MicroRNA alterations and associated aberrant DNA methylation patterns across multiple sample types in oral squamous cell carcinoma. PLoS One. 2011;6(11):e27840. Epub 2011 Nov 22. Wiklund ED, Gao S, Hulf T, Sibbritt T, Nair S, Costea DE, Villadsen SB, Bakholdt V, Bramsen JB, Sørensen JA, Krogdahl A, Clark SJ, Kjems J.

S100A14 inhibits proliferation of oral carcinoma derived cells through G1-arrest. Oral Oncol. 2012 Mar;48(3):219-25. Epub 2011 Oct 26. Sapkota D, Costea DE, Blø M, Bruland O, Lorens JB, Vasstrand EN, Ibrahim SO.

Orbital reconstruction after resection of giant calcifying cystic odontogenic tumor of mid-face. J Oral Maxillofac Surg. 2012 Jan;70(1):233-41. Epub 2011 Jul 13. Moen K, Lybak S, Jonsson HN, Seland H, Størksen K, Johannessen AC, Kråkenes J, Tornes K, Løes S.

Oral mucosal lesions in skin diseased patients attending a dermatologic clinic: a cross-sectional study in Sudan. BMC Oral Health. 2011 Sep 19;11:24.Suliman NM, Astrøm AN, Ali RW, Salman H, Johannessen AC.

Cancer, pre-cancer and normal oral cells distinguished by dielectrophoresis. Anal Bioanal Chem. 2011 Nov;401(8):2455-63. Epub 2011 Aug 30 Mulhall HJ, Labeed FH, Kazmi B, Costea DE, Hughes MP, Lewis MP.

Cancer stem cells in squamous cell carcinoma switch between two distinct phenotypes that are preferentially migratory or proliferative. Cancer Res. 2011 Aug 1;71(15):5317-26. Epub 2011 Jun 17, Biddle A, Liang X, Gammon L, Fazil B, Harper LJ, Emich H, Costea DE, Mackenzie IC.

S100A14 regulates the invasive potential of oral squamous cell carcinoma derived cell-lines in vitro by modulating expression of matrix metalloproteinases, MMP1 and MMP9. Eur J Cancer. 2011 Mar;47(4):600-10. Epub 2010 Nov 10. Sapkota D, Bruland O, Costea DE, Haugen H, Vasstrand EN, Ibrahim SO.

Induction of human epithelial stem/progenitor expansion by FOXM1. Cancer Res. 2010 Nov 15;70(22):9515-26. Epub 2010 Nov 9. Erratum in: Cancer Res. 2011 Jan 1;71(1):290. Gemenetzidis E, Costea DE, Parkinson EK, Waseem A, Wan H, Teh MT.

Scandinavian Fellowship for Oral Pathology and Oral Medicine: statement on oral pathology and oral medicine in the European Dental Curriculum. J Oral Pathol Med. 2010 Nov;39(10):800-e1. doi: 10.1111/j.1600-0714.2010.00939.x. Epub 2010 Sep 1. Kragelund C, Reibel J, Hadler-Olsen ES, Hietanen J, Johannessen AC, Kenrad B, Nylander K, Puranen M, Rozell B, Salo T, Syrjänen S, Søland TM, van der Waal I, van der Wal JE, Warfvinge G.

Pattern of malignant tumors registered at a referral oral and maxillofacial hospital in Sudan during 2006 and 2007. J Cancer Res Ther. 2010 Oct-Dec;6(4):473-7. Osman TA, Satti AA, Boe OE, Yang YH, Ibrahim SO, Suleiman AM.

Normal and malignant epithelial cells with stem-like properties have an extended G2 cell cycle phase that is associated with apoptotic resistance. BMC Cancer. 2010 Apr 28;10:166.Harper LJ, Costea DE, Gammon L, Fazil B, Biddle A, Mackenzie IC.

Coexpression and nuclear colocalization of metastasis-promoting protein S100A4 and p53 without mutual regulation in colorectal carcinoma.    Amino Acids. 2010 Feb 27. [Epub ahead of print] Berge G, Costea DE, Berg M, Rasmussen H, Grotterød I, Lothe RA, Mælandsmo GM, Flatmark K.

Khat alters the phenotype of in vitro-reconstructed human oral mucosa.  J Dent Res. 2010 Mar;89(3):270-5. Epub 2009 Dec 31. Lukandu OM, Neppelberg E, Vintermyr OK, Johannessen AC, Costea DE.

