Beta-delayed deuteron emission from (11)Li: decay of the halo

The deuteron-emission channel in the beta decay of the halo nucleus (11)Li was measured at the Isotope Separator and Accelerator facility at TRIUMF by implanting postaccelerated (11)Li ions into a segmented silicon detector. The events of interest were identified by correlating the decays of (11)Li with those of the daughter nuclei. This method allowed the energy spectrum of the emitted deuterons to be extracted, free from contributions from other channels, and a precise value for the branching ratio B(d)=1.30(13)x10(-4) to be deduced for E(c.m.)>200 keV. The results provide the first unambiguous experimental evidence that the decay takes place essentially in the halo of (11)Li and that it proceeds mainly to the (9)Li+d continuum, opening up a new means to study the halo wave function of (11)Li.

[Basal and myoepithelial phenotype of metastatic mammary carcinomas. A prognostic factor in the palliative situation?]

AIMS

The aim of the present study was to evaluate the prognostic impact of basal and myoepithelial phenotype in breast carcinomas (BBC and MBC) in the palliative situation.

METHODS

Paraffin-embedded material from 244 primary breast carcinomas of patients with subsequent metastatic disease was stained immunohistochemically for CK 5/6, CK14, smooth-muscle actin, p63, estrogen receptor and progesterone receptor. BBC was defined as positive for CK5/6 and/or CK14 and MBC as positive for SMA and/or p63. Clinical and pathological data were available for all patients and follow-up data for 96.3% (range 5 days-151 months).

RESULTS

Until the end of the follow-up period 90.2% of patients died and 6.1% are still alive. Of the tumours 28.7% could be classified as BBC and 8.2% as MBC. Kaplan Meier analysis revealed a trend for reduced survival after first diagnosis of metastasis (OASM) for BBC and MBC. Differences in survival were significant for BBC (log-rank =5.0; p=0.025), but not for MBC. CK5/6+ and CK14+ double positive tumours (n=18; 7.4%) were identified as a subgroup of BBC associated with reduced OASM (log-rank=8,6; p=0.003). This subgroup, but not BBC or MBC was an independent negative prognostic factor in a multivariate analysis including age, typing, tumour size, grading, axillary nodes, HR, Her2/neu, site of first metastasis and disease-free interval.

CONCLUSION

The association of BBC and MBC with reduced OASM in metastatic breast carcinomas is not independent from established prognostic factors. CK5/6+ CK14+ double positive tumours may be a subgroup of BBC with particularly unfavourable outcome.

KRAS mutation testing for predicting response to anti-EGFR therapy for colorectal carcinoma: proposal for an European quality assurance program

Novel therapeutic agents targeting the epidermal growth factor receptor (EGFR) have improved outcomes for patients with colorectal carcinoma. However, these therapies are effective only in a subset of patients. Activating mutations in the KRAS gene are found in 30-40% of colorectal tumors and are associated with poor response to anti-EGFR therapies. Thus, KRAS mutation status can predict which patient may or may not benefit from anti-EGFR therapy. Although many diagnostic tools have been developed for KRAS mutation analysis, validated methods and standardized testing procedures are lacking. This poses a challenge for the optimal use of anti-EGFR therapies in the management of colorectal carcinoma. Here we review the molecular basis of EGFR-targeted therapies and the resistance to treatment conferred by KRAS mutations. We also present guideline recommendations and a proposal for a European quality assurance program to help ensure accuracy and proficiency in KRAS mutation testing across the European Union.

Evaluation of Spondin-1 as a predictive marker for palliative 5-FU-based chemotherapy in metastatic colorectal cancer

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Background: An individualized tumor tailored chemotherapy may improve survival of patients with metastatic colorectal carcinoma (CRC). Therefore, we analyzed gene expression profiles of liver metastases and primaries of patients with CRC before application of a palliative 5-Fluorouracil based chemotherapy (AIO regimen) due to find predictive markers. These potential markers had to: (1) be highly expressed in the primary (2) and in the metastases, (3) be applicable to qRT-PCR of formalin-fixed paraffin embedded (FFPE) sections, and (4) remain their predictive power in a test set cohort. Methods: The training set consisted of 30 specimen from primary CRC and metastatic liver, which were laser micro dissected, the RNA was amplified and hybridized to Affymetrix HG U-133A microarrays. Additionally, RNA was isolated from FFPE sections of the same tumors and a qRT-PCR was performed for specific gene expression analysis. After surgery of the primary tumor all patients were treated with the AIO regimen. The test set consisted of 61 metastatic CRC patients, who were treated with the AIO regimen and where FFPE sections were available. Markers who showed promising predictive power and fulfilled criteria 1–3 (cp. background) were tested in the validation cohort. Response to chemotherapy was verified by CT scans according to WHO criteria. Results: By using statistical tests we identified some markers showing promising predictive power. However, most of them did not fulfill the further criteria. Spondin-1 expressions were very predictive for response (CR, PR) with a sensitivity of 62.5% and a specifity of 87.5% in the training set. Additionally, Spondin-1 was highly expressed as well in the tumors as in the metastases of CRC. Furthermore, the Affymetrix expression values for Spondin-1 were highly comparable with the RT-PCR data using FFPE sections from the same specimen. In the FFPE test set Spondin-1 remained its predictive value with sensitivity and specifity rates of 53.3% and 70.0%, respectively. Conclusions: Spondin-1 is an attractive candidate for further evaluation of response in CRC tumors treated with a 5-FU based chemotherapy as it is predictive and robust in terms of use in FFPE material. Further research with additional predictive markers to increase accuracy is ongoing.

[Table: see text]

Epithelial-mesenchymal and mesenchymal-epithelial transitions during cancer progression

Invasion by colorectal carcinomas is characterized by an epithelial-mesenchymal transition (EMT)-like de-differentiation of the tumor cells. However a re-differentiation towards an epithelial phenotype, resembling a mesenchymal-epithelial transition (MET) is detectable in metastases. This indicates that malignant progression is based on dynamic processes, which can not be explained solely by irreversible genetic alterations, but must be additionally regulated by the tumor environment. The main oncoprotein in colorectal cancer is the Wnt-pathway effector beta-catenin, which is overexpressed due to mutations in the APC tumor suppressor in most cases. EMT of the tumor cells is associated with a nuclear accumulation of the transcriptional activator beta-catenin, which is reversed in metastases. Nuclear beta-catenin is involved in two fundamental processes in embryonic development: EMT and stem cell formation. Accumulating data demonstrate that aberrant nuclear expression of beta-catenin can confere these two abilites also to tumor cells. The unusual combination of EMT with stem cell competence might result in a migrating tumor stem cell, which drives tumor invasion and metastasis.

Securin (hPTTG1) expression is regulated by beta-catenin/TCF in human colorectal carcinoma

Overexpression of the transcriptional activator β-catenin, mostly owing to loss-of-function mutations of the adenomatous polyposis coli (APC) tumour suppressor gene, is crucial for the initiation and progression of human colorectal carcinogenesis. Securin is a regulator of chromosome separation and its overexpression has been shown to be involved in different tumour-promoting processes, like transformation, hyperproliferation and angiogenesis, and correlates with tumour cell invasion. However, the molecular mechanism leading to securin overexpression in human colorectal cancer is unknown. Here we show a correlated high expression of β-catenin and securin (hPTTG1) in colorectal adenomas and carcinomas and further demonstrate that securin is a target of β-catenin transcriptional activation. This implies that deregulation of the β-catenin/T-cell factor-signalling pathway leads to overexpression of securin in human colorectal cancer, which subsequently may contribute to tumour progression.

Increased expression of high mobility group box 1 (HMGB1) is associated with an elevated level of the antiapoptotic c-IAP2 protein in human colon carcinomas

BACKGROUND

High mobility group box 1 (HMGB1) is a non-histone chromosomal protein implicated in a variety of biologically important processes, including transcription, DNA repair, V(D)J recombination, differentiation, and development. Overexpression of HMGB1 inhibits apoptosis, arguing that the molecule may act as an antiapoptotic oncoprotein. Indeed, increased expression of HMGB1 has been reported for several different tumour types. In this study, we analysed human colon carcinoma for HMGB1 as well as for c-IAP2 expression levels. c-IAP2 is an antiapoptotic protein which may be upregulated as a consequence of nuclear factor kappaB (NFkappaB) activation via HMGB1.

METHODS

A comparative genomic hybridisation (CGH) database comprising 1645 cases from different human tumour types was screened to detect cytogenetic changes at the HMGB1 locus. Immunohistochemical staining of human colon tissue microarrays and tumour biopsies, as well as western blot analysis of tumour lysates, were performed to detect elevated HMGB1 and c-IAP2 expression in colon carcinomas. The antiapoptotic potential of HMGB1 was analysed by measuring caspase activities, and luciferase reporter assays and quantitative polymerase chain reaction analysis were employed to confirm NFkappaB activation and c-IAP2 mRNA upregulation on HMGB1 overexpression.

RESULTS

According to CGH analysis, the genomic locus containing the HMGB1 gene was overrepresented in one third (35/96) of colon cancers. Correspondingly, HMGB1 protein levels were significantly elevated in 90% of the 60 colon carcinomas tested compared with corresponding normal tissues evaluable from the same patients. HMGB1 increased NFkappaB activity and led to co-overexpression of the antiapoptotic NFkappaB target gene product c-IAP2 in vitro. Furthermore, increased HMGB1 levels correlated with enhanced amounts of c-IAP2 in colon tumours analysed by us. Finally, we demonstrated that HMGB1 overexpression suppressed caspase-9 and caspase-3 activity, suggesting that HMGB1 interferes with the apoptotic machinery at the level of apoptosomal caspase-9 activation.

CONCLUSIONS

We identified in vitro a molecular pathway triggered by HMGB1 to inhibit apoptosis via c-IAP2 induction. Our data indicate a strong correlation between upregulation of the apoptosis repressing HMGB1 and c-IAP2 proteins in the pathogenesis of colon carcinoma.

Management of spontaneous enophthalmos due to silent sinus syndrome: a case report

Silent sinus syndrome (SSS) is a rare disease exhibiting unilateral enophthalmos and hypoglobus. A 26-year-old white female presented with right side enophthalmos and hypoglobus. There was no history of previous trauma or maxillary sinus diseases. A CT scan showed an opacified right maxillary antrum with decreased volume and downward bowing of the right orbital floor. From clinical and radiological findings the diagnosis SSS was made. Biopsies were collected from the maxillary sinus for the exclusion of malignancy. Two months later orbital floor reconstruction was carried out. Before antrostomy of the affected maxillary sinus, a relative enophthalmos of 4mm was determined. Five days after antrostomy the value reduced to 2.3mm. During the following 2 months the enophthalmos remained constant. At the end of the operation for orbital floor reconstruction it was 0.1mm. Five days after surgery the relative enophthalmos increased to 0.8mm. The value remained constant during the following 3 months. Initial antrostomy of the affected maxillary sinus may lead to a relevant, spontaneous reduction of enophthalmos. After a minimum period of 2 months a re-evaluation should be made, if a reconstruction of the orbital floor is still necessary for the correction of the globe position.

Terminal deoxynucleotidyl transferase-positive cells in trephine biopsies following bone marrow or peripheral stem cell transplantation reflect vigorous B-cell generation

AIMS

Bone marrow is the major site of B-cell generation in humans. While in early childhood a high number of B-cell precursors is found in the bone marrow, only very few such cells are usually detectable in adult bone marrow. To assess the number of immature B cells present after haematopoietic cell transplantation the number of terminal deoxynucleotidyl transferase (TdT)-positive cells in regenerating bone marrow of adult patients was analysed.

METHODS AND RESULTS

Bone marrow biopsy specimens were analysed from patients after allogeneic bone marrow transplantation (BMT; n = 14) or stem cell transplantation (SCT; n = 25) and autologous BMT (n = 9). Specimens from 11 untransplanted adult patients and 11 infants were also studied, as negative and positive controls, respectively. Immunohistochemistry was performed on paraffin-embedded bone marrow biopsy sections using TdT as a marker of lymphoid progenitors. Immunoreactivity for CD79a, CD20 and CD10 was used to confirm their B-cell origin. Using computer-assisted automated image analysis we quantitatively assessed the TdT+ cells present. We found a significant increase in the numbers of B-cell precursors in the bone marrow after allogeneic and autologous BMT/SCT compared with adult controls (P = 0.022). To analyse this in detail, we followed some patients after allogeneic BMT/SCT for up to 1445 days, when a marked B-cell increase was still detectable. However, the median number of TdT+ B cells after BMT/SCT was significantly lower than the number of equivalent B cells in infantile bone marrow biopsy specimens (P < 0.001).

CONCLUSIONS

Bone marrow of adult patients after BMT/SCT is capable of initiating vigorous precursor B-cell generation, which is not seen in untransplanted adults. However, the increase of immature B cells was variable in our study. Only in two young adult patients did it reach the magnitude of B-cell generation seen in infantile bone marrow where immunocompetent B cells are produced normally. A marked increase in number of immature B cells post-transplant may mimic B-cell acute lymphoblastic leukaemia (B-ALL). This is a potential problem in patients transplanted for B-ALL itself. Since reactive and neoplastic B-cell precursors share the same immunophenotype in paraffin-embedded tissue, additional tools, particularly molecular techniques, may have to be employed to establish the correct diagnosis.

Evidence for Pauli exchange leading to excited-state enhancement in electron transfer

Single- and double-electron transfer to autoionizing 1s2l2l(') configurations in fluorine ions have been investigated for 1.1 MeV/u collisions of F7+ and F8+ with He and Ne. The resulting Auger electron emission spectra show anomolously large intensities for the formation of the metastable 1s(2s2p 3P) 4P state compared to the similarly configured 1s(2s2p 3P) 2P- and 1s(2s2p 1P) 2P+ states. The large 4P intensity, which cannot be explained on the basis of spin statistics, is attributed instead to the Pauli exchange of similarly aligned electrons.

Epstein-Barr virus infection in colorectal neoplasms associated with inflammatory bowel disease: detection of the virus in lymphomas but not in adenocarcinomas

Epstein-Barr virus (EBV) is associated with several lymphoid and epithelial human malignancies. The latter include gastric adenocarcinomas, while sporadic colorectal adenocarcinomas (CRCs) have been reported to be EBV-negative. Recently, increased numbers of EBV-infected B lymphocytes have been detected in intestinal mucosal samples affected by ulcerative colitis (UC) and, to a lesser extent, Crohn's disease (CD). Both CRC and colorectal non-Hodgkin's lymphoma (NHL) are recognized complications of inflammatory bowel disease (IBD), but it is unclear to what extent EBV contributes to the development of these neoplasms. Seventeen cases of IBD-associated CRC and nine cases of IBD-associated colorectal NHL were therefore studied for the presence of EBV by in situ hybridization. EBV-positive cases were further studied for the expression of the EBV-encoded nuclear antigen (EBNA) 2 and the latent membrane protein (LMP) 1 of EBV by immunohistochemistry. Four out of seven cases of colorectal NHL associated with UC were shown to be EBV-positive. In addition, two of two colorectal NHLs developing in patients with CD were EBV-positive. Of the EBV-positive lymphomas, three displayed a pattern of EBV latent gene expression consistent with type I latency (EBNA2(-)/LMP1(-)), two a type II pattern (EBNA2(-)/LMP1(+)), and one a type III pattern (EBNA2(+)/LMP1(+)). These findings suggest that EBV infection is involved in the pathogenesis of a proportion of colorectal NHLs developing in IBD. Iatrogenic immunosuppression may contribute to the development of these lymphomas. By contrast, all 17 IBD-associated CRCs were EBV-negative, including a case of CRC occurring synchronously with an EBV-positive NHL. In conjunction with previous reports on sporadic CRCs, this suggests that EBV is not involved in the pathogenesis of CRC.

Late pulmonary metastasis in uterine PEComa

Perivascular epithelioid cell tumours (PEComas) other than angiomyolipoma, clear cell "sugar" tumour of the lung, and lymphangioleiomyomatosis are very rare mesenchymal tumours. The uterus seems to be the most prevalent site of involvement, but only 13 cases of uterine PEComa have been described. Three of these cases exhibited local aggressive behaviour and only one showed metastasis. Because of the extremely small number of cases, PEComas are considered tumours of uncertain malignant potential. This report describes a 68 year old woman, who presented with multiple pulmonary lesions seven years after the initial diagnosis of well differentiated endometrial stromal sarcoma. Histological and immunohistochemical analysis of the pulmonary lesions, in addition to re-evaluation of the primary uterine tumour, led to the final diagnosis of metastatic uterine PEComa. The findings indicate that any PEComa might have malignant potential. Spreading of this tumour to other organs might become evident even several years after primary manifestation.