Treatment response of colorectal cancer liver metastases to neoadjuvant or conversion therapy: a prospective multicentre follow-up study using MRI, diffusion-weighted imaging and 1H-MR spectroscopy compared with histology (subgroup in the RAXO trial)

BACKGROUND

Colorectal cancer liver metastases respond to chemotherapy and targeted agents not only by shrinking, but also by morphologic and metabolic changes. The aim of this study was to evaluate the value of advanced magnetic resonance imaging (MRI) methods in predicting treatment response and survival.

PATIENTS AND METHODS

We investigated contrast-enhanced MRI, apparent diffusion coefficient (ADC) in diffusion-weighted imaging and 1H-magnetic resonance spectroscopy (1H-MRS) in detecting early morphologic and metabolic changes in borderline or resectable liver metastases, as a response to first-line neoadjuvant or conversion therapy in a prospective substudy of the RAXO trial (NCT01531621, EudraCT2011-003158-24). MRI findings were compared with histology of resected liver metastases and Kaplan-Meier estimates of overall survival (OS).

RESULTS

In 2012-2018, 52 patients at four Finnish university hospitals were recruited. Forty-seven patients received neoadjuvant or conversion chemotherapy and 40 liver resections were carried out. Low ADC values (below median) of the representative liver metastases, at baseline and after systemic therapy, were associated with partial response according to RECIST criteria, but not with morphologic MRI changes or histology. Decreasing ADC values following systemic therapy were associated with improved OS compared to unchanged or increasing ADC, both in the liver resected subgroup (5-year OS rate 100% and 34%, respectively, P = 0.022) and systemic therapy subgroup (5-year OS rate 62% and 23%, P = 0.049). 1H-MRS revealed steatohepatosis induced by systemic therapy.

CONCLUSIONS

Low ADC values at baseline or during systemic therapy were associated with treatment response by RECIST but not with histology, morphologic or detectable metabolic changes. A decreasing ADC during systemic therapy is associated with improved OS both in all patients receiving systemic therapy and in the resected subgroup.

The Mutational Profile of Unicystic Ameloblastoma

BRAF V600E is the most common mutation in conventional ameloblastoma (AM) of the mandible. In contrast, maxillary AMs appear to harbor more frequently RAS, FGFR2, or SMO mutations. Unicystic ameloblastoma (UAM) is considered a less aggressive variant of ameloblastoma, amenable to more conservative treatment, and classified as a distinct entity. The aim of this study was to characterize the mutation profile of UAM ( n = 39) and to compare it to conventional AM ( n = 39). The associations between mutation status and recurrence probability were also analyzed. In the mandible, 94% of UAMs (29/31, including 8/8 luminal, 6/8 intraluminal, and 15/15 mural subtypes) and 74% of AMs (28/38) revealed BRAF V600E mutations. Among the BRAF wild-type cases, 1 UAM showed a missense SMO mutation (p.L412F), whereas 2 NRAS (p.Q61R), 2 HRAS (p.Q61R), and 2 FGFR2 (p.C383R) activating mutations were identified in AM. Of the 3 maxillary UAMs, only 1 revealed a BRAF V600E mutation. Taken together, our findings demonstrate high frequency of activating BRAF V600E mutations in both UAM and AM of the mandible. In maxillary UAMs, the BRAF V600E mutation prevalence appears to be lower as was shown for AM previously. It could therefore be argued that UAM and AM are part of the spectrum of the same disease. AMs without BRAF V600E mutations were associated with an increased rate of local recurrence ( P = 0.0003), which might indicate that routine mutation testing also has an impact on prognosis.

Oncological results of extended resection for locally advanced rectal cancer: the value of postirradiation MRI in predicting local recurrence

AIM

The primary purpose of this study was to analyse the overall survival and local recurrence rate after extended resection of locally advanced rectal cancer. The second aim was to determine the ability of the response to radiological irradiation to predict R0 resection.

METHOD

A retrospective study was performed of 94 consecutive patients with locally advanced rectal cancer operated on at the Helsinki University Hospital, Helsinki, Finland between 2005 and 2013. Data were collected from patient records. All patients were treated with an en bloc resection. Sixty-two patients received preoperative long-term chemoradiotherapy.

RESULTS

The 30-day mortality was 3.2%. Local recurrence occurred in 10 (10.6%) patients. The cumulative 1-, 3- and 5-year overall survival to each year was 89.4%, 68.3% and 51.8%. The most important prognostic factor for both local recurrence (P = 0.006) and survival (P = 0.003) was an R0 resection. A poor or no response seen on posttreatment MRI predicted local recurrence (P = 0.045) and decreased disease-free survival in patients treated curatively (P = 0.052). The histological tumour regression grade was not associated with local recurrence or survival.

CONCLUSION

Multivisceral resection offers a 5-year survival of over 50% and local control of advanced rectal cancer in nearly 90% of carefully selected patients.

Diminished salivary epidermal growth factor secretion: a link between Sjögren's syndrome and autoimmune gastritis?

OBJECTIVES

Healthy human labial salivary glands produce epidermal growth factor (EGF). In Sjögren's syndrome (SS), EGF staining is diminished. SS is also associated with chronic autoimmune corpus gastritis. We therefore hypothesized that EGF secretion would be diminished in SS and that this could affect gastric target cells.

METHODS

Salivary EGF secretion in SS was compared to that in healthy controls using an enzyme-linked immunosorbent assay (ELISA). EGF receptor (EGFR) immunoreactive cells in the gastric corpus of healthy human subjects were analysed using immunostaining.

RESULTS

Salivary secretion of EGF was diminished in SS patients (232.4, range 52.6-618.4, vs. 756.6, range 105.3-1631.6 pg/min, p = 0.002). Proton-pump positive parietal cells were mostly EGFR immunoreactive whereas very few pepsinogen I (PGI)-positive cells were EGFR positive.

CONCLUSIONS

As EGF is relatively acid resistant, salivary gland-derived EGF might participate in an exo/endocrine mode of parietal cell maintenance in the gastric corpus. Deficiency of salivary gland-derived EGF in SS patients may cause impairment of gastric parietal cells resulting in exposure of immunogenic cryptic antigens and loss of immunological self-tolerance.

Repeated intratumoral administration of ONCOS-102 leads to systemic antitumor CD8+ T-cell response and robust cellular and transcriptional immune activation at tumor site in a patient with ovarian cancer

Adenoviruses are excellent immunotherapeutic agents with a unique ability to prime and boost immune responses. Recombinant adenoviruses cause immunogenic cancer cell death and subsequent release of tumor antigens for antigen presenting cells, resulting in the priming of potent tumor-specific immunity. This effect may be further enhanced by immune-stimulating transgenes expressed by the virus. We report a case of a 38-year-old female with Stage 3 metastatic micropapillary serous carcinoma of the ovary. She was treated in a Phase I study with a granulocyte-macrophage colony stimulating factor (GMCSF)-expressing oncolytic adenovirus, Ad5/3-D24-GMCSF (ONCOS-102). The treatment resulted in progressive infiltration of CD8⁺ lymphocytes into the tumor and concomitant systemic induction of several tumor-specific CD8⁺ T-cell populations. The patient was alive at the latest follow up more than 20 months after initiation of the study.

