CiRS-7 Enhances the Liquid-liquid Phase Separation of miRISC and Promotes DNA Damage Repair.

Noncoding RNAs have been found to play important roles in DNA damage repair, whereas the participation of circRNA remains undisclosed. Here, we characterized ciRS-7, a circRNA containing over 70 putative miR-7-binding sites, as an enhancer of miRISC condensation and DNA repair. Both in vivo and in vitro experiments confirmed the condensation of TNRC6B and AGO2, two core protein components of human miRISC. Moreover, overexpressing ciRS-7 largely increased the condensate number of TNRC6B and AGO2 in cells, while silencing ciRS-7 reduced it. Additionally, miR-7 overexpression also promoted miRISC condensation. Consistent with the previous report that AGO2 participated in RAD51-mediated DNA damage repair, the overexpression of ciRS-7 significantly promoted irradiation-induced DNA damage repair by enhancing RAD51 recruitment. Our results uncover a new role of circRNA in liquid-liquid phase separation and provide new insight into the regulatory mechanism of ciRS-7 on miRISC function and DNA repair.

Diagnosis and Treatment Strategy of Nasogenic Olfactory Dysfunction.

Since the global outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a symptom of the onset of SARS-CoV-2, olfactory dysfunction (OD), has attracted tremendous attention. OD is not only a negative factor for quality of life but also an independent hazard and early biomarker for various diseases, such as Parkinson's and Huntington's diseases. Therefore, early identification and treatment of OD in patients are critical. Many etiological factors are responsible for OD based on current opinions. Sniffin'Sticks are recommended to identify the initial position (central or peripheral) for OD when treating patients clinically. It is worth emphasizing that the olfactory region in nasal cavity is recognized as the primary and critical olfactory receptor. Many nasal diseases, such as those with traumatic, obstructive and inflammatory causes, can lead to OD. The key question is no refined diagnosis or treatment strategy for nasogenic OD currently. This study summarizes the differences in medical history, symptoms, auxiliary examination, treatment and prognosis of different types of nasogenic OD by analyzing the current studies. We propose using olfactory training after 4-6 weeks of initial treatment for nasogenic OD patients with no significant improvement in olfaction. We hope that our research can provide valuable clinical guidance by systematically summarizing the clinical characteristics of nasogenic OD.

Trijugin- and mexicanolide-type limonoids from the fruits of Heynea trijuga that reverse multidrug resistance in MCF-7/DOX cells.

Eleven previously undescribed limonoids, trichisins A-K, including eight structural analogues A-H of trijugin and three H-J mexicanolide derivatives, together with two known mexicanolide derivatives were isolated from the fruits of Heynea trijuga Roxb. ex Sims. The structure determination was based on extensive physical data analyses (NMR, MS), and their basic skeletons and the absolute configurations of trichisins A, B, E, K and trichiconnarone A were assigned via X-ray crystallographic analysis (Cu Kα radiation). The hemiketal motifs in trijugins A, B, and E-G are rare in limonoids. Bioactivity screenings suggested that the trijugin H and mexicanolide-type trichiconnarones A and B limonoids were effective in reversing resistance in MCF-7/DOX cells at a nontoxic concentration of 50 µM with IC50 values of 12.45, 10.86, and 14.96 µM, respectively.

Reversal of multidrug resistance by icaritin in doxorubicin-resistant human osteosarcoma cells.

Multidrug resistance (MDR) is one of the major obstacles in cancer chemotherapy. Our previous study has shown that icariin could reverse MDR in MG-63 doxorubicin-resistant (MG-63/DOX) cells. It is reported that icariin is usually metabolized to icariside II and icaritin. Herein, we investigated the effects of icariin, icariside II, and icaritin (ICT) on reversing MDR in MG-63/DOX cells. Among these compounds, ICT exhibited strongest effect and showed no obvious cytotoxicity effect on both MG-63 and MG-63/DOX cells ranging from 1 to 10 µmol·L-1. Furthermore, ICT increased accumulation of rhodamine 123 and 6-carboxyfluorescein diacetate and enhanced DOX-induced apoptosis in MG-63/DOX cells in a dose-dependent manner. Further studies demonstrated that ICT decreased the mRNA and protein levels of multidrug resistance protein 1 (MDR1) and multidrug resistance-associated protein 1 (MRP1). We also verified that blockade of STAT3 phosphorylation was involved in the reversal effect of multidrug resistance in MG-63/DOX cells. Taken together, these results indicated that ICT may be a potential candidate in chemotherapy for osteosarcoma.

