Virus expression in different tissues of normal and tumor-bearing mice inoculated with a murine leukemia virus.

Evolution of virus expression in different lymphoid organs as well as in solid syngeneic tumors of mice inoculated with an MuLV was studied with the aid of in vitro XC co-culture technique. When normal adult mice of strain XLII were inoculated intraperitoneally with a cultured Rauscher virus (RC), the virus could be detected, 10 days after inoculation, only in bone marrow in small amounts and thereafter no virus could be found in any of the organs tested, including bone marrow, spleen, thymus, lymph node and kidney. However, when age- and sex-matched parallel mice bearing syngeneic subcutaneous non-viral tumors were inoculated similarly with the RC virus, the virus could be detected abundantly not only in bone marrow and spleen but also in tumors during the first 3 weeks and even 6 weeks after virus inoculation. Transitional decrease or disappearance of the virus was observed around the 25th-31st day in organs and tumors of the inoculated mice. When the tumor mass was removed from these mice by surgery, the virus disappeared rapidly and definitely from all the organs tested. The virus recovered from in vitro explanted and cultured tumors, taken from mice inoculated with the virus, induced typical lymphoid leukemia in BALB/c mice inoculated as newborns. However, from certain aspects (hypertrophy of the thymus and lymph nodes), this virus was different from the original RC virus.     

Rapid Growth and Spontaneous Metastasis of Human Germinal Tumors Ectopically Transplanted into Scid (Severe Combined Immunodeficiency) and Scid-nudestreaker Mice

Xenograft acceptance, growth and spontaneous metastasis of ectopically transplanted human germinal tumors were compared among scid mice, athymic nude mice and F₂ hybrids constructed from scid and nude mice, in relation to the impairments of T and B cell functions in these mice. In scid mice which are deficient in T and B cell functions, human yolk sac tumor (YST-2) that originated from the ovary grew to enormous sizes in 100% of the animals after both subcutaneous and intraperitoneal transplantation, while only half (59.1% and 51.9%) of the subcutaneous and none of the intraperitoneal transplants were accepted in usual athymic nude mice (BALB/c- nu/nu and CDl- nu/nu ). The YST-2 grew rapidly in scid mice, developing 3 to 10 times larger tumors compared to nude-streaker (AKR/J- nu^str/nu^str ) and usual nude mice, respectively. Furthermore, ectopically transplanted tumors spontaneously metastasized to distant organs (mostly to the lung) in scid mice (but less frequently in leaky scid mice), while metastases have never been found in nude mice. Although a xenograft of human classic (typical or pure) seminoma of the testis has never been established in nude mice, it grows slowly in one-third (36.4%) of scid mice and very rapidly in all of scid-nu ( scid/scid; nu^str/nu^str ) double mutant mice. Spontaneous metastases of xenografted seminomas were also observed in distant organs (lymph node, lung, liver, spleen, and kidney). The metastastic distribution of the two human germinal tumors in scid and scid- nu^str mice mimics that found in human. These results (xenograft acceptance, growth of transplanted tumors and degree of metastatic spread) were compatible with the level of T and B cell impairments indicated by FACS analysis, as well as mitogen responses, serum IgG and morphological features of the thymus.     

沉默乙酰肝素酶基因对胃癌生物学行为的影响

目的 探讨乙酰肝素酶(HPA)沉默对人胃癌裸鼠移植瘤生长、转移和血管形成的影响.方法 利用人胃癌SGC-7901细胞和HPA被沉默的SGC-7901-HPA-细胞,分别建立6只裸鼠皮下移植瘤模型,观察成瘤的时间、肿瘤生长速度和体积.应用逆转录聚合酶链反应(RT-PCR)和Western blot方法分别检测皮下移植瘤组织中HPA mRNA和蛋白的表达,应用免疫组织化学SP法检测皮下移植瘤组织的微血管密度(MVD).将皮下移植瘤细胞分别注射入6只裸鼠腹腔,建立腹腔转移瘤,并观察成瘤情况.结果 SGC-7901细胞和SGC-7901-HPA-细胞在裸鼠皮下均能生长出移植瘤,分别在接种后第4天后和第7天后出现肉眼可见的肿瘤,接种SGC-7901-HPA-细胞的裸鼠移植瘤生长较慢,MVD为(11.35±1.94)个/高倍视野,明显低于接种SGC-7901细胞组[(20.69±1.20)个/高倍视野,P＜0.05].接种SGC-7901-HPA-细胞与接种SGC-7901细胞的裸鼠皮下移植瘤组织相比,HPA mRNA和蛋白的表达均降低.由SGC-7901细胞皮下移植瘤组织建立腹腔转移瘤的裸鼠,有3只成瘤,在肝脏、大网膜、肠系膜、右肾形成了4处转移灶,且体积较大.而接种SGC-7901-HPA-细胞皮下移植瘤组织的裸鼠,仅有1只在肝脏和右肾形成了转移灶,而且瘤体较小.结论 HPA沉默后抑制了人胃癌在裸鼠体内的生长、转移和血管形成,HPA有可能成为预防和治疗胃癌的一个新靶H点.     

