Evaluation of time and dose in treating mammary adenocarcinoma with immunostimulants

Summary BCG, C. parvum, and reovirus were used as immunostimulants in treating murine mammary adenocarcinoma (A-10) after tumor burden had been minimized with BCNU. Immunostimulants were administered at different times with respect to chemotherapy. Different doses were used to determine the optimal response as measured by survival. BCG induced the best response when 6.67×10⁵ organisms were given 2 days after chemotherapy. The optimal response with C. parvum was observed after a dose of 0.35 mg was given 1 or 2 days after chemotherapy. Similarly, reovirus produced the best response when 10¹⁰ plaque-forming units were given 2 days after chemotherapy. These data are consistent with previous findings and support the notion that immunostimulants require an appropriate lymphoid substrate in order to induce an adequate anti-tumor response.Tge abbreviations used are: BCNU: 1,3-bis-(2-chloroethyl)-1-nitrosourea Saline: 0.9% NaCl solution; BCG: Bacillus Calmette-Guerin; C. parvum: Corynebacterium parvum; pfu: plaque-forming unitsThis study was supported, in part, by Contract No. N01-CB-43864 and Grant No. CA 14460 from The National Cancer Institute     

Rejection of reovirus-treated L1210 leukemia cells by mice

Summary L1210 leukemia cells were treated in vitro with 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and reovirus to determine their interactive effects on rejection of these tumor cells by mice. The cells were treated with BCNU at concentrations of 0, 3, or 10 M, incubated for 48 h, then treated with reovirus at a multiplicity of infection of 0, 10, 30, or 100 for 2, 6, or 12 h. The survival of mice injected with cells treated with any amount of reovirus, regardless of BCNU treatment, was greater than that of mice injected with untreated cells. Exposure of the cells to reovirus for 6 or 12 h increased the survival of mice injected with these cells as compared with that of mice injected with cells exposed to reovirus for 2 h. Of the survivors, 76% were resistant to subsequent challenge with untreated L1210 cells. These results suggest that activities associated with reovirus replication may cause modifications of L1210 cells that enable them to induce an immune response, thus facilitating their rejection. A lack of correlation between differences in DNA synthesis (measured by ³H-thymidine uptake) by treated cells and the ability of those cells to kill recipient mice indicates that rejection of cells treated with reovirus or BCNU is not due to a decrease in their ability to proliferate or, presumably, to generate lethal tumors. The survival of mice injected with treated L1210 cell preparations containing as few as 2.9% reovirus-infected cells was enhanced to the same degree as that of mice injected with those containing as many as 14.6% infected cells, indicating that modification of only a minor component of the tumor cell population is sufficient to alter the ability of the cells to generate a lethal tumor.This work was supported by a research grant from the Miami University Faculty Research Committee and a Sigma Xi Grant-in-Aid of Research     

Characteristics of reovirus-mediated chemoimmunotherapy of murine L1210 leukemia

Summary We have previously demonstrated the ability of reovirus to function synergistically with chemotherapy in the treatment of murine EL-4 lymphoma. This study characterizes this treatment regimen in the therapy of L1210 leukemia. Animals with an estimated tumor burden of 10⁷ cells were treated with 9 mg/kg 1,3-bis(2-chloroethyl)-1-nitrosourea. Reovirus type 3, which had been quantitated either by particles or plaque-forming units (pfu), was administered 48 h after chemotherapy. Complete remission of tumor was observed in 80% of the animals which received either 10¹¹ particles or 10⁹ pfu of reovirus. Cured animals were resistant to challenge with homologous tumor, but were susceptible to challenge with heterologous tumor. Reovirus undergoes limited replication at the tumor site, and virus-specific antibody appears only after disappearance of reovirus-infected cells and virus from the ascites fluid. Reovirus appears to function therapeutically by inducing a tumor-specific cytolytic immune response.     

Marrow allograft success inW/W v anemic mice: Relation to skin graft survival times

Genetically anemicW/W ^v mice were cured by marrow allografts from donors of 13 out of 18 tested strains that differed at non-H-2 histocompatibility alleles defined by skin or tumor grafting. They were also cured by donors from all four tested congenic lines whose antigenic differences had been defined by induction of serum antibodies. They were not cured acrossH-2 differences. Tail skin graft survival times on uncuredW/W ^v recipients were determined for all congenic lines used as marrow donors. The longest and shortest skin graft survival times predicted correctly marrow graft success or failure. NoW/W ^v mice were cured by marrow grafts from donors of the three congenic lines whose skin grafts were rejected in fewer than three weeks. Almost everyW/W ^v mouse grafted was cured by marrow grafts from donors of the 13 congenic lines whose skin grafts survived longest, from 11 to more than 25 weeks. Intermediate skin graft survival times failed to predict whether marrow grafts would succeed.W/W ^v mice were cured by marrow from four congenic lines with mean skin graft survival times of 4.2, 4.4, 8, and 9 weeks, while marrow grafts failed from other congenic lines with mean skin graft survival times of 3.3, 3.4, 4.8, and 8.7 weeks. The simplest explanation for these results is that the antigens specified by theH-2, H-3, H-4, H-25, andH-28 loci are strongly immunogenic on both marrow precursor cells and skin,H-17 andH-24 are strongly immunogenic on skin but not on marrow, andH-12 is strongly immunogenic on marrow precursor cells but less strongly on skin.     

In vitro induction of cell-mediated immunity to murine leukemia cells

Summary An adoptive chemoimmunotherapeutic model based on the use of chemotherapy and lymphocytes specifically sensitized against tumor cells in vitro was tested in mice transplanted with syngeneic leukemia cells. C57BL/6 and A strain mice were inoculated i.p. or i.v. (day 0) with lethal doses (1×10³–1×10⁵) of EL4 and YAC leukemia cells, respectively. Leukemic mice were subsequently treated (day 1 or day 3) with partially curative doses (80–140 mg/kg) of cyclophosphamide (Cy), followed by i.p. or i.v. administration of 1–3×10⁷ cytotoxic lymphocytes (CL) induced in macro-mixed leukocyte-tumor cell cultures (MLTC). The following results were obtained: untreated mice died with tumor within 20 days; mice receiving sensitized lymphocytes only showed a modest prolongation of survival and only 5–15% of the animals were cured; treatment with Cy alone or with Cy and normal lymphocytes prolonged survival considerably and cured 20–60% of the mice; mice subjected to Cy in conjunction with in vitro-sensitized lymphoid cells, either syngeneic or allogeneic, had survival rates of 80–100% (100 days). Under the conditions employed, no severe manifestations of clinical graft-versus-host (GVH) reaction were observed. These findings imply that in vitro-sensitized immunocytes and cytoreductive drugs can operate cumulatively.     

Chemotherapy Synergizes with Radioimmunotherapy Targeting La Autoantigen in Tumors

Background

To date, inefficient delivery of therapeutic doses of radionuclides to solid tumors limits the clinical utility of radioimmunotherapy. We aim to test the therapeutic utility of Yttrium-90 (⁹⁰Y)-radio-conjugates of a monoclonal antibody, which we showed previously to bind specifically to the abundant intracellular La ribonucleoprotein revealed in dead tumor cells after DNA-damaging treatment.

Methodology/Principal Findings

Immunoconjugates of the DAB4 clone of the La-specific monoclonal antibody, APOMAB®, were prepared using the metal chelator, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), and then radiolabeled with ⁹⁰Y. Mice bearing established subcutaneous tumors were treated with ⁹⁰Y-DOTA-DAB4 alone or after chemotherapy. Non-radiosensitizing cyclophosphamide/etoposide chemotherapy was used for the syngeneic EL4 lymphoma model. Radiosensitizing cisplatin/gemcitabine chemotherapy was used for the syngeneic Lewis Lung carcinoma (LL2) model, and for the xenograft models of LNCaP prostatic carcinoma and Panc-1 pancreatic carcinoma. We demonstrate the safety, specificity, and efficacy of ⁹⁰Y-DOTA-DAB4-radioimmunotherapy alone or combined with chemotherapy. EL4 lymphoma-bearing mice either were cured at higher doses of radioimmunotherapy alone or lower doses of radioimmunotherapy in synergy with chemotherapy. Radioimmunotherapy alone was less effective in chemo- and radio-resistant carcinoma models. However, radioimmunotherapy synergized with radiosensitizing chemotherapy to retard significantly tumor regrowth and so prolong the survival of mice bearing LL2, LNCaP, or Panc-1 subcutaneous tumor implants.

