Gene gun-mediated oral mucosal transfer of interleukin 12 cDNA coupled with an irradiated melanoma vaccine in a hamster model: successful treatment of oral melanoma and distant skin lesion

Buccal and Sublingual Vaccines: A Review on Oral Mucosal Immunization and Delivery Systems

Currently, most vaccines available on the market are for parental use; however, this may not be the best option on several occasions. Mucosal routes of administration such as intranasal, sublingual, and buccal generate great interest due to the benefits they offer. These range from increasing patient compliance to inducing a more effective immune response than that achieved through conventional routes. Due to the activation of the common mucosal immune system, it is possible to generate an effective systemic and local immune response, which is not achieved through parenteral administration. Protection against pathogens that use mucosal entry routes is provided by an effective induction of mucosal immunity. Mucosal delivery systems are being developed, such as films and microneedles, which have proven to be effective, safe, and easy to administer. These systems have multiple advantages over commonly used injections, which are simple to manufacture, stable at room temperature, painless for the patient since they do not require puncture. Therefore, these delivery systems do not require to be administered by medical personnel; in fact, they could be self-administered.

Physicochemical and Preclinical Evaluation of a Novel Buccal Measles Vaccine

The aim of this study is to develop an orally disintegrating film (ODF) containing a microparticulate measles vaccine formulation for buccal delivery. The measles vaccine microparticles were made with biocompatible and biodegradable bovine serum albumin (BSA) and processed by spray drying. These vaccine microparticles were incorporated in the ODF, consisting of Lycoat RS720®, Neosorb P60W® and Tween 80. The yield of the microparticles was approximately 85-95%, w/w. The mean size of the vaccine microparticles was 3.65 ± 1.89 μm and had a slightly negative surface charge of 32.65 ± 2.4 mV. The vaccine particles were nontoxic to normal cells at high concentrations (500 μg/2.5 × 10⁵ cells) of vaccine particles. There was a significant induction of innate immune response by vaccine microparticles which was observed in vitro when compared to blank microparticles (P < 0.05). The vaccine microparticles also significantly increased the antigen presentation and co-stimulatory molecules expression on antigen presenting cells, which is a prerequisite for Th1 and Th2 immune responses. When the ODF vaccine formulation was dosed in juvenile pigs, significantly higher antibody titers were observed after week 2, with a significant increase at week 4 and plateauing through week 6 comparative to naïve predose titers. The results suggest that the ODF measles vaccine formulation is a viable dosage form alternative to noninvasive immunization that may increase patient compliance and commercial distribution.

Primary mucosal melanoma of the oral cavity: current therapy and future directions

BACKGROUND

Primary mucosal melanoma of the oral cavity is a highly aggressive malignancy of melanocytic origin. The aim of this study is to report a case series of oral mucosal melanomas (OMMs) and provide a review of the literature with regard to treatment guidelines for and prognosis of this pathologic entity.

STUDY DESIGN

We report three cases of OMMs treated in our institutions and the results of a literature review, in which the words "oral" and "mucosal melanoma" were used as the main keywords.

RESULTS

Surgical resection of the primary tumor with wide resection margins appears to be the recommended primary treatment modality with the aim to achieve tumor-free margins. Elective neck dissection and adjuvant radiotherapy have been advocated for locoregional control. Chemotherapy has not been shown to improve survival and is mainly used for palliative purposes. Immunotherapy and biochemotherapy seem to significantly improve survival and could open new therapeutic horizons.

CONCLUSIONS

The prognosis of OMMs remains poor despite treatment. Early diagnosis and aggressive surgical resection followed by adjuvant therapies could be the key to improving survival. Multicenter randomized clinical trials, which may be difficult to conduct because of the rarity to the lesion, would aid in the development of new strategies.

DNA immunization

DNA immunization was discovered in early 1990s, and its use has been expanded from vaccine studies to a broader range of biomedical research areas, such as the generation of high-quality polyclonal and monoclonal antibodies as research reagents. In this unit, three common DNA immunization methods are described: needle injection, electroporation, and gene gun. In addition, several common considerations related to DNA immunization are discussed.

