Expression of the p73 protein in rectal cancers with or without preoperative radiotherapy

PURPOSE: To investigate p73 expression in normal mucosa, primary tumor, and metastasis in relation to radiotherapy (RT) response and clinicopathologic/biologic variables in rectal cancers. METHODS AND MATERIALS: p73 was immunohistochemically examined on biopsies (unirradiated, n=102), distant (from the large bowel, n=82), and adjacent (adjacent to primary tumor, n=89) normal mucosa samples, primary tumors (n=131), and lymph node metastasis (n=32) from rectal cancer patients participating in a clinical trial of preoperative RT. Seventy-four patients received surgery alone and 57 received additional RT. RESULTS: Cytoplasmic p73 was increased in the primary tumor compared with the distant or adjacent mucosa (p相似文献   

NK and CD8+ T cell-mediated eradication of poorly immunogenic B16-F10 melanoma by the combined action of IL-12 gene therapy and 4-1BB costimulation

In previous reports, systemic administration of a stimulatory monoclonal antibody directed against the 4-1BB receptor had no effect on survival or tumor burden in mice inoculated with the poorly immunogenic B16-F10 melanoma. We combined IL-12 gene transfer with 4-1BB costimulation to explore a previously noted cooperative anti-tumor effect against this model tumor. We hypothesize that the innate immune response mediated by IL-12-activated natural killer (NK) cells initiates the activation of the immune system, leading to the priming of T cells, whereas 4-1BB costimulation enhances the function of primed tumor-specific T cells. The effect of the combination therapy on the growth of subcutaneous (s.c.) tumors and pulmonary metastasis was examined. The combination therapy significantly retarded the growth of subcutaneously-inoculated tumors, and 50% of tumor-bearing mice survived with complete tumor regression. In contrast, neither IL-12 gene transfer nor anti-4-1BB antibody administration alone was as effective. Enhanced CTL activity against both B16-F10 tumor cells and TRP-2-pulsed EL4 syngeneic tumor cells was observed in tumor-bearing animals treated with the combination therapy 2 weeks after treatment and, in long-term survivors from this combination therapy, at >120 days. In a pulmonary metastatic model, only the combination therapy generated significant protection against metastasis. In vivo depletion of NK or CD8(+) but not CD4(+) subsets eliminated the protective immunity. Furthermore, NK cell depletion significantly reduced both tumor-specific CTL activity and the number of tumor-specific IFN-gamma-producing cells, suggesting that this synergistic effect requires the participation of both NK and CD8(+) T cells.     

Inhibition of spontaneous development of liver tumors by inoculation with dendritic cells loaded with hepatocellular carcinoma cells in C3H/HeNCRJ mice

We attempted to prevent spontaneous development of liver tumors by s.c. inoculation with DCs loaded with syngeneic HCC cells in C3H/HeNCrj mice. A new cell line, MIH-2, was established from an HCC that had developed spontaneously in a C3H/HeNCrj mouse. Bone marrow-derived DCs were loaded with irradiated MIH-2 cells by treatment with PEG. Fluorescence microscopy and flow-cytometric analysis showed that about 45% of PEG-treated DCs and MIH-2 cells (DC/MIH-2) were DCs loaded with MIH-2 cells. Thirteen-month-old mice received inoculations of DC/MIH-2 (9 x 10(5)/mouse) 4 times at 6-day intervals and were killed at 16 months of age to assess liver tumors. The incidence of liver tumors in these mice was significantly lower than that in mice not receiving inoculations (p < 0.05) but similar to that in 13-month-old mice (the age at which inoculation started), indicating that inoculation inhibited the development of new tumors. Splenocytes from inoculated mice, but not those from uninoculated mice, showed cytotoxic activity against MIH-2 cells. Cytotoxic activity was not elicited by CD4(+) T cells, CD8(+) T cells, or DX5(+) cells isolated from splenocytes but was elicited by adherent cells, identified as CD11b(+) macrophages. CD4(+) T cells, but not CD8(+) T cells, from inoculated mice produced IFN-gamma by incubation with DC/MIH-2. Cytotoxicity by splenocytes was attenuated by anti-IFN-gamma antibody. Immunization with DCs loaded with syngeneic HCC cells induces CD4(+) T cells that produce IFN-gamma by response to antigen of HCC, which would lead to macrophage activation to kill liver tumor cells at an early stage.     

Successful cancer vaccine therapy for carcinoembryonic antigen (CEA)-expressing colon cancer using genetically modified dendritic cells that express CEA and T helper-type 1 cytokines in CEA transgenic mice

This study was designed to determine whether the vaccination of genetically modified dendritic cells (DCs) simultaneously expressing carcinoembryonic antigen (CEA), granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin 12 (IL-12) can overcome the peripheral T-cell tolerance to CEA and thereby elicit a therapeutic response in CEA transgenic mice. CEA transgenic mice were immunized once by subcutaneous injection with DCs adenovirally transduced with CEA and T helper-type 1 cytokine genes. The cytotoxic activity of spleen cells against CEA-expressing tumors, MC38-CEA, in the mice immunized with DCs expressing CEA (DC-AxCACEA) was higher than that in those immunized with DCs-AxCALacZ (p < 0.0001), and was augmented by the cotransduction with the GM-CSF/IL-12 gene (p < 0.05). The vaccination with DC-AxCACEA/GM-CSF/IL-12 could elicit a more potent therapeutic immunity than the vaccination with DC-AxCACEA in subcutaneous tumor models (p < 0.0001), and 4 of 5 mice showed a complete eradication of the subcutaneous tumors in these vaccination groups. Even in a large tumor model, this vaccination therapy completely eliminated the subcutaneous tumors in all mice. This antitumor activity mostly vanished with the depletion of CD8(+) T cells and NK cells in vivo and was completely abrogated with the depletion of CD4(+) T cells. A histopathological examination showed no evidence of an autoimmune reaction. No other adverse effects were observed. This vaccination strategy resulted in the generation of highly efficient therapeutic immune responses against MC38-CEA in the absence of autoimmune responses and demonstrated no adverse effects, and may therefore be useful for future clinical applications as a cancer vaccine therapy.     

Depletion of CD4+CD25+ regulatory T cells enhances interleukin-2-induced antitumor immunity in a mouse model of colon adenocarcinoma

Interleukin 2 (IL)-2 induces antitumor immunity and clinical responses in melanoma and renal cell carcinoma. However, IL-2 also increases the number of CD4(+)CD25(+) regulatory T (Treg) cells that suppress antitumor immune responses. The aim of the present study was to elucidate the effect of depletion of Treg cells on IL-2-induced antitumor immunity. IL-2-transfected mouse colon adenocarcinoma (MC38/IL-2) cells were implanted subcutaneously or intrahepatically into male C57BL/6 mice, and tumor growth and the proportion of tumor-infiltrating lymphocytes with Treg-cell depletion in response to treatment with anti-CD25 monoclonal antibody (PC61) were determined. In mice treated with phosphate-buffered saline, 40-60% of MC38/IL-2 tumors were rejected. In contrast, all MC38/IL-2 tumors were rejected in mice treated with PC61. The number of tumor-infiltrating CD8(+) T cells in mice treated with PC61 was approximately twice that in mice treated with PBS. The numbers of tumor-infiltrating CD4(+) and natural killer cells were also increased significantly. To test the antimetastatic effects of IL-2 treatment in combination with Treg-cell depletion, human recombinant IL-2 (rIL-2) and PC61 were administered to mice implanted with MC38/mock cells in the spleen, and hepatic metastasis was investigated. The average liver weight in mice treated with rIL-2 plus PC61 was 1.04 +/- 0.03 g, less than that in mice treated with rIL-2 (2.04 +/- 0.51 g) or PC61 alone (1.81 +/- 0.38 g). We conclude that IL-2-induced antitumor immunity is enhanced by Treg-cell depletion and is due to expansion of the tumor-infiltrating cytotoxic CD8(+) T-cell population.     

