Experimental study of 32P-CP-PLLA microparticle on human pancreatic carcinoma in nude mice / 中华放射医学与防护杂志

ABSTRACT

Objective To study the therapeutic and toxic effects of 32 P-chromic phosphate-poly (L-lactic) acid (32p-CP-PLLA) microparticle intratumoral administration into BALB/c nude mice bearing BxPc-3 human pancreatic carcinoma.Methods Twenty four nude mice bearing tumors were injected with 0,9.3,18.5 and 37.0 M Bq 32p-CP-PLLA microparticle,respectively.The relative tumor growth rates were observed every day,and white blood cells,platelets and body weight were measured.At 14 d after administration,the tumors were removed,histological examination and immunohistochemical analysis were performed.Results The relative tumor growth rates of each treatment group was lower than 40％.Histological examination showed the degenerative necrosis at the site nearby the mircoparticle.Immunohistochemical analysis showed that the Microvessel density (MVD) and the expression of Bcl-2 in treated group were lower than those in control group.In contrast,the expression of bax in treated group were higher than those in control group.The ratio of Bcl-2/Bax protein significantly decreased in the treatment group,which were 3.83 ± 0.43,0.47 ± 0.13,1.10 ± 0.32,2.19 ± 0.57 for 0,9.3,18.5 and 37.0 MBq 32 P-CP-PLLA microparticle,respectively ( t =2.36 - 2.77,P ＜ 0.05).MVD were 31.2 ± 2.3,23.8 ± 1.5,14.8 ±0.8,11.0 ± 1.2,respectively.Dose dependence was observed in both HE and IHC staining after 14 d treatment ( t =2.30 - 2.57,P ＜ 0.05 ).Conclusions Intratumoral injection of 32p-CP-PLLA microparticle might be a safe,easy and effective radionuclide interventional therapy for pancreatic carcinoma.