Lnc RNA H19 is associated with poor prognosis in breast cancer patients and promotes cancer stemness

The role of tumor-derived exosomal LncRNA in tumor metastasis

Tumor metastasis regulated by multiple complicated pathways is closely related to variations in the tumor microenvironment. Exosomes can regulate the tumor microenvironment through various mechanisms. Exosomes derived from tumor cells carry a variety of substances, including long non-coding RNAs (lncRNAs), play important roles in intercellular communication and act as critical determinants influencing tumor metastasis. In this review, we elaborate on several pivotal processes through which lncRNAs regulate tumor metastasis, including the regulation of epithelial‒mesenchymal transition, promotion of angiogenesis and lymphangiogenesis, enhancement of the stemness of tumor cells, and evasion of immune clearance. Additionally, we comprehensively summarized a diverse array of potential tumor-derived exosomal lncRNA biomarkers to facilitate accurate diagnosis and prognosis in a clinical setting.

Doxorubicin loaded exosomes inhibit cancer-associated fibroblasts growth: in vitro and in vivo study

Cancer-associated fibroblast cells (CAFs) play a key role in the breast cancer (BC) microenvironment that induces resistance to chemotherapy. Adipose mesenchymal stem cells (ADMSCs) derived exosomes were utilized to deliver the doxorubicin (Dox) to BC cell lines (MDA-MB-231, MCF-7) and CAFs in both mono and co-culture systems. Immunocytochemistry (ICC) for VIMENTIN and flow cytometry for the CD45, CD34, CD73, and CD90 markers were used to confirm the phenotypic characteristics of CAFs and MSC cells. Dox was loaded into ADMSCs-derived exosomes (Exo-Dox) through sonication and its loading wasa confirmed by transmission electron microscope (TEM). Compared to free Dox, Exo-Dox showed a higher efficiency in inducing apoptosis and inhibiting growth and migration in co-culture cells with CAFs (P < 0.05). The up-regulation of H19 and UCA1 lncRNAs, associated with chemoresistance, was confirmed using real-time PCR in CAF-derived breast cancer patients, CAF-derived exosomes, and exosome-derived patient serums. H19 and UCA1 expression levels were significantly down-regulated in MDA-MB-231, MCF-7, and co-cultures of MDA-MB-231 and MCF-7 cells with CAFs that received Exo-Dox treatment. In vivo results indicated that ADMSCs-derived exosomes (MSC-Exos) can accumulate at the tumor site. Exo-Dox suppressed cancer cell growth and significantly decreased tumor size compared to PBS (p < 0.01). The findings confirmed the growth inhibition effects of Exo-Dox n in CAFs, BC cells, and tumor-bearing mice.

Deciphering the code: the pivotal role of lncRNAs in advancing TNBC therapy

Triple-negative breast cancer (TNBC) represents the most formidable subtype of breast cancer, characterized by a notable dearth in targeted therapeutic options. Deciphering the underlying molecular mechanisms of TNBC is pivotal for improving patient outcomes. Recent scientific advancements have spotlighted long non-coding RNAs (lncRNAs) as key players in the genesis, progression, and metastasis of cancers. This review delineates the significant influence of lncRNAs on the advancement, detection, and neoadjuvant chemotherapy efficacy in TNBC, detailing the diverse expression patterns of aberrant lncRNAs. The paper explores the specific mechanisms by which lncRNAs regulate gene expression in both the nucleus and cytoplasm, with a special focus on their involvement in TNBC's post-transcriptional landscape. Thorough investigations into TNBC-associated lncRNAs not only forge new avenues for early diagnosis and potent treatment strategies but also highlight these molecules as promising therapeutic targets, heralding an era of personalized and precision medicine in TNBC management.

Critical roles of long noncoding RNA H19 in cancer

Long noncoding RNAs (lncRNAs) are a category of noncoding RNAs characterized by their length, often exceeding 200 nucleotides. There is a growing body of data that indicate the significant involvement of lncRNAs in a wide range of disorders, including cancer. lncRNA H19 was among the initial lncRNAs to be identified and is transcribed from the H19 gene. The H19 lncRNA exhibits significant upregulation in a diverse range of human malignancies, such as breast, colorectal, pancreatic, glioma, and gastric cancer. Moreover, the overexpression of H19 is frequently associated with a worse prognosis among individuals diagnosed with cancer. H19 has been shown to have a role in facilitating several cellular processes, including cell proliferation, invasion, migration, epithelial-mesenchymal transition, metastasis, and apoptosis. This article summarizes the aberrant upregulation of H19 in human malignancies, indicating promising avenues for future investigations on cancer diagnostics and therapeutic interventions.

Critical role of exosome, exosomal non-coding RNAs and non-coding RNAs in head and neck cancer angiogenesis

Head and neck cancer (HNC) refers to the epithelial malignancies of the upper aerodigestive tract. HNCs have a constant yet slow-growing rate with an unsatisfactory overall survival rate globally. The development of new blood vessels from existing blood conduits is regarded as angiogenesis, which is implicated in the growth, progression, and metastasis of cancer. Aberrant angiogenesis is a known contributor to human cancer progression. Representing a promising therapeutic target, the blockade of angiogenesis aids in the reduction of the tumor cells oxygen and nutrient supplies. Despite the promise, the association of existing anti-angiogenic approaches with severe side effects, elevated cancer regrowth rates, and limited survival advantages is incontrovertible. Exosomes appear to have an essential contribution to the support of vascular proliferation, the regulation of tumor growth, tumor invasion, and metastasis, as they are a key mediator of information transfer between cells. In the exocrine region, various types of noncoding RNAs (ncRNAs) identified to be enriched and stable and contribute to the occurrence and progression of cancer. Mounting evidence suggest that exosome-derived ncRNAs are implicated in tumor angiogenesis. In this review, the characteristics of angiogenesis, particularly in HNC, and the impact of ncRNAs on HNC angiogenesis will be outlined. Besides, we aim to provide an insight on the regulatory role of exosomes and exosome-derived ncRNAs in angiogenesis in different types of HNC.

Tyrosine phosphorylation-mediated YAP1-TFAP2A interactions coordinate transcription and trastuzumab resistance in HER2+ breast cancer

Trastuzumab resistance in HER2+ breast cancer (BC) is the major reason leading to poor prognosis of BC patients. Oncogenic gene overexpression or aberrant activation of tyrosine kinase SRC is identified to be the key modulator of trastuzumab response. However, the detailed regulatory mechanisms underlying SRC activation-associated trastuzumab resistance remain poorly understood. In the present study, we discover that SRC-mediated YAP1 tyrosine phosphorylation facilitates its interaction with transcription factor AP-2 alpha (activating enhancer binding protein 2 alpha, TFAP2A), which in turn promotes YAP1/TEAD-TFAP2A (YTT) complex-associated transcriptional outputs, thereby conferring trastuzumab resistance in HER2+ BC. Inhibition of SRC kinase activity or disruption of YTT complex sensitizes cells to trastuzumab treatment in vitro and in vivo. Additionally, we also identify YTT complex co-occupies the regulatory regions of a series of genes related to trastuzumab resistance and directly regulates their transcriptions, including EGFR, HER2, H19 and CTGF. Moreover, YTT-mediated transcriptional regulation is coordinated by SRC kinase activity. Taken together, our study reveals that SRC-mediated YTT complex formation and transcriptions are responsible for multiple mechanisms associated with trastuzumab resistance. Therefore, targeting HER2 signaling in combination with the inhibition of YTT-associated transcriptional outputs could serve as the treatment strategy to overcome trastuzumab resistance caused by SRC activation.

