Research advances on dihydrofolate reductase inhibitors in the treatment of tumors and bacterial infections / 药学学报

Dihydrofolate reductase (DHFR) is a well-known key target in the treatment of tumors, bacterial infections, and parasitic infections; and it plays a critical role in the biosynthesis of cellular DNA. DHFR inhibitors interfere with one-carbon metabolism by inhibiting substrate binding to DHFR, thereby inhibiting cell proliferation. Research on DHFR inhibitors has continued since the 1940s. To date, a variety of DHFR inhibitors have come into the market, primarily used for anti-tumor, antibacterial, antiparasitic, and anti-inflammatory therapy. This review summarizes the research progress of DHFR inhibitors with antitumor or antibacterial effects in recent years based on the classification of single-target and dual-target and looks forward to the opportunities and challenges faced by the work in this field.

Advances in anti-tumor research of HDAC inhibitors and combination with PI3K inhibitors / 药学学报

Histone deacetylase (HDAC) is usually abnormally overexpressed, which mainly leads to the transcriptional repression of tumor suppressor genes. Histone deacetylase inhibitors (HDIs) exert anti-tumor biological effects by regulating nucleosome structure, inhibiting HDAC activity, and controlling the expression of tumor suppressor genes. There are currently 5 drugs on the market, but only for peripheral T-cell lymphoma and cutaneous T-cell lymphoma. In solid tumors, most of the HDAC inhibitors used have failed to achieve effective therapeutic effects. Phosphoinositide 3-kinase (PI3K) is the starting node of the PI3K-AKT-mTOR signaling pathway, which plays a very important role in the proliferation, migration, invasion, and differentiation of tumor cells. The abnormal activation of PI3K is closely related to the occurrence and development of tumors, and the combined use of HDAC and PI3K inhibitors and HDAC/PI3K dual-target inhibitors show synergistic anticancer activity. This article introduces the anti-tumor clinical and preclinical research progress of representative HDAC inhibitors and PI3K inhibitors, as well as HDAC/PI3K dual-target inhibitors.

Establishment and optimization of an enzyme-cell based high-throughput screening platform for IDO1 inhibitors / 药学学报

In this study, we used the tumor immunotherapy protein indoleamine 2,3-dioxygenase 1 (IDO1) as the target, and proposed an enzyme-cell-based tertiary IDO1 inhibitor high throughput screening platform. Firstly, the recombinant human IDO1 protein was expressed by genetic engineering and efficient IDO enzymatic screening system was established. Secondly, A172 cells stimulated with interferon-γ (IFNγ) or constructed plasmid which could highly express human IDO1 protein in HEK293 cells with transient transfection were used to construct the specific IDO1 cell based screening system. Finally, the effect of the compound on kynurenine and tryptophan in mouse plasma was determined by LC/MS/MS method on C57 mice, which could further verify the inhibitory effect of the selected compounds on IDO1 in vivo. The established and optimized enzyme-cell based screening model in this study can efficiently and effectively obtain IDO1 inhibitors in vitro, which lays a good foundation for the rapid development of clinical drugs. Procedures for animal study were performed with approval of the Animal Care and Use Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College.

The effects of different stimulators on the activation of human lymphocytes / 药学学报

The research aims to study the effects of different stimulants on the activation of human lymphocytes. Human peripheral blood mononuclear cells were prepared by density centrifugation. The blood's sample was provided by National Institutes for Food and Drug Control and approved by its Ethics Committee. The expressions of CD69 in CD3+CD4+ and CD3+CD8+ human T cells were detected by flow cytometry after administrated with CD3/CD28 antibody, phytohaemagglutinin (PHA), Staphylococcus auresus enterooxin B (SEB), interleukin (IL27) and PMA plus ionomycin for 24 h. The proliferation of lymphocyte was detected by CellTiter-Glo kit. The secreted IFNγ in supernatant of medium was examined by ELISA kit. The proliferation of lymphocytes had no change after exposed of CD3/CD28 antibody, SEB, IL27 and PMA plus ionomycin for 24 h. However, the CD69 expressions in CD3+CD4+ and CD3+CD8+ T cells and IFNγ productions were significantly increased by CD3/CD28 antibody, SEB, IL27 and PMA plus ionomycin at 24 h, indicating that CD3+CD4+ and CD3+CD8+ T cells were activated under above-mentioned stimulated condition. CD3/CD28 antibody, SEB, IL27 and PMA plus ionomycin were valid stimulants for T cell activation.

Research progress of indoleamine 2,3-dioxygenase 1 in tumor immunotherapy / 药学学报

IDO1 (indoleamine 2,3-dioxygenase 1) is one of the most significant checkpoint in tumor immunology. Numerous studies indicates that IDO1 is abnormally expressed in breast cancer, colorectal cancer, liver cancer and other tumor tissues, participating in tumor immune escape through multiple pathways. This review is prepared to elucidate the biological function of IDO1, highlight its pivotal role in tumor evasion, and summarize IDO1 inhibitors in the clinical trials.

