RETRACTED: Inhibition of miR-140-3p or miR-155-5p by antagomir treatment sensitize chordoma cells to chemotherapy drug treatment by increasing PTEN expression

In silico analysis and experimental validation shows negative correlation between miR-1183 and cell cycle progression gene 1 expression in colorectal cancer

MicroRNAs (miRNAs) are small noncoding RNAs that post-transcriptionally regulate gene expression by binding to the 3' untranslated regions (UTR) of target genes. Aberrant expression of miRNAs can lead to disease, including cancer. Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Among several factors, differential expression of miRNA can have serious consequences on disease progression. This study was designed to computationally identify and experimentally verify strong miRNA candidates that could influence CRC progression. In silico analysis of publicly available gene expression microarray datasets revealed significant upregulation of miR-1183 in CRC. Comparison of mRNA microarray expression data with predicted miR-1183 targets led to the identification of cell cycle progression gene 1 (CCPG1) as strong, negatively correlated miR-1183 target. Expression analysis by means of quantitative PCR validated the inverse correlation between miR-1183 and CCPG1 in colorectal cancer tissues. CCPG1 indirectly modulates the cell cycle by interacting with the PH/DH domain of Dbs (Rho-specific guanine nucleotide exchange factor). Interestingly, the computational analysis also showed that miR-1183 is upregulated in liver and gastric cancer. This finding is notable as the liver and stomach are the primary metastatic sites for colorectal cancer and hepatocellular carcinoma respectively. This novel finding highlights the broader implications of miR-1183 dysregulation beyond primary CRC, potentially serving as a valuable prognostic marker and a therapeutic target for both primary and metastatic CRC.

miR-140-3p attenuated the tumorigenesis of multiple myeloma via attenuating BZW2

BACKGROUND

Among B-cell lymphoma, multiple myeloma (MM) is an incurable malignancy. miR-140-3p was known to be an inhibitor in malignant tumors. However, the function of miR-140-3p in MM remains unclear.

METHODS

qRT-PCR was performed to determine the expressions of miR-140-3p and BZW2 mRNA. The protein level of BZW2 was determined by the western blot. Cell viability or cell apoptosis was detected by the MTT assay or flow cytometry, respectively. Binding between miR-140-3p and BZW2 was validated using the dual luciferase assay. Xenograft model was applied to verify the results of in vitro study.

RESULTS

The level of miR-140-3p was significantly downregulated in MM. Overpexression of miR-140-3p impaired the proliferation of MM cell lines and induced apoptosis in MM cells. miR-140-3p was validated to target BZW2 and inhibit the expression of BZW2. BZW2 was involved in the regulation of miR-140-3p on MM cell vitality and apoptosis. In vivo study revealed that miR-140-3p impeded tumorigenesis of MM cell line in nude mice.

CONCLUSION

Our present study revealed that miR-140-3p served as a suppressor in MM by negatively regulating BZW2. Thus, miR-140-3p could act as a new target for treating MM.

Noncoding RNAs and their therapeutics in paclitaxel chemotherapy: Mechanisms of initiation, progression, and drug sensitivity

The identification of agents that can reverse drug resistance in cancer chemotherapy, and enhance the overall efficacy is of great interest. Paclitaxel (PTX) belongs to taxane family that exerts an antitumor effect by stabilizing microtubules and inhibiting cell cycle progression. However, PTX resistance often develops in tumors due to the overexpression of drug transporters and tumor-promoting pathways. Noncoding RNAs (ncRNAs) are modulators of many processes in cancer cells, such as apoptosis, migration, differentiation, and angiogenesis. In the present study, we summarize the effects of ncRNAs on PTX chemotherapy. MicroRNAs (miRNAs) can have opposite effects on PTX resistance (stimulation or inhibition) via influencing YES1, SK2, MRP1, and STAT3. Moreover, miRNAs modulate the growth and migration rates of tumor cells in regulating PTX efficacy. PIWI-interacting RNAs, small interfering RNAs, and short-hairpin RNAs are other members of ncRNAs regulating PTX sensitivity of cancer cells. Long noncoding RNAs (LncRNAs) are similar to miRNAs and can modulate PTX resistance/sensitivity by their influence on miRNAs and drug efflux transport. The cytotoxicity of PTX against tumor cells can also be affected by circular RNAs (circRNAs) and limitation is that oncogenic circRNAs have been emphasized and experiments should also focus on onco-suppressor circRNAs.

CMTM3 suppresses chordoma progress through EGFR/STAT3 regulated EMT and TP53 signaling pathway

BACKGROUND

Chordomas are rare, slow-growing and locally aggressive bone sarcomas. At present, chordomas are difficult to manage due to their high recurrence rate, metastasis tendency and poor prognosis. The underlying mechanisms of chordoma tumorigenesis and progression urgently need to be explored to find the effective therapeutic targets. Our previous data demonstrates that EGFR plays important roles in chordoma development and CKLF-like MARVEL transmembrane domain containing (CMTM)3 suppresses gastric cancer metastasis by inhibiting the EGFR/STAT3/EMT signaling pathway. However, the roles and mechanism of CMTM3 in chordomas remain unknown.

METHODS

Primary chordoma tissues and the paired adjacent non-tumor tissues were collected to examine the expression of CMTM3 by western blot. The expression of CMTM3 in chordoma cell lines was tested by Real-time PCR and western blot. CCK-8 and colony forming unit assay were performed to delineate the roles of CMTM3 in cell proliferation. Wound healing and Transwell assays were performed to assess cell migration and invasion abilities. A xenograft model in NSG mice was used to elucidate the function of CMTM3 in vivo. Signaling pathways were analyzed by western blot and IHC. RNA-seq was performed to further explore the mechanism regulated by CMTM3 in chordoma cells.

RESULTS

CMTM3 expression was downregulated in chordoma tissues compared with paired normal tissues. CMTM3 suppressed proliferation, migration and invasion of chordoma cells in vitro and inhibited tumor growth in vivo. CMTM3 accelerated EGFR degradation, suppressed EGFR/STAT3/EMT signaling pathway, upregulated TP53 expression and enriched the TP53 signaling pathway in chordoma cells.

CONCLUSIONS

CMTM3 inhibited tumorigenesis and development of chordomas through activating the TP53 signaling pathway and suppressing the EGFR/STAT3 signaling pathway, which suppressed EMT progression. CMTM3 might be a potential therapeutic target for chordomas.

Combination of Metformin, Sodium Oxamate and Doxorubicin Induces Apoptosis and Autophagy in Colorectal Cancer Cells via Downregulation HIF-1α

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide in both sexes. Current therapies include surgery, chemotherapy, and targeted therapy; however, prolonged exposure to chemical agents induces toxicity in patients and drug resistance. So, we implemented a therapeutic strategy based on the combination of doxorubicin, metformin, and sodium oxamate called triple therapy (Tt). We found that Tt significantly reduced proliferation by inhibiting the mTOR/AKT pathway and promoted apoptosis and autophagy in CRC derived cells compared with doxorubicin. Several autophagy genes were assessed by western blot; ULK1, ATG4, and LC3 II were overexpressed by Tt. Interestingly, ULK1 was the only one autophagy-related protein gradually overexpressed during Tt administration. Thus, we assumed that there was a post-transcriptional mechanism mediating by microRNAs that regulate UKL1 expression during autophagy activation. Through bioinformatics approaches, we ascertained that ULK1 could be targeted by mir-26a, which is overexpressed in advanced stages of CRC. In vitro experiments revealed that overexpression of mir-26a decreased significantly ULK1, mRNA, and protein expression. Contrariwise, the Tt recovered ULK1 expression by mir-26a decrease. Due to triple therapy repressed mir-26a expression, we hypothesized this drug combination could be involved in mir-26a transcription regulation. Consequently, we analyzed the mir-26a promoter sequence and found two HIF-1α transcription factor recognition sites. We developed two different HIF-1α stabilization models. Both showed mir-26a overexpression and ULK1 reduction in hypoxic conditions. Immunoprecipitation experiments were performed and HIF-1α enrichment was observed in mir-26a promoter. Surprisingly, Tt diminished HIF-1α detection and restored ULK1 mRNA expression. These results reveal an important regulation mechanism controlled by the signaling that activates HIF-1α and that in turn regulates mir-26a transcription.

