Involvement of protein kinase C in melatonin's oncostatic effect in C6 glioma cells

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Published on Wednesday, 14 August 2019

Abstract

Classical anticancer therapies often are ineffective in patients with malignant glioma who have a survival of <1 year.

Our previous studies showed a potent inhibitory effect of melatonin on glioma cell proliferation.

This effect seems to be mediated by the well-known antioxidant properties of this molecule and the negative regulation of some intracellular effectors, such as the kinase Akt or the transcription factor nuclear factor (NF)-kappaB.

Finally, protein kinase C (PKC) also seems to be implicated in this effect although the intracellular pathways involved have not been elucidated.

In this study, we analyzed the role of PKC in the regulation by melatonin of intracellular effectors leading to inhibition of cell proliferation. Activation of PKC by incubation with triphorbol ester acetate (TPA) blocks the inhibitory effect of melatonin on Akt and NF-kappaB activity.

Moreover, incubation with melatonin induces a decrease in p21 expression in these cells that is partially blocked by co-incubation with TPA.

Taken together, these results suggest that melatonin's oncostatic effect on glioma cells is mediated, at least in part, by the inhibition of PKC activity which, in turn, results in Akt and NF-kappaB activity inhibition and modulation of cell cycle-related gene expression.

 

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See also:

- Official Web Site: The Di Bella Method;

- The Di Bella Method (A Fixed Part - Melatonin tablets. From 30-40mg/day up to 200mg/day orally in patients with advanced stage of cancer disease and/or patients without respond to traditional treatments);

- Melatonin with adenosine solubilized in water and stabilized with glycine for oncological treatment - technical preparation, effectivity and clinical findings;

- About Melatonin - In vitro, review and in vivo publications;

- The Di Bella Method (A Fixed Part - Cyclophosphamide 50mg tablets and/or Hydroxyurea 500mg tablets, one or two per day);

- 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;

- 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;

- The Synergism of Somatostatin, Melatonin, Vitamins Prolactin and Estrogen Inhibitors Increased Survival, Objective Response and Performance Status In 297 Cases of Breast Cancer;

- Complete objective response, stable for 5 years, with the Di Bella Method, of multiple-metastatic carcinoma of the breast;

- Evaluation of the safety and efficacy of the first-line treatment with somatostatin combined with melatonin, retinoids, vitamin D3, and low doses of cyclophosphamide in 20 cases of breast cancer: a preliminary report;

- The Di Bella Method (DBM) improved survival, objective response and performance status in a retrospective observational clinical study on 122 cases of breast cancer;

- Complete objective response to biological therapy of plurifocal breast carcinoma;

- Neuroblastoma: Complete objective response to biological treatment;

- Oesophageal squamocellular carcinoma: a complete and objective response;

- The Di Bella Method (DBM) in the treatment of prostate cancer: a preliminary retrospective study of 16 patients and a review of the literature.