Ubiquitin-dependent Argonauteprotein MEL1 degradation is essential for rice sporogenesis and phasiRNA target regulation.

MEIOSIS ARRESTED AT LEPTOTENE1 (MEL1), a rice (Oryza sativa) Argonaute (AGO) protein, has been reported to function specifically at premeiotic and meiotic stages of germ cell development and is associated with a novel class of germ cell-specific small noncoding RNAs called phased small RNAs (phasiRNAs). MEL1 accumulation is temporally and spatially regulated and is eliminated after meiosis. However, the metabolism and turnover (i.e. the homeostasis) of MEL1 during germ cell development remains unknown. Here, we show that MEL1 is ubiquitinated and subsequently degraded via the proteasome pathway in vivo during late sporogenesis. Abnormal accumulation of MEL1 after meiosis leads to a semi-sterile phenotype. We identified a monocot-specific E3 ligase, XBOS36, a CULLIN RING-box protein, that is responsible for the degradation of MEL1. Ubiquitination at four K residues at the N terminus of MEL1 by XBOS36 induces its degradation. Importantly, inhibition of MEL1 degradation either by XBOS36 knockdown or by MEL1 overexpression prevents the formation of pollen at the microspore stage. Further mechanistic analysis showed that disrupting MEL1 homeostasis in germ cells leads to off-target cleavage of phasiRNA target genes. Our findings thus provide insight into the communication between a monocot-specific E3 ligase and an AGO protein during plant reproductive development.

Comparison of therapeutic outcomes in esophageal squamous cell carcinoma following neoadjuvant chemoradiotherapy: A prospective observational cohort study.

BACKGROUND: Patients with locally advanced esophageal squamous cell carcinoma (ESCC) following neoadjuvant chemoradiotherapy (nCRT) may not always receive resection despite the possible achievement of a pathologic complete response (pCR) being associated with superior survival benefit. We aimed to compare outcomes among ESCC patients with or without pCR and those refusing surgery. METHODS: In total, 111 medically operable, non-cervical ESCC patients after the same protocol of nCRT (platinum/5-fluorouracil plus radiation 50Gy) were prospectively enrolled between 2011 and 2021. Eighty-three of them underwent esophagectomy comprising pCR (n = 32) and non-pCR (n = 51), while 28 operable patients declined surgery (refusal-of-surgery group). Predictors and survival data were analyzed. RESULTS: In terms of esophagectomy, 38.5% (32/83) patients achieved pCR. The pCR group exhibited better pretreatment performance status than the non-pCR group (adjusted odds ratio: 0.11, 95% confidence interval: 0.03-0.58; p = 0.01). Among pCR, non-pCR, and refusal-of-surgery groups, the 5-year overall survival (OS) rates were 56%, 29% and 50% (p = 0.08) and progression-free survival (PFS) rates were 52%, 28% and 36% (p = 0.07) respectively. The pCR group had significantly better OS and PFS than the non-PCR group (adjusted hazard ratio: 2.33 and 1.93, p = 0.02 and 0.049 respectively) but not the refusal-of-surgery group. CONCLUSION: Better pretreatment performance status is associated with higher chance of pCR. Consistent with previous studies, we found attainment of pCR confers the best OS and PFS. Suboptimal OS in the refusal-of-surgery group reflects some of them would have residual disease in addition to complete remission. Further studies are needed to identify prognostic factors of pCR to select candidates who could validly decline esophagectomy.

Risk factors of stent migration in esophageal cancer patients who underwent fully-covered self-expanding metal stents for malignant dysphagia or tracheoesophageal fistula.

BACKGROUND: More than 50% of esophageal cancer patients are diagnosed with advanced diseases and commonly experience dysphagia, some of whom even have tracheoesophageal fistula. Self-expandable metal stent (SEMS) is one of the recommended palliative methods, although complications such as chest pain and stent migration are not uncommon. The goal of this study was to examine the predictors of stent migration. METHODS: We conducted a retrospective cohort study to include patients with esophageal cancer and dysphagia/tracheoesophageal fistula. Clinicopathological information, stent characteristics and patient outcomes were collected for analysis, while side-effects of SEMS were recorded, potential predictors were examined, and patients' nutritional outcomes were compared in the migration and non-migration groups. RESULTS: A total of 54 patients with esophageal cancer who received fully covered SEMS between 2013 and 2022 were included. We found tumor across the esophagogastric junction (adjusted odds ratio (OR) = 32.64, P = 0.01) and the female sex (adjusted OR = 12.5, P = 0.02) were significant predictors for stent migration. There was a decreasing tendency in body mass index/body weight in migration and non-migration groups, but the former had a steeper downslope. CONCLUSION: Fully covered SEMS is a safe and effective strategy to palliate dysphagia or fistula. Tumor across esophagogastric junction and the female sex were higher risk predictors of stent migration. A careful patient selection would optimize the effects of SEMS placement, especially in those with short-expected lifespan.

Harmine inhibits the proliferation and migration and promotes the apoptosis of colon cancer cells via inhibition of the FAK/AKT and ERK1/2/CREB signaling pathways.

Harmine is present in a variety of medicinal plants, and its effects on colon cancer cells remain unclear. Here, we found that harmine exhibited significant inhibitory effects on the proliferation of colon cancer cells by inhibiting the phosphorylation levels of the FAK/AKT and ERK1/2/CREB. Furthermore, harmine also inhibited the migration of colon cancer cells and suppressed the expression levels of MMP-2, MMP-9, and VEGF. Additionally, harmine-induced apoptosis in colon cancer cells by regulating the expression of Bcl-2 and Bax. In conclusion, our findings suggest that harmine exerts a significant inhibitory effect on the development of colon cancer cells.

Next-Generation Sequencing in Lung Cancers-A Single-Center Experience in Taiwan.

Background and Objectives: Lung cancer is a leading cause of cancer mortality in Taiwan. With rapid advancement of targeted therapeutics in non-small cell lung cancers, next-generation sequencing (NGS) is becoming an important tool for biomarker testing. In this study, we describe institutional experience of NGS analysis in non-small cell carcinoma (NSCLC). Materials and Methods: A cohort of 73 cases was identified from the institutional pathology archive in the period between November 2020 and December 2022. Results: Adenocarcinoma was the most common histologic type (91.8%). Most patients presented with stage IIIB and beyond (87.7%). Twenty-nine patients (39.7%) were evaluated at the time of initial diagnosis, while the others had received prior chemotherapy or targeted therapy. The most frequently mutated gene was EGFR (63%), and this was followed by TP53 (50.7%), KRAS (13.7%), RB1 (13.7%), and CDKN2A (13.7%). Clinically actionable mutations associated with a guideline-suggested targeted therapy were identified in 55 cases (75.3%) overall, and in 47.1% of cases excluding EGFR TKI-sensitizing mutation. Biomarkers other than EGFR TKI-sensitizing mutations were compared. Cases without TKI-sensitizing EGFR mutation had more level 1 or 2 biomarkers (excluding EGFR TKI-sensitizing mutations) than cases with TKI-sensitizing EGFR mutations (47.1% versus 20.1%, p = 0.016). Progressive disease was associated with co-occurrence of clinically actionable mutations (20.5% versus 0%, p < 0.05). Eight of the nine cases with co-occurring actionable genetic alternations had an EGFR mutation. After an NGS test, 46.1% of actionable or potentially actionable genetic alternations led to patients receiving a matched therapy. Conclusions: Our study demonstrated that NGS analysis identifies therapeutic targets and may guide treatment strategies in NSCLC. NGS tests may be advantageous over multiple single-gene tests for optimization of treatment plans, especially for those with non-EGFR mutations or those with progressive disease.

Lobectomy Versus Sublobar Resection in Simultaneous Bilateral Thoracoscopic Lung Resection.

BACKGROUND: Simultaneous bilateral thoracoscopic lung resection (SBTLR) has been shown to be a feasible and efficacious approach for a wide range of pulmonary conditions. Our aim was to evaluate the impact of different procedures on surgical outcomes in patients receiving SBTLR. METHODS: Between 2012 and 2021, 207 patients with bilateral lung neoplasms who underwent SBTLR were retrospectively reviewed. Fifty-one patients received ipsilateral plus contralateral lobectomy or sublobectomy (lobar group), whilst 156 patients received bilateral sublobectomy (sublobar group). Propensity scores were calculated and matched. Perioperative and clinicopathologic outcomes were compared. RESULTS: The lobar group had a greater mean age (64.5 vs. 60.0 years, p = 0.008), longer operative time (254 vs. 205 min, p < 0.001), and more blood loss (74 vs. 46 ml, p < 0.001). The sublobar group had fewer complications (6.4 vs. 19.6%, p = 0.006), shorter hospital stay (4.8 vs. 7.4 days, p < 0.001), and lower hospital costs (p = 0.03). Among 50 pairs of matched groups, significant differences were found only in operative time, hospital stay, and costs. Maximum tumor size and pathological features differed significantly before and after matching (all p < 0.05), with the lobar group consistently demonstrating a larger main tumor (median, 2.5 cm) and a higher percentage of primary lung cancer (84%). Multivariate logistic regression analysis showed that a longer operative time was the factor associated with more complications (OR: 1.01; 95% CI 1.00-1.02, p = 0.002). CONCLUSIONS: With regard to SBTLR, our data suggests that sublobectomy may reduce the prolonged recovery, hospital costs, and complications incurred by lobectomy, without compromising oncological outcomes.

Experience of Simultaneous Bilateral Open Surgery and VATS for Pulmonary Metastasectomy.

BACKGROUND: Resection is the current treatment of choice for resectable bilateral pulmonary metastases. This study aimed to compare the differences in outcomes between simultaneous bilateral open and video-assisted thoracic surgery (VATS) for pulmonary metastasectomy. METHODS: Forty-three patients underwent pulmonary metastasectomy through one-stage bilateral open thoracotomy (n = 16) and VATS (n = 27) between 2011 and 2020. Perioperative and oncological data were analyzed. RESULTS: The predominant primary tumor histology in both groups was colorectal cancer. The operative time, blood loss, and pain score on postoperative day 1 (POD1) were higher in the open group (p < 0.001, 0.009, and 0.03, respectively). No significant differences in pain score on POD2 and POD3, postoperative length of stay, or complications were found. Notably, numbers of the resected metastatic lung nodules were significantly greater in the open group (median number: 9.5 vs. 3, p < 0.001). Recurrence-free survival (RFS) and overall survival (OS) were comparable. The median RFS was 15 months (interquartile range [IQR], 6-22) in the open group and 18 months (IQR, 8-47) in the VATS group. The median OS was 28 months (IQR, 14-44) and 29 months (IQR, 15-54) in the open group and VATS group, respectively. CONCLUSION: One-stage bilateral pulmonary metastasectomy is safe and reduces medical expenditures in selected patients regardless of surgical approach. Although the open group harbored a greater number of metastatic foci, perioperative and oncological outcomes were similar to that of the VATS group.

Intra-Articular Lactate Dehydrogenase A Inhibitor Oxamate Reduces Experimental Osteoarthritis and Nociception in Rats via Possible Alteration of Glycolysis-Related Protein Expression in Cartilage Tissue.

