| 1. |
- Farnebo, Lovisa
(författare)
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Predictive markers : for treatment sensitivity in head and neck squamous cell carcinoma
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Head and neck cancer is the sixth most common cancer world wide. In Sweden approximately 850 new cases are diagnosed each year, and two thirds are men. The past decades of improved treatment strategies have unfortunately not significantly improved the five-year survival rates for this group of patients. Therefore, it is important to rapidly find combinations of new and strong predictive markers for treatment response. Different predictive markers have been investigated for decades, without succeeding in finding means to securely predict response to treatment. Models to combine markers are called for.The aim of this thesis was to test multiple predictive markers on both gene and protein level to evaluate their predictive value for radiotherapy and cisplatin response. Furthermore, to combine, and correlate them to treatment response in order to extract the panel of markers that strongest correlated to the investigated treatment. Cell lines derived from 42 patients with head and neck squamous cell carcinoma (HNSCC) were used for protein quantification with Western blot and ELISA of the proteins survivin, Epidermal Growth Factor Receptor, Bcl-2, Bcl-XL, Bax, Bad, Bak, PUMA, Heat shock protein 70, MDM2, p53, SMAD4, Cyclooxygenase-2, and Cyclin D1. The expression of the selected proteins was related to the mean expression of normal oral keratinocytes (NOK) from healthy individuals. Furthermore, mutations in the p53 gene, along with single nucleotide polymorphisms in the genes of p53, MDM2, FGFR4, XRCC1, XRCC3, XPD, and XPC were analysed. To allow a large number of predictive markers on both protein and gene level to be combined and correlated to treatment response, the number of negative points (NNP) model was introduced. Both correlations of sensitivity to radiotherapy and to cisplatin treatment was analysed among the cell lines. In the first paper, including nine cell lines, the panel of EGFR, survivin, and splice site/missense p53 mutations correlated strongest to radioresponse. In paper II, 42 cell lines were used and the combination of survivin, Bcl-2, Bcl-XL, Bax, COX-2, and the p53 Arg72Pro polymorphism was found to most strongly correlate with radioresponse. In paper IV, the panel correlating strongest with cisplatin sensitivity consisted of EGFR, Hsp70, Bax, and Bcl-2 in combination with SNPs in the DNA-repair genes XRCC3 and XPD.The predisposition of the FGFR4 Gly388Arg polymorphism for the development of HNSCC was investigated in paper III. DNA was isolated from 110 tumour biopsies, and restriction fragment length polymorphism analysis showed that 58% of the individuals in the control group carried the FGFR4 Arg388 allele, whereas the frequency in the tumour group was 45%. The Gly388 allele gave a significantly higher risk of developing HNSCC, suggesting Gly388 to be the risk allele for cancer development. Furthermore, a novel mutation was found in the FGFR4 gene. The influence of this new mutation is however unknown.In conclusion, predictive markers for treatment sensitivity need to be combined to receive an accurate prediction of treatment response.
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| 2. |
- Jerhammar, Fredrik, 1979-
(författare)
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Predictive Markers of Treatment Resistance in Head and Neck Squamous Cell Carcinoma
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Head and neck cancer is a common malignancy with approximately 600 000 new cases yearly. Disappointingly, the overall survival has not increased over the last decades. The concept of personalized medicine, i.e. to treat every patient with an individually planned treatment regime has gathered increased interest, but requires the establishment of novel biomarkers that can predict treatment response.The aim of this thesis is to propose novel predictive single markers or combinations of markers of response to radiation, cisplatin and cetuximab. The general methodology is to evaluate common differences of cell lines resistant to radiation, cisplatin or cetuximab compared to sensitive counterparts.In paper I, we analysed the expression of 14 proteins involved in growth control and/or apoptosis by western blot and