Constitutively expression of the pathway-specific activators is an effective method to activate silent gene clusters and improve natural product production. In this study, nine shunt products of aminoansamycins (1-9) were identified from a recombinant mutant strain S35-LAL by overexpressed the large-ATP-binding regulator of the LuxR family (LAL) gene aas1 in Streptomyces sp. S35. All the compounds showed no anti-microbial, anti-T3SS and cytotoxic activities.
Biological Products/metabolism* ; Lactams, Macrocyclic/metabolism* ; Multigene Family ; Organisms, Genetically Modified ; Streptomyces/metabolism*

OBJECTIVE: To investigate the role of focal adhesion kinase (FAK) in extracellular signal-regulated kinase (ERK) signaling pathway mediated invadsion of trophoblasts. METHODS: We established a human extravillous cytotrophoblasts in vitro invasion model. Different concentrations of herbimycin A(FAK inhibitor)and PD98059 (ERK inhibitor) were given to observe the influence on the growth of trophoblast cells, FAK, ERK phosphorylation, and trophoblast invasion abilities. RESULTS: The expression of phosphorylated FAK in the extravillous cytotrophoblasts (EVCT) was inhibited by herbimycin A in a concentration-dependent manner and expression of phosphorylated ERK1/2 was also partially reduced. PD98059 had no effect on the expression of phosphorylated FAK. Herbimycin A and PD98059 suppressed the in vitro invasion of EVCT to various degrees. CONCLUSION ERK signaling pathway may be the common pathway for many invasive signals,and play a key role in the regulation of trophoblast invasion.
Benzoquinones ; pharmacology ; Cell Division ; physiology ; Cell Movement ; physiology ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; metabolism ; Flavonoids ; pharmacology ; Focal Adhesion Protein-Tyrosine Kinases ; antagonists & inhibitors ; metabolism ; Humans ; Lactams, Macrocyclic ; pharmacology ; Phosphorylation ; Rifabutin ; analogs & derivatives ; Signal Transduction ; physiology ; Trophoblasts ; cytology ; physiology

Ansamycins, such as rifamycin and ansamitocin, usually consist of a group of structural similar components. Geldanamycin, a benzenic ansamycin, has been found to consist of four structural similar components. We analyzed the geldanamycin (GDM) preparation from Streptomyces hygroscopicus 17997 by LC-ESI(+)-MS/MS, and discovered five novel and one known GDM analogues in trace amounts. Based on the ESI(+)-MS/MS spectra of these GDM analogues, and the present understanding of GDM biosynthesis, we proposed the possible chemical structures of these GDM analogues. Three novel GDM analogues, all having the same molecular formula of C29H42N2O10, were GDM biosynthetic derivatives with one of the three C-C double bonds between C2-C3, C4-C5 and C8-C9 in GDM changed to mono-hydroxylated C-C single bond. The other two novel GDM analogues, having the same molecular formula of C28H38N2O8, were 17(or 12, or 4)-desmethoxylgeldanamycin and 4,5-dihydro-10,11-dehydrate-17-desmethyl-17-hydroxylgeldanamycin, respectively. The known GDM analogue, having the molecular formula of C29H42N2O9, was 4, 5-dihydrogeldanamycin, an intermediate in GDM biosynthesis. The discovery of novel GDM analogues provided us new insights in understanding the biosynthetic details of GDM, and clues of obtaining GDM derivatives by gene-disruption and combinatorial biosynthesis.
Anti-Bacterial Agents ; chemistry ; Benzoquinones ; analysis ; chemistry ; Chromatography, Liquid ; methods ; Lactams, Macrocyclic ; analysis ; chemistry ; Tandem Mass Spectrometry ; methods

Geldanamycin (Gdm), an inhibitor of heat shock protein 90 (Hsp90), shows antitumor and antivirus bioactivity. Most Geldanamycin biosynthetic genes have been cloned from the genome library of Streptomyces hygroscopicus 17997. In this report, polyketide synthase (pks) gene, mono-oxygenase (gdmM) gene and carbamoyltransferase gene (gdmN) were subjected to inactivation. Three gene disrupted mutants (deltapks, deltagdmM and deltagdmN) were obtained by double crossover. No Geldanamycin production was detected in three mutant strains cultured in fermentation broth. Gene complementation experiments excluded the possible polar effect of gene disruption on other genes. These results confirmed that pks, gdmM and gdmN genes were essential for Geldanamycin biosynthesis.
Benzoquinones ; metabolism ; Carboxyl and Carbamoyl Transferases ; genetics ; Lactams, Macrocyclic ; metabolism ; Mixed Function Oxygenases ; genetics ; Polyketide Synthases ; genetics ; Streptomyces ; genetics ; metabolism

OBJECTIVETo explore the effect of heat shock protein 90 (HSP90) inhibitor (17-DMAG) and oxaliplatin on the proliferation and invasion of colorectal cancer.

