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Li HB, Huang G, Tu J, Lv DM, Jin QL, Chen JK, Zou YT, Lee DF, Shen JN, Xie XB. METTL14-mediated epitranscriptome modification of MN1 mRNA promote tumorigenicity and all-trans-retinoic acid resistance in osteosarcoma. EBioMedicine 2022; 82:104142. [PMID: 35810559 PMCID: PMC9272358 DOI: 10.1016/j.ebiom.2022.104142] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 06/15/2022] [Accepted: 06/21/2022] [Indexed: 11/29/2022] Open
Abstract
Background Osteosarcoma (OS) is the most common primary malignant bone tumor in adolescents. The molecular mechanism behind OS progression and metastasis remains poorly understood, which limits the effectiveness of current therapies. RNA N6-methyladenosine (m6A) modification plays a critical role in influencing RNA fate. However, the biological significance of m6A modification and its potential regulatory mechanisms in the development of OS remain unclear. Methods Liquid chromatography-tandem mass spectrometry (LC-MS/MS), dot blotting, and colorimetric ELISA were used to detect m6A levels. Western blotting, quantitative real-time PCR (RT-qPCR) and immunohistochemistry (IHC) were used to investigate METTL14 expression levels. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and transcriptomic RNA sequencing (RNA-seq) were used to screen the target genes of METTL14. RNA pull-down and RNA immunoprecipitation (RIP) assays were conducted to explore the specific binding of target genes and relevant m6A “readers”. RNA stability and polysome analysis assays were used to detect the half-lives and translation efficiencies of the downstream genes of METTL14. IHC and clinical data were applied to explore the clinical correlations of METTL14 and its downstream target genes with the prognosis of OS. Findings We observed the abundance of m6A modifications in OS and revealed that METTL14 plays an oncogenic role in facilitating OS progression. MeRIP-seq and RNA-seq revealed that MN1 is a downstream gene of METTL14. MN1 contributes to tumor progression and all-trans-retinoic acid (ATRA) chemotherapy resistance in OS. Mechanistically, MN1 is methylated by METTL14, specifically in the coding sequence (CDS) regions, and this modification is recognized by the specific m6A reader insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) to prevent MN1 mRNA degradation and promote it translation efficiency. IHC showed that MN1 expression was positively correlated with METTL14 and IGF2BP2 expression in OS tissues. The METTL14-IGF2BP2-MN1 panel demonstrated more promising prognostic value for OS patients than any of these molecules individually. Interpretation Our study revealed that METTL14 contributes to OS progression and ATRA resistance as an m6A RNA methylase by regulating the stability and translation efficiency of MN1 and thus provides both an underlying biomarker panel for prognosis prediction in OS patients. Funding This work was supported by the National Natural Science Foundation of China (Grants 81972510 and 81772864).
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Affiliation(s)
- Hong-Bo Li
- Department of Musculoskeletal Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China; Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Gang Huang
- Department of Musculoskeletal Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China; Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Jian Tu
- Department of Musculoskeletal Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China; Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Dong-Ming Lv
- Department of Musculoskeletal Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China; Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Qing-Lin Jin
- Department of Musculoskeletal Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China; Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Jun-Kai Chen
- Department of Musculoskeletal Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China; Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Yu-Tong Zou
- Department of Musculoskeletal Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China; Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Dung-Fang Lee
- Department of Integrative Biology & Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, TX 77030-1501, US
| | - Jing-Nan Shen
- Department of Musculoskeletal Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China; Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.
| | - Xian-Biao Xie
- Department of Musculoskeletal Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China; Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.
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Zanetti A, Affatato R, Centritto F, Fratelli M, Kurosaki M, Barzago MM, Bolis M, Terao M, Garattini E, Paroni G. All-trans-retinoic Acid Modulates the Plasticity and Inhibits the Motility of Breast Cancer Cells: ROLE OF NOTCH1 AND TRANSFORMING GROWTH FACTOR (TGFβ). J Biol Chem 2015; 290:17690-17709. [PMID: 26018078 DOI: 10.1074/jbc.m115.638510] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Indexed: 01/06/2023] Open
Abstract
All-trans-retinoic acid (ATRA) is a natural compound proposed for the treatment/chemoprevention of breast cancer. Increasing evidence indicates that aberrant regulation of epithelial-to-mesenchymal transition (EMT) is a determinant of the cancer cell invasive and metastatic behavior. The effects of ATRA on EMT are largely unknown. In HER2-positive SKBR3 and UACC812 cells, showing co-amplification of the ERBB2 and RARA genes, ATRA activates a RARα-dependent epithelial differentiation program. In SKBR3 cells, this causes the formation/reorganization of adherens and tight junctions. Epithelial differentiation and augmented cell-cell contacts underlie the anti-migratory action exerted by the retinoid in cells exposed to the EMT-inducing factors EGF and heregulin-β1. Down-regulation of NOTCH1, an emerging EMT modulator, is involved in the inhibition of motility by ATRA. Indeed, the retinoid blocks NOTCH1 up-regulation by EGF and/or heregulin-β1. Pharmacological inhibition of γ-secretase and NOTCH1 processing also abrogates SKBR3 cell migration. Stimulation of TGFβ contributes to the anti-migratory effect of ATRA. The retinoid switches TGFβ from an EMT-inducing and pro-migratory determinant to an anti-migratory mediator. Inhibition of the NOTCH1 pathway not only plays a role in the anti-migratory action of ATRA; it is relevant also for the anti-proliferative activity of the retinoid in HCC1599 breast cancer cells, which are addicted to NOTCH1 for growth/viability. This effect is enhanced by the combination of ATRA and the γ-secretase inhibitor N-(N-(3,5-difluorophenacetyl)-l-alanyl)-S-phenylglycine t-butyl ester, supporting the concept that the two compounds act at the transcriptional and post-translational levels along the NOTCH1 pathway.
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Affiliation(s)
- Adriana Zanetti
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano, Italy
| | - Roberta Affatato
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano, Italy
| | - Floriana Centritto
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano, Italy
| | - Maddalena Fratelli
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano, Italy
| | - Mami Kurosaki
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano, Italy
| | - Maria Monica Barzago
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano, Italy
| | - Marco Bolis
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano, Italy
| | - Mineko Terao
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano, Italy
| | - Enrico Garattini
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano, Italy
| | - Gabriela Paroni
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano, Italy.
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Peixoto PV, Klem MA, França TN, Nogueira VA. Hipervitaminose D em animais. PESQUISA VETERINARIA BRASILEIRA 2012. [DOI: 10.1590/s0100-736x2012000700001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Por meio de revisão da literatura, são apresentados dados referentes ao metabolismo da vitamina D, bem como aos principais aspectos toxicológicos, clínicos, bioquímicos, macroscópicos, microscópicos, ultraestruturais, imuno-histoquímicos e radiográficos de animais intoxicados natural e experimentalmente por essa vitamina, em diferentes espécies. Este estudo objetiva demonstrar a existência de muitas lacunas no conhecimento sobre mineralização fisiológica e patológica, em especial na mediação hormonal do fenômeno, bem como alertar para os riscos de ocorrência dessa intoxicação.
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Park EY, Pinali D, Lindley K, Lane MA. Hepatic vitamin A preloading reduces colorectal cancer metastatic multiplicity in a mouse xenograft model. Nutr Cancer 2012; 64:732-40. [PMID: 22642873 PMCID: PMC3829719 DOI: 10.1080/01635581.2012.687425] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Previous research in our laboratory showed that retinol inhibited all-trans retinoic acid (ATRA)-resistant human colon cancer cell invasion via a retinoic acid receptor-independent mechanism in vitro. The objective of the current study was to determine if dietary vitamin A supplementation inhibited metastasis of ATRA-resistant colon cancer cells in a nude mouse xenograft model. Female nude mice (BALB/cAnNCr-nu/nu, n = 14 per group) consumed a control diet (2,400 IU retinyl palmitate/kg diet) or a vitamin A supplemented diet (200,000 IU retinyl palmitate/kg diet) for 1 mo prior to tumor cell injection to preload the liver with vitamin A. HCT-116, ATRA-resistant, human colon cancer cells were intrasplenically injected. Mice continued to consume their respective diets for 5 wk following surgery. Consumption of supplemental vitamin A decreased hepatic metastatic multiplicity to 17% of control. Hepatic and splenic retinol and retinyl ester concentrations were significantly higher in the mice supplemented with vitamin A when compared to mice consuming the control diet. Supplemental vitamin A did not decrease body weight, feed intake, or cause toxicity. Thus, supplemental dietary vitamin A may decrease the overall number of hepatic metastasis resulting from colon cancer.
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Affiliation(s)
| | - Daniel Pinali
- School of Family and Consumer Sciences, Nutrition and Foods Program, Texas State University—San Marcos, San Marcos, TX 78666, USA
| | - Krista Lindley
- School of Family and Consumer Sciences, Nutrition and Foods Program, Texas State University—San Marcos, San Marcos, TX 78666, USA
| | - Michelle A. Lane
- School of Family and Consumer Sciences, Nutrition and Foods Program, Texas State University—San Marcos, San Marcos, TX 78666, USA
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Gallagher R, Keighley J, Tancabelic J, Garimella R, Pinson D, Templeton K, Tawfik O. Clinicopathologic correlation of vitamin D receptor expression with retinoid X receptor and MIB-1 expression in primary and metastatic osteosarcoma. Ann Diagn Pathol 2012; 16:323-9. [PMID: 22542077 DOI: 10.1016/j.anndiagpath.2012.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 01/26/2012] [Accepted: 01/27/2012] [Indexed: 01/05/2023]
Abstract
Vitamin D, in addition to its effects on bone, is important in cell cycle regulation. Vitamin D receptor (VDR) has been identified in breast, prostate, and colon cancers, as well as in canine and human osteosarcoma (OS) cell lines; however, it has not been well investigated in human OS-archived specimens. We correlated VDR, retinoid X receptor (RXR), and MIB-1 (Ki-67) expression in 110 archived OS cases with several clinicopathologic parameters including patient's age, sex, tumor location, tumor grade, and type and metastatic status. The expression of VDR and RXR was identified in human OS tissue obtained from primary and metastatic OS archival tissue. No statistically significant difference was found in VDR expression in relation with tumor grade, type, age, sex, or location. The expression of RXR was highest in higher-grade (P = .0006) and metastatic tumors but remained unchanged when correlated with tumor type, age, sex, or location. The expression of MIB-1 was statistically elevated in higher-grade tumors (P = .001), patients 25 years or younger (P = .04), tumors located in extremities (P = .005), and metastatic lesions, but was not impacted by tumor type or patient's sex. Proliferative activity was significantly reduced after treatment, as the mean MIB-1 expression dropped from 11% in primary biopsy samples to 6% in resection specimens. There appears to be a relationship between proliferative tumor activity and tumor grade, location, and metastasis. Additional studies on the analysis of the effects of vitamin D and RXR on OS proliferation, apoptosis, and differentiation are critical to further evaluate their potential role in OS treatment.
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Affiliation(s)
- Ryan Gallagher
- Department of Pathology and Laboratory Medicine, Kansas University Medical Center, Kansas City, USA
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Goupil RC, Bushey JJ, Peters-Kennedy J, Wakshlag JJ. Prevalence of 5-lipoxygenase expression in canine osteosarcoma and the effects of a dual 5-lipoxygenase/cyclooxygenase inhibitor on osteosarcoma cells in vitro and in vivo. Vet Pathol 2012; 49:802-10. [PMID: 22287649 DOI: 10.1177/0300985811432350] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Canine osteosarcoma is an insidious disease with few effective treatment modalities; therefore, use of pharmacologic intervention to improve mortality or morbidity is constantly sought. The use of cyclooxygenase enzyme inhibitors has been an area of interest with limited efficacy based on retrospective examination of tumor expression and in vivo cell proliferation models. Recently, examination of dual cyclooxygenase and 5-lipoxygenase inhibitors in human and canine oncology suggests that 5-lipoxygenase inhibitors may be an effective approach in vitro and during tumor induction in rodent models. Therefore, the authors decided to examine 5-lipoxygenase expression in primary canine osteosarcoma samples and have shown that approximately 65% of osteosarcomas label positive for cytoplasmic 5-lipoxygenase. Further examination of a cell culture and xenograft model shows similar 5-lipoxygenase expression. Surprisingly, a canine 5-lipoxygenase inhibitor (tepoxalin) significantly reduced cell proliferation at physiologic doses in vitro and diminished xenograft tumor growth in nude mice, suggesting that further investigation is needed. Traditionally, 5-lipoxygense leads to production of lipid mediators, such as leukotriene B(4) and 5-oxo-eicosatetraenoic acid, which, when added back to the media of tepoxalin-treated cells, did not recover cell proliferation. The lack of nuclear staining in primary and xenografted tumors and the lack of response to eicoasanoids suggest that lipid mediator production is not the primary means by which tepoxalin acts to alter proliferation. Regardless of the mechanisms involved in retarding cell proliferation, future investigation is warranted.
