Reduce proliferation of human bone marrow cells from acute myeloblastic leukemia with minimally differentiation by blocking lncRNA PVT1

lncRNA PVT1: a novel oncogene in multiple cancers

Long noncoding RNAs are involved in epigenetic gene modification, including binding to the chromatin rearrangement complex in pre-transcriptional regulation and to gene promoters in gene expression regulation, as well as acting as microRNA sponges to control messenger RNA levels in post-transcriptional regulation. An increasing number of studies have found that long noncoding RNA plasmacytoma variant translocation 1 (PVT1) plays an important role in cancer development. In this review of a large number of studies on PVT1, we found that PVT1 is closely related to tumor onset, proliferation, invasion, epithelial–mesenchymal transformation, and apoptosis, as well as poor prognosis and radiotherapy and chemotherapy resistance in some cancers. This review comprehensively describes PVT1 expression in various cancers and presents novel approaches to the diagnosis and treatment of cancer.

Knockdown of SOX12 Expression Induced Apoptotic Factors is Associated with TWIST1 and CTNNB1 Expression in Human Acute Myeloid Leukemia Cells

Recent improvements in molecular treatment and gene therapy led to discovering novel cancer remedies. Antisense LNA GapmeRs is a state-of-the-art molecular research field for diagnosing and treating various cancer types. Acute myeloid leukemia (AML) is a heterogeneous hematopoietic malignancy defined by the rapid accumulation and malignant proliferation of immature myeloid progenitors. SOX12 is a new potential target for acute myeloid leukemia. In this study, SOX12 was blocked by antisense LNA GapmeRs (ALG) in human AML cell lines (KG1 and M07e). Cells were transfected with Gapmer anti-SOX12 at 24, 48, and 72 h post-transfection. Transfection efficiency was assessed by a fluorescent microscope. Furthermore, evaluation of SOX12, TWIST1, CTNNB1, CASP3, and CASP9 expression was performed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Cell viability was determined by MTT assay. SOX12 expression was decreased remarkably in the ALG group. Moreover, SOX12 knockdown was associated with a decrease in TWIST1 and CTNNB1 expression. Besides, downregulation of SOX12 in both cell lines could induce apoptosis, probably through upregulation of CASP3 and CASP9. The findings reveal that SOX12 knockdown could be a new target for reducing AML cells proliferation through antisense therapy approach.

S100A8 inhibition in leukemic lymphoblasts induces sensitivity to chemotherapy and inhibition of disease relapse

Acute lymphoblastic leukemia (ALL) is the most common malignancy in children and relapsed B-ALL is the leading cause of mortality in children with leukemia due to a lack of response to treatment. S100A8 is a low molecular weight calcium-binding intracellular protein that is expressed in certain cells, and its increased expression is seen in most tumors as well as in relapsed childhood B-ALL cases. The present study indicates the important role of S100A8 in improving viability and resistance to chemotherapy in relapsed B-ALL lymphoblasts. S100A8 levels were compared in B-ALL and relapsed B-ALL lymphoblasts that were sensitive and resistant to Vincristine, respectively. S100A8 was inhibited in the lymphoblasts of two patients by antisense locked nucleic acid (LNA) GapmeRs and the decreased expression of S100A8 was evaluated using quantitative real-time PCR and ELISA. Then, the S100A8 antisense LNA GapmeRs-transfected cells were treated with Vincristine and the expression levels of S100A8 mRNA and S100A8 protein were re-determined. At all of these stages, cell viability and LC50 were assessed by MTT assay. The results showed that S100A8 levels in relapsed B-ALL lymphoblasts were significantly higher than B-ALL lymphoblasts. Moreover, the increase in S100A8 expression was proportionate to the increase in Vincristine resistance in these cells. The S100A8 knockdown procedure using antisense LNA GapmeRs decreased the cell viability and increased vincristine sensitivity in lymphoblasts of two patients, and it also increased the sensitivity to chemotherapy in relapsed B-ALL lymphoblasts. According to the findings of the present study, S100A8 is effective in developing lymphoblast resistance to chemotherapy, and its enhanced expression may contribute to shifting B-ALL into the relapse phase of the illness. As a result, S100A8 may be a valuable target for managing and improving relapses B-ALL.

Long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 gene (PVT1) modulates the proliferation and apoptosis of acute lymphoblastic leukemia cells by sponging miR-486-5p

Long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 gene (PVT1) is related to the progress of various cancers. Here, we illuminated the role of PVT1 in acute lymphoblastic leukemia (ALL) cell proliferation and apoptosis. PVT1 was upregulated in plasma samples from patients with ALL and ALL cell lines. PVT1 silencing repressed cell viability and enhanced cell apoptosis in Jurkat and SUP-B15 cells. PVT1 targeted microRNA-486-5p (miR-486-5p) and negatively modulated miR-486-5p expression. Upregulation of miR-486-5p decreased cell viability and increased ALL cell apoptosis. Mastermind Like Transcriptional Coactivator 3 (MAML3) was a downstream molecule of miR-486-5p and miR-486-5p mimic transfection weakened its expression in ALL cells. Rescue experiments proved that reintroduction of PVT1 counteracted the impacts of miR-486-5p in ALL cell proliferation and apoptosis. In vivo, PVT1 silencing repressed the tumor growth of SUP-B15 cells and reduced the expression of MAML3. Altogether, silencing of PVT1 inhibited ALL cell growth and induced cell apoptosis through sponging miR-486-5p.

The role of circular RNA plasmacytoma variant translocation 1 as a biomarker for prognostication of acute myeloid leukemia

OBJECTIVE

Circular RNA plasmacytoma variant translocation 1 (circ-PVT1) has been reported to be an oncogene and serves as a prognostic biomarker in several solid cancers and hematological malignancies. However, no study has been performed on the tumorigenesis role of circ-PVT1 in acute myeloid leukemia (AML). Thus, this study aimed to evaluate the correlation of circ-PVT1 with disease risk, clinical characteristics, cytogenetics/molecular genetics, and prognosis of AML.

METHODS

A total of 68 de novo AML patients, 30 disease controls and 30 health donors were enrolled in this study. Circ-PVT1 expression in bone marrow (BM) was determined. Complete remission (CR) status after induction therapy, event-free survival (EFS) and overall survival (OS) were evaluated in AML patients.

RESULTS

Circ-PVT1 expression was different among AML patients, disease controls and health donors, which was highest in AML patients, followed by disease controls and lowest in health donors. Meanwhile, circ-PVT1 could distinguish AML patients from health donors and disease controls by receiver operating characteristic curve analysis. Furthermore, circ-PVT1 was correlated with BM blasts and FLT3-ITD mutation, but not other clinical features, such as French-American-Britain subtypes in AML patients. Moreover, circ-PVT1 expression was lower in AML patients with CR compared with those without CR. Besides, high circ-PVT1 expression was correlated with shorter EFS and OS in AML patients. After adjustment by multivariate Cox's regression analysis, higher circ-PVT1 expression was an independent factor in predicting shorter EFS and OS for AML patients.

CONCLUSION

Circ-PVT1 potentially serves as a biomarker for evaluating the prognosis of AML patients.