Downregulation of microRNA-27b-3p enhances tamoxifen resistance in breast cancer by increasing NR5A2 and CREB1 expression

miRNAs that regulate apoptosis in breast cancer and cervical cancer

In today's world, one of the main problems is cancer, which still has a long way to go to cure it, and it brings a lot of financial and emotional costs to the people of society and governments. Breast cancer (BC) and cervical cancer (CC), two of the most common cancers, are caused by several genetic and environmental factors in women. These two cancers' involvement rate is higher than other cancers in women. microRNAs (miRNAs) are non-coding RNA molecules with a length of 18 to 24 nucleotides, which play an important role in post-translational changes. miRNAs themselves are divided into two categories, oncomiRs and tumor suppressors. OncomiRs have a part in tumor expansion and tumor suppressors prevent tumor development and progress. miRNAs can control cellular processes by regulating various pathways including autophagy, apoptosis, and signaling. Apoptosis is a type of programmed cell death that includes intrinsic and extrinsic pathways and is different from other cell death pathways such as necrosis and ferroptosis. Apoptosis controls the growth, differentiation, and death of cells by regulating the death of damaged and old cells, and since miRNAs are one of the factors that regulate apoptosis, and divided into two categories: pro-apoptotic and anti-apoptotic. We decided in this study to investigate the relationship between miRNAs and apoptosis in the most common women's cancers, BC and CC.

Oestrogen receptor positive breast cancer and its embedded mechanism: breast cancer resistance to conventional drugs and related therapies, a review

Traditional medication and alternative therapies have long been used to treat breast cancer. One of the main problems with current treatments is that there is an increase in drug resistance in the cancer cells owing to genetic differences such as mutational changes, epigenetic changes and miRNA (microRNA) alterations such as miR-1246, miR-298, miR-27b and miR-33a, along with epigenetic modifications, such as Histone3 acetylation and CCCTC-Binding Factor (CTCF) hypermethylation for drug resistance in breast cancer cell lines. Certain forms of conventional drug resistance have been linked to genetic changes in genes such as ABCB1, AKT, S100A8/A9, TAGLN2 and NPM. This review aims to explore the current approaches to counter breast cancer, the action mechanism, along with novel therapeutic methods endowing potential drug resistance. The investigation of novel therapeutic approaches sheds light on the phenomenon of drug resistance including genetic variations that impact distinct forms of oestrogen receptor (ER) cancer, genetic changes, epigenetics-reported resistance and their identification in patients. Long-term effective therapy for breast cancer includes selective oestrogen receptor modulators, selective oestrogen receptor degraders and genetic variations, such as mutations in nuclear genes, epigenetic modifications and miRNA alterations in target proteins. Novel research addressing combinational therapies including maytansine, photodynamic therapy, guajadiol, talazoparib, COX2 inhibitors and miRNA 1246 inhibitors have been developed to improve patient survival rates.

The Impact of miRNAs on the Efficacy of Tamoxifen in Breast Cancer Treatment: A Systematic Review

Seventy percent of breast cancer patients have an active estrogen receptor. Tamoxifen interferes with estrogen's ability to bind to cancer cells. The most challenging aspect of tamoxifen, however, is that breast cancer cells become resistant to its effects. Some studies have shown that alterations in miRNA expression contribute significantly to drug resistance in breast cancer. Therefore, the present systematic review aims to investigate miRNAs that significantly influence the response to tamoxifen treatment. The present study follows the PRISMA instructions. The Web of Science, PubMed, and Scopus databases were searched to retrieve English articles. The searches were conducted up to September 11, 2022. The search strategy included the terms "Tamoxifen", "Breast Neoplasm", and "MicroRNA". The inclusion criteria of this study are English, original, and experimental studies investigating miRNAs that are effective in the treatment efficacy of tamoxifen. A total of 565 articles were retrieved. After screening, 75 studies met our inclusion criteria. This systematic review study examined 105 miRNAs, of which 44 have a positive effect, and 47 miRNAs inhibit tamoxifen function. Fourteen miRNAs have a controversial effect, ie, some studies show positive and negative effects. The study of miRNAs affecting tamoxifen function in breast cancer patients may facilitate the identification of individuals at higher risk of disease recurrence. Conversely, it can potentially utilize appropriate interventions to defeat drug resistance effectively.

[MiR-26-3p regulates proliferation, migration, invasion and apoptosis of glioma cells by targeting CREB1]

OBJECTIVE

To investigate the regulatory role of miR-26b-3p in proliferation, migration and invasion of glioma.

METHODS

The expressions of miR-26b-3p and cAMP-responsive element binding protein 1 (CREB1) in gliomas of different pathological grades were detected with RT-qPCR and Western blotting. Bioinformatic methods were used to analyze the target sequence of miRNA-26b-3p binding to CREB1, and dual luciferase gene reporter experiment was performed to explore the mechanism for targeted regulation of CREB1 by miR-26b-3p. Glioma U251 cells were treated with miR-26b-3p mimic or inhibitor, and the changes in CREB1 expression and cell proliferation, migration, invasion and apoptosis were determined with Western blotting, CCK-8 assay, wound healing assay, Transwell assay, and flow cytometry.

RESULTS

The expression of miR-26b-3p decreased while CREB1 expression increased significantly as the pathological grade of gliomas increased (P < 0.05). Dual luciferase gene reporter experiment confirmed that CREB1 was a downstream target of miR-26b-3p. Inhibition of miR-26b-3p significantly upregulated the expression of CERB1, suppressed apoptosis and promoted proliferation and invasion of glioma cells, and overexpression of miR-26b-3p produced the opposite effects (P < 0.05).

CONCLUSION

MiR-26b-3p regulates CREB1 expression to modulate apoptosis, proliferation, migration and invasion of glioma cells, thereby participating in tumorigenesis and progression of glioma.

Progress in the Understanding of Estrogen Receptor Alpha Signaling in Triple-Negative Breast Cancer: Reactivation of Silenced ER-α and Signaling through ER-α36

Triple-negative breast cancer (TNBC) is an aggressive tumor that accounts for approximately 15% of total breast cancer cases. It is characterized by poor prognosis and high rate of recurrence compared to other types of breast cancer. TNBC has a limited range of treatment options that include chemotherapy, surgery, and radiation due to the absence of estrogen receptor alpha (ER-α) rendering hormonal therapy ineffective. However, possible targets for improving the clinical outcomes in TNBC exist, such as targeting estrogen signaling through membranous ER-α36 and reactivating silenced ER-α. It has been shown that epigenetic drugs such as DNA methyltransferase and histone deacetylase inhibitors can restore the expression of ER-α. This reactivation of ER-α, presents a potential strategy to re-sensitize TNBC to hormonal therapy. Also, this review provides up-to-date information related to the direct involvement of miRNA in regulating the translation of ER-α mRNA. Specific epi-miRNAs can regulate ER-α expression indirectly by post-transcriptional targeting of mRNAs of enzymes that are involved in DNA methylation and histone deacetylation. Furthermore, ER-α36, an alternative splice variant of ER-α66, is highly expressed in ER-negative breast tumors and activates MAPK/ERK pathway, promoting cell proliferation, escaping apoptosis, and enhancing metastasis. In the future, these recent advances may be helpful for researchers working in the field to obtain novel treatment options for TNBC, utilizing epigenetic drugs and epi-miRNAs that regulate ER-α expression. Also, there is some evidence to suggest that drugs that decrease the expression of ER-α36 may be effective in treating TNBC.

Evaluation of Long Non-coding RNA (LncRNA) in the Pathogenesis of Chemotherapy Resistance in Cervical Cancer: Diagnostic and Prognostic Approach

Cervical cancer (CC), caused by human papillomavirus (HPV), is a leading cause of female malignancies worldwide. Therefore, understanding the underlying mechanisms of CC development and identifying novel therapeutic targets are significantly important. Cisplatin resistance is a significant challenge in the management of CC. Recent studies highlighted the critical role of long non-coding RNAs (lncRNAs) in modulation of cisplatin resistance. This comprehensive review aims to collect the current understanding roles of lncRNAs and their involvement in cisplatin resistance in CC by highlighting key processes of cancer progression, including apoptosis, proliferation, angiogenesis and epithelial-to-mesenchymal transition (EMT). We discussed the role of lncRNA in CC resistance to cisplatin through molecular pathways and examined gene expression changes. We also discussed treatment strategies and factors that reduce CC resistance to cisplatin by targeting them.

Landscape of NcRNAs involved in drug resistance of breast cancer

Breast cancer (BC) leads to the most amounts of deaths among women. Chemo-, endocrine-, and targeted therapies are the mainstay drug treatments for BC in the clinic. However, drug resistance is a major obstacle for BC patients, and it leads to poor prognosis. Accumulating evidences suggested that noncoding RNAs (ncRNAs) are intricately linked to a wide range of pathological processes, including drug resistance. Till date, the correlation between drug resistance and ncRNAs is not completely understood in BC. Herein, we comprehensively summarized a dysregulated ncRNAs landscape that promotes or inhibits drug resistance in chemo-, endocrine-, and targeted BC therapies. Our review will pave way for the effective management of drug resistance by targeting oncogenic ncRNAs, which, in turn will promote drug sensitivity of BC in the future.

Non-Coding RNAs Modulating Estrogen Signaling and Response to Endocrine Therapy in Breast Cancer

The largest part of human DNA is transcribed into RNA that does not code for proteins. These non-coding RNAs (ncRNAs) are key regulators of protein-coding gene expression and have been shown to play important roles in health, disease and therapy response. Today, endocrine therapy of ERα-positive breast cancer (BC) is a successful treatment approach, but resistance to this therapy is a major clinical problem. Therefore, a deeper understanding of resistance mechanisms is important to overcome this resistance. An increasing amount of evidence demonstrate that ncRNAs affect the response to endocrine therapy. Thus, ncRNAs are considered versatile biomarkers to predict or monitor therapy response. In this review article, we intend to give a summary and update on the effects of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) on estrogen signaling in BC cells, this pathway being the target of endocrine therapy, and their role in therapy resistance. For this purpose, we reviewed articles on these topics listed in the PubMed database. Finally, we provide an assessment regarding the clinical use of these ncRNA types, particularly their circulating forms, as predictive BC biomarkers and their potential role as therapy targets to overcome endocrine resistance.

Targeted Therapy and Mechanisms of Drug Resistance in Breast Cancer

Breast cancer is the most common cause of cancer-related death in women worldwide. Multidrug resistance (MDR) has been a large hurdle in reducing BC death rates. The drug resistance mechanisms include increased drug efflux, enhanced DNA repair, senescence escape, epigenetic alterations, tumor heterogeneity, tumor microenvironment (TME), and the epithelial-to-mesenchymal transition (EMT), which make it challenging to overcome. This review aims to explain the mechanisms of resistance in BC further, identify viable drug targets, and elucidate how those targets relate to the progression of BC and drug resistance.

MicroRNA-433-3p enhances chemosensitivity of glioma to cisplatin by downregulating NR5A2

OBJECTIVE

We attempted to investigate influence of microRNA-433-3p on malignant progression of glioma and identify its molecular mechanism, thus laying groundwork for glioma management.

METHODS

Expression data along with clinical data of glioma were accessed from the TCGA database for differential and survival analyses to look for the target differentially expressed genes. Quantitative reverse transcriptase PCR (qRT-PCR) and western blot were utilized to assess NR5A2 mRNA and protein expression in different glioma cell lines, respectively. MTT, Transwell assay, and flow cytometry were carried out to assay the impact of NR5A2 on behaviors of glioma cells in vitro. Bioinformatics analysis was used to identify the upstream microRNA of NR5A2 in glioma, while dual-luciferase and western blot assays were used to detect binding of microRNA and NR5A2. Chemosensitivity of glioma cells was evaluated by cisplatin cytotoxicity test.

RESULTS

NR5A2 was upregulated in both glioma tissues and cell lines. Dual-luciferase assay result showed binding site of microRNA-433-3p on NR5A2 mRNA 3'UTR, and microRNA-433-3p reduced NR5A2 expression. Cell assays revealed that silencing NR5A2 could hamper proliferation, invasion, and migration and enhance chemosensitivity to cisplatin while promoting glioma cell apoptosis and blocking glioma cells in G0/G1 phase. Rescue experiments also indicated that microRNA-433-3p suppressed glioma malignant progression via inhibiting NR5A2.

CONCLUSION

MicroRNA-433-3p which is significantly poorly expressed in glioma targets NR5A2 to suppress glioma malignant progression and enhance chemosensitivity to cisplatin.

Stability of circulating microRNAs in serum

There is a strong body of evidence by several translational studies which demonstrate the potential of circulating miRNAs as a potential biomarker in oncology. However, recent reports documented varying stability of these small RNA molecules in serum samples. The aim of our pilot study was to evaluate the stability of miRNAs in serum in relation to food intake and sample storage. Serum miRNA expression levels of 16 different miRNAs from 8 healthy volunteers were quantified by real-time PCR. 4 samples from each donor were analysed—2 samples (fasting, in the morning and after food intake, at noon) were analysed within 24h and 2 samples (fasting and after food intake, at noon) were stored at -80°C for 14 days and subsequently analysed. Student´s t-test was used to determine significant differences. The detectability of the distinct miRNA as a surrogate for the stability of these small RNA molecules was slightly altered by the storage conditions, but only a miRNA 22-3p, out of the analysed 16 miRNAs, shows significant lower dCq expression (3.821 vs. 4.530; p<0,01) by qPCR dependent on storage conditions (-80°C vs. 4°C). However, miRNA levels were not affected by food intake. The difference between samples taken in the morning (fasting) and at noon (after a normal meal) did not show any significant differences. MiRNAs can be considered to be a relatively stable tool in laboratory diagnostics, but clearly every new assay needs thorough evaluation. The stability of miRNAs documented here in healthy volunteers shows their potential in the search for innovative biomarkers in oncology.

Microribonucleic Acid-15a-5p Alters Adriamycin Resistance in Breast Cancer Cells by Targeting Cell Division Cycle-Associated Protein 4

Objective

Although chemotherapy is one of the first line clinical treatment of tumors, the efficacy of chemotherapy has been severely restricted by the frequent occurrence of drug resistance phenomenon. Multiple studies found that miRNAs can regulate the chemosensitivity of tumor cells. Here, this study aimed to assess the potential role of the miR-15a-5p/cell division cycle-related protein 4 (CDCA4) axis in breast cancer (BC) resistance to Adriamycin.

Methods

In the present study, the relative expression of miRNA-15a-5p in MCF-7/ADR, MCF-7 and Hs578Bst was measured by qRT-PCR. MCF-7/ADR cells underwent transfection with an miR-15a-5p mimic and inhibitor, respectively. Transwell assays, flow cytometry and CCK8 were performed to examine the potential effects of the abnormal expression of miR-15a-5p. The association of aberrant miR-15a-5p expression with Adriamycin resistance in BC was determined in cultured MCF-7/ADR cells. Bioinformatics was employed to predict the genes targeted by miR-15a-5p. Moreover, the correlation between miR-15a-5p and its target gene, CDCA4, was evaluated based on qRT-PCR data.

Results

The expression of miR-15a-5p was significantly downregulated in MCF/ADR cells compared with MCF-7 and Hs578Bst cell lines. In the presence of Adriamycin, miR-15a-5p overexpression significantly increased cell chemosensitivity, as well as MCF-7/ADR cell proliferation, invasion, and migration, while promoting apoptosis and inducing cell-cycle arrest in the synthesis phase. CDCA4 RNA interference enhanced these effects as shown in our previous study. Bioinformatics identified CDCA4 as an miR-15a-5p target gene. qRT-PCR further demonstrated that CDCA4 and miR-15a-5p expression levels were inversely correlated.

Conclusion

Adriamycin resistance in BC cells was, at least in part, altered by mRNA-15a-5p via regulation of its target gene, CDCA4, by controlling the cell cycle, which may provide some novel ideas for BC chemotherapy in the future.

Role of SALL4 and Nodal in the prognosis and tamoxifen resistance of estrogen receptor-positive breast cancer

Despite the discovery of a number of different mechanisms underlying tamoxifen resistance, its molecular pathway is not completely clear. The upregulation of SALL4 and Nodal has been reported in breast cancer. Nevertheless, their role in tamoxifen resistance has not been investigated. In the present study, we compared Nodal and SALL4 expression in 72 tamoxifen sensitive (TAMS) and tamoxifen-resistant (TAMR) patients. Afterward, the correlation of expression data with clinicopathological features and survival of patients was studied. Results showed that both SALL4 and Nodal were significantly upregulated in TAMR compared to TAMS patients. Besides, there was a positive association between Nodal and SALL4 expression. Furthermore, we evaluated their correlation with the expression of Oct4, Nanog and Sox2 stemness markers. The results demonstrated that in most tissue samples there was a positive correlation between Nodal and SALL4 expression with these stemness markers. Besides, the overexpression of SALL4 and Nodal significantly correlated with the N stage. Moreover, the overexpression of SALL4 was associated with extracapsular invasion and lymphatic invasion. High level expressions of SALL4 and Nodal had a significant association with worse disease-free survival (DFS) rates. In addition, increased level of Nodal expression provides a superior predictor factor for DFS. The multivariate Cox regression analysis also revealed that for DFS, perineural invasion (PNI) was independently an unfavorable prognostic value. These findings suggest that the high expression of SALL4 and Nodal could contribute to tamoxifen resistance and worse survival rates in tamoxifen-treated ER⁺ breast cancer patients.

