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Thyroid cancer (TC) is the most prevalent endocrine malignancy, with a rising incidence in the past decade [...]

Anaplastic thyroid carcinoma (ATC) is a rare and extremely aggressive type of thyroid cancer, and the potential mechanisms involved in ATC progression remains unclarified. In this study, we found that forkhead box K2 (FOXK2) was upregulated in ATC tissues, and the expression of FOXK2 was associated with tumor size. Evidenced by RNA-seq and Chromatin immunoprecipitation (ChIP)-seq assays, FOXK2 positively regulated VEGF and VEGFR signaling network, among which only VEGFA could be noticed in both RNA-seq and ChIP-seq results. ChIP, dual-luciferase reporter system and functional experiments further confirmed that FOXK2 promoted angiogenesis by inducing the transcription of VEGFA. On VEGFR2 blockage by specific targeting agent, such as Apatinib, FOXK2 could rapidly trigger therapeutic resistance. Mechanical analyses revealed that VEGFA transcriptionally induced by FOXK2 could bind to VEGFR1 as a compensation for VEGFR2 blockage, which promoted angiogenesis by activating ERK, PI3K/AKT and P38/MAPK signaling in human umbilical vein endothelial cells (HUVECs). Synergic effect on anti-angiogenesis could be observed when VEGFR1 suppressor AF321 was included in VEGFR2 inhibition system, which clarified the pivot role of FOXK2 in VEGFR2 targeting therapy resistance. More importantly, the binding of VEGFA to VEGFR1 could further promoter FOXK2-mediated VEGFA transcription, which consequently constituted a positive feedback loop. Therefore, the novel loop VEGFA/VEGFR1/FOXK2 functioned importantly in resistance to VEGFR2 targeting therapy in FOXK2+ ATCs. Altogether, FOXK2 plays critical roles in ATC angiogenesis and VEGFR2 blockage resistance by inducing VEGFA transcription. FOXK2 represents a potentially new therapeutic strategy and biomarker for anti-angiogenic therapy against ATC.

Background Hypoxia-induced angiogenesis functions importantly in anaplastic thyroid cancer (ATC) progression. However, the therapeutic potential of broad-spectrum anti-angiogenic agent remains undefined. Anlotinib conventionally targets VEGFR, FGFR and PDGFR. Here, a novel role of anlotinib on ATC angiogenesis was illustrated. Methods Molecular expressions were established via tissue microarray. Multiple assays (tubule formation, 3D sprouting and chicken chorioallantoic membrane model) were used for angiogenic evaluation. Panels of molecular screening were achieved by antibody and PCR arrays. The loop binding motif of EGFR for homology modelling was prepared using Maestro. Results Anlotinib could dose- and time-dependently inhibit cell viability under normoxia and hypoxia and could repress hypoxia-activated angiogenesis more efficiently in vitro and in vivo. CXCL11 and phospho-EGFR were hypoxia-upregulated with a positive correlation. The cancer-endothelium crosstalk could be mediated by the positive CXCL11-EGF-EGFR feedback loop, which could be blocked by anlotinib directly targeting EGFR via a dual mechanism by simultaneous inhibitory effects on cancer and endothelial cells. The AKT-mTOR pathway was involved in this regulatory network. Conclusions The newly identified CXCL11-EGF-EGFR signalling provided mechanistic insight into the interaction between cancer and endothelial cells under hypoxia, and EGFR was a novel target. Anlotinib may be the encouraging therapeutic candidate in ATC.

