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1.
Mol Cancer Ther ; 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37963566

ABSTRACT

Aberrant N-linked glycosylation is a prominent feature of cancers. Perturbance of oligosaccharide structure on cell surfaces directly affects key processes in tumor development and progression. In spite of the critical role played by N-linked glycans in tumor biology, the discovery of small molecules that specifically disturbs the N-linked glycans is still under investigation. To identify more saccharide-structure-perturbing compounds, a repurposed drug screen by using a library consisting of 1530 FDA-approved drugs was performed. Interestingly, an antipsychotic drug, penfluridol, was identified as being able to decrease cell surface Wheat germ agglutinin (WGA) staining. In the presence of penfluridol, cell membrane glycoproteins PD-L1 shifted to a lower molecular weight. Further studies demonstrated that penfluridol treatment caused an accumulation of high-mannose oligosaccharides, especially Man5-7GlcNAc2 glycan structures. Mechanistically, this effect is due to direct targeting of MAN1A1 mannosidase, a Golgi enzyme involved in N-glycan maturation. Moreover, we found that altered glycosylation of PD-L1 caused by penfluridol disrupted interactions between PD-1 and PD-L1, resulting in activation of T-cell tumor immunity. In a mouse xenograft and glioma model, penfluridol enhanced the anti-tumor effect of the anti-PD-L1 antibody in vivo. Overall, these findings revealed an important biological activity of the antipsychotic drug penfluridol as an inhibitor of glycan processing and proposed a repurposed use of penfluridol in anti-tumor therapy through activation of T-cell immunity.

2.
Mediators Inflamm ; 2023: 5133505, 2023.
Article in English | MEDLINE | ID: mdl-37840694

ABSTRACT

Sepsis is one of the most severe complications and causes of mortality in the clinic. It remains a great challenge with no effective treatment for clinicians worldwide. Inhibiting the release of proinflammatory cytokines during sepsis is considered as an important strategy for treating sepsis and improving survival. In the present study, we have observed the effect of dimethyl fumarate (DMF) on lipopolysaccharide- (LPS-) induced sepsis and investigated the possible mechanism. By screening a subset of the Johns Hopkins Drug Library, we identified DMF as a novel inhibitor of nitric oxide synthesis in LPS-stimulated RAW264.7 cells, suggesting that DMF could be a potential drug to treat sepsis. To further characterize the effect of DMF on LPS signaling, TNF-α, MCP-1, G-CMF, and IL-6 expression levels were determined by using cytokine array panels. In addition, an endotoxemia model with C57BL/6 mice was used to assess the in vivo efficacy of DMF on sepsis. The survival rate was assessed, and HE staining was performed to investigate histopathological damage to the organs. DMF was found to increase the survival of septic mice by 50% and attenuate organ damage, consistent with the reduction in IL-10, IL-6, and TNF-α (inflammatory cytokines) in serum. In vitro experiments revealed DMF's inhibitory effect on the phosphorylation of p65, IκB, and IKK, suggesting that the primary inhibitory effects of DMF can be attributed, at least in part, to the inhibition of phosphorylation of IκBα, IKK as well as nuclear factor-κB (NF-κB) upon LPS stimulation. The findings demonstrate that DMF dramatically inhibits NO and proinflammatory cytokine production in response to LPS and improves survival in septic mice, raising the possibility that DMF has the potential to be repurposed as a new treatment of sepsis.


