Ferromagnetic Insulating Ground-State Resolved in Mixed Protons and Oxygen Vacancies-Doped La0.67Sr0.33CoO3 Thin Films via Ionic Liquid Gating

The realization of ferromagnetic insulating ground state is a critical prerequisite for spintronic applications. By applying electric field-controlled ionic liquid gating (ILG) to stoichiometry La0.67Sr0.33CoO3 thin films, the doping of protons (H+) has been achieved for the first time. Furthermore, a hitherto-unreported ferromagnetic insulating phase with a remarkably high Tc up to 180 K has been observed which can be attributed to the doping of H+ and the formation of oxygen vacancies (VO). The chemical formula of the dual-ion migrated film has been identified as La2/3Sr1/3CoO8/3H2/3 based on combined Co L23-edge absorption spectra and configuration interaction cluster calculations, from which we are able to explain the ferromagnetic ground state in terms of the distinct magnetic moment contributions from Co ions with octahedral (Oh) and tetrahedral (Td) symmetries following antiparallel spin alignments. Further density functional theory calculations have been performed to verify the functionality of H+ as the transfer ion and the origin of the novel ferromagnetic insulating ground state. Our results provide a fundamental understanding of the ILG regulation mechanism and shed light on the manipulating of more functionalities in other correlated compounds through dual-ion manipulation.

Synthesis and biological evaluation of 1-phenyl-tetrahydro-β-carboline-based first dual PRMT5/EGFR inhibitors as potential anticancer agents

Protein arginine methyltransferase 5 (PRMT5) and epidermal growth factor receptor (EGFR) are both involved in the regulation of various cancer-related processes, and their dysregulation or overexpression has been observed in many types of tumors. In this study, we designed and synthesized a series of 1-phenyl-tetrahydro-β-carboline (THβC) derivatives as the first class of dual PRMT5/EGFR inhibitors. Among the synthesized compounds, 10p showed the most potent dual PRMT5/EGFR inhibitory activity, with IC50 values of 15.47 ± 1.31 and 19.31 ± 2.14 μM, respectively. Compound 10p also exhibited promising antiproliferative activity against A549, MCF7, HeLa, and MDA-MB-231 cell lines, with IC50 values below 10 μM. Molecular docking studies suggested that 10p could bind to PRMT5 and EGFR through hydrophobic, π-π, and cation-π interactions. Furthermore, 10p displayed favorable pharmacokinetic properties and oral bioavailability (F = 30.6%) in rats, and administrated orally 10p could significantly inhibit the growth of MCF7 orthotopic xenograft tumors. These results indicate that compound 10p is a promising hit compound for the development of novel and effective dual PRMT5/EGFR inhibitors as potential anticancer agents.

[Clinical analysis of retropharyngeal lymph node metastasis in patients with hypopharyngeal squamous cell carcinoma]

Objective: To analyze the incidence and the related risk factors of retropharyngeal lymph node metastasis in patients with hypopharyngeal squamous cell carcinoma, evaluate the accuracy of preoperative enhanced CT in judging retropharyngeal lymph node metastasis, and investigate the impact of retropharyngeal lymph node metastasis on the prognosis. Methods: Retrospective analyses were made on 398 patients with hypopharyngeal squamous cell carcinoma who underwent surgery as the primary therapy and accepted retropharyngeal lymph node exploration and clearance during surgery in Shandong Provincial ENT Hospital from January 2014 to December 2019. Multivariate logistic regression analysis was used to clarify the related risk factors of retropharyngeal lymph node metastasis. Multivariate Cox regression analysis was used to investigate the impact of retropharyngeal lymph node metastasis on prognosis. The retropharyngeal lymph nodes of 218 cases with available preoperative enhanced CT images were evaluated by two experienced radiologists and compared with postoperative pathological results. Results: Retropharyngeal lymph node metastasis were confirmed in 54 of 398 (13.6%) cases according to postoperative pathology. The sensitivity and specificity of preoperative enhanced CT in the diagnosis of retropharyngeal lymph node metastasis were 34.6% and 91.1%, respectively, and the overall accuracy was 84.4%. Multivariate logistic regression analysis showed that the site of the primary lesion and pathological N stage were independent risk factors for retropharyngeal lymph node metastasis in hypopharyngeal squamous cell carcinoma. Patients with primary lesion located in the posterior wall of hypopharynx (OR=4.83, 95% CI: 1.27-18.40), N2 stage (OR=6.30, 95% CI: 2.25-17.67), and N3 stage (OR=26.89, 95% CI: 5.76-125.58) were prone to retropharyngeal lymph node metastasis. The 5-year overall survival rate of the 398 patients was 50.4%, and the 5-year disease-free survival rate was 48.3%. Multivariate Cox regression analysis showed that T stage, N stage, retropharyngeal lymph node metastasis, and radiotherapy were independent influencing factors for overall survival (T stage: HR=1.28, 95% CI: 1.06-1.54; N stage: HR=1.26, 95% CI: 1.14-1.40; retropharyngeal lymph node metastasis: HR=2.13, 95% CI: 1.47-3.08; radiotherapy: HR=0.54, 95% CI: 0.38-0.76) and disease-free survival of patients with hypopharyngeal squamous cell carcinoma (T stage: HR=1.26, 95% CI: 1.06-1.51; N stage: HR=1.25, 95% CI: 1.13-1.37; retropharyngeal lymph node metastasis: HR=2.24, 95% CI: 1.56-3.21; radiotherapy: HR=0.55, 95% CI: 0.40-0.77). Conclusions: Metastasis of retropharyngeal lymph nodes in hypopharyngeal squamous cell carcinoma is not rare. Enhanced CT is of low accuracy and limited value in diagnosing retropharyngeal lymph node metastasis. Primary lesions located in the posterior wall of the hypopharyngx, N2 stage, and N3 stage are independent high-risk factors for retropharyngeal lymph node metastasis. The prognosis of hypopharyngeal cancer patients with retropharyngeal lymph node metastasis is worse, and active surgical exploration and clearance can effectively reduce the mortality caused by retropharyngeal lymph node metastasis.

