Trastuzumab down-regulates Bcl-2 expression and potentiates apoptosis induction by Bcl-2/Bcl-XL bispecific antisense oligonucleotides in HER-2 gene--amplified breast cancer cells

Purpose: To investigate the possible existence of an antiapoptotic cross-talk between HER-2 and antiapoptotic Bcl-2 family members. Experimental design: Bcl-2 and Bcl-XL expression and apoptosis induction were analyzed in HER-2 gene-amplified (BT474) and nonamplified (ZR 75-1) breast cancer cell lines exposed to trastuzumab, alone or in combination with either Bcl-2/Bcl-XL bispecific antisense oligonucleotides (AS-4625) or the small-molecule Bcl-2 antagonist HA14-1. Results: In addition to HER-2 and epidermal growth factor receptor, trastuzumab down-regulated Bcl-2, but not Bcl-XL, protein, and mRNA expression in BT474 cells. Interestingly, trastuzumab-induced down-regulation of HER-2 and Bcl-2 was also observed in three of five and two of three breast cancer patients undergoing trastuzumab treatment, respectively. Despite Bcl-2 down-regulation, however, trastuzumab only marginally increased the rate of apoptosis (7.3 +/- 3.5%). We therefore investigated whether a combination of AS-4625 and trastuzumab might increase proapoptotic efficiency. AS-4625 treatment of BT474 cells decreased both Bcl-2 and Bcl-XL expression, resulting in a 21 +/- 7% net apoptosis induction; the combination of AS-4625 followed by trastuzumab resulted in a significantly stronger induction of apoptosis (37 +/- 6%, P <0.01) that was not observed with the reverse treatment sequence (trastuzumab followed by AS-4625). Similar results were obtained with the Bcl-2 antagonist HA14-1; indeed, exposure of BT474 cells to HA14-1 followed by trastuzumab resulted in a striking proapoptotic synergism (combination index=0.58 +/- 0.18), as assessed by isobologram analysis. Conclusions: Altogether our findings suggest that combined targeting of HER-2 and Bcl-2 may represent a novel, rational approach to more effective breast cancer therapy

A case of nodular sclerosis Hodgkin’s lymphoma repeatedly relapsing in the context of composite plasma cell-hyaline vascular Castleman’s disease: successful response to rituximab and radiotherapy

We report the case of an Epstein-Barr virus (EBV)- and human immunodeficiency virus-serum negative patient suffering from repeatedly relapsing classical Hodgkin’s Lymphoma (cHL) associated with a histological picture of plasma cell-hyaline vascular (PC-HV) form of Castleman’s disease (CD). The CD30- and CD15- positive, Reed-Sternberg/Hodgkin cells, only occasionally expressed the CD20 molecule, but not leukocyte common antigen and latent membrane protein-1. Single-strand polymerase chain reaction failed to detect human herpesvirus 8 or EBV in the involved tissues. At the time of second relapse in July 2005, the clinical picture was characterized by a palpable right hypogastric mass, disclosed at physical exam, in the absence of other enlarged peripheral lymph nodes, subjective symptoms or laboratory profile alterations. Combined hybrid-(18)F-fluorodeoxyglucose positron emission-computerized tomography (18F-FDG PET/CT) showed increased radionuclide uptake in multiple external iliac lymph nodes [standardized uptake value (SUV) of 7.4] and non-palpable left supraclavicular lymph nodes (SUV of 5.8). Relapsing cHL in the context of mixed PC-HV CD was documented in two of three surgically excised abdominal lymph nodes never previously enlarged or involved by any lymphoproliferative disease. Because of the limited disease extension and failure to induce continuous remission with previous conventional chemoradiotherapy, the patient was treated with six rituximab injections. This immunotherapy induced significant reduction in size of supraclavicular lymph nodes as evident at ultrasound (US) scan (<1 vs. 2.5 cm, post- vs. pretherapy), which was confirmed by the 18F-FDG PET/CT in October 2005, despite no modification in SUV of 4.2. 18F-FDG PET/CT also disclosed no radionuclide uptake by abdominal lymph nodes. Thus, a second course of four additional rituximab injections was given and subsequent 18F-FDG PET/CT indicated persistent, but reduced incorporation of radionuclide compared to the pretherapy value (SUV of 2.7) in the supraclavicular area and confirmed a normal metabolic activity in the iliac external lymph nodes. Because of uncertain persistent disease in the supraclavicular nodal site, involved-field radiotherapy (RT) was delivered in that area as consolidation treatment. After completion of rituximab and RT for 16 and 14 months respectively, US and 18F-FDG PET/CT exams were indicative of complete remission. This case is in concordance with previously published data suggesting that rituximab immunotherapy might be a valid option in the treatment of CD and also have a role in the management of relapsing cHL

Epidermal growth factor receptor gene copy number in 101 advanced colorectal cancer patients treated with chemotherapy plus cetuximab

<p>Abstract</p> <p>Background</p> <p>Responsiveness to Cetuximab alone can be mediated by an increase of Epidermal Growth factor Receptor (EGFR) Gene Copy Number (GCN). Aim of this study was to assess the role of EGFR-GCN in advanced colorectal cancer (CRC) patients receiving chemotherapy plus Cetuximab.</p> <p>Methods</p> <p>One hundred and one advanced CRC patients (43 untreated- and 58 pre-treated) were retrospectively studied by fluorescence in situ hybridization (FISH) to assess EGFR-GCN and by immunohistochemistry (IHC) to determine EGFR expression. Sixty-one out of 101 patients were evaluated also for k-ras status by direct sequencing. Clinical end-points were response rate (RR), progression-free survival (PFS) and overall survival (OS).</p> <p>Results</p> <p>Increased EGFR-GCN was found in 60/101 (59%) tumor samples. There was no correlation between intensity of EGFR-IHC and EGFR-GCN (p = 0.43). Patients receiving chemotherapy plus Cetuximab as first line treatment had a RR of 70% (30/43) while it was 18% (10/56) in the group with previous lines of therapy (p < 0.0001). RR was observed in 29/60 (48%) of patients with increased EGFR-GCN and in 6/28 (21%) in those without (p = 0.02). At multivariate analyses, number of chemotherapy lines and increased EGFR-GCN were predictive of response; EGFR-IHC score, increased EGFR-GCN and number of chemotherapy lines were significantly associated with a significant better PFS. Response to therapy was the only prognostic predictive factor for OS. In the 60 patients analyzed for k-ras mutations, number of chemotherapy lines, increased EGFR-GCN and k-ras wild type status predicted a better PFS.</p> <p>Conclusion</p> <p>In metastatic CRC patients treated with chemotherapy plus Cetuximab number of chemotherapy lines and increased EGFR-GCN were significantly associated with a better clinical outcome, independent of k-ras status.</p

Neuroacanthocytosis associated with a defect of the 4.1R membrane protein

BACKGROUND: Neuroacanthocytosis (NA) denotes a heterogeneous group of diseases that are characterized by nervous system abnormalities in association with acanthocytosis in the patients' blood. The 4.1R protein of the erythrocyte membrane is critical for the membrane-associated cytoskeleton structure and in central neurons it regulates the stabilization of AMPA receptors on the neuronal surface at the postsynaptic density. We report clinical, biochemical, and genetic features in four patients from four unrelated families with NA in order to explain the cause of morphological abnormalities and the relationship with neurodegenerative processes. CASE PRESENTATION: All patients were characterised by atypical NA with a novel alteration of the erythrocyte membrane: a 4.1R protein deficiency. The 4.1R protein content was significantly lower in patients (3.40 ± 0.42) than in controls (4.41 ± 0.40, P < 0.0001), reflecting weakened interactions of the cytoskeleton with the membrane. In patients IV:1 (RM23), IV:3 (RM15), and IV:6 (RM16) the 4.1 deficiency seemed to affect the horizontal interactions of spectrin and an impairment of the dimer self-association into tetramers was detected. In patient IV:1 (RM16) the 4.1 deficiency seemed to affect the skeletal attachment to membrane and the protein band 3 was partially reduced. CONCLUSION: A decreased expression pattern of the 4.1R protein was observed in the erythrocytes from patients with atypical NA, which might reflect the expression pattern in the central nervous system, especially basal ganglia, and might lead to dysfunction of AMPA-mediated glutamate transmission

Analysis of HER2 expression in primary urinary bladder carcinoma and corresponding metastases

We were interested in this recent article by Gardmark et al.[1], in which they describe their analysis of 90 patients with metastatic TCC of the urinary bladder to evaluate “the suitability of HER2 as a target in preparation for planned systemic therapies of HER2-positive urinary bladder carcinoma”. The authors examined HER2 expression using two different immunohistochemical stains (the HerceptTest and modified HerceptTest, MH). According to these authors, HER2 staining was positive in 79% of the primary tumours and 62% of the metastases when the MH staining and target-score criteria were applied. Moreover, in their conclusions section, they underlined that the primary goal of the study was to analyse over-expressed receptors for possible treatment with HER2 targeting agents. To that end, in our opinion, essential requisites are those of evaluating not only HER2 expression, but also gene amplification and chromosome 17 aneusomy. Many studies have evaluated HER2 protein expression and gene amplification rates; they report HER2 expression rates of 2–74%[2]. This variation is partly a result of differences in the methods used to assess HER2 and variability in the reporting of data. Both overexpression with no gene amplification and heterogeneity in HER2 expression are more common in bladder cancer than in breast cancer [3,4]. This is mainly explained by a high level of chromosome 17 polysomy in TCC. Latif et al.[5], in 75 TCC classified as G3pT2, showed polysomy 17 in 97%, increased HER2 copy number in 92% and HER2 gene amplification in 7% of cases examined. In our previous investigation, we reported that chromosome 17 aneusomy is present in 84% of examined superficial bladder cancer, but also in 47% and 21% of normal-appearing adjacent proximal and distal mucosa, respectively [6]. Moreover, in our recent article, we found, in 48 advanced bladder cancers, chromosome 17 polysomy in 42% and HER2 gene amplification in 15% of specimens. Our study strongly confirmed the importance of chromosome 17 polysomy in detecting HER2 amplification [7]. Evidence from breast cancer suggests that only tumours with HER2 gene amplification respond to the anti-HER2 therapy ( Herceptin) [8]. If this were true for bladder cancer, only a low proportion of patients would be suitable for treatment. In conclusion, Gardmark et al. should be more careful in stating that immunohistochemical staining is sufficient to select HER2-targeting in patients. We suggest that it would be useful to re-evaluate these results using fluorescence in situ hybridisation, which permits the simultaneous assessment of the chromosome 17 aneusomy and HER2 gene status

Silver(I)N-heterocyclic carbene complexes:Synthesis, characterization and antibacterial activity

Five new silver complexes having bidentate N-heterocyclic carbene ligands were synthesized and characterized by elemental analysis, IR, NMR and mass spectroscopic methods. Four of the ligands used are neutral, having an alcohol group on alkyl substituent of one of the two nitrogen atoms of the heterocycle [NHC-OH], the fifth, having a ligand alkoxide, is mono-anionic [NHC-O]. A study on the rate of hydrolysis of complexes synthesized, showed that they are stable to hydrolysis even after 24 h. Probably, the pincer effect of both [NHC-OH] and [NHC-O] ligands stabilizes these compounds. All the synthesized complexes do not show cytotoxicity, but they have a significant antibacterial activity. They were tested on Escherichia coli and Bacillus subtilis and data obtained demonstrate that the synthesized Ag-complexes are very promising candidates to be used as antimicrobial compound