MicroRNA-224 Promotes Tumorigenesis through Downregulation of Caspase-9 in Triple-Negative Breast Cancer

miR-484 as an "OncomiR" in Breast Cancer Promotes Tumorigenesis by Suppressing Apoptosis Genes

PURPOSE

Breast cancer (BC) is one of the most common causes of death among females. Cancer cells escape from apoptosis, causing the cells to proliferate uncontrollably. MicroRNAs (miRNAs) are known to regulate apoptosis in cancer cells.

OBJECTIVE

This study aimed to determine the change in miR-484 in different BC cells and its relationship with the apoptosis pathway.

METHODS

In the study, tumor and healthy tissue samples adjacent to the tumor were collected from 42 patients (6 benign, 36 malignant). Tissue samples were classified according to tumor type, tumor histological grade, proliferation index, and molecular subtypes. Gene expression levels were determined by quantitative real-time polymerase chain reaction (qRT-PCR), and protein levels were determined using the Western Blot method. The results were analyzed using the delta-delta Ct method.

RESULTS

Findings showed that miR-484 expression levels were higher in malignant tumors than in benign tumors, and higher in tumor tissues than healthy tissues. Additionally, it was determined that as Ki-67 levels and histological grade and aggressiveness increased, miR-484 expression levels also increased. In tumor tissue compared with healthy adjacent tissue, there was an increase in BCL2 expression and a decrease in Casp3 and Casp9 expression. Therefore, a positive correlation was found between miR-484 expression and BCL2, and a negative correlation was found between CASP3 and CASP9 expression.

CONCLUSION

Our results show that miR-484 may play a roll as an onco-miR in BC. Increased miR-484 and BCL2, and decreased Casp3, in breast tumor tissues suggest that Casp9 expression may increase uncontrolled cell proliferation by suppressing apoptosis in BC cells and may contribute to tumor progression.

Supervised multiple kernel learning approaches for multi-omics data integration

BACKGROUND

Advances in high-throughput technologies have originated an ever-increasing availability of omics datasets. The integration of multiple heterogeneous data sources is currently an issue for biology and bioinformatics. Multiple kernel learning (MKL) has shown to be a flexible and valid approach to consider the diverse nature of multi-omics inputs, despite being an underused tool in genomic data mining.

RESULTS

We provide novel MKL approaches based on different kernel fusion strategies. To learn from the meta-kernel of input kernels, we adapted unsupervised integration algorithms for supervised tasks with support vector machines. We also tested deep learning architectures for kernel fusion and classification. The results show that MKL-based models can outperform more complex, state-of-the-art, supervised multi-omics integrative approaches.

CONCLUSION

Multiple kernel learning offers a natural framework for predictive models in multi-omics data. It proved to provide a fast and reliable solution that can compete with and outperform more complex architectures. Our results offer a direction for bio-data mining research, biomarker discovery and further development of methods for heterogeneous data integration.

Reversal of the tamoxifen‑resistant breast cancer malignant phenotype by proliferation inhibition with bromosulfonamidine amino‑podophyllotoxin

One of the lignans isolated from plants within the genus Podophyllum is podophyllotoxin (PPT). PPT and its derivatives are pharmacologically active compounds with potential antiproliferative properties in several kinds of tumors. Although these compounds have been used to treat other malignancies, no PPT derivative-based chemotherapeutic agent has been used to cure tamoxifen (TAM)-resistant breast cancer in clinical trials, to the best of our knowledge. Thus, using TAM-resistant breast cancer as a disease model, the present study assessed the effects of a recently synthesized PPT derivative, bromosulfonamidine amino-PPT (BSAPPT), on TAM-resistant breast cancer. Using the tamoxifen-resistant breast cancer cell model (MCF-7/TAMR) in vitro, Cell Counting Kit-8 and colony formation assays were adopted to evaluate the effect of BSAPPT on cell proliferation. Cell apoptosis and cell cycle assays were used to assess the influence of BSAPPT on cell apoptosis and the cell cycle in MCF-7/TAMR. The targets of the potential mechanism of action were analyzed by RT-qPCR and western blotting. The present study demonstrated that BSAPPT suppressed MCF-7/TAMR cell proliferation in a dose-dependent manner. By modulating the level of expression of genes linked to both apoptosis and the cell cycle, BSAPPT triggered MCF-7/TAMR cells to undergo apoptosis and prevented them from entering the cell cycle. Consequently, BSAPPT blocked these cells from proliferating, thereby halting the malignant advancement of TAM-resistant breast cancer. Therefore, these findings indicate that new therapeutic agents involving BSAPPT may be developed to facilitate the treatment of TAM-resistant breast cancer.