A review of the endocrine resistance in hormone-positive breast cancer

Hormone-positive breast cancer (BC) is a unique heterogeneous disease with a favorable prognosis compared to other types of breast cancer. As tumor biology influences the prognosis and clinical treatment, a deep understanding of how the molecular mechanisms regulate hormone sensitivity or resistance is critical in improving the efficacy and overcoming the endocrine resistance. This article comprehensively reviews the endocrine resistance in hormone-positive BC from a molecular and genetic perspective, encompassing the updated treatment and developing direction. This review includes the mechanisms of hormone resistance, which vary from epigenetic changes, crosstalk between signaling networks, cell cycle aberrance, and even change in the tumor microenvironment (TME) or stem cell. These mechanisms may contribute to treatment resistance. Current targeted therapy for hormone-resistant tumors includes PI3K/AKT/mTOR and cdk4/6 inhibitors. Several relevant pathways, biomarkers, and predictor genes have also been identified. Immunotherapy so far has a relatively less crucial role in hormone-positive than in triple-negative BC. Furthermore, the methodology to identify the PDL1 is not standardized. In a molecule and gene study, next-generation sequencing with circulating tumor DNA (ctDNA) has recently appeared as a sensitive and minimally invasive tool worth investigating.

LncRNA AFAP1-AS1/miR-27b-3p/VEGF-C axis modulates stemness characteristics in cervical cancer cells

Background:

Long non-coding RNA (lncRNA) actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) functions as a competing endogenous RNA to regulate target genes expression by sponging microRNAs (miRs) to play cancer-promoting roles in cancer stem cells. However, the regulatory mechanism of AFAP1-AS1 in cervical cancer (CC) stem cells is unknown. The present study aimed to provide a new therapeutic target for the clinical treatment of CC.

Methods:

Hyaluronic acid receptor cluster of differentiation 44 variant exon 6 (CD44v6)(+) CC cells were isolated by flow cytometry (FCM). Small interfering RNAs of AFAP1-AS1 (siAFAP1-AS1) were transfected into the (CD44v6)(+) cells. The levels of AFAP1-AS1 were measured by quantitative real-time PCR (qRT-PCR). Sphere formation assay, cell cycle analysis, and Western blotting were used to detect the effect of siAFAP1-AS1. RNA pull-down and luciferase reporter assay were used to verify the relationship between miR-27b-3p and AFAP1-AS1 or vascular endothelial growth factor (VEGF)-C.

Results:

CD44v6(+) CC cells had remarkable stemness and a high level of AFAP1-AS1. However, AFAP1-AS1 knockdown with siAFAP1-AS1 suppressed the cell cycle transition of G(1)/S phase and inhibited self-renewal of CD44v6(+) CC cells, the levels of the stemness markers octamer-binding transcription factor 4 (OCT4), osteopontin (OPN), and cluster of differentiation 133 (CD133), and the epithelial-mesenchymal transition (EMT)-related proteins Twist1, matrix metalloprotease (MMP)-9, and VEGF-C. In the mechanism study, miR-27b-3p/VEGF-C signaling was demonstrated to be a key downstream of AFAP1-AS1 in the CD44v6(+) CC cells.

Conclusions:

LncRNA AFAP1-AS1 knockdown inhibits the CC cell stemness by upregulating miR-27b-3p to suppress VEGF-C.

From Micro to Long: Non-Coding RNAs in Tamoxifen Resistance of Breast Cancer Cells

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer mortality among women. Two thirds of patients are classified as hormone receptor positive, based on expression of estrogen receptor alpha (ERα), the main driver of breast cancer cell proliferation, and/or progesterone receptor, which is regulated by ERα. Despite presenting the best prognosis, these tumors can recur when patients acquire resistance to treatment by aromatase inhibitors or antiestrogen such as tamoxifen (Tam). The mechanisms that are involved in Tam resistance are complex and involve multiple signaling pathways. Recently, roles for microRNAs and lncRNAs in controlling ER expression and/or tamoxifen action have been described, but the underlying mechanisms are still little explored. In this review, we will discuss the current state of knowledge on the roles of microRNAs and lncRNAs in the main mechanisms of tamoxifen resistance in hormone receptor positive breast cancer. In the future, this knowledge can be used to identify patients at a greater risk of relapse due to the expression patterns of ncRNAs that impact response to Tam, in order to guide their treatment more efficiently and possibly to design therapeutic strategies to bypass mechanisms of resistance.

Regulation of aromatase expression: Potential therapeutic insight into breast cancer treatment

Estrogen signaling has been implicated in hormone-dependent breast cancer which constitutes >75% of breast cancer diagnosis and other malignancies. Aromatase, the key enzyme involved in the synthesis of estrogen, is often dysregulated in breast cancers. This has led to the administration of aromatase-inhibitors (AIs), commonly used for hormone-dependent breast cancers. Unfortunately, the increasing development of acquired resistance to the current AIs and modulators of estrogen receptors, following initial disease steadiness, has posed a serious clinical challenge in breast cancer treatment. In this review we highlight historical and recent advances on the transcriptional and post-translational regulation of aromatase in both physiological and pathological contexts. We also discuss the different drug combinations targeting various tumor promoting cell signaling pathways currently being developed and tested both in laboratory settings and in the clinic.

KDELR2 promotes breast cancer proliferation via HDAC3-mediated cell cycle progression

Background

Histone deacetylases (HDACs) engage in the regulation of various cellular processes by controlling global gene expression. The dysregulation of HDACs leads to carcinogenesis, making HDACs ideal targets for cancer therapy. However, the use of HDAC inhibitors (HDACi) as single agents has been shown to have limited success in treating solid tumors in clinical studies. This study aimed to identify a novel downstream effector of HDACs to provide a potential target for combination therapy.

Methods

Transcriptome sequencing and bioinformatics analysis were performed to screen for genes responsive to HDACi in breast cancer cells. The effects of HDACi on cell viability were detected using the MTT assay. The mRNA and protein levels of genes were determined by quantitative reverse transcription‐PCR (qRT‐PCR) and Western blotting. Cell cycle distribution and apoptosis were analyzed by flow cytometry. The binding of CREB1 (cAMP‐response element binding protein 1) to the promoter of the KDELR (The KDEL (Lys‐Asp‐Glu‐Leu) receptor) gene was validated by the ChIP (chromatin immunoprecipitation assay). The association between KDELR2 and protein of centriole 5 (POC5) was detected by immunoprecipitation. A breast cancer‐bearing mouse model was employed to analyze the effect of the HDAC3‐KDELR2 axis on tumor growth.

Results

KDELR2 was identified as a novel target of HDAC3, and its aberrant expression indicated the poor prognosis of breast cancer patients. We found a strong correlation between the protein expression patterns of HADC3 and KDELR2 in tumor tissues from breast cancer patients. The results of the ChIP assay and qRT‐PCR analysis validated that HDAC3 transactivated KDELR2 via CREB1. The HDAC3‐KDELR2 axis accelerated the cell cycle progression of cancer cells by protecting the centrosomal protein POC5 from proteasomal degradation. Moreover, the HDAC3‐KDELR2 axis promoted breast cancer cell proliferation and tumorigenesis in vitro and in vivo.

Conclusion

Our results uncovered a previously unappreciated function of KDELR2 in tumorigenesis, linking a critical Golgi‐the endoplasmic reticulum traffic transport protein to HDAC‐controlled cell cycle progression on the path of cancer development and thus revealing a potential therapeutical target for breast cancer.

The local anesthetic ropivacaine suppresses progression of breast cancer by regulating miR-27b-3p/YAP axis

Breast cancer is a prevalent malignancy with high mortality and poor prognosis. Ropivacaine is a widely used local anesthetic and presents potential anti-tumor activity. Nevertheless, the function of ropivacaine in breast cancer development remains elusive. Here, we tried to investigate the impact of ropivacaine on breast cancer progression and the underlying mechanism. Significantly, we revealed that ropivacaine was able to reduce the proliferation and induce the apoptosis of breast cancer cells. Ropivacaine could attenuate the invasion and migration in the cells. Mechanically, ropivacaine could enhance the miR-27b-3p expression and miR-27b-3p inhibited breast cancer progression in breast cancer cells. MiR-27b-3p targeted YAP in the breast cancer cells. Ropivacaine decreased the breast cancer progression by modulating miR-27b-3p/YAP axis in vitro. Ropivacaine could inhibit tumor growth in vivo. In conclusion, we discovered that the local anesthetic ropivacaine inhibits the progression of breast cancer via the miR-27b-3p/YAP axis. Our finding presents novel insights into the mechanism of ropivacaine inhibiting the development of breast cancer. Ropivacaine may potentially serve as an anti-tumor candidate in the therapeutic strategy of breast cancer.

