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Altered sialylation is closely associated with tumor progression and invasiveness. Micro-RNAs endogenous regulators of gene expression have been implicated in human thyroid carcinoma invasiveness. The objective of this study is to examine the alterations of miR-4299 and ST6GALNAC family in human follicular thyroid carcinoma during metastatic process. qRT-PCR showed the differential expressional profiles of miR-4299 and ST6GALNAC family in three kinds of thyroid cell lines (FTC-133,FTC-238, Nthy-ori 3-1) and clinical tissue specimens(malignant and borderline). The altered expression levels of ST6GALNAC4 were corresponding to invasive phenotypes of FTC-133 and FTC-238 cells both in vitro and in vivo. Further date indicated that miR-4299 regulated tumor progression and invasiveness by directly targeting ST6GALNAC4. This study implies the potential therapeutic application of miR-4299 and ST6GALNAC4 in modulating the invasion and tumorigenicity of follicular thyroid carcinoma cell. © 2015 IUBMB Life, 68(2):136-144, 2016 [ABSTRACT FROM AUTHOR]

The invasion and chemoresistance are crucial causes of morbidity and relapse for cancer patients. Axl is implicated in the modulation of cell invasion, cancer metastasis, and chemosensitivity in human breast carcinoma cell lines. Both breast cancer cell lines and tissues displayed increased expression of Axl, and it over expressed in highly metastatic breast cancer. The altered expression level of Axl was corresponding to the changed invasive phenotype and chemosensitivity of MDA-MB-231 cells both in vitro and in vivo. Further data indicated that experimental inhibition of Axl by RNAi assay inhibited phosphatidylinositol 3-kinase (PI3K)/Akt/GSK3β signaling pathway, resulted in the decrease of Slug expression, and further suppressed cell invasion properties and chemosensitivity. What is more, after the detection and statistics in human breast cancer specimens, we found the Axl expression was closely correlated with histological grade, lymph node metastasis, and clinical stage ( P < 0.01). Taken together, these findings indicate that Axl exerts the role of tumor metastasis and chemosensitivity through activation of the PI3K/Akt/GSK3β signaling pathway, which is transcriptionally regulated by Slug. Our findings support the possibility that Axl is a novel regulator. It means by targeting Axl or its related signaling pathways, we can reduce the invasion and chemosensitivity of breast tumor. © 2014 IUBMB Life, 66(7):507-518, 2014 [ABSTRACT FROM AUTHOR]

Metastasis of tumor cells is the most deadly attribute of breast cancer patients. Aberrant sialylation is closely associated with malignant phenotype of tumor cells, including invasiveness and metastasis. The objective of this study is to clarify the possible role and mechanism of ST6GalNAcII in the metastasis process of breast carcinoma. Real-time PCR, Western blot, and immunohistochemical were used to analyze differential expression of ST6GalNAc II in breast carcinoma cell lines and tissue specimens. PI3K/AKt signaling pathway was also analyzed. The high expression level of ST6GalNAcII was corresponding to invasive phenotype of breast cancer cells both in vitro and in vivo. Further data indicated that manipulation of ST6GalNAcII gene expression led to alter the activity of phosphoinositide-3 kinase (PI3K)/Akt signaling pathway. Blocking the PI3K/Akt pathway resulted in reduced capacity in invasion of MDA-MB-231 cells. ST6GalNAcII elucidated the unusual properties of invasion in breast cancer cell via modulating the PI3K/AKt signaling pathway. © 2014 IUBMB Life, 66(4):300-308, 2014 [ABSTRACT FROM AUTHOR]