Osteoarthritis (OA) is the most common form of arthritis and joint disorder worldwide. Metabolic reprogramming of osteoarthritic chondrocytes from oxidative phosphorylation to glycolysis results in the accumulation of lactate from glycolytic metabolite pyruvate by lactate dehydrogenase A (LDHA), leading to cartilage degeneration. In the present study, we investigated the protective effects of the intra-articular administration of oxamate (LDHA inhibitor) against OA development and glycolysis-related protein expression in experimental OA rats. The animals were randomly allocated into four groups: Sham, anterior cruciate ligament transection (ACLT), ACLT + oxamate (0.25 and 2.5 mg/kg). Oxamate-treated groups received an intra-articular injection of oxamate once a week for 5 weeks. Intra-articular oxamate significantly reduced the weight-bearing defects and knee width in ACLT rats. Histopathological analyses showed that oxamate caused significantly less cartilage degeneration in the ACLT rats. Oxamate exerts hypertrophic effects in articular cartilage chondrocytes by inhibiting glucose transporter 1, glucose transporter 3, hexokinase II, pyruvate kinase M2, pyruvate dehydrogenase kinases 1 and 2, pyruvate dehydrogenase kinase 2, and LHDA. Further analysis revealed that oxamate significantly reduced chondrocyte apoptosis in articular cartilage. Oxamate attenuates nociception, inflammation, cartilage degradation, and chondrocyte apoptosis and possibly attenuates glycolysis-related protein expression in ACLT-induced OA rats. The present findings will facilitate future research on LDHA inhibitors in prevention strategies for OA progression.

Higher pre-treatment skin sympathetic nerve activity and elevated resting heart rate after chemoradiotherapy predict worse esophageal cancer outcomes.

BACKGROUND: Chemoradiotherapy (CRT), which might affect the autonomic system, is the mainstay therapy for advanced esophageal squamous cell carcinoma (ESCC). Autonomic dysfunction has been found to possibly lead to cancer mortality in those with elevated resting heart rates (RHR). Skin sympathetic nerve activity (SKNA) is a new method of stimulating electrical signals in skin to evaluate autonomic function from sympathetic tone. In this study, we investigated the association between changes in RHR and autonomic function and ESCC mortality. METHODS: Thirty-nine stage II-IV ESCC patients receiving CRT between March 2019 and November 2020 were prospectively enrolled and carefully selected, followed up and received the same meticulous supportive care. Serial RHR was recorded every two weeks from before CRT to eight weeks after CRT and average SKNA were recorded before and four weeks after CRT. All-cause mortality was defined as primary outcome. RESULTS: We found the RHR of ESCC patients to be significantly elevated and peaking at four weeks after CRT (p < 0.001) and then to gradually decrease. Those with an elevated RHR above the cutoff level (18 beat-per-minute) at eight weeks after CRT had worse overall survival. In addition, those with higher baseline sympathetic tone (average SKNA ≥ 0.86 µV) also had poor outcome. CONCLUSIONS: Increased pre-treatment sympathetic tone and elevated RHR after CRT are alarm signs of poor ESCC outcome. Further exploration of the mechanisms underlying these associations could potentially lead to intervention strategies for reducing mortality. TRIAL REGISTRATION: This study is registered with ClinicalTrials.gov, identifier: NCT03243448.

Modification of activated carbon using urea to enhance the adsorption of dioxins.

Activated carbon is commonly used to remove dioxins from flue gas via adsorption. Improving the targeted adsorption capacity of activated carbon for dioxins can reduce the consumption of adsorbents and help achieve emission standards for target pollutants. Here, commercial coal-based activated carbon was used as a raw material and modified by urea impregnation along with treatment at high temperature under a nitrogen atmosphere. It was found that modification with urea effectively improved the pore structure of activated carbon while incorporating a certain amount of nitrogen. The best modification effect was achieved at a modification temperature of 600 °C, an impregnation ratio of urea to activated carbon of 1:1, and with high-temperature treatment for 2 h. The mesopore volume of the modified activated carbon (AC600) reached 0.38 cm3/g, accounting for 57.58% of the total pore volume. With an impregnation ratio of urea to activated carbon of 1:1, high-temperature treatment for 2 h, and a modification temperature of 800 °C, a certain amount of nitrogen was introduced into the carbon rings to form a modified activated carbon (AC800) rich in pyridine and pyrrole groups (atomic percentage = 4.84%). The activated carbon modified by urea and the unmodified activated carbon were subsequently selected for dioxin adsorption experiments using a dioxin generation and adsorption system. AC600 showed the highest adsorption efficiency for dioxins, reaching 97.65%, based on toxicity equivalents. Although AC800 has poor pore properties, it has more pyridine and pyrrole groups than AC600. Consequently, the efficiency of AC800 at adsorbing low-concentration dioxins reached 85.24% based on toxicity equivalents. Overall, this study describes two mechanisms for effectively modifying activated carbon with urea based on (1) optimizing the pore structure of activated carbon and (2) incorporating nitrogen.

