[Efficiency of Bakri intra uterine tamponade balloon use in postpartum hemorrhage: Before and after study]

OBJECTIVE

To assess the impact of the introduction of intrauterine balloon tamponade on second-line management practices for post-partum hemorrhage (PPH).

METHOD

This retrospective study was conducted in a tertiary care centre where arterial embolisation was not available. Two periods were compared, before (2008-2010) and after (2015-2017) the introduction of an intrauterine tamponade balloon protocol using the Bakri balloon. All consecutive patients with PPH refractory to sulprostone in the two periods were included. Outcomes studied were the incidence of invasive procedures (conservative surgery, embolisation, hysterectomy) as well as transfer to centres with arterial embolisation facilities.

RESULTS

A total of 109 patients had refractory PPH, 44 in the first period and 65 in the second period. The proportion of all PPH cases which required sulprostone did not differ between the periods (24.2 and 29.3%, respectively, P=0.25). There were significant decreases between the first and the second period in the proportion requiring a transfer to an embolisation centre (79.6% during period 1, vs. 6.2% respectively, P<0.001), embolisation (20.6% vs. 0%, P<0.001), uterine compression sutures (13.6% vs. 3.1% P=0.04) and surgical management (22.7% vs. 7.7%, P=0.025). The decrease in the incidence of hysterectomy did not reach statistical significance (11,4 vs. 1,5%, P=0.095). Among 29 cases of PPH following cesarean sections (14 in the first period and 15 in the second period), we observed a significant decrease in transfer rates (66.7% vs. 0%, P<0.01), as well as decreases in embolisation (26.7% vs. 0%, P=0.10) and invasive procedures (60% vs. 28.7%, P=0.089), which did not reach statistical significance.

CONCLUSION

The introduction of intrauterine tamponade was associated with a decrease in the need for invasive procedures. In a centre without access to on-site arterial embolisation, transfer rates were reduced improving patient comfort and reducing costs.

Enrichment of c-Met+ tumorigenic stromal cells of giant cell tumor of bone and targeting by cabozantinib

Giant cell tumor of bone (GCTB) is a very rare tumor entity, which is little examined owing to the lack of established cell lines and mouse models and the restriction of available primary cell lines. The stromal cells of GCTB have been made responsible for the aggressive growth and metastasis, emphasizing the presence of a cancer stem cell population. To identify and target such tumor-initiating cells, stromal cells were isolated from eight freshly resected GCTB tissues. Tumorigenic properties were examined by colony and spheroid formation, differentiation, migration, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, immunohistochemistry, antibody protein array, Alu in situ hybridization, FACS analysis and xenotransplantation into fertilized chicken eggs and mice. A sub-population of the neoplastic stromal cells formed spheroids and colonies, differentiated to osteoblasts, migrated to wounded regions and expressed the metastasis marker CXC-chemokine receptor type 4, indicating self-renewal, invasion and differentiation potential. Compared with adherent-growing cells, markers for pluripotency, stemness and cancer progression, including the CSC surface marker c-Met, were enhanced in spheroidal cells. This c-Met-enriched sub-population formed xenograft tumors in fertilized chicken eggs and mice. Cabozantinib, an inhibitor of c-Met in phase II trials, eliminated CSC features with a higher therapeutic effect than standard chemotherapy. This study identifies a c-Met⁺ tumorigenic sub-population within stromal GCTB cells and suggests the c-Met inhibitor cabozantinib as a new therapeutic option for targeted elimination of unresectable or recurrent GCTB.

The novel c-Met inhibitor cabozantinib overcomes gemcitabine resistance and stem cell signaling in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal malignancies. Cancer stem cells (CSCs), which are not targeted by current therapies, may be the reason for pronounced therapy resistance. A new treatment option in phase II trials is cabozantinib that inhibits the pancreatic CSC surface marker and tyrosine kinase receptor c-Met. The purpose of this study was to evaluate the effect of cabozantinib to stem-like features and therapy resistance. Established PDA cell lines, a gemcitabine-resistant subclone, non-malignant pancreatic ductal cells and primary spheroidal cultures from patient tumors were analyzed by MTT-assay, flow cytometry, colony and spheroid formation assays, western blotting, qRT-PCR, antibody protein array, immunohistochemistry and morphological features. Cabozantinib inhibited viability and spheroid formation and induced apoptosis in malignant cells with minor effects in non-malignant cells. After long-term cabozantinib treatment, PDA cells had altered anti- and pro-apoptotic signaling, but still responded to cabozantinib, as apoptosis only slightly decreased and viability only slightly increased suggesting a low resistance-inducing potential of cabozantinib. In parallel, c-Met expression and the pluripotency transcription factor SOX2 were downregulated, which might counteract development of full therapy resistance in long-term treated subclones. In single-treatment studies, cabozantinib increased efficacy of gemcitabine. Most importantly, cabozantinib strongly induced apoptosis and reduced viability in PDA cell lines, which are completely resistant toward gemcitabine. In primary, CSC-enriched spheroidal cultures cabozantinib downregulated CSC markers SOX2, c-Met and CD133 and induced apoptosis. These findings suggest that the clinical use of cabozantinib may be more effective than current chemotherapeutics.

Multiple pathway drug-resistance (review)

During the past few years it has become apparent that multiple mechanisms of resistance are playing a role in the clinical manifestations of drug resistance. In different organs and tumors, various components of the resistance phenotype are expressed to varying degrees. The cells utilize multiple pathways to overcome the cytotoxic effects of chemotherapeutic agents. No single mechanism can account for the full extent of resistance.

Prognostic value of oncoproteins for the survival of patients with nonsmall cell lung carcinomas

Patients with non-small cell lung carcinomas whose tumors showed an overexpression of the oncogenes c-fos and c-N-ras at the protein level had significantly shorter survival times than those without overexpression of these oncogene products. (c-fos: p=0.0002, c-N-ras: p=0.002). Multivariate analysis showed that expression of proteins coded by c-fos and c-N-ras is a significant prognostic factor in addition to tumor staging and DNA ploidy. The prognostic value is improved by combining the expression of c-fos and c-N-ras products. A significant correlation between the expression of c-fos and c-N-ras products and the tumor take rate in nude mice was found.

