| 1. |
- Farnebo, Lovisa, et al.
(författare)
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Combining factors on protein and gene level to predict radioresponse in head and neck cancer cell lines
- 2011
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Ingår i: Journal of Oral Pathology & Medicine. - : John Wiley and sons. - 0904-2512 .- 1600-0714. ; 40:10, s. 739-746
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Radiotherapy is the main therapy for head and neck squamous cell carcinoma (HNSCC); however, treatment resistance and local recurrence are significant problems, highlighting the need for predictive markers. In this study, we evaluated selected proteins, mutations, and single nucleotide polymorphisms (SNPs) involved in apoptosis, cell proliferation, and DNA repair alone or combined as predictive markers for radioresponse in 42 HNSCC cell lines. METHODS: The expression of epidermal growth factor receptor, survivin, Bax, Bcl-2, Bcl-XL, cyclooxygenase-2, and heat shock protein 70 was analyzed by ELISA. Furthermore, mutations and SNPs in the p53 gene as well as SNPs in the MDM2, XRCC1, and XRCC3 genes were analyzed for their relation to radioresponse. To enable the evaluation of the predictive value of several factors combined, each cell line was allocated points based on the number of negative points (NNP) system, and the NNP sum was correlated with radioresponse. RESULTS: Survivin was the only factor that alone was significantly correlated with the intrinsic radiosensitivity (r=0.36, p=0.02). The combination of survivin, Bax, Bcl-2, Bcl-XL, cyclooxygenase-2, and the p53 Arg72Pro polymorphism was found to most strongly correlate with radioresponse (r=0.553, p<0.001). CONCLUSION: These data indicate that the intrinsic radiosensitivity of 42 HNSCC cell lines can be predicted by a panel of factors on both the protein and gene levels. Moreover, among the investigated factors, survivin was the most promising biomarker of radioresponse.
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| 2. |
- Farnebo, Lovisa, et al.
(författare)
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Strong expression of survivin is associated with positive response to radiotherapy and improved overall survival in head and neck squamous cell carcinoma patients
- 2013
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Ingår i: International Journal of Cancer. - : Wiley-Blackwell. - 0020-7136 .- 1097-0215. ; 133:8, s. 1994-2003
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Tidskriftsartikel (refereegranskat)abstract
- Head and neck squamous cell carcinoma (HNSCC) is a malignancy that is associated with severe mortality despite advances in therapy. Todays standard treatment most commonly includes radiotherapy, often combined with chemotherapy or surgery. There are so far no established biomarkers to predict response to radiation, and thus the aim of this study was to investigate a series of markers that could potentially identify HNSCC patients who would benefit from radiotherapy. The selected markers, both proteins (epidermal growth factor receptor, survivin and p53), and single nucleotide polymorphisms (SNPs) in the genes of XRCC3, XRCC1, XPC, XPD, MDM2, p53 and FGFR4 were correlated to the response to radiotherapy and overall survival. Investigations were performed on pretreatment tumor biopsies from patients classified as responders or nonresponders to radiotherapy. Protein expression was examined using immunohistochemistry and the genotyping of specific SNPs was analyzed using PCR-RFLP or pyrosequencing. We found that survivin expression was significantly stronger in the responder group (p = 0.003) and that patients with a strong survivin expression had a significantly better overall survival (p andlt; 0.001). Moreover, downregulation of survivin by siRNA in two HNSCC cell lines significantly decreased their sensitivity to radiation. Among the SNPs analyzed, patients with the XPD Lys751Gln SNP had a significantly shorter overall survival (p = 0.048), and patients with the FGFR4 Gly388Arg SNP had a significantly longer overall survival (p = 0.010). In conclusion, our results suggest that survivin plays an important role in the response to radiotherapy and may be a useful marker for predicting radiotherapy response in patients with HNSCC. less thanbrgreater than less thanbrgreater thanWhats new? Resistance to radiation therapy is a significant problem in the treatment of head and neck squamous cell carcinoma (HNSCC) and has created a need for the discovery of markers predictive of radiotherapy response. One promising marker is survivin, an inhibitor of apoptosis. Here, in pre-treatment biopsies from 40 patients with HNSCC, strong survivin expression was significantly associated with response to radiotherapy and increased overall survival. The data also indicate that single nucleotide polymorphisms in the genes XPD and FGFR4 are other possible predictors of overall survival after radiotherapy.
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| 3. |
- Jakobsen Falk, Ingrid, et al.
