Regulation of cellular adhesion and fibronectin synthesis by 1 alpha,25-dihydroxyvitamin D3 | JoVE Visualize

Regulation of cellular adhesion and fibronectin synthesis by 1 alpha,25-dihydroxyvitamin D3

The Journal of Biological Chemistry|March 25, 1987

View abstract on PubMed

Summary

The steroid hormone 1 alpha,25-dihydroxyvitamin D3 (1,25-(OH)2D3) enhances cell adhesion by significantly increasing fibronectin (FN) synthesis and FN mRNA levels in various cancer cells. This suggests a potential role in cell differentiation and metastasis.

Area of Science:

Molecular Biology
Cell Biology
Endocrinology

Background:

Previous research indicated that 1 alpha,25-dihydroxyvitamin D3 (1,25-(OH)2D3) affects cell growth, morphology, and fibronectin (FN) levels in MG-63 human osteosarcoma cells.
Fibronectin is a key extracellular matrix protein involved in cell adhesion and other cellular processes.

Purpose of the Study:

To investigate the hypothesis that 1,25-(OH)2D3 enhances cellular adhesion by stimulating fibronectin (FN) synthesis.
To determine the kinetics and specificity of the 1,25-(OH)2D3-induced FN response.
To examine the effect of 1,25-(OH)2D3 on FN synthesis in other transformed cell lines.

Main Methods:

MG-63 human osteosarcoma cells were treated with 1,25-(OH)2D3.
Cell morphology, cell/substratum adhesion, and fibronectin (FN) production were assessed.
Fibronectin mRNA levels were measured using Northern blot hybridization.
Comparisons were made with other vitamin D metabolites and triamcinolone acetonide.

Main Results:

1,25-(OH)2D3 treatment altered cell morphology and increased cell/substratum adhesion in MG-63 cells, mimicking effects of exogenous FN.
A rapid and significant increase in FN synthesis (2-5 fold) was observed within 48 hours of 1,25-(OH)2D3 treatment, without affecting FN stability or distribution.
Fibronectin mRNA levels increased within 6 hours, with maximal induction at 24 hours, indicating transcriptional regulation.
The FN response was specific to 1,25-(OH)2D3, with other vitamin D metabolites showing minimal effect, and triamcinolone acetonide having only slight stimulatory effects.
1,25-(OH)2D3 also stimulated FN synthesis in TE-85 osteosarcomas, SW-480 colon carcinomas, and HL-60 myeloid leukemia cells.

Conclusions:

1 alpha,25-dihydroxyvitamin D3 (1,25-(OH)2D3) enhances cellular adhesion in MG-63 cells by stimulating fibronectin (FN) synthesis, likely through increased FN mRNA.
The findings suggest a potential role for 1,25-(OH)2D3 in modulating cell differentiation and tumor metastasis through its effects on fibronectin.