Inhibitory effects of interferon-gamma plasmid DNA on DMBA-TPA induced mouse skin carcinogenesis

Current status of skin cancers with a focus on immunology and immunotherapy

Skin cancer is one of the most widespread cancers, with a significant global health effect. UV-induced DNA damage in skin cells triggers them to grow and proliferate out of control, resulting in cancer development. Two common types of skin cancer include melanoma skin cancer (MSC) and non-melanoma skin cancer (NMSC). Melanoma is the most lethal form of skin cancer, and NMSC includes basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and other forms. The incidence of skin cancer is increasing in part owing to a demographic shift toward an aging population, which is more prone to NMSC, imposing a considerable financial strain on public health services. The introduction of immunostimulatory approaches for cancer cell eradication has led to significant improvements in skin cancer treatment. Over the last three decades, monoclonal antibodies have been used as powerful human therapeutics besides scientific tools, and along with the development of monoclonal antibody production and design procedures from chimeric to humanized and then fully human monoclonal antibodies more than 6 monoclonal antibodies have been approved by the food and drug administration (FDA) and have been successful in skin cancer treatment. In this review, we will discuss the epidemiology, immunology, and therapeutic approaches of different types of skin cancer.

Stimulatory effect of fluoxetine and desipramine, but not mirtazapine on C26 colon carcinoma hepatic metastases formation: association with cytokines

Due to the high prevalence of depression among cancer patients, antidepressant medications are frequently administered as adjuvant treatment. However, the safety of such medications in the development of metastasis is unclear. In this study, we investigated the effects of fluoxetine, desipramine, and mirtazapine on the liver metastasis of murine C26 colon carcinoma (cc). Balb/c male mice were administered these antidepressants intraperitoneally (i.p.) for 14 days following intrasplenic injections of C26 colon carcinoma cells. Desipramine and fluoxetine, but not mirtazapine, significantly increased the number of tumor foci and total volume of the tumor in liver tissue. This effect was associated with a decrease in the ability of splenocytes to produce interleukin (IL)-1β and interferon (IFN)-γ and an increase in their ability to produce interleukin (IL)-10. Similar changes were observed in plasma IL-1β, IFN-γ, and IL-10 levels. The current study demonstrates that the stimulatory effect of desipramine and fluoxetine, but not mirtazapine, on experimental colon cancer liver metastasis is associated with a suppression of immune defenses against the tumor.

Treatment with Light-Emitting Diodes of Wavelength 863 nm Delays DMBA/TPA-Induced Skin Tumor Formation and Decreases Proinflammatory Cytokine Levels in ICR Mice

The popularity of light/energy devices for cosmetic purposes (e.g., skin care) is increasing. However, the effects and underlying mechanisms remain poorly understood. Commencing in the 1960s, various studies have evaluated the beneficial effects of a light source on cells and tissues. The techniques evaluated include low-level light (laser) therapy and photobiomodulation (PBM). Most studies on PBM used red light sources, but, recently, many studies have employed near-infrared light sources including those of wavelength 800 nm. Here, we used a light-emitting diode (LED) array with a wavelength of 863 nm to treat DMBA/TPA-induced mouse skin tumors; treatment with the array delayed tumor development and reduced the levels of systemic inflammatory cytokines. These results suggest that light therapy could be beneficial. However, the effects were small. Further studies on different skin tumors using an optimized LED setup are required. Combination therapies (conventional methods and an LED array) may be useful.

Glucose-methanol-based fed-batch fermentation for the production of recombinant human interferon gamma (rhIFN-γ) and evaluation of its antitumor potential

Squamous cell carcinoma (SCC) is nonmelanoma skin cancer, which is very common in patients having T-cell immunosuppressant drugs. Anticancerous agents such as cytokines showed effective response on SCC. Human interferon-gamma (hIFN-γ), a type II cytokines, are having potent antiproliferative and immunomodulatory effects. In the current study, the fed-batch cultivation of recombinant Pichia pastoris was carried out, and its effect on cell biomass production, recombinant human interferon-gamma (rhIFN-γ) production, and the overflow metabolites was estimated. P. pastoris GS115 strain coexpressed with 6-phosphogluconolactonase (SOL3) and ribulose-phosphate 3-epimerase (RPE1) gene (GS115/rhIFN-γ/SR) resulted in 60 mg L^-1 of rhIFN-γ production, which was twofold higher as compared with the production from GS115/rhIFN-γ strain. The antiproliferative potential of rhIFN-γ was examined on the human squamous carcinoma (A431) cell lines. Cells treated with 80 ng mL^-1 of rhIFN-γ exhibited 50% growth inhibition by enhancing the production of intracellular reactive oxygen species levels and disrupting membrane integrity. Our findings highlight a state of art process development strategy for the high-level production of rhIFN-γ and its potential application as a therapeutic drug in SCC therapy.

