Non-Specific Blocking of miR-17-5p Guide Strand in Triple Negative Breast Cancer Cells by Amplifying Passenger Strand Activity

IGF1R-Targeted Delivery of a Bridged Nucleic Acid Oligonucleotide-Peptide Conjugate for MicroRNA-21 Inhibition in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC), defined by the absence of ER, PR, and Her2, impacts over 46,000 U.S. women annually, disproportionately affecting minority ethnic groups and individuals with BRCA1 mutations. Despite advancements such as PARP inhibitors, TNBC remains highly aggressive, with frequent recurrences and a 50% mortality rate within four years, underscoring the urgent need for more effective targeted therapies. MicroRNAs (miRNAs) represent a novel therapeutic approach. In TNBC, overexpressed miR-21 drives tumor progression, immune evasion, treatment resistance, and metastasis. Targeted miR-21 inhibition could curb these effects while minimizing harm to normal cells. We developed a peptide-conjugated miR-21 inhibitor targeting TNBC cells via the overexpressed IGF1 receptor (IGF1R), associated with poor prognosis. Using aminomethyl-bridged nucleic acid (BNA) chemistry, a serum-stable, low-toxicity anti-miR-21 RNA analog was created and tested for its effects on TNBC cell proliferation, apoptosis, tumor suppressor expression, and immune checkpoint regulation. Conjugation to an IGF1 peptide analog improved delivery, demonstrating tumor-specific biodistribution, efficacy, and safety in TNBC-bearing mice. The miR-21 inhibitor-peptide conjugate reduced proliferation, induced apoptosis, elevated tumor suppressors, and suppressed immune checkpoints in TNBC cell lines. In vivo , it targeted tumors, halted growth, and showed no liver or kidney toxicity, supporting its potential as a targeted, low-toxicity TNBC therapy.

Programmed cell death 4: A novel player in the pathogenesis of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a pathological condition recognized by menstrual cycle irregularities, androgen excess, and polycystic ovarian morphology, affecting a significant proportion of women of childbearing age and accounting for the most prevalent cause of anovulatory sterility. In addition, PCOS is frequently accompanied by metabolic and endocrine disturbances such as obesity, dyslipidemia, insulin resistance, and hyperinsulinemia, indicating the multiplicity of mechanisms implicated in the progression of PCOS. However, the exact pathogenesis of PCOS is yet to be elucidated. Programmed cell death 4 (PDCD4) is a ubiquitously expressed protein that contributes to the regulation of various cellular processes, including gene expression, cell cycle progression, proliferation, and apoptosis. Despite some disparities concerning its exact cellular effects, PDCD4 is generally characterized as a protein that inhibits cell cycle progression and proliferation and instead drives the cell into apoptosis. The apoptosis of granulosa cells (GCs) is speculated to take a major part in the occurrence and progression of PCOS by ceasing antral follicle development and compromising oocyte competence. Given the possible involvement of GC apoptosis in the progression of PCOS, as well as the contribution of PDCD4 to the regulation of cell apoptosis and the development of metabolic diseases, the current review aimed to discuss whether or how PDCD4 can play a role in the pathogenesis of PCOS by affecting GC apoptosis.

Dissecting the Roles of PDCD4 in Breast Cancer

The human programmed cell death 4 (PDCD4) gene was mapped at chromosome 10q24 and encodes the PDCD4 protein comprised of 469 amino acids. PDCD4 inhibits protein translation PDCD4 inhibits protein translation to suppress tumor progression, and its expression is frequently decreased in breast cancer. PDCD4 blocks translation initiation complex by binding eIF4A via MA-3 domains or by directly binding 5’ mRNA internal ribosome entry sites with an RNA binding domain to suppress breast cancer progression and proliferation. Numerous regulators and biological processes including non-coding RNAs, proteasomes, estrogen, natural compounds and inflammation control PDCD4 expression in breast cancer. Loss of PDCD4 expression is also responsible for drug resistance in breast cancer. HER2 activation downregulates PDCD4 expression by activating MAPK, AKT, and miR-21 in aromatase inhibitor-resistant breast cancer cells. Moreover, modulating the microRNA/PDCD4 axis maybe an effective strategy for overcoming chemoresistance in breast cancer. Down-regulation of PDCD4 is significantly associated with short overall survival of patients, which suggests that PDCD4 may be an independent prognostic marker for breast cancer.

