Expression of miR-21 and its targets (PTEN, PDCD4, TM1) in flat epithelial atypia of the breast in relation to ductal carcinoma in situ and invasive carcinoma

The Interplay Between Obesity and Aging in Breast Cancer and Regulatory Function of MicroRNAs in This Pathway

Breast cancer (BC) is a significant contributor to cancer-related deaths in women, and it has complex connections with obesity and aging. This review explores the interaction between obesity and aging in relation to the development and progression of BC, focusing on the controlling role of microRNAs (miRNAs). Obesity, characterized by excess adipose tissue, contributes to a proinflammatory environment and metabolic dysregulation, which are important in tumor development. Aging, associated with cellular senescence and systemic changes, further exacerbates these conditions. miRNAs, small noncoding RNAs that regulate gene expression, play key roles in these processes, impacting pathways involved in cell proliferation, apoptosis, and cancer metastasis, either as tumor suppressors or oncogenes. Importantly, specific miRNAs are implicated in mediating the impact of obesity and aging on BC. Exploring the regulatory networks controlled by miRNAs provides valuable information on new targets for therapy and predictive markers, demonstrating the potential for using miRNA-based interventions to treat BC in obese and elderly individuals. This review emphasizes the importance of integrated research strategies to understand the complex connections between obesity, aging, and miRNA regulation in BC.

The Genomic and Biologic Landscapes of Breast Cancer and Racial Differences

Breast cancer is a significant health challenge worldwide and is the most frequently diagnosed cancer among women globally. This review provides a comprehensive overview of breast cancer biology, genomics, and microbial dysbiosis, focusing on its various subtypes and racial differences. Breast cancer is primarily classified into carcinomas and sarcomas, with carcinomas constituting most cases. Epidemiology and breast cancer risk factors are important for public health intervention. Staging and grading, based on the TNM and Nottingham grading systems, respectively, are crucial to determining the clinical outcome and treatment decisions. Histopathological subtypes include in situ and invasive carcinomas, such as invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC). The review explores molecular subtypes, including Luminal A, Luminal B, Basal-like (Triple Negative), and HER2-enriched, and delves into breast cancer's histological and molecular progression patterns. Recent research findings related to nuclear and mitochondrial genetic alterations, epigenetic reprogramming, and the role of microbiome dysbiosis in breast cancer and racial differences are also reported. The review also provides an update on breast cancer's current diagnostics and treatment modalities.

CYB561 is a potential therapeutic target for breast cancer and is associated with immune cell infiltration

BACKGROUND

Breast cancer (BC), a common malignant tumor originating from the terminal ductal lobular unit of the breast, poses a substantial health risk to women. Previous studies have associated cytochrome b561 (CYB561) with a poor prognosis in BC; however, its underlying mechanism of this association remains unclear.

METHODS

We investigated the expression of CYB561 mRNA in BC using databases such as The Cancer Genome Atlas, Gene Expression Omnibus, Tumor-Normal-Metastatic plot, and Kaplan-Meier plotter databases. The prognostic value of CYB561 protein in BC was assessed in relation to its expression levels in tumor tissue samples from 158 patients with BC. The effect of CYB561 on BC progression was confirmed using in vivo and in vitro experiments. The biological functions and related signaling pathways of CYB561 in BC were explored using gene microarray, Innovative Pathway, Gene Ontology enrichment, and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. The correlation between CYB561 and the BC tumor immune microenvironment was evaluated using the CIBERSORT algorithm and single-cell analysis and further validated through immunohistochemistry of serial sections.

RESULTS

Our study demonstrated that upregulation of CYB561 expression predicted poor prognosis in patients with BC and that CYB561 knockdown inhibited the proliferation, migration, and invasive ability of BC cells in vitro. CYB561 knockdown inhibited BC tumor formation in vivo.CYB561 was observed to modulate downstream tropomyosin 1 expression. Furthermore, CYB561 expression was associated with macrophage M2 polarization in the BC immune microenvironment.

CONCLUSIONS

Elevated CYB561 expression suggests a poor prognosis for patients with BC and is associated with macrophage M2 polarization in the BC microenvironment. Therefore, CYB561 could potentially serve as a therapeutic target for BC treatment.

Expression of Selected miRNAs in Undifferentiated Carcinoma with Osteoclast-like Giant Cells (UCOGC) of the Pancreas: Comparison with Poorly Differentiated Pancreatic Ductal Adenocarcinoma

Undifferentiated carcinoma with osteoclast-like giant cells (UCOGC) of the pancreas represents a rare subtype of pancreatic ductal adenocarcinoma (PDAC). Despite a distinct morphology and specific clinical behavior, UCOGCs exhibit unexpected similarities in regard to DNA mutational profiles with conventional PDAC. Treating pancreatic ductal adenocarcinoma is particularly challenging, with limited prospects for cure. As with many other malignant neoplasms, the exploration of microRNAs (miRNAs, miRs) in regulating the biological characteristics of pancreatic cancer is undergoing extensive investigation to enhance tumor diagnostics and unveil the therapeutic possibilities. Herein, we evaluated the expression of miR-21, -96, -148a, -155, -196a, -210, and -217 in UCOGCs and poorly differentiated (grade 3, G3) PDACs. The expression of miR-21, miR-155, and miR-210 in both UCOGCs and G3 PDACs was significantly upregulated compared to the levels in normal tissue, while the levels of miR-148a and miR-217 were downregulated. We did not find any significant differences between cancerous and normal tissues for the expression of miR-96 and miR-196a in G3 PDACs, whereas miR-196a was slightly, but significantly, downregulated in UCOGCs. On the other hand, we have not observed significant differences in the expression of the majority of miRNAs between UCOGC and G3 PDAC, with the exception of miR-155. UCOGC samples demonstrated lower mean levels of miR-155 in comparison with those in G3 PDACs.

Circulating miRNA-21 Levels in Breast Cancer Patients Before and After Chemotherapy and Its Association with Clinical Improvement

Breast cancer is the most frequent type of cancer in women, many patients experience recurrences and metastasis. miR-21 (microRNA-21) as biomarker is under investigation for breast cancer. At present, there is very limited information available regarding effect of chemotherapy on miR-21 expression in breast cancer and its correlation with the clinical improvement. Hence, this study was planned to evaluate the effect of chemotherapy on miR-21 in metastatic breast cancer and its relationship with the clinical outcome. Females, aged-18-90 years diagnosed with Invasive Ductal Carcinoma of breast and candidate of neoadjuvant chemotherapy including Adriamycin (60 mg/m2), Cyclophosphamide (600 mg/m2) with or without Taxane (75-175 mg/m2) were included in the study. Before and after 42 days of staring of chemotherapy sample was collected for circulatory miR-21 and RECIST 1.1 criteria was applied to assess the clinical status. Blood samples for routine clinical biomarkers including liver function test and renal function tests was also collected. miR-21 expression before and after chemotherapy was assessed using standard method based on real time PCR. Expression of miR-21, RECIST criteria and other liver and kidney related biomarkers were compared before and after chemotherapy. After neoadjuvant chemotherapy expression of miR-21 was significantly increased by 5.65-fold. There was significant improvement in clinical scores based on RECIST criteria (0.046). No significant correlation was observed between miR-21 expression and difference in RECIST score (r = - 0.122, p = 0.570). Neoadjuvant chemotherapy causes clinical improvement in breast cancer patients however it is not correlated with the miR-21 expression which significantly increased after chemotherapy.

MicroRNA signatures differentiate types, grades, and stages of breast invasive ductal carcinoma (IDC): miRNA-target interacting signaling pathways

BACKGROUND

Invasive ductal carcinoma (IDC) is the most common form of breast cancer which accounts for 85% of all breast cancer diagnoses. Non-invasive and early stages have a better prognosis than late-stage invasive cancer that has spread to lymph nodes. The involvement of microRNAs (miRNAs) in the initiation and progression of breast cancer holds great promise for the development of molecular tools for early diagnosis and prognosis. Therefore, developing a cost effective, quick and robust early detection protocol using miRNAs for breast cancer diagnosis is an imminent need that could strengthen the health care system to tackle this disease around the world.

