TIP60-miR-22 axis as a prognostic marker of breast cancer progression

Current evidence regarding the cellular mechanisms associated with cancer progression due to cardiovascular diseases

Several large cohort studies in cardiovascular disease (CVD) patients have shown an increased incidence of cancer. Previous studies in a myocardial infarction (MI) mouse model reported increased colon, breast, and lung cancer growth. The potential mechanisms could be due to secreted cardiokines and micro-RNAs from pathological hearts and immune cell reprogramming. A study in a MI-induced heart failure (HF) mouse demonstrated an increase in cardiac expression of SerpinA3, resulting in an enhanced proliferation of colon cancer cells. In MI-induced HF mice with lung cancer, the attenuation of tumor sensitivity to ferroptosis via the secretion of miR-22-3p from cardiomyocytes was demonstrated. In MI mice with breast cancer, immune cell reprogramming toward the immunosuppressive state was shown. However, a study in mice with renal cancer reported no impact of MI on tumor growth. In addition to MI, cardiac hypertrophy was shown to promote the growth of breast and lung cancer. The cardiokine potentially involved, periostin, was increased in the cardiac tissue and serum of a cardiac hypertrophy model, and was reported to increase breast cancer cell proliferation. Since the concept that CVD could influence the initiation and progression of several types of cancer is quite new and challenging regarding future therapeutic and preventive strategies, further studies are needed to elucidate the potential underlying mechanisms which will enable more effective risk stratification and development of potential therapeutic interventions to prevent cancer in CVD patients.

MicroRNA-Mediated Regulation of Histone-Modifying Enzymes in Cancer: Mechanisms and Therapeutic Implications

In the past decade, significant advances in molecular research have provided a deeper understanding of the intricate regulatory mechanisms involved in carcinogenesis. MicroRNAs, short non-coding RNA sequences, exert substantial influence on gene expression by repressing translation or inducing mRNA degradation. In the context of cancer, miRNA dysregulation is prevalent and closely associated with various stages of carcinogenesis, including initiation, progression, and metastasis. One crucial aspect of the cancer phenotype is the activity of histone-modifying enzymes that govern chromatin accessibility for transcription factors, thus impacting gene expression. Recent studies have revealed that miRNAs play a significant role in modulating these histone-modifying enzymes, leading to significant implications for genes related to proliferation, differentiation, and apoptosis in cancer cells. This article provides an overview of current research on the mechanisms by which miRNAs regulate the activity of histone-modifying enzymes in the context of cancer. Both direct and indirect mechanisms through which miRNAs influence enzyme expression are discussed. Additionally, potential therapeutic implications arising from miRNA manipulation to selectively impact histone-modifying enzyme activity are presented. The insights from this analysis hold significant therapeutic promise, suggesting the utility of miRNAs as tools for the precise regulation of chromatin-related processes and gene expression. A contemporary focus on molecular regulatory mechanisms opens therapeutic pathways that can effectively influence the control of tumor cell growth and dissemination.

The Intricate Interplay between Cancer Stem Cells and Oncogenic miRNAs in Breast Cancer Progression and Metastasis

Complex signaling interactions between cancer cells and their microenvironments drive the clonal selection of cancer cells. Opposing forces of antitumor and tumorigenic potential regulate the survival of the fittest clones, while key genetic and epigenetic alterations in healthy cells force them to transform, overcome cell senescence, and proliferate in an uncontrolled manner. Both clinical samples and cancer cell lines provide researchers with an insight into the complex structure and hierarchy of cancer. Intratumor heterogeneity allows for multiple cancer cell subpopulations to simultaneously coexist within tumors. One category of these cancer cell subpopulations is cancer stem cells (CSCs), which possess stem-like characteristics and are not easily detectable. In the case of breast cancer, which is the most prevalent cancer type among females, such subpopulations of cells have been isolated and characterized via specific stem cell markers. These stem-like cells, known as breast cancer stem cells (BCSCs), have been linked to major events during tumorigenesis including invasion, metastasis and patient relapse following conventional therapies. Complex signaling circuitries seem to regulate the stemness and phenotypic plasticity of BCSCs along with their differentiation, evasion of immunosurveillance, invasiveness and metastatic potential. Within these complex circuitries, new key players begin to arise, with one of them being a category of small non-coding RNAs, known as miRNAs. Here, we review the importance of oncogenic miRNAs in the regulation of CSCs during breast cancer formation, promotion and metastasis, in order to highlight their anticipated usage as diagnostic and prognostic tools in the context of patient stratification and precision medicine.

Non-coding RNA's prevalence as biomarkers for prognostic, diagnostic, and clinical utility in breast cancer

Noncoding RNAs (ncRNAs), which make up a significant portion of the mammalian transcriptome and plays crucial regulatory roles in expression of genes and other biological processes, have recently been found. The most extensively researched of the sncRNAs, microRNAs (miRNAs), have been characterized in terms of their synthesis, roles, and significance in the tumor development. Its crucial function in the stem cell regulation, another class of sncRNAs known as aspirRNAs, has attracted attention in cancer research. The investigations have shown that long non-coding RNAs have a crucial role in controlling developmental stages, such as mammary gland development. Additionally, it has been discovered that lncRNA dysregulation precedes the development of several malignancies, including breast cancer. The functions of sncRNAs (including miRNAs and piRNAs) and lncRNAs in the onset and development of the breast cancer are described in this study. Additionally, future perspectives of various ncRNA-based diagnostic, prognostic, and therapeutic approaches also discussed.

Spatiotemporal Expression and Functional Analysis of miRNA-22 in the Developing Secondary Palate

OBJECTIVE

Normal development of the embryonic orofacial region requires precise spatiotemporal coordination between numerous genes. MicroRNAs represent small, single-stranded, non-coding molecules that regulate gene expression. This study examines the role of microRNA-22 (miR-22) in murine orofacial ontogeny.

METHODS

Spatiotemporal and differential expression of miR-22 (mmu-miR-22-3p) within the developing secondary palate was determined by in situ hybridization and quantitative real-time PCR, respectively. Bioinformatic approaches were used to predict potential mRNA targets of miR-22 and analyze their association with cellular functions indispensable for normal orofacial ontogeny. An in vitro palate organ culture system was used to assess the role of miR-22 in secondary palate development.