Due to technical challenges, single-site endoscopic thyroidectomy (SSET) is seldom reported and has been attempted in only limited cases. This large-scale study aimed to compare the clinical outcomes of standardized transareola SSET (TASSET) with those of conventional open thyroidectomy (COT) for thyroid cancer. The data were prospectively collected, and case-match study was performed at a ratio of 1:1 according to age, sex, body mass index, lesion size, number of lesion foci, lesion side, recurrent laryngeal nerve (RLN) exploration and pathology. Two hundred eligible patients underwent TASSET, and the same number of patients was selected for propensity score matching from 2256 patients who underwent COT. Perioperative data, including surgical profile, oncological and traumatic burdens, and cosmetic satisfaction, were analyzed. No significant differences were observed in blood loss or drainage between TASSET and COT groups. There were no differences in operation time between TASSET and COT (106.39 ± 28.44 vs 102.55 ± 23.10 min, p = 0.154). A total of 3.63 ± 1.82 lymph nodes (LNs) were retrieved from CND with 0.96 ± 1.42 positive in TASSET. In COT, the total and positive LN yields were 3.77 ± 1.91 and 0.99 ± 1.40 (p = 0.445, p = 0.802). Cancer recurrence was not observed in either group. There were no differences in the occurrence of permanent and transient hoarseness or RLN injuries. Postoperative flap seroma or hematoma occurred in 12 TASSET patients and 58 COT patients (p

BACKGROUND: Low levels of vitamin D and altered local vitamin D metabolism have been associated with the prevalence and aggressiveness of several cancers. However, the effect of vitamin D on papillary thyroid cancer (PTC) is controversial. This study aimed to evaluate the impact of preoperative serum vitamin D levels and local vitamin D metabolism on the clinicopathologic characteristics and prognosis of PTC. METHODS: In total, 1,578 patients with PTC and 128 patients with benign thyroid diseases were included. Clinical and pathologic data were analyzed to evaluate the role of vitamin D as a risk factor and prognostic marker in PTC. Moreover, a tissue microarray was used to investigate the role of local vitamin D metabolism in PTC progression. RESULTS: Participants with PTC were younger compared to those with benign disease. No significant differences in 25-hydroxy vitamin D [25(OH)D] levels were observed between benign and malignant cases. Among patients with PTC, analyses of prognostic features revealed that decreased 25(OH)D levels were not overtly associated with poor prognosis in PTC. Additionally, local vitamin D metabolism was not associated with the aggressiveness of PTC. CONCLUSIONS: Serum 25(OH)D determination may not contribute to risk assessment workup of thyroid nodules. Moreover, decreased preoperative serum vitamin D and local vitamin D metabolism were not associated with poor prognosis of PTC.

Skip metastasis is a specific type of papillary thyroid cancer lymph node metastasis (LNM). The present study aimed to clarify the typical clinical characteristics of skip metastasis and optimize the prediction model, so as to provide a more individual treatment mode for skip metastasis. We retrospectively analyzed 1075 PTC patients with different lymph node metastasis statuses from two clinical centers. Comparisons have been made between patients with skip metastasis and other types of LNM. Univariate and multivariate analyses were performed to detect the risk factors for skip metastasis with negative LNM, and a nomogram for predicting skip metastasis was established. The rate of skip metastasis was 3.4% (37/1075). Compared with other types of LNM, significant differences showed in tumor size, upper portion location, thyroid capsular invasion, and ipsilateral nodular goiter with the central lymph node metastasis (CLNM) group, and in age and gender with the lateral lymph node metastasis (LLNM) group. Four variables were found to be significantly associated with skip metastasis and were used to construct the model: thyroid capsular invasion, multifocality, tumor size > 1 cm, and upper portion. The nomogram had good discrimination with a concordance index of 0.886 (95% confidence interval [CI], 0.823 to 0.948). In conclusion, the significant differences between skip metastasis and other types of LNM indicated that the lymph node drainage pathway of skip metastasis is different from either CLNM or LLNM. Furthermore, we established a nomogram for predicting risk of skip metastasis, which was able to effectively predict the potential risk of skip metastasis in patients without preoperative LNM clue.

