Further investigation revealed that compound 28 inhibited tumor growth in an orthotopic breast-tumor model without causing hypercalcemia which is the main side effect of secosteroidal VDR modulators.
This study found that high expression of VDR in invasive breast tumors is associated with favorable prognostic factors and a low risk of breast cancer death.
The Vitamin D receptor (VDR) expressed in normal breast tissue and breast tumors has been suggested as a new prognostic biomarker in breast cancer (BC).
Furthermore, analysis of human breast tumors identified nuclear cathepsin L as a positive biomarker for TNBC, which correlates inversely with 53BP1 when vitamin D receptor (VDR) nuclear levels are low.
TN aggressive human breast tumors as well as transplantable xenografts obtained from SKBR3 expressed significantly lower levels of VDR but higher levels of CD44 expression.
In contrast, 1,25D 3 failed to alter radiosensitivity or promote autophagy in the BT474 breast tumor cell line with low-level expression of the vitamin D receptor.
Our results indicate that 24-hydroxylase, VDR and 1alpha-hydroxylase mRNA tissue expression is similar in both groups and no correlation between 24-hydroxylase, 1alpha-hydroxylase, and VDR expression in breast tumors was found.
Expression of mRNA for 1alpha-hydroxylase (27-fold; P < 5 x 10(-11)), vitamin D receptor (7-fold; P < 1.5 x 10(-8)), and 24-hydroxylase (4-fold; P < 0.02) was higher in breast tumors.