Patient and public involvement in health research in Norway: a survey among researchers and patient organisations

BACKGROUND

Patient and public involvement (PPI) in health research may improve both the relevance and quality of the research. There is however a lack of research investigating the experiences, attitudes and barriers towards PPI in clinical research in Norway. The Norwegian Clinical Research Infrastructure Network therefore conducted a survey among researchers and PPI contributors aiming to investigate experiences with PPI and identify current challenges for successful involvement.

METHODS

Two survey questionnaires were developed and distributed in October and November 2021. The survey targeting 1185 researchers was distributed from the research administrative system in the Regional Health Trusts. The survey targeting PPI contributors was distributed through Norwegian patient organisations, regional and national competence centers.

RESULTS

The response rate was 30% among researchers and was unobtainable from PPI contributors due to the survey distribution strategy. PPI was most frequently used in the planning and conduct of the studies, and less utilized in dissemination and implementation of results. Both researchers and user representatives were generally positive to PPI, and agreed that PPI might be more useful in clinical research than in underpinning research. Researchers and PPI contributors who reported that roles and expectations were clarified in advance, were more likely to experience a common understanding of roles and responsibilities in the research project. Both groups pointed to the importance of earmarked funding for PPI activities. There was a demand for a closer collaboration between researchers and patient organisations to develop accessible tools and effective models for PPI in health research.

CONCLUSIONS

Surveys among clinical researchers and PPI contributors indicate overall positive attitudes towards PPI in clinical research. However, more resources, such as budget, time, and accessible tools, are needed. Clarifying roles and expectations, and creating new PPI models under resource constraints can enhance its effectiveness. PPI is underutilized in disseminating and implementing research results, presenting an opportunity for improving healthcare outcomes.

Patient and public involvement in health research: A Nordic perspective

Patient and public involvement (PPI) in health research is of increasing interest internationally, as well as being a means to enhance the quality and relevance of research. PPI was one of the main themes and parallel sessions at The Nordic Health Research and Innovation Networks in Oslo in 2017. In this short comment/debate article, we outline some of the experiences from the event. Importantly, there are many common challenges. More collaboration across the borders could ensure a broader range of experience in the field and provide better ways of developing and evaluating PPI in health research.

Patient and public involvement in health research: A Nordic perspective

Patient and public involvement (PPI) in health research is of increasing interest internationally, as well as being a means to enhance the quality and relevance of research. PPI was one of the main themes and parallel sessions at The Nordic Health Research and Innovation Networks in Oslo in 2017. In this short comment/debate article, we outline some of the experiences from the event. Importantly, there are many common challenges. More collaboration across the borders could ensure a broader range of experience in the field and provide better ways of developing and evaluating PPI in health research.

Pursuit of performance excellence: a population study of Norwegian adolescent female cross-country skiers and biathletes with disordered eating

Aim

To examine the prevalence of disordered eating (DE) among the total population of Norwegian female cross-country skiers and biathletes at the junior level, and to determine whether sociodemographic characteristics predict DE among athletes.

Methods

A cross-sectional population study of Norwegian female junior cross-country skiers and biathletes (n=262), with a response rate of 86%. Descriptive statistics and logistic regression analyses explored the prevalence of DE and its relation to sports, competitive age groups, competitive status and education. DE was defined as meeting at least 1 of the following criteria from 2 subscales of the Eating Disorder Inventory-2: the Drive for Thinness score ≥15 and/or the Body Dissatisfaction score ≥14.

Results

18.7% of the athletes had DE. There was no significant difference in the occurrence of DE between the sports or the competitive age groups. Athletes who had dropped out of sports had a significantly higher occurrence of DE, while athletes who attended upper secondary schools of elite sports or general studies had a significantly higher occurrence of DE based on Drive for Thinness.

Conclusions

The number of female cross-country skiers and biathletes with DE is higher than that found in previous similar studies using the same screening instruments. Type of education and competitive status are significant predictors of DE, indicating that DE in addition to having adverse effects on an athlete's health, may also lead to early dropout of sport. This indicates that health and achievement are not always compatible within sports.

The interaction between Staphylococcus aureus SdrD and desmoglein 1 is important for adhesion to host cells

Staphylococcus aureus is known as a frequent colonizer of the skin and mucosa. Among bacterial factors involved in colonization are adhesins such as the microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). Serine aspartate repeat containing protein D (SdrD) is involved in adhesion to human squamous cells isolated from the nose. Here, we identify Desmoglein 1 (Dsg1) as a novel interaction partner for SdrD. Genetic deletion of sdrD in S. aureus NCTC8325-4 through allelic replacement resulted in decreased bacterial adherence to Dsg1- expressing HaCaT cells in vitro. Complementary gain-of-function was demonstrated by heterologous expression of SdrD in Lactococcus lactis, which increased adherence to HaCaT cells. Also ectopic expression of Dsg1 in HEK293 cells resulted in increased adherence of S. aureus NCTC8325-4 in vitro. Increased adherence of NCTC8325-4, compared to NCTC8325-4ΔsdrD, to the recombinant immobilized Dsg1 demonstrated direct interaction between SdrD and Dsg1. Specificity of SdrD interaction with Dsg1 was further verified using flow cytometry and confirmed binding of recombinant SdrD to HaCaT cells expressing Dsg1 on their surface. These data demonstrate that Dsg1 is a host ligand for SdrD.

Levonorgestrel-impregnated intrauterine device as treatment for endometrial hyperplasia: a national multicentre randomised trial

Objective

The purpose of this study was to investigate if the levonorgestrel-impregnated intrauterine device (LNG-IUS, Mirena®) is safe and effective as therapy for low-risk and medium-risk endometrial hyperplasia compared with oral medroxyprogesterone (MPA).

Design

A multicentre randomised trial.

Setting

Norway.

Population

In all, 170 women aged 30–70 years with low- or medium-risk endometrial hyperplasia who met inclusion criteria.

Methods

Patients were randomly assigned to one of three treatment arms: LNG-IUS; oral MPA 10 mg administered for 10 days per cycle, or continuous oral MPA 10 mg daily, for 6 months.

Main outcome measures

The primary outcome measure was normalisation or persisting hyperplasia.

Results

After 6 months all three treatment regimens showed significant effect when the outcome was evaluated as therapy response or not (P < 0.001). Responses were obtained for all the women in the LNG-IUS group (53/53, 95% CI 0.93–1.0) and for 96% of the women in the continuous oral group (46/48, 95% CI 0.86–0.99). Only 69% of the women in the cyclic oral group were responders (36/52, 95% CI 0.55–0.81). Adverse effects were relatively common with minimal differences between therapy groups.

Conclusion

In the first trial of its kind, women treated with the LNG-IUS showed histologically normal endometrium after 6 months of therapy for endometrial hyperplasia. Cyclical progestogens are found to be less effective compared with continuous oral therapy and LNG-IUS and should not be used for this purpose.

Expression of TWEAK/Fn14 in neuroblastoma: implications in tumorigenesis

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK), a member of the tumor necrosis factor (TNF) family of cytokines, acts on responsive cells via binding to a cell surface receptor called Fn14. TWEAK binding to an Fn14 receptor or constitutive Fn14 overexpression has been shown to activate nuclear factor κB signaling which is important in tumorigenesis and cancer therapy resistance. In the present study, we demonstrate that TWEAK and Fn14 are expressed in neuroblastoma cell lines and primary tumors, and both are observed at increased levels in high-stage tumors. The treatment of neuroblastoma cell lines with recombinant TWEAK in vitro causes increased survival, and this effect is partially due to the activation of NF-κB signaling. Moreover, TWEAK induces the release of matrix metalloprotease-9 (MMP-9) in neuroblastoma cells, suggesting that TWEAK may play a role in the invasive phase of neuroblastoma tumorigenesis. TWEAK-induced cell survival was significantly reduced by silencing the TWEAK and Fn14 gene functions by siRNA. Thus, the expression of TWEAK and Fn14 in neuroblastoma suggests that TWEAK functions as an important regulator of primary neuroblastoma growth, invasion and survival and that the therapeutic intervention of the TWEAK/Fn14 pathway may be an important clinical strategy in neuroblastoma therapy.

In NSCLC, VEGF-A response to hypoxia may differ between squamous cell and adenocarcinoma histology

AIM

To investigate if hypoxia induces vascular endothelial growth factor (VEGF)-A and VEGF-C secretion in non-small cell lung cancer (NSCLC) cells and if the secretion is cell type-dependent.

MATERIALS AND METHODS

Adenocarcinoma (AC) (H522, PAC) and squamous cell carcinoma (SCC) (H520) cell lines were exposed to hypoxia and normoxia. Supernatants were analysed with enzyme-linked immunosorbent assay (ELISA). Tissue microarrays, from 304 patients diagnosed with stage I-IIIA NSCLC, were immunohistochemically-stained and scored for VEGF-A and VEGF-C.

RESULTS

In vitro, VEGF-A expression in hypoxic AC cells was significantly higher than that in normoxic cells (H522: p=0.004, PAC; p=0.007). In contrast, hypoxia led to significantly reduced VEGF-A production in the SCC cell line compared to normoxic cells (p=0.005).

CONCLUSION

In vitro, AC and SCC exhibit different VEGF-A responses to hypoxia. Hypoxia mediates a pro-angiogenic response in AC, but apparently not in SCC.

Cancer-associated fibroblasts from human NSCLC survive ablative doses of radiation but their invasive capacity is reduced

Background

Cancer-Associated Fibroblasts (CAFs) are significant components of solid malignancies and play central roles in cancer sustainability, invasion and metastasis. In this study we have investigated the invasive capacity and matrix remodelling properties of human lung CAFs after exposure to ablative doses of ionizing radiation (AIR), equivalent to single fractions delivered by stereotactic ablative radiotherapy (SART) for medically inoperable stage-I/II non-small-cell lung cancers.

Methods

CAFs were isolated from lung tumour specimens from 16 donors. Initially, intrinsic radiosensitivity was evaluated by checking viability and extent of DNA-damage response (DDR) at different radiation doses. The migrative and invasive capacities of CAFs were thereafter determined after a sub-lethal single radiation dose of 18 Gy. To ascertain the mechanisms behind the altered invasive capacity of cells, expression of matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs) were measured in the conditioned media several days post-irradiation, along with expression of cell surface integrins and dynamics of focal contacts by vinculin-staining.

Results

Exposing CAFs to 1 × 18 Gy resulted in a potent induction of multiple nuclear DDR foci (> 9/cell) with little resolution after 120 h, induced premature cellular senescence and inhibition of the proliferative, migrative and invasive capacity. AIR promoted MMP-3 and inhibited MMP-1 appearance to some extent, but did not affect expression of other major MMPs. Furthermore, surface expression of integrins α2, β1 and α5 was consistently enhanced, and a dramatic augmentation and redistribution of focal contacts was observed.

Conclusions

Our data indicate that ablative doses of radiation exert advantageous inhibitory effects on the proliferative, migratory and invasive capacity of lung CAFs. The reduced motility of irradiated CAFs might be a consequence of stabilized focal contacts via integrins.

Prognostic markers for detection of coexistent carcinoma in high-risk endometrial hyperplasia

OBJECTIVES

Reliable predictive uterus-sparing methods are crucial for treatment decisions among women who wish to preserve fertility and for seriously ill patients for whom surgery is hazardous. Thus, prediction of myoinvasive carcinoma by objective histomorphometry (4C-rule) and subjective diagnosis (endometrial intraepithelial neoplasia, EIN) were investigated in high-risk endometrial biopsies.

PATIENTS AND METHODS

A total of 45 patients retrospectively diagnosed with high-risk hyperplasia, of whom ten were found to have concurrent carcinoma, were investigated. The histomorphometric 4C-rule and the EIN classification system were used for outcome prediction.

RESULTS

Myoinvasive disease was predicted with a sensitivity of 87% and a specificity of 79% by using 4C-rule assessment. The sensitivity and specificity of the EIN classification to predict coexistent carcinoma or not was 50% and 97%, respectively.

CONCLUSION

Six out of the seven reported cases with myoinvasion were correctly diagnosed with the 4C-rule assessment. In contrast, only three out of the seven myoinvasive cases were diagnosed as cancer using the EIN approach.

Porcine liver sinusoidal endothelial cells contribute significantly to intrahepatic ammonia metabolism

Ammonia metabolism in the liver has been largely credited to hepatocytes (HCs). We have shown that liver nonparenchymal cells that include liver sinusoidal endothelial cells (LSECs) produce ammonia. To address the limited knowledge regarding a role for LSECs in ammonia metabolism, we investigated the ammonia metabolism of isolated LSECs and HCs under three different conditions: (1) bioreactors containing LSECs (LSEC-bioreactors), (2) bioreactors containing HCs (HC-bioreactors), and (3) separate bioreactors containing LSECs and HCs connected in sequence (Seq-bioreactors). Our results showed that LSEC-bioreactors released six-fold more ammonia (22.2 nM/hour/10(6) cells) into the growth media than HC-bioreactors (3.3 nM/hour/10(6) cells) and Seq-bioreactors (3.8 nM/hour/10(6) cells). The glutamate released by LSEC-bioreactors (32.0 nM/hour/10(6) cells) was over four-fold larger than that released by HC-bioreactors and Seq-bioreactors (<7 nM/hour/10(6) cells). LSEC-bioreactors and HC-bioreactors consumed large amounts of glutamine (>25 nM/hour/10(6) cells). Glutaminase is known for catalyzing glutamine into glutamate and ammonia. To determine if this mechanism may be responsible for the large levels of glutamate and ammonia found in LSEC-bioreactors, immunolabeling of glutaminase and messenger RNA expression were tested. Our results demonstrated that glutaminase was present with colocalization of an LSEC-specific functional probe in lysosomes of LSECs. Furthermore, using a nucleotide sequence specific for kidney-type glutaminase, reverse-transcription polymerase chain reaction revealed that this isoform of glutaminase was expressed in porcine LSECs.

CONCLUSION

LSECs released large amounts of ammonia, perhaps due to the presence of glutaminase in lysosomes. The ammonia and glutamate released by LSECs in Seq-bioreactors were used by hepatocytes, suggesting an intrahepatic collaboration between these two cell types.

Expression of enzymes and receptors of the leukotriene pathway in human neuroblastoma promotes tumor survival and provides a target for therapy

The metabolism of arachidonic acid by the cyclooxygenase (COX) or lipoxygenase (LO) pathways generates eicosanoids that have been implicated in the pathogenesis of a variety of human diseases, including cancer. In this study, we examined the expression and significance of components within the 5-LO pathway in human neuroblastoma, an embryonal tumor of the sympathetic nervous system. High expression of 5-LO, 5-LO-activating protein (FLAP), leukotriene A(4) hydrolase, leukotriene C(4) synthase, and leukotriene receptors was detected in a majority of primary neuroblastoma tumors and all cell lines investigated. Expression of 5-LO and FLAP was evident in tumor cells but not in nonmalignant adrenal medulla where neuroblastomas typically arise. Moreover, neuroblastoma cells produce leukotrienes, and stimulation of neuroblastoma cells with leukotrienes increased neuroblastoma cell viability. Inhibitors of 5-LO (AA-861), FLAP (MK-886), or the leukotriene receptor antagonist montelukast inhibited neuroblastoma cell growth by induction of G(1)-cell cycle arrest and apoptosis. Similarly, specific 5-LO and leukotriene receptor silencing by small interfering RNA decreased neuroblastoma cell growth. These findings provide new insights into the pathobiology of neuroblastoma, and the use of leukotriene pathway inhibitors as a novel adjuvant therapy for children with neuroblastoma warrants further consideration.

Significant contribution of liver nonparenchymal cells to metabolism of ammonia and lactate and cocultivation augments the functions of a bioartificial liver

A bioartificial liver (BAL) will bridge patients with acute liver failure (ALF) to either spontaneous regeneration or liver transplantation. The nitrogen metabolism is important in ALF, and the metabolism of nonparenchymal liver cells (NPCs) is poorly understood. The scope of this study was to investigate whether cocultivation of hepatocytes with NPCs would augment the functions of a BAL (HN-BAL) compared with a BAL equipped with only hepatocytes (H-BAL). In addition, NPCs were similarly cultivated alone. The cells were cultivated for 8 days in simulated microgravity with serum-free growth medium. With NPCs, initial ammonia and lactate production were fivefold and over twofold higher compared with later time periods despite sufficient oxygen supply. Initial lactate production and glutamine consumption were threefold higher in HN-BAL than in H-BAL. With NPCs, initial glutamine consumption was two- to threefold higher compared with later time periods, whereas initial ornithine production and arginine consumption were over four- and eightfold higher compared with later time periods. In NPCs, the conversion of glutamine to glutamate and ammonia can be explained by the presence of glutaminase, as revealed by PCR analysis. Drug metabolism and clearance of aggregated gamma globulin, probes administered to test functions of hepatocytes and NPCs, respectively, were higher in HN-BAL than in H-BAL. In conclusion, NPCs produce ammonia by hydrolysis of amino acids and may contribute to the pathogenesis of ALF. High amounts of lactate are produced by NPCs under nonhypoxic conditions. Cocultivation augments differentiated functions such as drug metabolism and clearance of aggregated gamma-globulin.

Toll-like receptor 9 (TLR9) is present in murine liver sinusoidal endothelial cells (LSECs) and mediates the effect of CpG-oligonucleotides

BACKGROUND/AIMS

Bacterial DNA and synthetic oligonucleotides containing unmethylated motifs have become the focus of many studies due to their ability to activate cells of the innate immune system through interaction with Toll-like receptor 9 (TLR9). This study was undertaken to investigate if and how CpG-oligonucleotides (CpGs) activate liver sinusoidal endothelial cells (LSECs), known to be the main site of clearance of DNA-oligonucleotides from the circulation.

METHODS

Expression of TLR9 was analyzed by RT-PCR and immunohistochemistry. Production of IL-1beta and IL-6 was measured by ELISA.

RESULTS

Here we show for the first time that mouse LSECs express TLR9 mRNA and protein. Moreover, our findings suggest that CpGs are first taken up by LSECs by scavenger receptor(s)-mediated endocytosis, and then join TLR9 in the lysosomal compartments. Furthermore, we found that uptake of CpGs in LSECs results in the activation of transcription factor NF-kappaB and secretion of IL-1beta and IL-6.

CONCLUSIONS

The presence of functional TLR9 in LSECs emphasizes the importance of these cells in the innate defense mechanisms of the liver.

NSAIDs in neuroblastoma therapy

Cyclooxygenases (COX) catalyse the conversion of arachidonic acid to prostaglandins. COX-2 is upregulated in several adult epithelial cancers. In neuroblastoma it has been shown that the majority of primary tumours and cell lines express high levels of COX-2, whereas normal adrenal medullas from children do not express COX-2. Treatment of neuroblastoma cells with nonsteroidal anti-inflammatory drugs (NSAIDs), inhibitors of COX, induces caspase-dependent apoptosis via the intrinsic mitochondrial pathway. Established neuroblastoma xenografts in nude rats treated with the dual COX-1/COX-2 inhibitor, diclofenac, or the COX-2 specific inhibitor, celecoxib significantly inhibits neuroblastoma growth in vivo. In vitro, arachidonic acid and diclofenac synergistically induces neuroblastoma cell death. This effect is further pronounced when lipoxygenases is inhibited simultaneously. Proton MR-spectroscopy (1H MRS) of neuroblastoma cells treated with COX-inhibitors demonstrates accumulation of polyunsaturated fatty acids and depletion of choline compounds. Thus, 1H MRS, which can be performed with clinical MR-scanners, is likely to provide pharmacodynamic markers of neuroblastoma response to COX-inhibition. Taken together, these data suggest the use of NSAIDs as a novel adjuvant therapy for children with neuroblastoma.

Osteoprotegerin is expressed in colon carcinoma cells

BACKGROUND

Osteoprotegerin (OPG), a soluble member of the tumor necrosis factor family, is produced by various cell types and tissues and plays a key role in the physiological regulation of osteoclast differentiation and activity. Also, OPG is a soluble decoy receptor for tumor necrosis factor-related apoptosis-inducing factor (TRAIL). In the present study we investigated whether the human colon cancer cell lines HT-29 and SW-480 produce and secrete OPG in vitro.

MATERIALS AND METHODS

Expression of OPG mRNA was examined by RT-PCR. OPG protein was analysed by ELISA assay and immunostaining methods. The effect of OPG secretion on TRAIL-mediated apoptosis was also investigated.

RESULTS

By RT-PCR, it was demonstrated that mRNA transcripts for OPG were produced by both cell lines. By ELISA analysis, OPG was detected in the culture medium; and treatment of cells with proinflammatory cytokines TNF-alpha and IL-1beta increased OPG secretion significantly. Tumor xenografts in nude mice also were shown to express OPG by immunohistochemistry. When RANKL, which selectively binds OPG, was added to cell cultures along with recombinant TRAIL, apoptosis was shown to increase significantly.

CONCLUSION

These data indicate that OPG may be involved in tumorigenesis and the progression of colon cancer.

Cyclooxygenase-2 is expressed in neuroblastoma, and nonsteroidal anti-inflammatory drugs induce apoptosis and inhibit tumor growth in vivo

Neuroblastoma is the single most common and deadly tumor of childhood and is often associated with therapy resistance. Cyclooxygenases (COXs) catalyze the conversion of arachidonic acid to prostaglandins. COX-2 is up-regulated in several adult epithelial cancers and is linked to proliferation and resistance to apoptosis. We detected COX-2 expression in neuroblastoma primary tumors and cell lines but not in normal adrenal medullas from children. Treatment of neuroblastoma cells with nonsteroidal anti-inflammatory drugs, inhibitors of COX, induced caspase-dependent apoptosis via the intrinsic mitochondrial pathway. Treatment of established neuroblastoma xenografts in nude rats with the dual COX-1/COX-2 inhibitor diclofenac or the COX-2-specific inhibitor celecoxib significantly inhibited tumor growth in vivo (P < 0.001). In vitro, arachidonic acid and diclofenac synergistically induced neuroblastoma cell death. This effect was further pronounced when lipooxygenases were simultaneously inhibited. Proton magnetic resonance spectroscopy ((1)H MRS) of neuroblastoma cells treated with COX inhibitors demonstrated accumulation of polyunsaturated fatty acids and depletion of choline compounds. Thus, (1)H MRS, which can be performed with clinical magnetic resonance scanners, is likely to provide pharmacodynamic markers of neuroblastoma response to COX inhibition. Taken together, these data suggest the use of nonsteroidal anti-inflammatory drugs as a novel adjuvant therapy for children with neuroblastoma.

Synergistic induction of apoptosis in neuroblastoma cells using a combination of cytostatic drugs with interferon-gamma and TRAIL

The majority of high-risk neuroblastomas lack the expression of caspase-8 due to gene silencing which suggest a mechanism for the selection of tumour cells that are refractory to multiple cytotoxic drugs including tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). Inhibitors of DNA methyltransferases and IFN-gamma induce expression of caspase-8, and sensitise some neuroblastoma cells to TRAIL-mediated apoptosis. Here we demonstrate that a combination of cytostatic drugs with IFN-gamma and TRAIL synergistically induces neuroblastoma cell death, which may have implications for future therapy of children with neuroblastoma. Treatment of neuroblastoma cells with IFN-gamma induced caspase-8 expression in all cell lines investigated. In five of the neuroblastoma cell lines (SHEP-1, SK-N-AS, SK-N-FI, SH-SY-5Y and Kelly), IFN-gamma promoted TRAIL-mediated cleavage of caspase-8, initiating a caspase cascade involving caspase-7 and PARP followed by apoptosis. IFN-gamma-mediated facilitation of apoptosis was inhibited by the pan-caspase inhibitor zVAD-fmk and the caspase-8 specific inhibitor zIEDT-fmk, indicating an important role of caspase-8 in mediating sensitation by IFN-gamma in neuroblastoma cells. In three of the cell lines [SK-N-BE(2), SK-N-DZ and IMR-32] caspase-8 expression was induced by IFN-gamma, but the cells were still resistant to TRAIL-mediated apoptosis. The pattern of basal TRAIL receptor expression, decoy receptors, FLIP and FADD could not be correlated with resistance or sensitivity to TRAIL-induced apoptosis. Importantly, treatment of neuroblastoma cell lines with cytostatic drugs increased apoptosis in the TRAIL-sensitive cell lines whereas the resistant cell lines were susceptible to TRAIL-mediated apoptosis in the presence of the anticancer drugs. The mechanism of the increased susceptibility to apoptosis might results from drug-mediated up-regulation of the death receptors DR4 and DR5.

Heterogeneity in gamma-glutamyltransferase mRNA expression and glycan structures. Search for tumor-specific variants in human liver metastases and colon carcinoma cells

The enzyme gamma-glutamyltransferase (GGT) is frequently overexpressed in cancer cells and tissues and has significant utility as a cancer marker. Significant heterogeneity of the enzyme has been described due to both transcriptional and post-translational variations. For possible use in diagnosis and follow-up of patients with colorectal cancer, a search was performed for specific mRNA subtypes and glycan structures of the enzyme in liver metastases. We found no differences in the distribution of three GGT mRNA subtypes (fetal liver, HepG2, placenta) in metastatic tissue and normal liver tissue. Furthermore, the three subtypes were present in leukocytes isolated from both normal individuals and cancer patients. Two colon carcinoma cell lines (Colo 205 and HCC 2998) also displayed the three forms and no consistent changes in mRNA composition were noted after butyrate-induced differentiation of the cells. Thus, neither of the GGT mRNA subforms appear to be tumor-specific, although some qualitative and quantitative variations were noted. Two distinct glycosylation features were detected for GGT in metastatic tissue in contrast to normal liver GGT; an extreme sialic acid heterogeneity and a significant increase in beta1,6GlcNAc branching. The GGT glycans from the two colon carcinoma cell lines also possessed these features. As butyrate treatment of the cells resulted in an increased sialic acid content and a reduced beta1,6GlcNAc branching, the described carbohydrate structures appear to be part of a tumor-related pattern. We were, however, unable to identify such GGT isoforms in serum from patients with advanced colorectal cancer. This indicates that their usefulness in diagnostic use is doubtful.

Loss of expression of MLH1, MSH2, MSH6, and PTEN related to endometrial cancer in 68 patients with endometrial hyperplasia

Derangements in the tumor suppressor gene PTEN and the mismatch-repair genes, hMLH1, hMSH2, and hMSH6, have an important role in endometrial carcinogenesis. The purpose of this study was to assess immunohistochemically the pattern of protein expression for these genes in 68 patients with endometrial hyperplasia and to determine the relation of protein expression to cancer development or coexistence of cancers. Loss of expression of these genes also was evaluated as potential tumor markers for clinical use. PTEN and hMLH1 both showed loss of expression in 55% of specimens from 18 patients with subsequent or coexisting carcinoma. D&C specimens from 50 patients who did not develop cancer (10 patients underwent hysterectomy within 2 years; 40 had no hysterectomy; follow-up of 10-20 years), expressed protein at a much higher frequency (92% for PTEN and 98% for hMLH1). The parameter with the strongest independent relation to subsequent or coexisting carcinoma in a stepwise multiple logistic regression analysis was hMLH1. Evaluation of the investigated factors as prognostic markers for tumor development showed high specificity (92% for PTEN, 98% for MLH1) at the expense of sensitivity (56% for PTEN, 56% for MLH1). The results were compared with the results of the computerized image analysis algorithm, the D-score.

Tumor necrosis factor-related apoptosis-inducing ligand induces apoptosis in human articular chondrocytes in vitro

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is produced by immune cells and by mediating apoptosis, TRAIL plays an important role in tumor surveillance. TRAIL binds four different membrane-bound receptors: DR4, DR5, DcR1, and DcR2. The DR4- and DR5-receptors mediate apoptosis, whereas the others do not. We demonstrated by reverse transcriptase-polymerase chain reaction and flow cytometry that, in vitro, normal human articular chondrocytes express the receptors mediating apoptosis (DR4 and DR5) and one of the decoy receptors (DcR2). Also, we demonstrated that chondrocytes were subjected to cell death within few hours after challenge with TRAIL and that cytotoxicity was dose-dependent. Treated cells had apoptotic morphology accompanied by active caspase-3 immunoreactivity. These data indicate that normal human articular chondrocytes are susceptible to TRAIL-mediated apoptosis, which otherwise is typical for transformed cells, and also that death receptors and their respective ligands may have a crucial role in cartilage generation and destruction.

Differential regulation of gamma-glutamyltransferase mRNAs in four human tumour cell lines

Human gamma-glutamyltransferase (GGT) belongs to a multigenic family and at least three mRNAs are transcribed from the gene that codes for an active enzyme. Four human tumour cell lines (HepG2, LNCap, HeLa and U937) with different GGT levels were used to investigate how GGT activity, total GGT mRNA and each individual GGT mRNA subtype responded to tumour necrosis factor-alpha (TNF-alpha), 12-O-tetradecanoylphorbol 13-acetate (TPA) or sodium butyrate treatment. Butyrate reduced the GGT activity in HepG2 cells, and the level of total GGT mRNA accordingly, whereas TNF-alpha and TPA did not alter these parameters. In LNCap cells, TNF-alpha, TPA, and butyrate reduced the activity as well as the level of GGT total mRNA. In HeLa cells no significant changes were observed either in activity or in mRNA level whereas TPA induced both GGT activity and mRNA levels in U937 cells. The distribution of each GGT mRNA subtype (A, B and C) was found to be cell specific: type B mRNA was the major form in HepG2 cells, while type A was the major form in LNCap and HeLa, type A and type C were expressed almost at the same level in U937 cells. The GGT mRNA subtypes were also differently modulated in these cells after TNF-alpha, TPA or butyrate treatment, suggesting that they are regulated by distinct and cell type specific mechanisms.