Integration of TE Induces Cancer Specific Alternative Splicing Events

Alternative splicing of messenger RNA (mRNA) precursors contributes to genetic diversity by generating structurally and functionally distinct transcripts. In a disease state, alternative splicing promotes incidence and development of several cancer types through regulation of cancer-related biological processes. Transposable elements (TEs), having the genetic ability to jump to other regions of the genome, can bring about alternative splicing events in cancer. TEs can integrate into the genome, mostly in the intronic regions, and induce cancer-specific alternative splicing by adjusting various mechanisms, such as exonization, providing splicing donor/acceptor sites, alternative regulatory sequences or stop codons, and driving exon disruption or epigenetic regulation. Moreover, TEs can produce microRNAs (miRNAs) that control the proportion of transcripts by repressing translation or stimulating the degradation of transcripts at the post-transcriptional level. Notably, TE insertion creates a cancer-friendly environment by controlling the overall process of gene expression before and after transcription in cancer cells. This review emphasizes the correlative interaction between alternative splicing by TE integration and cancer-associated biological processes, suggesting a macroscopic mechanism controlling alternative splicing by TE insertion in cancer.

Pyroptosis-Related Gene to Construct Prognostic Signature and Explore Immune Microenvironment and Immunotherapy Biomarkers in Bladder Cancer

Bladder cancer is known to be the most common malignant tumor in the urinary system and has a poor prognosis; thus, new targets for drug treatment are urgently needed. Pyroptosis is defined as programmed cell death in the inflammatory form mediated by the gasdermin protein. It has therapeutic potential due to the synergistic effect of radiotherapy and chemotherapy, can reverse chemotherapy resistance, is able to regulate the body environment to alter tumor metabolism, and may enhance the response rate of the immune checkpoint inhibitor. Accordingly, this study attempted to explore the role of pyroptosis in bladder cancer. A prognostic model based on five pyroptosis-related genes was constructed by conducting univariate Cox survival and LASSO regression analyses using The Cancer Genome Atlas (TCGA) cohort. Patients were divided into high- and low-risk groups according to the median risk score, with all five PRGs having downregulated expression in the high-risk group. The high-risk group was shown to have a worse prognosis than the low-risk group, and survival differences between the two groups were then validated in the Gene Expression Omnibus (GEO) cohort. Moreover, the ROC curves demonstrated the model’s moderate predictive ability. The univariate and multivariate Cox regression analyses indicated that risk scores were found to serve as an independent prognosis factor for OS in bladder cancer patients. In addition, the high-risk group was observed to be associated with advanced N and TNM stages. A nomogram combining risk scores and clinical features was then established, with the ROC curve indicating that the AUC of TCGA training cohort in 3 and 5 years was 0.789 and 0.775, respectively. The calibration curve exhibited a high consistency between the actual survival rate and the predicted rate. Furthermore, the GO and KEGG analyses found that antigen processing and presentation of exogenous antigen, exogenous peptide antigen, and peptide antigen were enriched in the low-risk group. A higher abundance of tumor-infiltrating immune cells and additional active immune pathways were also noted in the low-risk group. In addition, immunotherapy biomarkers, including TMB, PD1, PD-L1, CTLA4, and LAG3, were shown to have higher levels in the low-risk group. Therefore, patients in the low-risk group may be potential responders to immune checkpoint inhibitors.

Footprints of microRNAs in Cancer Biology

MicroRNAs (miRNAs) are short non-coding RNAs involved in post-transcriptional gene regulation. Over the past years, various studies have demonstrated the role of aberrant miRNA expression in the onset of cancer. The mechanisms by which miRNA exerts its cancer-promoting or inhibitory effects are apparent through the various cancer hallmarks, which include selective proliferative advantage, altered stress response, vascularization, invasion and metastasis, metabolic rewiring, the tumor microenvironment and immune modulation; therefore, this review aims to highlight the association between miRNAs and the various cancer hallmarks by dissecting the mechanisms of miRNA regulation in each hallmark separately. It is hoped that the information presented herein will provide further insights regarding the role of cancer and serve as a guideline to evaluate the potential of microRNAs to be utilized as biomarkers and therapeutic targets on a larger scale in cancer research.