RESULTS

There was a progressive increase in miR-22 expression from GD12.5 to GD14.5 in palatal processes. On GD12.5 and GD13.5, miR-22 was expressed in the future oral, nasal, and medial edge epithelia. On GD14.5, miR-22 expression was observed in the residual midline epithelial seam (MES), the nasal epithelium and the mesenchyme, but not in the oral epithelium. Inhibition of miR-22 activity in palate organ cultures resulted in failure of MES removal. Bioinformatic analyses revealed potential mRNA targets of miR-22 that may play significant roles in regulating apoptosis, migration, and/or convergence/extrusion, developmental processes that modulate MES removal during palatogenesis.

CONCLUSIONS

Results from the current study suggest a key role for miR-22 in the removal of the MES during palatogenesis and that miR-22 may represent a potential contributor to the etiology of cleft palate.

An Immunocompetent Environment Unravels the Proto-Oncogenic Role of miR-22

MiR-22 was first identified as a proto-oncogenic microRNA (miRNA) due to its ability to post-transcriptionally suppress the expression of the potent PTEN (Phosphatase And Tensin Homolog) tumor suppressor gene. miR-22 tumorigenic role in cancer was subsequently supported by its ability to positively trigger lipogenesis, anabolic metabolism, and epithelial-mesenchymal transition (EMT) towards the metastatic spread. However, during the following years, the picture was complicated by the identification of targets that support a tumor-suppressive role in certain tissues or cell types. Indeed, many papers have been published where in vitro cellular assays and in vivo immunodeficient or immunosuppressed xenograft models are used. However, here we show that all the studies performed in vivo, in immunocompetent transgenic and knock-out animal models, unanimously support a proto-oncogenic role for miR-22. Since miR-22 is actively secreted from and readily exchanged between normal and tumoral cells, a functional immune dimension at play could well represent the divider that allows reconciling these contradictory findings. In addition to a critical review of this vast literature, here we provide further proof of the oncogenic role of miR-22 through the analysis of its genomic locus vis a vis the genetic landscape of human cancer.

The CK1δ/ϵ-Tip60 Axis Enhances Wnt/β-Catenin Signaling via Regulating β-Catenin Acetylation in Colon Cancer

Casein kinase 1δ/ϵ (CK1δ/ϵ) are well-established positive modulators of the Wnt/β-catenin signaling pathway. However, the molecular mechanisms involved in the regulation of β-catenin transcriptional activity by CK1δ/ϵ remain unclear. In this study, we found that CK1δ/ϵ could enhance β-catenin-mediated transcription through regulating β-catenin acetylation. CK1δ/ϵ interacted with Tip60 and facilitated the recruitment of Tip60 to β-catenin complex, resulting in increasing β-catenin acetylation at K49. Importantly, Tip60 significantly enhanced the SuperTopFlash reporter activity induced by CK1δ/ϵ or/and β-catenin. Furthermore, a CK1δ/CK1ϵ/β-catenin/Tip60 complex was detected in colon cancer cells. Simultaneous knockdown of CK1δ and CK1ϵ significantly attenuated the interaction between β-catenin and Tip60. Notably, inhibition of CK1δ/ϵ or Tip60, with shRNA or small molecular inhibitors downregulated the level of β-catenin acetylation at K49 in colon cancer cells. Finally, combined treatment with CK1 inhibitor SR3029 and Tip60 inhibitor MG149 had more potent inhibitory effect on β-catenin acetylation, the transcription of Wnt target genes and the viability and proliferation in colon cancer cells. Taken together, our results revealed that the transcriptional activity of β-catenin could be modulated by the CK1δ/ϵ-β-catenin-Tip60 axis, which may be a potential therapeutic target for colon cancer.

Chelidonium majus Induces Apoptosis of Human Ovarian Cancer Cells via ATF3-Mediated Regulation of Foxo3a by Tip60

Forkhead transcription factor 3a (Foxo3a) is believed to be a tumor suppressor as its inactivation leads to cell transformation and tumor development. However, further investigation is required regarding the involvement of the activating transcription factor 3 (ATF3)-mediated Tat-interactive protein 60 (Tip60)/Foxo3a pathway in cancer cell apoptosis. This study demonstrated that Chelidonium majus upregulated the expression of ATF3 and Tip60 and promoted Foxo3a nuclear translocation, ultimately increasing the level of Bcl-2-associated X protein (Bax) protein. ATF3 overexpression stimulated Tip60 expression, while ATF3 inhibition by siRNA repressed Tip60 expression. Furthermore, siRNA-mediated Tip60 inhibition significantly promoted Foxo3a phosphorylation, leading to blockade of Foxo3a translocation into the nucleus. Thus, we were able to deduce that ATF3 mediates the regulation of Foxo3a by Tip60. Moreover, siRNA-mediated Foxo3a inhibition suppressed the expression of Bax and subsequent apoptosis. Taken together, our data demonstrate that Chelidonium majus induces SKOV-3 cell death by increasing ATF3 levels and its downstream proteins Tip60 and Foxo3a. This suggests a potential therapeutic role of Chelidonium majus against ovarian cancer.

Epi-miRNAs: Regulators of the Histone Modification Machinery in Human Cancer

Cancer is a leading cause of death and disability worldwide. Epigenetic deregulation is one of the most critical mechanisms in carcinogenesis and can be classified into effects on DNA methylation and histone modification. MicroRNAs are small noncoding RNAs involved in fine-tuning their target genes after transcription. Various microRNAs control the expression of histone modifiers and are involved in a variety of cancers. Therefore, overexpression or downregulation of microRNAs can alter cell fate and cause malignancies. In this review, we discuss the role of microRNAs in regulating the histone modification machinery in various cancers, with a focus on the histone-modifying enzymes such as acetylases, deacetylases, methyltransferases, demethylases, kinases, phosphatases, desumoylases, ubiquitinases, and deubiquitinases. Understanding of microRNA-related aberrations underlying histone modifiers in pathogenesis of different cancers can help identify novel therapeutic targets or early detection approaches that allow better management of patients or monitoring of treatment response.

Regulation of the Effect of Physical Activity Through MicroRNAs in Breast Cancer

Physical activity and exercise can induce beneficial molecular and biological regulations that have been associated with an incidence of various diseases, including breast cancer. Recent studies demonstrated that the potential links between physical activity-induced circulating microRNAs (miRNAs) and cancer risk and progression. Here, we investigated whether altered miRNAs by exercise could influence breast cancer progression. After primary searching in PubMed and reviewing the full-text papers, candidate miRNAs altered by exercise in breast cancer were identified. Analysis of expression profiles and clinical outcomes of altered miRNAs using The Cancer Genome Atlas datasets showed altered miRNAs expressions were significantly associated with the patient's prognosis, whereas prognostic values of each miRNA varied in different stages and subtypes. In addition, altered miRNAs profiles regulated various target genes and key signaling pathways in tumorigenesis, including pathways in cancer and the PI3K-Akt signaling pathway; however, miRNAs regulated the expression of target genes differently according to tumor stages and subtypes. These results indicate that circulating miRNAs are promising noninvasive stable biomarkers for early detection, diagnosis, prognosis, and monitoring the response to clinical therapies of breast cancer. Moreover, stages and subtype-stratified approaches for breast cancer progression would be needed to evaluate the prognostic value of miRNAs for biomarkers and therapeutic targets.

MicroRNA-22 in female malignancies: Focusing on breast, cervical, and ovarian cancers

MicroRNAs (miRNAs), a novelty-defined class of regulatory genes, have revolutionized principles of classical bimolecular. These RNAs regulate the expression of a gene through inhibition of translational initiation or targeting mRNAs for degradation. MiRNAs act in several biological operations, including proliferation, differentiation, and cell death, and their expression is often abnormal in human diseases such as cancer. In recent years, miR-22 has attracted much attention from researchers. Its expression is downregulated in female malignancies such as breast, cervical, and ovarian cancers, exhibiting that miR-22 plays a tumor-suppressive function in these cancers. Also, different reports exist about the involvement of miR-22 in non-tumor diseases. In the present review, we report the results of performed studies on the potential roles of miR-22 in female malignancies with a focus on breast, cervical, and ovarian cancers. Also, we summary its predicted target genes in various cancers. In conclusion, it is effective for researchers to understand the role of miR-22 in different cellular operations.

ncRNA therapy with miRNA-22-3p suppresses the growth of triple-negative breast cancer

Deregulation of noncoding RNAs, including microRNAs (miRs), is implicated in the pathogenesis of many human cancers, including breast cancer. Through extensive analysis of The Cancer Genome Atlas, we found that expression of miR-22-3p is markedly lower in triple-negative breast cancer (TNBC) than in normal breast tissue. The restoration of miR-22-3p expression led to significant inhibition of TNBC cell proliferation, colony formation, migration, and invasion. We demonstrated that miR-22-3p reduces eukaryotic elongation factor 2 kinase (eEF2K) expression by directly binding to the 3' untranslated region of eEF2K mRNA. Inhibition of EF2K expression recapitulated the effects of miR-22-3p on TNBC cell proliferation, motility, invasion, and suppression of phosphatidylinositol 3-kinase/Akt and Src signaling. Systemic administration of miR-22-3p in single-lipid nanoparticles significantly suppressed tumor growth in orthotopic MDA-MB-231 and MDA-MB-436 TNBC models. Evaluation of the tumor response, following miR-22-3p therapy in these models using a novel mathematical model factoring in various in vivo parameters, demonstrated that the therapy is highly effective against TNBC. These findings suggest that miR-22-3p functions as a tumor suppressor by targeting clinically significant oncogenic pathways and that miR-22-3p loss contributes to TNBC growth and progression. The restoration of miR-22-3p expression is a potential novel noncoding RNA-based therapy for TNBC.

Identification of miRNA-Based Signature as a Novel Potential Prognostic Biomarker in Patients with Breast Cancer

To identify the novel, noninvasive biomarkers to assess the outcome and prognosis of breast cancer (BC), patients with high sensitivity and specificity are greatly desired. Herein, the miRNA expression profile and matched clinical features of BC patients were extracted from The Cancer Genome Atlas (TCGA) database. The preliminary candidates were screened out by the univariate Cox regression test. Then, with the help of LASSO Cox regression analysis, the hsa-let-7b, hsa-mir-101-2, hsa-mir-135a-2, hsa-mir-22, hsa-mir-30a, hsa-mir-31, hsa-mir-3130-1, hsa-mir-320b-1, hsa-mir-3678, hsa-mir-4662a, hsa-mir-4772, hsa-mir-493, hsa-mir-556, hsa-mir-652, hsa-mir-6733, hsa-mir-874, and hsa-mir-9-3 were selected to construct the overall survival (OS) predicting signature, while the hsa-mir-130a, hsa-mir-204, hsa-mir-217, hsa-mir-223, hsa-mir-24-2, hsa-mir-29b-1, hsa-mir-363, hsa-mir-5001, hsa-mir-514a-1, hsa-mir-624, hsa-mir-639, hsa-mir-659, and hsa-mir-6892 were adopted to establish the recurrence-free survival (RFS) predicting signature. Referring to the median risk scores generated by the OS and RFS formulas, respectively, subgroup patients with high risk were strongly related to a poor OS and RFS revealed by Kaplan-Meier (K-M) plots. Meanwhile, receiver operating curve (ROC) analysis validated the accuracy and stability of these two signatures. When stratified by clinical features, such as tumor stage, age, and molecular subtypes, we found that the miRNA-based OS and RFS classifiers were still significant in predicting OS/RFS and showed the best predictive values than any other features. Besides, functional prediction analyses showed that these targeted genes of the enrolled miRNAs were enriched in cancer-associated pathways, such as MAPK/RTK, Ras, and PI3K-Akt signaling pathways. In summary, our observations demonstrate that the novel miRNA-based OS and RFS signatures are independent prognostic indicators for BC patients and worthy to be validated by further prospective studies.

Prognostic role of microRNAs in breast cancer: A systematic review

MicroRNAs (miRNAs) have been found to play an important role in breast cancer, functioning either as potential oncogenes or tumor suppressor genes, but their role in the prognosis of patients remains unclear. The aim of the present review study is to highlight recent preclinical and clinical studies performed on both circulating and tissue-specific miRNAs and their potential role as prognostic markers in breast cancer. We systematically searched the PubMed database to explore the prognostic value of miRNAs in breast cancer. After performing the literature search and review, 117 eligible studies were identified. We found that 110 aberrantly expressed miRNAs have been associated with prognosis in breast cancer. In conclusion, the collective data presented in this review indicate that miRNAs could serve as novel prognostic tools in breast cancer, while the clinical application of these findings has yet to be verified.

Retracted: Ras-ERK1/2 signaling promotes the development of uveal melanoma by downregulating H3K14ac

Ras-extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) signaling has been proposed as the crucial regulators in the development of various cancers. Histone acetylation at H3 lysine 14 (H3K14ac) is closely associated with gene expression and DNA damage. However, whether H3K14ac participates in mediating Ras-ERK1/2-induced cell proliferation and migration in uveal melanoma cells remains unknown. The purpose of this study is to investigate the effect of H3K14ac on Ras-ERK1/2 affected uveal melanoma cell phenotypes. MP65 cells were transfected with Ras ^WT and Ras ^G12V/T35S , the unloaded plasmid of pEGFP-N1 served as a negative control. Protein levels of phosphorylated ERK1/2 ^Thr202 and H3K14ac were assessed by western blot assay. Cell viability, number of colonies, migration, and the downstream genes of ERK1/2 were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2-H-tetrazolium bromide, soft-agar colony formation, transwell, and chromatin immunoprecipitation assays. HA-tag vectors of CLR3 and TIP60 and the small interfering RNAs that specific for CLR3 and MDM2 were transfected into MP65 cells to uncover the effects of CLR3, TIP60, and MDM2 on Ras-ERK1/2 mediated H3K14ac expression and MP65 cell phenotypes. We found that, Ras-ERK1/2 decreased H3K14ac expression in MP65 cells, and H3K14ac significantly suppressed Ras-ERK1/2-induced cell viability, colony formation, and migration in MP65 cells. Moreover, the transcription of CYR61, IGFBP3, WNT16B, NT5E, GDF15, and CARD16 was regulated by H3K14ac. Additionally, CLR3 silence recovered H3K14ac expression and reversed the effect of Ras-ERK1/2 on MP65 cell proliferation, migration and the mRNAs of ERK1/2 downstream genes. Besides, Ras-ERK1/2 decreased H3K14ac expression by MDM2-mediated TIP60 degradation. In conclusion, Ras-ERK1/2 promoted uveal melanoma cells growth and migration by downregulating H3K14ac via MDM2-mediated TIP60 degradation.

miR-22 Regulates Invasion, Gene Expression and Predicts Overall Survival in Patients with Clear Cell Renal Cell Carcinoma

Background:

Clear cell renal cell carcinoma (ccRCC) is molecularly diverse and distinct molecular subtypes show different clinical outcomes. MicroRNAs (miRNAs) are essential components of gene regulatory networks and play a crucial role in progression of many cancer types including ccRCC.

Objective:

Identify prognostic miRNAs and determine the role of miR-22 in ccRCC.

Methods:

Hierarchical clustering was done in R using gene expression profiles of over 450 ccRCC cases in The Cancer Genome Atlas (TCGA). Kaplan-Meier analysis was performed to identify prognostic miRNAs in the TCGA dataset. RNA-Seq was performed to identify miR-22 target genes in primary ccRCC cells and Matrigel invasion assay was performed to assess the effects of miR-22 overexpression on cell invasion.

Results:

Hierarchical clustering analysis using 2,621 prognostic genes previously identified by our group demonstrated that ccRCC patients with longer overall survival expressed lower levels of genes promoting proliferation or immune responses, while better maintaining gene expression associated with cortical differentiation and cell adhesion. Targets of 26 miRNAs were significantly enriched in the 2,621 prognostic genes and these miRNAs were prognostic by themselves. MiR-22 was associated with poor overall survival in the TCGA dataset. Overexpression of miR-22 promoted invasion of primary ccRCC cells in vitro and modulated transcriptional programs implicated in cancer progression including DNA repair, cell proliferation and invasion.

Conclusions:

Our results suggest that ccRCCs with differential clinical outcomes have distinct transcriptomes for which miRNAs could serve as master regulators. MiR-22, as a master regulator, promotes ccRCC progression at least in part by enhancing cell invasion.

MicroRNA Regulation of Epigenetic Modifiers in Breast Cancer

Epigenetics refers to the heritable changes in gene expression without a change in the DNA sequence itself. Two of these major changes include aberrant DNA methylation as well as changes to histone modification patterns. Alterations to the epigenome can drive expression of oncogenes and suppression of tumor suppressors, resulting in tumorigenesis and cancer progression. In addition to modifications of the epigenome, microRNA (miRNA) dysregulation is also a hallmark for cancer initiation and metastasis. Advances in our understanding of cancer biology demonstrate that alterations in the epigenome are not only a major cause of miRNA dysregulation in cancer, but that miRNAs themselves also indirectly drive these DNA and histone modifications. More explicitly, recent work has shown that miRNAs can regulate chromatin structure and gene expression by directly targeting key enzymes involved in these processes. This review aims to summarize these research findings specifically in the context of breast cancer. This review also discusses miRNAs as epigenetic biomarkers and as therapeutics, and presents a comprehensive summary of currently validated epigenetic targets in breast cancer.

Regulatory network reconstruction of five essential microRNAs for survival analysis in breast cancer by integrating miRNA and mRNA expression datasets

Although many of the genetic loci associated with breast cancer risk have been reported, there is a lack of systematic analysis of regulatory networks composed of different miRNAs and mRNAs on survival analysis in breast cancer. To reconstruct the microRNAs-genes regulatory network in breast cancer, we employed the expression data from The Cancer Genome Atlas (TCGA) related to five essential miRNAs including miR-21, miR-22, miR-210, miR-221, and miR-222, and their associated functional genomics data from the GEO database. Then, we performed an integration analysis to identify the essential target factors and interactions for the next survival analysis in breast cancer. Based on the results of our integrated analysis, we have identified significant common regulatory signatures including differentially expressed genes, enriched pathways, and transcriptional regulation such as interferon regulatory factors (IRFs) and signal transducer and activator of transcription 1 (STAT1). Finally, a reconstructed regulatory network of five miRNAs and 34 target factors was established and then applied to survival analysis in breast cancer. When we used expression data for individual miRNAs, only miR-21 and miR-22 were significantly associated with a survival change. However, we identified 45 significant miRNA-gene pairs that predict overall survival in breast cancer out of 170 one-on-one interactions in our reconstructed network covering all of five miRNAs, and several essential factors such as PSMB9, HLA-C, RARRES3, UBE2L6, and NMI. In our study, we reconstructed regulatory network of five essential microRNAs for survival analysis in breast cancer by integrating miRNA and mRNA expression datasets. These results may provide new insights into regulatory network-based precision medicine for breast cancer.