Gold nanoparticle mediated cancer immunotherapy

Significant progress has been made in the field of cancer immunotherapy, where the goal is to activate or modulate the body's immune response against cancer. However, current immunotherapy approaches exhibit limitations of safety and efficacy due to systemic delivery. In this context, the use of nanotechnology for the delivery of cancer vaccines and immune adjuvants presents a number of advantages such as targeted delivery to immune cells, enhanced therapeutic effect, and reduced adverse outcomes. Recently, gold nanoparticles (AuNP) have been explored as immunotherapy carriers, creating new AuNP applications that merit a critical overview. This review highlights recent advances in the development of AuNP mediated immunotherapies that harness AuNP biodistribution, optical properties and their ability to deliver macromolecules such as peptides and oligonucleotides. It has been demonstrated that the use of AuNP carriers can improve the delivery and safety of immunotherapy agents, and that AuNP immunotherapies are well suited for synergistic combination therapy with existing cancer therapies like photothermal ablation.

FROM THE CLINICAL EDITOR

Cancer immunotherapy approaches are rapidly evolving and are some of the most promising avenues to approach malignancies. This review summarizes the role of gold nanoparticles in immunotherapy agent delivery, and in the development of synergistic therapies such as photothermal ablation.

Sinonasal carcinomas: epidemiology, pathology, and management

Sinonasal carcinomas are uncommon neoplasms accounting for approximately 3% to 5% of all upper respiratory tract malignancies. Sinonasal malignancies in most cases do not cause early symptoms and present in an advanced stage of disease. Exact staging necessitates a clinical and endoscopic examination with biopsy and imaging. Tumor resection using an open or endoscopic approach is usually considered the first treatment option. In general, sinonasal carcinomas are radiosensitive, so adjuvant or neoadjuvant radiation treatment may be indicated in advanced disease. Multidisciplinary surgical and medical oncologic approaches, including ablation and reconstruction, have enhanced the survival outcome over the past few decades.

Demographics and treatment trends in sinonasal mucosal melanoma

OBJECTIVES/HYPOTHESIS

To evaluate the population characteristics of mucosal melanoma of the nasal cavity and paranasal sinuses and determine the impact of the new staging classification.

STUDY DESIGN

Analysis of a national database.

METHODS

Patients were identified from the Surveillance, Epidemiology, and End Results tumor registry data with mucosal melanoma of the nasal cavity and paranasal sinuses between 2000 and 2007. Tumors were classified using the American Joint Committee on Cancer (AJCC) 6th edition site-specific staging as well as 7th edition staging for head and neck mucosal melanoma (HNMM). Incidence rates and descriptive statistics were calculated, and multivariate analysis was performed to examine the impact of demographic factors and staging on survival.

RESULTS

A total of 304 patients were identified. The incidence rate was 0.05 per 100,000. Fifty-six percent were female, 92% were >50 years old, and more than 90% were Caucasian; 81.6% of patients were treated with surgery, and 38.5% of patients received postoperative radiation. Overall, the 5-year survival rate was 24.2%. Significant differences in survival were observed for surgery with radiation (P = .005) and surgery alone (P = .04) compared with radiation alone. TNM staging using the AJCC 6th and 7th edition classification schemes yielded similar survival curves. However, the new classification for HNMM allows for better delineation of stage IV disease, revealing slightly improved survival for stage IVA disease.

CONCLUSIONS

HNMM is a rare disease with a poor prognosis. Surgery remains the treatment of choice, with some role for adjuvant therapy. The new staging classification for HNMM appears to more efficiently stage this disease. Demographics and therapeutic findings are discussed.

The effects of mesenchymal stem cells injected via different routes on modified IL-12-mediated antitumor activity

Owing to its tumor tropism and prolonged transgene expression, mesenchymal stem cell (MSC) has been considered as an ideal delivery vehicle for cancer gene therapies or therapeutic vaccines. In this study, we demonstrated that intratumoral (i.t.) injection of MSCs expressing modified interleukin-12 (MSCs/IL-12M) exhibited stronger tumor-specific T-cell responses and antitumor effects as well as more sustained expressions of IL-12 and interferon (IFN)-γ in both sera and tumor sites than did IL-12M-expressing adenovirus (rAd/IL-12M) in mice bearing both solid and metastatic tumors. Subcutaneous (s.c.) injection of MSCs/IL-12M at contralateral site of tumor exhibited similar levels of serum IL-12 and IFN-γ as i.t. injection, but much weaker antitumor effects in both B16F10 melanoma and TC-1 cervical cancer models than i.t. injection. Although intravenous (i.v.) injection elicited earlier peak serum levels of cytokines, it induced weaker tumor-specific T-cell responses and antitumor effects than i.t. injection, indicating that serum cytokine levels are not surrogate indicators of antitumor effects. Taken together, these results indicated that MSC is more efficient than adenovirus as a cytokine gene delivery vehicle and that i.t. injection of MSCs/IL-12M is the best approach to induce strong tumor-specific T-cell responses that correlate with anti-metastatic effects as well as inhibition of solid tumor growth, although MSCs themselves have an ability to migrate into the tumor site. In addition, MSCs/IL-12M embedded in Matrigel (MSCs/IL-12M/Matrigel) exhibited significant antitumor effects even in immunodeficient mice such as SCID and BNX mice lacking T, B and natural killer (NK) cells, but not in IFN-γ knockout mice. Our findings provide an optimal approach for designing an efficient clinical protocol of MSC-based cytokine gene therapy to induce strong tumor-specific T-cell responses and therapeutic anticancer efficacy.

Autocrine and paracrine chemokine receptor 7 activation in head and neck cancer: implications for therapy

BACKGROUND

The chemokine receptor 7 (CCR7) mediates survival and invasiveness of metastatic squamous cell carcinoma of the head and neck (SCCHN) to regional lymph nodes. Constitutive prosurvival signaling by the phosphoinositide-3 kinase/Akt pathway has been observed in SCCHN cells independent of epidermal growth factor receptor (EGFR) signaling.

METHODS

Human SCCHN cell lines were treated with agents that block or activate CCR7-mediated signaling, and Akt activation, cell viability in the presence or absence of EGFR inhibition, and cisplatin-induced apoptosis (in the presence or absence of Akt inhibition) were assessed by immunoblotting, the MTT assay, and the detection of annexin V, respectively. Expression and secretion of chemokines by primary tumors, metastatic nodes, and benign nodes of patients with SCCHN were determined by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The role of paracrine activation of CCR7 on tumor growth was analyzed by comparing the growth of orthotopic tumors derived from B7E3 murine oral carcinoma cells in wild-type BALB/c mice, in paucity of lymphoid T cell (plt, deficient in CCL19 and CCL21 expression) mice, and in plt mice in which the implanted B7E3 cells overexpressed CCR7 (n = 14 mice per group).

RESULTS

In the absence of exogenous ligand treatment, blockade of CCR7 signaling reduced levels of phosphorylated (activated) Akt and decreased SCCHN cell viability by up to 59% (95% confidence interval [CI] = 58.2% to 59.8%), enhancing the effect of EGFR inhibition. CCR7 stimulation protected metastatic SCCHN cells from cisplatin-induced apoptosis in an Akt-dependent manner. Metastatic nodes expressed and secreted higher levels of CCL19 than benign nodes or primary tumors. CCR7-positive murine SCCHN tumors grew more slowly in plt mice than in control BALB/c mice (mean average tumor volume on day 20 = 12.2 and 26.5 mm(3), respectively; difference = 14.3 mm(3), 95% CI = 12.3 to 17.1 mm(3)).

CONCLUSIONS

Secretion of CCL19 and CCL21 by SCCHN cells and by paracrine sources combine to promote activation of CCR7 prosurvival signaling associated with tumor progression and disease relapse. CCR7 and its cognate chemokines may be useful biomarkers of SCCHN progression, and blockade of CCR7-mediated signaling may enhance the efficacy of platinum- and EGFR-based therapies.

Cell and tissue targeting of nucleic acids for cancer gene therapy

Tumor targeting--per definition--includes any strategy to improve the specificity of the therapeutic nucleic acid towards the tumor site, while highest biological activity should be maintained. Targeting has been successfully achieved at the transcriptional, transductional or delivery level. For tumor-specific delivery, physical targeting methods like electroporation, hyperthermia, magnetofection, photochemical internalization or ultrasound, and biological targeting systems, including active and passive tumor targeting, have been developed. Therapeutic effects could be demonstrated with various targeted nucleic acid formulations, such as tumor-targeted DNA plasmids expressing p53 or tumor necrosis factor alpha, small interfering RNAs knocking down gene expression from tumor specific chromosomal translocations or gene expression of tumor neoangiogenic processes, as well as double stranded RNA poly inosine-cytosine which triggers apoptosis in targeted tumor cells.

