Biomedical subjects

Han-Dong Sun

Publications and source records attributed to Han-Dong Sun.

At least 19 recordsLinked to original sources

PubMed2026

Spatial proteogenomic profiling uncovers sensitization strategies for antibody-drug conjugate in HER2-positive breast cancer.

Antibody-drug conjugates (ADCs) have transformed the treatment of HER2-positive breast cancer, yet resistance remains poorly understood. Using imaging mass cytometry, we profiled 157 regions of interest comprising 912,360 single cells from 47 HER2-positive/hormone receptor-negative breast cancers treated with SHR-A1811 in the FASCINATE-N trial. Spatial proteomic analyses identified two determinants of ADC response: elevated tumor-cell H3K27ac expression was associated with improved ADC efficacy, whereas collagen-positive fibroblasts mediated resistance. Combining ADC with the histone deacetylase inhibitor chidamide or the collagen-modulating agent losartan produced synergistic antitumor effects in preclinical models. These biomarkers and therapeutic vulnerabilities were independently validated in patients with advanced HER2-positive disease receiving trastuzumab deruxtecan. Moreover, based on these spatial features, we developed a clinically applicable ADC barrier prediction model that can be implemented using multiplex immunofluorescence. Taken together, our findings reveal actionable spatial determinants of ADC efficacy and suggest potential combination therapeutic strategies.

Humans↗

PubMed2006

ent-Abietane diterpenoids from Isodon rubescens var. rubescens.

ent-Abietane diterpenoids, hebeiabinins A-F (1-5), together with seven known diterpenoids were isolated from leaves of Isodon rubescens var. rubescens. The structures of 1-5 were established on the basis of spectroscopic analyses, including application of 2D NMR spectroscopic techniques. The diterpenoids isolated were evaluated for the cytotoxicity against A549, HT-29, and K562 tumor cells. Compound 5 was the most active with IC(50) value of 0.91 microM against A549 cells.

Abietanes↗

PubMed2006

Synthesis and cytotoxicity of some new eriocalyxin B derivatives.

Eriocalyxin B (1) was regarded as the promising candidate for new anticancer agent because of its potent activity and novel mechanism of action. Systematic modifications of 1 were done, and nineteen derivatives were synthesized and their cytotoxicities against five tumor cell lines were evaluated. The structure-activity relationship (SAR) of 1 confirmed that the alpha,beta-unsaturated ketone moieties in ring A and D are the leading active sites; the 7,20-epoxy moiety, OH-6 and OH-7 play an important role in keeping the cytotoxicity. The 6,7-seco derivative 19 had remarkable activity while derivative 20 oxidized from 19 was completely inactive, which suggested that the carboxyl group could destroy the cytoxicity of 20 despite the presence of alpha,beta-unsaturated ketone moiety.

Antineoplastic Agents↗

PubMed2006

Maoecrystal Z, a cytotoxic diterpene from Isodon eriocalyx with a unique skeleton.

[structure: see text] A novel diterpene with an unprecedented tetracyclic 6,7:8,15-di-seco-7,20-olide-6,8-cyclo-ent-kaurane skeleton, named maoecrystal Z (1), has been isolated from the leaves of a Chinese medicinal herb, Isodon eriocalyx (Labiatae). Its structure was determined by comprehensive NMR and MS spectroscopic analysis coupled with single-crystal X-ray crystallographic diffraction. Compound 1 exhibited comparable inhibitory effect against human K562 leukemia, MCF7 breast, and A2780 ovarian tumor cells with IC(50) = 2.90, 1.63, and 1.45 microg/mL and with camptothecin and paclitaxel as the positive controls.

Antineoplastic Agents, Phytogenic↗

PubMed2006

Ferulic acid esters from Euphorbia hylonoma.

Octacosyl cis-ferulate (1), along with the trans isomer (2), cholest-5-en-3beta-ylhexadecanoate, chrysophanol and octadecanoic acid was isolated from the roots of Euphorbia hylonoma.

Coumaric Acids↗

PubMed2006

Eriocalyxin B inhibits nuclear factor-kappaB activation by interfering with the binding of both p65 and p50 to the response element in a noncompetitive manner.

Nuclear factor-kappaB (NF-kappaB) has been recognized to play a critical role in cell survival and inflammatory processes. It has become a target for intense drug development for the treatment of cancer, inflammatory, and autoimmune diseases. Here, we describe a potent NF-kappaB inhibitor, eriocalyxin B (Eri-B), an ent-kauranoid isolated from Isodon eriocalyx, an anti-inflammatory remedy. The presence of two alpha,beta-unsaturated ketones give this compound the uniqueness among the ent-kauranoids tested. Eri-B inhibited the NF-kappaB transcriptional activity but not that of cAMP response element-binding protein. It suppressed the transcription of NF-kappaB downstream gene products including cyclooxygenase-2 and inducible nitric-oxide synthase induced by tumor necrosis factor-alpha or lipopolysaccharide in macrophages and hepatocarcinoma cells. Chromatin immunoprecipitation assay indicated that Eri-B selectively blocked the binding between NF-kappaB and the response elements in vivo without affecting the nuclear translocation of the transcription factor. Down-regulation of the endogenous p65 protein sensitized the cells toward the action of the compound. Furthermore, in vitro binding assays suggested that Eri-B reversibly interfered with the binding of p65 and p50 subunits to the DNA in a noncompetitive manner. In summary, this study reveals the novel action of a potent NF-kappaB inhibitor that could be potentially used for the treatment of a variety of NF-kappaB-associated diseases. Modification of the structure of this class of compounds becomes the key to the control of the behavior of the compound against different cellular signaling pathways.

Base Sequence↗

PubMed2006

Diterpenoids from Isodon species and their biological activities.

Isodon species (Labiatae) are widely distributed plants, many of which are used in folk medicine. Over the past twenty years, they have received considerable phytochemical and biological attention. Thestructures of their many diterpenoids constituents, especially those with an ent-kaurane skeleton, have been elucidated. The significant phytochemical and pharmacological diterpenoids form the subject of this review. There are 290 references.

Diterpenes↗

PubMed2006

Antiproliferative ent-Kauranoids from Isodon parvifolius.

Nine new 7alpha,20-epoxy- ENT-kaurane diterpenoids, parvifolines O - W (1 - 9), together with five known analogues, lasiocarpanin (10), rosthorin A (11), longikaurin E (12), adenolin D (13) and longikaurin B (14), were isolated from the leaves of Isodon parvifolius. Their structures were determined by means of spectroscopic analysis. Selected diterpenoids (1 - 10) were tested for their antiproliferative activity against A549, HT-29 and K562 cells. Compounds 3, 7, 8 and 10 showed moderate inhibitory activity against all three cell lines.

Antineoplastic Agents, Phytogenic↗

PubMed2006

Dichotomains A and B: two new highly oxygenated phenolic derivatives from Dicranopteris dichotoma.

[structure: see text] Dichotomains A (1) and B (2), two new highly oxygenated phenolic derivatives that feature a spirodilactone moiety in their structures, were isolated from the fronds of Dicranopteris dichotoma. Their structures were elucidated on the basis of NMR and MS spectroscopic data, and the stereochemistry of 1 was finally determined by single-crystal X-ray diffraction. Compound 2 showed weak anti-HIV-1 activity.

Anti-HIV Agents↗

PubMed2006

Sphenadilactones A and B, two novel nortriterpenoids from Schisandra sphenanthera.

[structure: see text] Two novel nortriterpenoid compounds, sphenadilactones A (1) and B (2), have been isolated from the leaves and stems of Schisandrasphenanthera. The structural elucidation of 1 and 2 was accomplished by extensive NMR analysis. The relative stereochemistry of 1 was established by single-crystal X-ray crystallography. Both compounds were tested for their cytotoxicities against K562, A549, and HT-29, and compound 1 was further tested for its anti-HIV-1 activity.

Anti-HIV Agents↗

PubMed2006

Bisrubescensins A-C: three new dimeric ent-kauranoids isolated from isodon rubescens.

[reaction: see text] A phytochemical study of the secondary metabolites produced by the species of Isodon rubescens has led to the isolation of three new dimeric ent-kauranoids and two known ones. The most important of these compounds are bisrubescensin A (1), which contains an unprecedented C(23) ent-kaurane unit, and bisrubescensin C (3), which is the precursor of bisrubescensin B (2) from the viewpoint of biosynthesis. Their structures were determined on the basis of extensive spectroscopic analysis and chemical evidence.

Antineoplastic Agents, Phytogenic↗

PubMed2006

Rubriflordilactones A and B, two novel bisnortriterpenoids from Schisandra rubriflora and their biological activities.