The immune response to Hymenolepis nana in mice decreases tumorigenesis induced by 7,12 dimethylbenz-anthracene

BACKGROUND

Cancer is a high-impact disease throughout the world. A negative correlation has been established between the development of cancer and the Th2 immune response. Infection by helminth parasites is characterized by the induction of a strong and long-lasting Th2 response. The aim of this work was to evaluate the effect of the immune response induced by the infection with the helminth Hymenolepis nana, on the tumorigenesis induced by dimethylbenz-anthracene (DMBA) in mice.

METHODOLOGY

Four different groups of 14 female BALB/c mice were formed; Group A, dimethyl sulfoxide (DMSO) (vehicle) was administered cutaneously, Group B infected with H. nana, group C, cutaneously DMBA and finally Group D infected with H. nana and cutaneous DMBA. The tumor load was determined in those animals that developed cancerous lesions. In all groups were determined: serum concentration of IgE, IFNγ, IL-10, IL-5 and malondialdehyde (MDA). The inflammatory infiltrate was analyzed from skin samples and the expression of the main eosinophilic protein and myeloperoxidase was determined.

RESULTS

The group previously infected with H. nana had a reduced amount of tumors with smaller size, in comparison to the group that received only DMBA; this reduction was associated with lower levels of IFNγ and IL-10, while levels of IgE, IL-5 and MDA were higher. Further, the number of eosinophils and neutrophils was statistically higher in the animals that were previously infected with the helminth and developed less tumors.

CONCLUSION

The immune response induced by H. nana infection is associated with the reduction of tumors probably due to the activity of eosinophils and neutrophils.

A Synthetic Disaccharide Derivative of Diphyllin, TAARD, Activates Human Natural Killer Cells to Secrete Interferon-Gamma via Toll-Like Receptor-Mediated NF-κB and STAT3 Signaling Pathways

Natural products and their derivatives have long been used as pharmacological agents in the fight against cancer. Human natural killer (NK) cells are critical in our immune system in that they are capable of destroying tumor cells directly. However, there are few reports that elucidate the role of natural products in activating NK cells. In this study, we discovered that a synthetic disaccharide derivative of diphyllin, 4-O-{[2′′,3′′,4′′-tri-O-acetyl-α-D-arabinopyranosyl-(1′′→4′)]-2′,3′-di-O-acetyl-α-L-rhamnopyranosyl}diphyllin (TAARD), can alone stimulate interferon (IFN)-γ secretion in primary human NK cells and the NKL cell line. Additionally, it had an additive effect with IL-12 or IL-15 on IFN-γ production, but little adverse effects on NK cells. Mechanistically, TAARD induced the phosphorylation of NF-κB and STAT3, resulting in their binding on the IFNG promoter, which was dependent on TLR1 and TLR3 signaling, respectively. STAT3 and NF-κB knockdown with lentivirus shRNA as well as the NF-κB-specific inhibitor, N-tosyl-l-phenylalaninechloromethyl ketone, significantly suppressed TAARD-induced IFN-γ generation in primary NK cells. Blockade of TLR1 and TLR3 with neutralizing antibodies considerably decreased TAARD-induced activation of NF-κB and STAT3, respectively, as well as IFN-γ generation in NK cells. Collectively, our data suggest that TAARD can induce NK cell IFN-γ production through TLR1-NF-κB and TLR3-STAT3 signaling pathways, rendering its potential use as an agent for cancer prevention or treatment.

Secreted immunoregulatory proteins in the skin

The skin, thought initially to protect the body passively from pathogenic organisms and other environmental insults, is now recognised additionally as a sophisticated immune organ that actively regulates local immunity. Studies linking local innate and adaptive immunity to skin health and disease have revealed a complex network of cell communication and cytokine signalling. Here, we review the last 10 years of literature on this topic, and its relevance to skin immunity.