Icariin Regulates EMT and Stem Cell-Like Character in Breast Cancer through Modulating lncRNA NEAT1/TGFβ/SMAD2 Signaling Pathway

Metastases and drug resistance are the major risk factors associated with breast cancer (BC), which is the most common type of tumor affecting females. Icariin (ICA) is a traditional Chinese medicine compound that possesses significant anticancer properties. Long non-coding RNAs (lncRNAs) are involved in a wide variety of biological and pathological processes and have been shown to modulate the effectiveness of certain drugs in cancer. The purpose of this study was to examine the potential effect of ICA on epithelial mesenchymal transition (EMT) and stemness articulation in BC cells, as well as the possible relationship between its inhibitory action on EMT and stemness with the NEAT1/transforming growth factor β (TGFβ)/SMAD2 pathway. The effect of ICA on the proliferation (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony assays), EMT (Western blotting, immunofluorescence, and wound healing), and stemness (mammosphere formation assays, Western blotting) of BC cells were examined. According to the findings, ICA suppressed the proliferation, EMT, and stem cell-like in MDA-MB-231 cells, and exerted its inhibitory impact by downregulating the TGFβ/SMAD2 signaling pathway. ICA could significantly downregulate the expression of lncRNA NEAT1, and silencing NEAT1 enhanced the effect of ICA in suppressing EMT and expression of different stem cell markers. In addition, silencing NEAT1 was found to attenuate the TGFβ/SMAD2 signaling pathway, thereby improving the inhibitory impact of ICA on stemness and EMT in BC cells. In conclusion, ICA can potentially inhibit the metastasis of BC via affecting the NEAT1/TGFβ/SMAD2 pathway, which provides a theoretical foundation for understanding the mechanisms involved in potential application of ICA for BC therapy.

The emerging roles of long non-coding RNA (lncRNA) H19 in gynecologic cancers

Long non-coding RNA (lncRNA) H19 has gained significant recognition as a pivotal contributor to the initiation and advancement of gynecologic cancers, encompassing ovarian, endometrial, cervical, and breast cancers. H19 exhibits a complex array of mechanisms, demonstrating dualistic effects on tumorigenesis as it can function as both an oncogene and a tumor suppressor, contingent upon the specific context and type of cancer being investigated. In ovarian cancer, H19 promotes tumor growth, metastasis, and chemoresistance through modulation of key signaling pathways and interaction with microRNAs. Conversely, in endometrial cancer, H19 acts as a tumor suppressor by inhibiting proliferation, inducing apoptosis, and regulating epithelial-mesenchymal transition. Additionally, H19 has been implicated in cervical and breast cancers, where it influences cell proliferation, invasion, and immune evasion. Moreover, H19 has potential as a diagnostic and prognostic biomarker for gynecologic cancers, with its expression levels correlating with clinical parameters and patient outcomes. Understanding the functional roles of H19 in gynecologic cancers is crucial for the development of targeted therapeutic strategies and personalized treatment approaches. Further investigation into the intricate molecular mechanisms underlying H19's involvement in gynecologic malignancies is warranted to fully unravel its therapeutic potential and clinical implications. This review aims to elucidate the functional roles of H19 in various gynecologic malignancies.

p53-regulated lncRNAs in cancers: from proliferation and metastasis to therapy

Long non-coding RNAs (lncRNAs) have been identified as master gene regulators through various mechanisms such as transcription, translation, protein modification and RNA-protein complexes. LncRNA dysregulation is frequently associated with a variety of biological functions and human diseases including cancer. The p53 network is a key tumor-suppressive mechanism that transcriptionally activates target genes to suppress cellular proliferation in human malignancies. Recent research indicates that lncRNAs play an important role in the p53 signaling pathway. In this review, we summarize the current knowledge of lncRNAs in p53-relevant functions and provide an overview of how these altered lncRNAs contribute to tumor initiation and progression. We also discuss the association between lncRNA and up- or downstream genes of p53. These findings imply that lncRNAs can help identify cellular vulnerabilities that may prove to be promising potential biomarkers and therapeutic targets for cancer treatment.

Long non-coding RNA H19 enhances the pro-apoptotic activity of ITF2357 (a histone deacetylase inhibitor) in colorectal cancer cells

Introduction: Long non-coding RNA H19 (lncH19) is highly expressed in colorectal cancer (CRC) and plays critical roles in tumor development, proliferation, metastasis, and drug resistance. Indeed, the expression of lncH19 usually affects the outcomes of chemo-, endocrine, and targeted therapies. ITF2357 (givinostat) is a histone deacetylase inhibitor (HDACi) that revealed a significant anti-tumor action by inducing apoptosis in different tumor models, including leukemia, melanoma, and glioblastoma. However, no data are present in the literature regarding the use of this compound for CRC treatment. Here, we investigate the role of lncH19 in ITF2357-induced apoptosis in CRC cells. Methods: The HCT-116 CRC cell line was stably silenced for H19 to investigate the role of this lncRNA in ITF2357-induced cell death. Cell viability assays and flow cytometric analyses were performed to assess the anti-proliferative and pro-apoptotic effects of ITF2357 in CRC cell lines that are silenced or not for lncH19. RT-PCR and Western blot were used to study the effects of ITF2357 on autophagy and apoptosis markers. Finally, bioinformatics analyses were used to identify miRNAs targeting pro-apoptotic factors that can be sponged by lncH19. Results: ITF2357 increased the expression levels of H19 and reduced HCT-116 cell viability, inducing apoptosis, as demonstrated by the increase in annexin-V positivity, caspase 3 cleavage, and poly (ADP-ribose) polymerase (PARP-1) degradation. Interestingly, the apoptotic effect of ITF2357 was much less evident in lncH19-silenced cells. We showed that lncH19 plays a functional role in the pro-apoptotic activity of the drug by stabilizing TP53 and its transcriptional targets, NOXA and PUMA. ITF2357 also induced autophagy in CRC cells, which was interpreted as a pro-survival response not correlated with lncH19 expression. Furthermore, ITF2357 induced apoptosis in 5-fluorouracil-resistant HCT-116 cells that express high levels of lncH19. Conclusion: This study shows that lncH19 expression contributes to ITF2357-induced apoptosis by stabilizing TP53. Overall, we suggest that lncH19 expression may be exploited to favor HDACi-induced cell death and overcome 5-fluorouracil chemoresistance.

Long non-coding RNA H19: a potential biomarker and therapeutic target in human malignant tumors

Long non-coding RNAs play important roles in cellular functions and disease development. H19, as a long non-coding RNA, is pervasively over-expressed in almost all kinds of human malignant tumors. Although many studies have reported that H19 is closely associated with tumor cell proliferation, apoptosis, invasion, metastasis, and chemoresistance, the role and mechanism of H19 in gene regulation and tumor development are largely unclear. In this review, we summarized the recent progress in the study of the major functions and mechanisms of H19 lncRNA in cancer development and progression. H19 possesses both oncogenic and tumor-suppressing activities, presumably through regulating target gene transcription, mRNA stability and splicing, and competitive inhibition of endogenous RNA degradation. Studies indicate that H19 may involve in cell proliferation and apoptosis, tumor initiation, migration, invasion, metastasis and chemoresistance and may serve as a potential biomarker for early diagnosis, prognosis, and novel molecular target for cancer therapy.

Is H19 RNA a Useful Marker of Acromegaly and Its Complications? A Preliminary Study

Acromegaly is a rare endocrine disorder caused by somatotroph pituitary adenoma. Besides its typical symptoms, it contributes to the development of cardiovascular, metabolic, and bone comorbidities. H19 RNA is a long non-coding RNA and it is suspected to be involved in tumorigenesis, cancer progression, and metastasis. H19 RNA is a novel biomarker for the diagnosis and monitoring of neoplasms. Moreover, there might be an association between H19 and cardiovascular and metabolic diseases. We enrolled 32 acromegaly patients and 25 controls. We investigated whether whole blood H19 RNA expression is associated with the diagnosis of acromegaly. Correlations between H19 and tumour dimension, invasiveness, and biochemical and hormonal parameters were evaluated. We analysed the coincidence of acromegaly comorbidities with H19 RNA expression. In the results, we did not observe a statistically significant difference in H19 RNA expression between acromegaly patients and the controls. There were no correlations between H19 and the adenoma size and infiltration and patients' biochemical and hormonal statuses. In the acromegaly group, hypertension, goitre, and cholelithiasis were observed more frequently. The diagnosis of acromegaly was a factor contributing to the occurrence of dyslipidaemia, goitre, and cholelithiasis. We found an association between H19 and cholelithiasis in acromegaly patients. To conclude, H19 RNA expression is not a relevant marker for diagnosis and monitoring of acromegaly patients. There is a higher risk of hypertension, goitre, and cholelithiasis related to acromegaly. Cholelithiasis is associated with a higher H19 RNA expression.

Rewiring of the 3D genome during acquisition of carboplatin resistance in a triple-negative breast cancer patient-derived xenograft

Changes in the three-dimensional (3D) structure of the genome are an emerging hallmark of cancer. Cancer-associated copy number variants and single nucleotide polymorphisms promote rewiring of chromatin loops, disruption of topologically associating domains (TADs), active/inactive chromatin state switching, leading to oncogene expression and silencing of tumor suppressors. However, little is known about 3D changes during cancer progression to a chemotherapy-resistant state. We integrated chromatin conformation capture (Hi-C), RNA-seq, and whole-genome sequencing obtained from triple-negative breast cancer patient-derived xenograft primary tumors (UCD52) and carboplatin-resistant samples and found increased short-range (< 2 Mb) interactions, chromatin looping, formation of TAD, chromatin state switching into a more active state, and amplification of ATP-binding cassette transporters. Transcriptome changes suggested the role of long-noncoding RNAs in carboplatin resistance. Rewiring of the 3D genome was associated with TP53, TP63, BATF, FOS-JUN family of transcription factors and led to activation of aggressiveness-, metastasis- and other cancer-related pathways. Integrative analysis highlighted increased ribosome biogenesis and oxidative phosphorylation, suggesting the role of mitochondrial energy metabolism. Our results suggest that 3D genome remodeling may be a key mechanism underlying carboplatin resistance.

A Panel of Circulating Non-Coding RNAs in the Diagnosis and Monitoring of Therapy in Egyptian Patients with Breast Cancer

Background: Non-coding RNAs (ncRNAs) have recently been identified to have a pivotal role in many diseases, including breast cancer (BC). This study aims to investigate the relative quantification of long non-coding RNA (lncRNA) H19, microRNA (miR) 675-5p, 675-3p, and miR-let 7 in breast cancer patients. Methods: The study was performed on three groups: Group 1: 30 non-intervened BC female patients about to undergo breast surgery; group 2: 30 postoperative female BC patients about to receive adjuvant anthracycline chemotherapy; and group 3: 30 apparently healthy female volunteers as the control group. Plasma samples were drawn before and after the intervention in groups 1 and 2, with a single sample drawn from group 3. The relative quantification levels were compared with healthy control subjects and were related with the clinicopathological statuses of these patients. Results: There was a statistically significant increase in H19, miR-675-5p, miR-675-3p, and miR-let 7 in the non-intervened BC patients when compared to the control group. Surgery resulted in a significant reduction in all four ncRNAs under investigation. Chemotherapy brought about a significant increase in the level of miR-let 7, with no significant effect on the remaining parameters measured. The assay discriminated normal from BC where a receiver operating characteristic for the area under the curve (ROC_AUC) of miR-675-3p showed the maximal AUC of 1.000. The diagnostic sensitivity and specificity were also 100% when CA 15-3 and H19 were combined. Conclusion: The results strongly indicate that the panel of ncRNAs in this study can all potentially act as novel biomarkers whether alone or combined in the diagnosis of BC.

The Role of Long Noncoding RNA (lncRNAs) Biomarkers in Renal Cell Carcinoma

Renal cell carcinoma is one of the common cancers whose incidence and mortality are continuously growing worldwide. Initially, this type of tumour is usually asymptomatic. Due to the lack of reliable diagnostic markers, one-third of ccRCC patients already have distant metastases at the time of diagnosis. This underlines the importance of establishing biomarkers that would enable the prediction of the disease's course and the risk of metastasis. LncRNA, which modulates genes at the epigenetic, transcriptional, and post-transcriptional levels, appears promising. The actions of lncRNA involve sponging and sequestering target miRNAs, thus affecting numerous biological processes. Studies have confirmed the involvement of RNAs in various diseases, including RCC. In this review, we focused on MALAT1 (a marker of serious pathological changes and a factor in the promotion of tumorigenesis), RCAT1 (tumour promoter in RCC), DUXAP9 (a plausible marker of localized ccRCC), TCL6 (exerting tumour-suppressive effects in renal cancer), LINC00342 (acting as an oncogene), AGAP2 Antisense1 (plausible predictor of RCC progression), DLEU2 (factor promoting tumours growth via the regulation of epithelial-mesenchymal transition), NNT-AS1 (sponge of miR-22 contributing to tumour progression), LINC00460 (favouring ccRCC development and progression) and Lnc-LSG1 (a factor that may stimulate ccRCC metastasis).

ALDH1: A potential therapeutic target for cancer stem cells in solid tumors

Solid tumors can be divided into benign solid tumors and solid malignant tumors in the academic community, among which malignant solid tumors are called cancers. Cancer is the second leading cause of death in the world, and the global incidence of cancer is increasing yearly New cancer patients in China are always the first. After the concept of stem cells was introduced in the tumor community, the CSC markers represented by ALDH1 have been widely studied due to their strong CSC cell characteristics and potential to be the driving force of tumor metastasis. In the research results in the past five years, it has been found that ALDH1 is highly expressed in various solid cancers such as breast cancer, lung cancer, colorectal cancer, liver cancer, gastric cancer, cervical cancer, esophageal cancer, ovarian cancer, head,and neck cancer. ALDH1 can activate and transform various pathways (such as the USP28/MYC signaling pathway, ALDH1A1/HIF-1α/VEGF axis, wnt/β-catenin signaling pathway), as well as change the intracellular pH value to promote formation and maintenance, resulting in drug resistance in tumors. By targeting and inhibiting ALDH1 in tumor stem cells, it can enhance the sensitivity of drugs and inhibit the proliferation, differentiation, and metastasis of solid tumor stem cells to some extent. This review discusses the relationship and pathway of ALDH1 with various solid tumors. It proposes that ALDH1 may serve as a diagnosis and therapeutic target for CSC, providing new insights and new strategies for reliable tumor treatment.

Long non-coding RNA (lncRNA) H19 in human cancer: From proliferation and metastasis to therapy

Initiation and development of cancer depend on multiple factors that mutations in genes and epigenetic level can be considered as important drivers. Epigenetic factors include a large family of members and understanding their function in cancer has been a hot topic. LncRNAs are RNA molecules with no capacity in synthesis of proteins, and they have regulatory functions in cells. LncRNAs are localized in nucleus and cytoplasm, and their abnormal expression is related to development of tumor. This manuscript emphasizes on the role of lncRNA H19 in various cancers and its association with tumor hallmarks. The function of lncRNA H19 in most tumors is oncogenic and therefore, tumor cells increase its expression for promoting their progression. LncRNA H19 contributes to enhancing growth and cell cycle of cancers and by EMT induction, it is able to elevate metastasis rate. Silencing H19 induces apoptotic cell death and disrupts progression of tumors. LncRNA H19 triggers chemo- and radio-resistance in cancer cells. miRNAs are dually upregulated/down-regulated by lncRNA H19 in increasing tumor progression. Anti-cancer agents reduce lncRNA H19 in impairing tumor progression and increasing therapy sensitivity. A number of downstream targets and molecular pathways for lncRNA H19 have been detected in cancers including miRNAs, RUNX1, STAT3, β-catenin, Akt2 and FOXM1. Clinical studies have revealed potential of lncRNA H19 as biomarker and its association with poor prognosis. LncRNA H19 can be transferred to cancer cells via exosomes in enhancing their progression.

