Tumor Suppressor microRNA Research Articles

Analyzing of colorectal cancerrelated genes and microRNAs expression profiles in response to probiotics Lactobacillus acidophilus and Saccharomyces cerevisiae in colon cancer cell lines.

Colorectal cancer is the world's third most frequent cancer and the fourth cause of mortality. Probiotics play an important function in preventing metastasis as well as the growth and proliferation of malignant cancer cells. The study investigated the anticancer effect of Lactobacillus acidophilus supernatant and Saccharomyces cerevisiae yeast on colorectal cell lines, including HT29 and SW480 as a colorectal cancer model. The extract from the Lactobacillus acidophilus and Saccharomyces cerevisiae standard probiotics were prepared, and probiotics characterization was confirmed by morphological and Biochemical tests. The viability of HT29 and SW480 colon cancer cell lines on effecting probiotic supernatant was evaluated by measuring the MTT colorimetric method. Comparison of the expression profile of several genes involved in apoptosis, cell cycle, and metastatic pathway in HT29 and SW480 cell lines with the treatment of probiotics extract showed an upregulation in the BAX, CASP3, and CASP9 and down regulation BCl-2, MMP2, and MMP9 genes. Also, a comparison of microRNA expression profiles indicated an increase of miR 34, 135, 25, 16, 195, 27, 98, let7 and a decrease of miR 9, 106b, 17, 21, 155, 221. The findings of this study indicate that probiotics can effectively suppress the proliferation of colorectal cancer cells and even reverse their development. Additionally, the study of cellular genes and miRNA profiles associated with colorectal cancer have demonstrated that our probiotics play a crucial role in CRC prevention by increasing the expression of tumor suppressor microRNAs and their target genes while decreasing oncogenes.

Clinical and morphological features and unsolved issues in diagnosis of aggressive forms of papillary thyroid carcinoma

Differentiated thyroid cancer (DTC) is a disease with a favorable clinical course and high survival rate compared to other epithelial tumors. The majority of DTC (up to 85 %) is represented by various subtypes of papillary thyroid cancer (PTC). Aggressive forms of PTC characterized by early lymphogenous and hematogenous metastasis, low avidity to radioiodine therapy (RIT), low relapse-free survival rates and high mortality rate compared to other types of PTC occur among them. Preoperative diagnosis of PTC is based on the results of ultrasound (US) examination and fine-needle aspiration biopsy (FNA) with cytological examination of the aspirate. At the same time, the capabilities of cytological examination in determining the histological type of PTC are limited and it does not allow to predict its aggressiveness and plan adequate treatment. Molecular genetic tests of the tumor cytological and morphological material are effective in prognosis of aggressiveness of PTC due to the determination of specific mutations in the BRAF, TERT, RAS genes and the quantitative expression of oncogenic and tumor suppressive microRNAs. Some of these indicators are already used in the morphological classification of tumors of the endocrine system. At the same time, there are contradictory data concerning the connection of the molecular genetic portrait of PTC, the clinical manifestations of its aggressiveness (extrathyroidal invasion, early metastasis, and radioiodine resistance) and its pathomorphological structure. We tried to summarize and analyze the literature data regarding the diagnosis of aggressive variants of PTC.

Revolutionizing cancer therapy: nanoformulation of miRNA-34 - enhancing delivery and efficacy for various cancer immunotherapies: a review.

Despite recent advancements in cancer therapies, challenges such as severe toxic effects, non-selective targeting, resistance to chemotherapy and radiotherapy, and recurrence of metastatic tumors persist. Consequently, there has been considerable effort to explore innovative anticancer compounds, particularly in immunotherapy, which offer the potential for enhanced biosafety and efficacy in cancer prevention and treatment. One such avenue of exploration involves the miRNA-34 (miR-34) family, known for its ability to inhibit tumorigenesis across various cancers. Dysregulation of miR-34 has been observed in several human cancers, and it is recognized as a tumor suppressor microRNA due to its synergistic interaction with the well-established tumor suppressor p53. However, challenges have arisen with the therapeutic application of miR-34a. These include its susceptibility to degradation by RNase in serum, limiting its ability to penetrate capillary endothelium and reach target cells, as well as reports of immunoreactive adverse reactions. Furthermore, unexpected side effects may occur, such as the accumulation of therapeutic miRNAs in healthy tissues due to interactions with serum proteins on nano-vector surfaces, nanoparticle breakdown in the bloodstream due to shearing stress, and unsuccessful extravasation of nanocarriers to target cells owing to interstitial fluid pressure. Despite these challenges, miR-34a remains a promising candidate for cancer therapy, and other members of the miR-34 family have also shown potential in inhibiting tumor cell proliferation. While the in vivo applications of miR-34b/c are limited, they warrant further exploration for oncotherapy. Recently, procedures utilizing nanoparticles have been developed to address the challenges associated with the clinical use of miR-34, demonstrating efficacy both in vitro and in vivo. This review highlights emerging trends in nanodelivery systems for miR-34 targeting cancer cells, offering insights into novel nanoformulations designed to enhance the anticancer therapeutic activity and targeting precision of miR-34. As far as current knowledge extends, no similar recent review comprehensively addresses the diverse nanoformulations aimed at optimizing the therapeutic potential of miR-34 in anticancer strategies.

Hsa_circ_0001583 fuels bladder cancer metastasis by promoting staphylococcal nuclease and tudor domain containing 1-mediated MicroRNA decay

Muscle-invasive and metastatic bladder cancer indicates extra worse prognosis. Accumulating evidence roots for the prominent role of circular RNAs(circRNAs) in bladder cancer, while the mechanisms linking circRNAs and bladder cancer metastasis remain limitedly investigated. Here, we identified a significantly upregulated circRNA candidate, hsa_circ_0001583, from online datasets. Validated by qRT-PCR, PCR, sanger sequencing, actinomycin D and RNase R digestion experiments, hsa_circ_0001583 was proved to be a genuine circular RNA with higher expression levels in bladder cancer tissue. Through gain and loss of function experiments, hsa_circ_0001583 exhibited potent migration and invasion powers both in vitro and in vivo. The staphylococcal nuclease and Tudor domain containing 1 (SND1) was identified as an authentic binding partner for hsa_circ_0001583 through RNA pulldown and RIP experiments. Elevated levels of hsa_circ_0001583 could bind more to SND1 and protect the latter from degradation. Rescue experiments demonstrated that such interaction-induced increased in SND1 levels in bladder cancer cells enabled the protein to pump its endonuclease activity, leading to the degradation of tumor-suppressing MicroRNAs (miRNAs) including miR-126-3p, the suppressor of Disintegrin And Metalloproteinase Domain-Containing Protein 9 (ADAM9), ultimately driving cells into a highly migrative and invasive state. In summary, our study is the first to highlight the upregulation of hsa_circ_0001583 in bladder cancer and its role in downregulating miR-126-3p by binding to and stabilizing the SND1 protein, thereby promoting bladder cancer cell migration and invasion. This study adds hsa_circ_0001583 to the pool of bladder cancer metastasis biomarkers and therapeutic targets.

Restoration of Altered Oncogenic and Tumor Suppressor microRNA Expression in Breast Cancer and Colorectal Cancer Cell using Epicatechin.

MicroRNAs (miRNA) are small non-coding RNAs that regulate the function of mRNA post-transcriptionally in a tissue-specific manner. miRNA expressions are heavily dysregulated in human cancer cells through various mechanisms, including epigenetic changes, karyotype abnormalities, and miRNA biogenesis defects. miRNAs may act as either oncogenes or tumor suppressors under different conditions. Epicatechin is a natural compound found in green tea which possesses antioxidant and antitumor properties. The objective of this study is to investigate the effect of epicatechin treatment on the expression level of several oncogenic and tumor suppressor miRNAs in breast and colorectal cancer cell lines (MCF7 and HT-29) and identify its mechanism of action. The MCF-7 and HT29 cells were treated with epicatechin for 24 hours and untreated cells were considered control cultures. miRNA was isolated and qRT-PCR was used to measure the expression profile changes of different oncogenic and tumor suppressor miRNAs. Furthermore, the mRNA expression profile was also screened at different concentrations of epicatechin. Our results showed several-fold changes in miRNAs expression level, which is cell line specific. Also, epicatechin at different concentrations induces biphasic changes in mRNA expression levels in both cell lines. Our findings first time demonstrated that epicatechin can reverse the expression of these miRNAs and may trigger the cytostatic effect at a lower concentration.

ALOX5AP is a new prognostic indicator in acute myeloid leukemia

BackgroundThe overexpression of ALOX5AP has been observed in many types of cancer and has been identified as an oncogene. However, its role in acute myeloid leukemia (AML) has not been extensively studied. This study aimed to identify the expression and methylation patterns of ALOX5AP in bone marrow (BM) samples of AML patients, and further explore its clinical significance.MethodsEighty-two de novo AML patients and 20 healthy donors were included in the study. Meanwhile, seven public datasets from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were included to confirm the alteration of ALOX5AP. Receiver operating characteristic (ROC) curve analysis was applied to determine the discriminative capacity of ALOX5AP expression to discriminate AML. The prognostic value of ALOX5AP was identified by the Kaplan–Meier method and log-rank test. It was further validated in four independent cohorts (n = 1186). Significantly different genes associated with ALOX5AP expression were subsequently compared by LinkedOmics, and Metascape database.ResultsThe level of ALOX5AP expression was significantly increased in bone marrow cells of AML patients compared with healthy donors (P < 0.05). ROC curve analysis suggested that ALOX5AP expression might be a potential biomarker to discriminate AML from controls. ALOX5AP overexpression was associated with decreased overall survival (OS) in AML according to the TCGA data (P = 0.006), which was validated by other four independent cohorts. DNA methylation levels of ALOX5AP were significantly lower in AML patients compared to normal samples (P < 0.05), as confirmed in the Diseasemeth database and the independent cohort GSE63409. ALOX5AP level was positively associated with genes with proleukemic effects such as PAX2, HOX family, SOX11, H19, and microRNAs that act as oncogenes in leukemia, such as miR125b, miR-93, miR-494, miR-193b, while anti-leukemia-related genes and tumor suppressor microRNAs such as miR-582, miR-9 family and miR-205 were negatively correlated.ConclusionALOX5AP overexpression, associated with its hypomethylation, predicts poorer prognosis in AML.

The Clinical Significance of MicroRNAs in Colorectal Cancer Signaling Pathways: A Review.

Colorectal carcinoma (colon and rectum) is currently considered among the most prevalent malignancies of Western societies. The pathogenesis and etiological mechanisms underlying colorectal cancer (CRC) development remain complex and heterogeneous. The homeostasis and function of normal human intestinal cells is highly regulated by microRNAs. Therefore, it is not surprising that mutations and inactivation of these molecules appear to be linked with progression of colorectal tumors. Recent studies have reported significant alterations of microRNA expression in adenomas and CRCs compared with adjacent normal tissues. This observed deviation has been proposed to correlate with the progression and survival of disease as well as with choice of optimal treatment and drug resistance. MicroRNAs can adopt either oncogenic or tumor-suppressive roles during regulation of pathways that drive carcinogenesis. Typically, oncogenic microRNAs termed oncomirs, target and silence endogenous tumor-suppressor genes. On the other hand, tumor-suppressive microRNAs are critical in downregulating genes associated with cell growth and malignant capabilities. By extensively evaluating robust studies, we have emphasized and distinguished a discrete set of microRNAs that can modulate tumor progression by silencing specific driver genes crucial in signaling pathways including Wnt/b-catenin, epidermal growth factor receptor, P53, mismatch repair DNA repair, and transforming-growth factor beta.

CSIG-05. A FIRST COMPREHENSIVE ANALYSIS OF TRANSCRIBED ULTRA CONSERVED REGIONS UNCOVERS IMPORTANT REGULATORY FUNCTIONS OF NOVEL NON-CODING TRANSCRIPTS IN GLIOMAS