Interference from LncRNA SPRY4-IT1 restrains the proliferation, migration, and invasion of melanoma cells through inactivating MAPK pathway by up-regulating miR-22-3p

Melanoma is a common malignancy with a low survival rate worldwide. Long non-coding RNA Sprouty4-Intron 1 (SPRY4-IT1) is correlated with various cancers, including melanoma. Herein, the underlying molecular mechanisms of SPRY4-IT1 in melanoma were characterized. We found that SPRY4-IT1 level was upregulated in melanoma cells lines compared to the normal skin cells, while miR-22-3p was downregulated. According to of bioinformatics analysis, SPRY4-IT1 was a hypothetic target of miR-22-3p, and knockdown SPRY4-IT1 by sh-RNA (sh-SPRY4-IT1) markedly elevated the miR-22-3p level. Also, the target relationship was further confirmed by dual luciferase reporter assay. In addition, low-expression of SPRY4-IT1 impeded cell proliferation, invasion, migration, and epithelial-mesenchymal transition. Furthermore, western blot assay indicated that the enhanced miR-22-3p further decelerated the phosphorylation of p38MAPK, MAPKAPK and Hsp27, which indicates that miR-22-3p could inactivate the p38MAPK/MAPKAPK/Hsp27 signaling pathway. Overall, our results show that sh-SPRY4-IT1 inhibits cell proliferation and motility through inactivating MAPK signaling by up-regulating miR-22-3p. Therefore, designing targeted drugs against SPRY4-IT1 provides a new direction for the treatment of melanoma.

KAT5 promotes invasion and metastasis through C-MYC stabilization in ATC

Anaplastic thyroid cancer (ATC) is an aggressive cancer with poor clinical prognosis. However, mechanisms driving ATC aggressiveness is not well known. Components of the DNA damage response (DDR) are frequently found mutated or aberrantly expressed in ATC. The goal of this study is to establish the functional link between histone acetyltransferase lysine (K) acetyltransferase 5 (KAT5, a critical DDR protein) and ATC invasiveness using clinical, in vitro and in vivo models. We analyzed the expression of KAT5 by immunohistochemistry and assessed its relationship with metastasis and overall survival in 82 ATC patients. Using cellular models, we established functional connection of KAT5 expression and C-MYC stabilization. We then studied the impact of genetically modified KAT5 expression on ATC metastasis in nude mice. In clinical samples, there is a strong correlation of KAT5 expression with ATC metastasis (P = 0.0009) and overall survival (P = 0.0017). At the cellular level, upregulation of KAT5 significantly promotes thyroid cancer cell proliferation and invasion. We also find that KAT5 enhances the C-MYC protein level by inhibiting ubiquitin-mediated degradation. Further evidence reveals that KAT5 acetylates and stabilizes C-MYC. Finally, we prove that altered KAT5 expression influences ATC lung metastases in vivo. KAT5 promotes ATC invasion and metastases through stabilization of C-MYC, demonstrating it as a new biomarker and therapeutic target for ATC.

TIP60: an actor in acetylation of H3K4 and tumor development in breast cancer

AIM

The acetyltransferase TIP60 is reported to be downregulated in several cancers, in particular breast cancer, but the molecular mechanisms resulting from its alteration are still unclear.

MATERIALS & METHODS

In breast tumors, H3K4ac enrichment and its link with TIP60 were evaluated by chromatin immunoprecipitation-qPCR and re-chromatin immunoprecipitation techniques. To assess the biological roles of TIP60 in breast cancer, two cell lines of breast cancer, MDA-MB-231 (ER-) and MCF-7 (ER+) were transfected with shRNA specifically targeting TIP60 and injected to athymic Balb-c mice.

RESULTS

We identified a potential target of TIP60, H3K4. We show that an underexpression of TIP60 could contribute to a reduction of H3K4 acetylation in breast cancer. An increase in tumor development was noted in sh-TIP60 MDA-MB-231 xenografts and a slowdown of tumor growth in sh-TIP60 MCF-7 xenografts.

CONCLUSION

This is evidence that the underexpression of TIP60 observed in breast cancer can promote the tumorigenesis of ER-negative tumors.

Roles of microRNA in prostate cancer cell metabolism

MicroRNAs are non-coding RNA which functions as regulators of genes expression. MicroRNAs have shown their biological functions in cell proliferation, cell cycle, cell metabolism, apoptosis, invasion and metastasis. Cancer cells have the ability to grow in the absence of growth factors by increased metabolic activity. MicroRNAs regulate cell metabolic processes by targeting the key enzymes or transporters and change the metabolic activities by interfering with oncogenes/tumor suppressors, hypoxia, signalling pathways and cell adhesion. This review mainly explains the roles of microRNAs in prostate cancer cell metabolism, such as glucose uptake, glycolysis and lactate secretion, lipid metabolism and interaction with signalling pathways. The relation of microRNAs with hypoxia and cell adhesion in cell metabolism is also highlighted. Therefore, miRNAs help in regulating the metabolism of survived tumor cells, understanding such miRNA-mediated interaction could lead to new avenues in therapeutic application to treat PCa.