Rapid growth and spontaneous metastasis of human germinal tumors ectopically transplanted into scid (severe combined immunodeficiency) and scid-nudestreaker mice

Xenograft acceptance, growth and spontaneous metastasis of ectopically transplanted human germinal tumors were compared among scid mice, athymic nude mice and F2 hybrids constructed from scid and nude mice, in relation to the impairments of T and B cell functions in these mice. In scid mice which are deficient in T and B cell functions, human yolk sac tumor (YST-2) that originated from the ovary grew to enormous sizes in 100% of the animals after both subcutaneous and intraperitoneal transplantation, while only half (59.1% and 51.9%) of the subcutaneous and none of the intraperitoneal transplants were accepted in usual athymic nude mice (BALB/c-nu/nu and CD1-nu/nu). The YST-2 grew rapidly in scid mice, developing 3 to 10 times larger tumors compared to nude-streaker (AKR/J-nustr/nustr) and usual nude mice, respectively. Furthermore, ectopically transplanted tumors spontaneously metastasized to distant organs (mostly to the lung) in scid mice (but less frequently in leaky scid mice), while metastases have never been found in nude mice. Although a xenograft of human classic (typical or pure) seminoma of the testis has never been established in nude mice, it grows slowly in one-third (36.4%) of scid mice and very rapidly in all of scid-nustr (scid/scid; nustr/nustr) double mutant mice. Spontaneous metastases of xenografted seminomas were also observed in distant organs (lymph node, lung, liver, spleen, and kidney). The metastastic distribution of the two human germinal tumors in scid and scid-nustr mice mimics that found in human. These results (xenograft acceptance, growth of transplanted tumors and degree of metastatic spread) were compatible with the level of T and B cell impairments indicated by FACS analysis, as well as mitogen responses, serum IgG and morphological features of the thymus.     

Antimetastatic Effect of a Novel Indolocarbazole (NB-506) on IMC-HM Murine Tumor Cells Metastasized to the Liver

IMC-HM cells were isolated from spontaneously induced ascitic IMC carcinoma cells that had been maintained intraperitoneally in CDF₁ mice. Metastasis to the liver of subcutaneously implanted IMC-HM cells was detected 10 days after implantation into the flanks of mice (day 10), but metastasis to other organs was limited. Thereafter, however, tumor cells spread rapidly to lymph nodes, lung, spleen, ovary and other organs, and the mice died on day 13 to 18. We report here, together with the properties of IMC-HM cells, the effects of adriamycin, cisplatin, etoposide and a new indolocarbazole antitumor compound (NB-506) on this model of metastasis. Although these anticancer agents all inhibited the growth of the subcutaneous tumors, their effects on the life span of the tumor-bearing mice varied. Treatment with NB-506, started on day 1, more than doubled the survival period at doses 30 mg/m² to 900 mg/m². Further, treatment with NB-506, started on day 4 after resection of the primary tumor, inhibited growth of the metastasized tumor in the liver and other organs. Etoposide also increased the life span at a limited range of doses. However, the life-prolonging effects of adriamycin and cisplatin were marginal. These results demonstrate that IMC-HM carcinoma is a good model for spontaneous metastasis to the liver followed by lethal spread to many organs. Moreover, NB-506 was found to be highly effective against the growth not only of subcutaneous tumors, but also of tumors metastasized to the liver.     

Selection of metastatic variants from heterogeneous tumor cell lines using the chicken chorioallantoic membrane and nude mouse

The chicken chorioallantoic membrane was used to select variant tumor cell subpopulations from the murine melanoma B16-BL6 and the rat glioma C6 cell lines. Tumor cells were deposited on the chicken chorioallantoic membrane of eggs 10 days postfertilization. Upon hatching, chickens were autopsied, and organs were removed, minced, and implanted s.c. in C57BL/6J mice (for melanoma) or nude mice (for glioma). A glioma growing s.c. from a chicken lung implant metastasized to the liver of the recipient nude mouse, and a melanoma growing s.c. from a chicken liver implant metastasized to the lung of its murine host. The s.c. melanoma contained distinct black and gray areas. Cell lines were established from the s.c. glioma (C6-V-1), from a metastasis of the C6-V-1 tumor (C6-V-2), and from the black and gray regions of the melanoma. Marked differences in lung colonization were seen 14 days after 1 X 10(5) parent BL6, Black, or Gray cultured cells were injected by tail vein into C57BL mice. In four separate experiments, fewer than 15 lung foci per mouse were found when BL6 cells were injected, whereas 100 to several hundred lung melanoma colonies per mouse were observed when Black or Gray cells were inoculated. Four of 18 nude mice bearing the s.c. C6-V-1 glioma developed liver metastases; no metastases have been observed in 15 nude mice bearing the s.c. parent C6 glioma. Significant differences in sensitivities to antineoplastic drugs were demonstrated between parent and variant glioma cell lines. The 33-fold increase in sensitivity to vincristine determined for C6-V-1 cells compared to parent C6 cells was particularly striking. Results suggest that the use of the chicken chorioallantoic membrane in situ, together with the nude mouse, might provide a method suitable for the selection and isolation of aggressive variants in heterogeneous human tumors.     

Interactions with host macrophages and ability of human melanoma cell lines to grow in nude mice

The interactions of nude mouse macrophages with five human melanoma cell lines, characterized by their resistance to mouse NK activity and varying in their ability to grow s.c. in nude mice, were investigated. These lines were equally susceptible in vitro to both cytostatic and tumoricidal activities of activated peritoneal macrophages collected from nude mice inoculated 3 days previously with Brucella abortus B19R strains. I.p. injection of a poorly tumorigenic melanoma cell line (PTCL) in nude mice was followed by the local appearance of macrophages able to kill these cells in a 48-hr 3H-thymidine cytotoxicity assay. The level of tumoricidal macrophages was maximum for the first week and then slowly declined to disappear by the 4th week following PTCL inoculation. The use of an HTCL instead of a PTCL also induced macrophages able to kill HTCL cells, but the cytotoxicity level was lower and the activity disappeared more rapidly. In cross-experiments using PTCL-activated macrophages as effectors on HTCL targets, these cells were found to be less sensitive than PTCL cells when macrophages were taken at weeks 2 and 3 following PTCL inoculation. To investigate whether tumoricidal macrophages activated in vivo with human melanoma cells could also act in vivo, we inoculated these s.c. into nude mice, simultaneously with live HTCL cells. Peritoneal cells rich in melanoma-activated macrophages prevented HTCL growth in most recipients, whereas spleen cells from the same donor mice did not modify the tumor take. These data indicate that xenogeneic tumors could activate nude mouse macrophages in vivo and suggest that the ability of human tumors to grow in nude mice could be related to their capacity to activate host macrophages locally and to the susceptibility of human tumor cells to the tumoricidal activity of activated macrophages.     

Exceptional lethality for nude mice of cells derived from a primary human melanoma

BRO human melanoma cells, obtained from a biopsy of a highly aggressive and malignant primary tumor, were grown as xenografts in nude mice and in cell culture. These cells were exceptionally tumorigenic and malignant for nude mice. NIH-II nude mice survived 11.0 +/- 0.4 (S.E.) and 14.1 +/- 0.4 days after i.p. inoculation of 10(7) or 10(6) BRO cells, respectively, and lethal tumors developed in all mice inoculated i.p. with only 10(3) cells. The doubling time (2.3 days) of the volume of tumors formed after s.c. inoculation was comparable to the doubling time of these cells in culture. After i.p. or s.c. inoculation, BRO cells metastasized to the diaphragm and lungs, causing respiratory failure in most of the host mice. The original tumor and the cell line derived from it had undifferentiated structures with prominent nuclei and very large nucleoli. Karyotype abnormalities included a gigantic A group chromosome, a large D group chromosome, and an unusual double centromere chromosome not found typically in human melanoma cells. Due to the short and reproducible survival times of nude mice inoculated i.p. with BRO cells, this model system may be useful for rapidly determining the effects of experimental treatment on the survival of hosts bearing human tumor cells.     