Emerging role of lncRNAs in drug resistance mechanisms in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) originates in the squamous cell lining the mucosal surfaces of the head and neck region, including the oral cavity, nasopharynx, tonsils, oropharynx, larynx, and hypopharynx. The heterogeneity, anatomical, and functional characteristics of the patient make the HNSCC a complex and difficult-to-treat disease, leading to a poor survival rate and a decreased quality of life due to the loss of important physiologic functions and aggressive surgical injury. Alteration of driver-oncogenic and tumor-suppressing lncRNAs has recently been recently in HNSCC to obtain possible biomarkers for diagnostic, prognostic, and therapeutic approaches. This review provides current knowledge about the implication of lncRNAs in drug resistance mechanisms in HNSCC. Chemotherapy resistance is a major therapeutic challenge in HNSCC in which lncRNAs are implicated. Lately, it has been shown that lncRNAs involved in autophagy induced by chemotherapy and epithelial-mesenchymal transition (EMT) can act as mechanisms of resistance to anticancer drugs. Conversely, lncRNAs involved in mesenchymal-epithelial transition (MET) are related to chemosensitivity and inhibition of invasiveness of drug-resistant cells. In this regard, long non-coding RNAs (lncRNAs) play a pivotal role in both processes and are important for cancer detection, progression, diagnosis, therapy response, and prognostic values. As the involvement of more lncRNAs is elucidated in chemoresistance mechanisms, an improvement in diagnostic and prognostic tools could promote an advance in targeted and specific therapies in precision oncology.

Functional interplay between long non-coding RNAs and Breast CSCs

Breast cancer (BC) represents aggressive cancer affecting most women’s lives globally. Metastasis and recurrence are the two most common factors in a breast cancer patient's poor prognosis. Cancer stem cells (CSCs) are tumor cells that are able to self-renew and differentiate, which is a significant factor in metastasis and recurrence of cancer. Long non-coding RNAs (lncRNAs) describe a group of RNAs that are longer than 200 nucleotides and do not have the ability to code for proteins. Some of these lncRNAs can be mainly produced in various tissues and tumor forms. In the development and spread of malignancies, lncRNAs have a significant role in influencing multiple signaling pathways positively or negatively, making them promise useful diagnostic and prognostic markers in treating the disease and guiding clinical therapy. However, it is not well known how the interaction of lncRNAs with CSCs will affect cancer development and progression.

Here, in this review, we attempt to summarize recent findings that focus on lncRNAs affect cancer stem cell self-renewal and differentiation in breast cancer development and progression, as well as the strategies and challenges for overcoming lncRNA's therapeutic resistance.

Long non-coding RNA MAFG-AS1 promotes proliferation and metastasis of breast cancer by modulating STC2 pathway

Breast cancer is the most common cancer worldwide. A number of studies proposed that long non-coding RNA plays an essential role in the regulation of invasion and metastasis of various forms of malignancy, including lung cancer, gastric cancer, and bladder cancer. In this study, a long non-coding RNA(LncRNA) MAFG-AS1 was explored in detail to understand the significance in the etiology of breast cancer. The results indicated that expression of LncRNA MAFG-AS1 in the breast cancer tissues was significantly higher than the adjacent normal breast tissues and elevated expression level of LncRNA MAFG-AS1 was correlated to the larger tumor size, negative expression of ER, PR and lymph node metastasis. The potency of breast cancer proliferation, invasion, and metastasis was inhibited in the absence of LncRNA MAFG-AS1. Mechanically, LncRNA MAFG-AS1 was mainly located in the cytoplasm. The downstream target gene of LncRNA MAFG-AS1 was STC2 which might promote cell proliferation and metastasis in breast cancer and this study provides a new potential therapeutic target for breast cancer.

Gp130-Mediated STAT3 Activation Contributes to the Aggressiveness of Pancreatic Cancer through H19 Long Non-Coding RNA Expression

Simple Summary

The signal transducer and activator of transcription 3 (STAT3) activation correlate with the aggressiveness of pancreatic ductal adenocarcinoma (PDAC). We demonstrated that the autocrine/paracrine interleukin-6 (IL-6) or leukemia inhibitory factor (LIF)/glycoprotein 130 (gp130)/STAT3 pathway contributes to the maintenance of stemness features and membrane-type 1 matrix metalloproteinase (MT1-MMP) expression, and modulates transforming growth factor (TGF)-β1/Smad signaling-mediated epithelial-mesenchymal transition (EMT) and invasion through regulation of TGFβ-RII expression in PDAC cancer stem cell (CSC)-like cells. Furthermore, we demonstrated that p-STAT3 acts through the IL-6 or LIF/gp130/STAT3 pathway to access the active promoter region of metastasis-related long non-coding RNA H19 and contribute to its transcription in CSC-like cells. Therefore, the autocrine/paracrine IL-6 or LIF/gp130/STAT3 pathway in PDAC CSC-like cells exhibiting H19 expression is considered to be involved in the aggressiveness of PDAC, and inhibition of the gp130/STAT3 pathway is a promising strategy to target CSCs for the elimination of PDAC (146/150).

Abstract

Signaling pathways involving signal transducer and activator of transcription 3 (STAT3) play key roles in the aggressiveness of pancreatic ductal adenocarcinoma (PDAC), including their tumorigenesis, invasion, and metastasis. Cancer stem cells (CSCs) have been correlated with PDAC aggressiveness, and activation of STAT3 is involved in the regulation of CSC properties. Here, we investigated the involvement of interleukin-6 (IL-6) or the leukemia inhibitory factor (LIF)/glycoprotein 130 (gp130)/STAT3 pathway and their role in pancreatic CSCs. In PDAC CSC-like cells formed by culturing on a low attachment plate, autocrine/paracrine IL-6 or LIF contributes to gp130/STAT3 pathway activation. Using a gp130 inhibitor, we determined that the gp130/STAT3 pathway contributes to the maintenance of stemness features, the expression of membrane-type 1 matrix metalloproteinase (MT1-MMP), and the invasion of PDAC CSC-like cells. The gp130/STAT3 pathway also modulates the transforming growth factor (TGF)-β1/Smad pathway required for epithelial-mesenchymal transition induction through regulation of TGFβ-RII expression in PDAC CSC-like cells. Furthermore, chromatin immunoprecipitation assays revealed that p-STAT3 can access the active promoter region of H19 to influence this metastasis-related long non-coding RNA and contribute to its transcription in PDAC CSC-like cells. Therefore, the autocrine/paracrine IL-6 or LIF/gp130/STAT3 pathway in PDAC CSC-like cells may eventually facilitate invasion and metastasis, two hallmarks of malignancy. We propose that inhibition of the gp130/STAT3 pathway provides a promising strategy for targeting CSCs for the treatment of PDAC.

Molecular and cellular functions of long non-coding RNAs in prostate and breast cancer

Long noncoding RNAs (lncRNAs) are defined as noncoding RNA transcripts with a length greater than 200 nucleotides. Research over the last decade has made great strides in our understanding of lncRNAs, especially in the biology of their role in cancer. In this article, we will briefly discuss the biogenesis and characteristics of lncRNAs, then review their molecular and cellular functions in cancer by using prostate and breast cancer as examples. LncRNAs are abundant, diverse, and evolutionarily, less conserved than protein-coding genes. They are often expressed in a tumor and cell-specific manner. As a key epigenetic factor, lncRNAs can use a wide variety of molecular mechanisms to regulate gene expression at each step of the genetic information flow pathway. LncRNAs display widespread effects on cell behavior, tumor growth, and metastasis. They act intracellularly and extracellularly in an autocrine, paracrine and endocrine fashion. Increased understanding of lncRNA's role in cancer has facilitated the development of novel biomarkers for cancer diagnosis, led to greater understanding of cancer prognosis, enabled better prediction of therapeutic responses, and promoted identification of potential targets for cancer therapy.

