Citations

Fifteen percent of lung cancer cases occur in never-smokers and show characteristics that are molecularly and clinically distinct from those in smokers. Epidermal growth factor receptor ( EGFR ) gene mutations, which are correlated with sensitivity to EGFR-tyrosine kinase inhibitors (EGFR-TKIs), are more frequent in never-smoker lung cancers. In this study, microRNA (miRNA) expression profiling of 28 cases of never-smoker lung cancer identified aberrantly expressed miRNAs, which were much fewer than in lung cancers of smokers and included miRNAs previously identified (e.g., up-regulated miR-21) and unidentified (e.g., down-regulated miR-138) in those smoker cases. The changes in expression of some of these miRNAs, including miR-21, were more remarkable in cases with EGFR mutations than in those without these mutations. A significant correlation between phosphorylated-EGFR ( p -EGFR) and miR-21 levels in lung carcinoma cell lines and the suppression of miR-21 by an EGFR-TKI, AG1478, suggest that the EGFR signaling is a pathway positively regulating miR-21 expression. In the never-smoker–derived lung adenocarcinoma cell line H3255 with mutant EGFR and high levels of p -EGFR and miR-21, antisense inhibition of miR-21 enhanced AG1478-induced apoptosis. In a never-smoker–derived adenocarcinoma cell line H441 with wild-type EGFR , the antisense miR-21 not only showed the additive effect with AG1478 but also induced apoptosis by itself. These results suggest that aberrantly increased expression of miR-21, which is enhanced further by the activated EGFR signaling pathway, plays a significant role in lung carcinogenesis in never-smokers, as well as in smokers, and is a potential therapeutic target in both EGFR -mutant and wild-type cases.

PurposeSingle-agent gemcitabine (GEM) is standard treatment of metastatic pancreatic cancer. Fixed-dose rate (FDR) GEM and GEM plus oxaliplatin have shown promise in early clinical trials. E6201 was designed to compare overall survival (OS) of standard weekly GEM 1,000 mg/m2/30 minutes versus GEM FDR 1,500 mg/m2/150 minutes or GEM 1,000 mg/m2/100 minutes/day 1 plus oxaliplatin 100 mg/m2/day 2 every 14 days (GEMOX).MethodsThis trial included patients with metastatic or locally advanced pancreatic cancer, normal organ function, and performance status of 0 to 2. The study was designed to detect a 33% difference in median survival (hazard ratio [HR] ≤ 0.75 for either of the experimental arms) with 81% power while maintaining a significance level of 2.5% in a two-sided test for each of the two primary comparisons.ResultsEight hundred thirty-two patients were enrolled. The median survival and 1-year survival were 4.9 months (95% CI, 4.5 to 5.6) and 16% for GEM, 6.2 months (95% CI, 5.4 to 6.9), and 21% for GEM FDR (HR, 0.83; stratified log-rank P = .04), and 5.7 months (95% CI, 4.9 to 6.5) and 21% for GEMOX (HR, 0.88; stratified log-rank P = .22). Neither of these differences met the prespecified criteria for significance. Survival was 9.2 months for patients with locally advanced disease, and 5.4 months for those with metastatic disease. Grade 3/4 neutropenia and thrombocytopenia were greatest with GEM FDR. GEMOX caused higher rates of nausea, vomiting, and neuropathy.ConclusionNeither GEM FDR nor GEMOX resulted in substantially improved survival or symptom benefit over standard GEM in patients with advanced pancreatic cancer.

Abstract Microcephalin (MCPH1) is a BRCA1 COOH terminal (BRCT) domain containing protein involved in the cellular response to DNA damage that has been implicated in autosomal recessive primary microcephaly. MCPH1 is recruited to sites of DNA double-strand breaks by phosphorylated histone H2AX (γH2AX), but the mechanism by which MCPH1 contributes to the repair process remains to be determined. Here, we show that MCPH1 binds to BRCA2 and regulates the localization of BRCA2 and Rad51 at sites of DNA damage. The interaction occurs through the NH2 terminus of BRCA2 and the COOH terminal BRCT domains of MCPH1. Disruption of the interaction between MCPH1 and BRCA2 has no effect on the ability of BRCA2 to form a complex with Rad51 but is associated with substantially reduced levels of both BRCA2 and Rad51 at sites of DNA double-strand breaks. Uncoupling of MCPH1 from BRCA2 also interferes with Rad51-dependent and BRCA2-dependent homologous recombination repair activity. These results suggest that the role of MCPH1 in the DNA damage response is in part associated with the ability to localize BRCA2 to sites of DNA double-stand breaks. [Cancer Res 2009;69(13):5531–6]