Multi-omics analysis reveals copper-induced growth inhibition mechanisms of earthworm (Eisenia fetida)

Exposure to high concentrations of copper can cause toxic effects on the growth and development of organisms, but the relevant toxic mechanisms are far from fully understood. This study investigated the changes of metabolites, genes, and gut microorganisms in earthworms (Eisenia fetida) exposed to 0 (control), 67.58 (low), 168.96 (medium), and 337.92 (high) mg/kg of Cu in soil for 60 days. Differentially expressed genes (DEGs) and differential metabolites (DMs) at the low-, medium-, and high-level Cu exposure groups were identified and introduced into Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Integrated metabolomic and transcriptomic analysis revealed that amino acid metabolism, lipid metabolism, and carbohydrate metabolism are the major metabolic pathways disturbed by Cu exposure. Furthermore, Cu exposure significantly decreased the diversity of the intestinal bacterial community and affected the relative abundance (increased or decreased) of intestinal colonizing bacteria. This resulted in high energy expenditure, inhibited nutrient absorption and fatty acid synthesis, and weakened antioxidant and detoxification abilities, ultimately inhibiting the growth of E. fetida. These findings offer important clues and evidence for understanding the mechanism of Cu-induced growth and development toxicity in E. fetida and provide further data for risk assessment in terrestrial ecosystems.

Anisotropy Engineering of ZnO Nanoporous Frameworks: A Lattice Dynamics Simulation

The anisotropy engineering of nanoporous zinc oxide (ZnO) frameworks has been performed by lattice dynamics simulation. A series of zinc oxide (ZnO) nanoporous framework structures was designed by creating nanopores with different sizes and shapes. We examined the size effects of varying several features of the nanoporous framework (namely, the removal of layers of atoms, surface-area-to-volume ratio, coordination number, porosity, and density) on its mechanical properties (including bulk modulus, Young's modulus, elastic constant, and Poisson ratio) with both lattice dynamics simulations. We also found that the anisotropy of nanoporous framework can be drastically tuned by changing the shape of nanopores. The maximum anisotropy (defined by Y_max/Y_min) of the Young's modulus value increases from 1.2 for bulk ZnO to 2.5 for hexagon-prism-shaped ZnO nanoporous framework structures, with a density of 2.72 g/cm³, and, even more remarkably, to 89.8 for a diamond-prism-shape at a density of 1.72 g/cm³. Our findings suggest a new route for desirable anisotropy and mechanical property engineering with nanoporous frameworks by editing the shapes of the nanopores for the desired anisotropy.

A novel formamidase is required for riboflavin biosynthesis in invasive bacteria

Biosynthesis of riboflavin, the precursor of the redox cofactors FMN and FAD, was thought to be well understood in bacteria, with all the pathway enzymes presumed to be known and essential. Our previous research has challenged this view by showing that, in the bacterium Sinorhizobium meliloti, deletion of the ribBA gene encoding the enzyme that catalyzes the initial steps on the riboflavin biosynthesis pathway only causes a reduction in flavin secretion rather than riboflavin auxotrophy. This finding led us to hypothesize that RibBA participates in the biosynthesis of flavins destined for secretion, while S. meliloti has another enzyme that performs this function for internal cellular metabolism. Here, we identify and biochemically characterize a novel formamidase (SMc02977) involved in the production of riboflavin for intracellular functions in S. meliloti. This catalyst, which we named Sm-BrbF, releases formate from the early riboflavin precursor 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-phosphate (AFRPP) to yield 2,5-diamino-6-ribosylamino-4(3H)-pyrimidinone 5'-phosphate (DARoPP). We show that homologs of this enzyme are present in many bacteria, are highly abundant in the Rhizobiales order, and that sequence homologs from Brucella abortus and Liberobacter solanacearum complement the riboflavin auxotrophy of the Sm1021ΔSMc02977 mutant. Furthermore, we show that the B. abortus enzyme (Bab2_0247, Ba-BrbF) is also an AFRPP formamidase, and that the bab2_0247 mutant is a riboflavin auxotroph exhibiting a lower level of intracellular infection than the wild-type strain. Finally, we show that Sm-BrbF and Ba-BrbF directly interact with other riboflavin biosynthesis pathway enzymes. Together, our results provide novel insight into the intricacies of riboflavin biosynthesis in bacteria.

[Analysis of drug resistance pattern and genes of Salmonella.spp isolated from human infections in Anhui Province]

Objective: To investigate the drug resistance pattern and drug resistance genotypes of Salmonella. spp isolated from fecal specimens and anal swabs of diarrhea cases in Anhui Province. Methods: The 149 strains of Salmonella.spp isolated from feces and anal swabs of diarrhea cases in Anhui Province from April to October 2017 were selected. The serotypes of Salmonella.spp were identified by slide agglutination. The susceptibility of all strains to 14 antibiotics were determined by micro-broth dilution method. Sixty of the cephalosporin-resistant antibiotics were selected. The β-lactamase encoding genes bla(TEM), bla(SHV), bla(OXA-1), bla(OXA-2), bla(PER), bla(CMY), bla(CTX-M), and colistin resistance genes mcr-1 and mcr-2 were performed using the multi-PCR method. Results: Of the 149 diarrhea cases, the median (P(25), P(75)) of the age was 5.0 (1.1, 38.5). The 92 of them were male and 54.4% were children. Of the 149 strains of Salmonella.spp, 105 strains had different degrees of resistance to 13 antibiotics other than imipenem. The resistance rate of ampicillin was 55.0% (82/149), which was the highest. 53.0% strains (79 strains) were multidrug resistant, main of which were Salmonella typhimurium and Salmonella enteritidis. A total of 53 resistance patterns were detected, and 10 strains were resistant to ampicillin-ampicillin/sulbactam-tetracycline-chloramphenicol-cefazolin-trimethoprim/sulfamethoxazole, which was the most common resistance pattern. Among the 60 cephalosporin resistant strains, 45 strains carried bla(TEM-1), 6 of which also carried bla(CTX-M-14) and 3 of which also carried bla(CTX-M-65). All the 32 strains carried only bla(TEM-1) show resistance to ampicillin and 31 of them show resistance to cefazolin. There were 2 strains showing negative results of gene detection. mcr-1 was detected in a multidrug resistant strain. Conclusion: The resistance of Salmonella.spp to ampicillin shows a serious situation in this region, and there were a number of multidrug resistant strains. The bla(TEM-1) was the major drug resistance gene detected in this research. Detection of the mcr-1 suggests the emergence of surveillance to colistin resistance of Salmonella.spp in this area.

Abstract 340: Myosin Regulatory Light Chain: A Major Player in Defining the ‘OFF’ State of Cardiac Myosin

Myosin regulatory light chain (RLC) is a regulatory subunit of the myosin molecule, which plays a major role in stabilizing the Interacting Head Motif (IHM) of myosin in non-striated muscle. However, in striated muscle, its purpose is less well defined, and it is only in the past decade that researchers have started unraveling the function of RLC and its phosphorylation in muscle contraction. In this study, we report the role of human cardiac RLC in forming the Super-Relaxed State (SRX) of myosin in reconstituted full-length cardiac myosin thick filaments and show that removal of RLC destabilizes the ability of myosin to form the SRX state. Phosphorylation of the RLC with MLCK has the same effect, which renders the myosin to the ‘OFF’ state as confirmed by its ATPase activity. Interestingly we found that Ca 2+ and not Mg 2+ binding to synthetic myosin filaments had differential effects on the population of the myosin SRX state. At systolic Ca 2+ myosin exhibits lower SRX state than at diastolic Ca 2+ . This effect is obliterated in RLC-lacking myosin constructs such as sS1, or RLC stripped myosin filaments suggesting that Ca 2+ binding to RLC can activate the myosin from the ‘OFF’ state to a more active state. Naturally occurring cardiomyopathy-causing RLC mutants R58Q, K104E and D94A did not alter this property, but two of them, K104E and D94A abolished the phosphorylation regulation of the SRX state of myosin. Altogether, these observations demonstrate that either RLC phosphorylation or binding of systolic Ca 2+ can reduce the number of accessible myosin heads for contraction and could form the basis of the Ca 2+ -mediated activation of the sarcomeric thick filament and mutations in RLC can alter these abilities differentially.

Loss of CDH1 promotes the metastasis of hypopharyngeal squamous cell carcinoma through the STAT3-MMP-9 signaling pathway

BACKGROUND

Distant metastasis is the major cause of death in patients with hypopharyngeal squamous cell carcinoma (HSCC). CDH1 is correlated with tumor invasion and metastasis; however, its function in HSCC remains unclear.

METHODS

We used immunohistochemistry (IHC) staining to evaluate the expression of CDH1 in 31 and 78 specimens from primary HSCC patients with and without postoperative lung metastases respectively. Sulforhodamine B (SRB) and CCK-8 assays were used to test the proliferation of HSCC cells. Motility of HSCC cells was investigated by migration and invasion assays. Western blot analysis was used to measure the levels of CDH1 and other proteins.

RESULTS

We found that the low expression of CDH1 was significantly associated with postoperative lung metastasis in HSCC (P<0.001). Moreover, CDH1 was reduced concomitantly with the upregulation of MMP-9 in the same HSCC sample. Further mechanistic investigation showed that silencing CDH1 elevated the level of MMP-9, which was coupled with the phosphorylation of STAT3. Subsequently, inhibiting STAT3 either by siRNA transfection or by pharmacological suppression with AG490 attenuated MMP-9 upregulation and prevented the enhanced proliferation and invasion caused by CDH1 loss in FaDu cells.

CONCLUSIONS

CDH1 plays vital roles in HSCC metastasis and might serve as a potential therapeutic target for the clinical treatment of HSCC.

[The oncologic and functional outcomes of supracricoid partial laryngectomy for the treatment of laryngeal cancer]

Objective: To evaluate the oncologic and functional outcomes of laryngeal squamous cell carcinomas treated by supracricoid laryngectomy. Methods: The clinical data of 134 patients with laryngeal cancer who underwent supracricoid laryngectomy with cricohyoidoepiglottopexy (CHEP) or cricohyoidopexy (CHP) between July 2005 and April 2014 at Shandong Provincial ENT Hospital were retrospectively reviewed. Ninety-one patients including 31 cases of stage Ⅰ, 36 of stage Ⅱ, 18 of stage Ⅲ and 6 of stage Ⅳ underwent CHEP and 43 patients underwent CHP. Two patients received CHEP due to recurrence after open surgery and laser surgery. Three patients received CHP due to the recurrence of disease after open surgery and postradiotherapy persistence of disease. The Kaplan-Meier method was used to calculate the 3-year and 5-year survival rates. The Chi-square test was used to compare the survival rates between different surgical procedures. Results: All 91 patients who underwent CHEP had successful removals of PEG tubes, and 88 (96.7%) of them had tracheostomy tube decannulation. Among 43 patients with CHP, 42(97.6%) cases removal of PEG tubes(97.6%), including and 40(93.0%) cases with tracheostomy tube decannulation. There was one patient with local recurrence in all cases. In CHEP group, 3-year local control rate was 98.2%; 3-year and 5-year overall survival rate were 94.5% and 93.9%, respectively. In CHP group, 3-year local control rate was 97.6%; 3-year and 5-year overall survival rates were 86.0% and 83.3%, respectively. Pharyngeal fistula appeared in 2 cases of CHEP group and 4 cases of CHP group, and all of them were cured by conservative treatment. Conclusion: Supracricoid laryngectomy shows excellent oncologic and functional results for treatment of laryngeal cancer while maintaining laryngeal functions, especially in terms of local control rate and tracheostomy tube decannulation.

