Per Olaf Ekstrøm

  • Researcher; Dr. philos.
  • +47 2278 1847


Distribution of mitochondrial mutant fractions within  tumors.


Original articles

Dominguez-Valentin M, Nakken S, Tubeuf H, Vodak D, Ekstrøm PO, Nissen AM, Morak M, Holinski-Feder E, Holth A, Capella G, Davidson B, Evans DG, Martins A, Møller P, Hovig E (2019)
Results of multigene panel testing in familial cancer cases without genetic cause demonstrated by single gene testing
Sci Rep, 9 (1), 18555
DOI 10.1038/s41598-019-54517-z, PubMed 31811167

Dominguez-Valentin M, Nakken S, Tubeuf H, Vodak D, Ekstrøm PO, Nissen AM, Morak M, Holinski-Feder E, Martins A, Møller P, Hovig E (2018)
Identification of genetic variants for clinical management of familial colorectal tumors
BMC Med Genet, 19 (1), 26
DOI 10.1186/s12881-018-0533-9, PubMed 29458332

Dominguez-Valentin M, Evans DGR, Nakken S, Tubeuf H, Vodak D, Ekstrøm PO, Nissen AM, Morak M, Holinski-Feder E, Martins A, Møller P, Hovig E (2018)
Genetic variants of prospectively demonstrated phenocopies in BRCA1/2 kindreds
Hered Cancer Clin Pract, 16, 4
DOI 10.1186/s13053-018-0086-0, PubMed 29371908

Dominguez-Valentin M, Nakken S, Tubeuf H, Vodak D, Ekstrøm PO, Nissen AM, Morak M, Holinski-Feder E, Martins A, Møller P, Hovig E (2018)
Potentially pathogenic germline CHEK2 c.319+2T>A among multiple early-onset cancer families
Fam Cancer, 17 (1), 141-153
DOI 10.1007/s10689-017-0011-0, PubMed 28608266

Refinetti P, Warren D, Morgenthaler S, Ekstrøm PO (2017)
Quantifying mitochondrial DNA copy number using robust regression to interpret real time PCR results
BMC Res Notes, 10 (1), 593
DOI 10.1186/s13104-017-2913-1, PubMed 29132417

Arstad C, Refinetti P, Kristensen AT, Giercksky KE, Ekstrøm PO (2017)
Is detection of intraperitoneal exfoliated tumor cells after surgical resection of rectal cancer a prognostic factor of survival?
BMC Cancer, 17 (1), 406
DOI 10.1186/s12885-017-3365-7, PubMed 28592327

Refinetti P, Arstad C, Thilly WG, Morgenthaler S, Ekstrøm PO (2017)
Mapping mitochondrial heteroplasmy in a Leydig tumor by laser capture micro-dissection and cycling temperature capillary electrophoresis
BMC Clin Pathol, 17, 6
DOI 10.1186/s12907-017-0042-3, PubMed 28405177

Arstad C, Refinetti P, Warren D, Giercksky KE, Ekstrøm PO (2016)
Scanning the mitochondrial genome for mutations by cycling temperature capillary electrophoresis
Mitochondrial DNA A DNA Mapp Seq Anal, 29 (1), 19-30
DOI 10.1080/24701394.2016.1233532, PubMed 27728990

Refinetti P, Morgenthaler S, Ekstrøm PO (2016)
Cycling temperature capillary electrophoresis: A quantitative, fast and inexpensive method to detect mutations in mixed populations of human mitochondrial DNA
Mitochondrion, 29, 65-74
DOI 10.1016/j.mito.2016.04.006, PubMed 27166160

Joshi S, Schjølberg AR, Ekstrøm PO, De Angelis PM, Zucknick M, Andersen SN, Clausen OP (2016)
Tp53/p53 status in keratoacanthomas
J Cutan Pathol, 43 (7), 571-8
DOI 10.1111/cup.12713, PubMed 27020606

Ekstrøm PO, Nakken S, Johansen M, Hovig E (2015)
Automated amplicon design suitable for analysis of DNA variants by melting techniques
BMC Res Notes, 8, 667
DOI 10.1186/s13104-015-1624-8, PubMed 26559640

Heramb C, Ekstrøm PO, Tharmaratnam K, Hovig E, Møller P, Mæhle L (2015)
Ten modifiers of BRCA1 penetrance validated in a Norwegian series
Hered Cancer Clin Pract, 13 (1), 14
DOI 10.1186/s13053-015-0035-0, PubMed 26052370

