Long non-coding RNAs and TGF-β signaling in cancer

Identification of a SNAI1 enhancer RNA that drives cancer cell plasticity

Enhancer RNAs (eRNAs) are a pivotal class of enhancer-derived non-coding RNAs that drive gene expression. Here we identify the SNAI1 enhancer RNA (SNAI1e; SCREEM2) as a key activator of SNAI1 expression and a potent enforcer of transforming growth factor-β (TGF-β)/SMAD signaling in cancer cells. SNAI1e depletion impairs TGF-β-induced epithelial-mesenchymal transition (EMT), migration, in vivo extravasation, stemness, and chemotherapy resistance in breast cancer cells. SNAI1e functions as an eRNA to cis-regulate SNAI1 enhancer activity by binding to and strengthening the enrichment of the transcriptional co-activator bromodomain containing protein 4 (BRD4) at the local enhancer. SNAI1e selectively promotes the expression of SNAI1, which encodes the EMT transcription factor SNAI1. Furthermore, we reveal that SNAI1 interacts with and anchors the inhibitory SMAD7 in the nucleus, and thereby prevents TGF-β type I receptor (TβRI) polyubiquitination and proteasomal degradation. Our findings establish SNAI1e as a critical driver of SNAI1 expression and TGF-β-induced cell plasticity.

lncRNAs'p potential roles in the pathogenesis of cancer via interacting with signaling pathways; special focus on lncRNA-mediated signaling dysregulation in lung cancer

Lung cancer ranks among the most lethal types of cancer globally, with a high occurrence and fatality rate. The spread of cancer to other parts of the body, known as metastasis, is the primary cause of treatment failure and death in lung cancer cases. Current approaches for treating advanced lung cancer typically involve a combination of chemotherapy and targeted therapy. However, the majority of patients ultimately develop resistance to these treatments, leading to a worsened prognosis. In recent years, cancer biology research has predominantly focused on the role of protein-encoding genes in cancer development. Long non-coding RNAs (lncRNAs) are transcripts over 200 nucleotides in length that do not encode proteins but are crucial RNA molecules involved in numerous biological functions. While many functions of lncRNAs remain unknown, some have been linked to human diseases, including cancer. Studies have demonstrated that lncRNAs interact with other large molecules in the cell, such as proteins, DNA, and RNA, influencing various critical aspects of cancer. LncRNAs play a significant role in regulating gene expression and have a crucial function in the transcriptional regulation of cancer cells. They mediate various biological and clinical processes such as invasion, metastasis, apoptosis, and cell proliferation. Dysregulation of lncRNAs has been found to impact the process of carcinogenesis through advanced technologies like RNA sequencing and microarrays. Collectively, these long non-coding RNAs hold promise as potential biomarkers and therapeutic targets for human cancers. In this segment, we provide a comprehensive summary of the literature on the characteristics and formation of lncRNAs, along with an overview of their current known roles in lung cancer.

Extracellular Vesicle lncRNAs as Key Biomolecules for Cell-to-Cell Communication and Circulating Cancer Biomarkers

Extracellular vesicles (EVs) are secreted by almost every cell type and are considered carriers of active biomolecules, such as nucleic acids, proteins, and lipids. Their content can be uptaken and released into the cytoplasm of recipient cells, thereby inducing gene reprogramming and phenotypic changes in the acceptor cells. Whether the effects of EVs on the physiology of recipient cells are mediated by individual biomolecules or the collective outcome of the total transferred EV content is still under debate. The EV RNA content consists of several types of RNA, such as messenger RNA (mRNA), microRNA (miRNA), and long non-coding RNA (lncRNA), the latter defined as transcripts longer than 200 nucleotides that do not code for proteins but have important established biological functions. This review aims to update our insights on the functional roles of EV and their cargo non-coding RNA during cancer progression, to highlight the utility of EV RNA as novel diagnostic or prognostic biomarkers in cancer, and to tackle the technological advances and limitations for EV RNA identification, integrity assessment, and preservation of its functionality.

High-throughput sequencing reveals twelve cell death pattern prognostic target genes as potential drug-response-associated genes in the treatment of colorectal cancer cells with palmatine hydrochloride

Objectives

Palmatine Hydrochloride (PaH), an isoquinoline alkaloid from Phellodendron amurense and Coptis chinensis, has analgesic, anti-inflammatory, and anticancer properties. This study aimed to assess PaH’s effectiveness against SW480 colorectal cancer (CRC) cells and explore its molecular mechanisms.

Methods

PaH’s effects on SW480 CRC cells were evaluated using MTT assays for proliferation, scratch assays for migration, and flow cytometry for apoptosis. Differentially expressed genes (DEGs) were identified through high-throughput sequencing. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses assessed DEG roles. Prognostic significance related to programmed cell death (PCD) was analyzed using R-Package with TCGA data. RT-qPCR validated key genes identified.

Results

PaH significantly inhibited SW480 cell growth, invasion, and apoptosis. The MTT assay showed inhibition rates increased from 5.49 % at 25 μg/mL to 52.48 % at 400 μg/mL. Scratch assays indicated reduced cell invasion over 24, 48, and 72 h. Apoptosis rose from 12.36 % in controls to 45.54 % at 400 μg/mL. Sequencing identified 3,385 significant DEGs, primarily in cancer pathways (p=0.004). Among 35 PCD-related DEGs, Lasso Cox regression highlighted 12 key genes, including TERT, TGFBR1, WNT4, and TP53. RT-qPCR confirmed TERT and TGFBR1 downregulation (0.614-fold, p=0.008; 0.41-fold, p<0.001) and TP53 and WNT4 upregulation (5.634-fold, p<0.001; 5.124-fold, p=0.002).

Conclusions

PaH inhibits CRC cell proliferation, migration, and invasion by modulating key PCD genes, suggesting its potential as a CRC therapeutic agent.

Investigation of Non-Coding RNA-Related Autophagy Alterations in Drug-Resistant Multiple Myeloma Plasma Cells

Background & Objective

Multiple myeloma (MM) drug resistance is thought to be caused by the development of protective autophagy. This work aimed to assess the non-coding RNA (ncRNA) autophagy-related alterations in drug-resistant (DR) myeloma cells.

Methods

DR Plasma cells were extracted from the bone marrow of DR patients referred to Baghai 2 Hospital in Ahvaz, Iran. The cells were grown in RPMI-1640 media containing 10% FBS and 1% Pen/Strep and incubated at 37˚C and 5% CO2. After six passages, the plasma cells were precisely isolated and utilized as DR cells. The U266B1 cell line (IBRC C10148) was grown in the RPMI-1640 media containing 10% FBS and 1% Pen/Strep and utilized as drug-sensitive (DS) cells. The relative expression of the genes was determined using the Real-time PCR method. Statistical analysis of the data was performed using GraphPad Prism 8 software.

Results

When the DR cells were compared to the DS cells, there was a notable increase in the expression of ULK1 and LC3B. However, expression of P62 in the DR plasma cells showed a significant decrease compared to the DS plasma cells. The miR-1297 level was considerably higher in the DR cells than in the DS cells. Although, there was no statistically significant difference in the expression of miR-26a-5p between the DS and DR cells. The DR cells exhibited a statistically significant increase in the expression of MALAT1 and SNHG6.

Conclusion

Drug resistance in MM cells may result from overexpression of non-coding RNAs involved in autophagy.

Functional role of lncRNAs in gastrointestinal malignancies: the peculiar case of small nucleolar RNA host gene family

Long noncoding RNAs (lncRNAs) play crucial roles in normal physiology and are often de-regulated in disease states such as cancer. Recently, a class of lncRNAs referred to as the small nucleolar RNA host gene (SNHG) family have emerged as important players in tumourigenesis. Here, we discuss new findings describing the role of SNHGs in gastrointestinal tumours and summarize the three main functions by which these lncRNAs promote carcinogenesis, namely: competing with endogenous RNAs, modulating protein function, and regulating epigenetic marking. Furthermore, we discuss how SNHGs participate in different hallmarks of cancer, and how this class of lncRNAs may serve as potential biomarkers in cancer diagnosis and therapy.

Unboxing the network among long non-coding RNAs and TGF-β signaling in cancer

Deeper analysis of molecular mechanisms arising in tumor cells is an unmet need to provide new diagnostic and therapeutic strategies to prevent and treat tumors. The transforming growth factor β (TGF-β) signaling has been steadily featured in tumor biology and linked to poor prognosis of cancer patients. One pro-tumorigenic mechanism induced by TGF-β is the epithelial-to-mesenchymal transition (EMT), which can initiate cancer dissemination, enrich the tumor stem cell population, and increase chemoresistance. TGF-β signals via SMAD proteins, ubiquitin ligases, and protein kinases and modulates the expression of protein-coding and non-coding RNA genes, including those encoding larger than 500 nt transcripts, defined as long non-coding RNAs (lncRNAs). Several reports have shown lncRNAs regulating malignant phenotypes by directly affecting epigenetic processes, transcription, and post-transcriptional regulation. Thus, this review aims to update and summarize the impact of TGF-β signaling on the expression of lncRNAs and the function of such lncRNAs as regulators of TGF-β signaling, and how these networks might impact specific hallmarks of cancer.

TGFβ-induced long non-coding RNA LINC00313 activates Wnt signaling and promotes cholangiocarcinoma

Cholangiocarcinoma is a devastating liver cancer characterized by high aggressiveness and therapy resistance, resulting in poor prognosis. Long non-coding RNAs and signals imposed by oncogenic pathways, such as transforming growth factor β (TGFβ), frequently contribute to cholangiocarcinogenesis. Here, we explore novel effectors of TGFβ signalling in cholangiocarcinoma. LINC00313 is identified as a novel TGFβ target gene. Gene expression and genome-wide chromatin accessibility profiling reveal that nuclear LINC00313 transcriptionally regulates genes involved in Wnt signalling, such as the transcriptional activator TCF7. LINC00313 gain-of-function enhances TCF/LEF-dependent transcription, promotes colony formation in vitro and accelerates tumour growth in vivo. Genes affected by LINC00313 over-expression in CCA tumours are associated with KRAS and TP53 mutations and reduce overall patient survival. Mechanistically, ACTL6A and BRG1, subunits of the SWI/SNF chromatin remodelling complex, interact with LINC00313 and affect TCF7 and SULF2 transcription. We propose a model whereby TGFβ induces LINC00313 in order to regulate the expression of hallmark Wnt pathway genes, in co-operation with SWI/SNF. By modulating key genes of the Wnt pathway, LINC00313 fine-tunes Wnt/TCF/LEF-dependent transcriptional responses and promotes cholangiocarcinogenesis.

Targeting SMAD-Dependent Signaling: Considerations in Epithelial and Mesenchymal Solid Tumors

SMADs are the canonical intracellular effector proteins of the TGF-β (transforming growth factor-β). SMADs translocate from plasma membrane receptors to the nucleus regulated by many SMAD-interacting proteins through phosphorylation and other post-translational modifications that govern their nucleocytoplasmic shuttling and subsequent transcriptional activity. The signaling pathway of TGF-β/SMAD exhibits both tumor-suppressing and tumor-promoting phenotypes in epithelial-derived solid tumors. Collectively, the pleiotropic nature of TGF-β/SMAD signaling presents significant challenges for the development of effective cancer therapies. Here, we review preclinical studies that evaluate the efficacy of inhibitors targeting major SMAD-regulating and/or -interacting proteins, particularly enzymes that may play important roles in epithelial or mesenchymal compartments within solid tumors.

The long non-coding RNA LINC00707 interacts with Smad proteins to regulate TGFβ signaling and cancer cell invasion

BACKGROUND

Long non-coding RNAs (lncRNAs) regulate cellular processes by interacting with RNAs or proteins. Transforming growth factor β (TGFβ) signaling via Smad proteins regulates gene networks that control diverse biological processes, including cancer cell migration. LncRNAs have emerged as TGFβ targets, yet, their mechanism of action and biological role in cancer remain poorly understood.