Enolase 1 stimulates glycolysis to promote chemoresistance in gastric cancer

Chemotherapy is the major choice for the cancer treatment of early and advanced stages. However, intrinsic or acquired drug resistance significantly restricts the clinical efficacy of chemotherapy. It is critical to develop novel approaches to detect and overcome drug resistance. In this study, we demonstrated that accelerated glycolysis played a pivotal role in both intrinsic and acquired cisplatin-resistance of gastric cancer cells. The metabolic reprogramming of cisplatin-resistant cells was characterized by increased glycolysis dependence. Inhibition of glycolysis with glucose starvation or 2-Deoxy-D-glucose (2-DG) treatment significantly reversed drug resistance. By proteomic screening, we found the increased expression of the glycolytic enzyme Enolase 1 (ENO1) in cisplatin-resistant gastric cancer cells. Depletion of ENO1 by siRNA significantly reduced glycolysis and reversed drug resistance. Moreover, the increased expression of ENO1 was attributed to the down-regulation of ENO1-targeting miR-22, rather than activated gene transcriptional or prolonged protein stability. Finally, the elevated levels of ENO1 proteins were associated with the shorter overall survival of gastric cancer patients. In conclusion, ENO1 is a novel biomarker to predict drug resistance and overall prognosis in gastric cancer. Targeting ENO1 by chemical inhibitors or up-regulating miR-22 could be valuable to overcome drug resistance.

Tip60: updates

The maintenance of genome integrity is essential for organism survival. Therefore, eukaryotic cells possess many DNA repair mechanisms in response to DNA damage. Acetyltransferase, Tip60, plays a central role in ATM and p53 activation which are involved in DNA repair. Recent works uncovered the roles of Tip60 in ATM and p53 activation and how Tip60 is recruited to double-strand break sites. Moreover, recent works have demonstrated the role of Tip60 in cancer progression. Here, we review the current understanding of how Tip60 activates both ATM and p53 in response to DNA damage and his new roles in tumorigenesis.

miR-22 inhibits tumor growth and metastasis by targeting ATP citrate lyase: evidence in osteosarcoma, prostate cancer, cervical cancer and lung cancer

MicroRNAs (miRNAs) are non-coding small RNAs that function as negative regulators of gene expression involving in the tumor biology. ATP citrate lyase (ACLY), a key enzyme initiating de novo lipid synthesis, has been found to be upregulated in cancer cells, and its inhibition causes suppressive effects in a variety of tumors. At present, although several ACLY inhibitors have been reported, the potential role of miRNAs in interfering ACLY still needs further clarification. Herein, four different types of tumor cells including osteosarcoma, prostate, cervical and lung cancers were adopted in our study, and we have demonstrated that miR-22 directly downregulated ACLY. Moreover, miR-22 was proved to attenuate cancer cell proliferation and invasion, as well as promote cell apoptosis via inhibiting ACLY. Additionally, we confirmed the higher ACLY protein levels and the lower miR-22 expressions in hundreds of clinical samples of the four primary tumors, and a negative correlation relationship between ACLY and miR-22 was clarified. Finally, in the four animal models, we found that along with the loss of the ACLY expression, the miR-22-treated mice developed rather smaller tumors, less probabilities of distant metastasis, and fairly longer survivals. De novo lipogenesis suppression triggered by miR-22-ACLY axis may contribute to the inhibition of tumor growth and metastasis. These findings provide unequivocal proofs that miR-22 is responsible for the posttranscriptional regulation of ACLY, which yields promising therapeutic effects in osteosarcoma, prostate, cervical and lung cancers.

MiR-22 suppresses epithelial-mesenchymal transition in bladder cancer by inhibiting Snail and MAPK1/Slug/vimentin feedback loop

MicroRNAs (miRNAs) have been validated to play prominent roles in the occurrence and development of bladder cancer (BCa). MiR-22 was previously reported to act as a tumor suppressor or oncomiRNA in various types of cancer. However, its accurate expression, function, and mechanism in BCa remain unclear. Here, we find that miR-22 is frequently downregulated in BCa tissues compared with adjacent non-cancerous tissues. Overexpression of miR-22 significantly inhibits proliferation, migration, and invasion of BCa cells both in vitro and in vivo. Importantly, miR-22 is found to suppress cell proliferation/apoptosis by directly targeting MAPK1 (mitogen-activated protein kinase 1, ERK2) and inhibit cell motility by targeting both MAPK1 and Snail. Further statistical analysis shows that low-expression of MAPK1 or Snail is an independent prognostic factor for a better overall survival in patients with BCa (n = 401). Importantly, we describe an important regenerative feedback loop among vimentin, Slug and MAPK1 in BCa cells. MAPK1-induced Slug expression upregulates vimentin. Vimentin in turn activates MAPK1. By inhibiting Snail and MAPK1/Slug/vimentin feedback loop, miR-22 suppresses epithelial–mesenchymal transition (EMT) of BCa cells in vitro as well as in vivo. Taken together, this study reveals that miR-22 is critical to the proliferation, apoptosis and EMT progression in BCa cells. Targeting the pathway described here may be a novel approach for inhibiting proliferation and metastasis of BCa.

Can the microRNA expression profile help to identify novel targets for zoledronic acid in breast cancer?

Zoledronic acid (ZOL), belonging to third generation bisphosphonate family, is a potent inhibitor of osteoclast-mediated bone resorption, widely used to effectively prevent osteolysis in breast cancer patients who develop bone metastases. Low doses of ZOL have been shown to exhibit a direct anticancer role, by inhibiting cell adhesion, invasion, cytoskeleton remodelling and proliferation in MCF-7 breast cancer cells. In order to identify the molecular mechanisms and signaling pathways underlying the anticancer activity exerted by ZOL, we analyzed for the first time the microRNA expression profile in breast cancer cells. A large-scale microarray analysis of 377 miRNAs was performed on MCF7 cells treated with 10 μM ZOL for 24 h compared to untreated cells. Furthermore, the expression of specific ZOL-induced miRNAs was analyzed in MCF-7 and SkBr3 cells through Real-time PCR. Low-dose treatment with ZOL significantly altered expression of 54 miRNAs. Nine upregulated and twelve downregulated miRNAs have been identified after 24 h of treatment. Also, ZOL induced expression of 11 specific miRNAs and silenced expression of 22 miRNAs. MiRNA data analysis revealed the involvement of differentially expressed miRNAs in PI3K/Akt, MAPK, Wnt, TGF-β, Jak-STAT and mTOR signaling pathways, and regulation of actin cytoskeleton. Our results have been shown to be perfectly coherent with the recent findings reported in literature concerning changes in expression of some miRNAs involved in bone metastasis formation, progression, therapy resistance in breast cancer. In conclusion, this data supports the hypothesis that ZOL-induced modification of the miRNA expression profile contributes to the anticancer efficacy of this agent.

