CXCR2 inhibition overcomes ponatinib intolerance by eradicating chronic myeloid leukemic stem cells through PI3K/Akt/mTOR and dipeptidylpeptidase â £ (CD26).

This study explores the therapeutic potential of targeting CXCR2 in patients afflicted with ponatinib-resistant chronic myeloid leukemia (CML). Ponatinib, a third-generation tyrosine kinase inhibitor (TKI), was initially designed for treating patients with CML harboring the T315I mutation. However, resistance or intolerance issues may lead to treatment discontinuation. Additionally, TKIs have exhibited limitations in eradicating quiescent CML stem cells. Our investigation reveals the activation of CXC chemokine receptor 2 (CXCR2) signaling in response to chemotherapeutic stress. Treatment with the CXCR2 antagonist, SB225002, effectively curtails cell proliferation and triggers apoptosis in ponatinib-resistant CML cells. SB225002 intervention also results in the accumulation of reactive oxygen species and disruption of mitochondrial function, phenomena associated with TKI chemoresistance and apoptosis. Furthermore, we demonstrate that activated CXCR2 expression induces the activity of dipeptidylpeptidase Ⅳ (DPP4/CD26), a CML leukemic stem cell marker, and concomitantly inhibits the PI3K/Akt/mTOR pathway cascades. These findings underscore the novel role of CXCR2 in the regulation of not only ponatinib-resistant CML cells, but also CML leukemic stem cells. Consequently, our study proposes that targeting CXCR2 holds promise as a viable therapeutic strategy for addressing patients with CML grappling with ponatinib resistance.

Generation of the human pluripotent stem cell lines KUMi005-A from a patients with multiple myeloma.

Multiple myeloma (MM) progresses with abnormal monoclonal proliferation and accumulation of malignant plasma cells in the bone marrow. We established human induced pluripotent stem cells (iPSCs), KUMi005-A, from bone marrow samples of a patient with MM. This reprogrammed cell line has similar characteristics to human embryonic stem cells, such as proliferation properties and pluripotency. KUMi005-A iPSCs may be applicable in MM disease modeling and cell-based therapies.

Generation of human induced iPSC KUMi003-A from acute promyelocytic leukemia (APL) M3.

Acute promyelocytic leukemia (APL) M3 is an acute myeloid leukemia (AML) subtype and is characterized by the chromosomal translocation t(15;17)(p22;q11), which results in the fusion of the promyelocytic gene (PML) at 15q22 with the retinoic acid α-receptor gene (RARA) at 17q21. We generated an induced pluripotent stem cell line "KUMi003-A" from an APL M3 patient that is pluripotent and can differentiate into the three germ layers. This iPSC line will be useful as a disease model to investigate disease mechanisms specific to APL M3.

PVR (CD155) Expression as a Potential Prognostic Marker in Multiple Myeloma.

Poliovirus receptor (PVR, CD155) is upregulated during tumor progression, and PVR expression is associated with poor prognosis in cancer patients; however, prognostic implications for PVR in multiple myeloma (MM) have not been investigated. PVR plays an immunomodulatory role by interacting with CD226, CD96, and TIGIT. TIGIT is a checkpoint inhibitory receptor that can limit adaptive and innate immunity, and it binds to PVR with the highest affinity. We used immunohistochemistry, ELISA, qPCR, and flow cytometry to investigate the role of PVR in MM. PVR was highly expressed in patients with MM, and membrane PVR expression showed a significant correlation with soluble PVR levels. PVR expression was significantly associated with the Revised-International Staging System stage, presence of extramedullary plasmacytoma and bone lesion, percentage of bone marrow plasma cells (BMPCs), and ß2-microglobulin levels, suggesting a possible role in advanced stages and metastasis. Furthermore, TIGIT expression was significantly correlated with the percentage of BMPCs. Patients with high PVR expression had significantly shorter overall and progression-free survival, and PVR expression was identified as an independent prognostic factor for poor MM survival. These findings indicate that PVR expression is associated with MM stage and poor prognosis, and is a potential prognostic marker for MM.

Generation of a human induced pluripotent stem cell line KUMi006 from a patient with multiple myeloma.

In this study, we report the generation of a novel human induced pluripotent stem cell (hiPSC) line from bone marrow mononuclear cells of a patient with multiple myeloma, using an integrative Sendai virus vector. This pluripotent cell line has been shown to differentiate into three germ layers. Therefore, these induced pluripotent stem cells (iPSCs) will enable not only advances in cell therapy products but also the study of mechanisms.

A human pluripotent stem cell line KUMi004-A generated from a patient with chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is a type of blood cancer caused by the abnormal accumulation of malignant plasma cells. In this study, we generated CLL iPSCs (KUMi004-a) using the Sendai virus, confirming pluripotency. Also, it can differentiate into three primary germ layers. We expect this cell line could be helpful to understand the pathology of CLL.

