PRELIMINARY STUDIES ON BRAIN TARGETING OF INTRANASAL ATOMOXETINE LIPOSOMES

Objective: The objective of the present study was to evaluate the enhancement in brain uptake of liposomes containing atomoxetine (ATX-Lipo) for intranasal delivery in the management of Attention Deficit Hyperactivity Disorder (ADHD).Methods: ATX-Lipo and ATX mucoadhesive liposomes (ATX-Muco Lipo) with and without a vasoconstrictor phenylephrine (PHE) were prepared by lipid film hydration method and characterized for physicochemical parameters. Biodistribution and pharmacokinetic evaluation of ATX-Lipo in the brain and blood of Sprague Dawley rats following intranasal (i. n.) and intravenous (i. v.) administrations were examined using optimized technetium-labeled ([99]m Tc-labeled) atomoxetine formulations. Gamma scintigraphy imaging was performed in Sprague Dawley rats.Results: ATX-Lipo and ATX-Muco Lipo were found to be stable with average particle size of 404.35±1.86 nm and 510.50±1.22 nm respectively.[99]mTc tagged ATX-Lipo, ATX-Muco Lipo, ATX+PHE-Muco Lipo and ATX solution were found to be stable and suitable for in vivo studies. On comparing ATX concentrations after i. n. administrations of ATX-Lipo, ATX-Muco Lipo and ATX+PHE-Muco Lipo and i. v. administration of ATX-Lipo, brain/blood uptake ratios (BBR) at 30 min were found to be 0.161, 1.255, 0.331, and 0.003 respectively. These results revealed effective brain targeting following i. n. administration of mucoadhesive ATX liposomes. Higher drug targeting efficiency (% DTE) and direct transport percentage (%DTP) for mucoadhesive liposomes indicated considerable brain targeting from ATX-Muco liposomes. Gamma scintigraphy imaging of the rat brain conclusively demonstrated the greater extent of transport of atomoxetine by ATX+PHE-Muco Lipo (i. n.), when compared with ATX solution (i. n.) into the rat brain.Conclusion: This preliminary investigation demonstrates a considerable extent of transport of ATX into the brain through i. n. ATX+PHE-Muco Lipo, which may prove to be a new platform for better management of ADHD.Keywords: Intranasal delivery, Brain targeting, Mucoadhesive liposomes, Vasoconstrictor, Radiolabeling, Drug targeting efficiency, Direct transport percentage, Gamma scintigraphy

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

Loss of keratin 8 phosphorylation leads to increased tumor progression and correlates with clinico-pathological parameters of OSCC patients.

BACKGROUND: Keratins are cytoplasmic intermediate filament proteins expressed in tissue specific and differentiation dependent manner. Keratins 8 and 18 (K8 and K18) are predominantly expressed in simple epithelial tissues and perform both mechanical and regulatory functions. Aberrant expression of K8 and K18 is associated with neoplastic progression, invasion and poor prognosis in human oral squamous cell carcinomas (OSCCs). K8 and K18 undergo several post-translational modifications including phosphorylation, which are known to regulate their functions in various cellular processes. Although, K8 and K18 phosphorylation is known to regulate cell cycle, cell growth and apoptosis, its significance in cell migration and/or neoplastic progression is largely unknown. In the present study we have investigated the role of K8 phosphorylation in cell migration and/or neoplastic progression in OSCC. METHODOLOGY AND PRINCIPAL FINDINGS: To understand the role of K8 phosphorylation in neoplastic progression of OSCC, shRNA-resistant K8 phospho-mutants of Ser73 and Ser431 were overexpressed in K8-knockdown human AW13516 cells (derived from SCC of tongue; generated previously). Wound healing assays and tumor growth in NOD-SCID mice were performed to analyze the cell motility and tumorigenicity respectively in overexpressed clones. The overexpressed K8 phospho-mutants clones showed significant increase in cell migration and tumorigenicity as compared with K8 wild type clones. Furthermore, loss of K8 Ser73 and Ser431 phosphorylation was also observed in human OSCC tissues analyzed by immunohistochemistry, where their dephosphorylation significantly correlated with size, lymph node metastasis and stage of the tumor. CONCLUSION AND SIGNIFICANCE: Our results provide first evidence of a potential role of K8 phosphorylation in cell migration and/or tumorigenicity in OSCC. Moreover, correlation studies of K8 dephosphorylation with clinico-pathological parameters of OSCC patients also suggest its possible use in prognostication of human OSCC