Pharmacophore based virtual screening, molecular docking and molecular dynamic simulation studies for finding ROS1 kinase inhibitors as potential drug molecules.

Proto-oncogene receptor tyrosine kinase ROS-1 is one of the clinically important biomarker and plays a crucial role in regulation of a number of cellular functions including cell proliferation, migration and angiogenesis. Recently, inhibition of ROS1 kinase has proven to be a promising target of anticancer drugs for non-small cell lung cancer (NSCLC). The very few compounds have been used as potent drug molecules so far and the selective ROS1 inhibitors are relatively rare. Besides the currently available drugs such as Crizotinib and PF-06463922 are becoming sensitive due to mutations in the ROS1 protein. To curtail the problem of the resistant, present study was designed to identify the potent inhibitors against ROS1. Three different screening approaches such as structure based, Atom-based and pharmacophore based screening were carried out against commercially available databases and the retrieved best hits were further evaluated by Lipinski's filter. Thereafter the lead molecule was subjected to pocket specific docking with ROS1. The results show that, total of 9 molecules (3 from each screening) has good docking score (with range of -9.288 to -12.49 Kcal/Mol) and binding interactions within the active site of ROS1. In order to analyze the stability of the ligand- protein complexes, molecular dynamics simulation was performed. Thus, these identified potential lead molecules with good binding score and binding affinity with ROS1 may act as the potent ROS1 inhibitor, and that are worth considering for further experimental studies.Communicated by Ramaswamy H. Sarma.

The remarkable role of emulsifier and chitosan, dextran and PEG as capping agents in the enhanced delivery of curcumin by nanoparticles in breast cancer cells.

Curcumin has been found to be a powerful anti-cancer agent. However, its efficacy is limited by its poor solubility in aqueous medium. The bioavailability of curcumin was increased by poly (lactic-co-glycolic) acid [PLGA (60/40)] nanoparticles with different capping agents such as Chitosan, Dextran and PEG and emulsifier (Tocopherol Poly (Ethylene Glycol)1000 Succinate: TPGS) with good drug loading and delivery performance. The preparation of nanoparticles derived from PLGA was achieved by emulsion solvent evaporation method and the resultant nanoparticles were characterized. The encapsulation efficiency of curcumin by PLGA NPs with different capping agents such as Chitosan, PEG and Dextran and emulsifier lies in the range of 82% to 89% and the anti-oxidant activity is 80%. The in vitro anticancer activity of PLGA nanoparticles embedded with curcumin and different capping agents on MCF-7 indicates that they are more effective in arresting cell growth. The cellular uptake of TPGS emulsified dextran capped curcumin encapsulated PLGA NPs is much higher when compared to that of PLGA NPs with other capping agents, emulsifier and free curcumin.

Anticancer potential of ZnO nanoparticle-ferulic acid conjugate on Huh-7 and HepG2 cells and diethyl nitrosamine induced hepatocellular cancer on Wistar albino rat.

Drawbacks and limitations of recently available therapies to hepatocellular cancer (HCC) devoted the scientist to focus on emerging new strategies. ZnO nanoparticles (ZnONPs) based chemotherapeutics has been emanating as a promising approach to maximize therapeutic synergy facilitating the discovery of novel multitargeted combinations. In the present study we conjugated ZnONPs with ferulic acid (ZnONPs-FAC) characterized by computational, spectroscopic and microscopic techniques. In vitro anticancer potential has been evaluated by assessing cell viability, morphology, ROS generation, mitochondrial membrane permeability, comet assay, immunofluorescent staining of 8-OHdG, Ki67 and γ-H2AX, cell cycle analysis and western blot analysis and in vivo anticancer potential against DEN induced HCC was analyzed by histopathological and immunohistochemical methods. The results revealed that ZnONPs-FAC induces cell death through apoptosis and can suppress the DEN-induced HCC. Our study documents therapeutic potential of nanoparticle conjugated with phytochemicals, suggesting a new platform for combinatorial chemotherapy.

Oxystressed tumor microenvironment potentiates epithelial to mesenchymal transition and alters cellular bioenergetics towards cancer progression.