METHODS

We have analyzed putative miRNAs signatures in 100 breast cancer samples using two independent high fidelity array systems. Unique and common miRNA signatures from both array systems were validated using stringent double-blind individual TaqMan assays and their expression pattern was confirmed with tissue microarrays and northern analysis. In silico analysis were carried out to find miRNA targets and were validated with q-PCR and immunoblotting. In addition, functional validation using antibody arrays was also carried out to confirm the oncotargets and their networking in different pathways. Similar profiling was carried out in Brca2/p53 double knock out mice models using rodent miRNA microarrays that revealed common signatures with human arrays which could be used for future in vivo functional validation.

RESULTS

Expression profile revealed 85% downregulated and 15% upregulated microRNAs in the patient samples of IDC. Among them, 439 miRNAs were associated with breast cancer, out of which 107 miRNAs qualified to be potential biomarkers for the stratification of different types, grades and stages of IDC after stringent validation. Functional validation of their putative targets revealed extensive miRNA network in different oncogenic pathways thus contributing to epithelial-mesenchymal transition (EMT) and cellular plasticity.

CONCLUSION

This study revealed potential biomarkers for the robust classification as well as rapid, cost effective and early detection of IDC of breast cancer. It not only confirmed the role of these miRNAs in cancer development but also revealed the oncogenic pathways involved in different progressive grades and stages thus suggesting a role in EMT and cellular plasticity during breast tumorigenesis per se and IDC in particular. Thus, our findings have provided newer insights into the miRNA signatures for the classification and early detection of IDC.

microRNAs expression profile in phyllodes tumors of the breast

Proliferation of both stromal and epithelial components is a characteristic of fibroepithelial cancers of the breast. Certain fibroepithelial tumors of the breast, such as fibradenomas and phyllodes tumors, are challenging to distinguish and categorize. To find biomarkers for early diagnosis and improved disease management, it is crucial to deepen our understanding of the molecular pathogenesis pathways and tumor biology of PTs. It has been demonstrated that microRNAs (miRNAs) have significant roles in cancers; the expression pattern of miRNAs can help with cancer categorization and treatment. In contrast, little is understood about miRNAs in breast fibroepithelial cancers. This study was conducted retrospectively with the goal of assessing the expression of six mature miRNAs (hsa-miR-21, hsa-miR-155, hsa-miR-182, hsa-miR-34a, hsa-miR-148a, and hsa-miR-205) in breast fibroepithelial cancers using real-time PCR and predicting these miRNAs' targets using computational techniques. This study comprised 64 patients in total-55 with phyllodes tumors and 9 with fibroadenoma. The research was carried out at the Farhat Hached University Hospital's pathology department in Tunisia. These particular miRNAs expression levels were evaluated via qRT-PCR, and in silico techniques were utilized to predict potential miRNA targets. Analysis of miRNA expression in fibroadenoma and phyllodes tumor tissues revealed that miR-21, miR-155 and miR-182 were upregulated in PTs compared to fibroadenoma and normal tissues. We reported that miR-34a, miR-148a and miR-205 were downregulated in both borderline and malignant PTs compared to fibroadenoma and normal tissue. In silico miRNA target prediction suggested the involvement of these molecules in a wide context of cell signaling pathways.

Differential microRNAs Expression during Cancer Development, and Chemoprevention by Natural Compounds: A Comprehensive Review

MicroRNAs are short non-coding RNAs that inhibit gene expression at the post-transcriptional level. Abnormal microRNA expression has been associated with different human diseases, including cancer. Epigenetic changes, mutation, transcriptional deregulation, DNA copy number abnormalities, and defects in the biogenesis machinery play an important role in abnormal microRNA expression. Modulation of microRNAs by natural agents has emerged to enhance the efficacy of conventional chemotherapy through combinatorial therapeutic approach. This review summarizes the current understanding of abnormal microRNA expression in cancer, the different cellular mechanisms of microRNA, and their prevention by natural compounds. Understanding microRNA expression patterns during cancer development may help to identify stage-specific molecular markers. Natural compounds that exert regulatory effects by modulating microRNAs can be used in better cancer chemopreventive strategies by directly targeting microRNAs or as a way to increase sensitivity to existing chemotherapy regimens.

A dual-ratio fluorescent probe with a single excitation triple-signal to synchronously detect PTK7 and miRNA-21 for breast cancer early diagnosis

The measurement of tumor biomarker levels is of great significance for early diagnosis of breast cancer. The combination diagnosis of multiple tumor biomarkers will significantly improve the accuracy of early diagnosis. Here, we successfully developed a dual-ratio fluorescent sensing platform for the detection of breast cancer biomarkers (PTK7, miRNA-21) using single excitation triple-signal detection. Introducing three types of fluorescence nanomaterials with narrow emission peaks and long Stokes shift as signal markers, the three peaks (430 nm, 530 nm and 640 nm) of which do not interfere with each other in fluorescence spectra under a single excitation (360 nm). The sensing platform linked aptamer (apt) modified green fluorescence quantum dots (gQDs-apt1) and aptamer modified red fluorescence quantum dots (rQDs-apt2) to Fe3O4-cDNA1 and Fe3O4-cDNA2, respectively, via base complementary pairing with aptamer molecules. When PTK7/miRNA-21 is present in the system, gQDs-apt1/rQDs-apt2 bound to the Fe3O4 MNPs surface will be released to recover fluorescence. Upon DNase I digestion of free apt1 and apt2, the target molecules will be released to bind to gQDs-apt1/rQDs-apt2 for signal amplification. After magnetic separation, PTK7 and miRNA-21 can be quantified using the fluorescence intensity ratio of gQDs with bCDs and rQDs with bCDs at a single excitation of 360 nm wavelength. This method has high sensitivity, good selectivity, and can quantify both PTK7 and miRNA-21 simultaneously with an LOD of 0.426 ng mL-1 and 0.072 nM, respectively. Additionally, the sensing platform was used for serum detection of health man and breast cancer patients with satisfactory results.

MicroRNAs as biomarkers for early diagnosis, targeting and prognosis of prostate cancer

Globally, prostate cancer (PC) is leading cause of cancer-related mortality in men worldwide. Despite significant advances in the treatment and management of this disease, the cure rates for PC remains low, largely due to late detection. PC detection is mostly reliant on prostate-specific antigen (PSA) and digital rectal examination (DRE); however, due to the low positive predictive value of current diagnostics, there is an urgent need to identify new accurate biomarkers. Recent studies support the biological role of microRNAs (miRNAs) in the initiation and progression of PC, as well as their potential as novel biomarkers for patients' diagnosis, prognosis, and disease relapse. In the advanced stages, cancer-cell-derived small extracellular vesicles (SEVs) may constitute a significant part of circulating vesicles and cause detectable changes in the plasma vesicular miRNA profile. Recent computational model for the identification of miRNA biomarkers discussed. In addition, accumulating evidence indicates that miRNAs can be utilized to target PC cells. In this article, the current understanding of the role of microRNAs and exosomes in the pathogenesis and their significance in PC prognosis, early diagnosis, chemoresistance, and treatment are reviewed.

Melatonin targeting non-coding RNAs in cancer: Focus on mechanisms and potential therapeutic targets

Despite, melatonin is mainly known as a regulatory factor for circadian rhythm, its notable role in other fundamental biological processes, such as redox homeostasis and programmed cell death, has been found. In this line, a growing body of evidence indicated that melatonin could apply an inhibitory effect on the tumorigenic processes. Hence, melatonin might be considered an efficient adjuvant agent for cancer treatment. Besides, the physiological and pathological functions of non-coding RNAs (ncRNAs) in various disease, particularly cancers, have been expanded over the past two decades. It is well-established that ncRNAs can modulate the gene expression at various levels, thereby, ncRNAs. can regulate the numerous biological processes, including cell proliferation, cell metabolism, apoptosis, and cell cycle. Recently, targeting the ncRNAs expression provides a novel insight in the therapeutic approaches for cancer treatment. Moreover, accumulating investigations have revealed that melatonin could impact the expression of different ncRNAs in a multiple disorders, including cancer. Therefore, in the precent study, we discuss the potential roles of melatonin in modulating the expression of ncRNAs and the related molecular pathways in different types of cancer. Also, we highlighted its importance in therapeutic application and translational medicine in cancer treatment.

MiRNA expression deregulation correlates with the Oncotype DX® DCIS score

Background

Current clinical criteria do not discriminate well between women who will or those who will not develop ipsilateral invasive breast cancer (IBC), or a DCIS recurrence after a ductal carcinoma in situ (DCIS) diagnosis. The 12-gene Oncotype DX® DCIS assay (RT qPCR gene-based scoring system) was established and shown to predict the risk of subsequent ipsilateral IBC or DCIS recurrence. Recent studies have shown that microRNA (miRNA) expression deregulation can contribute to the development of IBC, but very few have evaluated miRNA deregulation in DCIS lesions. In this study, we sought to determine whether specific miRNA expression changes may correlate with Oncotype DX® DCIS scores.

Methods

For this study, we used archived formalin-fixed, paraffin-embedded (FFPE) specimens from 41 women diagnosed with DCIS between 2012 and 2018. The DCIS lesions were stratified into low (n = 26), intermediate (n = 10), and high (n = 5) risk score groups using the Oncotype DX® DCIS assay. Total RNA was extracted from DCIS lesions by macro-dissection of unstained FFPE sections, and next-generation small-RNA sequencing was performed. We evaluated the correlation between miRNA expression data and Oncotype score, as well as patient age. RT-qPCR validations were performed to validate the topmost differentially expressed miRNAs identified between the different risk score groups.

Results

MiRNA sequencing of 32 FFPE DCIS specimens from the three different risk group scores identified a correlation between expression deregulation of 17 miRNAs and Oncotype scores. Our analyses also revealed a correlation between the expression deregulation of 9 miRNAs and the patient’s age. Based on these results, a total of 15 miRNAs were selected for RT-qPCR validation. Of these, miR-190b (p = 0.043), miR-135a (p = 0.05), miR-205 (p = 0.00056), miR-30c (p = 0.011), and miR-744 (p = 0.038) showed a decreased expression in the intermediate/high Oncotype group when compared to the low-risk score group. A composite risk score was established using these 5 miRNAs and indicated a significant association between miRNA expression deregulation and the Oncotype DX® DCIS Score (p < 0.0021), between high/intermediate and low risk groups.

Conclusions

Our analyses identified a subset of 5 miRNAs able to discriminate between Oncotype DX® DCIS score subgroups. Together, our data suggest that miRNA expression analysis may add value to the predictive and prognostic evaluation of DCIS lesions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-022-01558-4.

Are Columnar Cell Lesions the Earliest Non-Obligate Precursor in the Low-Grade Breast Neoplasia Pathway?

Columnar cell lesions (CCLs) of the breast comprise a spectrum of morphologic alterations of the terminal duct lobular unit involving variably dilated and enlarged acini lined by columnar epithelial cells. The World Health Organization currently classifies CCLs without atypia as columnar cell change (CCC) and columnar cell hyperplasia (CCH), whereas flat epithelial atypia (FEA) is a unifying term encompassing both CCC and CCH with cytologic atypia. CCLs have been increasingly recognized in stereotactic core needle biopsies (CNBs) performed for the assessment of calcifications. CCLs are believed to represent the earliest non-obligate precursor of low-grade invasive breast carcinomas as they share molecular alterations and often coexist with entities in the low-grade breast neoplasia pathway. Despite this association, however, the risk of progression of CCLs to invasive breast carcinoma appears low and may not exceed that of concurrent proliferative lesions. As the reported upgrade rates of pure CCL/FEA when identified as the most advanced high-risk lesion on CNB vary widely, the management of FEA diagnosed on CNB remains controversial. This review will include a historical overview of CCLs and will examine histologic diagnostic criteria, molecular alterations, prognosis and issues related to upgrade rates and clinical management.

The Role and Interactions of Programmed Cell Death 4 and its Regulation by microRNA in Transformed Cells of the Gastrointestinal Tract

Data from GLOBOCAN 2020 estimates that there were 19.3 million new cases of cancer and 10.0 million cancer-related deaths in 2020 and that this is predicted to increase by 47% in 2040. The combined burden of cancers of the gastrointestinal (GI) tract, including oesophageal-, gastric- and colorectal cancers, resulted in 22.6% of the cancer-related deaths in 2020 and 18.7% of new diagnosed cases. Understanding the aetiology of GI tract cancers should have a major impact on future therapies and lessen this substantial burden of disease. Many cancers of the GI tract have suppression of the tumour suppressor Programmed Cell Death 4 (PDCD4) and this has been linked to the expression of microRNAs which bind to the untranslated region of PDCD4 mRNA and either inhibit translation or target the mRNA for degradation. This review highlights the properties of PDCD4 and documents the evidence for the regulation of PDCD4 expression by microRNAs in cancers of the GI tract.

Poly(rC) binding protein 1 benefits coxsackievirus B3 infection via suppressing the translation of p62/SQSTM1

Coxsackievirus B3 (CVB3) is a positive single-strand RNA virus causing myocarditis, pancreatitis and meningitis. During CVB3 infection, various host cellular components, including proteins and non-coding RNAs, interact with the virus and affect viral infection. Poly(rC) binding protein 1 (PCBP1) is a multifunctional RNA binding protein regulating transcription, translation and mRNA stability of a variety of genes. In this study, we observed a significant reduction of PCBP1 protein during CVB3 infection. By bioinformatic prediction and luciferase-assay verification, we confirmed that the expression of PCBP1 was directly inhibited by miR-21, a microRNA upregulated during CVB3 infection. Furthermore, we found that overexpression of PCBP1 promoted CVB3 infection and knocking down of PCBP1 inhibited it. In the subsequent mechanism study, our results revealed that PCBP1 blocked the translation of p62/SQSTM1 (sequestosome 1), an autophagy-receptor protein suppressing CVB3 replication, by interacting with the cis-element in the 5' untranslational region (5' UTR) of p62/SQSTM1. In summary, our studies have identified PCBP1 as a beneficial factor for CVB3 infection. These findings may deepen the understanding of host-virus interactions and provide a potential target for intervention of CVB3 infection.

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.

Melatonin promotes apoptosis of thyroid cancer cells via regulating the signaling of microRNA-21 (miR-21) and microRNA-30e (miR-30e)

Melatonin (MEL) is an effective therapeutic choice for thyroid cancer treatment. In this study, we aimed to explored the potential effect of MEL upon the drug sensitivity of cancer cells and the according underlying mechanisms. Thyroid cancer mice were established as a control group and a MEL group to observe the in vivo effect of MEL. Tumor size and weight in nude mice were detected to evaluate the effect of MEL on tumor growth. Immunohistochemistry assay (IHC) and Western blot were performed to analyze the expression of PTEN protein in tumor cells or tumor cells. After 32 days of cancer cell implantation, MEL was found to significantly repress tumor growth in nude mice approximately by half. Moreover, MEL also suppressed tumor cell proliferation, while apparently activating the apoptosis of tumor cells. In addition, hydrogen sulfide (H₂S) production was obviously elevated by MEL treatment. Mechanistically, the expression of phosphatase and tensin homolog (PTEN) was remarkably activated by MEL treatment in tumor tissues of implanted TPC-1 and BCPaP cells in nude mice. Meanwhile, MEL inhibited the expression of miR-21 and miR-30e and promoted the expression of lncRNA-cancer susceptibility candidate 7 (CASC7). Both miR-21 and miR-30e could suppress PTEN expression, while miR-21 could also inhibit the expression of lncRNA-CASC7. In conclusion, the results demonstrated that the MEL administration could downregulate the expression of miR-21 and miR-30e, which resulted in increased expression of PTEN, a pro-apoptotic tumor suppressor, to promote the apoptosis of thyroid cancer cells.

Signaling pathways modulated by miRNAs in breast cancer angiogenesis and new therapeutics

MicroRNAs (miRNAs) act as oncogenes or tumor suppressors by suppressing the expression of target genes, some of which are engaged in angiogenic signaling pathways directly or indirectly. Tumor development and metastasis are dependent on angiogenesis, and it is the main reason for the poor prognosis of cancer patients. New blood vessels are formed from pre-existing vessels when angiogenesis occurs. Thus, it is essential to develop primary tumors and the spread of cancer to surrounding tissues. MicroRNAs (miRNAs) are small noncoding RNAs involved in various biological processes. They can bind to the 3'-UTR of their target genes and prevent them from expressing. MiRNAs control the activity of endothelial cells (ECs) through altering many biological pathways, which plays a key role in cancer progression and angiogenesis. Recent findings revealed that tumor-derived extracellular vesicles participated directly in the control of tumor angiogenesis by delivering miRNAs to ECs. miRNAs recently show great promise in cancer therapies to inhibit angiogenesis. In this study, we showed the miRNA-regulated signaling pathways in tumor angiogenesis with highlighting the anti-angiogenic therapy response and miRNA delivery methods that have been used to inhibit angiogenesis in both in vivo and in vitro studies.