Combination therapy of murine liver cancer with il-12 gene and HSV-TK gene

Interleukin-12 (IL-12), produced by antigen-presenting cell, is a heterodimeric cytokine that has multiple immune regulatory functions, various studies have shown that IL-12 has multiple anti-tumor effects and anti-metastatic properties for many tumors.[1] Suicide gene approaches are also widely investigated recently, the gene products are capable of converting the non-toxic pro-drug to the active cytotoxic agent. The most commonly used suicide gene and pro-drug is the herpes simplex virus th…     

肺癌患者免疫功能变化测定及其临床意义

目的 探讨肺癌患者机体免疫功能变化及临床意义.方法 采用流式细胞术测定68例肺癌患者治疗前及20例健康志愿者外周静脉血中CD+3T、CD+4T、CD+8T、NK细胞以及Th1类细胞因子干扰素(INF)-γ、白细胞介素(IL)-2、肿瘤坏死因子(TNF)-α;Th2类细胞因子IL-4、IL-6、IL-10的水平.结果 肺癌患者外周血中CD+3T、CD+4T细胞、CD4/CD8值下降;CD+8T、NK细胞升高;TNF-α、IL-4、IL-6、IL-10水平均升高,Th1/Th2值降低,与对照组比较差异均有统计学意义,(P分别＜0.05～0.001).肺癌患者NK与CD3、CD4、CD8均呈负相关;CD4与Th2类细胞因子呈负相关.化疗前肺癌患者外周血淋巴细胞,Th1、Th2类细胞因子水平与病理类型、淋巴结转移、远处转移无关均(P＞0.05).结论 肺癌患者细胞免疫功能普遍低下,其中CD+4T细胞的数量和功能降低比较显著,其功能的降低可能与Th1/Th2因子失衡有关.     

Immunotherapy with concurrent subcutaneous GM-CSF,low-dose IL-2 and IFN-alpha in patients with progressive metastatic renal cell carcinoma

The purpose of the study was to determine toxicity, efficacy and immunologic effects of concurrent subcutaneous injections of low-dose interleukin-2 (LD-IL-2), granulocyte-monocyte colony-stimulating factor (GM-CSF) and interferon-alpha 2b (IFNalpha) in progressive metastatic renal cell carcinoma. In a multicentre phase II study, 59 evaluable patients received two to six cycles of subcutaneous IL-2 (4 mIU m(-2)), GM-CSF (2.5 microg kg(-1)) and IFNalpha (5 mIU flat(-1)) for 12 days per 3 weeks with evaluation after every two cycles. Cycles were repeated in responding or stable patients. Data were analysed after a median of 30 months follow-up (range 16-48 months). In 42 patients, the immunologic response was studied and related to response and survival. The main toxicity were flu-like symptoms, malaise and transient liver enzyme elevations, necessitating IL-2 reduction to 2 mIU m(-2) in 29 patients, which should be considered the maximal tolerable dose. The response was 24% (eight out of 34, three complete response (CR), five partial response (PR)) in patients with metachronic metastases and 12% (three out of 25, 2CR, 1PR) in patients with synchronic metastases. Overall response was 19% (11 out of 59). Median survival was 9.5 months. All tested patients showed expansion and/or activation of lymphocytes, T cells and subsets, NK cells, eosinophils and monocytes. Pretreatment HLA-DR levels on monocytes and number of CD4(+)HLA-DR(+) cells correlated with response. Pretreatment number of CD4(+)HLA-DR(+) cells and postimmunotherapy levels of lymphocytes, CD3(+), CD4(+) and CD8(+) T cells, but not of NK or B cells, correlated with prolonged survival. Immunotherapy with concurrent subcutaneous GM-CSF, LD-IL-2 and IFNalpha has limited toxicity, can be given as outpatient treatment and can induce durable CR. Response and survival with this form of immunotherapy seem to be more dependent on expansion/activation of T cells than of NK cells.     

A convenient cancer vaccine therapy with in vivo transfer of interleukin 12 expression plasmid using gene gun technology after priming with irradiated carcinoma cells

We studied interleukin (IL)-12 gene therapy using a gene gun as a new autologous vaccination strategy for cancer. In the first experiment, BALB/c mice were inoculated with syngeneic murine renal cancer cells (Renca) intradermally in the abdomen. This was followed by an injection of IL-12 expression plasmid using the gene gun. About 40% of the mice exhibited rejection of the tumor after the treatment and these mice also acquired immunological resistance against a secondary challenge with Renca cells. Based on these results, we examined whether antitumor activity can be potentiated when mice undergo combination treatment with intradermal inoculation of irradiated Renca cells and transfection with IL-12 gene. Inoculation of irradiated Renca cells alone was partially effective in inducing antitumor immunity, whereas the combined treatment remarkably intensified this effect. Moreover, this combined treatment inhibited tumor establishment and enhanced survival of the mice with tumor infiltration by CD4(+) and CD8(+) T cells, even when the treatment was started after tumor-implantation at a distant site. This antitumor effect was antigen specific and we confirmed the induction of antitumor cytotoxic T cells by this treatment. These results show that local cutaneous transfer of IL-12 expression plasmid using gene gun technology enhances systemic and specific antitumor immunity primed by irradiated tumor cells.     

Regression of engineered myeloma cells secreting interferon-gamma-inducing factor is mediated by both CD4(+)/CD8(+) T and natural killer cells

IL-18 is a novel cytokine that stimulates T and NK cell activity and has potent antitumor effects. In this study, a mouse IL-18 gene was transfected into the mouse myeloma cell line J558. Our data demonstrated that (i) inoculation of 0.5x10(6) engineered tumor cells J558/IL-18 into syngeneic mice induced a Th1 dominant immune response and resulted in tumor regression in all 8/8 mice; (ii) the IL-18 antitumor effect was significantly decreased in mice depleted of either the CD4(+), or CD8(+), or NK cell subset, respectively but was completely abrogated in mice depleted of both CD4(+) and CD8(+) T cells; (iii) in vivo neutralization of IFN-gamma was accompanied by the growth of J558/IL-18 tumor in all the mice; and (iv) the J558/IL-18 tumor regression further induced protective immunity against a subsequent challenge by the parental J558 tumor, which is mediated by CD8(+) T cells as examined in the cytotoxicity assay in vitro and in the animal study in vivo. Taken together, our findings indicate that: (i) IL-18 can induce antitumor immune responses mediated by both CD4(+)/CD8(+) T cells and NK cells; and (ii) it is associated with IFN-gamma production. This study thus highlights the potential utility of IL-18 as an antitumor agent, a role that it can fulfil alone or in combination with other immunomodulatory cytokines such as IL-12.     

Human tumor-derived exosomes selectively impair lymphocyte responses to interleukin-2

Exosomes are nanometer-sized vesicles, secreted by normal and neoplastic cells. The outcome following interaction between the cellular immune system and cancer-derived exosomes is not well understood. Interleukin-2 (IL-2) is a key factor supporting expansion and differentiation of CTL and natural killer (NK) cells but can also support regulatory T cells and their suppressive functions. Our study examined whether tumor-derived exosomes could modify lymphocyte IL-2 responses. Proliferation of healthy donor peripheral blood lymphocytes in response to IL-2 was inhibited by tumor exosomes. In unfractionated lymphocytes, this effect was seen in all cell subsets. Separating CD4(+) T cells, CD8(+) T cells, and NK cells revealed that CD8(+) T-cell proliferation was not inhibited in the absence of CD4(+) T cells and that NK cell proliferation was only slightly impaired. Other exosome effects included selective impairment of IL-2-mediated CD25 up-regulation, affecting all but the CD3(+)CD8(-) T-cell subset. IL-2-induced Foxp3 expression by CD4(+)CD25(+) cells was not inhibited by tumor exosomes, and the suppressive function of CD4(+)CD25(+) T cells was enhanced by exosomes. In contrast, exosomes directly inhibited NK cell killing function in a T-cell-independent manner. Analysis of tumor exosomes revealed membrane-associated transforming growth factor beta(1) (TGFbeta(1)), which contributed to the antiproliferative effects, shown by using neutralizing TGFbeta(1)-specific antibody. The data show an exosome-mediated mechanism of skewing IL-2 responsiveness in favor of regulatory T cells and away from cytotoxic cells. This coordinated "double hit" to cellular immunity strongly implicates the role of exosomes in tumor immune evasion.     