Long Non-Coding RNAs at the Chromosomal Risk Loci Identified by Prostate and Breast Cancer GWAS

Long non-coding RNAs (lncRNAs) are emerging as key players in a variety of cellular processes. Deregulation of the lncRNAs has been implicated in prostate and breast cancers. Recently, germline genetic variations associated with cancer risk have been correlated with lncRNA expression and/or function. In addition, single nucleotide polymorphisms (SNPs) at well-characterized cancer-associated lncRNAs have been analyzed for their association with cancer risk. These SNPs may occur within the lncRNA transcripts or spanning regions that may alter the structure, function, and expression of these lncRNA molecules and contribute to cancer progression and may have potential as therapeutic targets for cancer treatment. Additionally, some of these lncRNA have a tissue-specific expression profile, suggesting them as biomarkers for specific cancers. In this review, we highlight some of the cancer risk-associated SNPs that modulated lncRNAs with a potential role in prostate and breast cancers and speculate on how these lncRNAs may contribute to cancer development.

Long intergenic non-protein coding RNA 960 regulates cancer cell viability, migration and invasion through modulating miR-146a-5p/interleukin 1 receptor associated kinase 1 axis in pancreatic ductal adenocarcinoma

Long non-coding RNAs (lncRNAs) are considered as crucial regulatory factors in cancer biology. However, the biological function of long intergenic non-protein coding RNA 960 (LINC00960) in the tumorigenesis of pancreatic ductal adenocarcinoma (PDAC) is still unknown. The goal of this study is to investigate the role of LINC00960 in PDAC. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to examine the expression levels of LINC00960 in PDAC tissues and cell lines. After transfection, the loss-of-function models of LINC00960 or interleukin 1 receptor-associated kinase 1 (IRAK1) were established with BxPC-3 cells and Colo357 cells, and the malignant phenotypes of BxPC-3 cells and Colo357 cells were detected by CCK-8 assay, BrdU assay and Transwell assay, respectively. The interactions among LINC00960, miR-146a-5p and IRAK1 were predicted by bioinformatics analysis, and verified by luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay. The regulatory functions of LINC00960 and miR-146a-5p on IRAK1 were detected by Western blot. We demonstrated that the LINC00960 expression was increased in PDAC tissues and cell lines. Knocking down LINC00960 or IRAK1 could repress the viability, migration, and invasion of BxPC-3 and Colo357 cells. LINC00960 functioned as a molecular sponge for miR-146a-5p, and IRAK1 was verified as a target gene of miR-146a-5p. Additionally, LINC00960 could up-regulate IRAK1 expression via repressing miR-146a-5p, and the oncogenic properties of LINC00960 were partly reversed by miR-146a-5p. Our findings reveal that LINC00960 is a promoter of PDAC progression through regulating miR-146a-5p/IRAK1axis.

Aldehyde dehydrogenase 1 (ALDH1) immunostaining in axillary lymph node metastases is an independent prognostic factor in ALDH1-positive breast cancer

Objective

To determine whether aldehyde dehydrogenase 1 (ALDH1) immunostaining in axillary lymph node metastases in patients with breast cancer is associated with poor clinical prognosis.

Methods

This retrospective study reviewed data from the medical records of patients with immunohistochemistry-confirmed invasive ductal carcinoma (IDC) and 1–3 metastatic lymph nodes in the ipsilateral axilla between December 2012 and July 2015. The association between ALDH1 immunostaining in axillary lymph node metastases and clinical parameters and prognosis was analysed using χ²-test, Kaplan–Meier survival analysis, univariate and multivariate Cox regression analyses.

Results

A total of 229 patients with IDC were enrolled in the study. The median follow-up was 61 months (range, 20–89 months). Patients with ALDH1-positive axillary lymph node metastases had significantly shorter relapse-free survival and overall survival compared with those with ALDH1-negative axillary lymph node metastases. ALDH1 immunostaining in axillary lymph node metastases was a significant predictor of poor prognosis in univariate and multivariate analyses.

Conclusion

This large study with long-term follow-up suggests that ALDH1 immunostaining in axillary lymph node metastases is an independent predictor of poor prognosis in patients with breast cancer. The clinical relevance of this finding should be confirmed in further well-designed prospective studies.

Long noncoding RNA HOXC-AS3 enhances the progression of cervical cancer via activating ErbB signaling pathway

Emerging evidence reveals that long noncoding RNAs (lncRNAs) contribute to human tumorigenesis. Nevertheless, the function of HOXC cluster antisense RNA 3 (HOXC-AS3) in human cervical cancer (CC) remains largely unknown. The levels of HOXC-AS3, miR-105-5p and SOS1 in CC tissues and cells were monitored by reverse transcription-polymerase chain reaction (RT-PCR) and western blot (WB). Gain- and loss-of-function experiments were conducted to verify the function of HOXC-AS3 and miR-105-5p in CC cells. Meanwhile, cell proliferation, apoptosis, migration and invasion were examined by the cell counting kit-8 (CCK8) experiment, colony formation assay, flow cytometry and Transwell assay. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were carried out to test the regulatory interaction of HOXC-AS3, miR-105-5p and SOS1. In addition, in vivo experiment was performed to certain the role of HOXC-AS3 in tumorigenesis of CC. HOXC-AS3 was overexpressed in CC tissues (vs. adjacent normal tissues) and CC cells. Besides, the higher HOXC-AS3 profile was associated with the poorer clinical prognosis of CC patients. Overexpression of HOXC-AS3 promoted cell growth, migration and invasion, hampered apoptosis, whereas knocking down HOXC-AS3 exhibited the reverse effects. MiR-105-5p was a downstream target of HOXC-AS3, and it mediated the HOXC-AS3-induced oncogenic effects. Mechanistically, the bioinformatic analysis illustrated that SOS1 was targeted by miR-105-5p. Up-regulating SOS1 heightened the growth, migration and invasion of CC cells by enhancing the ErbB signaling pathway, which was reversed by miR-105-5p. Up-regulated HOXC-AS3 aggravates CC by promoting SOS1 expression via targeting miR-105-5p.

Long Non-Coding RNAs as Potential Diagnostic and Prognostic Biomarkers in Breast Cancer: Progress and Prospects

Breast cancer is the most common malignancy among women worldwide, excluding non-melanoma skin cancer. It is now well understood that breast cancer is a heterogeneous entity that exhibits distinctive histological and biological features, treatment responses and prognostic patterns. Therefore, the identification of novel ideal diagnostic and prognostic biomarkers is of utmost importance. Long non-coding RNAs (lncRNAs) are commonly defined as transcripts longer than 200 nucleotides that lack coding potential. Extensive research has shown that lncRNAs are involved in multiple human cancers, including breast cancer. LncRNAs with dysregulated expression can act as oncogenes or tumor-suppressor genes to regulate malignant transformation processes, such as proliferation, invasion, migration and drug resistance. Intriguingly, the expression profiles of lncRNAs tend to be highly cell-type-specific, tissue-specific, disease-specific or developmental stage-specific, which makes them suitable biomarkers for breast cancer diagnosis and prognosis.

Aberration of lncRNA LINC00460 is a Promising Prognosis Factor and Associated with Progression of Clear Cell Renal Cell Carcinoma

Purpose

Long noncoding RNAs have been studied more and more as potential prognostic markers. However, the prognostic of LINC00460 in clear cell renal cell carcinoma (ccRCC) has not been explored. In this study, the potential role of LINC00460 was investigated in ccRCC.

Patients and Methods

One hundred thirteen pairs of ccRCC tissues and para-normal tissues were collected. The expressions of LINC00460 in these tissues and ccRCC cells were evaluated via qRT-PCR. The prognostic value of LINC00460 was accessed with the use of Kaplan–Meier analysis and Cox proportional hazards model analysis. The influence of LINC00460 on ccRCC cell proliferation, migration, and invasion was determined via cell counting kit-8 (CCK-8) and Transwell assays.

