Systematic meta-analysis on percutaneous ethanol injection and percutaneous acid injection for the treatment of early HCC: A Cochrane analysis

e15657

Background: Hepatocellular carcinoma (HCC) is the fifth most common global cancer with high geographical variability. When HCC is detected early, percutaneous approaches such as percutaneous ethanol injection (PEI), percutaneous acetic acid injection (PAI), and radiofrequency thermal ablation (RFTA) have curative potential and represent low invasive alternatives to surgery. The role of percutaneous ethanol or acetic acid injection and other percutaneous interventions except RFTA has not been addressed in a systematic metaanalysis. The objective was to evaluate the effects of PEI and PAI for early HCC. Methods: A systematic search was performed in EMBASE, Cochrane Central, The Cochrane Hepato-Biliary Group Controlled Trials Register, Medline and Scopus as well as a handsearch of meeting abstracts. Only randomised controlled trials were included. RFTA studies were not considered. Primary endpoint was overall survival, secondary endpoints were cancer free survival, number and type of adverse events, duration of hospital stay, and quality of life. Results: 3 studies covering 261 patients were identified. Two studies compared PEI with PAI. 91 and 94 patients with one to three HCC-nodules ≤ 3cm underwent PEI and PAI, respectively. Overall survival (HR 1.47; 95% CI 0.68 to 3.19) and cancer free survival (HR 1.42; 95% CI 0.68 to 2.94) were not significantly different after treatment by PEI versus PAI. Both treatments were safe with no serious adverse events reported and modest pain being the most frequent adverse event. Data on the duration of hospital stay were inconclusive and data on quality of life not available. One study compared PEI with surgery. 38 patients were allocated to each treatment arm. There was no significant difference in survival (HR 1.57; 95% CI 0.53 to 4.61) and cancer free survival (HR 1.35; 95% CI 0.69 to 2.63). No serious adverse events were reported in the PEI group but 3 postoperative deaths occurred in the surgery arm. Conclusions: PEI and PAI are similarly effective and safe in patients with one to three small (≤ 3 cm) HCC nodules. Although the evidence is weaker, the beneficial effect of PEI is comparable to that of segmental liver resection and thus should be used preferentially due to its low morbidity and mortality.

No significant financial relationships to disclose.

[Prevention of gastrointestinal malignancies]

Malignancies of the gastrointestinal tract are the most common causes of cancer-related deaths in Germany. They also induce significant morbidity. Despite both surgical and medical therapeutic improvements, advanced stages of these cancers can rarely be cured. Preventive and screening measures are suitable to decrease gastrointestinal cancer-related mortality. Weight reduction and cessation of smoking are effective in preventing esophageal, pancreatic and colorectal cancer. Treatment of infections like chronic viral hepatitis and helicobacter pylori gastritis is able to protect from hepatocellular and gastric cancer, respectively. Colonoscopy is one of the best established screening methods. It allows early detection of colorectal neoplasia. Preneoplastic adenomas can be endoscopically removed during the same session. We here review simple prevention strategies and effective screening methods in gastrointestinal cancers of relevance in daily practice.

Bendamustine--a new approach to the treatment of advanced hepatocellular carcinoma?

AIMS

Therapeutic options for advanced hepatocellular carcinoma (HCC) are limited. Bendamustine, a bifunctional cytostatic agent with mainly alkylating effect may be an alternative.

METHODS

Five HCC cell lines were incubated in vitro with five different concentrations of bendamustine. In addition, cell lines Huh-7 and HepG2 were tested in a chimeric mouse model.

RESULTS

In vitro treatment with bendamustine resulted in an IC( 50 )<6 microg/mL in two, <12 microg/mL in one, and 12-23 microg/mL in two cell lines. In vivo, bendamustine reduced significantly tumor volume in chimeric mice.

CONCLUSION

Bendamustine demonstrated significant tumor growth inhibition both in vitro and in vivo at concentrations that can be reached in the plasma. The potential role of bendamustine therapy for HCC and its tolerability in impaired liver function is currently subject of a phase II study.

Capecitabine plus oxaliplatin (CapOx) versus capecitabine plus gemcitabine (CapGem) versus gemcitabine plus oxaliplatin (mGemOx): final results of a multicenter randomized phase II trial in advanced pancreatic cancer

BACKGROUND

To compare the efficacy and safety of three different chemotherapy doublets in the treatment of advanced pancreatic cancer (PC).

PATIENTS AND METHODS

At total of 190 patients were randomly assigned to receive capecitabine 1000 mg/m(2) twice daily on days 1-14 plus oxaliplatin 130 mg/m(2) on day 1 (CapOx), capecitabine 825 mg/m(2) twice daily on days 1-14 plus gemcitabine 1000 mg/m(2) on days 1 and 8 (CapGem) or gemcitabine 1000 mg/m(2) on days 1 and 8 plus oxaliplatin 130 mg/m(2) on day 8 (mGemOx). Treatment cycles were repeated every three weeks. The primary end point was progression-free survival (PFS) rate at 3 months; secondary end points included objective response rate, carbohydrate antigen 19-9 response, clinical benefit response, overall survival and toxicity.

RESULTS

The PFS rate after 3 months was 51% in the CapOx arm, 64% in the CapGem arm and 60% in the mGemOx arm. Median PFS was estimated with 4.2 months, 5.7 months and 3.9 months, respectively (P = 0.67). Corresponding median survival times were: 8.1 months (CapOx), 9.0 months (CapGem) and 6.9 months (mGemOx) (P = 0.56). Grade 3/4 hematological toxicities were more frequent in the two Gem-containing arms; grade 3/4 non-hematological toxicity rates did not exceed 15% in any arm.

CONCLUSION

CapOx, CapGem and mGemOx have similar clinical efficacy in advanced PC. Each regimen has a distinct but manageable tolerability profile.

Treatment of pancreatic cancer with two novel histone deacetylase inhibitors NVP-LAQ824 and NVP-LBH589

4624

Background: Pancreatic cancer is the fifth to sixth leading cause of cancer death in Europe and up to 90% of patients will present with locally advanced or metastatic disease. Unfortunately, little progress has been obtained from chemotherapy regimens in the past decade. Treatment with histone deacetylase inhibitors, like NVP-LAQ824 and NVP-LBH589, either alone or in combination with conventional chemotherapy may be a novel alternative. Methods: Cell-growth inhibition by NVP-LAQ824 and NVP-LBH589 was studied in vitro in 8 human pancreatic cancer cell lines by MTT assay. In addition, the anti-tumoral effect of NVP-LBH589 was studied in a chimeric mouse model. Anti-tumoral drug mechanism was assessed by immunoblotting for p21WAF-1, acH4, p42/p44, Phospho-p42/p44, AKT, Phospho- AKT, cell cycle analysis, TUNEL assay, and immunohistochemistry for MIB-1. Results: In vitro treatment with both compounds significantly suppressed the growth of all cancer cell lines (mean IC50 (6d) 0.06 and 0.03 μM, respectively) and was associated with hyperacetylation of nucleosomal histones H4, increased expression of p21WAF-1, and cell cycle arrest at G2/M-checkpoint. After 21 d, NVP-LBH589 alone reduced tumor mass in vivo by 70% and in combination with gemcitabine by 81% in comparison to placebo for cell line L3.6 pl. Further analysis of the tumor specimens revealed slightly increased apoptosis (TUNEL) and no significant reduction of cell proliferation (MIB-1). Protein levels of p42/p44, and AKT remained stable, whereas levels of Phospho-p42/p44 and Phospho-AKT increased. Conclusions: Our findings suggest that NVP-LBH589 > NVP-LAQ824 are active against human pancreatic cancer in vitro. In addition, NVP-LBH589 demonstrated significant in vivo activity and potentiated the efficacy of gemcitabine, although the precise mechanism of drug action is not yet completely understood. Therefore, further preclinical and clinical evaluation of this new drug for the treatment of pancreatic cancer is recommended.

No significant financial relationships to disclose.

Antireflux stents for palliation of malignant esophagocardial stenosis

Placement of self-expanding metal stents (SEMS) for palliation of malignant stenoses at the gastroesophageal junction is often associated with stent migration and reflux symptoms. SEMS with an antireflux mechanism have been developed to overcome the latter problem. The aim of this study was to evaluate the safety and efficacy of antireflux Z-stents. Patients with advanced squamous cell or adenocarcinoma of the distal esophagus or cardia suffering from dysphagia received an antireflux Z-stent. Technical success, complications of the procedure, clinical symptoms before and after stent placement, reinterventions and survival were recorded. Follow-up was accomplished by patient interviews and a standardized questionnaire for primary care physicians. Eighteen consecutive patients received an antireflux Z-stent. Seventeen of 18 stents were placed technically successful in a single endoscopic procedure. Mean dysphagia score improved from 2.2 to 0.6. Four patients (22%) had permanent reflux symptoms, an additional nine (50%) were taking proton pump inhibitors on a regular basis. In 10 patients, a re-intervention was necessary mainly due to dislocation of the stent. To ensure adequate nutrition three and two patients received a percutaneous gastrostomy and a jejunostomy, respectively. Median survival from stent insertion was 54 days (range, 3-201). Although placement of an antireflux Z-stent is technically feasible, its application is hampered by frequent stent migration and insufficient prevention of gastroesophageal reflux. Further technical improvements of stents or alternative methods like brachytherapy are required for satisfactory palliation of malignant gastroesophageal stenosis.

Irinotecan with 5-FU/FA in advanced biliary tract adenocarcinomas—A two-center phase II trial (GBFiri)

14088

Background: The majority of patients with biliary tract cancer present with advanced, unresectable tumors. Irinotecan and 5-Fluorouracil/folinic acid (FOLFIRI) have synergistic activity in gastrointestinal cancers. The aim of this study was to determine the tolerability and activity of systemic chemotherapy with FOLFIRI in patients with intrahepatic cholangiocarcinoma (CCC) or gallbladder cancer (GBC). Methods: This was a prospective, multicenter, non-randomised, open-label, phase II trial. Eligibility criteria: Inoperable adenocarcinoma of the biliary tract, measurable disease, age 18–80 years, ECOG PS 0–2. Patients received irinotecan 80 mg/m2 as a 30 min infusion, followed by folinic acid 500 mg/m2 over 2 h and 5-FU 2000 mg/m2 over 24h weekly × 6 followed by a 2 week rest. Treatment was continued until progression or limiting toxicity. Response to therapy was assessed after every other cycle according to RECIST criteria. Primary end point was response rate, secondary end points were overall survival, progression free survival and toxicity. Results: 30 pts (CCC 17, GBC 13) were enrolled. A total of 387 doses (Median 12.9; 1 to 36) were administered with an overall relative dose intensity of 98%. 30 patients are evaluable for safety. WHO grade 3/4 drug related adverse events occured in 7 patients (23%): Leukopenias in 2, anemia in 1, and diarrhea in 4 patients. 14 patients completed 2 cycles and were evaluable for response. Response rates: CR 0/30, PR 3/30 (10%) and SD 3/30 (10%). 8 patients presented with disease progression at restaging. Median overall survival: CCC 166 days, GBC 327 days. Progression-free-survival: CCC 84 days, GBC 159 days. Conclusions: FOLFIRI is a well tolerated regimen in patients with biliary cancer that can be safely administered on an outpatient basis. FOLFIRI has no substantial activity in CCC and moderate activity in GBC. Further studies are required to define a standard palliative chemotherapy for treatment of biliary cancer.

No significant financial relationships to disclose.

Radiochemotherapy followed by gemcitabine and capecitabine in extrahepatic bile duct cancer (EBDC): A phase I/II-trial

14087

Background: The 5-year survival rate of patients with resected EBDC is less than 30%. Phase II trials demonstrated that advanced EBDC responds to both chemotherapy with gemcitabine and capecitabine and to radiotherapy. Our objective was to define a feasible and effective postoperative therapy in patients with EBDC. Methods: Patients were eligible after surgery for EBDC. Surgery included resection of lymph node positive cancer, incomplete resections and diagnostic laparotomy in unresectable tumors. Patients received a fractionated radiotherapy with 49.6 Gy accompanied by gemcitabine 100 mg/m2 weekly × 5. After a two week rest patients were treated with gemcitabine (1000 mg/m2 IV D1+8 q3w) and capecitabine (1500 mg/m2 PO D1–14 q3w) on a 3-week cycle. Treatment continued for 6 cycles in nonmeasurable disease or until disease progression or intolerable toxicity. Primary endpoint was toxicity; secondary endpoints were response rate in measurable disease and overall survival. Results: 18 Patients (resectable/unresectable disease 7/11) were enrolled. Radiotherapy was completed in all patients and a total of 66 cycles of chemotherapy were applied. Anemia, fatigue, and nausea were the most common mild adverse events in 16, 14, and 16 patients, respectively. Grade 3 and 4 toxicity was rare after resection but frequent in unresectable disease and consisted of fatigue, nausea, duodenal ulcer, cachexia and cholangitis in 1, 2, 2, 4, and 4 patients, respectively. We observed a 50% disease stabilization rate in patients with measurable disease. Median overall survival was 7.9 months in patients with unresectable tumors. Median overall survival in patients after resection has not been reached after a median follow-up of 19.5 months. Conclusions: Radiochemotherapy with gemcitabine followed by gemcitabine and capecitabine is an active regimen with manageable toxicity after resection of EBDC but has significant toxicity in unresectable disease.

No significant financial relationships to disclose.

Two novel histone deacetylase inhibitors NVP-LAQ824 and NVP-LBH589 are active against biliary tract cancer and potentiate the efficacy of gemcitabine

4149

Background: Chromatin remodelling agents such as histone deacetylase inhibitors have been shown to modulate gene expression in tumor cells and inhibit tumor growth and angiogenesis. NVP-LAQ824 and NVP-LBH589 are two novel chemical entities belonging to a cinnamic hydroxamic acid class of compounds. Little is known about their efficacy for the treatment of biliary tract cancer. Methods: Cell-growth inhibition by NVP-LAQ824 and NVP-LBH589 was studied in vitro in 7 human biliary tract cancer cell lines by MTT assay. In addition, the anti-tumoral effect of NVP-LBH589 was studied in a chimeric mouse model. Anti-tumoral drug mechanism was assessed by immunoblotting for p21WAF-1, acH3Lys9 and acH4, cell cycle analysis, PARP assay, TUNEL assay, and immunhistochemistry for MIB-1. Results: In vitro treatment with both compounds significantly suppressed the growth of all cancer cell lines (mean IC50 (3d) 0.08 and 0.04 μM, respectively) and was associated with hyperacetylation of nucleosomal histones H3 and H4, increased expression of p21WAF-1, cell cycle arrest at G2/M-checkpoint, and induction of apoptosis (PARP cleavage). After 28 d, NVP-LBH589 reduced tumor mass by 66% (bile duct cancer) and 87% (gallbladder cancer) in vivo in comparison to placebo and potentiated the efficacy of gemcitabine. Further analysis of the tumor specimens revealed increased apoptosis (TUNEL) and reduced cell proliferation (MIB-1). Conclusions: Our findings suggest that NVP-LBH589 > NVP-LAQ824 are active against human biliary tract cancer in vitro. In addition, NVP-LBH589 demonstrated significant in vivo activity and potentiated the efficacy of gemcitabine. Therefore, further clinical evaluation of this new drug for the treatment of biliary tract cancer is recommended.

No significant financial relationships to disclose.

TIPS for Venoocclusive Disease Following Stem Cell Transplantation

Hepatic veno-occlusive disease (VOD) is a complication of allogeneic blood stem cell transplantation (SCT). Duplex ultrasound has been proposed to predict the outcome of VOD. We report here the case of a 39-year-old female patient with VOD following allogeneic SCT for AML. Repeated Doppler ultrasound examinations did not indicate a high-risk profile. However, the patient's condition deteriorated and was refractory to medical therapy. Transjugular intrahepatic portosystemic shunting (TIPS) was performed 19 days after transplantation and VOD resolved subsequently. VOD often has an unpredictable course. Transjugular intrahepatic portosystemic shunts may prove beneficial for patients with refractory disease.

Predictive value of heparanase expression in the palliative therapy of pancreatic cancer

BACKGROUND/AIMS

Patients with pancreatic ductal adenocarcinoma (PDA) have a median survival of less than six months from diagnosis. Palliative chemotherapy with the current standard gemcitabine does only marginally improve median survival. There may be subgroups of patients receiving palliative therapy that have a better prognosis. Factors predicting response to palliative therapy are ill-defined, though. Heparanase, an endoglycosidase degrading components of the extracellular matrix, promotes cell invasion, is involved in angiogenesis and plays a role in tumor metastases. It is expressed in PDA and its expression is associated with shorter postoperative survival after pancreatic resections.

METHODS

58 patients with inoperable PDA were treated with gemcitabine therapy. Tissue sections from primary or metastatic tumor were used for immunohistochemical analysis. Heparanase expression was determined and correlated to tumor response, time to progression and survival.

RESULTS

Heparanase expression was detectable by immunohistochemistry in 36 out of 58 (62%) patients analyzed. Overall survival was 7.4 vs. 13.3 months (p = 0.006) in heparanase-positive and -negative tumors, respectively. Progression-free survival was 1.3 vs. 3.4 months, respectively (p = 0.47).

CONCLUSION

Heparanase expression may be a useful marker to predict response to palliative therapy with gemcitabine in PDA.

Aktuelle Diagnostik und Therapie von Gallengangs- und Gallenblasenkarzinomen

Carcinoma of the biliary tree are rare tumours of the gastrointestinal tract with a rising incidence during the last years. Biliary neoplasms are classified into intra- and extrahepatic cholangiocarcinoma (Klatskin tumour, middle and distal extrahepatic tumours), gallbladder cancer, and ampullary carcinoma. Transformation of normal into malignant bile duct tissue requires a chain of consecutive gene mutations, similar to the adenoma-dysplasia-carcinoma-sequence in colon cancer. Abdominal ultrasound, combined non-invasive magnetic resonance cholangiography/tomography (MRC/MRT), and facultatively endoscopic retrograde cholangiography (ERC) for unclear diagnosis, represent the gold standard for primary diagnosis. For ampullary carcinoma, endosonography and endoscopic biopsy are the diagnostic tools of choice. Cure is attainable only by formal curative radical surgical resection. Increasing surgical radicality within the last years enabled clearly improved 5-year survival rates. In contrast, there has been no clinical benefit for adjuvant and neoadjuvant therapies. For palliation, bile duct stenting and photodynamic therapy are established methods. Radio- and chemotherapy should be reserved for clinical studies. New therapeutic approaches include brachytherapy, the use of modern chemotherapeutics, COX-2- and tyrosine kinase-receptor-inhibitors.

[Best supportive care of pancreatic carcinoma]

The incidence of pancreatic cancer is about 10,000 cases a year in Germany. The role of surgery as a curative modality is limited. The 5-year survival for all stages remains less than 5%. Pain, cachexia, jaundice, nausea, fatigue and depression are frequent symptoms which reduce the quality of life for affected patients. Therefore, amelioration of symptoms is a major goal of palliative care. Chemotherapy may yield a moderate survival benefit. Gemcitabine is the drug of choice in metastatic pancreatic cancer. In locally advanced disease, radiochemotherapy can be considered. Different treatment strategies against molecular targets are currently tested in clinical trials.

[Conservative and interventional endoscopic therapy of biliary tract carcinoma]

Endoscopic therapy is central to the palliative treatment of bile duct carcinoma. In obstructive jaundice, biliary drainage has few complications and relieves symptoms reliably. It can prevent further complications and is indispensable to the treatment of cholangitis. The principal drawback of biliary stents is stent occlusion and cholangitis. Prophylactic antibiotics were not proven to be effective. Technical details concerning material, number and location of stents await further clarification. Photodynamic therapy is an emerging adjunct to palliative therapy of biliary cancer. Preoperative biliary drainage in obstructive jaundice is not warranted as a routine intervention. It may be indicated, though, as preoperative bridging or to allow liver function to recover before major hepatic surgery. Finally, stenting of postoperative bile duct stenosis is gaining increasing acceptance.

[Esophagus, stomach, liver, pancreas carcinoma. What recommendations for prevention?]

A variety of carcinogens, in particular smoking, alcohol abuse and infections, are associated with an increased risk for the development of cancer of the upper gastrointestinal tract. Cancer prevention should start here, in particular since cessation of nicotine abuse, only moderate consumption of alcohol, and weight loss also have other positive effects on health. Where the indication is appropriate, H. pylori eradication, vaccination against hepatitis B and avoidance of exposure to hepatitis are well-founded prophylactic measures. Further screening measures make good sense only in high-risk groups, and are based on recommendations. It has, however, not yet been demonstrated that the screening of patients with Barrett's esophagus, liver cirrhosis, chronic hepatitis or gastric risk diseases actually can lower cancer-related deaths.

Heparanase is a prognostic indicator for postoperative survival in pancreatic carcinoma

British Journal of Cancer (2002) 87, 689–689. doi:10.1038/sj.bjc.6600504www.bjcancer.com

© 2002 Cancer Research UK

Correction to:British Journal of Cancer (2002) 86, 1270. doi:10.1038/sj/bjc/6600232

Heparanase expression is a prognostic indicator for postoperative survival in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma has a median survival of less than 6 months from diagnosis. This is due to the difficulty in early diagnosis, the aggressive biological behaviour of the tumour and a lack of effective therapies for advanced disease. Mammalian heparanase is a heparan-sulphate proteoglycan cleaving enzyme. It helps to degrade the extracellular matrix and basement membranes and is involved in angiogenesis. Degradation of extracellular matrix and basement membranes as well as angiogenesis are key conditions for tumour cell spreading. Therefore, we have analysed the expression of heparanase in human pancreatic cancer tissue and cell lines. Heparanase is expressed in cell lines derived from primary tumours as well as from metastatic sites. By immunohistochemical analysis, it is preferentially expressed at the invading edge of a tumour at both metastatic and primary tumour sites. There is a trend towards heparanase expression in metastasising tumours as compared to locally growing tumours. Postoperative survival correlates inversely with heparanase expression of the tumour reflected by a median survival of 34 and 17 month for heparanase negative and positive tumours, respectively. Our results suggest, that heparanase promotes cancer cell invasion in pancreatic carcinoma and could be used as a prognostic indicator for postoperative survival of patients.

A phase II pilot trial of 13-cis retinoic acid and interferon-alpha in patients with advanced pancreatic carcinoma

BACKGROUND

Advanced unresectable pancreatic adenocarcinoma has a dismal prognosis. The authors previously have shown that retinoic acid (RA) and interferon-alpha (IFN-alpha) inhibit growth and induce differentiation in human pancreatic carcinoma cells in vitro and in vivo. The purpose of this trial was to examine the feasibility and tolerability of a combination therapy of 13-cis RA and IFN-alpha in patients with advanced unresectable pancreatic carcinoma.

METHODS

Twenty-two patients (median age, 62 years) with histologically confirmed, unresectable pancreatic adenocarcinoma classified as International Union Against Cancer Stage III (5 patients) or IV (17 patients) were included. Patients received 1 mg/kg body weight 13-cis RA orally and 6 million IU IFN-alpha subcutaneously daily. Restaging by ultrasound, computed tomography scan, and chest X-ray was performed every 2 months.

RESULTS

No complete remission and 1 partial remission (PR) (4.5%) were observed. Fourteen patients (63.6%) demonstrated stable disease with a median duration of 5.0 months (range, 2.3-17.7+ months). Toxicity mainly was related to IFN-alpha and predominantly was hematologic (no toxicity was World Health Organization [WHO] Grade 4 and 13.6% were WHO Grade 3). Nonhematologic toxicities did not exceed Grade 2 (skin and oral mucosa) and mainly were related to 13-cis RA. The median survival of the patients with Stage III disease was 8.7 months (range, 6.8-23.9+ months) and was 7.4 months for patients with Stage IV disease (range, 0.9-19.2+ months), resulting in a median overall survival of 7.7 months (range, 0.9-23.9+ months).

CONCLUSIONS

Combination therapy with 13-cis RA and IFN-alpha is feasible and well tolerated in patients with advanced pancreatic carcinoma. Based on the median survival rates observed in this study this combination should be investigated further in Phase III trials.

[Tumor suppressor gene p53--function and significance in gastroenterology]

The p53 gene is a tumor suppressor gene. The encoded p53 protein directly induces the expression of genes that are involved in cell cycle regulation. p53 was named "guardian of the genome" for its prevention of an otherwise fatal outcome under DNA damaging conditions. Under these conditions p53 inhibits cell cycle progression or induces apoptosis. The p53 protein has been structurally and functionally divided into four domains, two of which are of crucial importance: The sequence specific DNA-binding domain and the aminoterminal transactivation domain. They are both required to trigger the downstream processes following p53 expression. Mutations and inactivation of p53 by oncogenes are frequent events in the development of human neoplasia. That includes gastrointestinal tumors with their mutational spectra reflecting tissue-specific influences of endogenous and exogenous factors in carcinogenesis. Despite considerable progress in molecular biology, clinical applicability of p53 in both diagnostic and therapeutic strategies has not yet been validated.

Characterization of [3H]pentazocine binding sites in post-mortem human frontal cortex

We investigated binding characteristics of [3H](+)-pentazocine in homogenates of post-mortem human frontal cortex. At equilibrium, specific binding was linear with protein concentration, was saturable, reversible, stereoselective, heat-labile and was nearly absent in the white matter. Saturation experiments revealed a KD of 3.68 +/- 0.46nM and a B(max) of 0.636 +/- 0.107 pmol/mg protein. The rank order of Ki values of competing substances was: haloperidol < N,N'-di(o-tolyl)guanidine (DTG) < (+)-SKF 10,047 < (-)-SKF 10,047. We also examined the influence of age, gender, hemisphere, post-mortem time and storage time of brain tissue at -80 degrees C on [3H](+)-pentazocine binding sites. Of these variables, only age was significantly related to [3H](+)-pentazocine binding (diminished binding with increasing age). Together, our results demonstrate the presence of specific [3H](+)-pentazocine binding sites in post-mortem human brain tissue. Furthermore, the binding sites decrease with increasing age and are apparently independent of gender, hemisphere, post-mortem time and storage time of brain tissue.

Affinity of 1-aminoadamantanes for the sigma binding site in post-mortem human frontal cortex

The 1-aminoadamantanes memantine (1-amino-3,5-dimethyl-adamantane) and amantadine (1-amino-adamantane) are clinically used as anti-parkinsonian, anti-spasticity, anti-dementia and antiviral drugs. In the present investigation we have tested a series of 1-aminoadamantane derivatives including memantine and amantadine for their ability to compete with [3H](+)-pentazocine in homogenates of post-mortem human frontal cortex. The Ki values ranged from 0.237 +/- 0.019 microM for 1-N-dimethyl-amino-3,5-dimethyl-adamantane to 20.25 +/- 16.48 microM for amantadine. The Ki value of memantine was 19.98 +/- 3.08 microM and was thus very similar to that of amantadine. Memantine, at therapeutic concentrations, probably does not interact with the sigma binding site. Amantadine, at therapeutic concentrations, probably binds both to the sigma site and to the phencyclidine (PCP) binding site of the N-methyl-D-aspartate (NMDA) receptor.