liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Promotion of intestinal polyposis in nitric oxide synthase 2 (NOS2) deficient Min mice and expression of genes in the Notch-1 pathway
Linköping University, Department of Biomedicine and Surgery, Cell biology. Linköping University, Faculty of Health Sciences.
Department of Caring Sciences, Örebro University, Örebro, SWEDEN.
Linköping University, Department of Biomedicine and Surgery, Cell biology. Linköping University, Faculty of Health Sciences.
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Nitric oxide synthase 2 (NOS2) expression has been found in several different tumor types, including colorectal cancers, but the role of NOS2 expression for cancer development is not fully understood. In the present study, we have investigated the role of NOS2 for intestinal polyp development in the APC Min/+ mouse and studied the mRNA expression by real time PCR of Notch-1 and p21 in normal murine small intestinal tissue and polyps from APC Min/+ NOS2+/+ and APC Min/+ NOS2-/- mice. A significant higher polyp frequency was found in mice with APC Min/+ NOS2-/- genotype compared to APC Min/+ NOS2+/+ mice. The expression of Notch-1 was significantly increased in polyps from the APC Min/+ NOS2+/+ mice compared to wild type small intestinal mucosa, but no difference was evident between the APC Min/+ NOS2+/+ and APC Min/+ NOS2-/- mice, which indicates that NOS2 expression does not affect the Notch-1 expression. No significant difference was found between the different mouse groups regarding the expression of p21. Collectively, NOS2 expression is a protective factor in intestinal polyposis, but its role in polyp development is still unclear.

National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:liu:diva-81928OAI: oai:DiVA.org:liu-81928DiVA: diva2:556590
Available from: 2012-09-25 Created: 2012-09-25 Last updated: 2012-09-25Bibliographically approved
In thesis
1. Molecular genetic aspects of colorectal cancer development
Open this publication in new window or tab >>Molecular genetic aspects of colorectal cancer development
2005 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Colorectal cancer (CRC) is one of the most common cancer diseases in the world after lung and female breast cancer and approximately 945 000 new cases are diagnosed every year. CRC is caused by genetic alterations in the DNA, which results in cell cycle acceleration, escape from apoptosis, senescence, angiogenesis, invasion and metastasis. In this thesis, we have investigated molecular genetic alterations for the development of CRC and focused on the MAPK pathway, HIF-1 α and NOS2 genes.

Alterations in the MAPK pathway have been found in several different cancer forms, including CRe. In the present study, we found somatic mutations in the MAPK pathway in 50% of the CRCs; 40% of the tumors carried mutations in the KRAS gene and 10% carried BRAF mutations. No genetic alterations were found in the ARAF or RAF-1 genes. B&4F gene mutations were present only in exon 15 and were associated with micro satellite instability. Three mutation types were identified; V599E, D593G and K600N, whereof the latter has not previously been described.

The hypoxia inducible factor (HIF)-la protein is involved in the oxygen sensing mechanism and several tumor types show HIF-la overexpression due to hypoxia. At normoxia, HIF-la is degraded by interaction with the von Hippel-Lindau (VHL) tumor suppressor protein followed by an ubiquitin-proteasome dependent degradation mechanism, which prevents HIF-l a from nuclear translocation and transcription of downstream target genes. Fifteen percent of CRC patients and normal healthy population was found to carry the P582S polymorphism in the HIF-1 α gene, which previously has been associated to higher transactivating capacity. In the present study, the polymorphism was associated to ulcerative tumor development. In addition, loss of heterozygosity of the wild type P582 allele in heterozygotes may contribute to the development of ulcerative CRCs. However, the overall mechanism for ulcerative tumor development is still unclear.

Nitric oxide (NO) is involved in several physiological processes, such as apoptosis, neurotransmission, angiogenesis and immune defence and is produced by three nitric oxide synthases; NOSl-3. In the present study, NOS2 upregulation was identified in CRCs compared to normal intestinal mucosa. Moreover, the contribution of NOS2 in CRC development was investigated in APCMin/+ and APCMin/+ NOS2-/- mice. The APCMin/+ NOS-/- mice developed a higher polyp frequency compared to APCMin/+ mice, indicating a protective role for the presence of NOS2 in intestinal cancer development. The elevated polyp formation in the APCMin/+ NOS-/- mice was independent of the expression of Notch-l and p21. We also investigated whether polymorphisms in the NOS2 promoter affected the onset of CRC, but no differences in allele or genotype frequencies were observed in normal healthy population compared to CRC patients.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2005. 83 p.
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 878
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-31156 (URN)16894 (Local ID)91-7373-856-5 (ISBN)16894 (Archive number)16894 (OAI)
Public defence
2005-01-21, Berzeliussalen, Halsouniversitetet, Campus US, Linköpings universitet, Linköping, 09:00 (Swedish)
Opponent
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2012-09-25Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Fransén, KarinSöderkvist, Peter

Search in DiVA

By author/editor
Fransén, KarinSöderkvist, Peter
By organisation
Cell biologyFaculty of Health Sciences
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 52 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf