MHC heterogeneity and response of metastases to immunotherapy.

In recent years, immunotherapy has proven to be an effective treatment against cancer. Cytotoxic T lymphocytes perform an important role in this anti-tumor immune response, recognizing cancer cells as foreign, through the presentation of tumor antigens by MHC class I molecules. However, tumors and metastases develop escape mechanisms for evading this immunosurveillance and may lose the expression of these polymorphic molecules to become invisible to cytotoxic T lymphocytes. In other situations, they may maintain MHC class I expression and promote immunosuppression of cytotoxic T lymphocytes. Therefore, the analysis of the expression of MHC class I molecules in tumors and metastases is important to elucidate these escape mechanisms. Moreover, it is necessary to determine the molecular mechanisms involved in these alterations to reverse them and recover the expression of MHC class I molecules on tumor cells. This review discusses the role and regulation of MHC class I expression in tumor progression. We focus on altered MHC class I phenotypes present in tumors and metastases, as well as the molecular mechanisms responsible for MHC-I alterations, emphasizing the mechanisms of recovery of the MHC class I molecules expression on cancer cells. The individualized study of the HLA class I phenotype of the tumor and the metastases of each patient will allow choosing the most appropriate immunotherapy treatment based on a personalized medicine.

Joint study of the associations of HLA-B and the transmembrane short tandem repeat polymorphism of MICA protein with alopecia areata shows independent associations of both with the disease.

BACKGROUND: Alopecia areata (AA) is a skin disease that produces hair loss in patches of skin. The underlying mechanism of AA is a loss of immune privilege of hair follicles, which are then attacked by natural killer (NK) cells. A previous genome-wide association study linked single nucleotide polymorphisms of the protein MHC class I chain-related A (MICA) to this disease. MICA is the ligand for the activating receptor NKG2D, expressed mainly by NK cells and CD8+ cytotoxic T cells. As the aforementioned study did not include short tandem repeats (STRs) of MICA, we decided to study these in relation to AA. AIM: To study the association of STRs with AA, alongside that of human leucocyte antigen (HLA) locus B, which is closely linked to MICA. METHODS: DNA amplicon size analysis was carried out, and HLA-B locus genomic typing was performed by PCR-sequence-specific oligonucleotide analysis. RESULTS: We observed an association between AA and both MICA*009 and HLA-B14; associations were also observed between HLA-B alleles and MICA alleles, which have both been previously found to be connected with AA, but never studied together. CONCLUSIONS: We conclude that it is important to study HLA-B and MICA together to avoid the influence of their association in experiments in which they are investigated separately.

Familial frontal fibrosing alopecia: A cross-sectional study of 20 cases from nine families.

BACKGROUND/OBJECTIVES: Frontal fibrosing alopecia (FFA) is a scarring alopecia whose prevalence is increasing. The pathogenesis of this disease is not well known. Genetic, environmental, hormonal and autoimmunity related factors have been considered; however, only a few cases of familial frontal fibrosing alopecia have been reported. MATERIAL AND METHODS: A cross-sectional study was performed at University Hospital in Granada (Spain). Twenty patients with frontal fibrosing alopecia belonging to nine different families were included, and clinical and dermoscopic features were analysed. RESULTS: Overall, 90% of the patients studied were women (mean age 61.4 years). About 50% of the patients had grade II frontal fibrosing alopecia at the time of diagnosis, whilst 35% had grades III or V. Mean recession was 2.83 cm in the frontal area and 1.99 cm in the temporo-parietal area. Daughters presented a shorter recession area and earlier debut of the disease than mothers. Androgenetic alopecia was found in only two patients (10%). The dermoscopic signs most commonly found were perifollicular erythema (85%), hyperkeratosis (85%), and absence of vellus hair in the hairline (78.9%). CONCLUSION: This study adds to the growing evidence that there is a genetic component to frontal fibrosing alopecia. The clinical pattern of frontal fibrosing alopecia was not different from that found in non-familial cases, but the debut of the disease in daughters of mothers with frontal fibrosing alopecia may be earlier.

Study of Human Leukocyte Antigen (HLA) in 13 cases of familial frontal fibrosing alopecia: CYP21A2 gene p.V281L mutation from congenital adrenal hyperplasia linked to HLA class I haplotype HLA-A*33:01; B*14:02; C*08:02 as a genetic marker.

