| 1. |
- Severinsson, Emelie
(författare)
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Experimental studies on ErbB targeted therapy in malignant melanoma
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Malignant melanoma has one of the fastest increasing incidences among the different types of cancer in the Western world. This raise can partly be ascribed to the change in sun habits that has taken place during the last decades, since the major external risk factor for melanoma is exposure to ultraviolet radiation. In the case of patients with early stages of melanoma, the prognosis is usually good and the disease may be cured by surgery alone. However, with conventional anti-cancer treatments, patients diagnosed with unresectable or metastatic melanoma have a very low 5-year survival rate ranging from less than 10 percent to about 20 percent, depending on the location and extent of metastatic spread. Despite the development of novel promising targeted drugs, such as the immunomodulating antibody ipilimumab and the B-raf inhibitor vemurafenib, that have been shown to significantly extend patient survival, there is still an urgent need for new and improved treatment strategies which can further increase the survival of patients with advanced malignant melanoma.The aim of this thesis was to investigate the anti-tumor effect of two different tyrosine kinase inhibitors (TKIs), gefitinib and canertinib, on human malignant melanoma cell lines with wild-type BRAF and NRAS. We investigated the effect of these two drugs on cell proliferation, survival and on the ErbB1-4 receptor phosphorylation, as well as the downstream signaling molecules Akt, Erk1/2 and Stat3. We also established a melanoma cell line resistant to gefitinib treatment and studied the resistance mechanisms developed by the cells.The aim of this thesis was to investigate the anti-tumor effect of two different tyrosine kinase inhibitors (TKIs), gefitinib and canertinib, on human malignant melanoma cell lines with wild-type BRAF and NRAS. We investigated the effect of these two drugs on cell proliferation, survival and on the ErbB1-4 receptor phosphorylation, as well as the downstream signaling molecules Akt, Erk1/2 and Stat3. We also established a melanoma cell line resistant to gefitinib treatment and studied the resistance mechanisms developed by the cells.In conclusion, gefitinib and canertinib display promising anti-tumor effects on ErbB-expressing malignant melanoma and might be used in future studies in combination with conventional chemotherapy or other targeted therapies in the treatment of malignant melanoma patients not harboring BRAF or NRAS mutations.
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| 2. |
- Aamand Grabau, Dorthe, et al.
(författare)
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The prevalence of immunohistochemically determined oestrogen receptor positivity in primary breast cancer is dependent on the choice of antibody and method of heat-induced epitope retrieval - prognostic implications?
- 2013
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Ingår i: Acta Oncologica. - : Informa Healthcare. - 0284-186X .- 1651-226X. ; 52:8, s. 1657-1666
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Tidskriftsartikel (refereegranskat)abstract
- Background. Oestrogen receptor (ER) status is important for the choice of systemic treatment of breast cancer patients. However, most data from randomised trials on the effect of adjuvant endocrine therapy according to ER status are based on the cytosol methods. Comparisons with immunohistochemical methods have given similar results. The aim of the present study was to examine whether different ER antibodies and heat-induced epitope retrieval (HIER) methods influence the prevalence of ER-positivity in primary breast cancer. Material and methods. This study is based on patients included in a clinical trial designed to compare the effect of two years of adjuvant tamoxifen versus no adjuvant systemic treatment in premenopausal women. From 1986 to 1991, 564 patients from two study centres in Sweden were enrolled and randomised. Patients were randomised independently of ER status. In the present study, ER status was assessed on tissue microarrays with the three different ER antibody/HIER combinations: 1D5 in citrate pH 6 (n = 390), SP1 in Tris pH 9 (n = 390) and PharmDx in citrate pH 6 (n = 361). Results. At cut-offs of 1% and 10%, respectively, the prevalence of ER-positivity was higher with SP1 (75% and 72%) compared with 1D5 (68% and 66%) and PharmDx (66% and 62%). At these cut-offs, patients in the discordant groups (SP1-positive and 1D5-negative) seem to have a prognosis intermediate between those of the double-positive and double-negative groups. Comparison with the ER status determined by the cytosol-based methods in the discordant group also showed an intermediate pattern. The repeatability was good for all antibodies and cut-offs, with overall agreement andgt;= 93%. Conclusion. The present study shows that the choice of antibody and HIER method influences the prevalence of ER-positivity. We suggest that this be taken into consideration when choosing a cut-off for clinical decision making.
