Combined allogeneic tumor cell vaccination and systemic interleukin 12 prevents mammary carcinogenesis in HER-2/neu transgenic mice

Emerging interleukin targets in the tumour microenvironment: implications for the treatment of gastrointestinal tumours

The effectiveness of antitumour immunity is dependent on intricate cytokine networks. Interleukins (ILs) are important mediators of complex interactions within the tumour microenvironment, including regulation of tumour-infiltrating lymphocyte proliferation, differentiation, migration and activation. Our evolving and increasingly nuanced understanding of the cell type-specific and heterogeneous effects of IL signalling has presented unique opportunities to fine-tune elaborate IL networks and engineer new targeted immunotherapeutics. In this review, we provide a primer for clinicians on the challenges and potential of IL-based treatment. We specifically detail the roles of IL-2, IL-10, IL-12 and IL-15 in shaping the tumour-immune landscape of gastrointestinal malignancies, paying particular attention to promising preclinical findings, early-stage clinical research and innovative therapeutic approaches that may properly place ILs to the forefront of immunotherapy regimens.

Prevention and Therapy of Metastatic HER-2+ Mammary Carcinoma with a Human Candidate HER-2 Virus-like Particle Vaccine

Vaccines are a promising therapeutic alternative to monoclonal antibodies against HER-2+ breast cancer. We present the preclinical activity of an ES2B-C001, a VLP-based vaccine being developed for human breast cancer therapy. FVB mice challenged with HER-2+ mammary carcinoma cells QD developed progressive tumors, whereas all mice vaccinated with ES2B-C001+Montanide ISA 51, and 70% of mice vaccinated without adjuvant, remained tumor-free. ES2B-C001 completely inhibited lung metastases in mice challenged intravenously. HER-2 transgenic Delta16 mice developed mammary carcinomas by 4−8 months of age; two administrations of ES2B-C001+Montanide prevented tumor onset for >1 year. Young Delta16 mice challenged intravenously with QD cells developed a mean of 68 lung nodules in 13 weeks, whereas all mice vaccinated with ES2B-C001+Montanide, and 73% of mice vaccinated without adjuvant, remained metastasis-free. ES2B-C001 in adjuvant elicited strong anti-HER-2 antibody responses comprising all Ig isotypes; titers ranging from 1−10 mg/mL persisted for many months. Antibodies inhibited the 3D growth of human HER-2+ trastuzumab-sensitive and -resistant breast cancer cells. Vaccination did not induce cytokine storms; however, it increased the ELISpot frequency of IFN-γ secreting HER-2-specific splenocytes. ES2B-C001 is a promising candidate vaccine for the therapy of tumors expressing HER-2. Preclinical results warrant further development towards human clinical studies.

Cancer Immunoprevention: Current Status and Future Directions

Cancer is one of the most serious diseases affecting health and the second leading cause of death worldwide. Despite the development of various therapeutic modalities to deal with cancer, limited improvement in overall survival of patients has been yielded. Since there is no certain cure for cancer, detection of premalignant lesions, and prevention of their progression are vital to the decline of high morbidity and mortality of cancer. Among approaches to cancer prevention, immunoprevention has gained further attention in recent years. Deep understanding of the tumor/immune system interplay and successful prevention of virally-induced malignancies by vaccines have paved the way toward broadening cancer immunoprevention application. The identification of tumor antigens in premalignant lesions was the turning point in cancer immunoprevention that led to designing preventive vaccines for various malignancies including multiple myeloma, colorectal, and breast cancer. In addition to vaccines, immune checkpoint inhibitors are also being tested for the prevention of oral squamous cell carcinoma (SCC), and imiquimod which is an established drug for the prevention of skin SCC, is a non-specific immunomodulator. Herein, to provide a bench-to-bedside understanding of cancer immunoprevention, we will review the role of the immune system in suppression and promotion of tumors, immunoprevention of virally-induced cancers, identification of tumor antigens in premalignant lesions, and clinical advances of cancer immunoprevention.

DNA vaccination against oncoantigens: A promise

The emerging evidence that DNA vaccines elicit a protective immune response in rodents, dogs and cancer patients, coupled with the US Food and Drug Administration (FDA) approval of an initial DNA vaccine to treat canine tumors is beginning to close the gap between the optimistic experimental data and their difficult application in a clinical setting. Here we review a series of conceptual and biotechnological advances that are working together to make DNA vaccines targeting molecules that play important roles during cancer progression (oncoantigens) a promise with near-term clinical impact.

Genetic Influences in Breast Cancer Drug Resistance

Breast cancer is the most common cancer in adult women aged 20 to 50 years. The therapeutic regimens that are commonly recommended to treat breast cancer are human epidermal growth factor receptor 2 (HER2) targeted therapy, endocrine therapy, and systemic chemotherapy. The selection of pharmacotherapy is based on the characteristics of the tumor and its hormone receptor status, specifically, the presence of HER2, progesterone receptors, and estrogen receptors. Breast cancer pharmacotherapy often gives different results in various populations, which may cause therapeutic failure. Different types of congenital drug resistance in individuals can cause this. Genetic polymorphism is a factor in the occurrence of congenital drug resistance. This review explores the relationship between genetic polymorphisms and resistance to breast cancer therapy. It considers studies published from 2010 to 2020 concerning the relationship of genetic polymorphisms and breast cancer therapy. Several gene polymorphisms are found to be related to longer overall survival, worse relapse-free survival, higher pathological complete response, and increased disease-free survival in breast cancer patients. The presence of these gene polymorphisms can be considered in the treatment of breast cancer in order to shape personalized therapy to yield better results.

Natural Killer Cell Defects in Breast Cancer: A Key Pathway for Tumor Evasion

As the most important innate immune component cancers invader, natural killer (NK) cells have a magnificent role in antitumor immunity without any prior sensitization. Different subsets of NK cells have distinct responses during tumor cell exposure, according to their phenotypes and environments. Their function is induced mainly by the activity of both inhibitory and activating receptors against cancerous cells. Since the immunosuppression in the tumor microenvironment of breast cancer patients has directly deteriorated the phenotype and disturbed the function of NK cells, recruiting compensatory mechanisms indicate promising outcomes for immunotherapeutic approaches. These evidences accentuate the importance of NK cell distinct features in protection against breast tumors. In this review, we discuss the several mechanisms involved in NK cells suppression which consequently promote tumor progression and disease recurrence in patients with breast cancer.

Associations between hepatocellular carcinoma risk and rs3212227 and rs568408 polymorphisms: a systematic review and meta-analysis

Background

Interleukin-12 (IL-12) is considered to be a risk factor for cancer; however, its role in hepatocellular carcinoma (HCC) remains unknown. This study aimed to explore the impacts of the IL-12 rs3212227 and rs568408 gene polymorphisms on HCC.

Methods

We searched PubMed, Embase, Web of Science, and Chinese Knowledge Infrastructure databases for studies on the associations between HCC and IL-12 rs568408 and rs3212227 polymorphisms published prior to 1 May 2020. The effects of the polymorphisms on HCC susceptibility were presented as odds ratios (ORs) and associated 95% confidence intervals.

Results

Seven studies were ultimately included, including 2375 cases and 3445 controls. The rs3212227 polymorphism was significantly associated with the risk of HCC in both the dominant model (CC+AC vs. AA, OR=1.22) and the allele model (C vs. A, OR=1.12). Combined analysis of rs568408 yielded a significant relative risk for HCC in the dominant (AA+AG vs. GG, OR=1.13), recessive (AA vs. AG+GG, OR=1.72), allele (A vs. G, OR=1.29), heterozygote (AG vs. GG, OR=1.27), and homozygote models (AA vs. GG, OR 1.17).