Abstract Most glioma research has focused on protein-coding genes and much less on non-coding RNAs (ncRNAs). Transcribed Ultra-Conserved Regions (TUCRs) represent a severely understudied class of ncRNAs that are highly conserved across multiple species, including 100% conservation in mouse and rat genomes. These 481 transcripts are highly resistant to variation and are commonly deregulated in cancer, which suggests regulatory and functional importance when considered along with their high degree of conservation. We performed the first-ever analysis of TUCRs in glioblastoma (GBM) and low-grade gliomas (LGG). We first annotated all TUCRs in gliomas and described their genomic locations. We then showed that numerous TUCRs are highly expressed and deregulated in gliomas, and that this deregulation is associated with clinical outcomes. We then used a WGCNA pipeline to predict the functions for all TUCRs in gliomas by compiling gene ontology (GO) terms for coregulated genes. These data were used to identify several TUCRs that are potentially relevant to glioma initiation and progression. Of these, we investigated the most highly upregulated intergenic TUCR, uc.110, in vitro and in vivo in GBM. Knockdown of uc.110 in vitro reduced GBM cell accumulation and invasion and knockdown in vivo inhibited GBM xenograft growth and increased animal survival. We then performed mechanistic analyses of uc.110 and found that it regulates the expression of a Wnt pathway member, membrane frizzled-related protein (MFRP). We discovered that uc.110 sponges the tumor suppressor microRNA miR-544, which targets and inhibits MFRP, thus increasing the bioavailability of MFRP in GBM. This study is the first of its kind in gliomas. It shows important regulatory roles for TUCRs in gliomas and outlines novel methods for studying TUCRs in any disease context.

Salicylate induces AMPK and inhibits c-MYC to activate a NRF2/ARE/miR-34a/b/c cascade resulting in suppression of colorectal cancer metastasis

Aspirin and its active metabolite salicylate have emerged as promising agents for the chemoprevention of colorectal cancer (CRC). Moreover, aspirin suppresses the progression of established CRCs. However, the underlying molecular mechanisms are not completely understood. Here we found that salicylate induces the expression of the miR-34a and miR-34b/c genes, which encode tumor suppressive microRNAs, in a p53-independent manner. Salicylate activated AMPK, thereby activating NRF2, which directly induced miR-34a/b/c expression via ARE motifs. In addition, salicylate suppressed c-MYC, a known repressor of NRF2-mediated transactivation, via activating AMPK. The suppression of c-MYC by salicylate was necessary for NRF2-mediated activation of miR-34a/b/c. Inactivation of miR-34a/b/c largely abrogated the inhibitory effects of salicylate on migration, invasion and metastasis formation by CRC cells. In the future, aspirin and its derivates may be used therapeutically to activate miR-34a and miR-34b/c in tumors that have lost p53.

MiR-4649-5p acts as a tumor-suppressive microRNA in triple negative breast cancer by direct interaction with PIP5K1C, thereby potentiating growth-inhibitory effects of the AKT inhibitor capivasertib

BackgroundTriple negative breast cancer (TNBC) is a particularly aggressive and difficult-to-treat subtype of breast cancer that requires the development of novel therapeutic strategies. To pave the way for such developments it is essential to characterize new molecular players in TNBC. MicroRNAs (miRNAs) constitute interesting candidates in this regard as they are frequently deregulated in cancer and contribute to numerous aspects of carcinogenesis.Methods and resultsHere, we discovered that miR-4649-5p, a miRNA yet uncharacterized in breast cancer, is associated with better overall survival of TNBC patients. Ectopic upregulation of the otherwise very low endogenous expression levels of miR-4646-5p significantly decreased the growth, proliferation, and migration of TNBC cells. By performing whole transcriptome analysis and physical interaction assays, we were able to identify the phosphatidylinositol phosphate kinase PIP5K1C as a direct target of miR-4649-5p. Downregulation or pharmacologic inhibition of PIP5K1C phenocopied the growth-reducing effects of miR-4649-5p. PIP5K1C is known to play an important role in migration and cell adhesion, and we could furthermore confirm its impact on downstream PI3K/AKT signaling. Combinations of miR-4649-5p upregulation and PIP5K1C or AKT inhibition, using the pharmacologic inhibitors UNC3230 and capivasertib, respectively, showed additive growth-reducing effects in TNBC cells.ConclusionIn summary, miR-4649-5p exerts broad tumor-suppressive effects in TNBC and shows potential for combined therapeutic approaches targeting the PIP5K1C/PI3K/AKT signaling axis.