Generation of induced pluripotent stem cell line KUMi002-A with normal karyotype from a patient with Philadelphia chromosome-positive chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is caused by the dysregulated tyrosine kinase activity of the BCR-ABL fusion protein. In this study, we generated induced pluripotent stem cells (iPSCs) with a normal karyotype, using cells from a patient with CML and a Philadelphia chromosome. These human iPSCs showed positive pluripotency markers and differentiated into three germ layers. This iPSC line can be useful for the study of CML, namely the biology of hematopoietic stem cells with normal karyotype in CML, and for the development of patient-specific immunological treatment.

Generation of the induced pluripotent stem cell line KUMi001-A carrying the Philadelphia chromosome from a chronic myeloid leukemia patient.

Chronic myeloid leukemia (CML) is caused by the BCR-ABL fusion protein, which dysregulates tyrosine kinase activity. In this study, we generated induced pluripotent stem cells (iPSCs) carrying the Philadelphia chromosome from a CML patient with the BCR-ABL fusion protein. CML iPSCs were positive for pluripotency markers and had the ability to differentiate into the three germ layers. This iPSC cell line could be useful for studying CML pathogenesis as well as for drug development to treat CML.

Prognostic Value of Galectin-9 Relates to Programmed Death-Ligand 1 in Patients With Multiple Myeloma.

Galectin-9 (Gal-9) expression can be negatively or positively associated with cancer patient prognosis, depending on the cancer type. However, the nature of this relationship remains unclear in multiple myeloma. Therefore, we evaluated the prognostic value of Gal-9 and its relationship with the expression of PD-L1 molecule, the most widely studied immune checkpoint inhibitor, in patients with newly diagnosed multiple myeloma. Gal-9 and PD-L1 levels in bone marrow aspirate samples were evaluated using immunofluorescence assays. Gal-9 positivity was defined as having ≥1% Gal-9-expressing plasma cells. PD-L1 expression was categorized as low or high based on its median value. The median OS of patients with positive and negative Gal-9 expression was 42 months and not reached, respectively. However, no significant difference was observed in OS between the two groups (P = 0.10). Patients with high PD-L1 expression had OS times of 14 and 43 months in the positive and negative Gal-9 expression groups, respectively. In the high PD-L1 expression group, patients expressing Gal-9 had significantly worse OS than those negative for it (P = 0.019). Multivariable Cox analysis confirmed that Gal-9 expression could independently predict shortened OS (hazard ratio, 1.090; 95% confidence interval, 1.015-1.171; P = 0.018) in patients with high PD-L1 expression. However, in the low PD-L1 expression group, patients with high Gal-9 expression exhibited a trend toward better OS (P = 0.816). Our results indicate that the prognostic value of Gal-9 may be related to PD-L1 expression in patients with newly diagnosed multiple myeloma.

CXCR2, a novel target to overcome tyrosine kinase inhibitor resistance in chronic myelogenous leukemia cells.

Chronic myeloid leukemia (CML) is a reciprocal translocation disorder driven by a breakpoint cluster region (BCR)-Abelson leukemia virus (ABL) fusion gene that stimulates abnormal tyrosine kinase activity. Tyrosine kinase inhibitors (TKIs) are effective in treating Philadelphia chromosome (Ph) + CML patients. However, the appearance of TKI-resistant CML cells is a hurdle in CML treatment. Therefore, it is necessary to identify novel alternative treatments targeting tyrosine kinases. This study was designed to determine whether C-X-C chemokine receptor 2 (CXCR2) could be a novel target for TKI-resistant CML treatment. Interleukin 8 (IL-8), a CXCR2 ligand, was significantly increased in the bone marrow serum of initially diagnosed CML patients and TKI-resistant CML cell conditioned media. CXCR2 antagonists suppressed the proliferation of CML cells via cell cycle arrest in the G2/M phase. CXCR2 inhibition also attenuated mTOR, c-Myc, and BCR-ABL expression, leading to CML cell apoptosis, irrespective of TKI responsiveness. Moreover, SB225002, a CXCR2 antagonist, caused higher cell death in TKI-resistant CML cells than TKIs. Using a mouse xenograft model, we confirmed that SB225002 suppresses tumor growth, with a prominent effect on TKI-resistant CML cells. Our findings demonstrate that IL-8 is a prognostic factor for the progression of CML. Inhibiting the CXCR2-mTOR-c-Myc cascade is a promising therapeutic strategy to overcome TKI-sensitive and TKI-insensitive CML. Thus, CXCR2 blockade is a novel therapeutic strategy to treat CML, and SB225002, a commercially available CXCR2 antagonist, might be a candidate drug that could be used to treat TKI-resistant CML.

Generation of normal induced pluripotent stem cell line KUMCi002-A from bone marrow CD34+ cells of patient with multiple myeloma disease having 13q deletion and IGH translocation.

Multiple myeloma (MM) is a hematological cancer characterized by an uncontrolled proliferation of antibody-secreting plasma cells within the bone marrow. Currently, cell therapy such as chimeric antigen receptor T-cell (CAR-T) based on induced pluripotent stem cells (iPSCs) has received attention for treating MM. However, the generation of iPSCs from MM patients appears to be very rarely reported. Here we generated an iPSC line from CD34+ bone marrow cells of a patient with MM using human placenta-derived cell conditioned medium (hPCCM), offering a relatively high efficiency in humanized conditions. This iPSC line might be a useful model for research on MM.