Microvessel density and vascular endothelial growth factor expression in human tumors of different localization

In order to study the angiogenic activity of individual human tumors, microvessel density and vascular endothelial growth factor (VEGF) expression were determined in 152 human tumors of different localization (lung, ovary, breast, colon/rectum, kidney) using immunohistochemistry. Considerable variability in vascular density has been noted between different tumors with the same histology as well as between tumors of different localization. Kidney and breast carcinomas exhibited significantly higher vessel counts than carcinomas of other localization (p<0.001). In most tumor types (lung, breast, ovarian, nephroblastoma) about two-thirds of the tumors expressed VEGF. In contrast, only 7 out of 20 colorectal carcinomas (35%) and 9 out of 20 kidney carcinomas (45%) and all small cell lung carcinomas (13/13) were positive for VEGF, despite a relatively low vascularity. These results indicate that each single tumor has its own pattern of vascularity and its variable expression of VEGF and that the individual determination of the degree of vascularization together with the assessment of one or more angiogenic peptides may provide valid information on the angiogenic activity of a tumor. This may lead to identification of those patients who are more likely to have benefit from antiangiogenic therapies.

Overexpression of C-fos and C-erbb1 encoded proteins in squamous-cell carcinomas of the lung of smokers

Seventy-eight human squamous cell carcinomas of the lung of previously untreated patients were analyzed for expression of c-fos and c-erbB1 proteins by means of immunohistochemistry. Of the tumors investigated expression of c-fos protein was detected in 60% and of c-erbB1 protein in 77%. Carcinomas of smokers significantly express more frequently c-fos and c-erbB1 protein than carcinomas of non-smokers (p<0.05).

Role of oxygenation and vascularization in drug resistance

Oxygenation status and tumor vascularization seem to be important factors in determining therapeutic effectiveness and patient prognosis. An abundance of data on tumor oxygenation and vascularization is available and it clearly shows that most human solid tumors are heterogeneously oxygenated and vascularized. They contain hypoxic regions. Such regions and areas of reduced vascularization can affect the response to a variety of drugs. Direct measurements of pO(2) and the vascular density in various types of tumors have, upon correlation of the data to therapeutic outcome, shown that low pO(2) values and low vascular density are associated with a decreased response to therapy. Therefore, oxygenation status and the extent of tumor vascularization may well be important factors contributing to the difficulty of successful therapy in certain types of tumors.

Resistance proteins in human kidney, breast, ovarian and lung-carcinoma - a comparative-analysis

The expression of P-glycoprotein (P-170), glutathione S-transferase-pi (GST-pi), dihydrofolate reductase (DHFR) and thymidylate synthase (TS) was analyzed immunohistochemically in human tumors of different origin. The resistance proteins were expressed at varying degree: all kidney carcinomas (n=25), 40 of 56 non-small cell lung carcinomas (NSCLC) (71%), 8 of 15 ovarian carcinomas (53%), 5 of 11 breast carcinomas (46%) and 3 of 14 small cell lung carcinomas (SCLC) (21%) expressed more than one resistance protein. A comparison of the immunohistochemical data with the clinical response rates as reported in literature, demonstrates an evident correlation between the number of resistance proteins and the clinical outcome.

Increased resistance to Doxorubicin in human non-small-cell lung carcinomas with metallothionein expression

Ninety-four human non-small cell lung carcinomas (NSCLC) of previously untreated patients were analyzed for the presence of metallothionein (MT) expression by means of immunohistochemistry. Of the tumors investigated, expression of MT was detected in 63%. The expression of MT was correlated with the results of doxorubicin resistance of the tumors in vitro. A significant relationship between MT expression and doxorubicin resistance was found (p=0.01). Significant correlations also exist between MT and P-glycoprotein or glutathione-S-transferase-pi expression respectively (p<0.005).

Early warning of EUSIG-defined hypotensive events using a Bayesian Artificial Neural Network

BACKGROUND

Hypotension is recognized as a potentially damaging secondary insult after traumatic brain injury. Systems to give clinical teams some early warning of likely hypotensive instability could be added to the range of existing techniques used in the management of this group of patients. By using the Edinburgh University Secondary Insult Grades (EUSIG) definitions for -hypotension (systolic arterial pressure <90 mmHg OR mean arterial -pressure <70 mmHg) we collected a group of ∼2,000 events by analyzing the Brain-IT database. We then constructed a Bayesian Artificial Neural Network (an advanced statistical modeling technique) that is able to provide some early warning when trained on this previously collected demographic and physiological data.

MATERIALS AND METHODS

Using EUSIG defined event data from the Brain-IT database, we identified a Bayesian artificial neural network (BANN) topology and constructed a series of datasets using a group of clinically guided input variables. This allowed us to train a BANN, which was then tested on an unseen set of patients from the Brain-IT database. The initial tests used a particularly harsh assessment criterion whereby a true positive prediction was only allowed if the BANN predicted an upcoming event to the exact minute. We have now developed the system to the point where it is about to be used in a two-stage Phase II clinical trial and we are also researching a more realistic assessment technique.

KEY RESULTS

We have constructed a BANN that is able to provide early warning to the clinicians based on a model that uses information from the physiological inputs; systolic and mean arterial pressure and heart rate; and demographic variables age and gender. We use 15-min SubWindows starting at 15 and 30 min before an event and process mean, slope and standard deviations. Based on 10 simulation runs, our current sensitivity is 36.25% (SE 1.31) with a specificity of 90.82% (SE 0.85). Initial results from a Phase I clinical study shows a model sensitivity of 40.95% (SE 6%) and specificity of 86.46% (SE 3%) Although this figure is low it is considered clinically useful for this dangerous condition, provided the false positive rate can be kept sufficiently low as to be practical in an intensive care environment.

CONCLUSION

We have shown that using advanced statistical modeling techniques can provide clinical teams with useful information that will assist clinical care.