Therapeutic value of restoration of tumor suppressor microRNAs in the development of lung cancer

Therapeutic value of restoration of tumor suppressor microRNAs in the development of lung cancer

Targeting FGFRs by pemigatinib induces G1 phase cell cycle arrest, cellular stress and upregulation of tumor suppressor microRNAs

BackgroundFibroblast growth factor receptor (FGFR) gene family alterations are found in several cancers, indicating their importance as potential therapeutic targets. The FGFR-tyrosine kinase inhibitor (TKI) pemigatinib has been introduced in the treatment of advanced cholangiocarcinoma and more recently for relapsed or refractory myeloid/lymphoid neoplasms with FGFR2 and FGFR1 rearrangements, respectively. Several clinical trials are currently investigating the possible combination of pemigatinib with immunotherapy.In this study, we analyzed the biological and molecular effects of pemigatinib on different cancer cell models (lung, bladder, and gastric), which are currently objective of clinical trial investigations.MethodsNCI-H1581 lung, KATO III gastric and RT-112 bladder cancer cell lines were evaluated for FGFR expression by qRT-PCR and Western blot. Cell lines were treated with Pem and then characterized for cell proliferation, apoptosis, production of intracellular reactive oxygen species (ROS), and induction of senescence. The expression of microRNAs with tumor suppressor functions was analyzed by qRT-PCR, while modulation of the proteins coded by their target genes was evaluated by Western blot and mRNA. Descriptive statistics was used to analyze the various data and student’s t test to compare the analysis of two groups.ResultsPemigatinib exposure triggered distinct signaling pathways and reduced the proliferative ability of all cancer cells, inducing G1 phase cell cycle arrest and strong intracellular stress resulting in ROS production, senescence and apoptosis. Pemigatinib treatment also caused the upregulation of microRNAs (miR-133b, miR-139, miR-186, miR-195) with tumor suppressor functions, along with the downregulation of validated protein targets with oncogenic roles (c-Myc, c-MET, CDK6, EGFR).ConclusionsThese results contribute to clarifying the biological effects and molecular mechanisms mediated by the anti-FGFR TKI pemigatinib in distinct tumor settings and support its exploitation for combined therapies.

TGFβ-induced circLTBP2 predicts a poor prognosis in intrahepatic cholangiocarcinoma and mediates gemcitabine resistance by sponging miR-338-3p

Intrahepatic cholangiocarcinoma (iCCA) is a deadly cancer worldwide with an increasing incidence and limited therapeutic options. Therefore, there is an urgent need to open the field to new concepts for identifying clinically relevant therapeutic targets and biomarkers. Here, we explored the role and the clinical relevance of circular RNA (circRNA) circLTBP2 in iCCA. Transforming growth factor β (TGFβ)-regulated circRNAs were identified by dedicated microarrays in human HuCC-T1 iCCA cell line, and their clinical relevance was evaluated in independent cohorts of patients. Gain and loss of function of circLTBP2 combined with functional tests was performed invitro and invivo in mice. RNA pulldown, microRNA sequencing, and RNA immunoprecipitation were performed to explore the sponging activity of circLTBP2. CircLTBP2 (has_circ_0032603) was identified as a novel TGFβ-induced circRNA in several cholangiocarcinoma cell lines. CircLTBP2 promotes tumour cell proliferation, migration, and resistance to gemcitabine-induced apoptosis invitro and tumour growth invivo. Mechanistically, circLTBP2 acts as a competitive RNA regulating notably the activity of the tumour suppressor microRNA miR-338-3p, leading to the overexpression of its pro-metastatic targets. The restoration of miR-338-3p levels in iCCA cells reversed the pro-tumourigenic effects driven by circLTBP2, including the resistance to gemcitabine-induced apoptosis. In addition, circLTBP2 expression predicted a reduced survival, as detected in not only tumour tissues but also serum extracellular vesicles isolated from patients with iCCA. CircLTBP2 is a novel effector of the pro-tumourigenic arm of TGFβ and a clinically relevant biomarker easily detected from liquid biopsies in iCCA. Intrahepatic cholangiocarcinoma (iCCA) is an aggressive cancer with limited therapeutic options. Opening the field to new concepts is urgently needed to improve the survival of patients. Here, we evaluated the role and the clinical relevance of circular RNA. We report that TGFβ-induced circLTBP2 contributes to CCA carcinogenesis and may constitute a clinically relevant prognostic biomarker detected in liquid biopsies.

