this study was to investigate the expression and predictive role of these DNA repair proteins for the outcome of radiotherapy in breast cancer patients.Patients and Methods: The protein expression of ATM and the proteins in the MRN complex were investigated using immunohistochemistry in tumours from 224 women with early breast cancer, who were randomised to receive post-operative radiotherapy or adjuvant chemotherapy (CMF).Results: Compared to normal breast tissue, the staining intensity of Mre11, Rad50, Nbs1 and ATM was reduced in a majority of the tumours. Weak expression of the MRN complex was correlated to high histological grade and ER negativity (p=0.01 and p=0.0001). Radiotherapy significantly reduced the risk of local recurrence as compared to chemotherapy (p=0.04). The greatest benefit of radiotherapy was seen in patients with moderate/strong expression of the MRN complex (RR=0.27, 95% C.I. 0.098-0.72, p=0.009), whereas patients with negative/weak MRN had no benefit of radiotherapy compared to CMF. These results suggest that an intact MRN complex is important for the tumour cell eradicating effect of radiotherapy.
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