Friis-Ottessen M, Burum-Auensen E, Schjølberg AR, Ekstrøm PO, Andersen SN, Clausen OP, De Angelis PM (2014)
TP53/p53 alterations and Aurora A expression in progressor and non-progressor colectomies from patients with longstanding ulcerative colitis
Int J Mol Med, 35 (1), 24-30
DOI 10.3892/ijmm.2014.1974, PubMed 25333414

Yri OE, Ekstrøm PO, Hilden V, Gaudernack G, Liestøl K, Smeland EB, Holte H (2013)
Influence of polymorphisms in genes encoding immunoregulatory proteins and metabolizing enzymes on susceptibility and outcome in patients with diffuse large B-cell lymphoma treated with rituximab
Leuk Lymphoma, 54 (10), 2205-14
DOI 10.3109/10428194.2013.774392, PubMed 23391141

Yri OE, Ekstrøm PO, Hilden V, Gaudernack G, Liestøl K, Smeland EB, Holte H (2012)
Polymorphisms in genes encoding interleukin-10 and drug metabolizing enzymes GSTP1, GSTT1, GSTA1 and UGT1A1 influence risk and outcome in Hodgkin lymphoma
Leuk Lymphoma, 53 (10), 1934-44
DOI 10.3109/10428194.2012.682307, PubMed 22475179

Ekstrøm PO, Warren DJ, Thilly WG (2012)
Separation principles of cycling temperature capillary electrophoresis
Electrophoresis, 33 (7), 1162-8
DOI 10.1002/elps.201100550, PubMed 22539319

Sørensen O, Andersen A, Olsen H, Alexandr K, Ekstrøm PO, Giercksky KE, Flatmark K (2010)
Validation and use of microdialysis for determination of pharmacokinetic properties of the chemotherapeutic agent mitomycin C - an experimental study
BMC Cancer, 10, 469
DOI 10.1186/1471-2407-10-469, PubMed 20809961

Sudo H, Li-Sucholeiki XC, Marcelino LA, Gruhl AN, Herrero-Jimenez P, Zarbl H, Willey JC, Furth EE, Morgenthaler S, Coller HA, Ekstrom PO, Kurzweil R, Gostjeva EV, Thilly WG (2008)
Fetal-juvenile origins of point mutations in the adult human tracheal-bronchial epithelium: absence of detectable effects of age, gender or smoking status
Mutat Res, 646 (1-2), 25-40
DOI 10.1016/j.mrfmmm.2008.08.016, PubMed 18824180

Kristensen AT, Wiig JN, Larsen SG, Giercksky KE, Ekstrøm PO (2008)
Molecular detection (k-ras) of exfoliated tumour cells in the pelvis is a prognostic factor after resection of rectal cancer?
BMC Cancer, 8, 213
DOI 10.1186/1471-2407-8-213, PubMed 18655729

Ekstrøm PO (2008)
Scanning for DNA variants by denaturant capillary electrophoresis
Methods Mol Biol, 439, 19-34
DOI 10.1007/978-1-59745-188-8_2, PubMed 18370093

Lind H, Ekstrøm PO, Ryberg D, Skaug V, Andreassen T, Stangeland L, Haugen A, Zienolddiny S (2007)
Frequency of TP53 mutations in relation to Arg72Pro genotypes in non small cell lung cancer
Cancer Epidemiol Biomarkers Prev, 16 (10), 2077-81
DOI 10.1158/1055-9965.EPI-07-0153, PubMed 17932356

Ekstrøm PO, Bjørheim J, Thilly WG (2007)
Technology to accelerate pangenomic scanning for unknown point mutations in exonic sequences: cycling temperature capillary electrophoresis (CTCE)
BMC Genet, 8, 54
DOI 10.1186/1471-2156-8-54, PubMed 17697348

Lind H, Zienolddiny S, Ekstrøm PO, Skaug V, Haugen A (2006)
Association of a functional polymorphism in the promoter of the MDM2 gene with risk of nonsmall cell lung cancer
Int J Cancer, 119 (3), 718-21
DOI 10.1002/ijc.21872, PubMed 16496380

Harbo HF, Ekstrøm PO, Lorentzen AR, Sundvold-Gjerstad V, Celius EG, Sawcer S, Spurkland A (2006)
Coding region polymorphisms in T cell signal transduction genes. Prevalence and association to development of multiple sclerosis
J Neuroimmunol, 177 (1-2), 40-5
DOI 10.1016/j.jneuroim.2006.04.021, PubMed 16764945

