No abstract

We have previously demonstrated that the CCR9/CCL25 signaling pathway plays an important role in drug resistance in human acute T-lymphocytic leukemia (T-ALL) by inducing activation of ERM protein with polarized distribution in T-ALL cell line MOLT4. However, the mechanism of action of the activated ERM protein in the drug resistance of MOLT4 cells induced by CCL25 remains uncharacterized. Here we investigated the mechanism of CCR9/CCL25-initiated drug resistance in CCR9-high-expressing T-ALL cells. Our results showed that 1) the function of P-gp was increased after treatment with CCL25; 2) P-gp colocalized and co-immunoprecipitated with p-ERM and F-actin in CCL25 treated cells; and 3) ERM-shRNA conferred drug sensitivity coincident with release of ERM interactions with P-gp and F-actin after treatment with CCL25. These data suggest it is pivotal that P-gp associate with the F-actin cytoskeleton through p-ERM in CCR9/CCL25 induced multidrug resistance of T-ALL cells. Strategies aimed at inhibiting P-gp-F-actin cytoskeleton association may be helpful in increasing the efficiency of therapies in T-ALL.

Adult T-cell acute lymphoblastic leukemia (T-ALL) is a refractory leukemia. We previously showed that CCL25/CCR9 promotes T-ALL metastasis. In the present study, we assessed the effects of CCL25 on Wnt expression and the effects of Wnt5a and CCL25 on PI3K/Akt and RhoA activation. Transwell assays and mouse xenograft experiments were utilized to assess the effects of Wnt5a and CCL25 on MOLT4 cell invasion, migration and metastasis. The effects of Wnt5a on MOLT4 cell actin polarization and pseudopodium formation were examined using laser scanning confocal microscopy and scanning electron microscopy. CCL25 induced Wnt5a expression in MOLT4 cells by promoting protein kinase C (PKC) expression and activation. Wnt5a promoted MOLT4 cell migration, invasion, actin polarization, and lamellipodium and filopodia formation via PI3K/Akt-RhoA pathway activation. These effects were rescued by PI3K/Akt or RhoA knockdown or inhibition. Additionally, Wnt5a in cooperation with CCL25 promoted MOLT4 cell mouse liver metastasis and stimulated RhoA activation. These results show that CCL25/CCR9 upregulates Wnt5a by promoting PKC expression and activation in MOLT4 cells. This in turn promotes cell migration and invasion via PI3K/Akt-RhoA signaling, enhancing cell polarization and pseudopodium formation. These findings indicate that the PI3K/Akt-RhoA pathway is likely responsible for Wnt5a-induced adult T-ALL cell migration and invasion.

Metastatic disease remains the primary cause of death for individuals with T cell acute lymphoblastic leukemia (T‐ALL). microRNAs (miRNAs) play important roles in the pathogenesis of T‐ALL by inhibiting gene expression at posttranscriptional levels. The goal of the current project is to identify any significant miRNAs in T‐ALL metastasis. We observed miR‐146b‐5p to be downregulated in T‐ALL patients and cell lines, and bioinformatics analysis implicated miR‐146b‐5p in the hematopoietic system. miR‐146b‐5p inhibited the migration and invasion in T‐ALL cells. Interleukin‐17A (IL‐17A) was predicted to be a target of miR‐146b‐5p; this was confirmed by luciferase assays. Interestingly, T‐ALL patients and cell lines secreted IL‐17A and expressed the IL‐17A receptor (IL‐17RA). IL‐17A/IL‐17RA interactions promoted strong T‐ALL cell migration and invasion responses. Gene set enrichment analysis (GSEA) and quantitative polymerase chain reaction (qPCR) analysis indicated that matrix metallopeptidase‐9 (MMP9), was a potential downstream effector of IL‐17A activation, and nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) signaling was also implicated in this process. Moreover, IL‐17A activation promoted T‐ALL cell metastasis to the liver in IL17A −/− mouse models. These results indicate that reduced miR‐146b‐5p expression in T‐ALL may lead to the upregulation of IL‐17A, which then promotes T‐ALL cell migration and invasion by upregulating MMP9 via NF‐κB signaling.

No abstract

Matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases, are involved in a variety of physiological and pathological processes. We analyzed 11 data sets from Gene Expression Omnibus Database and found that MMP7 and MMP15 were highly expressed in multiple carcinomas. GSE13204 showed that MMP7 and MMP15 were overexpressed in acute myeloid leukemia (AML) patients.The Cancer Genome Atlas data set exhibited that high expression of MMP7 or MMP15 in bone marrow (BM) of AML patients predicted poor overall survival. The χ 2 test results indicated that high expression level of MMP7 and MMP15 were correlated with high-risk stratification and high BM blast cell percentage in AML patients. To confirm these findings, we performed reverse-transcription quantitative polymerase chain reaction (RT-qPCR) and found that MMP7 and MMP15 were highly expressed in three AML cell lines. Further study showed that MMP7 and MMP15 were highly expressed both in BM and peripheral blood in collected AML samples compared with healthy individuals. Additionally, long noncoding RNA (lncRNA) microarray of BM samples of AML patients revealed that multiple lncRNAs were correlated with MMP7 and MMP15, suggesting that lncRNAs might be involved in the pathogenesis of AML via modulating MMPs. In conclusion, our study uncovers the potential roles of MMP7 and MMP15 in the prognosis of AML. K E Y W O R D S acute myeloid leukemia, matrix metalloproteinase-7, matrix metalloproteinase-15, overall survival, prognosis

Tripartite motif containing 28 (TRIM28) is a transcriptional regulator acting as an essential corepressor for Krüppel-associated box zinc finger domain-containing proteins in multiple tissue and cell types. An increasing number of studies have investigated the function of TRIM28; however, its prognostic value in breast cancer (BC) remains unclear. In the present study, the expression of TRIM28 was identified to be significantly higher in cancerous compared with healthy tissue samples. Furthermore, it was demonstrated that TRIM28 expression was significantly correlated with several clinicopathological characteristics of patients with BC, such as p53 mutation, tumor recurrence and Elston grade of the tumor. In addition, a protein-protein interaction network was created to illustrate the interactions of TRIM28 with other proteins. The prognostic value of TRIM28 in patients with BC was investigated using the Kaplan-Meier Plotter database, which revealed that high expression of TRIM28 is a predictor of poor prognosis in patients with BC. In conclusion, the results of the present study indicate that TRIM28 provides a survival advantage to patients with BC and is a novel prognostic biomarker, in addition to being a therapeutic target for the treatment of BC.

In previous study, we found that the chemokine receptor 9 (CCR9) was highly expressed on CD4 + T cells from patients with T-cell lineage acute lymphocytic leukemia (T-ALL) and mediated leukemia cell infiltration and metastasis. Combined use of interleukin 2 (IL-2) and IL-4 promoted the internalization of CCR9 and therefore attenuated leukemia cell infiltration and metastasis. In this study, we preliminarily investigated the mechanism of internalization of CCR9 on MOLT4 cell model (a human leukemia T-cell line, naturally expresses CCR9) and found that IL-2 upregulated the cell surface expression of IL-4R(CD124) greatly, whereas IL-4 had no significant influence on (CD25) and subunits (CD122) of IL-2R. Moreover, specific inhibitors, such as staurosporine, H89 and heparin, inhibited internalization of CCR9, which indicated a role of protein kinase C (PKC) and G protein-coupled kinase 2 (GRK2), respectively. Furthermore, GRK2 was upregulated and translocated to cell membrane in IL-2 and IL-4 treated cells which indicated that PKC could be a prerequisite for GRK2 activity.