A first-in-class fully modified version of miR-34a with outstanding stability, activity, and anti-tumor efficacy

Altered by defects in p53, epigenetic silencing, and genomic loss, the microRNA miR-34a represents one of the most clinically relevant tumor-suppressive microRNAs. Without question, a striking number of patients with cancer would benefit from miR-34a replacement, if poor miR-34a stability, non-specific delivery, and delivery-associated toxicity could be overcome. Here, we highlight a fully modified version of miR-34a (FM-miR-34a) that overcomes these hurdles when conjugated to a synthetically simplistic ligand. FM-miR-34a is orders of magnitude more stable than a partially modified version, without compromising its activity, leading to stronger repression of a greater number of miR-34a targets. FM-miR-34a potently inhibited proliferation and invasion, and induced sustained downregulation of endogenous target genes for >120 h following in vivo delivery. In vivo targeting was achieved through conjugating FM-miR-34a to folate (FM-FolamiR-34a), which inhibited tumor growth leading to complete cures in some mice. These results have the ability to revitalize miR-34a as an anti-cancer agent, providing a strong rationale for clinical testing.

Long Noncoding RNA PVT1 Promotes Prostate Cancer Metastasis by Increasing NOP2 Expression via Targeting Tumor Suppressor MicroRNAs [Retraction

[This retracts the article DOI: 10.2147/OTT.S242441.].

MiR-30e-5p regulates leukemia stem cell self-renewal through the Cyb561/ROS signaling pathway.

Leukemia stem cells (LSC) represent a crucial and rare subset of cells present in acute myeloid leukemia (AML); they play a pivotal role in the initiation, maintenance, and relapse of this disease. Targeting LSC holds great promise for preventing AML relapse and improving long-term outcomes. However the precise molecular mechanisms governing LSC self-renewal are still poorly understood. Here, we present compelling evidence that the expression of miR-30e-5p, a potential tumor-suppressive microRNA, is significantly lower in AML samples than in healthy bone marrow samples. Forced expression of miR- 30e effectively inhibits leukemogenesis, impairs LSC self-renewal, and delays leukemia progression. Mechanistically, Cyb561 acts as a direct target of miR-30e-5p in LSC, and its deficiency restricts the self-renewal of LSC by activating reactive oxygen series signaling and markedly prolongs recipients' survival. Moreover, genetic or pharmacological overexpression of miR-30e-5p or knockdown of Cyb561 suppresses the growth of human AML cells. In conclusion, our findings establish the crucial role of the miR-30e-5p/Cyb561/ROS axis in finely regulating LSC self-renewal, highlighting Cyb561 as a potential therapeutic target for LSC-directed therapies.

MicroRNA-1289 Functions as a Novel Tumor Suppressor in Oral Squamous Cell Carcinoma.

Recently, numerous tumor-suppressive microRNAs (TS-miRs) have been identified in human malignancies. Here, we attempted to identify novel TS-miRs in oral squamous cell carcinoma (OSCC). First, we transfected human OSCC cells individually with 968 synthetic miRs mimicking human mature miRs individually, and the growth of these cells was evaluated using the WST-8 assay. Five miR mimics significantly reduced the cell growth rate by less than 30%, and the miR-1289 mimic had the most potent growth inhibitory effect among these miRs. Subsequently, we assessed the in vivo growth-inhibitory effects of miR-1289 using a mouse model. The administration of the miR-1289 mimic-atelocollagen complex significantly reduced the size of subcutaneously xenografted human OSCC tumors. Next, we investigated the expression of miR-1289 in OSCC tissues using reverse transcription-quantitative PCR. The expression level of miR-1289 was significantly lower in OSCC tissues than in the adjacent normal oral mucosa. Furthermore, 15 genes were identified as target genes of miR-1289 via microarray and Ingenuity Pathway Analysis (IPA) microRNA target filtering. Among these genes, the knockdown of magnesium transporter 1 (MAGT1) resulted in the most remarkable cell growth inhibition in human OSCC cells. These results suggested that miR-1289 functions as a novel TS-miR in OSCC and may be a useful therapeutic tool for patients with OSCC.