Thoracoscopic Repair of Adult-Onset Congenital Tracheoesophageal Fistula Using a Polyglycolic Acid Sheet-Buttressed Stapler.

Congenital tracheoesophageal fistula (TEF) without esophageal atresia is usually diagnosed and treated in the neonatal period. It is uncommon to occur in adulthood. Conventional treatment of adult-onset TEF involves repair by either cervicotomy or thoracotomy. We reported the case of a 31-year-old male patient with clinical and radiographic evidence of congenital H-type TEF. Although this fistula was located at the level of the second thoracic vertebra, the repair of the anomaly was performed successfully using a thoracoscopic approach with the novel use of a polyglycolic acid sheet reinforcement.

Is a Chest Tube Necessary after Video-Assisted Thoracoscopic Mediastinal Tumor Resection?

BACKGROUND: The omission of chest tubes after thoracoscopic procedures such as sympathectomy, lung biopsy, and lung resection has proven efficacious in decreasing pain and length of hospital stay in some cases. However, its safety for mediastinal diseases remains unclear. This study evaluated the feasibility and outcome of eliminating chest drains after video-assisted thoracoscopic surgery (VATS) for mediastinal tumor resection. METHODS: We retrospectively investigated 70 patients receiving VATS mediastinal tumor resection in a single institution between January 2016 and November 2018. A total of 39 patients (drain group) received postoperative chest drains and 31 patients (no-drain group) did not. Group clinical outcomes and operation data were compared. A propensity score matching analysis was further performed to yield a fairer comparison. RESULTS: Before propensity score matching, the no-drain group had a higher prevalence of cystic lesions, a shorter operative time, and less blood loss compared with the drain group (p = 0.015, p = 0.018, and p < 0.001, respectively). After matching, the group differences in these perioperative variables lost significance (p = 0.095, 0.4, and 0.2, respectively). The no-drain group had lower postoperative day 2 pain scores and shorter postoperative hospital stays than the drain group, regardless of whether they were matched (pain: p = 0.028; hospital stay < 0.001) or not (pain: p = 0.003; hospital stay < 0.001). No major adverse events occurred in either group during hospitalization or follow-up period. CONCLUSION: Eliminating chest drain placement after VATS mediastinal tumor resection may benefit some patients and decrease postoperative pain and hospital stay without increasing complications or compromising patient safety.

Male adolescents with contralateral blebs undergoing surgery for primary spontaneous pneumothorax may benefit from simultaneous contralateral blebectomies.

BACKGROUND: In adults with primary spontaneous pneumothorax (PSP), contralateral recurrence occurs in about 25-28% when there are asymptomatic blebs. How to treat contralateral recurrence of PSP in pediatric populations remains controversial. This study evaluated the outcomes of excising contralateral blebs to prevent recurrence in adolescents being operated on for PSP under the same anesthesia. METHODS: One hundred thirty-two male PSP patients under age 19 were surgically treated in a single institution between January 2008 and December 2016. Thoracoscopic blebectomies with pleurodesis were performed in all patients. The patients were categorized into those with contralateral blebs receiving one-stage bilateral surgeries (32 patients), those with contralateral blebs only receiving unilateral surgeries (40 patients), and those without contralateral blebs only receiving unilateral surgeries (60 patients). Perioperative details and outcomes were retrospectively analyzed. RESULTS: Significant differences in contralateral recurrence rate were found among the three groups (0%, 30%, and 1%, respectively; P < 0.001). Multivariate analysis showed that being under 16.5 years old was a risk factor for overall recurrence (Hazard ratio [HR] 2.81, 95% confidence interval [CI] 1.08-7.30, P = 0.034). Moreover, patients who had contralateral blebs and only received unilateral surgery were at greater risk of overall recurrence (HR 6.06, 95% CI 1.77-20.75, P = 0.004). Kaplan-Meier analysis showed that contralateral and overall recurrence-free survival differed among the three groups (P < 0.0001, P = 0.0002). CONCLUSIONS: Although younger male PSP adolescents treated with surgery were more likely to have postoperative recurrences, the performance of simultaneous contralateral blebectomies in those receiving one-stage bilateral surgeries significantly reduced future contralateral recurrence without compromising patient safety.

