Design, synthesis, anti-tumor activity and mechanism of novel PROTACs as degraders of PD-L1 and inhibitors of PD-1/PD-L1 interaction.

Currently, antibody drugs targeting programmed cell death ligand 1 (PD-L1) have achieved promising results in cancer treatment, while the development of small-molecule drugs lags behind. In this study, we designed and synthesized a series of PD-L1-degrading agents based on the PROTAC design principle, utilizing the PD-L1 inhibitor A56. Through systematic screening of ligands and linkers and investigating the structure-activity relationship of the degraders, we identified two highly active compounds, 9i and 9j. These compounds enhance levels of CD4+, CD8+, granzyme B, and perforin, demonstrating significant in vivo antitumor effects with a tumor growth inhibition (TGI) of up to 57.35 %. Both compounds facilitate the internalization of PD-L1 from the cell surface and promote its degradation through proteasomal and lysosomal pathways, while also maintaining inhibition of the PD-1/PD-L1 interaction. In summary, our findings provide a novel strategy and mechanism for developing biphenyl-based PROTAC antitumor drugs targeting and degrading PD-L1.

Design, synthesis and biological evaluation of 2-methyl-(1,1'-biphenyl)-pyrimidine conjugates.

Small molecule inhibitors of biphenyl structure as core backbone have shown a significant effect on PD-1/PD-L1 axis, and 2-amino-pyrimidine structure is a promising privileged scaffold in medicinal chemistry and drug discovery. We designed by combination principles and synthesized 27 novel compounds with N-((2-methyl-[1,1'-biphenyl]-3-yl)methyl)pyrimidin-2-amine as a basic skeletal structure, and their anti-cancer activity was evaluated. Among compounds, 15a-d and 16b displayed strong anti-cancer effects on 9 tested cancer cell lines, in particular, the 16b did the highest inhibitive activity, but against HepG2 cells, and possessed the lowest IC50 value of 2.08 µΜ towards HT-29 cells.

Exosomal miR-146a Contributes to the Enhanced Therapeutic Efficacy of Interleukin-1ß-Primed Mesenchymal Stem Cells Against Sepsis.

Improving the immunomodulatory efficacy of mesenchymal stem cells (MSCs) through pretreatment with pro-inflammatory cytokines is an evolving field of investigation. However, the underlying mechanisms have not been fully clarified. Here, we pretreated human umbilical cord-derived MSCs with interleukin-1ß (IL-1ß) and evaluated their therapeutic effects in a cecal ligation and puncture-induced sepsis model. We found that systemic administration of IL-1ß-pretreated MSCs (ßMSCs) ameliorated the symptoms of murine sepsis more effectively and increased the survival rate compared with naïve MSCs. Furthermore, ßMSCs could more effectively induce macrophage polarization toward an anti-inflammatory M2 phenotype through the paracrine activity. Mechanistically, we demonstrated that ßMSC-derived exosomes contributed to the enhanced immunomodulatory properties of ßMSCs both in vitro and in vivo. Importantly, we found that miR-146a, a well-known anti-inflammatory microRNA, was strongly upregulated by IL-1ß stimulation and selectively packaged into exosomes. This exosomal miR-146a was transferred to macrophages, resulted in M2 polarization, and finally led to increased survival in septic mice. In contrast, inhibition of miR-146a through transfection with miR-146a inhibitors partially negated the immunomodulatory properties of ßMSC-derived exosomes. Taken together, IL-1ß pretreatment effectively enhanced the immunomodulatory properties of MSCs partially through exosome-mediated transfer of miR-146a. Therefore, we believe that IL-1ß pretreatment may provide a new modality for better therapeutic application of MSCs in inflammatory disorders. Stem Cells 2017;35:1208-1221.

Telomerase Deficiency Causes Alveolar Stem Cell Senescence-associated Low-grade Inflammation in Lungs.

Mutations of human telomerase RNA component (TERC) and telomerase reverse transcriptase (TERT) are associated with a subset of lung aging diseases, but the mechanisms by which TERC and TERT participate in lung diseases remain unclear. In this report, we show that knock-out (KO) of the mouse gene Terc or Tert causes pulmonary alveolar stem cell replicative senescence, epithelial impairment, formation of alveolar sacs, and characteristic inflammatory phenotype. Deficiency in TERC or TERT causes a remarkable elevation in various proinflammatory cytokines, including IL-1, IL-6, CXCL15 (human IL-8 homolog), IL-10, TNF-α, and monocyte chemotactic protein 1 (chemokine ligand 2 (CCL2)); decrease in TGF-ß1 and TGFßRI receptor in the lungs; and spillover of IL-6 and CXCL15 into the bronchoalveolar lavage fluids. In addition to increased gene expressions of α-smooth muscle actin and collagen 1α1, suggesting myofibroblast differentiation, TERC deficiency also leads to marked cellular infiltrations of a mononuclear cell population positive for the leukocyte common antigen CD45, low-affinity Fc receptor CD16/CD32, and pattern recognition receptor CD11b in the lungs. Our data demonstrate for the first time that telomerase deficiency triggers alveolar stem cell replicative senescence-associated low-grade inflammation, thereby driving pulmonary premature aging, alveolar sac formation, and fibrotic lesion.

The toll-like receptor 3 ligand, poly(I:C), improves immunosuppressive function and therapeutic effect of mesenchymal stem cells on sepsis via inhibiting MiR-143.

Mesenchymal stem cells (MSCs) are attractive candidates for clinical therapeutic applications. Recent studies indicate MSCs express active Toll-like receptors (TLRs), but their effect on MSCs and the underlying mechanisms remain unclear. In this study, we found that, after treating human umbilical cord MSCs with various TLR ligands, only TLR3 ligand, poly(I:C), could significantly increase the expression of cyclooxygenase-2 (COX-2). Furthermore, poly(I:C) could enhance MSCs' anti-inflammatory effect on macrophages. Next, we focused on the regulatory roles of microRNAs (miRNAs) in the process of poly(I:C) activating MSCs. Our experiments indicated that miR-143 expression was significantly decreased in MSCs with poly(I:C) treatment, and the expression level of miR-143 could regulate the effect of poly(I:C) on MSCs' immunosuppressive function. Subsequent results showed that the reporter genes with putative miR-143 binding sites from the transforming growth factor-ß-activated kinase-1 (TAK1) and COX-2 3' untranslated regions were downregulated in the presence of miR-143. In addition, mRNA and protein expression of TAK1 and COX-2 in MSCs was also downregulated with miR-143 overexpression, suggesting that TAK1 and COX-2 are target genes of miR-143 in MSCs. Consistent with miR-143 overexpression, TAK1 interference also attenuated MSCs' immunosuppressive function enhanced by poly(I:C). Additionally, it was shown that TLR3-activated MSCs could improve survival in cecal ligation and puncture (CLP)-induced sepsis, while miR-143 overexpression reduced the effectiveness of this therapy. These results proved that poly(I:C) improved the immunosuppressive abilities of MSCs, revealed the regulatory role of miRNAs in the process, and may provide an opportunity for potential novel therapies for sepsis.

LRP5 polymorphism-A potential predictor of the clinical outcome in advanced gastric cancer patients treated with EOF regimen.

PURPOSE: Wnt pathways control key biological processes that potentially impact on tumor progression and patient survival. The present study analyzed the polymorphism of lipoprotein-related receptor 5 (LRP5) (gene with key functions in Wnt signaling) and its impact on the response to chemotherapy and survival of patients with advanced gastric cancer (AGC). METHODS: A total of 107 consecutive patients with AGC treated with first-line chemotherapy of EOF regimen were enrolled in the present retrospective study. The association between single nucleotide polymorphism (SNP) of rs3736228 in LRP5 and the clinical outcomes of the patients was studied. RESULTS: The CC genotype of rs3736228 was significantly correlated with a higher disease control rate when compared to the CT and TT genotypes (89.3% and 61.8%, respectively, P<0.001). A univariate survival analysis also showed that the progression free survival (PFS) and overall survival (OS) for the patients with the TC and TT genotypes of rs3736228 were worse than for the patients with the CC genotype (PFS: 3.3 and 6.7 months, respectively, HR =0.454, P<0.001; OS: 8.1 months and 18.8 months, respectively, HR =3.056, P<0.001). A multivariate Cox model incorporates rs3736228 and clinical features, also identified rs3736228 was significantly associated with the PFS and OS. CONCLUSIONS: Our results firstly highlight the importance of LRP5 gene of Wnt pathway in the treatment of AGC and identify polymorphism of rs3736228 as independent predictor of disease control rate, PFS and OS in AGC patients treated with first-line chemotherapy of EOF regimen in the Chinese Han population.

The role of tumor-associated macrophages in lung cancer: From mechanism to small molecule therapy.

Tumor-associated macrophages (TAMs) are the main component of tumor-infiltrating immune cells in the lung tumor microenvironment. TAMs recruited to the lung cancer can create a suitable microenvironment for the growth and metastasis of lung cancer by secreting tumor promoting factors and interfering with the function of T cells. Currently, numerous studies have reported that small molecular drugs affect lung cancer progression by selectively targeting TAMs. The main ways include blocking the recruitment of monocytes or eliminating existing TAMs in tumor tissue, reprogramming TAMs into pro-inflammatory M1 macrophages or inhibiting M2 polarization of macrophages, interrupting the interaction between tumor cells and macrophages, and modulating immune function. Signaling pathways or cytokines such as CCL8, CCL2/CCR2, CSF-1/CSF-1R, STAT3, STAT6, MMPs, Caspase-8, AMPK α1, TLR3, CD47/SIRPα, have been reported to be involved in this process. Based on summarizing the role and mechanisms of TAMs in lung cancer progression, this paper particularly focuses on systematically reviewing the effects and mechanisms of small molecule drugs on lung cancer TAMs, and classified the small molecular drugs according to the way they affect TAMs. The study aims to provide new perspectives and potential therapeutic drugs for targeted macrophages treatment in lung cancer, which is of great significance and will provide more options for immunotherapy of lung cancer.

MicroRNA-181a regulates local immune balance by inhibiting proliferation and immunosuppressive properties of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) exhibit extensive self-renewal potential and can modulate immunocyte activation. Our previous study reported that miR-181a expression was significantly increased in placenta from women with severe preeclampsia (PE), but the mechanisms by which miR-181a regulates MSCs are unknown. In this study, we asked if and how miR-181a regulates MSCs' proliferation and immunosuppressive properties. We found that the expression of miR-181a in the MSCs derived from the umbilical cord and decidua of PE patients increased relative to MSCs derived from normal patients. Transfection with miR-181a oligos prevented MSCs proliferation but did not affect MSCs apoptosis. Overexpression of miR-181a blocked activation of the TGF-ß signaling pathway and caused downregulation of target gene (TGFBR1 and TGFBRAP1) mRNA and protein expression. Reporter genes with putative miR-181a binding sites from the TGFBR1 and TGFBRAP1 3'-untranslated regions (3'-UTRs) were downregulated in the presence of miR-181a, suggesting that miR-181a binds to TGFBR1 and TGFBRAP1 3'-UTRs. In contrast, transfection of MSCs with miR-181a oligo enhanced expression of IL-6 and indoleamine 2,3-dioxygenase by activating p38 and JNK signaling pathways, respectively. MSCs transfected with miR-181a also enhanced the proliferation of T cells in a short-term culture. Additionally, treatment with control MSCs, but not miR-181a transfected MSCs, improved dextran sulfate sodium-induced experimental colitis, suggesting that miR-181a attenuates the immunosuppressive properties of MSCs in vivo. Together, our data demonstrate that miR-181a is an important endogenous regulator in the proliferation and immunosuppressive properties of MSCs.

17ß-estradiol induces CD40 expression in dendritic cells via MAPK signaling pathways in a minichromosome maintenance protein 6-dependent manner.

OBJECTIVE: The human immune system exhibits sexual dimorphism in autoimmune diseases such as systemic lupus erythematosus (SLE). Female sex hormones, including 17ß-estradiol, are strongly implicated in the gender bias in SLE. CD40 is a costimulatory molecule and plays a crucial role in modulating the immune response of effector cells. We have previously shown that 17ß-estradiol up-regulated CD40 expression and altered minichromosome maintenance protein 6 (MCM6) gene expression in dendritic cells (DCs). The mechanism of the correlation between CD40 and MCM6 in the presence of 17ß-estradiol remains unknown. This study was undertaken to elucidate this mechanism and to explain the role of MCM6 in the gender bias in SLE. METHODS: Bone marrow-derived DCs transfected with small interfering RNA (siRNA) for MCM6 were treated with 17ß-estradiol in the absence or presence of CpG. The expression levels of costimulatory molecules, activity of MAPKs, and levels of MCM6 protein were measured. Moreover, the functions of DCs, including proliferation, apoptosis, endocytosis, and cytokine production, were analyzed. In addition, levels of messenger RNA for MCM6 were detected in DCs purified from SLE patients. RESULTS: Regardless of the presence or absence of CpG, 17ß-estradiol induced CD40 expression via the activation of p38 and JNK, but not ERK. The activation of p38 and JNK enhanced MCM6 expression, which then induced CD40 expression. Suppression of MCM6 in DCs abolished the up-regulation of 17ß-estradiol-induced CD40 expression. Importantly, MCM6 expression was significantly increased in SLE patients compared with healthy controls. CONCLUSION: Our findings indicate that 17ß-estradiol induces CD40 expression in DCs via p38 and JNK MAPKs in an MCM6-dependent manner. MCM6 may be a critical mediator of sex-based differences in autoimmune disease.

Design, synthesis and anti-tumor activity of novel benzothiophenonaphthalimide derivatives targeting mitochondrial DNA (mtDNA) G-quadruplex.

A series of new naphthalimide derivatives, benzothiophenonaphthalimides (7a-7g, 8a-8g), were designed and synthesized, of which compounds 8a-8g are hydrochloride salts of corresponding compounds 7a-7g. All compounds presented different anti-tumor activities for tumor cells tested by the CCK-8 assay. In particular, compound 7c displayed the strongest anti-tumor activity with an IC50 value of 0.59 ± 0.08 µM and the best selectivity for HepG2 cells. At the same time, it was observed that 7c could induce HepG2 cell apoptosis, hinder cancer cell migration and arrest the cell cycle at the G2/M phase. Further mechanism studies revealed that 7c selectively induced a G-rich HRCC DNA sequence in the mitochondria to form a G-quadruplex structure (G4) and stabilized it, which mediated the decrease in mitochondrial membrane potential and the production of reactive oxygen species, causing mitochondrial dysfunction. Finally, this led to proliferative inhibition and apoptosis of cancer cells and protective autophagy by promoting the expression of p-Erk1/2. The in vivo experimental results indicated that the compound 8c as a salt of 7c showed significant in vivo anti-tumor efficacy in the HepG2-xenograft mouse model with a tumor growth inhibition rate of 51.4% at a dose of 15 mg/kg. These results suggest that 7c possesses a different anti-tumor mechanism from the previous main reported mechanism of naphthalimide derivatives, which targets the nucleus. In brief, 7c has good anti-tumor activity in vitro and in vivo and may act as a leading compound in development of drugs against liver cancer.

Randomized phase II study of TX followed by XELOX versus the reverse sequence for chemo-naive patients with metastatic gastric cancer.

This research found that the clinical outcomes (PFS, ORR, OS) of the non-platinum-based doublet regimen (docetaxel capecitabine combination) were similar to those of the platinum-based (oxaliplatin capecitabine combination) when used as first line therapy for MGC patients. Background: Docetaxel, platinum and fluorouracil are the three most important drugs in the treatment of MGC. This study was to compare clinical outcomes of the docetaxel capecitabine combination and the oxaliplatin capecitabine combination as first-line therapy in MGC patients. Methods: In this phase II trial, MGC patients were randomly assigned and treated with either TX (capecitabine 1000 mg/m2/twice daily/1-14 days and docetaxel 60/75 mg/m2 on the 1st day) (because of toxicity, the dose of docetaxel was reduced to 60 mg/m2) or XELOX (capecitabine the same dose with TX and oxaliplatin 130 mg/m2 on the 1st day) as first-line therapy. After progression, patients were crossover to the other group as second-line treatment. Results: Total 134 MGC patients were randomized (69 in TX, 65 in XELOX). There was no significant difference between the PFS of the two groups (TX vs XELOX, 4.6 months vs 5.1 months, p=0.359), and the SFS (9.3 months vs 7.5 months, p=0.705), OS (13.1 months vs 9.6 months, p=0.261), and ORR (46.4% vs 46.2%) were also similar. Among patients with ascites, the TX group had significantly longer PFS and OS than the XELOX group. A total of 85 patients (48 in TX, 37 in XELOX) received second-line treatment, with overall survival of second-line chemotherapy (OS2) of 8.0 m and 5.3 m (p=0.046), respectively. Grade 3 to 4 treatment-related adverse events of first line treatment occurred more in TX group than that in XELOX group(60.6% vs 55.4%). Conclusion: TX regimen is an alternative choice of first-line treatment for MGC patients. We still need to explore the large number of cohort to confirm this results.

[Glossy ganoderma spore oil promotes apoptosis of human lung adenocarcinoma SPC-A1 through downregulation of miR-21].

OBJECTIVE: To investigate the effects of glossy ganoderma spore oil on the proliferation, apoptosis, expression of miR-21 and its target genes of human lung adenocarcinoma SPC-A1 cell line, and to explore its possible mechanism. METHOD: The SPC-A1 cells were treated with glossy ganoderma spore oil for 24 and 48 hours. The inhibition growth efficacy was determined using cell count kit (CCK-8). Cell morphological changes were observed by light microscopy. Cell apoptosis was analyzed by flow cytometry. The expression of miR-21, PTEN and PDCD4 were determined by Real-time PCR. RESULT: Glossy ganoderma spore oil concentration-dependently inhibited the SPC-A1 cell's proliferation. When the concentration of glossy ganoderma spore oil attained to 0.2%, the cells' morphology changed obviously. Glossy ganoderma spore oil could induce the apoptosis of SPC-A1 cells at low concentration. Glossy ganoderma spore oil down-regulated the expression of miR-21 and up-regulated the expression of PTEN and PDCD4 significantly. CONCLUSION: glossy ganoderma spore oil could inhibit the proliferation obviously and cause the changes of cell morphology. Furthermore, glossy ganoderma spore oil induced apoptosis of SPC-A1 cell through down-regulating the expression of miR-21 and up-regulating tumor suppressors.

Spatiotemporal clustering and meteorological factors affected scarlet fever incidence in mainland China from 2004 to 2017.

OBJECTIVE: To analyze the spatiotemporal dynamic distribution and detect the related meteorological factors of scarlet fever from an ecological perspective, which could provide scientific information for effective prevention and control of this disease. METHODS: The data on scarlet fever cases in mainland China were downloaded from the Data Center of the China Public Health Science, while monthly meteorological data were extracted from the official website of the National Bureau of Statistics. Global Moran's I, local Getis-Ord Gi⁎ hotspot statistics, and Kulldorff's retrospective space-time scan statistical analysis were used to detect the spatial and spatiotemporal clusters of scarlet fever across all settings. A spatial panel data model was conducted to estimate the impact of meteorological factors on scarlet fever incidence. RESULTS: Scarlet fever in China had obvious spatial, temporal, and spatiotemporal clustering, high-incidence spatial clusters were located mainly in the north and northeast of China. Nine spatiotemporal clusters were identified. A spatial lag fixed effects panel data model was the best fit for regression analysis. After adjusting for spatial individual effects and spatial autocorrelation (ρ = 0.5623), scarlet fever incidence was positively associated with a one-month lag of average temperature, precipitation, and total sunshine hours (all P-values < 0.05). Each 10 °C, 2 cm, and 10 h increase in temperature, precipitation, and sunshine hours, respectively, was associated with a 6.41% increment and 1.04% and 1.41% decrement in scarlet fever incidence, respectively. CONCLUSION: The incidence of scarlet fever in China showed an upward trend in recent years. It had obvious spatiotemporal clustering, with the high-risk areas mainly concentrated in the north and northeast of China. Areas with high temperature and with low precipitation and sunshine hours tended to have a higher scarlet fever incidence, and we should pay more attention to prevention and control in these places.

The Importance of Exosomal PD-L1 in Cancer Progression and Its Potential as a Therapeutic Target.

