Growth dependent cell proliferation kinetics of a human malignant melanoma grown in nude mice

Summary A human malignant melanoma was grown in nude mice. The tumour showed an exponential growth for several weeks which gradually slowed down, until following week 8 the tumour growth ceased. The reasons for this growth pattern were examined by labelling techniques (PLM, LI). The tumour cell production as quantified by the growth fraction, showed only a moderate reduction which, taken alone, could not explain the growth cessation. The important mechanism seems to be an increased loss of tumour cells during the intermitotic interval. While the loss of cells/h remains constant the total intermitotic cell loss is increased because the cell cycle times are prolonged by 50% from the exponential phase (45 h in week 3) to the plateau phase (66 h in week 8).     

Phorbol esters induce differentiation in human malignant T lymphoblasts

At nanomolar concentrations, phorbol ester, a class of potent tumor promoters, can promote differentiation in the human malignant T-lymphoblastic cell line MOLT-3. The optimal dose for induction, as measured by the increase of the number of cells containing sheep erythrocyte receptors (E-rosette assay), is between 8 and 16 nM 12-O-tetradecanoylphorbol 13-acetate (TPA), although there were significant increases of E-rosette-positive (E⁺) cells at concentrations as low as 1.6 nM TPA. The induction was linear for 4 days, then it reached a plateau. This induction was independent of the cell densities of the cultures, and the viability of the E⁺ cells remained high (95-100%) even after 10 days of culture in the presence of the tumor promoters. The E⁺ cells, when measured with the more stable 2-aminoethylisothiouronium bromide E-rosette assay, indicated that virtually all (75-95%) of the MOLT-3 cells became E⁺ by 4 days in culture. This induction by TPA was also accompanied by a dramatic drop in the plating efficiencies and a reduction in DNA synthesis. Examination of phorbol and other phrobol esters indicated that the ability to induce these cells correlated well with the tumor-promoting activities of these compounds, because only TPA and to a lesser extent phorbol 12,13,-dibenzoate induced E⁺ cells, while phorbol and 4α-phorbol 12,13-didecanoate had no effect. Studies of MOLT-3 cells depleted of E⁺ cells indicated that the induction of E⁺ cells cannot be explained solely on the basis of enrichment or stimulation of the background E⁺ cells in MOLT-3 cultures. Finally, we have shown that TPA also affected another differentiation marker, the loss of the enzyme terminal deoxyribonucleotidyl transferase. Terminal transferase activities and percentages of terminal-transferase-positive cells in these cultures were reduced to as low as 1/10th in 4 days in the presence of 16 nM TPA.     

Establishment of a nude mice model of human monocytic leukemia with CNS and multiorgan extramedullary infiltration

OBJECT: To establish a human monocytic leukemia model with central nervous system infiltration in BALB/c nude mice. METHODS: BALB/c nu/nu mice, pretreated by splenectomy, cytoxan intraperitoneal injection, and sublethal irradiation, were transplanted intravenously with human monocytic leukemic cell line SHI-1. The leukemic cells engrafted in the mice were traced by RT-PCR, histopathological examination, immunohistochemistry and FCM. RESULT: After engraftment of SHI-1 cells in SCI-nu/nu mice, multiple organs were involved and green solid neoplasms were formed in some organs. Paralysis was developed in some mice at both of the rear legs. Histopathological examination found that vertebral and skull bone marrow were replaced by leukemic cells. Leukemic cells penetrated to the surface of vertebrae, forming neoplasm, and entering to the subdural space, but seldom involving in the spinal parenchyma. In the brain, leukemic cells filled in the subdural space and pia-arachnoid, covered the surface of cerebrum, cerebellum and along the virchow-robin space on the surface of pia mater, eventually invading into the brain parenchyma. CONCLUSIONS: SHI-1 cells could engraft in the SCI-nu/nu mice, creating an efficient and reproducible experimental model of central nervous system leukemia (CNSL) and multiorgan infiltration. This experimental model may be useful for studies on the pathogenesis of CNSL.     

