Early Combined SHP2 Targeting Reverses the Therapeutic Resistance of Vemurafenib in Thyroid Cancer.

The BRAFV600E mutation is the most common oncogenic mutation in thyroid cancer, suggesting an aggressive subtype of thyroid cancer and poor prognosis. Vemurafenib, a selective inhibitor of BRAFV600E, may provide therapeutic benefit in various cancers including thyroid cancer. However, the prevalence of drug resistance remains a challenge because of the feedback activation of the MAPK/ERK and PI3K/AKT pathways. In treating thyroid cancer cells with vemurafenib, we have detected reactivation of the MAPK/ERK signaling pathway as a result of the release of multiple receptor tyrosine kinases (RTKs) from the negative feedback of ERK phosphorylation. SHP2 is an important target protein downstream of the RTK signaling pathway. Decreasing it through SHP2 knockdown or the use of an inhibitor of SHP2 (SHP099) was found to significantly increase the early sensitivity and reverse the late resistance to vemurafenib in BRAFV600E mutant thyroid cancer cells. Overall, our findings suggest that blocking SHP2 reverses the reactivation of the MAPK/ERK signaling pathway caused by the activation of RTKs and improves the sensitivity of thyroid cancer to vemurafenib, which has potential implications for mechanism-based early combination strategies to treat thyroid cancer.

Consistent analysis of differentially expressed genes across 7 cell types in papillary thyroid carcinoma.

Single-cell transcriptome sequencing (scRNA-seq) provides a higher resolution of cellular differences than bulk RNA-seq, enabling the dissection of cell-type-specific responses to perturbations in papillary thyroid carcinoma (PTC). However, cellular genomic features are highly heterogeneous and have a large number of genes without any expression signals, which hinders the statistical power to identify differentially expressed genes and may generate many false-positive results. To overcome this challenge, we conducted an integrative analysis on two PTC scRNA-seq datasets and cross-validated consistent differential expression. By combining results from 32 common cell types in the two studies, we identified 31 consistently differentially expressed genes (DEGs) across seven cell types, including B cells, endothelial cells, epithelial cells, monocytes, NK cells, smooth muscle cells, and T cells. Functional enrichment analysis revealed that these genes are important for the adaptive immune response and autoimmune thyroid diseases. The additional disease-free survival analysis also confirmed that these 31 genes significantly affected patient survival time in large scale thyroid cancer cohort. Furthermore, we experimentally validated one of the top consistent DEGs as a potential biomarker gene of PTC epithelial cells, KRT7, which may be a upstream gene for the NF-κB signaling pathway. The result shows that KRT7 may promote thyroid cancer metastasis through the epithelial-mesenchymal transition and NF-κB signaling pathway. In summary, our single-cell transcriptome integration-based approach may provide insights into the important role of NF-κB in the underlying biology of the PTC.

PARP inhibitor shuts down the global translation of thyroid cancer through promoting Pol II binding to DIMT1 pause.

Thyroid cancer has become the most frequent endocrine-related malignancy. Currently, a mounting body of evidences support the clinical strategies for extending the benefit of PARP inhibitors beyond BRCA-mutant cancers. However, the functions and molecular mechanisms of PARP inhibitors in thyroid cancers (TCs) are not fully understood. Here, on the one hand, we revealed that niraparib promotes the accumulation of DNA damage in TCs. On the other hand, we indicated that niraparib inhibits the transcription of DIMT1 through promoting Pol II pausing in a PAR-dependent manner, subsequently leading to a global translation inhibition in TCs. Meanwhile, we found that niraparib activates the NF-κB signaling pathway by inhibiting the PARylation of p65, which decreases its ubiquitination and degradation level through E3 ubiquitin ligase RNF146. Moreover, bortezomib (a small molecule inhibitor of the NF-κB signaling pathway) could significantly enhance the anti-tumor effect of niraparib on TCs in vitro and in vivo. Our findings provide mechanistic supports for the efficacy of PARP inhibitors in cancer cells lacking BRCA-mutant.

Identification and validation of eight estrogen-related genes for predicting prognosis of papillary thyroid cancer.