Rubriflordilactones A (1) and B (2), two novel highly unsaturated rearranged bisnortriterpenoids possessing a biosynthetically modified aromatic D-ring, were isolated from the leaves and stems of Schisandra rubriflora. Their structures were established on the basis of extensive spectroscopic methods, including two-dimensional NMR techniques, and confirmed by X-ray crystallographic analysis. Compound 1 showed weak anti-HIV-1 activity, and compound 2 exhibited an EC50 value of 9.75 microg/mL (SI=12.39) against HIV-1 replication with low cytotoxicity.

Anti-HIV Agents↗

PubMed2006

A pair of novel cytotoxic polyprenylated xanthone epimers from gamboges.

Two new polyprenylated xanthone epimers were isolated from gamboges of Garcinia hanburyi, and identified by detailed spectroscopic analysis as 30-hydroxygambogic acid (2a) and its (2S)-epimer 30-hydroxyepigambogic acid (2b). Both compounds exhibited significant cytotoxicities against the human leukemia K562/S and the corresponding doxorubicin-resistant K562/R cell lines (Table 2).

Cell Line, Tumor↗

PubMed2006

Cytotoxic ent-kauranoids from Isodon parvifolius.

Three new ent-kaurane diterpenoids, parvifoline Z (1), parvifoline AA (2), and parvifoline AB (3), together with 14 known compounds, were isolated from the leaves of Isodon parvifolius. The structures of the new compounds were elucidated by 1D- and 2D-NMR spectroscopy and mass spectrometry, and by comparison with known compounds. These three new diterpenoids included three types of ent-kauranoids, namely, C(20)-non-oxygenated-ent-kauranoid, 7,20-cyclo-ent-kauranoid and 6,7-seco-ent-kauranoid-7,20-olide. Compounds 1 and 2 exhibited significant cytotoxicities against A549, HT-29, and K562 cell lines.

Antineoplastic Agents, Phytogenic↗

PubMed2006

ent-Labdane diterpenoids from Andrographis paniculata.

Six new ent-labdane diterpenoids, 3-O-beta-D-glucopyranosyl-14,19-dideoxyandrographolide (1), 14-deoxy-17-hydroxyandrographolide (2), 19-O-[beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranoyl]-3,14-dideoxyandrographolide (3), 3-O-beta-d-glucopyranosylandrographolide (4), 12S-hydroxyandrographolide (5), and andrographatoside (6), together with 17 known analogues, were isolated from the aerial parts of Andrographis paniculata. The structures of 1-6 were determined by spectroscopic data analysis. All compounds isolated were evaluated for their inhibitory activity against several bacterial and fungal strains.

Andrographis↗

PubMed2006

Triterpenoids from Schisandra lancifolia with anti-HIV-1 activity.

A new trinorcycloartane triterpenoid, lancifodilactone H (1), and a new A ring-secocycloartane triterpenoid, lancifoic acid A (2), together with a known compound, nigranoic acid (3), were isolated from the leaves and stems of Schisandra lancifolia. Their structures were elucidated by spectroscopic data analysis. Compound 1 features a biosynthetically modified seven-membered lactone ring, which was confirmed by single-crystal X-ray diffraction. Compounds 1-3 exhibited weak anti-HIV-1 activity in vitro.

Anti-HIV Agents↗

PubMed2006

7alpha,20-epoxy-ent-kauranoids from Isodon parvifolius.

Nine new 7alpha,20-epoxy-ent-kaurane diterpenoids, parvifolines C-K (1-9), together with 12 known analogues, rabdoternin G (10), adenolin E (11), lasiodonin (12), lushanrubescensin F (13), parvifoliside (14), effusanin A (15), effusanin B (16), effusanin E (17), taibaihenryiin A (18), shikokianin (19), maoyecrystal J (20), and the acetonide of lasiodonin (21), were isolated from the leaves of Isodon parvifolius. The structures of compounds 1-9 were determined on the basis of spectroscopic methods including extensive 1D and 2D NMR analysis. The new diterpenoids (1-9) and lasiodonin (12) were evaluated for their inhibitory activity against A549, HT-29, and K562 cell lines.

Antineoplastic Agents, Phytogenic↗

PubMed2006

Nortriterpenoids from Schisandra lancifolia.

Six new nortriterpenoids, lancifodilactones I-N (1-6), as well as nine known ones, were isolated from the leaves and stems of Schisandra lancifolia. Their structures were elucidated on the basis of spectroscopic methods including 2D NMR analysis, and the structures of compounds 1 and 4 were further confirmed by single-crystal X-ray crystallography. In addition, all new compounds were tested for anti-HIV-1 activity.

Anti-HIV Agents↗