The Bcl-xL inhibitor of apoptosis is preferentially expressed in cutaneous squamous cell carcinoma compared with that in keratoacanthoma.

Keratoacanthoma (KA) is difficult to histologically distinguish from squamous cell carcinoma (SCC). Therefore, although KA is a benign self-resolving skin lesion, KA is commonly treated as SCC. Biomarkers to distinguish KA and SCC would thus be desirable. In search for specific markers, paraffin-embedded tissue samples from 25 SCC and 64 KA were arranged in a tissue microarray (TMA) and stained for immunologic cell-markers CD3, CD20 and CD68 as well as for proteins considered of relevance in tumorgenesis, namely NF kappaB/p65, I kappaB-alpha, STAT3, p53, TRAP-1, pRB, phosphorylated pRb, Cyld, p21, p16(INK4), Survivin, Bcl-xL, Caspase 3, Bak, FLK-1/VEGF-r2 and Ki-67. In addition, the tumors were tested for presence of human papillomavirus by PCR. We detected that the two lesions differed significantly in expression of Bcl-xL which was present in 84% of the SCC compared with only 15% in the KA (p < 0.001). The lower expression of the antiapoptotic protein Bcl-xL in KA is consistent with a possible role of apoptosis in the regression of KA.

Early onset of rejection in concordant hamster xeno hearts display signs of necrosis, but not apoptosis, correlating to the phosphocreatine concentration.

BACKGROUND: The importance of apoptosis contra necrosis for ischemia/reperfusion (RP) and acute rejection in concordant rodent xenotransplantation is largely unknown. We explored this question by comparing rodent allo and concordant xenotransplants with different morphological methods to detect apoptosis and biochemical data on the levels of high-energy phosphates obtained with in vitro 31Phosphorous Magnetic Resonance Spectroscopy (31P MRS). More specifically, we applied a hitherto unused method in transplantation research, apoptosis specific biotin labeled oligonucleotides designed with a 10 base pair stem region and a 20 nucleotides large loop that form a hairpin like shape. The results obtained with this method were compared to results obtained with the more widely used in situ 3'-end labeling of DNA (TUNEL) assay and extraction and gel electrophoresis of labeled DNA (DNA laddering). METHODS: Cervical heart transplantations were performed between inbred Lewis (L) (RT1l) to L, L to DA (RT1a) rats, hamster (H) to H and H to L (X) (n=5 for all groups except for X, n=9). All hearts were subjected to 30 min of cold ischemia (+4 degrees C) and 6 h of RP before explantation. In vitro 31P MRS was used to determine the phosphocreatine (PCr), beta-adenosine triphosphate (beta-ATP) concentrations and the PCr/beta-ATP ratio of the transplants. We correlated the biochemical data to haematoxylin and eosin (H & E) stained tissue slides scored for rejection, infiltration of antibodies and complement depositions, DNA extraction and gel electrophoresis of labeled DNA (DNA laddering), in situ 3'-end labeling of DNA (TUNEL) and the apoptosis specific hairpin probe assays scoring. RESULTS: The rejection score of the xeno grafts differed significantly compared to their syngeneic hamster to hamster controls (2.40 +/- 0.25 vs. 1.20 +/- 0.20; P=0.005) and they had a significantly higher TUNEL score, 228 +/- 15 vs. 2.44 +/- 0.32 (P=0.009), that correlated to changes in PCr concentration (P<0.001) and to the PCr/beta-ATP ratio (P=0.01). The uptake was mainly (90-95%) located to 1-2 microm large extra cellular 'granule'. A picture resembling early necrosis was seen on the H & E stainings and reflected in the Billingham rejection score above. CONCLUSIONS: After 6 h of RP the onset of acute rejection in the concordant hamster xeno hearts displayed features of early, possibly mitochondrial, necrosis, but not apoptosis, which correlated to changes in the PCr concentration and the PCr/beta-ATP ratio. The mechanism for the early rejection observed is unclear and might be caused by other factors in the sera apart from cellular components, antibodies and complement factors. Identification of the underlying mechanisms could enable us to design rational therapies that prevent activation of the recipient's innate immune response.

Cutaneous squamoproliferative lesions in kidney transplant recipients: an investigation of specific Epstein-Barr virus expression.

In a previous report we demonstrated Epstein-Barr virus expression in cutaneous squamous cell carcinomas from heart transplant recipients. In a comparative study, skin lesions from renal allograft recipients were investigated for the presence of Epstein-Barr virus. Thirty cutaneous squamoproliferative lesions from 10 kidney transplant recipients were examined for Epstein-Barr virus-specific gene expression. The techniques used for detection were polymerase chain reaction, in situ hybridization and immunohistochemistry. Epstein-Barr virus DNA was not detected by polymerase chain reaction in the neoplasias, and only single Epstein-Barr virus-positive carcinoma cells were shown by in situ hybridization in three cases of infiltrative squamous cell carcinomas. Immunohistochemistry for Epstein-Barr virus latent membrane protein 1 showed a negative result in all samples. These findings differ from our earlier investigations of cutaneous squamous cell carcinomas from heart transplant recipients where Epstein-Barr virus expressions were common. This may indicate that the part Epstein-Barr virus plays in the development of post-transplant, cutaneous squamoproliferative disorders is related to type of organ transplantation and/or grade of immunosuppression.

Sustained elevated concentrations of cardiac troponin T during acute allograft rejection after heart transplantation in children.

BACKGROUND: The diagnosis of acute rejection after heart transplantation is made on the basis of endomyocardial biopsy. In children, where the method may be associated with complications, a noninvasive alternative would be desirable. We evaluated the myocardial damage marker cardiac troponin T (cTnT) as a marker of rejection in children who have undergone heart transplantation. METHODS: Peripheral venous blood was collected in 124 endomyocardial biopsies in 14 children who had undergone heart transplantation (1-20 years of age). Serum levels of cTnT were compared with histologic rejection according to the International Society of Heart and Lung Transplantation (ISHLT) (grades 0-4). RESULTS: Seven children experienced nine episodes of acute rejection. During rejection, cTnT increased from 0.05+/-0.07 (mean+/-SD) microg/L to 0.26+/-0.27 microg/L and remained elevated 7 and 30 days thereafter (0.10+/-0.11 and 0.36+/-0.38 microg/L, respectively) before returning to normal after 50 to 430 days. In surveillance biopsies, cTnT displayed considerable variation at all rejection grades: ISHLT grade 0, median 0.03 microg/L (range 0.01-2.04 microg/L); ISHLT grade 1, median 0.06 microg/L (range 0.01-0.67 microg/L); ISHLT grade 2, median 0.10 microg/L (range 0.01-1.42 microg/L); and ISHLT grade 3, median 0.17 microg/L (range 0.01-0.93 microg/L). A receiver operating characteristics analysis for cTnT versus rejection grade revealed an area under the curve of 0.69, indicating a moderate predictive value for cTnT. However, a cutoff of 0.015 microg/L yielded a specificity of only 36%, with a sensitivity of 89%, whereas a cutoff of 0.1 microg/L resulted in sensitivity and specificity of 53% and 77%, respectively. CONCLUSIONS: Cardiac troponin T increased and remained elevated for at least 1 month during acute rejection. The diagnostic power of a single cTnT measurement was not sufficient to replace endomyocardial biopsy.