For Informed People Using Alternative Treatments

1. Evid Based Complement Alternat Med. 2013;2013:879746. doi: 10.1155/2013/879746. Epub 2013 Apr 7.

Melatonin Suppresses the Expression of 45S Preribosomal RNA and Upstream Binding Factor and Enhances the Antitumor Activity of Puromycin in MDA-MB-231 Breast Cancer Cells.

Jung JH, Sohn EJ, Shin EA, Lee D, Kim B, Jung DB, Kim JH, Yun M, Lee HJ, Park YK, Kim SH.

College of Oriental Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701, Republic of Korea.

Since the dysregulation of ribosome biogenesis is closely associated with tumor progression, in the current study, the critical role of ribosome biogenesis related signaling was investigated in melatonin and/or puromycin induced apoptosis in MDA-MB-231 breast cancer cells. Despite its weak cytotoxicity, melatonin from 3 mM attenuated the expression of 45S pre-ribosomal RNA (pre-rRNA), UBF as a nucleolar transcription factor, and fibrillarin at mRNA level and consistently downregulated nucleolar proteins such as UBF and fibrillarin at protein level in MDA-MB-231 cells. Furthermore, immunofluorescence assay revealed that UBF was also degraded by melatonin in MDA-MB- 231 cells. In contrast, melatonin attenuated the expression of survival genes such as Bcl- xL, Mcl-1, cyclinD1, and cyclin E, suppressed the phosphorylation of AKT, mTOR, and STAT3, and cleaved PARP and activated caspase 3 only at a high concentration of 12?mM. However, combined treatment of melatonin (3?mM) and puromycin (1?μM) synergistically inhibited viability, attenuated the expression of 45S pre-rRNA and UBF, and consistently downregulated UBF, XPO1 and IPO7, procaspase 3, and Bcl-xL in MDA-MB 231 cells. Overall, these findings suggest that melatonin can be a cancer preventive agent by combination with puromycin via the inhibition of 45S pre-rRNA and UBF in MDA-MB 231 breast cancer cells.

PMCID: PMC3638601 PMID: 23690862 [PubMed - in process]

2. Oncol Rep. 2013 May;29(5):2058-64. doi: 10.3892/or.2013.2314. Epub 2013 Feb 28.

Melatonin modulates aromatase activity and expression in endothelial cells.

Alvarez-García V, González A, Martínez-Campa C, Alonso-González C, Cos S.

Department of Physiology and Pharmacology, School of Medicine, University of Cantabria, 39011 Santander, Spain.

Melatonin is known to suppress the development of endocrine-responsive breast cancers by interacting with the estrogen signaling pathways. Paracrine interactions between malignant epithelial cells and proximal stromal cells are responsible for local estrogen biosynthesis. In human breast cancer cells and peritumoral adipose tissue, melatonin downregulates aromatase, which transforms androgens into estrogens. The presence of aromatase on endothelial cells indicates that endothelial cells may contribute to tumor growth by producing estrogens. Since human umbilical vein endothelial cells (HUVECs) express both aromatase and melatonin receptors, the aim of the present study was to evaluate the ability of melatonin to regulate the activity and expression of aromatase on endothelial cells, thus, modulating local estrogen biosynthesis. In the present study, we demonstrated that melatonin inhibits the growth of HUVECs and reduces the local

biosynthesis of estrogens through the downregulation of aromatase. These results are supported by three lines of evidence. Firstly, 1 mM of melatonin counteracted the testosterone-induced cell proliferation of HUVECs, which is dependent on the local biosynthesis of estrogens from testosterone by the aromatase activity of the cells. Secondly, we found that 1 mM of melatonin reduced the aromatase activity of HUVECs. Finally, by real-time RT-PCR, we demonstrated that melatonin significantly downregulated the expression of aromatase as well as its endothelial-specific aromatase promoter region I.7. We conclude that melatonin inhibits aromatase activity and expression in HUVECs by regulating gene expression of specific aromatase promoter regions, thereby reducing the local production of estrogens.

PMID: 23450505 [PubMed - in process]

3. BMC Cell Biol. 2013 Jan 7;14:1. doi: 10.1186/1471-2121-14-1.

Melatonin enhances DNA repair capacity possibly by affecting genes involved in DNA damage responsive pathways.

Liu R, Fu A, Hoffman AE, Zheng T, Zhu Y.

Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, China.

