TMJ-105, an extract of Carpesium cernuum, induced G2/M phase arrest and apoptosis via the JAK2/STAT3 axis and MAPKs signaling pathway in leukemia HEL cells.

Leukemia is a malignant tumor of the hematologic system. Studies have shown that cernuumolide J (TMJ-105), an extract of Carpesium cernuum, has anti-cancer effects, but the underlying mechanism is unclear. In this study, we investigated the effect of TMJ-105 on the proliferation of human leukemia HEL cells and its molecular mechanism. MTT analysis showed TMJ-105 had revealed that it shows significant IC50 in HEL cells at lower doses (1.79 ± 0.29 µmol/L) than in K562 cells (3.89 ± 0.80 µmol/L), and the suppression of HEL cell proliferation was time- and concentration-dependent. Meanwhile, TMJ-105 induced G2/M phase blockage, leading to DNA damage in HEL cells. TMJ-105 promoted HEL cells to release of reactive oxygen species (ROS) and changed mitochondrial membrane potential (MMP). Furthermore, TMJ-105 induced apoptosis by upregulating the cleaved-caspase9 and cleaved-caspase3 protein expression, while caspase pan inhibitor (Z-VAD-FMK) blocked the inhibition effect. Finally, TMJ-105 downregulated the phosphorylation of JAK2, STAT3 and Erk, and activated the phosphorylation of JNK and p38. Collectively, these results demonstrated that TMJ-105 inhibited proliferation of leukemia cells and the underlying mechanism via the JAK2/STAT3 axis and MAPKs signaling pathway. Based on these results, the present study suggested the sesquiterpene lactone TMJ-105 is a new chemotherapeutic agent for the treatment of leukemia.

A dual-targeting approach with anti-IL10R CAR-T cells engineered to release anti-CD33 bispecific antibody in enhancing killing effect on acute myeloid leukemia cells.

BACKGROUND: Immunotherapies, including chimeric antigen receptor (CAR) T cells and bispecific antibodies (BsAbs), encounter several challenges in the management of acute myeloid leukemia (AML), including limited persistence of these treatments, antigen loss and resistance of leukemia stem cells (LSCs) to therapy. METHODS: Here, we proposed a novel dual-targeting approach utilizing engineered anti-IL10R CAR-T cells to secrete bispecific antibodies targeting CD33. This innovative strategy, rooted in our previous research which established a connection between IL-10 and the stemness of AML cells, designed to improve targeting efficiency and eradicate both LSCs and AML blasts. RESULTS: We first demonstrated the superior efficacy of this synergistic approach in eliminating AML cell lines and primary cells expressing different levels of the target antigens, even in cases of low CD33 or IL10R expression. Furthermore, the IL10R CAR-T cells that secret anti-CD33 bsAbs (CAR.BsAb-T), exhibited an enhanced activation and induction of cytotoxicity not only in IL10R CAR-T cells but also in bystander T cells, thereby more effectively targeting CD33-positive tumor cells. Our in vivo experiments provided additional evidence that CAR.BsAb-T cells could efficiently redirect T cells, reduce tumor burden, and demonstrate no significant toxicity. Additionally, delivering bsAbs locally to the tumor sites through this strategy helps mitigate the pharmacokinetic challenges typically associated with the rapid clearance of prototypical bsAbs. CONCLUSIONS: Overall, the engineering of a single-vector targeting IL10R CAR, which subsequently secretes CD33-targeted bsAb, addresses the issue of immune escape due to the heterogeneous expression of IL10R and CD33, and represents a promising progress in AML therapy aimed at improving treatment outcomes.

Slow-replicating leukemia cells represent a leukemia stem cell population with high cell-surface CD74 expression.

Persistence of quiescent leukemia stem cells (LSCs) after treatment most likely contributes to chemotherapy resistance and poor prognosis of leukemia patients. Identification of this quiescent cell population would facilitate eradicating LSCs. Here, using a cell-tracing PKH26 (PKH) dye that can be equally distributed to daughter cells following cell division in vivo, we identify a label-retaining slow-cycling leukemia cell population from AML1-ETO9a (AE9a) leukemic mice. We find that, compared with cells not maintaining PKH-staining, a higher proportion of PKH-retaining cells are in G0 phase, and PKH-retaining cells exhibit increased colony formation ability and leukemia initiation potential. In addition, PKH-retaining cells possess high chemo-resistance and are more likely to be localized to the endosteal bone marrow region. Based on the transcriptional signature, HLA class II histocompatibility antigen gamma chain (Cd74) is highly expressed in PKH-retaining leukemia cells. Furthermore, cell surface CD74 was identified to be highly expressed in LSCs of AE9a mice and CD34+ human leukemia cells. Compared to Lin-CD74- leukemia cells, Lin-CD74+ leukemia cells of AE9a mice exhibit higher stemness properties. Collectively, our findings reveal that the identified slow-cycling leukemia cell population represents an LSC population, and CD74+ leukemia cells possess stemness properties, suggesting that CD74 is a candidate LSC surface marker.

Design, Synthesis, and Anti-Leukemic Evaluation of a Series of Dianilinopyrimidines by Regulating the Ras/Raf/MEK/ERK and STAT3/c-Myc Pathways.

Although the long-term survival rate for leukemia has made significant progress over the years with the development of chemotherapeutics, patients still suffer from relapse, leading to an unsatisfactory outcome. To discover the new effective anti-leukemia compounds, we synthesized a series of dianilinopyrimidines and evaluated the anti-leukemia activities of those compounds by using leukemia cell lines (HEL, Jurkat, and K562). The results showed that the dianilinopyrimidine analog H-120 predominantly displayed the highest cytotoxic potential in HEL cells. It remarkably induced apoptosis of HEL cells by activating the apoptosis-related proteins (cleaved caspase-3, cleaved caspase-9 and cleaved poly ADP-ribose polymerase (PARP)), increasing apoptosis protein Bad expression, and decreasing the expression of anti-apoptotic proteins (Bcl-2 and Bcl-xL). Furthermore, it induced cell cycle arrest in G2/M; concomitantly, we observed the activation of p53 and a reduction in phosphorylated cell division cycle 25C (p-CDC25C) / Cyclin B1 levels in treated cells. Additionally, the mechanism study revealed that H-120 decreased these phosphorylated signal transducers and activators of transcription 3, rat sarcoma, phosphorylated cellular RAF proto-oncogene serine / threonine kinase, phosphorylated mitogen-activated protein kinase kinase, phosphorylated extracellular signal-regulated kinase, and cellular myelocytomatosis oncogene (p-STAT3, Ras, p-C-Raf, p-MEK, p-MRK, and c-Myc) protein levels in HEL cells. Using the cytoplasmic and nuclear proteins isolation assay, we found for the first time that H-120 can inhibit the activation of STAT3 and c-Myc and block STAT3 phosphorylation and dimerization. Moreover, H-120 treatment effectively inhibited the disease progression of erythroleukemia mice by promoting erythroid differentiation into the maturation of erythrocytes and activating the immune cells. Significantly, H-120 also improved liver function in erythroleukemia mice. Therefore, H-120 may be a potential chemotherapeutic drug for leukemia patients.

A New Indole Derivative, LWX-473, Overcomes Glucocorticoid Resistance in Jurkat Cells by Activating Mediators of Apoptosis.

BACKGROUND: Glucocorticoids (GCs) are commonly used as the primary chemotherapy for lymphoid malignancies, including acute lymphoblastic leukemia (ALL). However, the development of GC resistance limits their prolonged use. METHODS: In this study, we investigated the potential of a newly synthesized indole derivative called LWX-473, in combination with the classic GC Dexamethasone (DEX), to enhance the responsiveness of Jurkat cells to GC treatment. RESULTS: Our findings demonstrate that LWX-473 alone or in combination with DEX significantly improves GC-induced cell apoptosis and arrests the cell cycle in the G1 phase. Notably, the combination of LWX-473 and DEX exhibits superior efficacy in killing Jurkat cells compared to LWX-473 alone. Importantly, this compound demonstrates reduced toxicity towards normal cells. CONCLUSIONS: Our study reveals that LWX-473 has the ability to restore the sensitivity of Jurkat cells to DEX by modulating the mitochondrial membrane potential, activating the expression of DEX-liganded glucocorticoid receptor (GR), and inhibiting key molecules in the JAK/STAT signaling pathway. These findings suggest that LWX-473 could be a potential therapeutic agent for overcoming GC resistance in lymphoid malignancies.