METHODSAfter 17-DMAG, oxaliplatin and half-dose combination of 2 drugs processing colorectal cancer SW480 and HCT116 cell lines, CCK8 assay was applied to detect cell viability. RT-PCR and Western blot were used to detect the expression level of the apoptosis-related molecules. Transwell chemokine axis experiment and Western blot were employed to detect cell invasion ability and the expression level of tumor metastasis-associated protein.

RESULTSThe growth of SW480 and HCT116 cells was inhibited after the administration of 17-DMAG and oxaliplatin(P<0.05) in dose- and time-dependent manner. Processed by 17-DMAG 100 nmol/L, oxaliplatin 50 mg/L and half-dose combination of 2 drugs, transcription level of the apoptosis inhibitory gene (Bcl-2) in SW480 and HCT116 cells was decreased, the level of apoptosis promoting gene (Bax) transcription and protein PARP-1 spliceosome expression was increased, and the above trend was more obvious when using half-dose combination of 2 drugs. Transwell chemokine axis experiments showed the penetrating relative percentage and expression level of MMP9 and integrin β3 decreased, especially for half-dose combination of 2 drugs.

CONCLUSION17-DMAG and oxaliplatin can co-inhibit the proliferation and invasion of colorectal cancer.

Antineoplastic Agents ; Apoptosis ; Benzoquinones ; Cell Proliferation ; Cell Survival ; Colorectal Neoplasms ; HCT116 Cells ; Humans ; Lactams, Macrocyclic ; Neoplasm Invasiveness ; Organoplatinum Compounds

OBJECTIVETo investigate the role of adhesion between fibronectin and fibroblasts in wound healing as well as tyrosine phosphorylation proteins in procollagen mRNA expression.

METHODSThe level of proalpha1 (I) mRNA and tyrosine phosphorylation protein were detected employing the techniques of RT-PCR and immunoblotting. After inhibition of tyrosine kinases, herbimycin A was added to the medium to block the pathway of tyrosine phosphorylation, the changes of procollagen mRNA and tyrosine phosphorylation proteins were further investigated.

RESULTSThe adhesion between fibroblasts and fibronectin in wound healing not only induced the production of 98kd and 65kd tyrosine phosphorylation protein, but also enhanced obviously the expression of procollagen alpha1 (I) mRNA. When the pathway of tyrosine phosphorylation was blocked, the level of procollagen alpha1 (I) mRNA lowered remarkably, accompanied by the decrease of 98kd, 65kd tyrosine phosphorylation proteins.

CONCLUSIONThe adhesion between fibronectin and fibroblasts plays an important role in expression increase of procollagen mRNA during wound healing, in the process of which tyrosine phosphorylation is a key step.

Adolescent ; Adult ; Benzoquinones ; Blotting, Western ; Child ; Female ; Fibroblasts ; metabolism ; Gene Expression ; Humans ; Lactams, Macrocyclic ; Male ; Phosphoproteins ; metabolism ; physiology ; Phosphorylation ; drug effects ; Procollagen ; genetics ; Quinones ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Rifabutin ; analogs & derivatives ; Skin ; drug effects ; metabolism ; pathology ; Tyrosine ; metabolism ; Wound Healing ; genetics ; physiology

OBJECTIVETo investigate the influence of various signal transduction modulators on the splenic T lymphocytes secretion of IL-2 and IL-10 in severely scalded mice, and to explore its mechanism.

METHODSThe mice were inflicted with 18% TBSA full-thickness scald by high-pressure heat vapour, and T lymphocytes were isolated from murine splenocytes through nylon wool column at 12 and 96 post-scald hours (PSH). Then the cells were divided into following groups: i. e. control, scald, scald and modulator [1 ml of 50 micromol/L PKC inhibitor ( H-7) , 30 micromol/L tetradecanoylphorbol-13-acetate (TPA) , 10micromol/L nonreceptor tyrosine protein kinase inhibitor (herbimycin) , 25 microg/ml of mitogen activated protein kinase kinase inhibitor (PD098059) , 100 nmol/L Calcium ionophore ( A23187) were added to the cells, respectively] groups. The scald group was subdivided into S1 (with scald at 12 PSH) and S2 (with scald at 96 PSH) groups. The modulator group was subdivided into modulator, S1 and modulator( the modulators were added into cells at 12 PSH) , and S2 and modulator( the modulators were added to cells at 96 PSH) groups. The influence of modulators to T lymphocyte secretion of IL-2 and IL-10 were observed.