Involucratusins A-H: Unusual Cadinane Dimers from Stahlianthus involucratus with Multidrug Resistance Reversal Activity.

Three novel cadinane dimers, involucratusins A-C (1-3), five unique nor-cadinane-dimers, involucratusins D-H (4-8), together with a known compound (9) were isolated from the rhizomes of Stahlianthus involucratus. Their challenging structures and absolute configurations were determined by spectroscopic data, CD experimentation, chemical conversions and single-crystal X-ray diffraction. Compounds 1-3 are unusual cadinane dimers with new connection and novel cores. Compound 4 is a unique nor-cadinane-dimer, and 5 and 6 are two pairs of hemiketal racemates with novel dinor-cadinane-dimer backbone. Compounds 7 and 8 represent unusual dodecanor-cadinane-dimer and tetradecanor-cadinane-dimer carbon skeletons, respectively. The possible biogenetic pathways of 1-8 were proposed, involving nucleophilic addition, SN2 nucleophilic displacement, [3 + 3] benzannulation, oxidative cleavage, decarboxylation, and oxidative phenol coupling reactions. Multidrug resistance (MDR) reversal activity assay of the isolates were evaluated in doxorubicin-resistant human breast cancer cells (MCF-7/DOX). The combined use of these novel cadinane dimers at a concentration of 10 µM increased the cytotoxicity of doxorubicin by 2.2-5.8-fold. It is the first report about the MDR reversal activity of cadinane dimers.

Meglumine: A novel and efficient catalyst for one-pot, three-component combinatorial synthesis of functionalized 2-amino-4H-pyrans.

An efficient one-pot synthesis of functionalized 2-amino-4H-pyrans by a meglumine-catalyzed three-component reaction has been developed. A broad range of substrates including aromatic and heteroaromatic aldehydes, isatin derivatives, and acenaphthenequinone are condensed with enolizable C-H activated compounds and alkylmalonates to give the desired products in high to excellent yields. This methodology provides an alternative approach for rapid access to construct a diversity-oriented library of 4H-pyrans.

Nimotuzumab enhances the radiosensitivity of cancer cells in vitro by inhibiting radiation-induced DNA damage repair.

BACKGROUND: Nimotuzumab is a humanized IgG1 monoclonal antibody specifically targeting EGFR. In this study, we aimed to investigate the molecular mechanisms of nimotuzumab in its effects of enhancing cancer cell radiosensitivity. PRINCIPAL FINDING: Lung cancer A549 cells and breast cancer MCF-7 cells were pretreated with or without nimotuzumab for 24 h before radiation to perform the clonogenic survival assay and to analyze the cell apoptosis by flow ctyometry. γ-H2AX foci were detected by confocal microscopy to assess the effect of nimotuzumab on radiation induced DNA repair. EGFR activation was examined and the levels of DNA damage repair related proteins in A549 cells at different time point and at varying doses exposure after nimotuzumab and radiation treatment were examined by Western blot. Pretreatment with nimotuzumab reduced clonogenic survival after radiation, inhibited radiation-induced EGFR activation and increased the radiation-induced apoptosis in both A549 cells and MCF-7 cells. The foci of γ-H2AX 24 h after radiation significantly increased in nimotuzumab pretreated cells with different doses. The phosphorylation of AKT and DNA-PKcs were remarkably inhibited in the combination group at each dose point as well as time point. CONCLUSIONS: Our results revealed that the possible mechanism of nimotuzumab enhancing the cancer radiosensitivity is that nimotuzumab inhibited the radiation-induced activation of DNA-PKcs through blocking the PI3K/AKT pathway, which ultimately affected the DNA DSBs repair.

D-penicillamine assisted hydrothermal synthesis of Bi2S3 nanoflowers and their electrochemical application.

Single crystalline flower-like Bi2S3 nanostructures were successfully synthesized via a simple, facile and green hydrothermal method, with the assistance of D-penicillamine. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and found their morphologies mainly depend on the ratios of Bi(3+) to D-penicillamine, as well as the reaction temperature and time. And the possible growth mechanism has been discussed in some detail. In addition, the as-prepared Bi2S3 nanoflowers show good hydrogen storage ability. This strategy can be potentially expanded to prepare other metal chalcogenides materials.

Construction of the yeast whole-cell Rhizopus oryzae lipase biocatalyst with high activity.