Conclusion

The IL-12 rs3212227 and rs568408 gene polymorphisms are associated with an increased risk of HCC.

Cancer Vaccines Co-Targeting HER2/Neu and IGF1R

(1) Background: Human epidermal growth factor receptor 2 (HER2)/neu-driven carcinogenesis is delayed by preventive vaccines able to elicit autochthonous antibodies against HER2/neu. Since cooperation between different receptor tyrosine kinases (RTKs) can occur in human as well as in experimental tumors, we investigated the set-up of DNA and cell vaccines to elicit an antibody response co-targeting two RTKs: HER2/neu and the Insulin-like Growth Factor Receptor-1 (IGF1R). (2) Methods: Plasmid vectors carrying the murine optimized IGF1R sequence or the human IGF1R isoform were used as electroporated DNA vaccines. IGF1R plasmids were transfected in allogeneic HER2/neu-positive IL12-producing murine cancer cells to obtain adjuvanted cell vaccines co-expressing HER2/neu and IGF1R. Vaccination was administered in the preneoplastic stage to mice prone to develop HER2/neu-driven, IGF1R-dependent rhabdomyosarcoma. (3) Results: Electroporated DNA vaccines for murine IGF1R did not elicit anti-mIGF1R antibodies, even when combined with Treg-depletion and/or IL12, while DNA vaccines carrying the human IGF1R elicited antibodies recognizing only the human IGF1R isoform. Cell vaccines co-expressing HER2/neu and murine or human IGF1R succeeded in eliciting antibodies recognizing the murine IGF1R isoform. Cell vaccines co-targeting HER2/neu and murine IGF1R induced the highest level of anti-IGF1R antibodies and nearly significantly delayed the onset of spontaneous rhabdomyosarcomas. (4) Conclusions: Multi-engineered adjuvanted cancer cell vaccines can break the tolerance towards a highly tolerized RTK, such as IGF1R. Cell vaccines co-targeting HER2/neu and IGF1R elicited low levels of specific antibodies that slightly delayed onset of HER2/neu-driven, IGF1R-dependent tumors.

Immune targeting of autocrine IGF2 hampers rhabdomyosarcoma growth and metastasis

Background

Insulin-like Growth Factor Receptor-1 (IGF1R) system sustains the genesis of rhabdomyosarcoma through IGF2 autocrine overexpression. While several IGF1R-targeted strategies have been investigated to interphere with rhabdomyosarcoma growth, no attempt to neutralize IGF2 has been reported. We therefore studied the possibility to hamper rhabdomyosarcoma growth with passive and active immune approaches targeting IGF2.

Methods

A murine model developing IGF2-overexpressing pelvic rhabdomyosarcoma, along with IGF2-independent salivary carcinoma, was used to investigate the efficacy and specificity of passive anti-IGFs antibody treatment. Active vaccinations with electroporated DNA plasmids encoding murine or human IGF2 were performed to elicit autochthonous anti-IGF2 antibodies. Vaccinated mice received the intravenous injection of rhabdomyosarcoma cells to study the effects of anti-IGF2 antibodies against developing metastases.

Results

Passive administration of antibodies neutralizing IGFs delayed the onset of IGF2-overexpressing rhabdomyosarcoma but not of IGF2-independent salivary carcinoma. A DNA vaccine against murine IGF2 did not elicit antibodies, even when combined with Treg-depletion, while a DNA vaccine encoding the human IGF2 gene elicited antibodies crossreacting with murine IGF2. Mice with anti-IGF2 antibodies were partially protected against the metastatic growth of IGF2-addicted rhabdomyosarcoma cells.

Conclusions

Immune targeting of autocrine IGF2 inhibited rhabdomyosarcoma genesis and metastatic growth.

OX40 triggering concomitant to IL12-engineered cell vaccine hampers the immunoprevention of HER2/neu-driven mammary carcinogenesis

This study evaluated the effects of combining an OX40 agonistic antibody (aOX40) with a cell vaccine targeting HER2/neu, called "Triplex". Such HER2/neu cell vaccine included two biological adjuvants (interleukin 12 (IL12) and allogeneic histocompatibility antigens) and was previously found able to prevent autochthonous HER2/neu-driven mammary carcinogenesis. Timing of aOX40 administration, concomitantly or after cell vaccination, gave opposite results. Unexpectedly, vaccine efficacy was hampered by concomitant OX40 triggering. Such decreased immunoprevention was likely due to a reduced induction of anti-HER2/neu antibodies and to a higher level of Treg activation. On the contrary, aOX40 administration after the completion of vaccination slightly but significantly increased immunopreventive vaccine efficacy, and led to increased production of GM-CSF and IL10. In conclusion, OX40 triggering can either impair or ameliorate immunoprevention of HER2/neu-driven mammary carcinogenesis depending on the schedule of aOX40 administration.

Disruption of IFN-I Signaling Promotes HER2/Neu Tumor Progression and Breast Cancer Stem Cells

Type I interferon (IFN-I) is a class of antiviral immunomodulatory cytokines involved in many stages of tumor initiation and progression. IFN-I acts directly on tumor cells to inhibit cell growth and indirectly by activating immune cells to mount antitumor responses. To understand the role of endogenous IFN-I in spontaneous, oncogene-driven carcinogenesis, we characterized tumors arising in HER2/neu transgenic (neuT) mice carrying a nonfunctional mutation in the IFNI receptor (IFNAR1). Such mice are unresponsive to this family of cytokines. Compared with parental neu^+/- mice (neuT mice), IFNAR1^-/- neu^+/- mice (IFNAR-neuT mice) showed earlier onset and increased tumor multiplicity with marked vascularization. IFNAR-neuT tumors exhibited deregulation of genes having adverse prognostic value in breast cancer patients, including the breast cancer stem cell (BCSC) marker aldehyde dehydrogenase-1A1 (ALDH1A1). An increased number of BCSCs were observed in IFNAR-neuT tumors, as assessed by ALDH1A1 enzymatic activity, clonogenic assay, and tumorigenic capacity. In vitro exposure of neuT⁺ mammospheres and cell lines to antibodies to IFN-I resulted in increased frequency of ALDH⁺ cells, suggesting that IFN-I controls stemness in tumor cells. Altogether, these results reveal a role of IFN-I in neuT-driven spontaneous carcinogenesis through intrinsic control of BCSCs. Cancer Immunol Res; 6(6); 658-70. ©2018 AACR.

Engineered exosomes emerging from muscle cells break immune tolerance to HER2 in transgenic mice and induce antigen-specific CTLs upon challenge by human dendritic cells

We recently described a novel biotechnological platform for the production of unrestricted cytotoxic T lymphocyte (CTL) vaccines. It relies on in vivo engineering of exosomes, i.e., nanovesicles constitutively released by all cells, with full-length antigens of choice upon fusion with an exosome-anchoring protein referred to as Nef^mut. They are produced upon intramuscular injection of a DNA vector and, when uploaded with a viral tumor antigen, were found to elicit an immune response inhibiting the tumor growth in a model of transplantable tumors. However, for a possible application in cancer immunotherapy, a number of key issues remained unmet. Among these, we investigated: (i) whether the immunogenic stimulus induced by the engineered exosomes can break immune tolerance, and (ii) their effectiveness when applied in human system. As a model of immune tolerance, we considered mice transgenic for the expression of activated rat HER2/neu which spontaneously develop adenocarcinomas in all mammary glands. When these mice were injected with a DNA vector expressing the product of fusion between Nef^mut and the extracellular domain of HER2/neu, antigen-specific CD8⁺ T lymphocytes became readily detectable. This immune response associated with a HER2-directed CTL activity and a significant delay in tumor development. On the other hand, through cross-priming experiments, we demonstrated the effectiveness of the engineered exosomes emerging from transfected human primary muscle cells in inducing antigen-specific CTLs. We propose our CTL vaccine platform as part of new immunotherapy strategies against tumors expressing self-antigens, i.e., products highly expressed in oncologic lesions but tolerated by the immune system.

