胃泌素释放肽DNA疫苗抑制EMT6乳腺癌生长的实验研究

目的：观察胃泌素释放肽（GRP）DNA疫苗对EMT6小鼠乳腺癌生长的抑制作用。方法：将构建的GRP DNA疫苗pCR3.1-VS-HSP65-TP-GRP6-M2肌肉注射免疫BALB/c雌性小鼠,2周1次,共5次。采用ELISA法对小鼠的血清中抗GRP-IgG类抗体进行检测。最后一次免疫后第2周,接种EMT6小鼠乳腺癌细胞。于肿瘤细胞接种后d14,处死全部动物,称量肿瘤的质量和测量肿瘤的体积。并对瘤组织进行常规HE染色。结果：pCR3.1-VS-HSP65-TP-GRP6-M2免疫BALB/c小鼠,可诱导抗GRP-IgG类抗体的产生。并对随后的EMT6肿瘤细胞攻击有显著的抑制作用（P〈0.01）,抑瘤率为46.53%。病理学检查结果显示,GRP DNA疫苗成功地激发了宿主的抗肿瘤免疫反应;与pCR3.1-VS-HSP65-TP对照组相比,GRP DNA疫苗免疫组小鼠EMT6肿瘤组织浸润性下降。结论：GRP DNA疫苗显著抑制EMT6乳腺癌生长,为此类疫苗应用研究奠定了基础。

Suppressing effect of gastrin-releasing peptide DNA vaccine on EMT6 breast cancer growth

AIM:To observe the inhibiting effect of the GRP DNA vaccine on EMT6 breast cancer tissue. METHODS:Female BALB/c mice were immunized intramuscularly with GRP DNA vaccine pCR3.1-VS-HSP65-TP-GRP6-M2 5 times at 2-weekly intervals. The specific anti-GRP antibody was detected by ELISA method .Two weeks after the last immunization,tumor challenge experiments were performed by using EMT6. After 14 d of challenge experiments, all mice were killed and tumors were weighted. Histological analysis of tumor tissue was carried out with HE staining. RESULTS:The specific anti-GRP antibodies were detected in the antiserum of the female BALB/c mice immunized with pCR3.1-VS-HSP65-TP-GRP6-M2 DNA vaccine. It showed that EMT6 tumor growth in mice of GRP DNA vaccine group was obviously suppressed (P<0.01) compared with that in pCR3.1-VS-HSP65-TP or saline control group, with tumor inhibitory rate of 46.53%. Histological analysis showed that GRP DNA vaccine successfully induced anti-tumor immune responses in vivo, and, the invasiveness of EMT6 tumor tissues was markedly decreased in mice of GRP DNA vaccine group compared with that in pCR3.1-VS-HSP65-TP control group. CONCLUSION: GRP DNA vaccine can significantly suppress the growth of EMT6 breast cancer in vivo, which lays a basis for further research.