Feasibility of radical cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei of appendiceal origin

BACKGROUND AND AIMS

We analyzed the feasibility of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients with pseudomyxoma peritonei.

MATERIAL AND METHODS

A prospective database comprised 90 consecutive patients with demonstrable pseudomyxoma peritonei collected during 48 months. These patients, referred to our unit for consideration for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, received both cytoreductive surgery and hyperthermic intraperitoneal chemotherapy if possible. We evaluated the factors associated with a successful procedure.

RESULTS

Hyperthermic intraperitoneal chemotherapy was successfully delivered to 56 of 90 patients (62%) with demonstrable pseudomyxoma peritonei. Tumor morphology of low grade (p = 0.013), age under 65 years (p = 0.004), and serum carcinoembryonic antigen level under 5.0 µg/L (p = 0.003) were associated with successful administration of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Mean peritoneal cancer index was lower (18.9 vs 32.6, p < 0.001) and age was younger (54.3 vs 61.6, p = 0.003) in patients who underwent hyperthermic intraperitoneal chemotherapy than in patients who did not. Four patients had complete cytoreductive surgery alone, and 20 patients underwent palliative debulking, but 10 were ineligible for this operation.

CONCLUSIONS

Although the combination of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is currently suggested the standard practice for pseudomyxoma peritonei, not all patients are eligible for this protocol. In this study, hyperthermic intraperitoneal chemotherapy was suitable for 62% of patients with pseudomyxoma peritonei of appendiceal origin.

Macrophage metalloelastase (MME) as adjuvant for intra-tumoral injection of oncolytic adenovirus and its influence on metastases development

Oncolytic adenoviruses are a promising treatment alternative for many advanced cancers, including colorectal cancer. However, clinical trials have demonstrated that single-agent therapy in advanced tumor masses is rarely curative. Poor spreading of the virus through tumor tissue is one of the major issues limiting efficacy. As oncolytic viruses kill preferentially cancer cells, high extracellular matrix (ECM) content constitutes potential barriers for viral penetration within tumors. In this study, the ECM-degrading proteases relaxin, hyaluronidase, elastase and macrophage metalloelastase (MME) were tested for their antitumor efficacy alone and in combination with oncolytic adenovirus. MME improved the overall antitumor efficacy of oncolytic adenovirus in subcutaneous HCT116 xenografts. In a liver metastatic colorectal cancer model, intra-tumoral treatment of primary tumors from HT29 cells with MME monotherapy or with oncolytic adenovirus inhibited tumor growth. Combination therapy showed no increased mortality in comparison with either monotherapy alone. Contradictory results of effects of MME on tumorigenesis and metastasis formation have been reported in the literature. This study demonstrates for the first time in a metastatic animal model that MME, as a monotherapy or in combination with oncolytic virus, does not increase tumor invasiveness. Co-administration of MME and oncolytic adenovirus may be a suitable approach for further optimization aiming at clinical applications for metastatic colorectal cancer.

Prognostic role of CIP2A expression in serous ovarian cancer

Background:

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an oncoprotein expressed in several solid cancers. Our purpose was to study its role in serous ovarian cancer patients, and the association to clinicopathological variables and molecular markers.

Methods:

We collected retrospectively 562 consecutive serous ovarian cancer patients treated at the Helsinki University Central Hospital. We stained tumour tissue microarrays for CIP2A by immunohistochemistry and constructed survival curves according to the Kaplan–Meier method. Associations to clinicopathological and molecular markers were assessed by the χ²-test.

Results:

We found strong cytoplasmic CIP2A immunoreactivity in 212 (40.4%) specimens, weak positivity in 222 (42.4%) specimens, and negative in 90 (17.2%). Immunopositive CIP2A expression was associated with high grade (P<0.0001), advanced stage (P=0.0005), and aneuploidy (P=0.001, χ²-test). Cancerous inhibitor of protein phosphatase 2A overexpression was also associated with EGFR protein expression (P=0.006) and EGFR amplification (P=0.043). Strong cytoplasmic CIP2A immunopositivity predicted poor outcome in ovarian cancer patients (P<0.0001, log-rank test).

Conclusion:

Our results show that CIP2A associates with reduced survival and parameters associated with high grade in ovarian cancer patients, and may thus be one of the factors that identify aggressive subtype (type II) of this disease.

High CIP2A immunoreactivity is an independent prognostic indicator in early-stage tongue cancer

BACKGROUND

No reliable prognostic markers exist for squamous cell carcinoma of the tongue, and its prognosis can even in early stages be unpredictable and survival poor despite treatment. A potential marker is oncoprotein cancerous inhibitor of PP2A (CIP2A), which acts as a prognostic marker in gastric and non-small cell lung cancers.

METHODS

We collected specimens of 73 stage T1N0M0 and T2N0M0 oral squamous cell carcinomas of the tongue, as well as samples from normal oral mucosa, dysplastic lesions, and invasive carcinomas (n=39). All samples were stained for CIP2A by immunohistochemistry. Survival curves were constructed according to the Kaplan-Meier method. The Cox proportional hazard model served for univariate and multivariate survival analysis.

RESULTS

High CIP2A immunoreactivity predicted poor survival in tongue cancer patients (P=0.027, logrank test). In multivariate survival analysis, CIP2A was an independent prognostic factor (HR 2.02, 95% confidence interval 1.07-3.82, P=0.030). Cytoplasmic CIP2A expression was higher in severe dysplasia than in mild dysplasia.

CONCLUSION

Our results suggest that high CIP2A expression characterises aggressive disease. Acting as a prognostic marker it might be of help when choosing patients for adjuvant treatment in tongue cancer patients.

Risk of cancer in patients with chronic pouchitis after restorative proctocolectomy for ulcerative colitis

AIM

The aim of this study was to evaluate the consequences of chronic pouchitis after restorative proctocolectomy for ulcerative colitis.

METHOD

Forty-two patients with chronic pouchitis underwent pouch endoscopy with biopsies after a median of 8.3 years of postoperative follow up. The pouchitis disease activity index (PDAI) was calculated. Morphological changes were recorded. Immunohistochemical analyses for cyclooxygenase 2 (COX-2), Ki-67 and p53 were performed, as was DNA flow cytometry. Endoscopy was also carried out in 10 patients without pouchitis and in nine healthy subjects.

RESULTS

In patients with chronic pouchitis, the PDAI was 6 (standard error of the mean ± 4). Eighteen (43%) patients used continuous medication. The PDAI correlated positively with villous atrophy (P < 0.05). None of the pouch biopsies showed dysplasia. COX-2 immunostaining was detected in 35 (83.3%) patients with chronic pouchitis, in five (50%) without pouchitis, but in none of the normal controls. COX-2 expression correlated with mucosal atrophy (P < 0.01). In 15 (35.7%) of 42 patients with chronic pouchitis, Ki-67 immunostaining was increased, but no increase was observed in either control group (P < 0.002). No p53 immunopositivity was found, and DNA flow cytometry was normal in all pouches. One of the patients developed adenocarcinoma at the anal anastomosis.

CONCLUSION

No dysplastic changes were detected during the first decade after surgery. Routine follow up of patients with chronic pouchitis with a hand-sewn anastomosis may not be necessary, although a small risk of cancer seems to remain at the anal anastomosis. The follow up should be focused on at-risk groups.

Prolonged systemic circulation of chimeric oncolytic adenovirus Ad5/3-Cox2L-D24 in patients with metastatic and refractory solid tumors

Eighteen patients with refractory and progressive solid tumors were treated with a single round of triple modified oncolytic adenovirus (Ad5/3-Cox2L-D24). Ad5/3-Cox2L-D24 is the first non-Coxsackie-adenovirus receptor-binding oncolytic adenovirus used in humans. Grades 1-2 flu-like symptoms, fever, and fatigue were seen in most patients, whereas transaminitis or thrombocytopenia were seen in some. Non-hematological grades 3-5 side effects were seen in one patient with grade 3 ileus. Treatment resulted in high neutralizing antibody titers within 3 weeks. Virus appeared in serum 2-4 days after treatment in 83% of patients and persisted for up to 5 weeks. One out of five radiologically evaluable patients had partial response (PR), one had minor response (MR), and three had progressive disease (PD). Two patients scored as PD had a decrease in tumor density. Tumor reductions not measurable with Response Evaluation Criteria In Solid Tumors (RECIST) were seen in a further four patients. PR, MR, stable disease, and PD were seen in 12, 23.5, 35, and 29.5% of tumor markers analyzed, respectively (N=17). Ad5/3-Cox2L-D24 appears safe for treatment of cancer in humans and extended virus circulation results from a single treatment. Objective evidence of anti-tumor activity was seen in 11/18 (61%) of patients. Clinical trials are needed to extend these findings.

Collagenase-2 (matrix metalloproteinase-8) plays a protective role in tongue cancer

Squamous cell carcinoma (SCC) of the tongue is the most common cancer in the oral cavity and has a high mortality rate. A total of 90 mobile tongue SCC samples were analysed for Bryne's malignancy scores, microvascular density, and thickness of the SCC sections. In addition, the staining pattern of cyclooxygenase-2, αvβ6 integrin, the laminin-5 γ2-chain, and matrix metalloproteinases (MMPs) -2, -7, -8, -9, -20, and -28 were analysed. The expression of MMP-8 (collagenase-2) was positively associated with improved survival of the patients and the tendency was particularly prominent in females. No sufficient evidence for a correlation with the clinical outcome was found for any other immunohistological marker. To test the protective role of MMP-8 in tongue carcinogenesis, MMP-8 knockout mice were used. MMP-8 deficient female mice developed tongue SCCs at a significantly higher incidence than wild-type mice exposed to carcinogen 4-Nitroquinoline-N-oxide. Consistently, oestrogen-induced MMP-8 expression in cultured HSC-3 tongue carcinoma cells, and MMP-8 cleaved oestrogen receptor (ER) α and β. According to these data, we propose that, contrary to the role of most proteases produced by human carcinomas, MMP-8 has a protective, probably oestrogen-related role in the growth of mobile tongue SCCs.

The DNA damage signalling kinase ATM is aberrantly reduced or lost in BRCA1/BRCA2-deficient and ER/PR/ERBB2-triple-negative breast cancer

The ataxia-telangiectasia-mutated (ATM) kinase is a key transducer of DNA damage signals within the genome maintenance machinery and a tumour suppressor whose germline mutations predispose to familial breast cancer. ATM signalling is constitutively activated in early stages of diverse types of human malignancies and cell culture models in response to oncogene-induced DNA damage providing a barrier against tumour progression. As BRCA1 and BRCA2 are also components of the genome maintenance network and their mutations predispose to breast cancer, we have examined the ATM expression in human breast carcinomas of BRCA1/2 mutation carriers, sporadic cases and familial non-BRCA1/2 patients. Our results show that ATM protein expression is aberrantly reduced more frequently among BRCA1 (33%; P=0.0003) and BRCA2 (30%; P=0.0009) tumours than in non-BRCA1/2 tumours (10.7%). Furthermore, the non-BRCA1/2 tumours with reduced ATM expression were more often estrogen receptor (ER) negative (P=0.0002), progesterone receptor (PR) negative (P=0.004) and were of higher grade (P=0.0004). In our series of 1013 non-BRCA1/2 cases, ATM was more commonly deficient (20%; P=0.0006) and p53 was overabundant (47%; P<0.0000000001) among the difficult-to-treat ER/PR/ERBB2-triple-negative subset of tumours compared with cases that expressed at least one of these receptors (10 and 16% of aberrant ATM and p53, respectively). We propose a model of 'conditional haploinsufficiency' for BRCA1/2 under conditions of enhanced DNA damage in precancerous lesions resulting in more robust activation and hence increased selection for inactivation or loss of ATM in tumours of BRCA1/2 mutation carriers, with implications for genomic instability and curability of diverse subsets of human breast cancer.

Decreased xanthine oxidoreductase is a predictor of poor prognosis in early-stage gastric cancer

BACKGROUND

Xanthine oxidoreductase (XOR) is a key enzyme in the degradation of DNA, RNA and high-energy phosphates. About half of the patients with breast cancer have a decrease in XOR expression. Patients with breast cancer with unfavourable prognosis are independently identified by the loss of XOR.

AIM

To assess the clinical relevance of XOR expression in gastric cancer.

METHODS

XOR levels were studied by immunohistochemistry in tissue microarray specimens of 337 patients with gastric cancer and the relation between XOR expression and a series of clinicopathological variables, as well as disease-specific survival, was assessed.

RESULTS

XOR was moderately decreased in 41% and was undetectable in another 14% of the tumours compared with the corresponding normal tissue. Decreased XOR was associated with advanced stage, deep tumour penetration, diffusely spread tumour location, positive lymph node status, large tumour size, non-curative disease, cellular aneuploidy, high S-phase fraction and high cyclooxygenase-2 expression, but not with p53 expression or Borrmann classification. Down regulation of XOR was associated with unfavourable outcome, and the cumulative 5-year gastric cancer-specific survival in patients with strong XOR expression was 47%, compared with 22% in those with moderate to negative expression (p<0.001). This was also true in patients with stage I-II (p = 0.01) and lymph node-negative (p = 0.02) disease, as well as in patients with smaller (< or =5 cm) tumours (p = 0.02).

CONCLUSION

XOR expression in gastric cancer may be a new marker for a more aggressive gastric cancer biology, similar to that previously reported for breast cancer.

MMP-2 but not MMP-9 associated with COX-2 and survival in gastric cancer

BACKGROUND AND AIM

Matrix metalloproteinases (MMPs) MMP-2 and MMP-9 can degrade type IV collagen of extracellular matrix and basal membranes. As cyclo-oxygenase-2 (COX-2) has been shown to activate MMPs, creating one of the COX-2-promoted pathways of tumour growth and metastasis, the prognostic role of MMP-2 and MMP-9 in gastric cancer was assessed and their association with COX-2 expression was evaluated.

MATERIALS AND METHODS

Samples were collected from 342 consecutive patients operated on for gastric cancer, of which 315 were acceptable for MMP-2, MMP-9 and COX-2 immunohistochemistry. Specimens were stained with specific antibodies, evaluated and categorised by two interpreters, and then correlated with clinical data and survival.

RESULTS

Epithelial MMP-2 immunoreactivity was associated with male sex, high stage, advanced penetration depth, non-curative surgery, high COX-2 expression and poor survival. Stromal MMP-2 expression correlated with high stage, intestinal type and non-curative surgery whereas MMP-9 correlated only with intestinal type. Stage, intent of surgery and COX-2 were independent prognostic factors.

CONCLUSIONS

Epithelial MMP-2 expression in gastric cancer is associated with aggressive forms, COX-2 and poor survival, although MMP-2 was not an independent prognostic factor. In gastric cancer tumour growth is apparently induced by COX-2, and invasion is mediated by MMP-2.

A heparan sulfate-targeted conditionally replicative adenovirus, Ad5.pk7-Delta24, for the treatment of advanced breast cancer

Conditionally replicating adenoviruses (CRAds) that replicate in tumor but less in normal cells are promising anticancer agents. A major determinant of their potency is their capacity for infecting target cells. The primary receptor for serotype 5 adenovirus (Ad5), the most widely used serotype in gene therapy, is the coxsackie-adenovirus receptor (CAR). CAR is expressed variably and often at low levels in various tumor types including advanced breast cancer. We generated a novel p16/retinoblastoma pathway-dependent CRAd, Ad5.pK7-Delta24, with a polylysine motif in the fiber C-terminus, enabling CAR-independent binding to heparan sulfate proteoglycans (HSPG). Ad5.pK7-Delta24 mediated effective oncolysis of all breast cancer cell lines tested. Further, we utilized noninvasive, fluorescent imaging for analysis of antitumor efficacy in an orthotopic model of advanced hormone refractory breast cancer. A therapeutic benefit was seen following both intratumoral and intravenous delivery. Murine biodistribution similar to Ad5, proven safe in trials, suggests feasibility of clinical safety testing. Interestingly, upregulation of CAR was seen in low-CAR M4A4-LM3 breast cancer cells in vivo, which resulted in better than expected efficacy also with an isogenic CRAd with an unmodified capsid. These results suggest utility of Ad5.pK7-Delta24 and the orthotopic model for further translational studies.

Cyclooxygenase-2 expression correlates with poor prognosis in pancreatic cancer

BACKGROUND

Cyclooxygenase-2 (COX-2) overexpression is related to poor outcome in several cancers. COX-2 is upregulated in 42-90% of pancreatic ductal adenocarcinomas and is a potential target for chemotherapy. Earlier studies have not shown the expression of COX-2 to be a prognostic factor in pancreatic cancer.

OBJECTIVE

To evaluate the prognostic value of COX-2 in a series of patients with pancreatic adenocarcinoma.

METHODS

128 patients operated on for pancreatic adenocarcinoma at Helsinki University Central Hospital between 1974 and 1998 provided sections from primary tumours which were immunohistochemically stained with a COX-2-antihuman monoclonal antibody.

RESULTS

Cytoplasmic COX-2 reactivity (>5%) occurred in 46 specimens (36%), correlating neither with age, sex, stage, size, tumour stage, nodal metastases, nor grade. Lack of COX-2 expression correlated with distant metastases (p = 0.026). In univariate survival analysis, COX-2 expression (p = 0.0114), stage (p = 0.0002), grade (p = 0.0001), and age (p = 0.042) had prognostic significance. One, two, and five year survival rates were 51%, 32%, and 8% in the COX-2 negative groups compared with 34%, 5%, and 5% in the COX-2 positive groups (p = 0.011). Prognostic significance was especially high for patients operated on with curative intent (p = 0.004). In multivariate analysis, COX-2 was an independent prognostic factor (hazard ratio = 1.6 (95% confidence interval, 1.1 to 2.3)).

CONCLUSIONS

Expression of COX-2 was associated with poor outcome from pancreatic ductal adenocarcinoma and was independent of tumour stage, grade, or age in multivariate analysis.

Non-steroidal anti-inflammatory drugs and the risk of oral cancer: a nested case-control study

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) seem to prevent several types of cancer, but could increase the risk of cardiovascular complications. We investigated whether use of NSAIDs was associated with a change in the incidence of oral cancer or overall or cardiovascular mortality.

METHODS

We undertook a nested case-control study to analyse data from a population-based database (Cohort of Norway; CONOR), which consisted of prospectively obtained health data from all regions of Norway. People with oral cancer were identified from the 9241 individuals in CONOR who were at increased risk of oral cancer because of heavy smoking (15 pack-years), and matched controls were selected from the remaining heavy smokers (who did not have cancer).

FINDINGS

We identified and analysed 454 (5%) people with oral cancer (279 men, 175 women, mean [SD] age at diagnosis 63.3 [13.2] years) and 454 matched controls (n=908); 263 (29%) had used NSAIDs, 83 (9%) had used paracetamol (for a minimum of 6 months), and 562 (62%) had used neither drug. NSAID use (but not paracetamol use) was associated with a reduced risk of oral cancer (including in active smokers; hazard ratio 0.47, 95% CI 0.37-0.60, p<0.0001). Smoking cessation also lowered the risk of oral cancer (0.41, 0.32-0.52, p<0.0001). Additionally, long-term use of NSAIDs (but not paracetamol) was associated with an increased risk of cardiovascular-disease-related death (2.06, 1.34-3.18, p=0.001). NSAID use did not significantly reduce overall mortality (p=0.17).

INTERPRETATION

Long-term use of NSAIDs is associated with a reduced incidence of oral cancer (including in active smokers), but also with an increased risk of death due to cardiovascular disease. These findings highlight the need for a careful risk-benefit analysis when the long-term use of NSAIDs is considered.

Expression of COX-2 is increased with age in papillary thyroid cancer

AIMS

To study cyclooxygenase-2 (COX-2) and matrix metalloproteinase-2 (MMP-2) expression in papillary thyroid cancer (PTC). Expression of COX-2 is elevated in various human tumours and it has an important role in carcinogenesis. MMP-2 is also an important component of the metastatic potential of tumours. In PTC the most important factor affecting survival is age, but it is poorly understood why older PTC patients have a worse prognosis.

METHODS AND RESULTS

This retrospective study comprised 108 patients with PTC, and we compared patients who were either younger than 35 (n = 59) or older than 55 (n = 49). Paraffin-embedded tumour samples were analysed for COX-2 and MMP-2 protein expression using immunohistochemistry. High (scores 2-3) COX-2 immunostaining was observed in 38/108 (35%) of the tumours, and COX-2 expression was significantly (P = 0.002) higher in the older age group (25/49; 51%) than in the young one (13/59; 22%).

CONCLUSIONS

Our study shows that COX-2 expression increases with age. It is possible that the age-related increase in COX-2 expression could explain the more aggressive behaviour of PTC in the older age group compared with the young one.

