Distinct patterns of cytokine and angiogenic factor modulation and markers of benefit for vandetanib and/or chemotherapy in patients with non-small-cell lung cancer.

PURPOSE: There is an unmet need for biomarkers for identifying patients likely to benefit from anticancer treatments, selecting dose, and understanding mechanisms of resistance. Plasma vascular endothelial growth factor (VEGF) and soluble VEGF receptor 2 (sVEGFR-2) are known to be modulated by VEGF pathway inhibitors. It is unknown whether chemotherapy or VEGFR inhibitor/chemotherapy combinations induce changes in these or other cytokines and angiogenic factors (CAFs) and whether such changes could be markers of benefit. METHODS: Thirty-five plasma CAFs were analyzed using multiplexed bead arrays and enzyme-linked immunosorbent assays from 123 patients with non-small-cell lung cancer in a randomized phase II study who received vandetanib, a VEGFR and epidermal growth factor receptor inhibitor, monotherapy carboplatin and paclitaxel (CP), or the combination (VCP). Changes in CAFs at days 8, 22, and 43 from baseline were correlated with progression risk. RESULTS: VEGF increased and sVEGFR-2 decreased by day 43 in the vandetanib arm, whereas a distinct pattern was observed in the CP and VCP arms, with significant decreases in interleukin (IL) -12, IL-1 receptor antagonist, and matrix metalloproteinase 9 (MMP-9) and increased macrophage chemoattractant protein 1. In each treatment arm, changes in different markers were associated with progression risk. For example, increases in IL-8 with VCP, MMP-9 with CP, and VEGF with vandetanib monotherapy were associated with increased progression risk, and increase in intercellular adhesion molecule 1 with vandetanib was associated with decreased risk. CONCLUSION: Vandetanib and chemotherapy treatment led to distinct patterns of CAF changes; the combination resembled chemotherapy alone. Changes in specific CAFs correlated with clinical outcome, but markers differed for each treatment arm. CAF profiling may provide insights into the biologic effects of treatment and identify drug-specific markers of activity and clinical benefit.

CD26 regulates p38 mitogen-activated protein kinase-dependent phosphorylation of integrin beta1, adhesion to extracellular matrix, and tumorigenicity of T-anaplastic large cell lymphoma Karpas 299.

CD26 is an antigen with key role in T-cell biology and is expressed on selected subsets of aggressive T-cell malignancies. To elucidate the role of CD26 in tumor behavior, we examine the effect of CD26 depletion by small interfering RNA transfection of T-anaplastic large cell lymphoma Karpas 299. We show that the resultant CD26-depleted clones lose the ability to adhere to fibronectin and collagen I. Because anti-integrin beta1 blocking antibodies also prevent binding of Karpas 299 to fibronectin and collagen I, we then evaluate the CD26-integrin beta1 association. CD26 depletion does not decrease integrin beta1 expression but leads to dephosphorylation of both integrin beta1 and p38 mitogen-activated protein kinase (MAPK). Moreover, our data showing that the p38MAPK inhibitor SB203580 dephosphorylates integrin beta1 and that binding of the anti-CD26 antibody 202.36 dephosphorylates both p38MAPK and integrin beta1 on Karpas 299, leading to loss of cell adhesion to the extracellular matrix, indicate that CD26 mediates cell adhesion through p38MAPK-dependent phosphorylation of integrin beta1. Finally, in vivo experiments show that depletion of CD26 is associated with loss of tumorigenicity and greater survival. Our findings hence suggest that CD26 plays an important role in tumor development and may be a novel therapeutic target for selected neoplasms.

Regulation of p38 phosphorylation and topoisomerase IIalpha expression in the B-cell lymphoma line Jiyoye by CD26/dipeptidyl peptidase IV is associated with enhanced in vitro and in vivo sensitivity to doxorubicin.

CD26 is a Mr 110,000 surface-bound glycoprotein with diverse functional properties, including having a key role in normal T-cell physiology and the development of certain cancers. In this article, we show that surface expression of CD26, especially its intrinsic dipeptidyl peptidase IV (DPPIV) enzyme activity, results in enhanced topoisomerase IIalpha level in the B-cell line Jiyoye and subsequent in vitro sensitivity to doxorubicin-induced apoptosis. In addition, we show that expression of CD26/DPPIV is associated with increased phosphorylation of p38 and its upstream regulators mitogen-activated protein kinase kinase 3/6 and apoptosis signal-regulating kinase 1 and that p38 signaling pathway plays a role in the regulation of topoisomerase IIalpha expression. Besides demonstrating that CD26 effect on topoisomerase IIalpha and doxorubicin sensitivity is applicable to cell lines of both B-cell and T-cell lineages, the potential clinical implication of our work lies with the fact that we now show for the first time that our in vitro results can be extended to a severe combined immunodeficient mouse model. Our findings that CD26 expression can be an in vivo marker of tumor sensitivity to doxorubicin treatment may lead to future treatment strategies targeting CD26/DPPIV for selected human cancers in the clinical setting. Our article thus characterizes the biochemical linkage among CD26, p38, and topoisomerase IIalpha while providing evidence that CD26-associated topoisomerase IIalpha expression results in greater in vitro and in vivo tumor sensitivity to the antineoplastic agent doxorubicin.