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Sesquiterpene Lactone Analogues Inhibit NFκB Signaling Pathway in Breast Cancer Cells

Malakpour, Atena (2016) MOBN01 20152
Degree Projects in Molecular Biology
Popular Abstract
Medicinal plants have been used for treatment of various human diseases for a long time in history. The Ambrosia arborescens Mill. plant grows in some of the developing Latin American countries such as Ecuador, Bolivia and Peru. Ambrosia arborescens Mill, has a ubiquitous amount of sesquiterpene lactone (SL) compounds that can be extracted exclusively from the aromatic leaves of this plant. It has been hypothesized that one of the main targets of SLs is the NFĸB transcription complex. It has been found that the NFĸB pathway is constitutively activated in a majority of mammary carcinoma cell lines and that NFĸB subunits are present in the cell nucleus of many breast cancer cells. Constitutive activation of this pathway in malignant cells... (More)
Medicinal plants have been used for treatment of various human diseases for a long time in history. The Ambrosia arborescens Mill. plant grows in some of the developing Latin American countries such as Ecuador, Bolivia and Peru. Ambrosia arborescens Mill, has a ubiquitous amount of sesquiterpene lactone (SL) compounds that can be extracted exclusively from the aromatic leaves of this plant. It has been hypothesized that one of the main targets of SLs is the NFĸB transcription complex. It has been found that the NFĸB pathway is constitutively activated in a majority of mammary carcinoma cell lines and that NFĸB subunits are present in the cell nucleus of many breast cancer cells. Constitutive activation of this pathway in malignant cells leads to translocation of the NFĸB protein to the nucleus, DNA binding and expression of anti-apoptotic as well as of cell cycle progression, angiogenesis, and metastasis stimulating proteins.
The purpose of the present study was to investigate the biological effect of 12 newly synthesized SL analogues and to analyse if they affected NFĸB signalling. The SL analogues were categorized into four major groups, based on the group added to the mother compound damsin by chemical synthesis. Initially the basal toxicity was evaluated using a dose response test after 72 hours of incubation with different concentrations of the SLs. Evaluation of inhibitory concentration 50 (IC50) gave at hand that JIMT-1 breast cancer cells were more sensitive than MCF-10A normal like cells to the growth inhibitory effect of SL treatment. The results show a structure activity relationship among the 12 SL analogues based on the structure of group added and its position.
Western blot was then used to evaluate the effect of SL treatment at IC50 for 72 hours on a number of proteins in the NFĸB pathway. However, there was no clear effect on most proteins investigated: p65, IκB-α, pIκB-α, p53, cyclin D1, and CDK2. The only protein showing a decreased expression after SL treatment was vimentin, which is transcriptionally regulated by NFĸB. An experimental system was developed to investigate if SL treatment could affect tumour necrosis factor α (TNFα)-induced NFκB translocation to the cell nucleus. Pre-treating JIMT-1 cells with any of the compounds at IC50 for 60 min inhibited TNFα-induced NFκB translocation. It was further shown that TNFα treatment for 60 min followed by SL treatment for 72 hours inhibited cell proliferation synergistically as each treatment alone had a lower effect.
To conclude, this work shows that SL analogues inhibit the translocation of NFκB to the nucleus and that combining SL and TNFα treatment results synergistic inhibition of cell proliferation that may be further exploited.



Supervisors: Stina Oredsson, Wendy Soria
Master´s Degree Project 45 credits in Molecular Biology
Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
author
Malakpour, Atena
supervisor
organization
course
MOBN01 20152
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8870657
date added to LUP
2016-04-04 12:13:59
date last changed
2016-04-04 12:13:59
@misc{8870657,
  author       = {Malakpour, Atena},
  language     = {eng},
  note         = {Student Paper},
  title        = {Sesquiterpene Lactone Analogues Inhibit NFκB Signaling Pathway in Breast Cancer Cells},
  year         = {2016},
}