RESUMEN
Shikonin is a naphthoquinone isolated from the traditional Chinese medicine Lithospermum. It has been used in the treatment of various tumors. However, the effects of shikonin on such diseases have not been fully elucidated. In the present study, we detected the exosome release of a breast cancer cell line (MCF-7) with shikonin treatment and found a positive relationship between the level of secreted exosomes and cell proliferation. We next analyzed miRNA profiles in MCF-7 cells and exosomes and found that some miRNAs are specifically sorted and abundant in exosomes. Knockdown of the most abundant miRNAs in exosomes and the MCF-7 proliferation assay showed that miR-128 in exosomes negatively regulates the level of Bax in MCF-7 recipient cells and inhibits cell proliferation. These results show that shikonin inhibits the proliferation of MCF-7 cells through reducing tumor-derived exosomal miR-128. The current study suggests that shikonin suppresses MCF-7 growth by the inhibition of exosome release.
Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Proliferación Celular/efectos de los fármacos , Naftoquinonas/administración & dosificación , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/genética , Exosomas/efectos de los fármacos , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Células MCF-7 , MicroARNs/biosíntesisRESUMEN
The use of smokeless tobacco (ST) is growing rapidly and globally. The consumption of ST is associated with an increased risk for developing chronic diseases, such as diabetes, hypercholesterolemia, and myocardial infarction, and has led to many public health problems. It is very important to access the toxicity of ST. This experiment presents data from 184-day toxicology studies in Sprague-Dawley (SD) rats designed to characterize the chronic effects of a smokeless tobacco extract (STE). The control group and treatment groups were matched for a range of nicotine levels. Animals were given STE by oral gavage with doses of 3.75 (low-dose), 7.50 (mid-dose) and 15.00 (high-dose) mg · nicotine/kg body weight/day for 184 days, followed by 30 days for recovery. Variables evaluated included body weights, feed consumption, clinical observations, clinical and anatomic pathology (including organ weights), and histopathology. Decreased body weights and organ weights (heart, liver and kidney) were found in animals in the mid-dose and high-dose groups. STE also showed moderate and reversible toxicity in esophagus, stomach, liver, kidney and lung.