Prognostic value of platelet recovery degree before and after achieving minimal residual disease negative complete remission in acute myeloid leukemia patients.

BACKGROUND: Risk stratification and prognosis prediction of acute myeloid leukemia (AML) are largely dependent on pre-treatment information. However, post-treatment data also provides much useful information. In this retrospective study, we explored whether the level of blood count recovery before and after the first minimal residual disease (MRD) negative complete remission (CR) is relevant to clinical outcomes of AML patients. METHODS: For each included patient, peripheral platelet counts were measured on the day before initial treatment (PLTpre), whereas platelet peak values (PLTpeak) were recorded after marrow recovery following the chemotherapy course inducing the first MRD-negative CR. The difference (DPLT) between these two values (DPLT = PLTpeak-PLTpre) was calculated. X-tile software was utilized to establish the optimal cut-point for DPLT, which was expected to distinguish CR patients with different clinical outcomes. A cross validation analysis was conducted to confirm the robustness of the established cut-point. The results were further tested by a Cox multivariate analysis. RESULTS: The optimal cut-point of DPLT was determined as 212 × 109/L. Patients in high DPLT group were observed to have a significantly better PFS (p = 0.016) and a better OS (without statistical significance, p = 0.106). Cox multivariate analysis showed that higher DPLT was associated with longer PFS (HR = 2.894, 95% CI: 1.320-6.345, p = 0.008) and longer OS (HR = 3.077, 95% CI: 1.130-8.376, p = 0.028). CONCLUSION: Platelet recovery degree before and after achieving MRD-negative CR (DPLT) is a potential predictor of clinical outcomes in CR patients. Higher DPLT value is associated with longer PFS and OS. Our findings may help to develop simple methods for AML prognosis evaluation.

Elevated BNP caused by recombinant human interleukin-11 treatment in patients with chemotherapy-induced thrombocytopenia.

Thrombocytopenia is a condition characterized by abnormally low levels of thrombocytes and often induced by chemotherapy. Recombinant human interleukin-11 (rhIL-11) is a cytokine that can stimulate thrombopoiesis and is commonly used to treat thrombocytopenia. We observed the side effects of rhIL-11 in 24 leukemia patients with chemotherapy-induced thrombocytopenia. To determine the cardiovascular effects of rhIL-11, we detected changes in the patients' serum brain natriuretic peptide (BNP), blood pressure fluctuations, weight change, and whether edema or heart failure occurred in leukemia patients after chemotherapy. The results showed that BNP was significantly elevated after using rhIL-11 (P < 0. 05) but regressed after 2-4 days. Furthermore, nine patients had edema and experienced weight gain, and four experienced acute left heart failure. In addition, the average blood pressure was 119/75 mmHg (range 139/86 mmHg to 99/64 mmHg) before rhIL-11 administration and 127/79 mmHg (range 146/89 mmHg to 108/69 mmHg) after rhIL-11 use. In conclusion, although rhIL-11 is useful for treating chemotherapy-induced thrombocytopenia, it is important to monitor the patients' clinical status and re-examine BNP levels frequently during the use of rhIL-11. Furthermore, senile patients should be given special attention. However, the appropriate timing to begin and discontinue rhIL-11 treatment needs further investigation.

EXT1, Regulated by MiR-665, Promotes Cell Apoptosis via ERK1/2 Signaling Pathway in Acute Lymphoblastic Leukemia.

BACKGROUND EXT1 is an endoplasmic reticulum-resident glycosyl transferase whose intracellular expression alters the biosynthesis and distribution of heparan sulfate. EXT1 is regarded as a classic tumor suppressor. MiR-665 can act as either an oncogene or tumor-suppressing gene in different tumors. The aim of the current study was to determine the function and molecular mechanisms of EXT1 and miR-665 in acute lymphoblastic leukemia (ALL). MATERIAL AND METHODS EXT1 expression in ALL was evaluated by real-time polymerase chain reaction (RT-PCR) and western blotting. The effects of EXT1 in ALL were explored by Cell Counting Kit-8 (CCK-8)/EdU assays, western blotting, flow cytometry, and in vivo tumorigenesis assays. Label-free quantification was used to detect differentially expressed proteins in EXT1-overexpressing Reh cells. RESULTS EXT1 expression is downregulated in ALL and negatively correlated with miR-665 expression. Moreover, low EXT1 and high miR-665 expression levels in adult ALL bone marrow tissues are correlated with poor patient survival. Our study showed that EXT1 modulates the proliferation and apoptosis of ALL cells in vitro and in vivo and that miR-665 promotes cell growth and inhibits apoptosis by suppressing EXT1. EXT1 promotes cell apoptosis via deactivating the ERK1/2 pathway. CONCLUSIONS In conclusion, this study is the first to confirm the association between low EXT1 levels and several clinical features of ALL. Low bone marrow EXT1 levels independently predict poor prognoses in adult ALL patients. Thus, our study suggests that EXT1- or miR-665-targeted strategies can confer the therapeutic effect of promoting apoptosis by deactivating the ERK1/2 pathway.