related them to intrinsic radiosensitivity (IR) in nine cell lines. No factor had a significant correlation to IR on its own. A combination of EGFR, survivin, Bak, Smad4, and Hsp70 had the best correlation to IR (R=0.886, p=0.001). Additionally, we analysed the presence of p53 mutations in the cell lines. All cell lines had at least one missense, splice site or loss of transcript mutation. To be able to combine protein expression and presence of p53 mutations we created a system designated the number of negative points (NNP). With this system we could extract that expression of EGFR, survivin, and p53 missense or splice site mutations had the best correlation to IR (R=0.990, p<0.001).In paper II we conducted a gene expression microarray analysis of three cell lines, from which common deregulations in two cisplatin resistant cell lines was compared to a cisplatin sensitive cell line. From a bioinformatic approach of gene ontology and molecular network analysis, we defined a transcriptional profile of 20 genes. Finally, key findings were analysed in a larger panel of cell lines, where high MMP-7 expression correlated with higher cisplatin resistance.Paper III compared 4 cell lines with high IR to a radiosensitive equivalent. Using a similar bioinformatic approach as paper II, we established a transcriptional profile of 14 genes. Analysis in a larger panel of cell lines revealed that FN1 expression predicts higher IR.Paper IV establishes the cetuximab sensitivity of 35 cell lines of which 12 were resistant and five were sensitive to cetuximab. After whole genome gene copy number analysis of five cetuximab resistant and five cetuximab sensitive cell lines, and verification of key findings in a larger cell line panel, the results show that the amplification of the YAP1 gene is coupled to cetuximab resistance.In summary, this thesis proposes a number of novel markers of resistance to radiation, cisplatin, and cetuximab which could influence treatment choice in the future, following verifications in primary tumor material.
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| 3. |
- Ansell, Anna, 1983-
(författare)
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Identification of Tumor Cell- and Stroma Derived Biomarkers of Treatment Response in Head and Neck Cancer
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Head and neck squamous cell carcinoma (HNSCC) poses a major health problem in the world with approximately 600 000 new cases yearly. Treatment resistance is a major problem within this patient group and despite advances in treatment strategies the overall survival rate has unfortunately not increased.One of the major components of the tumor microenvironment is the cancer associated fibroblasts (CAFs) which can modulate the treatment sensitivity, tumor growth, and the invasive potential of tumor cells.The aim of this thesis was to identify predictive markers for treatment response in HNSCC and to study the crosstalk between tumor cells and CAFs that may underlie treatment resistance.In paper I, we identified gene expression differences between one cisplatin sensitive cell line and two cisplatin resistant cell lines, by microarray analysis, and found that a high expression of matrix metalloproteinase (MMP) -7 was associated with resistance to cisplatin. In paper II, the epidermal growth factor (EGF) receptor ligands EGF, amphiregulin, and epiregulin were evaluated regarding their potential use as predictive biomarkers for cetuximab treatment response in tongue cancer cell lines and it was shown that EGF may serve as a marker for poor cetuximab response. In paper III and IV, we investigated the influence of CAFs on the proliferation, migration, gene expression, and cetuximab response of tumor cells. It was found that CAFs induced resistance to cetuximab in a MMP-dependent manner. In addition, a microarray analysis, comparing tumor cells co-cultured with CAFs and tumor cells cultured alone, revealed that CAFs induced multiple gene expression changes in tumor cells some of which are related to epithelial to mesenchymal transition. Some of these changes were found to be dependent on cell-cell contact.Taken together, we here suggest MMP-7 and EGF to be predictive markers of cisplatin and cetuximab response, respectively. We also show that CAFs protect HNSCC cells from cetuximab treatment; however, the factor responsible for the protective effect is yet to be discovered.