白细胞介素—12基因与HSV—TK基因联合治疗小鼠肝癌的研究

目的　观察白介素１２（ＩＬ１２） 基因与单纯疱疹病毒胸苷激酶（ＨＳＶＴＫ） 基因联合治疗小鼠肝癌的疗效。方法　将ＩＬ１２ 基因和ＨＳＶＴＫ 基因分别转导入小鼠肝癌ＭＭ４５Ｔ－Ｌｉ 细胞,获稳定表达的ＭＭ４５Ｔ－ＬｉＩＬ１２ 和ＭＭ４５Ｔ－ＬｉＴＫ。于Ｂａｌｂｃ 小鼠皮下接种ＭＭ４５Ｔ－Ｌｉ 细胞２ ×１０５ ,待肿瘤长至０－５～１－０ ｃｍ 时,将ＭＭ４５Ｔ．ＬｉＴＫ细胞与经６０ Ｃｏ 照射的ＭＭ４５Ｔ．ＬｉＩＬ１２ 细胞混合,行瘤内注射治疗,于治疗次日,腹腔注射Ｇａｎｃｉｃｌｏｖｉｒ（ＧＣＶ４０ ｍｇ·ｋｇ－ １·ｄ－ １） ,连续注射１０ 天。按同样方法观察对远侧接种的肿瘤的治疗作用,并通过细胞毒Ｔ淋巴细胞（ＣＴＬ） 活性检测及免疫组化染色,探讨其抗肿瘤机制。结果　ＭＭ４５Ｔ．ＬｉＩＬ１２ 与ＨＳＶＴＫＧＣＶ 联合治疗,肿瘤体积显著缩小,生长受到抑制,疗效显著优于单独治疗组（ Ｐ＜ ０．０１） 。有６０％ 小鼠的肿瘤完全消退,且观察２ 个月无肿瘤生长。两者联合治疗,对远侧肿瘤也具有明显的抗肿瘤作用（ Ｐ＜０．０５） 。ＭＭ４５Ｔ．ＬｉＩＬ１２ 与ＨＳＶＴＫＧＣＶ系统联合诱导的小鼠ＣＴＬ明显高于单     

CD8+ T cells induce complete regression of advanced ovarian cancers by an interleukin (IL)-2/IL-15 dependent mechanism.

PURPOSE: In vitro studies suggest that ovarian cancer evades immune rejection by fostering an immunosuppressive environment within the peritoneum; however, the functional responses of ovarian cancer-specific T cells have not been directly investigated in vivo. Therefore, we developed a new murine model to enable tracking of tumor-specific CD8(+) T-cell responses to advanced ovarian tumors. EXPERIMENTAL DESIGN: The ovarian tumor cell line ID8 was transfected to stably express an epitope-tagged version of HER-2/neu (designated Neu(OT-I/OT-II)). After i.p. injection into C57BL/6 mice, ID8 cells expressing Neu(OT-I/OT-II) gave rise to disseminated serous adenocarcinomas with extensive ascites. CD8(+) T cells expressing a transgenic T-cell receptor specific for the OT-I epitope of Neu(OT-I/OT-II) were adoptively transferred into tumor-bearing mice, and functional responses were monitored. Cytokine signaling requirements were evaluated by comparing the responses of wild-type donor T cells with those with genetic deletion of the interleukin (IL)-2/IL-15 receptor beta subunit (CD122) or the IL-2 receptor alpha subunit (CD25). RESULTS: On adoptive transfer into tumor-bearing hosts, wild-type OT-I T cells underwent a striking proliferative response, reaching peak densities of approximately 40% and approximately 90% of CD8(+) T cells in peripheral blood and ascites, respectively. OT-I cells infiltrated and destroyed tumor tissue, and ascites completely resolved within 10 days. By contrast, CD122(-/-) OT-I cells and CD25(-/-) OT-I cells proliferated in blood but failed to accumulate in ascites or tumor tissue or induce tumor regression. CONCLUSIONS: Contrary to expectation, advanced ovarian cancers can support extraordinary CD8(+) T-cell proliferation and antitumor activity through an IL-2/IL-15-dependent mechanism.     

