Substance P and neprilysin in chronic pancreatitis.

BACKGROUND/AIMS: We aimed to analyze substance P (SP) and neprilysin (NEP), the membrane metallopeptidase that degrades SP, in chronic pancreatitis (CP). METHODS: SP and NEP mRNA levels were analyzed by qRT-PCR in tissue samples from 30 patients with CP and 8 organ donors. In addition, SP serum levels were determined before and after surgery in the same patients, by means of a competitive ELISA assay. Genetic and epigenetic analyses of the NEP gene were also performed. RESULTS: SP mRNA expression levels were higher in CP tissues compared to controls (p = 0.0152), while NEP mRNA showed no significant differences between CP and healthy subjects (p = 0.2102). In CP patients, SP serum levels correlated with those in tissue, and after surgical resection SP serum levels were reduced compared to the preoperative values. Failure of NEP to overexpress in CP tissues was associated with significant miR-128a overexpression (p = 0.02), rather than with mutations in the NEP coding region or the presence of hypermethylation sites in the NEP promoter region. CONCLUSION: Tissue and serum levels of SP were increased in CP, while NEP levels remained unaltered. In an SP/NEP-mediated pathway, it would appear that NEP fails to provide adequate surveillance of SP levels. Failure of NEP to overexpress could be associated with miRNA regulation.

The ECM proteoglycan decorin links desmoplasia and inflammation in chronic pancreatitis.

BACKGROUND: Recurrent inflammation in chronic pancreatitis (CP) is not well understood. AIMS: To investigate whether decorin, an extracellular matrix (ECM) proteoglycan with macrophage modulating activity, is a pathogenic factor allowing diseased pancreatic stroma to sustain inflammation by affecting the cytokine profile of accumulating inflammatory cells. METHODS: Decorin was examined in 18 donors and 32 patients with CP by quantitative reverse transcription polymerase chain reaction (QRT-PCR), western blotting, and immunohistochemistry of pancreatic specimens. QRT-PCR was used to assess cytokine expression in donor peripheral blood mononuclear cells (PBMC), exposed or not to decorin in vitro, and to compare it with the cytokine profile of circulating and resident mononuclear cells (MNC) of patients with CP. RESULTS: In CP, desmoplasia is associated with overexpression of decorin in the growing ECM and enlarged pancreatic nerves. In culture, exposure of MNC to decorin stimulated expression of the MNC recruiting chemokine MCP-1. In biopsies, MNC infiltrates in decorin rich CP tissue showed a 300-fold upregulation of MCP-1 compared with decorin free peripheral blood, whereas no difference was found in basal MCP-1 expression in PBMC of patients versus donors. This effect was specific for MCP1-other inflammatory cytokines, such as interleukin 1beta and tumour necrosis factor alpha, were not affected. CONCLUSION: Decorin is a molecular marker of desmoplasia in CP, and excessive decorin may allow fibrotic masses to nourish and protract inflammation by deregulating the process of MNC accumulation and activation. These data provide a molecular basis for surgical resection of diseased tissue as a treatment option in CP.

Vanilloids in pancreatic cancer: potential for chemotherapy and pain management.

BACKGROUND: Success of chemotherapy and alleviation of pain are frequently less than optimal in pancreatic cancer patients, leading to increasing interest in new pharmacological substances, such as vanilloids. Our study addressed the question of whether vanilloids influence pancreatic cancer cell growth, and if vanilloids could be used for pain treatment via the vanilloid 1 receptor (VR1) in pancreatic cancer patients. METHODS: In vitro, the effect of resiniferatoxin (vanilloid analogue) on apoptosis and cell growth in pancreatic cancer cells--either alone, combined with 5-fluorouracil (5-FU), or combined with gemcitabine--was determined by annexin V staining, FACS analysis, and MTT assay, respectively. VR1 expression was evaluated on RNA and protein level by quantitative polymerase chain reaction and immunohistochemistry in human pancreatic cancer and chronic pancreatitis. Patient characteristics--especially pain levels--were registered in a prospective database and correlated with VR1 expression. RESULTS: Resiniferatoxin induced apoptosis by targeting mitochondrial respiration and decreased cell growth in pancreatic cancer cells without showing synergistic effects with 5-FU or gemcitabine. Expression of VR1 was significantly upregulated in human pancreatic cancer and chronic pancreatitis. VR1 expression was related to the intensity of pain reported by cancer patients but not to the intensity of pain reported by patients with chronic pancreatitis. CONCLUSIONS: Resiniferatoxin induced apoptosis in pancreatic cancer cells indicates that vanilloids may be useful in the treatment of human pancreatic cancer. Furthermore, vanilloid might be a novel and effective treatment option for neurogenic pain in patients with pancreatic cancer.

