Modulation of the antigenic phenotype of early-passage human melanoma cells derived from multiple autologous metastases by recombinant human leukocyte, fibroblast and immune interferon

Adipocyte extracellular vesicles decrease p16INK4A in melanoma: an additional link between obesity and cancer

Obesity is a recognized factor for increased risk and poor prognosis of many cancers, including melanoma. Here, using genetically engineered mouse models of melanoma (NRAS^Q61K transgenic expression, associated or not with Cdkn2A heterozygous deletion), we show that obesity increases melanoma initiation and progression by supporting tumor growth and metastasis thereby reducing survival. This effect is associated with a decrease in p16^INK4A expression in tumors. Mechanistically, adipocytes downregulate p16^INK4A in melanoma cells through β-catenin-dependent regulation, which increases cell motility. Furthermore, β-catenin is directly transferred from adipocytes to melanoma cells in extracellular vesicles, thus increasing its level and activity, which represses p16^INK4A transcription. Adipocytes from obese individuals have a stronger effect than those from lean individuals, mainly due to an increase in the number of vesicles secreted, thus increasing the amount of β-catenin delivered to melanoma cells, and, consequently, amplifying their effect. In conclusion, here, we reveal that adipocyte extracellular vesicles control p16^INK4A expression in melanoma, which promotes tumor progression. This work expands our understanding of the cooperation between adipocytes and tumors, particularly in obesity.

The Yin and Yang of Type I IFNs in Cancer Promotion and Immune Activation

Simple Summary

The crucial immune stimulatory functions exerted by Type I Interferons (IFNs) in cancer settings have been not only widely demonstrated during the last fifty years but also recently harnessed for therapy. However, depending on the dose and timing, and the downstream induced signatures, Type I IFNs can and do foster cancer progression and immune evasion. Dysregulations of Type I IFN signaling cascade are more and more frequently found in the tumor microenvironment, representing critical determinants of therapeutic innate and adaptive resistance to several anticancer treatments. Understanding when and through which genetic signatures Type I IFNs control or promote cancer growth is extremely urgent in order to prevent and by-pass the deleterious clinical effects and develop optimized innovative (combinatorial) strategies for an effective cancer management.

Abstract

Type I Interferons (IFNs) are key regulators of natural and therapy-induced host defense against viral infection and cancer. Several years of remarkable progress in the field of oncoimmunology have revealed the dual nature of these cytokines. Hence, Type I IFNs may trigger anti-tumoral responses, while leading immune dysfunction and disease progression. This dichotomy relies on the duration and intensity of the transduced signaling, the nature of the unleashed IFN stimulated genes, and the subset of responding cells. Here, we discuss the role of Type I IFNs in the evolving relationship between the host immune system and cancer, as we offer a view of the therapeutic strategies that exploit and require an intact Type I IFN signaling, and the role of these cytokines in inducing adaptive resistance. A deep understanding of the complex, yet highly regulated, network of Type I IFN triggered molecular pathways will help find a timely and immune“logical” way to exploit these cytokines for anticancer therapy.

Type-I-interferons in infection and cancer: Unanticipated dynamics with therapeutic implications

If there is a great new hope in the treatment of cancer, the immune system is it. Innate and adaptive immunity either promote or attenuate tumorigenesis and so can have opposing effects on the therapeutic outcome. Originally described as potent antivirals, Type-I interferons (IFNs) were quickly recognized as central coordinators of tumor-immune system interactions. Type-I-IFNs are produced by, and act on, both tumor and immune cells being either host-protecting or tumor-promoting. Here, we discuss Type-I-IFNs in infectious and cancer diseases highlighting their dichotomous role and raising the importance to deeply understand the underlying mechanisms so to reshape the way we can exploit Type-I-IFNs therapeutically.

Enhancement of Human Melanoma Antigen Expression by IFN-β

Although many immunotherapeutic investigations have focused on improving the effector limb of the antitumor response, few studies have addressed preventing the loss of tumor-associated Ag (TAA) expression, associated with immune escape by tumors. We found that TAA loss from human melanomas usually results from reversible gene down-regulation, rather than gene deletion or mutation. Previously, we showed that inhibitors of MAPK-signaling pathways up-regulate TAA expression in melanoma cell lines. We have now identified IFN-beta as an additional stimulus to TAA expression, including Melan-A/MART-1, gp100, and MAGE-A1. IFN-beta (but neither IFN-alpha nor IFN-gamma) augmented both protein and mRNA expression of melanocytic TAA in 15 melanoma lines (irrespective of initial Ag-expression levels). Treatment of low Ag melanoma lines with IFN-beta increased expression of melanocyte-lineage Ags, inducing susceptibility to lysis by specific CTLs. Treatment with IFN-beta also enhances expression of class I HLA molecules, thereby inducing both nominal TAA and the presenting HLA molecule. Data from fluorescent cellular reporter systems demonstrated that IFN-beta triggers promoter activation, resulting in augmentation of Ag expression. In addition to enhancing TAA expression in melanomas, IFN-beta also stimulated expression of the melanocytic Ag gp100 in cells of other neural crest-derived tumor lines (gliomas) and certain unrelated tumors. Because IFN-beta is already approved for human clinical use in other contexts, it may prove useful as a cotreatment for augmenting tumor Ag expression during immunotherapy.

Expression of melanoma-associated antigens in melanoma cell cultures

The efficiency of melanoma immunotherapy appears to depend on both melanoma- and immune system-specific factors. Melanoma-specific factors include melanoma-associated antigen (MAA) expression as well as HLA class I molecule expression. We investigated the expression of five MAA - Melan-A/MART-1, tyrosinase, gp100, MAGE-1 and MAGE-3 - by means of FACS analysis in 50 melanoma cell cultures and compared them to the cultures of human foreskin-derived melanocytes and melanoma cell line UKRV-Mel2. Melan-A, tyrosinase and gp100 expression was frequently reduced in melanoma cell cultures, compared to that in foreskin melanocytes, whereas MAGE-1 and MAGE-3 expression showed variable degree of upregulation, compared to that in foreskin melanocytes. The expression of all tested MAA demonstrated high interindividual variability. We further show that cell cultures derived from the same tissue sample are oligoclonal in nature, by demonstrating the presence of up to three cell populations bearing distinct MAA profile. Analysing samples derived from the same patient but each at a different time point, we show that MAA expression profile changes over time either in positive (increase) or in negative (decrease) direction. Finally, we demonstrate that brain metastasis-derived cell cultures significantly overexpress Melan-A and MAGE-3, compared to primary tumours and other metastatic sites (P-value range: 0.05-0.001). Elucidation of the MAA expression patterns and the kinetics within the same patient as well as during the course of the disease may help improve current and develop new immunotherapeutic strategies.

The biology of interferon-alpha and the clinical significance of anti-interferon antibodies

The therapeutic indications for Interferons (IFNs) have dramatically increased in number in recent years to include many different diseases of viral, malignant, angiogenic, allergic, inflammatory and fibrotic origin. In particular, the current pandemic of hepatitis C virus infection has further stimulated the requirement for a comprehensive understanding of both the mechanism of action of IFN and the reasons for therapeutic failure. The role of anti-IFN antibodies as a cause of treatment failure has been a particularly controversial area. In this review we will outline the biology and proposed mechanisms of action of IFN-alpha (IFN-alpha) and discuss the incidence, methods of detection and clinical significance of anti-IFN antibodies.

HLA-C heavy chains free of beta2-microglobulin: distribution in normal tissues and neoplastic lesions of non-lymphoid origin and interferon-gamma responsiveness

Lacking monospecific antibodies to HLA-C, the expression and synthesis of these molecules have been difficult to evaluate. Using biochemical and flow cytometry approaches, the present report demonstrates that the reactivity of the murine monoclonal antibody L31 is restricted to naturally occurring HLA-C (HLA-Cw1 through -Cw8), HLA-B8 and HLA-B51 heavy chains not associated with beta2-microglobin (beta2m). This is due to two properties of HLA-C heavy chains: (a) they share the L31 epitope which distinguishes them from all the HLA-A and most HLA-B molecules; (b) they accumulate intracellularly, in a beta2m-free form, in much greater amounts than most L31-reacting HLA-B heavy chains. On the basis of this restricted reactivity, a representative panel of normal and neoplastic human tissues and cells derived from HLA-B8- B51- individuals was selected and employed to assess the tissue distribution, surface expression and IFN-gamma responsiveness of beta2m-free HLA-C heavy chains. At variance from antibody W6/32 to beta2m-associated heavy chains, L31 stains normal and neoplastic tissues with a ground-glass pattern and weakly binds to the surface of viable cells, even after treatment with interferon gamma (IFN-gamma). Thus, beta2m-free HLA-C heavy chains are, for the most part, located intracellularly. In spite of their distinct cellular localization, L31- and W6/32-reacting molecules have an overlapping tissue distribution, undergo concordant changes upon transformation and are upregulated in their synthesis by IFN-gamma to a similar extent. These observations demonstrate a coordinate regulation of HLA-C with HLA-A and -B molecules. In addition, they indicate that the assembly of HLA-C is impaired in most body districts and IFN-gamma is unable to completely reverse this impairment. The present results are consistent with a low surface expression of HLA-C and with a privileged role of these molecules in signaling class I loss to cytotoxic effectors in pathological conditions.

