TAL1 mediates imatinib-induced CML cell apoptosis via the PTEN/PI3K/AKT pathway

Tannin alleviates glyphosate exposure-induced apoptosis, necrosis and immune dysfunction in hepatic L8824 cell line by inhibiting ROS/PTEN/PI3K/AKT pathway

Glyphosate can cause tissue damage such as liver and kidney in mammals. Tannin has anti-inflammatory, antibacterial and anti-inflammatory properties. However, the effect of glyphosate on the growth of L8824 cell line and the effect of tannin on antagonism of glyphosate through the ROS/PTEN/PI3K/AKT axis are unclear. In this study, L8824 cells were treated with glyphosate (50 μg/mL) and/or tannin (4.5 μM) for 24 h to establish a model. The results showed that glyphosate exposure increased ROS and MDA levels, decreased CAT and SOD activities. PTEN was activated and the PI3K/AKT signaling pathway was inhibited. The P53/Bcl-2/Bax/CytC/Caspase3 and RIPK1/RIPK3/MLKL pathways were also activated. In addition, the cytokines and antimicrobial peptides LEAP-2, TNF-α and IL-1β were increased while β-defensin, Hepcidin, IL-2 and IFN-γ were decreased. The use of tannin reduced the adverse effects of glyphosate exposure on L8824 cells significantly. In conclusion, tannin can trigger oxidative stress via PTEN/PI3K/AKT pathway to cause apoptosis, necroptosis and immune dysfunction of L8824 cells.

TSPAN32 suppresses chronic myeloid leukemia pathogenesis and progression by stabilizing PTEN

We report herein that TSPAN32 is a key node factor for Philadelphia (Ph+) leukemia pathogenesis. We found that TSPAN32 expression was repressed by BCR-ABL and ectopic TSPAN32 expression upon Imatinib treatment inhibited the proliferation of Ph+ cell lines. Tspan32 overexpression significantly prevented BCR-ABL induced leukemia progression in a murine model and impaired leukemia stem cell (LSC) proliferation. LSCs represent an obstacle for chronic myeloid leukemia (CML) elimination, which continually replenish leukemia cells and are associated with disease relapse. Therefore, the identification of essential targets that contribute to the survival and self-renewal of LSCs is important for novel curative CML. Mechanistically, TSPAN32 was shown to interact with PTEN, increased its protein level and caused a reduction in PI3K-AKT signaling activity. We also found that TSPAN32 was repressed by BCR-ABL via the suppression of an important transcription factor, TAL1. Ectopic expression of TAL1 significantly increased TSPAN32 mRNA and protein level, which indicated that BCR-ABL repressed TSPAN32 transcription by decreasing TAL1 expression. Overall, we identified a new signaling axis composed of "BCR-ABL-TAL1-TSPAN32-PTEN-PI3K-AKT". Our findings further complement the known mechanisms underlying the transformation potential of BCR-ABL in CML pathogenesis. This new signaling axis also provides a potential means to target PI3K-AKT for CML treatment.

miR-22-3p as a potential biomarker for coronary artery disease based on integrated bioinformatics analysis

Background: Coronary artery disease (CAD) is a common cardiovascular disease that has attracted attention worldwide due to its high morbidity and mortality. Recent studies have shown that abnormal microRNA (miRNA) expression is effective in CAD diagnoses and processes. However, the potential relationship between miRNAs and CAD remains unclear.

Methods: Microarray datasets GSE105449 and GSE28858 were downloaded directly from the Gene Expression Omnibus (GEO) to identify miRNAs involved in CAD. Target gene prediction and enrichment analyses were performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG).

Results: There were nine differentially expressed miRNAs in CAD patients compared to the controls. A total of 352 genes were predicted and subjected to GO analysis, which showed that differentially expressed genes (DEGs) were mainly associated with axon guidance, neuron projection guidance, neuron-to-neuron synapses, and postsynaptic density. According to the KEGG pathway analysis, the most enriched pathways were those involved in transcriptional misregulation in cancer, growth hormone synthesis, secretion and action, endocrine resistance, axon guidance, and Cushing syndrome. Pathway analysis was mainly involved in the HIPPO and prion disease signaling pathways. Furthermore, a competing endogenous RNA (ceRNA) interaction network centered on miR-22-3p revealed eight related transcription factors in the cardiovascular system. The receiver operating characteristic (ROC) curve analysis suggested that miR-22-3p may be a better CAD predictor.

Conclusion: The results indicate that miR-22-3p may function in pathophysiological CAD processes. Our study potentiates miR-22-3p as a specific biomarker for diagnosing CAD.

