The effect of IL-6 on the level of N-myc downstream regulated gene 2 and the growth and survival of colon cancer cells

Louise Dannemann Jørgensen

Studenteropgave: Speciale

Abstrakt

Cancer is a leading cause of death, and tumorigenesis is dependent on different mechanisms, including genomic changes and the immune system. Silencing of tumor suppressor genes is an important mechanism. The recently suggested tumor suppressor gene, NDRG2, has been correlated with down-regulation and decrease proliferation in cancers. Additionally, chronic inflammation and cancer development have been connected. Oncogenic transformation occurs in tumor cells exposed to repeated chronic inflammation, which may lead to epigenetic alterations and changed expression of tumor suppressor genes. The immune system supplies the tumor environment with cytokines including IL-6, which has been connected with chronic inflammation through its ability to activate STAT3 leading to inhibition of anti-tumor immunity. NDRG2 expression has been reported to modulate SOCS3 and STAT3 activity and further induce SOCS1 expression, which leads to down-regulation of STAT3 in breast cancer. It would therefore be interesting to study a possible connection between NDRG2 expression and IL-6 levels in colon cancer cells. The objective of this thesis was to study the expression of NDRG2 and examine a possible correlation between IL-6 and NDRG2 expression in colon cancer cell lines, SW480 and HCT116, by use of RT-qPCR and western blotting. Furthermore, distinct growth assays were performed to evaluate the effect on the growth rate in colon cancer cells of presence of IL-6 and NDRG2, separately and together. The expression of NDRG2 in colon cancer cells was found to be down-regulated both on mRNA and protein level, and the same was observed after treatment with IL-6 on mRNA level. The growth assays provided results indicating that SW480 cells transfected with the plasmid pcDNA6-NDRG2L-V5 had an increased growth rate, when compared with normal SW480 cells, and the same tendency was seen after treatment with IL-6, both in normal SW480 cells and transfected SW480 cells. Altogether, these results suggest that NDRG2 is down-regulated in both colon cancer cell lines, and that transfected cells treated with IL-6 show increased growth rate. This may indicate a potential correlation between NDRG2 and IL-6 in relation to growth in colon cancer cells.

UddannelserMedicinalbiologi, (Bachelor/kandidatuddannelse) Kandidat
SprogEngelsk
Udgivelsesdato31 maj 2014

Emneord

  • Colon cancer
  • NDRG2
  • IL-6