Ekstrøm PO, Bjørheim J (2006)
Evaluation of sieving matrices used to separate alleles by cycling temperature capillary electrophoresis
Electrophoresis, 27 (10), 1878-85
DOI 10.1002/elps.200500642, PubMed 16619298

Lorentzen AR, Celius EG, Ekstrøm PO, Wiencke K, Lie BA, Myhr KM, Ling V, Thorsby E, Vartdal F, Spurkland A, Harbo HF (2005)
Lack of association with the CD28/CTLA4/ICOS gene region among Norwegian multiple sclerosis patients
J Neuroimmunol, 166 (1-2), 197-201
DOI 10.1016/j.jneuroim.2005.06.002, PubMed 16005527

Hinselwood DC, Warren DJ, Ekstrøm PO (2005)
High-throughput gender determination using automated denaturant gel capillary electrophoresis
Electrophoresis, 26 (13), 2562-6
DOI 10.1002/elps.200410392, PubMed 15934052

Hinselwood DC, Abrahamsen TW, Ekstrøm PO (2005)
BRAF mutation detection and identification by cycling temperature capillary electrophoresis
Electrophoresis, 26 (13), 2553-61
DOI 10.1002/elps.200410427, PubMed 15948220

Li-Sucholeiki XC, Tomita-Mitchell A, Arnold K, Glassner BJ, Thompson T, Murthy JV, Berk L, Lange C, Leong-Morgenthaler PM, MacDougall D, Munro J, Cannon D, Mistry T, Miller A, Deka C, Karger B, Gillespie KM, Ekstrøm PO, Todd JA, Thilly WG (2005)
Detection and frequency estimation of rare variants in pools of genomic DNA from large populations using mutational spectrometry
Mutat Res, 570 (2), 267-80
DOI 10.1016/j.mrfmmm.2004.11.004, PubMed 15708585

Ekstrøm PO, Bjørge T, Dørum A, Longva AS, Heintz KM, Warren DJ, Hansen S, Gislefoss RE, Hovig E (2004)
Determination of hereditary mutations in the BRCA1 gene using archived serum samples and capillary electrophoresis
Anal Chem, 76 (15), 4406-9
DOI 10.1021/ac049788k, PubMed 15283579

Kristensen AT, Bjørheim J, Wiig J, Giercksky KE, Ekstrøm PO (2003)
DNA variants in the ATM gene are not associated with sporadic rectal cancer in a Norwegian population-based study
Int J Colorectal Dis, 19 (1), 49-54
DOI 10.1007/s00384-003-0519-7, PubMed 12827413

Minarik M, Minarikova L, Bjørheim J, Ekstrøm PO (2003)
Cycling gradient capillary electrophoresis: a low-cost tool for high-throughput analysis of genetic variations
Electrophoresis, 24 (11), 1716-22
DOI 10.1002/elps.200305384, PubMed 12783447

Bjørheim J, Abrahamsen TW, Kristensen AT, Gaudernack G, Ekstrøm PO (2003)
Approach to analysis of single nucleotide polymorphisms by automated constant denaturant capillary electrophoresis
Mutat Res, 526 (1-2), 75-83
DOI 10.1016/s0027-5107(03)00033-2, PubMed 12714185

Bjørheim J, Gaudernack G, Giercksky KE, Ekstrøm PO (2003)
Direct identification of all oncogenic mutants in KRAS exon 1 by cycling temperature capillary electrophoresis
Electrophoresis, 24 (1-2), 63-9
DOI 10.1002/elps.200390032, PubMed 12652573

Ekstrøm PO, Bjørheim J, Gaudernack G, Giercksky KE (2002)
Population screening of single-nucleotide polymorphisms exemplified by analysis of 8000 alleles
J Biomol Screen, 7 (6), 501-6
DOI 10.1177/1087057102238623, PubMed 14599347

Kristensen AT, Bjørheim J, Ekstrøm PO (2002)
Detection of mutations in exon 8 of TP53 by temperature gradient 96-capillary array electrophoresis
Biotechniques, 33 (3), 650-3
DOI 10.2144/02333pf01, PubMed 12238774