Papillary thyroid cancer (PTC) is one of the most common malignant tumors in female, and estrogen can affect its progression. However, the targets and mechanisms of estrogen action in PTC remain unclear. Therefore, this study focuses on the relationship between estrogen-related genes (ERGs) expression and prognosis in PTC, particularly neuropeptide U (NMU), and its important role in tumor progression. Based on The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, differentially expressed genes (DEGs) predominantly enriched in ERGs were identified between PTC and normal tissue. Then, we identified ERGs that contributed most to PTC prognosis, including Transducer of ERBB2 1 (TOB1), trefoil factor 1 (TFF1), phospholipase A and acyltransferase 3 (PLAAT3), NMU, kinesin family member 20A (KIF20A), DNA topoisomerase II alpha (TOP2A), tetraspanin 13 (TSPAN13), and carboxypeptidase E (CPE). In addition, we confirmed that NMU was highly expressed in PTC and explored the effect of NMU on PTC cells proliferation in vitro and in vivo. The results showed that the proliferative capacity of PTC cells was significantly reduced with NMU knockdown. Moreover, the phosphorylation levels of the Kirsten rat sarcoma virus (KRAS) signaling pathway were significantly lower with NMU knockdown. These results suggest that ERGs, especially NMU, may be novel prognostic indicators in PTC.

Attenuated effect of zinc gluconate on oxidative stress, inflammation, and angiogenic imbalance in pre-eclampsia rats.

AIMS: Pre-eclampsia (PE) is a common obstetric disease associated with oxidative stress, systemic inflammation, and angiogenic imbalance, whereas zinc (Zn) presents anti-oxidative and anti-inflammatory effects. This study is to investigate whether zinc gluconate (ZG) supplementation may ameliorate the early signs, adverse pregnancy outcomes, and pathogenic processes of PE in an animal model. MAIN METHODS: Forty pregnant Wistar rats were randomly divided into four groups: blank control (treated with normal saline, NS), Zn control (treated with ZG and followed by NS), PE model (treated with NS and followed by nitro-L-arginine methyl ester, L-NAME), and PE intervention (treated with ZG and followed by L-NAME). ZG (5 mg/kg/day) or NS was administered by gavage from day 0 to 19 of gestation, and L-NAME (80 mg/kg/day) or NS was subcutaneously injected from day 4 to 19 of gestation. The blood pressure, urinary protein, and pregnancy outcomes were recorded. Oxidative stress, inflammation, and angiogenic homeostasis were evaluated. KEY FINDINGS: PE rats exhibited oxidative stress (reduced SOD, CAT, and GSH, and increased MDA and 3-NT), inflammation (increased IL-6 and TNF-α), and angiogenic imbalance (reduced VEGF and PlGF, and increased sFlt-1). After intervention with ZG, the blood pressure and urinary protein levels were reverted, and the pregnancy outcomes were improved. The oxidative stress, inflammation, and angiogenic imbalance were effectively restored in accompany by increased Zn and MT levels. SIGNIFICANCE: ZG can ameliorate the early signs and pathological processes of PE in the animal model, indicating the value of zinc supplementation during pregnancy for PE prevention.

Pharmacological inhibition of Ref-1 enhances the therapeutic sensitivity of papillary thyroid carcinoma to vemurafenib.

The use of the BRAF inhibitor vemurafenib exhibits drug resistance in the treatment of thyroid cancer (TC), and finding more effective multitarget combination therapies may be an important solution. In the present study, we found strong correlations between Ref-1 high expression and BRAF mutation, lymph node metastasis, and TNM stage. The oxidative stress environment induced by structural activation of BRAF upregulates the expression of Ref-1, which caused intrinsic resistance of PTC to vemurafenib. Combination inhibition of the Ref-1 redox function and BRAF could enhance the antitumor effects of vemurafenib, which was achieved by blocking the action of Ref-1 on BRAF proteins. Furthermore, combination treatment could cause an overload of autophagic flux via excessive AMPK protein activation, causing cell senescence and cell death in vitro. And combined administration of Ref-1 and vemurafenib in vivo suppressed PTC cell growth and metastasis in a cell-based lung metastatic tumor model and xenogeneic subcutaneous tumor model. Collectively, our study provides evidence that Ref-1 upregulation via constitutive activation of BRAF in PTC contributes to intrinsic resistance to vemurafenib. Combined treatment with a Ref-1 redox inhibitor and a BRAF inhibitor could make PTC more sensitive to vemurafenib and enhance the antitumor effects of vemurafenib by further inhibiting the MAPK pathway and activating the excessive autophagy and related senescence process.

Preoperative supplementation of calcitriol and calcium relieves symptom and extent of hypocalcemia in patients undergoing total thyroidectomy and bilateral central compartment neck dissection: A prospective, randomized, open-label, parallel-controlled clinical study.

