In addition, the SP showed enhanced expression of genes related to cell invasion and migration, as well as to putative (melanoma) cancer stem cells (CSC) including ABCB1 and JARID1B.
In conclusion, these novel findings imply that the MDR1(+) cells represent melanoma stem cells and thus should be considered as a unique cellular target for future anti-melanoma therapies.
All the uveal melanomas studied expressed significant levels of the MDR-related MDR1, MRP1 (MDR-related protein 1) and LRP/MVP (lung resistance protein/major vault protein) messenger RNAs (mRNAs), produced their corresponding proteins and were able to functionally extrude daunomycin.
The study evaluated the contribution of serum PS100 assay to the detection of lymph node metastases during the follow-up of patients previously treated for a malignant melanoma, in addition to (99m)Tc sestamibi (MIBI) scintigraphy and investigation for gene MDR1, in order to detect chemoresistance phenomena.
These results demonstrate that p53 mutational status is a determinant of melanoma chemosensitivity. p53 may downregulate bcl-2 and P-glycoprotein to induce apoptosis in melanoma cells after chemotherapy.