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Two previous unreported epipolythiodioxopiperazines of the emestrin family, namely, noremestrin A ( 1 ) and secoemestrin E ( 2 ), were successfully isolated from the fungal source Emericella sp. 1454. Employing comprehensive spectroscopic techniques, such as high-resolution electrospray ionization mass spectrometry, infrared, and nuclear magnetic resonance (NMR), along with NMR and electronic circular dichroism calculations, the chemical structures of compounds 1 and 2 were elucidated. Particularly noteworthy is the distinctive nature of noremestrin A, representing the inaugural instance of a noremestrin variant incorporating a sulfur-bearing 15-membered macrocyclic lactone moiety. Compounds 1 and 2 exhibited weak cytotoxic activities against the human chronic myelocytic leukemia cell lines MEG-01 and K562.

Breast cancer stem cells (BCSCs) are the culprit of triple-negative breast cancer invasiveness and are heterogeneous. It is recognized that the combination of chemotherapy and differentiation therapy for killing BCSCs and non-BCSCs simultaneously is a reliable strategy. In this study, an oil-in-water nanoemulsion was prepared by high-pressure homogenization with coencapsulation of all-trans retinoic acid (ATRA) and doxorubicin (DOX). The preparation process was simple, and the production was easy to scale up. The particle size of the nanoemulsion was 127.2 ± 2.0 nm. Cellular toxicity assay showed that the composite index of the ATRA and DOX was less than 1 and exhibited a fine combined effect. In vivo antitumor efficacy showed that the compound nanoemulsion could reduce the proportion of BCSCs to 1.18% by inhibiting the expression of Pin1. In addition, the combination of ATRA and DOX could reduce the cardiotoxicity of DOX and had higher safety. Hopefully, this work can provide a new insight into developing pharmaceutically acceptable technology for treating BCSCs.

The acidic tumor microenvironment stands as a major obstacle to the efficient elimination of tumor cells. Norcantharidin (NCTD) is a powerful antitumor agent with multiple bioactivities. However, the effect of NCTD under acidic conditions is still unclear. Here, we report that NCTD can efficiently kill bladder cancer (BC) cells in acidic culture, and more intriguingly, NCTD can induce immunogenic cell death (ICD), thereby promoting antitumor immunity. In NCTD-treated BC cells, the surface-exposed calreticulin (ecto-CALR) was significantly increased. Consistently, co-culture with these cells promoted dendritic cell (DC) maturation. The NCTD-induced ICD is autophagy dependent, as autophagy inhibition completely blocked the NCTD-induced ecto-CALR and DC maturation. In addition, the DC showed a distinct maturation phenotype (CD80 high CD86 low ) in acidic culture, as compared to that in physiological pH (CD 80 high CD86 high ). Finally, the NCTD-induced ICD was validated in a mouse model. NCTD treatment significantly increased the tumor-infiltrating T lymphocytes in MB49 bladder cancer mice. Immunizing mice with NCTD-treated MB49 cells significantly increased tumor-free survival as compared to control. These findings demonstrate that NCTD could induce ICD in an acidic environment and suggest the feasibility to combine NCTD with anticancer immunotherapy to treat BC.

Background: Liquidambaris Fructus is the infructescences of Liquidambar formosana Hance and it has been used to treat some breast disease in Traditional Chinese Medicine. In the previous study we found the anti-breast cancer effect of triterpenoid in Liquidambaris Fructus. This study is a further investigation of the triterpenoids in Liquidambaris Fructus and aims to identify their anti-breast cancer targets, meanwhile, to estimate the rationality of the traditional applications of Liquidambaris Fructus., Methods: Triterpenoids in Liquidambaris Fructus were isolated and their structures were identified by NMR spectrums. Potential targets of these triterpenoids were predicted using a reverse pharmacophore mapping strategy. Associations between these targets and the therapeutic targets of breast cancer were analyzed by constructing protein-protein interaction network, and targets played important roles in the network were identified using Molecular Complex Detection method. Binding affinity between the targets and triterpenoids was studied using molecular docking method. Gene ontology enrichment analysis was conducted to reveal the biological process and signaling pathways that the identified targets were involved in., Results: Thirteen triterpenoids were identified and 6 of them were the first time isolated from Liquidambaris Fructus. Predicted ADME properties revealed a good druggability of these triterpenoids. We identified 18 protein targets which were closely related to breast cancer progression, especially triple-negative, basal-like or advanced stage breast cancers. The triterpenoids could bind with these targets as their inhibitors: hydrophobic skeleton is a favorable factor for them to stabilize at binding site and polar C17- or C3- substituent was necessary for binding. GO enrichment analysis indicated that inhibition of protein tyrosine kinases autophosphorylation might be the primary mechanism for the anti-breast cancer effect of the triterpenoids, and ErbB4 and EGFR were the most relevant targets., Conclusions: The study revealed that triterpenoids from Liquidambaris Fructus might exert anti-breast cancer effect by directly inhibit multiple protein targets and signaling pathways, especially ErbB4 and EGFR and related pathways. This study also brings up another hint that the traditional applications of Liquidambaris Fructus on hypogalactia should be reassessed systematically because it might suppress rather than promote lactation by inhibiting the activity of ErbB4.