Bisphenol A and its effects on the systemic organs of children

For the past two decades, growing research has been pointing to multiple repercussions of bisphenol A (BPA) exposure to human health. BPA is a synthetic oestrogen which primarily targets the endocrine system; however, the compound also disturbs other systemic organ functions, in which the magnitude of impacts in those other systems is as comparable to those in the endocrine system. To date, the discoveries on the association between BPA and health outcomes mainly came from animal and in vitro studies, with limited human studies which emphasised on children's health. In this comprehensive review, we summarised studies on human, in vivo and in vitro models to understand the consequences of pre-, post- and perinatal BPA exposure on the perinatal, children and adult health, encompassing cardiovascular, neurodevelopmental, endocrine and reproductive effects.Conclusion: Evidence from in vitro and animal studies may provide further support and better understanding on the correlation between environmental BPA exposure and its detrimental effects in humans and child development, despite the difficulties to draw direct causal relations of BPA effects on the pathophysiology of the diseases/syndromes in children, due to differences in body system complexity between children and adults, as well as between animal and in vitro models and humans. What is known: • Very limited reviews are available on how BPA adversely affects children's health. • Previous papers mainly covered two systems in children. What is new: • Comprehensive review on the detrimental effects of BPA on children health outcomes, including expectations on adult health outcomes following perinatal BPA exposure, as well as covering a small part of BPA alternatives. • Essentially, BPA exposure during pregnancy has huge impacts on the foetus in which it may cause changes in foetal epigenetic programming, resulting in disease onsets during childhood as well as adulthood.

A Novel TCGA-Validated, MiRNA-Based Signature for Prediction of Breast Cancer Prognosis and Survival

Breast cancer (BC) is the most common cancer affecting women and the leading cause of cancer-related deaths worldwide. Compelling evidence indicates that microRNAs (miRNAs) are inextricably involved in the development of cancer. Here, we constructed a novel model, based on miRNA-seq and clinical data downloaded from The Cancer Genome Atlas (TCGA). Data from a total of 962 patients were included in this study, and the relationships among their clinicopathological features, survival, and miRNA-seq expression levels were analyzed. Hsa-miR-186 and hsa-miR-361 were identified as internal reference miRNAs and used to normalize miRNA expression data. A five-miRNA signature, constructed using univariate and multivariate Cox regression, was significantly associated with disease-specific survival (DSS) of patients with BC. Kaplan–Meier (KM) and receiver operating characteristic (ROC) analyses were conducted to confirm the clinical significance of the five-miRNA signature. Finally, a nomogram was constructed based on the five-miRNA signature to evaluate its clinical value. Cox regression analysis revealed that a five-miRNA signature was significantly associated with DSS of patients with BC. KM analysis demonstrated that the signature could efficiently distinguish high- and low-risk patients. Moreover, ROC analysis showed that the five-miRNA signature exhibited high sensitivity and specificity in predicting the prognosis of patients with BC. Patients in the high-risk subgroup who received adjuvant chemotherapy had a significantly lower incidence of mortality than those who did not. A nomogram constructed based on the five-miRNA signature was effective in predicting 5-year DSS. This study presents a novel five-miRNA signature as a reliable prognostic tool to predict DSS and provide theoretical reference significance for individualized clinical decisions for patients with BC.

Oncogenesis and Tumor Inhibition by MicroRNAs and its Potential Therapeutic Applications: A Systematic Review

MicroRNAs appear as small molecule modifiers, which improve many new findings and mechanical illustrations for critically important biological phenomena and pathologic events. The best-characterized non-coding RNA family consists of about 2600 human microRNAs. Rich evidence has revealed their crucial importance in maintaining normal development, differentiation, growth control, aging, modulation of cell survival or apoptosis, as well as migration and metastasis as microRNAs dysregulation leads to cancer incidence and progression. By far, microRNAs have recently emerged as attractive targets for therapeutic intervention. The rationale for developing microRNA therapeutics is based on the premise that aberrantly expressed microRNAs play a significant role in the emergence of a variety of human diseases ranging from cardiovascular defects to cancer, and that repairing these microRNA deficiencies by either antagonizing or restoring microRNA function may yield a therapeutic benefit. Although microRNA antagonists are conceptually similar to other inhibitory therapies, improving the performance of microRNAs by microRNA replacement or inhibition that is a less well- described attitude. In this assay, we have condensed the last global knowledge and concepts regarding the involvement of microRNAs in cancer emergence, which has been achieved from the previous studies, consisting of the regulation of key cancer-related pathways, such as cell cycle control and the DNA damage response and the disruption of profile expression in human cancer. Here, we have reviewed the special characteristics of microRNA replacement and inhibition therapies and discussed explorations linked with the delivery of microRNA mimics in turmeric cells. Besides, the achievement of biomarkers based on microRNAs in clinics is considered as novel non-invasive biomarkers in diagnostic and prognostic assessments.