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| 3. |
- Adell, Gunnar C. E., 1953-, et al.
(författare)
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Apoptosis in rectal carcinoma : Prognosis and recurrence after preoperative radiotherapy
- 2001
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Ingår i: Cancer. - 0008-543X .- 1097-0142. ; 91:10, s. 1870-1875
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Rectal carcinoma is common, with considerable local recurrence and death rates. Preoperative radiotherapy and refined surgical techniques can improve local control. The aim of this study was to investigate the interaction between apoptosis and the outcome of rectal carcinoma, with and without short-term preoperative radiotherapy.METHODS: Specimens were from 162 patients from the Southeast Swedish Health Care region included in the Swedish Rectal Cancer Trial between 1987-1990. New sections from the paraffin blocks of the preoperative biopsies and the surgical specimens were examined for apoptosis using the terminal deoxynucleotidyl transferase mediated digoxigenin nick end labeling (TUNEL) method.RESULTS: The mean percentage of apoptotic cells was 0.3% (0-4%) and 1.1% (0-14.5%) for the preoperative biopsy and the surgical specimen, respectively. The authors analyzed the surgical specimens from nonirradiated patients and divided them into three groups by apoptotic index (AI) as follows: 0%, 0-1%, and > 1%. A high AI was associated with a decreased local recurrence rate compared with an intermediate or a low AI (P = 0.024). There was no significant relation between AI and survival. There was a significant reduction in the local recurrence rate for irradiated patients compared with the nonirradiated in the low (P = 0.015) and intermediate (P = 0.038) AI groups. In the high AI group, there were few recurrences and no significant difference was observed between irradiated and nonirradiated patients. The relative risk of death from rectal carcinoma in Dukes A-C patients was not significantly decreased by radiotherapy, but, in the intermediate AI group, there was a trend (P = 0.08) in favor of the irradiated patients.CONCLUSION: A high AI in rectal carcinoma indicated a decreased local recurrence rate.
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| 4. |
- Adell, Gunnar, 1953-, et al.
(författare)
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Decreased tumor cell proliferation as an indicator of the effect of preoperative radiotherapy of rectal cancer
- 2001
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - 0360-3016 .- 1879-355X. ; 50:3, s. 659-663
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Rectal cancer is a common malignancy, with significant local recurrence and death rates. Preoperative radiotherapy and refined surgical technique can improve local control rates and disease-free survival.PURPOSE: To investigate the relationship between the tumor growth fraction in rectal cancer measured with Ki-67 and the outcome, with and without short-term preoperative radiotherapy.Method: Ki-67 (MIB-1) immunohistochemistry was used to measure tumor cell proliferation in the preoperative biopsy and the surgical specimen.MATERIALS: Specimens from 152 patients from the Southeast Swedish Health Care region were included in the Swedish rectal cancer trial 1987-1990.RESULTS: Tumors with low proliferation treated with preoperative radiotherapy had a significantly reduced recurrence rate. The influence on death from rectal cancer was shown only in the univariate analysis. Preoperative radiotherapy of tumors with high proliferation did not significantly improve local control and disease-free survival. The interaction between Ki-67 status and the benefit of radiotherapy was significant for the reduced recurrence rate (p = 0.03), with a trend toward improved disease-free survival (p = 0.08). In the surgery-alone group, Ki-67 staining did not significantly correlate with local recurrence or survival rates.CONCLUSION: Many Ki-67 stained tumor cells in the preoperative biopsy predicts an increased treatment failure rate after preoperative radiotherapy of rectal cancer.
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| 5. |
- Adell, Gunnar, 1953-, et al.
(författare)
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p53 status : an indicator for the effect of preoperative radiotherapy of rectal cancer.
