Long noncoding RNA PCAT1, a novel serum-based biomarker, enhances cell growth by sponging miR-326 in oesophageal squamous cell carcinoma

The crosstalk between non-coding RNAs and cell-cycle events: A new frontier in cancer therapy

The cell cycle comprises sequential events during which a cell duplicates its genome and divides it into two daughter cells. This process is tightly regulated to ensure that the daughter cell receives identical copied chromosomal DNA and that any errors in the DNA during replication are correctly repaired. Cyclins and their enzyme partners, cyclin-dependent kinases (CDKs), are critical regulators of G- to M-phase transitions during the cell cycle. Mitogenic signals induce the formation of the cyclin/CDK complexes, resulting in phosphorylation and activation of the CDKs. Once activated, cyclin/CDK complexes phosphorylate specific substrates that drive the cell cycle forward. The sequential activation and inactivation of cyclin-CDK complexes are tightly controlled by activating and inactivating phosphorylation events induced by cell-cycle proteins. The non-coding RNAs (ncRNAs), which do not code for proteins, regulate cell-cycle proteins at the transcriptional and translational levels, thereby controlling their expression at different cell-cycle phases. Deregulation of ncRNAs can cause abnormal expression patterns of cell-cycle-regulating proteins, resulting in abnormalities in cell-cycle regulation and cancer development. This review explores how ncRNA dysregulation can disrupt cell division balance and discusses potential therapeutic approaches targeting these ncRNAs to control cell-cycle events in cancer treatment.

PVT1 promotes proliferation and macrophage immunosuppressive polarization through STAT1 and CX3CL1 regulation in glioblastoma multiforme

AIMS

This study aimed to investigate the role of plasmacytoma variant translocation 1 (PVT1), a long non-coding RNA, in glioblastoma multiforme (GBM) and its impact on the tumor microenvironment (TME).

METHODS

We assessed aberrant PVT1 expression in glioma tissues and its impact on GBM cell growth in vitro and in vivo. Additionally, we investigated PVT1's role in influencing glioma-associated macrophages. To understand PVT1's role in cell growth and the immunosuppressive TME, we performed a series of comprehensive experiments.

RESULTS

PVT1 was overexpressed in GBM due to copy number amplification, correlating with poor prognosis. Elevated PVT1 promoted GBM cell proliferation, while its downregulation inhibited growth in vitro and in vivo. PVT1 inhibited type I interferon-stimulated genes (ISGs), with STAT1 as the central hub. PVT1 correlated with macrophage enrichment and regulated CX3CL1 expression, promoting recruitment and M2 phenotype polarization of macrophages. PVT1 localized to the cell nucleus and bound to DHX9, enriching at the promoter regions of STAT1 and CX3CL1, modulating ISGs and CX3CL1 expression.

CONCLUSION

PVT1 plays a significant role in GBM, correlating with poor prognosis, promoting cell growth, and shaping an immunosuppressive TME via STAT1 and CX3CL1 regulation. Targeting PVT1 may hold therapeutic promise for GBM patients.

Small extracellular vesicles - A host for advanced bioengineering and "Trojan Horse" of non-coding RNAs

Small extracellular vesicles (sEVs) are a type of membranous vesicles that can be released by cells into the extracellular space. The relationship between sEVs and non-coding RNAs (ncRNAs) is highly intricate and interdependent. This symbiotic relationship plays a pivotal role in facilitating intercellular communication and holds profound implications for a myriad of biological processes. The concept of sEVs and their ncRNA cargo as a "Trojan Horse" highlights their remarkable capacity to traverse biological barriers and surreptitiously deliver their cargo to target cells, evading detection by the host-immune system. Accumulating evidence suggests that sEVs may be harnessed as carriers to ferry therapeutic ncRNAs capable of selectively silencing disease-driving genes, particularly in conditions such as cancer. This approach presents several advantages over conventional drug delivery methods, opening up new possibilities for targeted therapy and improved treatment outcomes. However, the utilization of sEVs and ncRNAs as therapeutic agents raises valid concerns regarding the possibility of unforeseen consequences and unintended impacts that may emerge from their application. It is important to consider the fundamental attributes of sEVs and ncRNAs, including by an in-depth analysis of the practical and clinical potentials of exosomes, serving as a representative model for sEVs encapsulating ncRNAs.

Exosome-mediated metabolic reprogramming: Implications in esophageal carcinoma progression and tumor microenvironment remodeling

Esophageal carcinoma is among the most fatal malignancies with increasing incidence globally. Tumor onset and progression can be driven by metabolic reprogramming, especially during esophageal carcinoma development. Exosomes, a subset of extracellular vesicles, display an average size of ∼100 nanometers, containing multifarious components (nucleic acids, proteins, lipids, etc.). An increasing number of studies have shown that exosomes are capable of transferring molecules with biological functions into recipient cells, which play crucial roles in esophageal carcinoma progression and tumor microenvironment that is a highly heterogeneous ecosystem through rewriting the metabolic processes in tumor cells and environmental stromal cells. The review introduces the reprogramming of glucose, lipid, amino acid, mitochondrial metabolism in esophageal carcinoma, and summarize current pharmaceutical agents targeting such aberrant metabolism rewiring. We also comprehensively overview the biogenesis and release of exosomes, and recent advances of exosomal cargoes and functions in esophageal carcinoma and their promising clinical application. Moreover, we discuss how exosomes trigger tumor growth, metastasis, drug resistance, and immunosuppression as well as tumor microenvironment remodeling through focusing on their capacity to transfer materials between cells or between cells and tissues and modulate metabolic reprogramming, thus providing a theoretical reference for the design potential pharmaceutical agents targeting these mechanisms. Altogether, our review attempts to fully understand the significance of exosome-based metabolic rewriting in esophageal carcinoma progression and remodeling of the tumor microenvironment, bringing novel insights into the prevention and treatment of esophageal carcinoma in the future.

MiR-3653 blocks autophagy to inhibit epithelial-mesenchymal transition in breast cancer cells by targeting the autophagy-regulatory genes ATG12 and AMBRA1

BACKGROUND

Metastasis is the main cause of tumor-associated death and mainly responsible for treatment failure of breast cancer. Autophagy accelerates tumor metastasis. In our work, we aimed to investigate the possibility of microRNAs (miRNAs) which participate in the regulation of autophagy to inhibit tumor metastasis.

METHODS

MiRNA array and comprehensive analysis were performed to identify miRNAs which participated in the regulation of autophagy to inhibit tumor metastasis. The expression levels of miR-3653 in breast cancer tissues and cells were detected by quantitative real-time polymerase chain reaction. In vivo and in vitro assays were conducted to determine the function of miR-3653. The target genes of miR-3653 were detected by a dual luciferase reporter activity assay and Western blot. The relationship between miR-3653 and epithelial-mesenchymal transition (EMT) was assessed by Western blot. Student's t -test was used to analyze the difference between any two groups, and the difference among multiple groups was analyzed with one-way analysis of variance and a Bonferroni post hoc test.

RESULTS

miR-3653 was downregulated in breast cancer cells with high metastatic ability, and high expression of miR-3653 blocked autophagic flux in breast cancer cells. Clinically, low expression of miR-3653 in breast cancer tissues (0.054 ± 0.013 vs . 0.131 ± 0.028, t  = 2.475, P  = 0.014) was positively correlated with lymph node metastasis (0.015 ± 0.004 vs . 0.078 ± 0.020, t  = 2.319, P  = 0.023) and poor prognosis ( P  < 0.001). miR-3653 ameliorated the malignant phenotypes of breast cancer cells, including proliferation, migration (MDA-MB-231: 0.353 ± 0.013 vs . 1.000 ± 0.038, t  = 16.290, P  < 0.001; MDA-MB-468: 0.200 ± 0.014 vs . 1.000 ± 0.043, t  = 17.530, P  < 0.001), invasion (MDA-MB-231: 0.723 ± 0.056 vs . 1.000 ± 0.035, t  = 4.223, P  = 0.013; MDA-MB-468: 0.222 ± 0.016 vs . 1.000 ± 0.019, t  = 31.050, P  < 0.001), and colony formation (MDA-MB-231: 0.472 ± 0.022 vs . 1.000 ± 0.022, t  = 16.620, P  < 0.001; MDA-MB-468: 0.650 ± 0.040 vs . 1.000 ± 0.098, t  = 3.297, P  = 0.030). The autophagy-associated genes autophagy-related gene 12 ( ATG12 ) and activating molecule in beclin 1-regulated autophagy protein 1 ( AMBRA1 ) are target genes of miR-3653. Further studies showed that miR-3653 inhibited EMT by targeting ATG12 and AMBRA1 .