Progress of non-coding RNAs in triple-negative breast cancer

Non-coding RNAs (ncRNAs) include miRNA, lncRNA, and circRNA. NcRNAs are involved in multiple biological processes, including chromatin remodeling, signal transduction, post-transcriptional modification, cell autophagy, carbohydrate metabolism, and cell cycle regulation. Triple negative breast cancer (TNBC) is notorious for high invasiveness and metastasis, poor prognosis, and high mortality, and it is the most malignant breast cancer, while the effective targets for TNBC treatment are still lacking. NcRNAs act as oncogenes or suppressor genes, as well as promote or inhibit the occurrence and development of TNBC. Here, we reviewed some important miRNAs, lncRNAs, circRNAs, their target(s) and molecular mechanisms in TNBC. It is benefited to understand the occurrence and development of TNBC, further some ncRNAs might be potential targets for TNBC treatment.

A bird's eye view of the advanced approaches and strategies for overshadowing triple negative breast cancer

Triple negative breast cancer (TNBC) is one of the most aggressive form of breast cancer. It is characterized by the absence of estrogen, progesterone and human epidermal growth factor receptors. The main issue with TNBC is that it exhibits poor prognosis, high risk of relapse, short progression-free survival and low overall survival in patients. This is because the conventional therapy used for managing TNBC has issues pertaining to poor bioavailability, lower cellular uptake, increased off-target effects and development of resistance. To overcome such pitfalls, several other approaches are explored. In this context, the present manuscript showcases three of the most widely used approaches which are (i) nanotechnology-based approach; (ii) gene therapy approach and (iii) Phytochemical-based approach. The ultimate focus is to present and explain the insightful reports based on these approaches. Further, the review also expounds on the identified molecular targets and novel targeting ligands which are explored for managing TNBC effectively. Thus, in a nutshell, the review tries to highlight these existing treatment approaches which might inspire for future development of novel therapies with a potential of overshadowing TNBC.

MicroRNA Biomarkers for Infectious Diseases: From Basic Research to Biosensing

In the pursuit of improved diagnostic tests for infectious diseases, several classes of molecules have been scrutinized as prospective biomarkers. Small (18–22 nucleotide), non-coding RNA transcripts called microRNAs (miRNAs) have emerged as promising candidates with extensive diagnostic potential, due to their role in numerous diseases, previously established methods for quantitation and their stability within biofluids. Despite efforts to identify, characterize and apply miRNA signatures as diagnostic markers in a range of non-infectious diseases, their application in infectious disease has advanced relatively slowly. Here, we outline the benefits that miRNA biomarkers offer to the diagnosis, management, and treatment of infectious diseases. Investigation of these novel biomarkers could advance the use of personalized medicine in infectious disease treatment, which raises important considerations for validating their use as diagnostic or prognostic markers. Finally, we discuss new and emerging miRNA detection platforms, with a focus on rapid, point-of-care testing, to evaluate the benefits and obstacles of miRNA biomarkers for infectious disease.

A miRNA-based diagnostic model predicts resectable lung cancer in humans with high accuracy

Lung cancer, the leading cause of cancer death worldwide, is most frequently detected through imaging tests. In this study, we investigated serum microRNAs (miRNAs) as a possible early screening tool for resectable lung cancer. First, we used serum samples from participants with and without lung cancer to comprehensively create 2588 miRNAs profiles; next, we established a diagnostic model based on the combined expression levels of two miRNAs (miR-1268b and miR-6075) in the discovery set (208 lung cancer patients and 208 non-cancer participants). The model displayed a sensitivity of 99% and specificity of 99% in the validation set (1358 patients and 1970 non-cancer participants) and exhibited high sensitivity regardless of histological type and pathological TNM stage of the cancer. Moreover, the diagnostic index markedly decreased after lung cancer resection. Thus, the model we developed has the potential to markedly improve screening for resectable lung cancer.

Asakura, Kadota et al. demonstrate the diagnostic potential of serum microRNAs for resectable lung cancer. Their diagnostic model based on the combined expression levels of two miRNAs predicts resectable lung cancer with 99% sensitivity, regardless of histological types and pathological stages of cancer, suggesting its promising, diagnostic utility.

MicroRNA delivery through nanoparticles

MicroRNAs (miRNAs) are attracting a growing interest in the scientific community due to their central role in the etiology of major diseases. On the other hand, nanoparticle carriers offer unprecedented opportunities for cell specific controlled delivery of miRNAs for therapeutic purposes. This review critically discusses the use of nanoparticles for the delivery of miRNA-based therapeutics in the treatment of cancer and neurodegenerative disorders and for tissue regeneration. A fresh perspective is presented on the design and characterization of nanocarriers to accelerate translation from basic research to clinical application of miRNA-nanoparticles. Main challenges in the engineering of miRNA-loaded nanoparticles are discussed, and key application examples are highlighted to underline their therapeutic potential for effective and personalized medicine.

MiR-17-5p may serve as a novel predictor for breast cancer recurrence

BACKGROUND

Recurrence following conventional therapies in patients with breast cancer is a major cause of morbidity and mortality. This study aimed to investigate potential predictive biomarkers for breast cancer recurrence especially microRNAs (miRNAs).

METHODS

The primary breast cancer patients who were scheduled to undergo curative resection in our hospital from May 2007 to May 2012 were recruited in this study. Clinical and pathological characteristics were compared in patients with or without recurrence. The expressions of tissue miRNAs by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) were also analyzed in patients with recurrence or not. Multivariate Cox analysis was fit to evaluate potential predicative factors for breast cancer recurrence. Kaplan-Meier plots was conducted to further evaluate the association between miR-17-5p expression and recurrence-free survival (RFS).

RESULTS

A total of 133 consecutive patients were enrolled into the final analysis and 29 of them have suffered recurrence within 5 years after the operation. Our results revealed tissue miR-17-5p expression as an independent risk factor for breast cancer recurrence (HR: 4.45; 95% CI: 1.58-11.53, P= 0.015). Patients with a higher miR-17-5p expression was significantly associated with a worse 5-year RFS by log-rank test (p= 0.017).

CONCLUSIONS

This study suggested that miR-17-5p might be a useful predictive factor for breast cancer recurrence.

Quantifying the prognostic significance of microRNA-17/17-5P in cancers: a meta-analysis based on published studies

Objective

The aim of this study was to investigate the prognostic value of mircoRNA-17 and mircoRNA-17-5P (miR-17/17-5P) in patients with cancer.

Materials and methods

We conducted a comprehensive search on published literature following the guidelines of the meta-analysis of observational studies in epidemiology group for design, implementation, and reporting. The methodological qualities for included studies were assessed using the quality in prognosis studies. The pooled hazard ratios (HRs) with 95% CIs for overall survival (OS) and progression-free survival/recurrence-free survival/disease-free survival (PFS/RFS/DFS) were calculated to appraise the associations between miR-17/17-5P expression and cancer prognosis.

Results

A total of 21 studies involving 2099 subjects were analyzed in evidence synthesis. The results showed that high expression of miR-17 was associated with poor OS (HR=2.14; 95% CI: 1.69-2.71, P<0.001) in patients with cancer, especially in Caucasian (HR=2.23; 95% CI: 1.58-3.14, P<0.001) and digestive tract cancer (HR=1.29, 95% CI: 1.03-1.63, P=0.03), and miR-17 expression was significantly correlated with PFS/RFS in cancer patients (HR=1.69, 95% CI: 1.29-2.22, P<0.001). miR-17-5P overexpression was significantly linked with poor OS in cancer patients (HR=1.66; 95% CI: 1.31-2.09, P=0.00), especially in Asian (HR=1.81; 95% CI: 1.37-2.40, P<0.001), digestive tract cancer (HR=1.80; 95% CI: 1.29-2.50, P<0.001), and serum sample (HR=1.76; 95% CI: 1.29-2.41, P<0.001). miR-17-5P expression was significantly associated with DFS in cancer patients (HR=1.58, 95% CI: 1.07-2.35, P=0.02).