METHODS

Whole-genome transcriptomics identified lncRNA genes regulated by TGFβ. Protein kinase inhibitors and RNA-silencing, in combination with cDNA cloning, provided loss- and gain-of-function analyses. Cancer cell-based assays coupled to RNA-immunoprecipitation, chromatin isolation by RNA purification and protein screening sought mechanistic evidence. Functional validation of TGFβ-regulated lncRNAs was based on new transcriptomics and by combining RNAscope with immunohistochemical analysis in tumor tissue.

RESULTS

Transcriptomics of TGFβ signaling responses revealed down-regulation of the predominantly cytoplasmic long intergenic non-protein coding RNA 707 (LINC00707). Expression of LINC00707 required Smad and mitogen-activated protein kinase inputs. By limiting the binding of Krüppel-like factor 6 to the LINC00707 promoter, TGFβ led to LINC00707 repression. Functionally, LINC00707 suppressed cancer cell invasion, as well as key fibrogenic and pro-mesenchymal responses to TGFβ, as also attested by RNA-sequencing analysis. LINC00707 also suppressed Smad-dependent signaling. Mechanistically, LINC00707 interacted with and retained Smad proteins in the cytoplasm. Upon TGFβ stimulation, LINC00707 dissociated from the Smad complex, which allowed Smad accumulation in the nucleus. In vivo, LINC00707 expression was negatively correlated with Smad2 activation in tumor tissues.

CONCLUSIONS

LINC00707 interacts with Smad proteins and limits the output of TGFβ signaling, which decreases LINC00707 expression, thus favoring cancer cell invasion. Video Abstract.

Role of long non-coding RNAs and TGF-β signaling in the regulation of breast cancer pathogenesis and therapeutic targets

The cytokine known as transforming growth factor (TGF) is essential for cell development, differentiation, and apoptosis in BC. TGF-β dysregulation can either promote or inhibit tumor development, and it is a key signaling pathway in BC spread. A recently identified family of ncRNAs known as lncRNAs has received a great deal of effort and is an important regulator of many cellular processes, including transcription of genes, chromatin remodeling, progression of the cell cycle, and posttranscriptional processing. Furthermore, both TGF-β signaling and lncRNAs serve as important early-stage biomarkers for BC diagnosis and prognosis and also play a significant role in BC drug resistance. According to recent studies, lncRNAs can regulate TGF-β by modulating its cofactors in BC. However, the particular functions of lncRNAs and the TGF-β pathway in controlling BC progression are not well understood yet. This review explores the lncRNAs' functional properties in BC as tumor suppressors or oncogenes in the regulation of genes, with a focus on dysregulated TGF-β signaling. Further, we emphasize the functional roles of lncRNAs and TGF-β pathway in the progression of BC to discover new treatment strategies and better comprehend the fundamental cellular pathways.

Role of Non-Coding RNAs in TGF-β Signalling in Glioma

Brain tumours and Gliomas, in particular, are among the primary causes of cancer mortality worldwide. Glioma diagnosis and therapy have not significantly improved despite decades of efforts. Autocrine TGF-β signalling promotes glioma proliferation, invasion, epithelial-to-mesenchymal transition (EMT), and drug resistance. Non-coding RNAs such as miRNA, lncRNA, and circRNAs have emerged as critical transcriptional and post-transcriptional regulators of TGF-β pathway components in glioma. Here, we summarize the complex regulatory network among regulatory ncRNAs and TGF-β pathway during Glioma pathogenesis and discuss their role as potential therapeutic targets for Gliomas.

LINC01116 affects patient survival differently and is dissimilarly expressed in ER+ and ER- breast cancer samples

BACKGROUND

Breast cancer is the most commonly detected cancer and one of the leading causes of cancer mortality. Emerging evidence supports that aberrant expression of lncRNAs is correlated with tumor progression and various aspects of tumor development.

AIM

This study aimed to evaluate the expression pattern of LINC01116 in breast cancer tissues and investigate the impact of LINC01116 on patients' survival.

METHODS AND RESULTS

Microarray and qRT-PCR data analysis were performed, and the KM-plotter database was used in this study. In addition, the gain of function approach was performed to examine the effect of LINC01116 on breast cancer cells in-vitro. The results exhibited that LINC01116 is meaningfully upregulated in the ER+ tumor specimens compared to the ER- ones. Also, relative to normal tissues, the expression of LINC01116 in ER+ and ER- tumor tissues significantly increased and decreased, respectively. ROC curve analysis revealed the power of LINC01116 in distinguishing ER+ from ER- samples. Additionally, the Kaplan-Meier survival analysis showed that the LINC01116 expression positively correlates with survival probability in all as well as ER+ patients. However, this correlation was negative in ER- patients. Furthermore, our results showed that the overexpression of LINC01116 induces TGF-β signaling in ER- cells (MDA-MB-231), and microarray data analysis revealed that LINC01116 is significantly upregulated in 17β-Estradiol treated MCF7 cells.

CONCLUSION

In conclusion, our results suggest that LINC01116 can be a potential biomarker in distinguishing ER+ and ER- tissues and has different effects on patients' survival based on ER status by affecting TGF-β and ER signaling.

Emerging role of transforming growth factor-β-regulated long non-coding RNAs in prostate cancer pathogenesis

Prostate cancer (PCa) is the most common malignancy in men. Despite aggressive therapy involving surgery and hormonal treatments, the recurrence and emergence of metastatic castration-resistant prostate cancer (CRPCa) remain a major challenge. Dysregulation of the transforming growth factor-β (TGF-β) signaling pathway is crucial to PCa development and progression. This also contributes to androgen receptor activation and the emergence of CRPC. In addition, TGF-β signaling regulates long non-coding RNA (lncRNA) expression in multiple cancers, including PCa. Here, we discuss the complex regulatory network of lncRNAs and TGF-β signaling in PCa and their potential applications in diagnosing, prognosis, and treating PCa. Further investigations on the role of lncRNAs in the TGF-β pathway will help to better understand PCa pathogenesis.