Early warning of EUSIG-defined hypotensive events using a Bayesian Artificial Neural Network

BACKGROUND

Hypotension is recognized as a potentially damaging secondary insult after traumatic brain injury. Systems to give clinical teams some early warning of likely hypotensive instability could be added to the range of existing techniques used in the management of this group of patients. By using the Edinburgh University Secondary Insult Grades (EUSIG) definitions for -hypotension (systolic arterial pressure <90 mmHg OR mean arterial -pressure <70 mmHg) we collected a group of ∼2,000 events by analyzing the Brain-IT database. We then constructed a Bayesian Artificial Neural Network (an advanced statistical modeling technique) that is able to provide some early warning when trained on this previously collected demographic and physiological data.

MATERIALS AND METHODS

Using EUSIG defined event data from the Brain-IT database, we identified a Bayesian artificial neural network (BANN) topology and constructed a series of datasets using a group of clinically guided input variables. This allowed us to train a BANN, which was then tested on an unseen set of patients from the Brain-IT database. The initial tests used a particularly harsh assessment criterion whereby a true positive prediction was only allowed if the BANN predicted an upcoming event to the exact minute. We have now developed the system to the point where it is about to be used in a two-stage Phase II clinical trial and we are also researching a more realistic assessment technique.

KEY RESULTS

We have constructed a BANN that is able to provide early warning to the clinicians based on a model that uses information from the physiological inputs; systolic and mean arterial pressure and heart rate; and demographic variables age and gender. We use 15-min SubWindows starting at 15 and 30 min before an event and process mean, slope and standard deviations. Based on 10 simulation runs, our current sensitivity is 36.25% (SE 1.31) with a specificity of 90.82% (SE 0.85). Initial results from a Phase I clinical study shows a model sensitivity of 40.95% (SE 6%) and specificity of 86.46% (SE 3%) Although this figure is low it is considered clinically useful for this dangerous condition, provided the false positive rate can be kept sufficiently low as to be practical in an intensive care environment.

CONCLUSION

We have shown that using advanced statistical modeling techniques can provide clinical teams with useful information that will assist clinical care.

Trigger characteristics of EUSIG-defined hypotensive events

BACKGROUND

Hypotension is a recognized -secondary insult after traumatic brain injury (TBI). There are many definitions of hypotension, an often cited example being the Brain Trauma Foundation's current (2007) "Guidelines for the Management of Severe Traumatic Brain Injury," which defines hypotension as systolic pressure <90 mmHg. However, this same document declares "The importance of mean arterial pressure, as opposed to systolic pressure should also be stressed, …." Our work shows that when using the Edinburgh University Secondary Insult Grades (EUSIG) definitions, which require monitoring of both systolic and mean arterial pressures, that most hypotensive events are in fact triggered by a breach of the mean arterial level of 70 mmHg. We suggest that close monitoring of mean arterial pressure would enable clinical teams to avoid more potentially damaging hypotensive events.

MATERIALS AND METHODS

An analysis of 100 patients from the Brain-IT database was performed. Using the EUSIG definitions, 2,081 events can be obtained by analyzing the systolic and mean blood pressures on a minute by minute basis. A software program was written to identify and classify the trigger pattern for each event. A categorical analysis of these triggering patterns has been carried out.

KEY RESULTS

Our analysis shows that most events are triggered by a drop in mean arterial pressure. In fact a large number of events (91%) occur where the mean arterial pressure is below the threshold limits whereas the systolic pressure does not cross the 90 mmHg limit at all.

CONCLUSION

We suggest that more emphasis should be placed on closely monitoring mean arterial pressure as well as systolic pressure when trying to guard against hypotensive problems in traumatically brain injured patients. In future work we will study the underlying physiological mechanisms and attempt to further classify concomitant conditions that may be contributing to the onset of a hypotensive event.

Sulforaphane targets pancreatic tumour-initiating cells by NF-kappaB-induced antiapoptotic signalling

BACKGROUND AND AIMS

Emerging evidence suggests that highly treatment-resistant tumour-initiating cells (TICs) play a central role in the pathogenesis of pancreatic cancer. Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is considered to be a novel anticancer agent; however, recent studies have shown that many pancreatic cancer cells are resistant to apoptosis induction by TRAIL due to TRAIL-activated nuclear factor-kappaB (NF-kappaB) signalling. Several chemopreventive agents are able to inhibit NF-kappaB, and favourable results have been obtained--for example, for the broccoli compound sulforaphane-in preventing metastasis in clinical studies. The aim of the study was to identify TICs in pancreatic carcinoma for analysis of resistance mechanisms and for definition of sensitising agents.

METHODS

TICs were defined by expression patterns of a CD44(+)/CD24(-), CD44(+)/CD24(+) or CD44(+)/CD133(+) phenotype and correlation to growth in immunodeficient mice, differentiation grade, clonogenic growth, sphere formation, aldehyde dehydrogenase (ALDH) activity and therapy resistance.

RESULTS

Mechanistically, specific binding of transcriptionally active cRel-containing NF-kappaB complexes in TICs was observed. Sulforaphane prevented NF-kappaB binding, downregulated apoptosis inhibitors and induced apoptosis, together with prevention of clonogenicity. Gemcitabine, the chemopreventive agents resveratrol and wogonin, and the death ligand TRAIL were less effective. In a xenograft model, sulforaphane strongly blocked tumour growth and angiogenesis, while combination with TRAIL had an additive effect without obvious cytotoxicity in normal cells. Freshly isolated patient tumour cells expressing markers for TICs could be sensitised by sulforaphane for TRAIL-induced cytotoxicity.

CONCLUSION

The data provide new insights into resistance mechanisms of TICs and suggest the combination of sulforaphane with TRAIL as a promising strategy for targeting of pancreatic TICs.

Immunohistochemical Detection of P Glycoprotein, Glutathione S Transferase and DNATopoisomerase II in Human Tumors

The expression of the drug resistance markers P glycoprotein (P-170), glutathione S transferase-pi (GST-pi) and DNA topoisomerase II (Topo II) was analyzed in 16 human kidney carcinoma cell lines, 18 hematological malignancies, and 14 human breast carcinomas. We found a tendency for coexpression of increased P-170 and GST-pi and of increased P-170 and decreased Topo II expression in kidney carcinoma cell lines. A similar tendency was found between P-170 and GST-pi expression in breast carcinomas. In contrast, hematological malignancies did not show such a coexpression of resistance markers. Furthermore, we found interrelationships between the expression of resistance markers, resistance to doxorubicin or vincristine, and doubling times of kidney carcinoma cell lines. This indicates that the proliferative activity of tumor cells plays a role for the expression of resistance markers and the development of resistance to cytostatic drugs.

The use of hyperventilation therapy after traumatic brain injury in Europe: an analysis of the BrainIT database

OBJECTIVE

To assess the use of hyperventilation and the adherence to Brain Trauma Foundation-Guidelines (BTF-G) after traumatic brain injury (TBI).

SETTING

Twenty-two European centers are participating in the BrainIT initiative.

DESIGN

Retrospective analysis of monitoring data.

PATIENTS AND PARTICIPANTS

One hundred and fifty-one patients with a known time of trauma and at least one recorded arterial blood-gas (ABG) analysis.

MEASUREMENTS AND RESULTS

A total number of 7,703 ABGs, representing 2,269 ventilation episodes (VE) were included in the analysis. Related minute-by-minute ICP data were taken from a 30 min time window around each ABG collection. Data are given as mean with standard deviation. (1) Patients without elevated intracranial pressure (ICP) (< 20 mmHg) manifested a statistically significant higher P(a)CO(2) (36 +/- 5.7 mmHg) in comparison to patients with elevated ICP (> or = 20 mmHg; P(a)CO(2): 34 +/- 5.4 mmHg, P < 0.001). (2) Intensified forced hyperventilation (P(a)CO(2) < or = 25 mmHg) in the absence of elevated ICP was found in only 49 VE (2%). (3) Early prophylactic hyperventilation (< 24 h after TBI; P(a)CO(2) < or = 35 mmHg, ICP < 20 mmHg) was used in 1,224 VE (54%). (4) During forced hyperventilation (P(a)CO(2) < or = 30 mmHg), simultaneous monitoring of brain tissue pO(2) or S(jv)O(2) was used in only 204 VE (9%).

CONCLUSION

While overall adherence to current BTF-G seems to be the rule, its recommendations on early prophylactic hyperventilation as well as the use of additional cerebral oxygenation monitoring during forced hyperventilation are not followed in this sample of European TBI centers.

DESCRIPTOR

Neurotrauma.

Improved lentiviral transduction of human mesenchymal stem cells for therapeutic intervention in pancreatic cancer

Genetic modification of human bone marrow mesenchymal stem cells (MSC) is highly valuable for their exploitation in basic science and therapeutic applications, for example in cancer. We present here a new, fast and easy-to-use method to enrich a functional population of lentiviral (LV)-transduced MSC expressing enhanced green fluorescent protein (eGFP). We replaced the eGFP gene by a fusion gene of puromycin acetyltransferase and eGFP. Upon LV gene transfer and puromycin selection, we quickly obtained a pure transduced MSC population, in which growth, differentiation capacity and migration preferences were not compromised. Furthermore, we are the first to report the migration velocity of MSC among which 30% were moving and velocity of about 15 mum h(-1) was not altered by LV transduction. Manipulated MSC underwent senescence one passage earlier than non-transduced cells, suggesting the use for therapeutic intervention in early passage numbers. Upon tail vein application in nude mice, the majority of LV-transduced MSC could be detected in human orthotopic pancreatic tumor xenografts and to a minor extent in mouse liver, kidney and lung. Together, LV transduction of genes to MSC followed by puromycin selection is a powerful tool for basic research and improves the therapeutic prospects of MSC as vehicles in gene therapy.

Apoptosis mediated by lentiviral TRAIL transfer involves transduction-dependent and -independent effects

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising anticancer agent, which selectively induces apoptosis in many transformed cells without apparent toxic side effects in normal tissue. We recently described the construction and characterization of a lentiviral vector for expression of TRAIL. In this report, we evaluate its suitability for therapeutic application. In vitro, we observed specific induction of apoptosis upon transduction in human lung cancer cells. Cell death was partially dependent on successful integration and TRAIL expression by the vectors, but was to some extent mediated by protein carryover, as we found TRAIL protein associated with virus particles. Transduction of subcutaneously growing lung tumors on nude mice with lentiviral TRAIL mediated a transient suppression of tumor growth. Analysis of tumor sections revealed that transduction efficiency of lentiviral control vector but not of lentiviral TRAIL vector was high. This was because of the direct cytotoxic activity of recombinant TRAIL present in viral particles, which prevented efficient tumor transduction. These data therefore suggest that enveloped viral vectors constitutively expressing TRAIL are well suited for ex vivo applications, such as the transduction of tumor-homing cells, but may have a lower effect when used directly for the transduction of tumor cells in vivo.

Specific resistance upon lentiviral TRAIL transfer by intracellular retention of TRAIL receptors

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in many transformed cells, suggesting TRAIL as an ideal candidate for cancer gene therapy. A main obstacle in cancer therapy is intrinsic or acquired therapy resistance of malignant cells. To study induction of resistance against TRAIL, we generated lentiviral vectors allowing efficient TRAIL expression and apoptosis induction in a variety of human cancer cell lines. Within days upon TRAIL overexpression, cells became resistant towards TRAIL, but not to CD95 ligation or DNA damage by cisplatin. Cell surface expression of TRAIL receptors 1 and 2 was completely abrogated in resistant cells due to intracellular retention of the receptors by TRAIL. SiRNA directed against TRAIL resensitized the resistant cells by restoring cell surface expression of TRAIL receptors. These findings represent a novel resistance mechanism towards TRAIL, specifically caused by TRAIL overexpression, and question the use of TRAIL expression in tumor-cell targeting gene therapy.

Corticosteroid-induced chemotherapy resistance in urological cancers

PURPOSE

Glucocorticoids such as dexamethasone are widely used for medication of urological diseases, e.g., as cotreatment of advanced prostate cancer, to improve appetite, weight loss, fatigue, relieve bone pain, diminish ureteric obstruction, to reduce the production of adrenal androgens, as an antiemetic in patients undergoing chemo- and/or radiotherapy together with serving as "standard" therapy arm in randomized studies. While the potent pro-apoptotic properties and the supportive effects of glucocorticoids to tumor therapy in lymphoid cells are well studied, the impact to growth of prostate and other urological carcinomas is unknown.