microRNA-140: A miRNA with diverse roles in human diseases

MicroRNA-140 (miR-140) has been shown to be associated with the pathogenesis of a wide range of pathologies including osteoarthritis, osteoporosis, renal fibrosis, ischemic conditions, and most importantly neoplasia. This miRNA has been shown to be down-regulated in a diversity of cancers namely breast cancer, gastrointestinal cancers, lung cancer, and prostate cancer. miR-140 has a lot of immune-related targets. Moreover, several miR-140 targets regulate cell proliferation, cell cycle transition, and apoptosis. This miRNA has been shown to be sponged by a number of lncRNAs and circ-RNAs. miR-140 has essential roles in the determination of the sensitivity of neoplastic cells to chemotherapeutic agents such as temozolomide, doxorubicin, and cisplatin. Besides, expression quantities of miR-140 in cancer tissues can be used for the prediction of clinical outcomes of patients with neoplasia. In the present paper, we describe the impact of miR-140 in neoplastic and non-neoplastic disorders.

Role of non-coding RNAs in modulating the response of cancer cells to paclitaxel treatment

Paclitaxel is a chemotherapeutic substance that is administered for treatment of an extensive spectrum of human malignancies. In spite of its potent short-term effects against tumor cells, resistance to paclitaxel occurs in a number of patients precluding its long-term application in these patients. Non-coding RNAs have been shown to influence response of cancer cells to this chemotherapeutic agent via different mechanisms. Mechanistically, these transcripts regulate expression of several genes particularly those being involved in the apoptotic processes. Lots of in vivo and in vitro assays have demonstrated the efficacy of oligonucleotide-mediated microRNAs (miRNA)/ long non-coding RNAs (lncRNA) silencing in enhancement of response of cancer cells to paclitaxel. Therefore, targeted therapies against non-coding RNAs have been suggested as applicable modalities for combatting resistance to this agent. In the present review, we provide a summary of studies which assessed the role of miRNAs and lncRNAs in conferring resistance to paclitaxel.

Participation of MicroRNAs in the Treatment of Cancer with Phytochemicals

Cancer is a global health concern and one of the main causes of disease-related death. Even with considerable progress in investigations on cancer therapy, effective anti-cancer agents and regimens have thus far been insufficient. There has been compelling evidence that natural phytochemicals and their derivatives have potent anti-cancer activities. Plant-based anti-cancer agents, such as etoposide, irinotecan, paclitaxel, and vincristine, are currently being applied in medical treatments for patients with cancer. Further, the efficacy of plenty of phytochemicals has been evaluated to discover a promising candidate for cancer therapy. For developing more effective cancer therapy, it is required to apprehend the molecular mechanism deployed by natural compounds. MicroRNAs (miRNAs) have been realized to play a pivotal role in regulating cellular signaling pathways, affecting the efficacy of therapeutic agents in cancer. This review presents a feature of phytochemicals with anti-cancer activity, focusing mainly on the relationship between phytochemicals and miRNAs, with insights into the role of miRNAs as the mediators and the regulators of anti-cancer effects of phytochemicals.

Downregulation of miR-140 is Correlated with Poor Prognosis and Progression of Thyroid Cancer

BACKGROUND

The incidence of thyroid cancer is increasing rapidly and there is an urgent need to explore novel therapeutic targets for thyroid cancer. MiR-140 has been reported to affect the progression of various cancers, which makes it possible to play a role in thyroid cancer. This study aimed to investigate the expression and role of miR-140 in thyroid cancer.

METHODS

The expression of miR-140 was investigated by reverse transcription-quantitative polymerase chain reaction (qRT-PCR) in thyroid cancer tissues and cell lines. The prognostic value of miR- 140 in thyroid cancer was evaluated by Kaplan-Meier survival and Cox regression. Moreover, the effects of miR-140 on cell proliferation, migration, and invasion of thyroid cancer were investigated by CCK-8 and Transwell assay.

RESULTS

MiR-140 was downregulated in thyroid cancer tissues and cells, which correlated with TNM stage and lymph node metastasis of patients. Patients with low miR-140 expression had a shorter survival time compared with that in patients with high miR-140 expression. Furthermore, miR-140 acts as an independent factor for the prognosis of thyroid cancer. Overexpression of miR-140 inhibited cell proliferation, migration, and invasion of thyroid cancer.

CONCLUSION

MiR-140 can serve as a potential prognostic factor for patients with thyroid cancer and suppress the progression of thyroid cancer, which provides new insight for the therapeutic target for thyroid cancer.

Translational Windows in Chordoma: A Target Appraisal

Chordomas are rare tumors that are notoriously refractory to chemotherapy and radiotherapy when radical surgical resection is not achieved or upon recurrence after maximally aggressive treatment. The study of chordomas has been complicated by small patient cohorts and few available model systems due to the rarity of these tumors. Emerging next-generation sequencing technologies have broadened understanding of this disease by implicating novel pathways for possible targeted therapy. Mutations in cell-cycle regulation and chromatin remodeling genes have been identified in chordomas, but their significance remains unknown. Investigation of the immune microenvironment of these tumors suggests that checkpoint protein expression may influence prognosis, and adjuvant immunotherapy may improve patient outcome. Finally, growing evidence supports aberrant growth factor signaling as potential pathogenic mechanisms in chordoma. In this review, we characterize the impact on treatment opportunities offered by the genomic and immunologic landscape of this tumor.

Exosomal MicroRNAs as Mediators of Cellular Interactions Between Cancer Cells and Macrophages

Tumor microenvironment consists of cancer cells and various stromal cells such as endothelial cells, cancer-associated fibroblasts (CAFs), myeloid-derived suppressor cells (MDSCs), neutrophils, macrophages, and other innate and adaptive immune cells. Of these innate immune cells, macrophages are an extremely heterogeneous population, and display both pro-inflammatory and anti-inflammatory functions. While M1 macrophages (classically activated macrophages) display anti-tumoral and pro-inflammatory functions, M2 macrophages display pro-tumoral and anti-inflammatory functions. Cellular interactions and molecular factors in the tumor microenvironment affect the polarization of macrophages. We review molecules and immune cells that influence the polarization status of macrophages. Tumor-associated macrophages (TAMs) generally express M2 phenotype, and mediate many processes that include tumor initiation, angiogenesis, and metastasis. A high number of TAMs has been associated with the poor prognosis of cancers. MicroRNAs (miRNAs) have been known to regulate cellular interactions that involve cancer cells and macrophages. Tumor-derived exosomes play critical roles in inducing the M1 or M2-like polarization of macrophages. The roles of exosomal miRNAs from tumor cells in the polarization of macrophages are also discussed and the targets of these miRNAs are presented. We review the effects of exosomal miRNAs from TAMs on cancer cell invasion, growth, and anti-cancer drug resistance. The relevance of exosomal microRNAs (miRNAs) as targets for the development of anti-cancer drugs is discussed. We review recent progress in the development of miRNA therapeutics aimed at elevating or decreasing levels of miRNAs.

Nicotine promotes tumor progression and epithelial-mesenchymal transition by regulating the miR-155-5p/NDFIP1 axis in pancreatic ductal adenocarcinoma

BACKGROUND

Nicotine, the major component of cigarette smoke, has been reported to promote pancreatic ductal adenocarcinoma (PDAC) growth and invasion. Deregulation of microRNA (miRNA) expression is found in many cancers, including PDAC. The effects of nicotine on miRNAs change in PDAC progression remain unknown.

METHODS

The effects of cigarette smoking/nicotine exposure on PDAC cell lines and tissues were evaluated. Quantitative real-time PCR and in situ hybridization assays were used to determine miR-155-5p expression in human PDAC tissue and cell lines upon cigarette smoking/nicotine exposure. Bioinformatics, loss-of-function experiments, luciferase reporter assay were performed to validate Nedd4 family interacting protein 1 (NDFIP1) as a direct target of miR-155-5p. The potentials of systemic miR-155-5p inhibitor-based therapy in overcoming nicotine exposure were evaluated in tumor xenograft model.

RESULTS

Nicotine promoted PDAC cells proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in a dose-response manner. MiR-155-5p was found to be highly expressed in PDAC cell lines and tissues upon cigarette smoking/nicotine exposure. Functional studies showed that miR-155-5p knockdown could override the enhancement of oncogenic activity due to nicotine exposure in vitro and in vivo by directly interacting with the 3' untranslated regions (UTRs) of NDFIP1.