Expression of miR-92a, miR-224 and miR-25 in non-small cell lung cancer and their correlation with clinical characteristics

OBJECTIVE

To analyze the correlation of the expression of microRNA-92a (miR-92a), microRNA-224 (miR-224), and microRNA-25 (miR-25) in non-small cell lung cancer with its clinical characteristics.

METHODS

This prospective study was performed in 125 non-small cell lung cancer patients admitted to our hospital between January 2019 and January 2020. All patients' cancer and adjacent tissue were collected and the expression of miR-92a, miR-224, and miR-25 were detected using real-time fluorescence quantitative RT-PCR. Data were analyzed using SPSS statistical software (version 20.0). Correlation analysis was conducted using Pearson correlation coefficient.

RESULTS

Compared with adjacent tissue, the relative expression of miR-92a, miR-224, and miR-25 in cancer tissue were increased (all P<0.001). There was no correlation between the expression of miR-92a, miR-224, and miR-25 and baseline data like gender, age, smoking history, and tumor size (all P>0.05). The relative expression of miR-92a, miR-224 and miR-25 in differentiated cancer patients were higher than those in highly and moderately differentiated cancer patients (all P<0.05). The relative expression of miR-92a, miR-224 and miR-25 in patients with lymph node metastasis (LNM) were increased when compared with those had no LNM (all P<0.001). Compared with stage I and II patients, the relative expression of miR-92a, miR-224 and miR-25 in stage III and IV patients were increased (all P<0.001). The relative expression of miR-92a, miR-224, and miR-25 were positively correlated to each other (all P<0.01).

CONCLUSION

miR-92a, miR-224, and miR-25 are overexpressed in non-small cell lung cancer and the expressions are related to the degree of differentiation, presence or absence of LNM, and TNM staging. In addition, the expression of miR-92a, miR-224 and miR-25 are positively correlated to each other. This suggests that miR-92a, miR-224, and miR-25 cooperatively participated in the occurrence and development of non-small cell lung cancer.

Experimental Study on the Correlation between miRNA-373 and HIF-1α, MMP-9, and VEGF in the Development of HIE

INTRODUCTION

Microribonucleic acids (miRNAs) have short (approximately 18 to 25) nucleotides and are evolutionarily conserved and endogenously expressed RNAs belonging to a family of noncoding RNA molecules. miRNA-373 regulates cell proliferation, migration, apoptosis, invasion, and repairing damaged DNA after hypoxia stress. Neonatal hypoxic-ischemic encephalopathy (HIE) refers to perinatal asphyxia caused by partial or complete hypoxia, reduced or suspended cerebral blood flow, and fetal or neonatal brain damage. We aim to investigate the relationship between miRNA-373 and HIF-1α, between miRNA-373 MMP-9, and between miRNA-373 VEGF in the occurrence and development of HIE.

METHODS

Human (children) samples were divided into four groups (n = 15 in each group) according to HIE severity. The patient group was divided into middle, moderate, and severe HIE groups. The control group included healthy children or children with nonneurological diseases. The expressions of miRNA-373, HIF-1α, MMP-9, and VEGF were assayed in the serum samples.

RESULTS

Our study showed a strong relationship between miRNA-373 and HIF-1α, between miRNA-373 and MMP-9, and between miRNA-373 and VEGF. The expression levels of miRNA-373, HIF-1α, MMP-9, and VEGF in the HIE groups were much higher than those of the control group.

CONCLUSION

The increased change in miRNA-373 expression has a certain diagnostic significance on neonatal HIE. In the occurrence and development of HIE, miRNA-373 is positively correlated with HIF-1α, MMP-9, and VEGF.