Camptothecin and khat (Catha edulis Forsk.) induced distinct cell death phenotypes involving modulation of c-FLIPL, Mcl-1, procaspase-8 and mitochondrial function in acute myeloid leukemia cell lines.  Mol Cancer. 2009 Nov 13;8:101. Bredholt T, Dimba EA, Hagland HR, Wergeland L, Skavland J, Fossan KO, Tronstad KJ, Johannessen AC, Vintermyr OK, Gjertsen BT.

Adverse effects of Sudanese toombak vs. Swedish snuff on human oral cells.  J Oral Pathol Med. 2010 Feb;39(2):128-40. Epub 2009 Oct 4.  Costea DE, Lukandu O, Bui L, Ibrahim MJ, Lygre R, Neppelberg E, Ibrahim SO, Vintermyr OK, Johannessen AC.

Cancer progression is associated with increased expression of basement membrane proteins in three-dimensional in vitro models of human oral cancer.  Arch Oral Biol. 2009 Oct;54(10):924-31. Epub 2009 Aug 11. Kulasekara KK, Lukandu OM, Neppelberg E, Vintermyr OK, Johannessen AC, Costea DE.

Early loss of mitochondrial inner transmembrane potential in khat-induced cell death of primary normal human oral cells.  Toxicology. 2009 Sep 19;263(2-3):108-16. Epub 2009 Jul 8. Lukandu OM, Bredholt T, Neppelberg E, Gjertsen BT, Johannessen AC, Vintermyr OK, Costea DE.

Sympathectomy suppresses tumor growth and alters gene-expression profiles in rat tongue cancer. Eur J Oral Sci. 2009 Aug;117(4):351-61 Raju B, Hultström M, Haug SR, Ibrahim SO, Heyeraas KJ.

Fusobacterium nucleatum enters normal human oral fibroblasts in vitro.   J Periodontol. 2009 Jul;80(7):1174-83. Dabija-Wolter G, Cimpan MR, Costea DE, Johannessen AC, Sørnes S, Neppelberg E, Al-Haroni M, Skaug N, Bakken V.

An intramuscular haemangioma of the tongue. Br J Oral Maxillofac Surg. 2009 Mar;47(2):165. Løes S, Johannessen AC, Tornes K.

Epithelial stem cells and malignancy.
J Anat. 2008 Jul;213(1):45-51.
Costea DE, Gammon L, Kitajima K, Harper L, Mackenzie IC.J Pathol. 2008 Jul;215(3):280-9.

Khat (Catha edulis) induces reactive oxygen species and apoptosis in normal human oral keratinocytes and fibroblasts.
Toxicol Sci. 2008 Feb 29.
Lukandu OM, Costea DE, Neppelberg E, Johannessen AC, Vintermyr OK.

Khat induces G1-phase arrest and increased expression of stress-sensitive p53 and p16 proteins in normal human oral keratinocytes and fibroblasts.

Eur J Oral Sci. 2008 Feb;116(1):23-30.
Lukandu OM, Costea DE, Dimba EA, Neppelberg E, Bredholt T, Gjertsen BT, Vintermyr OK, Johannessen AC.

Tissue engineering of oral dysplasia.  J Oral Pathol Med. 2008 Mar;37( 3):137-44. Gaballah K, Costea DE, Hills A, Gollin SM, Harrison P, Partridge M.

High interstitial fluid pressure in rat tongue cancer is related to increased lymph vessel area, tumor size, invasiveness and decreased body weight.  J Oral Pathol Med. 2008 Mar;37(3):137-44. Raju B, Haug SR, Ibrahim SO, Heyeraas KJ.

The changing face of p53 in head and neck cancer.
Int J Oral Maxillofac Surg. 2007 Dec;36(12):1123-38.
Partridge M, Costea DE, Huang X.

Sympathectomy decreases size and invasiveness of tongue cancer in rats.
Neuroscience. 2007 Nov 9;149(3):715-25. Epub 2007 Aug 16.
Raju B, Haug SR, Ibrahim SO, Heyeraas KJ.

Gene expression profile of oral squamous cell carcinomas from Sri Lankan betel quid users
Oncol RepOncol RepOncol RepOncol RepOncol Rep. 2007 Nov;18(5):1061-75.
Suhr ML, Dysvik B, Bruland O, Warnakulasuriya S, Amaratunga AN, Jonassen I, Vasstrand EN, Ibrahim SO.

DNA content, Cyclooxygenase-2 expression and loss of E-cadherin expression do not predict risk of malignant transformation in oral lichen planus. Eur Arch Otorhinolaryngol. 2007 Oct;264(10):1223-30. Epub 2007 May 25. Neppelberg E, Johannessen AC.

