Indole based prostate cancer agents

Cancer weakens the immune system which fails to fight against the rapidly growing cells. Among the various types of cancers, prostate cancer (PCa) is causing greater number of deaths in men after lung cancer, demanding advancement to prevent, detect and treat PCa. Several small molecule heterocycles and few peptides are being used as oncological drugs targeting PCa. Heterocycles are playing crucial role in the development of novel cancer chemotherapeutics as well as immunotherapeutics. Indole skeleton, being a privileged structure has been extensively used for the discovery of novel anticancer agents and the application of indole derivatives against breast cancer is well documented. The present article highlights the usefulness of indole linked heterocyclic compounds as well as the fused indole derivatives against prostate cancer.

Heterocyclic Moieties as HDAC Inhibitors: Role in Cancer Therapeutic

‘Epigenetic’ regulation of genes via post-translational modulation of proteins is a well explored approach for the disease therapies, particularly cancer chemotherapeutics. Histone deacetylases (HDACs) are one of the important epigenetic targets and are mainly responsible for balancing the acetylation/deacetylation of lysine amino acids on histone/nonhistone proteins along with histone acetyltransferase (HAT). HDAC inhibitors (HDACIs) have become an important biologically active compounds for the treatment of cancers due to cell cycle arrest, differentiation and apoptosis in tumor cells and thus leads to anticancer activity. Out of the four classes of HDAC i.e. Class I, II, III and IV, HDACIs act on Class-IV (Zinc dependent HDAC) and various FDA-approved drugs belong to this category. The required canonical pharmacophore model (zinc binding group, surface recognition cap and appropriate linker) supported by HDACIs, various heterocyclic moieties containing compounds exhibiting HDAC inhibitory activity and structure activity relationship of different synthetic derivatives reported during last twelve years have been summarized in this review.

The Effects of Microtubule Stabilizing Drugs on Macrophage Immune-Mediated Endocytosis

<p>Microtubule stabilizing drugs (MSD) bind and stabilize microtubules, thus inhibiting their normal function. MSD exhibit anti-mitotic effects which makes them attractive as cancer chemotherapeutics and much of existing research has focused on these effects in proliferating cells. In contrast, we are interested in assessing the effects of microtubule stabilization on non-proliferating cells, such as macrophages, to determine potential mitosis-independent actions of MSD on microtubule function. Thus, we investigated the effects of MSD on macrophage receptor-mediated endocytosis of low density lipoproteins (LDL) and found no significant effect on the ability of paclitaxel-treated macrophages to endocytose LDL. Alterations to macrophage phagocytic and killing efficiency due to treatment with paclitaxel, peloruside or docetaxel, as well as the recently discovered compounds, ixabepilone, mycothiazole, and zampanolide were investigated. Treatment with paclitaxel, peloruside or docetaxel did not significantly inhibit phagocytosis or killing of bacteria. Results from confocal microscopy suggest that paclitaxel alters phagocytic kinetics in macrophages. Respectively, zampanolide and mycothiazole significantly inhibited macrophage bactericidal and killing ability, while Ixabepilone enhanced bacterial killing. MSD treatment also altered production of tumor necrosis factor alpha (TNF-a) and nitric oxide (NO) during bacterial killing. Optimal activation of macrophages with IFN-y did not alter the effects of MSD. Taken together, these results suggest that MSD have multiple immunomodulatory effects unrelated to their anti-mitotic effects. The data suggests that during MSD treatment, macrophage activity maybe altered or impaired, thus modifying the ability of patients to fight off bacterial infections.</p>

The Effects of Microtubule Stabilizing Drugs on Macrophage Immune-Mediated Endocytosis

<p>Microtubule stabilizing drugs (MSD) bind and stabilize microtubules, thus inhibiting their normal function. MSD exhibit anti-mitotic effects which makes them attractive as cancer chemotherapeutics and much of existing research has focused on these effects in proliferating cells. In contrast, we are interested in assessing the effects of microtubule stabilization on non-proliferating cells, such as macrophages, to determine potential mitosis-independent actions of MSD on microtubule function. Thus, we investigated the effects of MSD on macrophage receptor-mediated endocytosis of low density lipoproteins (LDL) and found no significant effect on the ability of paclitaxel-treated macrophages to endocytose LDL. Alterations to macrophage phagocytic and killing efficiency due to treatment with paclitaxel, peloruside or docetaxel, as well as the recently discovered compounds, ixabepilone, mycothiazole, and zampanolide were investigated. Treatment with paclitaxel, peloruside or docetaxel did not significantly inhibit phagocytosis or killing of bacteria. Results from confocal microscopy suggest that paclitaxel alters phagocytic kinetics in macrophages. Respectively, zampanolide and mycothiazole significantly inhibited macrophage bactericidal and killing ability, while Ixabepilone enhanced bacterial killing. MSD treatment also altered production of tumor necrosis factor alpha (TNF-a) and nitric oxide (NO) during bacterial killing. Optimal activation of macrophages with IFN-y did not alter the effects of MSD. Taken together, these results suggest that MSD have multiple immunomodulatory effects unrelated to their anti-mitotic effects. The data suggests that during MSD treatment, macrophage activity maybe altered or impaired, thus modifying the ability of patients to fight off bacterial infections.</p>

Nanoparticles-in-soft microagglomerates as oral colon-specific cancer therapeutic vehicle