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| 4. |
- Jedliński, Adam
(författare)
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Understanding the Role of EGFR in the Treatment of Head and Neck Squamous Cell Carcinoma
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Head and neck squamous cell carcinoma (HNSCC) originates from the epithelial lining of the upper aerodigestive tract. It accounts for over 90 % of the malignancies found in the head and neck region. 600,000 new cases of HNSCC occur each year worldwide. Apart from causing painful lesions, HNSCC directly impacts the patient’s fundamental functions such as breathing and eating and also can disrupt the patient’s senses such as smell, taste, speech and even vision. Most cases of HNSCC require a combination of different treatments such as surgery, chemotherapy (primarily cisplatin based), and radiotherapy. Treatment decisions are largely based on the size of the tumor, the involvement of local lymph nodes, and distant spread. Treatment resistance and local recurrence are significant problems and to date no form of clinical treatment sensitivity prediction is available.A majority of HNSCC tumors overexpresses the epidermal growth factor receptor (EGFR). This receptor is involved in proliferation and DNA repair and is the target of a monoclonal antibody named cetuximab that selectively binds and inhibits EGFR. It is the only targeted therapy available to HNSCC patients and reserved for late stage patients in Sweden.Numerous investigators have searched for predictive markers and we hypothesized that since HNSCC is a very heterogeneous disease a single factor would not be able to predict the treatment outcome. In paper I we explore a panel of predictive factors using a point system, called the number of negative points (NNP), in which we could combine both proteins and genetic variations in an attempt to find a set of markers that could predict the intrinsic cisplatin sensitivity (ICS). The expression level of EGFR, Hsp70, Bax, Bcl-XL, survivin, and COX-2 was determined in 39 HNSCC cell lines. Moreover, the p53, MDM2, FGFR4, XPC, XPD, XRCC1, and XRCC3 genes were analyzed for the presence of specific single nucleotide polymorphisms (SNPs). Pearson’s correlation tests showed that EGFR was the only protein that alone correlated to ICS (r=0.388, P=0.015). The strongest correlation to ICS was found when combining SNPs in XRCC3 and XPD with the expression of EGFR, Hsp70, Bax, and Bcl-2 using the NNP system (r=0.614 P≤0.001).In paper II we assess the intrinsic radiosensitivity (IR), the ICS, and the intrinsic cetuximab sensitivity (ICmabS) as well as their combinations in 25 HNSCC cell lines established from HNSCC biopsies taken at the Department of Otorhinolaryngology and Head and Neck Surgery at Linköping University Hospital. Furthermore we investigate the EGFR status (consisting of EGFR gene copy number, EGFR mRNA, EGFR protein, pEGFR), pAkt and mRNA levels of the seven known EGFR ligands. No correlation was found between the different treatment sensitivities. Cetuximab treatment response was significantly correlated to epiregulin (EREG) mRNA expression (r=-0.408, P=0.043). Cetuximab resistant cell lines tended to have low levels of pEGFR (P=0.13) while resistant cell lines had a significantly lower expression of EGFR protein (P=0.04) and tended to have decreased levels of pAkt (P=0.13) and amphiregulin (AREG) mRNA (p=0.18).In paper III the functional importance of EGFR ligands in relation to proliferation and cetuximab sensitivity was investigated. Here we tried to diminish the tumor heterogeneity by selecting three cell lines that are derived from the same anatomical location but display different ICmabS. Signaling through the EGFR was stimulated with recombinant EGF, AREG or EREG or reduced by siRNA-mediated silencing of the aforementioned EGFR ligands. EGF downregulation suppressed the proliferation of all investigated tumor cell lines whereas the response to an increased level of EGF differed between EGFR overexpressing and EGFR non-overexpressing cell lines. Furthermore, tumor cells consistently displayed increased cetuximab resistance upon the addition of EGF, whereas EGF silencing was associated with an improved cetuximab response. The data regarding AREG and EREG were inconclusive.In paper IV we wanted to validate in vitro drug sensitivity testing of HNSCC cell lines in an in vivo xenograft model, and to identify treatment-induced changes in the EGFR signaling pathway that could be used as markers for cetuximab treatment response. In vitro ICmabS for the HNSCC cell lines UT-SCC-14 and UT-SCC-45 was established using a crystal violet assay. In order to determine the corresponding in vivo sensitivity, UT-SCC-14 and UT-SCC-45 xenografts were generated in female BALB/c (nu/nu) nude mice. Mice were given three injections of intraperitoneal cetuximab or PBS and the tumor volume was recorded continuously. The expression of EGFR, pEGFR, pSrc, and Ki67 in the tumor tissue was investigated by immunohistochemistry. The in vitro sensitivity was reproduced in the in vivo model. Furthermore a clear reduction of EGFR, pEGFR, and pSrc after cetuximab treatment was noted in UT-SCC-14, the cetuximab sensitive cell line while the cetuximab resistant UT-SCC-45 showed a slight increase in EGFR, pEGFR and pSrc.In conclusion, the EGFR ligand EGF is a potential predictive marker of poor cetuximab response and a possible treatment target. Moreover, treatment-induced downregulation of EGFR and pEGFR is associated with a good cetuximab response.
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