Computational Identification of Sex-Biased Biomarker MicroRNAs and Genes Associated with Immune Infiltration in Breast Cancer

MicroRNAs (miRNAs) perform their functions through targeting messenger RNAs (mRNAs). X chromosome-located (X-linked) miRNAs have a broad role in cell lineage determination, immune regulation, and oncogenesis. The regulating roles of miRNAs in cancer and immunity are often altered when aberrant expression happens. Sex-biased genes could contribute to cancer sex bias in the context of their expression change due to targeting miRNAs. How biological roles and associations with immune cell abundance levels for sex-biased gene-miRNA pairs in gender-related cancer (e.g., breast cancer) change due to the alteration of their expression pattern to identify candidate therapeutic markers has not been investigated thoroughly. Upon analyzing anti-correlated genes and miRNAs within significant clusters of 12 The Cancer Genome Atlas (TCGA) cancer types and the list of sex-biased genes and miRNAs reported from previous studies, 125 sex-biased genes (11 male-biased and 114 female-biased) were identified in breast cancer (BC). Seventy-three sex-biased miRNAs (40 male-biased and 33 female-biased) were identified across 5 out of 12 cancers (head and neck squamous cell carcinoma (HNSC), kidney chromophobe (KICH), kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), and lung adenocarcinoma (LUAD)). Correlation between the BC sex-biased genes and tumor infiltrating immune cell types was further evaluated. We found eight genes having high correlation with immune infiltration. Fifteen candidate female-biased BC genes targeted by 3 X-linked miRNAs (has-mir-18hashsa-mir-221, and hsa-mir-224) were pinpointed in this study. Our computational result indicates that many identified female-biased genes which have positive associations with immune cell abundance levels could serve as alternative therapeutic markers. Our analysis suggests that female-biased expression of BC candidate genes is likely influenced by their targeting miRNA(s).

Differential methylation and expression patterns of microRNAs in relation to breast cancer subtypes among American women of African and European ancestry

Aggressive high-grade, estrogen receptor negative (ER-) breast cancer is more common among American women of African ancestry (AA) than those of European ancestry (EA). Epigenetic mechanisms, particularly DNA methylation and altered microRNA (miRNA) expression, may contribute to racial differences in breast cancer. However, few studies have specifically characterized genome-wide DNA methylation-based modifications at the miRNA level in relation to ER+ and ER- subtype, and their functional role in the regulation of miRNA expression, especially among high risk AA women. In this study, we evaluated DNA methylation patterns of miRNA encoding genes and their effect on expression in breast tumors from both AA and EA women. The genome-wide methylation screen identified a total of 7,191 unique CpGs mapped to 1,292 miRNA genes, corresponding to 2,035 unique mature miRNAs. We identified differentially methylated loci (DMLs: (|delta β|)>0.10, FDR<0.05) between ER- and ER+ tumor subtypes, including 290 DMLs shared in both races, 317 and 136 were specific to AA and EA women, respectively. Integrated analysis identified certain DMLs whose methylation levels were significantly correlated with the expression of relevant miRNAs, such as multiple CpGs within miR-190b and miR-135b highly negatively correlated with their expression. These results were then validated in the TCGA dataset. Target prediction and pathway analysis showed that these DNA methylation-dysregulated miRNAs are involved in multiple cancer-related pathways, including cell cycle G1-S growth factor regulation, cytoskeleton remodeling, angiogenesis, EMT, and ESR1-mediated signaling pathways. In summary, our results suggest that DNA methylation changes within miRNA genes are associated with altered miRNA expression, which may contribute to the network of subtype- and race-related tumor biological differences in breast cancer. These findings support the involvement of epigenetic regulation of miRNA expression and provide insights into the relations of clinical-relevant miRNAs to their target genes, which may serve as potential preventative and therapeutic targets.

Advances in Understanding Mitochondrial MicroRNAs (mitomiRs) on the Pathogenesis of Triple-Negative Breast Cancer (TNBC)

Triple-negative breast cancer (TNBC) is characterized by poor outcome and the most challenging breast cancer type to treat worldwide. TNBC manifests distinct profile of mitochondrial functions, which dictates reprogrammed metabolism, fosters tumor progression, and notably serves as therapeutic targets. Mitochondrial microRNAs (mitomiRs) are a group of microRNAs that critically modulate mitochondrial homeostasis. By a pathway-centric manner, mitomiRs tightly orchestrate metabolic reprogramming, redox status, cell apoptosis, mitochondrial dynamics, mitophagy, mitochondrial DNA (mtDNA) maintenance, and calcium balance, leading to an emerging field of study in various cancer types, including TNBC. We herein review the recent insights into the roles and mechanism of mitomiRs in TNBC and highlight its clinical value in diagnosis and prognosis as well as vital advances on therapeutics of preclinical and clinical studies.