Switchable Power Generation in Triboelectric Nanogenerator Toward Chip-Less Wearable Power Module Applications.

A conceptual shift toward next-generation wearable electronics is driving research into self-powered electronics technologies that can be independently operated without plugging into the grid for external power feeding. Triboelectric nanogenerators (TENGs) are emerging as a key component of self-powered electronics, but a power type mismatch between supply and demand limits their direct implementation into wearable self-powered electronics. Here, a TENG with switchable power mode capability is reported where the charge flow direction is modulated over the course of slow and random mechanical stimuli, with exceptional rectification capabilities as high as ≈133, stable outputs over the cycles, and design flexibility in different platforms. Importantly, the remarkable switchable power generation with fabric counter materials illuminates a new path for the smooth integration of flexible TENGs into wearable self-powered electronics.

Calothrixin B derivatives induce apoptosis and cell cycle arrest on HEL cells through the ERK/Ras/Raf/MEK pathway.

BACKGROUND: Acute erythroleukemia (AEL) is acute myeloid leukemia characterized by malignant erythroid proliferation. AEL has a low survival rate, which has seriously threatened the health of older adults. Calothrixin B is a carbazole alkaloid isolated from the cyanobacteria Calothrix and exhibits anti-cancer activity. To discover more potential anti-erythroleukemia compounds, we used calothrixin B as the structural skeleton to synthesize a series of new compounds. METHODS: In the cell culture model, we evaluated apoptosis and cell cycle arrest using MTT assay, flow cytometry analysis, JC-1 staining, Hoechst 33258 staining, and Western blot. Additionally, assessing the curative effect in the animal model included observation of the spleen, HE staining, flow cytometry analysis, and detection of serum biochemical indexes. RESULTS: Among the Calothrixin B derivatives, H-107 had the best activity against leukemic cell lines. H-107 significantly inhibited the proliferation of HEL cells with an IC50 value of 3.63 ± 0.33 µM. H-107 induced apoptosis of HEL cells by damaging mitochondria and activating the caspase cascade and arrested HEL cells in the G0/G1 phase. Furthermore, H-107 downregulated the protein levels Ras, p-Raf, p-MEK, p-ERK and c-Myc. Pretreatment with ERK inhibitor (U0126) increased H-107-induced apoptosis. Thus, H-107 inhibited the proliferation of HEL cells by the ERK /Ras/Raf/MEK signal pathways. Interestingly, H-107 promoted erythroid differentiation into the maturation of erythrocytes and effectively activated the immune cells in erythroleukemia mice. CONCLUSION: Overall, our findings suggest that H-107 can potentially be a novel chemotherapy for erythroleukemia.

Universal Anti-CD7 CAR-T Cells Targeting T-ALL and Functional Analysis of CD7 Antigen on T/CAR-T Cells.

Chimeric antigen receptor T (CAR-T) cell therapy initiates new methods and turns the scale of clinical treatment on relapsed/refractory acute T lymphoblastic leukemia (T-ALL). In this study, we generated the second-generation CD7-targeting CAR-T cells with a new antigen-binding single-chain variable fragment sequence and made it universal via CRISPR-based knockout of TRAC and CD7 genes (termed UCAR-T). The CD7 UCAR-T cells can efficiently proliferate and lyse T-ALL tumor cell in vitro, along with prominent proinflammatory cytokines secretion. A Jurkat-based xenograft mouse model further verified the superior cytotoxicity of the UCAR-T cells in vivo. During the UCAR-T construction, we observed a CD4/CD8 ratio shift among CD7-/- T/CAR-T cells, which motivated us to further analyze the effects of CD7 antigen on T/CAR-T cells. We sorted out CD7+/- T or anti-CD19 CAR-T cells after partially CD7 knockout and performed functional, phenotypic detection, as well as translational analysis. CD7-/- CAR-T cells tended to be CD8 negative and showed slightly better cytotoxicity at long-term assay. RNA-seq further confirmed an elevation of activated CD4 memory cell subpopulation. However, limited distinction on crucial regulatory genes and pathways was revealed, suggesting the safety and feasibility of UCAR-T application as well as the potential translational rather than transcriptional regulation of CD7 antigen.

[Effects and Mechanisms of Homoharringtonine on Expression of CEBPA Protein].

OBJECTIVE: To investigate the effect of homoharringtonine (HHT) on CEBPA protein and explore the mechanism of HHT in the treatment of acute myeloid leukemia (AML) with double CEBPA mutations. METHODS: The K562 cell line expressing CEBPA p30 (K562 CEBPA p30) was established. Western blot was used to determine the changes of the expression of CEBPA protein in K562 CEBPA p30, U937 and MOLM-13 cell lines before and after treatments with HHT, daunorubicin (DNR) or cytarabine (Ara-C). The effects of protease inhibitors and protein synthesis inhibitors on the expression of CEBPA protein were also determined. RNA-seq was used to analyze the difference of gene expressions and pathway enrichments between HHT group and DNR group. RESULTS: Both the endogenous CEBPA protein in U937 and MOLM-13 cell lines and the exogenous CEBPA protein in K562 CEBPA p30 were decreased by HHT (P<0.05) while were not by DNR or Ara-C. Proteasome inhibitors can increase the expression of CEBPA protein (P<0.05) while protein synthesis inhibitors can decrease the expression of CEBPA protein (P<0.05). The ribosome biogenesis related pathways in K562 CEBPA p30 were upregulated in HHT group while were not in DNR group. CONCLUSION: HHT can inhibit the synthesis of CEBPA and reduce the expression of CEBPA protein and this may be the mechanism of HHT in the treatment of CEBPA-double-mutant AML.

Ballistic transport spectroscopy of spin-orbit-coupled bands in monolayer graphene on WSe2.

Van der Waals interactions with transition metal dichalcogenides were shown to induce strong spin-orbit coupling (SOC) in graphene, offering great promises to combine large experimental flexibility of graphene with unique tuning capabilities of the SOC. Here, we probe SOC-driven band splitting and electron dynamics in graphene on WSe2 by measuring ballistic transverse magnetic focusing. We found a clear splitting in the first focusing peak whose evolution in charge density and magnetic field is well reproduced by calculations using the SOC strength of ~ 13 meV, and no splitting in the second peak that indicates stronger Rashba SOC. Possible suppression of electron-electron scatterings was found in temperature dependence measurement. Further, we found that Shubnikov-de Haas oscillations exhibit a weaker band splitting, suggesting that it probes different electron dynamics, calling for a new theory. Our study demonstrates an interesting possibility to exploit ballistic electron motion pronounced in graphene for emerging spin-orbitronics.

Construction of CD19 targeted dual- and enhanced dual-antibodies and their efficiency in the treatment of B cell malignancy.

BACKGROUND: T cell-redirecting bispecific antibodies establish a connection between endogenous T cells and tumor cells, activating T cells function to eliminate tumor cells without ex vivo genetic alteration or manipulation. Here, we developed a novel dual-specific antibody (DuAb) and an enhanced DuAb (EDuAb) with different stimulation signal to activate T cells, and evaluated their impact on the treatment of acute lymphoblastic leukemia (ALL). METHODS: The expression plasmids of the DuAb and EDuAb containing CD80 molecule were constructed by cloning heavy chain and light chain variable fragments from anti-human CD19 (HI19a) and CD3 (HIT3a) monoclonal antibody hybridomas, respectively. The activation and the anti-tumor efficacy of human T cells mediated by DuAb and EDuAb were evaluated in vitro. B-cell ALL xenograft NSG mouse model was established to investigate the therapeutic effect in vivo. RESULTS: EDuAb promoted the optimal expansion of primary human T cells with low expression of inhibitory markers in vitro than DuAb did. Both DuAb and EDuAb showed a similar capability in inducing healthy donor T cells to specifically eliminate B-ALL cell lines and primary blasts from patients. The similar ability was also observed in the patient-derived T cells. In vivo study showed that both DuAb and EDuAb significantly alleviated tumor burden and extended survival of B-ALL xenograft NSG mice. The median survival of PBS, DuAb and EDuAb treatment groups were 27, 38 and 45 days, respectively. The phenotype of T cells and cytokine release in peripheral blood (PB) of B-ALL xenograft NSG mice on day 24 were analyzed as well. The results showed that the proportion of CD8+ T cells and cytokine levels, including IL-2, IFN-γ and TNF-α, were higher in the EDuAb group than that of DuAb. Moreover, both DuAb and EDuAb significantly decreased the residual leukemia cells in PB of B-ALL xenograft NSG mice. CONCLUSIONS: Both DuAb and EDuAb showed great potential as novel treatments for B-ALL in clinical applications. However, compared to DuAb, EDuAb showed a significant advantage in promoting the proliferation and survival of T cells. Furthermore, EDuAb showed a better promising effect on eliminating tumor cells and extending survival in vivo, which provides new insights for the development of new multi-specific antibodies.

