The effects of solar ultraviolet-b on the proteome and antioxidant defense systems in soybean leaves

Stratospheric ozone depletion has caused an increase in the amount of ultraviolet-B (UV-B) radiation reaching the earth's surface. Some investigations have demonstrated that UV-B has effects on protein accumulation and active oxygen species (AOS) metabolism in plants. Because of the unrealistically high UV-B level and low levels of ultraviolet-A (UV-A) and photosythetically active radiation (PAR) in indoor studies it has been questioned whether results from these studies can be extrapolated to field responses. In the present study two isolines of the soybean cultivar Clark with different flavonoid contents were grown in the field with or without natural levels of UV-B. The leaf proteome and AOS metabolism were examined. Ambient solar UV-B radiation changed AOS metabolism by decreasing superoxide dismutase activity and increasing the activities of ascorbate peroxidase, catalase and glutathione reductase relative to UV-B exclusion treatments. This resulted in decreased ascorbic acid and increased dehydroascorbate content. Proteomic analysis showed that the accumulations of 67 protein spots were significantly affected by solar UV-B. Proteins related to photosystems in photosynthesis were increased in abundance while enzymes involved in the primary carbon and nitrogen metabolism were decreased. This could lead to overreduction of the photosynthetic electron transport chain and enhance the formation of superoxide radicals and singlet oxygen. The magenta line, which has reduced flavonoid levels, had greater proteomic and oxidative responses than the standard line, suggesting that flavonoids act as screening compounds and antioxidants in protecting plants from UV-B radiation. These line-specific differences occurred even under UV-B exclusion, which may be due to high UV-A, PAR or temperature. More detailed studies are needed to elucidate the effects of other environmental factors on the soybean leaf proteome and AOS metabolism under field conditions

Venous thromboembolism after oral and maxillofacial oncologic surgery : report and analysis of 14 cases in Chinese population

Venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) is a leading cause of death in cancer patients. The aim of this study was to explore the potential risk factor of VTE in oral and maxillofacial oncological surgery. The data of patients who received operation in our institution were gathered in this retrospective study. A diagnosis of VTE was screened and confirmed by computer tomography angiography (CTA) of pulmonary artery or ultrasonography examination of lower extremity. Medical history and all perioperative details were analyzed. 14 patients were diagnosed as VTE, including 6 cases of PE, 7 cases of DVT, 1case of DVT and PE. The mean age of these patients was 62.07 years. Reconstruction was performed in 12 patients of these cases, most of which were diagnosed as malignance. Mean length of surgery was 8.74 hours, and lower extremity deep venous cannula (DVC) was performed in all these patients. We analyzed several characters of oral and maxillofacial surgery and suggested pay attention to lower extremity DVC which had a high correlation with DVT according to our data

CCND1 as a Predictive Biomarker of Neoadjuvant Chemotherapy in Patients with Locally Advanced Head and Neck Squamous Cell Carcinoma

BACKGROUND: Cyclin D1 (CCND1) has been associated with chemotherapy resistance and poor prognosis. In this study, we tested the hypothesis that CCND1 expression determines response and clinical outcomes in locally advanced head and neck squamous cell carcinoma (HNSCC) patients treated with neoadjuvant chemotherapy followed by surgery and radiotherapy. METHODOLOGY AND FINDINGS: 224 patients with HNSCC were treated with either cisplatin-based chemotherapy followed by surgery and radiotherapy (neoadjuvant group, n = 100) or surgery and radiotherapy (non-neoadjuvant group, n = 124). CCND1 expression was assessed by immunohistochemistry. CCND1 levels were analyzed with chemotherapy response, disease-free survival (DFS) and overall survival (OS). There was no significant difference between the neoadjuvant group and non-neoadjuvant group in DFS and OS (p = 0.929 and p = 0.760) when patients treated with the indiscriminate administration of cisplatin-based chemotherapy. However, in the neoadjuvant group, patients whose tumors showed a low CCND1 expression more likely respond to chemotherapy (p<0.001) and had a significantly better OS and DFS than those whose tumors showed a high CCND1 expression (73% vs 8%, p<0.001; 63% vs 6%, p<0.001). Importantly, patients with a low CCND1 expression in neoadjuvant group received more survival benefits than those in non-neoadjuvant group (p = 0.016), however patients with a high CCND1 expression and treated with neoadjuvant chemotherapy had a significantly poor OS compared to those treated with surgery and radiotherapy (p = 0.032). A multivariate survival analysis also showed CCND1 expression was an independent predictive factor (p<0.001). CONCLUSIONS: This study suggests that some but not all patients with HNSCC may benefit from neoadjuvant chemotherapy with cisplatin-based regimen and CCND1 expression may serve as a predictive biomarker in selecting patients undergo less than two cycles of neoadjuvant chemotherapy

A covalently bound inhibitor triggers EZH2 degradation through CHIP‐mediated ubiquitination