EphA2 receptor kinase could become a novel target for anti-glioblastoma treatment. Doxazosin previously identified acts like the endogenous ligand of EphA2 and induces cell apoptosis. Through lead structure modification a derivative of Doxazosin possessing unique dimeric structure showed an improvement in the activity. In the current study, we expanded the dimeric scaffold by lead optimization to explore the chemical space of the conjoining moieties and a slight variation to the core structure. 27 new derivatives were synthesized and examined with EphA2 overexpressed and wild type glioblastoma cell lines for cell proliferation and EphA2 activation. Three new compounds 3d, 3e, and 7bg showed potent and selective activities against the growth of EphA2 overexpressed glioblastoma cells. Dimer 3d modification replaces the long alkyl chain with a short polyethylene glycol chain. Dimer 7bg has a relatively longer polyethylene glycol chain in comparison to compound 3d and the length is more similar to the lead compound. Whereas dimer 3e has a rigid aromatic linker exploring the chemical space. The diversity of the linkers in the active suggest additional hydrogen binding sites has a positive correlation to the activity. All three dimers showed selective activity in EphA2 overexpressed cells, indicating the activity is correlated to the EphA2 targeting effect., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Background: Pulmonary large cell carcinoma (LCC) is a poorly differentiated and rare tumor with dismal outcome, and there are no recommended treatments for LCC. Little is known about the efficacy of postoperative chemotherapy in patients with early stage LCC., Methods: The patients with early stage I/II LCC in the Surveillance, Epidemiology and End Results (SEER) database between 2004 and 2015 were retrospectively reviewed. The overall survival (OS) of patients with LCC at different stages and treatments were evaluated by Kaplan-Meier analysis with log-rank test. Univariate and multivariate Cox proportional risk regression analysis were employed to determine the independent risk factors of OS. Finally, a nomogram was constructed to predict the 1 -, 3- and 5-year OS of early stage LCC patients., Results: A total of 1,099 pulmonary LCC cases were included in this study. 71.8% of patients were over 60 years old, and 66.7% of the tumor lesions located in the upper lobe, followed by the lower lobe (25.7%). Meanwhile, the majority of tumors showed poor differentiation (96.1%). The median OS of surgical patients with or without post-operative adjuvant chemotherapy was 61 and 47 months, respectively. Post-operative chemotherapy was associated with better OS (HR: 0.805; 95% CI: 0.676-0.959, P=0.020). For patients with tumor size >3 cm or IB stage tumor, the prognosis of postoperative chemotherapy was better than that of patients without chemotherapy. Multivariate Cox analysis revealed the age, stage and treatments were independent risk factors of OS for early stage LCC. The nomogram had a calibration index of 0.581., Conclusions: The incidence of LCC was high in the elderly, and it generally had poor differentiation. Post-operative chemotherapy is strongly recommended for patients with LCC at stage IB or higher.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is the first-line treatment in non-resectable non-small lung cancer (NSCLC) with EGFR mutation. However, EGFR-TIKs resistance would inevitably develop within 9-14 months after treatment. And, chemotherapy is the main treatment for EGFR-TKIs resistant patients. WEE1 kinase, a G2/M checkpoint regulator, was recently considered as a putative biomarker for the platinum-based chemo-response. The aim of this study is to clarify the relationship between WEE1 kinase and chemosensitivity in EGFR-TKIs resistant NSCLC. WEE1 expression was tested in EGFR-TKIs resistant cell lines (H1299, PC9/G2) and patients' specimens by western blot, qPCR and immunohistochemistry (IHC). In in vitro experiment, WEE1 expression was higher in EGFR-TKIs resistant than EGFR-TKIs sensitive cell lines and was gradually increased following cisplatin or gemcitabine treatment with the enrichment of G2/M cell cycle phase. And, for patients with acquired Icotinib/Gefitinib resistance, 58.4% (7/12) had increased WEE1 expression compared to its initial expression level. In order to explore the impact of WEE1 on chemo-response, WEE1 knockdown was conducted in EGFR-TKIs resistant H1299 and PC9/G2 cells. MTT and colony formation assay showed that the efficacy of cisplatin and gemcitabine was enhanced in the two cell lines after WEE1 knockdown. And, the IC50 value of cisplatin decreased from 8.64 μg/ml to 3.10 μg/ml or 2.38 μg/ml in H1299 and from 3.66 μg/ml to 0.97 μg/ml or 1.18 μg/ml in PC9/G2 after WEE1 knockdown with two specific shRNAs. This study revealed that WEE1 expression was increased after EGFR-TKIs resistance, and WEE1 knockdown could enhance chemosensitivity in EGFR-TKIs resistant NSCLC. It is suggested the combination of WEE1 inhibitor and chemotherapy might improve the clinical outcome of NSCLC patients with acquired EGFR-TKIs resistance., (Copyright © 2019 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Transforming growth factor‑β1 (TGF‑β1) has been demonstrated to promote epithelial‑mesenchymal transition (EMT), invasion and proliferation in tumors via the activation of Rac1 and β‑catenin signaling pathways. The present study investigated the effects of diallyl disulfide (DADS) on TGF‑β1‑induced EMT, invasion and growth of gastric cancer cells. TGF‑β1 treatment augmented EMT and invasion, concomitantly with increased expression of TGF‑β1, Rac1 and β‑catenin in gastric cancer cells. DADS downregulated the expression levels of TGF‑β1, Rac1 and β‑catenin. DADS, TGF‑β1 receptor inhibitor as well as Rac1 inhibitor antagonized the upregulation of the TGF‑β1‑induced expression of these genes, abolishing the enhanced effects of TGF‑β1 on EMT and invasion. Blocking the TGF‑β1 receptor through inhibition resulted in the decreased expression of Rac1 and β‑catenin. Rac1 inhibitor reduced the TGF‑β1‑induced β‑catenin expression. In addition, DADS and the aforementioned inhibitors attenuated the TGF‑β1‑induced tumor growth and the expression changes of E‑cadherin, vimentin, Ki‑67 and CD34 in nude mice. These data indicated that the blockage of TGF‑β1/Rac1 signaling by DADS may be responsible for the suppression of EMT, invasion and tumor growth in gastric cancer.