BACKGROUND: Melatonin, a hormone-like substance involved in the regulation of the circadian rhythm, has been demonstrated to protect cells against oxidative DNA damage and to inhibit tumorigenesis. RESULTS: In the current study, we investigated the effect of melatonin on DNA strand breaks using the alkaline DNA comet assay in breast cancer (MCF-7) and colon cancer (HCT-15) cell lines. Our results demonstrated that cells pretreated with melatonin had significantly shorter Olive tail moments compared to non- melatonin treated cells upon mutagen (methyl methanesulfonate, MMS) exposure, indicating an increased DNA repair capacity after melatonin treatment. We further examined the genome-wide gene expression in melatonin pretreated MCF-7 cells upon carcinogen exposure and detected altered expression of many genes involved in multiple DNA damage responsive pathways. Genes exhibiting altered expression were further analyzed for functional interrelatedness using network- and pathway-based bioinformatics analysis. The top functional network was defined as having relevance for "DNA Replication, Recombination, and Repair, Gene Expression, [and] Cancer". CONCLUSIONS: These findings suggest that melatonin may enhance DNA repair capacity by affecting several key genes involved in DNA damage responsive pathways.

PMCID: PMC3543845 PMID: 23294620 [PubMed - in process]

4. J Pineal Res. 2012 Aug 16. doi: 10.1111/jpi.12007. [Epub ahead of print]

Regulation of vascular endothelial growth factor by melatonin in human breast cancer cells.

Alvarez-García V, González A, Alonso-González C, Martínez-Campa C, Cos S.

Department of Physiology and Pharmacology, School of Medicine, University of Cantabria, Santander, Spain.

Melatonin exerts oncostatic effects on breast cancer by interfering with the estrogen- signaling pathways. Melatonin reduces estrogen biosynthesis in human breast cancer cells, surrounding fibroblasts and peritumoral endothelial cells by regulating cytokines that influence tumor microenvironment. This hormone also exerts antiangiogenic activity in tumoral tissue. In this work, our objective was to study the role of melatonin on the regulation of the vascular endothelial growth factor (VEGF) in breast cancer cells. To accomplish this, we cocultured human breast cancer cells (MCF-7) with human umbilical vein endothelial cells (HUVECs). VEGF added to the cultures stimulated the proliferation of HUVECs and melatonin (1 mm) counteracted this effect. Melatonin reduced VEGF production and VEGF mRNA expression in MCF-7 cells. MCF-7 cells cocultured with HUVECs stimulated the endothelial cells proliferation and increased VEGF levels in the culture media. Melatonin counteracted both stimulatory effects on HUVECs proliferation and on VEGF protein levels in the coculture media. Conditioned media from MCF-7 cells increased HUVECs proliferation, and this effect was significantly counteracted by anti- VEGF and 1 mm melatonin. All these findings suggest that melatonin may play a role in the paracrine interactions between malignant epithelial cells and proximal endothelial cells through a downregulatory action on VEGF expression in human breast cancer cells, which decrease the levels of VEGF around endothelial cells. Lower levels of VEGF could be important in reducing the number of estrogen-producing cells proximal to malignant cells as well as decreasing tumoral angiogenesis.

© 2012 John Wiley & Sons A/S.

PMID: 23013414 [PubMed - as supplied by publisher]

5. Cell Mol Life Sci. 2013 Jun;70(12):2139-2157. Epub 2012 Sep 25. Molecular mechanisms of melatonin's inhibitory actions on breast cancers. Proietti S, Cucina A, Reiter RJ, Bizzarri M.

Department of Clinical and Molecular Medicine, University "La Sapienza", Rome, Italy.

Melatonin is involved in many physiological functions and it plays an important role in many pathological processes as well. Melatonin has been shown to reduce the incidence of experimentally induced cancers and can significantly inhibit the growth of some human tumors, namely hormone-dependent cancers. The anticancer effects of melatonin have been observed in breast cancer, both in in vivo with models of chemically induced rat mammary tumors, and in vitro studies on human breast cancer cell lines. Melatonin acts at different physiological levels and its antitumoral properties are supported by a set of complex, different mechanisms of action, involving apoptosis activation, inhibition of proliferation, and cell differentiation.

PMID: 23007844 [PubMed - as supplied by publisher]

6. J Pineal Res. 2012 Jun 27. doi: 10.1111/j.1600-079X.2012.01027.x. [Epub ahead of print]

Genome-wide profiling in melatonin-exposed human breast cancer cell lines identifies differentially methylated genes involved in the anticancer effect of melatonin.

Lee SE, Kim SJ, Yoon HJ, Yu SY, Yang H, Jeong SI, Hwang SY, Park CS, Park YS. Department of Microbiology, School of Medicine, Kyung Hee University, Seoul, Korea.

Epigenetic alterations have emerged as an important mechanism involved in tumorigenesis. The epigenetic impact of DNA methylation in various types of human cancer is not completely understood. Previously, we observed melatonin-induced differential expression of miRNA and miRNA-related genes in human breast cancer cell lines that indicated an anticancer effect of melatonin. In this report, we further characterized epigenetic changes in melatonin-exposed MCF-7 cells through the analysis of DNA methylation profiles in breast cancer cells to provide new insights into the potential mechanisms of the anticancer effect of melatonin. Microarray-based DNA methylation and gene expression profiling were carried out using human breast cancer cell lines. We further identified a number of mRNAs whose expression levels show an inverse correlation with DNA methylation levels. The mRNA expression levels and methylation status of candidate genes in melatonin-exposed cells were confirmed by real-time quantitative PCR and bisulfite PCR. This approach led to the detection of cancer-related genes, which were oncogenic genes, including EGR3 and POU4F2/Brn-3b were down-regulated, while the tumor suppressor gene, GPC3, was up-regulated by 1 nm melatonin-treated MCF-7 cells. Our results provide detailed insights into the DNA methylation patterns induced by melatonin and suggest a

potential mechanism of the anticancer effect of aberrant DNA methylation in melatonin- treated breast cancer cells.

© 2012 John Wiley & Sons A/S.

PMID: 22856590 [PubMed - as supplied by publisher]

7. Expert Opin Investig Drugs. 2012 Jun;21(6):819-31. doi: 10.1517/13543784.2012.681045. Epub 2012 Apr 16.

Melatonin uses in oncology: breast cancer prevention and reduction of the side effects of chemotherapy and radiation.

Sanchez-Barcelo EJ, Mediavilla MD, Alonso-Gonzalez C, Reiter RJ.

University of Cantabria, Department of Physiology & Pharmacology, 39011 Santander, Spain. barcelo@unican.es

INTRODUCTION: The possible oncostatic properties of melatonin on different types of neoplasias have been studied especially in hormone-dependent adenocarcinomas. Despite the promising results of these experimental investigations, the use of melatonin in breast cancer treatment in humans is still uncommon. AREAS COVERED: This article reviews the usefulness of this indoleamine for specific aspects of breast cancer management, particularly in reference to melatonin's antiestrogenic and antioxidant properties: i) treatments oriented to breast cancer prevention, especially when the risk factors are obesity, steroid hormone treatment or chronodisruption by exposure to light at night (LAN); ii) treatment of the side effects associated with chemo- or radiotherapy. EXPERT OPINION: The clinical utility of melatonin depends on the appropriate identification of its actions. Because of its SERM (selective estrogen receptor modulators) and SEEM (selective estrogen enzyme modulators) properties, and its virtual absence of contraindications, melatonin could be an excellent adjuvant with the drugs currently used for breast cancer prevention (antiestrogens and antiaromatases). The antioxidant actions also make melatonin a suitable treatment to reduce oxidative stress associated with chemotherapy, especially with anthracyclines, and radiotherapy.

PMID: 22500582 [PubMed - indexed for MEDLINE]

8. Breast Cancer Res Treat. 2012 Apr;132(2):765-71. doi: 10.1007/s10549-012-1953-4. Epub 2012 Jan 12.

Melatonin suppresses aromatase expression and activity in breast cancer associated fibroblasts.

Knower KC, To SQ, Takagi K, Miki Y, Sasano H, Simpson ER, Clyne CD.

Cancer Drug Discovery Laboratory, Prince Henry's Institute of Medical Research, PO Box 5152, Clayton, VIC 3168, Australia. kevin.knower@princehenrys.org

The main biological active substance secreted by the pineal gland, melatonin (MLT), counteracts the effects of estrogens in breast cancer via exerting a number of its own oncostatic properties. Recent studies of postmenopausal women have identified that the major metabolite of MLT is statistically significantly associated with a lower risk of developing breast cancer. While MLT production decreases with age, breast cancer risk, however, increases with age and obesity. We hypothesize that MLT inhibits estrogen production in breast adipose fibroblasts (BAFs), the main local source of estrogen in breast tumors of postmenopausal women, by inhibiting transcription of the CYP19A1 gene that encodes the key enzyme aromatase. Normal BAFs were cultured from women undergoing breast reduction surgery, while breast cancer-associated fibroblasts (CAFs) were isolated from three women with estrogen receptor (ER) positive invasive ductal carcinomas. MTNR1A and MTNR1B receptor expression and CYP19A1 mRNA expression following MLT treatments were determined by qRT-PCR. BAFs express the G-protein coupled MLT receptors MTNR1A and MTNR1B with elevated levels of MTNR1A found in CAFs. Treatment of BAFs and CAFs with MLT resulted in significant suppression of CYP19A1 transcription and aromatase activity at pharmacological, physiological and sub- physiological concentrations. MLT suppression occurred through promoter-specific PI.4-, PI.3- and PII-derived CYP19A1 mRNA. Stimulation of CYP19A1 PII-mRNA and aromatase activity by prostaglandin E(2) (PGE(2)) were significantly attenuated by physiological doses of MLT. Lower levels of MLT in aging women may increase the risk of progressing ER- positive breast cancer through a decreased ability to suppress CYP19A1 expression and subsequent local estrogen production in BAFs/CAFs.