MicroRNA-96: A therapeutic and diagnostic tumor marker

Cancer has been always considered as one of the main human health challenges worldwide. One of the main causes of cancer-related mortality is late diagnosis in the advanced stages of the disease, which reduces the therapeutic efficiency. Therefore, novel non-invasive diagnostic methods are required for the early detection of tumors and improving the quality of life and survival in cancer patients. MicroRNAs (miRNAs) have pivotal roles in various cellular processes such as cell proliferation, motility, and neoplastic transformation. Since circulating miRNAs have high stability in body fluids, they can be suggested as efficient noninvasive tumor markers. MiR-96 belongs to the miR-183-96-182 cluster that regulates cell migration and tumor progression as an oncogene or tumor suppressor by targeting various genes in solid tumors. In the present review, we have summarized all of the studies that assessed the role of miR-96 during tumor progression. This review clarifies the molecular mechanisms and target genes recruited by miR-96 to regulate tumor progression and metastasis. It was observed that miR-96 mainly affects tumorigenesis by targeting the structural proteins and FOXO transcription factors.

The Role of Circulating MicroRNAs in Patients with Early-Stage Pancreatic Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is increasing in incidence and is still associated with a high rate of mortality. Only a minority of patients are diagnosed in the early stage. Radical surgery is the only potential curative procedure. However, radicality is reached in 20% of patients operated on. Despite the multidisciplinary approach in resectable tumors, early tumor recurrences are common. Options on how to select optimal candidates for resection remain limited. Nevertheless, accumulating evidence shows an important role of circulating non-coding plasma and serum microRNAs (miRNAs), which physiologically regulate the function of a target protein. miRNAs also play a crucial role in carcinogenesis. In PDAC patients, the expression levels of certain miRNAs vary and may modulate the function of oncogenes or tumor suppressor genes. As they can be detected in a patient's blood, they have the potential to become promising non-invasive diagnostic and prognostic biomarkers. Moreover, they may also serve as markers of chemoresistance. Thus, miRNAs could be useful for early and accurate diagnosis, prognostic stratification, and individual treatment planning. In this review, we summarize the latest findings on miRNAs in PDAC patients, focusing on their potential use in the early stage of the disease.

The role of microRNA-21 in the onset and progression of cancer

MicroRNAs (miRNAs), a class of small noncoding RNA, posttranscriptionally regulate the expression of genes. Aberrant expression of miRNA is reported in various types of cancer. Since the first report of oncomiR-21 involvement in the glioma, its upregulation was reported in multiple cancers and was allied with high oncogenic property. In addition to the downregulation of tumor suppressor genes, the miR-21 is also associated with cancer resistance to various chemotherapy. The recent research is appraising miR-21 as a promising cancer target and biomarker for early cancer detection. In this review, we briefly explain the biogenesis and regulation of miR-21 in cancer cells. Additionally, the review features the assorted genes/pathways regulated by the miR-21 in various cancer and cancer stem cells.

miR-155, miR-21, and let-7a Expressions in MCF-10A and MCF-7 Cell Lines after Low to High Dose Irradiation

OBJECTIVE

Ionizing radiation is a tremendous risk factor for cancer development. MicroRNAs (miRNAs) are regulators that utilize cell pathways, which are implicated in human cancer prognosis. In addition, miRNAs respond to anti-cancer therapy and proliferation after irradiation. However, the changes in miRNA expression profiles in response to irradiation have not been comprehensively analysed. The present study was designed to assess potential changes that occur in miRNA expression following irradiation.

MATERIALS AND METHODS

In this experimental study, we used quantitative real-time polymerase chain reaction (qRTPCR) to measure the expressions of miR-155, miR-21, and let-7a in MCF-10A (normal breast cells) and MCF-7 (breast cancer cells) six hours after the cells were exposed to five different irradiation doses (50, 100, 400, 2000, and 4000 mGY).

RESULTS

After irradiation from the low to high doses, we observed an upsurge in miR-155 (more than 100%) expression and reduction in let-7a (more than 87%) expression. However, there was an increase and a reduction in miR-21 expression (more than 100%).

CONCLUSION

Irradiation can play an important role in cancer development in normal breast cells (MCF-10A) at low dose irradiation. However, the results showed little difference at high doses of radiation.

Innovations in Biomaterial Design toward Successful RNA Interference Therapy for Cancer Treatment

Gene regulation using RNA interference (RNAi) therapy has been developed as one of the frontiers in cancer treatment. The ability to tailor the expression of genes by delivering synthetic oligonucleotides to tumor cells has transformed the way scientists think about treating cancer. However, its clinical application has been limited due to the need to deliver synthetic RNAi oligonucleotides efficiently and effectively to target cells. Advances in nanotechnology and biomaterials have begun to address the limitations to RNAi therapeutic delivery, increasing the likelihood of RNAi therapeutics for cancer treatment in clinical settings. Herein, innovations in the design of nanocarriers for the delivery of oligonucleotides for successful RNAi therapy are discussed.

Breast Cancer Response to Therapy: Can microRNAs Lead the Way?

Breast cancer (BC) is a leading cause of death among women with malignant diseases. The selection of adequate therapies for highly invasive and metastatic BCs still represents a major challenge. Novel combinatorial therapeutic approaches are urgently required to enhance the efficiency of BC treatment. Recently, microRNAs (miRNAs) emerged as key regulators of the complex mechanisms that govern BC therapeutic resistance and susceptibility. In the present review we aim to critically examine how miRNAs influence BC response to therapies, or how to use miRNAs as a basis for new therapeutic approaches. We summarized recent findings in this rapidly evolving field, emphasizing the challenges still ahead for the successful implementation of miRNAs into BC treatment while providing insights for future BC management.The goal of this review was to propose miRNAs, that might simultaneously improve the efficacy of all four therapies that are the backbone of current BC management (radio-, chemo-, targeted, and hormone therapy). Among the described miRNAs, miR-21 and miR-16 emerged as the most promising, closely followed by miR-205, miR-451, miR-182, and miRNAs from the let-7 family. miR-21 inhibition might be the best choice for future improvement of invasive BC treatment.New therapeutic strategies of miRNA-based agents alongside current standard treatment modalities could greatly benefit BC patients. This review represents a guideline on how to navigate this elaborate puzzle.

Synthetic RNA Modulators in Drug Discovery

RNAs are involved in an enormous range of cellular processes, including gene regulation, protein synthesis, and cell differentiation, and dysfunctional RNAs are associated with disorders such as cancers, neurodegenerative diseases, and viral infections. Thus, the identification of compounds with the ability to bind RNAs and modulate their functions is an exciting approach for developing next-generation therapies. Numerous RNA-binding agents have been reported over the past decade, but the design of synthetic molecules with selectivity for specific RNA sequences is still in its infancy. In this perspective, we highlight recent advances in targeting RNAs with synthetic molecules, and we discuss the potential value of this approach for the development of innovative therapeutic agents.

MicroRNAs as Epigenetic Determinants of Treatment Response and Potential Therapeutic Targets in Prostate Cancer

Prostate cancer (PCa) is the second most common tumor in men worldwide, and the fifth leading cause of male cancer-related deaths in western countries. PC is a very heterogeneous disease, meaning that optimal clinical management of individual patients is challenging. Depending on disease grade and stage, patients can be followed in active surveillance protocols or undergo surgery, radiotherapy, hormonal therapy, and chemotherapy. Although therapeutic advancements exist in both radiatiotherapy and chemotherapy, in a considerable proportion of patients, the treatment remains unsuccessful, mainly due to tumor poor responsiveness and/or recurrence and metastasis. microRNAs (miRNAs), small noncoding RNAs that epigenetically regulate gene expression, are essential actors in multiple tumor-related processes, including apoptosis, cell growth and proliferation, autophagy, epithelial-to-mesenchymal transition, invasion, and metastasis. Given that these processes are deeply involved in cell response to anti-cancer treatments, miRNAs have been considered as key determinants of tumor treatment response. In this review, we provide an overview on main PCa-related miRNAs and describe the biological mechanisms by which specific miRNAs concur to determine PCa response to radiation and drug therapy. Additionally, we illustrate whether miRNAs can be considered novel therapeutic targets or tools on the basis of the consequences of their expression modulation in PCa experimental models.