MicroRNAs and Long Noncoding RNAs as Novel Therapeutic Targets in Estrogen Receptor-Positive Breast and Ovarian Cancers

Aromatase inhibitors (AIs) such as anastrozole, letrozole, and exemestane have shown to prevent metastasis and angiogenesis in estrogen receptor (ER)-positive breast and ovarian tumors. They function primarily by reducing estrogen production in ER-positive post-menopausal breast and ovarian cancer patients. Unfortunately, current AI-based therapies often have detrimental side-effects, along with acquired resistance, with increased cancer recurrence. Thus, there is an urgent need to identify novel AIs with fewer side effects and improved therapeutic efficacies. In this regard, we and others have recently suggested noncoding RNAs (ncRNAs), specifically microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), as potential molecular targets for utilization in modulating cancer hallmarks and overcoming drug resistance in several cancers, including ER-positive breast and ovarian cancer. Herein, we describe the disruptive functions of several miRNAs and lncRNAs seen in dysregulated cancer metabolism, with a focus on the gene encoding for aromatase (CYP19A1 gene) and estrogen synthesis as a novel therapeutic approach for treating ER-positive breast and ovarian cancers. Furthermore, we discuss the oncogenic and tumor-suppressive roles of several miRNAs (oncogenic miRNAs: MIR125b, MIR155, MIR221/222, MIR128, MIR2052HG, and MIR224; tumor-suppressive miRNAs: Lethal-7f, MIR27B, MIR378, and MIR98) and an oncogenic lncRNA (MIR2052HG) in aromatase-dependent cancers via transcriptional regulation of the CYP19A1 gene. Additionally, we discuss the potential effects of dysregulated miRNAs and lncRNAs on the regulation of critical oncogenic molecules, such as signal transducer, and activator of transcription 3, β-catenin, and integrins. The overall goal of this review is to stimulate further research in this area and to facilitate the development of ncRNA-based approaches for more efficacious treatments of ER-positive breast and ovarian cancer patients, with a slight emphasis on associated treatment–delivery mechanisms.

NR5A2 transcriptional activation by BRD4 promotes pancreatic cancer progression by upregulating GDF15

NR5A2 is a transcription factor regulating the expression of various oncogenes. However, the role of NR5A2 and the specific regulatory mechanism of NR5A2 in pancreatic ductal adenocarcinoma (PDAC) are not thoroughly studied. In our study, Western blotting, real-time PCR, and immunohistochemistry were conducted to assess the expression levels of different molecules. Wound-healing, MTS, colony formation, and transwell assays were employed to evaluate the malignant potential of pancreatic cancer cells. We demonstrated that NR5A2 acted as a negative prognostic biomarker in PDAC. NR5A2 silencing inhibited the proliferation and migration abilities of pancreatic cancer cells in vitro and in vivo. While NR5A2 overexpression markedly promoted both events in vitro. We further identified that NR5A2 was transcriptionally upregulated by BRD4 in pancreatic cancer cells and this was confirmed by Chromatin immunoprecipitation (ChIP) and ChIP-qPCR. Besides, transcriptome RNA sequencing (RNA-Seq) was performed to explore the cancer-promoting effects of NR5A2, we found that GDF15 is a component of multiple down-regulated tumor-promoting gene sets after NR5A2 was silenced. Next, we showed that NR5A2 enhanced the malignancy of pancreatic cancer cells by inducing the transcription of GDF15. Collectively, our findings suggest that NR5A2 expression is induced by BRD4. In turn, NR5A2 activates the transcription of GDF15, promoting pancreatic cancer progression. Therefore, NR5A2 and GDF15 could be promising therapeutic targets in pancreatic cancer.

Long non-coding RNA OIP5-AS1 contributes to cisplatin resistance of oral squamous cell carcinoma through the miR-27b-3p/TRIM14 axis

Oral squamous cell carcinoma (OSCC) accounts for 90% of oral cavity cancer types, but the overall prognosis for patients with OSCC remains unfavorable. Cisplatin (DDP) is an effective drug in OSCC treatment, but DDP resistance weakens its therapeutic effect. Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) can trigger DDP resistance. The purpose of the current study was to explore the role and mechanism ofOIP5-AS1 in OSCC DDP resistance. In the present study, the expression levels of OIP5-AS1, microRNA (miR)-27b-3p and tripartite motif-containing 14 (TRIM14) were detected by reverse transcription-quantitative PCR. DDP resistance was measured using an MTT assay. Moreover, cell proliferation, migration and invasion were assessed by MTT, Transwell, and Matrigel assays. Protein expression levels of TRIM14, E-cadherin, N-cadherin and Vimentin were detected by western blot analysis. Putative binding sites between miR-27b-3p andOIP5-AS1 or TRIM14werepredicted with starBase and verified using a dual-luciferase reporter assay. The role of OIP5-AS1 in DDP resistance of OSCC in vivo was measured using a xenograft tumor model. It was observed that OIP5-AS1 was upregulated in DDP-resistant OSCC cells, and the knockdown of OIP5-AS1 improved DDP sensitivity in DDP-resistant OSCC cells. The present study identified that miR-27b-3p was a target of OIP5-AS1. Furthermore, miR-27b-3p silencing reversed the effect of OIP5-AS1 knockdown on DDP sensitivity in DDP-resistant OSCC cells. TRIM14was shown to be a direct target of miR-27b-3p, and TRIM14 overexpression abolished the effect of miR-27b-3p on DDP sensitivity in DDP-resistant OSCC cells. The results suggested that OIP5-AS1 increased TRIM14 expression by sponging miR-27b-3p. In addition, OIP5-AS1 knockdown enhanced DDP sensitivity of OSCC in vivo. Data from the present study indicated that OIP5-AS1 may improve DDP resistance through theupregulationTRIM14 mediated bymiR-27b-3p, providing a possible therapeutic strategy for OSCC treatment.

microRNA-499a promotes the progression and chemoresistance of cervical cancer cells by targeting SOX6

Emerging evidence has indicated that microRNAs are involved in multiple processes of cancer development. Previous studies have demonstrated that microRNA-499a (miR-499a) plays both oncogenic and tumor suppressive roles in several types of malignancies, and genetic variants in miR-499a are associated with the risk of cervical cancer. However, the biological roles of miR-499a in cervical cancer have not been investigated. Quantitative real-time PCR was used to assess miR-499a expression in cervical cancer cells. Mimics or inhibitor of miR-499a was transfected into cervical cancer cells to upregulate or downregulate miR-499a expression. The effects of miR-499a expression change on cervical cancer cells proliferation, colony formation, tumorigenesis, chemosensitivity, transwell migration and invasion were assessed. The potential targets of miR-499a were predicted using online database tools and validated using real-time PCR, Western blot and luciferase reporter experiments. miR-499a was significantly upregulated in cervical cancer cells. Moreover, overexpression of miR-499a significantly enhanced the proliferation, cell cycle progression, colony formation, apoptosis resistance, migration and invasion of cervical cancer cells, while inhibiting miR-499a showed the opposite effects. Further exploration demonstrated that Sex-determining region Y box 6 was the direct target of miR-499a. miR-499a-induced SOX6 downregulation mediated the oncogenic effects of miR-499a in cervical cancer. Inhibiting miR-499a could enhance the anticancer effects of cisplatin in the xenograft mouse model of cervical cancer. Our findings for the first time suggest that miRNA-499a may play an important role in the development of cervical cancer and could serve as a potential therapeutic target.

microRNA-27b inhibits cell proliferation and invasion in bladder cancer by targeting engrailed-2

Background: Bladder cancer is considered a malignant tumour characterised by great heterogeneity. Engrailed-2 may be a gene implicated in bladder cancer. Bioinformatics analysis found base pair complementation between microRNA-27b and engrailed-2. The present study aimed to investigate the reciprocal association between microRNA-27b and engrailed-2 in bladder cancer.

Methods: The microRNA-27b and the protein of engrailed-2 in the tissues and cells of the bladder were detected. The processes of apoptosis, proliferation, invasion, and migration of tumour cells were evaluated. The co-action between microRNA-27b and engrailed-2 was detected by a luciferase reporter system. Finally, the interaction between microRNA-27b and engrailed-2 was further verified in vivo.

Results: The study found that the expression level of microRNA-27b is lower in bladder cancer tissues and cells than that in neighbouring ordinary tissues, whereas the opposite outcome was observed regarding the expression level of engrailed-2. Furthermore, microRNA-27b expression level is not significantly linked to the age of patients with bladder cancer; however, it is significantly associated with the clinicopathological grade of bladder cancer. Notably, engrailed-2 is negatively regulated by microRNA-27b. Transfection with microRNA-27b was associated with a significant reduction in the activity of bladder cancer cells and promoted apoptosis, while engrailed-2 restoration effectively reversed the above effects of microRNA-27b on bladder cancer in vitro and in vivo.

Conclusions: In conclusion, engrailed-2 is engaged in the development and process of bladder cancer through the negative mediation of microRNA-27b; additionally, microRNA-27b/engrailed-2 could form a signalling pathway with a significant effect on the process of bladder cancer.