CONCLUSIONS

Our findings suggested that miR-3653 inhibits the autophagy process by targeting ATG12 and AMBRA1 , thereby inhibiting EMT, and provided a new idea and target for the metastasis of breast cancer.

Role of exosomal noncoding RNA in esophageal carcinoma

Esophageal cancer is a common malignant tumor with a high degree of malignancy. Understanding its pathogenesis and identifying early diagnostic biomarkers can significantly improve the prognosis of esophageal cancer patients. Exosomes are small double-membrane vesicles found in various body fluids containing various components (DNA, RNA, and proteins) that mediate intercellular signal communication. Non-coding RNAs are a class of gene transcription products that encode polypeptide functions and are widely detected in exosomes. There is growing evidence that exosomal non-coding RNAs are involved in cancer growth, metastasis and angiogenesis, and can also be used as diagnostic and prognostic markers. This article reviews the recent progress in exosomal non-coding RNAs in esophageal cancer, including research progress, diagnostic value, proliferation, migration, invasion, and drug resistance, provide new ideas for the precise treatment of esophageal cancer.

Identification and detection of plasma extracellular vesicles-derived biomarkers for esophageal squamous cell carcinoma diagnosis

Esophageal cancer is a malignant tumor with two-thirds of patients having a local recurrence or distant metastasis. To date, diagnostic biomarkers with high sensitivity and specificity are lacking. Extracellular vesicles (EVs) have shown their potential values as disease biomarkers as they carry specific proteins and RNAs derived from cancer cells. In this study, we investigate ESCC precision diagnostics from the insights of circulating EVs, and integrate the ultrafast EV isolation approach (EXODUS) and ELISA for fast detection and screening of ESCC patients. First, we isolate and characterize the high-purity plasma EVs with EXODUS and identify 401 proteins and 372 proteins from ESCC patient and healthy individuals, respectively. Further looking into the differentially expressed proteins (DEPs) of ESCC patients and enriched KEGG pathways, we discover EV-CD14 as a potential diagnostic biomarker for ESCC, which has been further validated as a significantly differentially expressed protein by Western Blot and immunogold labelling TEM. For fast screening and detection of ESCC towards clinical applications, we apply ELISA method to diagnose ESCC from 60 clinical samples based on circulating EV-CD14, which shows a high AUC value up to 96.0% for detection of ESCC in a test set (30 samples), and displays a high accuracy rate up to 90% for prediction of ESCC in a screening test (30 samples). Our results suggest that the circulating EV-CD14 may highly be related to the initiation and progression of ESCC, providing a novel method for the diagnosis and prognosis of ESCC towards clinical translations.

Exosomal LINC00355 promotes the malignant progression of gastric cancer through histone deacetylase HDAC3-mediated TP53INP1 transcriptional inhibition

AIMS

Exosomes are a subpopulation of extracellular vesicles (EV) derived from multivesicular body (MVB) that transmit various cellular molecular constituents, including long noncoding RNAs (lncRNAs), to promote intercellular communication. Our aim was to investigate the function and mechanism of exosomal LINC00355 in gastric cancer cells.

MAIN METHODS

Exosomal levels of LINC00355 in GC patients and healthy controls were measured by RT-qPCR. The effects of exosomal LINC00355 on GC cell viability, proliferation, migration and invasion were evaluated by CCK8, colony formation, Transwell and wound healing assays. The expression levels of Ki67 in xenograft tumor tissues were confirmed by immunohistochemistry assay, and apoptosis was analyzed by TUNEL apoptosis assay. Western blotting was used to monitor protein expression. RNA immunoprecipitation and RNA pulldown were performed to detect the interaction between LINC00355 and HDAC3. Chromatin immunoprecipitation was used to assess the interaction of HDAC3 with the TP53INP1 promoter.

KEY FINDINGS

Exosomal LINC00355 levels were higher in plasma from gastric cancer patients than in plasma from healthy volunteers. Exosomal LINC00355 promoted the proliferation, migration and invasion of gastric cancer cell lines. RNA sequence analysis demonstrated that LINC00355 knockdown downregulated histone deacetylase HDAC3 and upregulated TP53INP1. Mechanistic investigation indicated that exosomal LINC00355 interacted with HDAC3 to suppress TP53INP1 transcription, which promoted epithelial-mesenchymal transition (EMT).

SIGNIFICANCE

Exosomal LINC00355 plays a pivotal role in regulating EMT to induce the malignant progression of GC. Exosomal LINC00355 could be a promising biomarker in the early diagnosis and prognosis of GC.

Mechanisms of function and clinical potential of exosomes in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) remains one of the most lethal and widespread malignancies in China. Exosomes, a subset of tiny extracellular vesicles manufactured by all cells and present in all body fluids, contribute to intercellular communication and have become a focus of the search for new therapeutic strategies for cancer. A number of global analyses of exosome-mediated functions and regulatory mechanism in malignant diseases have recently been reported. There is extensive evidence that exosomes can be used as diagnostic and prognostic markers for cancer. However, our understanding of their clinical value and mechanisms of action in ESCC is still limited and has not been systematically reviewed. Here, we review current research specifically focused on the functions and mechanisms of action of ESCC tumor-derived exosomes and non-ESCC-derived exosomes in ESCC progression and describe opportunities and challenges in the clinical translation of exosomes.

Exosomal long non-coding RNAs: novel molecules in gastrointestinal cancers' progression and diagnosis

Gastrointestinal (GI) cancers arise in the GI tract and accessory organs, including the mouth, esophagus, stomach, liver, biliary tract, pancreas, small intestine, large intestine, and rectum. GI cancers are a major cause of cancer-related morbidity and mortality worldwide. Exosomes act as mediators of cell-to-cell communication, with pleiotropic activity in the regulation of homeostasis, and can be markers for diseases. Non-coding RNAs (ncRNAs), such as long non-coding RNAs (lncRNAs), can be transported by exosomes derived from tumor cells or non-tumor cells. They can be taken by recipient cells to alter their function or remodel the tumor microenvironment. Moreover, due to their uniquely low immunogenicity and excellent stability, exosomes can be used as natural carriers for therapeutic ncRNAs in vivo. Exosomal lncRNAs have a crucial role in regulating several cancer processes, including angiogenesis, proliferation, drug resistance, metastasis, and immunomodulation. Exosomal lncRNA levels frequently alter according to the onset and progression of cancer. Exosomal lncRNAs can therefore be employed as biomarkers for the diagnosis and prognosis of cancer. Exosomal lncRNAs can also monitor the patient's response to chemotherapy while also serving as potential targets for cancer treatment. Here, we discuss the role of exosomal lncRNAs in the biology and possible future treatment of GI cancer.

Antisense lncRNA NNT-AS1 promoted esophageal squamous cell carcinoma progression by regulating its sense gene NNT expression

Antisense lncRNAs were endogenous productions from the antisense strand of coding genes and were transcribed in the reverse direction of the sense gene. The purpose of this study was to evaluate the roles and functions of antisense lncRNAs in esophageal squamous cell carcinoma (ESCC). Differentially expressed antisense lncRNAs were initially screened based on transcriptome data of 119 paired ESCC samples in GSE53624 and were further validated in 6 paired ESCC samples from our institution. Log-rank test was adopted to identify ESCC prognosis-associated lncRNAs. Finally, functional assays were performed to reveal the functions of our identified antisense lncRNAs. In total, 174 antisense lncRNAs were differentially expressed in both GSE53624 and JSPH databases. Five of them were significantly associated with ESCC prognosis (NNT-AS1, NKILA, CCDC18-AS1, SLCO4A1-AS1, and AC110619.1). Of note, NNT-AS1 showed the most significant association with ESCC prognosis. The upregulation of NNT-AS1 was further confirmed in ESCC cells. Knockdown of NNT-AS1 inhibited ESCC cell proliferation, migration, promoted ESCC cells apoptosis, and induced cell cycle arrest in the G2/M stage. NNT-AS1 expression significantly correlated with its sense gene NNT. As expected, NNT-AS1 knockdown suppressed NNT expression. Inhibition of NNT repressed ESCC cell proliferation and migration, and accelerated ESCC cell apoptosis. Overexpression of NNT could rescue the suppressed proliferation and migration of ESCC cells induced by the silencing of NNT-AS1. In terms of mechanism, NNT-AS1 served as a competing endogenous RNA to sponge the miR-382-5p, which could inhibit NNT expression. Pathway enrichment analysis and western blot assay indicated that NNT-AS1 and NNT could regulate the cell cycle pathway. In conclusion, antisense lncRNA NNT-AS1 facilitated ECSS progression by targeting its sense gene NNT through sponging miR-382-5p. This study provided us with a deeper insight into the roles of antisense lncRNAs in ESCC and identified novel potential therapeutic targets.

CKAP2L, a crucial target of miR-326, promotes prostate cancer progression

Background

The overexpression of aberrant cell cycle signaling pathway associated protein has been implicated in multiple malignancies and the identification of all-important one among is the crux of the precise targeted therapy. CKAP2L (Cytoskeleton Associated Protein 2 Like) plays a newish role in cancer progression through activation of the process of cell cycle and mitosis. In this study, we aim to delineate the prominent dysregulated expression of CKAP2L and comprehensively reveal its deregulation in prostate cancer. 

Method

CKAP2L expression was examined in the normal and tumor tissues of prostate cancer patients with RT-QPCR and Western blot. IHC showed the different expression in normal prostate tissue, tissue of BPH, low Gleason Score and high Gleason Score prostate cancer patients. Transwell, colony formation, MTT and flow cytometry were performed to detected the changes in cellular function in vitro. The xenograft model was conducted for the changes in vivo. Dual luciferase and RIP proved the binding relation between CKAP2L and miR-326.

Results

In multiple datasets, CKAP2L was found upregulated and positively associated with Gleason grade and poor clinical outcomes of patients. shRNA mediated silence of CKAP2L suppressed cell proliferation, impaired monolayer formation, inhibited cell invasion. CKAP2L was confirmed to be the direct target of miR-326, which had a carcinostatic effect by binding the 3’untranslated regions (3’UTRs) of CKAP2L mRNA. The deletion of CKAP2L resulted in reduced expression of genes involved in the mitotic cell cycle such as multiple cyclin-dependent kinases and cyclins, but also several genes encoding proteins involved in chromosome segregation and spindle assembly.

Conclusion

Taken together, CKAP2L plays a carcinogenic role in prostate cancer by regulates the expression of cycle-associated proteins.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09762-3.

Long Non-Coding RNAs as Molecular Biomarkers in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a biliary system cancer that has the characteristics of strong invasiveness, poor prognosis, and few therapy choices. Furthermore, the absence of precise biomarkers for early identification and prognosis makes it hard to intervene in the early phase of initial diagnosis or recurring cholangiocarcinoma following surgery. Encouragingly, previous studies found that long non-coding RNA (lncRNA), a subgroup of RNA that is more than 200 nucleotides long, can affect cell proliferation, migration, apoptosis, and even drug resistance by altering numerous signaling pathways, thus reaching pro-cancer or anti-cancer outcomes. This review will take a retrospective view of the recent investigations on the work of lncRNAs in cholangiocarcinoma progression and the potential of lncRNAs serving as promising clinical biomarkers and therapeutic targets for CCA.

Noncoding RNAs and their therapeutics in paclitaxel chemotherapy: Mechanisms of initiation, progression, and drug sensitivity

The identification of agents that can reverse drug resistance in cancer chemotherapy, and enhance the overall efficacy is of great interest. Paclitaxel (PTX) belongs to taxane family that exerts an antitumor effect by stabilizing microtubules and inhibiting cell cycle progression. However, PTX resistance often develops in tumors due to the overexpression of drug transporters and tumor-promoting pathways. Noncoding RNAs (ncRNAs) are modulators of many processes in cancer cells, such as apoptosis, migration, differentiation, and angiogenesis. In the present study, we summarize the effects of ncRNAs on PTX chemotherapy. MicroRNAs (miRNAs) can have opposite effects on PTX resistance (stimulation or inhibition) via influencing YES1, SK2, MRP1, and STAT3. Moreover, miRNAs modulate the growth and migration rates of tumor cells in regulating PTX efficacy. PIWI-interacting RNAs, small interfering RNAs, and short-hairpin RNAs are other members of ncRNAs regulating PTX sensitivity of cancer cells. Long noncoding RNAs (LncRNAs) are similar to miRNAs and can modulate PTX resistance/sensitivity by their influence on miRNAs and drug efflux transport. The cytotoxicity of PTX against tumor cells can also be affected by circular RNAs (circRNAs) and limitation is that oncogenic circRNAs have been emphasized and experiments should also focus on onco-suppressor circRNAs.

TFAP2C-Mediated lncRNA PCAT1 Inhibits Ferroptosis in Docetaxel-Resistant Prostate Cancer Through c-Myc/miR-25-3p/SLC7A11 Signaling

Recent evidence has shown that the induction of ferroptosis is a new therapeutic strategy for advanced prostate cancer (PCa) when used as a monotherapy or in combination with second-generation antiandrogens. However, whether ferroptosis inducers are effective against docetaxel-resistant PCa remains unclear. In addition, the biological role and intrinsic regulatory mechanisms of long noncoding RNAs (lncRNAs) in ferroptosis and chemoresistance are not well understood. In this study, we established two acquired docetaxel-resistant PCa cell lines and found that docetaxel-resistant PCa cells developed tolerance toward ferroptosis. In addition, dysregulated lncRNAs in drug-resistant and -sensitive PCa cells were identified by RNA sequencing, and we identified that prostate cancer-associated transcript 1 (PCAT1) was highly expressed in the docetaxel-resistant PCa cell lines and clinical samples. Overexpression of PCAT1 inhibited ferroptosis and increased docetaxel resistance, which could be attenuated by PCAT1 knockdown. Furthermore, we revealed that PCAT1 inhibited ferroptosis by activating solute carrier family 7-member 11 (SLC7A11) expression via reducing iron accumulation and subsequent oxidative damage. Mechanistically, we demonstrated that PCAT1 interacted with c-Myc and increased its protein stability using nucleotides 1093-1367 of PCAT1 and 151-202 amino acids of c-Myc protein, thereby transcriptionally promoting SLC7A11 expression. In addition, PCAT1 facilitated SLC7A11 expression by competing for microRNA-25-3p. Finally, transcription factor AP-2 gamma (TFAP2C) activated PCAT1 expression at the transcriptional level to reduce ferroptosis susceptibility and enhance chemoresistance. Collectively, our findings demonstrated that TFAP2C-induced PCAT1 promotes chemoresistance by blocking ferroptotic cell death through c-Myc/miR-25-3p/SLC7A11 signaling.

Long Non-Coding RNA in Esophageal Cancer: A Review of Research Progress

In recent years, there has been significant progress in the diagnosis and treatment of esophageal cancer. However, owing to the lack of early diagnosis strategies and treatment targets, the prognosis of patients with esophageal cancer remains unsatisfactory. There is an urgent need to identify novel biomarkers and treatment targets for esophageal cancer. With the development of genomics, long-chain non-coding RNAs (LncRNAs), which were once considered transcriptional “noise,” are being identified and characterized rapidly in large numbers. Recent research shows that LncRNAs are closely related to a series of steps in tumor development and play an important regulatory role in DNA replication, transcription, and post-transcriptional regulation. The abnormal expression of LncRNAs leads to tumor cell proliferation, migration, invasion, and treatment resistance. This review focuses on the latest progress in research on the abnormal expression and functional mechanisms of LncRNAs in esophageal cancer. Further, it discusses the potential applications of these findings towards achieving an early diagnosis, improving treatment efficacy, and evaluating the prognosis of esophageal cancer.

Oncogenic lncRNAs alter epigenetic memory at a fragile chromosomal site in human cancer cells

Chromosome instability is a critical event in cancer progression. Histone H3 variant CENP-A plays a fundamental role in defining centromere identity, structure, and function but is innately overexpressed in several types of solid cancers. In the cancer background, excess CENP-A is deposited ectopically on chromosome arms, including 8q24/cMYC locus, by invading transcription-coupled H3.3 chaperone pathways. Up-regulation of lncRNAs in many cancers correlates with poor prognosis and recurrence in patients. We report that transcription of 8q24-derived oncogenic lncRNAs plays an unanticipated role in altering the 8q24 chromatin landscape by H3.3 chaperone-mediated deposition of CENP-A-associated complexes. Furthermore, a transgene cassette carrying specific 8q24-derived lncRNA integrated into a naïve chromosome locus recruits CENP-A to the new location in a cis-acting manner. These data provide a plausible mechanistic link between locus-specific oncogenic lncRNAs, aberrant local chromatin structure, and the generation of new epigenetic memory at a fragile site in human cancer cells.