- 1999
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Ingår i: Radiotherapy and Oncology. - 0167-8140 .- 1879-0887. ; 51:2, s. 169-174
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Rectal carcinoma is a common malignancy, with a history of high local recurrence rates following surgery. In recent years. preoperative radiotherapy and refined surgical technique have improved local control rates.AIM: To investigate the relationship between expression of nuclear p53 protein and the outcome in rectal carcinoma, with and without short-term preoperative radiotherapy.MATERIAL: Specimens from 163 patients from the Southeast Swedish Health Care region included in the Swedish rectal cancer trial between 1987-1990.METHOD: New sections from the paraffin blocks of the preoperative biopsy and the surgical specimen were examined immunohistochemically using a p53 antibody (PAb 1801).RESULT: Expression of nuclear p53 protein was seen in 41% of the tumours. The p53 negative patients treated with preoperative radiotherapy had a significant reduction of local failure compared with the non-irradiated p53 negative patients (P = 0.0008). In contrast, p53 positive patients showed no benefit from preoperative radiotherapy. The interaction between p53 status and the benefit of radiotherapy was statistically significant (P = 0.018).CONCLUSION: Expression of nuclear p53 protein in rectal carcinoma seems to be a significant predictive factor for local treatment failure after preoperative radiotherapy. Further investigations are necessary to select patients for preoperative treatment based on analysis of the preoperative biopsies.
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| 6. |
- Agrup, Måns, et al.
(författare)
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C-erbB-2 overexpression and survival in early onset breast cancer
- 2000
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Ingår i: Breast Cancer Research and Treatment. - 0167-6806 .- 1573-7217. ; 63:1, s. 23-29
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Tidskriftsartikel (refereegranskat)abstract
- Young breast cancer patients have a decreased survival rate and it has been demonstrated that young age is an independent predictor of adverse prognosis. Overexpression of c-erbB-2 protein (also known as HER-2/neu) has been shown to be a prognostic indicator in breast cancer in general and especially among patients with axillary nodal metastases. The present study was initiated to determine the prognostic significance of c-erbB-2 protein overexpression in early onset breast cancer.A population consisting of 110 young breast cancer patients, ≤ 36-year-old at diagnosis, was analyzed with immunohistochemical staining for c-erbB-2 protein.Thirty patients (27%) were found to overexpress the c-erbB-2 protein. C-erbB-2 positivity was significantly associated with poor survival when all patients were included in the analysis (P = 0.002) and for patients with axillary nodal metastases (P = 0.0007). No such association was found for node-negative patients. Furthermore, the difference in prognosis in relation to c-erbB-2 among node-positive patients was maintained, when these were stratified in groups treated or not treated with adjuvant chemotherapy.The study indicates that overexpression of c-erbB-2 protein is a strong prognostic factor in young breast cancer patients with axillary nodal metastases. Moreover, the adverse prognosis associated with c-erbB-2 overexpression in node-positive patients was observed whether or not the patients had received adjuvant chemotherapy.
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| 7. |
- Aguilar, Helena, et al.
(författare)
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VAV3 mediates resistance to breast cancer endocrine therapy
- 2014
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Ingår i: Breast Cancer Research. - : BioMed Central. - 1465-5411 .- 1465-542X. ; 16:3, s. R53-
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Endocrine therapies targeting cell proliferation and survival mediated by estrogen receptor alpha (ERalpha) are among the most effective systemic treatments for ERalpha-positive breast cancer. However, most tumors initially responsive to these therapies acquire resistance through mechanisms that involve ERalpha transcriptional regulatory plasticity. Here, we identify VAV3 as a critical component in this process.METHODS: A cell-based chemical compound screen was carried out to identify therapeutic strategies against resistance to endocrine therapy. Binding to ERalpha was evaluated by molecular docking analyses, an agonist fluoligand assay, and short-hairpin (sh) RNA-mediated protein depletion. Microarray analyses were performed to identify altered gene expression. Western blot of signaling and proliferation markers and shRNA-mediated protein depletion in viability and clonogenic assays were performed to delineate the role of VAV3. Genetic variation in VAV3 was assessed for association with the response to tamoxifen. Immunohistochemical analyses of VAV3 were carried out to determine the association with therapy response and different tumor markers. An analysis of gene expression association with drug sensitivity was carried out to identify a potential therapeutic approach based on differential VAV3 expression.RESULTS: The compound YC-1 was found to comparatively reduce the viability of cell models of acquired resistance. This effect was probably not due to activation of its canonical target (soluble guanylyl cyclase) but instead a result of binding to ERalpha. VAV3 was selectively reduced upon exposure to YC-1 or ERalpha depletion and, accordingly, VAV3 depletion comparatively reduced the viability of cell models of acquired resistance. In the clinical scenario, germline variation in VAV3 was associated with response to tamoxifen in Japanese breast cancer patients (rs10494071 combined P value = 8.4 x 10-4). The allele association combined with gene expression analyses indicated that low VAV3 expression predicts better clinical outcome. Conversely, high nuclear VAV3 expression in tumor cells was associated with poorer endocrine therapy response. Based on VAV3 expression levels and the response to erlotinib in cancer cell lines, targeting EGFR signaling may be a promising therapeutic strategy.CONCLUSIONS: This study proposes VAV3 as a biomarker and rationale signaling target to prevent and/or overcome resistance to endocrine therapy in breast cancer.
