KF-catalyzed direct thiomethylation of carboxylic acids with DMSO to access methyl thioesters.

With dimethyl sulfoxide (DMSO) as the methylthio source, a KF-catalyzed strategy was employed for the direct thiomethylation of carboxylic acids with DMSO for the preparation of methyl thioesters. In this process, a wide range of methyl thioesters were obtained in moderate to excellent yields. This novel strategy features the first use of DMSO as a methylthiolating agent for the construction of methyl thioesters, transition metal-free conditions, inexpensive reagents, easy workup, broad substrate scope and sustainability. Additionally, this procedure can be readily scaled up to a gram scale.

Lamin B2 promotes the malignant phenotype of non-small cell lung cancer cells by upregulating dimethylation of histone 3 lysine 9.

The relationship between Lamin B2 and tumor proliferation and migration is unclear. We explored the impact of Lamin B2 on non-small cell lung cancer (NSCLC) cells. Tissue microarray and immunohistochemistry were combined to evaluate Lamin B2 expression and its relationship with the clinicopathological factors found in NSCLC. Western blotting, immunofluorescence analysis, and bioinformatics were used to investigate the effects of Lamin B2 on various regulatory pathways in cancer. Cytological experiments were conducted to evaluate Lamin B2 expression in tumor cells. We conducted co-immunoprecipitation and chromatin immunoprecipitation to explore the molecular mechanisms underlying the relationship between Lamin B2 and NSCLC and evaluate the results of rescue experiments. Lamin B2 was highly expressed in NSCLC and positively correlated with lymph node metastasis. In NSCLC, Lamin B2 interacted with Cyclin D1, upregulating G9α expression, thus increasing H3K9me2 levels. H3K9me2 binds to the promoter region of the E-cadherin gene (CDH1) to induce CDH1 silencing and promotes cancer cell migration. Thus, we found that Lamin B2 was highly expressed in NSCLC cells and promoted their migration by increasing H3K9me2 levels, which induced E-cadherin gene silencing.

Supratentorial ependymoma with YAP1:FAM118B fusion: A case report.

We report a case of a 26-year-old Chinese man who had experienced three grand mal seizures in the past two months. Magnetic resonance imaging revealed a relatively well-circumscribed lesion in the left frontal lobe. A craniotomy with total excision of the tumor was performed. Histopathological investigations confirmed a grade 2 ependymoma according to the World Health Organization classification. Genetic analysis revealed a tumor harboring FAM118B fusion to YAP1, and no other genetic alterations or methylation of the O6 -methylguanine-DNA methyltransferase gene promoter were detected. This is the second case report of ependymoma with YAP1:FAM118B fusion.

Correction to: Axin gene methylation status correlates with radiosensitivity of lung cancer cells.

Following publication of the original article.

Odd-skipped related 1 inhibits lung cancer proliferation and invasion by reducing Wnt signaling through the suppression of SOX9 and ß-catenin.

The odd-skipped related 1 (OSR1) gene encodes a zinc-finger transcription factor. The expression and significance of OSR1 in human tumors remains unclear. We found that OSR1 was downregulated in lung cancers, and its expression was correlated with poor differentiation. Overexpression of OSR1 by OSR1 gene transfection into H1299 cells (H1299-OSR1) inhibited the proliferation and invasion of lung cancer cells. Knockdown of OSR1 with small interfering (si)RNA against OSR1 in A549 cells (A549-siOSR1) enhanced the proliferation and invasion of lung cancer cells. Western blot analysis showed that the expression level of GSK3ß increased, while that of p-GSK3ß, nuclear ß-catenin, cyclin D1, c-Myc and matrix metallopeptidase 7 significantly decreased in the H1299-OSR1 cells, and this pattern was reversed in the A549-siOSR1 cells compared to that in the control cells. Furthermore, upregulation of sex-determining region Y-box 9 (SOX9) by SOX9 gene transfection increased the expression of ß-catenin, which was inhibited by OSR1. The mRNA and protein expression levels of SOX9 and ß-catenin were reduced in H1299-OSR1 cells and increased in A549-siOSR1 cells. In conclusion, the expression of OSR1 was more reduced in lung cancer tissues than in normal lung tissues, and was correlated with poor differentiation. OSR1 downregulated the activity of the Wnt signaling pathway by suppressing the expression of SOX9 and ß-catenin.

Diffuse midline gliomas with histone H3-K27M mutation: A rare case with PNET-like appearance and neuropil-like islands.