Cancer stem cells – new and potentially important targets for the therapy of oral squamous cell carcinoma.
Oral Dis. 2006 Sep;12(5):443-54.
Costea DE, Tsinkalovsky O, Vintermyr OK, Johannessen AC, Mackenzie IC.

Species-specific fibroblasts required for triggering invasiveness of partially transformed oral keratinocytes.
Am J Pathol. 2006 Jun;168(6):1889-97.
Costea DE, Kulasekara K, Neppelberg E, Johannessen AC, Vintermyr OK.

Gene expression profiles of head and neck carcinomas from Sudanese and Norwegian patients reveal common biological pathways regardless of race and lifestyle.
Clin Cancer Res. 2006 Feb 15;12(4):1109-20.
Dysvik B, Vasstrand EN, Lovlie R, Elgindi OA, Kross KW, Aarstad HJ, Johannessen AC, Jonassen I, Ibrahim SO.

Loss of BCL-2 in the progression of oral cancer is not attributable to mutations.
J Clin Pathol. 2005 Nov;58(11):1157-62.
Loro LL, Johannessen AC,Vintermyr OK

Expression of p53, cyclin D1 and Ki-67 in pre-malignant and malignant oral lesions: association with clinicopathological parameters.
Anticancer Res. 2005 Nov-Dec;25(6C):4699-706.
Raju B, Mehrotra R, Oijordsbakken G, Al-Sharabi AK, Vasstrand EN, Ibrahim SO.

Apoptosis in normal and diseased oral tissues.
Oral Dis. 2005 Sep;11(5):274-87. Review.
Loro LL, Vintermyr OK, Johannessen AC.

Fibroblast control on epithelial differentiation is gradually lost during in vitro tumor progression.
Differentiation. 2005 Apr;73(4):134-41.
Costea DE, Johannessen AC,Vintermyr OK

The phenotype of in vitro reconstituted normal human oral epithelium is essentially determined by culture medium.
J Oral Pathol Med. 2005 Apr;34(4):247-52.
Costea DE, Dimba AO, Loro LL, Vintermyr OK, Johannessen AC

Khat (Catha edulis)-induced apoptosis is inhibited by antagonists of caspase-1 and -8 in human leukaemia cells.
Br J Cancer. 2004 Nov 1;91(9):1726-34.
Dimba EA, Gjertsen BT, Bredholt T, Fossan KO, Costea DE, Francis GW, Johannessen AC, Vintermyr OK.

Crucial effects of fibroblasts and keratinocyte growth factor on morphogenesis of reconstituted human oral epithelium.
J Invest Dermatol. 2003 Dec;121(6):1479-86.
Costea DE, Loro LL, Dimba EA, Vintermyr OK, Johannessen AC.

Catha edulis (Khat) induces cell death by apoptosis in leukemia cell lines.
Ann N Y Acad Sci. 2003 Dec;1010:384-8.
Dimba E, Gjertsen BT, Francis GW, Johannessen AC, Vintermyr OK.

Mutations of the cell cycle regulatory genes p16INK4A and p21WAF1 and the
metastasis-inducing gene S100A4 are infrequent and unrelated to p53 tumour
suppressor gene status and data on survival in oropharyngeal squamous cell
Anticancer Res. 2003 Nov-Dec;23(6C):4593-600.
Ibrahim SO, Lillehaug JR, Vasstrand EN.

Study of oral epithelial atypia among Sudanese tobacco users by exfoliative
Anticancer Res. 2003 Mar-Apr;23(2C):1943-9.
Ahmed HG, Idris AM, Ibrahim SO.

Cell death regulation in oral squamous cell carcinoma: methodological considerations and clinical significance.
J Oral Pathol Med. 2003 Mar;32(3):125-38.
Loro LL, Vintermyr OK, Johannessen AC.

Gene expression profile in oral squamous cell carcinomas and matching normal oral mucosal tissues from black Africans and white Caucasians: the case of the Sudan vs. Norway.
Oral Oncol 2003 Jan;39(1):37-48
Ibrahim SO, Aarsaether N, Holsve MK, Kross KW, Heimdal JH, Aarstad JH, Liavaag PG, Elgindi OA, Johannessen AC, Lillehaug JR, Vasstrand EN.

CD40, CD154, Bax and Bcl-2 Expression in Sjogren’s Syndrome Salivary Glands: a Putative Anti-Apoptotic Role During its Effector Phases.
Scand J Immunol 2002 Dec;56(6):561-71
Ohlsson M, Szodoray P, Loro LL, Johannessen AC, Jonsson R.

Decreased expression of bcl-2 in moderate and severe oral epithelia dysplasias.
Oral Oncol 2002 Oct;38(7):691-8
Loro LL, Johannessen AC, Vintermyr OK.

