The induction of apoptosis in human cervical carcinoma (HeLa) cells by gamma-linolenic acid

Autor: T.C. Viljoen, Christina J.S. Grobler, M. le Roux, Mona-Liza Lottering, M. De Kock, J.C. Seegers
Rok vydání: 1996
Předmět:
Programmed cell death
Transcription
Genetic
Proto-Oncogene Proteins c-jun
Clinical Biochemistry
Apoptosis
Enzyme-Linked Immunosorbent Assay
DNA Fragmentation
Protein Serine-Threonine Kinases
S Phase
Flow cytometry
Proto-Oncogene Proteins c-myc
HeLa
chemistry.chemical_compound
Proliferating Cell Nuclear Antigen
Proto-Oncogene Proteins
Cyclic AMP
medicine
Humans
cardiovascular diseases
gamma-Linolenic Acid
gamma-Linolenic acid
medicine.diagnostic_test
biology
G1 Phase
nutritional and metabolic diseases
DNA
Cell Biology
Flow Cytometry
biology.organism_classification
Molecular biology
Proliferating cell nuclear antigen
Proto-Oncogene Proteins c-raf
Biochemistry
chemistry
Cell culture
Calcium-Calmodulin-Dependent Protein Kinases
biology.protein
DNA fragmentation
lipids (amino acids
peptides
and proteins)
hormones
hormone substitutes
and hormone antagonists
HeLa Cells
Zdroj: Prostaglandins, Leukotrienes and Essential Fatty Acids. 55:403-411
ISSN: 0952-3278
DOI: 10.1016/s0952-3278(96)90123-4
Popis: A high concentration (50 micrograms/ml) of gamma-linolenic acid (GLA) induced morphological lesions typical of apoptosis, as well as DNA fragmentation, in HeLa cells. A lower concentration of GLA (20 micrograms/ml), caused an increased proliferating cell nuclear antigen (PCNA) labelling, with 92.7% cells positive, compared to 27.7% at a concentration of 50 micrograms/ml GLA. In correlation with these results, the number of cells with degraded DNA below the G0/G1 peak increased significantly in the 50 micrograms/ml GLA-treated cells, but increased only slightly in cells exposed to the lower level of GLA. The high levels of PCNA induced by 20 micrograms/ml GLA, in both G1 and S phases, may indicate a state of DNA repair synthesis, whilst at the higher concentration of GLA, most of the cells became apoptotic. Since apoptosis is associated with the deregulation of c-Myc expression, and as the Raf-1-MAP kinase cascade activates the expression of c-Myc and c-Jun, we investigated the effects of 20 and 50 micrograms/ml GLA on the Raf-1, c-Myc and c-Jun levels, and on the activity of MAP kinase. The results showed that 50 micrograms/ml GLA lowered the activity of MAP kinase. As expected with the decreased MAP kinase activity in the cells exposed to the higher level GLA, the c-Jun levels were also lowered. The levels of c-Myc, however, were increased. It is therefore possible that the deregulated expression of c-Myc in the HeLa cells exposed to the high level of GLA (50 micrograms/ml) may contribute to the induction of apoptosis in HeLa cells.
Databáze: OpenAIRE
Externí odkaz: