RNA interference for multiple myeloma therapy: targeting signal transduction pathways

Long noncoding RNA HOTAIR promotes breast cancer development through the lncRNA HOTAIR/miR-1/GOLPH3 axis

BACKGROUND

The lncRNA HOTAIR is frequently overexpressed in breast cancer tissues and plays an important role in the development of breast cancer. Here, we investigated the effect of the lncRNA HOTAIR on the biological behaviour of breast cancer cells and its molecular mechanism.

METHODS

We investigated the level of HOTAIR in breast cancer and its clinical pathological characteristics by bioinformatic methods. Then, we evaluated the effects of HOTAIR and miRNA-1 expression on the biological behaviour of breast cancer cells by qPCR, Cell Counting Kit-8 (CCK-8) assay, clonogenic assays, Transwell assay and flow cytometry for cell proliferation, invasion migration and apoptosis, and cell cycle analysis. Finally, the target genes of the lncRNA HOTAIR/miR-1/GOLPH3 regulatory axis were validated by luciferase reports.

RESULTS

The expression of HOTAIR in breast cancer tissues was significantly higher than that in normal breast tissues (P < 0.05). Silencing of HOTAIR suppressed cell proliferation, invasion and migration, promoted apoptosis and induced G1 phase block in breast cancer (P < 0.0001). We also verified that miR-1 is a target of HOTAIR and that GOLPH3 is a target of miR-1 by luciferase reporter assays (P < 0.001).

CONCLUSIONS

The expression of HOTAIR was significantly elevated in breast cancer tissues. Reducing the expression of HOTAIR inhibited the proliferation, invasion and migration of breast cancer cells and promoted apoptosis, and the mechanism was mainly the effect of the lncRNA HOTAIR/miR-1/GOLPH3 regulatory axis on the biological behaviour of breast cancer cells.

CircATIC Contributes to Multiple Myeloma Progression via miR-324-5p-Dependent Regulation of HGF

Circular RNA (circRNA) 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (circATIC; hsa_circ_0058058) was observed to be upregulated in multiple myeloma (MM) by former article. However, the function and exact mechanism of circATIC in MM development remain barely known. CircRNA-microRNA (miRNA)-messenger RNA (mRNA) axis was established through using bioinformatic databases (starbase, Circinteractome, and microT-CDS). Dual-luciferase reporter assay, RNA immunoprecipitation assay, and RNA-pull down assay were utilized to verify the target relationship between microRNA-324-5p (miR-324-5p) and circATIC or hepatocyte growth factor (HGF). CircATIC expression was upregulated in MM patients and cell lines. CircATIC interference notably hampered cell proliferation, migration, invasion, and glycolysis and induced cell apoptosis of MM cells. MiR-324-5p was a target of circATIC. CircATIC silencing-mediated effects in MM cells were largely overturned by the knockdown of miR-324-5p. HGF was a target of miR-324-5p, and circATIC upregulated the expression of HGF partly through sponging miR-324-5p in MM cells. MiR-324-5p suppressed the malignant behaviors of MM cells, which were largely counteracted by the overexpression of HGF in MM cells. CircATIC accelerated the proliferation, migration, invasion, and glycolysis and suppressed the apoptosis of MM cells through mediating miR-324-5p/HGF signaling.

Circular RNA_0000190 and its target microRNA-767-5p are dysregulated, and they are related to risk stratification as well as prognosis in multiple myeloma patients

BACKGROUND

This study aimed to explore the correlation between circular RNA_0000190 (circ_0000190) and microRNA-767-5p (miR-767-5p), and their correlations with biochemical indices, risk stratification, treatment response, and survival in multiple myeloma (MM) patients.

METHODS

Bone marrow (BM) plasma cells of 86 MM patients (during standard diagnostic procedures) and 30 healthy donors (HDs) (examination of the eligibility for BM transplantation) were obtained, among which circ_0000190 and miR-767-5p expressions were detected using reverse transcription quantitative polymerase chain reaction. In MM patients, Durie-Salmon stage and International Staging System (ISS) stage were assessed. Clinical responses (including complete response (CR) and objective response rate (ORR)) were assessed. The progression-free survival (PFS) and overall survival (OS) were calculated.