HLA antigen expression on uveal melanoma cells in vivo and in vitro

Immunotherapy with cytokines may be an additional option in the treatment of primary uveal melanoma or melanoma metastases. A study of the effect of cytokines on cultured uveal melanoma cells may predict the effect that cytokines may have in vivo. Knowledge about the influence of cytokines on HLA expression may be especially beneficial, as HLA expression is essential for immune recognition. However, little is known about the normal expression of the HLA antigens on uveal melanoma cells in tissue culture. We therefore determined the HLA expression on short-term cultures of uveal melanoma cells and compared the results to the expression on tissue sections of the original tumors. In vivo and in vitro expression of the monomorphic HLA class I determinants and of HLA-A (R = 0.77) correlated well. A slightly lower agreement was observed for expression of HLA-B (R = 0.68). In vitro growth was associated with a decrease in expression of the class II determinant HLA-DR. We conclude that expression of HLA class I on cultured melanoma cells corresponds to the expression on the original tumor, allowing the applicability of cultured cells as predictors of responsiveness to cytokines in vivo.

New approaches for the development and application of monoclonal antibodies for the diagnosis and therapy of human cancer

Monoclonal antibodies (MAbs) represent potentially important reagents for both the diagnosis and therapy of human cancer. Innovative approaches are resulting in the improved production of MAbs and an enhanced ability to use these molecules therapeutically. Application of genetic engineering to MAb development is also resulting in the production of MAbs displaying enhanced target specificity. Of particular value for cancer therapy will be catalytic, bispecific, anti-idiotypic and human MAbs. By using agents that can augment the expression of tumor-associated antigens on cancer cells, a further increase in the utility of MAbs in cancer therapy will be forthcoming.

Expression of growth factor receptors on human melanoma cells: comparison of modulating effects of interferons and retinoids

Autocrine and paracrine growth factors are important mediators in malignant transformation. Interferons (IFN) and retinoids (RX) are well-known differentiative and immunomodulating agents with effects on subsets of different human tumors including malignant melanoma. In this study, we examined the modulating effects of three IFN and seven different RX on human melanoma cell lines regarding growth factor receptor expression. Growth factor receptor expression, including PDGF-R, NGF-R, EGF-R, IR, IGF-I-R, TFR and c-kit, was studied by immunohistochemistry and FACSscan analysis. Both groups of substances modulated the expression of some growth factor receptors. Upregulation of PDGF-R was seen after treatment with IFN as well as with RX. In contrast, EGF-R was found to be downregulated in two EGF-R-positive cell lines by IFN and, on the other hand, induced by RX in two EGF-R-negative cell lines. The expression of NGF-R was modulated ambiguously by these substances but demonstrated a cell line specificity in the different melanoma cell lines tested. Additionally, some of the tested growth factor receptors were not markedly changed regarding their expression by treatment with IFN and RX (IR, IGF-I-R, c-kit, TFR).

Recombinant bifunctional molecule FV/IFN-gamma possesses the anti-tumor FV as well as the gamma interferon activities

Recombinant DNA techniques were used to clone, construct and express the bifunctional molecule FV/IFN-gamma. The FV/IFN-gamma is a single-chain 42KD fusion protein expressed in E. coli under control of the strong T7 bacteriophage promoter in the expression vector pT7-7-FV-IFN-gamma. The fused gene fragment FV-IFN-gamma containing a single-chain anti-TAG72 FV gene fragment as well as the human recombinant cDNA fragment of IFN-gamma molecule. The renatured soluble form of FV/IFN-gamma was purified from E. coli inclusion bodies using HTPT chromatography. The yield of this fusion protein was estimated at 10mg/L. Our data showed that the FV/IFN-gamma molecule retained the TAG72 antigen-binding specificity and the IFN-gamma activity as measured in ELISA, Western blotting and up-regulation of CEA expression by IFN-gamma. Therefore, it may prove to be useful in targeting the biological effect of IFN-gamma to tumor cells and stimulating its immune destruction.

Influence of interferon and radiation on serotonin content in primary carcinoid cell cultures

Carcinoids are in general thought to be radioresistent, and have not been subjected to radiation therapy, except for palliative purposes. Clinical experience has indicated that interferons might enhance radiation effect and toxicity. In order to examine the effect of radiation, the combination of radiation and interferon, and the usefulness of the main metabolic product of primary cell cultures--serotonin--as a response indicator, we exposed primary carcinoid cell cultures with and without interferon pretreatment to radiation (2 Gy and 8 Gy). Irradiation alone had no effect on the serotonin content of the medium at the low dose (2 Gy) and even at the high dose (8 gy) the effect was not significant. When cells were preincubated with 1,000 IU/ml alpha-interferon, however, irradiation with 8 Gy induced a significant reduction of the hormone concentration in the medium on day 12 to 54.9 +/- 8.0% of the control value (p = 0.026). We think our model may provide a useful tool for further exploration of these mechanisms.