Compound JCC76 selectively inhibited the proliferation of human epidermal growth factor 2 (Her2) over-expressed breast cancer cells. In the current study, a ligand based structural optimization was performed to generate new analogs, and we identified derivatives 16 and 17 that showed improved activity and selectivity against Her2 positive breast cancer cells. A structure activity relationship (SAR) was summarized. Compounds 16 and 17 were also examined by western blot assay to check their effect on Her2 protein. The results reveal that the compounds could decrease the Her2 protein, which explains their selectivity to Her2 over-expressed breast cancer cells. Furthermore, the compounds inhibited the chaperone activity of small chaperone protein that could stabilize Her2 protein., (Published by Elsevier Ltd.)

We have been studying the role of Hexamethylene bisacetamide (HMBA) Induced Protein 1 (HEXIM1) as a tumor suppressor whose expression is decreased in tamoxifen resistant and metastatic breast cancer. HMBA was considered the most potent and specific inducer for HMBA inducible protein 1 (HEXIM1) prior to our studies. Moreover, the ability of HMBA to induce differentiation is advantageous for its therapeutic use when compared to cytotoxic agents. However, HMBA induced HEXIM1 expression required at mM concentrations and induced dose limiting toxicity, thrombocytopenia. Thus we structurally optimized HMBA and identified a more potent inducer of HEXIM1 expression, 4a1. The studies reported herein tested the ability of 4a1 to induce HEXIM1 activities using a combination of biochemical, cell phenotypic, and in vivo assays. 4a1 induced breast cell differentiation, including the stem cell fraction in triple negative breast cancer cells. Clinically relevant HEXIM1 activities that are also induced by 4a1 include enhancement of the inhibitory effects of tamoxifen and inhibition of breast tumor metastasis. We also provide mechanistic basis for the phenotypic effects of 4a1. Our results support the potential of an unsymmetrical HMBA derivative, such as 4a1, as lead compound for further drug development., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Glaucocalyxin (Gln), an ent‑kaurane diterpenoid isolated from the Chinese traditional medicine, Rabdosia japonica, represents a novel class of anticancer drugs. GlnA is one of the three major forms of Gln and has demonstrated potent anticancer effects in a variety of cancer types. GlnB has only one structural difference from GlnA, an acetylated hydroxyl group at C14. This acetyl group results in high liposolubility and may enhance the antitumor activity of ent‑kaurane diterpenoid GlnB. However, few studies have reported the role of GlnB in cancer. The present study investigated the effect of GlnB in cervical cancer proliferation and cell death. Treatment with GlnB inhibits the proliferation of HeLa and SiHa cervical cancer cell lines in a dose‑dependent manner, as assessed by 3‑(4,5‑dimethylthiazol-2‑yl)-2,5 diphenyl tetrazolium bromide assays. In addition, GlnB increases the apoptotic cell population of HeLa and SiHa cells, as determined by fluorescence‑activated cell sorting analysis and enhanced poly (ADP‑ribose) polymerase 1 cleavage by western blotting. GlnB also induces increased light chain 3 II/I protein cleavage in both cells, indicating the induction of autophagy. Furthermore, GlnB treatment increased the expression of phosphatase and tensin homolog and decreased the expression of phosphorylated‑protein kinase B (Akt) in HeLa and SiHa cells, as assessed by western blotting. Taken together, the present results demonstrated that GlnB inhibited the proliferation of human cervical cancer cells in vitro through the induction of apoptosis and autophagy, which may be mediated by the phosphatidylinositol‑4,5‑bisphosphate 3‑kinase/Akt signaling pathway.

Curcumin shows growth-inhibition against tumor cells through multi-target mechanisms. Nevertheless, the poor stability and pharmacokinetics considerably limit its clinical functions. Increased effort has been put into the chemical alteration of curcumin to find potential analogues with improved bioavailability and antitumor activities. In this study, the antitumor activity of a novel curcuminoid (B63) in nasopharyngeal carcinoma (NPC) was examined. The MTT and colony formation assays were used to detect NPC cell viability and proliferation. Flow cytometry was used to detect cell cycle distribution. The Annexin V/PI staining assay and cleavage PARP and cleavage caspase-3 expression were used to examine apoptosis. Western blotting was used to examine the protein expression of endoplasmic reticulum (ER) stress pathway markers, XBP-1, ATF-4 and CHOP. The suppressive effect of B63 on tumor growth was examined in vivo by subcutaneously inoculated NPC in a tumor model using nude mice. Treatment with B63 potentially caused growth inhibition and apoptosis in NPC cells in a dose- and time-responsive manner. Its antitumor effect was associated with the ER stress activation. Nevertheless, the same dose of curcumin did not activate ER stress. In addition, knockdown of Chop attenuated B63-induced cell viability inhibition, suggesting that the apoptotic pathway is ER stress-dependent. The tumor volume and weight were significantly reduced by pretreating the NPC cells with B63 before implantation in the in vivo mouse model. B63 exhibited a more potent antitumor action than curcumin in NPC. These observations on the novel compound B63 indicate a novel candidate for NPC therapy.

