Beta-carotene's metabolism, distribution and influence upon cell proliferation and structure in NCl-H69 small cell lung cancer cells
Delivery of $\beta$-carotene in tetrahydrofuran slowed the growth of NCl-H69 small cell lung cancer cells. Analysis of cells and cellular fractions revealed that treated cells accumulated $\beta$-carotene as well as some polar metabolites, primarily in the crude nuclei. Cells were grown at concentrations (cells/ml) of $5\times10\sp4,$ $1\times10\sp5$ and $2\times10\sp5$ and treated with 20 $\mu$M and 40 $\mu$M $\beta$-carotene. Growth monitoring upto 25 days indicated an inverse relationship between the duration of $\beta$-carotene treatment and the rate of growth of the cells. Reverse-phase HPLC analysis of treated cells showed the presence of $\beta$-carotene, $\beta$-apo-12$\sp\prime$-carotenal, $\beta$-apo-8$\sp\prime$-carotenal, retinoic acid, retinol and retinal, with $\beta$-carotene accounting for the major material recovered. When cellular fractions were analyzed for $\beta$-carotene, it was found to be located primarily in the crude nuclei. The qualitative electron microscopic observation revealed $\beta$-carotene treated cells to contain more vacuoles and lipid droplets than control cells, indicating a more differentiated phenotype. Quantitative image analysis showed a decrease (p $<$ 0.05) in nuclear regularity and a decrease (p $<$ 0.05) in ratio of nucleus to cytoplasm in $\beta$-carotene treated cells, suggesting a less malignant phenotype.^ These results demonstrate that treatment of small cell lung cancer cells with $\beta$-carotene results in a reduced growth of the cells with concomitant changes in morphology. Further investigation is required to show a direct effect of $\beta$-carotene or its intracellular polar metabolites on these cells. Accumulation of $\beta$-carotene in the nucleus suggests a potential nuclear role. ^
Biology, Cell|Health Sciences, Nutrition|Health Sciences, Oncology
"Beta-carotene's metabolism, distribution and influence upon cell proliferation and structure in NCl-H69 small cell lung cancer cells"
Dissertations and Master's Theses (Campus Access).