Powerful Antiproliferative Activity Research Articles

Discovery of 4-((3,4-dichlorophenyl)amino)-2-methylquinolin-6-ol derivatives as EGFR and HDAC dual inhibitors

In patients with non-small cell lung cancer (NSCLC), the standard therapy consists of selective tyrosine kinase inhibitors that target epidermal growth factor receptors (EGFR). Nonetheless, their clinical utility is primarily limited by the development of resistance to drugs. HDAC inhibitors have been shown in studies to reduce the level of EGFR that is expressed and downregulate the EGFR-induced phosphorylation of AKT and ERK. Therefore, dual inhibitors of EGFR and HDAC provide a potential approach as combination treatment synergistically inhibited the growth of NSCLC. Herein, we examined the EGFR inhibition effect of twenty compounds which designed and synthesized by us previously. Among them, compounds 12c and 12d exhibited powerful antiproliferative activity against the NCI–H1975 cell line with IC50 values of 0.48 ± 0.07 and 0.35 ± 0.02 μM, correspondingly. In cell-free kinase assays, both 12c and 12d demonstrated target-specific EGFR inhibition against wild type (EGFRwt). Furthermore, the expression of EGFR and phosphorylation of the EGF-induced pathways were significantly suppressed under the treatment of 12c and 12d. Besides, both histones H3 and H4 exhibited increased levels of acetylation following 12c and 12d treatment. The animal experiments shown that 12d could prevent the growth of tumor, inhibited the expression of EGFR and the phosphorylation levels of p70 S6K, AKT and p38 MAPK in vivo, and did not cause organ damage to the mice during the experiment.Overall, the results illustrated that compound 12c and 12d could serve as effective EGFR and HDAC dual inhibitors in NSCLC cells. Our work offers an alternative strategy for NSCLC therapy.

Identification of novel and potent PROTACs targeting FAK for non-small cell lung cancer: Design, synthesis, and biological study

The intracellular non-receptor tyrosine protein kinase Focal adhesion kinase (FAK) is a key signalling regulator, which mediates tumor survival, invasion, metastasis, and angiogenesis through its kinase catalytic functions and non-kinase scaffolding functions. Previous efforts have clarified that it is crucial to address both FAK kinase and scaffolding functions instead of just inhibiting FAK kinase activity because it may be insufficient to completely block FAK signaling. Proteolysis targeting chimera (PROTAC) technology is a method of targeting a specific protein and inducing its degradation in the cell, which can simultaneously eliminate both kinase-dependent enzymatic functions and scaffolding functions. In current study, we designed and synthesized a series of novel FAK PROTACs and the optimal PROTAC B5 exhibited potent FAK affinity with an IC50 value of 14.9 nM. Furthermore, in A549 cells, PROTAC B5 presented strong FAK degradation activity (86.4% degradation @ 10 nM), powerful antiproliferative activity (IC50 = 0.14 ± 0.01 μM) and inhibited cell migration and invasion in a concentration-dependent manner. Additionally, the in vitro preliminary drug-like properties evaluation of PROTAC B5 showed outstanding plasma stability and moderate membrane permeability. Together, current results provided a promising FAK PROTAC B5 as lead compound for cancer-related drug discovery and FAK-degradation functions exploration in biological systems.

A new phenyl alkyl ester and a new combretin triterpene derivative from Combretum fragrans F. Hoffm (Combretaceae) and antiproliferative activity

AbstractThis work concerns the isolation and structure elucidation of compounds obtained from the extract of leaves and stem bark of Combretum fragrans F. Hoffm. Both extracts and some isolated compounds were tested for antiproliferative activity on glioblastoma (U87MG and C6 cells) and prostate (PC-3 cells) cancer cell lines using XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide inner salt) assay. The dichloromethane/methanol (1:1) extract of the leaves led to the isolation of two new compounds such as fragransinate (1) and combretin C (2), alongside five known compounds such as combretin A (3), belamcanidin (4), cirsilineol (5), velutin (6), and a mixture of β-sitosterol-3-O-β-d-glucopyranoside (10a) and stigmasterol-3-O-β-d-glucopyranoside (10b), whereas the methanol extract of the stem bark led to the isolation of three known compounds betulinic acid (7), bellericagenin B (8), and a mixture of β-sitosterol (9a) and stigmasterol (9b). The structure of compounds was elucidated by nuclear magnetic resonance and mass spectrometry data. The methanol extract of the stem bark showed a powerful antiproliferative activity on all tested cells, as well as the extract of leaves which also showed important cytotoxicity effect. Compound (3) showed good antiproliferative activity particularly on U87MG and PC-3 cells, whereas compound (5) exhibits moderated activity. Compounds (2) and (8) were not active on all tested cells.

