18 research outputs found
Total Synthesis of Decahydroquinoline Poison Frog Alkaloids ent-cis-195A and cis-211A
The total synthesis of two decahydroquinoline poison frog alkaloids ent-cis-195A and cis-211A were achieved in 16 steps (38% overall yield) and 19 steps (31% overall yield), respectively, starting from known compound 1. Both alkaloids were synthesized from the common key intermediate 11 in a divergent fashion, and the absolute stereochemistry of natural cis-211A was determined to be 2R, 4aR, 5R, 6S, and 8aS. Interestingly, the absolute configuration of the parent decahydroquinoline nuclei of cis-211A was the mirror image of that of cis-195A, although both alkaloids were isolated from the same poison frog species, Oophaga (Dendrobates) pumilio, from Panama
Total Synthesis of Decahydroquinoline Poison Frog Alkaloids ent-\u3ci\u3ecis\u3c/i\u3e-195A and \u3ci\u3ecis\u3c/i\u3e-211A
The total synthesis of two decahydroquinoline poison frog alkaloids ent-cis-195A and cis-211A were achieved in 16 steps (38% overall yield) and 19 steps (31% overall yield), respectively, starting from known compound 1. Both alkaloids were synthesized from the common key intermediate 11 in a divergent fashion, and the absolute stereochemistry of natural cis-211A was determined to be 2R, 4aR, 5R, 6S, and 8aS. Interestingly, the absolute configuration of the parent decahydroquinoline nuclei of cis-211A was the mirror image of that of cis-195A, although both alkaloids were isolated from the same poison frog species, Oophaga (Dendrobates) pumilio, from Panama
Treatment of near-infrared photodynamic therapy using a liposomally formulated indocyanine green derivative for squamous cell carcinoma.
Photodynamic therapy (PDT) is a less invasive option for cancer treatment that has evolved through recent developments in nanotechnology. We have designed and synthesized a novel liposome system that includes an indocyanine green (ICG) derivative, ICG-C18, in its bilayer. In addition to its use as an optical imager to visualize blood, lymphatic, and bile flow, ICG has also been used as an optical sensitizer. In the present report, we evaluate the use of our novel liposome system, LP-ICG-C18, in PDT for squamous cell carcinoma in an autologous murine model.An excitation pulse beam (300 μJ/pulse) of a single band (800 nm) was used for sensitization. The cytotoxicity of the photodynamic therapy was evaluated in terms of cellular morphology changes, methyl thiazolyl tetrazolium (MTT) assay results, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining. We tested the enhanced permeability and retention effect of LP-ICG-C18 in tumor-bearing C3H/He mice using a near-infrared fluorescence imaging system and fluorescence microscopy. We also examined the antitumor effect of PDT by measuring tumor volume in tumor-bearing mice.Cell death and apoptosis were only observed in the PDT group receiving LP-ICG-C18. LP-ICG-C18 itself had no cytotoxic activity and showed good biocompatibility. LP-ICG-C18 accumulated on the tumor 24 hours after injection and was retained for approximately 3 weeks. Tumor cell apoptosis following PDT with LP-ICG-C18 was also observed under optical microscopy, MTT assay, and TUNEL staining.These findings suggest that LP-ICG-C18 may be an effective intervening material in PDT for malignant disease
The effect of stress on efficacy of dendritic cell therapy for esophageal squamous cell carcinoma.
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TIP60 is required for tumorigenesis in non‐small cell lung cancer
Histone modifications play crucial roles in transcriptional activation, and aberrant epigenetic changes are associated with oncogenesis. Lysine (K) acetyltransferases 5 (TIP60, also known as KAT5) is reportedly implicated in cancer development and maintenance, although its function in lung cancer remains controversial. Here we demonstrate that TIP60 knockdown in non-small cell lung cancer cell lines decreased tumor cell growth, migration, and invasion. Furthermore, analysis of a mouse lung cancer model with lung-specific conditional Tip60 knockout revealed suppressed tumor formation relative to controls, but no apparent effects on normal lung homeostasis. RNA-seq and ChIP-seq analyses of inducible TIP60 knockdown H1975 cells relative to controls revealed transglutaminase enzyme (TGM5) as downstream of TIP60. Investigation of a connectivity map database identified several candidate compounds that decrease TIP60 mRNA, one that suppressed tumor growth in cell culture and in vivo. In addition, TH1834, a TIP60 acetyltransferase inhibitor, showed comparable antitumor effects in cell culture and in vivo. Taken together, suppression of TIP60 activity shows tumor-specific efficacy against lung cancer, with no overt effect on normal tissues. Our work suggests that targeting TIP60 could be a promising approach to treating lung cancer
Reconstitution of human PDAC using primary cells reveals oncogenic transcriptomic features at tumor onset
Abstract Animal studies have demonstrated the ability of pancreatic acinar cells to transform into pancreatic ductal adenocarcinoma (PDAC). However, the tumorigenic potential of human pancreatic acinar cells remains under debate. To address this gap in knowledge, we expand sorted human acinar cells as 3D organoids and genetically modify them through introduction of common PDAC mutations. The acinar organoids undergo dramatic transcriptional alterations but maintain a recognizable DNA methylation signature. The transcriptomes of acinar organoids are similar to those of disease-specific cell populations. Oncogenic KRAS alone do not transform acinar organoids. However, acinar organoids can form PDAC in vivo after acquiring the four most common driver mutations of this disease. Similarly, sorted ductal cells carrying these genetic mutations can also form PDAC, thus experimentally proving that PDACs can originate from both human acinar and ductal cells. RNA-seq analysis reveal the transcriptional shift from normal acinar cells towards PDACs with enhanced proliferation, metabolic rewiring, down-regulation of MHC molecules, and alterations in the coagulation and complement cascade. By comparing PDAC-like cells with normal pancreas and PDAC samples, we identify a group of genes with elevated expression during early transformation which represent potential early diagnostic biomarkers
Mimicking the evolution of a thermally stable monomeric four-helix bundle by fusion of four identical single-helix peptides
Image of resected tumor of mice in (A) HE staining, (B) Normal light image of fluorescence microscope, and (C) Fluorescence image of fluorescence microscope.
<p>Image of resected tumor of mice in (A) HE staining, (B) Normal light image of fluorescence microscope, and (C) Fluorescence image of fluorescence microscope.</p
The transition of temperature in the tumor and rectum during irradiation.
<p>The transition of temperature in the tumor and rectum during irradiation.</p