Unraveling the cytotoxic potential of Temozolomide loaded into PLGA nanoparticles

BACKGROUND: Nanotechnology has received great attention since a decade for the treatment of different varieties of cancer. However, there is a limited data available on the cytotoxic potential of Temozolomide (TMZ) formulations. In the current research work, an attempt has been made to understand the anti-metastatic effect of the drug after loading into PLGA nanoparticles against C6 glioma cells. Nanoparticles were prepared using solvent diffusion method and were characterized for size and morphology. Diffusion of the drug from the nanoparticles was studied by dialysis method. The designed nanoparticles were also assessed for cellular uptake using confocal microscopy and flow cytometry. RESULTS: PLGA nanoparticles caused a sustained release of the drug and showed a higher cellular uptake. The drug formulations also affected the cellular proliferation and motility. CONCLUSION: PLGA coated nanoparticles prolong the activity of the loaded drug while retaining the anti-metastatic activity

Fascin overexpression promotes neoplastic progression in oral squamous cell carcinoma

<p>Abstract</p> <p>Background</p> <p>Fascin is a globular actin cross-linking protein, which plays a major role in forming parallel actin bundles in cell protrusions and is found to be associated with tumor cell invasion and metastasis in various type of cancers including oral squamous cell carcinoma (OSCC). Previously, we have demonstrated that fascin regulates actin polymerization and thereby promotes cell motility in K8-depleted OSCC cells. In the present study we have investigated the role of fascin in tumor progression of OSCC.</p> <p>Methods</p> <p>To understand the role of fascin in OSCC development and/or progression, fascin was overexpressed along with vector control in OSCC derived cells AW13516. The phenotype was studied using wound healing, Boyden chamber, cell adhesion, Hanging drop, soft agar and tumorigenicity assays. Further, fascin expression was examined in human OSCC samples (N = 131) using immunohistochemistry and level of its expression was correlated with clinico-pathological parameters of the patients.</p> <p>Results</p> <p>Fascin overexpression in OSCC derived cells led to significant increase in cell migration, cell invasion and MMP-2 activity. In addition these cells demonstrated increased levels of phosphorylated AKT, ERK1/2 and JNK1/2. Our in vitro results were consistent with correlative studies of fascin expression with the clinico-pathological parameters of the OSCC patients. Fascin expression in OSCC showed statistically significant correlation with increased tumor stage (<it>P </it>= 0.041), increased lymph node metastasis (<it>P </it>= 0.001), less differentiation (<it>P </it>= 0.005), increased recurrence (<it>P </it>= 0.038) and shorter survival (<it>P </it>= 0.004) of the patients.</p> <p>Conclusion</p> <p>In conclusion, our results indicate that fascin promotes tumor progression and activates AKT and MAPK pathways in OSCC-derived cells. Further, our correlative studies of fascin expression in OSCC with clinico-pathological parameters of the patients indicate that fascin may prove to be useful in prognostication and treatment of OSCC.</p

Pentoxifylline modulates cell surface integrin expression and integrin mediated adhesion of B16F10 cells to extracellular matrix components

Our previous studies demonstrated that Pentoxifylline (PTX), a phosphodiesterase inhibitor could inhibit the lung homing of B16-F10 melanoma cells in C57BL/6 mice. In this study we have looked at the effect of PTX on cell surface integrin expression and integrin mediated adhesion of B16-F10 melanoma cells. B16F10 cells treated with PTX when injected through the tail vein of mice showed a 75% reduction in pulmonary nodules as compared to control untreated cells. PTX brought about a significant reduction in the integrin mediated adhesion of F10 cells to Fibronectin and Vitronectin (58.75% + 3.4 S.E and 60% + 1.7 S.E respectively if control was considered as 100 %). This inhibition in adhesion was evident upto 4 hours only and treatment for 24 hours brought about an increase in adhesion (135.5 % + 0.5 S.E). Flow cytometric analysis showed higher surface expressions of αv, α5 and αIIb integrin subunits in B16-F10 as compared to the low metastatic cell line B16-F1 suggesting a role for these integrins in determining the metastatic potential. PTX brought about a significant decrease in the cell surface expression of α5, αIIb and β1integrin subunits but not that of the αv subunit on B16-F10 cells. PTX also brought about a reduction in the total cellular protein levels of β1 and αv integrin subunits. Various isoforms of Protein Kinase C (PKC) has been shown to regulate integrin expression, localization and activity. Hence we looked at the effect of PTX on total cellular PKC activity. PTX brought about a significant reduction in total cellular PKC activity (82.66 + 0.593). Collectively our results indicate that the antimetastatic action of PTX is mediated, at least in part through its effects on adhesion and the surface expression of specific integrin receptors

Role of STAT3 in Cancer Metastasis and Translational Advances

Signal transducer and activator of transcription 3 (STAT3) is a latent cytoplasmic transcription factor, originally discovered as a transducer of signal from cell surface receptors to the nucleus. It is activated by tyrosine phosphorylation at position 705 leading to its dimerization, nuclear translocation, DNA binding, and activation of gene transcription. Under normal physiological conditions, STAT3 activation is tightly regulated. However, compelling evidence suggests that STAT3 is constitutively activated in many cancers and plays a pivotal role in tumor growth and metastasis. It regulates cellular proliferation, invasion, migration, and angiogenesis that are critical for cancer metastasis. In this paper, we first describe the mechanism of STAT3 regulation followed by how STAT3 is involved in cancer metastasis, then we summarize the various small molecule inhibitors that inhibit STAT3 signaling