The lncRNA LETS1 promotes TGF-β-induced EMT and cancer cell migration by transcriptionally activating a TβR1-stabilizing mechanism

Transforming growth factor-β (TGF-β) signaling is a critical driver of epithelial-to-mesenchymal transition (EMT) and cancer progression. In SMAD-dependent TGF-β signaling, activation of the TGF-β receptor complex stimulates the phosphorylation of the intracellular receptor-associated SMADs (SMAD2 and SMAD3), which translocate to the nucleus to promote target gene expression. SMAD7 inhibits signaling through the pathway by promoting the polyubiquitination of the TGF-β type I receptor (TβRI). We identified an unannotated nuclear long noncoding RNA (lncRNA) that we designated LETS1 (lncRNA enforcing TGF-β signaling 1) that was not only increased but also perpetuated by TGF-β signaling. Loss of LETS1 attenuated TGF-β-induced EMT and migration in breast and lung cancer cells in vitro and extravasation of the cells in a zebrafish xenograft model. LETS1 potentiated TGF-β-SMAD signaling by stabilizing cell surface TβRI, thereby forming a positive feedback loop. Specifically, LETS1 inhibited TβRI polyubiquitination by binding to nuclear factor of activated T cells (NFAT5) and inducing the expression of the gene encoding the orphan nuclear receptor 4A1 (NR4A1), a component of a destruction complex for SMAD7. Overall, our findings characterize LETS1 as an EMT-promoting lncRNA that potentiates signaling through TGF-β receptor complexes.

TGF-β mediated drug resistance in solid cancer

Transforming growth factor β (TGF-β) is an important signaling molecule which is expressed in three different isoforms in mammals (i.e. TGF-β1, -β2, and -β3). The interaction between TGF-β and its receptor triggers several pathways, which are classified into SMAD-dependent (canonical) and SMAD-independent (non-canonical) signaling, whose activation/transduction is finely regulated by several mechanisms. TGF-β is involved in many physiological and pathological processes, assuming a dualistic role in cancer progression depending on tumor stage. Indeed, TGF-β inhibits cell proliferation in early-stage tumor cells, while it promotes cancer progression and invasion in advanced tumors, where high levels of TGF-β have been reported in both tumor and stromal cells. In particular, TGF-β signaling has been found to be strongly activated in cancers after treatment with chemotherapeutic agents and radiotherapy, resulting in the onset of drug resistance conditions. In this review we provide an up-to-date description of several mechanisms involved in TGF-β-mediated drug resistance, and we report different strategies that are currently under development in order to target TGF-β pathway and increase tumor sensitivity to therapy.

MIR503HG: A potential diagnostic and therapeutic target in human diseases

LncRNAs are involved in many physiological and pathological processes, including chromatin remodeling, transcription, posttranscriptional gene expression, mRNA stability, translation, and posttranslational modification, and their functions depend on subcellular localization. MIR503HG is a lncRNA as well as a host gene for the miRNAs miR-503 and miR-424. MIR503HG functions independently or synergistically with miR-503. MIR503HG affects cell proliferation, invasion, metastasis, apoptosis, angiogenesis, and other biological behaviors. The mechanism of MIR503HG in disease includes interaction with protein, sponging miRNA to regulate downstream target gene, and participation in NF-κB, TGF-β, ERK/MAPK, and PI3K/AKT signaling pathways. In this review, we summarize the molecular mechanisms of MIR503HG in disease and its potential applications in diagnosis, prognosis, and treatment. We also raise some unanswered questions in this area, providing insights for future research.

The function of LncRNA-ATB in cancer

Cancer as a progressive and complex disease is caused by early chromosomal changes and stimulated cellular transformation. Previous studies reported that long non-coding RNAs (lncRNAs) play pivotal roles in the initiation, maintenance, and progression of cancer cells. LncRNA activated by TGF-β (ATB) has been shown to be dysregulated in different types of cancer. Aberrant expression of lncRNA-ATB plays an important role in the progression of diverse malignancies. High expression of LncRNA-ATB is associated with cancer cell growth, proliferation, metastasis, and EMT. LncRNA-ATB by targeting various signaling pathways and microRNAs (miRNAs) can trigger cancer pathogenesis. Therefore, lncRNA-ATB can be a novel target for cancer prediction and diagnosis. In this review, we will focus on the function of lncRNA-ATB in various types of human cancers.

LINC01711 promotes transforming growth factor-beta (TGF-β) induced invasion in glioblastoma multiforme (GBM) by acting as a competing endogenous RNA for miR-34a and promoting ZEB1 expression

GBM is the central nervous system's most aggressive and malignant tumor. TGF-β expression is elevated in GBM, and it promotes invasion and EMT. TGF-β regulates the expression of several lncRNAs, which promote glioma pathogenesis. Here we characterize the role of TGF-β-induced lncRNA- LINC01711 in glioma pathogenesis. We show that LINC01711 expression is significantly upregulated in GBM tissues and is associated with poor overall survival of GBM patients. Loss-of-function studies illustrate that LINC01711 promotes proliferation, migration, and invasion in GBM. In addition, LINC01711 depletion sensitizes glioma cells to Temozolomide (TMZ) induced apoptosis by inhibiting ZEB1 expression. LINC01711 functions as a competing endogenous RNA for miR-34a and promotes ZEB1 expression to regulate invasion. Our findings suggest that LINC01711 is an attractive therapeutic target for GBM.

New aspects of TGF-β superfamily signaling in development and disease (2022 FASEB meeting review)

The 13th Federation of American Societies for Experimental Biology (FASEB) Summer Research Conference, "TGF-β superfamily signaling in development and disease" was convened at the Grand Hotel in Malahide, Ireland in July 2022. The Transforming Growth Factor-β (TGF-β) family of secreted proteins consists of agents of intercellular communication found in all multicellular animals. Attending the meeting was a diverse group of scholars with shared interests in understanding TGF-β signaling mechanisms, normal functions, and the diseases associated with misregulation and mutation. Despite intense study over the previous 35 years, new features of TGF-β activity continue to be discovered. This meeting report offers 21 investigator-provided summaries that illustrate the breadth of the thought-provoking presentations. An emerging theme of the meeting was the power of cross-disciplinary studies, such as one combining immunology, biochemistry, and structural biology, to unravel the secrets of parasitic TGF-β mimics. Please join us at the next meeting.