Notch1 serves as a prognostic factor and regulates metastasis via regulating EGFR expression in hypopharyngeal squamous cell carcinoma

Objective

Hypopharyngeal squamous cell carcinoma (HSCC) remains one of the most lethal malignancies in head and neck. Notch1 has been validated to play prominent roles in the occurrence and development of various types of cancer. The aim of this study was to explore the function and underlying mechanism of Notch1 in HSCC.

Patients and methods

Seventy-one cancer tissue samples and adjacent noncancerous formalin-fixed paraffin embedded tissue specimens were analyzed by immunohistochemistry. As Notch1 is overexpressed in HSCC, we further questioned whether there was a relationship between Notch1 and the clinicopathological characteristics. After confirming the successful knockdown of Notch1 by siRNA, the migration and invasion after gene knockdown were investigated by Transwell chambers. We then tried to identify YBX1 and EGFR expression using real-time PCR (RT-PCR) and Western blot analyses. To further determine whether the downexpression of EGFR was caused by YBX1 and the overexpression of YBX1 was caused by gene amplification, the expression of EGFR was detected by RT-PCR and Western blot assays.

Results

We found that the expression of Notch1 and EGFR in HSCC tissues was upregulated compared with those in the adjacent noncancerous tissues. Further clinicopathological characteristics analysis revealed that the expression of Notch1 was positively correlated with distant metastasis (P=0.003) and tumor differentiation (P=0.031). The high expression of Notch1 is an independent prognostic factor for a poor overall survival in patients with HSCC (P=0.015, χ ²=10.403). Knocking down of Notch1 significantly inhibits the migration and invasion of FaDu cells in vitro. Mechanistic investigation reveals that Notch1 knockdown is found suppressing the expression of EGFR at transcriptional level. Interestingly, we further found that Notch1 knockdown also decreased the expression of YBX1, which is a transcription factor of EGFR. Moreover, the upregulation of YBX1 reverses the suppression of Notch1 on EGFR. Furthermore, forced overexpression of YBX1 induced the invasion of FaDu cells.

Conclusion

Taken together, we found a positively cross-linked role of Notch1 signaling in the outcome of HSCC, providing a novel valuable prognostic marker and potential therapeutic target for the treatment of HSCC patients. Notch1 is a core signaling molecule for regulating migration and invasion via interplaying with EGFR in HSCC cells.

Abstract 572: Role Of Human Cardiac RLC In Modulating The Super-relaxed State Of Myosin: A Cardiomyopathy Perspective

Myosin regulatory light chain (RLC) is a major regulatory subunit of the myosin molecule, the role of which has been well-characterized in non-striated muscle. However, in striated muscle, its purpose is less well defined, and it is only in the past decade that researchers have started unraveling the function of RLC and its phosphorylation in muscle contraction. Mutations in this protein result in ~ 2% of total familial cardiomyopathy, an autosomal dominant disorder, manifested by ventricular and septal hypertrophy and myofibrillar disarray that can lead to sudden cardiac death. In this study, we report the role of human cardiac RLC in forming the super-relaxed state (SRX) of myosin in reconstituted full-length cardiac myosin thick filaments. We show that the presence of RLC fine-tunes the ability of myosin to form the SRX state and that its removal depopulates the SRX state. A similar reduction in SRX population is also achieved by phosphorylating the RLC with MLCK. The second mechanism of RLC-mediated regulation in muscle is thought to be by the binding of either Mg 2+ or Ca 2+ to the N-terminal EF-hand domain. Mg 2+ did not affect myosin SRX population, but increasing Ca 2+ enhanced the population of the myosin SRX state. Preliminary SRX studies on cardiomyopathy-causing RLC mutants R58Q (HCM), K104E (HCM) and D94A (DCM) show that none of the mutants affects the SRX population in the dephosphorylated state of the RLC; however these mutants also do not affect the SRX population when RLC is phosphorylated, unlike the wild-type. Additionally, in micro-scale thermophoresis binding experiments, only the dephosphorylated form of the DCM-causing D94A RLC mutant exhibits weaker binding to the myosin lever arm as compared to WT RLC. Binding of the mutants resembles WT upon phosphorylation. Altogether, these observations demonstrate that either RLC phosphorylation or Ca 2+ binding to RLC can alter the number of accessible myosin heads for contraction and cardiomyopathy-causing RLC mutants can modify this mechanism to varying extents.

Characterization of a non-nudix pyrophosphatase points to interplay between flavin and NAD(H) homeostasis in Saccharomyces cerevisiae

The flavin cofactors FMN and FAD are required for a wide variety of biological processes, however, little is known about their metabolism. Here, we report the cloning and biochemical characterization of the Saccharomyces cerevisiae pyrophosphatase Fpy1p. Genetic and functional studies suggest that Fpy1p may play a key role in flavin metabolism and is the first-reported non-Nudix superfamily enzyme to display FAD pyrophosphatase activity. Characterization of mutant yeast strains found that deletion of fpy1 counteracts the adverse effects that are caused by deletion of flx1, a known mitochondrial FAD transporter. We show that Fpy1p is capable of hydrolyzing FAD, NAD(H), and ADP-ribose. The enzymatic activity of Fpy1p is dependent upon the presence of K+ and divalent metal cations, with similar kinetic parameters to those that have been reported for Nudix FAD pyrophosphatases. In addition, we report that the deletion of fpy1 intensifies the FMN-dependence of null mutants of the riboflavin kinase Fmn1p, demonstrate that fpy1 mutation abolishes the decreased fitness resulting from the deletion of the flx1 ORF, and offer a possible mechanism for the genetic interplay between fpy1, flx1 and fmn1.