(författare)
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Association of CYP2B6 Genotype with Survival and Progression Free Survival in Cyclophosphamide Treated Multiple Myeloma
- 2012
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Ingår i: Journal of Cancer Therapy. - : Scientific Research Publishing. - 2151-1934 .- 2151-1942. ; 3:1, s. 20-27
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Cyclophosphamide is a conventional pro-drug used in Multiple Myeloma (MM) and other malignancies. The highly polymorphic CYP2B6 is suggested as a major contributor in cyclophosphamide bioactivation, and GST en-zymes are involved in detoxification. Polymorphisms of these enzymes may affect enzyme expression and function as well as treatment outcome. The aim of this study was to investigate the impact of the CYP2B6 SNPs G516T, A785G and C1459T, GSTP1 SNP Ile105Val, and GSTM1 and GSTT1 null variants, on the outcome for cyclophosphamide treated MM patients, in order to find markers of value for individualised therapy. Methods: We used allele specific PCR and Pyrosequencing to investigate the impact of CYP2B6 SNPs G516T, A785G and C1459T, GSTP1 Ile105Val, and GSTM1 and GSTT1 variants, on the outcome for 26 cyclophosphamide treated multiple myeloma patients. Results and Major Conclusion: The CYP2B6 785G carriers had significantly shorter progression free survival (p = 0.048*) and overall survival (p = 0.037*) with 785G/G patients having the worst outcome compared to patients carrying the wild type. A shorter progression free survival was also indicated in patients carrying both CYP2B6 516T & 785G (p = 0.068). These results indicate a predictive role of CYP2B6 SNPs, particularly A785G, in cyclophosphamide treatment.
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| 4. |
- Stjernström, Annika, et al.
(författare)
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Alterations of INPP4B, PIK3CA and pAkt of the PI3K pathway are associated with squamous cell carcinoma of the lung
- 2014
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Ingår i: Cancer Medicine. - : John Wiley & Sons. - 2045-7634. ; 3:2, s. 337-348
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to investigate how alterations in the PI3K pathway correlate with non-small cell lung cancer subtypes squamous cell carcinoma (SSC) and adenocarcinoma (ADCA). We analyzed copy number variation and protein expression of INPP4B, protein expression of pAkt, PDPK1, and PTEN and mutational status of PIK3CA and PTEN in 180 cases. Nineteen% displayed loss of INPP4B copy, whereas 47% lacked expression, both showing correlation with SCC. Elevated pAkt expression was seen in 63% of all cases, also correlating to SCC. PDPK1 was expressed in 70%, more in male than female patients. Regarding PTEN, 50% displayed loss of expression, of which seven were identified with mutations in the phosphatase domain. We detected nine cases (5%) of PIK3CA mutations, all identified as the E545K hot spot mutation in the helical domain, all except one in SCC. When analyzing all PI3K pathway components together, we show that patients with at least one alteration in the PI3K pathway are twice as likely to have SCC, than ADCA. Interestingly, we also found a strong correlation between high pAkt expression and PTEN expression. As comparison, we also analyzed mitogen-activated protein kinase (MAPK) pathway genes, where we identified fifteen KRAS mutations (8%) and one BRAF mutation (1%), significantly associated to ADCA. No association was found to the Gly972Arg polymorphism of IRS-1, involved in activation of both PI3K and MAPK pathways. In conclusion, we show here that several components of the PI3K pathway, alone and in combination, are correlated to development of SCC of the lung.
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| 5. |
- Thunell, Lena, et al.
(författare)
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MDM2 SNP309 promoter polymorphism confers risk for hereditary melanoma
- 2014
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Ingår i: Melanoma research. - : Lippincott, Williams andamp; Wilkins. - 0960-8931 .- 1473-5636. ; 24:3, s. 190-197
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Tidskriftsartikel (refereegranskat)abstract
- The p53 pathway regulates stress response, and variations in p53, MDM2, and MDM4 may predispose an individual to tumor development. The aim of this study was to study the impact of genetic variation on sporadic and hereditary melanoma. We have analyzed a combination of three functionally relevant variants of the p53 pathway in 258 individuals with sporadic malignant melanomas, 50 with hereditary malignant melanomas, and 799 healthy controls. Genotyping was performed by PCR-restriction fragment length polymorphism, pyrosequencing, and allelic discrimination. We found an increased risk for hereditary melanoma in MDM2 GG homozygotes, which was more pronounced among women (P=0.035). In the event of pairwise combinations of the single nucleotide polymorphisms, a risk elevation was shown for MDM2 GG homozygotes/p53 wild-type Arg in hereditary melanoma (P=0.01). Individuals with sporadic melanomas of the superficial spreading type, including melanoma in situ, showed a slightly higher frequency of the MDM2 GG genotype compared with those with nodular melanomas (P=0.04). The dysplastic nevus phenotype, present in the majority of our hereditary melanoma cases and also in some sporadic cases, further enhanced the effect of the MDM2 GG genotype on melanoma risk (P=0.005). In conclusion, the results show an association between MDM2 SNP309 and an increased risk for hereditary melanoma, especially among women. Analysis of sporadic melanoma also shows an association between MDM2 and the superficial spreading melanoma subtype, as well as an association with the presence of dysplastic nevi in sporadic melanoma.
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