Production and bioprocess optimization of antitumor Epothilone B analogue from Aspergillus fumigatus, endophyte of Catharanthus roseus, with response surface methodology

Epothilones are secondary metabolites produced by Sorangium cellulosum with powerful antiproliferative activity against tumor cells by stabilizing their microtubule arrays, arresting their cellular division at G2-M phase. Unfortunately, the lower yield of epothilone is the challenge for its higher accessibility, thus, searching for alternative sources with promising epothilone producing potency is the prospective. Endophytic fungi are the potential repertoire for bioactive metabolites, thus exploring the epothilone producing potency of endophytic fungi of medicinal plants was objective. Thirty-two fungal isolates were recovered from the tested medicinal plants and their potency to produced epothilone have been assessed using the TLC, HPLC and molecular markers epoA, epoC and epoK. Aspergillus fumigatus EFBL, an endophyte of Catharanthus roseus, was the potent epothilone producer (21.5 μg/g biomass) as revealed from the chromatographic analyses and PCR of molecular markers. The chemical identity of extracted epothilone was verified from the HPLC, NMR, FTIR and LC–MS analyses as epothilone B analogue. The putative epoA gene from A. fumigatus was amplified using RT-PCR with the conservative corresponding primers to the active-sites of S. cellulosum. The amplicons of epoA was 517 bp displayed 98 % similarity with A. fumigatus PKS-NRPS domains, and 40 % similarity with epoA of S. cellulosum. From the in silico analyses, Val506, Ala605 and Ser630 are the conservative amino acids of epoA protein of A. fumigatus and S. cellulosum. Epothilone B from A. fumigatus displayed a strong antiproliferative activity against HepG-2, MCF-7 and LS174 T as revealed from the IC50 values 6.4, 8.7 and 10.21 μM, respectively. The productivity of epothilone B from A. fumigatus was optimized by surface response methodology with Plackett-Burman and Faced Centered Central Composite. With the Plackett-Burman design, the yield of epothilone (54.4–60.1 μg/g biomass) by A. fumigatus was increased by about 2.8–3.0 folds comparing to non-optimized cultures (21.5 μg/ g biomass). From the FCCD design, sucrose, tryptone and incubation time being the highest significant variables medium components affecting the epothilone yield of A. fumigatus. This is the first report exploring the feasibility of endophytic fungi for epothilone producing potency, that could be a novel platform for industrial production of epothilone.

The synthesis and biological evaluation of unsymmetrical 2,2-di(1H-indol-3-yl)-N-phenylacetamide derivatives

A mild and highly efficient method has been developed for the synthesis of unsymmetrical 2,2-di(1H-indol-3-yl)-N-phenylacetamide derivatives by the regioselective Friedel–Crafts alkylation of 2-hydroxy-2-(1H-indol-3-yl)-N-phenylacetamide derivatives with various indoles catalyzed by AlCl3 at room temperature in a short reaction time in high yields (up to 96%). All these compounds were screened for their antiproliferative activity against human colorectal carcinoma HCT116 cell line. The preliminary biological study showed that some of them exhibited moderate to good antiproliferative activity in vitro. Especially, compound 3e exerted the most powerful antiproliferative activity even better than the positive control MDM-2/p53 antagonist Nutlin-3a.

Different 6-Aryl-Fulvenes Exert Anti-proliferative effects on Cancer Cells.

Fulvenes represent a class of molecules very interesting under a chemical point of view because are easily accessible starting materials and are still poorly characterized for their biological activities, with the exception of acylfulvene and irofulvenes which have been reported to exert cytotoxic properties. Here, we describe the synthesis and characterization of several aryl-fulvenes together with their effects on cancer cell growth by MTT method. The cytotoxic potential was investigated on a panel of tumor cell lines such as breast MCF7 and SkBr3, endometrial Ishikawa, prostate LnCaP and lung A549, in comparison with the cis-diamminedichloroplatinum(II) (cisplatin) which is largely used for the treatment of different types of cancer. The evaluation of the cytotoxic activity of these compounds indicated that they are able to inhibit the proliferation of the aforementioned cancer cell types. In particular, the compound 4 exhibited the most powerful antiproliferative activity on all tumor cells evaluated with higher inhibitory effects respect to cisplatin and without altering the proliferation of human mammary MCF-10A epithelial cells.

The discovery and optimization of novel dual inhibitors of topoisomerase ii and histone deacetylase

A novel class of podophyllotoxin derivatives have been designed and synthesized based on the synergistic antitumor effects of topoisomerase II and histone deacetylase inhibitors. Their inhibitory activities towards histone deacetylases and Topo II and their cytotoxicities in cancer cell lines were evaluated. The aromatic capping group connection, linker length and zinc-binding group were systematically varied and preliminary conclusions regarding structure–activity relationships are discussed. Among all of the synthesized hybrid compounds, compound 24d showed the most potent HDAC inhibitory activity at a low nanomolar level and exhibited powerful antiproliferative activity towards HCT116 colon carcinoma cells at a low micromolar level. Further exploration of this series led to the discovery of potent dual inhibitor 32, which exhibited the strongest in vitro cytotoxic activity.