CONCLUSIONS

These data demonstrate that nicotine-regulated miR-155-5p/NDFIP1 promotes tumor progression and EMT of PDAC.

Role of miR-155-5p expression and its involvement in apoptosis-related factors in thyroid follicular carcinoma

WHAT IS KNOWN AND OBJECTIVE

Thyroid follicular carcinoma is a malignant tumor from thyroid follicular epithelium, which is prone to involve capsular and vascular invasion. The present study was conducted in order to detect the expression of microRNA-155-5p (miR-155-5p) in thyroid follicular carcinoma with an attempt to analyze its involvement in apoptosis-related factors.

METHODS

Forty-five patients with thyroid follicular carcinoma made up the observation group and 45 patients with thyroid follicular adenoma were included into the control group. Tissues of thyroid follicular carcinoma and thyroid follicular adenoma were obtained from the patients, and analysed for expression of miR-155-5p by real-time fluorescence quantitative PCR (qPCR). The expression of cysteine-containing aspartic acid protein hydrolase-3 (Caspase-3) in thyroid follicular carcinoma was detected with the use of Western Blot analyses. Immunohistochemical method was used to detect the expression of B-cell lymphoma protein-2 (Bcl-2) in thyroid follicular carcinoma.

RESULTS

There was significant difference in the expression of miR-155-5p between the two groups (Observation vs Control: 1.46 ± 0.42 vs 0.98 ± 0.33 P < .05). The expression of miR-155-5p was significantly different in the maximum diameter of tumor, vascular invasion and neural invasion (maximum diameter of tumor <4 cm vs ≥4 cm: 1.36 ± 0.40 vs 1.68 ± 0.32, vascular invasion N vs Y: 1.35 ± 0.42 vs 1.69 ± 0.39, Neural invasion N vs Y: 1.35 ± 0.38 vs 1.70 ± 0.31 P < .05). However, there was no significant difference in the expression of miR-155-5p in terms of different gender, age and group with or without lymph node metastasis (P > .05). Based on survival analysis, patients with high expression of miR-155-5p experienced short survival time (median survival time was 45 months, P < .05). There was a negative correlation between miR-155-5p and Caspase-3 (r = -.50, P < .05). In addition, positive correlation was observed between miR-155-5p and Bcl-2 (r = .55, P < .05).

WHAT IS NEW AND CONCLUSION

There was increased expression of miR-155-5p in thyroid follicular carcinoma. The abnormal expression of miR-155-5p may be an independent prognostic factor for thyroid follicular carcinoma associated with cell apoptosis.

Combination of Rapamycin and MK-2206 Induced Cell Death via Autophagy and Necroptosis in MYCN-Amplified Neuroblastoma Cell Lines

Neuroblastoma (NB) is the most common pediatric malignant extracranial solid tumor. Despite multi-modality therapies, the emergence of drug resistance is an obstacle in the treatment of high-risk NB patients (with MYCN amplification). In our previous study, we found that rapamycin and MK-2206 synergistically induced cell death in MYCN-amplified cell lines but the mechanisms remained unclear. In our present study, either 3-MA or necroatatin-1 blocked the cell death induced by rapamycin and MK-2206, but z-VAD-fmk did not block this cell death. The expressions of autophagy markers (ATG5, ATG7, Beclin-1, LC3 B) and the necroptosis marker RIPK3 increased and another necroptosis marker RIPK1 decreased after the combination treatment of rapamycin and MK-2206, and were accompanied by the morphological characteristics of autophagy and necroptosis. In NB xenograft tumor tissues, the expressions of autophagy and necroptosis markers were consistent with observations in vitro. These data suggested that autophagy and necroptosis contributed to the cell death induced by rapamycin and MK-2206 in NB cells. To understand the role of MYCN in this process, MYCN expression was downregulated in MYCN-amplified cell lines (NGP, BE2) using siRNAs and was upregulated in MYCN non-amplified cell lines (AS, SY5Y) using plasmid. We found the cell death induced by rapamycin and MK-2206 was MYCN-dependent. We also found that the metabolic activity in NB cells was correlated with the expression level of MYCN. This study delineates the role of MYCN in the cell death induced by combination treatment of rapamycin and MK-2206 in MYCN-amplified NB cells.

