Published on Tuesday, 28 April 2020
Abstract
We studied the effect of retinoic acid on the growth and secretory activity of the androgen-responsive prostatic carcinoma cell line LNCaP.
Our data showed that retinoic acid at 0.01 microM. stimulated the proliferation of LNCaP cells but inhibited their growth at 0.1 microM. under androgen-free conditions.
In the presence of 0.1 nM. dihydrotestosterone (DHT), LNCaP cell proliferation was inhibited by 10 microM. retinoic acid but not by lower concentrations of retinoic acid. Retinoic acid reduced LNCaP cell growth at concentrations of 0.1 microM. in the presence of 10 nM. DHT. Retinoic acid (10 microM.) also reduced the growth response of LNCaP cells to epidermal growth factor and transforming growth factor alpha and potentiated the inhibitory effect of transforming growth factor beta.
In additional studies, retinoic acid induced a dose-dependent increase in prostate specific antigen (PSA) secretion at concentrations of 0.1 to 1 microM.
Dihydrotestosterone (10 nM.) also enhanced the secretion of PSA by LNCaP cells, and this effect was potentiated in a dose-dependent fashion by the addition of retinoic acid at 0.1-10 microM. Competitive binding studies showed that retinoic acid did not bind to androgen receptors.
Overall, retinoic acid had a biphasic effect on LNCaP proliferation and promoted the secretion of PSA. The biphasic effect of retinoic acid on LNCaP growth should be considered in designing in vivo studies to determine the impact of retinoic acid on solid prostatic tumor growth.
In addition, the ability of retinoic acid to increase PSA secretion may complicate the interpretation of serum PSA levels used for diagnostic and prognostic purposes.
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See also:
- Official Web Site: The Di Bella Method;
- The Di Bella Method (A Fixed Part - All-Trans Retinoic Acid, Analogues and/or Derivatives - Approximately 60mg per day orally: 40mg per day Beta-Carotene/β-Carotene, 10mg per day ATRA and 10mg per day Axerophthol palmitate);
- All-Trans-Retinoic Acid (ATRA - analogues and/or derivatives) - In vitro, review and in vivo publications;
- Solution of retinoids in vitamin E in the Di Bella Method biological multitherapy;
- The Di Bella Method (A Fixed Part - Alpha tocopheryl acetate/Vitamin E, approximately 20 grams per day orally);
- Cancer and Vitamin E (analogues and/or derivatives) and cancer - In vitro, review and in vivo publications;
- 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);
- The Di Bella Method (A Fixed Part - Bromocriptine and/or Cabergoline);
- The Di Bella Method (A Fixed Part - Cyclophosphamide 50mg tablets and/or Hydroxyurea 500mg tablets, one or two per day);
- The Di Bella Method (DBM) in the treatment of prostate cancer: a preliminary retrospective study of 16 patients and a review of the literature;
- Congenital fibrosarcoma in complete remission with Somatostatin, Retinoids, Vitamin D3, Vitamin E, Vitamin C, Melatonin, Calcium, Chondroitin sulfate associated with low doses of Cyclophosphamide in a 14-year Follow Up.
- 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;
- Chronic Lymphocytic Leukemia: Long-Lasting Remission with Combination of Cyclophosphamide, Somatostatin, Bromocriptine, Retinoids, Melatonin, and ACTH;
- Somatostatin, retinoids, melatonin, vitamin D, bromocriptine, and cyclophosphamide in advanced non-small-cell lung cancer patients with low performance status;
- Somatostatin, retinoids, melatonin, vitamin D, bromocriptine, and cyclophosphamide in chemotherapy-pretreated patients with advanced lung adenocarcinoma and low performance status;
- Observations on the Report of a case of pulmonary adenocarcinoma with lymph node, hepatic and osseus metastasis;
- Neuroblastoma: Complete objective response to biological treatment;
- Oesophageal squamocellular carcinoma: a complete and objective response.