Mn-doped CsPb(Br/Cl)3 mixed-halide perovskites for CO2 photoreduction.

Halide perovskites have been employed as photocatalysts for CO2 photoreduction due to their excellent optical properties and unique electronic structure. However, their photocatalytic performance is relatively poor. Herein, we demonstrate a new strategy with Mn-doped CsPb(Br/Cl)3 mixed-halide perovskites as catalysts to enhance the efficiency of CO2 photoreduction. By tuning the content of Mn, a series of CsPb(Br/Cl)3:Mn perovskites are obtained and show high efficiency in CO2 conversion to CO and CH4. For the optimum catalyst sample, especially, the yields of CO and CH4 reach 1917 µmol g-1 and 82 µmol g-1 which are 14.2 and 1.4 times higher than those of CsPbBr3. This work provides new insights into improving the reactivity of perovskites in CO2 photoreduction.

CircRNAFisher: a systematic computational approach for de novo circular RNA identification.

Circular RNAs (circRNAs) are emerging species of mRNA splicing products with largely unknown functions. Although several computational pipelines for circRNA identification have been developed, these methods strictly rely on uniquely mapped reads overlapping back-splice junctions (BSJs) and lack approaches to model the statistical significance of the identified circRNAs. Here, we reported a systematic computational approach to identify circRNAs by simultaneously utilizing BSJ overlapping reads and discordant BSJ spanning reads to identify circRNAs. Moreover, we developed a novel procedure to estimate the P-values of the identified circRNAs. A computational cross-validation and experimental validations demonstrated that our method performed favorably compared to existing circRNA detection tools. We created a standalone tool, CircRNAFisher, to implement the method, which might be valuable to computational and experimental scientists studying circRNAs.

Protection Effect of Curcumin for Macrophage-Involved Polyethylene Wear Particle-Induced Inflammatory Osteolysis by Increasing the Cholesterol Efflux.

BACKGROUND Periprosthetic osteolysis, induced by wear particles and inflammation, is a common reason for failure of primary arthroplasty. Curcumin, a nature phenol from plants, has been reported to reduce the inflammation in macrophages. This study aimed to investigate the potential effect of curcumin on macrophage involved, wear particle-induced osteolysis and its mechanism. MATERIAL AND METHODS RAW264.7 macrophages were used to test the effects of polyethylene (PE) particles and curcumin on macrophage cholesterol efflux and phenotypic changes. A mouse model of PE particle-induced calvarial osteolysis was established to test the effects of curcumin in vivo. After 14 days of treatment, the bone quality of the affected areas was analyzed by micro-computed tomography (micro-CT) and histology, and the bone surrounding soft tissues were analyzed at the cellular and molecular levels. RESULTS We found that PE particles can stimulate osteoclastogenesis and produce an M1-like phenotype in macrophages in vitro. Curcumin enhanced the cholesterol efflux in macrophages, and maintained the M0-like phenotype under the influence of PE particles in vitro. Additionally, the cholesterol transmembrane regulators ABCA1, ABCG1, and CAV1 were enhanced by curcumin in vivo. We also found enhanced bone density, reduced osteoclastogenesis, and fewer inflammatory responses in the curcumin treated groups in our mouse osteolysis model. CONCLUSIONS Our study findings indicated that curcumin can inhibit macrophage involved osteolysis and inflammation via promoting cholesterol efflux. Maintaining the cholesterol efflux might be a potential strategy to prevent periprosthetic osteolysis after total joint arthroplasty surgery.

[Clinical Study of Enhanced Recovery after Surgery in Peri-operative Management of Total Hip Arthroplasty].

