Colossal negative magnetoresistance in field-induced Weyl semimetal of magnetic half-Heusler compound.

The discovery of topological insulators and semimetals triggered enormous interest in exploring emergent electromagnetic responses in solids. Particular attention has been focused on ternary half-Heusler compounds, whose electronic structure bears analogy to the topological zinc-blende compounds while also including magnetic rare-earth ions coupled to conduction electrons. However, most of the research in this system has been in band-inverted zero-gap semiconductors such as GdPtBi, which still does not fully exhaust the large potential of this material class. Here, we report a less-studied member of half-Heusler compounds, HoAuSn, which we show is a trivial semimetal or narrow-gap semiconductor at zero magnetic field but undergoes a field-induced transition to a Weyl semimetal, with a negative magnetoresistance exceeding four orders of magnitude at low temperatures. The combined study of Shubnikov-de Haas oscillations and first-principles calculation suggests that the exchange field from Ho 4f moments reconstructs the band structure to induce Weyl points which play a key role in the strong suppression of large-angle carrier scattering. Our findings demonstrate the unique mechanism of colossal negative magnetoresistance and provide pathways towards realizing topological electronic states in a large class of magnetic half-Heusler compounds.

Real-Space Observation of Ripple-Induced Symmetry Crossover in Ultrathin MnPS3.

Stacking order is expected to have a significant impact on the properties of van der Waals layered magnets, as it determines the crystallographic and magnetic symmetry. Recent synchrotron-based optical studies on antiferromagnetic MnPS3 have revealed a thickness-dependent symmetry crossover, suggesting possible different stackings in few-layer crystals from the bulk, which, however, has not been explicitly identified. Here, by using a combination of atomic-scale electron microscopy and theoretical calculations, we show that despite the bulk monoclinic stacking persists macroscopically down to bilayer, additional local rippling effect lifts the monoclinic symmetry of the few layers while preserving the trigonal symmetry of individual monolayers, leading to possible monolayer-like behavior in ultrathin MnPS3 samples. This finding reveals the profound impact of rippling on the microscopic symmetry of two-dimensional materials with weak interlayer interactions and raises the possibility of approaching the paradigmatic two-dimensional Néel antiferromagnetic honeycomb lattice in MnPS3 without reaching monolayer thickness.

Correction to: Hsa_circ_0058124 promotes papillary thyroid cancer tumorigenesis and invasiveness through the NOTCH3/GATAD2A axis.

In the original publication of this manuscript [1], the Fig. 6a invasion si-hsa_circ_0058124_2# group (row 2 right and row 3 right) and Fig. 9c TPC-1 clone formation assay control group (row 1 left) were misplaced and need to be revised. The updated figures are shown below.

Hsa_circ_0058124 promotes papillary thyroid cancer tumorigenesis and invasiveness through the NOTCH3/GATAD2A axis.

BACKGROUND: Despite a good and overall prognosis, papillary thyroid cancer (PTC) can still affect the quality of life of many patients, and can even be life-threatening due to its invasiveness and metastasis. Emerging studies demonstrate that circular RNAs (circRNAs) participate in the regulation of various cancers. However, the circRNA profile in invasive PTC is still not well understood. METHODS: Competing endogenous RNA (ceRNA) microarrays were performed to determine circRNAs contributed to the tumorigenesis and invasiveness of PTC. Bioinformatics methods were used to narrow down the candidate circRNAs. Quantitative real-time polymerase chain reaction (qRT-PCR) assays revealed a significant upregulation of hsa_circ_0058124 in PTC tissue and a close correlation with a poor prognosis for PTC patients. RNA fluorescence in situ hybridization and Cell fractionation assay were used to investigate the subcellular location of hsa_circ_0058124. Then, we examined the functions of hsa_circ_0058124 in PTC by cell proliferation, cell cycle, apoptosis, migration and invasion assay. Mechanistically, RNA sequencing and GSEA analysis were applied to predict the downstream pathway of hsa_circ_0058124. Dual-luciferase report assays were used to explore the potential miRNA sponge role of hsa_circ_0058124. Western blotting, cell proliferation, cell cycle, cell apoptosis, migration and invasion, and mouse xenograft assay were used to validate the effects of hsa_circ_0058124/NOTCH3/GATAD2A axis on PTC progression. RESULTS: In the current study, a novel hsa_circ_0058124 on 2q35 was identified and explored in PTC. Hsa_circ_0058124 is associated with the malignant features and poor outcomes of PTC patients. Hsa_circ_0058124 acts as an oncogenic driver that promotes PTC cell proliferation, tumorigenicity, tumor invasion, and metastasis, which functions as a competing endogenous RNA to modulate miRNA-218-5p and its target gene NUMB expression, and consequently with repression of the NOTCH3/GATAD2A signaling axis in vitro and in vivo. CONCLUSIONS: This study unveils a novel biomarker panel consisting of the hsa_circ_0058124/NOTCH3/GATAD2A axis which is critical for PTC tumorigenesis and invasiveness and may represent a novel therapeutic target for intervening in PTC progression.

