pVHL co-ordinately regulates CXCR4/CXCL12 and MMP2/MMP9 expression in human clear-cell renal cell carcinoma.

Loss of pVHL function, characteristic for clear-cell renal cell carcinoma (ccRCC), causes increased expression of CXCR4 chemokine receptor, which triggers expression of metastasis-associated MMP2/MMP9 in different human cancers. The impact of pVHL on MMP2/MMP9 expression and their relationship to CXCR4 and its ligand CXCL12 in ccRCC is unclear. By using reverse transcription PCR, immunofluorescence and immunohistochemistry, strong mRNA and protein expression of CXCR4, CXCL12, MMP2, MMP9 and MMP inhibitors TIMP1 and TIMP2 was found in VHL-null 786-O ccRCC cells. Loss of CXCR4/CXCL12 expression after restoration of VHL function in these cells was accompanied by a significant reduction of MMP2 and MMP9 expression, whereas neither TIMP1 nor TIMP2 expression was affected. Using real-time PCR analysis, higher MMP2 (p = 0.0134) and MMP9 (p = 0.067) mRNA expression levels were detected in primary ccRCC with strong CXCR4 compared to cases with weak CXCR4 expression. There was no association between CXCR4 and TIMP1 or TIMP2 mRNA expression. MMP2 protein expression data obtained by immunohistochemistry on a tissue microarray uncovered positive cytoplasmic staining in 290/380 (76%) primary ccRCCs. Co-expression of CXCR4 and MMP2 was found in 282 of these tumours (74%). Our in vitro and in vivo data strongly indicate that pVHL coordinately regulates expression of metastasis-associated genes CXCR4/CXCL12 and MMP2/MMP9 but the exact molecular mechanism of this regulation remains to be determined. Co-expression of CXCR4 and CXCL12, as demonstrated in VHL-null 786-O cells, might enable ccRCC progression and metastatic dissemination by autocrine receptor stimulation, even in the absence of exogenous CXCL12.

[mRNA expression analysis of metastatic markers in clear-cell renal cell carcinoma]. / mRNA expressionsanalyse von metastasierungsmarkern in klarzelligen nierenzellkarzinomen.

Deregulated expression of Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinases (TIMPs) is an important pre-requisite for metastatic processes in a variety of human tumor types including renal cell cancer. Own previous cDNA microarray studies demonstrated differential expression of several MMPs and TIMPs in normal renal tissue and renal cancer cell lines. In order to analyze MMP/TIMP expression in primary clear-cell renal cell carcinoma (ccRCC) tissues we have determined the mRNA abundance of MMP-2, MMP-9, TIMP-1 and TIMP-2 by RT-PCR in 29 ccRCC and 7 normal renal tissues. Compared to normal renal tissue, expression of MMP-2 and TIMP-2 was significantly reduced in 16 and 12 of 29 ccRCCs, respectively. In contrast, MMP-9 expression was significantly increased in 11 of 29 ccRCCs. No difference was seen for TIMP-1 transcription levels. Because expression of the metastasis-associated CXCR4 chemokine receptor is increased and associated with poor tumour-specific survival in ccRCC we also compared MMP/TIMP and CXCR4 expression in the given tissue samples. Expression of TIMP-1 and TIMP-2 did not correlate with CXCR4 expression levels, whereas mRNA expression of MMP-2 and MMP-9 was significantly higher in tumours with strong CXCR4 expression (p = 0.04 and p = 0.01, respectively). These preliminary results suggest the involvement of CXCR4, MMP-2, and MMP-9 in renal cancer progression.

Do we need a computed tomography examination in all patients with acute pancreatitis within 72 h after admission to hospital for the detection of pancreatic necrosis?

BACKGROUND: The aim of this prospective study was to define the role of an initial contrast-enhanced computed tomography (CT) obtained within 72 h after admission to hospital for determining the prognosis of acute pancreatitis and to investigate whether CT scans can be replaced by conventional prognostic parameters. METHODS: The study involves 231 patients admitted to the Lüneburg clinic with a first attack of acute pancreatitis from 1988 to 1995. In all of them, a contrast-enhanced CT was performed within 72 h of admission and scored according to Balthazar. The results were compared with the Ranson and Imrie laboratory prognostic scores and with parameters of the severity of the disease: the initial organ failure according to the Atlanta classification; days spent on intensive care unit or altogether in hospital; indication for artificial ventilation, dialysis and surgical intervention (necrosectomy); development of pancreatic pseudocysts; and mortality. RESULTS: Although there was a good statistical correlation between Ranson, Imrie, and Balthazar scores with the severity of the disease (P < 0.001 to P = 0.03), low and moderately raised Ranson (0-2, 0-5 points) and Imrie scores (0-1.0-3 points) failed to identify all patients with pancreatic necrosis with sufficient sensitivity rates (31.7; 78.0 and 39.0; 78.0%), positive (32.6; 25.3 and 75.0; 45.0%) and negative (91.0; 87.9 and 85.4; 84.8%) predictive values. CONCLUSIONS: A contrast-enhanced CT on admission correlates significantly with the severity of the disease and cannot be replaced by conventional laboratory prognostic scores. The decision to use a CT cannot depend on the results of the Ranson/Imrie scores.

CDKNA2A mutation analysis, protein expression, and deletion mapping of chromosome 9p in conventional clear-cell renal carcinomas: evidence for a second tumor suppressor gene proximal to CDKN2A.

Inactivation of tumor suppressor genes on chromosome 9p is considered a critical event in renal cell carcinoma pathogenesis. Alterations of CDKN2A on 9p21 have been reported in renal cancer cell lines, but their relevance for primary renal carcinomas is unclear. Loss of heterozygosity (LOH) was analyzed by using four polymorphic microsatellites at D9S970 (9p12-9p13), D9S171 (9p13), D9S1748 (9p21), and D9S156 (9p21) in 113 primary conventional clear-cell renal cell carcinomas (CRCCs). Allelic deletion was detected in 21 of 88 informative CRCCs (24%) with the highest rate of LOH being observed at D9S171 on 9p13 (20%). Chromosome 9p LOH was associated with short tumor-specific survival in stage pT3 RCC (P = 0.01). Fluorescence in situ hybridization analysis of 54 CRCCs revealed no homozygous CDKN2A deletions indicating that this mechanism of CDKN2A inactivation is rare in CRCC. Sequencing of 113 CRCCs showed that 13 tumors (12%) had a 24-bp deletion abrogating codons 4 through 11 of CDKN2A. Immunohistochemical CDKN2A expression was absent in normal renal tissue and was only detected in six of 382 CRCCs (1.5%) on a renal tumor microarray. These data suggest that CDKN2A alterations are present in a small subset of CRCCs and a second, yet unknown tumor suppressor gene proximal to the CDKN2A locus, may play a role in CRCC development.

Has blood glucose level measured on admission to hospital in a patient with acute pancreatitis any prognostic value?

BACKGROUND: Early detection of pancreatic necrosis allows better management of the disease. Contrast-enhanced computed tomography (CT) as the gold standard for detecting pancreatic necrosis is expensive. AIM OF THE STUDY: This study was to evaluate for the first time whether blood glucose estimation on hospital admission--a simple, cheap, readily available laboratory parameter--may detect pancreatic necrosis and have prognostic value in acute pancreatitis. METHODS: Single blood glucose estimation upon hospital admission was evaluated prospectively for detecting pancreatic necrosis and as a prognostic indicator. The study included 241 nondiabetic patients with a first attack of acute pancreatitis. All underwent CT within 72 h of admission. RESULTS: High blood glucose (> 125 mg/dl) correlated significantly with complex high clinical and biochemical prognostic scores (Ranson, Imrie), a high Balthazar score, pancreatic pseudocysts, and a long hospital stay, but not with organ failure, indication for artificial ventilation, dialysis, surgery, length of intensive care, and mortality. Pancreatic necrosis detection sensitivity of high blood glucose was 83%, specificity 49%, positive predictive value 28%, and negative predictive value 92%. CONCLUSION: A patient with normal blood glucose on admission is unlikely to have pancreatic necrosis. Contrast-enhanced CT would not be needed unless the patient fails to improve.

Which etiology causes the most severe acute pancreatitis?

BACKGROUND: The aim of the study was to define the prognostic role of etiology in the course of acute pancreatitis. METHODS: The study involved 208 consecutive patients with a first attack of acute pancreatitis. Etiology was biliary in 81 (39%) patients and alcohol abuse in 69 (33%); other etiologies were present in 16 (8%), and etiology remained unknown in 42 (20%). Etiology was correlated with the following parameters of severity of the disease: days in an intensive care unit (ICU); total hospital stay (THS); Ranson, Imrie, and Balthazar scores (contrast-enhanced computed tomography [CT] within 72 h of admission); indication of artificial ventilation, dialysis, or surgery; development of pancreatic pseudocysts; mortality. RESULTS: Alcoholic etiology correlated significantly more frequently than other subgroups with necrotizing pancreatitis, need for artificial ventilation, and development of pancreatic pseudocysts. For the other parameters, there were no significant differences between the etiologies. CONCLUSION: Patients with alcohol-induced acute pancreatitis should be given special attention because of the higher incidence of necrotizing pancreatitis and necessity for artificial ventilation. Whether the pronounced frequency of pseudocysts in alcoholics suggests progression to chronic pancreatitis has to be clarified in follow-up studies.

Presence and extent of extrapancreatic fluid collections are indicators of severe acute pancreatitis.

BACKGROUND: It has been suggested that early localization of both necrosis and extrapancreatic fluid collections by contrast-enhanced computed tomography (CT) can predict the outcome in severe acute pancreatitis. These two assumptions were evaluated. PATIENTS AND METHODS: This study comprises 228 patients with a first attack of acute pancreatitis admitted to our clinic from 1987 to 1995 and for whom the prognostic value of a contrast-enhanced CT obtained within 72 h of admission was prospectively evaluated. These CTs were retrospectively re-evaluated for the localization of pancreatic necrosis and extrapancreatic fluid collections. The indication for dialysis and artificial ventilation, the development of pancreatic pseudocysts, the necessity for surgery (necrosectomy), and mortality were used as clinical parameters. RESULTS: There was a significant correlation between the presence of pancreatic necrosis and extrapancreatic fluid collections versus the clinical parameters. The localization of pancreatic necrosis was of no importance for the outcome of the disease, whereas the increasing amount of extrapancreatic fluid collections paralleled the severity of acute pancreatitis. CONCLUSION: Pancreatic necrosis and extrapancreatic fluid collections are indicators for severe acute pancreatitis. Whereas the localization of pancreatic necrosis is not important for the outcome of the disease, the extent of extrapancreatic fluid collections is significantly correlated with a severe course.