lncRNA MIR503HG inhibits cell proliferation and promotes apoptosis in TNBC cells via the miR-224-5p/HOXA9 axis

Triple-negative breast cancer (TNBC) is a highly invasive subtype of breast cancer. This study investigated the molecular mechanism and influences of MIR503HG, miR-224-5p, and homeobox A9 (HOXA9) on TNBC cell growth and migration. Dual-luciferase reporter gene and RNA immunoprecipitation were performed to examine the regulation of MIR503HG, miR-224-5p, and HOXA9. Cell proliferation, apoptosis, migration, and invasion were evaluated by colony formation, flow cytometry, and Transwell assays. Finally, nude mice were employed to investigate the influence of MIR503HG on TNBC tumor growth. HOXA9 protein levels were detected by immunohistochemical staining. MIR503HG and HOXA9 expression were reduced in TNBC, while miR-224-5p was increased. Overexpression of MIR503HG or HOXA9 reduced the cell migration ability and proliferation and promoted apoptosis, and knockdown of MIR503HG or overexpression of miR-224-5p exhibited the opposite effects. Furthermore, MIR503HG promoted HOXA9 expression by inhibiting miR-224-5p. Overexpression of miR-224-5p reversed the effects of MIR503HG overexpression on TNBC cells, while overexpression of HOXA9 reversed the effect of MIR503HG knockdown. Additionally, an in vivo study proved that MIR503HG inhibited TNBC tumor growth via the miR-224-5p/HOXA9 axis. MIR503HG inhibited cell proliferation and promoted the apoptosis of TNBC cells via the miR-224-5p/HOXA9 axis, which may function as a novel target for the treatment of TNBC.

Resveratrol, curcumin, paclitaxel and miRNAs mediated regulation of PI3K/Akt/mTOR pathway: go four better to treat bladder cancer

Bladder cancer (BC) is a leading cause of death among urothelial malignancies that more commonly affect male population. Poor prognosis and resistance to chemotherapy are the two most important characteristics of this disease. PI3K/Akt/mTOR signaling pathway has been considered pivotal in the regulation of proliferation, migration, invasiveness, and metastasis. Deregulation of PI3K/Akt/mTOR signaling has been found in 40% of bladder cancers. Several microRNAs (miRNAs) have been reported to interact with the PI3K/Akt/mTOR signaling pathway with a different possible role in proliferation and apoptosis in bladder cancer. Thus, miRNAs can be used as potential biomarkers for BC. Natural compounds have been in the spotlight for the past decade due to their effective anti-proliferative capabilities. However, little is known of its possible effects in bladder cancer. The aim of this review is to discuss the interplay between PI3K/Akt/mTOR, miRNAs, and natural compounds and emphasize the importance of miRNAs as biomarkers and resveratrol, curcumin and paclitaxel as a possible therapeutic approach against bladder cancer.

miR-224 targets BTRC and promotes cell migration and invasion in colorectal cancer

Our study aims to investigate the impact of miR-224 on cell migration and invasion in colorectal cancer (CRC) as well as its molecular mechanisms. The results showed that miR-224 was significantly upregulated in CRC compared to normal tissues via the TCGA database. Overexpression of miR-224 promoted CRC cell migration and invasion, while inhibition of miR-224 demonstrated the opposite result via transwell assays. In addition, we found that BTRC was a target gene of miR-224 through the miRecords database and dual-luciferase assay, while western blot together with RT-qPCR showed that inhibition of miR-224 led to elevated BTRC expression in protein level but not in mRNA level, and also decreased the expression of β-catenin. In reference to the Human Protein Atlas, BTRC protein expression was higher in normal tissues than in CRC tissues. In conclusion, miR-224 regulates its target BTRC protein expression and its related Wnt/β-catenin pathway. Its impact on cell migration and invasion in CRC cells suggested that miR-224 could be a prospective therapeutic target for early-stage non-metastatic CRC.