BACKGROUND/OBJECTIVES: The aetiology of frontal fibrosing alopecia is unknown, and its genetic aspect remains uncharacterised. The aim of this report is to elucidate if major histocompatibility complex is associated with familial frontal fibrosing alopecia. METHODS: A case-control study was performed of 13 patients with frontal fibrosing alopecia belonging to six families. Their human leukocyte antigen profiles were compared to the data of 636 healthy controls without frontal fibrosing alopecia. Patients underwent high-resolution genomic typing for human leukocyte antigen class I and II loci by PCR-SSO for Luminex. In addition, CYP21A2 gene (major histocompatibility complex class III) mutations were detected by PCR-SSO on strips. RESULTS: 61.5% of patients shared CYP21A2 gene p.V281L linked to the F16A human leukocyte antigen class I haplotype (HLA-A*33:01; B*14:02; C*08:02; Pc < 0.000001). The patients F16A-negative shared other human leukocyte antigen class I haplotypes: Y16A (3/13) and S26 (2/13). CONCLUSION: CYP21A2 gene p.V281L mutation can be used as a genetic marker for susceptibility to familial frontal fibrosing alopecia. Both the linkage of the mutation to F16A and the fact that F16A-negative patients share other human leukocyte antigen class I haplotype, point to an antigen-driven mechanism in susceptible patients with these haplotypes.

Beard alopecia areata: a multicentre review of 55 patients.

BACKGROUND: Alopecia areata on the beard area (BAA) is a common clinical manifestation, but there are no studies about its characteristics. OBJECTIVE: To describe the epidemiology, comorbidities, clinical presentation, evolution, diagnostic findings and therapeutic choices in a series of patients with BAA. METHODS: This retrospective multicentre review included patients diagnosed with BAA as the first and unique clinical manifestation with at least 12 months of follow-up. Diagnosis was performed based on the typical clinical features. Extra-beard involvement was monitored in all cases. RESULTS: Overall, 55 male patients with a mean age of 39.1 years (range 20-74) were included. Twenty-five patients (45.5%) developed alopecia of the scalp during follow-up and more than 80% of cases appeared in the first 12.4 months. Clinical presentation of AA on the scalp was patchy AA (less than 5 patches) (52%), multifocal AA (28%), AA totalis (12%) and AA universalis (8%). Multivariate analysis revealed a trend of association between scalp involvement and family history of AA without statistical significance. CONCLUSIONS: According to this study, BAA may progress to scalp AA in a significant number of patients (45.5% of the patients with a follow-up interval of at least 12 months). In the group of patients who developed scalp AA, 80% of them did it within the first 12 months, so follow-up of patients with BAA is highly encouraged.

Alopecia areata totalis and universalis: a multicenter review of 132 patients in Spain.

BACKGROUND: Alopecia areata totalis (AAT) and universalis (AAU) pose a therapeutic challenge. OBJECTIVE: To describe the clinical and epidemiological features, therapeutic response and prognostic factors in a large series of patients diagnosed with AAT and AAU. METHODS: This retrospective multicenter study included patients diagnosed with AAT/AAU with a minimum follow-up of 12 months. Response was assessed based on the regrowth of scalp hair. RESULTS: In all, 132 patients (92 women and 40 men) - 80 (61%) diagnosed with AAU and 52 (39%) diagnosed with AAT - were included. The median time between the presentation of alopecia areata (AA) and the development of extensive AA was 1 year and it was less than 4 years in 121 patients (91%). There was an initial response to treatment in 64% of patients, although only 14% presented a persistent response. Adverse side effects from the medications used were detected in 33% of patients. The prognostic factors associated with poor response were the presence of AAU and a positive family history of AA. CONCLUSIONS: Treatment of AAT and AAU is challenging. Although an initial regrowth may be achieved, the duration of response is usually short. There were no significant differences on the effectiveness or duration of response between the various systemic therapies.

Generation of MHC class I diversity in primary tumors and selection of the malignant phenotype.