TGF-β at the crossroads of multiple prognosis in breast cancer, and beyond

Transforming growth factor β (TGF-β), a pluripotent cytokine and a multifunctional growth factor has a crucial role in varied biological mechanisms like invasion, migration, epithelial-mesenchymal transition, apoptosis, wound healing, and immunosuppression. Moreover, it also has an imperative role both in normal mammary gland development as well as breast carcinogenesis. TGF-β has shown to have a paradoxical role in breast carcinogenesis, by transitioning from a growth inhibitor to a growth promoter with the disease advancement. The inter-communication and crosstalk of TGF-β with different signaling pathways has strengthened the likelihood to explore it as a comprehensive biomarker. In the last two decades, TGF-β has been studied extensively and has been found to be a promising biomarker for early detection, disease monitoring, treatment selection, and tumor progression making it beneficial for disease management. In this review, we focus on the signaling pathways and biological activities of the TGF-β family in breast cancer pathogenesis and its role as a circulatory and independent biomarker for breast cancer progression and metastasis. Moreover, this review highlights TGF-β as a drug target, and the underlying mechanisms through which it is involved in tumorigenesis that will aid in the development of varied therapies targeting the different stages of breast cancer.

The emerging role of noncoding RNAs in the Hedgehog signaling pathway in cancer

Hedgehog (HH), a conserved signaling pathway, is involved in embryo development, organogenesis, and other biological functions. Dysregulation and abnormal activation of HH are involved in tumorigenesis and tumor progression. With the emergence of interest in noncoding RNAs, studies on their involvement in abnormal regulation of biological processes in tumors have been published one after another. In this review, we focus on the crosstalk between noncoding RNAs and the HH pathway in tumors and elaborate the mechanisms by which long noncoding RNAs and microRNAs regulate or are regulated by HH signaling in cancer. We also discuss the interaction between noncoding RNAs and the HH pathway from the perspective of cancer hallmarks, presenting this complex network as concisely as possible and organizing ideas for cancer diagnosis and treatment.

Identification of a pyroptosis-related lncRNA signature in the regulation of prognosis, metabolism signals and immune infiltration in lung adenocarcinoma

Pyroptosis is a cell death pathway that plays a significant role in lung adenocarcinoma (LUAD). Also, studies regarding the correlation between the expression of long non-coding RNAs (lncRNAs) and the mechanism of LUAD has aroused concern around the world. The purpose of this paper is to explore the underlying relationship of differentially expressed lncRNAs and pyroptosis-related genes. The least absolute shrinkage and selection operator (LASSO) algorithm and Cox regression were applied to construct a prognostic risk score model from the TCGA database. A pyroptosis-related five-lncRNA signature (CRNDE, HHLA3, MIR193BHG, LINC00941, LINC01843) was considered to be correlated to the prognosis and immune response of LUAD patients. In addition, the cytological experiments revealed that aberrantly expressed HHLA3 displayed a proliferation promotion role in LUAD cells A549 and H460. Next, the forest and nomogram plots have shown this lncRNA signature could be served as an independent prognostic factor for LUAD. The ROC curves further identified the prognostic value of the five-lncRNA signature. The infiltration of immune cells, such as T cells CD8, T cells CD4 memory resting, T cells CD4 memory activated and M0 macrophages were greatly different between the high-risk group and the low-risk group. It implicated that the signature is significantly effective in immunotherapy of LUAD patients. This study has supplied a novel pyroptosis-related lncRNA signature and provided a predictive model for prognosis and immune response of LUAD patients.

A novel biomarker NIFK-AS1 promotes hepatocellular carcinoma cell cycle progression through interaction with SRSF10

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common carcinomas all over the world, with high mortality and low survival rate. Notably, many studies have showed that a variety of molecules play vital roles in the progression of HCC. Therefore, it is urgent to find reliable biomarkers to diagnose HCC and developing novel strategies are required for the effective treatment of patients with HCC.

METHODS

This study obtained an HCC cohort from The Cancer Genome Atlas (TCGA). For prognostic analysis, the TCGA cohort was grouped according to different median boundaries. The key module associated with HCC was adopted by Weighted Gene Co-expression Network analysis (WGCNA). We also analyzed the survival ability, functional enrichment, and potential binding proteins of key lncRNAs. The expression of hub lncRNAs in HCC tissues and cell lines was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell Counting Kit-8 (CCK-8) and flow cytometry were applied to detect the cell proliferation, apoptosis, and cell cycle. The interaction between NIFK-AS1 and SRSF1 was examined using an RNA pull-down assay.

RESULTS

The green module is the key module in HCC. NIFK-AS1 was highly expressed in HCC tissues and correlated with a poor prognosis in HCC patients (P=0.008). NIFK-AS1 was also significantly associated with cell mitosis, the cell cycle, and other biological processes. NIFK-AS1 deletion prevented cell proliferation, induced apoptosis, caused G2/M arrest, and affected cell cycle progression. RNA pull-down validated the NIFK-AS1/SRSF10 interaction. The overexpression of NIFK-AS1 was sufficient to rescue the growth of SRSF10 knockdown HepG2 cells.

CONCLUSIONS

This study suggested that NIFK-AS1 promotes HCC cell cycle progression through interaction with SRSF10 and its findings provide new insights into therapeutic targets for HCC.