Modulation of the antigenic phenotype of human melanoma cells by differentiation-inducing and growth-suppressing agents

Tumor cells often display alterations in their normal program of cellular differentiation. A promising approach for the treatment of cancer involves the induction of terminal differentiation and a loss of proliferative capacity in cancer cells. In human melanoma cells, the combination of mezerein (MEZ) and fibroblast interferon (IFN-beta), results in a rapid and irreversible suppression of cell growth with a concomitant increase in the synthesis of melanin. The induction of terminal differentiation is associated with alterations in the expression of several cellular genes, including fibronectin, ISG-15 and ISG-54, and changes in the expression of specific cell surface antigens, including intercellular adhesion molecule-1 (ICAM-1) and HLA Class I antigens. In the HO-1 human melanoma cell line, induction of terminal differentiation by MEZ plus IFN-beta results in an induction and/or increased expression of ICAM-1, HLA Class I antigens and HLA Class II antigens. IFN-beta and MEZ alone can modulate expression of these antigens to a lower extent than does the combination of compounds. Induction of terminal differentiation and the irreversible suppression of cell growth is not a prerequisite for antigenic modulation in HO-1 cells. This is indicated by the inability of immune interferon (IFN-gamma), a strong inducer of ICAM-1, HLA Class I antigens and HLA Class II antigens synthesis, or the combination of IFN-beta plus IFN-gamma which synergistically but reversibly suppresses HO-1 growth, to induce melanin synthesis or terminal differentiation in HO-1 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigenic modulation of metastatic breast and ovary carcinoma cells by intracavitary injection of IFN-alpha

Antigenic modulation of major histocompatibility and tumour associated antigens was observed in neoplastic cells obtained from patients with pleural and abdominal effusions of breast and ovary carcinomas following a single intracavitary dose of 18 x 10(6) U recombinant IFN-alpha. This regimen resulted in antigenic modulation in seven out of 11 tested cases, suggesting a potential, although limited, responsiveness of at least a fraction of breast and ovary carcinoma cells to in situ biomodification with IFN-alpha.

Membrane compartmentalization of melanosomal gp75

A melanosomal integral membrane glycoprotein of 75 kD (gp75) has been previously identified as the human homologue of the product specified by the murine brown locus. We presently report that this molecule may be susceptible to limited proteolysis and extrinsic radioiodination in intact, live cells. Consequently, it is suggested that its cellular location might include the plasma membrane and/or a cellular compartment easily accessible to proteases and to chemically catalyzed vectorial iodination. This is of interest in view of the potential applicative value of gp75 as a target for the radioimmunoscintography of melanoma lesions.

Modulation of the antigenic phenotype of human breast carcinoma cells by modifiers of protein kinase C activity and recombinant human interferons

In the present study we have analyzed the effect of a synthetic protein kinase C (PKC) activator 3-(N-acetylamino)-5-(N-decyl-N-methylamino)-benzyl alcohol (ADMB) and the natural PKC-activating tumor-promoting agents 12-O-tetradecanoylphorbol 13-acetate (TPA) and mezerein on the antigenic phenotype of T47D human breast carcinoma cells. All three agents increased the surface expression of the tumor-associated antigen BCA 225 and various cellular antigens, including HLA class II antigens, intercellular adhesion molecule 1 (ICAM-1) and c-erbB-2. Expression of the same antigens was also upregulated to various extents in T47D cells by recombinant fibroblast (IFN beta) and immune (IFN gamma) interferon. Shedding of BCA 225 from T47D cells was induced by TPA, mezerein, IFN beta and IFN gamma, whereas ADMB did not display this activity. The ability of ADMB, TPA and mezerein to modulate the antigenic phenotype of T47D cells appears to involve a PKC-mediated pathway, since the PKC inhibitor, H-7, eliminates antigenic modulation. In contrast, the ability of IFN beta and IFN gamma to enhance the synthesis, expression and shedding of BCA 225, as well as to enhance HLA class II antigens, c-erbB-2 and ICAM-1 expression, was either unchanged or modestly reduced by simultaneous exposure to H-7. Analysis of steady-state mRNA levels for HLA class I antigens, HLA class II-DR beta antigen, ICAM-1 and c-erbB-2 indicated that the ability of H-7 to inhibit expression of these antigens in TPA-, mezerein- and ADMB-treated cells was not a consequence of a reduction in the steady-state levels of mRNAs for these antigens. The results of the present investigation indicate that the biochemical pathways mediating enhanced antigenic expression in T47D cells induced by TPA, mezerein and the synthetic PKC activator ADMB are different from those induced by recombinant interferons. Furthermore, up-regulation of antigenic expression in T47D cells can occur by a PKC-dependent or a PKC-independent pathway.