Anaplastic large-cell lymphoma (ALCL), as defined in the World Health Organization, is a heterogeneous category in which a subset of cases is associated with the t(2;5)(p23;q35) or variant translocations resulting in overexpression of anaplastic lymphoma kinase (ALK). p53 has not been assessed in currently defined subsets of ALCL tumors. In this study, we assessed ALK þ and ALKÀ ALCL tumors for p53 gene alterations using PCR, single-strand conformation polymorphism and direct sequencing methods. We also immunohistochemically assessed ALCL tumors for p53 expression. Three of 36 (8%) ALCL tumors (1/14 ALK þ , 2/22 ALKÀ) with adequate DNA showed p53 gene mutations. By contrast, p53 was overexpressed in 36 of 55 (65%) ALCL tumors (16 ALK þ , 20 ALKÀ). p21, a target of p53, was expressed in 15 of 31 (48%) ALCL tumors including seven of 15 (47%) p53-positive tumors. p21 expression in a subset of ALCL suggests the presence of functional p53 protein. Apoptotic rate was significantly higher in p53-positive than p53-negative tumors (mean 2.78 vs 0.91%, P ¼ 0.0003). We conclude that the p53 gene is rarely mutated in ALK þ and ALKÀ ALCL tumors. Nevertheless, wild-type p53 gene product is commonly overexpressed in ALCL and may be functional in a subset of these tumors.
BACKGROUNDPreclinical data indicate EGFR signals through both kinase-dependent and independent pathways and that combining a small-molecule EGFR inhibitor, EGFR antibody, and/or anti-angiogenic agent is synergistic in animal models.METHODSWe conducted a dose-escalation, phase I study combining erlotinib, cetuximab, and bevacizumab. The subset of patients with non-small cell lung cancer (NSCLC) was analyzed for safety and response.RESULTSThirty-four patients with NSCLC (median four prior therapies) received treatment on a range of dose levels. The most common treatment-related grade ≥2 adverse events were rash (n=14, 41%), hypomagnesemia (n=9, 27%), and fatigue (n=5, 15%). Seven patients (21%) achieved stable disease (SD) ≥6 months, two achieved a partial response (PR) (6%), and two achieved an unconfirmed partial response (uPR) (6%) (total=32%). We observed SD≥6 months/PR/uPR in patients who had received prior erlotinib and/or bevacizumab, those with brain metastases, smokers, and patients treated at lower dose levels. Five of 16 patients (31%) with wild-type EGFR experienced SD≥6 months or uPR. Correlation between grade of rash and rate of SD≥6 months/PR was observed (p<0.01).CONCLUSIONThe combination of erlotinib, cetuximab, and bevacizumab was well-tolerated and demonstrated antitumor activity in heavily pretreated patients with NSCLC.
SMADs are evolutionarily conserved transducers of the differentiation and growth arrest signals from the transforming growth factor/BMP (TGF/BMP) family of ligands. Upon receptor activation, the ligand-restricted SMADs1–35 are phosphorylated in the C-terminal MH2 domain and recruit the common subunit SMAD4/DPC-4 gene to the nucleus to mediate target gene expression. Frequent inactivating mutations of SMAD4, or less common somatic mutations ofSMAD2 seen in solid tumors, suggest that these genes have a suppressor function. However, there have been no identified mutations of SMAD5, although the gene localizes to the critical region of loss in chromosome 5q31.1 (chromosome 5, long arm, region 3, band 1, subband 1) in myelodysplasia (MDS) and acute myelogenous leukemia (AML). A ubiquitously expressed novel isoform,SMAD5β, encodes a 351 amino acid protein with a truncated MH2 domain and a unique C-terminal tail of 18 amino acids, which may be the functional equivalent of inactivating mutations. The levels of SMAD5β transcripts are higher in the undifferentiated CD34+ hematopoietic stem cells than in the terminally differentiated peripheral blood leukocytes, thereby implicating the β form in stem cell homeostasis. Yeast 2-hybrid interaction assays reveal the lack of physical interactions between SMAD5β and SMAD5 or SMAD4. The expression ofSMAD5β may represent a novel mechanism to protect pluripotent stem cells and malignant cells from the growth inhibitory and differentiation signals of BMPs.
Summary Purpose Angiogenesis plays a pivotal role in tumor growth and metastasis. Sorafenib, a tyrosine kinase inhibitor of vascular endothelial growth factor receptor (VEGFR), combined with bevacizumab, a monoclonal antibody to vascular endothelial growth factor (VEGF-A), would vertically inhibit VEGF/VEGFR signaling. A phase I trial was performed to assess safety, maximum tolerated dose (MTD), and clinical correlates. Experimental design Patients with advanced solid tumors refractory to standard therapy were eligible. In cohorts of escalating doses, patients received sorafenib daily for 28 days and bevacizumab every two weeks. Clinical correlates included VEGF polymorphisms. Expansion cohorts of responding tumor types were enrolled. Results One hundred fifteen patients were treated, and the MTD was identified as 200 mg twice daily sorafenib and 5 mg/kg bevacizumab every two weeks. Median number of prior therapies was four. Twenty-nine patients (25 %) achieved stable disease ≥6 months; six patients (5 %) achieved a partial response (total SD≥6 months/PR=35 (30 %)). 76 patients (66 %) experienced adverse events of grade 2 or higher, most commonly hand and foot syndrome (n=27, 24 %) and hypertension (n=24, 21 %). Dose-limiting toxicity occurred in eight patients (7 %), and 45 patients (39 %) required dose reduction for toxicity. Grade 3 and 4 hypertension was associated with longer time to treatment failure, overall survival, and higher response rate. Conclusions Combination sorafenib and bevacizumab was well-tolerated and demonstrated antitumor activity in heavily pretreated patients with advanced solid tumors.
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