Conclusions/Significance

We report proof-of-concept data supporting a unique form of radioimmunotherapy, which delivers bystander killing to viable cancer cells after targeting the universal cancer antigen, La, created by DNA-damaging treatment in neighboring dead cancer cells. Subsequently we propose that DAB4-targeted ionizing radiation induces additional cycles of tumor cell death, which further augments DAB4 binding to produce a tumor-lethal ‘genotoxic chain reaction’. Clinically, this approach may be useful as consolidation treatment after a drug-induced cell death among (small-volume) metastatic deposits, the commonest cause of cancer death.This article is part II of a two-part series providing proof-of-concept for the diagnostic and therapeutic use of the DAB4 clone of the La-specific monoclonal antibody, APOMAB®.     

Splenectomy before tumor inoculation prolongs the survival time of cachectic mice

The effects of splenectomy on the development of cachexia, tumor growth and animal survival were studied in tumor-bearing CDF1 mice. Mice were inoculated with two subclones of colon 26 adenocarcinoma, clone 20 (with a potent capacity to induce cachexia) and clone 5 (without such activity), and underwent splenectomy before or after tumor inoculation. Splenectomy significantly prolonged the survival of mice bearing clone 20 when it was performed prior to tumor inoculation, although the progression of cachexia and tumor growth were not affected. The survival rate was higher in splenectomized than it was in nonsplenectomized mice 20–40 days after tumor inoculation. Such effects on survival were not observed, however, in mice splenectomized after inoculation with clone 20 or in mice that underwent splenectomy either before or after inoculation with clone 5. The decrease of peripheral blood lymphocyte count observed in mice bearing clone 20 was magnified when splenectomy was performed before tumor inoculation, but the serum levels of tumor necrosis factor and interleukin-6 were comparable. These results indicate that cancer death from cachexia is not directly attributable to enhanced catabolism. The mechanism by which splenectomy ameliorates the survival of cachectic mice remains to be studied, although several changes observed in the splenectomized mice after inoculation, including decreases in the peripheral blood L3T4⁺ cells and Lyt-2⁺ cells on the 9th day and 15th day respectively, and increase in the L3T4⁺/Lyt-2⁺ cell ratio on the 15th day suggest the involvement of the modified host's immune response.     

The role of interferon-alpha in a successful murine tumor therapy

Combination therapy using reovirus type 3 and the chemo-therapeutic agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) is sufficient to cure approximately 80% of EL-4 lymphoma tumor-bearing BD2F1 male mice. Cured animals can be challenged with the EL-4 tumor, in the absence of the therapy, to yield 100% survival, whereas those challenged with heterologous tumor produce 0% survival. These results strongly suggest that a host-immune response is responsible for the observed therapeutic effect. Reovirus, a double-stranded RNA virus, is an efficient inducer of type I interferon. In an effort to determine the role of virus in this therapy, we substituted interferon-alpha (IFN-alpha) for reovirus in the therapy. Doses of IFN-alpha from 1000-10,000 U were capable of replacing reovirus to produce cure rates similar to reovirus. Spleen cells isolated from therapy-treated animals demonstrated high levels of cytotoxicity against the natural killer cell-sensitive cell line YAC-1, but not against EL-4 tumor. In vitro stimulation of isolated spleen cells by IFN-alpha resulted in a high level of natural killer cell activity, but no cytotoxicity against the EL-4 tumor. A significant antiproliferative effect against the EL-4 tumor in cell culture was demonstrated by IFN-alpha. Finally, therapy-treated, tumor-bearing mice that were injected with anti-IFN-alpha + -beta antibodies had similar survival levels as control mice, indicating that other cytokines might also play a role in promoting tumor killing. These investigations suggest that IFN-alpha may be a mediator of antitumor activity in the reovirus therapy system.     

Colon cancer cell vaccine prepared with replication-deficient vaccinia viruses encoding B7.1 and interleukin-2 induce antitumor response in syngeneic mice