Conclusion

High expression of miR-17 and miR-17-5P are significantly associated with poor survival in patients with cancer. This indicated that miR-17/17-5P may be a novel prognostic indicator in cancer.

Micelle-like nanoparticles as siRNA and miRNA carriers for cancer therapy

Gene therapy has emerged as an alternative in the treatment of cancer, particularly in cases of resistance to chemo and radiotherapy. Different approaches to deliver genetic material to tumor tissues have been proposed, including the use of small non-coding RNAs due to their multiple mechanisms of action. However, such promise has shown limits in in vivo application related to RNA's biological instability and stimulation of immunity, urging the development of systems able to overcome those barriers. In this review, we discuss the use of RNA interference in cancer therapy with special attention to the role of siRNA and miRNA and to the challenges of their delivery in vivo. We introduce a promising class of drug delivery system known as micelle-like nanoparticles and explore their synthesis and advantages for gene therapy as well as the recent findings in in vitro, in vivo and clinical studies.

MiR-17-5p enhances pancreatic cancer proliferation by altering cell cycle profiles via disruption of RBL2/E2F4-repressing complexes

The members of the miR-17-92 cluster are upregulated in various cancers and function as a cluster of oncogenic miRNA. Our study characterized a new function of miR-17-5p, a member of the miR-17-92 cluster, in regulating cell proliferation in pancreatic cancer. Our results indicate that miR-17-5p was up-regulated in pancreatic adenocarcinoma and directly targeted the retinoblastoma-like protein 2 (RBL2), a tumor suppressor belonging to the Rb family. High levels of miR-17-5p and low levels of RBL2 were associated with poor prognosis. RBL2 interacted with the transcription factor E2F4 and bound to the promoter regions of the E2F target genes. Disruption of the RBL2/E2F4 complex by miR-17-5p overexpression shifted the activity of E2F from gene repressing to gene activating, which induced cell cycle entry and proliferation. These results suggest that miR-17-5p promoted proliferation in pancreatic ductal adenocarcinoma cells (PDAC), and altered cell cycle profiles in vivo and in vitro, by disrupting the RBL2/E2F4-associated gene repressing complexes via direct targeting of RBL2. The new regulatory network, involving miR-17-5p and RBL2, emerges as a new target of PDAC treatment.

Differential expression of exosomal miRNAs between breast cancer patients with and without recurrence

BACKGROUND

Exosomal microRNAs (miRNAs) are promising candidate biomarkers for diagnosis or prognosis for breast cancer. We investigated the prognostic role of exosomal miRNAs in serum samples derived from patients with breast cancer and compared miRNA expression between serum and tumor tissues.

METHODS

The miRNA profile derived from exosome between breast cancer patients with recurrence (n = 16) and without recurrence (n = 16) were compared by miRNA PCR array. Further, we examined the expression of miRNAs derived from tissues in the patients with breast cancer with (n = 35) and without recurrence (n = 39) by qRT-PCR.

RESULTS

Of 384 miRNAs, three miRNAs (miR-338-3p, miR-340-5p, and miR-124-3p) were significantly upregulated and eight (miR-29b-3p, miR-20b-5p, miR-17-5p, miR-130a-3p, miR-18a-5p, miR-195-5p, miR-486-5p, and miR-93-5p) were significantly downregulated in the patients with recurrence. We evaluated the expression of the miRNAs in tumor tissues. The patients with recurrence had higher levels of miR-340 at their primary site as well as in the serum. In contrast, miR-195-5p, miR-17-5p, miR-93-5p, and miR-130a-3p, derived from tumor tissues that were downregulated in the serum from patients with recurrence, were higher in the patients with recurrence than in those with no recurrence. In logistic regression analysis, miR-340-5p, miR-17-5p, miR-130a-3p, and miR-93-5p were significantly associated with recurrence.