RESULTS

Circ_0000190 was decreased, but miR-767-5p was increased in MM patients compared with HDs. Circ_0000190 was negatively correlated with miR-767-5p in both HDs and MM patients. In MM patients, circ_0000190 was negatively correlated with ISS stage, serum creatinine, beta-2-microglobulin, and lactate dehydrogenase but was positively correlated with albumin. Whereas an opposite trend in miR-767-5p was observed. Regarding clinical response, circ_0000190 had the value for predicting increased ORR, while miR-767-5p had the value for predicting decreased CR and ORR. Circ_0000190 high expression was correlated with better PFS and OS, while miR-767-5p high expression was correlated with worse PFS and OS. Multivariate Cox's analyses revealed circ_0000190 high expression as an independent factor predicting better OS.

CONCLUSION

Circ_0000190 and its target miR-767-5p are dysregulated, and they are related to risk stratification and prognosis in MM patients.

CircRNA circ_0000190 inhibits the progression of multiple myeloma through modulating miR-767-5p/MAPK4 pathway

Background

Multiple myeloma (MM) accounts for 10% of all hematological malignancies. Dysregulation of microRNAs (miRNAs) or long non-coding RNAs (lncRNAs) has important impacts on progression of MM. Circular RNAs (circRNAs) are correlated with malignancy in the modulation of tumor progression. This study aims to investigate the effect of circ_0000190 on regulating the progression of MM.

Method

Microscopic examination via single molecule fluorescent in situ hybridization indicates the location of circ_0000190. qRT-PCR and Western blot were used to evaluate the expression of RNAs and proteins. Potential target of circ_0000190 was searched as miRNA, and examined by luciferase reporter assay. A computational screen was also conducted to search the potential target of miRNA. In vitro cell viability, proliferation, apoptosis assays and flow cytometric were performed to assess the effects of circ_0000190 and its target on MM. Mice model of human MM was established with subcutaneous xenograft tumor, qRT-PCR and western blot were performed to detect the underlying mechanisms of circ_0000190 on MM.

Results

Circ_0000190 was located in the cytoplasm, and down-regulated in both bone marrow tissue and peripheral blood, while the target of circ_0000190, miR-767-5p, was up-regulated, suggesting a negative correlation between them. The binding ability between circ_0000190 and miR-767-5p was confirmed by luciferase reporter assay. Moreover, circ_0000190 inhibited cell viability, proliferation and induced apoptosis of MM thus inhibiting cell progression, which is partially through the negative regulation of miR-767-5p. Mitogen-activated protein kinase 4 (MAPK4) is a direct target of miR-767-5p. In addition, over-expression of miR-767-5p promoted cell progression by directly targeting and regulating MAPK4. The MM model mice with administration of circ_0000190 suppressed tumor growth and progression.

Conclusion

Our results revealed that the ability of circ_0000190 to protect against MM was inherited through repression of miR-767-5p, and miR-767-5p might be a tumor drive through targeting MAPK4. Therefore, a novel role of circ_0000190 on regulating the progression of MM was found, and the clinical application of circRNAs might represent a strategy in MM.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1071-9) contains supplementary material, which is available to authorized users.

Bioconjugated Gold Nanoparticles Enhance siRNA Delivery in Prostate Cancer Cells

Here we describe a simple way to create a gold nanoparticle (AuNP)-based non-viral delivery system to deliver siRNA into prostate cancer cells. Therefore, positively charged polyethylenimine (PEI)-capped AuNPs were synthesized in water and further conjugated with the targeting ligand (folic acid) for folate receptors (AuNPs-PEI-FA). The AuNPs-PEI-FA could effectively complex small interfering RNA (siRNA) through electrostatic interaction. Flow cytometry displayed that AuNPs-PEI-FA could specifically deliver siRNA into LNCaP cells, a prostate cancer cell line overexpressing prostate-specific membrane antigen (PSMA) that exhibits a hydrolase enzymatic activity with a folate substrate. In contrast, internalization of siRNA into PC-3 cells, a prostate cancer cell line not expressing PSMA or folate receptors, was not achieved using AuNPs-PEI-FA.siRNA. Following endolysosomal escape, the AuNPs-PEI-FA-.siRNA formulation resulted in significant endogenous gene silencing when compared to the nontargeted formulation, suggesting the potential of AuNPs-PEI-FA for targeted delivery of therapeutic siRNAs in the treatment of prostate cancer.

Serum miR-30d as a novel biomarker for multiple myeloma and its antitumor role in U266 cells through the targeting of the MTDH/PI3K/Akt signaling pathway

Multiple myeloma (MM) is a hematological tumor and is characterized by the infiltration of malignant clonal plasma cells (PCs) in bone marrow. MicroRNAs (miRNAs or miRs) have been reported to play an important role in the genesis and progression of MM. However, little is known about the clinical diagnostic value and biological functions of miR-30d in MM. In this study, to investigate the role of miR-30d in MM, we used reverse transcription-quantitative polymerase chain reaction quantitative (RT-qPCR) to detect the relative expression level of miR-30d in the serum of 81 patients with primary MM and 78 healthy donors (HDs). The biological functions of miR-30d were then assessed by CCK-8 assay, flow cytometric analysis of apoptosis and western blot (WB) analysis in U266 cells. Moreover, the confirmation of the target gene of miR-30d was conducted by luciferase reporter assay. Our results indicated that miR-30d expression was significantly downregulated in the serum of patients with primary MM compared with that of the HDs and that it was significantly associated with several clinical indicators of MM. Further cell functional analyses using the U266 cells revealed that miR-30d functions as a tumor suppressor gene in MM by inhibiting cell viability and promoting cell apoptosis. Moreover, miR-30d was confirmed to directly bind to the 3'UTR of its target gene, metadherin (MTDH) and inhibit the activation of the downstream PI3K/Akt signaling pathway. On the whole, the findings of this study indicate that the serum expression level of miR-30d is of great significance to the diagnosis and treatment monitoring of patients with MM. Moreover, miR-30d carries out its antitumor role in U266 cells through the inhibition of the activation of the PI3K/Akt signaling pathway by negatively regulating MTDH, which reveals its potential for use as a therapeutic target for MM.

miR-26b-5p suppresses proliferation and promotes apoptosis in multiple myeloma cells by targeting JAG1

BACKGROUND

Though the levels of diagnosis and treatment of multiple myeloma (MM) have been largely improved recent years, the prognosis of these patients remain unacceptable. It is urgent for us to discover the exact mechanism and determine some new indicators for MM. MiRNAs play a critical role in the occurrence and progression of cancers, including MM. MiR-26b-5p has been reported to be closely related to cells proliferation in human pulmonary cancer, hepatocellular carcinoma and so on.

MATERIAL AND METHODS

Here, we measured the expression of miR-26b-5p in MM samples and cell lines by real-time PCR. Then, Kaplan-Meier Curves were applied to assess the effect of miR-26b-5p expression on MM patients prognosis. Functionally, MTT assay and Flow cytometry were conducted to explore the functions of miR-26b-5p in cells proliferation and apoptosis. Furthermore, bioinformatics tools, Pearson's correlation coefficient analysis, gain-and loss of-function experiments and rescue experiment were used to determine the relationship between JAG1 and miR-26b-5p in MM cells. In addition, we also confirmed the role of JAG1 in MM cells proliferation and apoptosis by gain-and loss of-function experiments.

RESULTS

Here, we reported for the first time that miR-26b-5p was under-expressed in MM by real-time PCR. Clinically, Kaplan-Meier Curves showed that MM patients with lower miR-26b-5p expression had worse prognosis. Functionally, MTT assay revealed that miR-26b-5p inhibited cells proliferation. Flow cytometry indicated that miR-26b-5p accelerated tumor cells apoptosis. Furthermore, bioinformatics tools, Pearson's correlation coefficient analysis gain-and loss of-function experiments showed that JAG1 was the target of miR-26b-5p in MM cells. And, gain-and loss of-function experiments for JAG1 confirmed that JAG1 was an oncogene in MM cells. What's more, rescue experiment showed that JAG1 mediated the function of miR-26b-5p in MM cells.

CONCLUSION

MiR-26b-5p acts as a tumor suppressor through suppressing cells proliferation and inducing cells apoptosis via directly targeting JAG1 in MM. MiR-26b-5p could be a potential and ponderable tumor target for MM in future.