A New 4-phenyl-1,8-naphthyridine Derivative Affects Carcinoma Cell Proliferation by Impairing Cell Cycle Progression and Inducing Apoptosis

In targeted cancer therapy the search for novel molecules led to the discovery of a plethora of small organic molecules inhibiting cancer cell proliferation. Among these, quinazoline and derivatives, such as quinolines and naphthyridines, have been considered as of particular interest. One of these, the naphthyridine derivative 4-phenyl-2,7-di(piperazin-1-yl)-1,8-naphthyridine, has been analyzed in detail in the present work. We found that this compound elicited a powerful anti-proliferative activity on carcinoma cells, with IC50 values comparable with paradigmatic microtubule-deranging drugs. The mechanisms underlying this effect were seemingly due to a framework of cellular alterations that include peculiar alterations of mitochondria, i.e. an increase of mitochondrial membrane potential (MMP), followed by the typical MMP loss leading to the release of apoptogenic factors, and cell death by apoptosis. Furthermore, the analysis of cell cycle revealed that a significant percentage of treated cells was in G2/M phase. This block was seemingly due to a target effect of the naphthyridine derivative on microtubular network dynamic instability, which impaired mitotic spindle formation, possibly leading to mitotic catastrophy. Since the dual effects of naphthyridine derivative on cell cycle and mitotic spindle were obtained at very low concentrations, i.e. micromolar concentrations, we hypothesize that this compound could represent a new promising tool in the control of cancer cell proliferation.

FoxP3 + Regulatory T Cells Suppress Early Stages of Granuloma Formation but Have Little Impact on Sarcoidosis Lesions

Sarcoidosis is characterized by a disproportionate Th1 granulomatous immune response in involved organs. It is also associated with both peripheral and intratissular regulatory T cell (Treg) expansion. These cells exhibit powerful antiproliferative activity, yet do not completely inhibit the production of either tumor necrosis factor-alpha or interferon-gamma. The origin of the observed Treg amplification and, more importantly, its impact on the evolution of sarcoidosis remain unresolved issues. Here, we show that CD4(+)CD45RA(-)FoxP3(bright) Tregs proliferate and accumulate within granulomas. However, circulating and tissue Treg numbers are neither correlated with the dissemination of the disease nor correlated locally with the extent of granulomatous inflammation. Rather, we found a positive correlation between the presence of Tregs in renal granulomas and the degree of interstitial fibrosis (r = 0.46, P = 0.03, n = 20). Furthermore, Treg depletion accelerates in vitro granuloma growth in mononuclear cell cultures of healthy controls, but not in those from patients with active sarcoidosis. The results of this study show that although healthy Tregs suppress the initial steps of granuloma formation, they have no positive influence on sarcoidosis lesions. Our findings argue for a more preventive than curative effect of Tregs on inflammatory processes.

Bis and Tris Indole Alkaloids from Marine Organisms: New Leads for Drug Discovery

The marine organisms are a rich source of varied natural products with unique functionality. Marine natural products chemistry has undergone an explosive growth during the past three decades. A variety of natural products of new molecular structures with diverse biological activities have been reported from marine flora and fauna, thus ensuring motivation in the search of newer natural products. The bis and trisindole alkaloids are a class of marine natural products that show unique promise in the development of new drug leads. 3-hydroxy staurosporine 51, an indolo carbazole having powerful antiproliferative activity. Hamacanthin A 1 and B 2, pyrazinone alkaloids have significant antimicrobial activity. Coscinamides 60-62 and Chondriamides 63-65 an indolic enamides which have anti-HIV and cytotoxic activity respectively. Gelluisine A 66 and B 67, trisindole alkaloids have strong anti-serotonin activity and strong affinity with somatostatin and neuropeptide Y receptors in receptor-binding assays. This report reviews the literature on these alkaloids of marine origin and highlights the isolation, structure, latest synthesis and specific biological activities including cytotoxicity, antiviral, antiparasitic, serotonin antagonism and other pharmacological activities of sixty-nine bis and trisindole alkaloids.

Enantiodivergent synthesis of muricatacin related lactones from d-xylose based on the latent symmetry concept: preparation of two novel cytotoxic (+)- and (−)-muricatacin 7-oxa analogs

Enantiodivergent formal synthesis of (+)- and (−)-muricatacins from d-xylose has been accomplished through utilization of the latent plane of symmetry present in the starting monosaccharide. This approach was extended to the preparation of two novel (+)- and (−)-muricatacin 7-oxa analogs ( 2 and ent- 2, respectively), which showed in vitro antitumor activity toward some human malignant cells. The analog ent- 2 showed a powerful antiproliferative activity against the K562 cell line, being 36-fold more potent than the standard cytotoxic agent, doxorubicin. Compound 2, however, showed a powerful cytotoxic activity against HL-60 cells, being more than 17-fold more potent with respect to the reference compound.

