Xenograft Model and Treatments

The SW1990 cells (5 × 10⁶) were suspended in 100 μl serum-free RPMI 1640 and subcutaneously injected into the left upper flank of each mouse (female BALB/c-nu/nu, 4–6 weeks old). Two weeks after the cell injection, in the setting of observable tumors, all mice were randomly allocated to four groups (six per group), including (1) MNS group, (2) CIK group, (3) MNS+CIK combining treatment group, and (4) control group. Mice in the MNS group were only injected intraperitoneally with MNS (20 mg/kg body weight) every other day. CIK group received only intravenously 100 μl (1 × 10⁶ cells) CIK cells. Combining treatment group was administered intraperitoneally with MNS (20 mg/kg body weight) and intravenously with 100 μl (1 × 10⁶ cells) CIK cells, while the control group received 200 μl vehicle material. Tumor volumes were measured before each injection, which was calculated as described: V (cm³) = width² (cm²) × length (cm)/2. Mice were treated every other day for 2 weeks. At the termination of the experiment, the mice were sacrificed by cervical dislocation, and the tumors were weighed immediately after dissection, then subjected to hematoxylin and eosin (H&E) staining and immunohistochemical analysis. Mice were manipulated and housed according to the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. The study was approved by the Committee on the Ethics of Animal Experiments of Chinese PLA General Hospital.