Polymeric nanoparticles can be conjugated with targeting ligand such as folate to elicit oral colon-specific drug delivery to treat colon cancer. Oral chemotherapy can be used as adjuvant, neo-adjuvant, or primary therapy. Nonetheless, oral cancer chemotherapeutics may experience premature drug release at the upper gastrointestinal tract due to the availability of a large specific dissolution surface area of nanoparticles leading to failure in colon cancer targeting. This study designed soft microagglomerates as carrier of nanoparticles to delay drug release. High molecular weight chitosan/pectin with covalent 5-fluorouracil/folate was processed into nanoparticles. Low molecular weight chitosan was spray-dried into nanoparticle aggregation vehicle. The soft agglomerates were produced by blending of nanoparticles and aggregation vehicle in specific weight ratios through vortex method. Adding aggregation vehicle promoted soft agglomeration with nanoparticles deposited onto its surfaces with minimal binary coalescence. Soft agglomerates prepared from 10:18 weight ratio of nanoparticles to nanoparticle aggregation vehicle using 1% chitosan solution concentration reduced the propensity of premature drug release of nanoparticles in the upper gastrointestinal region. Soft agglomerates reduced early drug release of cancer chemotherapeutics and was responsive to intracapsular sodium alginate coat to further sustain drug release. The soft microagglomerates are a viable dosage form in colon-specific drug delivery. Further study will focus on investigating intracapsular-coated soft agglomerates in vivo pharmacokinetics and pharmacodynamics behaviours with respect to local colorectal cancer.

Antiproliferative Activities of Methanolic Extract and Fractions of Tetrapleura Tetraptera Fruit

Most of the current cancer chemotherapeutics are associated with harsh and undesirable side effects, including toxicity and chemoresistance, driving the need for safer and more effective alternatives. In this study, the antiproliferative activities of the methanolic extract of Tetrapleura tetraptera fruits and nine different fractions (C1–C9) from the column chromatographic separation of the extract against leukemia (Jurkat) and human breast cancer (MCF-7) cell lines were investigated using a tetrazolium-based colorimetric assay. Phytochemical screening of the extract and fractions found alkaloids, carbohydrates, flavonoids, glycosides, phenols, saponins, steroids, tannins, and terpenoids in the methanolic extract. Most of the fractions exhibited antiproliferative activity (>100 μg/mL) with the Jurkat cells being more susceptible than the MCF-7 cells. Four of the collected fractions C4, C3, C5, and C2 had good selective indices in decreasing order of activity, in the case of Jurkat cells. Liquid chromatography-mass spectrometry analysis of all samples (except for C4 and C9) revealed that C1, C2, C3, and C5 each had a single component. More importantly, fractions C2, C3, and C5, which were selective to Jurkat cells, also had the same retention time of 1.846 min. Fractions C6 and C8 had two components, with C7 having four components. This study serves as a basis for further work to isolate and characterize potential anticancer agents from the fractions of extracts of T. tetraptera fruits.

Engineered EV-Mimetic Nanoparticles as Therapeutic Delivery Vehicles for High-Grade Serous Ovarian Cancer

High-grade serous ovarian cancer (HGSOC) is the most lethal gynecological malignancy among women. Several obstacles impede the early diagnosis and effective treatment options for ovarian cancer (OC) patients, which most importantly include the development of platinum-drug-resistant strains. Currently, extensive efforts are being put into the development of strategies capable of effectively circumventing the physical and biological barriers present in the peritoneal cavity of metastatic OC patients, representing a late stage of gastrointestinal and gynecological cancer with an extremely poor prognosis. Naturally occurring extracellular vesicles (EVs) have been shown to play a pivotal role in progression of OC and are now being harnessed as a delivery vehicle for cancer chemotherapeutics. However, there are limitations to their clinical application due to current challenges in their preparation techniques. Intriguingly, there is a recent drive towards the use of engineered synthetic EVs for the delivery of chemotherapeutics and RNA interference therapy (RNAi), as they show the promise of overcoming the obstacles in the treatment of OC patients. This review discusses the therapeutic application of EVs in OC and elucidates the potential use of engineered EV-mimetic nanoparticles as a delivery vehicle for RNAi therapy and other chemotherapeutics, which would potentially improve clinical outcomes of OC patients.

Recent advances in research of colchicine binding site inhibitors and their interaction modes with tubulin

Microtubules have been a concerning target of cancer chemotherapeutics for decades, and several tubulin-targeted agents, such as paclitaxel, vincristine and vinorelbine, have been approved. The colchicine binding site is one of the primary targets on microtubules and possesses advantages compared with other tubulin-targeted agents, such as inhibitors of tumor vessels and overcoming P-glycoprotein overexpression-mediated multidrug resistance. This study reviews and summarizes colchicine binding site inhibitors reported in recent years with structural studies via the crystal structures of complexes or computer simulations to discover new lead compounds. We are attempting to resolve the challenge of colchicine site agent research.

Development of a Bioassay for Continuous Monitoring of TWIST1 Activity

TWIST1 is a transcription factor that affects cell behavior during development and cell differentiation. Yet, it is better known for its roles in neoplasia through regulation of cell plasticity. The pathological contributions of TWIST1 in tumor initiation, angiogenesis, invasion, metastasis, and chemo-resistance have been the focus of much research. To-date, the only way to quantitatively measure the abundance of TWIST is by immunoblots. Yet, no bioassay exists that can detect TWIST1 activity. Thus, we present here a TWIST1 cell-based assay that allows measuring the amount of active TWIST1 non-invasively in living cells. The bioassay was characterized against previously described TWIST1 &ldquo;inhibitors&rdquo;, as well as by epigenetic modulators of TWIST1 gene expression. Moreover, we tested multiple cell lines, showing that the level of TWIST1 mRNA resembles that of the bioassay. We show that prostate cancer cells (PC3) undergoing EMT, migrate out of 3D-spheroids and have increased TWIST1 activity. This fast and reliable system to detect active TWIST1 in different biological conditions allows a detailed analysis of this factor, as well as it can be used for drug discovery, since TWIST1 is a potential target for cancer chemotherapeutics.