Recent developments in the application of plasmid DNA-based vectors and small interfering RNA therapeutics for cancer

Increased understanding of the molecular pathological mechanisms of cancer, the advent of novel molecular tools such as synthetic small interfering RNA (siRNA) or plasmid DNA-based vectors (pDNA), and technology for the in vivo delivery of such biomolecular therapeutics have provided an encouraging perspective for cancer therapy. Numerous pDNAs and siRNAs have been tested in preclinical cancer models, and these first approaches have reached clinical evaluation. The therapeutic effector mechanisms include interference with neoangiogenesis, blockage of cell division, promotion of apoptosis and sensitization to chemotherapy, delivery of cytotoxic genes, and activation of anticancer immune responses. Physical methods have been developed for highly effective regional delivery. A series of innovative "smart" formulations directs the current development toward safe and effective systemic tumor-targeted delivery of pDNA and siRNA.

Oral malignant melanoma: A review of the literature

Primary oral malignant melanoma (OMM) is a rare neoplasm, accounting for 0.5% of all oral malignancies. The etiology is unknown; tobacco use and chronic irritation may play some role. Clinically, OMM may mimick other pigmented lesions. A biopsy is required in order to establish the diagnosis. The reported risk of malignant cells spreading during invasive procedures and factors such as size of the lesion or anatomical limitations, may influence the diagnostic surgical procedure. Therapy of OMM is commonly based on surgical excision of the primary tumour, supplemented by radiotherapy, with chemotherapy and immunotherapy serving as adjuncts. Prognosis is poor, with a 5-year survival rate of approximately 15%.

Antitumor Activity of IFN-λ in Murine Tumor Models

IFN-lambda 1, -lambda 2 and -lambda 3 have been discovered as the latest members of the class II cytokine family and shown to possess antiviral activity. Murine B16 melanoma and Colon26 cancer cells were transduced with mouse IFN-lambda to determine whether IFN-lambda possesses antitumor activity. Overexpression of IFN-lambda induced cell surface MHC class I expression and Fas/CD95 Ag, induced significant caspase-3/7 activity, and increased p21(Waf1/Cip1) and dephosphorylated Rb (Ser(780)) in B16 cells in vitro. IFN-lambda expression in tumor cell lines markedly inhibited s.c. and metastatic tumor formation in vivo compared with mock transfections (p < 0.05). Moreover, IFN-lambda expression induced lymphocytic infiltrates, and an Ab-mediated immune cell depletion assay showed that NK cells were critical to IFN-lambda-mediated tumor growth inhibition. Hydrodynamic injection of IFN-lambda cDNA successfully targeted liver metastatic foci of Colon26 cells, and moderately decreased the mortality of mice with tumors. IFN-lambda overexpression in the liver increased NK/NKT cells and enhanced their tumor-killing activity, and suggested the activation of innate immune responses. Thus, IFN-lambda induced both tumor apoptosis and NK cell-mediated immunological tumor destruction through innate immune responses. These findings suggested that local delivery of IFN-lambda might prove a useful adjunctive strategy in the clinical treatment of human malignancies.

Photochemically enhanced gene delivery of EGF receptor-targeted DNA polyplexes

Epidermal growth factor receptor (EGFR) targeted DNA polyplexes, containing polyethylenimine (PEI) conjugated with EGF protein as cell-binding ligand for endocytosis and polyethylene glycol (PEG) for masking the polyplex surface charge, mediated a 3- to 30-fold higher luciferase gene expression in HUH7, HepG2 and A431 cell transfections than analogous untargeted PEG-PEI polyplexes. Transfection levels can be further enhanced by treatment of cells with amphiphilic photosensitizers followed by illumination. In this process photosensitizers localized in membranes of endocytic vesicles are activated by light, resulting in the destruction of endocytic membrane structures and releasing co-endocytosed polyplexes into the cell cytosol. Photochemical enhanced gene expression was observed in all cell lines, with the magnitude of enhancement depending on the particular PEI polyplex formulation and cell line, ranging between 2- and 600-fold. Importantly, improved gene transfer retained EGF receptor specificity, as demonstrated by comparison with ligand-free polyplexes and by receptor antibody or ligand competition experiments. These results suggest that this combined procedure enables a dual mode of targeting polyplexes: biological targeting via EGFR interaction, combined with physical targeting with light to direct a photochemical delivery of therapeutic genes to a desired location.