RESULTSAfter the addition of H-7, the IL-2 and IL-10 levels in each group were obviously lower than that in controls( P <0. 05 or 0.01) , and that in S1 and H7 group, S2 and H7 group were obviously lower than that in scald group at corresponding time-points( P <0.01). The levels of IL-10, and especially IL-2 were elevated by TPA, but they were markedly lower than that in control group after PD098059 pretreatment. The secretion of IL-2 and IL-10 was significantly suppressed by herbimycin in S1 and herbimycin, and S2 and herbimycin groups, but those in Sl and A21387[ (2 417+/-39) pg/ml, (2 793+/-25)pg/ml] , S2 and A21387 [ (921+/-50) pg/ml, (2 633+/-35)pg/ml] groups were evidently higher than those in S1[ (1 542+/-40)pg/ml, (2 390+/-15)pg/ml] , S2 [(328+/-19)pg/ml, (1 618+/-21)pg/ml,( P <0.05 or <0.01)]groups.

CONCLUSIONPKC, calcium, MAPKK and TPK play critical roles in the dysfunction of splenic T lymphocyte secretion of IL-2 and IL-10 in severely scalded mice, among which TPK and PKC are mainly targeted to IL-2 secretion, and MAPKK is targeted to IL-10 secretion. TPA and A23187 can markedly rectify the disturbance of IL-2/IL-10 secretion ratio by increasing the IL-2 secretion after scald.

Animals ; Benzoquinones ; pharmacology ; Burns ; metabolism ; Calcimycin ; pharmacology ; Calcium ; metabolism ; Cells, Cultured ; Female ; Flavonoids ; pharmacology ; Interleukin-10 ; metabolism ; Interleukin-2 ; metabolism ; Lactams, Macrocyclic ; pharmacology ; Lymphocyte Activation ; Male ; Mice ; Mice, Inbred Strains ; Mitogen-Activated Protein Kinase Kinases ; antagonists & inhibitors ; Protein Kinase C ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; Rifabutin ; analogs & derivatives ; Signal Transduction ; Spleen ; cytology ; T-Lymphocytes ; drug effects ; metabolism ; Tetradecanoylphorbol Acetate ; pharmacology

A geldanamycin (GDM) producing strain, Streptomyces hygroscopicus 17997, was isolated from Yunnan China soil by our institute researchers. GDM is an ansamycin antibiotic, which has the ability to bind with Hsp90 (Heat Shock Protein 90) and alter its function. Hsp90 is a chaperone protein involved in the regulation of the cell cycle, cell growth, cell survival, apoptosis, and oncogenesis. So it plays a key role in regulating the physiology of cells exposed to environmental stress and in maintaining the malignant phenotype of tumor cells. As an inhibitor of Hsp90, GDM possesses potent antitumor and antivirus bioactivity, but the hypato-toxicity and poor solubility in water limits its clinical use. Two GDM derivatives, 17-(Allylamino)-17-demethoxygeldanamycin (17-AAG) and 17-dimethylamino-ethylamino-17-demethoxygeldanamycin (17-DMAG), both showing lesser hepato-toxicity, are now in Phase II and Phase I clinic trials. In order to accomplish the structure modification of GDM by genetic means, an attempt to obtain the biosynthetic gene cluster of GDM from S. hygroscopicus 17997 was made. In this study, a pair of primers was designed according to a conserved sequence of one of possible post-PKS (polyketides synthase) modification genes, the carbamoyltransferase (CT) gene (gdmN) in GDM biosynthesis. The 732 bp PCR product was obtained from the S. hygroscopicus 17997 genomic DNA. Through the colony-PCR Binary Search Method, using the CT gene primers, six positive cosmid clones, CT1-6, were identified from the S. hygroscopicus 17997 cosmid genomic library. The CT gene containing fragments were verified and localized by Southern blot. The CT-4 positive cosmid was then sub-cloned and sequenced. Approximately 28.356kb of foreign gene sequence from CT-4 cosmid and by further PCR extension reaction was obtained. Based on BLAST analysis, this sequence contains 13 possible ORFs and their deduced functions are believed to be involved in GDM production. The ORF1 encoding products show homology (87%) with incomplete sixth module and complete seventh module of PKS, gdmA3, in S. hygroscopicus NRRL 3602. The ORF2-13 gene products are similar to gdmF(9 5%), gdmM(8 8%), gdmN (92%), gdmH (92%), I (93%), J (90%), K (93%), G (96%), gdmO (91%), gdmP (93%) and two transcription regulation genes gdmRI (83%) and gdmRII (90%). The obtained possible GDM biosynthetic gene cluster in S. hygroscopicus 17997 will facilitate the further functional analysis of the genes and to modify the structure of GDM through combinatorial biosynthesis.
Anti-Bacterial Agents ; metabolism ; Benzoquinones ; metabolism ; Carboxyl and Carbamoyl Transferases ; genetics ; Chromosome Mapping ; Cloning, Molecular ; DNA Primers ; genetics ; Lactams, Macrocyclic ; metabolism ; Multigene Family ; Streptomyces ; genetics ; metabolism