OBJECTIVE: To evaluate the clinical effect and rehabilitation benefit of enhanced recovery after surgery (ERAS) model in perioperative management of total hip arthroplasty (THA). METHODS: A retrospective study were conducted in THA patients from the database of big data Research Center of Biomedicine, West China Hospital of Sichuan University from 2013 to 2016. The differences of rehabilitation quality, rehabilitation efficiency and hospitalization cost between ERAS model (ERAS group) and traditional model (traditional group) were compared. RESULTS: 915 THA patients were included in the study, of which 497 patients were given ERAS peri-operative management and 418 patients in the traditional group. The rate of overall complications in the ERAS group was significantly lower than that in the traditional group (4.8% vs. 8.6%, P < 0.05), with lower rate of deep venous thrombosis (0.8% vs. 3.1%) and pulmonary infection (0.6% vs. 2.4%) in the ERAS group. Compared with the traditional group, the average length of stay in hospital was shorter in the ERAS group 〔(7.6±2.0) d vs. (10.9±2.9) d, P=0.039〕, as well as postoperative length of stay in hospital 〔(5.6±0.9) d vs. (8.6±2.0) d, P=0.028)〕. And the ERAS model reduced the total hospitalization cost by 4.8% to 7.1% (P < 0.05), of which the drug cost decreased by 17.2% to 24.9% (P < 0.05). CONCLUSIONS: ERAS model in THA is safe and effective. It can reduce hospitalization cost and help to control medical cost.

Cytoplasmic glutamine synthetase gene expression regulates larval development in Bactrocera dorsalis (Hendel).

In insects, glutamine synthetase (GS), a key enzyme in the synthesis of glutamine, has been reported to be associated with embryonic development, heat shock response, and fecundity regulation. However, little is known about the influence of GS on postembryonic development. In this study, we demonstrate that blocking the activity of GS in the oriental fruit fly (Bactrocera dorsalis) with use of a GS-specific inhibitor (L-methionine S-sulfoximine), led to a significant delay in larval development, pupal weight loss, and inhibition of pupation. We further identify cloned and characterized two GS genes (BdGS-c and BdGS-m) from B. dorsalis. The two GS genes identified in B. dorsalis were predicted to be located in the cytosol (BdGS-c) and mitochondria (BdGS-m), and homology analysis indicated that both genes were similar to homologs from other Dipterans, such as Drosophila melanogaster and Aedes aegypti. BdGS-c was highly expressed in the larval stages, suggesting that cytosolic GS plays a predominant role in larval development. Furthermore, RNA interference experiments against BdGS-c, to specifically decrease the expression of cytosolic GS, resulted in delay in larval development as well as pupal weight loss. This study presents the prominent role played by BdGS-c in regulating larval development and suggests that the observed effect could have been modulated through ecdysteroid synthesis, agreeing with the reduced expression of the halloween gene spook. Also, the direct effects of BdGS-c silencing on B. dorsalis, such as larval lethality, delayed pupation, and late emergence, can be further exploited as novel insecticide target in the context of pest management.

Targeting Tumor Associated Phosphatidylserine with New Zinc Dipicolylamine-Based Drug Conjugates.

A series of zinc(II) dipicolylamine (ZnDPA)-based drug conjugates have been synthesized to probe the potential of phosphatidylserine (PS) as a new antigen for small molecule drug conjugate (SMDC) development. Using in vitro cytotoxicity and plasma stability studies, PS-binding assay, in vivo pharmacokinetic studies, and maximum tolerated dose profiles, we provided a roadmap and the key parameters required for the development of the ZnDPA based drug conjugate. In particular, conjugate 24 induced tumor regression in the COLO 205 xenograft model and exhibited a more potent antitumor effect with a 70% reduction of cytotoxic payload compared to that of the marketed irinotecan when dosed at the same regimen. In addition to the validation of PS as an effective pharmacodelivery target for SMDC, our work also provided the foundation that, if applicable, a variety of therapeutic agents could be conjugated in the same manner to treat other PS-associated diseases.