PMID: 22237979 [PubMed - indexed for MEDLINE]

9. J Pineal Res. 2012 Apr;52(3):282-90. doi: 10.1111/j.1600-079X.2011.00940.x. Epub 2011 Dec 12.

Melatonin interferes in the desmoplastic reaction in breast cancer by regulating cytokine production.

Alvarez-García V, González A, Alonso-González C, Martínez-Campa C, Cos S.

Department of Physiology and Pharmacology, School of Medicine, University of Cantabria, Santander, Spain.

Melatonin exerts oncostatic effects on breast cancer by interfering with the estrogen signaling pathways. Melatonin inhibits aromatase enzyme in breast cancer cells and fibroblasts. In addition, melatonin stimulates the adipogenic differentiation of fibroblasts. Our objective was to study whether melatonin interferes in the desmoplastic reaction by regulating some factors secreted by malignant cells, tumor necrosis factor (TNF)-a, interleukin (IL)-11, and interleukin (IL)-6. To accomplish this, we co-cultured 3T3-L1 cells with MCF-7 cells. The addition of breast cancer cells to the co-cultures inhibited the differentiation of 3T3-L1 preadipocytes to mature adipocytes, by reducing the intracytoplasmic triglyceride accumulation, an indicator of adipogenic differentiation, and also stimulated their aromatase activity. Melatonin counteracted the inhibitory effect on adipocyte differentiation and aromatase activity induced by MCF-7 cells in 3T3-L1 cells. The levels of cytokines in the co-culture media were 10 times those found in culture of 3T3-L1 cells alone. Melatonin decreased the concentrations of cytokines in the media and counteracted the stimulatory effect induced by MCF-7 cells on the cytokine levels. One millimolar melatonin induced a reduction in TNF-a, IL-6, and IL-11 mRNA expression in MCF-7 and 3T3-L1 cells. The findings suggest that melatonin may play a role in the desmoplastic reaction in breast cancer through a downregulatory action on the expression of antiadipogenic cytokines, which decrease the levels of these cytokines. Lower levels of cytokines stimulate the differentiation of fibroblasts and decrease both aromatase activity and expression, thereby reducing the number of estrogen-producing cells proximal to malignant cells.

© 2011 John Wiley & Sons A/S.

PMID: 22151118 [PubMed - indexed for MEDLINE]

10. Recent Pat Endocr Metab Immune Drug Discov. 2011 May;5(2):109-23.

Melatonin, immune function and cancer.

Srinivasan V, Pandi-Perumal SR, Brzezinski A, Bhatnagar KP, Cardinali DP.

Sri Sathya Sai Medical Educational and Research Foundation, Prasanthi Nilayam, 40-Kovai Thirunagar Coimbatore-641014, India. sainivasan@yahoo.com

Melatonin is a natural substance ubiquitous in distribution and present in almost all species ranging from unicellular organisms to humans. In mammals, melatonin is synthesized not only in the pineal gland but also in many other parts of the body, including the eyes, bone

marrow, gastrointestinal tract, skin and lymphocytes. Melatonin influences almost every cell and can be traced in membrane, cytoplasmic, mitochondrial and nuclear compartments of the cell. The decline in the production of melatonin with age has been suggested as one of the major contributors to immunosenescence and development of neoplastic diseases. Melatonin is a natural antioxidant with immunoenhancing properties. T-helper cells play an important role for protection against malignancy and melatonin has been shown to enhance T-helper cell response by releasing interleukin-2, interleukin-10 and interferon-?. Melatonin is effective in suppressing neoplastic growth in a variety of tumors like melanoma, breast and prostate cancer, and ovarian and colorectal cancer. As an adjuvant therapy, melatonin can be beneficial in treating patients suffering from breast cancer, hepatocellular carcinoma or melanoma. In this paper, a brief review of recent patents on melatonin and cancer has also been presented.

PMID: 22074586 [PubMed - indexed for MEDLINE]