Results

The results revealed that LINC00460 was significantly enhanced in ccRCC tissues, as well as in ccRCC cell lines. The overexpression of LINC00460 was significantly associated with lymph node metastasis and TNM stage, and lead to poor overall survival. Knockdown of LINC00460 reduces the cell ability of proliferation, migration, and invasion. LINC00460 could sponge to miR-149-5p.

Conclusion

LINC00460 may be developed as a prognostic biomarker and molecular therapy target for ccRCC.

Precision treatment exploration of breast cancer based on heterogeneity analysis of lncRNAs at the single-cell level

BACKGROUND

Breast cancer (BC) is a complex disease with high heterogeneity, which often leads to great differences in treatment results. Current common molecular typing method is PAM50, which shows positive results for precision medicine; however, room for improvement still remains because of the different prognoses of subtypes. Therefore, in this article, we used lncRNAs, which are more tissue-specific and developmental stage-specific than other RNAs, as typing markers and combined single-cell expression profiles to retype BC, to provide a new method for BC classification and explore new precise therapeutic strategies based on this method.

METHODS

Based on lncRNA expression profiles of 317 single cells from 11 BC patients, SC3 was used to retype BC, and differential expression analysis and enrichment analysis were performed to identify biological characteristics of new subtypes. The results were validated for survival analysis using data from TCGA. Then, the downstream regulatory genes of lncRNA markers of each subtype were searched by expression correlation analysis, and these genes were used as targets to screen therapeutic drugs, thus proposing new precision treatment strategies according to the different subtype compositions of patients.

RESULTS

Seven lncRNA subtypes and their specific biological characteristics are obtained. Then, 57 targets and 210 drugs of 7 subtypes were acquired. New precision medicine strategies were proposed according to the different compositions of patient subtypes.

CONCLUSIONS

For patients with different subtype compositions, we propose a strategy to select different drugs for different patients, which means using drugs targeting multi subtype or combinations of drugs targeting a single subtype to simultaneously kill different cancer cells by personalized treatment, thus reducing the possibility of drug resistance and even recurrence.

Epigenetic Regulation of Breast Cancer Stem Cells Contributing to Carcinogenesis and Therapeutic Implications

Globally, breast cancer has remained the most commonly diagnosed cancer and the leading cause of cancer death among women. Breast cancer is a highly heterogeneous and phenotypically diverse group of diseases, which require different selection of treatments. Breast cancer stem cells (BCSCs), a small subset of cancer cells with stem cell-like properties, play essential roles in breast cancer progression, recurrence, metastasis, chemoresistance and treatments. Epigenetics is defined as inheritable changes in gene expression without alteration in DNA sequence. Epigenetic regulation includes DNA methylation and demethylation, as well as histone modifications. Aberrant epigenetic regulation results in carcinogenesis. In this review, the mechanism of epigenetic regulation involved in carcinogenesis, therapeutic resistance and metastasis of BCSCs will be discussed, and finally, the therapies targeting these biomarkers will be presented.

H19 Promotes HCC Bone Metastasis Through Reducing Osteoprotegerin Expression in a Protein Phosphatase 1 Catalytic Subunit Alpha/p38 Mitogen-Activated Protein Kinase-Dependent Manner and Sponging microRNA 200b-3p

BACKGROUND AND AIMS

Bone is the second most frequent site of metastasis for HCC, which leads to an extremely poor prognosis. HCC bone metastasis is typically osteolytic, involving the activation of osteoclasts. Long noncoding RNA H19 plays an important role in the pathogenesis of human cancers. Nonetheless, the mechanism underlying the participation of H19 in HCC bone metastasis remains unclear.

APPROACH AND RESULTS

The current study established a mouse HCC bone metastasis model by using serial intracardiac injection and cell isolation to obtain cells with distinct bone metastasis ability. H19 was highly expressed in these cells and in clinical HCC bone metastasis specimens. Both osteoclastogenesis in vitro and HCC bone metastasis in vivo were promoted by H19 overexpression, whereas these processes were suppressed by H19 knockdown. H19 overexpression attenuated p38 phosphorylation and further down-regulated the expression of osteoprotegerin (OPG), also known as osteoclastogenesis inhibitory factor. However, up-regulated OPG expression as well as suppressed osteoclastogenesis caused by H19 knockdown were recovered by p38 interference, indicating that p38 mitogen-activated protein kinase (MAPK)-OPG contributed to H19-promoted HCC bone metastasis. Furthermore, we demonstrated that H19 inhibited the expression of OPG by binding with protein phosphatase 1 catalytic subunit alpha (PPP1CA), which dephosphorylates p38. SB-203580-mediated inactivation of p38MAPK reversed the down-regulation of HCC bone metastasis caused by H19 knockdown in vivo. Additionally, H19 enhanced cell migration and invasion by up-regulating zinc finger E-box binding homeobox 1 through the sequestration of microRNA (miR) 200b-3p.

CONCLUSIONS

H19 plays a critical role in HCC bone metastasis by reducing OPG expression, which is mediated by the PPP1CA-induced inactivation of the p38MAPK pathway; and H19 also functions as a sponge for miR-200b-3p.

LncRNA SNHG17 Contributes to the Progression of Cervical Cancer by Targeting microRNA-375-3p

Purpose

Cervical cancer is a great threat to women’s health all over the world. Non-coding RNAs performed a wide range of functions. This study aimed to clarify the clinical significance and biological function of lncRNA SNHG17 and miRNA-375-3p (miR-375-3p) in cervical cancer (CC).

Patients and Methods

Blood samples from 124 CC patients and 119 healthy volunteers were collected. The relative expression of SNHG17 and miR-375-3p in CC patient serums and cells was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). The receiver operating curve (ROC) was plotted for diagnostic value estimation. The CCK-8 and transwell assay were conducted to explore the function of SNHG17 on CC cells. A luciferase reporter assay was carried out to confirm the interaction of SNHG17 and miR-375-3p. Rescue experiments were performed to verify the interaction.

Results

SNHG17 showed an ascending expression while miR-375-3p descended in the serum of CC patients. For SNHG17 and miR-375-3p, respectively, the AUC was 0.863 and 0.869, the sensitivity was 84.7% and 75.8%, and the specificity was 78.2% and 86.6%. Knockdown of SNHG17 inhibited proliferation, migration, and invasion of CC cells. Serum SNHG17 expression was negatively correlated with miR-375-3p expression, and miR-375-3p was the target miRNA of SNHG17. Rescue experiments verified the knockdown of SNHG17 inhibited cell growth through repressing miR-375-3p expression.

Conclusion

SNHG17 and miR-375-3p have the potential to be diagnostic markers for CC. Overexpression of SNHG17 in CC promoted the progression of CC partly via targeting miR-375-3p, implying a novel therapeutic target for CC emerging.

Long noncoding RNAs in triple-negative breast cancer: A new frontier in the regulation of tumorigenesis

In recent years, triple-negative breast cancer (TNBC) has emerged as the most aggressive subtype of breast cancer and is usually associated with increased mortality worldwide. The severity of TNBC is primarily observed in younger women, with cases ranging from approximately 12%-24% of all breast cancer cases. The existing hormonal therapies offer limited clinical solutions in completely circumventing the TNBC, with chemoresistance and tumor recurrences being the common hurdles in the path of TNBC treatment. Accumulating evidence has correlated the dysregulation of long noncoding RNAs (lncRNAs) with increased cell proliferation, invasion, migration, tumor growth, chemoresistance, and decreased apoptosis in TNBC. Various clinical studies have revealed that aberrant expression of lncRNAs in TNBC tissues is associated with poor prognosis, lower overall survival, and disease-free survival. Due to these specific characteristics, lncRNAs have emerged as novel diagnostic and prognostic biomarkers for TNBC treatment. However, the underlying mechanism through which lncRNAs perform their actions remains unclear, and extensive research is being carried out to reveal it. Therefore, understanding of mechanisms regulating the modulation of lncRNAs will be a substantial breakthrough in effective treatment therapies for TNBC. This review highlights the association of several lncRNAs in TNBC progression and treatment, along with their possible functions and mechanisms.

