The nude mouse as a model for the study of human pancreatic cancer.

The purpose of this study was to characterize an in vivo model of human pancreatic cancer suitable for chemotherapy and immunotherapy studies. In this study we report a 2-year experience in growing the MIA PaCa-2 (CRL 1420) human pancreatic cancer cell line in 92 adult (8 weeks old) and 256 young (3-6 weeks old) nude mice. Ten million tumor cells were transplanted into orthotopic (duodenal lobe of the pancreas) and/or heterotopic positions (hepatic and subcutaneous) and data on operative mortality, effect of total body irradiation (TBI), tumor growth kinetics, and survival are presented comparing the two age groups. Operative mortality was due to anesthetic intolerance which was higher in the young mouse population (13.4% versus 5.7%). Adult mice withstood TBI (500 rad) without mortality but young mice were highly sensitive to radiation damage and their maximum tolerated dose (LD50) was 425-450 rad. Subcutaneous tumors grew significantly more often in young compared to adult animals (97.9% versus 69%) and this finding was not affected by TBI (96.9% versus 75%), though tumors did appear more quickly after TBI. An average of 14.7 +/- 2.8 days was required for the subcutaneous tumors to become macroscopically apparent in the adult population compared with 3.1 +/- 0.8 days in the young mice. The largest subcutaneous tumor diameter 28 days following tumor implant averaged 9.3 +/- 0.6 mm in the young animals and 5.5 +/- 1.7 mm in the adult population (P less than 0.01). Treatment of young mice with human recombinant interleukin-2 (IL-2) (10,000 Units twice a day for 28 days) produced a 27% decrease in tumor growth. This effect was abolished by prior irradiation of the young mice with 375 rad TBI. Pancreatic tumor growth also occurred more consistently in young than in adult animals (91.2% versus 64.3%) and irradiation did not affect pancreatic tumor take in either group. Occasionally intrapancreatic tumor growth was associated with liver metastases in animals that were killed after 28 days (17.8% in young and 22.2% in adult animals). However, when more than 45 days elapsed before sacrificing the animals, the incidence of hepatic metastases increased to 57.1%. This was slightly less than the incidence of hepatic lesions found after direct injection of cancer cells into the liver by portal vein injection (71.4%). Direct extension of tumor into surrounding tissues was common with frequent involvement of the duodenum (83.7%), kidneys (30.6%), and other intraabdominal organs (43.9%). Survival was significantly longer in adult compared to young mice.(ABSTRACT TRUNCATED AT 400 WORDS)

The in vivo distribution of human peripheral blood lymphocytes and lymphokine-activated killer cells adoptively transferred in human pancreatic cancer-bearing nude mice.

In this study we evaluated human pancreatic cancer xenotransplanted into nude mice as a model suitable for adoptive immunotherapy studies. A pancreatic cancer cell line (MIA PaCa-2) was chosen and its growth in nude mice and sensitivity to lysis by human lymphokine-activated killer (LAK) cells were characterized. This line grew in 96% of the cases when young (4- to 6-week-old) Swiss/NIH nude mice were used. The line was highly sensitive to lysis by LAK cells in a standard chromium-51 release assay (67.8%), similarly to other cell lines known to be highly sensitive, such as K562 (75.6%) and the melanoma cell line SU.102 (53.1%). To assess their in vivo distribution, human peripheral blood lymphocytes (PBLs) and LAK cells were adoptively transferred into nude mice after labeling with indium-111 oxine. The results of this study show that adoptively transferred PBLs and LAK cells localize in this heterologous system as they do in autologous systems. PBLs are taken up mostly by the liver and spleen. The percentage of the administered dose of radioactivity taken up corrected by weight (percent dose per gram tissue) is 64.3 +/- 15.6%d/gm (liver) and 43.5 +/- 9.5%d/gm (spleen). LAK cells are taken up by liver (43.2 +/- 5.3%d/gm) and spleen (28.0 +/- 4.9%d/gm) but also localize significantly more than PBLs in other organs such as lungs (12.9 +/- 3.5%d/gm vs 1.4 +/- 0.3%d/gm, p less than 0.01), kidneys (19.1 +/- 2.1%d/gm vs 6.3 +/- 1.5%d/gm, p less than 0.001), and pancreatic tumors growing in orthotopic position (1.93 +/- 0.36%d/gm vs 0.56 +/- 0.06%d/gm, p less than 0.05). When the nude mice are pretreated with human recombinant tumor necrosis factor, localization of LAK cells compared with PBLs is even further enhanced both in tumors implanted in the pancreas (3.1 +/- 0.5%d/gm vs 0.56 +/- 0.06%d/gm, p less than 0.01) and in the subcutis (12.5 +/- 8.3%d/gm vs 0.95 +/- 0.29%d/gm, p less than 0.001).

A new human pancreatic carcinoma cell line developed for adoptive immunotherapy studies with lymphokine-activated killer cells in nude mice.

A human tumor cell line designated SU.86 has been established from a moderate-to-poorly differentiated pancreatic carcinoma of ductal origin specifically for adoptive immunotherapy studies. This line was characterized as to its ability to be lysed in vitro by autologous and allogeneic lymphokine-activated killer (LAK) and natural killer cells and to grow in nude mice. SU.86 has been growing continuously in cell culture for more than 100 passages since 22 September 1986. Transplantation orthotopically and heterotopically into athymic Swiss nude mice showed that tumor take was 100% in the orthotopic position when young (4 to 6 wk old) mice were used and 0% when adult (8 wk old) mice were used (P = 0.004). In the heterotopic position (subcutaneous), tumor take was 100% in neonate (2 to 3 wk old) and young mice and 50% in adults. The rate of tumor growth was inversely correlated with age (P less than 0.001). The histologic pattern is similar to that observed in most human pancreatic carcinomas with pseudoglandular structures and frequent mitotic figures. SU.86 has a doubling time of 77 h in vitro and produces carcinoembryonic antigen, 594 ng/10(6) cells in 3 d. Chromosomal analysis shows heterogeneity with two notable cell subpopulations. The cell line is moderately sensitive to lysis by LAK cells in a standard, 4-h chromium-51 release assay (35.4 +/- 4.0%). When grown together with LAK cells in vitro, it is lysed completely in culture in 8 to 15 d, depending on the serum concentration.