Subject(s)
NF-kappa B , Sepsis , Mice , Animals , NF-kappa B/metabolism , Lipopolysaccharides/toxicity , Dimethyl Fumarate/pharmacology , Dimethyl Fumarate/therapeutic use , Tumor Necrosis Factor-alpha/metabolism , Interleukin-6/metabolism , Mice, Inbred C57BL , Sepsis/chemically induced , Sepsis/drug therapy , Sepsis/metabolism , Cytokines/metabolism
3.
Biochem Biophys Res Commun ; 678: 158-164, 2023 10 20.
Article in English | MEDLINE | ID: mdl-37640001

ABSTRACT

Aromatic polyketide and phenylpropanoid derivatives are a large class of natural products produced by bacteria, fungi, and plants. The O-methylation is a unique decoration that can increase structural diversity of aromatic compounds and improve their pharmacological properties, but the substrate specificity of O-methyltransferase hinders the discovery of more natural products with O-methylation through biosynthesis. Here, we reported that the O-methyltransferase AurJ from plant pathogenic fungus Fusarium graminearum could methylate a broad range of natural substrates of monocyclic, bicyclic, and tricyclic aromatic precursors, exhibiting excellent substrate tolerance. This finding will partly change our stereotype about the specificity of traditional methyltransferases, and urge us to mine more O-methyltransferases with good substrate tolerance and discover more methylated natural products for drug discovery and development through directed evolution and combinatorial biosynthesis.


Subject(s)
Biological Products , Fusarium , Methyltransferases/genetics , Drug Discovery
4.
Phytomedicine ; 119: 154972, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37531903

ABSTRACT

BACKGROUND: As first-line clinical drugs, tripterygium glycoside tablets (TGTs) often have inconsistent efficacy and toxic side effects, mainly due to inadequate quality control. Therefore, clinically relevant quality standards for TGTs are urgently required. PURPOSE: Based on chemical substances and considering pharmacological efficacy, we aimed to develop an effective quality evaluation method for TGTs. METHODS: Representative commercial samples of TGTs were collected from different manufacturers, and qualitative UHPLC/LTQ-Orbitrap-MS and quantitative UHPLC-MS/MS analysis methods were successfully applied to evaluate their quality similarities and differences based on their chemical properties. Then the anti-immunity, anti-inflammatory and antitumor activities of TGTs and related monomers were evaluated using Jurkat, RAW264.7, MIA PaCa-2, and PANC-1 as cellular models. Subsequently, we predicted and verified small molecule-DCTPP1 interactions via molecular docking using the established DCTPP1 enzymatic activity assay. Finally, we performed a gray relational analysis to evaluate the chemical characteristics and biological effects of TGTs produced by different manufacturers. RESULTS: We collected 24 batches of TGTs (D01-D24) from 5 manufacturers (Co. A, Co. B, Co. C, Co. D, Co. E) for quality evaluation. The chemical composition analysis revealed significant differences in the substance bases of the samples. The D02, D18-D20 samples from Co. B constituted a separate group that differed from other samples, mainly in their absence of diterpenoids and triterpenoids, including triptolide, triptophenolide, and triptonide. In vitro anti-immunity, antitumor and anti-inflammatory tests using the same TGT concentration revealed that, except for D02, D18-D20, the remaining 20 samples exhibited different degrees of anti-immunity, antitumor and anti-inflammatory activity. Our experiments verified that triptolide, triptophenolide, and triptonide were all DCTPP1 inhibitors, and that TGTs generally exhibited DCTPP1 enzyme inhibitory activity. Moreover, the inhibitory activity of D02, D18-D20 samples from Co. B was much lower than that of the other samples, with a nearly tenfold difference in IC50. Further comprehensive analysis revealed a high correlation between DCTPP1 enzyme inhibition activity and the anti-immunity and antitumor and anti-inflammatory activities of these samples. CONCLUSION: The established DCTPP1 enzymatic activity assay proved suitable for quantitative pharmacological and pharmaceutical analysis to complement the existing quality control system for TGTs and to evaluate their effectiveness.