In vivo metastasis of human tumor transplant in T and NK cell immune-deficient mice

Beige-nude mice with combined T and NK cell deficiency were produced by introducing "nu" gene into the beige mice of C57BL/6 background. The beige-nude mice were characterized by morphological features, level and activity of the NK cell in spleen and peripheral blood. NK cell level of the beige-nude mice was higher than the beige mice and similar to the ordinary nude mice though its NK cell activity was markedly lower than the nude mice. Human lung adenocarcinoma (PAa) was transplanted subcutaneously to the beige-nude mice and nude mice of BALB/cA background. No metastasis was found in BALB/cA nude mice (0/7), while in beige-nude mice, spontaneous lymph node metastasis rate was 36.3% (4/11). It should be noted that the transplanted PAa metastasized to lungs, which had never been seen in BALB/cA nude mice in previous experiments. The increase of metastatic rate is correlated with the relative low NK cell activity of the beige-nude mice. Our observation is that the beige-nude mice could be a suitable experimental model for in vivo study on metastatic behavior of the human tumors.     

Establishment of highly metastatic human tumor cell line in nude mice

A total of 22 adult nude mice (7 approximately 17 weeks old) of BALB/cA origin were inoculated subcutaneously (SC) with human tumor cell lines derived from rhabdomyosarcoma and lung carcinomas, including squamous cell carcinoma, bronchiolo-alveolar carcinoma, small cell carcinoma, giant cell carcinoma and 2 types of adenocarcinoma. 12 neoplasms (54.5%) was confirmed at the initial transplantation and 7 serially transplantable tumors were established in 201 nude mice. Metastatic behavior of 7 human tumor cell lines grown in nude mice was judged histologically after sacrifice and SC transplanted tumors could either be highly metastatic (giant cell carcinoma), moderately metastatic (adenocarcinoma PAb), poorly metastatic (squamous cell carcinoma and adenocarcinoma PAa) or non-metastatic (small cell carcinoma and bronchiolo-alveolar carcinoma). The tumor from SC inoculated giant cell carcinoma (PG) could produce regional and/or distant lymph node metastases (12/12) and lung metastases (9/12) in BALB/cA nude mice maintained under semi-barrier system conditions. Six NIH nude mice developed metastatic tumor nodules both in the lymph node and lung (6/6) under the same condition. The highly metastasizing property of PG transplanted tumors remained after passage for as many as 18 times. The limitations of nude mice as an in vivo model for the study of tumor biology are discussed, eg. malignant neoplasms rarely metastasize when transplanted into nude mice. The use of such model (PG) could lead to a better understanding of the biology of metastasis, thus contributing to the development of new approaches to the therapy of metastasis.     

ABCE1-GFP肺腺癌动物模型的建立及免疫组化检测

目的:建立ABCE1-GFP（+）肺腺癌裸鼠动物模型,并进行免疫组化检测,为进一步探索ABCE1作为诊断治疗非小细胞肺癌靶点提供有用的工具。方法:应用前期实验中构建的稳定转染重组质粒pEGFP-C1-ABCE1及空载体pEGFP-C1的LTEP-a-2肺腺癌细胞株,接种于裸鼠背部侧翼至腋窝皮下,建立ABCE1-GFP肺腺癌动物模型。进行成瘤情况观察,并予以倒置荧光显微镜系统呈像。取材后进行免疫组织化学检测。结果:稳转细胞系皮下接种裸鼠后,全部成瘤,过表达组肿瘤体积大于空载体及对照组（P＜0.05）。过表达组肿瘤在荧光显微镜系统下可稳定表达绿色荧光,成功构建了ABCE1-GFP（+）肺腺癌皮下成瘤的裸鼠动物模型。免疫组织化学检测亦验证这一模型的确立。结论:稳定转染LTEP-a-2肺腺癌细胞可以用来成功建立皮下ABCE1-GFP（+）肺腺癌成瘤模型,是较为理想研究ABCE1在非小细胞肺癌中的基因功能的动物模型。     