Overexpression of fibroblast growth factor receptor 3 (FGFR3) correlates with more severe clinical features of hepatocellular carcinoma (HCC). Our previous study has shown that FGFR3∆7–9, a novel splicing mutation of FGFR3, contributes significantly to HCC malignant character, but the epigenetic mechanism is still elusive. In this study, through mass spectrometry and co-immunoprecipitation studies, we discover a close association between FGFR3∆7–9 and the DNA demethylase Ten-Eleven Translocation-2 (TET2). Unlike other certain types of cancer, mutation of TET2 is rare in HCC. However, activation of FGFR3∆7–9 by FGF1 dramatically shortens TET2 half-life. FGFR3∆7–9, but not wild-type FGFR3, directly interacts with TET2 and phosphorylates TET2 at Y1902 site, leading to the ubiquitination and proteasome-mediated degradation of TET2. Overexpression of a phospho-deficient mutant TET2 (Y1902F) significantly reduces the oncogenic potential of FGFR3∆7–9 in vitro and in vivo. Furthermore, FGFR3∆7–9 significantly enhances HCC cell proliferation through the TET2-PTEN-AKT pathway. Specifically, TET2 offsets the elevation of p-AKT level induced by FGFR3∆7–9 through directly binding to PTEN promoter and increasing 5-hmC. Therefore, through phosphorylation and inhibition of TET2, FGFR3∆7–9 reduces PTEN expression and substantiates AKT activation to stimulate HCC proliferation. Together, this study identifies TET2 as a key regulator of the oncogenic role of FGFR3∆7–9 in HCC carcinogenesis and sheds light on new therapeutic strategies for HCC treatment.

Background: Our previous study has shown that FGFR3∆7-9, a novel splicing mutation of FGFR3, contributes significantly to hepatocellular carcinoma (HCC) malignancy. However, the functional roles of oncogenic FGFR3∆7-9 are far more clear. In this study, we aimed to understanding regulatory mechanism, signaling, and clinical role of FGFR3∆7-9 in HCC carcinogenesis. Methods: Mass spectrometry and co-immunoprecipitation were employed to identify the interactors with FGFR3∆7-9. The expression and biological functions of DNA demethylase Ten-Eleven Translocation-2 (TET2) were detected in vivo and in vitro. The binding and tyrosine phosphorylation sites of TET2 to FGFR3∆7-9 were pinpointed structurally and functionally. Mechanism of TET2 in modulating PTEN expression was examined by chromatin immunoprecipitationassays and Methylation-Sensitive qPCR. Findings: It is the amount of TET2 rather than mutation functions more importantly in carcinogenesis. Downregulation of TET2 positively correlated with the poorer prognosis of HCC. TET2 could directly interact with FGFR3∆7-9 and phosphorylated at Y1902, which was the solo tyrosine phosphorylation site in the key binding fragment to FGFR3∆7-9. Phospho-deficient mutant TET2 (Y1902F) significantly reduced the tumorigenesis potential of FGFR3∆7-9 in vitro and in vivo. Through the ubiquitination and proteosomal degradation of TET2, FGFR3∆7-9 reduced PTEN expression, and then rescued the level of p-AKT to trigger the HCC cell growth advantage. Interpretation: The novel link between FGFR3∆7-9 and TET2 revealed the important functional roles of oncogenic FGFR3∆7-9 in HCC. FGFR3△7-9 promotes HCC progression via the phosphorylation and destabilization of TET2. Targeting the FGFR3△7-9/TET2-PTEN-AKT signaling axis may contribute to develop new therapeutic strategies for HCC treatment. Funding Statement: This work was supported by the following grants: National Natural Science Foundation of China (NSFC: 81772558), Shanghai Charity Research Foundation of Cancer Research, China Scholarship Council (201906230139), Ph.D. Innovation Fund of Shanghai Jiaotong University School of Medicine (BXJ201709), and “Visiting Programs for Graduate Students of Shanghai Jiaotong University School of Medicine” for this study. Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: Written informed consent was obtained and the research was approved by the local Ethics Committee and the Institutional Review Board. All patients were fully informed of the experimental procedures and were made aware of the potential risks and complications of the proposed treatment scheme. All animal studies were approved by the Ethics Committee of Ruijin Hospital, Shanghai Jiao Tong University School of Medicine.