Inhibition of DNA methyltransferase 1 (DNMT1) can reverse the malignant behavior of cancer cells by restoring expression of aberrantly silenced genes that are required for differentiation, senescence, and apoptosis. Clinically used DNMT1 inhibitors decitabine and azacitidine inhibit their target by covalent trapping after incorporation into DNA as azacytidine analogs. These nucleoside compounds are prone to rapid enzymatic inactivation in blood, posing challenges to the development of purely epigenetic dosing schedules. Non-nucleoside compounds that suppress expression or function of DNMT1 may overcome this problem. Using a high-throughput PCR-based site specific chromatin condensation assay, we identified a compound that reactivated Cyclin-Dependent Kinase Inhibitor 2A (CDKN2A) in myeloma cells and suppressed expression of DNMT1 from a library of 5120 chemically diverse small molecules. Lead optimization was performed to generate 26 new analogs with lung cancer proliferation and DNMT1 expression as activity readout. Two of the new derivatives showed 2 fold improvement of growth inhibiting potency and also decreased DNMT1 protein levels in lung cancer cells., (Published by Elsevier Ltd.)

Cyclooxygenase (COX) inhibitor Indomethacin analogs exhibited more potent cancer cell growth inhibition and apoptosis inducing activities than the parental compound. The anti-proliferative mechanism investigation of the analogs revealed that they inhibited tubulin polymerization at high concentrations whereas enhanced polymerization at low concentrations. The two opposite activities might antagonize each other and impaired the anti-proliferative activity of the derivatives eventually. In this study, we further performed lead optimization based on the structure activity relationship (SAR) generated. One of the new Indomethacin derivatives compound 11 {2-(4-(benzyloxy)phenyl)-N-(1-(4-bromobenzoyl)-3-(2-((2-(dimethylamino)ethyl)amino)-2-oxoethyl)-2-methyl-1H-indol-5-yl)acetamide} inhibited the proliferation of a panel of cancer cell lines with IC50s at the sub-micromole levels. Further study revealed that the compound only enhanced tubulin polymerization and was a tubulin stabilizer., (Published by Elsevier Ltd.)

The blood-brain barrier and the blood-brain tumor barrier (BBTB) prevent most drugs entering brain tumors. Complicated preparation procedures of drug delivery systems and damage to normal brain tissue have limited the application of many strategies for the treatment of brain tumor in clinical trials. We have designed a bradykinin analog, retro-inverso bradykinin (RI-BK), which is characterized by resistance to proteolysis and high binding activity with the bradykinin type 2 (B2) receptor. After systemic administration, RI-BK binds to B2 receptors and induces a change in zonula occluden-1 and depolymerization of F-actin to selectively open the BBTB. RI-BK increased the accumulation of drug-loaded nanocarriers in the glioma but not in normal brain. Co-administration with RI-BK enhanced the therapeutic efficiency of drug-loaded nanocarriers for glioma. These findings suggest that RI-BK could be translated into the clinic as an adjunctive treatment for malignant brain tumors., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Oleanolic acid has significant pharmacological activities, such as anti-tumor, regulating blood sugar level and liver protection, which are more effective compared with free aglyconeoleanolic acid. However, it is still unknown if oleanolic acid affects the proliferation of human bladder cancer. We utilized T24 cells to study the effect of oleanolic acid on the proliferation and apoptosis of human bladder cancer. In this study, we found that the anti-cancer effect of oleanolic acid significantly suppressed cell proliferation and increased apoptosis and caspase-3 activity of T24 cells. Furthermore, Akt, mTOR and S6K protein expression was greatly inhibited in T24 cells under oleanolic acid treatment. Meanwhile, ERK1/2 of phosphorylation protein expression was significantly promoted by oleanolic acid treatment. Taken together, we provided evidences that oleanolic acid was Akt/mTOR/S6K and ERK1/2 signaling-targeting anti-tumor agent. These findings represent new evidences that oleanolic acid suppresses the proliferation of human bladder cancer by Akt/mTOR/S6K and ERK1/2 signaling, and oleanolic acid may be used to prevent human bladder cancer.

CSUOH0901, a novel anticancer derivative of nimesulide, exhibits very promising anticancer activities in various cancer cell lines. In order to support further pharmacological and toxicological studies of this promising anticancer drug candidate, an LC-MS/MS method was developed and validated in accordance with the US Food and Drug Administration guidelines. The drug molecules were extracted from plasma samples by protein precipitation and then analyzed with LC-ESI-MS/MS. An excellent analyte separation was achieved using a phenomenex C18 column with a mobile phase of 90% methanol and 5 m m of ammonium formate. The validated linear dynamic range was between 0.5 and 100 ng/mL and the achieved correlation coefficient (r(2)) was >0.9996. The results of inter- and intra-day precision and accuracy were satisfactory, that is, <12% for accuracy and within ±5% for precision at a low and high quality control concentrations, respectively. In addition, the analyte and internal standard (JCC76) were found to be stable under the storage conditions at -20°C for about 2 months. Hence, the acquired results proved that the LC-ESI-MS/MS method developed is precise, accurate and selective for the quantification of CSUOH0901 in plasma, and can be used for pharmacokinetic studies., (Copyright © 2014 John Wiley & Sons, Ltd.)