Long non‑coding RNA PCAT1 sponges miR‑134‑3p to regulate PITX2 expression in breast cancer

Breast cancer (BC) is the most prevalent cancer among women. Long non‑coding (lnc)RNAs and microRNAs (miRs) both regulate the expression of key genes in tumorigenesis. The present study aimed to explore the molecular mechanism of the prostate cancer‑associated transcript 1 (PCAT1)/miR‑134‑3p/pituitary homeobox 2 (PITX2) in BC. Reverse transcription‑quantitative PCR was performed to examine the expression of miR‑134‑3p. Cell proliferation, viability, cell cycle, apoptosis and migration were analyzed using Cell Counting Kit‑8, colony formation, flow cytometry, wound healing and Transwell assays. Protein expression levels were determined by western blotting. The present study demonstrated that PCAT1 was significantly highly expressed in BC cells. Knockdown of PCAT1 significantly inhibited cell proliferation, migration and invasion, but promoted apoptosis in human BC cell lines. The results of the dual‑luciferase assay showed that PCAT1 targeted miR‑134‑3p, and PITX2 was a potential target of miR‑134‑3p. Western blotting results demonstrated that PCAT1 knockdown significantly reduced the protein expression levels of anti‑apoptotic protein Bcl‑2, and significantly upregulated the protein expression levels of proapoptotic proteins, Bax, cleaved caspase‑3 and cleaved caspase‑9. Furthermore, the effect of a miR‑134‑3p inhibitor on BC progression was rescued by the knockdown of PITX2 in cells transfected with short hairpin RNA‑lncRNA PCAT1. To conclude, the results of the present study indicated that the PCAT1/miR‑134‑3p/PITX2 axis could be a promising therapeutic target in BC treatment.

hsa_circ_0139402 Promotes Bladder Cancer Progression by Regulating hsa-miR-326/PAX8 Signaling

Background

Bladder cancer (BC) is a malignant and common malignant tumors. However, the prognosis of most patients with bladder cancer is still poor, and it is particularly important to identify early tumor diagnostic and treatment targets.

Materials and Methods

High-throughput sequencing was used to evaluate the expression level of circRNA in bladder cancer tissue. MTT assay, wound healing assay, and transwell assay were used to detect the cancer cells' proliferation, migration, and invasion affected by hsa_circ_0139402. The possible miRNA targets of hsa_circ_0139402 and downstream genes were detected by bioinformatics methods and dual-luciferase reporting experiment. FISH was used to observe their interaction.

Results

High-throughput sequencing result showed that the expression of hsa_circ_0139402 was highest in BC tissues and increased in metastatic tissues compared to that of nonmetastatic tissues. MTT assay, wound healing assay, and transwell assay revealed that sh-hsa_circ_0139402 could suppress BC cells' proliferation, invasion, and migration. Bioinformatics analysis, dual-luciferase reporter, and RIP assay showed that hsa_circ_0139402 can bind to hsa-miR-326, and PAX8 is a direct target of hsa-miR-326 in BC cell. Further, cytological studies found that hsa_circ_0139402 enhances BC cells' proliferation, migration, and invasion by targeting PAX8 via hsa-miR-326.

Conclusion

hsa_circ_0139402 plays a oncogene in BC and that can effectively promote cell proliferation, migration, invasion, and EMT by targeting Paired Box Protein Pax-8 (PAX8) via hsa-miR-326 and provides a potential therapeutic target for BC patients.

Oncogenic Role of Exosomal Circular and Long Noncoding RNAs in Gastrointestinal Cancers

Circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) are differentially expressed in gastrointestinal cancers. These noncoding RNAs (ncRNAs) regulate a variety of cellular activities by physically interacting with microRNAs and proteins and altering their activity. It has also been suggested that exosomes encapsulate circRNAs and lncRNAs in cancer cells. Exosomes are then discharged into the extracellular environment, where they are taken up by other cells. As a result, exosomal ncRNA cargo is critical for cell-cell communication within the cancer microenvironment. Exosomal ncRNAs can regulate a range of events, such as angiogenesis, metastasis, immune evasion, drug resistance, and epithelial-to-mesenchymal transition. To set the groundwork for developing novel therapeutic strategies against gastrointestinal malignancies, a thorough understanding of circRNAs and lncRNAs is required. In this review, we discuss the function and intrinsic features of oncogenic circRNAs and lncRNAs that are enriched within exosomes.

LncRNA NR038975, A Serum-Based Biomarker, Promotes Gastric Tumorigenesis by Interacting With NF90/NF45 Complex

Gastric cancer (GC) is one of the deadliest cancers, and long noncoding RNAs (lncRNAs) have been reported to be the important regulators during the occurrence and development of GC. The present study identified a novel and functional lncRNA in GC, named NR038975, which was confirmed to be markedly upregulated in the Gene Expression Profiling Interactive Analysis (GEPIA) dataset and our independent cohort of GC tissues. We firstly characterized the full-length sequence and subcellular location of NR038975 in GC cells. Our data demonstrated that upregulated NR038975 expression was significantly related to lymph node metastasis and TNM stage. In addition, knockdown of NR038975 inhibited GC cell proliferation, migration, invasion, and clonogenicity and vice versa. Mechanistically, RNA pull-down and mass spectrometry assays identified the NR038975-binding proteins and NF90/NF45 complex, and the binding was also confirmed by RNA immunoprecipitation and confocal experiments. We further demonstrated that genetic deficiency of NR038975 abrogated the interaction between NF45 and NF90. Moreover, NF90 increased the stability of NR038975. Thus, NR038975-NF90/NF45 will be an important combinational target of GC. Finally, we detected NR038975 in serum exosomes and serum of GC patients. Our results indicated that NR038975 was a biomarker for gastric tumorigenesis. The current study demonstrated that NR038975 is a novel lncRNA that is clinically and functionally engaged in GC progression and might be a novel diagnostic marker and potential therapeutic target.

The Emerging Role of Exosomes in Cancer Chemoresistance

Chemoresistance is an impending challenge in cancer treatment. In recent years, exosomes, a subtype of extracellular vesicles with a diameter of 40-150 nm in bloodstream and other bio-fluids, have attracted increasing interest. Exosomes contain proteins, nucleic acids, and lipids, which act as important signaling molecules. Many reports indicate that exosomes play critical roles in chemoresistance through intercellular interactions, including drug removal from cells, transfer of drug resistance phenotypes to other cancer cells, and the increase in plastic stem cell subsets. Exosomes can reflect the physiological and pathological state of parent cells. Owing to their elevated stability, specificity, and sensitivity, exosomes are served as biomarkers in liquid biopsies to monitor cancer chemoresistance, progression, and recurrence. This review summarizes the exosome-mediated mechanisms of cancer chemoresistance, as well as its role in reversing and monitoring chemoresistance. The scientific and technological challenges and future applications of exosomes are also explored.

Baseline lncRNA PCAT1 high expression and its longitude increment during induction therapy predict worse prognosis in multiple myeloma patients

BACKGROUND

Long noncoding RNA PCAT1 (lnc-PCAT1) involves in the proliferation and drug sensitivity of multiple myeloma (MM), while its prognostic role in MM patients is still obscure. This study aimed to explore the association of lnc-PCAT1 with MM risk, clinical characteristics, treatment response, progression-free survival (PFS), and overall survival (OS).

METHODS

A total of 83 symptomatic MM patients were enrolled in this study. Additionally, 30 healthy bone marrow donors as health controls were also recruited. Bone marrow plasma cell samples of MM patients and health donors were collected. Lnc-PCAT1 in bone marrow plasma cells was detected by reverse transcription-quantitative polymerase chain reaction.

RESULTS

Lnc-PCAT1 was increased in MM patients than in health donors (p < 0.001), and receiver operating characteristic (ROC) curve showed that lnc-PCAT1 had excellent capability of discriminating MM patients from health donors (area under curve: 0.932, 95% confidence interval: 0.889-0.976). In MM patients, lnc-PCAT1 was correlated with bone lesion (p = 0.024), higher β2 -MG (p = 0.005), LDH (p = 0.037), and presence of Del (17p) (p = 0.029). Lnc-PCAT1 was also associated with poor ISS stage (p = 0.013) and R-ISS stage (p = 0.005). Besides, lnc-PCAT1 was reduced after treatment (p < 0.001); meanwhile, lnc-PCAT1 before treatment was correlated with lower CR (p = 0.046) but not ORR (p = 0.185). Additionally, lnc-PCAT1 after treatment was associated with lower CR (p = 0.003) and ORR (p = 0.010). Furthermore, baseline Inc-PCAT1 high and Inc-PCAT1 increase after treatment were correlated with worse PFS and OS (all p < 0.05).

CONCLUSION

Lnc-PCAT1 dysregulation serves as a biomarker for diagnosis and prognosis for MM.

Metabolomic analysis of exosomal-markers in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a worldwide malignancy with high mortality rates and poor prognosis due to the lack of effective biomarkers for early detection. Exosomes have been extensively explored as attractive biomarkers for cancer diagnosis and treatment. However, little is known about exosome metabolomics and their roles in ESCC. Here, we performed a targeted metabolomic analysis of plasma exosomes and identified 196 metabolites, mainly including lipid fatty acids, benzene, amino acids, organic acids, carbohydrates and fatty acyls. We systematically compared metabolome patterns of exosomes via machine learning from patients with recrudescence and patients without recrudescence and demonstrated a marker set consisting of 3'-UMP, palmitoleic acid, palmitaldehyde, and isobutyl decanoate for predicting ESCC recurrence with an AUC of 98%. These metabolome signatures of exosomes retained a high absolute fold change value at all ESCC stages and were very likely associated with cancer metabolism, which could be potentially applied as novel biomarkers for diagnosis and prognosis of ESCC.

The Significance of Exosomes in Pathogenesis, Diagnosis, and Treatment of Esophageal Cancer

Esophageal cancer is one of the most common malignancy in China with high mortality. Understanding pathogenesis and identifying early diagnosis biomarkers can significantly improve the prognosis of patients with esophageal cancer. Exosomes are small vesicular structures containing a variety of components (including DNA, RNA, and proteins) mediating cell-to-cell material exchange and signal communication. Growing evidences have shown that exosomes and its components are involved in growth, metastasis and angiogenesis in cancer, and could also be used as diagnostic and prognostic markers. In this review, we summarized recent progress to elucidate the significance of exosomes in the esophageal cancer progression, microenvironment remodeling, therapeutic resistance, and immunosuppression. We also discuss the utility of exosomes as diagnostic and prognostic biomarkers and therapeutic tool in esophageal cancer.

TMEM161B-AS1 suppresses proliferation, invasion and glycolysis by targeting miR-23a-3p/HIF1AN signal axis in oesophageal squamous cell carcinoma

Mounting data have shown that long non-coding RNAs (lncRNAs) widely participate in tumour initiation, development, progression and glycolysis in a variety of tumours. However, the clinical prognosis and molecular mechanisms of TMEM161B-AS1 in oesophageal squamous cell carcinoma (ESCC) remain still unknown. Here, TMEM161B-AS1 and HIF1AN were significantly lower in ESCC tissues than in normal samples, and their low expressions were both related to TNM stage, lymph node metastasis and poor prognosis of ESCC patients. Functionally, TMEM161B-AS1 overexpression or miR-23a-3p depletion suppressed the proliferation, invasion and glycolysis as well as reduced glucose consumption and lactate production in ESCC cells. Mechanistically, TMEM161B-AS1 manipulated HIF1AN expression by competitively sponging miR-23a-3p in ESCC cells. MiR-23a-3p mimic and HIF1AN siRNA partly reversed cell phenotypes mediated by TMEM161B-AS1 in ESCC cells. Collectively, TMEM161B-AS1, miR-23a-3p and HIF1AN may be tightly involved in ESCC development and progression as well as patients' prognosis, and TMEM161B-AS1/miR-23a-3p/HIF1AN signal axis may be a promising target for the treatment of ESCC patients.

Clinical Implications of Exosomes: Targeted Drug Delivery for Cancer Treatment

Exosomes are nanoscale vesicles generated by cells for intercellular communication. Due to their composition, significant research has been conducted to transform these particles into specific delivery systems for various disease states. In this review, we discuss the common isolation and loading methods of exosomes, some of the major roles of exosomes in the tumor microenvironment, as well as discuss recent applications of exosomes as drug delivery vessels and the resulting clinical implications.

Long non-coding RNA SMASR inhibits the EMT by negatively regulating TGF-β/Smad signaling pathway in lung cancer

TGF-β/Smad signaling pathway plays an important role in EMT during cancer progression. Long non-coding RNAs (lncRNAs) are involved in various behaviors of cancer cells, including EMT. Here, we report a novel lncRNA adjacent to Smad3, named Smad3-associated long non-coding RNA (SMASR). SMASR is downregulated by TGF-β via Smad2/3 in lung cancer cells. Knockdown of SMASR induces EMT and increases the migration and invasion of lung cancer cells. Moreover, knockdown of SMASR promotes the phosphorylation of Smad2/3. Mechanistically, SMASR interacts with Smad2/3 and inhibits the expression of TGFBR1, the TGF-β type I receptor responsible for phosphorylation of Smad2/3, thus leading to inactivation of TGF-β/Smad signaling pathway. Clinically, SMASR is downregulated in lung cancer tissues. Collectively, our findings prove a critical role of SMASR in EMT of lung cancer by forming a negative feedback loop with TGF-β/Smad signaling pathway.

MIRLET7BHG promotes hepatocellular carcinoma progression by activating hepatic stellate cells through exosomal SMO to trigger Hedgehog pathway

Hepatocellular carcinoma (HCC), commonly caused by liver fibrosis, is a global challenge with high morbidity. Activation of hepatic stellate cells (HSCs) contributes to hepatic fibrosis. Exosomes are small vesicles that play a significant role in cell-to-cell communication. Smoothened (SMO) is the key signal transducer for Hedgehog pathway. This study was designed to study the function and underlying mechanism of SMO in HSC activation. Functional assays including 5-Ethynyl-2´-deoxyuridine, colony formation, wound healing, transwell, and sphere formation assays disclosed the function of SMO. Western blot analysis of exosome biomarkers, immunofluorescence staining assay, electron microscope, and flow cytometry revealed the existence of exosomes. Bioinformatics analyses and mechanistic assays uncovered the interplays between RNAs. Nude mice xenograft model was established to evaluate HCC tumor growth. We uncovered that SMO was an oncogene in HCC cells and was low-expressed in quiescent HSCs. Then, SMO was upregulated in HSCs cultured with HCC cells-conditioned medium. Next, it was revealed that HCC cells-derived exosomes activated HSCs by transmitting SMO to HSCs. Subsequently, we recognized that microRNA let-7b host gene (MIRLET7BHG) served as the competing endogenous RNA against miR-330-5p to upregulate SMO. In turn, SMO induced hedgehog pathway to promote GLI family zinc finger 1 (Gli1), leading to transcriptional activation of MIRLET7BHG in activated HSCs. In summary, this study demonstrated that Gli1-induced MIRLET7BHG facilitated HCC by activating HSCs through exosomal SMO to stimulate hedgehog pathway, providing a new road for HCC treatment.

NORAD accelerates chemo-resistance of non-small-cell lung cancer via targeting at miR-129-1-3p/SOX4 axis

Substantial researches indicated that long non-coding RNAs (lncRNAs) exerted profound effects on chemo-resistance in cancer treatment. Nonetheless, the role of NORAD in non-small-cell lung cancer (NSCLC) remains unclear. In the present study, we chose NSCLC cell lines H446 and A549 to explore the function of non-coding RNA activated damage (NORAD) in response to cisplatin (DDP) resistance of NSCLC. Experimental data manifested that NORAD was up-regulated in DDP-resistant NSCLC tissues and cells. NSCLC patients with high NORAD expression suffered a poor prognosis. NORAD knockdown resensitized H446/DDP and A549/DDP to DDP. Besides, NORAD acted as a molecular sponge of miR-129-1-3p. MiR-129-1-3p showed a low level of expression in DDP-resistant NSCLC tissues. Moreover, miR-129-1-3p overexpression impaired DDP resistance in H446/DDP and A549/DDP cells. SOX4 was the downstream target of miR-129-1-3p. Especially, SOX4 overexpression offset the effects of NORAD silence on H446/DDP and A549/DDP cells resistance to DDP. NORAD knockdown resensitized H446/DDP and A549/DDP to DDP in NSCLC via targeting miR-129-1-3p/SOX4 axis, offering a brand-new target for NSCLC chemo-resistance.

PCAT-1 facilitates breast cancer progression via binding to RACK1 and enhancing oxygen-independent stability of HIF-1α

Hypoxia induces a series of cellular adaptive responses that enable promotion of inflammation and cancer development. Hypoxia-inducible factor-1α (HIF-1α) is involved in the hypoxia response and cancer promotion, and it accumulates in hypoxia and is degraded under normoxic conditions. Here we identify prostate cancer associated transcript-1 (PCAT-1) as a hypoxia-inducible long non-coding RNA (lncRNA) that regulates HIF-1α stability, crucial for cancer progression. Extensive analyses of clinical data indicate that PCAT-1 is elevated in breast cancer patients and is associated with pathological grade, tumor size, and poor clinical outcomes. Through gain- and loss-of-function experiments, we find that PCAT-1 promotes hypoxia-associated breast cancer progression including growth, migration, invasion, colony formation, and metabolic regulation. Mechanistically, PCAT-1 directly interacts with the receptor of activated protein C kinase-1 (RACK1) protein and prevents RACK1 from binding to HIF-1α, thus protecting HIF-1α from RACK1-induced oxygen-independent degradation. These findings provide new insight into lncRNA-mediated mechanisms for HIF-1α stability and suggest a novel role of PCAT-1 as a potential therapeutic target for breast cancer.