Intratumor heterogeneity among cancer cells is promoted by reversible or irreversible genetic alterations and by different microenvironmental factors. There is considerable experimental evidence of the presence of a variety of malignant cell clones with a wide diversity of major histocompatibility class I (MHC-I) expression during early stages of tumor development. This variety of MHC-I phenotypes may define the evolution of a particular tumor. Loss of MHC-I molecules frequently results in immune escape of MHC-negative or -deficient tumor cells from the host T cell-mediated immune response. We review here the results obtained by our group and other researchers in animal models and humans, showing how MHC-I intratumor heterogeneity may affect local oncogenicity and metastatic progression. In particular, we summarize the data obtained in an experimental mouse cancer model of a methylcholanthrene-induced fibrosarcoma (GR9), in which isolated clones with different MHC-I expression patterns demonstrated distinct local tumor growth rates and metastatic capacities. The observed "explosion of diversity" of MHC-I phenotypes in primary tumor clones and the molecular mechanism ("hard"/irreversible or "soft"/reversible) responsible for a given MHC-I alteration might determine not only the metastatic capacity of the cells but also their response to immunotherapy. We also illustrate the generation of further MHC heterogeneity during metastatic colonization and discuss different strategies to favor tumor rejection by counteracting MHC-I loss. Finally, we highlight the role of MHC-I genes in tumor dormancy and cell cycle control.

Clinical Pathway for Patients with Acute or Chronic Urticaria: A Consensus Statement of the Andalusian Section of the Spanish Academy of Dermatology and Venereology (AEDV). / Proceso de atención al paciente con urticaria aguda y crónica. Documento de consenso de la sección territorial andaluza de la Academia Española de Dermatología y Venereología.

Attention has been focused on new ways to understand and manage urticaria ever since the recent addition of novel drugs to the therapeutic arsenal, the updating of clinical practice guidelines, and the publication of pathophysiologic insights. The Andalusian Section of the Spanish Academy of Dermatology and Venereology (AEDV) has developed a clinical pathway that defines quality-of-care characteristics and makes recommendations on decision-making affecting patients with urticaria. We present a patient-centered approach to care, in which the patient's clinical pathway through the health care system includes links between primary and hospital care to ensure continuity-a key feature of quality.

Process of Care for Patients With Benign Cysts and Tumors: Consensus Document of the Andalusian Regional Section of the Spanish Academy of Dermatology and Venereology (AEDV). / Proceso de atención a las personas con lesiones quísticas y tumorales benignas. Documento de consenso de la sección territorial andaluza de la Academia Española de Dermatología Médico-Quirúrgica y Venereología.

Benign skin lesions are a common reason for visits to primary care physicians and dermatologists. However, access to diagnosis and treatment for these lesions varies considerably between users, primarily because no explicit or standardized criteria for dealing with these patients have been defined. Principally with a view to reducing this variability in the care of patients with benign cysts or tumors, the Andalusian Regional Section of the Spanish Academy of Dermatology and Venereology (AEDV) has created a Process of Care document that describes a clinical pathway and quality-of-care characteristics for each action. This report also makes recommendations for decision-making with respect to lesions of this type.

Effect of thyroid hormone-nitric oxide interaction on tumor growth, angiogenesis, and aminopeptidase activity in mice.

This study evaluated the effects of thyroid hormone-NO interaction on tumor development, vascularization, vascular endothelial growth factor (VEGF), and aminopeptidase (AP) activity in a murine model of implanted Lewis's carcinoma. Experiments were performed in male CBA-C57 mice. Animals were untreated (controls) or treated with: T4, the antithyroid drug methimazole, the NO inhibitor L-NAME, T4+L-NAME, methimazole+NAME, the αvß3 integrin antagonist tetrac, T4+tetrac, the iNOS inhibitor aminoguanidine (AG), and T4 + AG; all treatments were for 6 weeks except for tetrac, administered for the last 11 days. Mice were subcutaneously inoculated with 1 × 10(6) exponentially growing Lewis carcinoma 3LL cells into the dorsum. Study variables 9 days later were tumor weight (TW), Hb content, an index of tumor vascularization, VEGF, and AP activity. T4 produced parallel increases in TW and angiogenesis. L-NAME reduced TW and angiogenesis in control, hyperthyroid, and hypothyroid mice, whereas AG had no effect on these variables. Tetrac arrested TW in normal and T4-treated mice but did not decrease angiogenesis in T4-treated animals. Negative correlations were found between TW and AP activity in tumors from control hyper- and hypothyroid groups and an inverse relationship was observed between TW and AP activities in tetrac-treated mice. T4 enhances TW and angiogenesis, in which NO participates, but requires activation of integrin αvß3 to promote carcinogenesis. NO blockade reduces TW, regardless of the thyroid status. Thyroid hormone negatively modulates AP activity in the tumor. Accordingly, blockade of the membrane TH receptor αvß3 integrin reduces TW associated with an increase in AP activity.