NSE from diffuse large B-cell lymphoma cells regulates macrophage polarization.

Background/aims: Diffuse large B-cell lymphoma (DLBCL) is a highly common type of malignant and heterogeneous non-Hodgkin's lymphoma. Tumor-associated macrophages, specially the M2-type, promote tumor progression and drug resistance. The clinical outcome of patients with high neuron-specific enolase (NSE) expression is worse than that with low NSE expression. The tumor-promoting mechanism of NSE, however, remains unclear. This study explored the role of NSE in macrophage polarization associated with the immune microenvironment of DLBCL. Results: Our results showed that NSE protein expression was higher in lymphoma cell lines than in the B lymphocytes. Functional studies demonstrated that upregulation of NSE in lymphoma cells could promote M2 polarization and migration ability of macrophage, thereby consequently promoting the progression of lymphoma in vitro and in vivo. Further mechanism studies revealed that lymphoma-derived exosomes could mediate NSE into macrophages, NSE enhanced nuclear p50 translocation with subsequent defective classical nuclear factor-κB activity in macrophages. Conclusions: These results indicate that NSE may be a potential target for lymphoma therapy and a prognosis marker for lymphoma.

Asparagine synthetase expression is associated with the sensitivity to asparaginase in extranodal natural killer/T-cell lymphoma in vivo and in vitro.

BACKGROUND: Although asparagine synthetase (AsnS) is associated with drug resistance in leukemia, its function in extranodal natural killer (NK)/T-cell lymphoma (ENKTL) remains unclear. METHODS: The present study investigated the relationship between baseline AsnS mRNA levels and response to asparaginase in ENKTL cell lines. It also determined whether upregulating or downregulating the AsnS mRNA level induces or reverses asparaginase-resistant phenotype. RESULTS: Interestingly, considerable differences were observed in the sensitivity to asparaginase of the five ENKTL cell lines. The AsnS expression levels were positively correlated with the IC50 values. In addition, the asparaginase resistance was induced or reversed by upregulating or downregulating the AsnS mRNA level in vivo and in vitro. Functional analyses indicated that AsnS did not affect the proliferation and apoptosis of ENKTL cells in the absence of asparaginase. CONCLUSION: Together, the data stress the importance of AsnS in the sensitivity to asparaginase in ENKTL and suggest a different therapeutic strategy for patients with a different level of AsnS expression.

CAR-T cells targeting CLL-1 as an approach to treat acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is one of the most common types of adult acute leukemia. Standard chemotherapies can induce complete remission in selected patients; however, a majority of patients eventually relapse and succumb to the disease. Thus, the development of novel therapeutics for AML is urgently needed. Human C-type lectin-like molecule-1 (CLL-1) is a type II transmembrane glycoprotein, and its expression is restricted to myeloid cells and the majority of AML blasts. Moreover, CLL-1 is expressed in leukemia stem cells (LSCs), but absent in hematopoietic stem cells (HSCs), which may provide a potential therapeutic target for AML treatment. METHODS: We tested the expression of CLL-1 antigen on peripheral blood cells and bone marrow cells in healthy donor and AML patients. Then, we developed a chimeric antigen receptor (CAR) containing a CLL1-specific single-chain variable fragment, in combination with CD28, 4-1BB costimulatory domains, and CD3-ζ signaling domain. We further investigate the function of CLL-1 CAR-T cells. RESULTS: The CLL-1 CAR-T cells specifically lysed CLL-1+ cell lines as well as primary AML patient samples in vitro. Strong anti-leukemic activity was observed in vivo by using a xenograft model of disseminated AML. Importantly, CLL-1+ myeloid progenitor cells and mature myeloid cells were specifically eliminated by CLL-1 CAR-T cells, while normal HSCs were not targeted due to the lack of CLL-1 expression. CONCLUSIONS: CLL-1 CAR-T represents a promising immunotherapy for the treatment of AML.