Progression of a human B cell chronic lymphocytic leukemia line in nude mice

Subcutaneous (s.c.) inoculation of the 85-4LN subline, derived from a lymph nodal metastasis of the Epstein-Barr virus (EBV) transformed human chronic lymphocytic leukemia (CLL) B cell line, EBV-CLL (1), produced progressively growing lethal tumors in 31/35 nonirradiated (88.6%) and 22/25 (88%) of whole-body irradiated (440 rad) nude mice. In contrast, EBV-CLL(1) could produce progressive tumors only in irradiated nude mice. All 85-4LN cells had Epstein-Barr virus nuclear antigen and reacted with pan B and anti-la antibodies. The morphology and ultrastructural features was consistent with the lymphoblastoid nature of the cells. In all s.c. tumor bearing mice, there was enlargement of the spleen and draining lymph nodes. Karyological studies revealed human cells in the spleen and draining nodes in all the mice investigated. Metastases in nonlymphoid organs were seen in 1/8 irradiated and 8/12 nonirradiated mice. The subline contained 77% cells with 47,XY, +12 and 23% cells with 45,XY karyotype. The clone with trisomy 12 did not have any growth advantage either in s.c. transplants or in splenic/lymph nodal metastases. Treatment with the maximum permissible doses of methotrexate (MTX) or chlorambucil (CBL) revealed xenografts to be more sensitive to MTX than CBL. A clone with a 1g+ marker, i.e., 46,XY,Dup(1) (q11----q32) appeared to be associated with resistance to CBL. We have not seen any previous report on the growth and dissemination of human CLL B cells in nonirradiated nude mice. The 85-4LN subline, thus, provides a model for studying the progression, dissemination and therapeutic response of human CLL-B cells.     

Functional T cells in athymic nude mice.

After passage of spleen cells from nu/nu mice over a nylon wool column, concanavalin A-responsive cells can be detected in the presence of 2-mercaptoethanol, and specific cytotoxic T lymphocytes can be generated without exposure to interleukin 2 (IL-2). The spleen cells of the nu/nu mice born of nu/nu parents and nursed by nu/nu mothers had significantly fewer Thy-1+ T cells and a lesser capacity to generate cytotoxic T lymphocytes than did the conventionally bred nu/nu mice. Nonetheless, such cells were clearly present. IL-2 may act to cause these post-thymic T cells to proliferate. Therefore, it seems inappropriate to consider IL-2 as an inducer of the differentiation of T cells in the absence of thymic influence on the basis of the capacity of IL-2 to induce the appearance of a T-lymphocyte population in nu/nu mice.     

Deoxycytidine kinase-mediated toxicity of deoxyadenosine analogs toward malignant human lymphoblasts in vitro and toward murine L1210 leukemia in vivo.

An inherited deficiency of adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4) produces selective lymphopenia and immunodeficiency disease in humans. Previous experiments have suggested that lymphospecific toxicity in this condition might result from the selective accumulation of toxic deoxyadenosine nucleotides by lymphocytes with high deoxycytidine kinase, levels and low deoxynucleotide dephosphorylating activity. The present experiments were designed to determine if deoxyadenosine analogs which are not substrates for adenosine deaminase might similarly be toxic toward lymphocytes and lymphoid tumors. Two such compounds, 2-chlorodeoxyadenosine and 2-fluorodeoxyadenosine, at concentrations of 3 nM and 0.15 microM, respectively, inhibited by 50% the growth of human CCRF-CEM malignant lymphoblasts in vitro. Each was phosphorylated in intact cells by deoxycytidine kinase accumulated as the nucleoside triphosphate, and inhibited DNA synthesis more than RNA synthesis. Both deoxynucleosides had significant chemotherapeutic activity against lymphoid leukemia L1210 in mice.     

Growth of Mycobacterium leprae in nude mice

Athymic nude mice were introduced in our laboratories in 1982. In this paper results over one year period of nude mice inoculated with small numbers of M. leprae are described. In this study we showed that 1 X 10(4) M. leprae with low numbers of viable bacilli inoculated into hind foot pads of nude mice housed both in vinyl plastic isolators and "clean room" conditions had the ability to grow and reach remarkable levels. There was dissemination of the infection to other uninoculated foot pads by six months.     

Establishment and characterization of liver metastatic model of human hepatoma in nude mice

We succeeded in producing the liver metastatic model of human hepatocellular carcinoma in athymic nude mice.The tumor, which was surgically obtained from a 59-year-old man with macro-trabecular hepatoma, was cut into small pieces and inoculated subcutaneously in athymic BALB/c nude mice. This transplanted tumor showed spontaneous liver metastases in 100% after the 3rd generation. There were also a few metastases in the spleen and lung. The metastatic liver tumors were resected and transplanted subcutaneously in other nude mice and, at present, the 18th generation has been maintained with 100% metastasizing characterization. All mice inoculated with this tumor were dead within 8 weeks due to liver metastases. The expression of intercellular adhesion molecule-1 (ICAM-1) was recognized on this tumor surface, however, a metastasizing capacity of this tumor could not be inhibited by pre-treatment of tumors with antibody against ICAM-1. Human leukocyte antigen (HLA) class I was also recognized, but lymphocyte function-associated antigen-1 (LFA-1) was not recognized. In the serum of tumor-transplanted nude mice or the medium of in vitro tumore culture, IL-1, IL-6 and type IV collagenase were not shown. This tumor also did not show the human platelet-aggregating activity. This spontaneous liver metastatic model was very rare and it was suggested that this model could be a useful tool for investigating the mechanism of liver metastasis of human hepatoma.     