Targeted nucleic acid delivery into tumors: new avenues for cancer therapy

Unique properties of tumors, such as abnormalities in the cell cycle and apoptosis, migration and metastasis, neoangiogenesis or unique antigen profiles are targets for therapeutic anti-cancer strategies. Beyond the selection of such strategies, additional specificity for the targeted tumor tissue can be accomplished in cancer gene therapy in several ways. Upon systemic administration, appropriately packaged therapeutic nucleic acid may be preferentially transported into the tumor tissue (targeted delivery); formulation can mediate the intracellular uptake of the nucleic acid into the nucleus of target cells only (transductional targeting); and/or the use of specific promotor/enhancer elements can restrict transcription of therapeutic genes to the target cells only (transcriptional targeting). Options for physical and biological targeting of nucleic acid formulations into tumors and therapeutic approaches are reviewed.

DNA immunization of the grafted liver by particle-mediated gene gun1

BACKGROUND

Direct DNA vaccination of liver allografts before transplantation may provide an effective strategy for inducing protective immunity to infection and malignancy.

METHODS

In this study, the authors examined the feasibility of gene gun-mediated vaccination of liver grafts. Using plasmids expressing luciferase and green fluorescent proteins, their expression was tested in a graft liver.

RESULTS

Protein expression was observed in the graft liver and significantly enhanced in hepatectomized rats. A short course of tacrolimus (FK506) also evoked the expression of these proteins. Effects of primary immunization to the liver on the humoral response were then tested using an expression plasmid encoding hepatitis B virus surface (HBs) antigen and were compared to that of skin immunization alone. The results showed that local immunization to the liver strongly induced antibody formation. Furthermore, the combination of an immunized partial liver graft with tacrolimus significantly enhanced antibody production against HBs antigen.

CONCLUSIONS

A DNA vaccine to the liver may be one strategy for preventing infectious disease associated with liver transplantation under tacrolimus treatment.

Current management of mucosal melanoma of the head and neck

While mucosal-based melanomas of the head and neck region are uncommon lesions, when they do arise they usually follow an inexorably aggressive course. Experience with these tumors is, necessarily, limited; as such, well-worked out treatment protocols for the treatment of such lesions are in short supply. It appears as though mucosal melanomas (MuMs) develop more frequently in the nasal cavity and paranasal sinus region, and less often in the oral cavity. It seems that the incidence of nodal metastasis is significantly lower for sinonasal MuMs than it is for MuMs of the oral cavity; this observation may influence decisions about performing neck dissection as a function of location of the primary MuM. At present, surgical excision remains the mainstay of treatment; however, anatomical complexities within the region can hamper attempts at complete excision. Radiotherapy has not traditionally been relied on for routine treatment of MuM, although some recent reports have challenged this view. Chemotherapy is, at present, employed principally in the treatment of disseminated disease and for palliation. As a diagnostic matter, MuM belongs to the class of tumors that, on light microscopy, may with some regularity be confused with other malignancies (including sarcomas, plasmacytomas, and carcinomas); as a consequence, this is a diagnosis which is often best confirmed by way of ancillary testing via immunohistochemical studies. A better grasp of the best means of treating MuM will likely come only when large referral centers are able to pool their experiences with these uncommon yet virulent malignancies.

Predominant cell-mediated immunity in the oral mucosa: gene gun-based vaccination against infectious diseases

BACKGROUND

Direct immunization via epithelial surfaces has been considered for many vaccine approaches, including DNA vaccines. It remains to be determined, however, which body site is suitable for genetic vaccination.

OBJECTIVE

To characterize the effects of the oral mucosa-mediated genetic vaccination, we compared antigen-specific immune responses of the oral mucosal DNA vaccine to the flank skin vaccination against influenza virus and malaria parasite.

METHODS

DNA vaccines against the influenza A/WSN/33 (H1N1) hemagglutinin and the malaria Plasmodium berghei circumsporozoite protein were administered respectively three times at 3-week intervals into the oral mucosa, skin, or liver of hamsters. The effects of their vaccine were evaluated by antigen-specific antibody production and cell-mediated killing activity. Furthermore, the in vivo malaria challenge test was also performed after the vaccination.