Cell-cell contacts trigger programmed necrosis and induce cyclooxygenase-2 expression

Necrosis was induced by cell-cell contacts of human dermal fibroblasts in three-dimensional culture. Dramatic induction of cyclooxygenase-2 (COX-2) expression was found throughout these necrotizing cell clusters, whereas no increase in expression of apoptosis markers was seen. The cells were rapidly committed to necrosis, and the process could not be reversed by allowing them to spread and adhere on a solid substrate. Induction of COX-2 expression was accompanied by greatly enhanced production of the prostaglandins E(2), I(2), and F(2alpha). When applied exogenously on necrotizing clusters, these prostaglandins delayed cell clustering and further enhanced COX-2 expression. Abolishing prostaglandin production by NS-398 or indomethacin reduced cell membrane damage (as measured by lactate dehydrogenase release into the culture medium). We also identified alpha-enolase-mediated plasminogen activation as the major extracellular proteolytic executor of necrotic cell death. In contrast to inhibition of COX-2, inhibition of plasminogen activation failed to inhibit membrane damage associated with necrosis. Intracellular proteolysis, by caspases, was shown to take part in COX-2 induction. Taken together, our results indicate that cell-cell contacts induce an actively programmed necrotic process that functionally involves COX-2, a known hallmark of inflammation and cancer.

COX-2 expression in striated muscle under physiological conditions

OBJECTIVES

The role of cyclooxygenase-2 (COX-2) in disease has been extensively studied, (Annu Rev Med (2002) 53:35; N Engl J Med (2001) 345:433) but less information is available with respect to possible physiological functions of COX-2. Information on how and where COX-2 is expressed under physiological conditions may increase our understanding of its physiological role. Previous studies have revealed a COX-2 dependent production of prostanoids under physiological conditions, without entirely determining the source of this production.

MATERIALS AND METHODS

To assess COX-2 expression under normal conditions, we analyzed tissue specimens that were removed from 30 healthy study subjects in conjunction with surgical procedure related to insertion of dental implants and from three patients which had muscle tissue from Quadriceps femoris muscle removed as part of surgical treatment of soft tissue sarcomas not directly affecting the muscle tissue. Immunohistochemistry and immunoblotting (Western blotting) was used to assess the presence of COX-2 protein.

RESULTS

In 25 of 30 patients (83%), COX-2 protein was expressed in striated muscle, as assessed by immunohistochemistry. All cases had COX-2 expression verified by Western blotting. In none of the 25 subjects with COX-2 expression did we notice concomitant inflammation of the adjacent submucosal tissue.

CONCLUSIONS

It is a novel finding that COX-2 is expressed in striated muscle under physiological conditions. COX-2 activity in striated muscle is a possible explanation for the hitherto unknown localization of prostanoids synthesis under physiological conditions.

Role of cyclooxygenase-2 in the development and treatment of oesophageal adenocarcinoma

BACKGROUND

Various studies suggest that aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) are promising anticancer agents. Epidemiological studies have found that long-term use of NSAIDs is associated with a reduced incidence of colorectal, gastric and oesophageal cancers, while experimental and clinical studies have demonstrated that treatment with NSAIDs causes a statistically significant reduction in both the number and the size of polyps in familial adenomatous polyposis (FAP) patients.

METHODS

In this review, the mechanisms by which NSAIDs exert their chemopreventive and antineoplastic effects are described.

RESULTS

Although the precise anticancer actions of NSAIDs are not fully explained, they probably involve inhibition of cyclooxygenase (COX), which is the rate-limiting enzyme in the conversion of arachidonic acid to prostaglandins. Two isoforms of this enzyme (COX-1 and COX-2) have been identified. COX-1 is constitutively expressed and considered to be a housekeeping gene, while COX-2 is not usually detectable in normal tissues, but can be readily induced in processes like inflammation, reproduction and carcinogenesis. The mechanisms by which COX-2 is thought to be involved in the carcinogenesis include resisting apoptosis, increasing cell proliferation, stimulating angiogenesis and modulating the invasive properties of cancer cells.

CONCLUSION

This report reviews the mechanisms by which COX-2 can contribute to carcinogenesis, its role in prognosis, and the possible place of selective COX-2 inhibitors in the prevention and treatment of gastrointestinal malignancies, focusing particularly on oesophageal cancer.

Comparison of cyclooxygenase 2 expression in adenocarcinomas of the gastric cardia and distal oesophagus

BACKGROUND

Adenocarcinomas of the gastric cardia and distal oesophagus are at present often considered as one clinical entity because of their comparable increasing incidence, prognosis, and optimal treatment options. However, it is still a matter of debate whether these malignancies have the same pathogenesis and genotype.

AIMS

The aim of this study was to analyse expression of cyclooxygenase 2 (COX-2) in cardia carcinomas, and correlate this expression with clinicopathological parameters and survival. The results were compared with the prognostic value of COX-2 found for Barrett carcinomas.

METHODS

Tumour sections of 134 consecutive patients undergoing potentially curative surgery for an adenocarcinoma of the gastric cardia and substantially invading the distal oesophagus were immunohistochemically stained using a COX-2 monoclonal antibody. Specimens were blindly scored based on intensity and extent of COX-2 immunopositivity.

RESULTS

COX-2 expression was negative to weak in 59% ("COX-2 low") and moderate to strong in 41% ("COX-2 high") of tumours. This was significantly lower than in Barrett carcinomas (p<0.0001). COX-2 expression was not correlated with any clinicopathological parameter. A correlation between elevated COX-2 expression and reduced survival, as described for Barrett carcinomas, was not identified for cardiac carcinomas.

CONCLUSIONS

There is a difference in COX-2 expression with respect to intensity and prognostic significance between adenocarcinomas of the gastric cardia and distal oesophagus. This suggests a different pathogenesis and different genetic constitution of these two cancers. Based on these findings, the role of selective COX-2 inhibitors in the treatment of adenocarcinomas of the gastric cardia is less promising than in Barrett carcinomas.

DNA copy number changes in young gastric cancer patients with special reference to chromosome 19

Only a few cytogenetic and genetic studies have been performed in gastric cancer patients in young age groups. In the present study we used the comparative genomic hybridisation (CGH) method to characterise frequent DNA copy number changes in 22 gastric cancer patients of 45 years or younger and three gastric cancer cell lines established from patients younger than 45 years. Analysis of DNA copy number changes revealed frequent DNA copy number increases at chromosomes 17q (52%), 19q (68%) and 20q (64%). To confirm the CGH results and to characterise the amplicon region on the most frequently amplified chromosome, chromosome 19, we carried out fluorescence in situ hybridisation (FISH) analysis and Southern blot analysis. Fluorescence in situ hybridisation with the bacterial artificial chromosome (BAC) clone mapped to 19q12 indicated a copy number increase in all eight tumour specimens studied. Southern blot analysis of six tumour specimens and three tumour cell lines, with five probes mapped to the 19q12-13.2 region, suggested cyclin E to be one of the candidate target genes in the 19q region for gastric cancer tumorigenesis. Cyclin E protein overexpression was verified in tumours with amplification on chromosome 19. Further studies are required to investigate the biological and clinical significance of 19q amplicon and cyclin E upregulation in gastric cancer of young patients.

Expression of cyclooxygenase-2 in intestinal goblet cells of pre-diabetic NOD mice

Cyclooxygenase, the rate-limiting enzyme in prostaglandin synthesis, is expressed in constitutive (COX-1) and inducible (COX-2) isoforms. The COX-2 has been proposed to be involved in development of autoimmune type 1 diabetes (T1D). We examined COX-2 expression in the gut-associated lymphoid tissue (GALT), and found COX-2 was strongly expressed in goblet cells of non-obese diabetic (NOD) mice at the apical villi at the age of 2.5 weeks, clearly before the onset of insulitis, while the expression in the control BALB/c mice was weak or absent at all ages (P < 0.001). Lipopolysaccharide (LPS) given intraperitoneally slightly increased COX-2 expression in the goblet cells and epithelium of both NOD and BALB/c mice. High-resolution confocal microscopy showed that the surroundings of the goblet cells contained no COX-2, implying that the enzyme is synthesized by the goblet cells. The COX-2 is secreted from goblet cells into the intestinal lumen along with mucins. The COX-2 concentration in the goblet cell of BALB/c and especially of NOD mice was markedly higher than that in the intraepithelial lymphocytes or lamina propria macrophages. High mucin COX-2 from goblet cells may increase luminal prostaglandin synthesis, alter epithelial permeability, modulate intestinal immune responses and modify functional properties of the lymphocytes in the GALT, which all may be important for the initiation of the autoimmune phenomenon in the NOD mice.

Molecular analysis of sulindac-resistant adenomas in familial adenomatous polyposis

PURPOSE

Sulindac causes the reduction of adenomas in familial adenomatous polyposis (FAP) patients, but complete regression is unusual, and breakthrough of colorectal carcinoma during sulindac treatment has been described. The molecular features related to sulindac resistance are unknown. Therefore, we investigated molecular alterations in adenomas from FAP patients with complete adenoma regression on sulindac (responsive patients) and from FAP patients with sulindac-resistant adenomas (resistant patients).

DESIGN

Fourteen baseline adenomas (removed before sulindac treatment) from six responsive patients were studied. Also, 9 baseline adenomas and 34 resistant adenomas (removed during sulindac treatment) from three resistant patients were analyzed. Using immunohistochemistry, we evaluated the expression of beta-catenin, cyclooxygenase-2 (Cox-2), p53, Bcl-2, and Bax. K-ras codon 12 mutations, loss of heterozygosity at 5q (APC locus), and microsatellite instability were studied with PCR-based techniques.

RESULTS

There were no significant differences between baseline adenomas from sulindac-responsive and -resistant patients (P > 0.05). There was less loss of membranous beta-catenin staining and less nuclear beta-catenin accumulation in resistant adenomas compared with baseline adenomas from the same (sulindac-resistant) patients (P < 0.01) or baseline adenomas from responsive patients (P < 0.01). Epithelial Cox-2 expression was less, though not significant, in resistant adenomas compared with baseline adenomas from resistant patients, but was significantly less in baseline adenomas from responsive patients (P < 0.01). K-ras mutations were found in 8 of 34 resistant adenomas (24%) and in none of the baseline adenomas (P < 0.05). Stromal Cox-2 expression, staining of p53 and Bcl-2, and loss of heterozygosity at 5q were comparable in both groups. Loss of Bax staining and microsatellite instability were not found in any adenoma.

CONCLUSIONS

Sulindac-resistant adenomas display less alteration in beta-catenin staining and less epithelial Cox-2 expression when compared with adenomas removed before sulindac treatment. K-ras mutations may contribute to sulindac-resistance. Continued research is needed to investigate molecular alterations related to sulindac resistance.

Increased expression of cyclooxygenase-2 in malignant pheochromocytomas

Pheochromocytomas are rare tumors of the adrenal medulla or the paraganglion system. There are no histological or chemical markers available that define the malignant behavior of these tumors; so far only the discovery of metastases reveals malignancy. Cyclooxygenase (Cox) is the key enzyme in conversion of arachidonic acid to PGs, and two isoforms, Cox-1 and Cox-2, have been identified. Cox-2 has been associated with carcinogenesis, and it is overexpressed in many human malignancies. We have now investigated the expression of Cox-2 in normal adrenal gland, in 92 primary pheochromocytomas and in six metastases using immunohistochemistry and Northern blot and Western blot analyses. Cox-2 protein was expressed in the adrenal cortex, whereas the medulla was negative as detected by immunohistochemistry. Interestingly, all malignant pheochromocytomas (n = 8), regardless of the primary location of the tumor, showed moderate or strong Cox-2 immunoreactivity, whereas 75% of the benign adrenal tumors (n = 36) showed no or only weak immunopositivity. The staining was negative or weak in 79% of the adrenal tumors that showed histologically suspicious features (n = 24), but had not metastasized. Most of the pheochromocytoma samples studied also expressed low levels of Cox-2 mRNA. Our data show that normal adrenal medulla does not express Cox-2 immunohistochemically. However, strong Cox-2 protein expression was found in malignant pheochromocytomas, whereas most benign tumors expressed Cox-2 only weakly. To our knowledge, this is the first report on Cox-2 expression in pheochromocytomas and enhanced expression in malignant pheochromocytomas. These findings suggest that negative or weak Cox-2 expression in pheochromocytomas favors benign diagnosis.

Increased expression of cyclooxygenase-2 in malignant pheochromocytomas

Pheochromocytomas are rare tumors of the adrenal medulla or the paraganglion system. There are no histological or chemical markers available that define the malignant behavior of these tumors; so far only the discovery of metastases reveals malignancy. Cyclooxygenase (Cox) is the key enzyme in conversion of arachidonic acid to PGs, and two isoforms, Cox-1 and Cox-2, have been identified. Cox-2 has been associated with carcinogenesis, and it is overexpressed in many human malignancies. We have now investigated the expression of Cox-2 in normal adrenal gland, in 92 primary pheochromocytomas and in six metastases using immunohistochemistry and Northern blot and Western blot analyses. Cox-2 protein was expressed in the adrenal cortex, whereas the medulla was negative as detected by immunohistochemistry. Interestingly, all malignant pheochromocytomas (n = 8), regardless of the primary location of the tumor, showed moderate or strong Cox-2 immunoreactivity, whereas 75% of the benign adrenal tumors (n = 36) showed no or only weak immunopositivity. The staining was negative or weak in 79% of the adrenal tumors that showed histologically suspicious features (n = 24), but had not metastasized. Most of the pheochromocytoma samples studied also expressed low levels of Cox-2 mRNA. Our data show that normal adrenal medulla does not express Cox-2 immunohistochemically. However, strong Cox-2 protein expression was found in malignant pheochromocytomas, whereas most benign tumors expressed Cox-2 only weakly. To our knowledge, this is the first report on Cox-2 expression in pheochromocytomas and enhanced expression in malignant pheochromocytomas. These findings suggest that negative or weak Cox-2 expression in pheochromocytomas favors benign diagnosis.

Expression of cyclooxygenase-2 in dysplasia of the stomach and in intestinal-type gastric adenocarcinoma

PURPOSE

Cyclooxygenase (Cox) is the key enzyme in conversion of arachidonic acid to prostanoids. Two Cox genes have been cloned, and expression of Cox-2 mRNA and protein has been shown to be elevated in several human malignancies and in animal models of carcinogenesis. The purpose of this study was to investigate Cox-2 protein expression in human gastric dysplasias and adenocarcinomas.

EXPERIMENTAL DESIGN

Performance of several Cox-2 antibodies was evaluated, after which Cox-2 protein expression was studied in 67 gastric cancer specimens and in eight definitive dysplasias by using immunohistochemistry.

RESULTS

Cox-2 positivity was detected in 58% (25/43) of the intestinal-type (well-differentiated) tumors and 6% (1/18) of diffuse-type (poorly differentiated) tumors. Consistent with these data, we detected higher expression of Cox-2 mRNA, protein, and enzymatic activity in well-differentiated gastric cancer cell lines (MKN-28 and MKN-74) when compared with poorly differentiated cell lines (HSC-39 and KATO III). Cox-2 immunoreactivity was localized to the carcinoma cells, but the stroma of the tumors was negative. However, strong Cox-2 positivity was consistently detected in stromal cells at sites of erosions and ulcerations. Furthermore, four of nine (44%) definitive dysplasias of the stomach that showed no evidence of invasion were positive for Cox-2.

CONCLUSIONS

Cox-2 is expressed by the neoplastic cells in the intestinal-type gastric adenocarcinoma and by precarcinogenic (dysplastic) lesions leading to this disease.

Constant expression of cyclooxygenase-2 gene in prostate and the lower urinary tract of estrogen-treated male rats

Expression of cyclooxygenase-2 (E. C. 1.14.99.1) in prostate and the lower urinary tract (LUT) of the neonatally estrogenized male rat has been studied by using a COX-2's PCR fragment of 724 nt spanning 3 introns and a 478nt internal standard for quantitative RT-PCR. The same fragment of 724 nt was used for RNA probe in Northern hybridization. Neonatal estrogenization (10 microg/day of diethylstilbestrol on days 1-5) had no effect on COX-2 expression in prostatic urethra, prostatic lobes, or bladder. Acute estrogen treatment of castrated animals did not induce COX-2 expression, either. In addition the differential expression of basal level of COX-2 in the different lobes of prostate in normal rat was demonstrated. Our results suggest a constant expression of COX-2 gene in prostate and the lower urinary tract of the neonatally estrogenized (neoDES) rats. The present study indicates that the increased expression of COX-2 is probably not essential for the estrogen-driven development of stromal inflammation or hyperplastic and dysplastic alterations in the prostate of neoDES rats.

Regulated expression of prostaglandin E(2) receptors EP2 and EP4 in human ovarian granulosa-luteal cells

Prostaglandins (PGs) have been implicated in regulation of ovarian function. We have previously shown that the expression of cyclooxygenase-2 and the receptor for PGF(2 alpha) are expressed in periovulatory human granulosa cells and upregulated by gonadotropins and cytokines in cultured human ovarian granulosa-luteal (GL) cells. We now show that transcripts for PGE(2) receptor subtypes EP2 and EP4 are expressed in freshly isolated human granulosa cells and in mouse ovaries as detected by Northern blot analysis. However, EP2 and EP4 receptor mRNA levels were low or nondetectable in cultured human GL cells suggesting that these transcripts may be under hormonal and/or cytokine regulation in the ovaries in vivo. Indeed, the proinflammatory cytokine interleukin-1 beta (IL-1 beta) stimulated expression of EP2 and EP4 transcripts in concentration- and time-dependent manner in the GL cells. Furthermore, the transcript for EP2 receptor was localized in the corpus luteum of the mouse ovary by in situ hybridization, and EP2 protein was expressed in human corpus luteum as detected by immunohistochemistry. Our data suggest that IL-1 beta induces expression of EP2 and EP4 receptors in human GL cells, and that EP2 receptor is expressed in both human and murine luteal glands.

Expression of cyclooxygenase-2 in human transitional cell carcinoma of the urinary bladder

Recent studies suggest that expression of cyclooxygenase-2 (Cox-2) is elevated in transitional cell carcinoma (TCC) of the urinary bladder and that inhibition of Cox-2 activity suppresses bladder cancer in experimental animal models. We have investigated the expression of Cox-2 protein in human TCCs (n = 85), in in situ carcinomas (Tis) of the urinary bladder (n = 17), and in nonneoplastic urinary bladder samples (n = 16) using immunohistochemistry. Cox-2 immunoreactivity was detected in 66% (67 of 102) of the carcinomas, whereas only 25% (4 of 16) of the nonneoplastic samples were positive (P: < 0.005). Cox-2 immunoreactivity localized to neoplastic cells in the carcinoma samples. The rate of positivity was the same in invasive (T1-3; 70%, n = 40) and in noninvasive (Tis and Ta; 65%, n = 62) carcinomas, but noninvasive tumors had a higher frequency (32%) of homogenous pattern of staining (>90% of the tumor cells positive) than the invasive carcinomas (10%) (P: < 0.05). However, several invasive TCCs exhibited the strongest intensity of Cox-2 staining in the invading cells, whereas other parts of the tumor were virtually negative. Finally, strong Cox-2 positivity was also found in nonneoplastic ulcerations (2 of 2) and in inflammatory pseudotumors (2 of 2), in which the immunoreactivity localized to the nonepithelial cells. Taken together, our data suggest that Cox-2 is highly expressed in noninvasive bladder carcinomas, whereas the highest expression of invasive tumors associated with the invading cells, and that Cox-2 may also have a pathophysiological role in nonneoplastic conditions of the urinary bladder, such as ulcerations and inflammatory pseudotumors.

Expression of cyclooxygenase-2 and prostanoid receptors by human myometrium

Prostanoids play an important role in the regulation of parturition. All reproductive tissues, including fetal membranes, decidua, and myometrium, have the capacity to synthesize prostanoids, and fetal membranes have been shown to express elevated levels of cyclooxygenase-2 (Cox-2) at the onset of labor. We have now investigated the expression of Cox-2 in human myometrium. Myometrial samples collected from women in labor during lower segment cesarean section expressed 15-fold higher levels of Cox-2 messenger ribonucleic acid (mRNA) compared to myometrial specimens collected from women not in labor, as detected by Northern blot analysis. Immunohistochemical detection of Cox-2 protein showed cytoplasmic staining in the smooth muscle cells of the myometrium. Cultured myometrial cells expressed low levels of Cox-2 mRNA under baseline conditions, but interleukin-1beta (IL-1beta) caused a 17-fold induction of expression of the Cox-2 transcript after incubation for 6 h. IL-1beta also induced expression of biologically active Cox-2 protein, as detected by immunofluorescence, Western blot analysis, and measuring the conversion of arachidonic acid to prostanoids in the presence and absence of a Cox-2-selective inhibitor, NS-398. PGE2 receptor subtype EP2 mRNA was expressed in cultured myometrial smooth muscle cells, whereas transcripts for EP1, EP3, EP4, FP, and IP were low or below the detection limit as measured by Northern blot analysis. However, IL-1beta stimulated expression of EP4 receptor mRNA. Our data suggest that expression of Cox-2 transcript is elevated at the onset of labor in myometrial smooth muscle cells, which may depend on induction by cytokines. As, in addition to Cox-2, the expression of prostanoid receptors is regulated, not only the production of prostanoids, but also responsiveness to them, may be modulated.

The Bmx tyrosine kinase is activated by IL-3 and G-CSF in a PI-3K dependent manner

Cytoplasmic protein tyrosine kinases play crucial roles in signaling via a variety of cell surface receptors. The Bmx tyrosine kinase, a member of the Tec family, is expressed in hematopoietic cells of the granulocytic and monocytic lineages. Here we show that Bmx is catalytically activated by interleukin-3 (IL-3) and granulocyte-colony stimulating factor (G-CSF) receptors. Activation of Bmx required phosphatidylinositol 3-kinase (PI-3K) as demonstrated by the ability of PI-3K inhibitors to block the activation signal. A green fluorescent protein (GFP) tagged Bmx was translocated to cellular membranes upon co-expression of a constitutively active form of PI-3K, further indicating a role for PI-3K in signaling upstream of Bmx. The expression of wild type Bmx in 32D myeloid progenitor cells resulted in apoptosis in the presence of G-CSF, while cells expressing a kinase dead mutant of Bmx differentiated into mature granulocytes. However, Bmx did not modulate IL-3-dependent proliferation of the cells. These results demonstrate distinct effects of Bmx in cytokine induced proliferation and differentiation of myeloid cells, and suggest that the stage specific expression of Bmx is critical for the differentiation of myeloid cells. Oncogene (2000) 19, 4151 - 4158

Vascular endothelial growth factor in human preterm lung

Endothelial cell damage is characteristic for respiratory distress syndrome and development of chronic lung disease. Vascular endothelial growth factor (VEGF) is an endothelial mitogen that takes part in the growth and repair of vascular endothelial cells. We measured VEGF in 189 tracheal aspirate samples (TAF), and in 24 plasma samples from 44 intubated preterm infants (gestational age, 27.3 +/- 2.0 wk; birth weight, 962 +/- 319 g) during their first postnatal week. VEGF in TAF increased from 25 +/- 12 pg/ml (mean +/- SEM) on Day 1 to 526 +/- 120 pg/ml on Day 7 (mean concentrations, 106 +/- 25 pg/ml on Days 1 to 3 and 342 +/- 36 pg/ml on Days 4 to 7). In plasma, mean concentration of VEGF during the first week was 48 +/- 6 pg/ml, with no increase observed. In TAF, higher VEGF was found in patients born to mothers with premature rupture of the membranes, or chorionamnionitis, whereas preeclampsia of the mother was associated with lower VEGF (all p < 0.05). In TAF, no correlations existed between VEGF and gestational age or birth weight, but a correlation existed between lecithin/sphengomyelin ratio and VEGF (p < 0.05). During Days 4 to 7 patients developing bronchopulmonary dysplasia (BPD) had lower VEGF in TAF than did those surviving without BPD (235 +/- 31 versus 383 +/- 50; p < 0.05). VEGF increased rapidly in the lungs of the preterm infant during the first days of life. VEGF may be indicative of pulmonary maturity and may participate in pulmonary repair after acute lung injury.

Expression of cyclooxygenase-2 in human lung carcinoma

Epidemiological studies indicate that the use of aspirin decreases incidence of and mortality from gastrointestinal cancers. A major target of aspirin and other nonsteroid anti-inflammatory drugs is cyclooxygenase (Cox), the rate-limiting enzyme in the conversion of arachidonic acid to prostanoids. Two Cox genes have been cloned (Cox-1 and Cox-2), of which Cox-2 has recently been found to be expressed in several human carcinomas. We have now studied the expression of Cox-2 mRNA and protein in human lung adenocarcinoma, squamous cell carcinoma, and small cell lung cancer. Cox-2 mRNA steady-state levels were high in well-differentiated adenocarcinoma samples, but low in poorly differentiated adenocarcinoma, squamous cell carcinoma, and small cell lung cancer, as detected by Northern blot analysis. Immunohistochemistry showed Cox-2 staining in 19 of 21 adenocarcinomas. However, well-differentiated adenocarcinomas contained more Cox-2 staining than the poorly differentiated ones. Expression of the Cox-2 protein was also seen in all 11 squamous cell carcinomas studied, although the level of staining seemed to be less than that in the adenocarcinomas. Small cell lung cancer specimens (n = 4) stained with a relatively weak intensity. Interestingly, atypical alveolar epithelium, which associates with asbestosis and idiopathic fibrosing alveolitis and is considered to be a precursor lesion for lung cancer, expressed the Cox-2 protein. Our data, thus, suggest that Cox-2 is expressed in human lung carcinomas and in precursor lesions leading to this malignancy.

Inhibition by nitric oxide-releasing compounds of prostacyclin production in human endothelial cells

1. The effects of two chemically unrelated nitric oxide (NO)-releasing compounds were studied on prostacyclin production in lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVECs). The cells expressed cyclooxygenase-2 (COX-2) protein and produced prostacyclin by NS-398-sensitive manner suggesting that prostacyclin production derives principally by COX-2 pathway. 2. A novel NO-releasing oxatriazole derivative GEA 3175 (1-30 microm) inhibited LPS-induced production of prostacyclin in HUVECs in a dose-dependent manner being more potent than the earlier known NO-donor S-nitroso-N-acetylpenicillamine (SNAP). 3. The effects of the two NO-donors on prostacyclin synthesis were reversed when red blood cells were added into the culture indicating that the effects are due to NO released from the compounds. 4. Addition of exogenous arachidonic acid into the culture did not alter the inhibitory action of NO-donors suggesting that phospholipases are not the target of action of NO. 5. The NO-donors did not inhibit prostacyclin production in the presence of a selective COX-2 inhibitor NS-398. These data suggest that NO affects COX-2 pathway rather than has an overall effect on cyclooxygenases. 6. NO-releasing compounds did not alter the level of COX-2 protein expression in LPS-treated HUVECs as measured by Western blot analysis. 7. The results suggest that NO-donors inhibit the activity of COX-2 in human endothelial cells. A link between NO and the regulation of eicosanoid synthesis could represent an important mechanism in controlling vascular and inflammatory responses in pathophysiological states and during treatment with nitrovasodilators.

Peripheral blood platelets express VEGF-C and VEGF which are released during platelet activation

VEGF-C is a recently characterised endothelial growth factor structurally related to vascular endothelial growth factor (VEGF). We studied the expression of VEGF-C and VEGF in the cells of peripheral blood and in the umbilical cord blood CD 34+ cells, representing haematopoietic progenitor cells. Expression of VEGF-C was detected in the CD34+ cells. In peripheral blood VEGF-C mRNA was restricted to platelets and T-cells. In contrast to the expression pattern of VEGF-C, VEGF mRNA was detected in all peripheral blood cell fractions studied, and also in CD34+ cells. VEGF-C mRNA was also detected in fresh bone marrow samples of acute leukaemia patients, but the expression did not show lineage specificity. VEGF-C and VEGF polypeptides were present in platelets and they were released from activated platelets together with the release of beta-thromboglobulin, suggesting that VEGF-C and VEGF reside in the alpha-granules of platelets. VEGF-C and VEGF, released from activated platelets, may have a role in angiogenesis during wound healing, and possibly also in other pathological conditions, such as atherosclerosis, tumour growth, and metastasis formation.