In vivo horizontal oncogenesis by a human tumor in nude mice.

A human mucinous cystadenocarcinoma of the ovary was propagated in nude mice. After cryopreservation of the 3rd-passage xenograft for 4 years, subsequent in vivo transplants showed the emergence of two distinct populations, one resembling the original human adenocarcinoma and the other resembling a spindle-cell sarcoma. These two tumor cell populations were confirmed to be human and murine, respectively, by cytogenetic study, and the epithelial tumor cells were further shown to be of human origin by immunoperoxidase staining of blood group A antigen. Separation of the two tumor cell populations in vitro permitted the independent propagation of the human and murine tumor cells in vitro and in vivo. The murine sarcoma was also capable of growth in ordinary BALB/c mice. These results indicate that human cancer cells can induce malignancy in adjacent, putatively normal, cells of nude mice in vivo.     

An animal model for human cellular immunotherapy: specific eradication of human acute lymphoblastic leukemia by cytotoxic T lymphocytes in NOD/scid mice

Adoptive immunotherapy using in vitro-generated donor-derived cytotoxic T lymphocytes (CTLs) can be effective in the treatment of relapsed leukemia after allogeneic transplantation. To determine effector cell characteristics that result in optimal in vivo antileukemic efficacy, we developed an animal model for human CTL therapy. Nonobese diabetic/severe combined immunodeficiency (NOD/scid) mice were inoculated with either of 2 primary human acute lymphoblastic leukemia (ALL), denoted as SK and OF. Anti-SK and anti-OF CTLs were generated in vitro by repeated stimulation of donor peripheral blood mononuclear cells with either SK or OF cells. Both CTL lines displayed HLA-restricted reactivity against the original targets and non-major histocompatibility class (MHC)-restricted cross-reactivity in vitro. The CTLs were administered intravenously weekly for 3 consecutive weeks to mice engrafted with either SK or OF leukemia. In 3 of 8 SK-engrafted and anti-SK-treated mice, complete remissions were achieved in blood, spleen, and bone marrow. In the remaining 5 animals partial remissions were observed. In 4 of 4 OF-engrafted anti-OF-treated mice partial remissions were observed. The antileukemic effect of specific CTLs was exerted immediately after administration and correlated with the degree of HLA disparity of the donor-patient combination. In cross-combination-treated animals, no effect on leukemic progression was observed indicating that in vivo antileukemic reactivity is mediated by MHC-restricted effector cells. The CTLs, however, displayed an impaired in vivo proliferative capacity. Ex vivo analysis showed decreased reactivity as compared to the moment of infusion. We therefore conclude that the model can be used to explore the requirements for optimal in vivo efficacy of in vitro- generated CTLs.     

Growth of primary human acute leukemia in severe combined immunodeficient mice

Seven populations of human leukaemic cells were implanted i.v. into sublethally irradiated severe combined immunodeficient (scid) mice. Growth of leukaemia was monitored by labelling murine peripheral blood (PB) cells with an anti-HLA monoclonal antibody and flow cytometric analysis. Two of the populations transplanted were fresh acute lymphoblastic leukaemia (ALL) bone marrow (BM) cells which both caused sustained proliferative growth in scid mice. Human cells accounted for up to a mean of 87% of the total nucleated cells (TNC) in the PB of these mice between weeks 12-15. One of these populations was passaged into fresh mice and frank leukaemia was again established. Three populations of cryopreserved acute myeloblastic leukaemia (AML) cells (2 obtained from PB and 1 from BM) and one population of cryopreserved biphenotypic acute leukaemia BM cells, only grew to a maximum of 4% within the 15 week period of the experiment. A cell population from an AML cell line (HL60), however, did engraft and proliferate resulting in a rapid deterioration of these mice between weeks 3-6 when the proportion of human cells accounted for 9% of the TNC in the PB.     

Growth inhibition of human pancreatic cancer cells by cholecystokinin receptor antagonist in tissue culture and in nude mice.

