Combination therapy of an anticancer drug with the FNIII14 peptide of fibronectin effectively overcomes cell adhesion-mediated drug resistance of acute myelogenous leukemia

Abstract

We investigated whether FNIII14, a 22-mer peptide derived from fibronectin (FN) that potently impairs interaction of FN with b1-integrin, could overcome cell adhesion-mediated drug resistance (CAM-DR) induced by very late antigen (VLA)-4-to-FN interaction in acute myelogenous leukemia (AML). Two AML cell lines, U937 cells and HL-60 cells, and fresh leukemic cells from six AML patients with high a4-integrin expression exhibited CAM-DR to cytosine arabinoside (Ara C) through VLA-4-to-FN interaction, while fresh leukemic cells from two AML patients with low a4-integrin expression did not display CAM-DR to Ara C. FNIII14 impaired VLA-4-to-FN interaction and restored sensitivity to Ara C in the CAM-DR leukemic cells. In these CAM-DR leukemic cells, upregulation of Bcl-2, which was induced through the focal adhesion kinase/Akt signal pathway upon VLA-4-to-FN interaction, was inhibited by FNIII14 treatment. In a mouse model of minimal residual disease (MRD) in bone marrow, 100% survival was achieved by combining FNIII14 with Ara C, whereas Ara C alone prolonged survival only slightly. The myelosuppression induced by Ara C was not augmented by the combination of FNIII14 in mouse experiments. Thus, the combination of anticancer drugs and FNIII14 holds promise to eradicate MRD in bone marrow after chemotherapy.

Functional and Structural Insights into ASB2α, a Novel Regulator of Integrin-dependent Adhesion of Hematopoietic Cells

“…ASB2␣S11D and ASB2␣F13E fragments were subcloned into the pEGFP-C3 expression vector. The pEGFP-C3-ASB2␣ (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), pEGFP-C3-ASB2␣ANK(1-3), pEGFP-C3-ASB2␣ANK(1-5), pEGFP-C3-ASB2␣ANK(1-7), pEGFP-C3-ASB2␣ANK(1-9), pEGFP-C3-ASB2␣ANK(1-10), pEGFP-C3-ASB2␣ANK(1-12), and pEGFP-C3-ASB2␣⌬NANK(1-12) plasmids were constructed as follows: (i) cloning sites were introduced using the QuikChange site-directed mutagenesis kit (Stratagene) at the 3Ј end of the DNA fragments of interest, (ii) the 3Ј parts of the ASB2 open reading frame were deleted following digestion and ligation of the vectors. The ASB2␣ANK(1-10) fragment was cloned into a derivative of pET21a (Novagen), in-frame with His 6 codons located downstream from the ASB2␣ sequence.…”

“…Accordingly, antibodies directed against VLA-4 prolong survival of mice in a bone marrow minimal residual disease model (10). Moreover, the FNIII14 peptide of fibronectin that impairs VLA-4-and VLA-5-mediated adhesion to fibronectin overcomes cell adhesion-mediated drug resistance (12). In this context, proteins controlling integrin-dependent adhesion of hematopoietic cells may represent novel therapeutic targets in AML.…”

Apoptotic Death of Hematopoietic Tumor Cells through Potentiated and Sustained Adhesion to Fibronectin via VLA-4

“…Monocytic differentiation of THP-1 cells was induced by incubation for 24 h with phorbol 12-myristate 13-acetate (10 ng/ml), as described previously (25). Patient leukemic cells were obtained by iliac bone marrow aspiration and cultured, as described previously (26), and this was accepted by the institutional review boards of Sapporo Medical University and Tokyo University of Science in accordance with the Declaration of Helsinki.…”

Influence of stress on extracellular matrix and integrin biology

“…VLA4 (a4b1) appears to mediate p27 regulation and CAM-DR in myeloma cells cultured on fibronectin, suggesting that other domains than RGD are involved (Hazlehurst et al, 2000). CAM-DR represents a promising approach for pharmacological interventions based on the inhibition of integrin-dependent signaling by statin (Schmidmaier et al, 2004), integrin expression by Bortezomib (Noborio-Hatano et al, 2009) or integrin-ECM binding by small molecules such as FNIII14 interfering with attachment to fibronectin (Matsunaga et al, 2008). Finally, it is important to note that, not only cell-tomatrix, but also cell-to-cell interaction may protect cells against drugs, and that gap-junction poisons, such as carbenoxyolone may act as chemosensitizers (Westhoff et al, 2008).…”