Diffuse midline glioma with histone H3-K27M mutation is a new tumor entity defined by the 2016 WHO Classification of Tumors of the Central Nervous System. A 51-year-old Chinese woman presented with neck pain for a month. Subsequent MRI revealed an intramedullary neoplasm extending from C5 to C7. Histologically, the cellular area of the tumor was composed of primitive, poorly differentiated, small cells with scant cytoplasm, nuclear molding, and brisk mitotic activity, exhibiting PNET-like appearance, while in the hypocellular area, oligodendroglioma-like cells were observed. More importantly, neuropil-like islands were observed in the cellular area. Microvascular proliferation was noted, with no necrosis. Besides histone H3K27M mutation, immunohistochemical staining also showed that the tumor cells were positive for oligodendrocyte lineage transcription factor 2 and ATRX. The neuropil-like areas were positive for synaptophysin, intermingled with scattered neuronal nuclear antigen positive cells. The Ki-67 proliferation index was about 30%, and tumor cells were highly immunopositive for p53. Sequencing for IDH1 codon 132 and IDH2 codon 172 gene mutations showed negative results. Furthermore, fluorescent analysis revealed 1p deletion in the lesion but no 19q deletion. Based on these findings, the tumor was diagnosed as diffuse midline gliomas with histone H3-K27M mutation in the spinal cord, corresponding to WHO grade IV. After 4 months of remission, the tumor recurred; 2 months later, the patient died. Herein, we report an extremely rare case of diffuse midline glioma with histone H3K27M mutation, which was morphologically characterized simultaneously by primitive neuroectodermal tumor-like appearance and neuropil-like islands.

Repression of ESR1 transcription by MYOD potentiates letrozole-resistance in ERα-positive breast cancer cells.

Transcriptional silencing of estrogen receptor α (ERα) expression is an important etiology contributing to the letrozole-resistance in ERα-positive breast cancer (BCa) cells, but the transcription factors responsible for this transcriptional repression remain largely unidentified. Here we report that the expression of the basic helix-loop-helix myogenic regulatory factor MYOD was abnormally up-regulated in letrozole-resistant BCa tissues and in experimentally-induced letrozole-resistant BCa cells. Overexpression of the exogenous MYOD impaired ERα expression and potentiated letrozole-resistance in letrozole-sensitive MCF7 cells, whereas MYOD knockdown could effectively restore ERα expression and thereby promote letrozole-sensitivity in letrozole-resistant MCF-7/LR cells. Mechanistically, MYOD was shown to be a potent corepressor of ESR1 transcription, and this transcriptional repression was significantly enhanced in the presence of letrozole treatment. Thus, targeted inhibition of MYOD may restore ERα level and lead to resensitization to letrozole-based hormone therapy, providing a novel therapeutic strategy for relapsed ERα-positive BCa patients. Our data also underscore an unexpected chemotherapeutic facet of MYOD, which may operate as a novel regulator of BCa biology.

Inversin correlates with the malignant phenotype of non-small cell lung cancer and promotes the invasiveness of lung cancer cells.

Inversin, encoded by NPHP2, is one of the 10 NPHP proteins known to be involved in nephronophthisis (an autosomal recessive cystic kidney). Although the previous reports showed that inversin played an important role in embryonic development and renal diseases, its function in cancer was not revealed clearly so far. As measured by immunohistochemical staining, inversin was highly expressed in the cytoplasm of lung cancer samples (63.4%, 161/254) compared with adjacent normal lung tissues (22.0%, 11/50, p < 0.01). Moreover, its expression was positively correlated with differentiation ( p = 0.014), tumor node metastasis staging ( p = 0.007), and lymph node metastasis ( p = 0.020). The overall survival of non-small cell lung cancer patients with inversin positive expression (45.41 ± 1.800 months) was significantly reduced compared with those with inversin negative expression (51.046 ± 2.238 months, p = 0.042). Consistently, we found that the invasion capacity of A549 cells transfected with inversin was significantly stronger than that of control cells ( p < 0.05), while inversin siRNA-treatment significantly reduced cell invasion in H1299 cells ( p < 0.05). Additionally, we demonstrated that inversin could upregulate the expression of N-cadherin, Vimentin, matrix metalloproteinase-2, and matrix metalloproteinase-9. Collectively, these results indicated that inversin might promote the tumorigenicity of lung cancer cells and serve as a novel therapeutic target of non-small cell lung cancer.

