PDZK1 Interacting Protein 1 Promotes the Progression of Papillary Thyroid Cancer

miR-101-3p-mediated role of PDZK1 in hepatocellular carcinoma progression and the underlying PI3K/Akt signaling mechanism

BACKGROUND

The molecular targets and associated mechanisms of hepatocellular carcinoma (HCC) have been widely studied, but the roles of PDZK1 in HCC are unclear. Therefore, the aim of this study is to explore the role and associated mechanisms of PDZK1 in HCC.

RESULTS

It was found that the expression of PDZK1 in HCC tissues was higher than that in paired paracancerous tissues. High expression of PDZK1 was associated with lymph node metastasis, degree of differentiation, and clinical stage. Upregulation of PDZK1 in HCC cells affected their proliferation, migration, invasion, apoptosis, and cell cycle, and also induced PI3K/AKT activation. PDZK1 is a downstream target gene of miR-101-3p. Accordingly, increase in the expression of miR-101-3p reversed the promotive effect of PDZK1 in HCC. Moreover, PDZK1 was found to accelerate cell proliferation and promote the malignant progression of HCC via the PI3K/AKT pathway.

CONCLUSION

Our study indicated that the miR-101-3p/PDZK1 axis plays a role in HCC progression and could be beneficial as a novel biomarker and new therapeutic target for HCC treatment.

Downregulation of cellular retinoic acid binding protein 1 fosters epithelial-mesenchymal transition in thyroid cancer

Cellular retinoic acid binding protein 1 (CRABP1) participates in the regulation of retinoid signaling. Previous studies showed conflicting results regarding the role of CRABP1 in tumor biology, including protumorigenic and tumor-suppressive effects in different types of cancer. Our bioinformatics analyses suggested that CRABP1 expression was downregulated in thyroid cancer. Ectopic expression of CRABP1 in thyroid cancer cells suppressed migratory and invasive activity without affecting cell growth or cell cycle distribution. In transformed normal thyroid follicular epithelial cells, silencing of CRABP1 expression increased invasiveness. Additionally, CRABP1 overexpression was associated with downregulation of the mesenchymal phenotype. Kinase phosphorylation profiling indicated that CRABP1 overexpression was accompanied by a decrease in phosphorylation of epidermal growth factor (EGF) receptor and downstream phosphorylation of Akt, STAT3, and FAK, which were reversed by exogenous EGF treatment. Immunohistochemical analysis of our tissue microarrays revealed an inverse association between CRABP1 expression and disease stage of differentiated thyroid cancer. Taken together, our results suggest that CRABP1 expression is aberrantly lost in thyroid cancer, and this downregulation promotes the epithelial-mesenchymal transition at least partly through modulating EGF receptor signaling.