Most solid tumors undergo hypoxia, leading to rapid cell division, metastasis and expansion of a cell population with hallmarks of cancer stem cells (CSCs). Tumor-selective replication of oncolytic adenoviruses may be hindered by oxygen deprivation in tumors. It is desirable to develop a potent oncolytic adenovirus, retaining its antitumor activity even in a hypoxic environment. We have previously generated an Oct4-dependent oncolytic adenovirus, namely Ad9OC, driven by nine copies of the Oct4 response element (ORE) for specifically killing Oct4-overexpressing bladder tumors. Here, we developed a novel Oct4 and hypoxia dual-regulated oncolytic adenovirus, designated AdLCY, driven by both hypoxia response element (HRE) and ORE. We showed that hypoxia-inducible factor (HIF)-2α and Oct4 were frequently overexpressed in hypoxic bladder cancer cells, and HIF-2α was involved in HRE-dependent and Oct4 transactivation. AdLCY exhibited higher cytolytic activities than Ad9OC against hypoxic bladder cancer cells, while sparing normal cells. AdLCY exerted potent antitumor effects in mice bearing human bladder tumor xenografts and syngeneic bladder tumors. It could target hypoxic CD44- and CD133-positive bladder tumor cells. Therefore, AdLCY may have therapeutic potential for targeting hypoxic bladder tumors and CSCs. As Oct4 is expressed in various cancers, AdLCY may be further explored as a broad-spectrum anticancer agent.

Using analogues of some marine steroidal oximes as precursors, a series of aza-B-homocholestane derivatives possessing different substituted groups at the 3-position of the steroidal nucleus were synthesized. Their biological activity against cancer cell proliferation was determined with multiple cancer cell lines. Aza-B-homocholestane derivatives possessing 3-hydroxyl, 3-hydroximino and 3-thiosemicarbazone groups displayed remarkable cytotoxicity to cancer cells via apoptosis inducing mechanism. Compounds 5, 10, 12, 15 and 18 exhibited better potency to inhibit cancer cell proliferation. In addition, compound 15 was further evaluated with three dimensional (3D) multicellular spheroids assay to determine its potency against spheroid growth. The structure-activity relationship (SAR) generated in the studies is valuable for the design of novel chemotherapeutic agents.

We provide evidence that type I IFN-induced STAT activation is diminished in cells with targeted disruption of the Rictor gene, whose protein product is a key element of mTOR complex 2. Our studies show that transient or stable knockdown of Rictor or Sin1 results in defects in activation of elements of the STAT pathway and reduced STAT-DNA binding complexes. This leads to decreased expression of several IFN-inducible genes that mediate important biological functions. Our studies also demonstrate that Rictor and Sin1 play essential roles in the generation of the suppressive effects of IFNα on malignant erythroid precursors from patients with myeloproliferative neoplasms. Altogether, these findings provide evidence for critical functions for Rictor/Sin1 complexes in type I IFN signaling and the generation of type I IFN antineoplastic responses.

Heat shock protein 27 (Hsp27) is a chaperone protein, and its expression is increased in response to various stress stimuli including anticancer chemotherapy, which allows the cells to survive and causes drug resistance. We previously identified lead compounds that bound to Hsp27 and tubulin via proteomic approaches. Systematic ligand based optimization in the current study significantly increased the cell growth inhibition and apoptosis inducing activities of the compounds. Compared to the lead compounds, one of the new derivatives exhibited much better potency to inhibit tubulin polymerization but a decreased activity to inhibit Hsp27 chaperone function, suggesting that the structural modification dissected the dual targeting effects of the compound. The most potent compounds 20 and 22 exhibited strong cell proliferation inhibitory activities at subnanomolar concentration against 60 human cancer cell lines conducted by Developmental Therapeutic Program at the National Cancer Institute and represented promising candidates for anticancer drug development.

It has been demonstrated that two-dimensional (2D) monolayer cancer cell proliferation assay for anti-cancer drug screening is a very artificial model and cannot represent the characteristics of three-dimensional (3D) solid tumors. The multi-cellular in vitro 3D tumor spheroid model is of intermediate complexity, and can provide a bridge to the gap between the complex in vivo tumors and simple in vitro monolayer cell cultures. In this study, a simple and cost-effective cancer 3D spheroid assay suitable for small molecule anti-cancer compound screening was developed, standardized and validated on H292 non-small lung cancer cell line. A pilot screening with this assay was performed utilizing a compound library consisting of 41 anti-cancer agents. The traditional 2D monolayer cell proliferation assay was also performed with the same cell line and compounds. A correlational study based on the IC(50) values from the 2D and 3D assays was conducted. There is low correlation with the two sets of biological data, suggesting the two screening methods provide different information regarding the potency of the tested drug candidates., (Published by Elsevier Ltd.)

