Inhibition of CYP27B1 and CYP24 Increases the Anti-proliferative Effects of 25-Hydroxyvitamin D 3 in LNCaP Cells

Abstract

Background/aim: Growing evidence suggests that vitamin D3 exerts anticancer effects. The present study aimed to evaluate 25-hydroxyvitamin D3 (25(OH)D3) as a potential endocrine factor regulating proliferation and vitamin D receptor expression in LNCaP prostate cancer cells.

Materials and methods: Cell counting after treatment was utilized to assess the effect of 25(OH)D3 on cell proliferation. Changes in mRNA expression of the vitamin D receptors, VDR and PDIA3, were evaluated using droplet digital polymerase chain reaction (ddPCR).

Results: 25(OH)D3 inhibited cell proliferation in a dose- and time-dependent manner. The inhibitory effect of 25(OH)D3 on cell proliferation was potentiated after inhibition of CYP17B1 and CYP24 by genistein, preventing further metabolism of 25(OH)D3 to 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3). Expression of PDIA3 and VDR mRNA increased after treatment with 25(OH)D3, whereas the ratio between PDIA3 and VDR mRNA remained unchanged.

Conclusion: 25(OH)D3 has a direct inhibitory effect on cell proliferation, which is enhanced and accelerated when the metabolism of 25(OH)D3 to 1,25(OH)2D3 and 24,25(OH)2D3 was inhibited by the CYP17B1 and CYP24 inhibitor genistein. Furthermore, treatment with 25(OH)D3 increased receptor transcript expression, suggesting an increased VDR stability and sensibility of the treated cells.

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See also:

- Official Web Site: The Di Bella Method;

- The Di Bella Method (A Fixed Part - Dihydrotachysterol, Alfacalcidol, synthetic Vitamin D3);

- Vitamin D (analogues and/or derivatives) and cancer - In vitro, review and in vivo publications;

- The Di Bella Method (A Fixed Part - Calcium, 2 grams per day, orally);

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

- The Di Bella Method (A Fixed Part - Bromocriptine and/or Cabergoline);

- The Di Bella Method (A Fixed Part - Somatostatin, Octreotide, Sandostatin LAR, analogues and/or derivatives);

- Somatostatin in oncology, the overlooked evidences - In vitro, review and in vivo publications;

- Publication, 2018 Jul: Over-Expression of GH/GHR in Breast Cancer and Oncosuppressor Role of Somatostatin as a Physiological Inhibitor (from Di Bella's Foundation);

- Publication, 2018 Sep: The over-expression of GH/GHR in tumour tissues with respect to healthy ones confirms its oncogenic role and the consequent oncosuppressor role of its physiological inhibitor, somatostatin: a review of the literature (from Di Bella's Foundation);

- Publication, 2019 Aug: The Entrapment of Somatostatin in a Lipid Formulation: Retarded Release and Free Radical Reactivity (from Di Bella's Foundation);

- Publication, 2019 Sep: Effects of Somatostatin and Vitamin C on the Fatty Acid Profile of Breast Cancer Cell Membranes (from Di Bella's Foundation);

- Publication, 2019 Sep: Effects of somatostatin, curcumin, and quercetin on the fatty acid profile of breast cancer cell membranes (from Di Bella's Foundation);

- Publication, 2020 Sep: Two neuroendocrine G protein-coupled receptor molecules, somatostatin and melatonin: Physiology of signal transduction and therapeutic perspectives (from Di Bella's Foundation);

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

- 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;

- 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;

- Neuroblastoma: Complete objective response to biological treatment;

- Oesophageal squamocellular carcinoma: a complete and objective response;

- Pancreatic Adenocarcinoma: clinical records on 17 patients treated with Di Bella's Method;

- The Di Bella Method Increases by the 30% the survival rate for Pancreas tumors and for this reason should be proposed as first line therapy for this type of cancer.