Effector and enhancing lymphoid cells in plasmacytoma-bearing mice. I. Methodological studies on the winn assay

Some parameters of the Winn assay for the detection of tumor-suppressing (“effector”) and tumor-enhancing lymphoid cells were studied in BALB/c mice. Spleen cells of mice that were preimmunized with mitomycin-C-treated MOPC-104E plasmacytoma cells were inhibitory in this test system for both the MOPC-104E and the HOPC-1 plasmacytomas, thus indicating cross-reactivity. Spleen cells taken from mice 6 days after the surgical removal of 15-day-old MOPC-104E tumors inhibited the growth of lethal doses of MOPC-104E cells in normal recipients, but no inhibition was observed 2 days after the removal of 18-day-old tumors. Spleen cells from mice bearing MOPC-104E for 13 days enhanced tumor growth. This enhancement was not influenced significantly by the wide dose range (from 10⁵ to 3 × 10⁷) of MOPC-104E cells used to initiate tumors in the lymphoid cell donors, although a tendency for stronger enhancing potential occurred after low tumor doses. When spleen cells from donors bearing MOPC-104E for 10 days were injected at the constant tumor-lymphocyte ratio of 1:30 with increasing numbers of tumor cells (from 5 × 10⁵ to 2 × 10⁶), tumor inhibition occurred at the lowest dose only, while no significant effect was observed at higher tumor cell doses. When a constant dose (5 × 10⁵) of tumor cells was injected with spleen cells from 10-day tumor-bearers at tumor/lymphocyte ratios of 1:10, 1:40 and 1:160, a significant tumor inhibition occurred only at the ratio of 1:40. The relevance of the Winn test to the study of immune mechanisms in tumor-bearing hosts is discussed.     

Immunological studies on mouse mammary tumors. I. Induction of resistance to tumor isograft in C3H/He mice

An isografted tumor MM2, originating from a spontaneous mammary tumor in a C3H/He/mouse, killed 4- to 5-week-old mice within 30 days through intraperitoneal injection of 2 × 10⁴ cells per mouse. It was shown that resistance to the isograft was induced by injection of 1.5 × 10⁵ or 2.0 × 10⁵ tumor cells sensitized with serum (5 μg antibody N) of rabbits immunized with the tumor. Four weeks after injection of the sensitized MM2 cells, 173 C3H/He mice were challenged intraperitoneally with fresh unsensitized MM2 in doses of 5 × 10⁵ to 1 × 10⁶ cells per mouse. Of these, 119 mice survived without any sign of tumor growth while all untreated mice died. The mean survival time for untreated mice was 18.1 days (± 1.7) when inoculated with 5 × 10⁵ cells and 16.2 days (± 1.8) when inoculated with 1 × 10⁶ cells. After the second challenge with the same number of fresh unsensitized cells, 117 out of 119 mice survived without any sign of tumor growth. All of 15 mice randomly selected from these resistant mice were tested for acceptance of skin grafts from normal C3H/He mice. The grafts showed no rejection even 150 days after the second graft. After hyperimmunization of these resistant mice, the serum of the spleen extract taken from the mice inhibited growth of tumors when the tumors were premixed in vitro and injected intraperitoneally into C3H/He mice.     

Partial nephrectomy in mice with milliwatt carbon dioxide laser and its influence on experimental metastasis

We have developed a surgical model to perform partial nephrectomy in mice using the milliwatt CO2 laser and have used this model for studying the influence of the sequel of surgery on experimental tumor metastasis. Strain A mice were subjected to partial nephrectomy using the milliwatt CO2 laser. The surgical procedure was time efficient, the blood loss was minimal, and the postoperative mortality was 6%. Immediately after surgery, the wound consisted of a superficial layer of charring and a deeper layer of thermal damage (coagulative necrosis). The wound healing was completed within 30 days and was accompanied by fibroblast infiltration and tubular regeneration but minimal inflammatory response. Seventy surgical mice were injected I.V. with TA3Ha murine mammary adenocarcinoma cells at different intervals (immediately to 30 days) after surgery. Among 38 mice inoculated with tumor cells immediately or up to 3 days after surgery, 18 (47%) showed histologically confirmed tumors at the site of surgical trauma. None of the 38 unoperated kidneys showed any evidence of tumor. This difference is statistically significant at a P value of less than 0.001. As the interval between surgery and tumor inoculation was increased to 7, 15, and 30 days, the frequency of tumor formation at the site of surgery decreased to 20% (2/10), 14% (2/14), and 0% (0/8), respectively. The results demonstrate that a) partial nephrectomy in mice is feasible with minimal mortality or apparent morbidity, b) the laser-induced surgical trauma favors implantation and growth of tumors, c) the frequency of tumor formation is related to the stage of wound healing, and d) the tumors are anatomically related to the healing wound but do not invade into the parenchymal tissue.     

Effect of selenium on growth rate of canine mammary carcinoma cells in athymic nude mice

A canine mammary tumor cell line established from a carcinoma of the solid type was used in this study. In 2 separate experiments, athymic nude mice were inoculated subcutaneously with 5 × 10⁶ viable tumor cells. All tumor-bearing mice received subcutaneous injections thrice weekly of 2 μg/g body wt of selenium as sodium selenite or phosphate buffered saline. Control, non-tumor-bearing mice were injected with either selenium or buffer. Selenium administration did not significantly alter the growth of non-tumor-bearing mice. However, body weight of tumor-bearing mice was reduced approximately 10%. The average volume of tumors in selenium treated mice was reduced 76% in experiment I and 74% in experiment II. (Supported in part by grant No. 81-7 from the American Cancer Society, Illinois Division, Inc., and USDA Grant No. 5901-9-0243.)     

131 I 标记血管靶向分子在肿瘤显像中的应用

 目的 研究¹³¹ I 标记的血管靶向分子（RGD10、F56、K237）的生物活性及在肿瘤部位的浓聚情况。方法 采用Iodogen法标记血管靶向分子,用Sep-PakC18柱纯化,通过HUVEC检测它们的免疫活性分数和亲和常数,用手持式丫相机检测和比较它们在荷A549肺腺癌裸鼠肿瘤部位的浓聚情况。结果 ¹³¹ I RGD10、¹³¹ I F56、¹³¹ Ⅰ-K237的免疫活性分数（IRF）分别为42．7％、55．1％和44．5％,与HUVEC的亲和常数Ka值分别为9．41×10⁷L／m01、3．87×10⁷L／mol和5．98×10⁷L／mol。3个¹³¹ I 标记的血管靶向分子中,¹³¹ I -RGD10在肿瘤部位的浓聚效果更为明显。结论 静脉注射¹³¹ Ⅰ-RGD10在肿瘤部位聚集,可望成为肿瘤早期核素显像诊断靶向分子。     

Irrigation does not dislodge or destroy tumor cells adherent to the tumor bed

Local recurrences in the surgical bed after tumor resection may be due to residual tumor cells “dropping” into the wound. Irrigation with water is often used to remove these cells. We designed experiments to determine whether irrigation would prevent tumor recurrence. Surgical wounds of uniform size in C57BL/6 mice were seeded with 5 × 10², 5 × 10³, 5 × 10⁴, 5 × 10⁵, or 5 × 10⁶ viable syngeneic B16-F10 melanoma cells to test the hypothesis that irrigation with water would decrease local tumor recurrence. The tumor-contaminated wounds were irrigated with distilled water or with saline (0.9% NaCl) immediately or 5, 30, 60, 120, or 240 min after seeding. Control wounds were seeded but not irrigated. The technique of irrigation was altered in a second group of experiments such that the amount of time the tumor cells were exposed to the water or saline was 5, 10, or 15 min. To determine the rapidity and durability of tumor cell attachment to host tissue, 1 × 10⁴ viable B16-F10 tumor cells were seeded in vitro onto freshly cut disks of syngeneic mouse dermis. The tissue was irrigated with saline or distilled water 0, 2, 5, 10, 15, 30, 60, 120, or 240 min later. Tumor growth was observed in all the mice and neither the mechanical action of irrigation nor the hypotonic effect of distilled water changed the rate of growth. Scanning electron microscopy (SEM) demonstrated stable and firm attachment to mouse tissue within seconds of seeding with no noticeable dislodgement or cytotoxicity by either saline or water irrigation. The data suggest that the commonly used technique of irrigating the bed of the resected tumor may not be of value in preventing local recurrences. © 1993 Wiley-Liss, Inc.     

Immunoprophylaxis and immunotherapy for a murine fibrosarcoma with C. granulosum and C. parvum

Prophylactic and therapeutic effectiveness of killed C. granulosum and C. parvum bacteria was investigated against a methylcholanthrene-induced fibrosarcoma in syngeneic C₃Hf/Bu mice. Subcutaneous or intravenous treatment of mice with 0.25 mg of these bacteria greatly reduced the number of tumor nodules (metastases, colonies) in the lung generated by 10⁵ or 10⁶ fibrosarcoma cells inoculated intravenously 7 days later. The treatment also prolonged the survival of tumor-cell recipients, and to some mice afforded complete protection against tumor growth. Number of lung metastases and survival of the recipients were more affected by intravenous than by subcutaneous treatment with the bacteria. Given intravenously to mice 3 days after intravenous inoculation of 2×10⁵ fibrosarcoma cells, these non-specific immunostimulants significantly reduced the number of pulmonary colonies and prolonged survival of mice. In contrast, subcutaneous application of the bacteria was only slightly effective. Both C. granulosum and C. parvum administered intravenously to mice 3 days following subcutaneous injection of 4×10⁵ fibrosarcoma cells did not affect the development of subcutaneous tumors. However, when the tumors had grown to 25-17 mm in diameter 67% and 80% of them underwent complete and lasting regressions in mice treated with C. granulosum and C. parvum, respectively. C. granulosum and C. parvum were approximately equally effective against both intravenously and subcutaneously injected tumor cells.     

Human melanoma growth in the peritoneal cavity of the athymic mouse—A model for in vivo study of cell-mediated immunity

Intraperitoneal injections of 2 × 10⁷ SH-Me cells (human metastatic melanoma cells) to 20 Balb/c nu/nu mice (Group A) and 1 × 10⁷ cells to 20 mice (Group B) were performed. All animals were studied clinicopathologically. Five animals in Group A were sacrificed serially, revealing marked tumor growth of the melanoma within the peritoneal cavity. These tumors grew in multiple nodular configurations and tumor ascites was present by the third week. The remaining 15 animals in Group A were allowed to progress and seven subsequently died with mouse viral hepatitis (MVH). These animals had suppressed tumor growth. The remaining eight animals died of peritoneal carcinomatosis with survival time of 24.1 ± 5.0 days. Eight of the animals in Group B died of mouse viral hepatitis while the remainder died of peritoneal tumor without distant metastasis. Survival time in these animals was 23.8 ± 2.6 days. Both 2 × 10⁷ and 1 × 10⁷ tumor cells injected intraperitoneally will constantly produce tumor nodules in non-MHV-infected nude mice with similar survival. This experimental model has proven useful for in vivo study to assess the immunoreactivity of melanoma patient cells reactive against target tumor cells.     

树突状细胞疫苗对人化荷人膀胱癌SCID鼠循环微转移转归的影响

Objective  To study the effect of dendritic cells loaded with whole tumor antigen on hematogenous micrometastasis of bladder cancer model in hu-PBL-SCID mice. Methods  T24-3 cell subset was selected from human bladder transitional cell carcinoma T24 cell line by Boyden chamber system. The SCID mice intraperitoneally injected with 4 × 10⁷ hu-PBL and subcutaneously injected with 3 × 10⁶ T24-3 cells were named hu-PBL-T24-3-SCID model. Human IgG level in the blood plasma of mice was detected by ELISA, and human CD3⁺, CD4⁺, CD8⁺ T cells in blood and spleen cells of mice were detected by FCM analysis for human immune reconstruction study. Human CK20 mRNA expression in mice peripheral blood was detected by RT-PCR to investigate metastasis of tumor cells. The PBMCs were isolated from human peripheral blood, and were induced into DCs by co-culture with rhGM-CSF and rhIL-4 in vitro. The DC vaccines were produced by co-culturing with whole tumor antigen which was purified through freezing and melting T24-3 cell subset. After T24-3 cells injected into SCID mice for 5 weeks, the mice were treated with DC vaccines. Results  All mice were initially treated at 5th week. The expression of CK20 mRNA in peripheral blood of DC vaccines treated mice was the lowest. There was 2 mice showing CK20 mRNA expression and 3 mice with metastasis tumor in PBS group. MMP-7 mRNA expression in tumor tissues of DC vaccines treated mice was statistically lower than that of PBS group (P < 0.01). Conclusion  DC vaccines have a good effect on hu-PBL-SCID mice bladder cancer model by reducing hematogenous micrometastasis.     

Regional administration of natural killer cells in a rat hepatic metastasis model results in better tumor infiltration and anti-tumor response than systemic administration

A syngeneic rat liver metastasis model, the CC531 colon carcinoma cell line in Wag rats, was used to study the homing properties and anti-tumor effects of adoptively transferred, interleukin-2 (IL-2)-activated, cultured natural killer (A-NK) cells. To identify the route of administration that gives the highest tumor infiltration, 1.5 × 10⁸ A-NK cells were dyed with fluorescent rhodamine and injected via 4 different routes into rats, bearing subcapsularly induced (day 10) liver metastases. The routes chosen were: jugular vein, portal vein, hepatic artery and directly into the peritoneal cavity (i.p). The rats were sacrificed 20 hr after administration of A-NK cells. The highest (p < 0.05) infiltration of tumors by A-NK cells was found both at the tumor border and in the tumor center after injection via the hepatic artery: 65 ± 7 A-NK cells/mm² at the tumor border and 26 ± 14 A-NK cells/mm² in the center of the tumor (jugular vein infusion: 32 ± 10 and 9 ± 5 A-NK cells/mm², respectively; portal vein infusion: 36 ± 13 and 7 ± 4 A-NK cells/mm², respectively). No A-NK cells were detected in the liver after i.p. injection. Rats bearing day 5 tumors were injected with 1.5 × 10⁸ A-NK cells via the hepatic artery or via the jugular vein (n = 5 and n = 6 respectively). Regional administration of A-NK cells via the hepatic artery resulted in a significant (p < 0.05) lower weight (35 ± 23 mg) of tumors than did systemic administration (70 ± 10 mg). Our results suggest that both the level of tumor infiltration by adoptively transferred A-NK cells and the therapeutic outcome depend on the route of administration. Int. J. Cancer 75:233–238, 1998. © 1998 Wiley-Liss, Inc.     

Antitumor Effect of PSK at a Distant Site: Inductions of Interleukin-8-like Factor and Macrophage Chemotactic Factor in Murine Tumor

The antitumor effect of PSK, a Coriolus preparation, at a distant site was analyzed with the use of a double grafted tumor system in which male BALB/c mice received simultaneous intradermal inoculations of Meth-A tumor in the right (10⁶ cells) and the left (2 × 10⁵ cells) flanks and were then injected with PSK in the right tumor on the third day thereafter. The antitumor effect of intratumoral administration of PSK in the right tumor on days 3, 4 and 5 was compared with the effect of surgical resection of the right tumor on day 5. Three out of 8 mice given PSK intratumorally became tumor-free whereas no mouse tumor-free in the left flank was found among the surgically resected mice. As regards sinecomitant immunity, tumor inoculation into the right flank followed by intratumoral administration of PSK on days 3 and 5 and surgical excision of the primary tumor on day 6 resulted in complete rejection of a tumor challenge in the left flank on day 21. The combination of presurgical intratumoral injections of PSK (more than 2 times) and postoperative oral administration of PSK appeared to be most effective in eradicating secondary tumors. Isolated TILs (tumor-infiltrating lymphocytes), obtained from the right tumor (treated with PSK) and the left tumor on day 10 in the double grafted tumor system were cultured in RPMI1640 with 10% fetal calf serum for 24 h. The culture supernatants were harvested and tested for the presence of chemotactic activity for neutrophils or macrophages. Significant neutrophil chemotactic factor (NCF) and macrophage chemotactic factor (MCF) activities were detected in the culture media from PSK-treated TILs that had been cultured for 24 h. Neither significant neutrophil nor macrophage chemotactic activity was detected in the media from untreated TILs. NCF and MCF activities were also detected in the culture supernatant from PSK-treated tumor tissue on day 6. PSK-induced NCF in the murine tumor was neutralized by treatment with anti-human IL-8 IgG, and might be murine IL-8-like factor. Therefore, neutrophil and macrophage infiltrations of tumors following intratumoral injections of PSK are probably mediated by inductions of IL-8-like factor and MCF.     

A phase I dose escalation study of Ad GV.EGR.TNF.11D (TNFerade™ Biologic) with concurrent chemoradiotherapy in patients with recurrent head and neck cancer undergoing reirradiation

BackgroundAdGV.EGR.TNF.11D (TNFerade™ Biologic) is a replication-deficient adenoviral vector expressing human tumor necrosis factor alpha (TNF-α) under the control of the chemoradiation-inducible EGR-1 promoter. TNF-α has been shown to function as a radiation sensitizer. We conducted a phase I dose escalation study to determine the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) of TNFerade™ Biologic, when added to chemoradiotherapy in poor prognosis patients with recurrent, previously irradiated head and neck cancer (HNC).MethodsTNFerade™ Biologic was injected intratumorally on day 1 of each 14-day cycle and dose-escalated in log increments from 4 × 10⁹ to 4 × 10¹¹ PU. Daily radiation, infusional 5-fluorouracil (5-FU), and hydroxyurea were given on days 1–5 for seven cycles (FHX). Tumor biopsies were obtained before, during, and after treatment.ResultsFourteen patients were treated. DLT was reached at a dose level of 3 (4 × 10¹¹ PU) with three thrombotic events. The response rate was 83.3%. The median survival was 9.6 months. One patient (7.1%) remained alive 3 years after treatment. Biopsies were obtained in 90% of patients. Nearly all tumors expressed adenovirus receptors, TNF-α, and TNF-α receptors. Adenoviral DNA was detected in three biopsies from one patient.ConclusionsTNFerade™ Biologic can be safely integrated with FHX chemoradiotherapy at an MTD of 4 × 10¹⁰ PU. Monitoring for thrombotic events is indicated.     

EXPERIMENTAL THERAPY FOR SOLID TUMORS BY IN SITU RETROVIRAL MEDIATED GENE TRANSFER

ＥＸＰＥＲＩＭＥＮＴＡＬＴＨＥＲＡＰＹＦＯＲＳＯＬＩＤＴＵＭＯＲＳＢＹＩＮＳＩＴＵＲＥＴＲＯＶＩＲＡＬＭＥＤＩＡＴＥＤＧＥＮＥＴＲＡＮＳＦＥＲＺｈｏｕｚｈｏｎｇｊｕｎ；周中军；ＺｈｏｕＡｉｒｕ；周爱儒；ＷａｎｇＪｉａｎｍｉｎｇ；王建明；ＴａｎｇＪｉａ...     

FACTORS INFLUENCING THE EFFECT OF RADIOIMMUNOTHERAPY ON LIVER CANCER

Factors influencing the therapeutic effect of radiolmmunotherapy with 131I labeled anti- human hepa-tocellular carcinoma (HCC) ferritin antibody (131I -FtAb) on thirty three patients with surgically proven unresectable HCC were studied. Multi- variable analysis with Cox' s regression model revealed that the statistically sig-nifieant factors include tumor size, activity of 131I administered each time and the second-look resection. Survival of patients with tumor diameter less than 10 cm was higher than that of patients with tumor diameter more than 10 cm (1-year survival; 84% versus 50%) 3-year survival; 63% versus 9% ). Patients administered with 5. 55×108 Bq to 9. 25× 10(?) of 131I-FtAb each time yielded better effect than those administered with more than 9. 25×108 Bq of 131I -FtAb (1-year, survival: 86% ver- sus 55%; 3-year survival: 50% versus 18%). When tumor shrank, patients underwent second-look resection had a higher survival than those without receiving second- look resection (1- year survi     

