ABSTRACT
MicroRNAs (miRNAs or miRs) are small noncoding RNAs derived from genome to control target gene expression. Recently we have developed a novel platform permitting high-yield production of bioengineered miRNA agents (BERA). This study is to produce and utilize novel fully-humanized BERA/miR-328-3p molecule (hBERA/miR-328) to delineate the role of miR-328-3p in controlling nutrient uptake essential for cell metabolism. We first demonstrated successful high-level expression of hBERA/miR-328 in bacteria and purification to high degree of homogeneity (>98%). Biologic miR-328-3p prodrug was selectively processed to miR-328-3p to suppress the growth of highly-proliferative human osteosarcoma (OS) cells. Besides glucose transporter protein type 1, gene symbol solute carrier family 2 member 1 (GLUT1/), we identified and verified large neutral amino acid transporter 1, gene symbol solute carrier family 7 member 5 (LAT1/) as a direct target for miR-328-3p. While reduction of LAT1 protein levels by miR-328-3p did not alter homeostasis of amino acids within OS cells, suppression of GLUT1 led to a significantly lower glucose uptake and decline in intracellular levels of glucose and glycolytic metabolite lactate. Moreover, combination treatment with hBERA/miR-328 and cisplatin or doxorubicin exerted a strong synergism in the inhibition of OS cell proliferation. These findings support the utility of novel bioengineered RNA molecules and establish an important role of miR-328-3p in the control of nutrient transport and homeostasis behind cancer metabolism.
ABSTRACT
Several methodologies could be used to characterize vegetable oil besides estimating thermal modification provided by high temperatures. These techniques are used as a proper tool to determine compositional and functional analysis of food ingredients and finished products. In general, vegetable oils are extracted from seeds like the rapeseed (canola oil) soybean (soybean oil), among others. In the present study vegetable oils such as canola and soybean were heated at a temperature of 100°C from 1h up to 28 h and the degraded products were measured to assess the oil stability at temperature. The determination of acid number, peroxide value and iodine number by chemical analysis was carried out for the estimation of the oxidative heat stability of these oils. Ultravioletvisible spectroscopy strategy was also used to better comprehend this phenomenon, since it greatly improve the performance of measurements, in order to step up sensitivity. The findings demonstrated that vegetable oils thermal deteriorated as seen in the batocromic displacement of the samples heated and increasing the specific absorption in 350 nm. These data were capable to highlight the differences observed in the degree of unsaturation of oils.
Inúmeras metodologias podem ser utilizadas para caracterizar óleos vegetais, além de estimar modificações térmicas ocasionadas por altas temperaturas. Estas técnicas são usadas como ferramentas específicas para determinar a composição e função de ingredientes em alimentos e em produtos finais processados. Em geral, óleos vegetais são extraídos de sementes como a colza ou soja, entre outros. No presente trabalho, óleos vegetais como canola e soja foram aquecidos a temperatura de 100 °C entre 1 e 28 horas e os produtos de degradação foram medidos para avaliar a estabilidade do óleo na temperatura. As determinações da acidez, índice de peróxido e índice de iodo por análises químicas foram realizadas para estimar a estabilidade e a oxidação térmica dos óleos. A espectroscopia ultravioleta visível foi uma estratégia também utilizada para melhor compreender este fenômeno, uma vez que esta técnica aumenta o desempenho nas quantificações e quando se objetiva o incremento na sensibilidade. Os resultados demonstraram a deterioração térmica dos óleos vegetais através do deslocamento batocrômico das amostras aquecidas e o aumento da absorção a 350 nm. Estes dados ressaltam as diferenças observadas no grau de insaturação dos óleos.