The pro-oxidant buthionine sulfoximine (BSO) reduces tumor growth of implanted Lewis lung carcinoma in mice associated with increased protein carbonyl, tubulin abundance, and aminopeptidase activity.

This study evaluated the effects of the pro-oxidant buthionine sulfoximine (BSO) and of the interaction between BSO and TETRAC, an antagonist of αvß3 integrin, on tumor development and aminopeptidase (AP) activity in a murine model of implanted Lewis's carcinoma. Male CBA-C57 mice were untreated (controls) or treated with BSO (222 mg/100 mL in drinking water), TETRAC (10 mg/kg/day, i.p.), or BSO + TETRAC. BSO for 28 days and TETRAC were given for the last 20 days. Mice were subcutaneously inoculated with 1 × 10(6) Lewis carcinoma 3LL cells into the dorsum. Study variables were tumor weight (TW); Hb, as index of tumor-mediated angiogenesis; vascular endothelial growth factor (VEGF) protein abundance; protein carbonyl content; α-tubulin abundance; and GluAp, AlaAp, and AspAp activities. BSO produced a major decrease in TW (203 ± 18 mg) with respect to controls (365 ± 26) and a reduction in Hb content. The TETRAC group also showed marked reductions in TW (129 ± 15) and Hb concentration associated with a reduced VEGF content. The BSO + TETRAC group showed a major TW reduction (125 ± 13); although, the difference with the TETRAC group was not significant. BSO treatment increased protein carbonyl and tubulin abundance in comparison to controls. The activity of all APs was increased in the three experimental groups and was strongly and negatively correlated with TW. In conclusion, administration of BSO reduced the TW, which inversely correlated with protein carbonyl content, suggesting a loss of microtubule polymerization. The finding of a negative correlation between TW and AP activity opens up new perspectives for the study of APs as tumor growth modulators.

The tumour suppressor Fhit positively regulates MHC class I expression on cancer cells.

MHC class I (MHC-I) molecules are ubiquitously expressed on the cells of an organism. Study of the regulation of these molecules in normal and disease conditions is important. In tumour cells, the expression of MHC-I molecules is very frequently lost, allowing these cells to evade the immune response. Cancers of different histology have shown total loss of MHC-I molecule expression, due to a coordinated transcriptional down-regulation of various antigen-processing machinery (APM) components and/or MHC-I heavy chains. The mechanisms responsible for these alterations remain unclear. We determined the possible genes involved by comparing MHC-I-positive with MHC-I-negative murine metastases derived from the same fibrosarcoma tumour clone. MHC-I-negative metastases showed transcriptional down-regulation of APM and MHC-I heavy chains. The use of microarrays and subtraction cDNA libraries revealed four candidate genes responsible for this alteration, but two of them were ruled out by real-time RT-PCR analyses. The other two genes, AP-2α and Fhit tumour suppressors, were studied by using siRNA to silence their expression in a MHC-I-positive metastatic cell line. AP-2α inhibition did not modify transcriptional expression of APM components or MHC-I heavy chains or surface expression of MHC-I. In contrast, silencing of the Fhit gene produced the transcriptional down-regulation of APM components and MHC-I heavy chains and decreased MHC-I surface expression. Moreover, transfection of Fhit in MHC-I-negative tumour cell lines restored MHC-I cell surface expression. These data indicate that defects in Fhit expression may promote MHC-I down-regulation in cancer cells and allow escape from immunosurveillance(#).

MHC class I molecules act as tumor suppressor genes regulating the cell cycle gene expression, invasion and intrinsic tumorigenicity of melanoma cells.

The alteration of MHC class I (MHC-I) expression is a frequent event during cancer progression, allowing tumor cells to evade the immune system. We report that the loss of one major histocompatibility complex haplotype in human melanoma cells not only allowed them to evade immunosurveillance but also increased their intrinsic oncogenic potential. A second successive defect in MHC-I expression, MHC-I total downregulation, gave rise to melanoma cells that were more oncogenic per se in vivo and showed a higher proliferation rate and greater migratory and invasive potential in vitro. All these processes were reversed by restoring MHC-I expression via human leukocite antigen-A2 gene transfection. MHC-I cell surface expression was inversely correlated with intrinsic oncogenic potential. Modifications in the expression of various cell cycle genes were correlated with changes in MHC-I expression; the most important differences among the melanoma cell lines were in the transcriptional level of AP2-alpha, cyclin A1 and p21WAF1/CIP1. According to these results, altered MHC-I expression in malignant cells can directly increase their intrinsic oncogenic and invasive potential and modulate the expression of cell cycle genes. These findings suggest that human leukocite antigen class I molecules may act directly as tumor suppressor genes in melanoma.

Immunotherapy eradicates metastases with reversible defects in MHC class I expression.

Tumor or metastatic cells lose MHC class I (MHC-I) expression during cancer progression as an escape mechanism from immune surveillance. These defects in MHC-I may be reversible by cytokines or different agents (soft lesions) or irreversible due to structural defects (hard lesions). The nature of these MHC-I alterations might determine the success or failure of immunotherapy treatments. In this study, we have used an MHC-I-positive murine fibrosarcoma tumor clone, GR9-A7, which generates multiple lung and lymph node metastases with reversible MHC-I alterations after treatment with IFN-γ. Four different antitumor treatments were carried out after primary tumor excision to determine their capacity to inhibit spontaneous metastatic colonization of the GR9-A7 tumor clone. We found that 2 different immunotherapy protocols (CpG plus autologous irradiated-GR9-A7 cells and protein-bound polysaccharide K (PSK) and 1 chemoimmunotherapy (docetaxel plus PSK) induced eradication of metastases. In contrast, chemotherapy with docetaxel alone produced only partial reduction in the number of metastases. Flow cytometric analysis of lymphocyte populations showed an immunosuppression in GR9-A7 tumor-bearing host, which could be reverted by immunotherapy treatments. Our results suggest that irreversible or reversible MHC-I alterations in tumor target cells may determine its progression or regression independently of the type of immunotherapy used.

The escape of cancer from T lymphocytes: immunoselection of MHC class I loss variants harboring structural-irreversible "hard" lesions.

The discovery of tumor antigens recognized by T lymphocytes has stimulated the development of a variety of cancer treatment protocols aimed at enhancing antitumor-specific T cell responses and tumor rejection. However, immunotherapy-mediated regression of established tumors and clearly positive clinical response to such treatment has not been achieved yet despite the induction of T cells directed against tumor antigens. The failure of the modern immunotherapy protocols can be explained by different tumor escape mechanisms that have been defined in various types of malignancy. The loss or downregulation of MHC class I antigens in tumor cells is one of the best analyzed mechanisms. In this review, we show experimental evidence obtained in our laboratory on human tumors and in a mouse cancer model suggesting that the molecular mechanism responsible for the MHC class I alteration in tumor cells might have a crucial impact on tumor recovery of normal H-2/HLA expression during the natural history of tumor development or after immunotherapy. When the preexisting molecular lesion underlying tumor MHC class I alteration is reversible (regulatory or soft), class I expression can be recovered leading to regression of tumor lesion. In contrast, if the HLA class I alteration is irreversible in nature (structural or hard), the lesion will progress killing the host. This is a new vision of the role of MHC class I alteration in tumors that can explain the failure of immunotherapy in a variety of different clinical protocols.

Alterations of HLA class I expression in human melanoma xenografts in immunodeficient mice occur frequently and are associated with higher tumorigenicity.