NK细胞对人鼻咽癌细胞CNE2裸鼠皮下移植瘤的抑制作用

 目的 研究同种异体NK细胞对人鼻咽癌细胞（CNE2）裸鼠皮下移植瘤的抑制作用。方法PCR-SSP法检测CNE2细胞HLA-A、B、Cw表型、NK细胞KIR表型（选择3例健康者为试验对象）,磁珠分离法分离NK细胞并进行体外培养扩增,LDH释放法测定NK细胞对CNE2细胞的体外杀伤活性。12只BALB/c裸鼠分为两组,每组6只,对照组裸鼠每只皮下接种1×106CNE2细胞,治疗组裸鼠每只皮下接种1×106CNE2细胞,同时每只经尾静脉注入3×107NK细胞,观察两组裸鼠成瘤时间、成瘤率、肿瘤体积变化、计算抑瘤率。结果 CNE2细胞表面HLA-A、B、Cw表型为A2,24;B18,35;Cw4,7,3例健康者均表达KIR2DL1、KIR2DL3、KIR3DL1、KIR3DL2。效靶比5∶1、10∶1、20∶1、30∶1时,NK细胞对CNE2细胞的杀伤活性分别为（9.37±2.14）%、（27.14±1.82）%、（36.40±4.28）%and（54.67±2.80）%。对照组和NK细胞治疗组肿瘤出现时间分别为（10.00±2.68）d、（18.80±1.64）d,（P〈0.01）,成瘤率分别为100%（6/6）、83.33%（5/6）,对照组和NK细胞治疗组裸鼠的瘤重分别为（2.22±0.09）g、（1.42±0.09）g,（P〈0.01）,NK治疗组的抑瘤率为36.04%。肿瘤组织石蜡切片病理学鉴定为低分化鳞状上皮细胞癌,NK细胞治疗组可见角化肿瘤细胞,较多的淋巴细胞浸润和大量细胞坏死区。结论 NK细胞对鼻咽癌裸鼠皮下移植瘤有明显的抑制作用,有希望成为治疗鼻咽癌的新方法。     

Leukemia Cell–Selective Uptake of Cytarabine and Daunorubicin in the Bone Marrow Compartment Mediated by CPX-351 Liposome Injection

BackgroundAnticancer drug combinations such as cytarabine plus daunorubicin can act synergistically, additively or antagonistically depending on the ratio of the agents being combined. We have shown that delivering synergistic cytarabine-to-daunorubicin drug ratios in vivo using nanoscale liposomes (CPX-351 liposome injection) provides dramatic efficacy improvements compared to the free drug cocktail in a wide range of preclinical leukemia models without exacerbating myelosuppressive effects. This enhanced efficacy is associated with increased and prolonged delivery of the synergistic drug ratio to bone marrow. Promising signs of efficacy have been observed with CPX-351 in previously treated patients with AML with poor prognosis. We aim to investigate the pharmacodynamic basis for the potent therapeutic activity of CPX-351.Patients and MethodsA bone marrow–engrafting CCRF-CEM human leukemia xenograft model was developed. CPX-351 was injected intravenously (I.V.), and the bone marrows of femurs from tumor bearing mice were subsequently harvested. Cells were analyzed by flow cytometry, and leukemia cells were separated from normal bone marrow cells using anti-CD45 coated magnetic nanoparticles. Cells were analyzed for intracellular cytarabine-to-daunorubicin and liposome content using ³H-Cyt, HPLC, and ¹⁴C-lipid, respectively.ResultsTwenty-eight days after I.V. tumor inoculation, femurs contained approximately equal numbers of CCRF-CEM and normal bone marrow cell populations that could be readily separated and quantitatively harvested by antibody-coated magnetic nanoparticle-mediated isolation. Eighteen hours after CPX-351 I.V. injection, bone marrows of the tumor bearing mice contained 82.6 ng cytarabine, 63.0 ng daunorubicin, and 1.2 μg liposomal lipid per total femur aspirate. Within the separated cell populations, leukemia cells contained 5.9 ng cytarabine, 8.2 ng daunorubicin, and 0.16 μg liposomal lipid per 10⁶ cells. These intracellular levels were 9.5-, 2.2-, and 1.9-fold higher than those observed in the normal bone marrow cell population. Confocal microscopy on cells incubated with CPX-351 in vitro demonstrated that CPX-351 liposomes are taken up intact by human leukemia cells and subsequently release the drugs intracellularly.ConclusionCPX-351 was designed to enhance the antitumor efficacy of cytarabine-to-daunorubicin combination therapy by encapsulating both agents within a drug carrier that maintains the synergistic 5:1 molar ratio for extended times after injection. The potent anti-leukemic activity obtained in the absence of significant nonhematologic toxicity with this formulation may be due, in part, to the selective accumulation of CPX-351 into leukemia cells.     

