β-carotene alters the morphology of NHI-H69 small cell lung cancer cells

Abstract

The effect of β-carotene on the morphology of NCI-H69 small cell lung cancer cells that had undergone βcarotene-induced growth reduction (P < 0.05) was examined. The cells were grown at 1 × 108 cells/L and were cultured with or without 20 μmol/L β-carotene. The qualitative electron microscopic observations revealed that β-carotene-treated cells contained more vacuoles than control cells not treated with β-carotene. The quantitative image analysis showed a significantly smaller (P < 0.05) value of the nuclear roundness factor for treated cells compared with control cells, indicating an irregular nuclear morphology of β-carotene-treated cells. The major diameter of the cells and the minor diameter of the nuclei were significantly smaller (P < 0.05), and the nuclear perimeter was significantly larger (P < 0.05) in β-carotene-treated cells. The ratio of nucleus to cytoplasm was significantly less (P < 0.05) in β-carotene-treated cells compared with control cells, indicating a less malignant growth of the cells. These results demonstrate that the treatment of small cell lung cancer cells with β-carotene induces morphological changes in the cells concomitant with a reduction in their proliferation. Further investigation is required to show a direct effect of β-carotene or its intracellular polar metabolites on the morphology of these cells.