Objective: To detect the inhibitory effect of a p38MAPK inhibitor SB203580 in combination with gefitinib on lung adenocarcinoma cell line PC-9 cells and A549 cells, and its cellular and molecular mechanisms of action., Methods: MTT test was used to detect the growth inhibition of PC-9 and A549 cells by SB203580 alone and in combination with gefitinib. Cell apoptosis and cell cycles were determined by flow cytometry. The expressions of p38 and phosphorylated -p38 proteins in the two cell lines were analyzed by immunofluorescence microscopy. The associated protein expression was determined by Western-blot., Results: Compared with the SB203580 group and gefitinib group, the growth inhibition and cell apoptosis of PC-9 cells in the SB203580 + gefitinib group were significantly increased (P < 0.05). The inhibition rate of PC-9 cells of 2 µmol/L SB203580 + 0.01 µmol/L gefitinib group was (46.6 ± 2.4)%, significantly higher than that induced by 0.01 µmol/L gefitinib (12.7 ± 1.5%) (P < 0.05). Immunofluorescence microscopy showed a low expression of phosphorylated-p38 protein in A549 cells and high expression in PC-9 cells. Flow cytometry showed that PC-9 cells in the SB203580 + gefitinib group were (77.35 ± 2.83)% at G0/G1 phase, (3.38 ± 0.84)% at S phase, and (19.56 ± 1.99)% at G2/M phase. Western-blotting showed that compared with the control group, the expression of phosphorylated Akt and phospho-p38 proteins in PC-9 cells of the SB203580 + gefitinib group was almost completely suppressed., Conclusions: The results indicate that the small molecular inhibitor SB203580 can effectively enhance the inhibitory effect of gefitinib on lung adenocarcinoma PC-9 cells. The enhanced inhibitory effect of SB203580 may be correlated with the blockage of p38MAPK signal transduction pathway.

Drug design is crucial for the effective discovery of anti-cancer drugs. The success or failure of drug design often depends on the leading compounds screened in pre-clinical studies. Many efforts, such as in vivo animal experiments and in vitro drug screening, have improved this process, but these methods are usually expensive and laborious. In the post-genomics era, it is possible to seek leading compounds for large-scale candidate small-molecule screening with multiple OMICS datasets. In the present study, we developed a computational method of prioritizing small molecules as leading compounds by integrating transcriptomics and toxicogenomics data. This method provides priority lists for the selection of leading compounds, thereby reducing the time required for drug design. We found 11 known therapeutic small molecules for breast cancer in the top 100 candidates in our list, 2 of which were in the top 10. Furthermore, another 3 of the top 10 small molecules were recorded as closely related to cancer treatment in the DrugBank database. A comparison of the results of our approach with permutation tests and shared gene methods demonstrated that our OMICS data-based method is quite competitive. In addition, we applied our method to a prostate cancer dataset. The results of this analysis indicated that our method surpasses both the shared gene method and random selection. These analyses suggest that our method may be a valuable tool for directing experimental studies in cancer drug design, and we believe this time- and cost-effective computational strategy will be helpful in future studies in cancer therapy.

JCC76 is a novel nimesulide analog that selectively inhibits the human epidermal growth factor receptor 2 (HER2) overexpressing breast cancer cell proliferation and tumor progression. To support further pharmacological and toxicological studies of JCC76, a novel and rapid method using liquid chromatography and electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) has been developed and validated for the quantification of the compound in rat plasma. A C₁₈ column was used for chromatographic separation, and the mobile phase was aqueous ammonium formate (pH 3.7; 5 mm)-methanol (1:9, v/v) with an isocratic elution. With a simple liquid-liquid extraction procedure using the mixture of methyl tert-butyl ether-hexane (1:2, v/v), the mean extraction efficiency of JCC76 in rat plasma was determined as 89.5-97.3% and no obvious matrix effect was observed. This method demonstrated a linear calibration range from 0.3 to 100 ng/mL for JCC76 in rat plasma and a small volume of sample consumption. The intra- and inter-assay accuracy and precision were within ±10%. The pharmacokinetics of JCC76 was also profiled using this validated method in rats. In conclusion, this rapid and sensitive method has been proven to effectively quantify JCC76 for pharmacokinetics study., (Copyright © 2011 John Wiley & Sons, Ltd.)

We previously developed a series of anticancer agents based on cyclooxygenase-2 (COX-2) inhibitor nimesulide as a lead compound. However, the molecular targets of these agents still remain unclear. In this study, we synthesized a biotinylated probe based on a representative molecule of the compound library and performed protein pull-down assays to purify the anticancer targets of the compound. Via proteomic approaches, the major proteins bound to the probe were identified to be tubulin and heat shock protein 27 (Hsp27), and the compound inhibited tubulin polymerization by binding at the colchicine domain. However, the tubulin inhibitory effect of the compound activated the Hsp27 phosphorylation and possibly overrode the direct Hsp27 inhibitory effects, which made it difficult to solely validate the Hsp27 target. Taken together, the compound was a dual ligand of tubulin and Hsp27, inhibited tubulin polymerization, and had the potential to be a class of new chemotherapeutic agents., (© 2012 American Chemical Society)

Cyclooxygenase-2 (COX-2) inhibitor nimesulide inhibits the proliferation of various types of cancer cells mainly via COX-2 independent mechanisms, which makes it a good lead compound for anti-cancer drug development. In the presented study, a series of new nimesulide analogs were synthesized based on the structure-function analysis generated previously. Some of them displayed very potent anti-cancer activity with IC(50)s around 100 nM-200 nM to inhibit SKBR-3 breast cancer cell growth. CSUOH0901 (NSC751382) from the compound library also inhibits the growth of the 60 cancer cell lines used at National Cancer Institute Developmental therapeutics Program (NCIDTP) with IC(50)s around 100 nM-500 nM. Intraperitoneal injection with a dosage of 5  mg/kg/d of CSUOH0901 to nude mice suppresses HT29 colorectal xenograft growth. Pharmacokinetic studies demonstrate the good bioavailability of the compound., (Published by Elsevier Masson SAS.)