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Affiliation(s)
- R C Goupil
- Department of Clinical Sciences, Cornell University College of Veterinary Medicine, VMC 1-120, Box 34, Ithaca, NY 14853, USA
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Malone EK, Rassnick KM, Wakshlag JJ, Russell DS, Al-Sarraf R, Ruslander DM, Johnson CS, Trump DL. Calcitriol (1,25-dihydroxycholecalciferol) enhances mast cell tumour chemotherapy and receptor tyrosine kinase inhibitor activity in vitro and has single-agent activity against spontaneously occurring canine mast cell tumours*. Vet Comp Oncol 2010; 8:209-20. [DOI: 10.1111/j.1476-5829.2010.00223.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Coomer AR, Farese JP, Milner R, Taylor D, Salute ME, Rajon DA, Bova FJ, Siemann DW. Development of an intramuscular xenograft model of canine osteosarcoma in mice for evaluation of the effects of radiation therapy. Am J Vet Res 2009; 70:127-33. [PMID: 19119958 DOI: 10.2460/ajvr.70.1.127] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To develop an IM xenograft model of canine osteosarcoma in mice for the purpose of evaluating effects of radiation therapy on tumors. ANIMALS 27 athymic nude mice. PROCEDURES Mice were randomly assigned to 1 of 3 groups of 9 mice each: no treatment (control group), radiation at 10 Gy, or radiation at 15 Gy. Each mouse received 5 x 10(5) highly metastasizing parent osteosarcoma cells injected into the left gastrocnemius muscle. Maximum tumor diameter was determined with a metric circles template to generate a tumor growth curve. Conscious mice were restrained in customized plastic jigs allowing local tumor irradiation. The behavior and development of the tumor xenograft were assessed via evaluations of the interval required for tumor-bearing limbs to reach diameters of 8 and 13 mm, extent of tumor vasculature, histomorphology of tumors, degree of tumor necrosis, and existence of pulmonary metastasis and clinical disease in affected mice. RESULTS Tumor-bearing limbs grew to a diameter of 8 mm (0.2-g tumor mass) in a mean +/- SEM interval of 7.0 +/- 0.2 days in all mice. Interval to grow from 8 to 13 mm was significantly prolonged for both radiation therapy groups, compared with that of the control group. Histologic evaluation revealed the induced tumors were highly vascular and had characteristics consistent with those of osteosarcoma. Pulmonary metastasis was not detected, and there was no significant difference in percentage of tumor necrosis between groups. CONCLUSIONS AND CLINICAL RELEVANCE A reliable, repeatable, and easily produced IM xenograft model was developed for in vivo assessment of canine osteosarcoma.
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Affiliation(s)
- Alastair R Coomer
- Departments of Small Animal Clinical Sciences College of Medicine, University of Florida, Gainesville, FL 32610, USA
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Giovannucci E. The epidemiology of vitamin D and cancer incidence and mortality: a review (United States). Cancer Causes Control 2005; 16:83-95. [PMID: 15868450 DOI: 10.1007/s10552-004-1661-4] [Citation(s) in RCA: 432] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Accepted: 07/27/2004] [Indexed: 11/30/2022]
Abstract
In vitro and animal studies indicate that vitamin D may have anti-cancer benefits, including against progression and metastasis, against a wide spectrum of cancers. Supporting an anti-cancer effect of vitamin D is the ability of many cells to convert 25(OH)D, the primary circulating form of vitamin D, into 1,25(OH)2D, the most active form of this vitamin. No epidemiologic studies have directly measured vitamin D concentrations or intakes on risk of total cancer incidence or mortality. However, higher rates of total cancer mortality in regions with less UV-B radiation, and among African-Americans and overweight and obese people, each associated with lower circulating vitamin D, are compatible with a benefit of vitamin D on mortality. In addition, poorer survival from cancer in individuals diagnosed in the months when vitamin D levels are lowest suggests a benefit of vitamin D against late stages of carcinogenesis. The only individual cancer sites that have been examined directly in relation to vitamin D status are colorectal, prostate and breast cancers. For breast cancer, some data are promising for a benefit from vitamin D but are far too sparse to support a conclusion. The evidence that higher 25(OH)D levels through increased sunlight exposure or dietary or supplement intake inhibit colorectal carcinogenesis is substantial. The biologic evidence for an anti-cancer role of 25(OH)D is also strong for prostate cancer, but the epidemiologic data have not been supportive. Although not entirely consistent, some studies suggest that higher circulating 1,25(OH)2D may be more important than 25(OH)D for protection against aggressive, poorly-differentiated prostate cancer. A possible explanation for these divergent results is that unlike colorectal tumors, prostate cancers lose the ability to hydroxylate 25(OH)D to 1,25(OH)2D, and thus may rely on the circulation as the main source of 1,25(OH)2D. The suppression of circulating 1,25(OH)2D levels by calcium intake could explain why higher calcium and milk intakes appear to increase risk of advanced prostate cancer. Given the potential benefits from vitamin D, further research should be a priority.
