Objective

To test if retinoic acid (RA) can induce differentiation of  Human Neuroblastoma cancer stem cell line (SH-SY5Y) into normal neurons and offer a chance for cure for patients with Neuroblastoma.

Background:

Neuroblastoma is a neurological malignancy with high relapse rate and mortality in young children despite optimal treatment.

Retinoic acid (RA), a compound of vitamin A, can induce cell differentiation. It is used as treatment in acute promyelocytic leukemia by inducing differentiation of cancer cells. Whether RA can induce differentiation of Neuroblastoma cancer stem cell line SH-SY5Y is unknown. 

Material and methods

• SH-SY5Y  human neuroblastoma stem cells.

• RA, 1.25, 2.5, 5 and 10 micromolar (mm) concentrations, prepared along with 2% and 10% Fetal bovine serum (FBS) media. 

• Cells are plated in wells of 2% and 10% FBS and incubated for 24 hours.

• RA concentrations from 1.25 to 10 mm added to wells with 2% and 10% FBS. 

• Media replaced daily for 5 days.

• Plate fixed using phosphate buffered saline.

• Stain for neurons using 0.1% Triton X-100

• TUJ1 primary antibody and secondary antibody mIgC129 added. 

• Cells imaged for differentiation into neurons under fluorescent microscope 

Results

RA incremental concentrations from 1.25 to 10 mm concentration were tested with FBS of 2% and 1 %. FBS poor media resulted in cell death. Concentration of RA  below 5 mm did not induce optimal cell differentiation.

The optimal concentration of 10 mm retinoic acid and 10% fetal bovine serum effectively induces the differentiation of neuroblastoma stem cell lines into neurons, presenting a potential therapeutic strategy.

Conclusion:

Neuroblastoma is a high-risk malignancy in children. This study suggests that retinoic acid, in combination with the optimal concentration of fetal bovine serum, can induce differentiation of the SH-SY5Y human neuroblastoma stem cell line. Testing retinoic acid in vivo should be considered, as it may offer a potential chance for cure for neuroblastoma patients.