KEY MESSAGES

We established a novel, exosome-based method to produce unrestricted CTL vaccines. This strategy is effective in breaking the tolerance towards tumor self-antigens. Our method is also useful to elicit antigen-specific CTL immunity in humans. These findings open the way towards the use of this antitumor strategy in clinic.

Chemo-immunotherapy induces tumor regression in a mouse model of spontaneous mammary carcinogenesis

Tumor-specific immune tolerance represents an obstacle for the development of effective anti-tumor immune responses through cancer vaccines. We here evaluated the efficacy of chemo-immunotherapy in breaking tumor-specific immune tolerance in an almost incurable mouse model of spontaneous carcinogenesis.Transgenic HER-2/neu mice bearing large mammary tumors received the adoptive transfer of splenocytes and serum isolated from immune donors, with or without pre-conditioning with cyclophosphamide. Treatment efficacy was assessed by monitoring tumor growth by manual inspection and by magnetic resonance imaging. The same chemo-immunotherapy protocol was tested on tumor-free HER-2/neu mice, to evaluate the effects on tumor emergence.Our data show that chemo-immunotherapy hampered carcinogenesis and caused the regression of large mammary tumor lesions in tumor-bearing HER-2/neu mice. The complete eradication of a significant number of tumor lesions occurred only in mice receiving cyclophosphamide shortly before immunotherapy, and was associated with increased serum anti HER-2/p185 antibodies and tumor leukocyte infiltration. The same protocol significantly delayed the appearance of mammary tumors when administered to tumor-free HER-2/neu mice, indicating that this chemo-immunotherapy approach acted through the elicitation of an effective anti-tumor immune response. Overall, our data support the immune-modulatory role of chemotherapy in overcoming cancer immune tolerance when administered at lymphodepleting non-myeloablative doses shortly before transfer of antigen-specific immune cells and immunoglobulins. These findings open new perspectives on combining immune-modulatory chemotherapy and immunotherapy to overcome immune tolerance in cancer patients.

A Limited Autoimmunity to p185neu Elicited by DNA and Allogeneic Cell Vaccine Hampers the Progression of Preneoplastic Lesions in HER-2/NEU Transgenic Mice

Prevention of the progression of precancerous lesions by vaccines is a virtually uncharted territory. Their potential, however, is being assessed in transgenic mice which develop autochthonous tumors with defined stages of progression. In this paper we show that the DNA micro-array technology significantly helps assessment of the preventive efficacy of a combined DNA and cell vaccine. All female rat Her-2/neu transgenic BALB/c (BALB-neuT) mice develop an invasive carcinoma in each of their mammary glands within 25 weeks of age. This is elicited by the activated transforming rat Her-2/neu oncogene embedded in their genome. We have previously shown that vaccination of mice bearing multiple in situ carcinomas with DNA plasmids which code for the extracellular and transmembrane domain of rat p185neu, the product of the rat Her-2/neu oncogene, followed by a boost with rat p185neu+ allogeneic cells engineered to secrete interferon-γ, keeps 48% of mice tumor free until week 32. We have now extended our follow-up until mice reach one year of age and show that protection vanishes as time progresses. This observation suggests that the accuracy of the results studying immunotherapy against life-threatening tumors is a function of the length of the follow-up. The application of microarrays, and the concordance of morphologic and gene expression data led us to identify antibody as the main mechanism induced by vaccination. Protection is associated with a break of tolerance and a limited autoimmunity against the

Effect of interleukin 12 gene therapy on microvessel density and microenvironment in a rabbit model of VX2 liver cancer

AIM: To evaluate the effect of interleukin-12 (IL-12) gene therapy on microvessel density and microenvironment in a post-chemoembolization VX2 liver cancer model, and to investigate its anti-tumor mechanism.

METHODS: Rabbits with VX2 hepatic tumors were randomized into 4 groups, with eight rabbits in each group. Interventional procedure protocols were performed as follows: 0.9% saline solution (group 1, control), transcatheter arterial chemoembolization alone (group 2, lipiodol + mitomycin), intra-arterial IL-12 gene infusion (group 3, IL-12 gene therapy alone), and intra-arterial IL-12 gene infusion in combination with chemoembolization (group 4, IL-12 plus chemoembolization). Fourteen days after therapy, tumor tissues of the sacrificed animals were explanted for immunohistochemistry to evaluate microvessel density, effector T cells (CD3⁺, CD4⁺, and CD8⁺) and regulatory T cells (FoxP3⁺).

RESULTS: The microvessel density and FoxP3⁺ T cells in group 2 were significantly higher than those in group 1, but the differences in CD3⁺, CD4⁺, and CD8⁺ T cells between the two groups were not significant. The microvessel density in gene therapy groups (groups 3 and 4) were significantly lower, and CD3⁺, CD4⁺, and CD8⁺ T cells in these two groups were significantly higher than those in groups 1 and 2. The differences in CD3⁺, CD4⁺, and CD8⁺ T cells between the two gene therapy groups (groups 3 and 4) were not significant. The difference in FoxP3⁺ T cells was not significant between before and after IL-12 gene therapy. The differences in the level of FoxP3 were not significant between groups 3 and 1, as well as between groups 4 and 2.

CONCLUSION: IL-12 gene therapy can inhibit angiogenesis and induce effector T cell (CD3⁺, CD4⁺, and CD8⁺) infiltration in the VX2 liver cancer model, but the efficacy appears to be limited by the regulatory T cells (FoxP3⁺) existing in the tumors and overexpressed after chemoembolization.

Genetic variants in IL12 influence both hepatitis B virus clearance and HBV-related hepatocellular carcinoma development in a Chinese male population

IL12 plays a major role not only in inducing appropriate immune responses against viral infections (including HBV) but also in the antitumor immune response. This study was conducted to investigate the relationships of genetic variants in IL12 with hepatitis B virus (HBV) clearance and development of HBV-related hepatocellular carcinoma (HCC). We genotyped three single nucleotide polymorphisms (SNPs) of the IL12A (rs568406 and rs2243115) and IL12B (rs3212227) in 395 HBV-positive HCC patients, 293 persistent HBV carriers and 686 subjects with HBV natural clearance from southern China, using the improved multiplex ligase detection reaction (iMLDR) method. Logistic regression analysis adjusted for age, smoking, and alcohol consumption status showed that rs568408 variant genotypes were significantly associated with host HBV-related HCC risk when compared with persistent HBV carriers, and carriers of the GA + AA genotype decreased the HCC risk in comparison with GG carriers (adjusted OR = 0.53, 95 % CI 0.35-0.80, P = 0.002). No relationships between the rs2243115 and rs3212227 SNPs and HCC risk were observed (all P > 0.05). Besides, rs568408 showed an approaching significant effect on susceptibility to HBV persistent infection (adjusted OR = 1.34, 95 % CI 0.99-1.81, P = 0.057 in dominant genetic models). Furthermore, the TG haplotype was observed to be associated with a significantly increased risk of HBV-related HCC (OR = 1.42, 95 % CI 1.10-1.83, P = 0.006), while TA haplotype was associated with a decreased risk of HBV-related HCC (OR = 0.61, 95 % CI 0.45-0.83, P = 0.002). Our results reveal that the IL12A rs568408 variant may be a marker SNP for risk of both HBV clearance and HBV-related HCC development.