Abstract The invasion of malignant glioma cells into the surrounding normal brain precludes effective clinical treatment. In this report, we investigated the role of the NH2-terminal FERM domain in the regulation of the promigratory function of Pyk2. We report that the substitution of residues that constitute a small cleft on the surface of the F3 module of the FERM domain do not significantly alter Pyk2 expression but result in the loss of Pyk2 phosphorylation. A monoclonal antibody, designated 12A10, specifically targeting the Pyk2 FERM domain was generated and recognizes an epitope located on the β5C-α1C surface of the F3 module of the FERM domain. Amino acid substitutions in the F3 module that resulted in the loss of Pyk2 phosphorylation also inhibited the binding of 12A10, suggesting that the 12A10 epitope overlaps a site that plays a role in Pyk2 activity. Conjugation of 12A10 to a membrane transport peptide led to intracellular accumulation and inhibition of glioma cell migration in a concentration-dependent manner. A single chain Fv fragment of 12A10 was stable when expressed in the intracellular environment, interacted directly with Pyk2, reduced Pyk2 phosphorylation, and inhibited glioma cell migration in vitro. Stable intracellular expression of the 12A10 scFv significantly extended survival in a glioma xenograft model. Together, these data substantiate a central role for the FERM domain in regulation of Pyk2 activity and identify the F3 module as a novel target to inhibit Pyk2 activity and inhibit glioma progression. [Mol Cancer Ther 2009;8(6):1505–14]

Abstract Using biopsy specimens from patients with B-cell non-Hodgkin's lymphoma, we observed a significantly low frequency of TH17 cells, including several samples with no detectable amount of interleukin (IL)-17–producing cells present in the tumor microenvironment. We found that, in the absence of lymphoma B cells, treatment with IL-1β/IL-6 or lipopolysaccharide (LPS) enhanced IL-17 expression in CD4+ T cells and this enhancement was attenuated when CD4+ T cells were cocultured with lymphoma B cells. Blockade of CD27-CD70 or CD28-CD80/86 interactions by anti-CD70 or anti-CD80/86 antibodies restored LPS-mediated induction of IL-17 expression in CD4+ T cells cocultured with lymphoma B cells. Because a subset of lymphoma B cells express IL-2 and given that IL-2 signaling is critically important in the development of regulatory T (Treg) cells, we tested the role of IL-2 signaling in TH17 cell development. We found that treatment with anti-IL-2 antibody to interrupt IL-2 signaling significantly inhibited Foxp3 expression in CD4+ T cells. In contrast, interruption of IL-2 signaling up-regulated IL-17 expression in CD4+ T cells and restored lymphoma-mediated down-regulation of IL-17–producing cells. Furthermore, the reversal of Treg cell activity by LPS or CpG-A resulted in an enhancement of IL-17–producing cells. Taken together, our study indicated that lymphoma B cells play an important role in skewing the balance between Treg and TH17 cells resulting in the establishment of a profoundly inhibitory tumor microenvironment. [Cancer Res 2009;69(13):5522–30]

Purpose To define the optimal dose of Polyphenon E for chronic daily administration and tolerability in patients with chronic lymphocytic leukemia (CLL). Patients and Methods Previously untreated patients with asymptomatic Rai stage 0 to II CLL were eligible for participation. Polyphenon E with a standardized dose of epigallocatechin-3-gallate (EGCG) was administered using the standard phase I design with three to six patients per dose level (range, 400 to 2,000 mg by mouth twice a day). Trough plasma EGCG levels were measured 1 month after initiation of therapy. Response was classified using the National Cancer Institute (NCI) Working Group (WG) Criteria. Results Thirty-three eligible patients were accrued to dose levels 1 to 8. The maximum-tolerated dose was not reached. The most common adverse effects included transaminitis (33%, all grade 1), abdominal pain (30% grade 1, 0% grade 2, and 3% grade 3), and nausea (39% grade 1 and 9% grade 2). One patient experienced an NCI WG partial remission. Other signs of clinical activity were also observed, with 11 patients (33%) having a sustained ≥ 20% reduction in absolute lymphocyte count (ALC) and 11 (92%) of 12 patients with palpable adenopathy experiencing at least a 50% reduction in the sum of the products of all nodal areas during treatment. Trough plasma EGCG levels after 1 month of treatment ranged from 2.9 to 3,974 ng/mL (median, 40.4 ng/mL). Conclusion Daily oral EGCG in the Polyphenon E preparation was well tolerated by CLL patients in this phase I trial. Declines in ALC and/or lymphadenopathy were observed in the majority of patients. A phase II trial to evaluate efficacy using 2,000 mg twice a day began in November 2007.

