Assessment of HER2 gene amplification in adenocarcinomas of the stomach or gastroesophageal junction in the INT-0116/SWOG9008 clinical trial

Antitumor effects of cisplatin implants against human gastric cancer in nude mice

AIM: To assess the antitumor effects of cisplatin implants vs common cisplatin injection in a xenograft nude mouse model of human gastric cancer.

METHODS: A xenograft nude mouse model of human gastric cancer was established by subcutaneously injecting SGC7901 cells in Balb/c nude mice. The model mice were divide into four groups randomly: A (intravenous injection of PBS via the tail vein), B (intravenous injection of cisplatin via the tail vein), C (intratumor injection of cisplatin), and D (cisplatin implantation). After drug intervention, tumor weight and volume were calculated. Tumor tissues were observed by HE staining. The protein expression of spleen tyrosine kinase (SYK)/human epidermal growth factor receptor 2 (HER2), phosphate and tension homology deleted on chromsome ten (PTEN)/the sixth variant form of adhesion molecule CD44 (CD44v6) and cysteinyl aspartate specific protease 3 (Caspase3)/Survivin in tumor tissue was detected by immunohistochemistry. Cell apoptosis was detected by flow cytometry.

RESULTS: Sustained-release cisplatin significantly promoted apoptosis, suppressed tumor growth, enhanced the expression of SYK (group D: 73.42 ± 4.92 vs group C: 30.42 ± 3.92, P < 0.05; group B: 14.14 ± 2.84 vs group A: 5.06 ± 2.96, P < 0.05), PTEN (group D: 62.46 ± 4.36 vs group C: 29.82 ± 2.22, P < 0.05; group B: 16.06 ± 4.26 vs group A: 6.44 ± 2.84, P < 0.05) and Caspase3 (group D: 77.58 ± 6.28 vs group C: 31.26 ± 4.76, P < 0.05; group B: 15.24 ± 4.64 vs group A: 10.82 ± 2.72, P < 0. 05), and reduced the expression of HER2 (group D: 16.32 ± 4.82 vs group C: 34.82 ± 7.32, P < 0.05; group B: 45.8 ± 6.60 vs group A: 77.34 ± 9.04, P < 0.05), CD44v6 (group D: 4.60 ± 1.40 vs group C: 10.32 ± 1.72, P < 0.05; group B: 28.10 ± 5.60 vs group A: 69.02 ± 1.52, P < 0.05) and Survivin (group D: 18.42 ± 4.62 vs group C: 31.3 ± 9.50, P < 0.05; group B: 69.66 ± 9.46 vs group A: 84.64 ± 5.04, P < 0.05).

CONCLUSION: Cisplatin implants exert anticancer effects against human gastric cancer in nude mice by promoting apoptosis and altering the expression of SYK, PTEN, Caspase3, HER2, CD44v6, and Survivin.

Effect of cisplatin implantation on human gastric carcinoma xenograft growth in nude mice and tumor expression of SYK and HER2

AIM: To assess the effect of cisplatin implantation on human gastric carcinoma xenograft growth and tumor expression of SYK and HER2 in nude mice, and to discuss the mechanism of action of sustained-release cisplatin.

METHODS: A xenograft model of human gastric carcinoma was established by subcutaneous injection of SGC7901 cells in Balb/c nude mice. The mice were then randomly divided into four groups to receive intravenous injection of PBS (group A), intravenous injection of cisplatin (group B), intratumor injection of cisplatin (group C), and implantation of cisplatin (group D). After drug intervention, tumor weight and tumor inhibition rate were measured. Tumor tissues were observed after HE staining. Expression of SYK/HER2 was detected by immunohistochemsitry. Besides, the cell suspensions prepared from the tumor tissues from the four groups were tested by FCM.

RESULTS: Sustained-release cisplatin could promote apoptosis and suppress tumor growth significantly, and it also could enhance the expression of SYK (group D: 73.42 ± 4.92 vs group C: 30.42 ± 3.92, P < 0.05; group B: 14.14 ± 2.84 vs group A: 5.06 ± 2.96, P < 0.05) and reduce the expression of HER2 (group D: 16.32 ± 4.82 vs group C: 34.82 ± 7.32, P < 0.05; group B: 45.8 ± 6.60 vs group A: 77.34 ± 9.04, P < 0.05).

CONCLUSION: Cisplatin implantation induces tumor cell apoptosis and exerts anticancer function possibly by enhancing the expression of SYK and reducing the expression of HER2.