Mesothelin-specific cell-based vaccine generates antigen-specific immunity and potent antitumor effects by combining with IL-12 immunomodulator

Ovarian cancer is a gynecologic malignancy with a high mortality rate. In the present study, we developed a novel cell-based vaccine, Meso-VAX, to generate mesothelin antigen-specific immune responses and immunotherapy against ovarian cancer. Mesothelin, a secreted protein anchored at the cell membrane, has recently been identified as a potential new tumor antigen for ovarian cancer. In this study, mice vaccinated with Meso-VAX and adeno-associated virus (AAV)-IL-12 exhibited dramatic increases in the number of mesothelin-specific CD4(+) helper and CD8(+) cytotoxic T-cell precursors, higher titers of anti-mesothelin Abs and in vitro tumor killing activity, and all of these mice were tumor-free after 60 days of tumor challenge. In addition, a significant reduction in peritoneal tumors and longer survival were noted in the mice vaccinated with Meso-VAX combined with AAV-IL-12. CD4(+) helper and CD8(+) cytotoxic T lymphocytes were essential for the antitumor effect generated by Meso-VAX combined with AAV-IL-12. The post-vaccination sera of the mice vaccinated with Meso-VAX and AAV-IL-12 also showed mesothelin-specific complement-dependent cell-mediated cytotoxicity. Our results suggest that a Meso-VAX cell-based vaccine combined with AAV-IL-12 can generate antigen-specific immunological responses and antitumor effects on ovarian cancer.

Intradermal DNA Electroporation Induces Cellular and Humoral Immune Response and Confers Protection against HER2/neu Tumor

Skin represents an attractive target for DNA vaccine delivery because of its natural richness in APCs, whose targeting may potentiate the effect of vaccination. Nevertheless, intramuscular electroporation is the most common delivery method for ECTM vaccination. In this study we assessed whether intradermal administration could deliver the vaccine into different cell types and we analyzed the evolution of tissue infiltrate elicited by the vaccination protocol. Intradermal electroporation (EP) vaccination resulted in transfection of different skin layers, as well as mononuclear cells. Additionally, we observed a marked recruitment of reactive infiltrates mainly 6–24 hours after treatment and inflammatory cells included CD11c⁺. Moreover, we tested the efficacy of intradermal vaccination against Her2/neu antigen in cellular and humoral response induction and consequent protection from a Her2/neu tumor challenge in Her2/neu nontolerant and tolerant mice. A significant delay in transplantable tumor onset was observed in both BALB/c (p ≤ 0,0003) and BALB-neuT mice (p = 0,003). Moreover, BALB-neuT mice displayed slow tumor growth as compared to control group (p < 0,0016). In addition, while in vivo cytotoxic response was observed only in BALB/c mice, a significant antibody response was achieved in both mouse models. Our results identify intradermal EP vaccination as a promising method for delivering Her2/neu DNA vaccine.

The Promise of Preventive Cancer Vaccines

Years of unsuccessful attempts at fighting established tumors with vaccines have taught us all that they are only able to truly impact patient survival when used in a preventive setting, as would normally be the case for traditional vaccines against infectious diseases. While true primary cancer prevention is still but a long-term goal, secondary and tertiary prevention are already in the clinic and providing encouraging results. A combination of immunopreventive cancer strategies and recently approved checkpoint inhibitors is a further promise of forthcoming successful cancer disease control, but prevention will require a considerable reduction of currently reported toxicities. These considerations summed with the increased understanding of tumor antigens allow space for an optimistic view of the future.

Interleukin-15 is required for immunosurveillance and immunoprevention of HER2/neu-driven mammary carcinogenesis

Introduction

We previously demonstrated that HER2/neu-driven mammary carcinogenesis can be prevented by an interleukin-12 (IL-12)-adjuvanted allogeneic HER2/neu-expressing cell vaccine. Since IL-12 can induce the release of interleukin-15 (IL-15), in the present study we investigated the role played by IL-15 in HER2/neu driven mammary carcinogenesis and in its immunoprevention.

Methods

HER2/neu transgenic mice with homozygous knockout of IL-15 (here referred to as IL15KO/NeuT mice) were compared to IL-15 wild-type HER2/neu transgenic mice (NeuT) regarding mammary carcinogenesis, profile of peripheral blood lymphocytes and splenocytes and humoral and cellular responses induced by the vaccine.

Results

IL15KO/NeuT mice showed a significantly earlier mammary cancer onset than NeuT mice, with median latency times of 16 and 20 weeks respectively, suggesting a role for IL-15 in cancer immunosurveillance. Natural killer (NK) and CD8+ lymphocytes were significantly lower in IL15KO/NeuT mice compared to mice with wild-type IL-15. The IL-12-adjuvanted allogeneic HER2/neu-expressing cell vaccine was still able to delay mammary cancer onset but efficacy in IL-15-lacking mice vanished earlier: all vaccinated IL15KO/NeuT mice developed tumors within 80 weeks of age (median latency of 53 weeks), whereas more than 70 % of vaccinated NeuT mice remained tumor-free up to 80 weeks of age. Vaccinated IL15KO/NeuT mice showed less necrotic tumors with fewer CD3+ lymphocyes and lacked perforin-positive infiltrating cells compared to NeuT mice. Concerning the anti-vaccine antibody response, antibody titer was unaffected by the lack of IL-15, but less antibodies of IgM and IgG1 isotypes were found in IL15KO/NeuT mice. A lower induction by vaccine of systemic interferon-gamma (IFN-γ) and interleukin-5 (IL-5) was also observed in IL15KO/NeuT mice when compared to NeuT mice. Finally, we found a lower level of CD8+ memory cells in the peripheral blood of vaccinated IL15KO/NeuT mice compared to NeuT mice.

Conclusions

We demonstrated that IL-15 has a role in mammary cancer immunosurveillance and that IL-15-regulated NK and CD8+ memory cells play a role in long-lasting immunoprevention, further supporting the potential use of IL-15 as adjuvant in immunological strategies against tumors.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-015-0588-x) contains supplementary material, which is available to authorized users.

Adenovirally delivered enzyme prodrug therapy with herpes simplex virus-thymidine kinase in composite tissue free flaps shows therapeutic efficacy in rat models of glioma

INTRODUCTION

Free flap gene therapy exploits a novel therapeutic window when viral vectors can be delivered into a flap ex vivo. The authors investigated the therapeutic potential of an adenovirally-delivered thymidine kinase/ganciclovir prodrug system expressed following vector delivery into a free flap.

METHODS

The authors demonstrated direct in vitro cytotoxicity by treating a panel of malignant cell lines with the thymidine kinase/ganciclovir system and demonstrated significant cell kill proportional to the multiplicity of infection of adenoviral vector expressing thymidine kinase. Bystander cytotoxicity was demonstrated using conditioned media from producer cells (expressing adenovirally-delivered thymidine kinase and treated with ganciclovir) to demonstrate cytotoxicity in naive tumor cells. The authors investigated the effect of adenoviral vector expressing thymidine kinase/ganciclovir therapy in vivo, using models of microscopic and macroscopic residual disease in a rodent superficial inferior epigastric artery flap model.

RESULTS

The authors observed retardation of tumor volume growth in both microscopic (p = 0.0004) and macroscopic (p = 0.0005) residual disease models and prolongation of animal survival. Gene expression studies demonstrated that viral genomic material was found predominantly in flap tissues but declined over time.