Expression of IL-27 in murine carcinoma cells produces antitumor effects and induces protective immunity in inoculated host animals

A novel cytokine interleukin-27 (IL-27), composed of p28 and Epstein-Barr virus-induced gene 3 (EBI3), is produced from activated dendritic cells and is involved in an early phase of T-helper type I differentiation. We examined whether Colon 26 murine colon carcinoma cells that were retrovirally transduced with the p28-linked EBI3 gene (Colon 26/IL-27) could produce antitumor effects in inoculated mice. Although proliferation in vitro of Colon 26/IL-27 cells was not different from that of parent cells, syngeneic BALB/c mice rejected Colon 26/IL-27 tumors inoculated and subsequently acquired tumor-specific protective immunity. In contrast, mice inoculated with Colon 26 cells transduced with either the p28 or EBI3 gene developed tumors and survival of the mice remained the same as that of the mice inoculated with parent cells. Syngeneic nude mice developed Colon 26/IL-27 tumors, but the growth was retarded compared to that of parent tumors. Depletion of natural killer cells from nude mice with anti-asialo GM(1) antibody diminished the growth retardation of Colon 26/IL-27 tumors. Survival of severe combined immunodeficient mice that received subcutaneous inoculation of Colon 26/IL-27 cells was not different from that of the immunodeficient mice inoculated with parent cells. Interferon-gamma was produced from CD4(+) and CD8(+) T, and natural killer cells of the mice that rejected Colon 26/IL-27 tumors and cytotoxic activity against Colon 26 cells were also detected from the mice. These data collectively suggest that expressed IL-27 in tumors produces T cell-dependent and-independent antitumor effects and is a possible therapeutic strategy for cancer.     

Establishment of Nude Mice Lacking NK Cells and Their Application for Human Tumor Xenografts

Objective: Nude mice are used as a recipient for human tumor cell xenografts. However, the success rate of xenotransplantation is unsatisfactory due to high natural killer (NK) activity. To overcome this limitation, we established nude mice with no NK cells, and compared the transplantation efficiency with that in nude mice. Methods: BALB/c Nude Jak3-/- (Nude-J) mice were established by crossing BALB/c Nude mice and BALB/c Jak-3-/- mice. Hematopoietic malignant cell lines (BCBL-1 and Z138) were implanted subcutaneously to compare the tumorigenicity in Nude-J mice with Nude Rag-2/Jak3 double deficient (Nude RJ) mice and nude mice. Results: Nude-J mice showed complete loss of NK and T lymphocytes, whereas B lymphocytes remained. Both BCBL-1 and Z138 human lymphoid malignant cell lines formed almost the same sizes of subcutaneous tumors in Nude-J and Nude RJ mice, whereas they formed no or only small tumors in nude mice. Splenocytes from Nude-J mice showed no cytotoxic activity in vitro. Conclusion: Nude-J mice can be a valuable tool for human tumor cell transplantation studies.     

Ascites form of a human cancer serially transplantable in nude mice.

Human adenocarcinoma cells injected into the peritoneal cavities of BALB/c nude mice (nu/nu) induced ascites carcinoma. The inoculant was obtained from subcutaneous tumors produced in nude mice by an injection of ascites cells from a patient with carcinomatous peritonitis caused by mucinous adenocarcinoma of the stomach. An ascitic fluid began to accumulate 45 days after inoculation and reached the maximum volume within 120 days. Dispersed stomach cancer cells in the ascites could be serially transplanted in nude mice in an ascites form. The morphology of these cells was similar to that of the original cells in the ascitic fluid of a patient with carcinomatous peritonitis.     

