Retinoic acid enhances VIP receptor expression and responsiveness in human neuroblastoma cell, SH-SY5Y

Abstract

Retinoic acid (RA) induces partial differentiation of neuroblastoma (NB) cells in vitro.

In the human NB line, SH-SY5Y (a neuroblastic subclone of SK-N-SH), RA was previously shown to enhance the stimulatory (PGE1) and inhibitory (opioid) regulation of adenylyl cyclase.

Since these cells are also sensitive to cAMP stimulation by vasoactive intestinal peptide (VIP), we have tested the effects of RA on VIP receptor expression and function.

Pretreatment of SH-SY5Y cells with 10 microM RA over 6 days dramatically increased VIP receptor number from approximately 3,000 to approximately 70,000 sites per cell and enhanced threefold the cAMP accumulation after external VIP addition, while VIP immunoreactive content in the cells increased 2-3-fold.

In the light of the recently proposed autocrine function of VIP in this cell lineage, the strong enhancement of the VIP system may contribute to the differentiation effects of RA.

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See also:

- All-Trans-Retinoic Acid (ATRA - analogues and/or derivatives);

- The Di Bella Method (A Fixed Part - All-Trans Retinoic Acid, Analogues and/or Derivatives);

- The Di Bella Method (A Fixed Part - Alpha tocopheryl acetate/Vitamin E);

- Neuroblastoma: Complete objective response to biological treatment;

- The Di Bella Method DBM improved survival objective response and performance status in a retrospective observational clinical study on 23 tumours of the head and neck;

- Recurrent Glioblastoma Multiforme (grade IV – WHO 2007): a case of complete objective response achieved by means of the concomitant administration of Somatostatin and Octreotide – Retinoids – Vitamin E – Vitamin D3 – Vitamin C – Melatonin – D2 R agonists (Di Bella Method – DBM) associated with Temozolomide;

- Oesophageal squamocellular carcinoma: a complete and objective response.