Subject(s)
Cardiac Glycosides , Drugs, Chinese Herbal , Glycosides/pharmacology , Glycosides/analysis , Drugs, Chinese Herbal/chemistry , Tandem Mass Spectrometry/methods , Tripterygium/chemistry , Molecular Docking Simulation , Tablets/chemistry , Biomarkers
5.
ACS Synth Biol ; 12(7): 1908-1923, 2023 07 21.
Article in English | MEDLINE | ID: mdl-37404005

ABSTRACT

Fungi, particularly filamentous fungi and macrofungi, have a very powerful ability to produce secondary metabolites and can serve as excellent chassis cells for the production of enzymes or natural products of great value in synthetic biology. Thus, it is imperative to establish simple, reliable, and efficient techniques for their genetic modification. However, the heterokaryosis of some fungi and the dominance of nonhomologous end-joining (NHEJ) repair mechanisms in vivo have been greatly affecting the efficiency of fungal gene editing. In recent years, the CRISPR/Cas9 system has been applied as a widely used gene editing technology in life science research and has also played an important role in the genetic modification of filamentous and macrofungi. The various functional components (cas9, sgRNA, promoter, and screening marker) of the CRISPR/Cas9 system and its development, as well as the difficulties and potential of the CRISPR/Cas9 system in filamentous fungus and macrofungi, are the main topics of this paper.


Subject(s)
CRISPR-Cas Systems , RNA, Guide, CRISPR-Cas Systems , CRISPR-Cas Systems/genetics , Gene Editing/methods , Fungi/genetics , Genes, Fungal
6.
Biochemistry ; 62(16): 2371-2381, 2023 08 15.
Article in English | MEDLINE | ID: mdl-37490721

ABSTRACT

Strong, psychedelic indolethylamines (IAAs) are typically present in trace amounts in the majority of species, but they build up significantly in the skin of amphibian toads, especially N-methylated 5-hydroxytryptamine (5-HT) analogues. However, there is no pertinent research on the investigation of indoleamine N-methyltransferase (INMT) in amphibians, nor is there any adequate information on the key amino acids that influence the activity of known INMTs from other species. Herein, we focused on Bufo toad INMT (BINMT) for the first time and preliminarily identified BINMT 1 from the transcriptomes of Bufo gargarizans active on tryptamine, 5-HT, and N-methyl-5-HT. We established the enzyme kinetic characteristics of BINMT 1 and identified the essential amino acids influencing its activity via molecular docking and site-directed mutagenesis. Subsequently, we carried out sequence alignment and phylogenetic tree analysis on 43 homologous proteins found in the genome of B. gargarizans with BINMT 1 as the probe and selected seven of them for protein expression and activity assays. It was found that only three proteins possessing the highest similarity to BINMT 1 had INMT activity. Our research unveils the binding residues of BINMT for 5-HT analogues for the first time and initiates the study of INMTs in amphibian toads, serving as a tentative reference for further study of BINMT and providing insight into the comprehension of BINMT's catalytic mechanism and its role in the biosynthesis of 5-HT analogues in Bufo toads. It also contributes to the expansion of the INMT library to help explore and explain interspecies evolution in the future.


Subject(s)
Bufonidae , Serotonin , Animals , Serotonin/metabolism , Molecular Docking Simulation , Phylogeny , Bufonidae/genetics , Bufonidae/metabolism , Methyltransferases/metabolism
7.
J Am Chem Soc ; 145(16): 8896-8907, 2023 04 26.
Article in English | MEDLINE | ID: mdl-37043819