Binding of programmed cell death ligand 1 (PD-L1) to its receptor programmed cell death protein 1 (PD-1) can lead to the inactivation of cytotoxic T lymphocytes, which is one of the mechanisms for immune escape of tumors. Immunotherapy based on this mechanism has been applied in clinic with some remaining issues such as drug resistance. Exosomal PD-L1 derived from tumor cells is considered to play a key role in mediating drug resistance. Here, the effects of various tumor-derived exosomes and tumor-derived exosomal PD-L1 on tumor progression are summarized and discussed. Researchers have found that high expression of exosomal PD-L1 can inhibit T cell activation in in vitro experiments, but the function of exosomal PD-L1 in vivo remains controversial. In addition, the circulating exosomal PD-L1 has high potential to act as an indicator to evaluate the clinical effect. Moreover, therapeutic strategy targeting exosomal PD-L1 is discussed, such as inhibiting the biogenesis or secretion of exosomes. Besides, some specific methods based on the strategy of inhibiting exosomes are concluded. Further study of exosomal PD-L1 may provide an effective and safe approach for tumor treatment, and targeting exosomal PD-L1 by inhibiting exosomes may be a potential method for tumor treatment.

Achieving and control of partial denitrification in anoxic-oxic process of real municipal wastewater treatment plant.

Partial denitrification is an alternative process to provide stable nitrite for anammox. In this study, based on full-scale and lab-scale experiments, achieving and control of partial denitrification and the microbial mechanism were studied for 17 months in municipal wastewater treatment plant (MWWTP). Using glucose (GLC) as sole carbon source, partial denitrification was successfully achieved with nitrite accumulation percentage (NAP) higher than 90%; whereas, using sodium acetate (NaAc) as sole carbon source, nitrite accumulation was effectively controlled with economic and efficient carbon usage. Candidatus Competibacter and Thaurea were the dominant communities for partial denitrification. Denitrifying glycogen accumulating organisms (DGAOs), Thauera, denitrifying phosphorus accumulating organisms (DPAOs), GAOs, PAOs and denitrifiers coexisted in MWWTP, resulting in COD specific removal rate (CODSRR) of 883.10 ~ 1188.92mgN/gMLVSS/h during partial denitrification. Through adjustment of Anoxic-Oxic (A/O) operation to anoxic operation, the growth of GAOs and PAOs could be limited.

A 1,10-phenanthroline derivative selectively targeting telomeric G-quadruplex induces cytoprotective autophagy, causing apoptosis of gastric cancer cells.

AIMS: This study aimed to evaluate the ability of compound 13d to induce autophagy and to promote apoptosis of tumor cells and its interaction mechanism. MATERIALS AND METHODS: Using CCK-8 assay, transwell assay, fluorescence resonance energy transfer melting analysis (FRET), transmission electron microscopy, flow cytometry assay, immunofluorescence assay, Western blot analysis, and wound healing assay. KEY FINDINGS: The results indicated that compound 13d could induce autophagy and apoptosis of gastric cancer cells. Moreover, the findings of CCK-8 assay, colony formation, migration and invasion assay, and wound healing assay revealed that compound 13d would effectively inhibit cell proliferation, migration, and invasion. Its IC50 value is about 2.4 µM against gastric cancer cells, which is similar to positive drug­platinum. 13d specific induction of telomere G-quadruplex formation was proved in extracellular FRET melting assay, and indirectly affected telomerase activity. G-quadruplex formation promoted cell apoptosis and autophagy. Upon incorporating the autophagy inhibitors 3-MA and HCQ, the expression of the autophagy marker protein LC3 was then checked, suggesting that the compound 13d influences the autophagy flux. Furthermore, knocking down the autophagy-related gene Atg5 to reduce the level of autophagy enhances the anti-tumor activity and increases apoptotic cells' proportion. Mechanistic experiments have shown that blocking the Akt/m-TOR signal pathway plays a crucial role in autophagy and G-quadruplex induced telomere dysfunction. DNA damage is the leading cause of autophagy. Compound 13d combined with autophagy inhibitor can inhibit tumor cells more effectively. SIGNIFICANCE: Our findings demonstrate that compound 13d as a telomeric G-quadruplex ligand induces Telomere dysfunction, DNA damage response, autophagy, and apoptosis in gastric cancer cells by blocking the Akt/m-TOR signaling pathway.

Discovery of Pyrrole-imidazole Polyamides as PD-L1 Expression Inhibitors and Their Anticancer Activity via Immune and Nonimmune Pathways.