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Affiliation(s)
- Edward Giovannucci
- Channing Laboratory, Department of Medicine, Harvard Medical School and Brigham and Women's Hospital, 181 Longwood Avenue, Boston, MA 02115, USA.
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Nakagawa K, Sasaki Y, Kato S, Kubodera N, Okano T. 22-Oxa-1alpha,25-dihydroxyvitamin D3 inhibits metastasis and angiogenesis in lung cancer. Carcinogenesis 2005; 26:1044-54. [PMID: 15718253 DOI: 10.1093/carcin/bgi049] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
1alpha,25-Dihydroxyvitamin D(3) (1alpha,25-D(3)) has potent antiproliferative and anti-invasive properties in vitro in cancer cells. However, its calcemic effect in vivo limits its therapeutic applications. Here, we report the efficacy of 22-oxa-1alpha,25-dihydroxyvitamin D(3) (22-oxa-1alpha,25-D(3)), a low calcemic analog of vitamin D, against the development of metastatic lung carcinoma after an intravenous injection of green fluorescent protein-transfected Lewis lung carcinoma (LLC-GFP) cells in C57BL/6 mice. The mice injected with tumor cells were implanted simultaneously with osmotic minipumps containing either 1alpha,25-D(3), 22-oxa-1alpha,25-D(3) or vehicle. The 1alpha,25-D(3) treatment group had been hypercalcemic, but the 22-oxa-1alpha,25-D(3) and vehicle treatment groups remained normocalcemic for the duration of the experiment. The total number of lung metastases, lung weight and the expression of GFP mRNA in the lung were markedly decreased in 1alpha,25-D(3) and 22-oxa-1alpha,25-D(3)-treated mice. In the in vitro experiment, 1alpha,25-D(3) and 22-oxa-1alpha,25-D(3) reduced the expression of matrix metalloproteinase (MMP)-2, MMP-9, vascular endothelial growth factor and parathyroid hormone-related protein in LLC-GFP cells. Furthermore, in the angiogenesis assay, the number of tumor cells or basic fibroblast growth factor-induced angiogenesis was reduced in 1alpha,25-D(3) and 22-oxa-1alpha,25-D(3)-treated mice. Moreover, using a new experimental model of vitamin D receptor (VDR) null mutant (VDR(-/-)) mice with corrected hypocalcemia and hypervitaminosis D, we examine the anti-cancer effect of 22-oxa-1alpha,25-D(3) without other functions induced by 22-oxa-1alpha,25-D(3) in the host. In the VDR(-/-) mice, 22-oxa-1alpha,25-D(3) directly inhibited the metastatic activity of LLC-GFP cells in a dose-dependent manner without exerting a direct influence on the calcemic activity or other actions regulated by 22-oxa-1alpha,25-D(3) in the host. These results indicate that the inhibition of metastasis and angiogenesis-inducing activity in cancer cells seemed to be a major mechanism responsible for the anti-cancer effects of 22-oxa-1alpha,25-D(3). Our findings show that 22-oxa-1alpha,25-D(3) is beneficial for the prevention of metastasis in lung carcinoma.
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Affiliation(s)
- Kimie Nakagawa
- Department of Hygienic Sciences, Kobe Pharmaceutical University, Japan
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