ABSTRACT

Ficellomycin, azinomycins, and vazabitide A are nonribosomal peptide natural products characterized by an amino acid unit that contains a similar 1-azabicyclo[3.1.0]hexane (ABCH) pharmacophore. This unit is derived from diamino-dihydroxy-heptanic acid (DADH); however, the process through which linear DADH is cyclized to furnish an ABCH ring system remains poorly understood. Based on the reconstitution of the route of the ABCH-containing unit by blending genes/enzymes involved in the biosynthesis of ficellomycin and azinomycins, we report that ABCH formation is completed by an oxidase heterotetramer with the association of a nonribosomal peptide synthetase (NRPS). The DADH precursor was prepared in Escherichia coli to produce a conjugate subjected to in vitro enzymatic hydrolysis for offloading from an amino-group carrier protein. To furnish an aziridine ring, DADH was processed by C7-hydroxyl sulfonation and sulfate elimination-coupled cyclization. Further cyclization leading to an azabicyclic hexane pharmacophore was proved to occur in the NRPS, where the oxidase heterotetramer functions in trans and catalyzes α,ß-dehydrogenation to initiate the formation of a fused five-membered nitrogen heterocycle. The identity of ABCH was validated by utilization of the resultant ABCH-containing unit in the total biosynthesis of ficellomycin. Biochemical characterization, crystal structure, and site-specific mutagenesis rationalize the catalytic mechanism of the unusual oxidase heterotetramer.


Subject(s)
Hexanes , Peptides , Peptides/metabolism , Peptide Synthases/metabolism
8.
BMC Oral Health ; 23(1): 139, 2023 03 10.
Article in English | MEDLINE | ID: mdl-36899301

ABSTRACT

BACKGROUND: Children's dental anxiety is common in dental clinics. This study aimed to determine the interrater agreement between children's self-reported and their mothers' proxy-reported dental anxiety and its affecting factors. METHODS: In this cross-sectional study performed in a dental clinic, primary school students and their mothers were assessed for enrollment eligibility. The Modified Dental Anxiety Scale plus Facial Image Scale (MDAS-FIS) was employed to test both the children's self-reported and their mothers' proxy-reported dental anxiety independently. The interrater agreement was analyzed using percentage agreement and the linear weighted kappa (k) coefficient. Factors affecting children's dental anxiety were analyzed using univariate and multivariate logistic regression models. RESULTS: One hundred children and their mothers were enrolled. The median ages of the children and mothers were 8.5 and 40.0 years old, respectively, and 38.0% (38/100) of the children were female. The scores of children's self-reported dental anxiety were significantly higher than their mothers' proxy-reported dental anxiety (MDAS-Questions 1-5, all p < 0.05); moreover, there was no agreement between the two groups in terms of all anxiety hierarchies (kappa coefficient = 0.028, p = 0.593). In the univariate model, a total of seven factors (age, gender, maternal anxiety, number of dental visits, mother's presence or absence, oral health status, and having siblings or not) were involved for analysis, and age [every 1-year increase, odds ratio (OR) = 0.661, 95% confidence interval (CI) = 0.514-0.850, p = 0.001], several dental visits (every 1 visit increase, OR = 0.409, 95% CI = 0.190-0.880, p = 0.022), and mother presence (OR = 0.286, 95% CI = 0.114-0.714, p = 0.007) were affecting factors. In the multivariate model, only age (every 1 year increase) and maternal presence were associated with 0.697-fold (95% CI = 0.535-0.908, p = 0.007) and 0.362-fold (95% CI = 0.135-0.967, p = 0.043) decreases in the risk of children's dental anxiety during dental visits and treatment, respectively. CONCLUSION: There was no significant agreement between elementary school students' self-reported dental anxiety and mothers' proxy ratings of children's dental anxiety, which suggests that self-reported dental anxiety by children should be encouraged and adopted, and the mother's presence during dental visits is strongly recommended.


Subject(s)
Dental Anxiety , Mothers , Adult , Child , Female , Humans , Cross-Sectional Studies , East Asian People , Self Report
9.
Angew Chem Int Ed Engl ; 62(14): e202216989, 2023 03 27.
Article in English | MEDLINE | ID: mdl-36750406

ABSTRACT

Natural products with the 3,6-diene-2,5-diketopiperazine core are widely distributed in nature; however, the biosynthetic mechanism of 3,6-diene-2,5-diketopiperazine in fungi remains to be further elucidated. Through heterologous expression and biochemical investigation of an FeII /2-oxoglutarate-dependent oxidase (AspE) and a heme-dependent P450 enzyme (AspF), we report that AspE, AspF and subsequent dehydration account for the formation of the 3,6-diene-2,5-diketopiperazine substructure of brevianamide K from Aspergillus sp. SK-28, a symbiotic fungus of mangrove plant Kandelia candel. More interestingly, in-depth investigation of the enzymatic mechanism showed that AspE promotes hydroxylation of brevianamide Q with unprecedented stereoinversion through hydrogen atom abstraction and water nucleophilic attack from the opposite face of the resultant iminium cation intermediate.


