calcipotriene and Lung-Neoplasms

Low vitamin D status is considered as a risk factor for breast cancer and has prognostic significance. Furthermore, vitamin D deficiency increases after adjuvant cancer therapy, which alters bone metabolism increasing the risk of osteoporosis. It is now postulated that vitamin D supplementation in breast cancer treatment delays the recurrence of cancer thereby extending survival. We evaluated the impact of calcitriol and its low-calcemic analogs, PRI‑2191 and PRI‑2205, on the tumor growth, angiogenesis, and metastasis of 4T1 mouse mammary gland cancer. Gene expression analysis related to cancer invasion/metastasis, real‑time PCR, ELISA, western blotting, and histochemical studies were performed. In vitro studies were conducted to compare the effects of calcitriol and its analogs on 4T1 and 67NR cell proliferation and expression of selected proteins. Calcitriol and its analogs increased lung metastasis without influencing the growth of primary tumor. The levels of plasma 17β-estradiol and transforming growth factor β (TGFβ) were found to be elevated after treatment. Moreover, the results showed that tumor blood perfusion improved and osteopontin (OPN) levels increased, whereas vascular endothelial growth factor (VEGF) and TGFβ levels decreased in tumors from treated mice. All the studied treatments resulted in increased collagen content in the tumor tissue in the early step of tumor progression, and calcitriol caused an increase in collagen content in lung tissue. In addition, in vitro proliferation of 4T1 tumor cells was not found to be affected by calcitriol or its analogs in contrast to non-metastatic 67NR cells. Calcitriol and its analogs enhanced the metastatic potential of 4T1 mouse mammary gland cancer by inducing the secretion of OPN probably via host cells. In addition, OPN tumor overexpression prevailed over the decreasing tumor TGFβ level and blood vessel normalization via tumor VEGF deprivation induced by calcitriol and its analogs. Moreover, the increased plasma TGFβ and 17β-estradiol levels contributed to the facilitation of metastatic process.

Topics: Animals; Calcitriol; Cell Growth Processes; Cell Line, Tumor; Dihydroxycholecalciferols; Female; Lung Neoplasms; Mammary Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Neoplasm Metastasis; Neovascularization, Pathologic; Real-Time Polymerase Chain Reaction; Tumor Microenvironment

A group of deltanoids has been used for studying the inhibition of cell growth and proliferation in two small cell lung carcinoma (SCLC) in vitro. The biologically active deltanoid, 1,25 dihydroxyvitamin D3 (1,25 (OH)2D3), has functions beyond its classical roles of stimulating calcium transport and serum calcium. It also causes the differentiation of a variety of precursor cells and suppresses growth. Although 1,25(OH)2D3 has an inhibitory effect on growth of certain malignant cells, its hypercalcemic effect has prevented clinical applications. Several new deltanoids, which showed comparable or even greater abilities to induce differentiation and to inhibit proliferation, have been identified. Furthermore, these synthetic deltanoids have been shown to be less effective on calcium metabolism and less hypercalcemic. We have selected four synthetic deltanoids; MC-903, 1 alpha-OH-pregnacalciferol, 19-nor-24 homo, and 19-nor-22(E). When compared with 1,25 (OH)2D3, these deltanoids showed considerable potency on cell growth and proliferation in the NCI-H82 and the NCI-H209 SCLC lines. Cells were treated with various concentrations of deltanoids. They inhibited the growth and proliferation of both SCLC cells in vitro in a time-and dose-dependent manner, as determined by cell number and 3H-thymidine uptake. 19-nor-22(E) showed an antiproliferative effect significantly comparable to 1,25(OH)2D3 in the NCI-H82 cell line 1 alpha-OH-pregnacalciferol, 19-nor-24 homo, and 19-nor-22(E) inhibited the cell growth in the NCI-H209 cells within the same significance as 1,25 (OH)2D3. The degree of the suppressive effect of the deltanoids was cell line dependent.

Topics: Calcitriol; Carcinoma, Small Cell; Cell Division; Dihydroxycholecalciferols; Dose-Response Relationship, Drug; Humans; Hypercalcemia; Lung Neoplasms; Structure-Activity Relationship; Tumor Cells, Cultured