BET bromodomain inhibition rescues PD-1-mediated T-cell exhaustion in acute myeloid leukemia

Sustained expression of programmed cell death receptor-1 (PD-1) is correlated with the exhaustion of T cells, and blockade of the PD-1 pathway is an effective immunotherapeutic strategy for treating various cancers. However, response rates are limited, and many patients do not achieve durable responses. Thus, it is important to seek additional strategies that can improve anticancer immunity. Here, we report that the bromodomain and extraterminal domain (BET) inhibitor JQ1 inhibits PD-1 expression in Jurkat T cells, primary T cells, and T-cell exhaustion models. Furthermore, JQ1 dramatically impaired the expression of PD-1 and T-cell immunoglobulin mucin-domain-containing-3 (Tim-3) and promoted the secretion of cytokines in T cells from patients with acute myeloid leukemia (AML). In line with that, BET inhibitor-treated CD19-CAR T and CD123-CAR T cells have enhanced anti-leukemia potency and resistant to exhaustion. Mechanistically, BRD4 binds to the NFAT2 and PDCD1 (encoding PD-1) promoters, and NFAT2 binds to the PDCD1 and HAVCR2 (encoding Tim-3) promoters. JQ1-treated T cells showed downregulated NFAT2, PD-1, and Tim-3 expression. In addition, BET inhibitor suppressed programmed death-ligand 1 (PD-L1) expression and cell growth in AML cell lines and in primary AML cells. We also demonstrated that JQ1 treatment led to inhibition of leukemia progression, reduced T-cell PD-1/Tim-3 expression, and prolonged survival in MLL-AF9 AML mouse model and Nalm6 (B-cell acute lymphoblastic leukemia cell)-bearing mouse leukemia model. Taken together, BET inhibition improved anti-leukemia immunity by regulating PD-1/PD-L1 expression, and also directly suppressed AML cells, which provides novel insights on the multiple effects of BET inhibition for cancer therapy.

Correlation of the transcription factors IRF4 and BACH2 with the abnormal NFATC1 expression in T cells from chronic myeloid leukemia patients

OBJECTIVE

T cell dysfunction is a common characteristic of patients with myeloid leukemia and is closely related to clinical efficacy and prognosis. In order to clarify the mechanisms leading to the T cell dysfunction, we characterized the gene expression profile of T cells from chronic myelogenous leukemia (CML) patients by microarray analysis and investigated the related regulating pathway.

METHODS

We employed gene expression profiling, bioinformatics and real-time quantitative reverse transcription PCR (RT-qPCR) to detect genes differentially expressed in CML patients versus healthy donors.

RESULTS

There were 1704 genes differentially expressed between CD3⁺ T cells from CML patients and healthy donors, including 868 up-regulated genes and 836 down-regulated genes, which mostly related to T cell functional pathways. In particular, lower expression of NFATC1, a member of the TCR signaling pathway, was detected in CD3⁺ T cells from CML patients. We further found that the expression of IRF4 and BACH2, transcription factors that potentially regulate NFATC1, in CD3⁺ T cells from CML patients was significantly lower than that in healthy donors.

CONCLUSION

We for the first time observed the altered gene expression profiles of CD3⁺ T cells from CML patients, and the results suggested that IRF4, BACH2 and NFATC1 may be involved in regulating T cell dysfunction in CML patients in the form of a transcriptional regulatory network. These findings may provide potential targets for tyrosine kinase inhibitors in combination with other targeted immunotherapies .

Targeting metabolism: A potential strategy for hematological cancer therapy

Most hematological cancer-related relapses and deaths are caused by metastasis; thus, the importance of this process as a target of therapy should be considered. Hematological cancer is a type of cancer in which metabolism plays an essential role in progression. Therefore, we are required to block fundamental metastatic processes and develop specific preclinical and clinical strategies against those biomarkers involved in the metabolic regulation of hematological cancer cells, which do not rely on primary tumor responses. To understand progress in this field, we provide a summary of recent developments in the understanding of metabolism in hematological cancer and a general understanding of biomarkers currently used and under investigation for clinical and preclinical applications involving drug development. The signaling pathways involved in cancer cell metabolism are highlighted and shed light on how we could identify novel biomarkers involved in cancer development and treatment. This review provides new insights into biomolecular carriers that could be targeted as anticancer biomarkers.

Physalin B inhibits cell proliferation and induces apoptosis in undifferentiated human gastric cancer HGC-27 cells

BACKGROUND

Physalin B (PB) from Physalis angulata L. (Solanaceae) is a naturally occurring secosteroid with multiple biological activities, including anti-inflammatory and anticancer activity. However, PB's effects and mechanisms in human gastric cancer (GC) cells are not well characterized.

METHODS

The undifferentiated GC cell line HGC-27 and semi-differentiated GC cell line SGC-7901 were treated with PB. Cell counting kit-8 (CCK-8) and colony formation assays were performed to evaluate cell viability. Apoptosis and the cell cycle were assessed by Annexin V/PI and PI/RNase DNA staining assays, respectively, and Western blotting was used to evaluate the expression of a protein.

RESULTS

PB significantly inhibited the proliferation of HGC-27 cells in a dose- and time-dependent manner. Moreover, PB induced G0/G1 cycle arrest and caspase-dependent apoptosis of HGC-27 cells. Cleaved caspases 8, 3, and 7, poly(ADP)-ribose polymerase (PARP), and the cyclin-dependent kinase (CDK) inhibitor p-Chk2 was induced by PB in HGC-27 cells, while the cell cycle-related proteins cyclin D1, cyclin D3, CDK4, CDK6, cyclin E, and phosphorylated retinoblastoma tumor suppressor protein (p-Rb) were downregulated in a dose-dependent manner.