Subject(s)
Cytochrome P-450 Enzyme System , Ferrous Compounds , Hydroxylation , Cytochrome P-450 Enzyme System/metabolism , Catalysis
10.
Bioresour Bioprocess ; 10(1): 2, 2023 Jan 09.
Article in English | MEDLINE | ID: mdl-38647644

ABSTRACT

Physcion is an anthraquinone compound observed dominantly in medicinal herbs. This anthraquinone possesses a variety of pharmaceutically important activities and has been developed to be a widely used antifungal biopesticide. Herein, we report on the effective preparation of 3R-torosachrysone (4), a tetrahydroanthracene precursor of physcion, in Aspergillus oryzae NSAR1 by heterologous expression of related genes mined from the phlegmacins-producing ascomycete Talaromyces sp. F08Z-0631. Conditions for converting 4 into physcion were studied and optimized, leading to the development of a concise approach for extracting high-purity physcion from the alkali-treated fermentation broth of the 4-producing A. oryzae strain.

11.
Fungal Genet Biol ; 161: 103700, 2022 07.
Article in English | MEDLINE | ID: mdl-35504456

ABSTRACT

The high efficiency and elegance of terpene synthases is fascinating in constructing the molecular skeleton of complicated terpenoids with multiple chiral centers. Although the rapid development of sequencing technology has led to the discovery of an increasing number of terpene synthases, the cyclization mechanisms of some terpene synthases remains elusive. Here, we report that a chimeric sesquiterpene synthase from Steccherinum ochraceum is responsible for the biosynthesis of (+)-hirsutene, a linear triquinane sesquiterpene. Structural validation, and isotope labeling experiments demonstrate that the biosynthesis of (+)-hirsutene employs an unusual cyclization mode, involving three different cyclization processes (C1-C11, C2-C9, C3-C6), one intramolecular 1,2-hydride shift (C9-C10) and three successive 1,2-alkyl shifts to construct the 5-5-5 fused ring skeleton of (+)-hirsutene.


Subject(s)
Alkyl and Aryl Transferases , Sesquiterpenes , Alkyl and Aryl Transferases/genetics , Catalysis , Polycyclic Sesquiterpenes , Polyporales , Terpenes
12.
ACS Chem Biol ; 17(4): 791-796, 2022 04 15.
Article in English | MEDLINE | ID: mdl-35274920

ABSTRACT

Phlegmacins are homodimeric dihydroanthracenone natural products featuring two torosachrysone monomers unsymmetrically conjugated by 7,10'-coupling. Herein, we report the identification and characterization of the biosynthetic gene cluster of phlegmacins in ascomycete Talaromyces sp. F08Z-0631. On the basis of the heterologous reconstitution of the phlegmacin pathway in Aspergillus oryzae, we demonstrated an unprecedented laccase-involved unsymmetrically regioselective oxidative coupling reaction. The association of laccase PhlC and the fasciclin partner protein PhlB was verified to be indispensable for the coupling activity. Intriguingly, both proteins can be transferred and located independently at the mitochondrial membrane. Notably, only their subcellular colocalization led to the occurrence of oxidative dimerization. These observations add new insights into the poorly understood catalytic mechanisms of various laccases involved in the biosynthesis of secondary metabolites, particularly those functioning with variable partners.


