Inhibition of human glioma U251 cells growth in vitro and in vivo by hydroxyapatite nanoparticle-assisted delivery of short hairpin RNAs against SATB1

Abstract

Special AT-rich sequence-binding protein-1 (SATB1) has been reported to be over-expressed in many human tumors and knockdown of SATB1 can inhibit tumor growth. The present study was designed to determine the role of SATB1 in the growth of human glioma U251 cells using the plasmid-based SATB1 short hairpin RNA (shRNA) delivered by hydroxyapatite nanoparticles in vitro and in vivo. The in vitro growth, invasion and angiogenesis assays of human glioma U251 cells were done. U251 cells tumor blocks were transplanted into the nude mice. CaCl2-modified hydroxyapatite nanoparticles carrying shRNA-SATB1 plasmids were injected into the tumors. The apoptosis of the tumor U251 cells was examined with TUNEL assay and flow cytometer (FCM). The tumor growth and immunohistochemistry were measured. The expression level of SATB1 mRNA was investigated by RT-PCR. The expression levels of SATB1, Cyclin D1, MMP-2, VEGF, Bax and Caspase-9 protein were determined by western blot analysis. The results showed that hydroxyapatite nanoparticles-delivered shRNA-SATB1 could significantly inhibit the growth, invasion and angiogenesis of U251 cells in vitro and the growth of U251 cells in vivo. FCM results showed that Nano HAP-shRNA-SATB1-induced apoptosis (up to 67.8 %). SATB1 expression was strongly down-regulated in the tumor U251 cells. Cyclin D1, MMP-2 and VEGF were also down-regulated in the tumor tissues that also displayed significant increased in Bax expression and Caspase-9 activity. These results show that Nano HAP-shRNA-SATB1 can inhibit the growth of human glioma U251 cells in vitro and in vivo, and hydroxyapatite nanoparticles can be used for the in vitro and in vivo delivery of plasmid-based shRNAs into U251 cells.

Functional relevance of SATB1 in immune regulation and tumorigenesis

“…Since the discovery of SATB1, its role in the pathogenesis of various cancers has been investigated. Importantly, upregulation of SATB1 has been shown to promote many pathological features across a wide range of cancers [38,39] including breast [1,[40][41][42], colorectal [2,[43][44][45], lung [46,47], nasopharyngeal [48], oesophageal [3,49,50], gastric [51,52], pancreatic [53,54], ovarian [32,55,56], liver [57][58][59], prostate [60][61][62][63], bladder [64,65], and brain [66][67][68][69][70]. In most cancers, the SATB1 expression is positively associated with increased tumour size, lymph node involvement and metastasis [71,72], tumour progression [1,2], poor prognosis [50,56] and reduced overall survival [49,54].…”

Monoclonal Antibody-Targeted Fluorescein-5-isothiocyanate-Labeled Biomimetic Nanoapatites: A Promising Fluorescent Probe for Imaging Applications

“…For these reasons, Aps have been widely used as vehicles for different types of molecules such as DNA for the expression of exogenous and possibly therapeutic genes , or RNA in the form of siRNA to silence or interfere with specific genes. − Proteins have also been successfully coupled. ,− Additionally, Aps have been used as a drug delivery system, for example, for antibiotics and chemotherapeutics. ,− …”