Validation of Core Ingredients and Molecular Mechanism of Cinobufotalin Injection Against Liver Cancer.

Purpose: Cinobufotalin injection has obvious curative effects on liver cancer patients with less toxicity and fewer side effects than other therapeutic approaches. However, the core ingredients and mechanism underlying these anti-liver cancer effects have not been fully clarified due to its complex composition. Methods: Multidimensional network analysis was used to screen the core ingredients, key targets and pathways underlying the therapeutic effects of cinobufotalin injection on liver cancer, and in vitro and in vivo experiments were performed to confirm the findings. Results: By construction of ingredient networks and integrated analysis, eight core ingredients and ten key targets were finally identified in cinobufotalin injection, and all of the core ingredients are tightly linked with the key targets, and these key targets are highly associated with the cell cycle-related pathways, supporting that both cinobufotalin injection and its core ingredients exert anti-liver cancer roles by blocking cell cycle-related pathways. Moreover, in vitro and in vivo experiments confirmed that either cinobufotalin injection or one of its core ingredients, cinobufagin, significantly inhibited cell proliferation, colony formation, cell cycle progression and xenograft tumor growth, and the key target molecules involved in the cell cycle pathway such as CDK1, CDK4, CCNB1, CHEK1 and CCNE1, exhibit consistent changes in expression after treatment with cinobufotalin injection or cinobufagin. Interestingly, some key targets CDK1, CDK4, PLK1, CHEK1, TTK were predicted to bind with multiple of core ingredients of cinobufotalin injection, and the affinity between one of the critical ingredients cinobufagin and key target CDK1 was further confirmed by SPR assay. Conclusion: Cinobufotalin injection was confirmed to includes eight core ingredients, and they play therapeutic effects in liver cancer by blocking cell cycle-related pathways, which provides important insights for the mechanism of cinobufotalin injection antagonizing liver cancer and the development of novel small molecule anti-cancer drugs.

New Evolutionary Insights into RpoA: A Novel Quorum Sensing Reprograming Factor in Pseudomonas aeruginosa.

Quorum-sensing (QS) coordinates the expression of virulence factors in Pseudomonas aeruginosa, an opportunistic pathogen known for causing severe infections in immunocompromised patients. QS has a master regulator, the lasR gene, but in clinical settings, P. aeruginosa isolates have been found that are QS-active but LasR-null. In this study, we developed an experimental evolutionary approach to identify additional QS-reprogramming determinants. We began the study with a LasR-null mutant with an extra copy of mexT, a transcriptional regulator gene that is known to be able to reprogram QS in laboratory LasR-null strains. In this strain, spontaneous single mexT mutations are expected to have no or little phenotypic consequences. Using this novel method, which we have named "targeted gene duplication followed by mutant screening", we identified QS-active revertants with mutations in genes other than mexT. One QS-active revertant had a point mutation in rpoA, a gene encoding the α-subunit of RNA polymerase. QS activation in this mutant was found to be associated with the downregulated expression of mexEF-oprN efflux pump genes. Our study therefore uncovers a new functional role for RpoA in regulating QS activity. Our results indicate that a RpoA-dependent regulatory circuit controlling the expression of the mexEF-oprN operon is critical for QS-reprogramming. In conclusion, our study reports on the identification of non-MexT proteins associated with QS-reprogramming in a laboratory strain, shedding light on possible QS activation mechanisms in clinical P. aeruginosa isolates.

Dissecting the roles and clinical potential of YY1 in the tumor microenvironment.

Yin-Yang 1 (YY1) is a member of the GLI-Kruppel family of zinc finger proteins and plays a vital dual biological role in cancer as an oncogene or a tumor suppressor during tumorigenesis and tumor progression. The tumor microenvironment (TME) is identified as the "soil" of tumor that has a critical role in both tumor growth and metastasis. Many studies have found that YY1 is closely related to the remodeling and regulation of the TME. Herein, we reviewed the expression pattern of YY1 in tumors and summarized the function and mechanism of YY1 in regulating tumor angiogenesis, immune and metabolism. In addition, we discussed the potential value of YY1 in tumor diagnosis and treatment and provided a novel molecular strategy for the clinical diagnosis and treatment of tumors.

BRD7 inhibits enhancer activity and expression of BIRC2 to suppress tumor growth and metastasis in nasopharyngeal carcinoma.

