KDM1A promotes thyroid cancer progression and maintains stemness through the Wnt/ß-catenin signaling pathway.

Background: Cancer stem cells (CSCs) are highly tumorigenic, chemotherapy-resistant, tumor growth-sustaining, and are implicated in tumor recurrence. Previous studies have shown that lysine-specific histone demethylase 1A (KDM1A) is highly expressed in several human malignancies and CSCs. However, the role of KDM1A in CSCs and the therapeutic potential of KDM1A inhibitors for the treatment of the advanced thyroid cancer are poorly understood. Methods: Firstly, KDM1A was identified as an important epigenetic modifier that maintained the stemness of thyroid cancer through a mini histone methylation modifier screen and confirmed in thyroid cancer tissues and cell lines. RNA sequence was performed to discover the downstream genes of KDM1A. The underlying mechanisms were further investigated by ChIP, IP and dual luciferase reporter assays, gain and loss of function assays. Results: Here we report that KDM1A regulates the stemness of thyroid cancer and promotes thyroid cancer progression via the Wnt/ß-catenin pathway. Mechanistically, KDM1A down-regulates two antagonists of the canonical Wnt pathway, APC2 and DKK1, by demethylating H3K4me1/2 of the APC2 promoter region and the nonhistone substrate HIF-1α, resulting in the inhibition of APC2 transcription and the activation of the HIF-1α/microRNA-146a/DKK1 axis. Importantly, we also demonstrate that GSK-LSD1, a highly selective inhibitor of KDM1A, significantly inhibits thyroid cancer progression and enhances the sensitivity of thyroid cancer to chemotherapy. Conclusions: KDM1A plays an important role in thyroid cancer progression and maintains stemness, our study provides a new strategy for the therapy of advanced thyroid cancer.

LDHA induces EMT gene transcription and regulates autophagy to promote the metastasis and tumorigenesis of papillary thyroid carcinoma.

Papillary thyroid carcinoma (PTC) is one of the most common kinds of endocrine-related cancer and has a heterogeneous prognosis. Metabolic reprogramming is one of the hallmarks of cancers. Aberrant glucose metabolism is associated with malignant biological behavior. However, the functions and mechanisms of glucose metabolism genes in PTC are not fully understood. Thus, data from The Cancer Genome Atlas database were analyzed, and lactate dehydrogenase A (LDHA) was determined to be a potential novel diagnostic and therapeutic target for PTCs. The research objective was to investigate the expression of LDHA in PTCs and to explore the main functions and relative mechanisms of LDHA in PTCs. Higher expression levels of LDHA were found in PTC tissues than in normal thyroid tissues at both the mRNA and protein levels. Higher expression levels of LDHA were correlated with aggressive clinicopathological features and poor prognosis. Moreover, we found that LDHA not only promoted PTC migration and invasion but also enhanced tumor growth both in vitro and in vivo. In addition, we revealed that the metabolic products of LDHA catalyzed induced the epithelial-mesenchymal transition process by increasing the relative gene H3K27 acetylation. Moreover, LDHA knockdown activated the AMPK pathway and induced protective autophagy. An autophagy inhibitor significantly enhanced the antitumor effect of FX11. These results suggested that LDHA enhanced the cell metastasis and proliferation of PTCs and may therefore become a potential therapeutic target for PTCs.

Antitumor effects of anlotinib in thyroid cancer.

There is no effective treatment for patients with poorly differentiated papillary thyroid cancer or anaplastic thyroid cancer (ATC). Anlotinib, a multi-kinase inhibitor, has already shown antitumor effects in various types of carcinoma in a phase I clinical trial. In this study, we aimed to better understand the effect and efficacy of anlotinib against thyroid carcinoma cells in vitro and in vivo. We found that anlotinib inhibits the cell viability of papillary thyroid cancer and ATC cell lines, likely due to abnormal spindle assembly, G2/M arrest, and activation of TP53 upon anlotinib treatment. Moreover, anlotinib suppresses the migration of thyroid cancer cells in vitro and the growth of xenograft thyroid tumors in mice. Our data demonstrate that anlotinib has significant anticancer activity in thyroid cancer, and potentially offers an effective therapeutic strategy for patients of advanced thyroid cancer type.

RNA-dependent chromatin targeting of TET2 for endogenous retrovirus control in pluripotent stem cells.

Ten-eleven translocation (TET) proteins play key roles in the regulation of DNA-methylation status by oxidizing 5-methylcytosine (5mC) to generate 5-hydroxymethylcytosine (5hmC), which can both serve as a stable epigenetic mark and participate in active demethylation. Unlike the other members of the TET family, TET2 does not contain a DNA-binding domain, and it remains unclear how it is recruited to chromatin. Here we show that TET2 is recruited by the RNA-binding protein Paraspeckle component 1 (PSPC1) through transcriptionally active loci, including endogenous retroviruses (ERVs) whose long terminal repeats (LTRs) have been co-opted by mammalian genomes as stage- and tissue-specific transcriptional regulatory modules. We found that PSPC1 and TET2 contribute to ERVL and ERVL-associated gene regulation by both transcriptional repression via histone deacetylases and post-transcriptional destabilization of RNAs through 5hmC modification. Our findings provide evidence for a functional role of transcriptionally active ERVs as specific docking sites for RNA epigenetic modulation and gene regulation.

Rho differentially regulates the Hippo pathway by modulating the interaction between Amot and Nf2 in the blastocyst.

The Hippo pathway modulates the transcriptional activity of Yap to regulate the differentiation of the inner cell mass (ICM) and the trophectoderm (TE) in blastocysts. Yet how Hippo signaling is differentially regulated in ICM and TE cells is poorly understood. Through an inhibitor/activator screen, we have identified Rho as a negative regulator of Hippo in TE cells, and PKA as a positive regulator of Hippo in ICM cells. We further elucidated a novel mechanism by which Rho suppresses Hippo, distinct from the prevailing view that Rho inhibits Hippo signaling through modulating cytoskeleton remodeling and/or cell polarity. Active Rho prevents the phosphorylation of Amot Ser176, thus stabilizing the interaction between Amot and F-actin, and restricting the binding between Amot and Nf2. Moreover, Rho attenuates the interaction between Amot and Nf2 by binding to the coiled-coil domain of Amot. By blocking the association of Nf2 and Amot, Rho suppresses Hippo in TE cells.