IQ-domain GTPase-activating protein 1 promotes the malignant phenotype of invasive ductal breast carcinoma via canonical Wnt pathway.

IQ-domain GTPase-activating protein 1 is a scaffolding protein with multidomain which plays a role in modulating dishevelled (Dvl) nuclear translocation in canonical Wnt pathway. However, the biological function and mechanism of IQ-domain GTPase-activating protein 1 in invasive ductal carcinoma (IDC) remain unknown. In this study, we found that IQ-domain GTPase-activating protein 1 expression was elevated in invasive ductal carcinoma, which was positively correlated with tumor grade, lymphatic metastasis, and poor prognosis. Coexpression of IQ-domain GTPase-activating protein 1 and Dvl in the nucleus and cytoplasm of invasive ductal carcinoma was significantly correlated but not in the membrane. Postoperative survival in the patients with their coexpression in the nucleus and cytoplasm was obviously lower than that without coexpression. The positive expression rates of c-myc and cyclin D1 were significantly higher in the patients with nuclear coexpression of Dvl and IQ-domain GTPase-activating protein 1 than that with cytoplasmic coexpression, correlating with poor prognosis. IQ-domain GTPase-activating protein 1 significantly enhanced cell proliferation and invasion in invasive ductal carcinoma cell lines by interacting with Dvl in cytoplasm to promote Dvl nuclear translocation so as to upregulate the expression of c-myc and cyclin D1. Collectively, our data suggest that IQ-domain GTPase-activating protein 1 may promote the malignant phenotype of invasive ductal carcinoma via canonical Wnt signaling, and it could be used as a potential prognostic biomarker for breast cancer patients.

HPV16 E6/E7 upregulates HIF-2α and VEGF by inhibiting LKB1 in lung cancer cells.

Long-term persistent infection of HPV16 E6/E7 is frequently associated with lung cancers, especially in non-smokers and in Asians. However, molecular mechanisms of HPV16 E6/E7 induction of lung cancer are not fully understood. Using bi-directional genetic manipulation and four well-established lung cancer cell lines, we showed HPV16 E6/E7 downregulated expression of liver kinase B1 at both protein and messenger RNA levels; liver kinase B1 downregulated hypoxia-inducible factor 2α at protein level but not at messenger RNA level, and hypoxia-inducible factor 2α upregulated vascular endothelial growth factor at both protein and messenger RNA levels. This is the first study to show hypoxia-inducible factor 2α as a downstream effector of liver kinase B1 in lung cancer cells. Our results indicate that HPV16 E6/E7 indirectly upregulated the expression of vascular endothelial growth factor by inhibition of liver kinase B1 expression and upregulation of hypoxia-inducible factor 2α expression, thus propose a human papillomavirus-liver kinase B1-hypoxia-inducible factor 2α-vascular endothelial growth factor axis for the tumorigenesis of lung cancer. Our study also provides new evidence to support the critical role of liver kinase B1 in the pathogenesis of human papillomavirus-related lung cancer and suggests novel therapeutic targets.

Cerebellar hemangioblastoma with perivascular pseudorosette formation and glial differentiation: A case report.

Hemangioblastoma is a well-circumscribed, highly vascular, lipid-rich and low-grade tumor of uncertain histogenesis. Its histopathological features have been well established. Herein, we present a case of cerebellar hemangioblastoma in a 43-year-old woman. Histologically, the tumor was predominantly composed of cellular areas showing eosinophilic or vacuolated stromal cells arranged in nests and sheets. Focally, conventional reticular areas could be seen. Additionally, in some areas, the stromal cells were arranged radially around blood vessels, exhibiting perivascular pseudorosette structures, which were similar mostly to those of ependymomas. Immunohistochemically, the stromal cells markedly showed diffused staining for Vimentin, S-100, CD56, NSE, inhibin-a, podoplanin, alpha-Thalassemia/mental retardation syndrome X and carbonic anhydrase IX, and were negative for cytokeratin, epithelial membrane antigen, oligodendrocyte transcription factor 2, neuronal nuclear antigen, synaptophysin, isocitrate dehydrogenase 1 (R132H), P53 and CD34. Interestingly, the reticular and cellular areas either showed no or individual scattering of the GFAP-positive cells, respectively, while, the perivascular pseudorosette areas strongly and diffusely expressed GFAP. Nuclear mitosis and necrosis were not observed. The MIB-1 antibody labeling index was especially low (about 3%). Based on these findings, the patient was diagnosed with cerebellar hemangioblastoma. In the present case, we documented a distinctive histological appearance of perivascular pseudorosettes in hemangioblastoma and provided the evidence for stromal cells with glial differentiation.