BRD7 functions as a crucial tumor suppressor in numerous malignancies including nasopharyngeal carcinoma (NPC). However, its function and exact mechanisms involved in tumor progression are not well understood. Here, we found that the B7BS was a potential enhancer region of BIRC2, and BRD7 negatively regulated the transcriptional activity and expression of BIRC2 by targeting the activation of the BIRC2 enhancer. Moreover, BIRC2 promoted cell proliferation, migration, invasion as well as xenograft tumor growth and metastasis in vivo, thus functioning as an oncogene in NPC. Furthermore, the recovery of BIRC2 expression could rescue the inhibitory effect of BRD7 on cell proliferation, migration, invasion and xenograft tumor growth and metastasis. In addition, BIRC2 was highly-expressed in NPC tissues, and positively correlated with the TNM stage and negatively correlated with the expression of BRD7. Therefore, these results suggest that BRD7 suppresses tumor growth and metastasis thus functioning as a tumor suppressor at least partially by negatively regulating the enhancer activity and expression of BIRC2, and targeting the BRD7/BIRC2 regulation axis might be a potential strategy for the diagnosis and treatment of NPC.

Asymmetric synthesis of bis(tertiary arsines): highly stereoselective alkylations of diastereomers of a chiral phosphine-stabilized bis(arsenium triflate).

The addition of organolithium reagents to an equilibrating mixture of diastereomers of a phosphine-stabilized 1,2-ethanediylbis(phenylarsenium triflate) containing chiral arsenic stereocenters and an enantiomerically pure, atropisomeric tertiary phosphepine derived from lithiated (aR)-2,2'-dimethyl-1,1'-binaphthalene generates unequal mixtures of diastereomers and enantiomers of chelating 1,2-ethanediylbis(tertiary arsines), chiral at arsenic, with liberation of the (aR(P))-phosphepine. Thus, the addition of methyllithium in diethyl ether at -95 degrees C to a dichloromethane solution of the complex (R*(As),R*(As))-(+/-)/(R*(As),S*(As))-1,2-[(R(3)P)PhAsCH(2)CH(2)AsPh(PR(3))](OTf)(2), where R(3)P is (aR(P))-[2-(methoxymethyl)phenyl]phosphepine, generates (R*(As),R*(As))-(+/-)-1,2-ethanediylbis(methylphenylarsine) in 78% diastereoselectivity and 95% enantioselectivity in favor of the (R(As),R(As)) enantiomer. Under similar conditions, the addition of n-butyllithium in hexanes to a solution of the bis(phosphepine-stabilized)-diarsenium triflate at -95 degrees C gives the corresponding (R*(As),R*(As))-(+/-)-1,2-ethanediylbis[(n-butyl)phenylarsine) in 77% diastereoselectivity and 93% enantioselectivity in favor of the (R(As),R(As)) enantiomer.

Facile C-H bond activation: synthesis of the N4C donor set pentadentate ligand 1,4-bis(2-pyridylmethyl)-1,4-diazacyclononane (dmpdacn) and a structural study of its alkyl-cobalt(III) complex [Co(dmpdacn-C)(OH2)](ClO4)2.H2O and its hydroxylated derivative [Co(dmpdacnOH-O)Cl](ClO4)2.C3H6O.

The 1,4-bis(2-pyridylmethyl)-1,4-diazacyclononane (dmpdacn) ligand with a N(4)C donor set deprotonates at a CH(2) gamma to an amine under extraordinarily mild conditions (pH 7) and binds as a pentadentate ligand to Co(III) as the [Co(dmpdacn-C)(OH(2))](2+) complex. This complex was characterized by 1D and 2D NMR techniques, and a single-crystal X-ray structure is reported. In an alternative synthesis from Co(II), dmpdacn, and air, the same C-bonded complex is obtained along with a novel hydroxylated Co(III) complex [Co(dmpdacnOH-O)Cl](2+) which has been similarly characterized. Here the carbanion has been oxidized, a C- to O-bonded rearrangement has taken place, and the bound aqua group is replaced by Cl(-). The base hydrolysis kinetics of the hydroxylated Co(III) complex are reported, and mechanisms for this and the unusually facile C-H cleavage and CH(2) oxidation reactions are discussed.

The first structurally characterised perchlorato-cobalt(III) complexes, involving the C-bonded macrobicyclic ligand 1,4,8,11-tetraazabicyclo[9.5.2]octadecane.

Two isomeric C-bonded complexes, sym-anti-[Co(L-C)(OH2)]2+ and sym-syn-[Co(L-C)(OH2)]2+ (L = 1,4,8,11-tetraazabicyclo[9.5.2]octadecane) when crystallised from aqueous NaClO4 remarkably yielded the corresponding perchlorato complexes, confirmed by the single crystal X-ray structures.