Transcriptomic Analyses Reveal Long Non-Coding RNA in Peripheral Blood Mononuclear Cells as a Novel Biomarker for Diagnosis and Prognosis of Hepatocellular Carcinoma

Novel biomarkers are highly required for the diagnosis and predicting prognosis of hepatocellular carcinoma (HCC). In this study, we investigated the profiles of long non-coding RNAs (lncRNAs) obtained from the peripheral blood mononuclear cells (PBMCs) of patients with HCC and PBMCs from a co-culture model using transcriptomic analysis. The differentially expressed lncRNAs (DElncRNAs) were then characterized and integrated as cancer-induced lncRNAs. Among them, three up-regulating DElncRNAs including MIR4435-2HG, SNHG9 and lnc-LCP2-1 and one down-regulating, lnc-POLD3-2, were identified. The functional analysis showed that these enriched lncRNAs were mainly associated with carcinogenesis and immune responses. Following further validation in PBMCs samples (100 HBV-related HCC, 100 chronic hepatitis B and 100 healthy controls), MIR4435-2HG, lnc-POLD3-2 and their combination were revealed to be sensitive biomarkers in discriminating HCC from non-HCC (AUROC = 0.78, 0.80, and 0.87, respectively), particularly among individuals with normal serum alpha-fetoprotein levels. Additionally, high circulating SNHG9 expression was shown to be an independent prognostic factor of overall survival in patients with HCC. These results indicate that determining these lncRNAs in PBMCs could serve as novel diagnostic and prognostic biomarkers for HBV-related HCC.

Long noncoding RNA Smyca coactivates TGF-β/Smad and Myc pathways to drive tumor progression

Background

Metastasis and chemoresistance are major culprits of cancer mortality, but factors contributing to these processes are incompletely understood.

Methods

Bioinformatics methods were used to identify the relations of Smyca expression to clinicopathological features of human cancers. RNA-sequencing analysis was used to reveal Smyca-regulated transcriptome. RNA pull-down and RNA immunoprecipitation were used to examine the binding of Smyca to Smad3/4 and c-Myc/Max. Chromatin immunoprecipitation and chromatin isolation by RNA purification were used to determine the binding of transcription factors and Smyca to various gene loci, respectively. Real-time RT-PCR and luciferase assay were used to examine gene expression levels and promoter activities, respectively. Xenograft mouse models were performed to evaluate the effects of Smyca on metastasis and chemoresistance. Nanoparticle-assisted gapmer antisense oligonucleotides delivery was used to target Smyca in vivo.

Results

We identify lncRNA Smyca for its association with poor prognosis of many cancer types. Smyca potentiates metabolic reprogramming, migration, invasion, cancer stemness, metastasis and chemoresistance. Mechanistically, Smyca enhances TGF-β/Smad signaling by acting as a scaffold for promoting Smad3/Smad4 association and further serves as a Smad target to amplify/prolong TGF-β signaling. Additionally, Smyca potentiates c-Myc-mediated transcription by enhancing the recruitment of c-Myc/Max complex to a set of target promoters and c-Myc binding to TRRAP. Through potentiating TGF-β and c-Myc pathways, Smyca synergizes the Warburg effect elicited by both pathways but evades the anti-proliferative effect of TGF-β. Targeting Smyca prevents metastasis and overcomes chemoresistance.

Conclusions

This study uncovers a lncRNA that coordinates tumor-relevant pathways to orchestra a pro-tumor program and establishes the clinical values of Smyca in cancer prognosis and therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13045-022-01306-3.

Survivin, Sonic hedgehog, Krüppel-like factors, and p53 pathway in serous ovarian cancer: an immunohistochemical study

OBJECTIVE

Survivin was previously associated with tumor stage and grade in ovarian cancer and interfered with the tumor's drug sensitivity. In addition, Survivin expression was found to be regulated by the Sonic hedgehog (Shh) pathway, Krüppel-like factor (KLF) family proteins, and p53 pathway. The main aim of this study was to assess the prognostic values of immunohistochemical expression of Survivin, Klf5, Klf11, Shh, p53, p21, and Mdm2 in a cohort of high grade ovarian serous cancers. Other aims were comparison between high- and low-grade ovarian serous cancer and between platinum-resistant and the other cases. The last aim was to assess the correlations among the immunohistochemical expression of the studied proteins.

METHODS

Retrospective cohort study to assess immunohistochemical expression of Survivin, Klf5, Klf11, Shh, p53, p21, and Mdm2 in a tissue microarray of primary tumor samples among 73 women affected by high-grade ovarian serous cancer and 9 by low-grade ovarian serous cancer.

RESULTS

Klf5 and Shh cytoplasmic staining were associated to short overall survival (HR 6.38, CI.95 2.25 - 18.01, p<0.05 and 2.25, CI.95 1.19-4.23, p<0.05 respectively). In addition, cytoplasmic Klf5 staining, high Klf11 and p53 nuclear staining were associated with platinum resistance (p<0.05). Cytoplasmic Shh score was significantly correlated to the immunohistochemical expression of Klf5, Klf11, Mdm2, and Survivin.

CONCLUSIONS

Our data highlight the possible role of Klf5 and Shh as prognostic markers, meanwhile confirming the role of the KLF family proteins and p53 in ovarian cancer drug resistance. Moreover, Shh appeared to play an important role in the intracellular network of ovarian neoplasia.

The crosstalk between long non-coding RNAs and the hedgehog signaling pathway in cancer

Hedgehog (Hh) is a conserved signaling pathway that is involved in embryo development as well as adult tissue maintenance and repair in invertebrates and vertebrates. Abnormal activation of this pathway in various types of malignant drug- and apoptosis-resistant tumors has made it a therapeutic target against tumorigenesis. Thus, understanding the molecular mechanisms that promote the activation or inhibition of this pathway is critical. Long non-coding RNAs (lncRNAs), a subclass of non-coding RNAs with a length of > 200 nt, affect the expression of Hh signaling components via a variety of transcriptional and post-transcriptional processes. This review focuses on the crosstalk between lncRNAs and the Hh pathway in carcinogenesis, outlines the broad role of Hh-related lncRNAs in tumor progression, and illustrates their clinical diagnostic, prognostic, and therapeutic potential in tumors.