2B4 inhibits the apoptosis of natural killer cells through phosphorylated extracellular signal-related kinase/B-cell lymphoma 2 signal pathway.

BACKGROUND AIMS: Decades after the identification of natural killer (NK) cells as potential effector cells against malignantly transformed cells, an increasing amount of research suggests that NK cells are a prospective choice of immunocytes for cancer immunotherapy in addition to T lymphocytes for cancer immunotherapy. Recent studies have led to a breakthrough in the combination of hematopoietic stem-cell transplantation with allogeneic NK cells infusion for the treatment of malignant tumors. However, the short lifespan of NK cells in patients is the major impediment, limiting their efficacy. Therefore, prolonging the survival of NK cells will promote the application of NK-cell immunotherapy. As we have known, NK cells use a "missing-self" mechanism to lyse target cells and exert their functions through a wide array of activating, co-stimulatory and inhibitory receptors. Our previous study has suggested that CD244 (2B4), one of the co-stimulatory receptors, can improve the function of chimeric antigen receptor NK cells. However, the underlying mechanism of how 2B4 engages in the function of NK cells requires further investigation. Overall, we established a feeder cell with the expression of CD48, the ligand of 2B4, to investigate the function of 2B4-CD48 axis in NK cells, and meanwhile, to explore whether the newly generated feeder cell can improve the function of ex vivo-expanded NK cells. METHODS: First, K562 cells overexpressing 4-1BBL and membrane-bound IL-21 (mbIL-21) were constructed (K562-41BBL-mbIL-21) and were sorted to generate the single clone. These widely used feeder cells (K562-41BBL-mbIL-21) were named as Basic Feeder hereinafter. Based on the Basic feeder, CD48 was overexpressed and named as CD48 Feeder. Then, the genetically modified feeder cells were used to expand primary NK cells from peripheral blood or umbilical cord blood. In vitro experiments were performed to compare proliferation ability, cytotoxicity, survival and activation/inhibition phenotypes of NK cells stimulated via different feeder cells. K562 cells were injected into nude mice subcutaneously with tail vein injection of NK cells from different feeder system for the detection of NK in vivo persistence and function. RESULTS: Compared with Basic Feeders, CD48 Feeders can promote the proliferation of primary NK cells from peripheral blood and umbilical cord blood and reduce NK cell apoptosis by activating the p-ERK/BCL2 pathway both in vitro and in vivo without affecting overall phenotypes. Furthermore, NK cells expanded via CD48 Feeders showed stronger anti-tumor capability and infiltration ability into the tumor microenvironment. CONCLUSIONS: In this preclinical study, the engagement of the 2B4-CD48 axis can inhibit the apoptosis of NK cells through the p-ERK/BCL2 signal pathway, leading to an improvement in therapeutic efficiency.

Additive Manufacturing of Thermoelectric Microdevices for 4D Thermometry.

Thermometry, the process of measuring temperature, is one of the most fundamental tasks not only for understanding the thermodynamics of basic physical, chemical, and biological processes but also for thermal management of microelectronics. However, it is a challenge to acquire microscale temperature fields in both space and time. Here, a 3D printed micro-thermoelectric device that enables direct 4D (3D Space + Time) thermometry at the microscale is reported. The device is composed of freestanding thermocouple probe networks, fabricated by bi-metal 3D printing with an outstanding spatial resolution of a few µm. It shows that the developed 4D thermometry can explore dynamics of Joule heating or evaporative cooling on microscale subjects of interest such as a microelectrode or a water meniscus. The utilization of 3D printing further opens up the possibility to freely realize a wide range of on-chip, freestanding microsensors or microelectronic devices without the design restrictions by manufacturing processes.

Loop CD20/CD19 CAR-T cells eradicate B-cell malignancies efficiently.

