Expression of BMP6 is Associated with its Methylation Status in Colorectal Cancer Tissue but Lacks Prognostic Significance

  • Published : 2014.09.15


Background: The study aimed to evaluate the incidence of CpG island promoter methylation of BMP6, a member of the transforming growth factor beta family, in tissue samples from colorectal cancers (CRC) and look for its association with BMP6 expression and clinicopathological correlation. Materials and Methods: Methylation specific PCR for the BMP6 promoter region was performed with 85 frozen tissue samples of CRC and 45 of normal colon. Methylation status of MLH1 was also determined by the same method. Expression of BMP6 was evaluated by immunohistochemistry (IHC), using Allred's scoring system. The methylation status was analyzed against clinical and pathological parameters in CRC. Results: The study revealed BMP6 hypermethylation in 34 of 85 tumor specimens (40%), and 15 out of 45 normal tissue samples from CRC (33%). The incidence of hypermethylation was inversely correlated with IHC score. Allred's scores of 7 or more were correlated with lower frequency of BMP6 hypermethylation (29% compared to 50% in the remaining, p-value 0.049). However, there was no association between hypermethylation status and any clinicopathological parameters. The methylation status of BMP6 was not correlated with that of MLH1, a key methylation determinant in CRC. On survival analysis, there was no significant difference in progress-free survival (PFS) between the cases with and without hypermethylation (2-year PFS 74% and 76%, respectively). Conclusions: CpG island methylation of BMP6 is found in high frequency in CRC and this epigenetic event is associated with suppressed protein expression in the tumor tissue. However, the marker is not associated with tumor progression of the disease.


  1. Choudhury KR, Yagle KJ, Swanson PE, et al (2010). A robust automated measure of average antibody staining in immunohistochemistry images. J Histochem Cytochem, 58, 95-107.
  2. Bejrananda T, Phukaoloun M, Boonpipattanapong T, et al (2010-2011). WT1 expression as an independent marker of poor prognosis in colorectal cancers. Cancer Biomark, 8, 35-42.
  3. Chaiyapan W, Duangpakdee P, Boonpipattanapong T, et al (2013). Somatic mutations of K-ras and BRAF in Thai colorectal cancer and their prognostic value. Asian Pac J Cancer Prev, 14, 329-32.
  4. Du J, Yang S, An D, et al (2009). BMP-6 inhibits microRNA-21 expression in breast cancer through repressing delta EF1 and AP-1. Cell Res, 19, 487-96.
  5. Fang WJ, Zheng Y, Wu LM, et al (2012). Genome-wide analysis of aberrant DNA methylation for identification of potential biomarkers in colorectal cancer patients. Asian Pac J Cancer Prev, 13, 1917-21.
  6. Hebrok M, Kim SK, Jacques BS, et al (2000). Regulation of pancreas development by hedgehog signaling. Development, 127, 4905-13.
  7. Herman JG, Umar A, Polyak K, et al (1998). Incidence and functional consequences of hMLH1 promoter hypermethylation in colorectal carcinoma. Proc Natl Acad Sci USA, 95, 6870-5.
  8. Imai N, Iwai A, Hatakeyama S, et al (2001). Expression of bone morphogenetic proteins in colon carcinoma with heterotopic ossification. Pathol Int, 51, 643-8.
  9. Jemal A, Bray F, Center MM, et al (2011). Global cancer statistics. CA Cancer J Clin, 61, 69-90.
  10. Khuhaprema T, Srivatanakul P (2008). Colon and rectum cancer in Thailand: an overview. Jpn J Clin Oncol, 38, 237-43.
  11. Kim IY, Lee DH, Lee DK, et al (2003). Decreased expression of bone morphogenetic protein (BMP) receptor type II correlates with insensitibity to BMP-6 in human renal cell carcinoma cells. Clinical Cancer Res, 9, 6046-51.
  12. Kim MS, Lee J, Sidransky D (2010). DNA methylation markers in colorectal cancer. Cancer Metastasis Rev, 29, 181-206.
  13. Alexander C, Piloto S, Le Pabic P, et al (2014). Wnt signaling interacts with bmp and edn1 to regulate dorsal-ventral patterning and growth of the craniofacial skeleton. PLoS Genet, 10, 1004479.
  14. Barekati Z, Radpour R, Lu Q, et al (2012). Methylation signature of lymph node metastases in breast cancer patients. BMC Cancer, 12, 244.
  15. Kimura K, Toyooka S, Tsukuda K, et al (2008). The aberrant promoter methylation of BMP3b and BMP6 in malignant pleural mesotheliomas. Oncol Rep, 20, 1265-8.
  16. Kraunz KS, Nelson HH, Liu M, et al (2005). Interaction between the bone morphogenetic proteins and Ras/MAP-kinase signaling pathways in lung cancer. Br J Cancer, 93, 949-52.
  17. Lee GT, Kang DI, Ha YS, et al (2014). Prostate cancer bone metastases acquire resistance to androgen deprivation via WNT5A-mediated BMP-6 induction. Br J Cancer, 110, 1634-44.
  18. Liu G, Liu YJ, Lian WJ, et al (2014). Reduced BMP6 expression by DNA methylation contributes to EMT and drug resistance in breast cancer cells. Oncol Rep, 32, 581-8.
  19. Lowery JW, de Caestecker MP (2010). BMP signaling in vascular development and disease. Cytokine Growth Factor Reviews, 21, 287-98.
  20. Pederson L, Ruan M, Westendorf JJ, et al (2008) Regulation of bone formation by osteoclasts involves Wnt/BMP signaling and the chemokine sphingosine-1-phosphate. Proc Natl Acad Sci USA, 105, 20764-9.
  21. Perr HA, Ye J, Gitelman SE (1999). Smooth muscle expresses bone morphogenetic protein (Vgr-1/BMP-6) in human fetal intestine. Biol Neonate, 75, 210-4.
  22. Ro TB, Holt RU, Brenne AT, et al (2004). Bone morphogenetic protein-5, -6 and -7 inhibit growth and induce apoptosis in human myeloma cells. Oncogene, 23, 3024-32.
  23. Sammons J, Ahmed N, El-Sheemy M, et al (2004). The role of BMP-6, IL-6, and BMP-4 in mesenchymal stem celldependent bone development: effects on osteoblastic differentiation induced by parathyroid hormone and vitamin D(3). Stem Cells Dev, 13, 273-80.
  24. Spanjol J, Djordjevic G, Markic D, et al (2010). Role of bone morphogenetic proteins in human prostate cancer pathogenesis and development of bone metastases: immunohistochemical study. Coll Antropol, 34, 119-25.
  25. Tamada H, Kitazawa R, Gohji K, et al (2001). Epigenetic regulation of human bone morphogenetic protein 6 gene expression in prostate cancer. J Bone Miner Res, 16, 487-95.
  26. Taniguchi A, Nemoto Y, Yokoyama A, et al (2008). Promoter methylation of the bone morphogenetic protein-6 gene in association with adult T-cell leukemia. Int J Cancer, 123, 1824-31.
  27. Xiao YT, Xiang LX, Shao JZ (2007). Bone morphogenetic protein. Biochem Biophys Res Commun, 362, 550-3.
  28. Yuen HF, Chan YP, Cheung WL, et al (2008). The prognostic significance of BMP-6 signaling in prostate cancer. Mod Pathol, 21, 1436-43.
  29. Zhang M, Wang Q, Yuan W, et al (2007). Epigenetic regulation of bone morphogenetic protein-6 gene expression in breast cancer cells. J Steroid Biochemistry Mol Biol, 105, 91-7.

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