[Treatment and prognosis of 264 patients with hypopharyngeal carcinoma]

Objective: To investigate the key factors influencing the prognosis of hypopharyngeal carcinoma and the therapeutic methods improving the efficacy of treatments for hypopharyngeal carcinoma. Methods: Two hundred and sixty-four cases of hypopharyngeal squamous cell carcinoma treated from May 2010 to May 2015 were analyzed retrospectively. There were 211 cases of pyriform sinus carcinoma, 37 cases of posterior pharyngeal wall carcinoma, and 16 cases of postcricoid carcinoma. According to UICC 2002 criteria, 2 cases were for stage Ⅰ, 14 for stage Ⅱ, 32 for stage Ⅲ and 216 for stage Ⅳ. Postoperative circumferential defects existed in 112 (42.4%) cases, and 86 of them were reconstructed with free jejunum transplantation. Among all cases, 54 patients (20.5%) had the preservation of laryngeal functions after surgery and 210 patients (79.5%) with total laryngectomy; 238 cases (90.2%) underwent bilateral cervical lymph node dissection and 203 patients received posterior pharyngeal lymph node exploration and dissection, with positive metastases for posterior pharyngeal lymph nodes in 36 cases (17.7%). Eight cases with cervical lymph node metastasis extensively involving the soft tissue, prevertebral fascia or encases carotid artery received preoperative radiotherapy of 50 Gy. After surgery 13 patients received concurrent radiotherapy and chemotherapy, 337 underwent adjuvant radiotherapy with a dose of 50-60 Gy each, and 14 patients did not receive radiotherapy or did not completed their radiotherapy programs. SPSS 13.0 saftware was used to analyze the data. Results: All patients were followed up for more than 2 years. With Kaplan-Meier method, the 2-, 3- and 5-years survival rates were 69.6%, 62.8% and 51.3%, respectively. There were significant differences in 3-year survival rates between T1-2 group (75.5%) and T3-4 group (59.2%) (χ(2)=4.282 P=0.039), N0 group (81.6%) and N+ group (58.2%) (χ(2)=6.802 P=0.009), laryngeal functions preserved (81.8%) and unpreserved group (58.9%) (χ(2)=5.314 P=0.021). Multivariate Logistic regression analysis showed that cervical lymph node metastasis was an independent prognostic factor (P=0.027). The success rate of free jejunum transplantation was 98.8%. Local recurrence, cervical lymph node recurrence, second primary cancer, and distant metastasis accounted respectively for 11.2%, 18.8%, 12.5% and 45.0% of death cases. Conclusions: The prognosis-associated factors for hypopharyngeal carcinoma should be taken into account, including the evaluation of the carcinogenesis of the mucosal area, early screening of premalignant lesion or second primary cancer in the esophagus and dissection of the posterior pharyngeal lymph nodes, which will help to improve the local control rate and recent survival rate in patients with hypopharyngeal cancer.

[Significance of retropharyngeal node dissection in treatment of hypopharyngeal carcinoma]

Objective: investigate the incidence of retropharyngeal lymph node (RPLN) metastasis and the risk factors for RPLN metastasis in hypopharyngeal cancer, and the relationship of planned dissection of the RPLN with the survival and tumor control rates in patients with hypopharyngeal cancer. Methods: A total of 203 patients with hypopharyngeal squamous cell carcinoma who underwent radical surgery as initial treatment from February 2011 to July 2015 were analyzed retrospectively. There were 167 cases of pyriform sinus carcinoma, 23 cases of posterior pharyngeal wall carcinoma, and 13 cases of postcricoid carcinoma. Results: The incidence of RPLN metastasis in HPC was 17.7%, with a highest rate of 43.5% in pharyngeal wall carcinoma. The incidence of RPLN metastasis in T3-4 pyriform sinus carcinoma was 18.3%, which significantly higher than 2.8% in T1-2 cases(χ(2)=5.360, P=0.020). The rate of RPLN metastasis was 23.8% in N2b-3 and 8.6% in N0-2a, with a statistically significant difference(χ(2)=7.637, P=0.006). There was no statistically significant difference in overall survival rates between patients with and without RPLN metastasis(P>0.05). Data were analyzed by SPSS 13.0 software. Conclusions: RPLN metastasis is not rare in hypopharyngeal carcinoma. Planned dissection of the RPLN should be performed with the initial surgery in patients with advanced hypopharyngeal cancer, especially posterior pharyngeal wall carcinoma, T3-4 pyriform sinus carcinoma and staged N2b-3 disease, which can reduce the regional recurrence rate and provided with a better prognosis.

Elevated AEG-1 expression in macrophages promotes hypopharyngeal cancer invasion through the STAT3-MMP-9 signaling pathway

Macrophages play a critical role in tumor invasion and metastasis, which remain major causes of mortality in patients with hypopharyngeal cancer. Here we investigate the effect of an oncogene, AEG-1 expressed in macrophages on the invasion of hypopharyngeal cancer cells. AEG-1 is more highly expressed in macrophages of human hypopharyngeal cancer samples compared with adjacent non-tumor controls. Using matrigel invasion assay system, THP-1-derived macrophages with forced AEG-1 overexpression enhance FaDu cell invasion whereas macrophages with AEG-1 silence inhibit. Matrix metalloproteinase 9 (MMP-9), which is important in tumor invasion and metastasis through degrading extracellular matrix, is up-reulated by AEG-1 partly through NF-κB p65 in macrophages. Intriguingly, macrophage AEG-1 also induces MMP-9 up-regulated expression in FaDu cells. Furthermore, macrophage AEG-1 activates signal transducer and activator of transcription 3 (STAT3) in FaDu cells, which is responsible for macrophage AEG-1-induced an increase in MMP-9 expression and invasion of FaDu cells. This is the first to demonstrate that macrophage AEG-1 promotes tumor invasion through up-regulation of MMP-9 in both macrophages and cancer cells. Thus, the results provide evidences that macrophage AEG-1 contributes to promotion of tumor invasion, and represents as a potential target in hypopharyngeal cancer therapy.

