Xenogen ivis lumina system

For the semi-quantitative analysis of in vivo photon emission, animals were injected i.p. with 80 mg/kg of luciferin (Beetle Luciferin Potassium Salt; Promega, Madison, WI, USA) 15 min prior the imaging session. For the imaging, mice were anaesthetized using isofluorane (Isofluorane-Vet; Merial, Lyon, France) and kept under anesthesia during the 5 minutes of the session carried out with a CCD camera: both ventral and dorsal acquisition (Xenogen IVIS Lumina System; Caliper, PerkinElmer company). Photon emission in selected body areas was measured using the Living Image Software (Caliper, PerkinElmer company). The analysis was done in ventral view: whole body, thymus, hepatic area, abdomen, limbs, vagina and in dorsal view in wound area and expressed as photon/second/cm2/steradiant (p/s/cm2/sr).

The 4‐5‐week‐old BALB/c female nude mice were provided by Vital River Laboratory Animal Technology Co., Ltd (Beijing, China) and randomly divided into 16 groups. Mice were given subcutaneous injection of an equal number (5×10⁶) of HGC‐27/R or MKN‐45/R cells via left armpits. This study determined tumor volume (V) by the formula V = 0.5 × L × W². From day 7 post‐inoculation, tumor diameter and width were measured every 3 days until the xenograft volume had reached 200 mm³. Animals were given subsequent injection of PBS, FAM‐si‐TMEM44‐AS1 only, CGE, or CGE/FAM‐si‐TM4M44‐AS1 into tail vein (n = 3 in each group). Six hours post‐injection, these mice were euthanized, the organs isolated, and the complex biodistribution examined using Xenogen IVIS Lumina system (IVIS spectrum, PerkinElmer). Next, mice were administered equal volumes of PBS, CGE, siRNA, CGE/siRNA (half with and half without 5‐FU treatment [10 mg kg⁻¹, intraperitoneal injection]) once every 3 d via the tail vein. Tumor volumes were measured weekly. After treatment for 35 d, all animals were subject to euthanasia, followed by collection of tumors, organs, and blood serum. All the animal studies gained approval from the Institutional Animal Care and Use Committee of the First Affiliated Hospital, Sun Yat‐sen University. The animal procedures were carried out in line with guidelines of the National Institutes of Health.