Phyllodes tumor of the breast: role of Axl and ST6GalNAcII in the development of mammary phyllodes tumors.

Abstract

Phyllodes tumor exhibits an aggressive growth. The expression of many biological markers has been explored to discriminate between different grades of phyllodes tumor and to predict their behavior. The purpose of this study was to evaluate the implications of Axl and ST6GalNAcII in phyllodes tumors. Real-time PCR, Western blot, and immunohistochemical were used to analyze differential expression of ST6GalNAcII and Axl in phyllodes tumor (PT) cell lines and tissue specimens. RNAi assay, ECM invasion assay, and tumorigenicity assay were used to analyze the altered expression of ST6GalNAcII gene effects on the expression of Axl and invasive ability of phyllodes tumor cells in vitro and in vivo. Compared to benign tumors, borderline and malignant ones showed a remarkable increase in mRNA levels of Axl and ST6GalNAcII gene, and it was higher in malignant tumor cells than in borderline tumor cells. When ST6GalNAcII was silenced, compared to the control, the expression level of Axl was significantly reduced in malignant tumor cell transfectants and knockdown of ST6GalNAcII gene significantly inhibited invasive activity in malignant tumor cells. The high expression of ST6GalNAcII and Axl was significantly correlated with tumor grade and distance metastasis by immunohistochemical analysis. Axl and ST6GalNAcII expression increases with increasing tumor grade in mammary phyllodes tumors. ST6GalNAc II might be participated in the glycosylation of Axl, and this Axl glycosylation may mediate the tumorigenicity, invasion, and distant metastasis of PT cells.

• Authors: Dongliang Ren, Yanyan Li, Yanxin Gong, Jingchao Xu, Xiaolong Miao, Xiangnan Li, Chen Liu, Li Jia, Yongfu Zhao
• Journal: Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine (Tumour Biol) Vol. 35 Issue 10 Pg. 9603-12 (Oct 2014) ISSN: 1423-0380 [Electronic] Netherlands
• PMID: 24961352 (Publication Type: Journal Article, Retracted Publication)

Chemical References

• Proto-Oncogene Proteins
• Sialyltransferases
• galactosyl-1-3-N-acetylgalactosaminyl-specific 2,6-sialyltransferase
• Receptor Protein-Tyrosine Kinases
• Axl Receptor Tyrosine Kinase

Topics

• Adult
• Aged
• Animals
• Blotting, Western
• Breast Neoplasms (metabolism, pathology)
• Female
• Heterografts
• Humans
• Immunohistochemistry
• Mice
• Middle Aged
• Neoplasm Invasiveness
• Phyllodes Tumor (metabolism, pathology)
• Proto-Oncogene Proteins (biosynthesis)
• Real-Time Polymerase Chain Reaction
• Receptor Protein-Tyrosine Kinases (biosynthesis)
• Sialyltransferases (biosynthesis)
• Tissue Array Analysis
• Transcriptome
• Axl Receptor Tyrosine Kinase