RESULTS

Significant specific antibody production was not observed in each case, but interferon-gamma production and cell-mediated killing activity were strongly induced in splenic lymphocytes from hamsters with the oral vaccination. The in vivo malaria challenge after the oral mucosal vaccination significantly delayed the blood-appearance day of the parasites in comparison with other immunization sites (P<0.05).

CONCLUSION

These results suggest that gene immunization via the oral mucosa may induce cell-mediated immunity more efficiently than via the skin or liver, and that the oral mucosa may be one of the most suitable tissues for gene gun-based DNA vaccination against infectious diseases.

Long-lasting gene expression by particle-mediated intramuscular transfection modified with bupivacaine: combinatorial gene therapy with IL-12 and IL-18 cDNA against rat sarcoma at a distant site

The immune response is modulated by genetic adjuvants using plasmid vectors expressing cytokines. Skeletal muscle can express a foreign gene intramuscularly administered via a needle injection, and the potential of muscle as a target tissue for somatic gene therapy in treating cancer has been explored. In the present study, we investigated the efficacy of particle-mediated intramuscular transfection modified with a local anesthetic agent, bupivacaine, on luciferase and green fluorescent protein. The results indicate that these proteins are more efficiently expressed and persist longer in muscle modified in this way compared with the needle-injection method. Using an established rat sarcoma model, particle-mediated intramuscular gene-gun therapy with a combination of IL-12 and IL-18 cDNA was conducted. Growth of the distant sarcoma was significantly inhibited by particle-mediated intramuscular combination gene therapy, and the survival rate was also improved. Furthermore, the combination gene-gun therapy maintained significant levels of interferon-gamma and induced a high activity of tumor-specific cytotoxic T lymphocytes. These results suggest that the sustained local delivery of IL-12 and IL-18 cDNA using intramuscular gene-gun therapy modified with bupivacaine can induce long-term antitumor immunity, and can provide the great advantage of inhibiting the disseminated tumor.

Gene therapy for the treatment of oral squamous cell carcinoma

Despite advances in surgery, radiotherapy, and chemotherapy, the survival of patients with oral squamous cell carcinoma has not significantly improved over the past several decades. Treatment options for recurrent or refractory oral cancers are limited. Gene therapy for oral cancer is currently under investigation in clinical trials. The goal of cancer gene therapy is to introduce new genetic material into target cells without toxicity to non-target tissues. This review discusses the techniques used in cancer gene therapy for oral squamous cell carcinoma and summarizes the ongoing strategies that are being evaluated in clinical trials.

Bilayer films for mucosal (genetic) immunization via the buccal route in rabbits

PURPOSE

The oral buccal mucosa may be an ideal site for mucosal immunization, allowing for the needle-free administration of cost-effective vaccines. A novel mucoadhesive bilayer film was developed to test the feasibility of this route of immunization in rabbits.

METHODS

Bilayer films were developed using different ratios of Noveon and Eudragit S-100 as the mucoadhesive layer and a pharmaceutical wax as the impermeable backing layer. Optimal 3/8-inch films were post-loaded with 100 microg of plasmid DNA (CMV-beta-gal) or beta-galactosidase protein. The in vitro release rates and stability of the postloaded antigens were determined. The films were applied to the buccal pouch of rabbits on days 0. 7, and 14, and the humoral and splenocyte proliferative immune responses to beta-gal were determined through day 28 and compared to those responses after conventional subcutaneous injection of adjuvanted protein.

RESULTS

The weight ratio of Noveon and Eudragit S-100 had a significant effect on adhesion time of bilayer films. Postloaded plasmid DNA and beta-gal remained stable after being released from bilayer films (release of -60-80% in 2 h for both). Buccal immunization using novel bilayer films (109 +/- 6-microm thickness) containing plasmid DNA led to comparable antigen-specific IgG titer to that of subcutaneous protein injection. All rabbits immunized with plasmid DNA via the buccal route but none by the subcutaneous route with protein antigen demonstrated splenocyte proliferative immune responses.

CONCLUSION

The feasibility of buccal (genetic) immunization with these novel bilayer films was demonstrated.