Extracellular Vesicles and Transforming Growth Factor β Signaling in Cancer

Complexity in mechanisms that drive cancer development and progression is exemplified by the transforming growth factor β (TGF-β) signaling pathway, which suppresses early-stage hyperplasia, yet assists aggressive tumors to achieve metastasis. Of note, several molecules, including mRNAs, non-coding RNAs, and proteins known to be associated with the TGF-β pathway have been reported as constituents in the cargo of extracellular vesicles (EVs). EVs are secreted vesicles delimited by a lipid bilayer and play critical functions in intercellular communication, including regulation of the tumor microenvironment and cancer development. Thus, this review aims at summarizing the impact of EVs on TGF-β signaling by focusing on mechanisms by which EV cargo can influence tumorigenesis, metastatic spread, immune evasion and response to anti-cancer treatment. Moreover, we emphasize the potential of TGF-β-related molecules present in circulating EVs as useful biomarkers of prognosis, diagnosis, and prediction of response to treatment in cancer patients.

Transforming Growth Factor-Beta-Regulated LncRNA-MUF Promotes Invasion by Modulating the miR-34a Snail1 Axis in Glioblastoma Multiforme

Transforming growth factor beta (TGF-β)-regulated long-non-coding RNAs (lncRNAs) modulate several aspects of tumor development such as proliferation, invasion, metastasis, epithelial to mesenchymal transition (EMT), and drug resistance in various cancers, including Glioblastoma multiforme (GBM). We identified several novel differentially expressed lncRNAs upon TGF-β treatment in glioma cells using genome-wide microarray screening. We show that TGF-β induces lncRNA-MUF in glioma cells, and its expression is significantly upregulated in glioma tissues and is associated with poor overall survival of GBM patients. Knockdown of lncRNA-MUF reduces proliferation, migration, and invasion in glioma cells and sensitizes them to temozolomide (TMZ)-induced apoptosis. In addition, lncRNA-MUF downregulation impairs TGF-β-induced smad2/3 phosphorylation. In line with its role in regulating invasion, lncRNA-MUF functions as a competing endogenous RNA (ceRNA) for miR-34a and promotes Snail1 expression. Collectively, our findings suggest lncRNA-MUF as an attractive therapeutic target for GBM.

Long Noncoding RNAs as Emerging Regulators of COVID-19

Coronavirus disease 2019 (COVID-19), which has high incidence rates with rapid rate of transmission, is a pandemic that spread across the world, resulting in more than 3,000,000 deaths globally. Currently, several drugs have been used for the clinical treatment of COVID-19, such as antivirals (radecivir, baritinib), monoclonal antibodies (tocilizumab), and glucocorticoids (dexamethasone). Accumulating evidence indicates that long noncoding RNAs (lncRNAs) are essential regulators of virus infections and antiviral immune responses including biological processes that are involved in the regulation of COVID-19 and subsequent disease states. Upon viral infections, cellular lncRNAs directly regulate viral genes and influence viral replication and pathology through virus-mediated changes in the host transcriptome. Additionally, several host lncRNAs could help the occurrence of viral immune escape by inhibiting type I interferons (IFN-1), while others could up-regulate IFN-1 production to play an antiviral role. Consequently, understanding the expression and function of lncRNAs during severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection will provide insights into the development of lncRNA-based methods. In this review, we summarized the current findings of lncRNAs in the regulation of the strong inflammatory response, immune dysfunction and thrombosis induced by SARS-CoV-2 infection, discussed the underlying mechanisms, and highlighted the therapeutic challenges of COVID-19 treatment and its future research directions.

A Robust Prognostic Gene Signature Based on eRNAs-Driven Genes in Prostate Cancer

Prostate cancer (PCa) is the second most common malignancy in men, but its exact pathogenetic mechanisms remain unclear. This study explores the effect of enhancer RNAs (eRNAs) in PCa. Firstly, we screened eRNAs and eRNA -driven genes from The Cancer Genome Atlas (TCGA) database, which are related to the disease-free survival (DFS) of PCa patients;. screening methods included bootstrapping, Kaplan-Meier (KM) survival analysis, and Pearson correlation analysis. Then, a risk score model was established using multivariate Cox analysis, and the results were validated in three independent cohorts. Finally, we explored the function of eRNA-driven genes through enrichment analysis and analyzed drug sensitivity on datasets from the Genomics of Drug Sensitivity in Cancer database. We constructed and validated a robust prognostic gene signature involving three eRNA-driven genes namely MAPK15, ZNF467, and MC1R. Moreover, we evaluated the function of eRNA-driven genes associated with tumor microenvironment (TME) and tumor mutational burden (TMB), and identified remarkable differences in drug sensitivity between high- and low-risk groups. This study identified a prognostic gene signature, which provides new insights into the role of eRNAs and eRNA-driven genes while assisting clinicians to determine the prognosis and appropriate treatment options for patients with PCa.

Molecular Pathogenesis of Pulmonary Fibrosis, with Focus on Pathways Related to TGF-β and the Ubiquitin-Proteasome Pathway

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal interstitial lung disease. During the past decade, novel pathogenic mechanisms of IPF have been elucidated that have shifted the concept of IPF from an inflammatory-driven to an epithelial-driven disease. Dysregulated repair responses induced by recurrent epithelial cell damage and excessive extracellular matrix accumulation result in pulmonary fibrosis. Although there is currently no curative therapy for IPF, two medications, pirfenidone and nintedanib, have been introduced based on understanding the pathogenesis of the disease. In this review, we discuss advances in understanding IPF pathogenesis, highlighting epithelial-mesenchymal transition (EMT), the ubiquitin-proteasome system, and endothelial cells. TGF-β is a central regulator involved in EMT and pulmonary fibrosis. HECT-, RING finger-, and U-box-type E3 ubiquitin ligases regulate TGF-β-Smad pathway-mediated EMT via the ubiquitin-proteasome pathway. p27 degradation mediated by the SCF-type E3 ligase, Skp2, contributes to the progression of pulmonary fibrosis by promotion of either mesenchymal fibroblast proliferation, EMT, or both. In addition to fibroblasts as key effector cells in myofibroblast differentiation and extracellular matrix deposition, endothelial cells also play a role in the processes of IPF. Endothelial cells can transform into myofibroblasts; therefore, endothelial-mesenchymal transition can be another source of myofibroblasts.