CONCLUSIONS

The authors describe the utility of virally delivered enzyme/prodrug therapy, using a free flap as a vehicle for delivery. They discuss the merits and limitations of this approach and the unique role of therapeutic free flaps among reconstructive techniques available to the plastic surgeon.

Plant virus particles carrying tumour antigen activate TLR7 and Induce high levels of protective antibody

Induction of potent antibody is the goal of many vaccines targeted against infections or cancer. Modern vaccine designs that use virus-like particles (VLP) have shown efficacy for prophylactic vaccination against virus-associated cancer in the clinic. Here we used plant viral particles (PVP), which are structurally analogous to VLP, coupled to a weak idiotypic (Id) tumour antigen, as a conjugate vaccine to induce antibody against a murine B-cell malignancy. The Id-PVP vaccine incorporates a natural adjuvant, the viral ssRNA, which acts via TLR7. It induced potent protective anti-Id antibody responses in an in vivo mouse model, superior to the "gold standard" Id vaccine, with prevalence of the IgG2a isotype. Combination with alum further increased antibody levels and maintained the IgG2a bias. Engagement of TLR7 in vivo was followed by secretion of IFN-α by plasmacytoid dendritic cells and by activation of splenic CD11chi conventional dendritic cells. The latter was apparent from up-regulation of co-stimulatory molecules and from secretion of a wide range of inflammatory cytokines and chemokines including the Th1-governing cytokine IL-12, in keeping with the IgG2a antibody isotype distribution. PVP conjugates are a novel cancer vaccine design, offering an attractive molecular form, similar to VLP, and providing T-cell help. In contrast to VLP, they also incorporate a safe "in-built" ssRNA adjuvant.

The antigenic repertoire of premalignant and high-risk lesions

Prophylactic vaccines have been a major advance in preventing the development of infections after exposure to pathogens. When contemplating an effective approach to cancer prevention, vaccines offer unique advantages over other more standard approaches: First, once appropriately stimulated, antigen-specific T cells will travel to all sites of disease and eradicate cells bearing the proteins to which the T cells have been primed by vaccination. Second, successful immunization will further result in the development of immunologic memory, providing lifelong immunologic surveillance. There is evidence of an adaptive tumor immune infiltrate even at the earliest stages of breast and colon cancer development. Furthermore, there is measurable immunity to lesion-associated antigens present in patients who will eventually develop malignancy even before cancer is clinically evident. Recent studies are beginning to unmask the preinvasive antigenic repertoire for these two malignancies. Preliminary experiments in transgenic mouse models of mammary and intestinal tumors suggest that immunization against antigens expressed in preinvasive and high-risk lesions may be effective in preventing the development of invasive malignancy.

Tumor suppressor genes promote rhabdomyosarcoma progression in p53 heterozygous, HER-2/neu transgenic mice

Human sarcomas arise suddenly, thus preempting the study of preneoplastic and early neoplastic lesions. To explore the natural history of these tumors we studied male mice carrying a heterozygous deletion of p53 and an activated HER-2/neu transgene (BALB-p53Neu mice), that develop urethral rhabdomyosarcomas with nearly full penetrance and early onset (4 months of age). Among genes prominently upregulated in preneoplastic tissue, and more highly expressed in tumors, we found the insulin-like growth factor 2 (Igf2) and tumor suppressors, p19Arf and p21Cip1. In urethral tissues of male mice p53 was less expressed than in female mice, whereas HER-2/neu was more expressed, a combination not found in other skeletal muscles of the same mice that could contribute to the anatomic and sexual specificity of BALB-p53Neu rhabdomyosarcoma. Upregulation of p19Arf and p21Cip1 was additively determined by HER-2/neu activation and by p53 inactivation. Silencing of p19Arf or p21Cip1 in rhabdomyosarcoma cell lines can inhibit cell growth and motility, thus suggesting that these genes can contribute to growth autonomy and malignancy of tumor cells. In vivo injection of gene-silenced cells highlighted selective variations in organ-specific metastatic ability, indicating that overexpression of p19Arf and p21Cip1 controlled both tumor cell-intrinsic properties and microenvironmental interactions. The onset of pelvic rhabdomyosarcoma in BALB-p53Neu male mice is triggered by the coincidental overexpression of HER-2/neu and hypoexpression of the residual p53 allele, that foster p53 loss, Igf2 autocriny and overexpression of p19Arf and p21Cip1, a phenotype that could provide novel potential targets for cancer prevention and therapy.

Interleukin-12B+1188A/C polymorphism contributes to increased hepatocellular carcinoma susceptibility: evidence from a meta-analysis

BACKGROUND

Interleukin-12 (IL-12) is a multifunctional cytokine that induces interferon (IFN)-γ secretion and plays an important role in antitumor immunity. The IL-12B +1188A/C polymorphism was found to correlate with a decreased cytokine production and/or activity, which may lead to increased susceptibility to cancers including hepatocellular carcinoma (HCC). Previous epidemiological studies investigating the association between IL-12B +1188A/C polymorphism and HCC risk reported inconsistent results. We performed a meta-analysis to derive a precise estimation of the association.

METHODS

All studies published up to July 2014 on the association between IL-12B +1188A/C polymorphism and HCC risk were identified by searching electronic databases including PubMed, Embase, Cochrane library, and Chinese Biomedical Literature database (CBM). Data were extracted by two independent authors and the odds ratios (ORs) together with corresponding 95% confidence intervals (CIs) were used to assess the association between IL-12B +1188A/C polymorphism and HCC risk.

RESULTS

Five studies with 1864 cases and 2077 controls were included in the meta-analysis. We observed that the IL-12B +1188A/C polymorphism was significantly correlated with increased HCC risk when all studies were pooled into the meta-analysis (CC vs. AA: OR=1.306, 95% CI 1.063-1.606, P=0.011; AC vs. AA: OR=1.193, 95% CI 1.014-1.405, P=0.034; CC+AC vs. AA: OR=1.260, 95% CI 1.098-1.445, P=0.001). In subgroup analyses by ethnicity, source of control, and study quality, significant increased HCC risk was found in Asians, hospital-based studies, and high quality studies.

CONCLUSIONS

The present meta-analysis suggests that the IL-12B+1188A/C polymorphism is a low-penetrant risk factor for HCC development, especially among Asians. Further large and well-designed studies are needed to confirm this association.

Th1 cytokine-based immunotherapy for cancer

Cytokine-based immunotherapy is executed by harnessing cytokines to activate the immune system to suppress tumors. Th1-type cytokines including IL-1, IL-2, IL-12 and granulocyte-macrophage colony-stimulating factor are potent stimulators of Th1 differentiation and Th1-based antitumor response. Many preclinical studies demonstrated the antitumor effects of Th1 cytokines but their clinical efficacy is limited. Multiple factors influence the efficacy of immunotherapy for tumors. For instance immunosuppressive cells in the tumor microenvironment can produce inhibitory cytokines which suppress antitumor immune response. Most studies on cytokine immunotherapy focused on how to boost Th1 response; many studies combined cytokine-based therapy with other treatments to reverse immunosuppression in tumor microenvironment. In addition, cytokines have pleiotropic functions and some cytokines show paradoxical activities under different settings. Better understanding the physiological and pathological functions of cytokines helps clinicians to design Th1-based cancer therapy in clinical practice.

