H19/miR-675-5p Targeting SFN Enhances the Invasion and Metastasis of Nasalpharyngeal Cancer Cells

Decreased expression of H19/miR-675 ameliorates hypoxia-induced oxaliplatin resistance in colorectal cancer

Hypoxic microenvironment, a hallmark of solid tumors, contributes to chemoresistance, and long noncoding (lnc) RNAs are involved in hypoxia-induced drug resistance. However, the role of lncRNAs in hypoxic tumor chemotherapy resistance remains unclear. Here, we aimed to elucidate the effects of lncRNAs in hypoxia-mediated resistance in colorectal cancer (CRC), as well as the underlying mechanisms. The results indicated that the expression of lncRNA H19 was enhanced in hypoxia- or oxaliplatin-treated CRC cells; moreover, H19 contributed to drug resistance in CRC cells both in vitro and in vivo. Mechanistically, H19 was noted to act as a competitive endogenous RNA of miR-675-3p to regulate epithelial-mesenchymal transition (EMT). Notably, an miR-675-3p mimic could attenuate the effects of H19 deficiency in CRC cells with hypoxia-induced chemoresistance. In conclusion, H19 downregulation may counteract hypoxia-induced chemoresistance by sponging miR-675-3p to regulate EMT; as such, the H19/miR-675-3p axis might be a promising therapeutic target for drug resistance in CRC.

Stratifin (SFN) Regulates Cervical Cancer Cell Proliferation, Apoptosis, and Cytoskeletal Remodeling and Metastasis Progression Through LIMK2/Cofilin Signaling

The aberrant expression of Stratifin (SFN) is intricately associated with the initiation and progression of numerous tumors. This study aims to investigate whether SFN regulates the metastasis of cervical cancer cells through the LIMK2/Cofilin signaling pathway. In this study, we compared the expression of SFN in normal cervical tissues and cervical carcinoma tissues. We established SFN overexpression and SFN silencing cellular models to assess the invasive and migratory capabilities of cervical cancer cells using transwell and scratch assays. YO-PRO-1/PI and EdU staining were employed to evaluate apoptotic and proliferative capacities, while Actin-Tracker Green-488 was utilized to investigate cytoskeletal remodeling. The expression levels of SFN, LIMK2, p-LIMK2, Cofilin, and p-Cofilin were examined through Western blotting and immunofluorescence. Our findings revealed elevated expression of SFN in cervical squamous cell carcinoma tissues. SFN overexpression was observed to enhance invasion and migration of cervical cancer cells, induce cytoskeletal remodeling, facilitate cell proliferation, and suppress apoptosis. Furthermore, SFN overexpression upregulated the expression levels of LIMK2, p-LIMK2, Cofilin, and p-Cofilin. Conversely, silencing SFN exerted opposite effects. SFN plays an important role in the diagnosis of cervical cancer. SFN can regulate cervical cancer cell proliferation, apoptosis, cytoskeletal remodeling and metastasis through LIMK2/Cofilin signaling.

N6-methyladenosine-modified oncofetal lncRNA MIR4435-2HG contributed to stemness features of hepatocellular carcinoma cells by regulating rRNA 2'-O methylation

BACKGROUND

The unique expression pattern endows oncofetal genes with great value in cancer diagnosis and treatment. However, only a few oncofetal genes are available for clinical use and the underlying mechanisms that drives the fetal-like reprogramming of cancer cells remain largely unknown.

METHODS

Microarray assays and bioinformatic analyses were employed to screen for potential oncofetal long non-coding RNAs (lncRNAs) in hepatocellular carcinoma (HCC). The expression levels of MIR4435-2HG, NOP58 ribonucleoprotein (NOP58), insulin like growth factor 2 mRNA binding protein 1 (IGF2BP1) and stem markers were detected by quantitative polymerase chain reaction. The 2'-O-methylation (2'-O-Me) status of rRNA were detected through reverse transcription at low dNTP concentrations followed by PCR. The regulation of MIR4435-2HG by IGF2BP1 was explored by RNA immunoprecipitation (RIP), methylated RIP (MeRIP) and dual-luciferase assays. The interaction between MIR4435-2HG and NOP58 was investigated by RNA Pulldown, RIP and protein stability assays. In vitro and in vivo function assays were performed to detect the roles of MIR4435-2HG/NOP58 in HCC.

RESULTS

MIR4435-2HG was an oncofetal lncRNA associated with poor prognosis in HCC. Functional experiments showed that overexpression of MIR4435-2HG remarkably enhanced the stem-cell properties of HCC cells, promoting tumorigenesis in vitro and in vivo. Mechanically, MIR4435-2HG directly bound NOP58 and IGF2BP1. IGF2BP1 upregulated MIR4435-2HG expression in HCC through N6-methyladenosine (m6A) modification. Moreover, MIR4435-2HG protected NOP58 from degradation, which raised rRNA 2'-O-Me levels and promoted internal ribosome entry site (IRES)-dependent translation of oncogenes.