MiR-155-5p exerts tumor-suppressing functions in Wilms tumor by targeting IGF2 via the PI3K signaling pathway

BACKGROUND

MicroRNA-155-5p (miR-155-5p) has been reported to play an oncogenic role in different human malignancies; however, its role in Wilms tumor (WT) remains unclear.

METHODS

Differentially expressed miRNAs (DE-miRNAs) and mRNAs (DEGs) in WT blood and tissues were identified by using miRNA microarray and RNA-sequencing. Bioinformatics prediction and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to predict the potential functions of DE-miRNAs. DE-miRNAs and DEGs in WT obtained from Gene Expression Omnibus (GEO) and Therapeutically Applicable Research to Generate Effective Treatments (TARGET) were identified by using the "edgeR" package. RT-qPCR was used to explore miR-155-5p and IGF2 expression and their clinical significance in WT specimens. A rhabdoid cell line (G401) and Ewing sarcoma cell line (SK-NEP-1) were used. Immunohistochemical staining, western blotting and dual-luciferase reporter assays were performed to study the mechanisms involved. The CCK-8, flow cytometry, wound healing and transwell assays were performed to identify the effects of miR-155-5p and IGF2 knockdown on cell proliferation, apoptosis, migration and invasion, respectively.

RESULTS

MiR-155-5p was downregulated in both blood and tissues from WT patients who did not receive chemotherapy before surgery but was upregulated in tissues from WT patients who had received chemotherapy before surgery. IGF2, PI3K, AKT and mTOR were found to be upregulated in WT tissues. Additionally, miR-155-5p and IGF2 were significantly correlated with TNM stage and lymphatic metastasis in WT patients. Molecular mechanism exploration indicated that IGF2 was downregulated by miR-155-5p via direct binding to its 3' untranslated region in cell lines. Furthermore, IGF2, PI3K, AKT and mTOR expression was inversely correlated with miR-155-5p expression, and PI3K, AKT and mTOR expression was positively correlated with IGF2 expression in cell culture. Functional studies demonstrated that miR-155-5p upregulation and IGF2 knockdown suppressed cell proliferation, migration and invasion and induced cell apoptosis. Moreover, the tumor-suppressing effects of miR-155-5p in cells were abrogated by miR-155-5p inhibitor treatment.

CONCLUSIONS

Taken together, these findings suggest that miR-155-5p functions as a tumor suppressor in WT through inactivating the PI3K/AKT/mTOR signaling pathway by directly targeting IGF2. Thus, miR-155-5p might be a novel therapeutic target for WT.

[Expression of miR-155-5p in Wilms tumor and its regulatory role in proliferation, migration and apoptosis of Wilms tumor cells in vitro]

OBJECTIVE

explore the expression of miR-155-5p in Wilms tumor and its effect in regulating the proliferation, migration and apoptosis of Wilms tumor cells.

METHODS

Specimens of tumor tissues and paired adjacent tissues were obtained from 40 patients with Wilms tumor for detection of the expression levels of miR-155-5p using RT-qPCR. Wilms tumor cell line G401 was transfected with miR-155-5p mimics and miR-155-5p inhibitor to induce miR-155-5p over-expression and its inhibition, respectively, and the changes in the cell proliferation, migration and apoptosis were assessed using cell counting kit-8 (CCK-8), wound healing assay and fl ow cytometry.

RESULTS

RT-qPCR showed that the expression of miR-155-5p decreased significantly in Wilms tumor tissues as compared with normal kidney tissues and was significantly associated with TNM stage (P < 0.05). In G401 cells, over-expression of miR-155-5p significantly inhibited the cell proliferation and migration and promoted cell apoptosis (P < 0.05), and down-regulation of miR-155-5p obviously enhanced the proliferation and migration and suppressed apoptosis of the cells (P < 0.05).

CONCLUSIONS

miR-155-5p is down-regulated in Wilms tumor and its expression level is correlated with TNM stage. miR-155-5p participates in the progression of Wilms tumor by inhibiting the proliferation and migration and promoting apoptosis of the tumor cells, and may serve as a novel biomarker for diagnosis, therapy and prognostic evaluation of Wilms tumor.

