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. 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. 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. CLL-1 CAR-T represents a promising immunotherapy for the treatment of AML.

Background/Aims: The metabolic features of cancer cells have long been acknowledged to be altered and to provide new therapeutic opportunities. The expression of glycolytic enzyme enolase 2 (ENO2) was found to be closely associated with the clinical features of acute lymphoblastic leukemia (ALL) patients, but its functions remain unclear in ALL. Methods: We evaluated the association between ENO2 mRNA expression in bone marrow mononuclear cells (BM-MNCs) and the efficacy of chemotherapy, and further explored the function of ENO2 in ALL. The molecular mechanisms of ENO2 expression and its effects on cell growth, glycolysis and glucocorticoid resistance were explored by Cell Counting Kit-8, glucose-consumption assay, Quantitative RT-PCR, Western blotting and in vivo tumorigenesis in NOD/SCID mice. Results: The results showed that ENO2 mRNA expression in BM-MNCs was significantly decreased when patients completed induction chemotherapy and reached complete remission (CR). ENO2 mRNA expression was increased when patients suffered relapse. Functional studies demonstrated that ENO2 promoted cell growth, glycolysis, and glucocorticoid resistance, all of which were effectively inhibited when ENO2 was silenced with shRNAs. Further studies revealed that ENO2 up-regulated various glycolysis-related genes and enhanced Akt activity with subsequent glycogen synthase kinase3β (GSK-3β) phosphorylation, inducing cell proliferation and glycolysis. The combination of silencing ENO2 and 2-deoxyglucose (2-DG) synergistically inhibited leukemia cell survival. Conclusions: These results indicate that ENO2 may be a biological marker for monitoring chemotherapeutic efficacy and relapse in ALL. ENO2 may provide a potential therapeutic strategy for ALL.

Beclin 1 is a main actor of autophagy. The expression of Beclin 1 and its prognostic role in gastric cancer is largely unexplored. The purpose of the present study is to investigate the expression of beclin 1 in gastric cancer cells, tissues and its relationship with prognosis. The expression of Beclin 1 was detected in 271 specimens of lymph-node positive gastric cancer patients by immunohistochemistry. The correlation of Beclin 1 expression to clinicopathologic features and survival of gastric cancer was studied. Beclin-1 expression in gastric cancer cell lines and clinical specimens is also detected using reverse transcription-PCR and Western blotting. Beclin 1 is up-regulated at both mRNA and protein levels in six gastric cancer cell lines compared with those in normal gastric mucosa cell line (GES-1). The expression of Beclin-1 in gastric clinical specimens is also higher than those in the adjacent noncancerous tissues. Of the 271 patients, 229 (84.5%) were Beclin 1 high expression tumors by immunohistochemistry. Beclin 1 expression is closely associated with intravascular embolus. Kaplan-Meier analysis showed high beclin 1 expression was associated with longer overall survival. Both univariate analysis and multivariate analysis revealed that Beclin 1 expression were independent prognostic factors in the patients with node-positive gastric cancer. Our findings strongly suggest that Beclin 1 has a potential role in tumorigenesis of gastric cancer and could be a promising biomarker for predicting the prognosis of patients with lymph node-positive gastric cancer. It might also serve as a novel therapeutic target for gastric cancer treatment.

Both mTOR and Skp2 play critical roles in gastric cancer (GC) tumorigenesis. However, potential mechanisms for the association between these two proteins remains unidentified. The regulatory role for mTORC1 in Skp2 stability was tested using ubiquitination assay. The functions of p-Skp2 (phosphorylation of Skp2) were studied in vitro and in vivo. Expression of p-Skp2 and p-mTOR (phosphorylation of mTOR) were shown in GC lines and in 169 human primary GC tissues. mTORC1 can directly interact with Skp2 and phosphorylated Skp2 at Ser64, which sequentially protect Skp2 from ubiquitination and degradation. Furthermore, the phospho-deficient p-Skp2 (S64) mutant significantly suppresses GC cell proliferation and tumorigenesis. The expression of p-Skp2 was associated with p-mTOR in GC cell lines and tissues. Interestingly, the combination of p-Skp2 and p-mTOR was a better predictor of survival than either factor alone. The mTORC1 function to regulate Skp2 by Ser64 phosphorylation may represent an oncogenic event in GC tumorigenesis. Moreover, our study also indicates that Skp2 Ser64 expression is a potential indicator in the treatment of GC patients using mTORC1 inhibitor.

Acute myeloid leukaemia (AML) is a heterogeneous disease with a difficult to predict prognosis. Ferroptosis, an iron‐induced programmed cell death, is a promising target for cancer therapy. Nevertheless, not much is known about the relationship between ferroptosis‐related genes and AML prognosis. Herein, we retrieved RNA profile and corresponding clinical data of AML patients from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Univariate Cox analysis was employed to identify ferroptosis‐related genes significantly associated with AML prognosis. Next, the least absolute shrinkage and selection operator (LASSO) regression was employed to establish a prognostic ferroptosis‐related gene profile. 12 ferroptosis‐related genes were screened to generate a prognostic model, which stratified patients into a low‐ (LR) or high‐risk (HR) group. Using Kaplan‐Meier analysis, we demonstrated that the LR patients exhibited better prognosis than HR patients. Moreover, receiver operating characteristic (ROC) curve analysis confirmed that the prognostic model showed good predictability. Functional enrichment analysis indicated that the infiltration of regulatory T cells (Treg) differed vastly between the LR and HR groups. Our prognostic model can offer guidance into the accurate prediction of AML prognosis and selection of personalized therapy in clinical practice.

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.