JCC76 is a derivative of cyclooxygenase-2(COX-2) selective inhibitor nimesulide and exhibits potent anti-breast cancer activity. It selectively induces apoptosis of Her2 positive breast cancer cells. However, the specific molecular targets of JCC76 still remain unclear, which significantly withdraw the further drug development of JCC76. To identify the molecular targets of JCC76, a six carbon linker and biotin conjugated JCC76 probe was designed and synthesized. The anti-proliferation activity of the probe and its analogs was evaluated., (Published by Elsevier Ltd.)

Purpose: To investigate the effects of gefitinib (EGFR-TKI), LY294002 (PI3K inhibitor) and U0126 (MEK inhibitor) on proliferation and apoptosis in five non-small cell lung cancer (NSCLC) cell lines (PC9, PC9/AB2, H1975, H1299 and A549)., Methods: The inhibitory rates of cells were tested by MTT and apoptosis was detected through flow cytometry when treated with gefitinib, LY294002 and U0126., Results: The sensitivity to gefitinib was different in different cell lines, which was associated with EGFR mutation type. The cells with EGFR mutation were more sensitive than those with EGFR wild-type, except PC9/AB2 cells. LY294002 and U0126 can inhibit cell proliferation and promote apoptosis in all five cell lines. The sensitivity to gefitinib was restored partially in the resistant cell lines by combining gefitinib with LY294002 or U0126. The effects on cell proliferation and apoptosis were stronger in cells with EGFR mutation when PI3K/AKT pathway was blocked, however, for cells with EGFR wild-type, the effects were stronger when the MEK pathway was blocked. When the PI3K and MEK pathways were blocked together, proliferation inhibition and apoptosis level in NSCLC cells was similar to that in cells treated with EGFR TKI. There were some differences according to EGFR mutation type, suggesting that EGFR mutations may result in alterations of downstream signaling pathways., Conclusion: The sensitivity of gefitinib resistant cell lines can be restored partially when the two downstream signaling pathways are blocked. However, these cells were still drug resistant, suggesting that the activation of PI3K and MEK pathways is not the only mechanism of EGFR-resistance.

A novel dual-targeted peptide containing an alpha V integrins specific ligand and a neuropilin-1 specific motif was developed which showed an increased specific targeting affinity to tumors. Active dual-targeted liposomes were then produced with this peptide and exhibited greater binding activity than single-targeted liposomes in vitro. Paclitaxel entrapped in this formulation greatly increased the uptake of paclitaxel in the targeting cells and significantly suppressed the growth of HUVEC and A549 cells compared with general paclitaxel injections (Taxol) and single-targeted paclitaxel liposomes. The treatment of tumor xenograft models with dual-targeted paclitaxel liposomes also resulted in better tumor growth inhibition than any other treatment groups. Therefore, the dual-targeted paclitaxel liposomes prepared in the present study might be a more promising drug for cancer treatment. Furthermore, the dual-targeting approach may produce synergistic effects that can be applied in the development of new targeted drug delivery systems.

Objective: To study the drug resistance mechanism of non-small cell lung cancer (NSCLC) cell line PC9/AB2 with acquired drug resistance to gefitinib., Methods: The human lung adenocarcinoma cell line PC9 was cultured in vitro, and was induced by MNNG to obtain the cell line PC9/AB2 with acquired drug resistance to gefitinib. The sensitivity of the cell line PC9 and PC9/AB2 to gefitinib was determined by MTT assay. The effects of gefitinib on cell apoptosis of the 2 cell lines were determined by flow cytometry. The genomic DNA of the 2 cell lines were extracted, and then the exons 19-21 of EGFR gene were amplified by PCR and sequenced. The protein expression of c-MET and integrin beta1 in the 2 cell lines was determined by Western blot method. The adhesion ability and migration ability of the 2 cell lines were determined by adhesion test and scratch assay., Results: (1) The data form MTT and apoptosis detection showed that the IC50 of PC9/AB2 cells was (24.2+/-5.5) micromol/L, 576 times higher than PC9 cells [IC50 (0.04+/-0.01) micromol/L]. Given the same concentration of gefitinib, the apoptosis rate of PC9 cells was 38.48%, while that of PC9/AB2 cells was 2.2%. (2) The results of gene sequencing showed that there was a deletion of 15 bp in both exon 19 of the 2 cell lines, while no T790M mutation occurred. (3) The results from Western blot showed that there was no significant difference in protein expression of c-MET between the 2 cell lines, while the protein expression of integrin beta1 in PC9/AB2 cells was significantly higher than that of the PC9 cells. (4) The result from adhesion test and scratch assay showed that the adhesion ability and migration ability of the PC9/AB2 cells was significantly higher that those of PC9 cells., Conclusion: The high expression of integrin beta1 may be associated with acquired drug resistance of NSCLC cell line PC9/AB2 to gefitinib.

A series of COX-2 selective inhibitor nimesulide derivatives were synthesized. Their anti-cell proliferation activities were evaluated with a long-term estrogen deprived MCF-7aro (LTEDaro) breast cancer cell line, which is the biological model of aromatase inhibitor resistance for hormone-dependent breast cancer. Compared to nimesulide which inhibited LTEDaro cell proliferation with an IC(50) at 170.30 microM, several new compounds showed IC(50) close to 1.0 microM.