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| 8. |
- 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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| 9. |
- Ahnström Waltersson, Marie, 1976-
(författare)
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Cell cycle alterations and 11q13 amplification in breast cancer : prediction of adjuvant treatment response
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The growth and development of the breast is to a large extent regulated by oestrogens through the oestrogen receptor (ER). Activation of the ERα triggers transcription of genes that are important for cell proliferation and stimulates entry into the G1 phase of the cell cycle. In breast cancer the ERα is often upregulated and is therefore a suitable target for adjuvant therapies such as tamoxifen. Although tamoxifen is an effective treatment in most cases, tumours sometimes acquire resistance to the drug. The aim of this thesis was to investigate the impact of G1 phase proteins and 11q13 amplification on prognosis and treatment response in breast cancer. The material used was from a clinical trial in which postmenopausal breast cancer patients were randomised to chemotherapy or radiotherapy and tamoxifen or no adjuvant treatment. We studied the expression of cyclin D1, cyclin E and Rb with immunohisochemistry and amplification of CCND1 and PAK1 with real time PCR. We found that among patients with high tumour expression of cyclin D1, overexpression of ErbB2 was associated with reduced recurrence-free survival. Both cyclin D1 and cyclin E overexpression were associated with reduced tamoxifen response. High expression of cyclin D1 has been found to induce ligand independent activation of ERα in breast cancer cells and might also switch tamoxifen from acting as an antagonist to an agonist. Overexpression of cyclin E has been shown to be associated with expression of low molecular weight isoforms of the protein that possess an increased kinase activity and are insensitive to p21 and p27 inhibition. Furthermore, amplification of 11q13, and in particular the gene PAK1, was a strong predictor of tamoxifen resistance. The pak1 protein is involved in phosphorylation and ligand independent activation of the ERα. We also found that lost expression of either p53 or Rb reduced the patients benefit from radiotherapy compared with patients with normal expression of both proteins. Normally, ionizing radiation upregulates p53 resulting in G1 arrest or apoptosis. If either functional p53 or Rb is missing the cells can proceed from G1 to the S phase despite damaged DNA. The expression of the microRNA, miR-206, was analysed with real time PCR, and the results showed that high expression of miR-206 correlated to low expression of ERα and 11q13 amplification. In vitro studies have shown that miR-206 negatively regulates the expression of ERα. Taken together the G1 regulators and amplification of 11q13 seem to have an important role in predicting the patient’s response to adjuvant therapy.
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| 10. |
- Ahnström Waltersson, Marie, 1976-, et al.
(författare)
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miR-206 expression is downregulated in cyclin D1 amplified breast tumours
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Amplification in the 11q13 region has been found in around 15% of all breast cancers and is strongly correlated with oestrogen receptor (ER) positive tumours. We have previously found that amplification of at least one of the genes PAK1 or CCND1 is associated with decreased recurrencefree survival among ER+ patients. Other genes in the amplicon might also contribute to this effect and situated close to CCND1 are the FGF-3, -4 and - 19 genes. The FGF-4 protein has been shown to inhibit the expression of the ERα regulator miR-206 in chicken embryo. In this study we analysed 23 tumours with and 27 tumours without previously detected 11q13 amplification to explore if 11q13 amplification is associated with decreased levels of miR-206 and if miR-206 is associated with ER expression. Using real-time PCR, we found that miR-206 expression was inversely correlated to CCND1 and 11q13 amplification (P=0.016 and P=0.022 respectively). Tumours with low miR-206 expression had higher levels of ERα than tumours with intermediate and high expression (P=0.043). We conclude that miR-206 might be an important regulator of the ERα. Our finding that low mir-206 is associated with CCND1 amplification and thereby also FGF-4 amplification points towards the possibility of a miR-206 regulator, FGF-4 or another FGF, present in the amplicon.
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