CD19 chimeric antigen receptor (CAR) T cells have shown robust efficacy in relapsed and refractory acute lymphoblastic leukemia (R/R ALL), but compromising result in chronic lymphoblastic leukemia (CLL) and non-Hodgkin's lymphoma (NHL). CD19 relapse and the lack of CAR-T cell persistence which result in treatment failure are considerable obstacles to overcome. CAR-T targeting CD20 is an option for salvaging CD19 CAR-T failure. Previous studies have established variant structures of bispecific CAR-T which could avoid antigen-loss and immune escape. Here, we constructed tandem and loop CAR structures targeting both CD19 and CD20 antigen. Bispecific CAR-T cells could eliminate either CD19 or CD20 negative lymphoma cells, suggesting they exhibited dual antigen targeting of CD19 and CD20. By comparing the efficiency of four bispecific CAR modified T cells, it was found that loop2019 CAR was the best structure among them to eradicate lymphoma cell lines and patients' primary lymphoma or CLL cells in a very low dose in vitro and prolong the survival time dramatically in lymphoma xenograft mice model. These data highlighted the potential of loop2019 CAR-T in clinical treatment.

Synthetic flavagline derivative 1-chloroacetylrocaglaol promotes apoptosis in K562 erythroleukemia cells through miR-17-92 cluster genes.

Chronic myeloid leukemia accounts for human deaths worldwide and could enhance sevenfold by 2050. Thus, the treatment regimen for this disorder is highly crucial at this time. Flavaglines are a natural class of cyclopentane benzofurans exhibiting various bioactivities like anticancer action. Despite the antiproliferative activity of flavaglines against diverse cancer cells, their roles and mechanism of action in chronic myeloid leukemia (CML) remain poorly understood. Thus, this study examines the antiproliferative effect of a newly synthesized flavagline derivative, 1-chloracetylrocaglaol (A2074), on erythroleukemia K562 cells and the zebrafish xenograft model. The study revealed that A2074 could inhibit proliferation, promote apoptosis, and boost megakaryocyte differentiation of K562 cells. This flavagline downregulated c-MYC and miR-17-92 cluster genes, targeting upregulation of the apoptotic protein Bcl-2-like protein 11 (BIM). The work uncovered a critical role of the c-MYC-miR-17-92-BIM axis in the growth and survival of CML cells.

Garmultin-A Incites Apoptosis in CB3 Cells Through miR-17-5p by Attenuating Poly (ADP-Ribose) Polymerase-1.

Background: Leukemia accounts for a large number of deaths, worldwide, every year. Treating this ailment is always a challenging job. Recently, oncogenic miRNA leading to apoptosis are highly promising targets of many natural products. In this study, Garmultin-A (GA), isolated from the bark of Garcinia multiflora, was elucidated for its anti-leukemic effect in CB3 cells. Methods: The effect of the compound on CB3 cell viability was detected by MTT assay and apoptosis by FITC Annexin V/PI and Hochest 33258 staining. The western blot analysis assessed the BAX, BCL2, cMYC, pERK, and PARP-1 protein levels. Autodock analysis predicted the ligand-protein interactions. q-RT-PCR quantified the miR-17-5p expression. Luciferase assay confirmed the interaction between PARP-1 and miR-17-5p. Results: We uncover that GA leads to apoptosis by inducing overexpression of miR-17-5p and significantly downregulate PARP-1 protein levels in CB3 cells. The overexpression of miR-17-5p promotes apoptosis, and the miR-17-5p antagomirs restore GA-triggered apoptosis. Notably, we disclose that PARP-1 is a direct target of miR-17-5p. Increased pro-apoptotic and reduced anti-apoptosis protein levels were also observed in GA-treated CB3 cells. Conclusion: These results provide critical insights that GA could induce apoptosis in CB3 cells through targeting miR-17-5p by attenuating PARP-1. Thus, GA could act as a novel therapeutic agent for erythroleukemia.

[Bone Marrow Osteoblasts Promotes the Proliferation Leukemia Stem Cell by Up-regulating Interleukin-1].