Systematic identification of key functional modules and genes in esophageal cancer

BACKGROUND

Esophageal cancer is associated with high incidence and mortality worldwide. Differential expression genes (DEGs) and weighted gene co-expression network analysis (WGCNA) are important methods to screen the core genes as bioinformatics methods.

METHODS

The DEGs and WGCNA were combined to screen the hub genes, and pathway enrichment analyses were performed on the hub module in the WGCNA. The CCNB1 was identified as the hub gene based on the intersection between DEGs and the greenyellow module in WGCNA. Expression levels and prognostic values of CCNB1 were verified in UALCAN, GEPIA2, HCMDB, Kaplan-Meier plotter, and TIMER databases.

RESULTS

We identified 1,044 DEGs from dataset GSE20347, 1,904 from GSE29001, and 2,722 from GSE111044, and 32 modules were revealed by WGCNA. The greenyellow module was identified as the hub module in the WGCNA. CCNB1 gene was identified as the hub gene, which was upregulated in tumour tissues. Moreover, esophageal cancer patients with higher expression of CCNB1 showed a worse prognosis. However, CCNB1 'might not play an important role in immune cell infiltration.

CONCLUSIONS

Based on DEGs and key modules related to esophageal cancer, CCNB1 was identified as the hub gene, which offered novel insights into the development and treatment of esophageal cancer.

Serum lnc34a is a potential prediction biomarker for bone metastasis in hepatocellular carcinoma patients

Background

Early screening and intervention therapies are crucial to improve the prognosis of hepatocellular carcinoma (HCC) patients with bone metastasis. We aimed to identify serum lncRNA as a prediction biomarker in HCC bone metastasis.

Methods

The expression levels of lnc34a in serum samples from 157 HCC patients were detected by quantitative real-time polymerase chain reaction (PCR). Univariate analysis and multivariate analysis were performed to determine statistically significant variables.

Results

Expression levels of lnc34a in serum from HCC patients with bone metastasis were significantly higher than those without bone metastasis. The high expressions of lnc34a, vascular invasion and Barcelona Clinic Liver Cancer (BCLC) stage were associated with bone metastasis by analysis. Moreover, lnc34a expression was specifically associated with bone metastasis rather than lung or lymph node metastasis in HCC.

Conclusions

High serum lnc34a expression was a independent risk factor for developing bone metastasis in HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07808-6.

A novel prognostic mRNA/miRNA signature for esophageal cancer and its immune landscape in cancer progression

Mounting evidence shows that MicroRNAs (miRNAs) and their target genes are aberrantly expressed in many cancers and are linked to tumor occurrence and progression, especially in esophageal cancer (EC). This study purposed to explore new biomarkers related to the prognosis of EC and to uncover their potential mechanisms in promoting tumor progression. We identified 162 differentially expressed miRNAs and 4555 differentially expressed mRNAs in EC. Then, a risk model involving three miRNAs (miR‐4521, miR‐3682‐3p, and miR‐1269a) was designed to predict prognosis in EC patients. Furthermore, 7 target genes (Rho GTPase‐activating protein 24, Chromobox 3, Contactin‐associated protein 2, ELOVL fatty acid elongase 5, LIF receptor subunit alpha, transmembrane protein 44, and transmembrane protein 67) were selected for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses to reveal their potential mechanisms in promoting EC progression. After a series of correlation analyses, miRNA target genes were found to be significantly positively or negatively associated with immune infiltration, tumor microenvironment, cancer stemness properties, and tumor mutation burden at different degrees in EC. To further elucidate the role of miRNA signature in cancer progression, we performed a pan‐cancer analysis to determine whether these genes exert similar effects on other tumors. Interestingly, the miRNA target genes altered expression on tumor immunity; however, pan‐cancer progression was the same as that of EC. Thus, we explored the immune landscape of the miRNA signature and its target genes in EC and pan‐cancer. These findings demonstrated the versatility and effectiveness of our model in various cancers and provided a new direction for cancer management.

LncRNA PCAT1 Interacts with DKC1 to Regulate Proliferation, Invasion and Apoptosis in NSCLC Cells via the VEGF/AKT/Bcl2/Caspase9 Pathway

Long noncoding RNAs (lncRNAs) are increasingly recognized as indispensable components of the regulatory network in the progression of various cancers, including nonsmall cell lung cancer (NSCLC). The lncRNA prostate cancer associated transcript 1 (PCAT1) has been involved in tumorigenesis of multiple malignant solid tumors, but it is largely unknown that what is the role of lncRNA-PCAT1 and how it functions in the progression of lung cancer. Herein, we observed that lncRNA PCAT1 expression was upregulated in both human NSCLC tissues and cell lines, which was determined by qualitative polymerase chain reaction analysis. Then, gain-and loss-of-function manipulations were performed in A549 cells by transfection with a specific short interfering RNA against PCAT1 or a pcDNA-PCAT1 expression vector. The results showed that PCAT1 not only promoted NSCLC cell proliferation and invasion but also inhibited cell apoptosis. Bioinformatics and expression correlation analyses revealed that there was a potential interaction between PCAT1 and the dyskerin pseudouridine synthase 1 (DKC1) protein, an RNA-binding protein. Then, RNA pull-down assays with biotinylated probes and transcripts both confirmed that PCAT1 directly bounds with DKC1 that could also promote NSCLC cell proliferation and invasion and inhibit cell apoptosis. Moreover, the effects of PCAT1 and DKC1 on NSCLC functions are synergistic. Furthermore, PCAT1 and DKC1 activated the vascular endothelial growth factor (VEGF)/protein kinase B (AKT)/Bcl-2/caspase9 pathway in NSCLC cells, and inhibition of epidermal growth factor receptor, AKT, or Bcl-2 could eliminate the effect of PCAT1/DKC1 co-overexpression on NSCLC cell behaviors. In conclusion, lncRNA PCAT1 interacts with DKC1 to regulate proliferation, invasion, and apoptosis in NSCLC cells via the VEGF/AKT/Bcl-2/caspase9 pathway.

Progress of Mesenchymal Stem Cell-Derived Exosomes in Tissue Repair

Mesenchymal stem cells (MSCs) are a kind of adult stem cells with self-replication and multidirectional differentiation, which can differentiate into tissue-specific cells under physiological conditions, maintaining tissue self-renewal and physiological functions. They play a role in the pathological condition by lateral differentiation into tissue-specific cells, replacing damaged tissue cells by playing the role of a regenerative medicine , or repairing damaged tissues through angiogenesis, thereby, regulating immune responses, inflammatory responses, and inhibiting apoptosis. It has become an important seed cell for tissue repair and organ reconstruction, and cell therapy based on MSCs has been widely used clinically. The study found that the probability of stem cells migrating to the damaged area after transplantation or differentiating into damaged cells is very low, so the researchers believe the leading role of stem cell transplantation for tissue repair is paracrine secretion, secreting growth factors, cytokines or other components. Exosomes are biologically active small vesicles secreted by MSCs. Recent studies have shown that they can transfer functional proteins, RNA, microRNAs, and lncRNAs between cells, and greatly reduce the immune response. Under the premise of promoting proliferation and inhibition of apoptosis, they play a repair role in tissue damage, which is caused by a variety of diseases. In this paper, the biological characteristics of exosomes (MSCs-exosomes) derived from mesenchymal stem cells, intercellular transport mechanisms, and their research progress in the field of stem cell therapy are reviewed.

Knockdown of lncRNA PCAT1 Enhances Radiosensitivity of Cervical Cancer by Regulating miR-128/GOLM1 Axis

Purpose

Cervical cancer (CC) is the fourth most common cancer with high death rate in females. The study aims to detect the mechanism of long non-coding RNA (LncRNA) PCAT1 on radiosensitivity of CC.

Methods

The expression of PCAT1, miR-128 and GOLM1 in CC tissues and cells was measured by qRT-PCR. Different doses of X-ray were used for radiation treatment of CC cells and 6 Gy was chosen to perform the following experiments. The proliferation, migration and invasion of CC cells were measured by MTT assay, wound healing assay and transwell assay, respectively. The target relationships among PCAT1, miR-128 and GOLM1 were predicted by StarBase and TargetScan and verified by luciferase reporter assay. The protein level of GOLM1 was determined by Western blot. The xenograft tumor model was constructed in nude mice to verify the effect of PCAT1 on radiosensitivity of CC in vivo.

Results

The PCAT1 expression was upregulated in CC tissues and cells. PCAT1 silencing enhances radiosensitivity of CC cells on proliferation, migration and invasion. MiR-128 was the target of PCAT1 and was negatively regulated by PCAT1. Upregulation of miR-128 enhances radiosensitivity of CC cells on proliferation, migration and invasion. GOLM1 was a target of miR-128 and was negatively regulated by miR-128. Upregulation of GOLM1 and downregulation of miR-128 both reversed the enhanced effect of PCAT1 knockdown on radiosensitivity of CC cells, which partly promoted the proliferation, migration and invasion of CC cells.