Over-expression of miR-206 decreases the Euthyrox-resistance by targeting MAP4K3 in papillary thyroid carcinoma.

PURPOSE: microRNAs (miRNAs) play a critical role in drug resistance of multiple cancers including papillary thyroid carcinoma (PTC), indicating the potential of miRNAs as chemoresistance regulators in cancer treatment. The aim of this paper is to explore the relationship between miR-206 and chemoresistance of PTC. METHODS: qRT-PCR was conducted to examine the expression of miR-206 in PTC tissues, parental and TPC-1/euthyrox. The CCK-8 assay, EdU assay and flow cytometry were performed to test cells viability, proliferation and apoptosis, respectively. Luciferase reporter assay was used to confirm the potential target of miR-206. Western blotting analysis was performed to evaluate the expressions of related-proteins. RESULTS: miR-206 was significantly down-regulated in PTC tissues, parental and TPC-1/euthyrox. Moreover, the expression of miR-206 was exceptionally lower in TPC-1/euthyrox cells than that in TPC-1 cells. Furthermore, we found that over-expression of miR-206 could notably decrease the IC50 values both in TPC-1 and TPC-1/euthyrox cells, which indicated that miR-206 played an essential role in the euthyrox resistance in PTC. In addition, up-regulation of miR-206 inhibited the proliferation, induced apoptosis, suppressed the expressions of multidrug resistance-related proteins, including p-gp, MRP, BCRP and LRP, in euthyrox-resistant PTC cells. Besides, over-expression of miR-206 could notably promoted the expression of NIS, an intrinsic membrane protein that mediates the active transport of iodide into the thyroid and other tissues, playing a critical role in the progress. Further, miR-206 was demonstrated to be able to bind to MAP4K3 and negatively regulated the expression of MAP4K3. Besides, MAP4K3 was clearly up-regulated in PTC tissues, parental and TPC-1/euthyrox cells, and down-regulation of miR-206 attenuated the effect of si-MAP4K3 on the euthyrox sensitivity in euthyrox-resistant PTC cells. Moreover, TPC-1/euthyrox cells transfected with miR-206 mimics could significantly inhibit the expressions of p-p38, p-JNK and p-Erk, which indicated that miR-206 might play an essential role in the euthyrox resistance in PTC by negatively regulating the p38 and JNK signaling pathway. CONCLUSION: miR-206 contributed to euthyrox resistance in PTC cells through blockage p38 and JNK signaling pathway by targeting MAP4K3, providing a potential therapeutic application for the treatment of patients with euthyrox-resistant PTC in the further.

Circulating Long Noncoding RNAs as Biomarkers for Predicting Head and Neck Squamous Cell Carcinoma.

BACKGROUND/AIMS: The anatomical complexity of the head and neck region and the lack of sufficiently specific and sensitive biomarkers often lead to the diagnosis of head and neck squamous cell carcinoma (HNSCC) at advanced stages. To identify novel biomarkers for early diagnosis of primary HNSCC through a minimally invasive method, we investigated circulating long noncoding RNA (lncRNA) levels in plasma of HNSCC patients. METHODS: The global lncRNA expression profiles of HNSCC patients were measured using microarray and next-generation RNA-sequencing (RNA-seq) data from both circulating and tissue samples. The diagnosis prediction model based on the lncRNA signatures and clinical features was evaluated by multi-stage validation and risk score analysis. RESULTS: The data showed that 432 lncRNA transcripts were differentially expressed by fold changes of > 4 in circulating samples and 333 in tissues samples, respectively. Only 12 lncRNAs consistently emerged in these two kinds of samples. After the risk score analysis including a multistage validation, we identified three lncRNAs, namely, HOXA11-AS, LINC00964 and MALAT1, which were up-regulated in the plasma of HNSCC patients compared with those in healthy controls with merged areas under the curve (AUCs) in training and validation sets of 0.925 and 0.839, respectively. CONCLUSION: HOXA11-AS, LINC00964 and MALAT1 might be potential circulating biomarkers for the early detection of HNSCC in the future.