Subject(s)
Ascomycota , Aspergillus oryzae , Ascomycota/genetics , Aspergillus oryzae/genetics , Dimerization , Laccase/genetics , Multigene Family , Oxidation-Reduction
13.
Org Lett ; 23(6): 2342-2346, 2021 03 19.
Article in English | MEDLINE | ID: mdl-33683897

ABSTRACT

Rifamycins have been clinically utilized against mycobacterial infections for more than 50 years; however, their biosynthesis has not been fully elucidated. Here, on the basis of in vivo gene deletions, in vitro enzyme assays, isotope labeling, and site-directed mutations, we found that a flavin-dependent monooxygenase encoded by a rifamycin biosynthetic gene cluster, Rif-Orf17, not only converted the naphthoquinone chromophore of rifamycin S into benzo-γ-pyrone but also linearized rifamycin SV through phenolic hydroxylation. Both oxidation routes lead to inactivation of rifamycins.


Subject(s)
Flavins/chemistry , Mixed Function Oxygenases/chemistry , Rifamycins/chemistry , Anti-Bacterial Agents/biosynthesis , Anti-Bacterial Agents/chemistry , Flavins/metabolism , Molecular Structure , Multigene Family , Oxidation-Reduction , Rifamycins/metabolism
14.
Nat Prod Rep ; 38(4): 843-860, 2021 04 28.
Article in English | MEDLINE | ID: mdl-33146205

ABSTRACT

Covering: 2000 to 2020 Triptolide is a bioactive diterpene triepoxide isolated from Tripterygium wilfordii Hook F, a traditional Chinese medicinal plant whose extracts have been used as anti-inflammatory and immunosuppressive remedies for centuries. Although triptolide and its analogs exhibit potent bioactivities against various cancers, and inflammatory and autoimmune diseases, none of them has been approved to be used in the clinic. This review highlights advances in material sourcing, molecular mechanisms, clinical progress and new drug design strategies for triptolide over the past two decades, along with some prospects for the future course of development of triptolide.


Subject(s)
Diterpenes/pharmacology , Phenanthrenes/pharmacology , Animals , Autoimmune Diseases/drug therapy , Diterpenes/isolation & purification , Drug Design , Drug Discovery , Epoxy Compounds/isolation & purification , Epoxy Compounds/pharmacology , Forecasting , Humans , Inflammation/drug therapy , Neoplasms/drug therapy , Phenanthrenes/isolation & purification , Tripterygium/chemistry
15.
iScience ; 23(9): 101536, 2020 Sep 25.
Article in English | MEDLINE | ID: mdl-33083765

ABSTRACT

A major hurdle in the treatment of cancer is chemoresistance induced under hypoxia that is characteristic of tumor microenvironment. Triptolide, a potent inhibitor of eukaryotic transcription, possesses potent antitumor activity. However, its clinical potential has been limited by toxicity and water solubility. To address those limitations of triptolide, we designed and synthesized glucose-triptolide conjugates (glutriptolides) and demonstrated their antitumor activity in vitro and in vivo. Herein, we identified a lead, glutriptolide-2 with an altered linker structure. Glutriptolide-2 possessed improved stability in human serum, greater selectivity toward cancer over normal cells, and increased potency against cancer cells. Glutriptolide-2 exhibits sustained antitumor activity, prolonging survival in a prostate cancer metastasis animal model. Importantly, we found that glutriptolide-2 was more potent against cancer cells under hypoxia than normoxia. Together, this work provides an attractive glutriptolide drug lead and suggests a viable strategy to overcome chemoresistance through conjugation of cytotoxic agents to glucose.