Background: Hypocalcemia is the most common complication that challenges surgeons performing total thyroidectomy. Conventional postoperative calcium and calcitriol supplement has been reportedly effective; however, a time lag has been reported before taking effect. Therefore, the role of preoperative strategy is yet to be determined. Study design: In this prospective, randomized, open-label, parallel-controlled phase II clinical study (registration number: ChiCTR2200059815), a short-term preoperative administration of calcitriol and calcium was proposed in 210 patients undergoing total thyroidectomy and bilateral central compartment neck dissection. Patients were recruited and randomized (1:1:1) into three groups: (A) combined (preoperative calcitriol and calcium), (B) calcium only (preoperative calcium only), and (C) control (no preoperative intervention). Finally, a total of 172 patients were qualified for final analysis. Results: Our data showed that 16 of 63 patients (25.4%) in the combined group had symptomatic hypocalcemia, whereas more patients from the control group (25 of 57 patients, 43.9%, P = 0.033) had symptomatic hypocalcemia. Further, the postoperative calcium level in the combined group is higher than in the control group (2.15 ± 0.15 vs. 2.09 ± 0.15 mmol/L, P = 0.031). Moreover, patients from the combined group showed lower calcium rates of <2.00 mmol/L (12.7% vs. 28.1%, P = 0.036). Remarkably, compared with the control group, patients with transient hypoparathyroidism in the combined group showed fewer rates for both symptomatic and biochemical hypocalcemia (28.6% vs. 61.1% for symptomatic hypocalcemia; 47.6% vs. 75% for biochemical hypocalcemia). Patients without transient hypoparathyroidism in all three groups showed no significant difference in rates for either symptomatic or biochemical hypocalcemia, indicating that this preoperative strategy is only effective for patients with transient hypoparathyroidism. We did not observe such beneficial effects in patients from the calcium group. Conclusions: Preoperative administration of calcitriol and calcium could reduce symptomatic and biochemical hypocalcemia, especially for those with transient hypoparathyroidism. Moreover, this maneuver could be recommended as a clinical routine in patients undergoing total thyroidectomy and bilateral central compartment neck dissection. Clinical Trial Registration: http://www.chictr.org.cn/edit.aspx?pid=164316&htm=4, identifier ChiCTR2200059815.

Inhibition of BRAF Sensitizes Thyroid Carcinoma to Immunotherapy by Enhancing tsMHCII-mediated Immune Recognition.

CONTEXT: Multiple mechanisms play roles in restricting the ability of T-cells to recognize and eliminate tumor cells. OBJECTIVE: To identify immune escape mechanisms involved in papillary thyroid carcinoma (PTC) to optimize immunotherapy. SETTING AND DESIGN: iTRAQ analysis was conducted to identify proteins differentially expressed in PTC samples with or without BRAFV600E mutation. Molecular mechanisms regulating tumor cell evasion were investigated by in vitro modulations of BRAF/MAPK and related pathways. The pathological significance of identified tumor-specific major histocompatibility complex class II (tsMHCII) molecules in mediating tumor cell immune escape and targeted immune therapy was further evaluated in a transgenic mouse model of spontaneous thyroid cancer. RESULTS: Proteomic analysis showed that tsMHCII level was significantly lower in BRAFV600E-associated PTCs and negatively correlated with BRAF mutation status. Constitutive activation of BRAF decreased tsMHCII surface expression on tumor cells, which inhibited activation of CD4+ T-cells and led to immune escape. Pathway analysis indicated that the transforming growth factor (TGF)-ß1/SMAD3-mediated repression of tsMHCII, which could be reversed by BRAF inhibition (BRAFi). Targeting this pathway with a combined therapy of BRAF inhibitor PLX4032 and anti-PD-1 antibody efficiently blocked tumor growth by increasing CD4+ T-cell infiltration in a transgenic PTC mouse model. CONCLUSIONS: Our results suggest that BRAFV600E mutation in PTC impairs the expression of tsMHCII through the TGF-ß1/SMAD3 pathway to enhance immune escape. Combined treatment with PLX4032 and anti-PD-1 antibody promotes recognition and elimination of PTC by the immune system in a pre-clinical mouse model, and therefore offers an effective therapeutic strategy for patients with advanced PTC.

The mechanisms of celastrol in treating papillary thyroid carcinoma based on network pharmacology and experiment verification.

BACKGROUND: Celastrol, a triterpene present in the traditional Chinese medicine (TCM) Triptergium wilfordii, has been demonstrated to have remarkable anticancer activity. However, its specific mechanism on papillary thyroid carcinoma (PTC) remains to be elucidated. METHODS: Potential targets of celastrol were screened from public databases. Through the Gene Expression Omnibus (GEO) online database, we obtained the bioinformatics analysis profile of PTC, GSE33630, and analyzed the differentially expressed genes (DEGs). Then, a protein-protein interaction (PPI) network was constructed by utilizing the STRING database. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted. Finally, drug interactions between hub genes and celastrol were verified by molecular docking. RESULTS: Four core nodes (MMP9, JUN, ICAM1, and VCAM1) were discerned via constructing a PPI network of 47 common targets. Through functional enrichment analysis, it was confirmed that the above target genes were basically enriched in the interleukin-17 (IL-17), nuclear factor kappa-B (NF-κB), and tumor necrosis factor (TNF) signaling pathways, which are involved in the inflammatory microenvironment to inhibit the development and progression of tumors. Molecular docking results demonstrated that celastrol has a strong binding efficiency with the 4 key proteins. CONCLUSIONS: In this research, it was demonstrated that celastrol can regulate a variety of proteins and signaling pathways against PTC, providing a theoretical basis for future clinical applications.

