Antiglycopeptide Mouse Monoclonal Antibody LpMab-21 Exerts Antitumor Activity Against Human Podoplanin Through Antibody-Dependent Cellular Cytotoxicity and Complement-Dependent Cytotoxicity

2017 ◽  
Vol 36 (1) ◽  
pp. 20-24 ◽  
Author(s):  
Yukinari Kato ◽  
Akiko Kunita ◽  
Masashi Fukayama ◽  
Shinji Abe ◽  
Yasuhiko Nishioka ◽  
...  
Blood ◽  
2008 ◽  
Vol 112 (4) ◽  
pp. 1329-1337 ◽  
Author(s):  
Yu-Tzu Tai ◽  
Myles Dillon ◽  
Weihua Song ◽  
Merav Leiba ◽  
Xian-Feng Li ◽  
...  

Abstract Currently, no approved monoclonal antibody (mAb) therapies exist for human multiple myeloma (MM). Here we characterized cell surface CS1 as a novel MM antigen and further investigated the potential therapeutic utility of HuLuc63, a humanized anti-CS1 mAb, for treating human MM. CS1 mRNA and protein was highly expressed in CD138-purified primary tumor cells from the majority of MM patients (more than 97%) with low levels of circulating CS1 detectable in MM patient sera, but not in healthy donors. CS1 was expressed at adhesion-promoting uropod membranes of polarized MM cells, and short interfering RNA (siRNA) targeted to CS1 inhibited MM cell adhesion to bone marrow stromal cells (BMSCs). HuLuc63 inhibited MM cell binding to BMSCs and induced antibody-dependent cellular cytotoxicity (ADCC) against MM cells in dose-dependent and CS1-specific manners. HuLuc63 triggered autologous ADCC against primary MM cells resistant to conventional or novel therapies, including bortezomib and HSP90 inhibitor; and pretreatment with conventional or novel anti-MM drugs markedly enhanced HuLuc63-induced MM cell lysis. Administration of HuLuc63 significantly induces tumor regression in multiple xenograft models of human MM. These results thus define the functional significance of CS1 in MM and provide the preclinical rationale for testing HuLuc63 in clinical trials, either alone or in combination.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1833-1833
Author(s):  
Takeshi Harada ◽  
Shuji Ozaki ◽  
Asuka Oda ◽  
Hiroe Amou ◽  
Shiro Fujii ◽  
...  

Abstract Abstract 1833 Multiple myeloma (MM) is a B-cell malignancy characterized by the accumulation of neoplastic plasma cells in the bone marrow. During the last decade, treatment of MM has been improved by incorporating bortezomib, thalidomide, and lenalidomide (LEN) into conventional cytotoxic and transplantation regimens in newly diagnosed and relapsed/refractory MM patients. However, MM still remains incurable despite the implementation of these new treatment options, so more efficacious therapies are needed to further improve the prognosis of MM. Monoclonal antibody (mAb)-based immunotherapy has recently become an alternative strategy for treatment of cancers. Our previous studies have shown that HM1.24 (CD317) is selectively expressed on terminally differentiated normal and neoplastic plasma cells and, moreover, expressed on the side population of MM cells that represents MM cancer stem cells. We have previously generated a humanized mAb (AHM) specific to HM1.24 for the treatment of MM. AHM carries an Fc region derived from human IgG1-k and exhibits the ability to induce antibody-dependent cellular cytotoxicity (ADCC) against human MM cells in the presence of human effector cells. To improve the efficacy of AHM, we have developed a defucosylated mAb (YB-AHM) with a higher affinity to Fc gamma RIII. LEN is a structural analog of thalidomide with more potent immunomodulatory activities. Several studies have shown that LEN activates NK cell function and enhances NK cell-mediated lysis of both MM cell lines and patient MM cells in vitro. Here, we evaluated the efficacy of combination therapy of YB-AHM and LEN. First, we investigated whether LEN stimulates the expression of HM1.24 on MM cells. LEN alone did not affect HM1.24 expression, but in the presence of peripheral blood mononuclear cells (PBMCs) LEN augmented the expression of HM1.24 in MM cell lines and primary MM cells. In PBMCs, expression levels of CD56 increased after stimulation with LEN. These results suggest that LEN might augment the ADCC activity by enhancing HM1.24 antigen and NK activity. Next, we evaluated ADCC activity of YB-AHM against RPMI 8226 cells by using flow cytometric PKH-26 assay. When we used PBMCs from healthy donors (n=5) as effectors, ADCC activity of YB-AHM was increased in an E:T ratio-dependent manner. Importantly, YB-AHM induced significantly higher ADCC activity compared with AHM (24±6% vs 11±7%, p<0.05; mAb, 100 ng/mL; E:T ratio, 10). Treatment of PBMCs with LEN (3 micro M for 2 days) slightly enhanced ADCC activity of AHM (12±5%) and YB-AHM (30±6%). In PBMCs from MM patients (n=11), YB-AHM induced ADCC activity (36±15%) that was further enhanced by treatment with LEN (45±15%). To evaluate the efficacy of this combination therapy in a more physiological manner, we assessed the efficacy of YB-AHM using total bone marrow mononuclear cells (BMMCs) from MM patients that contained both MM cells and effector cells. BMMCs were stimulated with LEN (3 micro M) for 2 days and further incubated with YB-AHM for 24 hours. Cytotoxicity was evaluated by the number of CD38-positive MM cells in total BMMCs using flow cytometry. YB-AHM plus LEN significantly reduced the number of MM cells (10.3%) compared to YB-AHM alone (21.6%) in patient No.1. Finally, RPMI 8226 cells were co-cultured with YB-AHM and LEN-stimulated PBMCs from MM patients, and MM colony formation was examined using methylcellulose assay. Colony formation of RPMI 8226 was significantly suppressed by YB-AHM and LEN-stimulated PBMCs compared to control (14±8 vs 49±10 colonies, p<0.01), suggesting that this combination therapy can target MM cancer stem cells. Thus, these results indicate that combining defucosylated HM1.24 mAb with immunomodulatory drugs provides a novel therapeutic strategy in patients with MM. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1839-1839
Author(s):  
Takeshi Harada ◽  
Shuji Ozaki ◽  
Asuka Oda ◽  
Masami Iwasa ◽  
Shiro Fujii ◽  
...  