Acetylation of TIP60 at K104 is essential for metabolic stress-induced apoptosis in cells of hepatocellular cancer

Tumor cells often encounter hypoglycemic microenvironment due to rapid cell expansion. It remains elusive how tumors reprogram the genome to survive the metabolic stress. The tumor suppressor TIP60 functions as the catalytic subunit of the human NuA4 histone acetyltransferase (HAT) multi-subunit complex and is involved in many different cellular processes including DNA damage response, cell growth and apoptosis. Attenuation of TIP60 expression has been detected in various tumor types. The function of TIP60 in tumor development has not been fully understood. Here we found that suppressing TIP60 inhibited p53 K120 acetylation and thus rescued apoptosis induced by glucose deprivation in hepatocellular cancer cells. Excitingly, Lys-104 (K104), a previously identified lysine acetylation site of TIP60 with unknown function, was observed to be indispensable for inducing p53-mediated apoptosis under low glucose condition. Mutation of Lys-104 to Arg (K104R) impeded the binding of TIP60 to human NuA4 complex, suppressed the acetyltransferase activity of TIP60, and inhibited the expression of pro-apoptotic genes including NOXA and PUMA upon glucose starvation. These findings demonstrate the critical regulation of TIP60/p53 pathway in apoptosis upon metabolic stress and provide a novel insight into the down-regulation of TIP60 in tumor cells.

MRGBP as a potential biomarker for the malignancy of pancreatic ductal adenocarcinoma

MORF4-related gene-binding protein (MRGBP), which is also known as chromosome 20 open reading frame 20 (C20orf20), is commonly highly expressed in several types of malignant tumors and tumor progression. However, the expression pattern and underlying mechanism of MRGBP in pancreatic ductal adenocarcinoma (PDAC) remain unknown. In the study, we found that MRGBP was frequently upregulated in PDAC tissues and cell lines. In addition, the upregulation of MRGBP was positively associated with TNM stage, T classification, and poor prognosis. Knockdown of MRGBP in the PDAC cell lines ASPC-1 and Mia PaCa-2 by transiently transfected with small interfering RNA (siRNA) drastically attenuated the proliferation, migration, and invasion of those cells, whereas ectopic MRGBP overexpression in BxPC-3 cells produced exactly the opposite effect. Furthermore, we also found that overexpression of MRGBP remarkably led to cell morphological changes and induced an increased expression of mesenchymal marker Vimentin, whereas a decreased expression of epithelial marker E-cadherin. Taken together, this study indicates that MRGBP acts as a tumor oncogene in PDAC and is a promising target of carcinogenesis.

Tat-interactive Protein-60KDA (TIP60) Regulates the Tumorigenesis of Lung Cancer In Vitro

Histone acetyltransferases (HATs) play vital functions in the tumorigenesis of many solid organ malignancies. We previously screened a human HATs cDNA library and identified Tat-interactive protein-60KDa (TIP60) as a candidate critical HATs in the origination of lung cancer. In this study, our data suggested that overexpression of TIP60 inhibited the cell viability of A549 and H1299 cells since day 2. Compared to the control group, the viability of these two lung cancer cells was inhibited by 25% and 19% at day 6 with the overexpression of TIP60. It increased by 36% and 26% when TIP60 was knockdown for 6 days. The invasion ability of these two cells was also restrained when TIP60 was overexpressed. While knockdown of TIP60 had the opposite effect. Inhibition of TIP60 significantly promoted the expression of molecules in AKT signaling pathway especially c-Myc. Furthermore, compared to paired tumor-adjacent tissue, lung cancer tumors had low expression of TIP60. Therefore, we concluded that TIP60 might inhibit the viability and invasion ability of lung cancer cells through down-regulation of AKT signaling pathway.

Targeting cancer using KAT inhibitors to mimic lethal knockouts

Two opposing enzyme classes regulate fundamental elements of genome maintenance, gene regulation and metabolism, either through addition of an acetyl moiety by histone acetyltransferases (HATs) or its removal by histone de-acetyltransferases (HDAC), and are exciting targets for drug development. Importantly, dysfunctional acetylation has been implicated in numerous diseases, including cancer. Within the HAT superfamily the MYST family holds particular interest, as its members are directly involved in the DNA damage response and repair pathways and crucially, several members have been shown to be down-regulated in common cancers (such as breast and prostate). In the present study we focus on the development of lysine (K) acetyltransferase inhibitors (KATi) targeting the MYST family member Tip60 (Kat5), an essential protein, designed or discovered through screening libraries. Importantly, Tip60 has been demonstrated to be significantly down-regulated in many cancers which urgently require new treatment options. We highlight current and future efforts employing these KATi as cancer treatments and their ability to synergize and enhance current cancer treatments. We investigate the different methods of KATi production or discovery, their mechanisms and their validation models. Importantly, the utility of KATi is based on a key concept: using KATi to abrogate the activity of an already down-regulated essential protein (effectively creating a lethal knockout) provides another innovative mechanism for targeting cancer cells, while significantly minimizing any off-target effects to normal cells. This approach, combined with the rapidly developing interest in KATi, suggests that KATi have a bright future for providing truly personalized therapies.

MicroRNA-22 inhibits cell growth and metastasis in breast cancer via targeting of SIRT1

MicroRNAs (miRs), which are a class of small non-coding RNAs, are key regulators of gene expression via induction of translational repression or mRNA degradation. However, the molecular mechanism of miR-22 underlying the malignant progression of breast cancer, remains to be elucidated. The present study aimed to explore the regulatory mechanism of miR-22 in breast cancer cell growth and metastasis. Reverse transcription-quantitative polymerase chain reaction data revealed that miR-22 was significantly downregulated in breast cancer tissues, compared with adjacent non-tumor tissues. Furthermore, the miR-22 levels were further decreased in stage III–IV, compared with stage I–II breast cancer. In addition, low miR-22 levels were significantly associated with the poor differentiation, metastasis and advanced clinical stages of breast cancer. Sirtuin1 (SIRT1) was demonstrated to act as a direct target gene of miR-22 and its protein expression negatively regulated by miR-22 in the MCF-7 breast cancer cell line. Furthermore, SIRT1 expression levels were significantly upregulated in breast cancer tissues, compared with adjacent non-tumor tissues. SIRT1 levels were observed to be increased in stage III–IV when compared with stage I–II breast cancer. miR-22 overexpression decreased the proliferation, migration and invasion of MCF-7 cells, whereas overexpression of SIRT1 eliminated the suppressive effects of the miR-22 overexpression on the malignant phenotype of MCF-7 cells. The results of the present study therefore suggested that miR-22 demonstrated suppressive effects on breast cancer growth and metastasis via targeting SIRT1, and thus the miR-22/SIRT1 axis may be used as a novel and potential therapeutic target for breast cancer in the future.