New insights into IL-12-mediated tumor suppression

During the past two decades, interleukin-12 (IL-12) has emerged as one of the most potent cytokines in mediating antitumor activity in a variety of preclinical models. Through pleiotropic effects on different immune cells that form the tumor microenvironment, IL-12 establishes a link between innate and adaptive immunity that involves different immune effector cells and cytokines depending on the type of tumor or the affected tissue. The robust antitumor response exerted by IL-12, however, has not yet been successfully translated into the clinics. The majority of clinical trials involving treatment with IL-12 failed to show sustained antitumor responses and were associated to toxic side effects. Here we discuss the therapeutic effects of IL-12 from preclinical to clinical studies, and will highlight promising strategies to take advantage of the antitumor activity of IL-12 while limiting adverse effects.

Intratumoral delivery of recombinant vaccinia virus encoding for ErbB2/Neu inhibits the growth of salivary gland carcinoma cells

Background

The antitumor activity induced by intratumoral vaccination with poxvirus expressing a tumor antigen was shown to be superior to that induced by subcutaneous vaccination. Salivary gland carcinomas overexpress ErbB2. Trastuzumab, a monoclonal antibody to ErbB2, was proposed for salivary gland tumors treatment. We explored the effectiveness of intratumoral vaccination with the recombinant vaccinia virus ErbB2/Neu (rV-neuT) vaccine in hampering the growth of transplanted Neu-overexpressing BALB-neuT salivary gland cancer cells (SALTO) in BALB-neuT mice.

Methods

BALB-neuT male mice were subcutaneously injected with SALTO tumor cells and intratumorally vaccinated twice with different doses of either rV-neuT or V-wt (wild-type). Tumors were measured weekly. The presence of anti-ErbB2/Neu antibodies was assayed by ELISA, immunoprecipitation or indirect immunofluorescence. Biological activity of immune sera was investigated by analyzing antibody-dependent cellular cytotoxicity (ADCC), SALTO cells proliferation and apoptosis, ErbB2/Neu receptor down regulation and ERK1/2 phosphorylation. Anti-Neu T cell immunity was investigated by determining the release of IL-2 and IFN-gamma in T cells supernatant. Survival curves were determined using the Kaplan-Meier method and compared using the log-rank test. Differences in tumor volumes, number of apoptotic cells, titer of the serum, percentage of ADCC were evaluated through a two-tailed Student’s t-test.

Results

rV-neuT intratumoral vaccination was able to inhibit the growth of SALTO cancer cells in a dose-dependent manner. The anti-Neu serum titer paralleled in vivo antitumor activity of rV-neuT vaccinated mice. rV-neuT immune serum was able to mediate ADCC, inhibition of SALTO cells proliferation, down regulation of the ErbB2/Neu receptor, inhibition of ERK1/2 phosphorylation and induction of apoptosis, thus suggesting potential mechanisms of in vivo tumor growth interference. In addition, spleen T cells of rV-neuT vaccinated mice released IFN-gamma and IL-2 upon in vitro stimulation with several Neu-specific peptides located in the extracellular domain of Neu sequence.

Conclusions

rV-neuT intratumoral vaccination could be employed to induce an efficient antitumor response and reject transplanted salivary gland tumors. Our findings may have important implications for the design of cancer vaccine protocols for the treatment of salivary gland tumors and other accessible tumors using intratumoral injection of recombinant vaccinia virus.

Various ways to improve whole cancer cell vaccines

Immunotherapy based on whole cancer cell vaccines is regarded as a promising avenue for cancer treatment. However, limited efficacy in the first human clinical trials calls for more optimized whole cancer cell vaccines and better patient selection. It is suggested that whole cancer cell vaccines consist preferably of immunogenically killed autologous cancer stem cells associated with dendritic cells. Adjuvants should stimulate both immune effector cells and memory cells, which could be achieved through their correct dosage and timing of administration. There are indications that whole cancer cell vaccination is less effective in patients who are immunocompromised, who have specific genetic defects in their immune or cancer cells, as well as in patients in an advanced cancer stage. However, such patients form the bulk of enrolled patients in clinical trials, prohibiting an objective evaluation of the true potential of whole cancer cell immunotherapy. Each key point will be discussed.

Vaccines against human HER2 prevent mammary carcinoma in mice transgenic for human HER2

Introduction

The availability of mice transgenic for the human HER2 gene (huHER2) and prone to the development of HER2-driven mammary carcinogenesis (referred to as FVB-huHER2 mice) prompted us to study active immunopreventive strategies targeting the human HER2 molecule in a tolerant host.

Methods

FVB-huHER2 mice were vaccinated with either IL-12-adjuvanted human HER2-positive cancer cells or DNA vaccine carrying chimeric human-rat HER2 sequences. Onset and number of mammary tumors were recorded to evaluate vaccine potency. Mice sera were collected and passively transferred to xenograft-bearing mice to assess their antitumor efficacy.

Results

Both cell and DNA vaccines significantly delayed tumor onset, leading to about 65% tumor-free mice at 70 weeks, whereas mock-vaccinated FVB-huHER2 controls developed mammary tumors at a median age of 45 weeks. In the DNA vaccinated group, 65% of mice were still tumor-free at about 90 weeks of age. The number of mammary tumors per mouse was also significantly reduced in vaccinated mice. Vaccines broke the immunological tolerance to the huHER2 transgene, inducing both humoral and cytokine responses. The DNA vaccine mainly induced a high and sustained level of anti-huHER2 antibodies, the cell vaccine also elicited interferon (IFN)-γ production. Sera of DNA-vaccinated mice transferred to xenograft-carrying mice significantly inhibited the growth of human HER2-positive cancer cells.

Conclusions

Anti-huHER2 antibodies elicited in the tolerant host exert antitumor activity.

Preclinical HER-2 Vaccines: From Rodent to Human HER-2

Effective prevention of human cancer with vaccines against viruses, such as HBV and HPV, raises the question whether also non-virus related tumors could be prevented with immunological means. Studies in HER-2-transgenic mice showed that powerful anti-HER-2 vaccines, could almost completely prevent the onset of mammary carcinoma. Protective immune responses were orchestrated by T cells and their cytokines, and effected by antibodies against HER-2 gene product p185. Analogous findings were reported in a variety of other cancer immunoprevention systems, thus leading to the definition of oncoantigens, optimal target antigens that are causally involved in carcinogenesis and cancer progression. Prophylactic HER-2 vaccines were also effective in preventing metastasis outgrowth, indicating that concepts and approaches developed for cancer immunoprevention could prove fruitful in cancer immunotherapy as well. The availability of cancer-prone mice carrying a human HER-2 transgene is now fostering the design of novel vaccines against human p185. A further bridge toward human cancer was recently provided by novel immunodeficient models, like Rag2^−/−;Il2rg^−/− mice, which are permissive for metastatic spread of human HER-2+ cancer cells and can be engrafted with a functional human immune system, allowing for the first time the study of vaccines against oncoantigens to elicit human immune responses against human cancer cells in vivo.

Genetic susceptibility of cervical cancer

Epidemiological and laboratory-based studies have identified infection with one of 15 high-risk human papillomavirus (HPV) types as a necessary but not sufficient cause of cervical cancer. The prevalence of genital HPV infections is high in young women, but most of the infections regress without interventions. Host genetic variations in genes involved in immune response pathways may be related to HPV clearance, and HPV E6/E7 oncoproteins interacting or downstream genes, both coding and non-coding, may contribute to the outcome of high risk HPV infection and cervical cancer. Of specific interest for this review has been the selection of genetic variants in genes involved in the above-referred pathways with a summary of their applications in association studies. Because the supportive and opposing data have been reported in different populations, well-designed international collaborative studies need to be conducted to define the consistency of the associations, paving the way to better define the patients at high risk of developing cervical cancer.