OBJECTIVE: To explore the extrinsic regulation mechanism of bone marrow microenvironment in leukemia cells, and investigate the promoting effect of osteoblast niche on the proliferation and self-renewal of leukemia stem cell by up-regulating the expression of interleukin-1 (IL-1) in leukemia cell. METHODS: The gene expression profiles on leukemia cells derived from AE9a mouse bone marrow endosteum and central bone marrow were determined by RNA sequencing and gene set enrichment analysis (GSEA). Quantitative real-time PCR (qRT-PCR) was used to detect the expression of IL-1 in AE9a mouse leukemia cells co-cultured with or without osteoblasts in vitro. In addition, qRT-PCR was also used to determine the expression of IL-1 in bone marrow mononuclear cell (BMMNC) from 43 patients with acute myeloid leukemia (AML). For leukemia cells co-cultured with osteoblasts or treated with IL-1ß, colony forming ability of AE9a leukemia cells was determined by colony formation assay. RESULTS: In AE9a leukemia mouse, RNA-seq data and GSEA showed that the enrichment of the upregulated genes in leukemia cells located in endosteum fell into inflammatory response gene set, among them, IL-1α and IL-1ß were significantly higher expressed in AE9a leukemia cells that located osteoblast niche (IL-1α: P<0.001, IL-1ß:P<0.001). After AE9a leukemia cells were co-cultured with osteoblasts in vitro, the expression of IL-1α and IL-1ß in leukemia cells were increased by 2.5 and 3.5 times respectively. In colony formation assay, the number of colonies was increased significantly after leukemia cells were co-cultured with osteoblasts (P<0.001). In addition, when AE9a leukemia cells were treated with IL-1ß, the number of colonies was also increased significantly (P<0.01). In AML patients, BMMNC with high percentage of CD34 positive cells exhibited higher level of IL-1 expression. CONCLUSION: Osteoblast niche can promote leukemia cell proliferation and self-renewal through up-regulating the expression of IL-1 in leukemia cells. In AML patients, the expression level of IL-1 was correlated to the percentage of CD34 positive cells in BMMNC.

Acute myeloid leukemia fusion genes can be found in CD33-negative cells.

INTRODUCTION: Targeted therapies and immunotherapies are emerging strategies for the treatment of leukemia. CD33 is a common and important therapeutic target for cellular immunotherapy or antibody immunotherapy. Drugs on targeting CD33 are also emerging. However, acute myeloid leukemia (AML) relapse still occurs after treatment with targeted CD33, for which the mechanism is unknown. METHODS: We used fluorescence in situ hybridization and real-time polymerase chain reaction to detect the expression of fusion genes in different populations of cells from AML patients. RESULT: Fusion gene can be express in CD33 negative cell proportions in newly diagnosed and relapsed AML patients. CONCLUSION: There are fusion genes in CD33-negative cells that are might not be cleared by CD33 targeting therapy. And this might be the source of relapse.

Design, Synthesis, and Antileukemic Evaluation of a Novel Mikanolide Derivative Through the Ras/Raf/MEK/ERK Pathway.

Chronic myeloid leukemia (CML) accounts for a major cause of death in adult leukemia patients due to mutations or other reasons for dysfunction in the ABL proto-oncogene. The ubiquitous BCR-ABL expression stimulates CML by activating CDK1 and cyclin B1, promoting pro-apoptotic, and inhibiting antiapoptotic marker expression along with regulations in RAS pathway activation. Thus, inhibitors of cyclins and the RAS pathway by ERK are of great interest in antileukemic treatments. Mikanolide is a sesquiterpene dilactone isolated from several Asteraceae family Mikania sp. plants. Sesquiterpene dilactone is a traditional medicine for treating ailments, such as flu, cardiovascular diseases, bacterial infections, and other blood disorders. It is used as a cytotoxic agent as well. The need of the hour is potent chemotherapeutic agents with cytotoxic effects inhibition of proliferation and activation of apoptotic machinery. Recently, ERK inhibitors are used in clinics as anticancer agents. Thus, in this study, we synthesized 22-mikanolide derivatives that elucidated to be potent antileukemic agents in vitro. However, a bioactive mikanolide derivative, 3g, was found with potent antileukemic activity, through the Ras/Raf/MEK/ERK pathway. It can arrest the cell cycle by inhibiting phosphorylation of CDC25C, triggering apoptosis, and promoting DNA and mitochondrial damage, thus suggesting it as a potential chemotherapeutic agent for leukemia patients.