The Human pancreatic carcinoma cell line KP-1N and its clone KP-1NL which has a high rate of liver metastasis were established. Ki-ras DNA point mutation on the codon 12 was found. The growth of KP-1N was stimulated by a physiological range of concentration (10(-11)-10(-10) M) of cholecystokinin and the increase was inhibited by the addition of a cholecystokinin receptor antagonist (CR 1505). Daily injections of CR 1505 (35 mg/kg) diminished the number of tumor colonies in the liver that were formed after an intrasplenic injection of the highly liver metastatic KP-1NL cells. These results suggest that cholecystokinin antagonists may be useful as growth inhibitors for some pancreatic cancer.     

人胃癌裸鼠原位移植模型的生物学行为研究

目的建立人胃癌裸鼠胃壁原位移植瘤模型，并与相应的皮下移植瘤作比较，以探讨宿主器官微环境对胃癌细胞浸润及转移等生物学行为的影响．方法将人胃癌细胞系ＭＧｃ８０３及其克隆株Ｃ１１癌细胞分别接种于裸鼠胃壁及背部皮下，比较原位和皮下移植瘤的成瘤率、生长率、生长方式及浸润、转移等生物学行为，以及体外回复培养后瘤细胞的增殖能力．结果胃壁原位及皮下移植瘤体内成瘤率、生长率及形态学上均无明显不同；其体外增殖能力也无显著性差异．但皮下移植瘤多呈局限性生长，无肝、脾、肾转移，其转移仅限于肺及个别局部淋巴结．胃壁原位移植瘤则浸润破坏胃壁各层组织结构，并直接蔓延到邻近各器官组织．其转移既有经血道至肝、肺、脾、肾等部位，也有经淋巴道至多数局部及远处淋巴结，其淋巴结的转移率较皮下移植瘤有显著增高（Ｐ＜００５）；且多伴有腹、盆腔内广泛种植性转移．结论裸鼠胃壁微环境较皮下组织更适合于人胃癌ＭＧｃ８０３及Ｃ１１移植瘤的浸润及转移的表达，该原位移植瘤模型的恶性生物学行为更接近临床胃癌患者的体内侵袭及转移的实际．     

9-nitro-camptothecin delays growth of U-937 leukemia tumors in nude mice and is cytotoxic or cytostatic for human myelomonocytic leukemia lines in vitro

Abstract: The camptothecin derivatives 9-nitro-camptothecin (9NC) and 9-amino-camptothecin (9AC) inhibit similarly growth of HL-60, KG-1, and U-937 cells in vitro, whereas growth of THP-1 cells is inhibited by 9AC, but not by 9NC. Growth inhibition is accompanied by enlargement of cells which contain one (HL-60, THP-1) or more (KG-1, U-937) nuclei. Flow cytometry studies showed that 9NC-treated HL-60 and U-937 cells accumulate in the S and G² phases of the cell cycle; then they die by apoptosis, with the HL-60 cells being more sensitive than U-937 cells to 9NC. In contrast, 9NC-treated KG-1 and THP-1 cells accumulate in S and G² phases, but resist death by apoptosis. Of the cell lines tested, only U-937 cells xenografted in nude mice generated subcutaneous myeloid tumors, which exhibited a delayed growth in the presence of 9NC. Further, 9NC-treated advanced U-937 tumors regressed temporarily, indicating that U-937 cells consist of 9NC-sensitive and 9NC-resistant populations.     

Hypersensitivity pneumonitis in athymic nude mice. Additional evidence of T cell dependency.

We previously demonstrated that C57 Black/6 mice develop lung lesions similar to human hypersensitivity pneumonitis (HP) by repeated transnasal administration of Thermoactinomyces vulgaris (Tv) antigen. To elucidate the role of T cells in the development of this disease, Tv antigen (90 micrograms/day) was transnasally administered to athymic nude C57 Black/nu/nu (nu) mice and their littermates (+/nu) three times a week for 3 wk. The nude mice developed minimal lung lesions, whereas their thymus-intact littermates (+/nu) showed changes equivalent to those in C57 Black/6. Changes in local inflammatory cell responses were evaluated by bronchoalveolar lavage, and increases in the numbers of lymphocytes and macrophages were significantly less severe in the nude mice than in the +/nu mice. Interestingly, the increase in polymorphonuclear leukocytes 6 h after the last antigen inoculation was equivalently seen in both groups. When spleen-derived T cells (more than 95% Thy-1.2+) from the sensitized +/nu mice were adoptively transferred to nude mice, the HP-like lesions in the recipients were found after Tv antigen challenge. These results suggest that Thy-1.2+ T cell-mediated immunity was necessary for the development of HP in this murine model.