Progression toward metastatic phenotype with loss of growth-inhibiting tumor-cell/cell interactions in vivo

Five autonomous sub lines, T4-O1320, T4-O1320CY, T4-O1165, T4-O1145 and T4-O196, were established from the transplantable hormone-dependent mouse mammary tumor, TPDMT-4, by pass aging under different conditions. These autonomous tumors were characterized by rapid growth in DDD virgin mice and the parental TPDMT-4 by no growth in these mice. Thus, 10⁵ T4-O1320, 2 × 10⁴ T4-O1320CY, 2 × 10³ T4-O1165, 2 × 10³ T4-O1145 and 10³ T4-O196 cells were co-injected with 5 × 10² TPDMT-4 cells into virgin mice to determine whether or not hormone-dependent tumor cells influence the growth of autonomous tumor cells. TPDMT-4 cells retarded the growth of T4-O1320 and T4-O1320CY tumors but accelerated that of T4-O1165, T4-O1145 and T4-O196. Irradiated TPDMT-4 cells stimulated the growth of all the sub lines except T4-O1320. In 3-dimensional collagen-gel culture, T4-O1320 and T4-O1320CY cells formed branched or stellate structures similar to normal mammary glands, as did TPDMT-4, but T4-O1165, T4-O1145 and T4-O196 cells grew as rounded masses with knobs and showed a completely different morphology. T4-O1165, T4- O1145 and T4-O196 cells, but not the others, had lung-colonizing ability. Chromosomal aberration was found in T4-O1320CY and T4-O196 but not in the others. Thus, the susceptibility of autonomous sub line tumor cells to growth-inhibitory regulation from the parental hormone-dependent tumor cells correlated well with growth morphology within collagen gels and meta-static ability, but not with chromosomal aberration. The results suggest that meta-statically-competent tumor-cell variants, once they appear, may have a growth advantage in hormone- dependent mammary tumors. © 1995 Wiley-Liss, Inc.     

Progression of a Weakly Tumorigenic Mouse Fibrosarcoma at the Site of Early Phase of Inflammation Caused by Plastic Plates

To elucidate tumor progression-enhancing factor(s), we examined the effects of host inflammation and host immunological status on in vivo tumor progression. One × 10⁴ cells of QR clones (QR-32, -20 and -18), regressor tumor clones of 3-methylcholanthrene-induced fibrosarcoma, were unable to grow when injected s.c. into C57BL/6 mice in cell suspension form. However, QR clones grew and were lethal when s.c. implanted, attached to plastic plates. Furthermore, the tumor lines (QRpP) obtained from the tumors which had arisen from the plate-attached QR-32 clone cells no longer required plastic plates for their growth in normal mice, and had acquired stable malignant phenotypes. Although QR-32 cells became lethal when injected at the site of plastic plate implantation 1, 5 and 10 days before tumor injection, few tumors developed when plastic plates had been implanted 20 or 30 days before tumor injection. We established culture clones from the tumors arising in normal mice and mice immunosuppressed by irradiation. Clones derived from the tumors which had arisen in normal mice after implantation with plastic plates were lethal when re-implanted in normal mice (71%). On the other hand, clones derived from the tumors that arose in irradiated mice with or without plastic plates were lethal in only a few normal mice, when re-implanted (20 and 8%, respectively). These results indicate that QR clone cell progression is enhanced by the early phase of inflammation at the site of plastic plate implantation and that the progression-enhancing activity of co-implantation with a plastic plate is inhibited by previous whole-body irradiation of hosts.