Long Non-Coding RNAs as Functional Codes for Oral Cancer: Translational Potential, Progress and Promises

Oral cancer is one of the leading malignant tumors worldwide. Despite the advent of multidisciplinary approaches, the overall prognosis of patients with oral cancer is poor, mainly due to late diagnosis. There is an urgent need to develop valid biomarkers for early detection and effective therapies. Long non-coding RNAs (lncRNAs) are recognized as key elements of gene regulation, with pivotal roles in various physiological and pathological processes, including cancer. Over the past few years, an exponentially growing number of lncRNAs have been identified and linked to tumorigenesis and prognosis outcomes in oral cancer, illustrating their emerging roles in oral cancer progression and the associated signaling pathways. Herein, we aim to summarize the most recent advances made concerning oral cancer-associated lncRNA, and their expression, involvement, and potential clinical impact, reported to date, with a specific focus on the lncRNA-mediated molecular regulation in oncogenic signaling cascades and oral malignant progression, while exploring their potential, and challenges, for clinical applications as biomarkers or therapeutic targets for oral cancer.

The noncoding MIR100HG RNA enhances the autocrine function of transforming growth factor β signaling

Activation of the transforming growth factor β (TGFβ) pathway modulates the expression of genes involved in cell growth arrest, motility, and embryogenesis. An expression screen for long noncoding RNAs indicated that TGFβ induced mir-100-let-7a-2-mir-125b-1 cluster host gene (MIR100HG) expression in diverse cancer types, thus confirming an earlier demonstration of TGFβ-mediated transcriptional induction of MIR100HG in pancreatic adenocarcinoma. MIR100HG depletion attenuated TGFβ signaling, expression of TGFβ-target genes, and TGFβ-mediated cell cycle arrest. Moreover, MIR100HG silencing inhibited both normal and cancer cell motility and enhanced the cytotoxicity of cytostatic drugs. MIR100HG overexpression had an inverse impact on TGFβ signaling responses. Screening for downstream effectors of MIR100HG identified the ligand TGFβ1. MIR100HG and TGFB1 mRNA formed ribonucleoprotein complexes with the RNA-binding protein HuR, promoting TGFβ1 cytokine secretion. In addition, TGFβ regulated let-7a-2-3p, miR-125b-5p, and miR-125b-1-3p expression, all encoded by MIR100HG intron-3. Certain intron-3 miRNAs may be involved in TGFβ/SMAD-mediated responses (let-7a-2-3p) and others (miR-100, miR-125b) in resistance to cytotoxic drugs mediated by MIR100HG. In support of a model whereby TGFβ induces MIR100HG, which then enhances TGFβ1 secretion, analysis of human carcinomas showed that MIR100HG expression correlated with expression of TGFB1 and its downstream extracellular target TGFBI. Thus, MIR100HG controls the magnitude of TGFβ signaling via TGFβ1 autoinduction and secretion in carcinomas.

LncRNA LINC01116 Contributes to Cisplatin Resistance in Lung Adenocarcinoma

Background

Long non-coding RNAs (lncRNAs) have been found to contribute to cisplatin resistance in several cancers; however, the role of lncRNA LINC01116 in cisplatin resistance remains unknown in non-small-cell lung cancer. This study aimed to examine the contribution of LINC01116 to cisplatin resistance in lung adenocarcinoma (LAD).

Materials and Methods

Cisplatin-resistant A549/DDP cells were generated by treatment with cisplatin by dose escalation. LINC01116 expression was compared between A549 and A549/DDP cells, and between cisplatin-resistant and non-resistant LAD specimens. The cell viability, colony formation, proliferation, migration and invasion were measured using MTT and Transwell assays, and cell apoptosis and cell cycle were detected using flow cytometry. The expression of E-cadherin and Vimentin was quantified. LAD xenografts were modeled in nude mice to investigate the role of LINC01116 on the resistance of LAD to cisplatin.

Results

MTT assay measured the IC₅₀ values of 13.49 ± 1.62 and 3.52 ± 1.33 μg/mL for A549/DDP and A549 cells, respectively. LINC01116 was overexpressed in cisplatin-resistant LAD specimens and A549/DDP cells (P < 0.05). Knockdown of LINC01116 inhibited cell viability, proliferation, migration and invasion, promoted apoptosis and enhanced the sensitivity to cisplatin in A549/DDP cells, while LINC01116 overexpression promoted cell viability, proliferation, migration and invasion, inhibited apoptosis and reduced the sensitivity to cisplatin in A549 cells. LINC01116 knockdown resulted in a 2.1-fold increase in E-cadherin expression and a 56% reduction in Vimentin expression in A549/DDP cells, and LINC01116 overexpression resulted in a 45% reduction in E-cadherin expression and a 1.82-fold increase in Vimentin expression in A549 cells.

Conclusion

Dysregulation of lncRNA LINC01116 expression results in resistance of LAD to cisplatin via the EMT process. Our findings support the oncogenic role of LINC01116 to promote the development of cisplatin resistance in LAD, and LINC01116 may be a novel predictor of poor response to cisplatin.

Long non-coding RNAs and TGF-β signaling in cancer

Cancer is driven by genetic mutations in oncogenes and tumor suppressor genes and by cellular events that develop a misregulated molecular microenvironment in the growing tumor tissue. The tumor microenvironment is guided by the excessive action of specific cytokines including transforming growth factor-β (TGF-β), which normally controls embryonic development and the homeostasis of young or adult tissues. As a consequence of the genetic alterations generating a given tumor, TGF-β can preserve its homeostatic function and attempt to limit neoplastic expansion, whereas, once the tumor has progressed to an aggressive stage, TGF-β can synergize with various oncogenic stimuli to facilitate tumor invasiveness and metastasis. TGF-β signaling mechanisms via Smad proteins, various ubiquitin ligases, and protein kinases are relatively well understood. Such mechanisms regulate the expression of genes encoding proteins or non-coding RNAs. Among non-coding RNAs, much has been understood regarding the regulation and function of microRNAs, whereas the role of long non-coding RNAs is still emerging. This article emphasizes TGF-β signaling mechanisms leading to the regulation of non-coding genes, the function of such non-coding RNAs as regulators of TGF-β signaling, and the contribution of these mechanisms in specific hallmarks of cancer.