CONCLUSIONS

PB inhibits proliferation via cyclin-dependent kinase and induces caspase-dependent apoptosis in HGC-27 cells, suggesting that PB might be a novel and effective agent for undifferentiated GC therapy.

Imatinib reduces the fertility of male mice by penetrating the blood-testis barrier and inducing spermatogonia apoptosis

Imatinib, the first generation of tyrosine kinase inhibitor, is used to treat and improve the prognosis of chronic myelogenous leukemia (CML). Clinical data suggest that imatinib could cross the blood-testis barrier and reduces the fertility of patients with CML-chronic phase. However, its exact molecular mechanism has not been fully elucidated. In this study, adult male Kunming mice were treated with different doses of imatinib for 8 weeks. The fertility was evaluated, and the sex hormone levels in the blood were detected by enzyme-linked immunosorbent assay. Histological changes were detected by hematoxylin and eosin staining. The concentration of imatinib in semen and blood was detected by liquid chromatography-mass spectrometry. The ultrastructure of blood-testis barrier and apoptotic bodies were observed by transmission electron microscope. The expression of blood-testis barrier function-regulating protein, Mfsd2a, and apoptosis-associated proteins in testis tissue was detected by immunohistochemistry and Western blot. The results indicated that the fertility of male mice was significantly decreased in a dose-dependent manner after imatinib treatment. Certain hormones in the serum were increased in imatinib treatment groups. Sperm morphology and testicular tissue showed various changes after imatinib treatment. The blood-testis barrier was destroyed and the concentration of imatinib in semen was similar to that in blood after imatinib treatment. Apoptosis was significantly increased in testis tissue after imatinib treatment. Collectively, these results suggest that imatinib can alter blood-testis barrier function, induce apoptosis of spermatogonia, and adversely affect fertility by reducing the number of spermatozoa, decreasing sperm motility and increasing the deformity rate.

Role of PI3K/AKT pathway in cancer: the framework of malignant behavior

Given that the PI3K/AKT pathway has manifested its compelling influence on multiple cellular process, we further review the roles of hyperactivation of PI3K/AKT pathway in various human cancers. We state the abnormalities of PI3K/AKT pathway in different cancers, which are closely related with tumorigenesis, proliferation, growth, apoptosis, invasion, metastasis, epithelial-mesenchymal transition, stem-like phenotype, immune microenvironment and drug resistance of cancer cells. In addition, we investigated the current clinical trials of inhibitors against PI3K/AKT pathway in cancers and found that the clinical efficacy of these inhibitors as monotherapy has so far been limited despite of the promising preclinical activity, which means combinations of targeted therapy may achieve better efficacies in cancers. In short, we hope to feature PI3K/AKT pathway in cancers to the clinic and bring the new promising to patients for targeted therapies.

The PI3K subunits, P110α and P110β are potential targets for overcoming P-gp and BCRP-mediated MDR in cancer

BACKGROUND

PI3K/AKT is a vital signaling pathway in humans. Recently, several PI3K/AKT inhibitors were reported to have the ability to reverse cancer multidrug resistance (MDR); however, specific targets in the PI3K/AKT pathways and the mechanisms associated with MDR have not been found because many of the inhibitors have multiple targets within a large candidate protein pool. AKT activation is one presumed mechanism by which MDR develops during cancer treatment.

METHODS

The effects of inhibiting PI3K 110α and 110β by BAY-1082439 treatment and CRISPR/Cas9 knockout were examined to determine the possible functions of BAY-1082439 and the roles of PI3K 110α and 110β in the reversal of MDR that is mediated by the downregulation of P-gp and BCRP. Inhibition of AKT with GSK-2110183 showed that the downregulation of P-gp and BCRP is independent of generalized AKT inactivation. Immunofluorescence, immunoprecipitation, MTT, flow cytometry and JC-1 staining analyses were conducted to study the reversal of MDR that is mediated by P-gp and BCRP in cancer cells. An ATPase assay and a structural analysis were also used to analyze the potential mechanisms by which BAY-1082439 specifically targets PI3K 110α and 110β and nonspecifically influences P-gp and BCRP.

RESULTS

By inhibiting the activation of the PI3K 110α and 110β catalytic subunits through both the administration of BAY-1082439 and the CRISPR/Cas9 deletion of Pik3ca and Pik3cb, the ATP-binding cassette transporters P-gp/ABCB1 and BCRP/ABCG2 were downregulated, thereby reestablishing the drug sensitivity of human epidermoid carcinoma and non-small cell lung cancer (NSCLC) MDR cells. Inhibition of AKT did not reverse the MDR mediated by P-gp or BCRP. The ABC family proteins and AKT may play MDR-enhancing roles independently.

CONCLUSIONS

The reversal of the dual functions of ABC-transporter-mediated and AKT-activation-enhanced MDR through the inhibition or knockout of PI3K 110α or 110β promises to improve current strategies based on combined drug treatments to overcome MDR challenges.