The lncRNA RP3-439F8.1 promotes GBM cell proliferation and progression by sponging miR-139-5p to upregulate NR5A2

BACKGROUND

Nuclear Receptor Subfamily 5 Group A Member 2 (NR5A2, LRH-1) is an oncogene in a wide range of cancer types. Bioinformatics analysis on glioblastoma multiforme (GBM) tumors has revealed that the miR-139-5p-NR5A2 axis may be putatively regulated by the long non-coding RNA (lncRNA) RP3-439F8.1. This led us to hypothesize the existence of a RP3-439F8.1-miR-139-5p-NR5A2 regulatory axis in GBM cells.

METHODS

Gene expression analysis was performed in GBM tumor samples and normal controls from our hospital, the Cancer Genome Atlas Glioblastoma Multiforme (TCGA-GBM) cohort, and the Gene Expression Omnibus (GEO) database (GSE7696). Cell proliferation, apoptosis, Matrigel Transwell, colony formation, and cell cycle assays were performed in T98 G and U251 cells in vitro. An orthotopic U251 xenograft murine model was employed to test the effects of RP3-439F8.1 knockdown in vivo.

RESULTS

NR5A2 was upregulated in the three independent GBM tumor cohorts. In vitro, NR5A2 overexpression enhanced GBM cell proliferation, colony formation, invasiveness, and G0-G1 cell cycle phase shift via co-activating β-catenin/TCF4 signaling, with no apparent effect upon apoptosis. In contrast, RP3-439F8.1 knockdown produced the opposite effects. RP3-439F8.1 knockdown reduced tumor progression in vivo, increasing overall survival in model mice. Further in vitro experiments revealed that RP3-439F8.1 acts as a competing endogenous RNA (ceRNA) to regulate NR5A2 by sponging the microRNA miR-139-5p. These findings were clinically validated by a positive correlation between RP3-439F8.1 and NR5A2 and a negative correlation between RP3-439F8.1 and miR-139-5p in GBM tumors.

CONCLUSIONS

Our study supports a tumorigenic role for RP3-439F8.1 in GBM through the RP3-439F8.1/miR-139-5p/NR5A2 axis.

Comprehensive Transcriptomic Analysis Reveals Dysregulated Competing Endogenous RNA Network in Endocrine Resistant Breast Cancer Cells

Background

Tamoxifen and fulvestrant, both approved for endocrine therapy, have remarkably increased the prognosis of hormone receptor-positive breast cancer patients. However, acquired resistance to endocrine therapy greatly reduces its clinical efficacy. Accumulating evidence suggests a pivotal role of non-coding RNAs (ncRNAs) in breast cancer endocrine resistance, but the specific functions of ncRNAs in tamoxifen and fulvestrant resistance remain largely unknown.

Methods

Microarray analysis was performed for endocrine therapy sensitive (MCF-7), tamoxifen-resistant (LCC2), and dual tamoxifen and fulvestrant-resistant (LCC9) breast cancer cells. Gene ontology and pathway analysis were conducted for functional prediction of the unannotated differentially expressed ncRNAs. Competing endogenous RNA regulatory networks were constructed.

Results

We discovered a total of 3,129 long non-coding RNAs (lncRNAs), 13,556 circular RNAs (circRNAs), 132 microRNAs, and 3358 mRNAs that were significantly differentially expressed. We constructed co-expression networks for lncRNA-mRNA, circRNA-mRNA, and microRNA-mRNA. In addition, we established lncRNA-microRNA-mRNA and circRNA-microRNA-mRNA regulatory networks to depict ncRNA crosstalk and transcriptomic regulation of endocrine resistance.

Conclusions

Our study delineates a comprehensive profiling of ncRNAs in tamoxifen and fulvestrant resistant breast cancer cells, which enriches our understanding of endocrine resistance and sheds new light on identifying novel endocrine resistance biomarkers and potential therapeutic targets to overcome endocrine resistance.

miRNA Expression Profiles in Luminal A Breast Cancer-Implications in Biology, Prognosis, and Prediction of Response to Hormonal Treatment

Breast cancer, which is the most common malignancy in women, does not form a uniform nosological unit but represents a group of malignant diseases with specific clinical, histopathological, and molecular characteristics. The increasing knowledge of the complex pathophysiological web of processes connected with breast cancercarcinogenesis allows the development of predictive and prognostic gene expressionand molecular classification systems with improved risk assessment, which could be used for individualized treatment. In our review article, we present the up-to-date knowledge about the role of miRNAs and their prognostic and predictive value in luminal A breast cancer. Indeed, an altered expression profile of miRNAs can distinguish not only between cancer and healthy samples, but they can classify specific molecular subtypes of breast cancer including HER2, Luminal A, Luminal B, and TNBC. Early identification and classification of breast cancer subtypes using miRNA expression profilescharacterize a promising approach in the field of personalized medicine. A detection of sensitive and specific biomarkers to distinguish between healthy and early breast cancer patients can be achieved by an evaluation of the different expression of several miRNAs. Consequently, miRNAs represent a potential as good diagnostic, prognostic, predictive, and therapeutic biomarkers for patients with luminal A in the early stage of BC.

Long non-coding RNA Hsp4 alleviates lipopolysaccharide-induced apoptosis of lung epithelial cells via miRNA-466m-3p/DNAjb6 axis

Acute lung injury (ALI), as a life-threatening syndrome, is mainly characterized with diffuse alveolar injury, excessive pulmonary inflammation, edema and apoptosis of lung epithelial cells. This study investigated the effects of LncRNA Hsp4 (Hsp4, ENSMUST00000175718) on lipopolysaccharide (LPS)-induced apoptosis of MLE-12 cells. In our research, we found that LPS treatment remarkably induced apoptosis of MLE-12 cells and decreased the expression of Hsp4. Overexpression of Hsp4 significantly reversed LPS-induced cell apoptosis through inhibiting mTOR signaling, while suppression of Hsp4 presented opposite effects. Further results showed that Hsp4 positively regulated the expression of miR-466m-3p. Knockdown of miR-466m-3p reversed LPS-induced cell apoptosis via increasing the levels of DNAjb6 which was confirmed to be the target gene of miR-466m-3p. This finding will be helpful for further understanding the critical roles of Hsp4 in ALI and may provide potential targets for ALI diagnosis and treatment.

Connecting the Missing Dots: ncRNAs as Critical Regulators of Therapeutic Susceptibility in Breast Cancer

Whether acquired or de novo, drug resistance remains a significant hurdle in achieving therapeutic success in breast cancer (BC). Thus, there is an urge to find reliable biomarkers that will help in predicting the therapeutic response. Stable and easily accessible molecules such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are regarded as valuable prognostic biomarkers and therapeutic targets since they act as crucial regulators of the various mechanisms involved in BC drug resistance. Here, we reviewed the current literature on ncRNAs as mediators of resistance to systemic therapies in BC. Interestingly, upon integrating data results from individual studies, we concluded that miR-221, miR-222, miR-451, Urothelial Carcinoma Associated 1 (UCA1), and Growth arrest-specific 5 (GAS5) are strong candidates as prognostic biomarkers and therapeutic targets since they are regulating multiple drug resistance phenotypes in BC. However, further research around their clinical implications is needed to validate and integrate them into therapeutic applications. Therefore, we believe that our review may provide relevant evidence for the selection of novel therapeutic targets and prognostic biomarkers for BC and will serve as a foundation for future translational research in the field.

Nuclear-mitochondrial crosstalk: On the role of the nuclear receptor liver receptor homolog-1 (NR5A2) in the regulation of mitochondrial metabolism, cell survival, and cancer

Liver receptor homolog-1 (LRH-1, NR5A2) is an orphan nuclear receptor with widespread activities in the regulation of development, stemness, metabolism, steroidogenesis, and proliferation. Many of the LRH-1-regulated processes target the mitochondria and associated activities. While under physiological conditions, a balanced LRH-1 expression and regulation contribute to the maintenance of a physiological equilibrium, deregulation of LRH-1 has been associated with inflammation and cancer. In this review, we discuss the role and mechanism(s) of how LRH-1 regulates metabolic processes, cell survival, and cancer in a nuclear-mitochondrial crosstalk, and evaluate its potential as a pharmacological target.

Long Non-Coding RNA KCNQ1OT1 Promotes Multidrug Resistance in Chordoma by Functioning as a Molecular Sponge of miR-27b-3p and Subsequently Increasing ATF2 Expression

Background

Chordoma, a rare bone tumor, occurs most commonly at the sacrococcygeal and skull base region. To date, chemotherapy is used to treat patients with advanced-stage chordoma. However, multidrug resistance (MDR) greatly hinders the effect of chemotherapy in chordoma. Here, we studied the correlation between KCNQ1OT1 and chemotherapy resistance.

Methods

RT-PCR assay was used to examine KCNQ1OT1, miR-27b-3p, and ATF2 mRNA expression. CCK8 assay was exercised to detect IC₅₀ values of cisplatin in chordoma cells. ATF2 protein expression was detected by Western blot.

Results

KCNQ1OT1 was increased in chemotherapy-resistant patients and cisplatin-resistant cells, and downregulation of KCNQ1OT1 expression weakened MDR in chordoma. In addition, KCNQ1OT1 promoted MDR in chordoma by sponging miR-27b-3p and subsequently increasing ATF2 expression.

