The impact of the association between Val16Ala-SOD2 SNP and SOD2 immunohistochemistry expression in the prognosis of patients with esophageal cancer.

INTRODUCTION: Esophageal cancer is an extensive public health issue worldwide, warranting the search for biomarkers related to its risk and progression. Previous studies have indicated an association between Val16AlaSOD2 single nucleotide polymorphism in the gene encoding the enzyme superoxide dismutase 2 and esophageal cancer. However, further investigations are needed to clarify its role in disease risk and progression. OBJECTIVE: To investigate the role of Val16AlaSOD2-SNP in esophageal cancer progression and in the survival of patients METHODS: Tumor samples were utilized for Val16Ala-SNP genotyping, while SOD2 expression levels in tissue were assessed using immunohistochemistry. A SOD2 Val16Ala-SNP database was used to obtain information on the genotype of healthy individuals. Risk and overall survival analyzes were performed. RESULTS: The Val16Ala SNP was associated with an increased risk of esophageal cancer (RR 2.18, 95%CI 1.23-3.86), regardless of age and gender, but did not have a significant effect on patient survival. In contrast, weak SOD2 expression demonstrated a significantly associated with poor overall survival after treatment, independent of other clinicopathological variables (HR, 0.41; 95% CI, 0.22-0.79 P = 0.007). CONCLUSIONS: Val16Ala SNP was positively associated with esophageal cancer, and the expression of SOD2 was an independent prognostic marker.

MR imaging features of brain stem hypoplasia in familial horizontal gaze palsy and scoliosis.

We report the case of a child with horizontal gaze palsy, pendular nystagmus, and discrete thoracolumbar scoliosis. MR imaging of the brain depicted pons hypoplasia with an absence of the facial colliculi, hypoplasia, butterfly configuration of the medulla, and the presence of a deep midline pontine cleft (split pons sign). These MR imaging findings suggest familial horizontal gaze palsy with progressive kyphoscoliosis, a rare congenital disorder. To the best of our knowledge, MR imaging findings of only 4 similar cases, with or without progressive idiopathic scoliosis, have been reported. We discuss the pathogenesis substratum of this entity. Early recognition of this rare entity is important if supportive therapeutic measures in progressive scoliosis are to be applied.

Defective expression of adhesion molecules on human bladder tumour and human tumour cell lines.

The pattern of expression of cell adhesion molecules, i.e., leucocyte function associated antigen 3 (LFA-3) and intercellular adhesion molecule 1 (ICAM-1) on human bladder tumour biopsy specimens was investigated. Attempts were also made to study the pattern of induction of these molecules by established human cell lines in response to cytokines. The results indicated that 15 of 25 tumour biopsy specimens were negative for ICAM-1, and amongst the remaining 10, only 1 showed strong positivity, whilst LFA-3 was expressed in 21 of 23 cases. Unlike LFA-3, the pattern of ICAM-1 expression on established tumour cell lines was different in that there were 7 of 21 cases showing positive staining. The parallel investigation of ICAM-1 and major histocompatibility complex class II antigen expression on bladder tumours showed that in 11 of 18 cases, there was a concomitant expression or complete absence of these molecules. In the remaining 7, there were 6 cases where only class II expression was observed. Exposure of cell lines to interferons alpha or gamma had no effects on LFA-3 expression. In contrast, interferon gamma induced ICAM-1 on all the eight lines with constitutive ICAM-1 expression, whereas interferon alpha upregulated only 2 of these 8 lines. The mean +/- SD values for ICAM-1 expression on the eight inducible lines were 617 +/- 406 cpm before and 943 +/- 471 cpm (p = 0.001) after interferon gamma stimulation. The pattern of ICAM-1 inducibility of a bladder cell line Fen to interferon remained unchanged following transfection of a beta2-microglobulin gene and correction of cell surface HLA class I antigens. These results indicate that there was a significant minority of bladder tumours and tumour cell lines with abnormal cell adhesion molecule expression. In some cases, the abnormality in cell lines could not be corrected by cytokine stimulation. It is possible that these abnormalities may play a critical role in the overall tumour strategy for escape from immunological detection.

Super-sensitive epithelial cell line and colorimetric assay to replace the conventional K562 target and chromium release assay for assessment of non-MHC-restricted cytotoxicity.

Using colorimetric MTT assay the susceptibility of a newly established bladder epithelial cell line, Fen cells was compared with conventional target cells, i.e., K562 and Daudi and other epithelial lines for investigation of non-specific killing activity (NK/LAK) of effector cells previously activated with interleukin-2 (IL-2). The results showed that Fen cell line was more sensitive than K562 and Daudi targets and this was seen whether the effector cells were IL-2-activated or not. The percent killing of effector cells from nine normal donors against Fen, K562 and Daudi targets at effector/target (E/T) ratio of 10/1 after IL-2 activation were 63.4 +/- 7.3, 42.6 +/- 4.3 (p = 0.0001) and 38.6 +/- 5.1 (p = 0.0001) respectively. The corresponding values for inactivated effector cells at 50/1, E/T ratio were 44.8 +/- 9.0, 25.1 +/- 8.3 (p = 0.0001) and 24.4 +/- 9.4 (p = 0.0001) indicating exquisite sensitivity of Fen cells to NK/LAK killing. The susceptibility of Fen cells was found to increase by pre-treatment of target cells with interferons (IFN). Thus the percent killing of untreated, IFN-alpha (1000 U/ml), beta (2000 U/ml) and gamma (100 U/ml) treated cells were 52%, 64% (p = 0.005), 70% (p = 0.001) and 67% (p = 0.001) respectively. These results indicated that Fen cells were more susceptible to NK/LAK killing than the conventional K562 and Daudi target cells. These results and the epithelial origin of Fen cells indicate that this cell line might prove to be a more realistic system to replace the conventional approach for assessment of NK/LAK activity in patients with cancer of epithelial origin.

Intensity of class I antigen expression on human tumour cell lines and its relevance to the efficiency of non-MHC-restricted killing.

A modified tetrazolium reduction assay (MTT) was used to assess the relation between HLA class I antigen expression on tumour cells and their susceptibility as a target for non-MHC restricted LAK/NK cytotoxicity using interleukin-2 activated peripheral blood mononuclear cells (MNC) from normal individuals. At 20/1 effector/target ratio this ranged from no killing to 77%. The efficiency of killing was dependent on duration of effector cell culture with IL-2, peaking at day 10 and declining thereafter. This killing could be enhanced by addition of other cytokines including interferons alpha, beta and gamma. Study of a panel of 15 tumour cell lines using a single effector showed that there was no statistically significant inverse correlation (using Spearman rank test) between the degree of tumour class I expression and LAK/NK killing at 20/1 (r = 0.23 P = 0.39) and 10/1 (r = 0.30, P = 0.27) and at 5/1 E/T ratio r = 0.47, P = 0.08) respectively. Lack of inverse correlation between these two parameters came from study of one bladder tumour line (FEN), whose absent class I antigens had been corrected by transfection with beta 2 microglobulin gene. At high E/T ratio (20/1) there was an increase in the susceptibility of target cells to lysis (36% parent cell, 45% transfected cell), whilst at lower E/T ratios (1/1) there was significantly more killing of the non-transfected cells (10% vs 31%). The addition of anti-class I antibody W6/32 increased killing by 18% but this was non-specific as the same increase occurred with a class II antibody. These data suggest that overall there was not an inverse correlation between class I expression and LAK/NK killing at high E/T ratios, whilst at low (5/1 or lower) E/T ratios this correlation nearly reached statistical significance suggesting that the conflicting literature reports may be due to a threshold levels of effector cells above which the masking effects of MHC antigens disappears.

Induction of MHC antigens by tumour cell lines in response to interferons.

The induction of major histocompatibility complex antigens by interferons (IFN) on 17 established tumour cell lines was investigated by radio binding. One bladder (Fen) and two testis lines (Tera I and Ha) lacked class I antigens and IFN-gamma failed to induce their expression. However, IFN-gamma upregulated these antigens on lines expressing low class I antigens (Tera II and EP2102) with little or no significant effect on high class I expressing lines (T24 and RT112). In one bladder line (Wil) IFN-gamma, whilst failing to alter monomorphic class I, upregulated polymorphic HLA-A2 and A3 antigens. None of the 17 lines expressed class II antigens, but could all be induced by IFN-gamma except T24, TccSup, Tera II and Lan lines. This defect was not due to the absence of IFN-gamma receptor, since under the same conditions intracellular adhesion molecule 1 was upregulated. IFN-alpha, whilst failing to have any effect on class II, induced class I antigens. IFN-beta showed no activity on either class I or II antigens when used alone. However, in combination, it inhibited IFN-gamma induced class II antigens. Thus, it may be possible to study cells from fresh tumours to preselect the minority of patients who might benefit from cytokine therapy.

Correlation between class I antigen expression and the ability to generate tumour infiltrating lymphocytes from bladder tumour biopsies.

Analysis of tissue sections from transurethrally resected bladder tumours using anti-CD3 antibody showed the presence of T lymphocytes in intra-epithelial layers in eight of 12 cases investigated. In a larger group of patients, Tumour Infiltrating Lymphocyte (TIL) growth was established from six of 19 cases using Interleukin-2 (IL-2) and conditioned medium (CM) and resulted in the expansion of TILs up to 100-fold. TILs from these individuals were phenotyped with W6/32 (anti-HLA-A,B,C), HB55 (anti-DR) and anti-CD3 antibodies using FAC sorter. The mean +/- s.d. frequency of positive staining with these antibodies were 96.7 +/- 4.0%, 87.5 +/- 10.0% and 82.5 +/- 7.8% respectively, indicating the activated nature of these T cells. The cytotoxic activity of these TILs against Daudi (ie, LAK activity) cell line at 25/1 E/T ratios varied from 26.3 +/- 3.2 to 62.8 +/- 5.2%. In one case where TILs and autologous tumour cell line were established, cytotoxicity studies showed low level of cytotoxicity against the autologous tumour cells (15.8 +/- 1.6%) compared with 62.8 +/- 5.2% against Daudi. Staining of tumour sections from these 19 individuals with W6/32 and BBM.1 revealed positive staining in six of six that developed TILs but only six of 13 (46%) cases, whose tumour failed to grow TILs (P less than 0.02, Fisher exact test). These results are indicative of the presence of IL-2 passageable T cells in bladder cancer biopsy and demonstrate that the successful expansion of these cells correlates with the normal expression of class I antigens on the tumour cells.