Extracellular vesicle (ECV)-modified polyethylenimine (PEI) complexes for enhanced siRNA delivery in vitro and in vivo

Extracellular vesicles (ECVs) are secreted cell-derived membrane particles involved in intercellular signaling and cell-cell communication. By transporting various bio-macromolecules, ECVs and in particular exosomes are relevant in various (patho-) physiological processes. ECVs are also released by cancer cells and can confer pro-tumorigenic effects. Their target cell tropism, effects on proliferation rates, natural stability in blood and immunotolerance makes ECVs particularly interesting as delivery vehicles. Polyethylenimines (PEIs) are linear or branched polymers which are capable of forming non-covalent complexes with small RNA molecules including siRNAs or antimiRs, for their delivery in vitro and in vivo. This study explores for the first time the combination of PEI-based nanoparticles with naturally occurring ECVs from different cell lines, for the delivery of small RNAs. ECV-modified PEI/siRNA complexes are analyzed by electron microscopy vs. ECV or complex alone. On the functional side, we demonstrate increased knockdown efficacy and storage stability of PEI/siRNA complexes upon their modification with ECVs. This is paralleled by enhanced tumor cell-inhibition by ECV-modified PEI/siRNA complexes targeting Survivin. Pre-treatment with various inhibitors of cellular internalization reveals alterations in cellular uptake mechanisms and biological activities of PEI/siRNA complexes upon their ECV modification. Extending our studies towards PEI-complexed antimiRs against miR-155 or miR-1246, dose-dependent cellular and molecular effects are enhanced in ECV-modified complexes, based on the de-repression of direct miRNA target genes. Differences between ECVs from different cell lines are observed regarding their capacity of enhancing PEI/siRNA efficacies, independent of the target cell line for transfection. Finally, an in vivo therapy study in mice bearing s.c. PC3 prostate carcinoma xenografts reveals marked inhibition of tumor growth upon treatment with ECV^PC3-modified PEI/siSurvivin complexes, based on profound target gene knockdown. We conclude that ECV-modification enhances the activity of PEI-based complexes, by altering pivotal physicochemical and biological nanoparticle properties.

Microarray expression profiles and bioinformatics analysis of mRNAs, lncRNAs, and circRNAs in the secondary temozolomide-resistant glioblastoma

Temozolomide is a first line anti-tumor drug used for the treatment of patients with Glioblastoma multiforme (GBM). However, the drug resistance to temozolomide limits its clinical application. Therefore, novel strategies to overcome chemoresistance are desperately needed for improved treatment of human GBM. Here, we simultaneously detected, for the first time, the expression profiles of mRNAs, lncRNAs, and circRNAs in three pairs of secondary temozolomide-resistant glioblastoma (STRG) and matched primary glioblastoma tissues by microarrays. Using these data, we discovered a total of 92 mRNA, 299 lncRNAs and 53 circRNAs were altered in human glioma tissue after chemotherapy with temozolomide. The functions of differentially expressed lncRNAs, circRNAs were annotated by analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The results showed that the highest enriched GO terms of the upregulated lncRNAs were embryonic forelimb morphogenesis (BP), extracellular space (CC), and serine-type endopeptidase activity (MF). Meanwhile, GO:0035360(BP), PRC1 complex (CC), and ubiquitin-protein transferase activity (MF) were the highest enriched GO terms targeted by downregulated lncRNAs. The NF-kappa B signaling pathway were significantly enriched in the STRG. However, circRNAs highest enriched GO term was viral process, chromosome, and protein transporter activity, respectively. KEGG pathway analysis showed that circRNAs in the network were enriched in ErbB signaling pathway. Furthermore, we also predicted the potential role of these differentially expressed ncRNAs and constructed a network of lncRNAs-mRNAs and circRNAs-miRNAs to show their interactions. After a series of bioinformatics analyses, we found that low expression of NONHSAT163779 and high expression of circ_0043949 are closely related to the chemoresistance of STRG. Our findings revealed the alteration of expression patterns of mRNAs, lncRNAs, and circRNAs in the secondary temozolomide-resistant glioblastoma for the first time. NONHSAT163779 and hsa_circ_0043949 might be potential therapeutic targets and prognostic biomarkers for the treatment of glioblastoma.