16.
Cancer Cell Int ; 20: 415, 2020.
Article in English | MEDLINE | ID: mdl-32863773

ABSTRACT

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a common kind of squamous cell carcinoma of the head and neck, which is a threat to public health. Long noncoding RNAs (lncRNAs) are associated with the development of various diseases, including cancers. LncRNA titin antisense RNA 1 (TTN-AS1) is known as a crucial regulatory factor in several cancers. Nevertheless, the specific functions of TTN-AS1 in OSCC remains obscure. METHODS: The expression of TTN-AS1 in OSCC samples or cells was analyzed through qRT-PCR. Colony formation assay, EdU assay, flow cytometry assay, TUNEL assay and wound healing assay were conducted to estimate the functions of TTN-AS1 in OSCC cells. RIP and luciferase reporter assays were utilized to detect the interaction between TTN-AS1 and miR-411-3p as well as between miR-411-3p and NFAT5. RESULTS: TTN-AS1 expression was stronger in OSCC cells. Knockdown of TTN-AS1 effectively restrained cell proliferation and migration but had inductive role in apoptosis. Moreover, TTN-AS1 could function as the miR-411-3p sponge in OSCC and miR-411-3p exerted the inhibitory functions on OSCC cell growth. In addition, NFAT5 was proven as the target of miR-411-3p. Rescue assay indicated that overexpressing NFAT5 could reverse the inhibitory function of TTN-AS1 depletion on cell growth. CONCLUSION: lncRNA TTN-AS1 contributed to the progression of OSCC via miR-411-3p/NFAT5 axis.

17.
Biomed Opt Express ; 11(2): 1061-1072, 2020 Feb 01.
Article in English | MEDLINE | ID: mdl-32133237

ABSTRACT

Lung cancer is the leading cause of death in cancer patients, and microwave ablation (MWA) has been extensively used in clinical treatment. In this study, we characterized the spectra of MWA-treated and untreated lung squamous cell carcinoma (LSCC) tissues, as well as healthy lung tissue, and conducted a preliminary analysis of spectral variations associated with MWA treatment. The results of characteristic spectral analysis of different types of tissues indicated that MWA treatment induces an increase in the content of nucleic acids, proteins, and lipid components in lung cancer tissues. The discriminant model based on the principal component analysis - linear discriminant analysis (PCA-LDA) algorithm together with leave-one-out cross validation (LOOCV) method yield the sensitivities of 90%, 80%, and 96%, and specificities of 86.2%, 93.8%, and 100% among untreated and MWA-treated cancerous tissue, and healthy lung tissue, respectively. These results indicate that Raman spectroscopy combined with multivariate analysis techniques can be used to explore the biochemical response mechanism of cancerous tissue to MWA therapy.

18.
Int J Med Sci ; 17(5): 577-590, 2020.
Article in English | MEDLINE | ID: mdl-32210707

ABSTRACT

Confocal Raman microspectral imaging was adopted to elucidate the cellular drug responses of osteosarcoma cells (OC) to N-[N-(3, 5-difluorophenyl acetyl)-L-alanyl]-sphenylglycine butyl ester (DAPT), a γ-secretase inhibitor, by identifying the drug induced subcellular compositional and structural changes. Methods: Spectral information were acquired from cultured osteosarcoma cells treated with 0 (Untreated Group, UT), 10 (10 µM DAPT treated, 10T), 20 µM (20 µM DAPT treated, 20T) DAPT for 24 hours. A one-way ANOVA and Tukey's honest significant difference (HSD) post hoc multiple test were sequentially applied to address spectral features among three groups. Multivariate algorithms such as K-means clustering analysis (KCA) and Principal component analysis (PCA) were used to highlight the structural and compositional differences, while, univariate imaging was applied to illustrate the distribution pattern of certain cellular components after drug treatment. Results: Major biochemical changes in DAPT-induced apoptosis came from changes in the content and structure of proteins, lipids, and nucleic acids. By adopted multivariate algorithms, the drug induced cellular changes was identified by the morphology and spectral characteristics between untreated cells and treated cells, testified that DAPT mainly acted in the nuclear region. With the increase of the drug concentration, the content of main subcellular compositions, such nucleic acid, protein, and lipid decreased. In an addition, DAPT-induced nuclear fragmentation and apoptosis was depicted by the univariate Raman image of major cellular components (nucleic acids, proteins and lipids). Conclusions: The achieved Raman spectral and imaging results illustrated detailed DAPT-induced subcellular compositional and structural variations as a function of drug dose. Such observations can not only explain drug therapeutic mechanisms of OC DAPT treatment, and also provide new insights for accessing the medicine curative efficacy and predicting prognosis.


