Early tumor-cell gene expression changes may predict the response to first-line bortezomib-based therapy in patients with newly diagnosed multiple myeloma.

PURPOSE: Maximizing the response rate to first-line therapy in patients with multiple myeloma (MM) is important because it leads to improved outcome. Gene-expression studies have identified prognostic gene sets in patients receiving bortezomib-based therapy. Comparison of the lists of genes derived from two gene-expression-based models (GEP70, GEP80) showed that they overlap in three genes, namely PSMD4, BIRC5, and KIAA1754. An unanswered question is whether early gene-expression changes can be used as predictors of the response to first-line bortezomib. In this study we aimed to examine the predictive value of gene expression changes for the depth of response after bortezomib-based therapy in newly diagnosed MM. METHODS: We prospectively assessed the relation between early PSMD4, BIRC5, and KIAA1754 gene expression changes (before therapy and one week later) and the response rate after bortezomib-based therapy in 25 patients with newly diagnosed MM. Gene expression was studied by RT-PCR on CD138-selected plasma cells, and changes were recorded as upregulation, downregulation, or unchanged. RESULTS: Whereas baseline prognostic factors including genetic lesions and stage were not predictive of the response rate, we found that early BIRC5 and KIAA1754 gene-expression changes were significantly associated with the depth of response to bortezomib (p=0.001 and p<0.001, respectively). PSMD4 was not predictive of the depth of response. KIAA1754 upregulation was linked to complete remission (CR) or very good partial remission (VGPR). BIRC5 upregulation was linked to stable disease (SD) or progressive disease (PD). We also observed that BIRC5 upregulation was associated with worse progression-free survival (PFS). CONCLUSIONS: Our results suggest that BIRC5 and KIAA1754 gene-expression changes may predict the response to bortezomib-based therapy. These data may have relevance for the stratification and early adaptation of first-line treatment in patients with newly diagnosed MM.

Opposing effects of bortezomib-induced nuclear factor-κB inhibition on chemical lung carcinogenesis.

Since recent evidence indicates a requirement for epithelial nuclear factor (NF)-κB signaling in lung tumorigenesis, we investigated the impact of the NF-κB inhibitor bortezomib on lung tumor promotion and growth. We used an experimental model in which wild-type mice or mice expressing an NF-κB reporter received intraperitoneal urethane (1 g/kg) followed by twice weekly bortezomib (1 mg/kg) during distinct periods of tumor initiation/progression. Mice were serially assessed for lung NF-κB activation, inflammation and carcinogenesis. Short-term proteasome inhibition with bortezomib did not impact tumor formation but retarded the growth of established lung tumors in mice via effects on cell proliferation. In contrast, long-term treatment with bortezomib resulted in significantly increased lung tumor number and size. This tumor-promoting effect of prolonged bortezomib treatment was associated with perpetuation of urethane-induced inflammation and chronic upregulation of interleukin-1ß and proinflammatory C-X-C motif chemokine ligands (CXCL) 1 and 2 in the lungs. In addition to airway epithelium, bortezomib inhibited NF-κB in pulmonary macrophages in vivo, presenting a possible mechanism of tumor amplification. In this regard, RAW264.7 macrophages exposed to bortezomib showed increased expression of interleukin-1ß, CXCL1 and CXCL2. In conclusion, although short-term bortezomib may exert some beneficial effects, prolonged NF-κB inhibition accelerates chemical lung carcinogenesis by perpetuating carcinogen-induced inflammation. Inhibition of NF-κB in pulmonary macrophages appears to play an important role in this adverse process.

Tumor necrosis factor-alpha promotes malignant pleural effusion.

Tumor necrosis factor (TNF)-alpha is present in the microenvironment of human tumors, including malignant pleural effusion (MPE). Although the cytokine is produced in the pleural cavity by both tumor and host cells, its effects on MPE formation are unknown. In these studies, we sought to determine the role of TNF-alpha in the pathogenesis of MPE and to assess the therapeutic effects of its neutralization in a preclinical model. For this, MPEs were generated in immunocompetent mice using intrapleural injection of mouse lung adenocarcinoma cells. The roles of tumor- and host-derived TNF-alpha were assessed using combined experimentation with TNF-alpha gene-deficient mice and in vivo TNF-alpha neutralization. To expand the scope of preclinical data, TNF-alpha and vascular endothelial growth factor (VEGF) expression were determined in human cancer cell lines and human MPE. In the MPE model, TNF-alpha of host and tumor origin was present. TNF-alpha neutralization significantly limited tumor dissemination, effusion formation, vascular hyperpermeability, TNF-alpha and VEGF expression, and angiogenesis, thereby improving survival. In contrast, these variables were not different between TNF-alpha gene-sufficient and TNF-alpha gene-deficient mice. In mouse cancer cells, TNF-alpha functioned via nuclear factor-kappaB- and neutral sphingomyelinase-dependent pathways to induce TNF-alpha and VEGF, respectively. These results were recapitulated in human cancer cells, and a correlation was detected between TNF-alpha and VEGF content of human MPE. We conclude that tumor-derived TNF-alpha is important in the development of MPE in mice, and provide preclinical evidence supporting the efficacy of TNF-alpha blockade against malignant pleural disease.

A central role for tumor-derived monocyte chemoattractant protein-1 in malignant pleural effusion.

BACKGROUND: Tumor cells in malignant pleural effusions (MPEs) are an important source of monocyte chemoattractant protein (MCP)-1. However, the role of tumor-derived MCP-1 in the pathogenesis and progression of MPE has not been determined. METHODS: B16 mouse skin melanoma cells, which are deficient in MCP-1 expression, and mouse Lewis lung cancer (LLC) cells, which express high levels of MCP-1, were engineered to stably express MCP-1 and short hairpin RNAs (shRNAs) targeting the MCP-1 transcript, respectively. Cells were injected into the pleural cavities of syngeneic immunocompetent mice, and MPE volume and pleural tumors were quantified at necropsy (day 14). MCP-1 and other mediators were determined by cytometric bead array and enzyme-linked immunosorbent assay, and mononuclear and endothelial cells were identified by immunolabeling of F4/80 and factor VIII-related antigen respectively. Mouse survival was assessed using Kaplan-Meier analysis. Vascular permeability in mice with MPE was assessed using albumin-binding Evans blue. Statistical tests were two-sided. RESULTS: LLC cells expressing shRNA against MCP-1 elaborated less than 5% of the MCP-1 level in cells expressing nonspecific shRNA (control cells), and intrapleural delivery of these cells resulted in less MPE (mean MPE volume = 86 and 585 muL, respectively; difference = 499 muL; 95% confidence interval [CI] = 331 to 669 muL; P < .001), reduced MCP-1 levels in the pleural fluid, and lower mortality than when control cells were delivered. Overexpression of MCP-1 in intrapleurally injected B16 melanoma cells led to increased MPE and reduced survival. In mice with MPE, MCP-1 was a potent inducer of vascular permeability, mononuclear recruitment, and, in pleural tumors, of angiogenesis. CONCLUSION: MCP-1 produced by tumor cells is an important determinant of their capacity to induce the formation of MPE and may be a useful target for the treatment of malignant pleural disease.