 A replication-deficient recombinant vaccinia virus, NYVAC, was developed by deleting 18 open reading frames in the vaccinia virus genome. Recombinant NYVAC, encoding the murine T cell co-stimulatory gene B7.1 (CD 80) (NYVAC-B7.1) and the murine interleukin-2 gene (NYVAC-IL-2), were prepared and the expression of B7.1 and the secretion of IL-2 were respectively confirmed in vitro. The use of these viruses to prepare a potent tumor cell vaccine was studied in a syngeneic murine CC-36 colon adenocarcinoma model. Mice were immunized on days 1 and 8 with 10⁶ irradiated CC-36 cells that were infected with 10⁷ plaque-forming units of either NYVAC-B7.1, NYVAC-IL-2 or a control virus, NYVAC-HR, which encodes a vaccinia virus host-range gene. These mice were then challenged with 10⁸ viable CC-36 tumor cells on day 15. All mice (10/10) in a group that had received no vaccination and all mice (20/20) in a group that had received a control vaccine of CC-36/NYVAC-HR developed tumor 4-weeks after tumor cell challenge. Interestingly, only 16/20 mice in a group that had received CC-36/NYVAC-B7.1 showed the development of tumor after the same interval. The protection against tumor development and the reduction in tumor burden (as mean tumor diameter, 4 weeks after tumor challenge) were significant in this group when compared to groups that were either unvaccinated or vaccinated with CC-36/NYVAC-HR (mean tumor diameter = 6.51±3.2 mm compared to 26.5±0.9 mm or 26.2±1.8 mm respectively) (P = < 0.05). The protection against tumor in a group of mice that received CC-36/NYVAC-IL-2 vaccination was similar to that in the unvaccinated group or the group receiving a CC-36/NYVAC-HR control vaccination. However, in a survival experiment, mice that received either CC36/NYVAC-B7.1 or CC-36/NYVAC-IL-2 vaccination on the day of tumor transplantation survived significantly longer than mice that had not been vaccinated (median survival 60+ days, 60+ days or 23.5 days respectively) (P = <0.05). Interestingly, when a therapeutic tumor vaccination was performed on day 4 after tumor transplantation, mice that had been vaccinated with either CC36/NYVAC-B7.1 or CC-36/NYVAC-IL-2 did not show an improved survival when compared to mice in the control that had not been vaccinated (median survival 28 days compared to 26 days or 25 days respectively). However, mice that had received a therapeutic vaccination with CC-36 cells infected with both NYVAC-B7.1 and NYVAC-IL-2, 4 days after tumor transplantation, survived significantly longer than control mice that had not received any vaccination (median survival 29.5 days compared to 25 days respectively) (P<0.05). These results suggest that a replication-deficient recombinant NYVAC encoding the B7.1 gene and NYVAC encoding the IL-2 gene can be used to produce an effective vaccinia-virus-augmented tumor cell vaccine. Received: 2 March 1998 / Accepted 23 March 1998     

Uptake of 2-fluoro-2-deoxy-d-[U-14C]-glucose during chemotherapy in murine Lewis lung tumor

Mice bearing intramuscular Lewis lung tumor were treated with BCNU and doxorubicin (ADM) to study chemotherapy-induced changes in the uptake of 2-fluoro-2-deoxy-[U-¹⁴C]glucose (FDG). A decreased FDG uptake, tumor regression and a diminished proportion of aneuploid versus diploid cells as evaluated by DNA flow cytometry were seen after treatment with BCNU but not with ADM; HPLC indicated that most of the ¹⁴C activity in tumors was from FDG6-phosphate. The results suggest that changes in FDG uptake reflect the effectiveness of antitumor therapy. FDG may be valuable in follow-up studies of cancer treatment.     

Enhanced tumor susceptibility of immunocompetent mice infected with lymphocytic choriomeningitis virus

Summary Mice infected i.v. with high doses of lymphocytic choriomeningitis virus (LCMV; 10⁵–10⁶ plaqueforming units) 8–10 days prior to challenge with the methylcholanthrene-induced fibrosarcoma tumor cell line MC57G or the melanoma cell line B16 tumor cells showed an enhanced tumor susceptibility with respect to both growth kinetics of the tumor and the minimal dose necessary for tumor take. After transient initial growth, MC57G tumor cells were all rejected by uninfected C57BL/6 mice by day 14. Mice preinfected i.v. with LCMV 3 weeks before or at the time of tumor challenge, but not those infected 2 months before or 7 days after, showed increasing tumor growth, the tumor take being 100% for 10⁶, 50% for 10⁵ and 37% for 10⁴ MC57G tumor cells injected into the footpad compared with resistance to 10⁶ cells in normal mice. B16 melanoma cells also grew more rapidly in LCMV-preinfected mice and by day 40 tumors were established with about 100 times fewer cells, i.e. about 10³ compared with 3×10⁴–3×10⁵ for uninfected mice. Analysis of the growth of tumor cells in normal and in LCMV-carrier mice revealed that the latter mice were not more susceptible to LCMV-infected than to uninfected MC57G. Since LCMV-carrier mice fail to mount LCMV-specific T cell responses, these results suggest that anti-LCMV-specific T cells may be responsible for acquired immunodeficiency hampering immune surveillance against the tumors studied.Supported by grants from the Swiss National Science Foundation 3.259–0.87 and the Kanton of Zürich     

Improvement of heart function in postinfarct heart failure swine models after hepatocyte growth factor gene transfer: comparison of low-, medium- and high-dose groups

Despite advances in surgical and reperfusion therapy, there is no effective therapy currently exists to prevent the progressive decline in cardiac function following myocardial infarction. Hepatocyte growth factor has potent angiogenic and anti-apoptotic activities. The aim of this study was to investigate the therapeutic effect and dose–effect relationship on postinfarction heart failure with different doses of adenovirus-mediated human hepatocyte growth factor (Ad₅-HGF) transference in swine models. Totally twenty swine were randomly divided into four groups: (a) control group (null- Ad₅, 1 ml); (b) low-dose group (1 × 10⁹ Pfu/ml Ad₅-HGF, 1 ml); (c) medium-dose group (5 × 10⁹ Pfu/ml Ad₅-HGF, 1 ml); (d) high-dose group (1 × 10¹⁰ Pfu/ml Ad₅-HGF, 1 ml). Four weeks after left anterior descending coronary artery (LAD) ligation, different doses of Ad₅-HGF were transferred in three therapeutic groups via right coronary artery. Four and seven weeks after LAD ligation, gate cardiac perfusion imaging was performed to evaluate cardiac perfusion and left ventricular ejection fraction (LVEF). Seven weeks after surgery, the apoptotic index of cardiocyte was observed by TUNEL, the expression of Bcl-2, Bax, α-SMA and Factor VIII in the border zones were evaluated by immunohistochemistry, respectively. Four weeks after myocardial infarction, no significant difference was observed among four groups. Three weeks after Ad₅-HGF transfer, the improvement of cardiac perfusion and LVEF was obviously observed, especially after 1 × 10¹⁰ Pfu Ad₅-HGF transfer. TUNEL assay showed that 5 × 10⁹ Pfu and 1 × 10¹⁰ Pfu Ad₅-HGF treatment had a obvious reduction in the apoptotic index compared with the null-Ad₅ group, especially after 1 × 10¹⁰ Pfu Ad₅-HGF treatment. The expression of Bcl-2 protein was increased and the expression of Bax protein was inhibited in the 5 × 10⁹ Pfu and 1 × 10¹⁰ Pfu Ad₅-HGF groups compared with the null-Ad₅ group. The vessel density of Factor VIII⁺ and α-SMA⁺ was increased in Ad₅-HGF groups compared with the null-Ad₅ group. There were no significant differences in angiogenesis, reducing apoptosis and ameliorating heart function between the 1 × 10⁹ Pfu Ad₅-HGF group and the null-Ad₅ group. Although no statistical difference was observed between 1 × 10¹⁰ Pfu and 5 × 10⁹ Pfu Ad₅-HGF groups, the cardiac protective effects of 1 × 10¹⁰ Pfu Ad₅-HGF treatment were greater than 5 × 10⁹ Pfu Ad₅-HGF treatment. Different doses of Ad5-HGF injected via noninfarct-related artery could induce angiogenesis, reduce apoptosis and ameliorate heart function, and the cardiac protective effects of 1 × 10¹⁰ Pfu Ad5-HGF is of most significance.     

替吉奥联合阿帕替尼对晚期复发转移食管癌患者T细胞亚群和血清肿瘤标志物水平的影响

摘要 目的：观察晚期复发转移食管癌经阿帕替尼联合替吉奥治疗后的疗效及对患者T细胞亚群和血清肿瘤标志物水平的影响。方法：病例搜集时间为2015年3月至2018年3月,病例搜集范围为我院接收的晚期复发转移食管癌患者70例。采用信封抽签法将患者分为对照组和实验组,各为35例。对照组给予替吉奥治疗,实验组在对照组的基础上联合阿帕替尼治疗,两组均连续化疗2个周期。对比两组化疗2个周期后的客观缓解率、疾病控制率;对比两组化疗前、化疗2个周期后的T细胞亚群和血清肿瘤标志物水平;对比两组中位总生存期（mOS）、中位无进展生存期（mPFS）及生命质量评分,记录两组化疗期间毒副反应发生情况。结果：实验组的客观缓解率45.71%、疾病控制率68.57%高于对照组的22.86%、42.86%（P<0.05）。两组化疗2个周期后CD3⁺、CD4⁺、CD4⁺/ CD8⁺均较化疗前降低,但实验组高于对照组（P<0.05）;CD8⁺较化疗前升高,但实验组低于对照组（P<0.05）。两组化疗2个周期后肿瘤特异性生长因子（TSGF）、癌胚抗原（CEA）、糖类抗原199（CA199）较化疗前降低,且实验组低于对照组（P<0.05）。实验组的mOS、mPFS长于对照组（P<0.05）,两组化疗结束后3个月QLQ-OES24评分均升高,且实验组高于对照组（P<0.05）。两组不良反应发生率对比,差异无统计学意义（P>0.05）。结论：晚期复发转移食管癌经阿帕替尼联合替吉奥治疗后,病情得到有效控制,血清肿瘤标志物水平降低更为显著,同时还可减轻免疫抑制,延长mOS、mPFS,且不增加毒副反应,近期疗效可靠。     

The Combination of a Low-Dose Chemotherapeutic Agent, 5-Fluorouracil,and an Adenoviral Tumor Vaccine Has a Synergistic Benefit on Survival in a Tumor Model System

Standard cancer therapies, particularly those involving chemotherapy, are in need of modifications that both reduce short-term and long-term side effects as well as improve the overall survival of cancer patients. Here we show that combining low-dose chemotherapy with a therapeutic vaccination using an adenovirus encoding a model tumor-associated antigen, ovalbumin (Ad5-OVA), had a synergistic impact on survival in tumor-challenged mice. Mice that received the combinatorial treatment of Ad5-OVA plus low-dose 5-fluorouracil (5-FU) had a 95% survival rate compared to 7% and 30% survival rates for Ad5-OVA alone and 5-FU alone respectively. The presence of 5-FU enhanced the levels of OVA-specific CD8⁺ T lymphocytes in the spleens and draining lymph nodes of Ad5-OVA-treated mice, a phenomenon that was dependent on the mice having been tumor-challenged. Thus 5-FU may have enhanced survival of Ad5-OVA-treated mice by enhancing the tumor-specific immune response combined with eliminating tumor bulk. We also investigated the possibility that the observed therapeutic benefit may have been derived from the capacity of 5-FU to deplete MDSC populations. The findings presented here promote the concept of combining adenoviral cancer vaccines with low-dose chemotherapy.     

Successful adoptive immunotherapy with OK432-inducible activated natural killer cells in tumor-bearing mice

We had demonstrated that the NK cell mediated cytotoxicity of murine spleen cells could be augmented byin vivo priming and subsequentin vitro challenge with a streptococcal preparation OK432, and the cell surface phenotype of induced killer cells was Thy-1⁺, asialo GM1⁺, suggesting that the activated cells were of NK lineage (OK-NK cell). We had also clarified that IL-2 played a major role in inducing the OK-NK cells via the production of IFN-. In this study, we examined the effect of adoptive transfer of OK-NK cells on syngeneic tumors in mice. Mice were implanted with SP2 myeloma cells intraperitoneally (i.p.), or C26 colon adenocarcinoma cells subcutaneously to make the models of peritonitis carcinomatosa or solid tumor, and the OK-NK cells were transferred i.p. or intratumorally, adoptively. By the adoptive transfer of OK-NK cells, 92% of mice bearing SP2-tumor had be cured. The tumor growth of C26-solid tumor was inhibited, and the survival rate of mice bearing C26-tumor was significantly increased. The intratumoral remnants of¹²⁵I-labelled OK-NK cells were 61, 27 and 8% at 4, 12 and 36h after intratumoral transfer, respectively. By multiple transfer of OK-NK cells, the antitumor effect was more effectively augmented than that of a single transfer. Results in this study suggested that OK-NK cells could be useful for the therapy of cancer patients.     