Trigger-activated autonomous DNA machine for amplified liver cancer biomarker microRNA21 imaging.

MicroRNA-21 (miRNA-21) is a kind of RNA that exists in biological fluids such as blood, urine and saliva. It has over expression in liver cancer and has different expression in different stages of cancer. However, due to the characteristics of small base number, short length, low abundance and easy degradation of miRNA-21, the detection of miRNA-21 is a challenging subject. Visualization, sensitive, specific and stable detection of tumor suppressor or oncogene microRNAs (miRNAs) remains challenging and is highly significant for clinical diagnostics. To solve this problem, we have developed a target-triggered hybridization assembly DNA machine for intracellular miRNA imaging based on strand displacement amplification (SDA) and branched hybridization chain reaction (B-HCR). In this approach, the target miRNA could hybridize with the template probe to trigger the SDA, resulting in the formation of nicked fragments (NFs) that hybridized with hairpin probe1 (HP1). The opened HP1 could hybridize with hairpin probe2 (HP2), leading to the self-assembly of hyperbranched DNA nanostructures through B-HCR. As expected, the newly developed method exhibits a detection limit down to 11.3pM miRNA-21 and achieves high selectivity toward miRNA-21 against other interfering miRNAs. Due to its superior sensitivity and selectivity, our method can be further used to detect miRNA-21 in human serum samples. By taking advantage of intelligent design, the proposed method was also used for image miRNA-21 expression levels in different cell lines. This method shows a broad application in clinical diagnosis.

Delivery of miR-200c-3p Using Tumor-Targeted Mesoporous Silica Nanoparticles for Breast Cancer Therapy.

Despite advances in breast cancer treatment, it remains the leading cause of cancer-related death in women worldwide. In this context, microRNAs have emerged as potential therapeutic targets but still present some limitations for in vivo applications. Particularly, miR-200c-3p is a well-known tumor suppressor microRNA that inhibits tumor progression and metastasis in breast cancer through downregulating ZEB1 and ZEB2. Based on the above, we describe the design and validation of a nanodevice using mesoporous silica nanoparticles for miR-200c-3p delivery for breast cancer treatment. We demonstrate the biocompatibility of the synthesized nanodevices as well as their ability to escape from endosomes/lysosomes and inhibit tumorigenesis, invasion, migration, and proliferation of tumor cells in vitro. Moreover, tumor targeting and effective delivery of miR-200c-3p from the nanoparticles in vivo are confirmed in an orthotopic breast cancer mouse model, and the therapeutic efficacy is also evidenced by a decrease in tumor size and lung metastasis, while showing no signs of toxicity. Overall, our results provide evidence that miR-200c-3p-loaded nanoparticles are a potential strategy for breast cancer therapy and a safe and effective system for tumor-targeted delivery of microRNAs.

CREB1 activation promotes human papillomavirus oncogene expression and cervical cancer cell transformation.

Human papillomaviruses (HPVs) infect the oral and anogenital mucosa and can cause cancer. The high-risk (HR)-HPV oncoproteins, E6 and E7, hijack cellular factors to promote cell proliferation, delay differentiation and induce genomic instability, thus predisposing infected cells to malignant transformation. cAMP response element (CRE)-binding protein 1 (CREB1) is a master transcription factor that can function as a proto-oncogene, the abnormal activity of which is associated with multiple cancers. However, little is known about the interplay between HPV and CREB1 activity in cervical cancer or the productive HPV lifecycle. We show that CREB is activated in productively infected primary keratinocytes and that CREB1 expression and phosphorylation is associated with the progression of HPV+ cervical disease. The depletion of CREB1 or inhibition of CREB1 activity results in decreased cell proliferation and reduced expression of markers of epithelial to mesenchymal transition, coupled with reduced migration in HPV+ cervical cancer cell lines. CREB1 expression is negatively regulated by the tumor suppressor microRNA, miR-203a, and CREB1 phosphorylation is controlled through the MAPK/MSK pathway. Crucially, CREB1 directly binds the viral promoter to upregulate transcription of the E6/E7 oncogenes, establishing a positive feedback loop between the HPV oncoproteins and CREB1. Our findings demonstrate the oncogenic function of CREB1 in HPV+ cervical cancer and its relationship with the HPV oncogenes.