Chronic pancreatitis: the perspective of pain generation by neuroimmune interaction.

Chronic pancreatitis (CP) is an inflammatory, often painful, disease of the exocrine pancreas which leads to exocrine insufficiency. The pathophysiology of pain in CP is incompletely understood. Several hypotheses have been advanced, including pancreatic and extrapancreatic causes. Here, the different pain hypotheses are discussed and evidence is presented that neuroimmune interactions are significant in the pathogenesis of pain generation and inflammation in CP. A better understanding of the complex cellular and molecular mechanisms of neuroimmune interactions should offer possibilities for innovative therapy and long term disease prevention.

Beneficial effects of Batimastat (BB-94), a matrix metalloproteinase inhibitor, in rat experimental colitis.

BACKGROUND AND AIMS: Matrix metalloproteinases (MMPs) represent a group of enzymes that regulate cell-matrix composition playing a major role in the inflammatory response. In the present study we evaluated the ability of the MMP inhibitor Batimastat (BB-94) to modify the course of experimental colitis induced in the rat by trinitrobenzensulfonic acid (TNB). METHODS: Colitis was induced in 40 rats by intracolonic administration of TNB. Animals were divided into four groups of ten rats each: group 1 received only intracolonic TNB, group 2 received TNB+5 mg/kg intraperitoneal BB-94, group 3 TNB+10 mg/kg BB-94 and group 4 TNB+20 mg/kg BB-94. The MMP inhibitor was administered 30 min before induction of colitis and twice daily until death. Ten rats receiving only intracolonic 0.9% saline served as controls. Animals were killed after seven days; segments of colon were removed and used for histological score of inflammation and myeloperoxidase (MPO) activity. RESULTS: Rats receiving only intracolonic 0.9% saline showed no evidence of colitis. The inflammation score was 0.9, MPO activity 0.235 U/mg. Group 1 (TNB-treated rats) exhibited a high inflammation score (12.4) and MPO activity (0.715 U/mg). Conversely, BB-94-treated rats showed, compared to the TNB group, a significantly lower inflammation score and MPO activity in a dose-dependent fashion. Group 2: inflammatory score 10.1, MPO activity 0.474 (p < 0.05 vs. TNB); group 3: inflammatory score 8.3, MPO activity 0.287 (p < 0.01 vs. TNB); group 4: inflammatory score 5.0, MPO activity 0.256 (p < 0.01 vs. TNB). CONCLUSIONS: Treatment with BB-94 has dose-dependent beneficial effects on the inflammatory alterations in rat experimental colitis. Thus, the inhibition of MMPs may represent a novel therapeutic approach for treatment of intestinal inflammation.

Expression of interleukin 8 (IL-8) and substance P in human chronic pancreatitis.

BACKGROUND: Changes in substance P content and a relationship between the degree of perineural inflammation and pain has been demonstrated in chronic pancreatitis. Whether a relationship exists between neural alteration and pancreatic inflammation (neurogenic inflammation) is not known. AIMS: In the present study we evaluated gene expression of preprotachykinin A (PPT-A), the gene encoding substance P, and interleukin 8, a proinflammatory and hyperalgesic mediator whose release is co-regulated by substance P. PATIENTS: Pancreatic tissue specimens obtained from 21 patients (16 male, five female) with chronic pancreatitis and 18 healthy organ donors (nine male, nine female) were analysed. METHODS: Gene expression of PPT-A and interleukin 8 was studied by northern blot analysis. Respective proteins were localised using immunohistochemistry. RESULTS: Northern blot analysis showed that PTT-A mRNA expression levels were present at comparable levels in normal and chronic pancreatitis tissue samples. In contrast, interleukin 8 mRNA was expressed at very low levels in normal controls but was increased 41-fold (p<0. 001) in chronic pancreatitis tissue samples. Using immunohistochemistry, interleukin 8 protein was localised mainly in immune cells often found around enlarged pancreatic nerves. In addition, in chronic pancreatitis, intense interleukin 8 immunostaining was present in metaplastic ductal cells of the atrophic pancreatic parenchyma. In chronic pancreatitis samples there was a positive relationship between interleukin 8 mRNA levels and the presence of ductal metaplasia (r=0.795; p<0.001) and the inflammation score (r=0.713; p<0.001). CONCLUSIONS: Our data indicate that in chronic pancreatitis, the increase in substance P in enlarged pancreatic nerves is not caused by enhanced intrapancreatic PTT-A mRNA expression, suggesting that the location of substance P synthesis is outside of the pancreas. In addition, localisation of interleukin 8 positive immune cells around pancreatic nerves further supports the existence of neuroimmune interactions as a pathophysiological mechanism in chronic pancreatitis.

Connective tissue growth factor in human liver cirrhosis.

BACKGROUND: Connective tissue growth factor (CTGF) belongs to a family of factors that regulate fibrogenesis and wound healing. While the significance of transforming growth factor beta (TGF-beta) in liver fibrosis is well established, the role of CTGF in fibrosing hepatopathy is still unknown. METHODS: CTGF was analyzed in 10 normal and in 16 cirrhotic liver tissue samples. Northern blot analysis was used to examine the concomitant expression of CTGF and TGF-beta1 mRNAs, and the cellular localization of CTGF mRNA was studied by in situ hybridization. For identification of myofibroblasts and activated hepatic stellate cells, alpha-smooth muscle actin (alpha-SMA) immunohistochemistry was used. RESULTS: Northern blot analysis showed 6.5-fold enhanced expression of CTGF mRNA and 7.8-fold enhanced expression of TGF-beta1 mRNA in liver cirrhosis in comparison with normal controls (p<0.01). By in situ hybridization, CTGF mRNA was detectable in only a few spindle cells in the portal tracts in normal liver samples. In contrast, there was strong expression of CTGF mRNA in fibroblasts and myofibroblast-like cells present in fibrous septa surrounding the cirrhotic nodules, in stellate cells, in endothelial cells and in mesenchymal cells around ductular proliferations, and in ductular epithelial cells. There was a strong correlation between CTGF mRNA and TGF-beta1 mRNA as well as the degree of fibrosis (p<0.01). CONCLUSIONS: Overexpression of CTGF in liver cirrhosis, especially in fibroblasts/myofibroblasts and stellate cells, suggests that this novel factor may play an important role in hepatic fibrosis.

Mechanisms of pain in chronic pancreatitis.

Pain is a leading symptom in chronic pancreatitis (CP) and often its management necessitates surgical intervention. Nevertheless the presence of different hypotheses, the pathophysiology of pain is not understood, thus the indications for therapy remain controversial. Increased pressure within the ductal system and/or the parenchyma has been suggested to be one of the causes of pain. This controversial theory has been substantiated by the demonstration of a relationship between intrapancreatic pressure and intensity of pain. On the other hand, recent studies have shown the inflammatory involvement of intrapancreatic nerve fibres in a so called "neuroimmune interaction". In fact, infiltration of inflammatory cells around the nerves together with an increase in the number of nerve fibres in the fibrotic pancreatic tissue have been proposed as a possible cause of pain in chronic pancreatitis. Moreover, immunohistological studies have shown that the amount of neurotransmitters, such as substance P and calcitonin gene related peptide, is increased in afferent pancreatic nerves and a close interrelationship between pain and immune cell infiltration of the nerves has been reported in CP. In addition to these hypothesis, extrapancreatic causes such as common bile duct obstruction and duodenal stenosis are discussed. This article review points to the different pathogenic mechanisms of pancreatic pain in CP.

Down-regulation of nerve growth factor in poorly differentiated and advanced human esophageal cancer.

BACKGROUND: Binding of nerve growth factor (NGF) to its receptor TrkA leads to intracellular tyrosine kinase activation and regulates the growth and differentiation of various non-neuronal tumours. PATIENTS AND METHODS: In the present study NGF and TrkA were analysed by Northern blot analysis, in situ hybridisation and immunohistochemistry in 41 esophageal cancer samples in comparison to normal controls. RESULTS: NGF mRNA (P < 0.01), but not TrkA mRNA was down-regulated in esophageal cancer samples compared with normal tissues. In the normal esophagus, NGF mRNA and protein was present in epithelial cells of the entire epithelial layer and TrkA mRNA and protein was present in epithelial cells of the basal layer. In esophageal cancer NGF and TrkA mRNA and protein were present in the cancer cells. Down-regulation of NGF correlated with poor differentiation (P < 0.01) and advanced tumour stage (P < 0.01). Low TrkA expression was related to advanced tumour stage (P < 0.05). CONCLUSION: A loss of activation of the NGF/TrkA pathway occurs during tumour progression and may contribute to loss of tumour differentiation in esophageal cancer.

Nerve growth factor and Trk high affinity receptor (TrkA) gene expression in inflammatory bowel disease.

BACKGROUND: Nerve growth factor (NGF), a target derived factor for survival and maintenance of peripheral and central neurones, has been implicated in several chronic inflammatory processes. AIMS: To analyse the concomitant presence of NGF and its high affinity receptor TrkA in patients undergoing surgery for Crohn's disease (CD) and ulcerative colitis (UC). PATIENTS: CD tissues were obtained from 33 patients and UC tissue samples from 12 patients undergoing surgery. Normal intestinal tissue samples were obtained from 30 individuals through an organ donor programme. METHODS: Expression of NGF and TrkA was studied by northern blot analysis. Using in situ hybridisation and immunohistochemistry, the respective mRNA moieties and proteins were localised. Western blot analysis was used to confirm the specificity of NGF and TrkA antibodies. RESULTS: In CD, NGF mRNA was increased in 60% (2.4-fold; p<0.01) and TrkA mRNA in 54% (1.3-fold; p<0.05) of samples. In UC, NGF mRNA expression was enhanced in 58% (2.4-fold; p<0.01) and TrkA mRNA expression in 50% (1.5-fold; p<0.05) of samples. In situ hybridisation showed that NGF and TrkA mRNA were often concomitantly present in polymorphonuclear-like cells of the lamina propria, in mast cells, and in a few ganglia of Auerbach's plexus and Meissner's plexus. Immunohistochemistry revealed that lamina propria cells and inflammatory cells (mainly mast cells) were NGF and TrkA immunopositive. NGF was also present in Meissner's plexus (especially in CD) and TrkA in enteric glia surrounding intestinal ganglia. CONCLUSIONS: The concomitant enhanced expression of NGF and its receptor suggests activation of this pathway in chronic inflammation in CD and UC. The presence of NGF and TrkA in both neural and non-neural structures in CD and UC supports the hypothesis that neuroimmune interactions occur and are activated in both disorders.

Nerve growth factor and its high-affinity receptor in chronic pancreatitis.

OBJECTIVE: To study the mechanisms that are involved in nerve growth and contribute to pain generation in chronic pancreatitis (CP). SUMMARY BACKGROUND DATA: Chronic pancreatitis is a painful disease associated with characteristic nerve changes, including an increase in nerve number and diameter. The mechanisms that influence nerve growth are not known. Nerve growth factor (NGF) and its high-affinity tyrosine kinase receptor A (TrkA) are involved in neural development and survival and growth of central and peripheral nerves. METHODS: Nerve growth factor and TrkA were investigated by Northern blot analysis, in situ hybridization, and immunohistochemical staining in the pancreases of 24 patients with CP, and the findings were correlated with clinical parameters. RESULTS: By Northern blot analysis, NGF and TrkA mRNA expression were increased in 42% (13.1-fold) and 54% (5.5-fold) of the CP samples (p < 0.01), respectively. In situ hybridization revealed that in CP, enhanced NGF mRNA expression was present in metaplastic ductal cells, in degenerating acinar cells, and in acinar cells dedifferentiating into tubular structures. TrkA mRNA was intensely present in the perineurium. Further, enhanced NGF and TrkA mRNA signals were also present in intrapancreatic ganglia cells in CP samples. Immunohistochemistry confirmed the in situ hybridization findings. Analysis of the molecular findings with clinical parameters revealed a significant relation (p < 0.05) between NGF mRNA levels and pancreatic fibrosis (r = 0.64) and acinar cell damage (r = 0.74) and between TrkA mRNA and pain intensity (r = 0.84). CONCLUSION: Activation of the NGF/TrkA pathway occurs in CP. It might influence neural morphologic changes and the pain syndrome in this disorder.

Neuroimmune appendicitis.

BACKGROUND: 15-25% of appendices removed from patients with suspected appendicitis appear normal on histological examination. The cause of pain in such patients is unknown. Since the content of neuropeptides seems to be altered in chronic inflammation, we investigated possible changes in peptidergic innervation for substance P (SP), vasoactive intestinal peptide (VIP), and growth-associated protein-43 (GAP-43). METHODS: Appendices classified as showing acute appendicitis, non-acute appendicitis (clinical signs of acute appendicitis, but histologically not inflamed), or normal were processed for SP, VIP, and GAP-43 immunocytochemistry. The density of SP immunostaining was assessed by digitised morphometry. FINDINGS: 31 appendix specimens were studied (16 acute, 15 non-acute). 16 specimens were used as controls. Expression of GAP-43 was increased in the non-acute appendices. We observed larger amounts of SP-immunoreactive and VIP-immunoreactive nerves in the mucosal layer of the appendix in patients with non-acute appendicitis than in controls and patients with acute appendicitis (mean % area SP-immunoreactive 0.0496 [SD 0.0113] non-acute, 0.0221 [0.0049] acute, 0.0229 [0.0068] controls). In addition, a close spatial relation between SP-immunoreactive and VIP-immunoreactive nerve fibres and lymphoid cells was detected in the outer zone of lymph follicles. INTERPRETATION: Neuroproliferation in the appendix, in association with an increase in neurotransmitters SP and VIP, may be involved in the pathophysiology of acute right abdominal pain in the absence of an acute inflammation of the appendix. Our data, together with increasing knowledge about the way in which the nervous system and immune cells interact, suggest that neuroimmune appendicitis is a distinct pathological entity.

Connective tissue growth factor is a regulator for fibrosis in human chronic pancreatitis.

OBJECTIVE: To evaluate the parameters that mediate fibrogenesis in chronic pancreatitis (CP). BACKGROUND: Connective tissue growth factor (CTGF), which is regulated by transforming growth factor beta (TGF-beta), has recently been implicated in skin fibrosis and atherosclerosis. In the present study, the authors analyzed the concomitant presence of TGF-beta1 and its signaling receptors-TGF-beta receptor I, subtype ALK5 (TbetaR-I(ALK5)), and TGF-beta receptor II (TbetaR-II)-as well as CTGF and collagen type I in the pancreatic tissue of patients undergoing surgery for chronic pancreatitis. PATIENTS AND METHODS: CP tissue samples were obtained from 40 patients (8 women, 32 men) undergoing pancreatic resection. Tissue samples of 25 previously healthy organ donors (12 women, 13 men) served as controls. The expression of TGF-beta1, TbetaR-I(ALK5), TbetaR-II, CTGF, and collagen type I was studied by Northern blot analysis. By in situ hybridization and immunohistochemistry, the respective mRNA moieties and proteins were localized in the tissue samples. RESULTS: Northern blot analysis showed that CP tissue samples exhibited concomitant enhanced mRNA expression of TGF-beta1 (38-fold), TbetaR-II (5-fold), CTGF (25-fold), and collagen type I (24-fold) compared with normal controls. In addition, TbetaR-I(ALK5) mRNA was increased in 50% of CP tissue samples (1.8-fold). By in situ hybridization, TGF-beta1, TbetaR-I(ALK5), and TbetaR-II mRNA were often seen to be colocalized, especially in the ductal cells and in metaplastic areas where atrophic acinar cells appeared to dedifferentiate into ductal structures. In contrast, CTGF was located in degenerating acinar cells and principally in fibroblasts surrounding these areas. Moreover, CTGF mRNA expression levels correlated positively with the degree of fibrosis in CP tissues. CONCLUSION: The concomitant overexpression of CTGF, collagen type I, TGF-beta1, and its signaling receptors in CP suggests that these proteins contribute to enhanced extracellular matrix synthesis and accumulation, resulting finally in the fibrogenesis observed in CP.

SR140333, a substance P receptor antagonist, influences morphological and motor changes in rat experimental colitis.

The etiology of inflammation, edema, and smooth muscle contraction characteristic of inflammatory bowel disease is not clearly understood. There is evidence that several neuropeptides, including substance P (SP), may play a role. In this study we evaluated the ability of a SP-antagonist (SR140333) to modify the course of experimental colitis induced in the rat by trinitrobenzene sulfonic acid (TNB). Colitis was induced in 24 rats using TNB applied by intrarectal enema. Twelve TNB-treated rats received SR140333, 0.1 mg/kg intraperitoneally, 30 min before the administration of TNB and every 48 hr until death. Twelve rats receiving only intrarectal 0.9% saline served as controls. Rats of each group were killed after 14 days. At day 14, the control group showed no signs of inflammation whereas the TNB-treated rats without SR140333 treatment exhibited a well-established colitis. The TNB-treated group had a higher level of inflammation, as seen histologically and by the significantly greater weight of colon strips, compared to the controls (0.30 +/- 0.09 g vs 0.13 +/- 0.03 g, P < 0.001) and to the SR140333-treated rats (0.30 +/- 0.09 g vs 0.14 +/- 0.05 g, P < 0.001). In addition, smooth muscle contractility was significantly reduced in the inflamed colons of TNB-treated rats when compared with the controls (carbachol: 42.7 +/- 20.3 vs 254.2 +/- 69.78 mg/mm2; SP: 18.5 +/- 10.02 vs 89.45 +/- 23.17 mg/mm2; KCl: 11.4 +/- 2.2 vs 98.32 +/- 33.57 mg/mm2, P < 0.01). However, SR140333-treated rats showed a recovery from inflammation and motor alterations caused by TNB (carbachol: 150.9 +/- 46.1 mg/mm2, P < 0.01; SP: 32.5 +/- 9.4 mg/mm2, P < 0.05; KCl: 125.7 +/- 36.1 mg/mm2, P < 0.01). In conclusion, treatment with SP antagonist SR140333 reduces the severity of colitis and has beneficial effects on the concomitant alterations of contractility. Thus, the blockade of substance P may represent a possibility in the treatment of intestinal inflammation.

Transforming growth factor-betas and their signaling receptors are coexpressed in Crohn's disease.

OBJECTIVE: To evaluate mechanisms that contribute to tissue repair and tissue remodeling in Crohn's disease (CD). SUMMARY BACKGROUND DATA: Transforming growth factor-betas (TGF-betas) are involved in different chronic inflammatory disorders. They function by binding to two receptors, type I (TbetaR-I) subtype ALK5 and type II (TbetaR-II), which are concomitantly required for signal transduction. METHODS: Tissues were obtained from 18 patients with CD (10 female patients, 8 male patients, median age 38.7 years [range 16 to 58 years]) undergoing surgery because of CD-related complications. Tissue samples of 18 healthy organ donors (10 female subjects, 8 male subjects, median age 50.3 years [range 15 to 65 years]) served as controls. The expression and localization of TGF-beta1, TGF-beta2, TGF-beta3, TbetaR-IALK5, TbetaR-II, and TbetaR-III were studied by Northern blot analysis, in situ hybridization, and immunohistochemistry. RESULTS: On Northern blot analysis, 94% of the CD samples exhibited enhanced TGF-beta1, TGF-beta3, and TbetaR-II mRNA expression compared with controls. TGF-beta2 was increased in 72%, TbetaR-IALK5 in 72%, and TbetaR-III in 82% of the patients with CD. On in situ hybridization and immunohistochemical analysis, TGF-beta1, TbetaR-IALK5, and TbetaR-II were seen to be colocalized in the lamina propria cells and in the lymphocytes closest to the luminal surface, but also in the remaining epithelial cells, and in fibroblasts of CD tissue samples. CONCLUSIONS: The concomitant overexpression of TGF-betas and their signaling receptors in CD points to a potential role of these regulatory molecules in the pathophysiology of CD. Activation of TGF-beta-mediated pathways might promote the repair of mucosal injury by enhancing the process of reepithelization, but might also contribute to extracellular matrix generation and subsequently to intramural fibrosis and intestinal obstruction.

KAI1, a new metastasis suppressor gene, is reduced in metastatic hepatocellular carcinoma.

Down-regulation of KAI1 expression has been shown to be associated with formation of metastases or disease progression in prostate and pancreatic cancer. In the present study we analyzed the expression pattern of KAI1 in metastatic and nonmetastatic hepatocellular carcinomas (HCCs) in comparison with normal livers to evaluate whether alteration of KAI1 also facilitates the metastatic ability in this malignancy. Thirty-nine primary HCCs and 10 normal liver tissue samples were studied for KAI1 messenger RNA (mRNA) expression with use of Northern blot analysis and in situ hybridization. By Northern blot analysis, moderate to strong KAI1 mRNA expression was present in normal liver samples. In contrast, KAI1 mRNA expression in tissue samples of primary HCCs was markedly decreased compared with normal controls. The normal/tumor ratio of KAI1 mRNA expression was 2.6:1 (P <.01). Primary HCCs that gave rise to metastasis showed significantly lower KAI1 mRNA levels than nonmetastasized HCCs (P <. 05). As seen by in situ hybridization, moderate to strong cytoplasmic KAI1 mRNA staining was present in almost all normal hepatocytes. Bile ducts, blood vessels, and connective tissue showed no or only faint KAI1 mRNA expression in the normal liver samples. In nonmetastatic HCCs, the cancer cells exhibited in situ hybridization signals that were similar to the normal controls. In contrast, most of the primary HCC cells in samples with metastases showed only faint or moderate KAI1 mRNA expression predominantly in the perinuclear regions. When KAI1 mRNA expression of primary hepatocellular cancer cells was compared with metastasized cancer cells in lymph nodes, with intrahepatic satellite metastasis, or with peritoneal metastasis in the same patients, significantly lower (P <.01) KAI1 mRNA levels were present in the metastasized HCC cells. Reduced KAI1 mRNA in HCC cells seems to influence their metastatic ability and thereby enhances the malignant potential of HCC.

Activation of the serine proteinase system in chronic kidney rejection.

BACKGROUND: Activation of the serine proteinase system is an important mechanism that contributes to tissue remodeling. In the present study, we analyzed the expression of urokinase plasminogen activator (uPA), urokinase plasminogen activator receptor (uPAR), and plasminogen activator inhibitor type 1 (PAI-1) in samples of chronically rejected human kidneys. METHODS: Using Northern blot analysis, immunohistochemistry, and a uPA activity assay, specimens from 10 chronically rejected kidneys and 10 normal kidney samples were analyzed. RESULTS: By Northern blot analysis, the expression of uPAR and PAI-1 mRNA was 2.9-fold (P<0.05) and 2.3-fold (P<0.05) increased in chronically rejected kidney samples, respectively, compared with normal controls. In contrast, uPA mRNA levels in chronically rejected kidneys were comparable to those in the normal controls. Immunohistochemical analysis in normal kidneys showed weak immunostaining of uPA, moderate to intense uPAR and PAI-1 immunostaining in proximal tubules, and moderate immunostaining in distal tubules, but no signal in the glomeruli or cortical vessels. A similar staining pattern was found in the distal and proximal tubules in rejected kidney tissue samples. However, in the rejected kidneys, the number of tubules was markedly reduced. In addition, within the glomeruli of rejected kidney samples, there was positive immunostaining for uPA, uPAR, and PAI-1 in the mesangial cells, but negative staining in most of the endothelial cells, whereas the normal kidneys revealed no immunoreactivity in these structures. CONCLUSION: The demonstrated up-regulation of uPA/uPAR/PAI-1 in chronic renal rejection is consistent with the plasminogen/plasmin system contributing to tissue remodeling in this disorder. These factors might activate latent transforming growth factor-betas, which have been reported to be enhanced in this disorder, contributing to the generation of the extracellular matrix.