Expression of PRL proteins at invasive margin of rectal cancers in relation to preoperative radiotherapy

PURPOSE: PRL-3 (phosphatase of regenerating liver) is involved in metastasis of colorectal cancer; however, its therapeutic implication in cancer patients has not been studied. We investigated the relationships of PRL expression to radiotherapy (RT) in rectal cancer patients. METHODS AND MATERIALS: Phosphatase of regenerating liver expression was immunohistochemically examined in distant (n = 36) and adjacent (n = 82) normal mucosa, primary tumor (n = 125), biopsy specimens (n = 96), and lymph node metastasis (n = 30) from rectal cancer patients participating in a clinical trial of preoperative RT. RESULTS: Phosphatase of regenerating liver expression was increased from the distant to adjacent mucosa and to the primary tumor (p < 0.05). PRL was highly expressed at the invasive margin in 28% of the primary tumors and 26% of the metastases. In the RT group, strong PRL expression at the invasive margin was related to distant recurrence (p = 0.006) and poor survival (p = 0.01), but not in the non-RT group. The survival significance remained even after adjusting for Dukes' stage and differentiation (p = 0.02). Additional multivariate analyses showed that the correlation with prognostic significance of PRL differed between the RT and non-RT groups (p = 0.01). CONCLUSION: Phosphatase of regenerating liver expression (rather than PRL-3 alone) at the invasive margin predicted resistance to RT and unfavorable survival in rectal cancer patients with preoperative RT.     

Antitumor efficacy of a human interleukin-12 expression plasmid demonstrated in a human peripheral blood leukocyte/human lung tumor xenograft SCID mouse model

Genes encoding the p35 and p40 subunits of human interleukin-12 (IL-12) and the bacterial aminoglycoside phosphotransferase were cloned into a mammalian expression plasmid. The resultant plasmid, pCMVIL-12neo, was used to transfect human lung tumor cell lines in vitro. Stably transfected subclones were generated and found to secrete human IL-12 for at least 10 days following a lethal dose of gamma-radiation. The ability of the IL-12--producing tumor cells to promote an antitumor response in vivo was evaluated in SCID mice co-engrafted subcutaneously with human peripheral blood lymphocytes (PBLs) and viable human lung tumor cells (SCID-Winn assay). Using this model system, it was established that IL-12 released locally into tumors by irradiated IL-12--transfected cells activated the human PBL and promoted their ability to suppress tumor development in a dose-dependent fashion. PBL subset depletion studies revealed that the antitumor effect promoted by the IL-12--modified cells was dependent on the presence of human CD8(+) T cells and, to a lesser extent, human CD56(+) natural killer cells within the xenograft. We conclude that (a) irradiated human lung tumor cells genetically modified with pCMVIL-12neo secrete bioactive human IL-12 at concentrations sufficient to promote a human lymphocyte-mediated antitumor response in the microenvironment of the xenograft, and (b) that the SCID-Winn assay provides a useful model for the preclinical evaluation of cytokine-based human immunotherapy protocols.     

Failed adoptive immunotherapy with tumor-specific T cells: reversal with low-dose interleukin 15 but not low-dose interleukin 2

Adoptive immunotherapy with tumor-specific T cells has emerged as a valid approach for prevention or treatment of diseases, such as melanoma and EBV-associated lymphoma. As interleukin (IL) 15 promotes survival of CD8(+) memory CTLs, we hypothesized that it could be used to enhance antitumor immunity in vivo through the maintenance of adoptively transferred memory CTL. To test this, we treated mice bearing P1A(+) tumors with adoptively transferred T cells possessing a transgenic Valpha8(+) T-cell receptor specific for the P1A tumor antigen (called P1CTL). Mice were then randomized to receive daily low-dose IL-15 (0.5 microg/day) or PBS. Mice receiving the transgenic P1CTL and IL-15 experienced a significantly delayed tumor relapse or complete tumor regression (P < 0.002 compared with PBS), with a striking persistence of the CD8(+) Valpha8(+) P1CTL compared with mice receiving the CD8(+) Valpha8(+) P1CTL and PBS vehicle (26.3 versus 5.1% P < 10(-5)). Animals exhibiting complete tumor regression had a significant population of CD8(+) Valpha8(+) P1CTL (46%) that persisted with IL-15 treatment until 140 days after adoptive transfer and successfully defended them against tumor rechallenge without IL-15. Low-dose IL-2 afforded no protection over vehicle and resulted in lower percentages of T cells with an activated memory phenotype, lower Bcl-2 expression, and lower ex vivo antitumor cytotoxicity compared with mice treated with IL-15. Collectively, the data support the notion that exogenous low-dose IL-15 therapy can enhance and even reverse the limited efficacy of adoptively transferred tumor-specific T-cell therapy and may do so in a fashion that is superior and distinct from exogenous IL-2 therapy.     