Objective: To explore the sensitivity of tumor cell lines with acquired resistance to gefitinib to several chemotherapeutic drugs and provide preclinical basis of available chemotherapy regimens after failure of molecular targeted therapy., Methods: Human lung adenocarcinoma cell lines PC9 and PC9/G with acquired resistance to gefitinib were cultured in vitro. The sensitivity to chemotherapeutic drugs and inhibition rate of cell proliferation was determined by MTT assay. Effects of drugs on apoptosis and expression of P-170 were determined by flow cytometry. Difference of gene expression profile between PC9 and PC9/G cells was analyzed by DNA microarray. Western blot was used to test the expression of Akt, phospho-Akt and integrin beta1., Results: The resistance index of PC9/G cells to cisplatin was about 5.4-fold compared with that of PC9 cells. LY294002 may significantly elevate the sensitivity of PC9/G cells to cisplatin (P < 0.05). PC9/G cells were more sensitive to docetaxel than PC9 cells. No significant difference of sensitivity to pemetrexed was found between these two cell lines. Expression level of P-170 in PC9/G cells was lower than that in PC9 cells. In PC9/G cells, the expression of integrin beta1 and DNA healing gene was high and expression of gene during mitosis was low. The level of expression of Akt, phospho-Akt and integrin beta1 in PC9/G cells was higher than that in PC9 cells., Conclusion: In PC9/G cells, a cell line with acquired resistance to gefitinib, over-expression of PI3K, integrin and DNA restoration gene and continuous activation of PI3K is found to be correlated with resistance to cisplatin. Docetaxel or pemetrexed is a more reasonable choice than cisplatin for treatment of NSCLC patients who failed to respond to EGFR-TKI.

Combinatorial chemistry approaches facilitate drug discovery processes and result in structural modifications of lead compounds that enhance pharmacological activity, improve pharmacokinetic properties, or reduce unwanted side effects. Epidemiological and animal model studies have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) can act as chemopreventive agents. The cyclooxygenase-2 (COX-2) inhibitor nimesulide shows anticancer effects in several cancer cell lines via COX-2-dependent and -independent mechanisms. The molecular structure of nimesulide was used as a starting scaffold to design novel sulfonanilide analogs and examine the structural features that contribute to this anticancer effect. A systematic combinatorial chemical approach was used to generate diversely substituted sulfonanilide derivatives that were tested for their effects on the proliferation of human breast cancer cells. Structure-function analysis indicated that the inhibition of cell growth by compounds derived from the novel sulfonanilides required a bulky terminal phenyl ring, a methanesulfonamide, and a hydrophobic carboxamide moiety.

Aromatase converts androgens to estrogens and is a particularly attractive target in the treatment of estrogen receptor positive breast cancer. Previously, the COX-2 selective inhibitor nimesulide and analogs decreased aromatase expression and enzyme activity independent of COX-2 inhibition. In this manuscript, a combinatorial approach was used to generate diversely substituted novel sulfonanilides by parallel synthesis. Their pharmacological evaluation as agents for suppression of aromatase activity in SK-BR-3 breast cancer cells was extensively explored. A ligand-based pharmacophore model was elaborated for selective aromatase modulation (SAM) using the Catalyst HipHop algorithms. The best qualitative model consisted of four features: one aromatic ring, two hydrogen bond acceptors, and one hydrophobic function. Several lead compounds have also been tested in aromatase transfected MCF-7 cells, and they significantly suppressed cellular aromatase activity. The results suggest that both genomic and nongenomic mechanisms of these compounds are involved within the aromatase suppression effect.

Aromatase converts androgens to estrogens and is a particularly attractive target in the treatment of estrogen receptor positive breast cancer. The enzyme is encoded by the CYP19 gene, which is expressed in a tissue-specific manner. Prostaglandin E2 (PGE2), the major product of cyclooxygenase-2 (COX-2), stimulates aromatase gene expression via protein kinase A and C signaling pathways. Our previous study demonstrated that COX-2 selective inhibitor nimesulide decreased aromatase activity from the transcriptional level in breast cancer cells. In this manuscript, the synthesis and biological evaluation of a series of nimesulide analogues as potential selective aromatase expression regulators are described. Several novel sulfonanilide compounds demonstrate IC50 values from 0.33 to 2.68 microM in suppressing aromatase enzyme activity in SK-BR-3 breast cancer cells and are 10- to 80-fold more active than nimesulide. Also, the sulfonanilide compounds selectively decrease aromatase gene expression in breast cancer cells, without exhibiting cytotoxic or apoptotic effects at low micromole concentrations.

The water extract of Anoectochilus formosanus Hayata showed a potent tumor inhibitory activity in BALB/c mice after subcutaneous transplantation of CT-26 murine colon cancer cells. The tumor-inhibition ratios of mice pre-administered with A. formosanus for 2 days before tumor transplantation, and treated further for 12 consecutive days, were 55.4% and 58.9% at the oral dose of 50 and 10 mg/mouse per day, respectively. Even for the tumor-bearing mice, after oral administration of the water extract of A. formosanus for 12 consecutive days, the tumor inhibition ratios were still 23.8% and 40.5% at doses of 50 and 10 mg/mouse, respectively. Because the low-concentration water extract of A. formosanus does not show direct cytotoxicity in CT-26 tumor cells, we observed further that oral administration of the water extract of A. formosanus may activate murine immune responses, such as stimulating the proliferation of lymphoid tissues and activating the phagocytosis of peritoneal macrophages against Staphylococcus aureus. This study suggests that the antitumor activity of A. formosanus may be associated with its potent immunostimulating effect. It is worth further analyzing the immunomodulating component purified from A. formosanus, and evaluating its potential value for the treatment of human cancers.