Animal models are widely used to study the biological behavior of human tumors in vivo. Murine immunodeficient models are used to test novel human anti-tumor therapies, and humanized mice are employed to study immunotherapeutic protocols. We find that human melanoma cell lines lose HLA class I surface expression after growth in immunodeficient mice and that this phenomenon occurs frequently and is reproducible. This HLA loss is due to a coordinated down-regulation of APM and HLA heavy chain expression at the transcriptional level. It is produced by epigenetic modifications and can be reversed by treatment with histone deacetylase inhibitors or IFN-gamma. These HLA alterations only appear during in vivo growth and not during successive in vitro passages. Interestingly, these new tumor variants with HLA class I loss show higher tumorigenicity per se and may represent a more advanced state of the original tumor. Lack of MHC class I expression on tumor cells represents a frequent escape mechanism from the immune response. Our results indicate that tumor variants with alterations in MHC can also appear in vivo after the immunoescape phase in the absence of anti-tumor immune response. Our findings suggest that any studied parameter, i.e., HLA expression, of malignant cells in xenograft models, has to be evaluated before and after growth in immunodeficient mice, in order to design more appropriate immunotherapy and chemotherapy treatments against tumor cells growing in vivo.

Restoration of MHC-I on Tumor Cells by Fhit Transfection Promotes Immune Rejection and Acts as an Individualized Immunotherapeutic Vaccine.

The capacity of cytotoxic-T lymphocytes to recognize and destroy tumor cells depends on the surface expression by tumor cells of MHC class I molecules loaded with tumor antigen peptides. Loss of MHC-I expression is the most frequent mechanism by which tumor cells evade the immune response. The restoration of MHC-I expression in cancer cells is crucial to enhance their immune destruction, especially in response to cancer immunotherapy. Using mouse models, we recovered MHC-I expression in the MHC-I negative tumor cell lines and analyzed their oncological and immunological profile. Fhit gene transfection induces the restoration of MHC-I expression in highly oncogenic MHC-I-negative murine tumor cell lines and genes of the IFN-γ transduction signal pathway are involved. Fhit-transfected tumor cells proved highly immunogenic, being rejected by a T lymphocyte-mediated immune response. Strikingly, this immune rejection was more frequent in females than in males. The immune response generated protected hosts against the tumor growth of non-transfected cells and against other tumor cells in our murine tumor model. Finally, we also observed a direct correlation between FHIT expression and HLA-I surface expression in human breast tumors. Recovery of Fhit expression on MHC class I negative tumor cells may be a useful immunotherapeutic strategy and may even act as an individualized immunotherapeutic vaccine.

HLA and melanoma: multiple alterations in HLA class I and II expression in human melanoma cell lines from ESTDAB cell bank.

Altered HLA class I and class II cell surface expression has been reported in many types of malignancy and represents one of the major mechanism by which tumour cells escape from T lymphocytes. In this report, we review the results obtained from the study of constitutive and IFN-gamma-induced expression of HLA class I and II molecules in 91 human melanoma cell lines from the European Searchable Tumour Cell Line Database, and compare them with published data on HLA expression in other types of cancer. Various types of alterations in HLA class I cell surface expression were found in a high percentage (67%) of the studied cell lines. These alterations range from total to selective HLA class I loss and are associated with beta2-microglobulin gene mutations, transcriptional downregulation of HLA class I genes and antigen processing machinery components, or with the loss of heterozygosity in chromosome 6. The most frequently observed phenotype is selective downregulation of HLA-B locus, reversible after treatment with IFN-gamma. The expression of constitutive- or IFN-gamma induced-surface expression of at least one HLA class II locus is positive in 71.5% of the analysed cell lines. Four different HLA class II expression phenotypes were defined, and a positive correlation between the expression of class I and II molecules is discussed. More detailed information on the HLA expression patterns and others immunological characteristics of these melanoma cell lines can be found on the following website http://www.ebi.ac.uk/ipd/estdab .

MHC class I antigens and immune surveillance in transformed cells.

MHC class I antigens play a crucial role in the interaction of tumor cells with the host immune system, in particular, in the presentation of peptides as tumor-associated antigens to cytotoxic lymphocytes (CTLs) and in the regulation of cytolytic activity of natural killer (NK) cells. In this review we discuss the role of MHC class I antigens in the recognition and elimination of transformed cells and in the generation of tumor immune escape routes when MHC class I losses occur in tumors. The different altered MHC class I phenotypes and their distribution in different human tumors are the main topic of this review. In addition, molecular defects that underlie MHC alterations in transformed cells are also described in detail. Future research directions in this field are also discussed, including the laboratory analysis of tumor MHC class I-negative variants and the possible restoration of MHC class I expression.