Figure 2.

HXR9 inhibits esophageal squamous cell carcinoma cell proliferation and retards tumor growth in vivo. A, KYSE70, KYSE150, KYSE450 and HEEC (normal human esophagus epithelial cell) were seed in 96‐well plates, and then treated for 24 h with gradient concentrations of HXR9 or CXR9. Cell viability was assessed using CCK‐8 staining. Results are presented as percentage of viable cells (mean ± SEM), averaged from three independent experiments, each with four replicates. HXR9 inhibited proliferation of KYSE70, KYSE150 and KYSE450 compared to HEEC; all cell lines tested did not show apparent cytotoxicity for CXR9. B, KYSE70, KYSE150, KYSE450 were treated with HXR9 or CXR9 for 8 h prior to seeding in 6‐well plates. After 2 weeks, obtained colonies were visualized and counted. C, HXR9 treatment inhibited PI3K‐AKT pathway activation in all cell lines tested. Densitometry quantification of PI3K and AKT expression is presented. D, KYSE70 and KYSE150 cells were s.c. injected into the right groin of nude mice. When average tumor volume reached 100 mm³ for KYSE70 and 200 mm³ for KYSE150, mice were given an initial dose of HXR9 of 100 mg/kg (i.v. or injected directly into tumors), followed by twice weekly treatments at 10 mg/kg. Tumor volume was measured every 2–3 days. Tumor growth curves indicated that HXR9 slowed down tumor growth significantly compared to CXR9, and mice given HXR9 showed significant tumor volume reduction from day 6. However, the HXR9‐treated mice did not suffer greater weight loss. ***P < 0.05