CONCLUSIONS

This study identified an oncofetal lncRNA MIR4435-2HG, characterized the role of MIR4435-2HG/NOP58 in stemness maintenance and proliferation of HCC cells, and confirmed m6A as a 'driver' that reactivated MR4435-2HG expression in HCC.

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

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

A PARP1-related prognostic signature constructing and PARP-1 inhibitors screening for glioma

The current standard treatments of glioma include surgical resection, supplemented with radiotherapy and chemotherapy, but the prognosis is poor. PARP-1 (Poly ADP-ribose polymerase 1) is a hot spot for cancer-targeted therapy and was reported to be significantly elevated in glioma. In this study, we analyzed the role of PARP-1 in DNA damage repair, constructed a PARP1-related DNA-repair prognostic signature (DPS), and screened targeted drugs for glioma. RNA-seq data of 639 glioma samples were downloaded from the GEO (Gene Expression Omnibus) database and divided into PARP1_H and PARP1_L according to the front and rear thirds of the expression level of PARP-1. First, we systematically analyzed the influence of PARP-1 on DNA damage repair, prognosis, and chemoradiotherapy sensitization of glioma. All glioma patients and patients with radiotherapy or chemotherapy had a better prognosis in PARP1_L than in PARP1_H. Next, differentially expressed DNA-repair related genes (DEGs) were identified between PARP1_H and PARP1_L by LASSO (Least Absolute Shrinkage and Selection Operator) Cox analysis and applied for constructing DPS. Based on the four-gene DPS, we then developed a new nomogram to assess overall survival in glioma patients. Additionally, PARP-1 was proved an effective target for glioma therapy. So, a series of computer-aided techniques, including Discovery Studio 4.5, Schrodinger, and PyMol, were applied for the virtual screening of favorable PARP-1 inhibitors. In conclusion, this study investigated the effect of PARP-1 on glioma prognosis and the sensitization effect of radiotherapy and chemotherapy, established a novel nomogram to evaluate the overall survival of glioma patients, and further explored targeted therapy for glioma.

lncRNA H19 promotes glioblastoma multiforme development by activating autophagy by sponging miR-491-5p

Glioblastoma multiforme (GBM) is a malignant cancer with severely poor survival, and the cells continue to thrive during hypoxia and toxic stress through autophagy. To validate the oncogenic role of long noncoding RNA H19 in GBM progression and examine whether autophagy and/or miR-491-5p participate in the process. The expression of H19 and autophagy-related genes in GBM and healthy control tissues was assessed via quantitative polymerase chain reaction. In addition, cell viability, proliferation, apoptosis and autophagy were respectively determined via cell counting kit-8 assay, clone formation assay, flow cytometry, western blotting and green fluorescent protein–microtubule-associated protein 1 light chain 3 alpha fluorescence analysis in vitro. Furthermore, a rescue assay was performed using rapamycin or miR-491-5p antagomir to examine the role of autophagy or miR-491-5p in H19-mediated regulation of proliferation and apoptosis. RNA pull-down and dual-luciferase reporter assays were employed to analyze the interaction between H19 and miR-491-5p. Additionally, tumor growth in a xenograft-bearing mouse model and autophagy in tumor mass were analyzed in vivo. The expression H19 was increased in GBM and was positively correlated with LC3 or Beclin-1. Silencing H19 inhibited growth and promoted apoptosis in GBM cells both in vitro and in vivo, and miR-491-5p was identified as one of the important mediators. H19 regulated the autophagy signaling pathway at least partly via miR-491-5p. Increased H19 expression in GBM exerts oncogenic effects by sponging miR-491-5p and enhancing autophagy. Therefore, H19 may be explored as a target for GBM therapy.

Long non-coding RNA titin-antisense RNA1 contributes to growth and metastasis of cholangiocarcinoma by suppressing microRNA-513a-5p to upregulate stratifin

Cholangiocarcinoma (CCA) is one of the most common histological types of primary hepatic malignancy and is associated with poor overall prognosis, causing a ponderous burden on human life. Hence, it is necessary to elucidate the pathogenesis of CCA. The objective of our research was to shed light on the mechanism through which long non-coding RNA titin-antisense RNA1 (lncRNA TTN-AS1) is involved in the development of CCA. Reverse transcription quantitative polymerase chain reaction was used to detect TTN-AS1 expression in CCA samples and cells. Functional experiments were performed using the Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, transwell, and in vivo tumor growth assays. The relationship between TTN-AS1, miR-513a-5p, and stratifin (SFN) was explored using a dual luciferase reporter assay, RNA immunoprecipitation (RIP) experiment, and Pearson correlation analysis. The result showed that TTN-AS1 and SFN are highly expressed in CCA tissues. Bioinformatics analysis, luciferase reporter and RIP experiments revealed the correlation between TTN-AS1, miR-513a-5p, and SFN. In addition, silencing TTN-AS1 mitigated CCA cell proliferation and migration. Mechanistically, miR-513a-5p is sponged by TTN-AS1. The miR-513a-5p inhibitor abolished the effect of TTN-AS1 silencing on the aggressive behaviors of CCA cells. Furthermore, we showed that miR-513a-5p is a regulator of CCA by targeting SFN. TTN-AS1 induced CCA cell growth and metastasis via the miR-513a-5p/SFN pathway, which offers a new strategy for therapeutic interventions for CCA.