The usage of m-CPBA (meta-chloroperbenzoic acid) is limited on large scale due to its thermal instability, although it is a good oxidant and well-accepted in laboratory scale. In our recent project, m-CPBA was used for an oxidation reaction, and an explosion hazard was identified. To ensure the safe use of m-CPBA on large scale, the stability of m-CPBA in different solvents was investigated, and it was found that besides the incompatibility between m-CPBA and DMF reported earlier, the intrinsic instability of m-CPBA/DCM solution at high concentration (low onset temperature and large exotherm) can also cause a major problem on large scale. Therefore, process parameters such as concentration of m-CPBA, addition sequence, and handling temperature have been investigated and successfully applied in pilot plant for a large scale reaction using 8 kg of m-CPBA.

N-myc downstream-regulated gene 1 (NDRG1) has been reported to act as a key regulatory molecule in tumor progression-related signaling pathways, especially in tumor metastasis. However, the related mechanism has not been fully discovered yet. Herein we demonstrated that the novel molecule of cell migration and invasion, caveolin-1, has direct interaction with NDRG1 in human colorectal cancer (CRC) cells. Moreover, we discovered that NDRG1 reduces caveolin-1 protein expression through promoting its ubiquitylation and subsequent degradation via the proteasome in CRC cells. In addition, caveolin-1 mediates the suppressive function of NDRG1 in epithelial–mesenchymal transition, migration and invasion in vitro and metastasis in vivo. These results help to fulfill the potential mechanisms of NDRG1 in anti-metastatic treatment for human colorectal cancer.

The first asymmetric synthesis of natural indole alkaloid (+)-decursivine was accomplished. The key step involves the PIFA-mediated intramolecular [3 + 2] cycloaddition of 5-hydroxytryptophan with a substituted cinnamamide in a highly diastereoselective manner.

With the catalysis of CuI/3,4,7,8-tetramethyl-1,10-phenanthroline, various ketones smoothly underwent the intramolecular O-vinylation with vinyl bromides leading to the efficient synthesis of the corresponding multisubstituted furans.

With the catalysis of CuI/trans-N,N'-dimethylcyclohexane-1,2-diamine, a number of carboxylic acids underwent efficient intramolecular O-vinylation with vinyl bromides leading to the synthesis of the corresponding five- and six-membered enol lactones. The same catalytic system also led to the efficient cycloisomerization of alkynoic acids.

A general and highly efficient synthesis of 4-alkylidene-2-azetidinones was achieved by the Cu(I)-catalyzed intramolecular C-N coupling of amides with vinyl bromides. This 4-exo ring closure was found to be fundamentally preferred over other modes (5-exo, 6-exo, and 6-endo) of cyclization under copper catalysis. Tandem C-N bond formation was then successfully developed to allow the convenient generation of medium-sized lactams.

Phospholipid scramblase 1 (PLSCR1) is a multiply palmitoylated protein which is localized in either the cell membrane or nucleus depending on its palmitoylated state. The increasing evidence showed the biological roles of PLSCR1 in cell signaling, maturation and apoptosis. To investigate the functions of PLSCR1 in leukemic cells, we generated an inducible PLSCR1-expressing cell line using myeloid leukemic U937 cells. In this cell line, PLSCR1 was tightly regulated and induced upon tetracycline withdrawal. Our results showed that inducible PLSCR1 expression arrested the proliferation of U937 cells at G1 phase. Meanwhile, PLSCR1-overexpressing U937 cells also underwent granulocyte-like differentiation with increased sensitivity to etoposide-induced apoptosis. Furthermore, we also found that PLSCR1 induction increased cyclin-dependent kinase inhibitors p27(Kip1) and p21(Cip1) proteins, together with downregulation of S phase kinase-associated protein 2 (SKP2), an F-box subunit of the ubiquitin-ligase complex that targets proteins for degradation. Additionally, PLSCR1 induction significantly decreased c-Myc protein and antiapoptotic Bcl-2 protein. Although the exact mechanism by which PLSCR1 regulates these cellular events and gene expression remains unresolved, our results suggest that PLSCR1 plays the antagonistic role regarding leukemia development. These data will shed new insights into understanding the biochemical and biological functions of PLSCR1 protein.