Antitumor activity of a novel PARP1/2 inhibitor YHP-743 / 药学学报

Poly(ADP-ribose) polymerase (PARP)-1 and PARP2 function as ADP-ribosylases involved in DNA repair. PARP1/2 is highly expressed in cancers and emerged as an attractive target for antitumor drug. In this study, we investigated the antitumor activity of a novel PARP1/2 inhibitor YHP-743 in vitro and in vivo. The results showed that YHP-743 had potent enzymatic inhibitory activity against PARP1 and PARP2 to down-regulate the PAR level. YHP-743 not only inhibited breast cancer cells with genes deficiency of homologous recombination repair, but also potentiated chemotherapy agent's cytotoxicity, such as temozolomide, topotecan, cisplatin and doxorubicin. YHP-743 elicited good antitumor activity in combination with temo-zolomide in vivo.

The effect of triptolide derivative LB-1 on imiquimod-induced psoriasiform inflammation of BALB/c mice / 药学学报

The aim of present study was to explore the effect of triptolide derivative LB-1 on imiquimod (IMQ) induced psoriasiform inflammation in BALB/c mice, and to investigate the immune mechanism of LB-1 in the prevention and treatment of psoriasis. In the present study, topical application of IMQ for seven days induced the psoriasiform inflammation in BALB/c mice. This is a promising mouse model of psoriasis for the natural immune reaction compared to those induced by xenograft, trangenic or gene knockout. psoriasis area and severity index (PASI) score, hematoxylin-eosin (HE) staining and flowcytometry were employed to investigate the changes of psoriasiform inflammation, histopathological response and percentage of T cells, respectively. The result showed that LB-1 significantly attenuated the psoriasiform inflammation. Com-pared with model group, PASI score were decreased in the LB-1 group. In the isolated immunocytes of spleen, LB-1 decreased percentage of CD8+ (P +/CD8+ T cells at the dosage of 2 mg·kg-1 (P + T cells and CD3+ T cells at the dosage of 4 mg·kg-1. In conclusion, the present study demonstrated that LB-1 attenuated psoriasiform inflammation induced by imiquimod in BALB/c mice. The mechanism of LB-1 action may be related to change percentage of CD4+ T, CD8+ T cells in the spleen. These results provide a basis for LB-1 or other triptolide derivative in the intervention of psoriasis in the future.

Establishment of a glioma orthotopic xenograft model based on imaging technology / 药学学报

Orthotopic xenograft model of human brain cancer cells is a good preclinical model for evaluation of antitumor compounds. In the present study, an orthotopic xenograft model of U87MG-mCherry-luc was established in Balb/c nude mice and the tumor growth was monitored via imaging technology including magnetic resonance imaging (MRI), in vivo imaging (IVI) and micro-CT. Furthermore, the model was evaluated with a positive drug temozolomide. Our data suggest that integrated imaging technology including MRI, IVI and micro-CT in orthotopic xenograft model can be used to facilitate monitoring of cancer progression and evaluate antitumor activity of drugs against glioma.

Olaparib potentiates the antitumor effect of Taxol on 4T1 breast cancer / 药学学报

Poly (ADP-ribose) polymerase 1/2(PARP1/2) can catalyze the poly (ADP ribose) (PAR) substrate protein modification and play an important role in the regulation of DNA damage repair, cell death and transcriptional activity. The PARP inhibitor olaparib (AZD2281) can be used as a sensitizer of radiotherapy and chemotherapy in the cancer treatment. Through establishment of biological fluorescent labeled 4T1 ectopic breast tumor model, we found that olaparib exhibited a poor effect on 4T1 breast cancer alone. However, in the combination with Taxol, olaparib significantly increased the anti-tumor effect of Taxol, and reduced the PAR levels of the tumor tissues. Importantly, olaparib did not amplify the toxicity of chemotherapy drugs. This study suggests that olaparib is a representative of the PARP inhibitor that can enhance Taxol 's antitumor effect in the 4T1 ectopic breast tumor model, which sets the foundation for future study of the mechanism of olaparib action.

A novel HIF-1 inhibitor--manassantin A derivative LXY6099 inhibits tumor growth / 药学学报

Hypoxia-inducible factor-1 (HIF-1) is a key transcription factor on hypoxia responses in mammalian tissues. HIF-1 plays as a positive factor in solid tumor and leads to hypoxia-driven responses that enhance its downstream gene expression for tumor growth and survival. LXY6099 was obtained by the structural modification and optimization of manassantin A (MA) as a high potent HIF-1 inhibitor. Antitumor activity of LXY6099 was observed in this study. LXY6099 with an IC50 value of 2.46 x 10(-10) mol x L(-1) showed more sensitive inhibition activity to HIF-1 than that of MA detected by reporter gene assay (> 100 folds). It showed strong inhibition on the growth of human solid tumor cell lines. Furthermore, LXY6099 exhibited significant antitumor activity against established human tumor xenografts in nu/nu mice with treatment of MX-1 breast cancer. Thus, LXY6099 as a novel HIF-1 inhibitor could be further developed into anti-cancer agents.

