Reduced efficacy of the Plk1 inhibitor BI 2536 on the progression of hepatocellular carcinoma due to low intratumoral drug levels.

Highly promising preclinical data obtained in cultured cells and in nude mice bearing xenografts contrast with the rather modest clinical efficacy of Polo-like kinase 1 (Plk1) inhibitors. In the present study, we investigated if Plk1 might be a suitable target in hepatocellular carcinoma (HCC) and if a genetically engineered mouse tumor model that well reflects the tumor cell and micro-environmental features of naturally occurring cancers might be suitable to study anti-Plk1 therapy. Analysis of Plk1 expression in human HCC samples confirmed that HCC express much higher Plk1 levels than the adjacent normal liver tissue. Inhibition of Plk1 by an adenovirus encoding for a short hairpin RNA against Plk1 or by the small-molecule inhibitor BI 2536 reduced the viability of HCC cell lines and inhibited HCC xenograft progression in nude mice. Treatment of transforming growth factor (TGF) α/c-myc bitransgenic mice with BI 2536 during hepatocarcinogenesis reduced the number of dysplastic foci and of Ki-67-positive cells within the foci, indicating diminished tumorigenesis. In contrast, BI 2536 had no significant effect on HCC progression in the transgenic mouse HCC model as revealed by magnetic resonance imaging. Measurement of BI 2536 by mass spectrometry revealed considerably lower BI 2536 levels in HCC compared with the adjacent normal liver tissue. In conclusion, low intratumoral levels are a novel mechanism of resistance to the Plk1 inhibitor BI 2536. Plk1 inhibitors achieving sufficient intratumoral levels are highly promising in HCC treatment.

Acoustic Radiation Force Impulse-Imaging for the evaluation of the thyroid gland: a limited patient feasibility study.

PURPOSE: Real-time tissue elastography, a qualitative elastography method, has shown promising results in the diagnostic work up of thyroid nodules. However, to our knowledge no study has evaluated a quantitative elastography method in the thyroid gland. The present study is a feasibility study evaluating Acoustic Radiation Force Impulse-Imaging, a novel quantitative elastography method in the thyroid gland. METHODS: ARFI-imaging involves the mechanical excitation of tissue using short-duration acoustic pulses to generate localized displacements in tissue. The displacements induce a lateral shear-wave propagation which is tracked using multiple laterally positioned ultrasound "tracking" beams. Inclusion criteria were: thyroid nodules ≥1cm, non-functioning or hypo-functioning on radionuclide scanning, and cytological/histological assessment of thyroid nodule as reference method. All patients received conventional ultrasound, and examination of the thyroid gland including Power Doppler Ultrasound using a 9MHz linear transducer, in addition real-time elastography (RTE) was performed at 9MHz frequency and ARFI-imaging was performed at 4MHz using Siemens (ACUSON S2000) B-mode-ARFI combination transducer. RESULTS: Sixty nodules in 55 patients were analyzed. Three nodules were papillary carcinoma. The stiffer the tissue the faster the shear wave propagates. The results obtained indicated that the shear wave velocity in thyroid lobes ranged between 0.5 and 4.9m/s. The median velocity of ARFI-imaging in the healthy nodule-free thyroid gland, as well as in benign and malignant thyroid nodules was 1.98m/s (range: 1.20-3.63m/s), 2.02m/s (range: 0.92-3.97m/s), and 4.30m/s (range: 2.40-4.50m/s), respectively. While no significant difference in median velocity was found between healthy thyroid tissue and benign thyroid nodules, a significant difference was found between malignant thyroid nodules on the one hand and healthy thyroid tissue (p=0.018) or benign thyroid nodules (p=0.014) on the other hand. Specificity of ARFI-imaging for the differentiation of benign and malignant thyroid nodules was comparable with RTE (91-95%). CONCLUSIONS: ARFI can be performed in the thyroid tissue with reliable results.

Acoustic radiation force impulse-imaging and transient elastography for non-invasive assessment of liver fibrosis and steatosis in NAFLD.

BACKGROUND: Transient elastography (TE) and acoustic radiation force impulse (ARFI)-imaging have shown promising results for the staging of liver fibrosis. AIM: The aim of the present study was to compare ARFI of the left and right liver lobe with TE using the standard and obese probes for the diagnosis of liver fibrosis in NAFL/NASH. In addition, liver steatosis is evaluated using the novel controlled attenuation parameter (CAP). METHODS: Sixty-one patients with NAFLD/NASH were included in the study. All patients received TE with both probes, ARFI of both liver lobes and CAP. The results were compared with liver histology. RESULTS: 57 patients were included in the final analysis. The diagnostic accuracy for TE measurements with the M-and XL-probe and for ARFI of the right and left liver lobe was 0.73, 0.84, 0.71 and 0.60 for the diagnosis of severe fibrosis, and 0.93, 0.93, 0.74 and 0.90 for the diagnosis of cirrhosis, respectively. No significant difference of results was observed between TE and ARFI in the subgroup of patients with reliable TE-measurement when taking into account the best results of both methods. However, while a significant correlation could be found for TE with histological liver fibrosis, the correlation of ARFI with liver fibrosis was not statistically significant. A significant correlation was found for CAP with histological steatosis (r=0.49, p<0.001). CONCLUSIONS: No significant difference in diagnostic accuracy for the non-invasive assessment of liver fibrosis was found for transient elastography and ARFI. Nevertheless TE significantly correlated with liver fibrosis while ARFI did not. CAP enables the non-invasive assessment of steatosis.

Transient elastography with a new probe for obese patients for non-invasive staging of non-alcoholic steatohepatitis.

OBJECTIVE: Transient elastography (TE) has shown promising results for the staging of liver fibrosis in patients with non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) with the limitation that 25% of obese patients cannot be examined with the standard TE probe. The aim of this study was to evaluate a new XL probe for obese patients for the staging of liver fibrosis in NAFLD/NASH. METHODS: Fifty patients with NAFLD/NASH and histological assessment of liver fibrosis were included in the study. All patients received TE with the standard probe (M probe) and the new XL probe, and the results were compared with liver histology. RESULTS: The diagnostic accuracy expressed as the area under the ROC curve for TE measurements with the M probe and the XL probe was 0.80 and 0.82 for the diagnosis of significant fibrosis, and 0.91 and 0.95 for the diagnosis of liver cirrhosis, respectively. Eighty-three percent of the patients who could not be measured with the M probe could be measured using the XL probe. CONCLUSION: Transient elastography using the XL probe for obese patients can be performed with comparable diagnostic accuracy to the standard probe and enables the examination of significantly more obese patients.

Sequential therapy of transarterial chemoembolisation and sorafenib in intermediate stage hepatocellular carcinoma.

INTRODUCTION: Prolongation of median survival can be achieved for intermediate Barcelona Clinic Liver Cancer stage hepatocellular carcinoma (HCC) by transarterial chemoembolisation (TACE). TACE might induce induction of angiogenic factors, especially in patients not responding to TACE, which might result in further tumour progression with development of new satellite lesions. CASE REPORT: Here, we report a patient with intermediate stage HCC, who initially responded to TACE, but developed new satellite lesions. After careful discussion, TACE was stopped, and a sequential treatment with sorafenib, a vascular endothelial growth factor receptor and RAF tyrosinkinase inhibitor, was started, resulting in a progression-free survival of 10 months. DISCUSSION: The presented case demonstrates the feasibility of sequential TACE and sorafenib treatment. Results of ongoing controlled, clinical trials in this regard are awaited.

Assessment of liver fibrosis and steatosis in PBC with FibroScan, MRI, MR-spectroscopy, and serum markers.

BACKGROUND: In recent years noninvasive methods have been evaluated for the assessment of liver fibrosis predominantly in patients with viral hepatitis. In this study, transient elastography (FibroScan), magnetic resonance imaging (MRI), magnetic resonance (MR)-spectroscopy, and serum markers were compared in patients with primary biliary cirrhosis (PBC) for the assessment of liver fibrosis and steatosis. METHODS: Forty-five patients with PBC and histologic assessment of liver fibrosis received transient elastography and examinations for serum markers of fibrosis and steatosis. In addition, 41 out of 45 patients received contrast-enhanced MRI and 38 out of 45 patients received proton MR-spectroscopy. RESULTS: The adjusted accuracy (area under the receiver operating characteristic) for the diagnosis of histologic-stage > or = II for FibroScan, MRI-contrast enhancement and Forns index was 80%, 83%, and 69%, and for the diagnosis of liver cirrhosis 95%, 91%, and 94%, respectively. No correlation of histologic-stage was observed for FibroTest and AST to platelet ratio index. Histologic steatosis significantly correlated with body mass index (r=0.46), the SteatoTest (r=0.39), homeostasis model assessment of insulin resistance (r=0.46), and MR-spectroscopy (r=-0.76). The accuracy for the diagnosis of histologic steatosis was best with MR-spectroscopy (88%). CONCLUSIONS: Contrast-enhanced MRI and FibroScan can be used with comparable results for the assessment of liver fibrosis in patients with PBC and seem to supplement each other. MR-spectroscopy represents the best method for highly accurate noninvasive measurement of liver steatosis.

Role of transarterial chemoembolization for hepatocellular carcinoma before liver transplantation with special consideration of tumor necrosis.

Several authors suggest that local ablative therapies, specifically transarterial chemoembolization (TACE), may control tumor progression of hepatocellular carcinoma (HCC) in patients who are on the waiting list for liver transplantation (orthotopic liver transplantation, OLT). There is still no evidence if TACE followed by OLT is able to prevent recurrence of tumor, to prolong survival rate of the patients on the waiting list, or to improve the survival after OLT. We report 27 patients with HCC who underwent OLT. From these patients, 15 were pre-treated with TACE alone or in combination with percutaneous ethanol injection (PEI) or laser-induced thermo therapy (LITT). Mean time on the waiting list was 214 d for treated patients and 133 d for untreated patients. Comparing pre-operative imaging and histopathological staging post-transplant, we found 13 patients with tumor progression out of which five were treated with TACE. In two of the TACE patients a decrease of lesions could be achieved. In a single patient, there was no evidence of any residual tumor. Only one patient displayed tumor progression prior to OLT despite undergoing TACE. Comparison of outcome in patients undergoing TACE or having no TACE was not statistically significant (p = 0.5). In addition, our analysis showed that progression either in the total study population or in the TACE group alone is associated with a significant poorer outcome concerning overall survival (p = 0.02 and p = 0.02).

Liver fibrosis in viral hepatitis: noninvasive assessment with acoustic radiation force impulse imaging versus transient elastography.

PURPOSE: To compare, in a pilot study, acoustic radiation force impulse (ARFI) imaging technology integrated into a conventional ultrasonography (US) system with both transient elastography (TE) and serologic fibrosis marker testing for the noninvasive assessment of liver fibrosis. MATERIALS AND METHODS: Informed consent was obtained from all subjects, and the local ethics committee approved the study. ARFI imaging involved the mechanical excitation of tissue with use of short-duration acoustic pulses to generate localized displacements in tissue. The displacements resulted in shear-wave propagation, which was tracked by using US correlation-based methods and recorded in meters per second. Eighty-six patients with chronic viral hepatitis underwent TE, ARFI imaging, and serum fibrosis marker testing. Results were compared with liver biopsy findings, which served as the reference standard. RESULTS: ARFI imaging (rho = 0.71), TE (rho = 0.73), and serum fibrosis marker test (rho = 0.66) results correlated significantly with histologic fibrosis stage (P < .001). Median ARFI velocities ranged from 0.84 to 3.83 m/sec. Areas under the receiver operating characteristic curve for the accuracy of ARFI imaging, TE, and serum fibrosis marker testing were 0.82, 0.84, and 0.82, respectively, for the diagnosis of moderate fibrosis (histologic fibrosis stage, > or = 2) and 0.91, 0.91, and 0.82, respectively, for the diagnosis of cirrhosis. CONCLUSION: ARFI imaging is a promising US-based method for assessing liver fibrosis in chronic viral hepatitis, with diagnostic accuracy comparable to that of TE in this preliminary study. SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/252/2/595/DC1.

Interleukin-2 in CD8+ T cells correlates with Banff score during organ rejection in liver transplant recipients.

The aim of this study is to compare the histological grading of acute organ rejection according to the Banff score with intracellular interleukin-2 (IL-2) concentrations in cytotoxic CD8+ T cells from peripheral blood samples. 66 recipients after liver transplantation and 20 healthy controls were included into this study. Blood samples of liver transplant recipients were collected beside routine visits or, in case of suspected organ rejection, with additional liver biopsy. For cytometry, the blood cells were stained with CD3, CD8 and intracellular-IL-2. The percentage of cells with detectable intracellular IL-2 was significantly increased in patients with acute rejection (n = 7, P < 0.001, t Test) compared to recipients without rejection. The percentage of cells with detectable intracellular IL-2 (mean +/- SEM) was 7.6 +/- 0.9% in rejection patients, 2.3 +/- 0.22% in stable liver transplant recipients, and 14 +/- 2.99% in healthy controls. Intracellular IL-2 correlates to the Banff score in rejection patients (Spearmans-rho = 0.81, P < 0.05). This cytometric method shows a good sensitivity (71%) with a cut-off based on a high specificity of 95% for histological proven organ rejection in our study cohort. Measurement of intracellular IL-2 in cytotoxic CD8+ T-lymphocytes by flow cytometry correlates very well to the histological grading according to the Banff score and shows a good sensitivity and excellent specificity in acute organ rejection.

Expression of activation-induced cytidine deaminase in malignant lymphomas infiltrating the bone marrow.

Somatic hypermutation of immunoglobulin genes and class switch recombination are pivotal processes in the germinal center (GC) reaction and have been implicated in the development of malignant B-cell lymphoma. Both processes require the enzyme activation-induced cytidine deaminase (AID). Expression of AID is largely restricted to GC B cells and B cells that undergo class switch recombination outside the GC. AID is also expressed in many B-cell lymphomas. This study investigates the expression of AID of malignant lymphomas infiltrating the bone marrow. Bone marrow trephines (n=130) with infiltration of Hodgkin lymphoma and non-Hodgkin lymphoma of B cell and T-cell type and trephines with reactive lymphoid follicles (n=16) were analyzed immunohistochemically for AID protein. AID is expressed in bone marrow infiltrates of malignant lymphomas. AID was generally detected in lymphomas of GC origin. Tumor cells of hairy cell leukemia are mostly AID. There is apparently no different expression of AID found in bone marrow infiltrates of malignant lymphomas compared with a control group with nodal malignant lymphoma infiltrates (n=105). These results suggest that the expression pattern of AID in lymphoma infiltrates in the bone marrow reflects that of extramedullary lymphoma infiltrates.

Fatal haemorrhage due to extensive fragility of medium- and large-sized arteries and veins in a young patient with neurofibromatosis 1.

BACKGROUND: Neurofibromatosis type 1 (NF1) is one of the most frequently inherited diseases. Vascular manifestations have been reported, mostly concerning stenosis of the renal artery or spontaneous rupture of single arteries. Also, venous aneurysms have been reported. METHODS: We present clinical and pathological findings of a young patient with NF1 with lethal bleeding due to spontaneous rupture of a lumbal and renal artery. RESULTS: High fragility of several arteries as well as veins in the abdominal and pelvic arterial and venous system resulted in a destroyed vessel structure caused by invading neurogen fibres. CONCLUSIONS: In rare cases, NF1 is associated with a severe systemic vasculopathy concerning the arterial and venous vascular system.

Autologous blood as a submucosal fluid cushion for endoscopic mucosal therapies: results of an ex vivo study.

OBJECTIVE: Submucosal injection of fluid is used to elevate lesions in order to prevent perforation, which is the most calamitous complication during endoscopic resection therapies. There are several injection options when performing mucosal elevation (normal saline (NS), sodium hyaluronate (SH), etc.). Submucosal injection of fresh, autologous blood offers some advantages because of its specific properties: corpuscular components ensure prolonged elevation and procoagulatory constituents prevent post-interventional bleeding. The purpose of this study was to compare the ex vivo performance of autologous blood as a submucosal fluid cushion (SFC) with that of NS, SH and DW (dextrose water). MATERIAL AND METHODS: The proximal third of a resected porcine stomach was cut into squares. One millilitre NS, DW, SH and fresh porcine blood was injected into the submucosa. The height and duration of the submucosal injections were objectively measured during 1 h. Mucosal elevations were resected using an electro snare. RESULTS: The initial height and width of the mucosal elevations were comparable for SH and blood, and significantly higher compared with NS and DW. Mucosal elevation after injecting autologous blood persisted significantly longer compared with NS (p <0.05), but did not differ from hyaluronate. Histopathological examination of the resected specimen confirmed the appropriate submucosal injection of these substances. CONCLUSIONS: Submucosal injection of autologous blood with a standard endoscopic injection needle is possible and generates adequate mucosal elevation for the resection of high-quality specimens. This procedure could offer a "gratis" option for SFC as opposed to the expensive SH. Further clinical studies are needed to substantiate its use.

Bone marrow trephines containing lymphoid aggregates from patients with rheumatoid and other autoimmune disorders frequently show clonal B-cell infiltrates.

In bone marrow trephines, morphological and immunohistochemical criteria may not be sufficient to discriminate reactive from malignant lymphoid infiltrates. The aim of this study was to determine whether the detection of clonal immunoglobulin heavy chain (IGH) gene rearrangements is a reliable and specific marker for malignant B-cell clones in bone marrow biopsies. Bone marrow trephines with infiltration by different types of low-grade B-cell non-Hodgkin lymphoma (n = 32), reactive lymphoid hyperplasia (n = 18), and reactive lymphoid aggregates (n = 15), including 5 patients with rheumatoid or other autoimmune disorders, were analyzed by morphology, immunohistochemistry, IGH gene rearrangement (polymerase chain reaction), and DNA sequence analysis in selected cases. In 22 (68.8%) of 32 patients with B-cell non-Hodgkin lymphoma, a clonal IGH gene rearrangement was detected. Of the reactive cases, 1 of 18 patients with lymphoid hyperplasia demonstrated clonality, and 9 (60%) of 15 patients with reactive lymphoid aggregates gave a clonal result (GeneScan analysis). DNA sequence analysis was performed in 7 of the latter patients confirming clonality in 6. Four of the patients with B-cell clonality had an autoimmune disorder. None of these patients developed a malignant lymphoma during follow-up. Thus, the molecular detection of a clonal rearrangement of the IGH gene may support the diagnosis of a malignant lymphoma infiltrating the bone marrow. However, morphologically and immunohistochemically benign lymphoid aggregates might also harbor B-cell clones especially in patients with autoimmune disorders. Therefore, the detection of clonality has to be interpreted with utmost care and does not qualify for the unequivocal diagnosis of a malignant B-cell lymphoma.

Isthmus-preserving total bilobectomy: an adequate operation for C-cell hyperplasia.

BACKGROUND: Autopsy studies show that C cells deriving from the ultimobranchial body and migrating into the thyroid do not reach the isthmus region and are distributed along the vertical axes of thyroid lobes. This was confirmed in a surgical series of 58 patients (34 with preoperatively normal and 24 with elevated serum calcitonin) where no calcitonin-positive cells were demonstrable immunohistochemically within separately investigated isthmi. Consequently, isthmus-preserving total bilateral lobectomy (IPTB) may be regarded as an adequate surgical procedure for C-cell hyperplasia (CCH). PATIENTS AND METHODS: IPTB was performed from October 2001 to December 2004 in 64 patients, 59 patients with nodular goiter and slightly to moderately elevated serum calcitonin (stimulated under 500 pg/ml) (group A, apparently sporadic cases) and in 5 patients undergoing prophylactic surgery for hereditary medullary thyroid carcinoma (MTC) with intermediate- or low-risk RET mutations (non-634) (group B). The surgical procedure focused on meticulous total extracapsular resection of both thyroid lobes, preservation of an isthmus remnant of about 3 ml (smaller in children), and histologic workup of the border zones of resection in addition to that of the completely removed lobes. When malignancy could be proven intraoperatively (7 patients) or when the isthmus turned out to contain nodular lesions (4 patients), completion total thyroidectomy (plus lymphadenectomy) was performed as a one-stage procedure. Second-stage total thyroidectomy was performed in 3 cases. Thus, IPTB was the definitive surgical procedure in 50 patients (45 of group A and all 5 of group B). RESULTS: In all of the 50 definite IPTB cases, postoperative serum calcitonin was below the measurable limit (2 pg/ml); stimulated calcitonin was below the measurable limit in 47 (including all of group B) and was measurable in 3 sporadic cases in a lower-normal range between 2.4 and 3.5 pg/ml. Genetic screening of the apparently sporadic cases with CCH was positive in one (codon 791). The risk of recurrent laryngeal nerve paralysis seems not to be elevated (0% permanent); permanent hypocalcemia occurred in 1 patient (2%). Follow-up data of 37 patients, median 18 (6-36) months, showed continuously nonmeasurable serum calcitonin with one exception, where it was in the normal range after 18 months. All IPTB patients are still under substitution therapy with L-thyroxine (median 125 mug/day) with decreasing tendency in all 3 children after prophylactic operation, the latter also showing an increasing volume of well-vascularized isthmi (from 1.5 to 2.5 ml). CONCLUSION: IPTB reliably removes all C cells. There may not be need for total thyroidectomy (TTx) in cases with CCH. When necessary, completion TTx can be performed easily without additional risk. IPTB leaves a functionally relevant remnant, corresponding to that of a subtotal resection. This might be of importance especially for prophylactic surgery in children where the isthmus can compensate for the loss of thyroid function with time.

Primary intestinal aspergillosis after high-dose chemotherapy and autologous stem cell rescue.

Primary invasive aspergillosis of the gut is a rare event and is associated with high mortality. We report for the first time on a patient who had isolated aspergillosis of the small bowel after autologous stem cell transplantation. Diagnosis of invasive aspergillosis of the gut was based on abdominal pain, galactomannan antigenemia and isolation of Aspergillus fumigatus from the stool and was later confirmed by pathohistologic examination. No other site of invasive aspergillosis was evident. The patient was successfully treated with early surgery and combination antifungal therapy.

Nodular lymphoid lesion of the liver with simultaneous focal nodular hyperplasia and hemangioma: discrimination from primary hepatic MALT-type non-Hodgkin's lymphoma.

Nodular lymphoid lesion (NLL) of the liver is a rare but unique entity and has also been termed reactive lymphoid hyperplasia of the liver. We describe the histological, immunohistochemical and molecular biologic findings of a case with NLL and two other tumors of the liver. The nodular lymphoid mass found in the liver was composed of heterogeneous small lymphocytes forming reactive follicles. Plasma cells, few immunoblasts, centroblasts, few macrophages, epithelioid cells, and giant cells were seen. The lymphoid infiltrate displaced the adjacent hepatic parenchyma. By immunohistochemistry and molecular studies, the lymphocytes were found to be polyclonal. The diagnosis of NLL was made. In addition to NLL, focal nodular hyperplasia and hemangioma were detected. The discrimination of NLL from primary hepatic malignant non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue-type may pose diagnostic difficulties and may require the use of immunohistochemical and molecular techniques. The simultaneous occurrence of NLL with focal nodular hyperplasia and hemangioma in the liver has not been described before.

BRAF mutations in colorectal carcinoma suggest two entities of microsatellite-unstable tumors.

BACKGROUND: Alterations of BRAF have been implicated in the carcinogenesis of colorectal tumors with microsatellite instability (MSI). These alterations were attributed to defective DNA mismatch repair, which underlies MSI. It was the objective of this study to clarify the role of BRAF in colorectal carcinoma with MSI. METHODS: After sequencing for BRAF and KRAS in 82 colorectal tumor samples with or without MSI, mismatch repair protein expression was analyzed by immunohistochemistry, and promoter methylation of hMLH1 was analyzed with a methylation-specific polymerase chain reaction. Results were correlated with the germline status of hMLH1 or hMSH2 and clinical characteristics. RESULTS: BRAF was mutated more often in tumors with MSI than in tumors without MSI (27% vs. 5%; P = 0.016). The most prevalent BRAF alteration, V599E, occurred only in tumors with MSI. BRAF V599E was associated with more frequent hMLH1 promoter methylation (P = 0.07) and loss of hMLH1 (P = 0.02). The median age of patients with BRAF V599E was older compared with the median age of patients without this mutation (P = 0.001; 78 vs. 49 yrs). No BRAF alterations occurred in patients with germline mutations of mismatch repair genes. Five novel BRAF mutations were identified. CONCLUSIONS: Although BRAF V599E was common in colorectal carcinomas with MSI, it was not a consequence of deficient mismatch repair. The current data showed instead that the BRAF V599E mutation was associated only with a subgroup of colorectal carcinomas with MSI that were obtained from older patients without hereditary nonpolyposis colorectal carcinoma and showed epigenetic silencing of hMLH1. These results indicated that tumors with MSI caused by epigenetic MLH1 silencing have a distinct mutational background from that of tumors with genetic loss of mismatch repair, suggesting that there are two genetically distinct entities of microsatellite-instable tumors.

In vitro chemosensitivity to gemcitabine, oxaliplatin and zoledronic acid predicts treatment response in metastatic gastric cancer.

Individual response of disseminated cancer to chemotherapy is unpredictable. In vitro chemotherapy-induced apoptosis can be measured and might be a method to evaluate in vivo activity of tested drugs. In this report, tumor cells of a patient with signet cell carcinoma of the stomach and diffuse bone marrow infiltration were cultured and tested for in vitro chemosensitivity. The drugs gemcitabine, oxaliplatin and zoledronic acid were found to induce in vitro tumor cell apoptosis synergistically, and subsequently were used as combination chemotherapy regimen. An initially existing disseminated intravascular coagulopathy quickly resolved and after 6 months of treatment on ongoing complete response was induced, thus confirming the results of in vitro chemosensitivity testing.

BAX and caspase-5 frameshift mutations and spontaneous apoptosis in colorectal cancer with microsatellite instability.

BACKGROUND AND AIMS: Hereditary nonpolyposis colorectal cancer (HNPCC) and a subset of sporadic colorectal cancers are characterized by microsatellite instability (MSI) and inactivating frameshift mutations of target genes. Inactivation of BAX, caspase-5 ( cas-5), and other genes coding for pro-apoptotic proteins might contribute to tumor progression by enhancing escape from apoptosis. The aim of this study was to further characterize the role of BAX and cas-5 inactivation for spontaneous apoptosis. METHODS: Twenty-five colorectal cancers with MSI were analyzed for frameshift mutations in the BAX (G)8 and cas-5 (A)10 tract by fluorescence PCR, cloning, and sequencing. The rate of spontaneous apoptosis was examined by in situ DNA nick end-labeling. The results were compared with 25 stage-matched microsatellite stable (MSS) colorectal cancers. RESULTS: In colorectal cancer with MSI frameshift mutations in BAX and cas-5 were present in 16 of 25 (64%) and in 12 of 25 (48%) tumors, respectively, whereas neither mutant BAX nor cas-5 alleles were detected in all stage-matched sporadic MSS colorectal cancer. Tumors with MSI showed a higher apoptotic rate than MSS tumors (2.5+/-1.0 vs. 2.1+/-0.7; p <0.05), whereas the presence of BAX or cas-5 frameshift mutations had only minor influence on this finding (2.4+/-1.1% and 2.5+/-0.9%, respectively). CONCLUSION: Mismatch-repair deficiency itself is associated with increased spontaneous apoptosis, not further accelerated by either inactivating BAX or cas-5 frameshift mutations.

Reversal of bone marrow angiogenesis in chronic myeloid leukemia following imatinib mesylate (STI571) therapy.

The effect of imatinib mesylate (imatinib) therapy on angiogenesis and myelofibrosis was investigated and compared with interferon (IFN) and hydroxyurea (HU) in 98 patients with newly diagnosed Philadelphia chromosome-positive/BCR-ABL(+) (Ph(+)/BCR-ABL(+)) chronic myeloid leukemia in first chronic phase and no other pretreatment. By means of immunostaining (CD34) and morphometry, a relationship between microvessel frequency and fiber density was detectable in initial bone marrow (BM) biopsies and sequential examinations after at least 8 months of therapy. First-line monotherapy with imatinib induced a significant reduction (normalization in comparison with controls) of microvessels and reticulin fibers. In most patients, decrease in BM vascularity was associated with a complete cytogenetic response. A significant anti-angiogenic effect was also observed after HU treatment, contrasting with IFN administration or combination regimens (IFN plus HU). In conclusion, our data support the anti-angiogenic capacity of imatinib by normalization of vascularity. In contrast, hematologic response following IFN treatment is independent from BM angiogenesis.