OBJECTIVETo investigate the effect of 17-AAG combined with paclitaxel (PTX) on the proliferation and apoptosis of esophageal squamous cell carcinoma cell line Eca-109 in vitro.

METHODSEca-109 cells were treated with 17-AAG and PTX either alone or in combination. The proliferation of Eca-109 cells was detected by MTT assay, and the cell cycle changes and cell apoptosis were determined by flow cytometry.

RESULTSCompared with the control group, both 17-AAG and PTX significantly inhibited the proliferation of Eca-109 cells. A combined treatment of the cells with 0.5 µmol/L PTX and 0.625 µmol/L 17-AAG produced an obviously stronger inhibitory effect on the cell proliferation than either of the agents used alone (P<0.01). Flow cytometry showed that, 17-AAG and PTX used alone caused Eca-109 cell cycle arrest in G2/M phase and S phase, respectively, and their combined use caused cell cycle arrest in both G2/M and S phases. The cell apoptosis rates of Eca-109 cells treated with 17-AAG, PTX and their combination were 4.52%, 10.91%, and 29.88%, respectively, all significantly higher than that in the control group (1.32%); the combined treatment resulted in a distinct apoptotic peak that was significantly higher than that caused by either of the agents alone.

CONCLUSION17-AAG and PTX can inhibit cell proliferation and promote apoptosis of Eca-109 cells, and their combination produces stronger effects in inhibiting cell proliferation and increasing cell apoptosis.

Apoptosis ; Benzoquinones ; pharmacology ; Carcinoma, Squamous Cell ; pathology ; Cell Cycle Checkpoints ; Cell Line, Tumor ; drug effects ; Cell Proliferation ; Esophageal Neoplasms ; pathology ; Humans ; Lactams, Macrocyclic ; pharmacology ; Paclitaxel ; pharmacology

Anaplastic lymphoma kinase (ALK) fusions represent the second most common oncogenic driver mutation in non-small cell lung cancer (NSCLC). As the new class of 3rd generation of ALK tyrosine kinase inhibitor (TKI), lorlatinib has shown robust potency and brain-penetrant clinical activity against a wide spectrum of multiple resistance mutations within the ALK domain detected during crizotinib and 2nd generation ALK TKI treatment. Lorlatinib is generally well-tolerated with unique adverse drug reaction/adverse event, including hyperlipidemia and central nervous system effects, which are mostly mild to moderate severity and manageable through dosage modifications and/or standard medical intervention. For advanced NSCLC with ALK positivity, patients should be evaluated for baseline characteristics and pre-existing medication, informed of the potential toxicities, and periodically monitored to balance benefits and risks. Moreover, a multidisciplinary group of experts is essential to establish a comprehensive diagnostic and therapeutic strategy.
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Aminopyridines ; Carcinoma, Non-Small-Cell Lung/pathology* ; China ; Consensus ; Drug Resistance, Neoplasm/genetics* ; Drug-Related Side Effects and Adverse Reactions/drug therapy* ; Humans ; Lactams ; Lactams, Macrocyclic/adverse effects* ; Lung Neoplasms/pathology* ; Protein Kinase Inhibitors/adverse effects* ; Protein-Tyrosine Kinases/genetics* ; Pyrazoles