Micro-RNA: The darkhorse of cancer

The discovery of micro RNAs (miRNA) in cancer has opened up new vistas for researchers in recent years. Micro RNAs area set of small, endogenous, highly conserved, non-coding RNAs that control the expression of about 30% genes at post-transcriptional levels. Typically, microRNAs impede the translation and stability of messenger RNAs (mRNA), control genes associated with cellular processes namely inflammation, cell cycle regulation, stress response, differentiation, apoptosis, and migration. Compelling findings revealed that miRNA mutations or disruption correspond to diverse human cancers and suggest that miRNAs can function as tumor suppressors or oncogenes. Here we summarize the literature on these master regulators in clinical settings from last three decades as both abrupt cancer therapeutics and as an approach to sensitize tumors to chemotherapy. This review highlights (I) the prevailing perception of miRNA genomics, biogenesis, as well as function; (II) the significant advancements in regulatory mechanisms in the expression of carcinogenic genes; and (III) explains, how miRNA is utilized as a diagnostic and prognostic biomarker for the disease stage indicating survival as well as therapeutic targets in cancer.

The Multifaceted Role and Utility of MicroRNAs in Indolent B-Cell Non-Hodgkin Lymphomas

Normal B-cell development is a tightly regulated complex procedure, the deregulation of which can lead to lymphomagenesis. One common group of blood cancers is the B-cell non-Hodgkin lymphomas (NHLs), which can be categorized according to the proliferation and spread rate of cancer cells into indolent and aggressive ones. The most frequent indolent B-cell NHLs are follicular lymphoma and marginal zone lymphoma. MicroRNAs (miRNAs) are small non-coding RNAs that can greatly influence protein expression. Based on the multiple interactions among miRNAs and their targets, complex networks of gene expression regulation emerge, which normally are essential for proper B-cell development. Multiple miRNAs have been associated with B-cell lymphomas, as the deregulation of these complex networks can lead to such pathological states. The aim of the present review is to summarize the existing information regarding the multifaceted role of miRNAs in indolent B-cell NHLs, affecting the main B-cell subpopulations. We attempt to provide insight into their biological function, the complex miRNA-mRNA interactions, and their biomarker utility in these malignancies. Lastly, we address the limitations that hinder the investigation of the role of miRNAs in these lymphomas and discuss ways that these problems could be overcome in the future.

Clinical Significance of PDCD4 in Melanoma by Subcellular Expression and in Tumor-Associated Immune Cells

Simple Summary

While targeting programmed cell death (PDCD) 1 is a central treatment against melanoma, little is known about the related protein PDCD4. We defined differences in melanoma PDCD4 subcellular localization (either total cellular or nuclear-only) during oncogenesis, evaluated its presence on tumor-infiltrating immune cells, and determined its impact on survival. High PDCD4 expression resulted in improved survival in patients with primary and intracranial but not extracranial metastatic melanoma. High PDCD4 levels in surrounding tumor tissue were also associated with increased infiltrating immune cells. PDCD4 may be a potentially useful biomarker in melanoma to help guide our understanding of patient prognosis. Methods to increase PDCD4 in those with melanoma brain metastases may also help improve disease response.

Abstract

Little is known about the subcellular localization and function of programmed cell death 4 (PDCD4) in melanoma. Our past studies suggest PDCD4 interacts with Pleckstrin Homology Domain Containing A5 (PLEKHA5) to influence melanoma brain metastasis outcomes, as high intracranial PDCD4 expression leads to improved survival. We aimed to define the subcellular distribution of PDCD4 in melanoma and in the tumor microenvironment during neoplastic progression and its impact on clinical outcomes. We analyzed multiple tissue microarrays with well-annotated clinicopathological variables using quantitative immunofluorescence and evaluated single-cell RNA-sequencing on a brain metastasis sample to characterize PDCD4+ immune cell subsets. We demonstrate differences in PDCD4 expression during neoplastic progression, with high tumor and stromal PDCD4 levels associated with improved survival in primary melanomas and in intracranial metastases, but not in extracranial metastatic disease. While the expression of PDCD4 is well-documented on CD8+ T cells and natural killer cells, we show that it is also found on B cells and mast cells. PDCD4 expression in the tumor microenvironment is associated with increased immune cell infiltration. Further studies are needed to define the interaction of PDCD4 and PLEKHA5 and to evaluate the utility of this pathway as a therapeutic target in melanoma brain metastasis.

MiR-21 Is Required for the Epithelial-Mesenchymal Transition in MDA-MB-231 Breast Cancer Cells

Breast cancer (BCa) is one of the leading health problems among women. Although significant achievements have led to advanced therapeutic success with targeted therapy options, more efforts are required for different subtypes of tumors and according to genomic, transcriptomic, and proteomic alterations. This study underlines the role of microRNA-21 (miR-21) in metastatic MDA-MB-231 breast cancer cells. Following the knockout of miR-21 from MDA-MB-231 cells, which have the highest miR-21 expression levels compared to MCF-7 and SK-BR-3 BCa cells, a decrease in epithelial-mesenchymal transition (EMT) via downregulation of mesenchymal markers was observed. Wnt-11 was a critical target for miR-21, and the Wnt-11 related signaling axis was altered in the stable miR-21 knockout cells. miR-21 expression was associated with a significant increase in mesenchymal markers in MDA-MB-231 BCa cells. Furthermore, the release of extracellular vesicles (EVs) was significantly reduced in the miR-21 KO cells, alongside a significant reduction in relative miR-21 export in EV cargo, compared with control cells. We conclude that miR-21 is a leading factor involved in mesenchymal transition in MDA-MB-231 BCa. Future therapeutic strategies could focus on its role in the treatment of metastatic breast cancer.

Nanotechnology, in silico and endocrine-based strategy for delivering paclitaxel and miRNA: Prospects for the therapeutic management of breast cancer

Breast cancer is one of the most prevalent and reoccurring cancers and the second most common reason of death in women. Despite advancements in therapeutic strategies for breast cancer, early tumor recurrence and metastasis in patients indicate resistance to chemotherapeutic medicines, such as paclitaxel due to the abnormal expression of ER and EGF2 in breast cancer cells. Therefore, the development of alternatives to paclitaxel is urgently needed to overcome challenges involving drug resistance. An increasing number of studies has revealed miRNAs as novel natural alternative substances that play a crucial role in regulating several physiological processes and have a close, adverse association with several diseases, including breast cancer. Due to the therapeutic potential of miRNA and paclitaxel in cancer research, the current review focuses on the differential roles of various miRNAs in breast cancer development and treatment. miRNA delivery to a specific target site, the development of paclitaxel and miRNA formulations, and nanotechnological strategies for the delivery of nanopaclitaxel in the management of breast cancer are discussed. These strategies involve improving the cellular uptake and bioavailability and reducing the toxicity of free paclitaxel to achieve accumulation tumor site. Furthermore, a molecular docking study was performed to ascertain the enhanced anticancer activity of the nanoformulation of ANG1005 and Abraxane. An in silico analysis revealed that ANG1005 and Abraxane nanoformulations have superior and significantly enhanced interactions with the proteins α-tubulin and Bcl-2. Therefore, ANG1005 and Abraxane may be more suitable in the therapeutic management of breast cancer than the existing free paclitaxel. miRNAs can revert abnormal gene expression to normalcy; since miRNAs serve as tumor suppressors. Therefore, restoration of particular miRNAs levels as a replacement therapy may be an effective endocrine potential strategy for treating ER positive/ negative breast cancers.