CONCLUSIONS

Several exosomal miRNAs may be useful biomarkers to predict breast cancer recurrence. We show the different expression patterns of miRNAs between tumor tissues and serum. These findings may suggest selective mechanism of release of exosomal miRNAs by cancer cells to regulate their progression.

OncomiR-17-5p: alarm signal in cancer?

Soon after microRNAs entered the stage as novel regulators of gene expression, they were found to regulate -and to be regulated by- the development, progression and aggressiveness of virtually all human types of cancer. Therefore, miRNAs in general harbor a huge potential as diagnostic and prognostic markers as well as potential therapeutic targets in cancer. The miR-17-92 cluster was found to be overexpressed in many human cancers and to promote unrestrained cell growth, and has therefore been termed onco-miR-1. In addition, its expression is often dysregulated in many other diseases. MiR-17-5p, its most prominent member, is an essential regulator of fundamental cellular processes like proliferation, autophagy and apoptosis, and its deficiency is neonatally lethal in the mouse. Many cancer types are associated with elevated miR-17-5p expression, and the degree of overexpression might correlate with cancer aggressiveness and responsiveness to chemotherapeutics - suggesting miR-17-5p to be an alarm signal. Liver, gastric or colorectal cancers are examples where miR-17-5p has been observed exclusively as an oncogene, while, in other cancer types, like breast, prostate and lung cancer, the role of miR-17-5p is not as clear-cut, and it might also act as tumor-suppressor. However, in all cancer types studied so far, miR-17-5p has been found at elevated levels in the circulation. In this review, we therefore recapitulate the current state of knowledge about miR-17-5p in the context of cancer, and suggest that elevated miR-17-5p levels in the plasma might be a sensitive and early alarm signal for cancer ('alarmiR'), albeit not a specific alarm for a specific type of tumor.

miR-17 as a diagnostic biomarker regulates cell proliferation in breast cancer

Background

MicroRNAs (miRNAs) have been shown to be involved in the initiation and progression of cancers in the literature. In this study, we aimed to evaluate the clinicopathological role of miR-17 in breast cancer.

Materials and methods

The expression of miR-17 was measured in 132 breast cancer tissues and paired adjacent normal tissues by using real-time quantitative polymerase chain reaction. The association between miR-17 expression levels and clinicopathological parameters was also analyzed. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and flow cytometry assays were used to investigate the role of miR-17 in the regulation of breast cancer cells.

Results

The expression of miR-17 was remarkably increased in breast cancer tissues and cell lines. Clinical association analysis revealed that a high expression of miR-17 was prominently associated with poor survival time in breast cancer. Overexpression of miR-17 promoted cell proliferation and induced tumor growth.

Conclusion

Our findings clarified that the upregulation of miR-17 played a vital role in breast cancer progression and suggested that miR-17 could be used as a prognostic biomarker for breast cancer.

Brown Seaweed Fucoidan Inhibits Cancer Progression by Dual Regulation of mir-29c/ADAM12 and miR-17-5p/PTEN Axes in Human Breast Cancer Cells

In this study, we observed that brown seaweed fucoidan inhibited human breast cancer progression by upregulating microRNA (miR)-29c and downregulating miR-17-5p, thereby suppressing their target genes, a disintegrin and metalloproteinase 12 (ADAM12) and phosphatase and tensin homolog (PTEN), respectively. Moreover, fucoidan reduced the luciferase activity of 3'-untranslated region reporter; treatment of cells with the miR-29c mimic or miR-17-5p inhibitor also produced similar results. These effects of fucoidan inhibited the epithelial-mesenchymal transition in breast cancer cells, as evidenced by an increase in E-cadherin and a drop in N-cadherin, and inhibited breast cancer cell survival, as evidenced by the activation of the phosphoinositide 3-kinase/Akt pathway. Taken together, these findings demonstrate that fucoidan inhibits breast cancer progression by regulating the miR-29c/ADAM12 and miR-17-5p/PTEN axes. Fucoidan is a potential chemopreventive/chemotherapeutic agent for breast cancer.