Ekstrøm PO, Bjørheim J (2002)
Reducing the cost of consumables used for ABI 310 genetic analyzer
Anal Biochem, 306 (1), 148-9
DOI 10.1006/abio.2002.5656, PubMed 12069426

Bjørheim J, Minarik M, Gaudernack G, Ekstrøm PO (2002)
Mutation detection in KRAS Exon 1 by constant denaturant capillary electrophoresis in 96 parallel capillaries
Anal Biochem, 304 (2), 200-5
DOI 10.1006/abio.2002.5629, PubMed 12009696

Bjørheim J, Gaudernack G, Ekstrøm PO (2001)
Mutation analysis of TP53 exons 5-8 by automated constant denaturant capillary electrophoresis
Tumour Biol, 22 (5), 323-7
DOI 10.1159/000050634, PubMed 11553863

Bjørheim J, Ekstrøm PO, Fossberg E, Børresen-Dale AL, Gaudernack G (2001)
Automated constant denaturant capillary electrophoresis applied for detection of KRAS exon 1 mutations
Biotechniques, 30 (5), 972-5
DOI 10.2144/01305st01, PubMed 11355359

Ekstrøm PO, Wasserkort R, Minarik M, Foret F, Thilly WG (2000)
Two-point fluorescence detection and automated fraction collection applied to constant denaturant capillary electrophoresis
Biotechniques, 29 (3), 582-4, 586-9
DOI 10.2144/00293rr01, PubMed 10997272

Ekstrøm PO, Børresen-Dale AL, Qvist H, Giercksky KE, Thilly WG (1999)
Detection of low-frequency mutations in exon 8 of the TP53 gene by constant denaturant capillary electrophoresis (CDCE)
Biotechniques, 27 (1), 128-34
DOI 10.2144/99271rr01, PubMed 10407675

Ekstrøm PO, Andersen A, Saeter G, Giercksky KE, Slørdal L (1997)
Continuous intratumoral microdialysis during high-dose methotrexate therapy in a patient with malignant fibrous histiocytoma of the femur: a case report
Cancer Chemother Pharmacol, 39 (3), 267-72
DOI 10.1007/s002800050571, PubMed 8996531

Ekstrøm PO, Giercksky KE, Andersen A, Slørdal L (1997)
Alterations in methotrexate pharmacokinetics by naproxen in the rat as measured by microdialysis
Life Sci, 60 (24), PL 359-64
DOI 10.1016/s0024-3205(97)00241-5, PubMed 9188769

Ekstrøm PO, Giercksky KE, Andersen A, Bruland OS, Slørdal L (1997)
Intratumoral differences in methotrexate levels within human osteosarcoma xenografts studied by microdialysis
Life Sci, 61 (19), PL275-80
DOI 10.1016/s0024-3205(97)00839-4, PubMed 9364204

Ekstrøm PO, Andersen A, Warren DJ, Giercksky KE, Slørdal L (1996)
Determination of extracellular methotrexate tissue levels by microdialysis in a rat model
Cancer Chemother Pharmacol, 37 (5), 394-400
DOI 10.1007/s002800050403, PubMed 8599860

Ekstrøm PO, Anderson A, Warren DJ, Giercksky KE, Slørdal L (1995)
Pharmacokinetics of different doses of methotrexate at steady state by in situ microdialysis in a rat model
Cancer Chemother Pharmacol, 36 (4), 283-9
DOI 10.1007/bf00689044, PubMed 7628046

Review articles

Ekstrøm PO, Khrapko K, Li-Sucholeiki XC, Hunter IW, Thilly WG (2008)
Analysis of mutational spectra by denaturing capillary electrophoresis
Nat Protoc, 3 (7), 1153-66
DOI 10.1038/nprot.2008.79, PubMed 18600220

Bjørheim J, Ekstrøm PO (2005)
Review of denaturant capillary electrophoresis in DNA variation analysis
Electrophoresis, 26 (13), 2520-30
DOI 10.1002/elps.200410403, PubMed 15934053


Ekstrøm PO (1997)
The use of microdialysis to investigate extracellular pharmacokinetics of methotrexate
University of Oslo, Oslo, 1 b. (flere pag.)
BIBSYS 972142363, ISBN 82-7722-076-6

Ekstrøm PO (1995)
Mikrodialyse av metotrexat i en rottemodell: en teknikk for bestemmelse av et cytostatikums vevsdistribusjon
[P.O. Ekstrøm>, Oslo, 1 b. (flere pag.)
BIBSYS 951032674