Supporting data on enhanced reprogramming of human CD34+ hematopoietic stem cells to induced pluripotent stem cells using human placenta-derived cell conditioned medium.

The data presented herein support "Generation of an induced pluripotent stem cell line KUMCi001-A from CD34+ bone marrow cells of a patient with acute lymphoblastic leukemia using human placenta-derived cell conditioned medium." The supplementary data were as follows. (1) Comparison of reprogramming efficiency of human placenta-derived cell conditioned medium with defined medium (mTeSR™1) and the generation of induced pluripotent stem cells (iPSCs) from a patient with acute lymphoblastic leukemia (ALL) with significantly higher reprogramming efficiency than that of the defined medium (P ≤ 0.05). (2) Evaluation of differentiation capability of the generated ALL_iPSCs into hematopoietic stem cells (HSCs) and comparison with normal iPSCs using the colony-forming unit (CFU) assay. ALL_iPSCs manifested all lineages for hematopoiesis in their colonies similar to normal iPSCs. (3) ALL_iPSCs showed a considerably higher number of burst-forming unit-erythroid colonies indicating the presence of more erythroid progenitors than normal iPSCs; this tendency was confirmed in the CFU assay of ALL_CD34+ cells. This has been previously reported as a feature of ALL. Thus, the hematopoietic characteristics of the donor patient with ALL appear to be maintained in our ALL_hiPSC line although the karyotype was normalized during reprogramming.

Generation of an induced pluripotent stem cell line KUMCi001-A from CD34+ bone marrow cells of a patient with acute lymphoblastic leukemia using human placenta-derived cell conditioned medium.

Many patients with acute lymphoblastic leukemia (ALL) show relapse post-chemotherapy. Therefore, it is important to develop a human induced pluripotent stem cell (hiPSC) line from ALL cells to verify the pathophysiology. However, the low efficiency of the established reprogramming protocol has hampered the development of ALL hiPSC lines. Our recently reported novel reprogramming method, using human placenta-derived cell conditioned medium (hPCCM), offers a relatively higher efficiency in humanized conditions. Here, we generated an hiPSC line from ALL-derived CD34+ bone marrow cells, using hPCCM for reprogramming. This hiPSC line might be a useful model for studies on ALL.

CXCR2 Ligands and mTOR Activation Enhance Reprogramming of Human Somatic Cells to Pluripotent Stem Cells.

Induced pluripotent stem cell (iPSC) technology has great promise in regenerative medicine and disease modeling. In this study, we show that human placenta-derived cell conditioned medium stimulates chemokine (C-X-C motif) receptor 2 (CXCR2) in human somatic cells ectopically expressing the pluripotency-associated transcription factors Oct4, Sox2, Klf4, and cMyc (OSKM), leading to mechanistic target of rapamycin (mTOR) activation. This causes an increase in endogenous cMYC levels and a decrease in autophagy, thereby enhancing the reprogramming efficiency of human somatic cells into iPSCs. These findings were reproduced when human somatic cells after OSKM transduction were cultured in a widely used reprogramming medium (mTeSR) supplemented with CXCR2 ligands interleukin-8 and growth-related oncogene α or an mTOR activator (MHY1485). To our knowledge, this is the first report demonstrating that mTOR activation in human somatic cells with ectopic OSKM expression significantly enhances the production of iPSCs. Our results support the development of convenient protocols for iPSC generation and further our understanding of somatic cell reprogramming.

Human feeder cells can support the undifferentiated growth of human and mouse embryonic stem cells using their own basic fibroblast growth factors.

In the culture system using human feeder cells, the mechanism through which these cells support undifferentiated growth of embryonic stem cells (ESCs) has not been well investigated. Here, we explored the mechanisms of 3 kinds of human feeder cells, including human placental cells from the chorionic plate, human bone marrow stromal cells, and human foreskin fibroblasts. First, we determined that undifferentiated growth of 2 kinds each of human (H1 and HSF6) and mouse (D3 and CE3) ESCs was possible in all human feeder cell types tested (human placental cells, human bone marrow stromal cells, and human foreskin fibroblasts), without the need for exogenous cytokine supplementation including basic fibroblast growth factor (bFGF) and leukemia inhibitory factor. We then prepared their corresponding endogenous bFGF-knockout feeders using siRNA and tried to maintain human and mouse ESCs in their undifferentiated state; however, neither human nor mouse ESCs could be maintained in bFGF-knockout human feeder cells. The expressions of stemness markers such as Oct-4 and Nanog were significantly decreased in the bFGF-knockout group compared with those in the controls, and differentiation had already occurred, despite the undifferentiated morphologic appearance of the ESCs. In conclusion, human feeder cells are able to support the undifferentiated growth of human and mouse ESCs via bFGF synthesis. Further, a bFGF-dependent pathway might be crucial for maintaining the undifferentiated characteristics of mouse and human ESCs.