Research progress of hypoxia-inducible factor 1 inhibitors against tumors / 药学学报

Hypoxia occurs in chronic and acute vascular diseases and tumor formation. The ability of tumor cells to maintain a balance between an adaptation to hypoxia and cell death is regulated by a family of transcription factors called hypoxia-inducible factor 1 (HIF-1). Tumor hypoxia mediated by HIF-1 would facilitate the likelihood of resistance to chemotherapy and radiotherapy, proliferation, metastasis and the invasive potential; all of which culminate in a decrease in patient survival. And HIF-1 alpha subunit decides the activity of HIF-1, which is regulated by oxygen. So understanding the role of HIF in signal pathway, drug resistance mechanism and its feature is crucial for developing novel anticancer therapies. In recent years, more attentions have focused on HIF-1 alpha inhibitors. It is expected that development of more potent and selective HIF inhibitors will provide an effective treatment of cancer and other HIF-related diseases. So we will focus on the biological characteristics and mechanism of HIF-1 to review currently studied HIF-1 inhibitors.

Development of a novel screening assay for inhibitors targeting HIF-1alpha and P300 interaction / 药学学报

Hypoxia is a general characteristic of most solid malignancies and intimately related to cancer progression. Homeostatic response to hypoxia is primarily mediated by hypoxia inducible factor-1alpha (HIF-1alpha) that elicits transcriptional activity through recruitment P300 coactivator. Targeting the interaction of HIF- alpha and P300 would thus constitute a novel approach for cancer treatment by suppressing tumor angiogenesis and metastasis. Here, a screening assay was developed for inhibitors targeting the interaction between HIF-1alpha and P300. The nucleotide sequence of human HIF-1alpha and P300 were cloned into pBIND and pACT vectors, named pBIND-HIF1alpha and pACT-P300. The interaction of HIF-1alpha and P300 was identified in HEK293 cell using mammalian two-hybrid system. And compound chetomin decreased their interaction in this mammalian two-hybrid system. We further verified HIF-1 inhibition effect of chetomin in U251-HRE cells. Therefore, we established a screening assay combined HIF-1alpha and P300 mammalian two-hybrid system and U251-HRE reporter assay for HIF-1 selective inhibitors.

Screening and identification of the upregulators of ATP-binding cassette transporter A1 / 药学学报

ATP-binding cassette transporter A1 (ABCA1) promotes cholesterol and phospholipid efflux from cells to lipid-poor apolipoprotein A-I (apoA-I), and plays a key role in the initial steps of the whole process of reverse cholesterol transport (RCT). Upregulation of ABCA1 is beneficial for atherosclerosis (AS) prevention and/or therapy, which indicated that ABCA1 was a target for anti-AS drug development. In the previous study, a high-throughput screening method was established using ABCA1p-LUC HepG2 cell line to find the upregulators of ABCA1. In the present study, compound 2030421B was found using this method, with EC50 of 0.50 microg x mL(-1). The compound was further identified as an upregulator of ABCA1 expression by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting analysis. Studies also showed that the 2030421B could induce apoA-I-mediated cholesterol efflux and inhibit lipids uptake into mouse peritoneal macrophages RAW264.7.

Gene expressions of LTC4 synthase homologs in Con A-induced mouse hepatitis and regulative effect of cyclosporine A / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To explore the gene expressions of LTC4 synthase homologs in concanavalin A (Con A)-induced mouse hepatitis and regulation role of cyclosporine A (Cs A) treatment.</p><p><b>METHODS</b>Male Balb/c mouse liver injury model was developed by iv injection of Con A (20 mg/kg) and protected by Cs A pretreatment (150 mg/kg) before Con A administration. Blood samples were collected at indicated times after Con A treatment with or without Cs A pretreatment. Liver damage was assessed by serum transaminase ALT and AST measurement and histological evaluation. Meantime, three LTC4 synthase homolog gene expressions were determined by RT-PCR.</p><p><b>RESULTS</b>Serum ALT and AST upregulation were accompanied with histological damage at 2 h after Con A administration, and further aggravated at 8 h. mGST2 gene expression increased 1.7 fold at 2 h and 1.9 fold at 8 h, while the expression of LTC4 S and mGST3 changed little. Pretreatment with Cs A prevented mouse liver from injury by Con A and partly inhibited the mGST2 gene expression upregulation.</p><p><b>CONCLUSIONS</b>Administration of Con A in mouse lead to a significant increase of mGST2 gene expression without any significant effect on LTC4 S and mGST3 mRNA levels. Cs A pretreatment results in protection of liver damage, whereas fails to fully inhibit the increase of mGST2 gene expression.</p>