Conclusion

Silencing of PCAT1 enhanced radiosensitivity of CC via targeting miR-128/GOLM1, which provided a new idea for treating CC.

PCAT1 induced by transcription factor YY1 promotes cholangiocarcinoma proliferation, migration and invasion by sponging miR-216a-3p to up-regulate oncogene BCL3

This study was designed to illustrate the function and role of PCAT1 in CCA. The relative expression was confirmed by RT-qPCR and western blot. The biological function of PCAT1 was evaluated by CCK8, EdU, colony formation, wound healing, transwell, and subcutaneous tumor formation assays. Protein levels of EMT markers were measured by western blot. The binding relationship was predicted by JASPAR and starBase. The binding of YY1 to PCAT1 promoter was assessed by ChIP and luciferase reporter. The binding capacity between miR-216a-3p and PCAT1 as well as BCL3 was assessed by luciferase reporter and AGO2-RIP assays. In this study, we found that PCAT1 was up-regulated in CCA tissues and cells, and the PCAT1 overexpression was associated with poor prognosis. Moreover, PCAT1 was assessed as an independent risk factor of prognosis for CCA patients. Amplified PCAT1 was found to promote tumor proliferation, migration, invasion and EMT process, whereas PCAT1 knockdown inhibited these malignant phenotypes. Mechanistically, PCAT1 was predominantly localized in the cytoplasm and competitively bound miR-216a-3p to increase BCL3 expression. In addition, PCAT1 was activated by transcription factor YY1. This study revealed that PCAT1 acted as an oncogene in CCA, and the YY1/PCAT1/miR-216a-3p/BCL3 axis exhibited critical functions in CCA progression.

A novel long noncoding RNA, LOC440173, promotes the progression of esophageal squamous cell carcinoma by modulating the miR-30d-5p/HDAC9 axis and the epithelial-mesenchymal transition

Countless evidence suggests that long noncoding RNAs (lncRNAs) are involved in human malignant cancers, including esophageal squamous cell carcinoma (ESCC), although their exact function remains unclear. In the present study, we aimed to investigate the roles and molecular mechanisms of the lncRNA LOC440173 in ESCC progression. Microarray analysis and quantitative real-time polymerase chain reaction were conducted to measure the expression levels of LOC440173 and miR-30d-5p. The biological function of this lncRNA was investigated using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, clone formation, and transwell assays, as well as flow cytometry and Western blot analysis. The function of LOC440173 was validated in vivo using tumor xenografts. The regulatory network of LOC440173/miR-30d-5p/HDAC9 was established using bioinformatic analysis and verified with dual-luciferase reporter assays, RNA immunoprecipitation assay, and rescue experiments. The expression level of LOC440173 was significantly increased in ESCC tissues and esophageal carcinoma cells. High LOC440173 expression was correlated with histological grade, tumor invasion depth, lymph node metastasis, and TNM stage. Overexpression of LOC440173 promoted esophageal cancer cell proliferation, migration, and invasion, as well as the epithelial-mesenchymal transition (EMT) process in vitro, and facilitated tumor growth in vivo. MicroRNA-30d-5p (miR-30d-5p) was downregulated in ESCC tissues and acted as a direct binding target of LOC440173 during the regulation of HDAC9 expression in esophageal carcinoma cells. In conclusion, LOC440173 exerts a promotive role in ESCC tumorigenesis by targeting the miR-30d-5p/HDAC9 axis and regulating the EMT process. LOC440173 might be a new therapeutic target for the treatment of ESCC.

Long Noncoding RNA EBLN3P Promotes the Progression of Liver Cancer via Alteration of microRNA-144-3p/DOCK4 Signal

BACKGROUND

Therapy for patients with liver cancer in the advanced stage remains a great challenge, and there are very few approved treatments. Although accumulated evidence demonstrates the importance of lncRNAs in liver cancer, data on the functional roles and molecular mechanisms of endogenous bornavirus-like nucleoprotein (EBLN3P) have been rarely reported.

MATERIALS AND METHODS

The bioinformatics prediction software ENCORI was used to predict the putative binding sites of EBLN3P. The regulatory roles of EBLN3P and miR-144-3p in cell proliferation, migration and invasion ability were verified by the Cell Counting Kit-8, wound healing and Transwell assays, respectively. The interactions among EBLN3P, miR-144-3p and DOCK4 were explored by a luciferase assay and Western blotting. The expression of EBLN3P and microRNA (miR)-144-3p in liver cancer tissues was quantified by reverse transcription-quantitative PCR, and the expression of dedicator of cytokinesis 4 (DOCK4) was quantified by immunohistochemical analysis.

RESULTS

The present results revealed that overexpression of EBLN3P or knockdown of miR-144-3p promoted liver cancer cell proliferation, migration and invasion. Bioinformatics analysis and a luciferase assay demonstrated that EBLN3P directly interacts with miR-144-3p to attenuate miR-144-3p binding to the 3'-untranslated region of DOCK4. Furthermore, the mechanistic investigations showing that the miR-144-3p/DOCK4 regulatory loop was activated by knockdown of miR-144-3p or overexpression of DOCK4 validate the roles of EBLN3P in promoting liver cancer cell proliferation, migration and invasion in vitro. Elevated levels of EBLN3P and DOCK4 and decreased miR-144-3p expression were observed in both liver cancer tissues and cell lines.

CONCLUSION

The present study is the first to demonstrate that EBLN3P may act as a ceRNA to modulate DOCK4 expression by competitively sponging miR-144-3p, leading to the regulation of liver cancer progression, which provides new insights for liver cancer diagnosis and treatment.

Biological functions and clinical applications of exosomal long non-coding RNAs in cancer

Exosomes are extracellular vesicles secreted by donor cells, and one of the important roles of exosomes is intercellular communication. Exosomes contain proteins, lipids, DNA and RNA. The components exert their functions by modulating the cellular processes of recipient cells. Exosomal long non‐coding RNAs (lncRNAs) are important components and play multiple roles in tumorigenesis and tumour development. In this review, we summarize the biological functions and clinical applications of exosomal lncRNAs in cancer. Exosomal lncRNAs regulate cell proliferation, metastasis, drug resistance and angiogenesis in human cancers. Since exosomal lncRNAs are associated with clinicopathological characteristics of cancer, these might be potentially useful biomarkers for diagnosis and prognosis of cancer. Exosomal lncRNAs participate in multiple processes of cancer progression, which makes them promising therapeutic targets for cancer treatment.

Serum long non-coding RNA LINC00887 as a potential biomarker for diagnosis of renal cell carcinoma

The identification of non‐invasive biomarkers for the detection of renal cell carcinoma (RCC) in early‐stage patients may help improve disease outcome. Certain long non‐coding RNAs (lncRNAs) have been reported to be possible biomarkers for the diagnosis and prognosis of cancer. Here, we examined the suitability of the lncRNA LINC00887 as a potential biomarker for RCC because its expression has been shown to be elevated in RCC tissue versus normal tissue in the Gene Expression Profiling Interactive Analysis (GEPIA) database. We found that LINC00887 expression is significantly increased in early‐stage RCC tissues and the serum of early‐stage RCC patients compared to matched normal tissues and the serum of healthy subjects, respectively. We also demonstrated that elevated serum LINC00887 is generated from the tumor tissues of RCC patients. Moreover, a receiver operating characteristic (ROC) curve was generated to analyze the diagnostic value of serum LINC00887. The area under the ROC cure differentiating early‐stage RCC patients from healthy subjects was 0.8001, with a sensitivity of 71.05% and a specificity of 89.87%. Furthermore, we found that LINC00887 promotes RCC cell proliferation in vitro. Taken together, our findings suggest that a serum LINC00887 signature is associated with RCC cell proliferation and may be a potential biomarker for the detection of early‐stage RCC.

Identification of APEX2 as an oncogene in liver cancer

BACKGROUND

DNA damage is one of the critical contributors to the occurrence and development of some cancers. APEX1 and APEX2 are the most important molecules in the DNA damage, and APEX1 has been identified as a diagnostic and prognostic biomarker in liver hepatocellular carcinoma (LIHC). However, the expression of APEX2 and its functional mechanisms in LIHC are still unclear.

AIM

To examine the expression of APEX2 and the potential mechanism network in LIHC.