Annona muricata leaves extracts prevent DMBA/TPA-induced skin tumorigenesis via modulating antioxidants enzymes system in ICR mice

Annona muricata, locally known as soursop has been reported to exhibit antiproliferative activities against various cancer cell lines. In this current study, we have investigated the antitumor promotion of various fractions of Annona muricata leaves (AML); hexane (AMLH), dichloromethane (AMLD) and methanol (AMLM) fraction respectively on 7, 12-dimethylbenz[α]anthracene (DMBA) induced and 12-0-tetradecaboylphorbol-13-acetate (TPA) promoted skin tumorigenesis in mice via morphological assessment, biochemical analysis and histopathological evaluation. The results of the study revealed significant inhibition in tumor incidence, tumor burden and tumor volume in the groups received AMLH and AMLD, respectively, and suppressive effects in group received AMLM compared with carcinogen control group at week 21. Superoxide dismutase, catalase, and lipid peroxidation levels were returned to near normal by administration of AML to DMBA/TPA-induced mice. The above findings were supported by histopathological studies, in which the extensive epidermal hyperplasia in carcinogen control group was restored to normal in AML treated groups. Whilst, annonacin, a major annaonaceous acetogenin was found to be the highest in AMLH and AMLD. From the present study, it can be inferred that AML supressed DMBA/TPA-induced skin tumor and this antitumor-promoting activity may be linked to the antioxidant/free radical-scavenging constituents of the extract and annonacin contained in the extracts.

PAD2 overexpression in transgenic mice augments malignancy and tumor-associated inflammation in chemically initiated skin tumors

We previously found that transgenic mice overexpressing MMTV-FLAG-hPAD2 (PAD2OE) developed spontaneous skin lesions, with a subset of these lesions progressing to invasive squamous cell carcinoma (SCC). The goal of this report was to better understand the potential mechanisms by which PAD2 overexpression promotes skin cancer. Here, PAD2OE mice were treated with the carcinogen, 9,10-dimethyl-1,2-benzanthracene and with O-tetradecanoylphorbol-13-acetate and then scored for papilloma formation. Additionally, tumor sections were evaluated for evidence of tumor cell invasion and inflammation. We found that the total number of papillomas was significantly increased in PAD2OE mice compared to controls. Histopathologic analysis of the lesions found that in PAD2OE skin tumors progressed to invasive SCC more frequently than controls. Additionally, we found that PAD2OE lesions were highly inflamed, with a dense inflammatory cell infiltrate and an associated increase in nuclear phospho-STAT3 (signal transducer and activator of transcription 3) in the transgenic tumors. These data suggest that overexpression of the hPAD2 transgene in the epidermis increases the malignant conversion rate of benign tumors by promoting an inflammatory microenvironment.

Immune-Stimulatory Effects of Rapamycin Are Mediated by Stimulation of Antitumor γδ T Cells

The FDA-approved mTOR inhibitor rapamycin mediates important immune effects, but its contributions to the anticancer effects of the drug are unclear. Here we report evidence that rapamycin-mediated cancer protection relies upon stimulation of γδ T cells. In a well-established mouse model of carcinogen and inflammation-driven skin carcinogenesis, IFNγ recruited γδ TCRmid T cells to the epidermis where rapamycin boosted their perforin-dependent antitumor properties. These antitumor cells were mostly Vγ5-Vγ4-Vγ1- in phenotype. IFNγ signals were required in both hematopoietic and nonhematopoietic cells for rapamycin to optimally promote epidermal infiltration of γδ TCRmid T cells, as mediated by CXCR3-CXCL10 interactions, along with the antitumor effects of these cells. In mouse xenograft models of human squamous cell carcinoma, rapamycin improved human γδ T-cell-mediated cancer cell killing. Our results identify immune mechanisms for the cancer prevention and treatment properties of rapamycin, challenging the paradigm that mTOR inhibition acts primarily by direct action on tumor cells. Cancer Res; 76(20); 5970-82. ©2016 AACR.

IFNγ-responsiveness of endothelial cells leads to efficient angiostasis in tumours involving down-regulation of Dll4

Although IFNγ is regarded as a key cytokine in angiostatic response, our poor understanding of its effective cellular target drastically limits its clinical trials against angiogenesis-related disorders. Here, we investigated the effect of IFNγ on endothelial cells (ECs) and possible molecular mechanisms in angiostasis. By employing Tie2(IFNγR) mice, in which IFNγR expression was reconstituted under the control of Tie2 promoter in IFNγR-deficient mice, we found that the response of ECs to IFNγ was highly effective in inhibiting blood supply and retarding tumour growth. Interestingly, the expression of IFNγR on Tie2(-) cells did not inhibit, but promoted tumour growth in control wild-type mice. Mechanism studies showed that IFNγ reacting on ECs down-regulated the delta-like ligand 4 (Dll4)/Notch signalling pathway. Accordingly, overexpression of Dll4 in human ECs diminished the effect of IFNγ on ECs. This study demonstrates that the action of IFNγ on ECs, but not other cells, is highly effective for tumour angiostasis, which involves down-regulating Dll4. It provides insights for EC-targeted angiostatic therapy in treating angiogenesis-associated disorders in the clinic.