Association of IL27 gene polymorphisms and HBV-related hepatocellular carcinoma risk in a Chinese population

BACKGROUND AND OBJECTIVE

Hepatocellular carcinoma (HCC) is multifactorial, and the genetic background may be a crucial etiologic factor. Interleukin-27 (IL-27) is a novel IL-12 family member which plays an important role in antitumor immunity. Mutations in the IL27 gene may lead to altered cytokine production and/or activity and thus modulate individual's susceptibility to HCC. In this study, we investigated the association between IL27 gene polymorphisms and HBV-related diseases risk in a Chinese population.

METHODS

Studied subjects were divided into four groups: 112 patients with chronic hepatitis B (CHB), 65 patients with hepatitis B virus (HBV)-related liver cirrhosis (LC), 107 patients with HBV-related HCC, and 105 healthy controls. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) strategy and polymerase chain reaction-sequence specific primer (PCR-SSP) strategy were used to detect IL27 gene -964A/G and 2905T/G polymorphisms, respectively. DNA sequencing was used to validate genotype results.

RESULTS

There were no significant differences in the genotype and allele frequencies of IL27 gene polymorphisms between the groups of patients and healthy controls. Furthermore, no association was found between the distributions of the haplotypes and HCC risk.

CONCLUSION

These findings indicate that the genetic variants in IL27 gene may not contribute to HCC development. Further studies with large sample size should be conducted to validate this association.

Cancer vaccines: state of the art of the computational modeling approaches

Cancer vaccines are a real application of the extensive knowledge of immunology to the field of oncology. Tumors are dynamic complex systems in which several entities, events, and conditions interact among them resulting in growth, invasion, and metastases. The immune system includes many cells and molecules that cooperatively act to protect the host organism from foreign agents. Interactions between the immune system and the tumor mass include a huge number of biological factors. Testing of some cancer vaccine features, such as the best conditions for vaccine administration or the identification of candidate antigenic stimuli, can be very difficult or even impossible only through experiments with biological models simply because a high number of variables need to be considered at the same time. This is where computational models, and, to this extent, immunoinformatics, can prove handy as they have shown to be able to reproduce enough biological complexity to be of use in suggesting new experiments. Indeed, computational models can be used in addition to biological models. We now experience that biologists and medical doctors are progressively convinced that modeling can be of great help in understanding experimental results and planning new experiments. This will boost this research in the future.

Peptide vaccines and targeting HER and VEGF proteins may offer a potentially new paradigm in cancer immunotherapy

The ErbB family (HER-1, HER-2, HER-3 and HER-4) of receptor tyrosine kinases has been the focus of cancer immunotherapeutic strategies while antiangiogenic therapies have focused on VEGF and its receptors VEGFR-1 and VEGFR-2. Agents targeting receptor tyrosine kinases in oncology include therapeutic antibodies to receptor tyrosine kinase ligands or the receptors themselves, and small-molecule inhibitors. Many of the US FDA-approved therapies targeting HER-2 and VEGF exhibit unacceptable toxicities, and show problems of efficacy, development of resistance and unacceptable safety profiles that continue to hamper their clinical progress. The combination of different peptide vaccines and peptidomimetics targeting specific molecular pathways that are dysregulated in tumors may potentiate anticancer immune responses, bypass immune tolerance and circumvent resistance mechanisms. The focus of this review is to discuss efforts in our laboratory spanning two decades of rationally developing peptide vaccines and therapeutics for breast cancer. This review highlights the prospective benefit of a new, untapped category of therapies biologically targeted to EGF receptor (HER-1), HER-2 and VEGF with potential peptide 'blockbusters' that could lay the foundation of a new paradigm in cancer immunotherapy by creating clinical breakthroughs for safe and efficacious cancer cures.

Mathematical modeling of the immune system recognition to mammary carcinoma antigen

The definition of artificial immunity, realized through vaccinations, is nowadays a practice widely developed in order to eliminate cancer disease. The present paper deals with an improved version of a mathematical model recently analyzed and related to the competition between immune system cells and mammary carcinoma cells under the action of a vaccine (Triplex). The model describes in detail both the humoral and cellular response of the immune system to the tumor associate antigen and the recognition process between B cells, T cells and antigen presenting cells. The control of the tumor cells growth occurs through the definition of different vaccine protocols. The performed numerical simulations of the model are in agreement with in vivo experiments on transgenic mice.

Optimal vaccination schedule search using genetic algorithm over MPI technology

BACKGROUND

Immunological strategies that achieve the prevention of tumor growth are based on the presumption that the immune system, if triggered before tumor onset, could be able to defend from specific cancers. In supporting this assertion, in the last decade active immunization approaches prevented some virus-related cancers in humans. An immunopreventive cell vaccine for the non-virus-related human breast cancer has been recently developed. This vaccine, called Triplex, targets the HER-2-neu oncogene in HER-2/neu transgenic mice and has shown to almost completely prevent HER-2/neu-driven mammary carcinogenesis when administered with an intensive and life-long schedule.

METHODS

To better understand the preventive efficacy of the Triplex vaccine in reduced schedules we employed a computational approach. The computer model developed allowed us to test in silico specific vaccination schedules in the quest for optimality. Specifically here we present a parallel genetic algorithm able to suggest optimal vaccination schedule.

RESULTS & CONCLUSIONS

The enormous complexity of combinatorial space to be explored makes this approach the only possible one. The suggested schedule was then tested in vivo, giving good results. Finally, biologically relevant outcomes of optimization are presented.

Single nucleotide polymorphism in the interleukin 12B gene is associated with risk for breast cancer development

We analysed the association of a single nucleotide polymorphism (SNP) in the gene encoding the IL-12 subunit p40 (IL12B, rs3212227, A>C) with breast cancer. The SNPs allelic and genotypic frequencies were compared between patients (n = 191) and healthy (n = 194) women in a case-control study from Croatia. The major allele (A) was associated with susceptibility to breast cancer (P = 0.003; OR = 1.67; 95% CI: 1.17-2.38). Likewise, the minor allele (C) was significantly correlated with protection (P = 0.003; OR = 0.60; 95% CI: 0.42-0.86). At the genotype level, AA homozygosity was significantly associated with predisposition to disease (P = 0.013; OR = 1.68, 95% CI: 1.09-2.59), whereas the minor allele homozygosity (CC) was correlated with protection to disease (P = 0.020, OR = 0.28, 95% CI: 0.09-0.91). The heterozygous genotype showed no significant correlation with disease. The product of the IL12B gene (IL-12 p40) can either form a homodimeric cytokine or be part of two pro-inflammatory (IL-12 and IL-23) cytokines. It is presently unclear whether the major allele is associated with higher or lower protein levels of IL-12 p40 and IL-12 p70, which are critical in inflammation and adaptive immune responses. However, as the A allele is high producer of IL12B (p40) mRNA, these results might imply that higher levels of IL-12 p40 (either as homodimers or joined with one or both of the other two subunits) predispose to breast cancer.