Potential miRNAs for miRNA-Based Therapeutics in Breast Cancer

MicroRNAs (miRNAs) are small non-coding RNAs that can post-transcriptionally regulate the genes involved in critical cellular processes. The aberrant expressions of oncogenic or tumor suppressor miRNAs have been associated with cancer progression and malignancies. This resulted in the dysregulation of signaling pathways involved in cell proliferation, apoptosis and survival, metastasis, cancer recurrence and chemoresistance. In this review, we will first (i) provide an overview of the miRNA biogenesis pathways, and in vitro and in vivo models for research, (ii) summarize the most recent findings on the roles of microRNAs (miRNAs) that could potentially be used for miRNA-based therapy in the treatment of breast cancer and (iii) discuss the various therapeutic applications.

Characterization and Cytotoxicity of Polyprenol Lipid and Vitamin E-TPGS Hybrid Nanoparticles for Betulinic Acid and Low-Substituted Hydroxyl Fullerenol in MHCC97H and L02 Cells

Background

This study demonstrated an innovative formulation including the polyprenol (GBP) lipid and vitamin E-TPGS hybrid nanoparticles (NPs) which was aimed to control the transfer of betulinic acid (BA) and low-substituted hydroxyl fullerenol (C₆₀(OH)_n). Additionally, it developed BA-C₆₀(OH)n-GBP-TPGS-NPs delivery system and researched the anti-hepatocellular carcinoma (HCC) effects.

Materials and Methods

The NPs were prepared by nanoprecipitation with ultrasonic-assisted emulsification (UAE) method. It was characterized by scanning electronic microscopy (SEM), transmission electron microscopy (TEM), FTIR spectrum, size distribution and zeta potential. Physical and chemical properties were evaluated through measurement of drug release, stability studies, drug loading efficiency (DE) and encapsulation efficiency (EE). Biological activities were evaluated through measurement of MTT assay, lactate dehydrogenase leakage assay (LDH), cell proliferation assays, cell apoptosis analysis, comet assay, wound healing assay, cell invasion and Western blot analysis.

Results and Conclusions

The NPs exhibited clear distribution characteristics, improved solubility and stability. BA and C₆₀(OH)_n for the NPs displayed a biphasic release pattern with sustained drug release properties. The mixture of C₆₀(OH)_n with different hydroxyl groups may have a certain effect on the stability of the NPs system itself. The NPs could effectively inhibit MHCC97H cell proliferation, migration and invasion in vitro. Combined use of C₆₀(OH)_n and BA in GBP lipids may improve the inhibit effect of C₆₀(OH)_n or BA against HCC cells and reduce cytotoxicity and genotoxicity of C₆₀(OH)_n for normal cells. We concluded that one of the important mechanisms of BA-C₆₀(OH)_n-GBP-TPGS-NPs inhibiting MHCC97H cells is achieved by up-regulating the expression of Caspase-3, Caspase-8 and Caspase-9.

miR-125b and miR-223 Contribute to Inflammation by Targeting the Key Molecules of NFκB Pathway

The contribution of miRNA in the pathogenesis of ulcerative colitis (UC) has emerged in the past few decades. Differential miRNA expression has been demonstrated in UC patients, and their ability to target the genes involved in inflammatory pathway has also been explored in recent years. miR-125b and miR-223 have been demonstrated to get upregulated within the colonic mucosa of UC patients. Here, we explored the biological relevance of miR-125b and miR-223 altered expression during UC by identifying the potential gene targets for miR-125b and miR-223. TRAF6 and A20, the signaling molecules involved in the NFκB pathway, were identified as target genes for miR-125b while IKKα was identified as a gene target for miR-223. The colonic mucosal samples from UC patients exhibited a significant rise in miR-125b and miR-223 expression while a subsequent downregulation was observed in the expression of TRAF6, A20, and IKKα. This negative correlation between miRNAs and their respective target genes was validated by co-transfecting miR-125b and miR-223 in HT29 cells. Co-transfection with miR-125b resulted in a marked decline in the expression of TRAF6 and A20, while the miR-223 co-transfected cells exhibited lower IKKα expression levels. Additionally, co-transfection with miR-125b or miR-223 in HT29 cells caused higher p65 and pro-inflammatory cytokines (IL-8 and IL-1β) expression upon LPS stimulation. From our findings, we highlight the possible contribution of miR-125b and miR-223 in regulating the inflammatory response during UC by negatively regulating the expression of TRAF6, A20, and IKKα. Therefore, we conclude that these two miRNAs could be considered as potential candidates for developing promising biomarkers for screening and diagnosis of UC.