利用细胞膜片技术构建新型前列腺癌皮下移植瘤动物模型

背景与目的：传统前列腺癌皮下移植瘤模型的建立采取细胞悬液注射方式,但该方式存在较大局限性。探索利用细胞膜片技术构建新型前列腺癌皮下移植瘤动物模型的可行性。方法：将人前列腺癌细胞系DU145接种至35 mm温度敏感性细胞培养皿中,连续培养制备前列腺癌细胞膜片,并采用H-E染色和免疫组织化学方法鉴定。根据研究目的,设置细胞悬液组和细胞膜片组,细胞悬液组在BALB/c裸小鼠皮下注射DU145细胞悬液,细胞膜片组在裸小鼠皮下注射DU145细胞膜片。移植后4周处死裸小鼠,剥离两组移植瘤作进一步组织学分析,包括胶原纤维含量、局部浸润及血管生成情况。同时,解剖前列腺癌常见的转移脏器,如骨、肺和肝脏等,评估两组的全身转移情况。结果：培养1周后可制备前列腺癌DU145细胞膜片,大体观察呈现半透明胶质薄片,具备较好的组织学强度。组织学染色见膜片状结构,平均厚度约为(32.6±7.5)μm。DU145细胞标志物vimentin高表达,E-cadherin低表达,胶原纤维含量丰富,在膜片中高表达。皮下移植4周后,H-E染色显示,细胞膜片组肿瘤结构致密,有明显周围肌肉浸润,而细胞悬液组肿瘤存在较多空泡,与周围组...     

Murine Liver Metastasis Model Using L5178Y-ML Lymphoma and the Effect of Antitumor Agents on the Metastasis

A reproducible tumor model for liver metastasis has been developed from murine L5178Y lymphoma line by sequential cycles of subcutaneous inoculation of liver tumor cells, that were originally generated in livers of female (BALB/c × DBA/2)F₁ mice by injecting the parental cells into the tail vein. This variant (L5178Y-ML) metastasized predominantly to the liver after intravenous or subcutaneous injection. The livers of the animals killed 9 days after intravenous implantation of 5 × 10⁵ tumor cells were about 3 times the weight of control livers. All tumor-bearing mice died 10 to 12 days after inoculation. Subcutaneous implantation of L5178Y-ML in the side flank of mice induced metastatic nodules spontaneously in the livers. The tumor cells proliferated more in livers than in the implanted sites, compared with the parental L5178Y cells. The effects of 5-fluorouracil, mitomycin C, cis -platinum and doxorubicin on the liver metastasis of L5178Y-ML were examined at subtoxic doses; 5-fluorouracil was the most effective in both inhibiting the tumor growth in livers and prolonging the survival period of mice. This model provides a useful tool for the experimental therapy of hepatic tumors in mice.     

Reconstituted basement membrane (matrigel) enhances the growth of human glioma cell lines in nude mice

Transplantation of human cancers into immunologically deficient mice is widely used to study potential therapeutic interventions in vivo. For brain tumor research, however, several factors limit more widespread application of this animal model. First, only a minority of human glioma-derived cell lines are tumorigenic in nude mice. In addition, even for tumorigenic cell lines, tumor take is variable and growth is often slow for tumors derived from cell inoculums. Reconstituted components of tumor basement membrane (matrigel) have been found to improve the growth in nude mice of several types of human tumors originating outside the central nervous system when premixed with the tumor cells before subcutaneous inoculation. We investigated the ability of matrigel to enhance the growth in nude mice of tumors derived from the human glioma cell lines U-251 MG, U-373 MG, SNB-78 and SNB-101.Athymic nude mice (NIH Swiss background, nu/nu genotype) were inoculated subcutaneously with 1.0 × 10⁶ tumor cells alone or after premixing with an equal volume of liquid matrigel. U-251 and U-373 cells were tumorigenic, with palpable tumors present by about 2 to 3 weeks. Co-injection of these cell lines with matrigel resulted in higher tumor-take rates, from 6/10 to 8/8 animals for U-251 at 60 days, and from 9/12 to 11/11 animals for U-373 at 60 days. Matrigel also enhanced tumor growth, with tumors at 45 days significantly larger than those formed in the absence of matrigel, for both cell lines (p < 0.01). SNB-78 and SNB-101 cells did not give rise to progressively enlarging solid tumors with or without matrigel.Matrigel enhances the growth of tumorigenic human gliomas in athymic nude mice. This technique provides a model with more consistent tumor take and more rapid growth kinetics for human glioma cell lines that are tumorigenic in nude mice.The U.S. Government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged     

Biologic and biochemical differences between in vitro and in vivo passaged Friend erythroleukemia cells. I. Tumorigenicity and capacity to metastasize