Conclusion

KCNQ1OT1 is proved to be strikingly raised in the chemotherapy-resistant group and to promote MDR in chordoma. Our findings demonstrated the role of the KCNQ1OT1/miR-27b-3p/ATF2 axis in MDR of chordoma, which provides new insight into the molecular mechanism of chordoma MDR, and may determine the effect of therapy after receiving chemotherapy by detecting the expression of KCNQ1OT1 in serum.

SRF Potentiates Colon Cancer Metastasis and Progression in a microRNA-214/PTK6-Dependent Manner

Objective

Serum response factor (SRF), a sequence-specific transcription factor, is closely related to metastasis of gastric cancer, a digestive tract cancer. Herein, we probed the effect of SRF on metastasis and progression of colon cancer (CC), another digestive tract disorder, and the detailed mechanism.

Methods

Microarray analysis was conducted on tumor and adjacent tissues to filter differentially expressed miRNA, followed by RT-qPCR validation in CC cell lines. The transcription factor and the target gene of microRNA-214 (miR-214) were predicted, and their binding relationships were tested by luciferase reporter assays and ChIP assays. Subsequently, SRF and protein tyrosine kinase 6 (PTK6) expression in CC patients and cells was evaluated by RT-qPCR, while JAK2 and STAT3 expression in cells by Western blot analysis. To further explore functions of miR-214, PTK6 and SRF on CC, CC cells were delivered with si-PTK6, miR-214 mimic and/or SRF overexpression.

Results

miR-214 expressed poorly in CC tissues and cell lines, which related to advanced TNM staging and survival. miR-214 mimic inhibited proliferation, migration, invasion, xenograft tumor growth and metastasis of CC cells. SRF, overexpressed in CC samples and cells, suppressed the transcription of miR-214. Meanwhile, SRF upregulation counteracted the inhibitory role of miR-214 mimic in CC cell growth. miR-214 negatively regulated PTK6 expression to impair the JAK2/STAT3 pathway activation, thereby halting CC cell proliferation, migration, invasion, xenograft tumor growth and metastasis.

Conclusion

Altogether, miR-214 may perform as a tumor suppressor in CC, and the SRF/miR-214/PTK6/JAK2/STAT3 axis could be applied as a biomarker and potential therapeutic target.

Potential insights from population kinetic assessment of progression-free survival curves

Progression-free survival (PFS) curves follow first order kinetics on exponential decay nonlinear regression analysis (EDNLRA). Some exhibit 1-phase-decay, some have 2-phase-decay, some are convex. We digitized, performed EDNLRA and generated log-linear plots for 887 published PFS curves for incurable solid tumors treated with various systemic therapies. Proportion of curves fitting 2-phase-decay varied by therapy (p < 0.0001). For 13 therapies, >64 % of PFS curves had 2-phase-decay. This included epidermal growth factor receptor inhibitors in unselected lung cancer patients (some with, some without mutations), immune checkpoint inhibitors, interferon, breast cancer hormonal therapies, and selected others, suggesting 2 distinct, potentially identifiable subpopulations with differing progression rates. For 22 other therapies, <25 % of PFS curves had 2-phase-decay. Only 1 therapy was in the mid-range. Small cell lung and colon carcinomas were particularly likely to yield highly convex curves (p < 0.006), probably from discontinuation of effective therapies. PFS curve shape may yield biological and clinical insights.

Macrophages confer resistance to BET inhibition in triple-negative breast cancer by upregulating IKBKE

BET inhibitors (BETi) exhibit a strong anti-tumor activity in triple-negative breast cancer (TNBC). However, BETi resistance has been reported in TNBC. The mechanisms of resistance have not been demonstrated. Tumor-associated macrophages (TAMs) are frequently involved in cancer cells resistance to chemotherapy, also associated with poor prognosis in TNBC. However, the role of TAMs in BETi resistance remains unknown. Here, we found that BETi JQ1 and I-BET151 exerted anti-tumor effects in TNBC by decreasing IKBKE expression to attenuate NF-κB signaling. TAMs have been reported to associate with chemoresistance in breast cancer. Here, we firstly found that TNBC-stimulated TAMs activated NF-κB signaling by upregulating IKBKE expression to enhance breast cancer cells resistance to BETi. The IKBKE levels were also proved to be higher in clinical TNBC tissues than Non-TNBC tissues, suggesting feedback induction of IKBKE expression by TNBC-stimulated TAMs in TNBC. Moreover, the induction of IKBKE by TAMs in TNBC cells was identified to be associated with STAT3 signaling, which was activated by TAM-secreted IL-6 and IL-10. Lastly, the combination of inhibitors of BET and STAT3 exerted a synergistic inhibition effects in TAM-cocultured or TAM CM-treated TNBC cells in vitro and in vivo. Altogether, our findings illustrated TNBC-activated macrophages conferred TNBC cells resistance to BETi via IL-6 or IL-10/STAT3/IKBKE/NF-κB axis. Blockade of IKBKE or double inhibition of BET and STAT3 might be a novel strategy for treatment of TNBC.

Impact of NR5A2 and RYR2 3'UTR polymorphisms on the risk of breast cancer in a Chinese Han population

OBJECTIVES

The NR5A2 and RYR2 genes are important players in steroid metabolism and play an important role in cancer research. In this research, we want to evaluate the effect of NR5A2 and RYR2 polymorphisms on breast cancer (BC).

METHODS

Four single nucleotide polymorphisms on NR5A2 and RYR2 were selected to genotype by Agena MassARRAY in 379 BC patients and 407 healthy controls. Using the PLINK software to calculate the Odds ratio (OR) and 95% confidence intervals (CIs) via the logistic regression analysis to evaluate the risk for BC.

RESULTS

We found that NR5A2 rs2246209 significantly decreased the risk of BC with the AA genotype (OR 0.58, 95%CI 0.34-0.99, p = 0.049), and recessive model (OR 0.59, 95%CI 0.35-0.99, p = 0.046); rs12594 in the RYR2 gene significantly decreased the risk of BC in the GG genotype (OR 0.44, 95%CI 0.22-0.88, p = 0.020), and recessive model (OR 0.43, 95%CI 0.21-0.85, p = 0.016). Further stratification analysis showed that NR5A2 rs2246209 was related to a lower incidence of BC affected by age, lymph nodes metastasis, and tumor stage; RYR2 rs12594 was related to a decreased BC risk restricted by age, estrogen receptor (ER), progesterone receptor (PR), menopausal status, tumor size, and tumor stage. Rs12594 in the RyR2 gene remained significant on the genetic susceptibility of PR-positive BC after Bonferroni correction (p < 0.0125).

CONCLUSIONS

This study provides an evidence that NR5A2 rs2246209 and RYR2 rs12594 decreased the risk of breast cancer.

Alterations in Plasma microRNA and Protein Levels in War Veterans with Chronic Mild Traumatic Brain Injury

Blast-related mild traumatic brain injury (mTBI) is considered the "signature" injury of the wars in Iraq and Afghanistan. Identifying biomarkers that could aid in diagnosis and assessment of chronic mTBI are urgently needed, as little progress has been made toward identifying blood-based biomarkers of repetitive mTBI in the chronic state. Addressing this knowledge gap is especially important in the population of military veterans who are receiving assessment and care often years after their last exposure. Circulating microRNAs (miRNAs), especially those encapsulated in extracellular vesicles (EVs), have gained interest as a source of biomarkers for neurological conditions. To identify biomarkers for chronic mTBI, we used next generation sequencing (NGS) to analyze miRNAs in plasma and plasma-derived EVs from 27 Iraq and Afghanistan war veterans with blast-related chronic mTBI, 11 deployed veteran non-TBI controls, and 31 civilian controls. We identified 32 miRNAs in plasma and 45 miRNAs in EVs that significantly changed in the chronic mTBI cohort compared with control groups. These miRNAs were predominantly associated with pathways involved in neuronal function, vascular remodeling, blood-brain barrier integrity, and neuroinflammation. In addition, the plasma proteome was analyzed and showed that the concentrations of C-reactive protein (CRP) and membrane metalloendopeptidase (MME) were elevated in chronic mTBI samples. These plasma miRNAs and proteins could potentially be used as biomarkers and provide insights into the molecular processes associated with the long-term health outcomes associated with blast-related chronic mTBI.