During tumorigenesis, cancer cells generate complex, unresolved interactions with the surrounding oxystressed cellular milieu called tumor microenvironment (TM) that favors spread of cancer to other body parts. This dissemination of cancer cells from the primary tumor site is the main clinical challenge in cancer treatment. In addition, the significance of enhanced oxidative stress in TM during cancer progression still remains elusive. Thus, the present study was performed to investigate the molecular and cytoskeletal alterations in breast cancer cells associated with oxystressed TM that potentiates metastasis. Our results showed that depending on the extent of oxidative stress in TM, cancer cells exhibited enhanced migration and survival with reduction of chemosensitivity. Corresponding ultrastructural analysis showed radical cytoskeletal modifications that reorganize cell-cell interactions fostering transition of epithelial cells to mesenchymal morphology (EMT) marking metastasis, which was reversed upon antioxidant treatment. Decreased E-cadherin and increased vimentin, Twist1/2 expression corroborated the initiation of EMT in oxystressed TM-influenced cells. Further evaluation of cellular energetics demonstrated significant metabolic reprogramming with inclination towards glucose or external glutamine from TM as energy source depending on the breast cancer cell type. These observations prove the elemental role of oxystressed TM in cancer progression, initiating EMT and metabolic reprogramming. Further cell-type specific metabolomic analysis would unravel the alternate mechanisms in cancer progression for effective therapeutic intervention. Graphical abstract Schematic representation of the study and proposed mechanism of oxystressed TM influenced cancer progression. Cancer cells exhibit a close association with tumor microenvironment (TM), and oxystressed TM enhances cancer cell migration and survival and reduces chemosensitivity. Oxystressed TM induces dynamic cytomorphological variations, alterations in expression patterns of adhesion markers, redox homeostasis, and metabolic reprogramming that supports epithelial to mesenchymal transition and cancer progression.

Chitosan Tethered Colloidal Gold Nanospheres for Drug Delivery Applications.

Gold Nanospheres (AuNS) have been widely explored as an emerging system for various biomedical applications including drug delivery, bioimaging and photomedicine. However, method of synthesizing nanoparticles and its toxicity including bioaccumulation has been a problem of concern. In the present study, we explored the appropriateness of 12.0 ±1.99 nm chitosan reduced AuNS in vivo models with respect to its bioavailability and toxicity against various concentrations (2.5-7.5 mg/kg). Administration of AuNS did not show any signs of morbidity. Inductively coupled plasma optical emission spectrometry (ICP-OES) analysis of blood (0.156 ± 0.154), urine (0.084 ± 0.08) and tissues indicates gradual dissipation and obligatory clearance within 24 h time interval. Nevertheless, pres- ence of AuNS in blood after 24 h confirms the bioavailability of AuNS demonstrating the evidence for no immune clearance and efficient tissue uptake. Further, brain shows the lowest quantity of injected AuNS. From this result, we determine this chitosan monolayer protected AuNS could cross the blood brain barrier and enter to the neural tissues. Interestingly there was no evidence of toxicity in any of the organs. In conclusion, our data suggest that AuNS injected though tail vain were easily taken up by tissues and does not produce sub-acute physiological damage even at high concentrations tested, supporting chitosan reduced AuNS as biocompatible, nontoxic nanoconjugates for targeted drug delivery and other biomedical applications.

Comparative bioactive studies between wild plant and callus culture of Tephrosia tinctoria pers.

Tephrosia tinctoria, a perennial under shrub of Fabaceae family, is endemic to Western Ghats. In this study, friable whitish yellow callus was developed after 45 days using Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic acid (2.0 mg/l) + 6-benzylaminopurine (0.5 mg/l) in various explants of T. tinctoria. The ethyl acetate extracts of leaf (LE), stem (SE), and root (RE) were compared with leaf (LCE), stem (SCE), and root (RCE) derived callus, for antioxidant and antiproliferative activities. The SE possessed the highest phenolic and flavonoid content among all the extracts tested and showed a significant antioxidant assays. The study of anticancer activity on human hepatocellular carcinoma (HepG2) cell line revealed that the callus extracts especially RCE possessed significant inhibition of cell growth (IC50 20 µg/ml) at 72 h treatment period on analysis with MTT assay. The apoptotic cell death was observed through DNA fragmentation analysis in HepG2 cells treated with the T. tinctoria extracts. The gas chromatography-mass spectrometry finger printing profile showed that more than 60 % percentage of metabolites are similar in both SE and SCE. The higher percentage area of antioxidant compound (stigmast-4-en-3-one) was observed in SE (2.01 %) and higher percentage area of anticancer compound (phenol, 2,4-bis(1,1-dimethylethyl)) in SCE (0.91 %). In addition to that, callus extracts contain squalene, which is used for target deliver and also used as anticancer drug. Thus, the present study revealed that the T. tinctoria has potent antioxidant and antiproliferative activity and the callus culture can be used for the production of the bioactive compounds due to the endemic nature of this plant.