Genome-wide identification of m6A-associated functional SNPs as potential functional variants for thyroid cancer.

m6A methylation has been demonstrated to be one of the most important epigenetic regulation mechanisms in cell differentiation and cancer development especially m6A derived diagnostic and prognostic biomarkers have been identified in the past several years. However, systemic investigation to the interaction between germline single-nucleotide polymorphisms (SNPs) and m6A has not been conducted yet. In this study, we collected previous identified significant thyroid cancer associated SNPs from UKB cohort (358 cases and 407,399 controls) and ICR cohort (3,001 patients and 287,550 controls) and thyroid eQTL (sample size = 574 from GTEx project) and m6A-SNP (N = 1,678,126) were applied to prioritize the candidate SNPs. Finally, five candidate genes (PLEKHA8, SMUG1, CDC123, RMI2, ACSM5) were identified to be thyroid cancer associated m6A-related genetic susceptibility. Loss and gain function studies of m6A writer proteins confirm that ACSM5 is regulated by m6A methylation of mRNA. Moreover, ACSM5 is downregulated in thyroid cancer and inversely correlated with PTC malignancy and patient survival. Together, our study highlight mRNA-seq and m6A-seq double analysis provided a novel approach to identify cancer biomarkers and understanding the heterogeneity of human cancers.

Immune gene signature delineates a subclass of thyroid cancer with unfavorable clinical outcomes.

Thyroid cancer (THCA) is a heterogeneous disease with multiple clinical outcomes Immune cells regulate its progression. Three immunomolecular subtypes (C1, C2, C3) were identified in gene expression data sets from TCGA and GEO databases. Among them, subtype C3 had highest frequency of BRAF mutations, lowest frequency of RAS mutations, highest mutation load and shorter progression-free survival. Functional enrichment analysis for the genes revealed that C1 was up-regulated in the ERK cascade pathway, C2 was up-regulated in cell migration and proliferation pathways, while C3 was enriched in body fluid, protein regulation and response to steroid hormones functions. Notably, the three molecular subtypes exhibit differences in immune microenvironments as shown by timer database and analysis of immune expression signatures. The abundance of B_cell, CD4_Tcell, Neutrophil, Macrophage and Dendritic cells in C2 subtype were lower than in C1 and C3 subtypes Leukocyte fraction, proliferation macrophage regulation, lymphocyte infiltration, IFN gamma response and TGF beta response scores were significantly higher in C3 compared with C1 and C2 subtypes. Unlike C3 subtype, it was observed that C1 and C2 subtypes were significantly negatively correlated with most immune checkpoint genes in two different cohorts. The characteristic genes were differentially expressed between cancer cells, adjacent tissues, and metastatic tissues in different cohorts. In summary, THCA can be subclassified into three molecular subtypes with distinct histological types, genetic and transcriptional phenotypes, all of which have potential clinical implications.

One-step activation of high-graphitization N-doped porous biomass carbon as advanced catalyst for vanadium redox flow battery.

In this paper, we reported a one-step activation strategy to prepare highly graphitized N-doped porous carbon materials (KDC-FAC) derived from biomass, and adopted ferric ammonium citrate (FAC) as active agent. At high temperature, FAC was decomposed into Fe- and NH3-based materials, further increasing graphitization degree, introducing N-containing functional groups and forming porous structure. KDC-FAC has superior electrocatalytic activity and stability towards V2+/V3+ and VO2+/VO2+ redox reactions. High graphitization degree can enhance the conductivity of carbon material, and porous structure is conducive to increase reaction area of vanadium redox couples. Moreover, N-containing functional groups are beneficial to improve the electrode wettability and serve as active sites. The single cell tests demonstrate that KDC-FAC modified cell exhibits good adaptability under high current density and superb stability in cycling test. Compared with pristine cell, the energy efficiency of KDC-FAC modified cell is increased by 9% at 150 mA cm-2. This biomass-derived carbon-based material proposed in our work is expected to be an excellent catalyst for vanadium redox flow battery.