[Reconstruction with free jejuna flap for the defect after removal of hypopharyngeal and cervical esophageal caneer: clinical analyses of 103 cases]

Objective: To report our experience in reconstruction with free jejunal flap for circumferential defect following resection of hypopharygeal and cervical esophageal carcinoma. Methods: A retrospective analysis was conducted to evaluate the outcomes of reconstruction with free jejunal flaps for circumferential defects in 103 patients treated from Aug 2008 to Mar 2015. Among them, 84 were hypopharyngeal carcinoma and 19 were cervical esophageal carcinoma; 31 patients had total pharyngolaryngectomy, 70 had total pharyngolaryngectomy and cervical esophagectomy and 2 had laryngeal preservation. All patients underwent bilateral neck dissection and 84 underwent retropharyngeal lymph node dissection. Results: The 3 year overall survival rate was 51.6% and disease-specific survival rate was 50%. The 5 year overall survival rate was 39.1%. No in-hospital death, one patient had unsalvageable flap failure and underwent second reconstruction with free jejunal flap. The success rate for the free jejunal flaps was 99% (102/103). Pharyngocutanous fistula occurred in 3 patients and all healed with conservative treatment. Satisfactory oral intake was achieved in all patients. Conclusions: Oncological and functional outcomes of reconstruction with free jejunal flap for circumferential defects of hypopharynx and cervical esophagus were satisfying. Multidisciplinary cooperation is helpful to improve surgical success rate. Free jejunal flap is an ideal method for reconstruction of circumferential hypopharyngeal and cervical esophageal defects after removal of tumor.

Identification and characterization of the missing phosphatase on the riboflavin biosynthesis pathway in Arabidopsis thaliana

Despite the importance of riboflavin as the direct precursor of the cofactors flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), the physiologically relevant catalyst dephosphorylating the riboflavin biosynthesis pathway intermediate 5-amino-6-ribitylamino-2,4(1H,3H) pyrimidinedione 5'-phosphate (ARPP) has not been characterized from any organism. By using as the query sequence a previously identified plastidial FMN hydrolase AtcpFHy1 (At1g79790), belonging to the haloacid dehalogenase (HAD) superfamily, seven candidates for the missing ARPP phosphatase were found, cloned, recombinantly expressed, and purified. Activity screening showed that the enzymes encoded by AtcpFHy1, At4g11570, and At4g25840 catalyze dephosphorylation of ARPP. AtcpFHy1 was renamed AtcpFHy/PyrP1, At4g11570 and At4g25840 were named AtPyrP2 and AtGpp1/PyrP3, respectively. Subcellular localization in planta indicated that AtPyrP2 was localized in plastids and AtGpp1/PyrP3 in mitochondria. Biochemical characterization of AtcpFHy/PyrP1 and AtPyrP2 showed that they have similar K_m values for the substrate ARPP, with AtcpFHy/PyrP1 having higher catalytic efficiency. Screening of 21 phosphorylated substrates showed that AtPyrP2 is specific for ARPP. Molecular weights of AtcpFHy/PyrP1 and AtPyrP2 were estimated at 46 and 72 kDa, suggesting dimers. pH and temperature optima for AtcpFHy/PyrP1 and AtPyrP2 were ~7.0-8.5 and 40-50°C. T-DNA knockout of AtcpFHy/PyrP1 did not affect the flavin profile of the transgenic plants, whereas silencing of AtPyrP2 decreased accumulation of riboflavin, FMN, and FAD. Our results strongly support AtPyrP2 as the missing phosphatase on the riboflavin biosynthesis pathway in Arabidopsis thaliana. The identification of this enzyme closes a long-standing gap in understanding of the riboflavin biosynthesis in plants.

Afatinib down-regulates MCL-1 expression through the PERK-eIF2α-ATF4 axis and leads to apoptosis in head and neck squamous cell carcinoma

Afatinib is the second generation of irreversible inhibitor of EGFR, HER2 and HER4, which has shown encouraging phase II and III clinical outcomes in the treatment of head and neck squamous cell carcinoma (HNSCC). However, the molecular mechanism of afatinib-induced apoptosis in HNSCC is poorly understood. In the present investigation, we discovered that down-regulation of MCL-1, an anti-apoptotic member of BCL-2 family, was responsible for afatinib-triggered apoptosis. And the inactivation of AKT-mTOR signaling caused by afatinib lead to translational inhibition of MCL-1 expression. As a crucial branch of ER stress, PERK-eIF2α-ATF4 axis was also stimulated in HNSCC cells after afatinib incubation. Silencing either eIF2α or ATF4 by siRNA transfection relieved afatinib-caused suppression of AKT-mTOR activity, attenuating MCL-1 down-regulation as well as subsequent apoptosis. Collectively, the results show that afatinib hampers AKT-mTOR activation by stimulating PERK-eIF2α-ATF4 signaling pathway, giving rise to MCL-1 down-regulation mediated apoptosis in HNSCC cells. Therefore, our findings reveal the elaborate molecular network of afatinib-induced apoptosis in HNSCC, which would provide substantial theoretical underpinnings for afatinib clinical application and highlight its promising prospect in HNSCC treatment.