NR5A2 synergizes with NCOA3 to induce breast cancer resistance to BET inhibitor by upregulating NRF2 to attenuate ferroptosis

BET inhibitors (BETi) exert an excellent anti-cancer activity in breast cancer. However, the identification of new potential targets to enhance breast cancer sensitivity to BETi is still an enormous challenge. Both NR5A2 and NCOA3 are frequently involved in cancer cells resistance to chemotherapy, also associated with poor prognosis in breast cancer. However, the functions of NR5A2 and NCOA3 in BETi resistance remains unknown. In this study, we found that BETi JQ1 and I-BET151 exhibited anti-cancer effects in breast cancer by inducing ferroptosis. NCOA3 as a coactivator synergized with NR5A2 to prevent BETi-induced ferroptosis. Mechanistically, we identified NR5A2 synergized with NCOA3 to increase expression of NRF2, a transcription factor that controls the expression of many antioxidant genes. Moreover, inhibition of NR5A2 or NCOA3 using small molecule inhibitors enhanced anti-cancer effects of BETi against breast cancer in vivo and in vitro. Altogether, our findings illustrated NR5A2 synergized with NCOA3 to confer breast cancer cells resistance to BETi by induction of NRF2. Inhibition of NR5A2/NCOA3 combined with BETi might be a novel strategy for treatment of breast cancer.

Non-coding RNAs in drug resistance of head and neck cancers: A review

Head and neck cancer (HNC), which includes epithelial malignancies of the upper aerodigestive tract (oral cavity, oropharynx, pharynx, hypopharynx, larynx, and thyroid), are slowly but consistently increasing, while the overall survival rate remains unsatisfactory. Because of the multifunctional anatomical intricacies of the head and neck, disease progression and therapy-related side effects often severely affect the patient's appearance and self-image, as well as their ability to breathe, speak, and swallow. Patients with HNC require a multidisciplinary approach involving surgery, radiation therapy, and chemotherapeutics. Chemotherapy is an important part of the comprehensive treatment of tumors, especially advanced HNC, but drug resistance is the main cause of poor clinical efficacy. The most important determinant of this phenomenon is still largely unknown. Recent studies have shown that non-coding RNAs have a crucial role in HNC drug resistance. In addition, they can serve as biomarkers in the diagnosis, treatment, and prognosis of HNCs. In this review, we summarize the relationship between non-coding RNAs and drug resistance of HNC, and discuss their potential clinical application in overcoming HNC chemoresistance.

Mechanisms of Multidrug Resistance in Cancer Chemotherapy

Cancer is one of the main causes of death worldwide. Despite the significant development of methods of cancer healing during the past decades, chemotherapy still remains the main method for cancer treatment. Depending on the mechanism of action, commonly used chemotherapeutic agents can be divided into several classes (antimetabolites, alkylating agents, mitotic spindle inhibitors, topoisomerase inhibitors, and others). Multidrug resistance (MDR) is responsible for over 90% of deaths in cancer patients receiving traditional chemotherapeutics or novel targeted drugs. The mechanisms of MDR include elevated metabolism of xenobiotics, enhanced efflux of drugs, growth factors, increased DNA repair capacity, and genetic factors (gene mutations, amplifications, and epigenetic alterations). Rapidly increasing numbers of biomedical studies are focused on designing chemotherapeutics that are able to evade or reverse MDR. The aim of this review is not only to demonstrate the latest data on the mechanisms of cellular resistance to anticancer agents currently used in clinical treatment but also to present the mechanisms of action of novel potential antitumor drugs which have been designed to overcome these resistance mechanisms. Better understanding of the mechanisms of MDR and targets of novel chemotherapy agents should provide guidance for future research concerning new effective strategies in cancer treatment.

A Novel lncRNA HOXC-AS3 Acts as a miR-3922-5p Sponge to Promote Breast Cancer Metastasis

Purpose: The function of long noncoding RNAs (lncRNA) in breast cancer metastasis remains largely unknown. In this work, the role of HOXC-AS3 in breast cancer progression was investigated.Methods: By using Cancer Genome Atlas (TCGA) Database, we investigated the expression of HOXC-AS3 in breast cancer and explored the association between HOXC-AS3 expression and prognosis. Then, we studied the biological function of HOXC-AS3 in cell migration and invasion both in vitro and in vivo. Furthermore, the target miRNA of HOXC-AS3, and the target mRNA of miR-3922-5p were proved.Results: HOXC-AS3 is aberrantly overexpressed in breast cancers especially the HER2⁺ type. Moreover, high expression of HOXC-AS3 has a relationship with poor clinical outcomes of breast cancer. In addition, HOXC-AS3 regulates cell Invasion and migration both in vitro and in vivo. Our results demonstrated that miR-3922-5p was a direct target of HOXC-AS3, and PPP1R1A was a target of miR-3922-5p in breast cancer.Conclusions: The novel lncRNA HOXC-AS3 acts as a miR-3922-5p sponge to upregulate PPP1R1A protein expression, and thus results in promoting breast cancer metastasis. HOXC-AS3 could be a novel therapeutic target for breast cancer therapeutics.

NAMPT regulates PKM2 nuclear location through 14-3-3ζ: Conferring resistance to tamoxifen in breast cancer

The resistance against tamoxifen therapy has become one of the major obstacles in the clinical treatment of breast cancer. Nicotinamide phosphoribosyltransferase (NAMPT) is an essential enzyme catalyzing nicotinamide adenine dinucleotide biosynthesis and is important for tumor metabolism. The study here sought to explore the effect of NAMPT on breast cancer survival with tamoxifen conditioning. We found that NAMPT was highly expressed in breast cancer cells compared with normal mammary epithelial cells. Inhibition of NAMPT by FK866 inhibited cell viability and aggravated apoptosis in cancer cells treated with 4-hydroxytamoxifen. NAMPT overexpression upregulated 14-3-3ζ expression. Knockdown of 14-3-3ζ reduced cell survival and promoted apoptosis. Activation of Akt signaling, rather than ERK1/2 pathway, is responsible for 14-3-3ζ regulation by NAMPT overexpression. Furthermore, NAMPT overexpression led to PKM2 accumulation in the cell nucleus and could be dampened by 14-3-3ζ inhibition. In addition, NAMPT overexpression promoted xenografted tumor growth and apoptosis in nude mice, while 14-3-3ζ inhibition attenuated its effect. Collectively, our data demonstrate that NAMPT contributes to tamoxifen resistance through regulation of 14-3-3ζ expression and PKM2 translocation.

Tumor-associated macrophages: an accomplice in solid tumor progression

In many solid tumor types, tumor-associated macrophages (TAMs) are important components of the tumor microenvironment (TME). Moreover, TAMs infiltration is strongly associated with poor survival in solid tumor patients. In this review, we describe the origins of TAMs and their polarization state dictated by the TME. We also specifically focus on the role of TAMs in promoting tumor growth, enhancing cancer cells resistance to chemotherapy and radiotherapy, promoting tumor angiogenesis, inducing tumor migration and invasion and metastasis, activating immunosuppression. In addition, we discuss TAMs can be used as therapeutic targets of solid tumor in clinics. The therapeutic strategies include clearing macrophages and inhibiting the activation of TAMs, promoting macrophage phagocytic activity, limiting monocyte recruitment and other targeted TAMs therapies.

Clinical Theragnostic Relationship between Drug-Resistance Specific miRNA Expressions, Chemotherapeutic Resistance, and Sensitivity in Breast Cancer: A Systematic Review and Meta-Analysis

Awareness of breast cancer has been increasing due to early detection, but the advanced disease has limited treatment options. There has been growing evidence on the role of miRNAs involved in regulating the resistance in several cancers. We performed a comprehensive systematic review and meta-analysis on the role of miRNAs in influencing the chemoresistance and sensitivity of breast cancer. A bibliographic search was performed in PubMed and Science Direct based on the search strategy, and studies published until December 2018 were retrieved. The eligible studies were included based on the selection criteria, and a detailed systematic review and meta-analysis were performed based on PRISMA guidelines. A random-effects model was utilised to evaluate the combined effect size of the obtained hazard ratio and 95% confidence intervals from the eligible studies. Publication bias was assessed with Cochran’s Q test, I² statistic, Orwin and Classic fail-safe N test, Begg and Mazumdar rank correlation test, Duval and Tweedie trim and fill calculation and the Egger’s bias indicator. A total of 4584 potential studies were screened. Of these, 85 articles were eligible for our systematic review and meta-analysis. In the 85 studies, 188 different miRNAs were studied, of which 96 were upregulated, 87 were downregulated and 5 were not involved in regulation. Overall, 24 drugs were used for treatment, with doxorubicin being prominently reported in 15 studies followed by Paclitaxel in 11 studies, and 5 drugs were used in combinations. We found only two significant HR values from the studies (miR-125b and miR-4443) and our meta-analysis results yielded a combined HR value of 0.748 with a 95% confidence interval of 0.508–1.100; p-value of 0.140. In conclusion, our results suggest there are different miRNAs involved in the regulation of chemoresistance through diverse drug genetic targets. These biomarkers play a crucial role in guiding the effective diagnostic and prognostic efficiency of breast cancer. The screening of miRNAs as a theragnostic biomarker must be brought into regular practice for all diseases. We anticipate that our study serves as a reference in framing future studies and clinical trials for utilising miRNAs and their respective drug targets.