Surface display is effectively utilized to construct a whole-cell biocatalyst. Codon optimization has been proven to be effective in maximizing production of heterologous proteins in yeast. Here, the cDNA sequence of Rhizopus oryzae lipase (ROL) was optimized and synthesized according to the codon bias of Saccharomyces cerevisiae, and based on the Saccharomyces cerevisiae cell surface display system with α-agglutinin as an anchor, recombinant yeast displaying fully codon-optimized ROL with high activity was successfully constructed. Compared with the wild-type ROL-displaying yeast, the activity of the codon-optimized ROL yeast whole-cell biocatalyst (25 U/g dried cells) was 12.8-fold higher in a hydrolysis reaction using p-nitrophenyl palmitate (pNPP) as the substrate. To our knowledge, this was the first attempt to combine the techniques of yeast surface display and codon optimization for whole-cell biocatalyst construction. Consequently, the yeast whole-cell ROL biocatalyst was constructed with high activity. The optimum pH and temperature for the yeast whole-cell ROL biocatalyst were pH 7.0 and 40 °C. Furthermore, this whole-cell biocatalyst was applied to the hydrolysis of tributyrin and the resulted conversion of butyric acid reached 96.91% after 144 h.

Effect of celecoxib on proliferation, apoptosis, and survivin expression in human glioma cell line U251.

BACKGROUND AND OBJECTIVE: Celecoxib, one of the new generation of non-steroidal anti-inflammatory drugs (NSAIDs), has a specific inhibitory effect on COX-2. Studies have shown that celecoxib can inhibit the proliferation of tumor cells and induce cell apoptosis, which has been confirmed in colorectal tumors and familial adenomatous polyposis. This study explored the effect of celecoxib on the proliferation and apoptosis of human glioma cell line U251 and elucidated the correlation between the effect of celecoxib and the expression of survivin. METHODS: U251 cells were treated with different concentrations of celecoxib. Cell morphologic changes were observed by optical microscopy. MTT assay was used to detect the absorbance value and to calculate inhibition and survival rates. The rates of apoptosis of U251 cells after 48 h of treatment with celecoxib were assessed by flow cytometry. The expression of survivin was analyzed by immunocytochemistry (ICC) and Western blot analysis. The expression of survivin mRNA was determined by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Significant morphologic changes were shown in U251 cells after treatment with celecoxib. The MTT assay results revealed that celecoxib inhibited the proliferation of U251 cells and the inhibitory rates significantly increased in a dose-and time-dependent manner. After 48 h of treatment with celecoxib, the apoptotic cells could be obviously observed, and the apoptosis rate significantly increased with increases in concentrations of celecoxib. The expression of survivin was observed in the control group, however, the expression of survivin was significantly down-regulated as the concentration of celecoxib increased. The level of survivin mRNA expression in U251 cells was significantly down-regulated after treatment with different concentrations of celecoxib (P < 0.05). CONCLUSIONS: The inhibition of proliferation and apoptosis in U251 cells could be induced by celecoxib in a dose-and time-dependent manner, and its mechanism might be the downregulation of the expression of survivin.

Correlation of ¹8F-FDG PET activity with expressions of survivin, Ki67, and CD34 in non-small-cell lung cancer.

PURPOSE: This work investigates the correlation between positron emission tomography (PET) images and the expressions of survivin, Ki67, and CD34, as well as the clinicopathological characteristics of non-small-cell lung cancer (NSCLC). METHODS: Thirty-three NSCLC cases were scanned with ¹8F-fluorodeoxyglucose (¹8F-FDG), PET before surgery. Tumor resections were used to evaluate the expressions of survivin, Ki67, and CD34 by immunohistochemical assay. Maximum standardized uptake value (SUVmax), immunohistochemical results, as well as clinicopathological characteristics in NSCLC were compared and analyzed. RESULTS: The average SUVmax for the 33 NSCLC was 10.5 ± 5.4. The expressions of survivin and Ki67 were 84.8% (28 of 33) and 72.7% (24 of 33), respectively. The median count of microvasculature vessel density labeled by CD34 was 24.5 ± 6.7. In the entire group, SUVmax was significantly correlated to Ki67, histological type, as well as clinical type (P = 0.010, 0.048, 0.029, respectively). It revealed a median survival of 33 ± 0.6 months for SUVmax below 11 versus a median survival of 27 ± 1.3 months for SUVmax values above 11 (P = 0.013). There were no significant correlations between SUVmax and expressions of survivin and CD34, and no correlations involving age, sex, differentiation, tumor node metastasis stage, and lymph node metastasis. CONCLUSION: SUV-indexed FDG metabolic activity correlated significantly with proliferative activity (Ki67 expression) as well as the histological and clinical tumor type. These biological predictive markers combined with ¹8F-FDG PET might provide more useful information on the diagnosis and prognosis of patients with NSCLC. These conclusions require confirmation with further studies.