The potential function of microRNAs as biomarkers and therapeutic targets in multiple myeloma

Multiple myeloma (MM), accounting for ~1% of all types of human cancer and 13% of all hematological malignancies, is characterized by the malignant proliferation of monoclonal plasma cells (PCs) in the bone marrow. MM leads to end stage organ impairment, including bone lesions, renal dysfunction, hypercalcemia and anemia. So far, the specific pathogenesis of MM remains unclear and no early-stage sensitive biomarker of MM has been well characterized. Furthermore, treating MM is difficult, as the majority of patients eventually relapse or become refractory following treatment using presently available methods. To date, a number of studies have demonstrated that microRNAs (miRNAs) may serve crucial functions in the progression of numerous cancers, including MM. During the tumorigenesis and pathogenesis of MM, there are multiple carcinogenic events that involve the pernicious transformation from normal to malignant PCs. miRNAs, as oncogenes or tumor suppressors, regulate MM progression-related signaling pathways. In the present review, the up-to-date preliminary basic studies and associated clinical works on the underlying mechanisms of aberrant miRNA profiling in MM have been summarized, including an evaluation of its value as a potential biomarker and a novel therapeutic strategy for MM.

Mesenchymal stem cells can induce regulatory T cells via modulating miR-126a but not miR-10a

Among the different immunosuppressive properties attributed to mesenchymal stem cells (MSCs), one relies on their ability to induce regulatory T cells (iTregs) from conventional T cells under particular inflammatory context. Stable Foxp3 expression plays a major role in the phenotypic and functional stability of iTregs. However, the mechanism behind Foxp3 induction in iTregs by MSCs remains unknown. Here, we assessed the possible effect of MSCs on miR-126a and miR-10a expression in iTregs and, consequently on Foxp3 stability, a regulatory pathway that has not yet been explored. We first demonstrated that in vitro MSC-iTreg generation was directly associated with strong modifications of miR-126a. We next infused high doses of MSCs in a murine model of allogeneic skin transplantation (C57BL/6 into Balb/c). This treatment significantly prolonged skin allograft survival compared to PBS treated mice. When splenocytes from grafted mice were collected, we observed that the expression of Foxp3 gene was elevated at day 5 and 10 post-graft merely in MSCs treated mice. Moreover, Foxp3 expression was not associated with modified miR-10a expression comparable to in vitro experiments. Thus, our data identify a solid mechanism where MSCs induce conversion of conventional T cells to iTregs through strong modifications of miR-126a. Although miR-10a expression level remains unchanged in vitro and in vivo, we observed expression of this miR in MSC-DC condition.

Bioconjugated gold nanoparticles enhance cellular uptake: A proof of concept study for siRNA delivery in prostate cancer cells

The chemistry of gold nanoparticles (AuNPs) facilitates surface modifications and thus these bioengineered NPs have been investigated as a means of delivering a variety of therapeutic cargos to treat cancer. In this study we have developed AuNPs conjugated with targeting ligands to enhance cell-specific uptake in prostate cancer cells, with a purpose of providing efficient non-viral gene delivery systems in the treatment of prostate cancer. As a consequence, two novel AuNPs were synthesised namely AuNPs-PEG-Tf (negatively charged AuNPs with the transferrin targeting ligands) and AuNPs-PEI-FA (positively charged AuNPs with the folate-receptor targeting ligands). Both bioconjugated AuNPs demonstrated low cytotoxicity in prostate cancer cells. The attachment of the targeting ligand Tf to AuNPs successfully achieved receptor-mediated cellular uptake in PC-3 cells, a prostate cancer cell line highly expressing Tf receptors. The AuNPs-PEI-FA effectively complexed small interfering RNA (siRNA) through electrostatic interaction. At the cellular level the AuNPs-PEI-FA specifically delivered siRNA into LNCaP cells, a prostate cancer cell line overexpressing prostate specific membrane antigen (PSMA, exhibits a hydrolase enzymic activity with a folate substrate). Following endolysosomal escape the AuNPs-PEI-FA.siRNA formulation produced enhanced endogenous gene silencing compared to the non-targeted formulation. Our results suggest both formulations have potential as non-viral gene delivery vectors in the treatment of prostate cancer.