MiR-107 down-regulates SIAH1 expression in human breast cancer cells and silencing of miR-107 inhibits tumor growth in a nude mouse model of triple-negative breast cancer.

We have reported that SIAH1 is down-regulated and associated with apoptosis and invasion in human breast cancer. However, the molecular mechanisms leading to SIAH1 down-regulation remain to be elucidated. Here, we demonstrated that miR-107 directly down-regulates SIAH1 expression in human breast cancer cells. Over- expression of miR-107 reduced SIAH1 expression, promoted human breast cancer cell proliferation, colony formation, migration and invasion, and inhibited apoptosis. On the contrary, silencing of miR-107 increased SIAH1 expression and inhibited the tumor growth of MDA-MB-231 cells, a kind of triple-negative breast cancer (TNBC) cells, in vitro and in vivo. Our results reveal that miR-107 is an upstream regulator for SIAH1 down-regulation in human breast cancer cells and miR-107 provides a potential effective target for the treatment of TNBC.

FBXO25 promotes cell proliferation, invasion, and migration of NSCLC.

FBXO25 is a recently discovered protein that belongs to the Fbx class of the F-box family of proteins, and F-box proteins play a crucial role in tumorigenesis. However, the function of FBXO25 in cancer was not revealed so far. As measured by immunohistochemical staining, FBXO25 was highly expressed in the cytoplasm and nucleus of lung cancer samples (64.2 %, 136/212), compared with adjacent normal lung tissues (23.3 %, 7/30, p < 0.01). In addition, its expression was positively correlated with TNM staging (p < 0.001) and lymph node metastasis (p = 0.017). The overall survival of non-small-cell lung cancer (NSCLC) patients with FBXO25-positive expression (40.646 ± 1.745 months) was significantly reduced compared with those with FBXO25-negative expression (46.548 ± 2.176 months, p = 0.023). Consistently, we found that the proliferation, invasion, and migration capacity of A549 cells transfected with FBXO25 were significantly greater than those of control cells, while interference of FBXO25 could significantly inhibit cell proliferation, invasion, and migration in H1299 cells. Furthermore, we demonstrated that FBXO25 could regulate the expression of ß-catenin, YAP, some cyclins, and matrix metalloproteinases (MMPs). Collectively, these results indicate that FBXO25 may promote the tumorigenicity of lung cancer cells and might serve as a novel therapeutic target of NSCLC.

Overexpression of HPV16 E6/E7 mediated HIF-1α upregulation of GLUT1 expression in lung cancer cells.

High-risk human papillomavirus (HPV) infection may play an important role in non-small cell lung carcinoma (NSCLC) development. However, some recent studies have proved that it was not directly associated with lung cancer. The aim of this study was to evaluate the underlying molecular mechanism that HPV16 regulate the expression of GLUT1 and may promote the development of lung cancer. HPV16, HIF-1α, and GLUT1 were detected in pleural effusions of patients with lung cancer (n = 95) and with benign lung disease (n = 55) by immunocytochemistry. Western blotting and qRT-PCR were used to detect the expression chances of HPV16 E6/E7, HIF-1α, and GLUT1 in lung cancer cells. HPV16, HIF-1α, and GLUT1 were significantly more likely to be expressed in the malignant group than in the benign group as detected by immunocytochemistry (ICC), and HIF-1α was significantly correlated with HPV16 or GLUT1 in the malignant group (P < 0.01). Expression changes of E6 and E7 significantly promoted the protein expression of HIF-1α, the expression of both protein and mRNA of GLUT1, but had no effect on the expression of HIF-1α mRNA in lung cancer cells. After inhibition of HIF-1α, it obviously downregulated the expression of both protein and mRNA of GLUT1 in lung cancer cells. E6 and E7 regulated the expression of GLUT1 may be due to the mediation of HIF-1α in lung cancer cells. These results suggest that both E6 and E7 play the important role in the regulation of Warburg effect and may be a valuable therapeutic target for HPV-related cancer.

ARVCF expression is significantly correlated with the malignant phenotype of non-small cell lung cancer.