Triple negative breast cancer in the era of miRNA

The objective of this review is to elucidate the role of miRNAs in triple negative breast cancer (TNBC). To achieve our goal, we searched databases such as PubMed, ScienceDirect, Springer, Web of Science and Scopus. We retrieved up to 1233 articles, based a rigorous selection criterion, only 197 articles were extensively reviewed. We selected articles only addressing TNBC, but not other types of breast cancer, with the employed approach being miRNA analysis and/or profiling. Our extensive review resulted in grouping of miRNAs into categories in which specific members of miRNAs have roles in specific mechanism in TNBC i.e., carcinogenesis, invasion, metastasis, apoptosis, diagnosis, prognosis, and treatment. TNBC is an aggressive subtype of breast cancer; therefore, different approaches for accurate diagnosis, prognosis and treatment are needed. In this review we summarize the up-to-date miRNA profiling, prognostic, and therapeutic findings that add to the route of controlling TNBC.

Circulating miR-155, let-7c, miR-21, and PTEN levels in differential diagnosis and prognosis of idiopathic granulomatous mastitis and breast cancer

This study investigates whether the circulating miR-155, let-7c, miR-21, and PTEN levels to be used in the differential diagnosis of patients with idiopathic granulomatous mastitis (IGM) and breast cancer (BC). Forty-five patients with BC, 50 patients with IGM, and 48 healthy volunteers were included in the study. Serum miR-21 expression was significantly higher in BC (fold change = 2.42) and IGM group (fold change = 1.33) compared to control (p < .001). Serum miR-155 and let-7c expression levels were significantly lower in both groups compared to the control group (p < .001). miR-21 expression in BC was significantly higher than IGM (fold change = 1.976; p < .001). PTEN levels in BC were significantly higher than IGM (p < .001) and significantly lower than the control group (p < .001); the IGM group was significantly lower than the control group (p < .001). In addition to radiological data, serum miR-21 and PTEN levels may be noninvasive biomarkers that can help differentiate IGM from BC. The results of the study will lead to future studies in the differential diagnosis of IGM and BC.

Nuclear PDCD4 Expression Defines a Subset of Luminal B-Like Breast Cancers with Good Prognosis

The hormone receptor-positive (estrogen and/or progesterone receptor (PR)-positive) and HER2-negative breast cancer (BC) subtype is a biologically heterogeneous entity that includes luminal A-like (LumA-like) and luminal B-like (LumB-like) subtypes. Decreased PR levels is a distinctive biological feature of LumB-like tumors. These tumors also show reduced sensitivity to endocrine therapies and poorer prognosis than LumA-like tumors. Identification of biomarkers to accurately predict disease relapse in these subtypes is crucial in order to select effective therapies. We identified the tumor suppressor PDCD4 (programmed cell death 4), located in the nucleus (NPDCD4), as an independent prognostic factor of good clinical outcome in LumA-like and LumB-like subtypes. NPDCD4-positive LumB-like tumors presented overall and disease-free survival rates comparable to those of NPDCD4-positive LumA-like tumors, indicating that NPDCD4 improves the outcome of LumB-like patients. In contrast, NPDCD4 loss increased the risk of disease recurrence and death in LumB-like compared with LumA-like tumors. This, along with our results showing that LumB-like tumors present lower NPDCD4 positivity than LumA-like tumors, suggests that NPDCD4 loss contributes to endocrine therapy resistance in LumB-like BCs. We also revealed that PR induces PDCD4 transcription in LumB-like BC, providing a mechanistic explanation to the low PDCD4 levels in LumB-like BCs lacking PR. Finally, PDCD4 silencing enhanced BC cell survival in a patient-derived explant model of LumB-like disease. Our discoveries highlight NPDCD4 as a novel biomarker in LumA- and LumB-like subtypes, which could be included in the panel of immunohistochemical markers used in the clinic to accurately predict the prognosis of LumB-like tumors.

MicroRNA's - The vibrant performers in the oral cancer scenario

MicroRNAs (miRNAs) are a family of small non-coding (18–22 nucleotide) RNA molecules. These molecules regulate gene expression by either inhibiting mRNA translation or by degrading mRNA. A single miRNA can control the expression of target genes, and the expression of a target gene can be regulated by multiple miRNAs. They are key regulators of various biological and pathological processes. These include cell proliferation, development and tumorigenesis. Novel studies have discovered definite signature miRNAs in the initiation and progression of cancers. Interestingly, miRNAs have also been found in fragile genomic sites that are associated with increased cancer risk.

These micro RNAs regulate the expression of several genes that play a crucial role in the transition of normal oral mucosa through dysplasia to malignancy. The aim of this review is to recapitulate the current understanding of the many miRNAs that have been identified, the genes that they target and the role that they play in the carcinogenic pathway. The review also highlights the prospective role of miRNAs in the diagnosis, prognosis and treatment of oral cancers.

ALKBH4 Functions as a Suppressor of Colorectal Cancer Metastasis via Competitively Binding to WDR5

BACKGROUND

Epithelial-Mesenchymal Transition (EMT) is a major process in the initiation of tumor metastasis, where cancer cells lose sessile epithelial potential and gain mesenchymal phenotype. Large-scale cell identity shifts are often orchestrated on an epigenetic level and the interplay between epigenetic factors and EMT progression was still largely unknown. In this study, we tried to identify candidate epigenetic factors that involved in EMT progression.

METHODS

Colorectal cancer (CRC) cells were transfected with an arrayed shRNA library targeting 384 genes involved in epigenetic modification. Candidate genes were identified by real-time PCR. Western blot, RNA-seq and gene set enrichment analysis were conducted to confirm the suppressive role of ALKBH4 in EMT. The clinical relevance of ALKBH4 in CRC was investigated in two independent Renji Cohorts and a microarray dataset (GSE21510) from GEO database. In vitro transwell assay and in vivo metastatic tumor model were performed to explore the biological function of ALKBH4 in the metastasis of CRC. Co-IP (Co-Immunoprecipitation) and ChIP (Chromatin Immunoprecipitation) assays were employed to uncover the mechanism.

RESULTS

We screened for candidate epigenetic factors that affected EMT process and identified ALKBH4 as a candidate EMT suppressor gene, which was significantly downregulated in CRC patients. Decreased level of ALKBH4 was associated with metastasis and predicted poor prognosis of CRC patients. Follow-up functional experiments illustrated overexpression of ALKBH4 inhibited the invasion ability of CRC cells in vitro, as well as their metastatic capability in vivo. Mechanistically, CO-IP and ChIP assays indicated that ALKBH4 competitively bound WDR5 (a key component of histone methyltransferase complex) and decreased H3K4me3 histone modification on the target genes including MIR21.

CONCLUSIONS

This study illustrated that ALKBH4 may function as a novel metastasis suppressor of CRC, and inhibits H3K4me3 modification through binding WDR5 during EMT.

MiR-629-5p promotes the invasion of lung adenocarcinoma via increasing both tumor cell invasion and endothelial cell permeability

Tumor invasion underlies further metastasis, the leading cause for cancer-related deaths. Deregulation of microRNAs has been identified associated with the malignant behavior of various cancers, including lung adenocarcinoma (LUAD), the major subtype of lung cancer. Here, we showed the significantly positive correlation between miR-629-5p level and tumor invasion in LUAD specimens (n = 49). In a human LUAD metastasis mouse model, H1650 cells (high level of miR-629-5p) were more aggressive than A549 cells (low level of miR-629-5p) in vivo, including higher incidence of vascular invasion and pulmonary colonization. Ectopic expression of miR-629-5p in A549 cells also increased their invasive capability. Then we identified that miR-629-5p promotes LUAD invasion in a mode of dual regulation via tumor cells invasion and endothelial cells permeability, respectively. In tumor cells, miR-629-5p enhanced motility and invasiveness of tumor cells by directly targeting PPWD1 (a cyclophilin), which clinically related to tumor invasion in LUAD specimens. Restoring PPWD1 protein significantly attenuated the invasion-promoting effects of miR-629-5p. Besides, exosomal-miR-629-5p secreted from tumor cells could be transferred to endothelial cells and increased endothelial monolayers permeability by suppressing CELSR1 (a nonclassic-type cadherin), which had a low level in the endothelial cells of invasive LUAD specimens. Activating the expression of CELSR1 in endothelial cells markedly blocked the effect of miR-629-5p. Our study suggests the dual roles of miR-629-5p in tumor cells and endothelial cells for LUAD invasion, implying a therapeutic option to targeting miR-629-5p using the "one stone, two birds" strategy in LUAD.