Cloned interferon-sensitive (745) and interferon-resistant (3Cl-8) Friend erythroleukemia cells (FLC) passaged in vitro, are not very tumorigenic when first injected intraperitoneally (i.p.) into syngeneic DBA/2 mice although they do form solid tumors when injected subcutaneously (s.c.). By serially passaging FLC (either 745 or 3Cl-8 cells) i.p. in DBA/2 mice, we obtained two different FLC lines capable of growing i.p. and inducing tumor ascites. The s.c. injection of DBA/2 mice with these in vivo passaged FLC resulted in tumor metastases in the liver and spleen, whereas metastases were not observed in mice inoculated s.c. with in vitro passaged FLC. The capacity of in vivo passaged FLC to metastasize was acquired after several i.p. passages. This highly malignant behavior was a stable characteristic of these cells. All the clones derived from in vivo passaged FLC and passaged more than 14 times in vitro induced hemorrhagic ascites when injected i.p., and metastasized to the liver and spleen when injected s.c. The phenotype of sensitivity or resistance to the inhibitory effect of alpha/beta mouse interferon on virus replication and cell multiplication was conserved during serial i.p. passages and maintained in the clones derived from in vivo passaged cells. These FLC showed a decreased capacity to differentiate in vitro upon treatment with dimethylsulfoxide (DMSO) and a reduced production of Friend leukemia virus with respect to the original clones passaged in vitro.     

Human esophageal carcinoma cell lines: prostaglandin production, biological properties, and behavior in nude mice

Prostaglandin production by two continuous human esophageal carcinoma cell lines HCU 18 and HCU 39 derived from poorly and moderately differentiated source tumors, respectively, was investigated. Behavior of both lines in vitro and upon sc inoculation into athymic randombred BALB/c nude mice was also assessed. Approximately half the xenografts induced by HCU 18 cells were invasive, whereas those initiated by HCU 39 cells were all well encapsulated. Although metastases were not detected in mice given injections of HCU 39 cells, metastatic tumors developed in 2 mice inoculated with HCU 18 cells. In addition, HCU 18 cells produced significantly more prostaglandin E (PGE) and prostaglandin F (PGF) than HCU 39 cells. These findings suggest a relationship between PGE and PGF production by human esophageal carcinoma cells and their invasive and metastatic potential in athymic mice.     

Enhanced tumor growth and metastatic spread of an MH134 variant lacking a part of the MM antigen: a possible role of antibody-dependent cellular cytotoxicity in control of tumor growth and metastases

The role of antibody-dependent cellular cytotoxicity (ADCC) in host defense against tumor growth and metastasis was investigated with MH134, an MM antigen-positive murine hepatoma, and MH134-M, a variant with enhanced tumorigenesis and metastasis, in syngeneic C3H/HeN mice. When inoculated subcutaneously into C3H/HeN mice, MH134-M tumors grew more rapidly than did MH134 tumors and consistently metastasized to the draining lymph nodes, whereas MH134 tumors did not. Also, MH134-M exhibited a significantly greater lung colonization potential than did MH134, when inoculated intravenously into C3H/HeN mice. In BALB/c nu/nu mice, however, solid MH134 tumors grew and metastasized to the same extent as MH134-M, indicating that there is no significant intrinsic difference between these two tumor lines in proliferative or metastatic capacity. Enzyme-linked immunosorbent assay (ELISA) and immunoblotting, performed after SDS-PAGE analysis of cellular extracts with a monoclonal antibody (MAb) that recognizes a part of the MM-antigen, revealed that the cells of MH134-M lack at least a part of the MM antigen. Sera of C3H/HeN mice bearing solid MH134 tumors were found to contain anti-MM-antigen antibodies, when tested by immunoblotting of SDS-PAGE-developed materials. Cytotoxicity testing in which thioglycollate-induced peritoneal macrophages were used as effector cells revealed that antibodies present in sera strongly induced ADCC to MH134 but not to MH134-M. On the other hand, sera of MH134-M tumor-bearing C3H/HeN mice neither contained anti-MM-antigen antibodies nor induced ADCC to MH134 or MH134-M tumor cells. Intravenous injection of carrageenan into C3H/HeN mice bearing solid MH134 tumors significantly enhanced tumor growth, whereas the growth of subcutaneously injected MH134-M tumors was not influenced by this treatment. These results suggest that the enhanced tumorigenesis and metastasis of the MH134-M line in C3H/HeN mice are based, at least in part, on significant loss of the MM antigen and the resultant inability to induce ADCC-triggering antibody production during tumor growth.