Abstract Enhancer of zeste homolog 2 (EZH2) has been characterized as a critical oncogene and a promising drug target in human malignant tumors. The current EZH2 inhibitors strongly suppress the enhanced enzymatic function of mutant EZH2 in some lymphomas. However, the recent identification of a PRC2‐ and methyltransferase‐independent role of EZH2 indicates that a complete suppression of all oncogenic functions of EZH2 is needed. Here, we report a unique EZH2‐targeting strategy by identifying a gambogenic acid (GNA) derivative as a novel agent that specifically and covalently bound to Cys668 within the EZH2‐SET domain, triggering EZH2 degradation through COOH terminus of Hsp70‐interacting protein (CHIP)‐mediated ubiquitination. This class of inhibitors significantly suppressed H3K27Me3 and effectively reactivated polycomb repressor complex 2 (PRC2)‐silenced tumor suppressor genes. Moreover, the novel inhibitors significantly suppressed tumor growth in an EZH2‐dependent manner, and tumors bearing a non‐GNA‐interacting C668S‐EZH2 mutation exhibited resistance to the inhibitors. Together, our results identify the inhibition of the signaling pathway that governs GNA‐mediated destruction of EZH2 as a promising anti‐cancer strategy

Root proteomic responses to heat stress in two Agrostis grass species contrasting in heat tolerance

Protein metabolism plays an important role in plant adaptation to heat stress. This study was designed to identify heat-responsive proteins in roots associated with thermotolerance for two C3 grass species contrasting in heat tolerance, thermal Agrostis scabra and heat-sensitive Agrostis stolonifera L. Plants were exposed to 20 °C (control), 30 C (moderate heat stress), or 40 °C (severe heat stress) in growth chambers. Roots were harvested at 2 d and 10 d after temperature treatment. Proteins were extracted and separated by two-dimensional polyacrylamide gel electrophoresis. Seventy protein spots were regulated by heat stress in at least one species. Under both moderate and severe heat stress, more proteins were down-regulated than were up-regulated, and thermal A. scabra roots had more up-regulated proteins than A. stolonifera roots. The sequences of 66 differentially expressed protein spots were identified using mass spectrometry. The results suggested that the up-regulation of sucrose synthase, glutathione S-transferase, superoxide dismutase, and heat shock protein Sti (stress-inducible protein) may contribute to the superior root thermotolerance of A. scabra. In addition, phosphoproteomic analysis indicated that two isoforms of fructose-biphosphate aldolase were highly phosphorylated under heat stress, and thermal A. scabra had greater phosphorylation than A. stolonifera, suggesting that the aldolase phosphorylation might be involved in root thermotolerance

Tumor-Initiating Cells Are Enriched in CD44hi Population in Murine Salivary Gland Tumor

Tumor-initiating cells (T-ICs) discovered in various tumors have been widely reported. However, T-IC populations in salivary gland tumors have yet to be elucidated. Using the established Pleomorphic Adenoma Gene-1 (Plag1) transgenic mouse model of a salivary gland tumor, we identified CD44high (CD44hi) tumor cells, characterized by high levels of CD44 cell surface expression, as the T-ICs for pleomorphic adenomas. These CD44hi tumor cells incorporated 5-bromo-2-deoxyuridine (BrdU), at a lower rate than their CD44negative (CD44neg) counterparts, and also retained BrdU for a long period of time. Cell surface maker analysis revealed that 25% of the CD44hi tumor cells co-express other cancer stem cell markers such as CD133 and CD117. As few as 500 CD44hi tumor cells were sufficient to initiate pleomorphic adenomas in one third of the wildtype mice, whereas more than 1×104 CD44neg cells were needed for the same purpose. In NIH 3T3 cells, Plag1 was capable of activating the gene transcription of Egr1, a known upregulator for CD44. Furthermore, deletion of sequence 81–96 in the Egr1 promoter region abolished the effect of Plag1 on Egr1 upregulation. Our results establish the existence of T-ICs in murine salivary gland tumors, and suggest a potential molecular mechanism for CD44 upregulation

Comparison of protein solubilization methods suitable for proteomic analysis of soybean seed proteins

Extraction of soybean seed proteins for two-dimensional polyacrylamide gel electrophoresis (2D–PAGE) and mass spectrometry analysis is challenging and inconsistent. In this study, we compared four different protein extraction/solubilization methods—urea, thiourea/urea, phenol, and a modified trichloroacetic acid (TCA)/acetone—to determine their efficacy in separating soybean seed proteins by 2D–PAGE. In all four methods, seed storage proteins were well separated by 2D–PAGE with minor variations in the intensity of the spots. The thiourea/urea and TCA methods showed higher protein resolution and spot intensity of all proteins compared with the other two methods. In addition, several less abundant and high molecular weight proteins were clearly resolved and strongly detected using the thiourea/urea and TCA methods. Protein spots obtained from the TCA method were subjected to mass spectrometry analysis to test their quality and compatibility. Fifteen protein spots were selected, digested with trypsin, and analyzed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF–MS) and liquid chromatography mass spectrometry (LC–MS). The proteins identified were β-conglycinin, glycinin, Kunitz trypsin inhibitor, alcohol dehydrogenase, Gly m Bd 28K allergen, and sucrose binding proteins. These results suggest that the thiourea/urea and TCA methods are efficient and reliable methods for 2D separation of soybean seed proteins and subsequent identification by mass spectrometry