Interleukin-12B rs3212227 polymorphism and cancer risk: a meta-analysis

IL-12 plays a very important role in the development and progress of cancer. IL-12B rs3212227 polymorphism has been reported and many studies have focused on the role of this polymorphism in various cancers. However, the association between IL-12B rs3212227 polymorphism and cancer risk remains controversial. Therefore, we performed a systematic meta-analysis to estimate the overall cancer risk associated with this gene polymorphism and to quantify any potential between-study heterogeneity. PubMed and Embase databases were searched for case-control studies published up to April 1, 2012 that investigated IL-12B rs3212227 polymorphism and cancer risk. Odds ratios (OR) with 95 % confidence intervals (95 % CI) were used to access the strength of this association. Heterogeneity among articles and publication bias were also verified. Ten studies with 2,954 cancer patients and 3,276 healthy controls were included. This meta-analysis showed that there was a significant association between IL-12B rs3212227 polymorphism and overall cancer risk (CC/AC vs AA: OR = 1.32, 95 % CI = 1.06-1.63). When stratified by cancer type, we found a significant increased risk in cervical and nasopharyngeal cancer (OR = 1.34, 95 % CI = 1.04-1.73; OR = 2.03, 95 % CI = 1.57-2.63, respectively). In the stratified analysis, we also observed a similar association in population-based studies (OR = 1.34, 95 % CI = 1.00-1.80), Asian populations (OR = 1.33, 95 % CI = 1.06-1.67) and European populations (OR = 1.54, 95 % CI = 1.04-2.28). According to the results of our meta-analysis, IL-12B rs3212227 polymorphism probably is associated with a high risk of cancer.

Human responses against HER-2-positive cancer cells in human immune system-engrafted mice

Background:

Human immune system (HIS)-engrafted mice are new tools to investigate human immune responses. Here, we used HIS mice to study human immune responses against human HER-2-positive cancer cells and their ability to control tumour growth and metastasis.

Methods:

BALB/c Rag2^−/−, Il2rg^−/− mice were engrafted with CD34⁺ or CD133⁺ human cord blood hematopoietic stem cells (HSC) and vaccinated with human HER-2-positive cancer cells SK-OV-3 combined to human IL-12.

Results:

Both CD34⁺ or CD133⁺ human HSC gave long-term engraftment and differentiation, both in peripheral blood and in lymphoid organs, and production of human antibodies. Vaccinated mice produced specific anti-HER-2 human IgG. An s.c. SK-OV-3 challenge was significantly inhibited (but not abolished) in both vaccinated and non-vaccinated HIS mice. Tumours were heavily infiltrated with human and murine cells, mice showed NK cells and production of human interferon-γ, that could contribute to tumour growth inhibition. Vaccinated HIS mice showed significantly inhibited lung metastases when compared with non-vaccinated HIS mice and to non-HIS mice, along with higher levels of tumour-infiltrating human dendritic cells.

Conclusion:

Anti-HER-2 responses were elicited through an adjuvanted allogeneic cancer cell vaccine in HIS mice. Human immune responses elicited in HIS mice effectively inhibited lung metastases.

Interleukin-12: clinical usage and molecular markers of cancer susceptibility

The last decade has seen the emergence of immunomodulators as therapeutic agents in cancer treatment. Interleukins (ILs) are a category of small cell-signaling molecules that organize communication and interaction between immune cells and therefore they could be used as perfect immunomodulators. IL-12 is a promising candidate for cancer immunotherapy since it plays a major role in development of antitumor immune response. Numerous studies report that IL-12 promotes an effective destruction of cancer cells both in vivo and in vitro. In addition, IL-12 has anti-angiogenic activity and it is able to dramatically decrease tumor-supportive activities of tumor-associated macrophages. The first part of the review is devoted to immunobiology of IL-12. Signaling pathways of IL-12 as well as clinical trials of this cytokine are discussed. The second part of the review is concerned on the inherited variations in IL-12A and IL-12B genes that could modulate cancer susceptibility, and as a consequence, possess predictive, therapeutic, or prognostic significance. It is known that functional single nucleotide polymorphisms (SNPs) in IL-12A and IL-12B genes may dramatically affect on protein expression level, or alter its functions, which may lead to immune disorders, autoimmune diseases, and eventually contribute to cancer occurrence. The list of genetic polymorphisms for further investigations might include the following: IL-12B_+1188A/C (rs3212227), IL-12A_+277G/A (rs568408), IL-12A_-798T/A (rs582054), IL-12A_-504T/G (rs190533), IL-12A_-1148T/C (rs2243123), and IL-12B_+16974 A/C. Perhaps, some of these SNPs may become an attractive target for oncogenomics and possibly could be used in programs of early cancer diagnosis as well as cancer prevention in the nearest future.

A vaccine targeting angiomotin induces an antibody response which alters tumor vessel permeability and hampers the growth of established tumors

Angiomotin (Amot) is one of several identified angiostatin receptors expressed by the endothelia of angiogenic tissues. We have shown that a DNA vaccine targeting Amot overcome immune tolerance and induce an antibody response that hampers the progression of incipient tumors. Following our observation of increased Amot expression on tumor endothelia concomitant with the progression from pre-neoplastic lesions to full-fledged carcinoma, we evaluated the effect of anti-Amot vaccination on clinically evident tumors. Electroporation of plasmid coding for the human Amot (pAmot) significantly delayed the progression both of autochthonous tumors in cancer prone BALB-neuT and PyMT genetically engineered mice and transplantable TUBO tumor in wild-type BALB/c mice. The intensity of the inhibition directly correlated with the titer of anti-Amot antibodies induced by the vaccine. Tumor inhibition was associated with an increase of vessels diameter with the formation of lacunar spaces, increase in vessel permeability, massive tumor perivascular necrosis and an effective epitope spreading that induces an immune response against other tumor associated antigens. Greater tumor vessel permeability also markedly enhances the antitumor effect of doxorubicin. These data provide a rationale for the development of novel anticancer treatments based on anti-Amot vaccination in conjunction with chemotherapy regimens.

The antitumor effects of adenoviral-mediated, intratumoral delivery of interleukin 23 require endogenous IL-12

Interleukin (IL)-23 is a member of the IL-12 family of heterodimeric cytokines, comprised of p19 and p40 subunits, which exhibits immunostimulatory properties similar to IL-12. We have demonstrated previously that adenoviral-mediated, intratumoral delivery of IL-23 (Ad.IL-23) was able to induce systemic antitumor immunity. Here we demonstrate that Ad.IL-23 requires endogenous IL-12 for conferring an antitumor effect after adenoviral-mediated, intratumoral delivery. In contrast, Ad.IL-12 does not require IL-23 for its antitumor effects although endogenous IL-23 appears important for induction of systemic antitumor immunity by IL-12. However, despite the requirement for endogenous IL-12, co-delivery of IL-23 and IL-12 does not provide even an additive local or systemic antitumor effect, regardless of the dose. We further demonstrate that although the use of a single-chain IL-23 (scIL-23) results in higher level of expression and a more pronounced IL-23-mediated antitumor effect, there is still no synergy with IL-12. These results demonstrate that although significant antitumor effects are achieved by intratumoral injection of adenovirus expressing either scIL-23 or IL-12 alone and that IL-23 requires endogenous IL-12 for maximum antitumor benefit, the combined use of these cytokines provides no additive or synergistic effect.

Association of IL-12p40 +1188 A/C polymorphism with nasopharyngeal cancer risk and tumor extension

The interleukin 12 (IL-12) cytokine, encoded by polymorphic genes, plays a central role in the T helper 1 cell-mediated immunity against tumors. We investigated whether the 3' untranslated region +1188 A/C polymorphism (rs 3212227) influences the nasopharyngeal carcinoma (NPC) risk in Tunisian patients. DNA analysis of 247 patients and 284 healthy individuals showed a higher frequency of the 1188 C allele and the CC genotype in patients than in controls (P = 0.00001 and P = 0.00005) suggesting that the C variant allele is associated with the susceptibility to NPC. Additional testing showed that the homozygous CC genotype is also associated with advanced stage of the tumor extension at presentation (P = 0.022). Our data suggest that the impaired production of IL-12 behaves as a risk factor for NPC occurrence and progression.