José María Romero

Coordinated downregulation of the antigen presentation machinery and HLA class I/β2-microglobulin complex is responsible for HLA-ABC loss in bladder cancer

Downregulation of MHC class I expression is a widespread phenomenon used by tumor cells to escape antitumor T‐cell‐mediated immune responses. These alterations may play a role in the clinical course of the disease. The aim of our study was to investigate the molecular mechanism underlying the absence of HLA‐class I molecule expression in bladder cancer cells. Microdissected tumor tissues were characterized by real‐time quantitative PCR for the expression of HLA‐ABC, β2‐microglobulin and the members of the antigen processing machinery (APM) of HLA class I molecules (LMP2, LMP7, TAP1, TAP2 and tapasin). Our results showed that irreversible HLA loss by mutations in the β2‐microglobulin gene was not the cause of low HLA class I expression in bladder cancers. In contrast, we observed a coordinated transcription downregulation of HLA‐ABC and β2‐microglobulin and APM genes in microdissected tumor tissue derived from bladder carcinomas. This mechanism may represent a major factor for the downregulation of HLA class I expression and in the subsequent direct recognition of cancer cells by cytolytic T lymphocytes. Because this regulatory mechanism is frequently reversible by IFN‐gamma treatment, we conclude that HLA class I expression should be a major consideration for immunotherapeutic purposes in patients with bladder cancer.

Analysis of HLA class I expression in progressing and regressing metastatic melanoma lesions after immunotherapy

Despite the potential efficacy of cancer immunotherapy in preclinical studies, it did not show yet significant positive clinical results in humans with only a small number of cancer patients demonstrating objective tumor regression. This poor clinical outcome can be explained by the generation of sophisticated tumor immune escape mechanism, in particular, abnormalities in the expression of HLA class I antigens. We have studied the expression of HLA class I antigens in ten metastatic lesions obtained from a melanoma patient undergoing immunotherapy. Five lesions were obtained after Interferon-alpha-2b treatment and five after autologous vaccination plus BCG (M-VAX). Eight metastases were regressing after immunotherapy while two were progressing. The eight regressing metastases showed high level of HLA class I expression, whereas the two progressing lesions had low levels as measured by real time PCR and immunohistological techniques. These results indicate a strong association between HLA class I expression and progression or regression of the metastatic lesions. Our data support the hypothesis that the level of HLA class I expression is an important parameter of tumor immune escape that needs to be monitored.

HLA class I expression in metastatic melanoma correlates with tumor development during autologous vaccination

Our knowledge of the mechanisms underlying tumor-specific immune response and tumor escape has considerably increased. HLA class I antigen defects remain an important tumor escape mechanism since they influence the interactions between tumor cells and specific T and NK cells in the course of malignant disease. We have studied here HLA class I expression in six subcutaneous metastases obtained from a melanoma patient immunized with an autologous melanoma cell vaccine (M-VAX). We report in this paper that HLA class I antigen expression on these metastatic lesions strongly correlated with the course of the disease. The three metastases that were partially regressing at the time of their excision showed a strong HLA class I expression, whereas the progressing ones showed a very weak or negative staining with most of the anti-HLA class I mAbs used. Real-time quantitative PCR of the samples obtained from microdissected tumor tissue revealed a significant difference in the mRNA levels of HLA-ABC heavy chain and β2m between the two types of metastases, i.e., lower levels in progressing metastases and high levels in regressing ones, confirming the immunohistological findings. This is, to our knowledge, the first report where the clinical outcome of different HLA class I positive and negative melanoma metastases can be clearly correlated with the regression and progression of the disease, respectively.

Genetic polymorphisms of RANTES, IL1-A, MCP-1 and TNF-A genes in patients with prostate cancer

BackgroundInflammation has been implicated as an etiological factor in several human cancers, including prostate cancer. Allelic variants of the genes involved in inflammatory pathways are logical candidates as genetic determinants of prostate cancer risk. The purpose of this study was to investigate whether single nucleotide polymorphisms of genes that lead to increased levels of pro-inflammatory cytokines and chemokines are associated with an increased prostate cancer risk.MethodsA case-control study design was used to test the association between prostate cancer risk and the polymorphisms TNF-A-308 A/G (rs 1800629), RANTES-403 G/A (rs 2107538), IL1-A-889 C/T (rs 1800587) and MCP-1 2518 G/A (rs 1024611) in 296 patients diagnosed with prostate cancer and in 311 healthy controls from the same area.ResultsDiagnosis of prostate cancer was significantly associated with TNF-A GA + AA genotype (OR, 1.61; 95% CI, 1.09–2.64) and RANTES GA + AA genotype (OR, 1.44; 95% CI, 1.09–2.38). A alleles in TNF-A and RANTES influenced prostate cancer susceptibility and acted independently of each other in these subjects. No epistatic effect was found for the combination of different polymorphisms studied. Finally, no overall association was found between prostate cancer risk and IL1-A or MCP-1 polymorphisms.ConclusionOur results and previously published findings on genes associated with innate immunity support the hypothesis that polymorphisms in proinflammatory genes may be important in prostate cancer development.

LOH at 6p21.3 region and HLA class I altered phenotypes in bladder carcinomas

Alterations in HLA class I antigen expression have been frequently described in different epithelial tumors and are thought to favor tumor immune escape from T lymphocyte recognition. Multiple molecular mechanisms are responsible for these altered HLA class I tumor phenotypes. Some are structural defects that produce unresponsiveness to treatment with interferons. Others include alterations in regulatory mechanisms that can be switched on by treatment of tumor cells with different cytokines. One important mechanism belonging to the first group is loss of heterozygosity (LOH) at chromosome region 6p21.3, which can lead to HLA haplotype loss. In this investigation, the frequency of LOH at 6p21 chromosome region was studied in 69 bladder carcinomas. Short tandem repeat analysis showed that 35% of cases had LOH in this chromosome region. By considering these results together with immunohistological findings previously published by our group, we identified a distribution pattern of HLA class I altered phenotypes in bladder cancer. The most frequently altered phenotype in bladder carcinomas was total loss of HLA class I expression (17 cases, 25%), followed by phenotype II associated with HLA haplotype loss (12 cases, 17.5%), and HLA allelic loss (ten cases, 14.5%). Nine cases (13%) were classified as having a compound phenotype, five cases (7%) as having HLA locus loss, and in 16 cases (23%) no alteration in HLA expression was detected. An important conclusion of this report is that a combination of different molecular and immunohistological techniques is required to precisely define which HLA alleles are lost during tumor progression and to characterize the underlying mechanisms of these losses. These studies should be performed when a cancer patient is to be included in an immunotherapy protocol that aims to stimulate different immune effector mechanisms.

Analysis of HLA–ABC locus-specific transcription in normal tissues

We developed a novel human leukocyte antigen HLA–ABC locus-specific quantitative real-time polymerase chain reaction (PCR) to determine the locus-specific gene expression of HLA–ABC in peripheral blood leukocytes (PBLs, nu2009=u200953), colon mucosa (nu2009=u200915), and larynx mucosa (nu2009=u200915). Laser-assisted tissue microdissection allowed us to study the selected cells without interference from surrounding stroma. We report evidence on the specificity of the technique, describing the HLA–ABC locus-specific gene expression patterns found in the PBLs and two solid tissues studied. PBLs showed a higher gene expression of HLA-B than of HLA-A or HLA-C (pu2009=u20094.7u2009×u200910−10 and pu2009=u20091.6u2009×u200910−6, respectively). In solid tissue, HLA-A and HLA-B gene expressions were similar and HLA-C expression lower. In particular, in larynx mucosa, significant differences were found between HLA-A and HLA-C expressions and between HLA-B and HLA-C expressions (pu2009=u20096.5u2009×u200910−4 and pu2009=u20098.1u2009×u200910−4, respectively). The same differences were observed in colon mucosa, but significance was not reached (pu2009=u20090.08 and pu2009=u20090.06, respectively). Differences in locus-specific regulation may be related to the control of cytotoxic responses of NK and CD8 positive T cells. Gene expression of HLA–ABC specific locus showed no intra-individual variability, but there was a high inter-individual variability. This may result from differences in the expression of common regulatory factors that control HLA–ABC constitutive expression.

Magnetic properties and crystal structure of {μ-pyrazine}bis[(aqua)(2,6-xylylaminodiacetato)copper(II)]. A pyrazine-bridged dinuclear copper(II) complex

The preparation, spectroscopic and magnetic study, and crystal structure of the complex {μ-pyrazine}bis[(aqua)(2,6- xylylaminodiacetato)copper(II)], [Cu2(L)2(H2O)2(pyz)], are reported. It crystallizes in the monoclinic space group P21/n with cell constants a=13.309(3), b=7.590(2), c=15.459(3) A, β=100.90(3)°, Z=2, R=0.038, Rw=0.045. The structure consists of neutral dinuclear [Cu2(L)2(H2O)2(pyz)] molecules, in which the copper(II) ions are bridged by a molecule of pyrazine, with a Cu···Cu distance of 5.786 A. Each of the CuN2O3 coordination polyhedra can be described as a square-based pyramid with a small distortion toward trigonal-bipyramid. The bridging pyrazine molecule is bonded in equatorial position and canted out of the basal coordination plane by 20.8°. The magnetic study indicates that a weak antiferromagnetic interaction operates between the copper(II) ions with an exchange coupling constant of −3.7 cm−1. The magnitude of the exchange interaction is discussed on the basis of structural data.

A polymorphism in the interleukin-10 promoter affects the course of disease in patients with clear-cell renal carcinoma

In the tumor microenvironment, interleukin (IL)-10 production has a pleiotropic ability to positively and negatively influence the function of innate and adaptive immunity against cancer. This study investigated whether IL-10 genetic polymorphisms that influence gene expression levels play a role in the risk and clinical course of clear-cell renal cell carcinoma (RCC). We analyzed the allelic and haplotype frequency formed by alleles at -1082(G/A), -819(C/T), and -592(C/A) of the IL-10 gene in RCC (n = 126) and healthy individuals (n = 176). The frequency of IL-10 polymorphic variants was similar between patients and controls. However, -1082 G/A IL-10 genotype showed a significant association with three prognostic indicators: advanced disease stage (p = 0.002), higher tumor size (p = 0.001), and presence of adenopathy (p = 0.006). Our results can be explained by the contradictory antitumor or pro-tumorigenic relationship between this molecule and cancer. Genotypes associated with high or low levels of IL-10 gene expression (GG or AA-1082 IL-10) were both associated with a more favorable course of the disease. We propose the hypothesis that the -1082 GA medium expression genotype confers a tumor-promoting phenotype, likely resulting from the immunosuppressive effects of anti-tumor Th-1 responses in conjunction with the insufficient inhibition of tumor angiogenesis at this intermediate level of IL-10 expression.

Crystal and molecular structure of methyl α-d-galactopyranoside 3-(sodium sulfate) monohydrate

Abstract The crystal and molecular structure of methyl α- d -galactopyranoside 3-(sodium sulfate) monohydrate has been determined by X-ray diffraction. The molecular structure has a distorted chair conformation 4C1. The conformation of the hydroxymethyl group is gauche-cis and the methyl group is gauche-trans with respect to the pyranoid ring. The distorted sodium ion environment has seven closest oxygens of two different molecules. Coordination with (O-5, O-4, O-6) and (O-1, O-2), related by translational symmetry along the a axis, together with water oxygen O-1W and O-9 of the sulfate group, complete the first coordination sphere of sodium. A complex hydrogen-bond pattern involves all oxygens of the sulfate group as acceptors, linking molecules in [100] through O-7. The hydroxyl groups on C-2 and C-4 also participate in the bonding pattern. The complex packing by hydrogen bonds and ion coordination results in relevant differences with respect to the structure of other surface pyranosides.

Polymorphisms in inflammatory response genes in metastatic renal cancer

Inflammation has been implicated as an etiological factor in different human cancers. Allelic variations in the genes implicated in inflammation are candidates as genetic determinants or markers of renal carcinoma risk. The present stud investigates whether polymorphisms of the genes that give rise to increases in the levels of proinflammatory cytokines and chemokines are associated with an increased risk of renal carcinoma. To this effect, a number of case-control studies were designed to assess the correlation between renal carcinoma and polymorphisms IL10-1082 A/G (rs 1800896), IL10-592 A/C (rs 1800872), IL10-819 C/T (rs 1800871), IL10-1082 A/G, IL4-590 C/T (rs 2243250), TNF-A-308 A/G (rs 1800629), RANTES-403 G/A (rs 2107538), IL1-A-889 C/T (rs 1800587), MCP-1 2518 G/A (rs 1024611), CTLA-4/+49 A/G (rs 231775) and CTLA-4 CT60 A/G (rs 3087243) in 127 renal carcinoma patients and in 176 healthy subjects. The results obtained in relation to cytokine polymorphism IL-10-1082 A/G indicate that AG heterozygosity status is the principal risk factor in relation to locally advanced or metastatic tumor stage and renal carcinoma. In the case of the molecule CTLA4, the results obtained in renal cancer reveal an association between the polymorphisms of the CTLA-4 gene and an increased risk of developing renal cell carcinoma. A high genotypic frequency of polymorphisms CTLA4/CT60-AA and CTLA4/A49G-AA is observed in patients with renal cell carcinoma versus the controls. An association has been established between polymorphism CTLA4/CT60 and tumor grade in patients with renal cell carcinoma. Logistic regression analysis has confirmed these data, demonstrating a high frequency of the AA genotype in patients with high-grade tumors. The results obtained support the hypothesis that different genetic factors implicated in the regulation of adaptive immune responses, stromal cell composition and local cytokine production levels may be crucial elements in the modification of the clinicopathological parameters of renal carcinoma.