Non-Coding RNAs as Regulators and Markers for Targeting of Breast Cancer and Cancer Stem Cells

Breast cancer is regarded as a heterogeneous and complicated disease that remains the prime focus in the domain of public health concern. Next-generation sequencing technologies provided a new perspective dimension to non-coding RNAs, which were initially considered to be transcriptional noise or a product generated from erroneous transcription. Even though understanding of biological and molecular functions of noncoding RNA remains enigmatic, researchers have established the pivotal role of these RNAs in governing a plethora of biological phenomena that includes cancer-associated cellular processes such as proliferation, invasion, migration, apoptosis, and stemness. In addition to this, the transmission of microRNAs and long non-coding RNAs was identified as a source of communication to breast cancer cells either locally or systemically. The present review provides in-depth information with an aim at discovering the fundamental potential of non-coding RNAs, by providing knowledge of biogenesis and functional roles of micro RNA and long non-coding RNAs in breast cancer and breast cancer stem cells, as either oncogenic drivers or tumor suppressors. Furthermore, non-coding RNAs and their potential role as diagnostic and therapeutic moieties have also been summarized.

Genome-wide screening of abberant methylated drivers combined with relative risk loci in bladder cancer

Background

To explore important methylation‐driven genes (MDGs) and risk loci to construct risk model for prognosis of bladder cancer (BCa).

Methods

We utilized TCGA‐Assembler package to download 450K methylation data and corresponding transcriptome profiles. MethylMix package was used for identifying methylation‐driven genes and functional analysis was mainly performed based on ConsensusPathDB database. Then, Cox regression method was utilized to find prognostic MDGs, and we selected 17 hub genes via stepwise regression and multivariate Cox models. Kruskal‐Wallis test was implemented for comparisons between risk with other clinical variables. Moreover, we constructed the risk model and validated it in http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE13507. Gene set enrichment analysis was performed using the levels of risk score as the phenotype. Additionally, we further screened out the relative methylation sites associated with the 17 hub genes. Cox regression and Survival analysis were conducted to find the specifically prognostic sites.

Results

Two hundred and twenty‐eight MDGs were chosen by ConsensusPathDB database. Results revealed that most conspicuous pathways were transcriptional mis‐regulation pathways in cancer and EMT. After Cox regression analysis, 17 hub epigenetic MDGs were identified. We calculated the risk score and found satisfactory predictive efficiency by ROC curve (AUC = 0.762). In the validation group from http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE13507, 17 hub genes remained higher predictive value with AUC = 0.723 and patients in high‐risk group. Meanwhile, Kruskal‐Wallis test revealed that higher risk score correlated with a higher level of TNM stage, tumor grade, and advanced pathological stages. Then, identified 38 risk methylated loci that highly associated with prognosis. Last, gene set enrichment analysis revealed that high‐risk level of MDGs may correlate with several important pathways, including MAPK signaling pathway and so on.

Conclusion

Our study indicated several hub‐MDGs, calculated novel risk score and explored the prognostic value in BCa, which provided a promising approach to BCA prognosis assessment.

PLEKHA5 regulates tumor growth in metastatic melanoma

BACKGROUND

PLEKHA5 has previously been identified as a novel molecule implicated in melanoma brain metastasis, a disease that continues to portend a poor prognosis. The aim of this study was to further investigate the functional role of PLEKHA5 in disseminated melanoma.

METHODS

The impact of PLEKHA5 on proliferation and tumor growth was examined in vitro and in melanoma xenograft models, including brain-tropic melanomas (melanomas tending to disseminate to the brain). In vitro loss- and gain-of-function studies were used to explore the underlying mechanisms of PLEKHA5-mediated tumor growth and the crosstalk between PLEKHA5 and PI3K/AKT/mTOR or MAPK/ERK signaling. The clinical relevance of PLEKHA5 dysregulation was further investigated in a cohort of matched cranial and extracranial melanoma metastases.

RESULTS

PLEKHA5 stable knockdown negatively regulated cell proliferation by inhibiting the G₁ -to-S cell cycle transition, which coincided with upregulation of the cell cycle regulator PDCD4. Conversely, ectopic PLEKHA5 expression exhibited the inverse effect. PLEKHA5 knockdown significantly inhibited tumor growth, whereas its overexpression upregulated the growth of tumors, which was induced by cranial and subcutaneous inoculation of cells in nude mice. PLEKHA5 modulation affected PDCD4 protein stability and was coupled with changes in PI3K/AKT/mTOR pathway signaling. High PDCD4 expression in cerebral specimens was associated with better overall survival.

CONCLUSIONS

This study further supports the role of PLEKHA5 as a regulator of melanoma growth at distant sites, including the brain. Furthermore, the results highlight the significance of PDCD4 dysregulation in disseminated melanoma and implicate PDCD4 as a possible causal link between PLEKHA5 and cell proliferation and growth.

A longitudinal study on circulating miR-21 as a therapeutic effect marker in head and neck squamous cell carcinoma

The aim of the study is to investigate plasma miR-21 for a possible therapeutic effect determination marker in head and neck squamous cell carcinoma (HNSCC). Plasma samples are obtained from 86 HNSCC patients and 29 non-cancer volunteers who had been treated at Mie University Hospital between May 2015 and December 2016, and plasma miR-21 expression was measured using real-time quantitative reverse transcription polymerase chain reaction. In addition, plasma miR-21 level of advanced HNSCC patients including 22 non-recurrent cases and 11 recurrent cases before and after treatment was analyzed using a longitudinal design. Plasma miR-21 expression in 86 HNSCC patients was obviously higher than in 29 control patients (P < 0.0001). The area under the curve (AUC) for plasma miR-21 was 0.756 (95% confidence interval: 0.661-0.851). Furthermore, our longitudinal study of plasma miR-21 showed that the expression level of plasma miR-21 was significantly reduced at the time point of 2 months after treatment in case of no recurrence. On the other hand, plasma miR-21 was not decreased after treatment in case of 10 patients who had developed recurrences during the follow-up period. This study may provide new insights into the role of plasma miR-21 as a biomarker for HNSCC, and plasma miR-21 would be useful for early detection of tumor recurrence after operation or chemoradiotherapy.

MicroRNA Expression Levels and Histopathological Features of Colorectal Cancer

INTRODUCTION

Non-coding RNAs have opened a new window in cancer biology. MicroRNAs (miRNAs), as a family of non-coding RNAs, play an important role in the gene regulation. The aberrant expression of these small molecules has been documented to involve in colorectal cancer (CRC) pathogenesis. This study aimed to examine the expression of miRNAs in CRC and to correlate their expression levels with histological markers (Ki-67 and CD34).

MATERIALS AND METHODS

Tumor tissues and matched normal adjacent tissues were collected from 36 patients with newly diagnosed CRC. Immunohistochemical (IHC) staining of tumor tissues was performed for Ki-67 (proliferation) and CD34 (angiogenesis) markers, and the immunoexpression staining scores were obtained. A polyadenylation SYBER Green quantitative real-time PCR technique was used to quantify the expression of a panel of five CRC-related miRNAs (hsa-miR-21, 31, 20a, 133b, and 145). Histopathological (H) scores and miRNA expression levels were correlated with clinicopathological features including the degree of differentiation, staging, and lymphovascular invasion.

RESULTS

Our results showed the significant difference between the two groups for the expression level of hsa-miR-21, hsa-miR-31, hsa-miR-145, and miR-20a (P < 0.001), but not for hsa-miR-133b (P = 0.57). Further analysis revealed an inverse significant correlation between hsa-miR-145 and Ki-67 (r = - 0.942, P < 0.001). While a positive correlation was observed between hsa-miR-21 and Ki-67 (r = 0.920, P < 0.001), and hsa-miR-21 and CD34 (r = 0.981, P < 0.001). Also, a positive correlation between hsa-miR-31 and Ki-67 (r = 0.913, P < 0.001), hsa-miR-31 and CD34 (r = 0.798, P < 0.05), hsa-miR-20a and Ki-67 (r = 0.871, P < 0.001), and hsa-miR-20a and CD34 (r = 0.890, P < 0.001) was found.

CONCLUSION

Dysregulation of miRNAs and correlation with molecular histopathology indicate a biological role for miRNAs in various cellular processes including cell proliferation and angiogenesis in CRC development. On the other hand, the pattern of miRNA expression and its correlation with histological markers are potentially valuable to apply as diagnostic biomarkers for CRC.