Subject(s)
Cellular Structures/drug effects , Dipeptides/pharmacology , Osteosarcoma/drug therapy , Amyloid Precursor Protein Secretases/antagonists & inhibitors , Animals , Cell Line, Tumor , Dipeptides/therapeutic use , Drug Screening Assays, Antitumor , Mice , Osteosarcoma/chemistry , Principal Component Analysis , Spectrum Analysis, Raman
19.
Appl Microbiol Biotechnol ; 103(16): 6759-6769, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31230100

ABSTRACT

Confocal Raman microspectral imaging (CRMI) is an advanced cell-imaging method that maps endogenous molecular compositions with their unique spectral fingerprint indicators. The aim of this work was to provide a visualized understanding of subcellular features of live osteosarcoma cells using a 532-nm laser excitation without the use of dyes or molecular probes. Both malignant osteoblast and spindle osteosarcoma cells derived from the BALB/c mouse osteosarcoma cell line K7M2 were investigated in this work. After preprocessing the obtained spectral dataset, K-means cluster analysis (KCA) is employed to reconstruct Raman spectroscopic maps of single biological cells by identifying regions of the cellular membrane, cytoplasm, organelles, and nucleus with their corresponding mean spectra. Principal component analysis (PCA) was further employed to indicate variables of significant influence on the separation of the spectra of each cellular component. The biochemical components of the two cell types were then extracted by showing the spectral and distribution features attributed to proteins, lipids, and DNA. Using this standardized CRMI technique and multivariate analysis approaches, the results obtained could be a sound foundation for a typical Raman imaging protocol of live cellular biomedical analysis.


Subject(s)
Biological Factors/analysis , Cell Line, Tumor/chemistry , Nonlinear Optical Microscopy/methods , Osteosarcoma/pathology , Single-Cell Analysis/methods , Animals , Mice , Mice, Inbred BALB C , Multivariate Analysis
20.
Molecules ; 24(11)2019 May 30.
Article in English | MEDLINE | ID: mdl-31151168

ABSTRACT

Raman spectroscopy facilitates accurate and minimally invasive investigation on biomedical samples to reveal their molecular-level biological information. In this work, the cancer field effects of squamous cell carcinoma (SCC) tissues were illustrated by Raman microspectroscopy. Referenced with hematoxylin and eosin (H&E) stained microscopic images, the biochemical variations during SCC progress were meticulously described by the Raman spectral features in different pathological areas of two lesion types, including the biochemical changes in collagen, lipids, DNA, and other components of SCC diffusion and metastasis. The experimental results demonstrated that the intensities of the Raman peaks representing collagen (853, 936, and 1248 cm-1) were decreased, whereas the intensities of peaks corresponding to DNA (720, 1327 cm-1) and lipids (1305 cm-1) were increased significantly in cancerous lesions, which testified that SCC originates from the epidermis and invades the dermis gradually. The achieved results not only described the molecular mechanism of skin carcinogenesis, but also provided vital reference data for in vivo skin cancer diagnosis using Raman spectroscopy.


Subject(s)
Carcinoma, Squamous Cell/pathology , Skin Neoplasms/pathology , Spectrum Analysis, Raman , Adult , Biopsy , Female , Humans , Immunohistochemistry , Male , Middle Aged , Neoplasm Invasiveness , Neoplasm Metastasis , Spectrum Analysis, Raman/methods
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