MicroRNA-34a suppresses the invasion and migration of colorectal cancer cells by enhancing EGR1 and inhibiting vimentin

MicroRNAs (miRNAs/miRs) are small non-coding RNAs that serve a post-transcriptional regulatory role in eukaryotes. Previous studies have demonstrated that the expression of miR-34a in colorectal cancer (CRC) tissues is decreased compared with that in normal colorectal tissues. However, the role of miR-34a in the invasion and metastasis of CRC remains unclear. In the present study, the levels of miR-34a expression were measured in various CRC cell lines. The cells were transfected with miR-34a mimics or inhibitors in order to assess the proliferation rate, and the colony forming, invasive and migratory abilities. Furthermore, the protein expression levels of vimentin and early growth response protein 1 (EGR1) were examined by western blot analysis. The results revealed that the expression of miR-34a was low in SW620, RKO, LoVo and Caco-2 cell lines and high in the SW480 and SW1116 cell lines. The migration, invasion and proliferation levels of SW480 cells were facilitated by decreasing the expression of miR-34a. Transient transfection with miR-34a mimics in SW620 cells caused a notable decrease in cell migration, invasion and proliferation levels compared with the control group, and a downregulation of vimentin and upregulation of EGR1 protein expression. The present study demonstrated that miR-34a was deregulated in a highly invasive CRC cell lines, and that it may attenuate the migratory, invasive and proliferative capabilities of CRC cells by enhancing the expression of EGR1 and inhibiting that of vimentin. The results of the present study represent important progress towards understanding the mechanisms of CRC recurrence and metastasis.

miR-23b and miR-27b are oncogenic microRNAs in breast cancer: evidence from a CRISPR/Cas9 deletion study

BACKGROUND

Altered expression of microRNAs (miRNAs) is known to contribute to cancer progression. miR-23b and miR-27b, encoded within the same miRNA cluster, are reported to have both tumor suppressive and oncogenic activity across human cancers, including breast cancer.

METHODS

To clarify this dichotomous role in breast cancer, miR-23b and miR-27b were knocked out using CRISPR/Cas9 gene knockout technology, and the role of endogenous miR-23b and miR-27b was examined in a breast cancer model system in vitro and in vivo.

RESULTS

Characterization of the knockout cells in vitro demonstrated that miR-23b and miR-27b are indeed oncogenic miRNAs in MCF7 breast cancer cells. miR-23b and miR-27b knockout reduced tumor growth in xenograft nude mice fed a standard diet, supporting their oncogenic role in vivo. However, when xenograft mice were provided a fish-oil diet, miR-27b depletion, but not miR-23b depletion, compromised fish-oil-induced suppression of xenograft growth, indicating a context-dependent nature of miR-27b oncogenic activity.

CONCLUSIONS

Our results demonstrate that miR-23b and miR-27b are primarily oncogenic in MCF7 breast cancer cells and that miR-27b may have tumor suppressive activity under certain circumstances.

miR-27b-3p/MARCH7 regulates invasion and metastasis of endometrial cancer cells through Snail-mediated pathway

Ubiquitin E3 ligase membrane-associated RING-CH-type finger 7 (MARCH7), also known as axotrophin, was originally identified in mouse embryonic stem cells. MARCH7 is involved in T-cell proliferation, neuronal development, and the immune system. However, its role in endometrial cancer (EC) remains unclear. This study aimed to investigate the role of MARCH7 in EC. Quantitative polymerase chain reaction, immunohistochemistry, and western blot analysis were used to examine the expression of MARCH7, E-cadherin, Snail, and Vimentin in EC cell lines or clinical specimens. The role of MARCH7 in maintaining EC cell malignant phenotype was determined by transwell assay and using xenograft tumor model. Dual-luciferase reporter gene assay was performed to determine whether MARCH7 is an authentic target of miR-27b-3p. Our data showed that the expression level of MARCH7 in EC tissues was higher than that in normal endometrium tissues. The level of MARCH7 was positively associated with that of Snail and Vimentin, clinical stage, and histological grade, while negatively associated with that of E-cadherin. Knockdown of MARCH7 inhibited the invasion and metastasis of EC cells in vitro and in vivo. The opposite effect was observed after overexpressing MARCH7. MARCH7 promoted invasion and metastasis of EC cells via the Snail-mediated pathway. Furthermore, MARCH7 was demonstrated to be an authentic target of miR-27b-3p, and miR-27b-3p decreased the stimulus effect induced by MARCH7. These data indicate that MARCH7 may be an oncogenic factor and a therapeutic target for EC. miR-27b-3p/MARCH7 may also regulate EC cell invasion and metastasis via the Snail-mediated pathway.

The Orphan Nuclear Receptors Steroidogenic Factor-1 and Liver Receptor Homolog-1: Structure, Regulation, and Essential Roles in Mammalian Reproduction

Nuclear receptors are intracellular proteins that act as transcription factors. Proteins with classic nuclear receptor domain structure lacking identified signaling ligands are designated orphan nuclear receptors. Two of these, steroidogenic factor-1 (NR5A1, also known as SF-1) and liver receptor homolog-1 (NR5A2, also known as LRH-1), bind to the same DNA sequences, with different and nonoverlapping effects on targets. Endogenous regulation of both is achieved predominantly by cofactor interactions. SF-1 is expressed primarily in steroidogenic tissues, LRH-1 in tissues of endodermal origin and the gonads. Both receptors modulate cholesterol homeostasis, steroidogenesis, tissue-specific cell proliferation, and stem cell pluripotency. LRH-1 is essential for development beyond gastrulation and SF-1 for genesis of the adrenal, sexual differentiation, and Leydig cell function. Ovary-specific depletion of SF-1 disrupts follicle development, while LRH-1 depletion prevents ovulation, cumulus expansion, and luteinization. Uterine depletion of LRH-1 compromises decidualization and pregnancy. In humans, SF-1 is present in endometriotic tissue, where it regulates estrogen synthesis. SF-1 is underexpressed in ovarian cancer cells and overexpressed in Leydig cell tumors. In breast cancer cells, proliferation, migration and invasion, and chemotherapy resistance are regulated by LRH-1. In conclusion, the NR5A orphan nuclear receptors are nonredundant factors that are crucial regulators of a panoply of biological processes, across multiple reproductive tissues.

Comprehensive analysis of differentially expressed profiles of long non-coding RNAs and messenger RNAs in kaolin-induced hydrocephalus

BACKGROUNDS

The pathophysiology of hydrocephalus induced brain damage remains unclear. Long non-coding RNAs (lncRNAs) have been demonstrated to be implicated in many central nervous system diseases. However, the roles of lncRNAs in hydrocephalus injury are poorly understood.

METHODS

The present study depicted the expression profiles of lncRNAs and messenger RNAs (mRNAs) in C57BL/6 mice with kaolin-induced hydrocephalus and saline controls using high-throughput RNA sequencing. Afterward, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to identify potential targets that correlated with hydrocephalus. In addition, co-expression networks and cis- and trans-regulation were predicted using bioinformatics methods. Finally, representative lncRNAs and mRNAs were further validation using quantitative real-time polymerase chain reaction.

RESULTS

A total of 1575 lncRNAs and 1168 mRNAs were differentially expressed (DE) in hydrocephalus. GO and KEGG analyses indicated several immune and inflammatory response-associated pathways may be important in the hydrocephalus. Besides, functional enrichment analysis based on co-expression network showed several similar pathways, such as chemokine signaling pathway, phagosome, MAPK signaling pathway and complement and coagulation cascade. Cis-regulation prediction revealed 5 novel lncRNAs might regulate their nearby coding genes, and trans-regulation revealed several lncRNAs participate in pathways regulated by transcription factors, including BPTF, FOXM1, NR5A2, P2RX5, and NR6A1.

CONCLUSIONS

In conclusion, our results provide candidate genes involved in hydrocephalus and suggest a new perspective on the modulation of lncRNAs in hydrocephalus.

LINC01857 as an oncogene regulates CREB1 activation by interacting with CREBBP in breast cancer

Breast cancer is a one of the most malignant threats among women worldwide. However, the mechanism underlying breast cancer development remains unclear. Long noncoding RNAs (lncRNAs) have been reported to participate in breast cancer. Whether lncRNA LINC01857 is involved in breast cancer requires investigation. In this study, we found that LINC01857 was highly expressed in breast cancer tissues and cells (p < 0.05). High LINC01857 expression predicted poor prognosis in breast cancer patients. Functionally, LINC01857 silencing impaired proliferation and enhanced apoptosis of breast cancer cells ( p < 0.05). Decreased LINC01857 inhibited breast cancer cells migration and invasion ability ( p < 0.05). In terms of mechanism, LINC01857 promoted H3K27Ac deposition on CREB1 promoter and initiated its transcription by recruiting CREBBP. Overexpression of CREB1 reversed the biological behavior of breast cancer cells induced by LINC01857 silencing ( p < 0.05). Taken together, our findings demonstrated that LINC01857 promoted breast cancer development by promoting H3K27Ac and CREB1 transcription via enhancing CREBBP enrichment in the CREB1 promoter region.