吉非替尼联合PC化疗方案对表皮生长因子受体突变阳性晚期肺腺癌患者免疫功能、凋亡因子和肿瘤标志物的影响

摘要 目的：探讨吉非替尼联合铂类加环磷酰胺（PC）化疗方案对表皮生长因子受体（EGFR）突变阳性晚期肺腺癌患者免疫功能、凋亡因子和肿瘤标志物的影响。方法：选取南通大学附属肿瘤医院2018年3月~2020年3月期间收治的92例EGFR阳性晚期肺腺癌患者,根据随机数字表法分为对照组（PC化疗）和实验组（吉非替尼联合PC化疗）,各为46例。观察两组疗效、肿瘤标志物、免疫功能、凋亡因子变化情况、肿瘤无进展生存时间（PFS）、总生存时间（OS）和不良反应发生率。结果：实验组的客观缓解率、疾病控制率均高于对照组（P<0.05）。两组治疗后血清癌胚抗原（CEA）、细胞角蛋白-19片段（CYFRA21-1）、鳞状细胞癌抗原（SCC-Ag）水平较治疗前均下降,且实验组较对照组低（P<0.05）。治疗后两组CD8⁺升高,但实验组较对照组低;而治疗后CD3⁺、CD4⁺、CD4⁺/CD8⁺均下降,但实验组较对照组高（P<0.05）。两组治疗后血清Livin水平较治疗前下降,且实验组低于对照组（P<0.05）,两组治疗后血清PDCD5、P53、Bax水平较治疗前均升高,且实验组均高于对照组（P<0.05）。两组不良反应发生率组间对比无明显差异（P>0.05）。实验组的PFS、OS高于对照组（P<0.05）。结论：吉非替尼联合PC化疗方案治疗EGFR突变阳性晚期肺腺癌患者,可调节血清凋亡因子和肿瘤标志物水平,有效改善患者的免疫功能和预后。     

Increased efficiency of immunotherapy using irradiated tumor cells

Summary The efficacy of irradiated tumor cells combined with chemotherapy or non-specific immunostimulation with complete Freund's adjuvant was tested in a model of minimal residual tumor-bearing syngeneic mice. Male C57BL/6J mice were innoculated in the right rear leg with live tumor cells from a methylcholanthrene induced fibrosarcoma. The tumor was resected when it reached 0.7 cm in diameter and animals were treated with doses of irradiated tumor cells (XTC) from the primary tumor ranging in number from 1×10³ to 9×10³. Best survival was noted using 5×10³ XTC combined with irradiated tumor cells of liver or pulmonary metastases origin, complete Freund's adjuvant or cytoxan. The combination of irradiated tumor cells of metastatic origin did not enhance the therapeutic effect of XTC alone. Freund's adjuvant was not of benefit in enhancing the efficacy of XTC. However, improved survival was noted when chemotherapy in the form of cytoxan was used to supplement XTC. Our data suggests that XTC is more efficacious as a mode of immunotherapy than are live tumor cells. The dose of XTC used is critical in determining its effect. Chemotherapy appears to enhance the benefit of XTC.Research fellow from Zhejiang Medical University, Hongzhou, ChinaSupported by the Brigham Surgical Group, Inc.     

Adoptive chemoimmunotherapy of a syngeneic murine lymphoma with long-term lymphoid cell lines expanded in T cell growth factor

Summary Recently techniques have been developed for the long-term growth of cytotoxic T-lymphoid cells in vitro with T cell growth factor (TCGF). We have investigated the use of these in vitro-expanded T cells for the immunotherapy of a disseminated syngeneic murine FBL-3 lymphoma. In this model, mice with disseminated tumor were treated on day 5 with 180 mg cytoxan/kg and then 5 h later were given lymphoid cells IP. In vivo-immunized lymphocytes resulted in significantly improved survival in three of three experiments, curing 52% of 38 animals, compared with treatment with cytoxan alone (0 of 31 cured) or cytoxan plus unimmunized cells (0 of 40 cured) (P<0.0005). In vivo-immunized lymphocytes were re-exposed to FBL-3 tumor in vitro for 5 days in complete medium (CM) or lectin-free TCGF (LF-TCGF). Both groups showed significantly improved survival in six of six experiments. Cytoxan cured 17% of 66 animals, while cytoxan plus normal lymphocytes after IVS cured 6% of 47 animals. In vivo-immunized cells resensitized in vitro to FBL-3 in CM or LF-TCGF cured 82% of 50 animals (P<0.001) and 72% of 61 animals (P<0.001), respectively. Cells from in vivo- and in vitro-sensitized lymphocytes exhibited no cytotoxicity in our in vitro ⁵¹Cr-release assay; expansion of these cells resulted in significant specific lysis of fresh FBL-3 targets. Adoptive transfer of immune lymphocytes resensitized to FBL-3 tumor in vitro and expanded in LF-TCGF conferred a significant survival benefit (P<0.001, curing 7 of 27 animals) compared with all controls. These expanded cells were then continuously grown in LF-TCGF for 2 1/2 months. Again, in vivo-immunized lymphocytes resensitized to FBL-3 tumor and expanded in LF-TCGF for 2 1/2 months cured 56% of the animals with disseminated tumor, significantly prolonging survival over that recorded in any control group (P<0.0002). Irradiation of these same cells totally abolished their efficacy. Clones were generated from IVS and continuously grown in LF-TCGF. Two of these clones were very cytotoxic for fresh FBL-3 (>4,000 lytic units/10⁶ cells). When adoptively transferred to mice in this chemoimmunotherapy model these cytotoxic clones significantly enhanced survival over that recorded following treatment with cytoxan alone (P<0.00001), though prolongation of survival was small. Implications of these results for application of these techniques to other less antigenic tumors and human cancers are discussed.     