The immune paradox of sarcoidosis and regulatory T cells

Sarcoidosis is characterized by extensive local inflammation (granuloma, cytokine secretion) associated with anergy (poor response to antigens in vitro and in vivo). We postulated that this paradoxical situation would correspond to a disequilibrium between effector and regulatory T lymphocytes (T reg cells). We show that CD4+CD25brightFoxP3+ cells accumulate at the periphery of sarcoid granulomas, in bronchoalveolar lavage fluid, and in peripheral blood of patients with active disease. These cells exhibited powerful antiproliferative activity, yet did not completely inhibit TNF-α production. Sarcoidosis is therefore associated with a global T reg cell subset amplification whose activity would be insufficient to control local inflammation. At the same time, peripheral T reg cells exert powerful antiproliferative activity that may account for the state of anergy. Altogether, these findings advance our conceptual understanding of immune regulation in a way that resolves the immune paradox of sarcoidosis and permit us to envisage a profound clinical impact of T reg cell manipulation on immunity.

A phase I trial of a novel mTOR inhibitor AP23573 administered weekly (wkly) in patients (pts) with refractory or advanced malignancies: A pharmacokinetic (PK) and pharmacodynamic (PD) analysis

3150 Background:AP23573 is a non-prodrug rapamycin analog that potently inhibits mTOR, a downstream effector of the PI3K/Akt and nutrient pathways. AP23573 demonstrated powerful antiproliferative activity in vitroand antitumor activity in mouse xenograft studies. Methods: This trial is utilizing an accelerated dose escalation scheme to determine safety and tolerability, establish a maximum tolerated dose, and characterize the PK and PD of AP23573. AP23573 is administered as 30-minute IV infusion wkly on 4-week cycles, and tumor responses are evaluated every 2 cycles. Potential PD markers are being assessed using western blot analysis of peripheral blood mononuclear cells. Results: As of 12/01/03: 9 pts (4M/5F), median age 55 yrs (range 27–79 yrs), have received doses ranging from 6.25 to 25 mg in 3 dose level cohorts (total cycles, 15; median cycles, 2/pt). No dose limiting toxicities or AP23573-related serious adverse events have been observed. Common reversible side effects for first cycle have been grade 1 chills, diarrhea, fatigue, rash, anorexia, mucositis, and one pt had grade 2 anemia. PK analyses (doses 6.25 and 12.5 mg) suggest a mean AP23573 half-life of 46–52 hours, with AP23573 concentration levels generally remaining above in vitro antiproliferation IC50 levels until the next wkly dose. PD analyses (doses 12.5 and 25 mg) show inhibition of mTOR activity until the next wkly dose as measured by decrease in phosphorylated 4EBP1 levels. One of 5 evaluable pts has stable medullary thyroid cancer for > 2 months. Conclusions: AP23573 can be administered safely using this schedule. There is evidence of a substantial PD effect at dose levels associated with minimal toxicity, and early evidence of antitumor activity. Given the promising PD findings, further dose escalation and new pt enrollment will include evaluation of maximum effective dose of AP23573 based on PK/PD relationship. If substantial interindividual PK variability is observed, the trial also is prospectively designed to evaluate the relevance of genetic variants in candidate drug metabolism genes. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration ARIAD Pharmaceuticals, Inc. ARIAD Pharmaceuticals, Inc. ARIAD Pharmaceuticals, Inc.

A phase I trial of a novel mTOR inhibitor AP23573 administered weekly (wkly) in patients (pts) with refractory or advanced malignancies: A pharmacokinetic (PK) and pharmacodynamic (PD) analysis

3150 Background:AP23573 is a non-prodrug rapamycin analog that potently inhibits mTOR, a downstream effector of the PI3K/Akt and nutrient pathways. AP23573 demonstrated powerful antiproliferative activity in vitroand antitumor activity in mouse xenograft studies. Methods: This trial is utilizing an accelerated dose escalation scheme to determine safety and tolerability, establish a maximum tolerated dose, and characterize the PK and PD of AP23573. AP23573 is administered as 30-minute IV infusion wkly on 4-week cycles, and tumor responses are evaluated every 2 cycles. Potential PD markers are being assessed using western blot analysis of peripheral blood mononuclear cells. Results: As of 12/01/03: 9 pts (4M/5F), median age 55 yrs (range 27–79 yrs), have received doses ranging from 6.25 to 25 mg in 3 dose level cohorts (total cycles, 15; median cycles, 2/pt). No dose limiting toxicities or AP23573-related serious adverse events have been observed. Common reversible side effects for first cycle have been gra...