[Effectiveness and safety of intragastric balloon for treatment of morbid obesity].

OBJECTIVE: To evaluate the effectiveness and safety of intragastric balloon (IGB) for the treatment of obese Chinese. METHODS: IGB was placed into the stomachs of 48 Chinese patients in Hong Kong, 13 males and 35 females; aged 39 +/- 9 (18 - 65), with the mean baseline body weight (BW) of 106 +/- 26 kg and mean body mass index (BMI) of (40 +/- 9) kg/m(2), 34 (70.8%) with coexistent obesity-related morbidities, who failed to respond to other weight reducing treatment, via routine gastroscopy under intravenous conscious sedation. Restricted balanced diet with 1200 kcal/day and exercise of 150 minutes/week were prescribed after the balloon placement. The IGB was removed endoscopically after at most 180 days. Follow-up was conducted once a week during the first month and then once a month. RESULTS: The median hospital stay and treatment duration were 1 (IQR 1:2.25) day and 174 (IQR 166:181) days respectively. The BW, BMI, and waist circumference were significantly decreased after the IGB placement (all P < 0.01) with the mean BW loss of (13 +/- 7) kg, mean BMI loss of (5 +/- 3) kg/m(2), mean excessive body weight loss of (45 +/- 36)%, and mean waist circumference loss of (12 +/- 8) cm. 66.7% of the patients were satisfied with the treatment. No serious complication related to IGB was noted. CONCLUSION: IGB is a safe and effective device that achieves moderate weight loss in obese Chinese.

A new picfeltarraenone glycoside from Picria fel-terrae.

AIM: To investigate the chemical constituents from Picria fel-terrae Lour. METHODS: Column chromatography techniques were used to isolate the chemical constituents, physico-chemical constants and spectroscopic analysis were employed for structural elucidation. Results Two triterpenoids named picfeltarraenone I (1) and picfeltarraenin XI (2) were isolated, and their structures were established to be 3,11,22-trioxo-16alpha-hydroxy-(20S,24)-epoxy-cucurbit-5,23-diene (1) and 3,11,22-trioxo-16alpha-hydroxy-(20S,24)-epoxy-cucurbit-5, 23-diene-2beta-O-beta-D-glucopyranoside (2), respectively. CONCLUSION: Compound 2 is a new compound, the 13CNMR data of compound 1 is reported for the first

Clinical and dosimetric factors of radiation-induced esophageal injury: radiation-induced esophageal toxicity.

AIM: To analyze the clinical and dosimetric predictive factors for radiation-induced esophageal injury in patients with non-small-cell lung cancer (NSCLC) during three-dimensional conformal radiotherapy (3D-CRT). METHODS: We retrospectively analyzed 208 consecutive patients (146 men and 62 women) with NSCLC treated with 3D-CRT. The median age of the patients was 64 years (range 35-87 years). The clinical and treatment parameters including gender, age, performance status, sequential chemotherapy, concurrent chemotherapy, presence of carinal or subcarinal lymph nodes, pretreatment weight loss, mean dose to the entire esophagus, maximal point dose to the esophagus, and percentage of volume of esophagus receiving >55 Gy were studied. Clinical and dosimetric factors for radiation-induced acute and late grade 3-5 esophageal injury were analyzed according to Radiation Therapy Oncology Group (RTOG) criteria. RESULTS: Twenty-five (12%) of the two hundred and eight patients developed acute or late grade 3-5 esophageal injury. Among them, nine patients had both acute and late grade 3-5 esophageal injury, two died of late esophageal perforation. Concurrent chemotherapy and maximal point dose to the esophagus > or =60 Gy were significantly associated with the risk of grade 3-5 esophageal injury. Fifty-four (26%) of the two hundred and eight patients received concurrent chemotherapy. Among them, 25 (46%) developed grade 3-5 esophageal injury (P = 0.0001<0.01). However, no grade 3-5 esophageal injury occurred in patients who received a maximal point dose to the esophagus <60 Gy (P = 0.0001<0.01). CONCLUSION: Concurrent chemotherapy and the maximal esophageal point dose > or =60 Gy are significantly associated with the risk of grade 3-5 esophageal injury in patients with NSCLC treated with 3D-CRT.