IL-13 but not IL-4 signaling via IL-4Rα protects mice from papilloma formation during DMBA/TPA two-step skin carcinogenesis

Interleukin 4 (IL-4) was shown to be tumor-promoting in full carcinogenesis studies using 3-methylcholanthrene (MCA). Because heretofore the role of IL-4 in DMBA/TPA (9,10-dimethyl-1,2-benz-anthracene/12-O-tetradecanoylphorbol-13-acetate) two-stage carcinogenesis was not studied, we performed such experiments using either IL-4(-/-) or IL-4Rα(-/-) mice. We found that IL-4Rα(-/-) but not IL-4(-/-) mice have enhanced papilloma formation, suggesting that IL-13 may be involved. Indeed, IL-13(-/-) mice developed more papillomas after exposure to DMBA/TPA than their heterozygous IL-13-competent littermate controls. However, when tested in a full carcinogenesis experiment, exposure of mice to 25 μg of MCA, both IL-13(-/-) and IL-13(+/-) mice led to the same incidence of tumors. While IL-4 enhances MCA carcinogenesis, it does not play a measurable role in our DMBA/TPA carcinogenesis experiments. Conversely, IL-13 does not affect MCA carcinogenesis but protects mice from DMBA/TPA carcinogenesis. One possible explanation is that IL-4 and IL-13, although they share a common IL-4Rα chain, regulate signaling in target cells differently by employing distinct JAK/STAT-mediated signaling pathways downstream of IL-13 or IL-4 receptor complexes, resulting in different inflammatory transcriptional programs. Taken together, our results indicate that the course of DMBA/TPA- and MCA-induced carcinogenesis is affected differently by IL-4 versus IL-13-mediated inflammatory cascades.

Probiotic modulation of dendritic cell function is influenced by ageing

Dendritic cells (DCs) are critical for the generation of T-cell responses. DC function may be modulated by probiotics, which confer health benefits in immunocompromised individuals, such as the elderly. This study investigated the effects of four probiotics, Bifidobacterium longum bv. infantis CCUG 52486, B. longum SP 07/3, Lactobacillus rhamnosus GG (L.GG) and L. casei Shirota (LcS), on DC function in an allogeneic mixed leucocyte reaction (MLR) model, using DCs and T-cells from young and older donors in different combinations. All four probiotics enhanced expression of CD40, CD80 and CCR7 on both young and older DCs, but enhanced cytokine production (TGF-β, TNF-α) by old DCs only. LcS induced IL-12 and IFNγ production by DC to a greater degree than other strains, while B. longum bv. infantis CCUG 52486 favoured IL-10 production. Stimulation of young T cells in an allogeneic MLR with DC was enhanced by probiotic pretreatment of old DCs, which demonstrated greater activation (CD25) than untreated controls. However, pretreatment of young or old DCs with LPS or probiotics failed to enhance the proliferation of T-cells derived from older donors. In conclusion, this study demonstrates that ageing increases the responsiveness of DCs to probiotics, but this is not sufficient to overcome the impact of immunosenescence in the MLR.

Noninvasive delivery of siRNA and plasmid DNA into skin by fractional ablation: erbium:YAG laser versus CO₂ laser

The present study was conducted to evaluate the impacts of fractional erbium (Er):YAG and CO2 lasers on skin permeation of small interfering (si)RNA and plasmid (p)DNA vectors. In vitro skin delivery was determined with a Franz diffusion cell. In vivo absorption was investigated by observing fluorescence and confocal microscopic imaging. Fractional laser-mediated ablation of the skin resulted in significant enhancement of dextran and siRNA penetration. Respective fluxes of dextran (10 kDa) and siRNA, which had similar molecular size, with Er:YAG laser irradiation at 5 J/cm(2) were 56- and 11-fold superior to that of intact skin. The respective permeation extents of dextran and siRNA by the CO2 laser at 4 mJ/400 spots were 42- and 12-fold greater than that of untreated skin. Fluorescence and confocal images showed increased fluorescence intensities and penetration depths of siRNA and pDNA delivery. According to an examination of the follicular permeant amount and fluorescence microscopy, hair follicles were important deposition areas for fractional laser-assisted delivery, with the Er:YAG modality revealing higher follicular siRNA selectivity than the CO2 modality. This is the first report of siRNA and pDNA penetrating the skin with a sufficient amount and depth with the assistance of fractional lasers.