ABSTRACT
BACKGROUND: Nanosphere, an ideal nonviral gene delivery vector, is not excellence of immunogenicity and oncogenicity. Nanotechnology and gene interference are used to block hypoxia-inducible factor 1 alpha (HIF-1α) expression in esophageal squamous carcinoma tissue and decrease tolerance of malignant cells to chemotherapeutics. Theoretically, they become effective methods to inhibit malignant cell growth of esophageal squamous carcinoma. OBJECTIVE: To study the inhibitory effect of small interference RNA targeting HIF-1α (siRNA-HIF-1α) nanospheres on human esophageal squamous cancer TE-1 cell growth. DESIGN, TIME AND SETTING: Based on in vitro cultured esophageal squamous cancer TE-1 cells, a completely randomized controlled study was performed at the Central Laboratory, the Third Hospital Affiliated to Sun Yat-sen University from January 2007 to December 2008. MATERIALS: siRNA-HIF-1α was synthesized by Shanghai Bioengineering Company; siRNA-HIF-1α nanospheres were prepared using solvent evaporation technique; human esophageal squamous cancer TE cell strain was provided by Shanghai Cell Bank of the Chinese Academy of Sciences. METHODS: TE-1 cells cultured in vitro were assigned into four groups: saline, gene-free nanospheres, siRNA-HIF-1α, and siRNA-HIF-1α nanospheres groups. MAIN OUTCOME MEASURES: HIF-1α mRNA expression was detected by RT-PCR; HIF-1α protein expression was detected by Western blot; apoptosis of TE-1 cells was determined by flow cytometry; TE-1 cell growth was examined by MTT. RESULTS: At 72 hours after treatment, both HIF-1α mRNA expression and HIF-1α protein expression in the siRNA-HIF-1α nanospheres group were significantly less than other three groups (P < 0.01), but apoptotic rate was significantly greater than other three groups (P < 0.01). TE-1 cell growth was remarkably inhibited in the siRNA-HIF-1α nanospheres group, which was significantly different compared with other three groups (P < 0.01).CONCLUSION: siRNA-HIF-1α nanospheres can specifically reduce both HIF-1α mRNA and HIF-1α protein expressions in esophageal squamous carcinoma TE-1 cells, significantly increase tumor cell apoptosis, and remarkably inhibit TE-1 cell growth.