Upregulation Of miR-153 Inhibits Triple-Negative Breast Cancer Progression By Targeting ZEB2-Mediated EMT And Contributes To Better Prognosis

Background

Triple-negative breast cancer (TNBC) is the most malignant type of breast cancer. MicroRNAs (miRs) and their corresponding molecular targets are associated with the occurrence and development of various human malignancies. However, the roles of the microRNA-153 (miR-153) and zinc finger E-box-binding homeobox 2 (ZEB2)-induced epithelial–mesenchymal transition (EMT) in TNBC and predictive effect of miR-153 on the prognosis of TNBC have not been fully elucidated.

Materials and methods

Relative miR-153 expression level was examined by RT-qPCR assay in TNBC tissues of 60 patients and TNBC cell lines (SKBR3, BT-549 and MDA-MB-231). Cell proliferation ability, invasion ability and migration ability were measured by CCK8 assay, Transwell invasion assay and wound healing assay, respectively. Luciferase reporting experiment was used to confirm that there was a miR-153-binding site in ZEB2 3ʹ-UTR. The expression of ZEB2 in tissues and its relationship with miR-153 were analyzed with immunohistochemistry method. Relative ZEB2, E-cadherin, N-cadherin and Vimentin mRNA and protein expression levels were observed with RT-qPCR and Western blot, respectively. Based on risk factors, a prognostic model was established according to the Cox proportional risk model, and the prognostic risk factors of TNBC patients were predicted and analyzed.

Results

The expression of miR-153 in TNBC tissues and cells was declined (all P<0.01), and upregulation of miR-153 inhibited proliferation, invasion and migration of TNBC cells (all P<0.01). In addition, miR-153 regulated ZEB2/EMT link in TNBC, and ZEB2 overexpression reversed the tumor-suppressive effect of miR-153 in TNBC. Moreover, miR-153 was an independent predictive factor that was associated with excellent prognosis in TNBC patients.

Conclusion

miR-153 may inhibit TNBC proliferation, invasion and migration by regulating ZEB2/EMT link. Therefore, miR-153 is expected to be a molecular target and prognostic marker for TNBC.

MicroRNA biogenesis, gene silencing mechanisms and role in breast, ovarian and prostate cancer

Micro-ribonucleic acids (miRNAs) are important class of short regulatory RNA molecules involved in regulation of several essential biological processes. In addition to Dicer and Drosha, over the past few years several other gene products are discovered that regulates miRNA biogenesis pathways. Similarly, various models of molecular mechanisms underlying miRNA mediated gene silencing have been uncovered through which miRNA contribute in diverse physiological and pathological processes. Dysregulated miRNA expression has been reported in many cancers manifesting tumor suppressive or oncogenic role. In this review, critical overview of recent findings in miRNA biogenesis, silencing mechanisms and specifically the role of miRNA in breast, ovarian and prostate cancer will be described. Recent advancements in miRNA research summarized in this review will enhance the molecular understanding of miRNA biogenesis and mechanism of action. Also, role of miRNAs in pathogenesis of breast, ovarian and prostate cancer will provide the insights for the use of miRNAs as biomarker or therapeutic agents for the cancers.

Mechanisms of Chemotherapy Resistance in Triple-Negative Breast Cancer-How We Can Rise to the Challenge

Triple-negative (TNBC) is the most lethal subtype of breast cancer owing to high heterogeneity, aggressive nature, and lack of treatment options. Chemotherapy remains the standard of care for TNBC treatment, but unfortunately, patients frequently develop resistance. Accordingly, in recent years, tremendous effort has been made into elucidating the mechanisms of TNBC chemoresistance with the goal of identifying new molecular targets. It has become evident that the development of TNBC chemoresistance is multifaceted and based on the elaborate interplay of the tumor microenvironment, drug efflux, cancer stem cells, and bulk tumor cells. Alterations of multiple signaling pathways govern these interactions. Moreover, TNBC's high heterogeneity, highlighted in the existence of several molecular signatures, presents a significant obstacle to successful treatment. In the present, in-depth review, we explore the contribution of key mechanisms to TNBC chemoresistance as well as emerging strategies to overcome them. We discuss novel anti-tumor agents that target the components of these mechanisms and pay special attention to their current clinical development while emphasizing the challenges still ahead of successful TNBC management. The evidence presented in this review outlines the role of crucial pathways in TNBC survival following chemotherapy treatment and highlights the importance of using combinatorial drug strategies and incorporating biomarkers in clinical studies.