Mutations of the cell cycle arrest gene p21WAF1, but not the metastasis-inducing gene S100A4, are frequent in oral squamous cell carcinomas from Sudanese toombak dippers and non-snuff-dippers from the Sudan, Scandinavia, USA and UK.
Anticancer Res 2002 May-Jun;22(3):1445-51
Ibrahim SO, Lillehaug JR, Dolphine O, Johnson NW, Warnakulasuriya KA, Vasstrand EN.

Gross genomic aberrations in precancers: clinical implications of a long-term follow-up study in oral erythroplakias.
J Clin Oncol. 2002 Jan 15;20(2):456-62
Sudbo J, Kildal W, Johannessen AC, Koppang HS, Sudbo A, Danielsen HE, Risberg B, Reith A.

Maintained CD40 and loss of polarised CD40 ligand expression in oral squamous cell carcinoma.
Anticancer Res 2001 Jan-Feb;21(1A):113-7
Loro LL, Ohlsson M, Vintermyr OK, Liavaag PG, Jonsson R, Johannessen AC.

Apoptosis and expression of Bax and Bcl-2 in snuff- and non-snuff associated oral squamous cell carcinomas.
Anticancer Res 2000 Sep-Oct;20(5A):2855-60
Loro LL, Vintermyr OK, Ibrahim SO, Idris AM, Johannessen AC.

Oral squamous cell carcinoma is associated with decreased bcl-2/bax expression ratio and increased apoptosis.
Hum Pathol 1999 Sep;30(9):1097-105
Loro LL, Vintermyr OK, Liavaag PG, Jonsson R, Johannessen AC.

Expression of biomarkers (p53, transforming growth factor alpha, epidermal growth factor receptor, c-erbB-2/neu and the proliferative cell nuclear antigen) in oropharyngeal squamous cell carcinomas.
Oral Oncol. 1999 May;35(3):302-13.
Ibrahim SO, Lillehaug JR, Johannessen AC, Liavaag PG, Nilsen R, Vasstrand EN.

Mutations of the p53 gene in oral squamous-cell carcinomas from Sudanese dippers of nitrosamine-rich toombak and non-snuff-dippers from the Sudan and Scandinavia.
Int J Cancer. 1999 May 17;81(4):527-34.
Ibrahim SO, Vasstrand EN, Johannessen AC, Idris AM, Magnusson B, Nilsen R, Lillehaug JR.

Suppression of Fas receptor and negative correlation of Fas ligand with differentiation and apoptosis in oral squamous cell carcinoma.
J Oral Pathol Med. 1999 Feb;28(2):82-7.
Loro LL, Vintermyr OK, Johannessen AC, Liavaag PG, Jonsson R.

The Swedish snus and the Sudanese toombak: are they different?
Oral Oncol 1998 Nov;34(6):558-66
Idris AM, Ibrahim SO, Vasstrand EN, Johannessen AC, Lillehaug JR, Magnusson B, Wallstrom M, Hirsch JM, Nilsen R.

Expression of keratin 13, 14 and 19 in oral squamous cell carcinomas from Sudanese snuff dippers: lack of association with human papillomavirus infection.
APMIS 1998 Oct;106(10):959-69
Ibrahim SO, Bertelsen B, Kalvenes MB, Idris AM, Vasstrand EN, Nilsen R, Johannessen AC.

Expression of keratin 13, 14 and 19 in oral hyperplastic and dysplastic lesions from Sudanese and Swedish snuff-dippers: association with human papillomavirus infection.
Anticancer Res 1998 Jan-Feb;18(1B):635-45
Ibrahim SO, Warnakulasuriya KA, Idris AM, Hirsch JM, Johnson NW, Johannessen AC.

Immunohistochemical detection of p53 in archival formalin-fixed tissues of lip and intraoral squamous cell carcinomas from Norway.
APMIS 1997 Oct;105(10):757-64
Ibrahim SO, Johannessen AC, Vasstrand EN, Lillehaug JR, Nilsen R.

Expression of c-erbB proto-oncogene family members in squamous cell carcinoma of the head and neck
Anticancer Res 1997 Nov-Dec;17(6D):4539-46
Ibrahim SO, Vasstrand EN, Liavaag PG, Johannessen AC, Lillehaug JR.

Immunohistochemical detection of p53 in non-malignant and malignant oral lesions associated with snuff dipping in the Sudan and Sweeden.
Int J Cancer 1996 Dec 11;68(6):749-53
Ibrahim SO, Johannessen AC, Idris AM, Hirsch JM, Vasstrand EN, Magnusson B, Nilsen R.