METHODS

We conducted a pan-cancer analysis of the expression of APEX1 and APEX2 using the interactive TIMER tool. GEO datasets, including GSE14520, GSE22058, and GSE64041, were used to compare the APEX2 expression level in tumor tissues and adjacent non-tumor tissues. Then, we calculated the 5-year survival rate according to the web-based Kaplan-Meier analysis. We included the TCGA liver cancer database in GSEA analysis based on the high and low APEX2 expression, showing the potential mechanisms of APEX2 in LIHC. After that, we conducted Pearson correlation analysis using GEPIA2. Next, we performed quantitative polymerase chain reaction (qPCR) assay to examine the APEX2 levels in normal liver cell line LO2 and several liver cancer cell lines, including HepG2, Huh7, SMMC7721, and HCCLM3. APEX2 in HCCLM3 cells was knocked down using small interfering RNA. The role of APEX2 in cell viability was confirmed using CCK-8. Dual-luciferase reporter assay was performed to examine the promoter activity of CCNB1 and MYC.

RESULTS

APEX1 and APEX2 are both highly expressed in the tumor tissues of BLCA, BRCA, CHOL, COAD, ESCA, HNSC, LIHC, LUAD, LUSC, READ, and STAD. APEX2 overexpression in LIHC was validated using GSE14520, GSE22058, and GSE64041 datasets. The survival analysis showed that LIHC patients with high expression of APEX2 had a lower overall survival rate, even in the AJCC T1 patients. High level of APEX2 could indicate a lower overall survival rate in patients with or without viral hepatitis. The GSEA analysis identified that kinetochore and spindle microtubules are the two main cellular components of APEX2 in GO Ontology. APEX2 was also positively associated with molecular function regulation of chromosome segregation and DNA replication. The results of KEGG analysis indicated that APEX2 expression was positively correlated with cell cycle pathway and pro-oncogenic MYC signaling. Pearson correlation analysis showed that APEX2 had a significant positive correlation with CCNB1 and MYC. APEX2 level was higher in liver cancer cell lines than in normal liver LO2 cells. Small interfering RNA could knock down the APEX2 expression in HCCLM3 cells. Knockdown of APEX2 resulted in a decrease in the viability of HCCLM3 cells as well as the expression and promoter activity of CCNB1 and MYC.

CONCLUSION

APEX2 is overexpressed in LIHC, and the higher APEX2 level is associated with a worse prognosis in overall survival. APEX2 is closely involved in the biological processes of chromosome segregation and DNA replication. APEX2 expression is positively correlated with the pro-oncogenic pathways. Knockdown of APEX2 could inhibit the cell viability and CCNB1 and MYC pathways, suggesting that APEX2 is an oncogene in LIHC, which could be a potential pharmaceutic target in the anti-tumor therapy.

lncRNA IGKJ2-MALLP2 suppresses LSCC proliferation, migration, invasion, and angiogenesis by sponging miR-1911-3p/p21

Because advanced laryngeal squamous cell carcinoma (LSCC) is diagnosed as a malignant tumor with a poor prognosis, the associated mechanisms still need to be further investigated. As key players in the development and progression of LSCC, lncRNAs have attracted increasing attention from many researchers. In this study, a novel lncRNA termed IGKJ2‐MALLP2 was identified and investigated for its effects on the development of LSCC. IGKJ2‐MALLP2 expression was confirmed by RT‐qPCR in 78 pairs of tissues and human laryngeal carcinoma cell lines. The results of this study showed that the expression of IGKJ2‐MALLP2 was reduced in LSCC tissues and displayed close relationships with tumor stage, lymph node metastasis, and clinical stage. Using a dual‐luciferase reporter assay, the ability of miR‐1911‐3p to bind both IGKJ2‐MALLP2 and p21 mRNA was demonstrated. IGKJ2‐MALLP2 could upregulate p21 expression by competitively binding miR‐1911‐3p. Moreover, IGKJ2‐MALLP2 effectively hindered the invasion, migration, and proliferation of AMC‐HN‐8 and TU212 tumor cells. Furthermore, its high expression could hinder the secretion of VEGF‐A and suppress angiogenesis. As revealed by the results of in vitro experiments, IGKJ2‐MALLP2 overexpression could restrict tumor growth and blood vessel formation in a xenograft model of LSCC. As indicated from the mentioned findings, IGKJ2‐MALLP2, which mediates p21 expression by targeting miR‐1911‐3p, was capable of regulating LSCC progression and could act as an underlying therapeutic candidate to treat LSCC.

Quantitative Proteomics Analysis Indicates That Upregulation of lncRNA HULC Promotes Pathogenesis of Glioblastoma Cells

Purpose

Glioblastoma (GBM) is an aggressive central nervous system (CNS) cancer and a serious threat to human health. The long noncoding RNA (lncRNA) HULC has been implicated in GBM, but the molecular mechanism is uncertain. This study used quantitative proteomic analysis for global identification of HULC-regulated proteins in glioblastoma cells and identification of potential biomarkers.

Materials and Methods

qRT-PCR was used to determine the expression of HULC in U87 cells stably transfected with HULC or an empty vector (control). The CCK-8 assay, transwell assay, and wound-scratch assay were used to measure cell proliferation, invasion, and migration. Quantitative proteomics using Tandem Mass Tag (TMT) labeling, high-performance liquid chromatography (HPLC) fractionation, and liquid chromatography–mass spectrometry (LC-MS/MS) analysis were used to identify differentially expressed proteins (DEPs). Screened proteins were validated by parallel reaction monitoring (PRM) and Western blotting.

Results

Overexpression of HULC led to increased cell proliferation, invasion, and migration. HULC overexpression also led to significant upregulation of 37 proteins and downregulation of 78 proteins. Bioinformatics analysis indicated these proteins had roles in cellular component, biological process, and molecular function. PRM results of 8 of these proteins (PTK2, TNC, ITGAV, LASP1, MAPK14, ITGA1, GNA13, RRAS) were consistent with the LC-MS/MS and Western blotting results.

Conclusion

The results of present study suggest that lncRNA HULC promotes GBM cell proliferation, invasion, and migration by regulating RRAS expression, suggesting that RRAS may be a potential biomarker or therapeutic target for this cancer.

Tumor-Secreted Exosomal lncRNA POU3F3 Promotes Cisplatin Resistance in ESCC by Inducing Fibroblast Differentiation into CAFs

Cancer-associated fibroblasts (CAFs), an activated subpopulation of fibroblasts, occupy a central position in the tumor microenvironment and have been shown to promote chemoresistance in multiple cancer types by secreting inflammatory cytokines. Herein, we report that tumor-secreted exosomal long non-coding RNAs (lncRNAs) can regulate cisplatin resistance in esophageal squamous cell carcinoma (ESCC) through transformation of normal fibroblasts (NFs) to CAFs. Primary CAFs and matched NFs were isolated from tumor tissues and matched normal esophageal epithelial tissues of ESCC patients. Fluorescence microscopy and qRT-PCR were used to investigate the transportation of exosomal lncRNAs from ESCC cells to NFs. To identify the specific lncRNAs involved, 14 ESCC-related lncRNAs were measured in NFs after incubation with exosomes from ESCC cells. We demonstrated that lncRNA POU3F3 can be transferred from ESCC cells to NFs via exosomes and that it mediated fibroblast activation. Activated fibroblasts further promoted proliferation and cisplatin resistance of ESCC cells through secreting interleukin 6 (IL-6). Moreover, our clinical data showed that high levels of plasma exosomal lncRNA POU3F3 correlated significantly with lack of complete response and poor survival in ESCC patients. Therefore, these data demonstrate that lncRNA POU3F3 is involved in cisplatin resistance in ESCC and that this effect is mediated through exosomal lncRNA POU3F3-induced transformation of NFs to CAFs.

LncRNA OIP5-AS1 promotes cell proliferation and migration and induces angiogenesis via regulating miR-3163/VEGFA in hepatocellular carcinoma

Long noncoding RNAs (lncRNAs) have been reported to play a significant role in the occurrence and progression of tumors. In different tumors, they can either act as an oncogene or tumor suppressor via modulating various target mRNAs. OIP5-AS1 belongs to lncRNA family. It has been reported to be involved in the tumorigenesis of some cancers, such as bladder cancer, gastric cancer, and multiple myeloma. However, the role it plays in hepatocellular carcinoma (HCC) remains unclear. This study aims to explore the inherent mechanism of lncRNA OIP5-AS1 in HCC. In the first place, qRT-PCR found that OIP5-AS1 and VEGFA expressions were significantly increased while miR-3163 was obviously reduced in HCC cells and tissues. Next, a series of functional experiments found that knockdown of OIP5-AS1 suppressed HCC cell proliferation, migration and angiogenesis abilities while promoting cell apoptosis simultaneously. Last but not least, miR-3163 inhibition or VEGFA overexpression can reverse the anti-tumor effect of OIP5-AS1. In summary, OIP5-AS1 affects HCC proliferation, metastasis, and angiogenesis in HCC by regulating VEGFA expression through sponging miR-3163.