A TrkB–STAT3–miR-204-5p regulatory circuitry controls proliferation and invasion of endometrial carcinoma cells

Abstract

BackgroundWe previously identified TrkB as an oncogene involved in promoting metastasis in endometrial carcinoma (EC). Here, we sought to delineate the effect of changes in TrkB expression on the global profile of microRNAs (miRNAs) in EC cells and further investigated the correlation between the expression of certain miRNA and TrkB in the clinicopathologic characteristics of EC patients.Methods and resultsUsing quantitative reverse transcription-PCR (qRT-PCR), we found that expression of TrkB mRNA has no significant difference in transcript levels between normal endometrium and EC cells captured by laser capture microdissection, while immunohistochemistry results demonstrated a markedly higher expression of TrkB protein in EC tissues. The microRNA array showed that ectopic overexpression and knockdown of TrkB expression caused global changes in miRNA expression in EC cells. qRT-PCR results showed that elevated TrkB repressed miR-204-5p expression in EC cells. Furthermore, immunoblotting assays revealed that TrkB overexpression in IshikawaTrkB cells noticeably increased JAK2 and STAT3 phosphorylation, which, however, was aborted by TrkB knockdown in HEC-1BshTrkB cells. Moreover, ChIP assays showed that phospho-STAT3 could directly bind to STAT3-binding sites near the TRPM3 promoter region upstream of miR-204-5p. Interestingly, using bioinformatics analysis and luciferase assays, we identified TrkB was a novel target of miR-204-5p. Functionally, the MTT assays, clonogenic and Transwell assays showed that miR-204-5p significantly suppressed the clonogenic growth, migration and invasion of EC cells. Furthermore, miR-204-5p also inhibited the growth of tumor xenografts bearing human EC cells. Importantly, we found lower miR-204-5p expression was associated with advanced FIGO stages, lymph node metastasis and probably a lower chance for survival in EC patients.ConclusionsThis study uncovers a new regulatory loop involving TrkB/miR-204-5p that is critical to the tumorigenesis of EC and proposes that reestablishment of miR-204-5p expression could be explored as a potential new therapeutic target for this disease.

Transformer 2β and miR-204 regulate apoptosis through competitive binding to 3′ UTR of BCL2 mRNA

“…42 miR-204 also regulates expression of an oncogene, neurotrophic receptor tyrosine kinase B, and promotes metastasis in endometrial carcinoma. 43 Imam et al 44 showed that the genomic locus encoding miR-204 is frequently lost in multiple cancers, including breast and ovarian cancers, and pediatric renal tumors. They suggest that miR-204 targets distinct genes involved in tumorigenesis including BDNF.…”

miR-204-5p Inhibits Proliferation and Invasion and Enhances Chemotherapeutic Sensitivity of Colorectal Cancer Cells by Downregulating RAB22A

“…We and other groups have shown that miR-204 is downregulated in multiple human cancers (7,(15)(16)(17)(18)(19)(20)(21)(22)(23). CpG methylation represents an important mechanism responsible for the inactivation of genes, including miRNAs.…”

“…miR-204 has been reported to function as a tumor suppressor in a variety of human cancers through different mechanisms (15)(16)(17)(18)(19)(20)(21)(22)(23), suggesting its extensive function in tumorigenesis. For example, miR-204 inhibited tumor growth in renal clear cell carcinoma (17) and pancreatic cancer (32) and suppressed invasion in endometrial cancer (23), glioma (21), gastric cancer (16), intrahepatic cholangiocarcinoma (16), and head and neck tumor (18).…”

“…7). Several studies have also shown that miR-204 is frequently downregulated in other cancers, suggesting a common role of miR-204 in human tumorigenesis (15)(16)(17)(18)(19)(20)(21)(22)(23). However, the role of miR-204-5p in colorectal cancer remains undefined.…”

Atypical Cell Populations Associated with Acquired Resistance to Cytostatics and Cancer Stem Cell Features: The Role of Mitochondria in Nuclear Encapsulation

“…Even more important was the global change in the physiology of these cells forced by etoposide toward acquirement of the CSC status. In addition, the analysis and validation of iCSC microRNAs isolated from 79HF6 glioblastoma cells revealed a subtle deregulation of different miRNAs such as miR204-5p known to contribute to tumor aggressiveness and metastatic behavior (Díaz-Carballo et al, 2008b;Bao et al, 2013;Qiu et al, 2013). We decided to take a descriptive rather than analytic approach to the miRNA results, as the understanding of the function of the studied representatives and this field in general is still evolving (Fig.…”