Loss of ZNF215 imprinting is associated with poor five-year survival in patients with cytogenetically abnormal-acute myeloid leukemia

Genomic imprinting is a form of epigenetic regulation and imprinted genes are silenced in a parental-specific manner. Imprinting is associated with various human diseases and cancers, but its roles in leukemogenesis remains elusive. In this study, the expression of a panel of 16 human imprinted genes was investigated using real-time quantitative polymerase chain reaction and 8 of them were further validated in 114 patients newly diagnosed with cytogenetically abnormal-acute myeloid leukemia (CA-AML) and 85 healthy subjects. Our results demonstrated upregulated expression of 8 imprinted genes (C15orf2, COPG2, H19, IGF2, PEG3-AS1, PRIM2, SLC22A3 and ZNF215) was observed in patients with CA-AML (p < 0.001). Patients' survival days were negatively correlated with the expression levels of H19 (p = 0.024), PGE3-AS1 (p = 0.038), and ZNF215 (p = 0.012). Multivariate logistic regression analysis further revealed the expression level ZNF215 can be used as a predictor for five-year survival for patients with CA-AML (p = 0.009) with a hazard ratio of 0.870 (95.0% confident interval: 0.784-0.965). Our results demonstrated that loss of imprinting of imprinted genes is critical for the leukemogenesis of AML under CA condition, and loss of ZNF215 imprinting is associated with poor five-year survival of patients with CA-AML.

Non-coding RNA in cancer

Majority of the human genome is transcribed to RNAs that do not encode proteins. These non-coding RNAs (ncRNAs) play crucial roles in regulating the initiation and progression of various cancers. Given the importance of the ncRNAs, the roles of ncRNAs in cancers have been reviewed elsewhere. Thus, in this review, we mainly focus on the recent studies of the function, regulatory mechanism and therapeutic potential of the ncRNAs including microRNA (miRNA), long ncRNA (lncRNA), circular RNA (circRNA) and PIWI interacting RNA (piRNA), in different type of cancers.

Vitamin D and Non-coding RNAs: New Insights into the Regulation of Breast Cancer

Breast cancer, a life-threatening serious disease with a high incident rate among women, is responsible for thousands of cancer-associated death worldwide. Numerous investigations have evaluated the possible mechanisms related to this malignancy. Among them, non-coding RNAs (ncRNAs), i.e., microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs have recently attracted attention of researchers. In addition to recent studies for evaluating the role of ncRNAs in breast cancer etiology, some investigations have revealed that vitamin D has regulatory and therapeutic roles in breast cancer. Moreover, an important link between vitamin D and ncRNAs in cancer therapy has been highlighted. Herein, the aim of this study was to discuss the available data on the mentioned link in breast cancer.

The Role of Autophagy and lncRNAs in the Maintenance of Cancer Stem Cells

Simple Summary

Cancer stem cells (CSCs) represent a distinct cancer subpopulation that can influence the tumour microenvironment, in addition to cancer progression and relapse. A multitude of factors including CSC properties, long noncoding RNAs (lncRNAs), and autophagy play pivotal roles in maintaining CSCs. We discuss the methods of detection of CSCs and how our knowledge of regulatory and cellular processes, and their interaction with the microenvironment, may lead to more effective targeting of these cells. Autophagy and lncRNAs can regulate several cellular functions, thereby promoting stemness factors and CSC properties, hence understanding this triangle and its associated signalling networks can lead to enhanced therapy response, while paving the way for the development of novel therapeutic approaches.

Abstract

Cancer stem cells (CSCs) possess properties such as self-renewal, resistance to apoptotic cues, quiescence, and DNA-damage repair capacity. Moreover, CSCs strongly influence the tumour microenvironment (TME) and may account for cancer progression, recurrence, and relapse. CSCs represent a distinct subpopulation in tumours and the detection, characterisation, and understanding of the regulatory landscape and cellular processes that govern their maintenance may pave the way to improving prognosis, selective targeted therapy, and therapy outcomes. In this review, we have discussed the characteristics of CSCs identified in various cancer types and the role of autophagy and long noncoding RNAs (lncRNAs) in maintaining the homeostasis of CSCs. Further, we have discussed methods to detect CSCs and strategies for treatment and relapse, taking into account the requirement to inhibit CSC growth and survival within the complex backdrop of cellular processes, microenvironmental interactions, and regulatory networks associated with cancer. Finally, we critique the computationally reinforced triangle of factors inclusive of CSC properties, the process of autophagy, and lncRNA and their associated networks with respect to hypoxia, epithelial-to-mesenchymal transition (EMT), and signalling pathways.

LncRNAs and microRNAs as Essential Regulators of Stemness in Breast Cancer Stem Cells

Breast cancer is an aggressive disease with a high incidence in women worldwide. Two decades ago, a controversial hypothesis was proposed that cancer arises from a subpopulation of "tumor initiating cells" or "cancer stem cells-like" (CSC). Today, CSC are defined as small subset of somatic cancer cells within a tumor with self-renewal properties driven by the aberrant expression of genes involved in the maintenance of a stemness-like phenotype. The understanding of the underlying cellular and molecular mechanisms involved in the maintenance of CSC subpopulation are fundamental in the development and persistence of breast cancer. Nowadays, the hypothesis suggests that genetic and epigenetic alterations give rise to breast cancer stem cells (bCSC), which are responsible for self-renewal, tumor growth, chemoresistance, poor prognosis and low survival in patients. However, the prominence of bCSC, as well as the molecular mechanisms that regulates and promotes the malignant phenotypes, are still poorly understood. The role of non-coding RNAs (ncRNAs), such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) acting as oncogenes or tumor suppressor genes has been recently highlighted by a plethora of studies in breast cancer. These ncRNAs positively or negatively impact on different signaling pathways that govern the cancer hallmarks associated with bCSC, making them attractive targets for therapy. In this review, we present a current summary of the studies on the pivotal roles of lncRNAs and microRNAs in the regulation of genes associated to stemness of bCSC.

Targeting cancer stem cells for reversing therapy resistance: mechanism, signaling, and prospective agents

Cancer stem cells (CSCs) show a self-renewal capacity and differentiation potential that contribute to tumor progression and therapy resistance. However, the underlying processes are still unclear. Elucidation of the key hallmarks and resistance mechanisms of CSCs may help improve patient outcomes and reduce relapse by altering therapeutic regimens. Here, we reviewed the identification of CSCs, the intrinsic and extrinsic mechanisms of therapy resistance in CSCs, the signaling pathways of CSCs that mediate treatment failure, and potential CSC-targeting agents in various tumors from the clinical perspective. Targeting the mechanisms and pathways described here might contribute to further drug discovery and therapy.

The long non-coding RNA landscape in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a type of breast cancer that has a higher risk of distant recurrence and metastasis, leading to a relatively aggressive biological behaviour and poor outcome. So far, the clinical management of TNBC is challenging because of its heterogeneity and paucity of specific targeted therapy. Recently, various studies have identified a lot of differently expressed long non-coding RNAs (lncRNAs) in TNBC. Those lncRNAs have been reported to play important roles in the multistep process of TNBC tumorigenesis. Here, we review the biological characteristics of lncRNAs, and present the current state of knowledge concerning the expression, function and regulation of lncRNAs in TNBC. Accumulating studies explored the potential lncRNAs-based therapeutics in TNBC, including the techniques of genetic modification using antisense oligonucleotides, locked nucleic acid and RNA nanotechnology. In current review, we also discuss the future prospects of studies about lncRNAs in TNBC and development of lncRNA-based strategies for clinical TNBC patients.