Postsurgical adjuvant chemoimmunotherapy with recombinant interleukin-2 and 1,3-bis-(2-chloroethyl)-1-nitrosurea on spontaneous metastases of a non-immunogenic murine tumour

Summary The efficacy of the association of recombinant interleukin-2 (rIL-2) with chemotherapy has been investigated on an experimental model representative of clinical tumours, i.e. on post-surgical spontaneous metastases of a non-immunogenic tumour. We used the M5076 ovarian reticulum cell sarcoma, which metastatizes to the liver after intra-footpad implantation. Such a tumour appeared to be non-immunogenic by a variety of commonly used in vivo assays. Four clinically widely employed drugs, i.e. doxorubicin,cis-diamminedichloroplatinum II, cyclophosphamide and 1,3-bis-(2-chloroethyl)-1-nitrosurea (BCNU), were tested and BCNU proved to be the most effective one when administered as single injection at the maximum tolerated dose (33 mg/kg i.p.) 1 day after tumour excision. When moderate doses of rIL-2 (6 × 10⁵ IU in three injections per day for 5 days) were administered at three different intervals after BCNU, namely before the nadir of white blood cells (1 day after BCNU), at the nadir (3 days after BCNU) or at recovery (6 days after BCNU), no increase in BCNU antitumour activity was observed. The same results were obtained by administering rIL-2 for 5 days before BCNU. Higher doses of rIL-2 (1.2 × 10⁶ IU in three injections per day for 5 days), which were always well tolerated in sham-excised non-tumour-bearing mice, proved lethal in two out of four experiments in tumour-bearing animals. In the two experiments in which no lethality was observed, the administration of high doses of rIL-2 1 or 6 days after BCNU significantly increased the antitumour activity of BCNU alone. rIL-2 alone was not active even when administered at high doses. These results indicate that high but not moderate doses of rIL-2 may increase the activity of BCNU against a non-immunogenic tumour. Moreover, they suggest that rIL-2 tolerability is reduced in tumour-bearing mice.     

Importance of signaling via the IFN-α/β receptor on host cells for the realization of the therapeutic benefits of cyclophosphamide for mice bearing a large MOPC-315 tumor

Here we show that low-dose cyclophosphamide (CY), that depends for its therapeutic effectiveness on the immunopotentiating activity of the drug for T cell-mediated tumor-eradicating immunity, is curative for ~80% of wild-type (WT) mice bearing a large s.c. MOPC-315 tumor, but only for ~10% of IFN-α/βR^−/− mice bearing a large s.c. MOPC-315 tumor. Histopathological examination of the s.c. tumors of such mice on day 4 after the chemotherapy revealed that the low dose of CY led to accumulation of T lymphocytes in both the WT and the IFN-α/βR^−/− mice. However, in the CY treated tumor bearing WT mice the T lymphocytes were present throughout the tumor mass and in direct contact with tumor cells, but in the CY treated tumor bearing IFN-α/βR^−/− mice most of the T lymphocytes remained in blood vessels. In addition to being important for CY-induced transendothelial migration of T lymphocytes into the tumor mass, we show here that signaling via the IFN-α/βR is also important for CY-induced control of metastatic tumor progression in the spleen and liver of the tumor bearing mice. Finally, CY cured tumor bearing WT mice were resistant to a subsequent challenge with MOPC-315 tumor cells, but the few CY cured tumor bearing IFN-α/βR^−/− mice were not. Thus, signaling via the IFN-α/βR on host cells in MOPC-315 tumor bearers is important for CY-induced: (a) transendothelial migration of T lymphocytes into the tumor mass and the eradication of the primary tumor, (b) control of metastatic tumor progression, and (c) resistance to a subsequent tumor challenge. This work was supported by Research Grant 03-19 from the American Cancer Society-Illinois Division.