Metabolic engineering of enhanced glycerol-3-phosphate synthesis to increase lipid production in Synechocystis sp. PCC 6803

With the growing attention to global warming and energy sustainability, biosynthesis of lipids by photosynthetic microorganisms has attracted more interest for the production of renewable transportation fuels. Recently, the cyanobacterium Synechocystis sp. PCC 6803 has been widely used for biofuel production through metabolic engineering because of its efficient photosynthesis and well-developed genetic tools. In lipid biosynthesis, glycerol-3-phosphate (G3P) is a key node for both CO2 fixation and lipid metabolism in cyanobacteria. However, few studies have explored the use of G3P synthesis to improve photosynthetic lipid production. In this study, metabolic engineering combined with flux balance analysis (FBA) was conducted to reveal the effect of G3P synthesis on lipid production. Heterologous genes that encoded glycerol-3-phosphate dehydrogenase (GPD) and diacylglycerol acyltransferase (DGAT) were engineered into Synechocystis sp. PCC 6803 to enhance G3P supply and lipid production. The resultant recombinant Synechocystis produced higher levels of lipids without a significant reduction in cell growth. Compared with the wild-type strain, lipid content and productivity of the engineered cyanobacteria increased by up to 36 and 31 %, respectively, under autotrophic conditions. Lipid production under mixotrophic conditions of the engineered cyanobacteria was also investigated. This work demonstrated that enhanced G3P synthesis was an important factor in photosynthetic lipid production and that introducing heterologous GPD and DGAT genes was an effective strategy to increase lipid production in Synechocystis sp. PCC 6803.

MicroR-140-5p suppresses tumor cell migration and invasion by targeting ADAM10-mediated Notch1 signaling pathway in hypopharyngeal squamous cell carcinoma

MicroRNAs (miRNAs) are small non-coding RNAs of approximately 22 nucleotides that negatively regulate gene expression at the post-transcriptional level. Downexpression of miR-140-5p was reported in some human cancers, and combined with a reduction of cell migration and invasion, suggesting that miR-140-5p functions as a tumor suppressor. However, little is known about the expression and function of miR-140-5p in hypopharyngeal squamous cell carcinoma (HSCC). In this research, we found that miR-140-5p was significantly downregulated in HSCC tissues and correlated to tumor classification and lymph node metastasis. Restoration of miR-140-5p suppressed the migration and invasion of FaDu cells, and decreased the protein expression levels of ADAM10. Furthermore, the luciferase reporter assay revealed that miR-140-5p was directly bound to ADAM10 mRNA and knockdown of ADAM10 could inhibit FaDu cell migration and invasion and reduced the protein expression levels of and Notch1 intracellular domain (NICD1). Of note, knockdown of Notch1 could inhibit the migration and invasion of FaDu cells and rescued the effect of miR-140-5p inhibitor in FaDu cells. Taken together, our study demonstrates that miR-140-5p suppresses tumor migration and invasion by inhibiting ADAM10-mediated Notch1 signaling pathway and suggests that miR-140-5p could have potential therapeutic applications in HSCC.

[Expression and effect of microRNA-214 in advanced hypopharyngeal carcinoma]

OBJECTIVE

To investigate the expression of microRNA-214(miR-214) in advanced hypopharyngeal carcinoma tissues and its effects on the invasion, migration and colone formation of FaDu cells.

METHODS

miR-214 expression in 30 cases of advanced hypopharyngeal carcinoma tissues and normal hypopharyngeal mucosa tissues was detected by real-time quantitative polymerase chain reaction (RT-qPCR). miR-214 was upregulated through transfecting the overexpression vector hsa-mir-214 into FaDu cells. The influences of miR-214 upregulation on the invasion, migration, clone formation and Twist expression were measured by Transwell invasion, Transwell migration, plate clone formation and Western blot assays, respectively.

RESULTS

The expression of miR-214 in advanced hypopharyngeal carcinoma tissues (0.311 ± 0.206) was significantly less than normal hypopharyngeal mucosa tissues (1.620 ± 1.394; t = 5.09, P < 0.05) . The expression of miR-214 was notably upregulated after tranfected with hsa-mir-214 compared with the negative control group (t = 6.347, P < 0.05). The migration and invasion ability of FaDu cells transfeced with hsa-mir-214 was decreased by comparison with negative control cells (t = 11.6, P < 0.01; t = 6.499, P < 0.05). There was no significant difference of the average clony number and the cloning efficiency between the experimental and negative control groups (t = 0.592, P > 0.05).

RESULTS

of Western blot assay showed that, Twist expression in the miR-214-overexpressed group was apparently decreased compared with that in the control group (t = 6.545, P < 0.05).

CONCLUSIONS

miR-214 is expressed at a low level in advanced hypopharyngeal carcinoma tissues, and can obviously inhibit the invasion and migration abilities of FaDu cells, possibly because of its inhibiting effect on Twist expression. Additionally, miR-214 plays no significant role in the proliferation of FaDu cells.

Epithelial cell adhesion molecule is overexpressed in hypopharyngeal carcinoma and suppresses the metastasis and proliferation of the disease when downregulated

The epithelial cell adhesion molecule (EpCAM) is overexpressed in the majority of human epithelial carcinomas, and its overexpression is associated with proliferation and neoplastic transformation. However, the precise molecular mechanism involved in EpCAM-related proliferation and metastasis in hypopharyngeal carcinoma is unknown. The aim of the present study was to identify the role of EpCAM in the metastasis and proliferation of hypopharyngeal carcinoma. An immunohistochemical staining assay indicated that EpCAM was overexpressed in primary hypopharyngeal carcinoma tissues, and that this overexpression correlated with the tumor size and lymph node metastasis. In the following treatment of the hypopharyngeal carcinoma FaDu cell line with EpCAM, the downregulation of EpCAM was found to significantly suppress cell metastasis and proliferation, as detected by Transwell, clone formation and MTT assays. Additionally, western blot analysis revealed that EpCAM downregulation increased the expression of the adhesion- and proliferation-related factors, E-cadherin, α-catenin and β-catenin, in the cytoskeleton, as well as β-catenin expression in the nucleus. In conclusion, the present study indicated that EpCAM is a potential oncogene and contributes to the metastasis of hypopharyngeal carcinoma. The current study is the first to provide evidence for the potential value of targeting EpCAM in hypopharyngeal carcinoma therapy.

