Maria R. Oliva

HLA class I gene expression on human primary tumours and autologous metastases: demonstration of selective losses of HLA antigens on colorectal, gastric and laryngeal carcinomas.

The expression of HLA class I antigens was studied in 99 primary tumour (colorectal, gastric and laryngeal carcinomas) and 57 autologous metastases using immunohistological techniques and monoclonal antibodies against class I monomorphic determinants, HLA-B isotypic determinants and HLA polymorphic determinants. Fourteen per cent of colorectal, 9.6% of gastric and 20% of laryngeal carcinomas completely lacked class I molecules. Selective losses of HLA-B antigens were also detected in 8.8, 3.4 and 5.8% of these tumours respectively. Taking into account complete and selective loss of HLA-B the average alteration in the class I molecules expression totalled 21%. The comparison of class I expression between primary tumours and autologous metastases showed differences in 24% of the patients. These differences consisted mainly in a decrease of class I expression by metastases. Nevertheless, four types of divergence were detected in laryngeal carcinomas, namely: +/-, +/+, -/+, -/-. In addition, a clear correlation between degree of differentiation and class I expression was observed in laryngeal tumours. Finally, when class I gene RFLPs were compared with DNA from 15 tumours and autologous normal mucosa or peripheral lymphocytes, no differences were detected between these samples.

Genetic alterations and oxidative metabolism in sporadic colorectal tumors from a Spanish community

Deletions of loci on chromosomes 5q, 17p, 18q, and 22q, together with the incidence of p53 mutations and amplification of the double minute‐2 gene were investigated in the sporadic colorectal tumors of 44 patients from a Spanish community. Chromosome deletions were analyzed by means of loss of heterozygosity analysis using a restriction fragment length polymorphism assay. Allelic losses were also detected by polymerase chain reaction (PCR)‐single‐stranded conformation polymorphism (SSCP) analysis of a polymorphic site in intron 2 of the p53 gene. The percentages of genetic deletions on the screened chromosomes were 39.3% (5q), 58.3% (17p), 40.9% (18q), and 40% (22q). Mutations in p53 exons 2–9 were examined by PCR‐SSCP analysis and direct sequencing of the mutated region. Twenty of 44 tumor samples (45.45%) showed mutations at various exons except for exons 2, 3, and 9, the most frequent changes being G → T transversion and C → T transition. Because oxygen‐free radicals play a role in the carcinogenesis process, we evaluated the oxidative status of the colorectal tumors. Antioxidant activities, lipid peroxidation, and DNA‐damaged product concentrations in colon tumors and normal mucosa were compared. In tumor tissues, superoxide dismutase and catalase decreased fourfold and twofold, respectively, whereas glutathione peroxidase and reduced glutathione increased threefold. Malondialdehyde and 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) levels were twofold higher in colorectal tumors than in normal mucosa. Seven of 10 DNA tumor samples (70%) showing higher values of 8‐OHdG also had genetic alterations at different chromosomal loci. In these samples, the p53 gene was deleted or mutated in 71.4% of cases. We concluded that the observed changes in the oxidative metabolism of the tumor cells and the consecutive increase in DNA damage may potentiate the genomic instability of different chromosomal regions, leading to further cell malignancy and tumor expansion. Mol. Carcinog. 18:232–243, 1997.

FDG-PET/CT tumor segmentation-derived indices of metabolic activity to assess response to neoadjuvant therapy and progression-free survival in esophageal cancer: correlation with histopathology results.

Purpose:To evaluate the diagnostic and prognostic abilities of PET tumor segmentation-derived indices of metabolic activity for the assessment of response to neoadjuvant chemoradiotherapy and progression-free survival in patients with esophageal cancer. Methods:Twenty-five patients with histologically confirmed esophageal cancer were retrospectively evaluated. The patients underwent PET-CT imaging before and after completion of neoadjuvant therapy. Images were evaluated visually and quantitatively with a three-dimensional threshold-based region-growing program, which calculates SUVm, SUVa of the entire tumor, metabolic tumor length (Lm) and volume (Vm) before and after therapy (SUVm1, SUVm2, SUVa1, SUVa2, Lm1, Lm2, Vm1, and Vm2, respectively). Percentage changes in these metabolic variables before and after therapy were also calculated (%SUVm, %SUVa, %Lm, %Vm, respectively). Results:SUVm1 (P = 0.018), SUVa1 (P = 0.019), Lm1 (P = 0.016), and Vm1 (P = 0.016) correlated with T-status. Advanced stage tumors (T3 + T4) had significantly higher glucose metabolism, metabolic length, and volume. Moreover, Lm1 >47.4 mm and Vm1 >29 cm3 were the best predictors of the level of tumor invasiveness. SUVm1 >12.7 and SUVa1 >5.9 could differentiate patients with positive lymph nodes from those without at presentation. %SUVa >32.3% and the SUVa1 >5.5 proved to be reliable predictors of pathologic response. SUVa2 >3.55 and SUVm2 >4.35 were the best predictors of disease progression during follow-up, with the latter having the best prognostic value. Conclusions:This study showed that FDG-PET tumor segmentation-derived indices of metabolic activity play a definite role in the evaluation of response to neoadjuvant chemoradiotherapy and progression-free survival in patients with esophageal cancer.

CT Features of Hepatic Venoocclusive Disease and Hepatic Graft-Versus-Host Disease in Patients After Hematopoietic Stem Cell Transplantation

OBJECTIVE We conducted this study to evaluate whether CT scans could be used to differentiate hepatic venoocclusive disease from hepatic graft-versus-host disease in patients treated with hematopoietic stem cell transplantation. SUBJECTS AND METHODS We retrospectively evaluated 18 patients (eight women, 10 men; mean age, 42.4 years) after hematopoietic stem cell transplantation with biopsy-proven hepatic venoocclusive disease (n = 5), hepatic graft-versus-host disease (n = 6), or both (n = 7). Two radiologists reviewed abdominal and pelvic CT scans for hepatomegaly (> 18 cm), splenomegaly (> 13 cm), size of main portal and right hepatic veins, presence of periportal edema, gallbladder wall edema, hydropic gallbladder, ascites, and small-bowel wall thickening. CT and histopathology findings were correlated using analysis of variance and Fisher-Free-man-Holton tests. RESULTS Ascites and periportal edema were present in all five patients with venoocclusive disease, but of six patients with graft-versus-host disease, ascites was seen in two (p < 0.05) and periportal edema in only one (p < 0.05). Small-bowel wall thickening was encountered in five patients with graft-versus-host disease and in none with venoocclusive disease (p < 0.05). The right hepatic vein diameter in patients with venoocclusive disease (mean, 0.27 cm) was significantly smaller than the right hepatic vein diameter in patients with graft-versus-host disease (mean, 0.87 cm; p < 0.05). CONCLUSION In patients treated with hematopoietic stem cell transplantation, CT findings of periportal edema, ascites, and a narrow right hepatic vein suggest venoocclusive disease rather than graft-versus-host disease. Small-bowel wall thickening suggests graft-versus-host disease.

Liver cancer imaging: role of CT, MRI, US and PET

Liver imaging in patients with a history of known or suspected malignancy is important because the liver is a common site of metastatic spread, especially tumours from the colon, lung, pancreas and stomach, and in patients with chronic liver disease who are at risk for developing hepatocellular carcinoma. Since benign liver lesions are common, liver-imaging strategies should incorporate liver lesion detection and characterisation. Survey examination in patients with a known extra-hepatic malignancy to exclude the presence of hepatic and extra-hepatic involvement is normally undertaken with a contrast-enhanced computed tomography examination. When patients with hepatic metastases are being considered for metastasesectomy, they undergo a staging examination with contrast-enhanced magnetic resonance imaging (MRI) using tissue-specific contrast agents. Patients with chronic liver disease who are at risk for hepatocellular carcinoma undergo periodic liver screening for focal liver detection, usually with ultrasonography (US) with MRI being used when US is equivocal. Finally, contrast-enhanced MRI with extra-cellular gadolinium chelates is preferred for characterisation of indeterminate hepatic masses with liver biopsy used when tissue diagnosis is needed.

Phenotypic expression of histocompatibility antigens in human primary tumours and metastases

HLA class I and II expression was studied on 244 (177 primary and 67 metastatic) solid human tumours of different origin. Alkaline immunophosphatase (APAAP) and immunoperoxidase were used on cryostatic sections to stain MHC antigens. Monomorphic MoAbs were used against class I heavy chain, β2-microglobulin, DR, DQ and DP molecules.Class I expression was homogeneous on colon, melanoma and epidermoidal primitive tumours. Loss of HLA class I antigens was more frequent on basal cell carcinomas and sarcomas and was related to tumour differentiation on larynx carcinoma. Class I expression was heterogeneous on breast, larynx and stomach primitive neoplasias. Class I negative tumours were more frequent on metastatic than on primitive melanomas. Divergence of class I between primary tumours and autologous metastases was observed on melanomas, larynx and colorectal carcinomas.Class II expression was heterogeneous on all tumours and in a large number of cases was associated with high intensity of leukocytic infiltrate. HLA-DR expression was higher than HLA-DP and HLA-DQ (DR>DP>DQ) and was related to tumour progression. Four human tumour cell lines were modulated with recombinant interferon-γ for HLA class I and II antigens. Different HLA profiles were obtained: increased class I and II expression, increased class II or a low response.Finally, class I genes from 22 tumours were compared with autologous normal cells by Southern blot analysis: 12 tumours were class I positive and 10 negative. No clear differences in RFLP were observed that could be associated with class I rearrangement. The results are discussed in relation to the role that histocompatibility antigens may play in tumour progression and invasiveness.

MHC CLASS I AND II ANTIGENS ON GASTRIC CARCINOMAS AND AUTOLOGOUS MUCOSA

The expression of HLA class I and II antigens was analysed in 30 primary gastric carcinomas, 27 autologous lymph node metastases and 25 autologous gastric mucosae. We used an immune alkaline phosphatase technique on cryostatic sections and mAbs directed against HLA class I monomorphic determinants, HLA‐B locus‐specific products and HLA‐DR, ‐DP and ‐DQ molecules. In addition HLA class I genes were analysed in tumour tissue and compared by Southern blots with the RFLP from autologous mucosa using locus‐specific HLA probes. Finally the infiltrating mononuclear cells were studied on gastric tumours and adjacent mucosa with mAbs defining CD4, CD8 and CD11b differentiation antigens.

HLA molecules in basal cell carcinoma of the skin

Fifty basal cell carcinomas (BCC) and 8 samples of healthy skin were studied for HLA class I and class II antigen expression and for the presence of mutations in codon 12 of the K-ras and H-ras genes. All samples of healthy skin and of epithelium near the tumor showed high levels of class I molecules, whereas 38% of the tumors showed complete absence. Sixty-two percent of the tumors presented positive class I expression with heterogeneous staining. These losses were due to the simultaneous lack of heavy chain and beta 2-microglobulin. Selective losses of HLA-A or HLA-B antigens were not detected. Class II antigens were absent in most of the tumors, only two tumors showing a few weakly positive cells with anti-HLA-DR mAb. The loss of class I expression correlated significantly with the degree of histological differentiation and aggressiveness. We were unable to correlate class I expression with clinical size, depth of invasion or the extent of leukocytic infiltrate surrounding the tumor. Analysis by PCR amplification of codon 12 of the K-ras and H-ras oncogenes detected H-ras mutations in 1 out of 50 cases, and no K-ras mutations in any of the tumors studied. Thus, a positive relationship between K-ras and H-ras mutations and BCC tumorigenesis or MHC alterations seems unlikely in this neoplasia.

The Role of Glutathione in Protection against DNA Damage Induced by Rifamycin SV And Copper(II) Ions

Incubation of calf thymus DNA in the presence of rifamycin SV induces a decrease in the absorbance of DNA at 260 nm. The effect, was found to be proportional to the antibiotic concentration and enhanced by copper(II) ions. In the presence of rifamycin SV and copper(II), a significant increase in thiobarbituric acid-reactive (TBA-reactive) material is also observed. This effect is inhibited to different degrees by the following antioxidants: catalase 77%; thiourea 72%; glutathione (GSH) 62%; ethanol 52%; and DMSO 34%, suggesting that both hydrogen peroxide (H2O2) and hydroxyl radicals (OH.) are involved in DNA damage. Rifamycin SV-copper(II) mixtures were also found to induce the production of peroxidation material from deoxyribose and, in this case, glutathione and ethanol were the most effective antioxidant substrates with inhibition rates of 91% and 88% respectively. Electrophoretic studies show that calf thymus DNA becomes damaged after 20 min. incubation in the presence of both agents together and that the damaged fragments run with migration rates similar to those obtained by the metal chelating agent 1,10-phenanthroline. Normal DNA electrophoretic pattern was found to be preserved by catalase, and GSH at physiological concentrations and by thiourea. No protection is observed in the presence of ethanol or DMSO. The results obtained indicate the involvement of different reactive species in the degradation process of DNA due to rifamycin SV-copper(II) complex and emphasize the role of reduced glutathione as an oxygen free radical scavenger.

Glomerulocystic kidney disease: MRI findings.

Glomerulocystic kidney disease (GCKD) is a rare form of renal cystic disease characterized by cystic dilation of Bowmans capsule. The imaging findings of small renal cysts with a predominant cortical and subcapsular distribution allows for distinction from other, more common, polycystic kidney diseases. The appearance and distribution of the renal cysts by magnetic resonance imaging allow for a definitive diagnosis of GCKD.