Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C1522282 (EMT)
 2,868 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Poly r(C) binding protein (PCBP) 1 or heterogeneous ribonucleoprotein (hnRNP) E1 is a RNA binding protein functional in multiple biological processes. PCBP1 has been shown to function as a tumor suppressor by negatively regulating translation of EMT inducer proteins in different cancers. Loss of PCBP1 expression or its Akt2-mediated phosphorylation at serine residue 43 has both been indicated to de-repress its regulation of EMT inducer proteins. However, its role in thyroid carcinoma has not been elucidated. Here we report that PCBP1 expression is significantly downregulated in thyroid carcinoma patients. In vitro kinase assay revealed that immunoprecipitated PCBP1 from transient or stably transfected thyroid carcinoma cells can be phosphorylated by recombinant Akt2 kinase. In situ analysis revealed that PCBP1 is a putative target of miR-490-3p, which was further confirmed by PCBP1 3'UTR-based reporter assays using the wild-type or a miR-490 seed mutant 3'UTR. The endogenous regulation of the PCBP1 3'UTR reporter by miR-490-3p could be rescued by transfection of miR-490 antagomir in WRO and BCPAP cells. Stably overexpressing PCBP1 BCPAP cells attenuated tumor formation completely as compared to empty vector overexpressing cells in xenograft assay. Cumulatively, our results indicate that PCBP1 functions as a tumor suppressor in thyroid carcinoma and that its expression is down regulated by high expression of the miR-490-3p observed in thyroid carcinoma patients.
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PMID:Poly r(C) binding protein (PCBP) 1 is a negative regulator of thyroid carcinoma. 2764 47

Poly r(C) binding protein (PCBP) 1 or heterogeneous ribonucleoprotein (hnRNP) E1 is a RNA binding protein that plays a vital role in a wide variety of biological processes. PCBP1 has been shown to function as a tumor suppressor by negatively regulating translation of pro-metastatic proteins in different cancers. Loss of PCBP1 expression or its Akt2-mediated phosphorylation at serine 43 residue has both been indicated to de-repress its regulation of EMT inducer proteins. Our previous work has established that PCBP1 functions as a tumor suppressor in thyroid cancer, where its translation is inhibited by microRNA-490-3p. Here we show that thyroid cancer patients can be divided into 2 cohorts based on miR-490-3p expression and PCBP1 mRNA expression-one cohort with high PCBP1 mRNA expression and basal miR-490-3p expression and a second cohort with low PCBP1 mRNA expression and high miR-490-3p expression. However, PCBP1 protein expression is also downregulated in the cohort with high PCBP1 mRNA expression, with expression levels similar to what is observed in patients with the low PCBP1 mRNA expression. Our analysis shows that PCBP1 mRNA is actively translated in patients with high PCBP1 mRNA expression, but that the protein is post translationally degraded by the proteasome machinery. Our results thus elucidate a novel mechanism responsible for down regulation of PCBP1 expression in thyroid cancer. It will be important in future to identify the mechanism that causes degradation of PCBP1 protein and to identify if similar mechanisms are active in other tumors characterized by low PCBP1 protein expression.
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PMID:Poly r(C) binding protein (PCBP) 1 expression is regulated at the post-translation level in thyroid carcinoma. 2833 99