MicroRNAs as Key Effectors in the p53 Network

The guardian of the genome p53 is embedded in a fine-spun network of MicroRNAs. p53 is able to activate or repress directly the transcription of MicroRNAs that are participating in the tumor-suppressive mission of p53. On the other hand, the expression of p53 is under tight control of MicroRNAs that are either targeting directly p53 or factors that are modifying its protein level or activity. Although the most important function of p53 is suggested to be transcriptional regulation, there are several nontranscriptional functions described. One of those regards the modulation of MicroRNA biogenesis. Wild-type p53 is increasing the maturation of selected MicroRNAs from the primary transcript to the precursor MiRNA by interacting with the Microprocessor complex. Furthermore, p53 is modulating the mRNA accessibility for certain MicroRNAs by association with the RISC complex and transcriptional regulation of RNA-binding proteins. In this way p53 is able to remodel the MiRNA-mRNA interaction network. As wild-type p53 is employing MicroRNAs to suppress cancer development, gain-of-function mutant p53 proteins use MicroRNAs to confer oncogenic properties like chemoresistance and the ability to drive metastasis. Like its wild-type counterpart mutant p53 is able to regulate MicroRNAs transcriptionally and posttranscriptionally. Mutant p53 affects the MiRNA processing at two cleavage steps through interfering with the Microprocessor complex and by downregulating Dicer and KSRP, a modulator of MiRNA biogenesis. Thus, MicroRNAs are essential components in the p53 pathway, contributing substantially to combat or enhance tumor development depending on the wild-type or mutant p53 context.

Molecular mechanisms and clinical applications of miR-22 in regulating malignant progression in human cancer (Review)

miRNAs (microRNAs) have been validated to play fateful roles in the occurrence and development of cancers by post-transcriptionally targeting 3′-untranslated regions of the downstream gene mRNAs to repress mRNA expression. Mounting investigations forcefully document that not only does miR-22 biologically impinge on the processes of senescence, energy supply, angiogenesis, EMT (epithelial-mesenchymal transition), proliferation, migration, invasion, metastasis and apoptosis, but also it genetically or epigenetically exerts dual (inhibitory/promoting cancer) effects in various cancers via CNAs (copy number alterations), SNPs (single nucleotide polymorphisms), methylation, acetylation and even more momentously hydroxymethylation. Additionally, miR-22 expression may fluctuate with cancer progression in the body fluids of cancer patients and miR-22 could amplify its inhibitory or promoting effects through partaking in positive or negative feedback loops and interplaying with many other related miRNAs in the cascade of events, making it possible for miR-22 to be a promising and complementary or even independent cancer biomarker in some cancers and engendering profound influences on the early diagnosis, therapeutics, supervising curative effects and prognosis.

Berberine upregulates miR-22-3p to suppress hepatocellular carcinoma cell proliferation by targeting Sp1

MicroRNA-22-3p (miR-22-3p) is downregulated in hepatocellular carcinoma (HCC), which contributes to the development and progression of HCC. In this study, berberine treatment upregulated miR-22-3p expression in HepG2 cells. Therefore, we investigated whether berberine suppresses the proliferation of HCC cells and explored the underlying mechanism. The HCC HepG2 cell line was treated with a gradient of berberine concentrations (0-300 μM) for 48 h, and 100 μM berberine inhibited cell growth at 24 h. The HepG2 cells were then incubated with 100 μM berberine for 0-48 h, and after treatment for 24 h, berberine markedly suppressed HepG2 cell growth and significantly upregulated miR-22-3p expression. Berberine also downregulated the expression of SP1, CCND1, and BCL2, determined with western blotting. Dual luciferase reporter assays and western blot analyses showed that miR-22-3p directly targeted SP1, thereby suppressing the expression of its downstream targets, CCND1 and BCL2. SP1 knockdown with small interfering RNA also reduced CCND1 and BCL2 expression in HepG2 cells. Therefore, we conclude that berberine treatment suppresses cancer cell growth by regulating miR-22-3p and SP1 and its downstream targets, CCND1 and BCL2, in HCC.

miRpower: a web-tool to validate survival-associated miRNAs utilizing expression data from 2178 breast cancer patients

PURPOSE

The proper validation of prognostic biomarkers is an important clinical issue in breast cancer research. MicroRNAs (miRNAs) have emerged as a new class of promising breast cancer biomarkers. In the present work, we developed an integrated online bioinformatic tool to validate the prognostic relevance of miRNAs in breast cancer.

METHODS

A database was set up by searching the GEO, EGA, TCGA, and PubMed repositories to identify datasets with published miRNA expression and clinical data. Kaplan-Meier survival analysis was performed to validate the prognostic value of a set of 41 previously published survival-associated miRNAs.

RESULTS

All together 2178 samples from four independent datasets were integrated into the system including the expression of 1052 distinct human miRNAs. In addition, the web-tool allows for the selection of patients, which can be filtered by receptors status, lymph node involvement, histological grade, and treatments. The complete analysis tool can be accessed online at: www.kmplot.com/mirpower . We used this tool to analyze a large number of deregulated miRNAs associated with breast cancer features and outcome, and confirmed the prognostic value of 26 miRNAs. A significant correlation in three out of four datasets was validated only for miR-29c and miR-101.

CONCLUSIONS

In summary, we established an integrated platform capable to mine all available miRNA data to perform a survival analysis for the identification and validation of prognostic miRNA markers in breast cancer.