Oncogenic role of early growth response-1 in liver cancer through the regulation of the microRNA-675/sestrin 3 and the Wnt/β-catenin signaling pathway

Early growth response-1 (EGR1) is a multi-domain protein and an immediate early transcription factor that is induced during liver injury and controls the expression of a variety of genes implicated in metabolism, cell proliferation, and tumorigenesis. Liver cancer (LC) is a highly malignant disease with high mortality worldwide. This study focused on the function of EGR1 in LC development and the mechanism of action. Two LC-related datasets GSE101728 and GSE138178 downloaded from the Gene Expression Omnibus (GEO) database were used for identification of key genes involved in cancer progression. A microarray analysis was conducted to identify differentially expressed microRNAs (miRNAs) after EGR1 knockdown. The target gene of miR-675 was identified by integrated analysis. EGR1 and miR-675 were highly expressed, whereas sestrin 3 (SESN3) was poorly expressed in LC tissues and cells. High EGR1 expression was associated with poor liver function and disease severity in patients with LC. Knockdown of EGR1 weakened proliferation and invasiveness of LC cells. EGR1 bound to the miR-675 promoter and increased its transcription, and miR-675 bound to SESN3 mRNA to induce its downregulation. miR-675 upregulation promoted the malignance of LC cells, but further upregulation of SESN3 reduced invasiveness of cells. SESN3 was enriched in the Wnt/β-catenin signaling. EGR1 and miR-675 activated the Wnt/β-catenin through downregulating SESN3. This study demonstrated that EGR1 promotes the malignant behaviors of LC cells through mediating the miRNA-675/SESN3/Wnt/β-catenin axis.

Non-coding RNAs in necroptosis, pyroptosis and ferroptosis in cancer metastasis

Distant metastasis is the main cause of death for cancer patients. Recently, the newly discovered programmed cell death includes necroptosis, pyroptosis, and ferroptosis, which possesses an important role in the process of tumor metastasis. At the same time, it is widely reported that non-coding RNA precisely regulates programmed death and tumor metastasis. In the present review, we summarize the function and role of necroptosis, pyrolysis, and ferroptosis involving in cancer metastasis, as well as the regulatory factors, including non-coding RNAs, of necroptosis, pyroptosis, and ferroptosis in the process of tumor metastasis.

Long non-coding RNAs in nasopharyngeal carcinoma: biological functions and clinical applications

Nasopharyngeal carcinoma (NPC) is one of the most common head and neck malignancies. It has obvious ethnic and regional specificity. Long non-coding RNAs (LncRNAs) are a class of non-protein coding RNA molecules. Emerging research shows that lncRNAs play a key role in tumor development, prognosis, and treatment. With the deepening of sequence analysis, a large number of functional LncRNAs have been found in NPC, which interact with coding genes, miRNAs, and proteins to form a complex regulatory network. However, the specific role and mechanism of abnormally expressed lncRNAs in the pathogenesis of NPC is not fully understood. This article briefly introduced the concept, classification, and functional mechanism of lncRNAs and reviewed their biological functions and their clinical applications in NPC. Specifically, we described lncRNAs related to the occurrence, growth, invasion, metastasis, angiogenesis, and cancer stem cells of NPC; discussed lncRNAs related to Epstein-Barr virus infection; and summarized the role of lncRNAs in NPC treatment resistance. We have also sorted out lncRNAs related to Chinese medicine treatment. We believe that with the deepening of lncRNAs research, tumor-specific lncRNAs may become a new target for the treatment and a biomarker for predicting prognosis.

14-3-3 σ: A potential biomolecule for cancer therapy

As more studies have focused on the function of 14-3-3 proteins, their role in tumor progression has gradually improved. In the 14-3-3 protein family, 14-3-3σ is the protein that is most associated with tumor occurrence and development. In some malignancies, 14-3-3σ acts as a tumor suppressor via p53 and tumor suppressor genes. In most tumors, 14-3-3σ overexpression increases resistance to chemotherapy and radiotherapy and mediates the G2-M checkpoint after DNA damage. Although 14-3-3σ overexpression has been closely associated with poorer prognosis in pancreatic, gastric and colorectal cancer, its role in gallbladder and nasopharyngeal cancer remains less clear. As such, the function of 14-3-3σ in specific cancer types needs to be further clarified. It has been hypothesized that a role may be related to its molecular chaperone function combined with various protein ligands. In this review, we examine the role of 14-3-3σ in tumor development and drug resistance. We discuss the potential of targeting 14-3-3σ regulators in cancer therapy and treatment.