Lipotrope deficiency inhibits cell growth and induces programmed cell death in human breast cancer cell line MCF-7

To determine the effects of lipotrope modification on breast cancer cell growth and cell death, the human breast cancer cell line MCF-7 was assigned to grow in one of three lipotrope treatment media for four days. The treatment media included lipotrope-control medium (LCM), containing all required lipotropes; lipotrope-deficient medium (LDM), lacking all lipotropes but supplying homocysteine instead; and lipotrope-additive medium (LAM), containing twice as much of each lipotrope as LCM. Cell count and [3H]thymidine incorporation into DNA revealed that LDM slowed cell growth and inhibited cell proliferation in the MCF-7 cell line. Gel electrophoresis showed significant DNA degradation with the appearance of fragments in LDM-treated cells, whereas the DNA in LCM and LAM cells was largely intact. The LDM group displayed more apoptotic bodies as detected by in situ immunohistochemistry. The gene expression level of bcl-2 was lower in cells treated with LDM than in those treated with LCM and LAM, whereas p53 gene expression did not appear different among the three treatment groups. It is concluded that lipotrope deficiency inhibits cell growth and induces programmed cell death in the human breast cancer cell line MCF-7.