Abstract Esophageal adenocarcinoma risk in Barrett's esophagus (BE) is increased 30- to 125-fold versus the general population. Among all BE patients, however, neoplastic progression occurs only once per 200 patient-years. Molecular biomarkers are therefore needed to risk-stratify patients for more efficient surveillance endoscopy and to improve the early detection of progression. We therefore performed a retrospective, multicenter, double-blinded validation study of eight BE progression prediction methylation biomarkers. Progression or nonprogression were determined at 2 years (tier 1) and 4 years (tier 2). Methylation was assayed in 145 nonprogressors and 50 progressors using real-time quantitative methylation-specific PCR. Progressors were significantly older than nonprogressors (70.6 versus 62.5 years; P < 0.001). We evaluated a linear combination of the eight markers, using coefficients from a multivariate logistic regression analysis. Areas under the ROC curve (AUC) were high in the 2-year, 4-year, and combined data models (0.843, 0.829, and 0.840; P < 0.001, <0.001, and <0.001, respectively). In addition, even after rigorous overfitting correction, the incremental AUCs contributed by panels based on the 8 markers plus age versus age alone were substantial (Δ-AUC = 0.152, 0.114, and 0.118, respectively) in all 3 models. A methylation biomarker–based panel to predict neoplastic progression in BE has potential clinical value in improving both the efficiency of surveillance endoscopy and the early detection of neoplasia. [Cancer Res 2009;69(10):4112–5]

Abstract Previous studies have suggested that minor alleles for ERCC4 rs744154, TNF rs361525, CASP10 rs13010627, PGR rs1042838, and BID rs8190315 may influence breast cancer risk, but the evidence is inconclusive due to their small sample size. These polymorphisms were genotyped in more than 30,000 breast cancer cases and 30,000 controls, primarily of European descent, from 30 studies in the Breast Cancer Association Consortium. We calculated odds ratios (OR) and 95% confidence intervals (95% CI) as a measure of association. We found that the minor alleles for these polymorphisms were not related to invasive breast cancer risk overall in women of European descent: ECCR4 per-allele OR (95% CI) = 0.99 (0.97-1.02), minor allele frequency = 27.5%; TNF 1.00 (0.95-1.06), 5.0%; CASP10 1.02 (0.98-1.07), 6.5%; PGR 1.02 (0.99-1.06), 15.3%; and BID 0.98 (0.86-1.12), 1.7%. However, we observed significant between-study heterogeneity for associations with risk for single-nucleotide polymorphisms (SNP) in CASP10, PGR, and BID. Estimates were imprecise for women of Asian and African descent due to small numbers and lower minor allele frequencies (with the exception of BID SNP). The ORs for each copy of the minor allele were not significantly different by estrogen or progesterone receptor status, nor were any significant interactions found between the polymorphisms and age or family history of breast cancer. In conclusion, our data provide persuasive evidence against an overall association between invasive breast cancer risk and ERCC4 rs744154, TNF rs361525, CASP10 rs13010627, PGR rs1042838, and BID rs8190315 genotypes among women of European descent. (Cancer Epidemiol Biomarkers Prev 2009;18(5):1610–6)

Abstract The t(2;14)(p16;q32) has been reported previously in only 12 cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The clinicopathologic features have been incompletely described. We describe 6 new cases of CLL/SLL with t(2;14)(p16;q32). All had marrow involvement, 4 had absolute lymphocytosis, 4 had lymphadenopathy, and 3 had hepatosplenomegaly. All showed atypical lymphocyte morphologic features with plasmacytoid differentiation and irregular nuclei; 3 had increased prolymphocytes. Flow cytometry demonstrated typical immunophenotypes in 5 and an atypical immunophenotype in 1. All expressed ZAP70; 5 assessed showed unmutated IgVH genes. Karyotyping identified t(2;14)(p16;q32) as the sole abnormality in 1, primary abnormality in 2, and part of a complex karyotype in 3. Fluorescence in situ hybridization analysis revealed BCL11A/IgH rearrangement in all. After chemotherapy, 3 patients died of disease and 3 were alive with disease (median follow-up, 80 months). We conclude that CLL/SLL with t(2;14) (p16;q32) and BCL11A/IgH rearrangement is characterized by atypical morphologic features and unmutated IgVH genes.