Abstract Abstract 1839 The implementation of hematopoietic stem cell transplantation and new agents such as bortezomib, thalidomide, and lenalidomide (Len) has dramatically improved survival in patients with multiple myeloma (MM). However, most MM patients eventually relapse after achieving of complete response. The existence of cancer stem cells is suggested to cause the relapse and considered as an important therapeutic target. We have demonstrated that HM1.24 (CD317) is selectively over-expressed on neoplastic plasma cells and that a defucosylated humanized monoclonal antibody (mAb) specific to HM1.24 (YB-AHM) is able to induce potent antibody-dependent cellular cytotoxicity (ADCC) against human MM cells in the presence of human effector cells. On the other hand, Len, an immunomodulatory drug, has been shown to activate NK cells to enhance their ADCC activity. Recently, we have reported that “side population (SP)” cells expelling a Hoechst 33342 dye represent a fraction with cancer stem cell-like property in MM cells. Moreover, we have found that MM cancer stem-like cells over-express pluripotency-associated transcription factors such as Sox2 and Nanog, and that these factors are useful for evaluating the potential of MM cancer stem-like cells. Here, we evaluated the efficacy of the combinatory therapy of YB-AHM and Len on MM cancer stem-like cells. We first examined the expression levels of the target molecule, HM1.24 on SP fraction of MM cells. Although SP cells expressed higher levels of ABC transporter ABCG2 compared with main population (MP) cells, HM1.24 was highly expressed in both SP and MP fractions in MM cells. We next examined the inhibitory effect of YB-AHM and Len on clonogenic activity of MM cell lines. RPMI 8226, U266, and OPM-2 cells were pre-incubated with YB-AHM (0.1 μg/ml) and Len (3 μM)-stimulated peripheral blood mononuclear cells (PBMCs) at an effector/target (E/T) ratio of 10 for 4 hours, and then were cultured into H4034 methylcellulose medium. Colony formation of MM cells was examined after 14 days. Treatment with YB-AHM and Len-stimulated PBMCs significantly suppressed the colony formation of MM cell lines compared with the no-treatment group (4±5 vs 62±2 colonies/well in RPMI 8226, p<0.01; 21±4 vs 43±8 colonies/well in U266, p<0.05; and 16±2 vs 84±4 colonies/well in OPM-2, p<0.01), suggesting that the combination therapy can target clonogenic MM cells. The mRNA expression levels of Sox2 and Nanog on MM cell lines and primary MM cells were also decreased when treated with YB-AHM (0.1 μg/ml) and Len-stimulated PBMCs (E/T=10) for 24 hours. Notably, this combination therapy decreased the mRNA expression of these transcription factors even in bortezomib-resistant MM cell line, OPM-2/BTZ. Finally, we examined the cytotoxic activity of YB-AHM plus Len using patients' bone marrow mononuclear cells (BMMCs) containing both target MM cells and autologous effector cells. BMMCs were stimulated with Len (3 μM) for 48 hours and further incubated with YB-AHM (0.1 μg/ml) for 24 hours. The cytotoxic activity was evaluated by counting CD38-positive MM cells in total BMMCs using flow cytometry. When we examined BMMCs from 10 MM patients, the combination of YB-AHM plus Len significantly induced MM cell death compared with controls (mean cytotoxicity, 46±23% vs 7±10%, p<0.01). Collectively, these results demonstrate that defucosylated HM1.24 mAb and Len in combination induce ADCC to eradicate MM cancer stem-like cells in bone marrow environment. Therefore, this combination might provide a novel therapeutic strategy targeting clonogenic drug-resistant clones in MM. Disclosures: Nakamura: Janssen Pharmaceutical K.K.: Honoraria. Abe:Janssen Pharmaceutical K.K.: Honoraria, Research Funding. Iida:Janssen Pharmaceutical K.K.: Honoraria.


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