Sinorhizobium meliloti flavin secretion and bacteria-host interaction: role of the bifunctional RibBA protein

Sinorhizobium meliloti, the nitrogen-fixing bacterial symbiont of Medicago spp. and other legumes, secretes a considerable amount of riboflavin. This precursor of the cofactors flavin mononucleotide and flavin adenine dinucleotide is a bioactive molecule that has a beneficial effect on plant growth. The ribBA gene of S. meliloti codes for a putative bifunctional enzyme with dihydroxybutanone phosphate synthase and guanosine triphosphate (GTP) cyclohydrolase II activities, catalyzing the initial steps of the riboflavin biosynthesis pathway. We show here that an in-frame deletion of ribBA does not cause riboflavin auxotrophy or affect the ability of S. meliloti to establish an effective symbiosis with the host plant but does affect the ability of the bacteria to secrete flavins, colonize host-plant roots, and compete for nodulation. A strain missing the RibBA protein retains considerable GTP cyclohydrolase II activity. Based on these results, we hypothesize that S. meliloti has two partly interchangeable modules for biosynthesis of riboflavin, one fulfilling the internal need for flavins in bacterial metabolism and the other producing riboflavin for secretion. Our data also indicate that bacteria-derived flavins play a role in communication between rhizobia and the legume host and that the RibBA protein is important in this communication process even though it is not essential for riboflavin biosynthesis and symbiosis.

[Effect of epithelial cell adhesion molecule on metastasis in hypopharyngeal carcinoma FaDu cells]

OBJECTIVE

To investigate the effect of knockdown of EpCAM by siRNA on invasion, migration, and colony abilities in hypopharyngeal carcinoma FaDu cells.

METHODS

A siRNA against EpCAM was employed to inhibit the expression of EpCAM in FaDu cells. Measurements included the Transwell assay for invasion and migration, plate colony formation assay for cell colony ability, Western blot assay for EpCAM, E-cadherin, and β-catenin expressions in total protein, cytoplasm, and cytoskeleton, respectively.

RESULTS

mRNA and protein expressions of EpCAM were suppressed significantly in FaDu cells transfected by EpCAM siRNA (t = 6.46, P < 0.05; t = 10.25, P < 0.05) . Transwell assay showed in transwell assay, the average invasive cells in EpCAM siRNA cells (26.33 ± 3.71) was less than that in FaDu cells (61.47 ± 6.70; t = 7.95, P < 0.05)and control cells (54.13 ± 6.51; t = 6.42, P < 0.05); the average number of migration cells in EpCAM siRNA cells (79.87 ± 8.44) was lower than that in FaDu (167.53 ± 11.49; t = 10.90, P < 0.05) cells and control cells (162.13 ± 13.45; t = 8.97, P < 0.05). In plate colony formation assay, the average colony number of EpCAM siRNA cells was (78.00 ± 5.57), which was less than that of FaDu cells(177.30 ± 16.50; t = 9.78, P < 0.05) and control cells (173.67 ± 13.50; t = 11.35, P < 0.05). Western blot assays showed, silencing of EpCAM increased the expressions of E-cadherin (t = 4.58, P = 0.01) and β-catenin (t = 3.76, P = 0.02) in cytoskeleton, and decreased the expressions of E-cadherin (t = 6.60, P < 0.05) and β-catenin (t = 8.20, P < 0.05) in cytoplasm.

CONCLUSIONS

The knockdown of EpCAM inhibits the invasion, migration, and colony formation abilities of FaDu cells, which is probably related to the regulation of E-cadherin and β-catenin in cytoplasm and cytoskeleton, and EpCAM may be a promising gene therapy target for hypopharyngeal carcinoma.

Tumor necrosis factor α induces epithelial-mesenchymal transition and promotes metastasis via NF-κB signaling pathway-mediated TWIST expression in hypopharyngeal cancer

Epithelial-mesenchymal transition (EMT) is an important mechanism in cancer metastasis. Tumor necrosis factor α (TNFα) can induce cancer invasion and metastasis associated with EMT. However, the underlying mechanisms are not entirely clear. Therefore, we investigated whether TNFα has an effect on EMT and invasion and metastasis in human hypopharyngeal cancer FaDu cells, and further explored the potential mechanisms. In the present study, we demonstrated that TNFα induced EMT in FaDu cells and promoted FaDu cell migration and invasion. TNFα-induced EMT was characterized by a change from well organized cell-cell adhesion and cell polarity to loss of cell-cell contacts, cell scattering and increased expression of vimentin and N-cadherin accompanied by a decrease in E-cadherin. Furthermore, we found that p65 translocated to the nucleus after TNFα stimulation and increased the nuclear expression of TWIST. We demonstrated that TNFα treatment also increased the expression of TWIST by activating the NF-κB signaling pathway. While p65 was inhibited by siRNA-65 or BAY11-7082 (inhibitor of NF-κB), TWIST expression was also decreased. Therefore, we conclude that TNFα induces EMT and promotes metastasis via NF-κB signaling pathway-mediated TWIST expression in hypopharyngeal cancer.

Classifying DNA assembly protocols for devising cellular architectures

DNA assembly is one of the most fundamental techniques in synthetic biology. Efficient methods can turn traditional DNA cloning into time-saving and higher efficiency practice, which is a foundation to accomplish the dreams of synthetic biologists for devising cellular architectures, reprogramming cellular behaviors, or creating synthetic cells. In this review, typical strategies of DNA assembly are discussed with special emphasis on the assembly of long and multiple DNA fragments into intact plasmids or assembled compositions. Constructively, all reported strategies were categorized into in vivo and in vitro types, and protocols are presented in a functional and practice-oriented way in order to portray the general nature of DNA assembly applications. Significantly, a five-step blueprint is proposed for devising cell architectures that produce valuable chemicals.