In recent years, PD-1 immune checkpoint inhibitors based on monoclonal antibodies have revolutionized cancer therapy, but there still exist unresolved issues, such as the high cost, the relatively low response rates, and so on, compared with small-molecule drugs. Herein a type of pyrrole-imidazole (Py-Im) polyamide as a small-molecule DNA binder was designed and synthesized, which could competitively bind to the same double-stranded DNA stretch in the PD-L1 promoter region as the STAT3 binding site and thus downregulate PD-L1 expression. It was demonstrated that the Py-Im polyamides directly caused apoptosis in tumor cells and retarded cell migration in the absence of T cells through inhibiting the Akt/caspase-3 pathway. Also, in a coculture system, they enhanced the T-cell-mediated killing of tumor cells by the reversal of immune escape. Because such polyamides induced antitumor effects via both immune and nonimmune pathways, they could be further developed as promising PD-L1 gene-targeting antitumor drugs.

Simultaneous determination of thyroxine and triiodothyronine in pharmaceutical formulations using capillary electrophoresis with amperometric detection.

A simple, reliable and repeatable method, based on CE with amperometric detection has been developed for the simultaneous separation and determination of thyroxine (T(4)) and 3,3',5-triiodothyronine (T(3)). A carbon disk electrode was used as working electrode in this system and exhibited a good response at 1.05 V (versus Hg/Hg(2)Cl(2), 3 mol/L KCl) for two analytes. The CE separations were investigated in detail. At 21 kV of applied voltage, the two compounds were separated within 11 min in 0.05 mol/L Na(2)B(4)O(7)-NaOH buffer (pH 11.3). And the detection limits were as low as 1.0x10(-7) mol/L for T(4) and 8.5x10(-8) mol/L for T(3) (S/N=3), respectively. The proposed method was applied to analyze T(4) and T(3) in pharmaceutical formulations, and the results were satisfactory.

Exosomes as drug carriers for cancer therapy and challenges regarding exosome uptake.

With the development of biomedicine, exosomes are rapidly developing as a new therapy for tumors. As biological carriers, exosomes possess biological activity and can transport their contents between cells. The contents are natural or artificially loaded with biomolecules or chemical drugs. Exosomes deliver biomolecules or chemical drugs into the pathological sites of recipient, which can effectively inhibit the progression of tumors. However, the treatments of tumors through the delivery of exosomes are not sufficiently accurate or efficient, and various challenges need to be overcome. Exosomes from different cell sources possess different characteristics, as well as different specificity for various cells. In the future, for the promotion and application of exosomes, it is of great significance to understand how to select appropriate exosomes loaded with biomolecules or chemical drugs for different tumors types, and how to deliver exosomes to recipient cells accurately and efficiently. This review introduces the application and challenges of exosomes as delivery carriers in tumors.

Anti-cancer activity of benzoxazinone derivatives via targeting c-Myc G-quadruplex structure.

AIMS: This study aimed to analyze the impact of four synthesized benzoxazinone derivatives as screening drugs on c-Myc-overexpressed cancer cells (H7402, HeLa, SK-RC-42, SGC7901, and A549) and to explore their interaction mechanisms in detail. MATERIALS AND METHODS: Using morphological analysis, real-time cytotoxicity analysis, wound healing assay, reverse transcription PCR, electrophoretic mobility shift assay, and circular dichroism spectroscopy techniques. KEY FINDINGS: Results revealed that these four compounds could inhibit proliferation of SK-RC-42, SGC7901, and A549 cells in five cancer cell lines to varying degrees and significantly hinder migration. More importantly, the RT-PCR assay showed that the compounds could surprisingly downregulate the expression of c-Myc mRNA in a dose-dependent manner in the five cancer cells, which may be one of the causes of cancer cell proliferation in vitro inhibition. Further EMSA assays demonstrated that at the molecular level of DNA, four compounds can induce the formation of G-quadruplexes (G4-DNAs) in the c-Myc gene promoter. In addition, the CD result of compound 1 clearly indicates that it specifically induces a c-Myc GC-rich 36mer double-stranded DNA in the c-Myc promoter to form a G-quadruplex hybrid configuration. In conclusion, the compounds studied could dose-dependently inhibit the growth and migration of the cancer cells being investigated. This is positively associated with the reduction of overexpression of the c-Myc gene, which may be significantly regulated by the association of compounds with the G-quadruplexes produced in the c-Myc gene promoter region. SIGNIFICANCE: We conclude that three compounds merit further study, particularly against non-small-cell lung cancer, as leading compounds of anticancer drugs.