International audience; Investigation of the mechanism of the NHC-initiated hydrosilylation of styryl alcohols in the presence of a dihydrosilane suggests a general base catalysis mechanism and not the activation of the dihydrosilane by the NHC.

The reduction of ketones, esters and the imine (XXIV) under mild conditions is achieved with diphenylsilane in the presence of TAC.

The hydrosilylation of carbonyl derivatives has been explored by the activation of diphenylsilane in the presence of a catalytic amount of an N-heterocyclic carbene (NHC). Presumably, a hypervalent silicon intermediate featuring strong Lewis acid character allows dual activation of both the carbonyl moiety and the hydride at the silicon center. Reduction under mild conditions could be accomplished using this organocatalytic process. Some interesting selectivities have been encountered. © Georg Thieme Verlag Stuttgart · New York.

The carbene derived from triazolium salt TRC catalyzes the title reactions to give the corresponding saturated alcohols or (E)-alkenols, correspondingly, after quenching of the resulting siloxanes with Bu4NF.

Reducing alkenes to tears: Addition of structurally diverse N-heterocyclic carbenes (NHCs) to silicon allows the reduction of propargylic and styryl alcohols through an organocatalyzed silylation/direct hydride transfer tandem reaction (see scheme). Catalytic turnover is enabled by the switch to and from hypervalent silicon. This provides a new synthetic application of NHC-main group element complexes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The title reaction can be applied to the preparation of a broad spectrum of target compounds and benzopyran (XVI).

With the catalysis of CuI/trans-N,N'-dimethylcyclohexane-1,2-diamine, a number of carboxylic acids underwent efficient intramolecular O-vinylation with vinyl bromides leading to the synthesis of the corresponding five- and six-membered enol lactones. The same catalytic system also led to the efficient cycloisomerization of alkynoic acids.

With CuI as the catalyst and K3PO4 center dot 3H(2)O as the base, highly efficient intramolecular S-vinylation of thiols with vinyl chlorides or bromides was successfully implemented without the help of an additional ligand. Moreover, the competition experiments revealed that the 4-exo cyclization is fundamentally preferred over other modes (5-exo, 6-exo, and 6-endo) of cyclization.

With CuI as the catalyst and K3PO4 center dot 3H(2)O as the base, highly efficient intramolecular S-vinylation of thiols with vinyl chlorides or bromides was successfully implemented without the help of an additional ligand. Moreover, the competition experiments revealed that the 4-exo cyclization is fundamentally preferred over other modes (5-exo, 6-exo, and 6-endo) of cyclization.

Hypoxia or hypoxia mimetic has been shown to induce differentiation together with the accumulation of hypoxia-inducible factor-1alpha (HIF-1alpha) protein of myeloid leukemic cells and normal hematopoietic progenitors. To provide direct evidence for the role of HIF-1alpha in acute myeloid leukemia (AML) cell differentiation and its mechanisms, we generated myeloid leukemic U937T transformants, in which HIF-1alpha was tightly induced by tetracycline withdrawal. The results showed that the conditional HIF-1alpha induction triggered granulocytic differentiation of these transformants, while the suppression of HIF-1alpha expression by specific short hairpin RNAs (shRNAs) effectively inhibited hypoxia-induced differentiation of U937 cells, as evidenced by morphology, maturation-related antigens as well as expressions of myeloid differentiation signatures and hematopoietic cells-specific cytokine receptors. The specific shRNAs-inhibited expression of HIF-1beta, an essential partner for transcription activity of HIF-1, failed, while the inhibition of hematopoietic differentiation-critical CCAAT/enhancer-binding protein-alpha (C/EBPalpha) significantly eliminated HIF-1alpha-mediated myeloid leukemic cell differentiation. Collectively, this work provided several lines of direct evidence for the role of HIF-1alpha protein through its nontranscriptional activity in myeloid cell differentiation, in which C/EBPalpha elicits a role as an effector downstream to HIF-1alpha. These discoveries would shed new insights for understanding mechanisms underlying leukemogenesis and designing the new therapeutic strategy for differentiation induction of AML.