Inhibition of miR-21 rescues liver regeneration after partial hepatectomy in ethanol-fed rats

Liver regeneration is a clinically significant tissue repair process that is suppressed by chronic alcohol intake through poorly understood mechanisms. Recently, microRNA-21 (miR-21) has been suggested to serve as a crucial microRNA (miRNA) regulator driving hepatocyte proliferation after partial hepatectomy (PHx) in mice. However, we reported recently that miR-21 is significantly upregulated in ethanol-fed rats 24 h after PHx, despite inhibition of cell proliferation, suggesting a more complex role for this miRNA. Here, we investigate how inhibition of miR-21 in vivo affects the early phase of liver regeneration in ethanol-fed rats. Chronically ethanol-fed rats and pair-fed control animals were treated with AM21, a mixed locked nucleic acid-DNA analog antisense to miR-21 that inhibited miR-21 in vivo to undetectable levels. Liver regeneration after PHx was followed by cell proliferation marker and gene expression analysis, miRNA profiling, and cell signaling pathway analysis. Although liver regeneration was not significantly impaired by AM21 in chow-fed rats, AM21 treatment in ethanol-fed animals completely restored regeneration and enhanced PHx-induced hepatocyte proliferation to levels comparable to those of untreated or chow-fed animals. In addition, a marked deposition of α-smooth muscle actin, a marker of stellate cell activation, which was evident in ethanol-treated animals after PHx, was effectively suppressed by AM21 treatment. Gene expression analysis further indicated that suppression of stellate cell-specific profibrogenic profiles and the Notch signaling contributed to AM21-mediated rescue from deficient hepatocyte proliferation in ethanol-fed animals. Our results indicate that the impact of miR-21 balances proproliferative effects with antiproliferative profibrogenic actions in regulating distinctive regenerative responses in normal vs. disease conditions.

Silencing of Prrx1b suppresses cellular proliferation, migration, invasion and epithelial-mesenchymal transition in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a highly aggressive tumour subtype associated with poor prognosis. The mechanisms involved in TNBC progression remains largely unknown. To date, there are no effective therapeutic targets for this tumour subtype. Paired-related homeobox 1b (Prrx1b), one of major isoforms of Prrx1, has been identified as a new epithelial-mesenchymal transition (EMT) inducer. However, the function of Prrx1b in TNBC has not been elucidated. In this study, we found that Prrx1b was significantly up-regulated in TNBC and associated with tumour size and vascular invasion of breast cancer. Silencing of Prrx1b suppressed the proliferation, migration and invasion of basal-like cancer cells. Moreover, silencing of Prrx1b prevented Wnt/β-catenin signaling pathway and induced the mesenchymal-epithelial transition (MET). Taken together, our data indicated that Prrx1b may be an important regulator of EMT in TNBC cells and a new therapeutic target for interventions against TNBC invasion and metastasis.

GFRα2 prompts cell growth and chemoresistance through down-regulating tumor suppressor gene PTEN via Mir-17-5p in pancreatic cancer

Nerve growth factors and their receptors have received an increasing attention in certain cancers since they play an important role in regulating tumorigenesis, biological process and metastasis. Here we aimed at characterizing a new function of one of the subtypes of growth factor receptors (GFR), GFRα2, in pancreatic cancer. In this study, we showed that GFRα2 was up-regulated in pancreatic adenocarcinoma and was positively correlated with tumor size and perineural invasion, which indicated that it may be associated with cell growth and apoptosis. Mechanically, we discovered that high GFRα2 expression level leads to PTEN inactivation via enhancing Mir-17-5p level.