Role of tumor cell surface lysosome-associated membrane protein-1 (LAMP1) and its associated carbohydrates in lung metastasis

Purpose: Expression of lysosome-associated membrane protein-1 (LAMP1) on the surface correlates with metastatic potential of B16 melanoma cells. Downregulation of their expression in high metastatic (B16F10) cells reduced their surface expression and metastatic potential. Present investigations explore if overexpression of LAMP1 on the surface of low metastatic (B16F1) cells augment their metastatic ability, and if so, how? Methods: B16F1 cells were transduced with lentiviral vector carrying mutant-LAMP1 (Y386A) (mutLAMP1). Surface expression of LAMP1 and carbohydrates was analyzed by flow cytometry, immunofluorescence and/or immunoprecipitation and Western blotting. Cell spreading and motility were assessed on components of extracellular matrix (ECM) (fibronectin) and basement membrane (BM) (matrigel), and galectin-3-coated coverslips/plates. Metastatic potential was assessed using experimental metastasis assay. Results: Pre-incubation with anti-LAMP1 antibodies significantly reduced lung metastasis of B16F10 cells. Overexpression of mutLAMP1 significantly increased its surface expression on B16F1 cells, resulting in increased cellular spreading and motility on fibronectin and matrigel. LAMP1 is the major carrier of poly-N-acetyllactosamine (polyLacNAc) on B16F10 cells. However, significantly higher expression of mutLAMP1 had no effect on galectin-3 binding on cell surface or on spreading or motility of cells on galectin-3-coated coverslips/plates. These cells also failed to show any gain in metastatic ability. This could be because LAMP1 from these cells carried significantly lower levels of polyLacNAc in comparison with B16F10 cells. Conclusions: PolyLacNAc on B16F10 cells and galectin-3 on lungs are the major participants in melanoma metastasis. Although surface LAMP1 promotes interactions with organ ECM and BM, carbohydrates on LAMP1 play a decisive role in dictating lung metastasis

Resveratrol inhibits type II phosphatidylinositol 4-kinase: a key component in pathways of phosphoinositide turn over

Resveratrol has anti-inflammatory, cardio protective and cancer chemopreventive properties. The molecular targets for resveratrol in early signaling cascades are not well understood. Resveratrol inhibits type II PtdIns 4-kinase but not PtdIns 3-kinase activity in vitro. Resveratrol directly binds to the enzyme with a Kd of 7.2 μM. Kinetic studies show that resveratrol competes with PtdIns binding. Inhibition of PtdIns 4-kinase activity by resveratrol/phenylarsine oxide reduces Jurkat cell adhesion to matrigel/fibronectin coated surfaces, suggesting a role for type II PtdIns 4-kinase in lymphocyte infiltration to the sites of inflammation.© Elsevie

Resveratrol inhibits type II phosphatidylinositol 4-kinase : a key component in pathways of phosphoinositide turn over

Resveratrol has anti-inflammatory, cardio protective and cancer chemopreventive properties. The molecular targets for resveratrol in early signaling cascades are not well understood. Resveratrol inhibits type II PtdIns 4-kinase but not PtdIns 3-kinase activity in vitro. Resveratrol directly binds to the enzyme with a Kd of 7.2 μM. Kinetic studies show that resveratrol competes with PtdIns binding. Inhibition of PtdIns 4-kinase activity by resveratrol/phenylarsine oxide reduces Jurkat cell adhesion to matrigel/fibronectin coated surfaces, suggesting a role for type II PtdIns 4-kinase in lymphocyte infiltration to the sites of inflammation

Type II phosphatidylinositol 4-kinase β is an integral signaling component of early T cell activation mechanisms

The early signaling events in T cell activation through CD3 receptor include a rapid change in intra cellular free calcium concentration and reorganization of actin cytoskeleton. Phosphatidylinositol 4-kinases (PtdIns 4-kinases) are implicated as key components in these early signaling events. The role of type II PtdIns 4-kinase β in CD3 receptor signaling was investigated with the help of short hairpin RNA sequences. Cross-linking of CD3 receptors on Jurkat T Cells with monoclonal antibodies showed an early increase in type II PtdIns 4-kinase activity and co-localization of type II PtdIns 4-kinase β with CD3 ζ. Transfection of Jurkat T Cells with shRNAs inhibited CD3 receptor mediated type II PtdIns 4-kinase activation with a concomitant reduction in intra cellular calcium release, suggesting a role for type II PtdIns 4-kinase β in CD3 receptor signal transduction. Knock-down of type II PtdIns 4-kinase β with shRNAs also correlated with a decrease in PtdIns 4-kinase activity in cytoskeleton fractions and reduced adhesion to matrigel surfaces. These results indicate that type II PtdIns 4-kinase β is a key component in early T cell activation signaling cascades

Growth pattern w.r.t the initial tumor volume.

<p>Growth pattern w.r.t the initial tumor volume.</p