Genetic and molecular biology of breast cancer among Iranian patients

Abstract

Background, Breast cancer (BC) is one of the leading causes of cancer related deaths in Iran. This high ratio of mortality had a rising trend during the recent years which is probably associated with late diagnosis.

Main body

Therefore it is critical to define a unique panel of genetic markers for the early detection among our population. In present review we summarized all of the reported significant genetic markers among Iranian BC patients for the first time, which are categorized based on their cellular functions.

Conclusions

This review paves the way of introducing a unique ethnic specific panel of diagnostic markers among Iranian BC patients. Indeed, this review can also clarify the genetic and molecular bases of BC progression among Iranians.

Correlation between microRNA-21, microRNA-206 and estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 in breast cancer

BACKGROUND

Although the function of microRNA-21 and microRNA-206 in breast cancer cells have been investigated in vitro, their association with estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) are not reported.

METHODS

ER, PR, HER2, and Ki-67 staining pattern were utilized to classify 75 breast cancer patients recruited. The malignancy was predicted with tumor nodes metastases (TNM) classification. RT-qPCR was performed to detect the relative expression of ER, PR, and HER2 in tumor samples and microRNA-21 and microRNA-206 in the serum. Spearman's correlation analysis was used to determine the association between different molecules. According to the staining pattern, the breast cancer patients were classified into five types.

RESULTS

microRNA-21 was up-regulated in HER2 positive and Basal-like breast cancer types, while microRNA-206 was up-regulated in Luminal A and B types of breast cancer. microRNA-21 expression negatively correlated with the level of ER and PR but positively correlated with HER2 expression and tumor malignancy, while microRNA-206 showed the opposite trend. Neither microRNA-21 nor microRNA-206 showed any significant correlation with the age of the patients.

CONCLUSION

Both microRNA-21 and microRNA-206 closely correlate with ER, PR, and HER2 expression, which can be considered as clinical biomarkers.

GLUT1-mediated effective anti-miRNA21 pompon for cancer therapy

Oncogenic microRNAs are essential components in regulating the gene expression of cancer cells. Especially miR21, which is a major player involved of tumor initiation, progression, invasion and metastasis in several cancers. The delivery of anti-miR21 sequences has significant potential for cancer treatment. Nevertheless, since anti-miR21 sequences are extremely unstable and they need to obtain certain concentration to function, it is intensely difficult to build an effective delivery system for them. The purpose of this work is to construct a self-assembled glutathione (GSH)-responsive system with tumor accumulation capacity for effective anti-miR21 delivery and cancer therapy. A novel drug delivery nanosphere carrying millions of anti-miR21 sequences was developed through the rolling circle transcription (RCT) method. GSH-responsive cationic polymer polyethyleneimine (pOEI) was synthesized to protect the nanosphere from degradation by Dicer or other RNase in normal cells and optimize the pompon-like nanoparticle to suitable size. Dehydroascorbic acid (DHA), a targeting molecule, which is a substrate of glucose transporter 1 (GLUT 1) and highly expressed on malignant tumor cells, was connected to pOEI through PEG, and then the polymer was used for contracting a RNA nanospheres into nanopompons. The anti-miR21 nanopompons showed its potential for effective cancer therapy.

Non-coding RNAs as potential therapeutic targets in breast cancer

Paradigm shifting studies especially involving non-coding RNAs (ncRNAs) during last few decades have significantly changed the scientific perspectives regarding the complexity of cellular signalling pathways. Several studies have shown that the non-coding RNAs, initially ignored as transcriptional noise or products of erroneous transcription; actually regulate plethora of biological phenomena ranging from developmental processes to various diseases including cancer. Current strategies that are employed for the management of various cancers including that of breast fall short when their undesired side effects like Cancer Stem Cells (CSC) enrichment, low recurrence-free survival and development of drug resistance are taken into consideration. This review aims at exploring the potential role of ncRNAs as therapeutics in breast cancer, by providing a comprehensive understanding of their mechanism of action and function and their crucial contribution in regulating various aspects of breast cancer progression such as cell proliferation, angiogenesis, EMT, CSCs, drug resistance and metastasis. In addition, we also provide information about various strategies that can be employed or are under development to explore them as potential moieties that may be used for therapeutic intervention in breast cancer.

Delivery of Anti-miRNA for Triple-Negative Breast Cancer Therapy Using RNA Nanoparticles Targeting Stem Cell Marker CD133

Triple-negative breast cancer (TNBC) is an aggressive disease with a short median time from relapse to death. The increased aggressiveness, drug resistance, disease relapse, and metastasis are associated with the presence of stem cells within tumors. Several stem cell markers, such as CD24, CD44, CD133, ALDH1, and ABCG2, have been reported, but their roles in breast cancer tumorigenesis remain unclear. Herein, we apply RNA nanotechnology to deliver anti-microRNA (miRNA) for TNBC therapy. The thermodynamically and chemically stable three-way junction (3WJ) motif was utilized as the scaffold to carry an RNA aptamer binding to CD133 receptor and a locked nuclei acid (LNA) sequence for miRNA21 inhibition. Binding assays revealed the specific uptake of the nanoparticles to breast cancer stem cells (BCSCs) and TNBC cells. Functional assays showed that cancer cell migration was reduced, miR21 expression was inhibited, and downstream tumor suppressor PTEN and PDCD4 expressions were upregulated. In vitro and in vivo studies revealed that these therapeutic RNA nanoparticles did not induce cytokine secretion. Systemic injection of these RNA nanoparticles in animal trial demonstrated high specificity in TNBC tumor targeting and high efficacy for tumor growth inhibition. These results revealed the clinical translation potential of these RNA nanoparticles for TNBC therapy.

A perspective on the diagnostics, prognostics, and therapeutics of microRNAs of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive and prevalent subtype of breast cancer in women worldwide. Currently, chemotherapy remains the main modality for the treatment at an early stage, as there is no approved targeted therapy for early TNBC. In this review, we investigate the use of microRNAs (miRNAs), which play a key role in the post-transcriptional regulation of genes involved in the key biological processes, namely proliferation, differentiation, angiogenesis, migration, apoptosis, and carcinogenesis. Here, we emphasize the importance of the recent advances related to miRNAs, involving diagnosis, prognosis, and treatment of TNBC. We focus on the development, optimization, and stabilization of miRNA-based drugs; improvement of miRNA delivery; and control of the off-target effects of miRNA therapeutics. We speculate as to which features may present themselves as promising approaches in the treatment of TNBC.

Long non-coding RNA MEG3 suppresses the development of bladder urothelial carcinoma by regulating miR-96 and TPM1

We aimed at investigating effects of long non-coding RNA maternally expressed 3 (MEG3) on the proliferation, cell cycle and apoptosis of bladder urothelial carcinoma cells and regulatory relationships among lncRNA MEG3, miR-96 and α-tropomyosin 1 (TPM1). Human clinical data from The Cancer Genome Atlas (TCGA) which contains bladder urothelial carcinoma tissues and adjacent tissues were used for analysis. The expression profiles of MEG3, miR-96, TPM1, cell cycle-related genes and apoptosis-related genes were examined by real-time quantitative polymerase chain reaction (RT-qPCR) and western blot. Regulating relationship among MEG3, miR-96 and TPM1 was confirmed by dual luciferase reporter assay. MTT assay and flow cytometry were performed to observe cell proliferation, cell cycle and apoptosis. The effects of lncRNA MEG3 on bladder urothelial carcinoma were confirmed both in vivo and in vitro. The mRNA expression and protein expression of MEG3, TPM1 were down-regulated in carcinoma tissues, whereas miR-96 expression was up-regulated. MEG3 overexpression resulted in miR-96 downregulation along with TPM1 upregulation, which inhibited cell proliferation and cell cycle but promoted cell apoptosis of bladder urothelial carcinoma cells in vitro, and at the same time inhibited tumor growth in vivo. In this process, expressions of apoptosis-related protein BCL2 associated X (Bax), cleaved-caspase 3 was up-regulated, whereas apoptosis regulator protein (Bcl-2) expression was suppressed when MEG3 was overexpressed, and cell cycle-related protein Cyclin D1 was down-regulated. LncRNA MEG3 low-expression promotes the proliferation and inhibits apoptosis of bladder urothelial carcinoma cells by regulating miR-96 along with TPM1.