Novel Antimitotic Agent SP-1-39 Inhibits Head and Neck Squamous Cell Carcinoma.

Effective management of head and neck cancer (HNC) poses a significant challenge in the field of oncology, due to its intricate pathophysiology and limited treatment options. The most common HNC malignancy is head and neck squamous cell carcinoma (HNSCC). HNSCC treatment includes a combination of surgery, radiation, and chemotherapy. While HNSCC is treatable if diagnosed early, this is often not the case and is considered incurable once in its late stages and metastatic disease has developed. Therapies are also limited once resistant disease has occurred. SP-1-39, a novel colchicine-binding site inhibitor (CBSI), has been recently reported for its potential efficacy in a variety of cancer cell lines including breast, melanoma, pancreatic, and prostate. SP-1-39 also shows abilities to overcome paclitaxel resistance in a paclitaxel-resistant prostate cancer xenograft model. To evaluate the potential of SP-1-39 as a new HNSCC treatment option, herein we systematically performed preclinical studies in HNSCC models using SP-1-39 and demonstrated that, in vitro, SP-1-39 inhibits the proliferation of 2 HNSCC cell lines with low nanomolar IC50 values (1.4 to 2.1 nM), induces HNSCC cell apoptosis in a dose-dependent manner, interferes with migration of HNSCC cells, and leads to HNSCC cell cycle arrest in the G2/M phase. In vivo, SP-1-39 suppresses the primary tumor growth of a Detroit 562 subcutaneous xenograft mouse model in 6- to 8-wk-old, male NSG (NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ) mice, with no detectable cytotoxic effects at a low dose of 2.5 mg/kg. This efficacy of SP-1-39 is better when compared with the treatment using a reference chemotherapy drug, paclitaxel at 10 mg/kg. Collectively, these data demonstrate that SP-1-39 is a promising candidate for further development for more efficacious HNSCC treatment.

Sorción y solubilidad de materiales formulados con resina / Sorption and solubility of several materials formulated with resin

El objetivo de este estudio fue determinar la sorción y solubilidad de cuatro resinas compuestas: Tetric Ceram (Vivadent), Ecusit (DMG), Degufill (Degussa) y Z-250 (3M-Espe); y dos resinas modificadas con poliácido: Luxat (DMG) e Ionosit (DMG). Cinco especímenes circulares (15 mm x 0.85 mm) de cada material fueron preparados y pulidos con discos de carburo de silicio. Los especímenes fueron desecados en una estufa a 37° C hasta que se registró un peso constante (mo) y, posteriormente, se introdujeron en agua destilada a 37° C (m1). Una vez estabilizado su peso fueron desecados nuevamente, colocados en una campana al vacío (60° C, 24 h) y pesados por última vez (m2). El cálculo de la sorción (A) y solubilidad (S) se realizó mediante expresiones matemáticas interrelacionadas: A = m1 - m2/V; S = m0 - m2/ V Los tests de AMOVA y Student Newman Keuls mostraron diferencias en la sorción y solubilidad según el material estudiado (p<0.05). Ionosit presentó los valores más altos de sorción y Tetric Ceram y Ecusit los más bajos. La sorción de Luxat fue más elevada que la de Degufill, pero la de ambos materiales fue similar a la del Z-250. La solubilidad de Ionosit fue también significativamente más alta que la de los demás materiales. Las resinas compuestas evaluadas y Luxat presentaron unos valores de solubilidad similares (AU)

The aim of this study was to determine the sorption and solubility of four resin composites: Tetric Ceram (Vivadent), Ecusit (DMG), Degufill (Degussa) and Z-250 (3M-Espe); and two polyacid-modified resins: Luxat (DMG) and lonosit (DMG). Five discs (15 mm x 0.85 mm) of each material were prepared and ground wet to remove poorly polymerized suface layers. Discs were conditioned in a desiccator (37º C) until a constant weight was achieved using an analytic balance (mo); immersed in distilled water 37º C (m1) and finally into a vacuum oven (60º C, 24 h) and reweighted (m2). Sorption (A) and solubility (S) were calculated: A = m1 - m2 / V; S = mo - m2 / V. ANOVA and SNK tests showed statistical differences among the studied materials. lonosit showed the highest sorption and Tetric Ceram and Ecusit the lowest. Luxat presented higher sorption than Degufill, but both materials showed similar sorption values compared with Z-250. The higher solubility was obtained by lonosit. No statistical differences were found among resin composites and Luxat (AU)

Propiedades mecánicas de resinas compuestas modificadas o no con poliácidos / Mechanical properties of resin composites modified or not with polyacids

Objetivo: Determinar la resistencia a la flexión y el módulo de elasticidad de cinco resinas compuestas: Tetric Ceram, Ecusit, Spectrum TPH, Filtek Z-250, Degufill mineral; y dos resinas modificadas con poliácidos: Luxat e Ionosit. Material y método: Se prepararon cinco muestras de cada material en un molde metálico rectangular (22x2x2 mm). Las muestras fueron polimerizadas, primero en el centro y luego en ambos extremos con una lámpara de luz halógena y después se conservaron en agua a 37° C durante 48 horas. Las muestras se pulieron para eliminar la capa de resina superficial y se sometieron al ensayo de flexión en 3 puntos con una máquina de tracción universal Instron con una velocidad de travesaño del mm/min. Los resultados (MPa) fueron analizados mediante los tests de AMOVA y Student-Newman-Keuls (p<0.05). Resultados: La resistencia a la flexión y el módulo de elasticidad de la resina compuesta modificada con poliácidos Ionosit fueron significativamente menores que los determinados para los demás materiales evaluados (AU)

The aim of this study was to determine the flexural strength and modulus of elasticity of five resin composites: Tetric Ceram, Ecusit, Spectrum TPH, Filtek Z-250, Degufill mineral; and two polyacid-modified resin composites: Luxat e lonosit. Five rectangular specimens of each material were prepared (22x2x2 mm). They were light-cured, first in the middle and after in both extremes, by means of a visible-light curing unit. The specimens were stored in water at 37° C for 48 hours and ground to eliminate the resin layer inhibited by oxygen. Three-point bending test was performed in an universal testing machine (Instron) at a cross-head speed of 1mm/min. Results were expressed in MPa and analysed by ANOVA and Student-Newman-Keuls tests (p<0.05). Flexural strength and modulus of elasticity of the polyacid-modified resin composite, lonosit, were significantly lower than the values obtained for the rest of the materials evaluated (AU)