LncRNA PCAT7 promotes the malignant progression of breast cancer by regulating ErbB/PI3K/Akt pathway

Aim: This study aimed to explore the mechanism of lncRNA PCAT7 underlying the progression of breast cancer, which will provide a basis for accurate diagnosis and targeted treatment. Methods: Data from The Cancer Genome Atlas data associated with breast cancer were used to identify the target lncRNA. In vitro experiments were conducted to detect gene expression and the effect of the lncRNA on cancer cell activities. Results: PCAT7 was found to be highly expressed in breast cancer tissue and cells, which activated the ErbB/PI3K/Akt pathway to potentiate cancer cell proliferation, migration and invasion and suppress apoptosis. Conclusion: PCAT7 is likely to promote tumor cell activities by activating ErbB/PI3K/Akt pathway, in turn potentiating tumor malignant progression.

The long non coding RNA H19 as a biomarker for breast cancer diagnosis in Lebanese women

Breast cancer is the most common cancer in women worldwide. Minimally invasive percutaneous image-guided biopsies are the current cornerstone in the diagnosis of breast lesions detected on mammography/ultrasonography/MRI or palpable clinically. However, apparently benign breast disease seen on benign biopsies is a limiting factor for diagnosis and a risk factor of breast cancer especially in the high-risk category patients. Hypothesizing that molecular changes often occur before morphological variations, the levels of the LncRNA H19 were measured in anonymous tissues obtained from 79 women's image guided breast biopsies, and correlated with cancer progression and aggressiveness. Using a double-blinded approach, H19 might be attributed an interesting role of a more sensitive biomarker in core breast biopsies, independently of the radiological/clinical classification and distant from the clinical management. We established different thresholds for H19 levels in normal versus proliferative, versus malignant tissues. Additionnally, H19 could act as an intra-group risk marker categorizing the biopsies in normal versus benign, versus precancerous breast tissue, and as a prognostic factor in cancerous lesions discriminating aggressive versus nonaggressive lesions. Our study suggests that the lncRNA H19 could be a potential marker for breast cancer diagnosis, prognosis and risk management.

Breast Cancer Stem Cells: Biomarkers, Identification and Isolation Methods, Regulating Mechanisms, Cellular Origin, and Beyond

Despite recent advances in diagnosis and treatment, breast cancer (BC) is still a major cause of cancer-related mortality in women. Breast cancer stem cells (BCSCs) are a small but significant subpopulation of heterogeneous breast cancer cells demonstrating strong self-renewal and proliferation properties. Accumulating evidence has proved that BCSCs are the driving force behind BC tumor initiation, progression, metastasis, drug resistance, and recurrence. As a heterogeneous disease, BC contains a full spectrum of different BC subtypes, and different subtypes of BC further exhibit distinct subtypes and proportions of BCSCs, which correspond to different treatment responses and disease-specific outcomes. This review summarized the current knowledge of BCSC biomarkers and their clinical relevance, the methods for the identification and isolation of BCSCs, and the mechanisms regulating BCSCs. We also discussed the cellular origin of BCSCs and the current advances in single-cell lineage tracing and transcriptomics and their potential in identifying the origin and lineage development of BCSCs.

Icariin attenuates endothelial-mesenchymal transition via H19/miR-148b-3p/ELF5 in ox-LDL-stimulated HUVECs

Atherosclerosis is the main cause of cardio-cerebrovascular diseases. Endothelial-mesenchymal transition plays an important role in atherosclerosis. Icariin has a protective effect on atherosclerosis; however, the underlying mechanism remains unclear. In this study, we explored the molecular mechanism underlying the protective function of icariin in oxidized low-density lipoprotein-stimulated human umbilical vein endothelial cells. H19, a long non-coding RNA, was identified to be downregulated in the background of the oxidized low-density lipoprotein-induced endothelial-mesenchymal transition in human umbilical vein endothelial cells. Icariin upregulated H19 expression and inhibited the transformation of endothelial cells into interstitial cells. Overexpression of H19 affected endothelial-mesenchymal transition in oxidized low-density lipoprotein-stimulated human umbilical vein endothelial cells, whereas H19 knockdown reversed endothelial protective effects of icariin and reduced human umbilical vein endothelial cell migration. Knockdown of H19 significantly downregulated oxidized low-density lipoprotein-induced E74-like factor 5 and upregulated miR-148b-3p, which was reversed by icariin. Thus, icariin may play a protective role in atherosclerosis, and H19 may be a potential therapeutic target.

Identification and characterization of functional long noncoding RNAs in cancer

Long noncoding RNAs (lncRNAs) have emerged as key regulators in a variety of cellular processes that influence disease states. In particular, many lncRNAs are genetically or epigenetically deregulated in cancer. However, whether lncRNA alterations are passengers acquired during cancer progression or can act as tumorigenic drivers is a topic of ongoing investigation. In this review, we examine the current methodologies underlying the identification of cancer-associated lncRNAs and highlight important considerations for evaluating their biological significance as cancer drivers.

Long noncoding RNA Linc00337 functions as an E2F1 co-activator and promotes cell proliferation in pancreatic ductal adenocarcinoma

BACKGROUND

Long noncoding RNA (lncRNA) Linc00337 has been implicated in lung, gastric, colorectal and esophageal squamous cell carcinoma progression via various mechanisms; however, its clinicopathological significance and role in pancreatic ductal adenocarcinoma (PDAC) progression remains largely unknown.

METHODS

Multiple approaches such as bioinformatic analysis, Transfection, quantitative real-time-PCR, Western blotting, animal studies, RNA-immunoprecipitation (RIP), RNA-pulldown and RNA-Fluorescence in situ hybridization (RNA-FISH) and were utilized to explore the role of Linc00337 in PDAC.

RESULTS

Here we identified Linc00337 is an oncogenic lncRNA during PDAC progression. We found that the expression of Linc00337 is elevated in PDAC tissues and the higher Linc00337 predicts dismal prognosis. Functionally, Linc00337 promotes PDAC cell proliferation and cell cycle transition both in vitro and in vivo. Mechanistically, Linc00337 binds to E2F1 and functions as an E2F1 coactivator to trigger the targets expression during PDAC progression.

CONCLUSION

Our results demonstrate a reciprocal regulation mechanism between Linc00337 and E2F1 in PDAC progression and report the clinical value of Linc00337 for PDAC prognosis and treatment.

Exosomal lncRNA FAM225A accelerates esophageal squamous cell carcinoma progression and angiogenesis via sponging miR-206 to upregulate NETO2 and FOXP1 expression

Esophageal cancer is one of the leading causes of cancer‐related deaths worldwide. FAM225A is a novel lncRNA, only has been explored in nasopharyngeal carcinoma tumorigenesis. This study aims to investigate the regulatory mechanism of FAM225A in esophageal squamous cell carcinoma (ESCC). We discovered that FAM225A exhibited higher expression in ESCC. The silence of FAM225A attenuated cell viability, migration, and invasion, but facilitated cell apoptosis in ESCC. Exosome‐mediated transfer of lncRNA FAM225A could participate in ESCC progression. In addition, we found that miR‐206 bound to FAM225A. Moreover, we further demonstrated that FAM225A absorbed miR‐206 to upregulate NETO2 and FOXP1 expression, and FOXP1 acted as a transcription factor to enhance FAM225A expression. Eventually, it was revealed that the overexpression of NETO2 or FOXP1 rescued the effects of FAM225A repression on ESCC progression. Our results suggested that FAM225A upregulated NETO2 and FOXP1 expression by sponging miR‐206 to accelerate ESCC progression and angiogenesis. These results determined the biological role of lncRNA FAM225A in ESCC tumorigenesis, and FAM225A may be a promising biomarker for ESCC treatment.