Experimental therapeutic approaches to adenocarcinoma: the potential of tumor cells engineered to express MHC class II molecules combined with naked DNA interleukin-12 gene transfer

We have previously shown that TS/A murine mammary adenocarcinoma cells, induced to express high surface expression of MHC class II molecules by stable transfection of CIITA, resulted in high rate (92%) of tumor rejection and tumor immunity to subsequent homologous tumor challenges. The immunological basis of tumor response is based on tumor-specific CD4(+) T helper type 1 (Th1) in the priming phase and tumor-specific CD8(+) T cells as the major effector cells. IL-12 is the crucial cytokine that drives Th1 polarization in conjunction with inducing strong cellular-based immune responses. We have previously shown in the same tumor model that a naked DNA IL-12 gene transfer was effective in preventing tumor angiogenesis in an immunopreventive approach when administrated at least 2 days prior to the tumor inoculation. Here we indicate that the combination of the two approaches in immunotherapy of established tumors is efficacious in delaying tumor growth but not in completely eradicating the tumor.     

A case of locally advanced rectal cancer had a pathological complete response to XELOX Therapy

The patient was a 62-year-old man with bowel obstruction in a locally advanced rectal cancer. Computed tomography (CT) scan of the abdomen showed tumor enlargement(11.4 × 9.0 cm)that invaded the urinary bladder, but no distant metastasis. XELOX therapy was planned in order to shrink or eliminate the tumor after a sigmoid colostomy. Four courses of XELOX therapy were perfomed. Consequently, the level of the tumor marker had been restored to a normal range. CT scan revealed marked shrinkage of the tumor (6.1 × 5.2 cm) and a sharply-defined border between the tumor and the urinary bladder. Three weeks after chemotherapy, a low anterior resection as a radical surgery, and a temporary ileostomy were performed. The post-operative course was good. The histological effect was judged to be grade 3. There were no viable cancer cells in the rectal tumor and lymph nodes. The patient is alive and has been disease-free for 10 months after the operation. XELOX therapy as pre-operative chemotherapy might be safe and effective for patients with locally advanced rectal cancer.     

Intratumoral therapy with IL13-PE38 results in effective CTL-mediated suppression of IL-13Ralpha2-expressing contralateral tumors.

PURPOSE: IL13-PE38, a targeted cytotoxin comprised of interleukin 13 (IL-13) and a mutated form of Pseudomonas exotoxin, induces specific killing of tumor cells expressing abundant levels of the IL-13Ralpha2 chain. We hypothesized that tumor cells killed by the cytotoxin may release antigens and/or apoptotic bodies when cells are dying, which then induce adoptive immunity, and that the PE38 portion of IL13-PE38 may act as a stimulant for the induction of a CTL response. EXPERIMENTAL DESIGN: To test this hypothesis, we established D5 melanoma tumors with or without expression of the IL-13Ralpha2 chain in both flanks of C57BL/6 mice, and then IL13-PE38 was injected in the right flank tumors only. Results and CONCLUSIONS: When animals with IL-13Ralpha2-expressing D5 tumor (right) were injected with IL13-PE38, right flank tumors expressing the IL-13Ralpha2 chain not only showed dramatic regression but contralateral tumors (left flank) also showed tumor regression. Cell depletion experiments in tumor-bearing animals indicated that both CD8(+) and CD4(+) T cells contribute to the regression of contralateral tumors through CTL activation in the periphery and cellular infiltration into tumors. In addition, intratumoral treatment into s.c. tumors of mice bearing metastatic lung tumors with IL13-PE38 showed not only the reduction of treated s.c. tumor but also the reduction of lung metastasis. Thus, IL13-PE38 mediates an antitumor effect not only directly but also indirectly by inducing a host CD8(+) T cell immune response. Accordingly, targeted cytotoxins may be used to treat local disease even if they cannot be administered systemically, and yet may still induce a reasonable systemic antitumor response.