METHODS

We isolated cells from surgical resections of 21 prostate tumors and measured apoptosis and viability in these primary cells and 17 established cell lines from human prostate, bladder, renal cell and testicular carcinomas.

RESULTS

We found that dexamethasone induces resistance regarding exposure to several cytotoxic agents such as taxol, gemcitabine, cisplatin, 5-FU and gamma-irradiation in 86% of the freshly isolated prostate tumors and in 100% of the established urological cell lines. No difference in dexamethasone-mediated protection was found in normal, benign and malignant prostate tumors.

CONCLUSIONS

These data show for the first time that dexamethasone induced therapy resistance in urological carcinomas is not the exception but a more common phenomenon and implicate that glucocorticoids may have two faces in cancer therapy, a beneficial and a dangerous one.

Dexamethasone desensitizes hepatocellular and colorectal tumours toward cytotoxic therapy

The glucocorticoid dexamethasone is frequently used as co-treatment in cytotoxic cancer therapy, e.g. to prevent nausea, to protect normal tissue or for other reasons. While the potent pro-apoptotic properties and the supportive effects of glucocorticoids to tumour therapy in lymphoid cells are well studied, the impact to cytotoxic treatment of colorectal and hepatocellular carcinoma is unknown. We tested apoptosis-induction, viability, tumour growth and protein expression using 8 established cell lines, 18 surgical specimen and a xenograft on nude mice. In the presence of dexamethasone we found strong inhibition of apoptosis in response to 5-FU, cisplatin, gemcitabine or gamma-irradiation, enhanced viability and tumour growth of colorectal and hepatocellular carcinomas. No correlation with age, gender, histology, TNM, the p53 status and induction of therapy resistance by dexamethasone co-treatment could be detected. These data show that glucocorticoid-induced resistance occurs not occasionally but is common in colorectal and hepatocellular carcinomas implicating that the use of glucocorticoids may be harmful for cancer patients.

Dexamethasone-induced cisplatin and gemcitabine resistance in lung carcinoma samples treated ex vivo

Chemotherapy for lung cancer not only has severe side effects but frequently also exhibits limited, if any clinical effectiveness. Dexamethasone (DEX) and similar glucocorticoids (GCs) such as prednisone are often used in the clinical setting, for example, as cotreatment to prevent nausea and other symptoms. Clinical trials evaluating the impact of GCs on tumour control and patient survival of lung carcinoma have never been performed. Therefore, we isolated cancer cells from resected lung tumour specimens and treated them with cisplatin in the presence or absence of DEX. Cell number of viable and dead cells was evaluated by trypan blue exclusion and viability was measured by the MTT-assay. We found that DEX induced resistance toward cisplatin in all of 10 examined tumour samples. Similar results were found using gemcitabine as cytotoxic drug. Survival of drug-treated lung carcinoma cells in the presence of DEX was longlasting as examined 2 and 3 weeks after cisplatin treatment of a lung carcinoma cell line. These data corroborate recent in vitro and in vivo xenograft findings and rise additional concerns about the widespread combined use of DEX with antineoplastic drugs in the clinical management of patients with lung cancer.

Induction of apoptosis in experimental human B cell lymphomas by conditional TRAIL-expressing T cells

In the present study, we demonstrate the utility of a non-tumour-forming T-cell line for the inducible gene transfer of tumour necrosis factor (TNF)-related apoptosis-inducing ligand (Apo2L/TRAIL), which has been shown to selectively induce apoptosis in malignant but not in normal cells. To generate T cells inducible for TRAIL expression, we stably transfected Jurkat cells with TRAIL in the context of the Tet-On system. The switched on cells strongly expressed TRAIL mRNA, whose protein product was expressed on the cell surface. Paracrine induction of apoptosis in human target tumour cells was solely found for membrane-bound TRAIL. The Jurkat-TRAIL cells itself survived due to clonal selection of TRAIL-resistant cells. Jurkat-TRAIL cells had an additive effect with cytotoxic drugs in vitro, since cell death was enhanced. To elucidate the antitumoral activity of these Jurkat-TRAIL cells in vivo, we injected them intratumorally in xenografts of human Burkitt lymphomas. Switching on expression of TRAIL by adding tetracycline to the drinking water of the mice strongly reduced tumour growth by apoptosis in a caspase-dependent manner. Thus, non-tumour-forming T-cell lines offer a novel method for gene transfer and inducible expression of TRAIL in tumour therapy.

Protein expression profiles indicative for drug resistance of non-small cell lung cancer

Data obtained from multiple sources indicate that no single mechanism can explain the resistance to chemotherapy exhibited by non-small cell lung carcinomas. The multi-factorial nature of drug resistance implies that the analysis of comprising expression profiles may predict drug resistance with higher accuracy than single gene or protein expression studies. Forty cellular parameters (drug resistance proteins, proliferative, apoptotic, and angiogenic factors, products of proto-oncogenes, and suppressor genes) were evaluated mainly by immunohistochemistry in specimens of primary non-small cell lung carcinoma of 94 patients and compared with the response of the tumours to doxorubicin in vitro. The protein expression profile of non-small cell lung carcinoma was determined by hierarchical cluster analysis and clustered image mapping. The cluster analysis revealed three different resistance profiles. The frequency of each profile was different (77, 14 and 9%, respectively). In the most frequent drug resistance profile, the resistance proteins P-glycoprotein/MDR1 (MDR1, ABCB1), thymidylate-synthetase, glutathione-S-transferase-pi, metallothionein, O6-methylguanine-DNA-methyltransferase and major vault protein/lung resistance-related protein were up-regulated. Microvessel density, the angiogenic factor vascular endothelial growth factor and its receptor FLT1, and ECGF1 as well were down-regulated. In addition, the proliferative factors proliferating cell nuclear antigen and cyclin A were reduced compared to the sensitive non-small cell lung carcinoma. In this resistance profile, FOS was up-regulated and NM23 down-regulated. In the second profile, only three resistance proteins were increased (glutathione-S-transferase-pi, O6-methylguanine-DNA-methyltransferase, major vault protein/lung resistance-related protein). The angiogenic factors were reduced. In the third profile, only five of the resistance factors were increased (MDR1, thymidylate-synthetase, glutathione-S-transferase-pi, O6-methylguanine-DNA-methyltransferase, major vault protein/lung resistance-related protein).

Ocular bioavailability of ciprofloxacin in sustained release formulations

A novel sustained release delivery system of ciprofloxacin for the eye was developed. The system consists of a viscosity enhancer (carbopol gel or hydroxypropylmethylcellulose solution) plus a penetration enhancer (dodecylmaltoside) to overcome penetration barriers and loss due to wash-out and thus achieve the desired ciprofloxacin ocular absorption. The present studies were designed to assess the ocular penetration and bioavailability of ciprofloxacin in sustained release formulations. In vitro studies in rabbits indicated an approximate 10-fold increase in drug penetration through the rabbit cornea using the penetration enhancer, dodecylmaltoside. In vivo bioavailability studies demonstrate that these formulations provided a long drug duration in the cornea. After administration of a single topical dose of ciprofloxacin (0.3%/30 microL), corneal levels greater than the Minimum Inhibitory Concentration (MIC90) (0.5 microg/g) were observed through eight hours. These sustained release formulations delivered 10-fold more drug into the aqueous humor than the standard solution formulation. Maximum ciprofloxacin concentrations in the aqueous humor (0.5-0.7 microg/mL) were attained between one and two hours after dosing. Using these sustained release formulations, ciprofloxacin can penetrate to the anterior chamber of the eye in concentrations that are inhibitory for most gram-negative and gram-positive organisms. These topical ocular formulations have prophylactic utility for prevention of post-surgical infection, offering greater efficacy and safety than currently available treatments.

Role of angiogenesis in drug resistance

Tumor angiogenesis seems to be an important factor in determining therapeutic effectiveness and patient prognosis. An abundance of data on tumor angiogenesis is available and it clearly shows that most human solid tumors are heterogeneously vascularized and oxygenated and contain hypoxic regions. Such regions and areas of reduced vascularization can affect the response to a variety of drugs. Direct measurements of angiogenesis in various types of tumors have, upon correlation of the data with therapeutic outcome, shown that a high vascular density is associated with a decreased response to therapy and short overall survival time. Therefore, the extent of tumor angiogenesis may well be an important factor contributing to the difficulty of successful therapy in certain tumor types.

Clinical estimation of the growth rate of lung cancer

It is well known that the growth rate of lung tumors is closely related to prognosis and is an important determinant of responsiveness to therapy and curability. In this study, the velocity of tumor growth was calculated by dividing the area of the lesion at presentation divided by the time elapsed since symptoms were first noted. This parameter was applied to a group of patients with lung cancer and the predictive value of the velocity of tumor growth was assessed. Survival expectancy was found to be closely related to the growth rate of the tumors. The median survival time of patients with more slowly growing tumors was 102 weeks, while that of patients with fast-growing tumors was 30 weeks (log-rank test, p=0.00001). Linear regression analysis between velocity of tumor growth and tumor cell proliferation as measured by the PCNA-labelling index revealed a significant correlation between these two parameters. In conclusion, the velocity of a tumor measured in this way is an independent and significant prognostic factor for patients with lung cancer and may be used to non-invasively assess lung cancer proliferation in vivo, identifying rapidly growing tumors with poor prognosis that could benefit from a more aggressive therapy.

Angiostatin expression in non-small cell lung cancer

Angiostatin, a potent inhibitor of angiogenesis, tumor growth, and metastasis, was examined in a panel of human lung cancer cell lines with Western blot analysis and in 143 primary non-small cell lung carcinomas with immunohistochemistry. Thirty-four of 143 cases (24%) stained positively. Patients with angiostatin-positive tumors survived longer (146 weeks) than patients with angiostatin-negative tumors (77 weeks; log-rank test: P = 0.07; rank-sum test: P = 0.02). To determine whether combining stimulating and inhibiting factors might improve the prognostic capability, both angiostatin and vascular endothelial growth factor (VEGF) were analyzed together with respect to patient survival. The median survival time of patients with angiostatin-positive/VEGF-negative carcinomas was 184 weeks, whereas the median survival time of patients with angiostatin-negative/VEGF-positive tumors was only 52 weeks. The angiostatin-positive tumors exhibited an increased incidence of apoptosis and a reduced capability to be transplanted into nude mice, but these differences did not reach or were only of borderline statistical significance.

A community-based assessment of heat-related morbidity in North Philadelphia

A 6-month community-based study designed to (1) determine the perceptions and barriers affecting the overall quality of life of isolated older adults greater than 65 years of age, (2) assess their risk factors, health attitudes, and beliefs concerning their susceptibility to heat-related conditions, and (3) evaluate the effectiveness of an age-specific innovative intervention program consisting of a specially marked clock-like thermometer and other creative educational materials was conducted among 34 participants during the spring and summer of 1997 in north Philadelphia. The study objectives were measured at preintervention (baseline) and at 8 weeks postintervention follow-up using a 24-item pretest/posttest self-administered questionnaire. We report the short-term benefit of our intervention, theorize that innovative strategies targeting at-risk older adults should be culturally sensitive and age-specifically appropriate, and recommend that more vigorous research methods should be implemented to lend credence to our findings.

Association of telomerase expression with successful heterotransplantation of lung cancer

This study analyzed whether the expression of telomerase may serve as prognostic factor for the aggressiveness of human non-small cell lung carcinomas. To this purpose the expression of telomerase measured by immunohistochemistry was compared with the take rate of the primary tumors that were heterotransplanted into nude mice. Formalin-fixed, paraffin-embedded specimens of 97 non-small cell lung carcinomas from primarily untreated patients were analyzed for the expression of telomerase by a goat polyclonal antibody (clone C-20). Moderate or strong telomerase-staining was found in 78 (80%) cases. Age, gender, stage and histology had no influence on the telomerase expression. It was discovered that of the 19 telomerase-negative carcinomas only five (26%) exhibited growth in nude mice while of the 78 telomerase-positive cases 37 (47%) were successfully transplanted. To confirm these results, alcohol-fixed, paraffin-embedded cancer specimens from another group of patients (n=58) were analyzed for telomerase expression by a rabbit polyclonal antibody (clone H-231). Corresponding results were obtained. The take rate of telomerase-negative carcinomas was only 36%; the take rate of telomerase-positive carcinomas was 59%. These data suggest that high telomerase expression does indeed correlate with the aggressiveness of non-small cell lung carcinomas.

Glucose-related protein (GRP78) and its relationship to the drug-resistance proteins P170, GST-pi, LRP56 and angiogenesis in non-small cell lung carcinomas

Several studies have documented that induction of the glucose-related protein (GRP78) is associated with the development of drug-resistance to antitumor drugs. However, nothing has been reported concerning GRP78 in human lung tumors and its relationship to several resistance proteins and angiogenesis. Therefore, this study analyzed the expression of GRP78 in a series of 62 consecutive lung cancer patients and examined whether or not a relationship exists between GRP78, several resistance proteins and microvessel density (MVD). Secondary, it evaluated the relationship of GRP78, LRP56 and GST-pi in cancer cell lines under hypoxic conditions and in sensitive and resistant cell lines. We determined that a relationship exists between GRP78 and the resistance proteins P170, LRP56 and GST-pi in human lung cancer. Furthermore, we observed an up-regulation of GRP78 in the resistant cell lines LUTC-ML54, OAW-Dox and OAW-Tax, but not in sensitive cell lines. Abnormal vascularization of malignant tumors is associated with the development of hypoxic regions. In hypoxic regions, several proteins, including drug resistance proteins, are expressed in greater quantities. Our study detected an inverse correlation between GRP78 and MVD. Carcinomas with low MVD exhibited a higher expression of GRP78. Furthermore, protein expression of GRP78, GST-pi and LRP56 increased in the cell lines A-549, RPMI-2650 and SC-MES-1 under hypoxic conditions. These observations suggest that hypoxia, tumor vascularization and the simultaneous expression of many resistance-related proteins, including GRP78, may play an important role in drug response and therapeutic effectiveness.

Pathophysiologic basis of contrast enhancement in breast tumors

While the diagnostic benefits of gadolinium (Gd)-chelate contrast agents are firmly established in magnetic resonance imaging (MRI) of tumors, the pathophysiologic basis of the enhancement observed and its histopathologic correlate remained vague. Tumor angiogenesis is fundamental for growth and metastasis and also of interest in new therapeutic concepts. By correlative analysis of a) histology; b) vascular density (CD31); and c) vascular permeability (vascular permeability factor/vascular endothelial growth factor [VPF/VEGF]), we found a) significantly (P < 0.001) faster exchange rates in malignant compared with benign breast lesions; b) distinct differences in enhancement characteristics between the histologic types (invasive ductal carcinoma, invasive lobular carcinoma, and ductal carcinoma in situ); and c) dependence of enhancement kinetics on the VPF/VEGF expression. The pathophysiologic basis for the differences in contrast enhancement patterns of tumors detectable by MRI is mainly due to vascular permeability, which leads to more characteristic differences than vascular density. MRI is able to subclassify malignant breast tumors due to their different angiogenetic properties.

Biological characterization of subgroups of squamous cell lung carcinomas

Recently, Pezzella et al. (Am. J. Pathol., 1997, 151: 1417-1423, 1997) reported on a subgroup of non-small cell lung carcinomas that had no morphological evidence of neoangiogenesis but appeared to grow and were highly aggressive. In this investigation, we subdivided 87 squamous cell lung carcinomas into four subgroups according to angiogenesis (low and high vessel density) and tumor growth (low and high tumor cell proliferation). The aim was to find differences, if any, in the angiogenic status and clinical behavior between these subgroups. We identified a group of tumors with low angiogenesis and high tumor cell proliferation that was characterized by high expression of vascular endothelial growth factor, low expression of basic fibroblast growth factor, reduced apoptosis, increased incidence of metastases, and short survival times. These data show that even squamous cell lung carcinomas are a heterogeneous group of tumors that can be subdivided in tumors with different biological properties and different clinical behaviors.

Inverse correlation between apoptotic (Fas ligand, caspase-3) and angiogenic factors (VEGF, microvessel density) in squamous cell lung carcinomas

In order to explore whether apoptosis is associated with angiogenesis in lung cancer, immunohistochemistry was employed to determine the pro-apoptotic factors Fas ligand (FasL) and caspase-3 (Cas-3) in 70 squamous cell lung carcinomas. Furthermore, the vascular endothelial growth factor (VEGF) and the microvessel density (MVD) were analyzed. The comparison between MVD and the pro-apoptotic factors demonstrated that the apoptotic factors are inversely related to MVD (Cas-3: p = 0.011, FasL: not significant). In order to confirm this result, FasL and Cas-3 were also compared with the expression of VEGF. Again, an inverse correlation between VEGF and the pro-apoptotic factors was found (Cas-3: p = 0.019, FasL: p = 0.008). The inverse correlation between angiogenesis and apoptosis may be explained by the activation of pro-apoptotic and anti-angiogenic factors caused by hypoxia.

Xenotransplantability of human squamous cell lung cancer in nude mice is not affected by angiogenic factors

Sixty-two human squamous cell lung carcinomas were analyzed for expression of various angiogenic growth factors and their receptors using immunohistochemistry. The data were correlated with xenotransplantability of these tumors in nude mice. None of the factors investigated did show an association with xenotransplantability. However, there was a trend that specimens lacking VEGF165 were established as xenografts at a higher incidence (52%) than those expressing VEGF165 (39%).

Relationship of urokinase and urokinase receptor in non-small cell lung cancer to proliferation, angiogenesis, metastasis and patient survival

The purpose of the analysis was to ascertain whether the expression of components of the plasminogen activation system possesses an association with several biological parameters. The expression of urokinase (uPA) and urokinase receptor (uPAR) was analyzed in 137 non-small cell lung carcinomas by immunohistochemistry. No relationship could be observed between the proliferative activity of the carcinomas measured by flow cytometry and the expressions of uPA and uPAR. In addition, there was no association of the expressions of uPA or uPAR and vessel density (angiogenesis), neither any significant correlation between the expressions of uPA or uPAR and metastasis. The median survival was shorter for patients with uPA positive carcinomas than for those with uPA negative tumors (60 vs. 111 weeks; p=0.018). The relative risk estimate for patients with uPA positive tumors was increased by a factor of 1.8. In contrast, the expression of uPAR showed no significant correlation with overall survival.

Angiogenesis and cigarette smoking in squamous cell lung carcinomas: an immunohistochemical study of 28 cases

Angiogenesis in tumors is influenced by several factors which in turn are associated with chemoresistance or radioresistance. Moreover, the tumors of smokers are known to be relatively resistant to chemotherapy. This investigation attempts to determine whether or not a relationship exists between cigarette smoking and angiogenesis in lung cancer. Tumor samples from 14 non-smokers and 14 heavy cigarette smokers were selected for this study. The populations were matched for age, sex and tumor stage. Resistance to doxorubicin, microvessel density, the expression of vascular endothelial growth factor (VEGF) and thrombospondin (TSP) were analyzed in both populations. Tumors of smokers were more frequently resistant to doxorubicin in vitro, had lower vessel counts and a reduced expression of VEGF compared to tumors of nonsmokers. In contrast, TSP was significantly increased in the tumors of smokers. These data show that angiogenesis in lung tumors is linked to a patient's smoking habits.

PD-ECGF, bFGF, and VEGF expression in non-small cell lung carcinomas and their association with lymph node metastasis

The angiogenic factors PD-ECGF, bFGF and VEGF were determined immunohistochemically in 168 non-small cell lung carcinomas to investigate whether the expression of these parameters is correlated with lymph node metastasis of patients. The expressions of the above mentioned factors was indeed associated with lymph node metastasis, but the results were not statistically significant. However, a combination of the factors PD-ECGF, bFGF and VEGF significantly improved the prognostic information. The number of tumors with lymph node involvement increased with the number of angiogenic factors. Only 43% of the patients had-lymph node involvement when all factors were negative whereas 77% showed metastasis when all factors were positive (one factor positive: 53%, two factors positive: 68). This result is statistically significant (p = 0.002, test for trend).

Expression of platelet-derived endothelial cell growth factor in non-small cell lung carcinomas: relationship to various biological factors

The expression of platelet-derived endothelial cell growth factor (PD-ECGF) was determined immunohistochemically in 143 non-small cell lung carcinomas. Staining was observed in 48% of the cases. A relationship between histology, stage, erbB-1, erbB-2, ras and PD-ECGF expression was not found. A relationship of borderline significance was observed between PD-ECGF and p53 expression. There was also no relationship between PD-ECGF expression and proliferative activity (G1 phases, S phases, cyclin A). In contrast, a correlation between PD-ECGF- and VEGF-expression was detectable (p=0.009). Furthermore, PD-ECGF expression was related to the response of lung carcinomas to doxorubicin (p=0.0004). Of 35 sensitive tumors, 26 carcinomas were PD-ECGF-positive (74%) while of 108 resistant carcinomas only 43 tumors (40%) exhibited PD-ECGF expression.

Association between nm23-H1 expression, proliferation and apoptosis in non-small cell lung carcinomas

Twelve non-small cell lung carcinomas and adjacent normal lung tissues were examined for mutations of the nm23-H1 gene by using SSCP analysis and for an expression of the nm23-H1 protein by immunohistochemistry. No mutations could be found in either the carcinomas or in the adjacent normal tissues. In contrast, six of 12 carcinomas showed protein expression while only one adjacent normal lung tissue yielded a positive staining result. Therefore, the expression of nm23-H1 protein was analysed in a larger group of non-small cell lung carcinomas (n = 185) to determine whether or not the expression of nm23 protein may be of prognostic relevance. Only a weak relationship between nm23-H1 expression and lymph node involvement was observed. However, a significant correlation between proliferation and nm23-H1 expression was detected. Additionally, a direct correlation between apoptosis and nm23-H1 expression or between myc and nm23-H1 expression was found. Finally, non-small cell lung carcinomas that expressed nm23-H1 protein were more frequently sensitive to doxorubicin than carcinomas that did not express this protein.

O6-methylguanine-DNA methyltransferase activity and sensitivity to cyclophosphamide and cisplatin in human lung tumor xenografts

The DNA repair protein O6-methylguanine-DNA methyl-transferase (MGMT) is a main determinant of resistance of cells to the cytostatic effects of O6-alkylguanine-generating alkylating agents. The purpose of our study was to assay MGMT activity in cells of lung cancers and to correlate MGMT levels with chemotherapy response to cyclophosphamide (CTX) and cisplatin (DDP). MGMT levels were determined in 14 human lung tumor xenografts. There was a wide variation of MGMT expression in these tumors, ranging from 10 to 984 fmol/mg protein. There was also a wide range in the sensitivity of the xenografts to CTX and DDP, as measured by specific growth delay. When the MGMT levels of the different xenograft lines were compared with the corresponding responses to CTX and DDP, a close correlation was found between MGMT activity and CTX (lin reg., r = -0.83, p < 0.05). The higher the MGMT activity, the less pronounced was the growth-inhibiting effect of CTX. With DDP, no such correlation was found. Our results indicate that the in vivo response of tumors to CTX is related to the level of MGMT expression.

Smoking-related increase of O6-methylguanine-DNA methyltransferase expression in human lung carcinomas

Eighty-three non-small cell lung carcinomas (NSCLC) of previously untreated patients were analysed for expression of O6-methylguanine-DNA methyltransferase (MGMT) by means of immunohistochemistry. Expression of MGMT was detected in 62 of 83 tumours (75%). There was a significant difference in MGMT staining between smokers and non-smokers (P = 0.001). Tumours of smokers expressed more frequently MGMT than tumours of non-smokers. There was a trend of MGMT expression to be higher in tumours of patients smoking >20 cigarettes/day than patients smoking <20 cigarettes/day. Abstinence from smoking resulted in a significant decrease in MGMT expression (lin reg r = -0.59, P < 0.05). These results demonstrate that MGMT expression in human lung carcinomas is influenced by smoking habits of the patients.