Armadillo repeat gene deleted in velo-cardio-facial syndrome (ARVCF) is a member of the p120 catenin (p120ctn) family; it contains nine central Armadillo repeats and binds to the juxtamembrane domain of E-cadherin. We used immunohistochemistry to measure ARVCF expression in 121 patients with NSCLC and western blotting to examine differences in ARVCF expression between lung cancer and adjacent normal lung tissues. We interfered with ARVCF expression in two lung cancer cell lines and measured its effects on invasion and proliferation. ARVCF expression correlated with the malignant phenotype and poor prognosis. We also observed ARVCF-dependent changes in small GTPase (mainly RhoA) activity in lung cancer cells. We confirmed that ARVCF plays an important role in the malignant phenotype.

Expression and diagnostic implications of carbonic anhydrase IX in several tumours with predominantly clear cell morphology.

AIMS: High expression of carbonic anhydrase IX (CA IX) has been reported in clear cell renal cell carcinoma (ccRCC); few studies have reported CA IX expression in other tumours with predominantly clear cell morphology. The aim of study was to examine the expression and diagnostic implications of CA IX in these latter tumours. METHODS AND RESULTS: An immunohistochemical study was performed of 159 tumours with predominantly clear cell morphology. The results showed that, in addition to primary (25/25) and metastatic (10/11) ccRCC, CA IX was also expressed in breast (2/2), pulmonary (3/5) and hepatic (1/4) clear cell carcinoma, urothelial carcinoma with clear cell change (3/6), clear cell meningioma (4/6) and ependymoma (2/3), haemangioblastoma (10/10), and clear cell hidradenoma (5/6). However, while strong and diffuse positivity for CA IX was observed in ccRCC, clear cell breast carcinoma, haemangioblastoma, and clear cell hidradenoma, the other cases showed predominantly focal positivity for CA IX. In particular, CA IX staining was often seen at the periphery of necrotic areas. CONCLUSIONS: Our results indicate that strong and diffuse CA IX expression may be useful for differentiating ccRCC from several clear cell tumours, with the exception of clear cell breast carcinoma, haemangioblastoma, and clear cell hidradenoma.

δ-catenin promotes the malignant phenotype in breast cancer.

δ-Catenin is a member of the p120 catenin family. Similar to p120ctn, δ-catenin contains nine central Armadillo repeats and binds to the juxtamembrane domain (JMD) of E-cadherin. We used immunohistochemistry to detect δ-catenin expression in breast carcinoma (128 cases), and δ-catenin mRNA and protein expression was detected by reverse transcription-polymerase chain reaction and Western blotting (45 cases). The effects of δ-catenin on the activity of small GTPases and the biological behavior of breast cancer cells were explored by pulldown, flow cytometry, methyl thiazolyl tetrazolium, and Matrigel invasion assays. The results showed that δ-catenin expression increased in breast cancer tissues and was associated with a higher degree of malignancy (invasive lobular breast cancer, high tumor-node-metastasis stage, lymph node metastasis, and C-erbB-2+) and poor prognosis. Postoperative survival was shorter in patients with δ-catenin-positive expression than in patients with negative expression. δ-Catenin may regulate Cdc42/Rac1 activity, promote proliferation and invasion of breast cancer cells, and alter cell cycle progression. We conclude that δ-catenin tends to overexpress in breast carcinoma and promotes the malignant phenotype.

Proliferative role of TRAF4 in breast cancer by upregulating PRMT5 nuclear expression.

In this study, we examined protein arginine methyltransferase 5 (PRMT5) and tumor necrosis factor receptor-associated 4 (TRAF4) expression in breast cancer to find the interaction mechanism between the two. We examined TRAF4 and PRMT5 expression by immunohistochemistry and found that their expression is positively correlated in breast cancer. Besides, PRMT5 expression was significantly associated with histological type and tumor size (p < 0.05). PRMT5 nuclear expression was significantly associated with HER2 expression (p < 0.05). PRMT5 and TRAF4 were both overexpressed in breast cancer tissues and cells, and we found that PRMT5 binds to the zinc finger structures in TRAF4 by coimmunoprecipitation and Western blotting. We also tested the potential regulatory effect between TRAF4 and PRMT5. TRAF4 upregulated PRMT5 expression, which occurred predominantly in the nucleus, on which TRAF4 promotion of cell proliferation in breast cancer is mainly dependent. PRMT5 may play an important role in activation of the NF-κB signaling pathway.