MSC-AS1 induced cell growth and inflammatory mediators secretion through sponging miR-142-5p/DDX5 in gastric carcinoma

YTHDC1-Mediated lncRNA MSC-AS1 m6A Modification Potentiates Laryngeal Squamous Cell Carcinoma Development via Repressing ATXN7 Transcription

Laryngeal squamous cell carcinoma (LSCC) has the highest mortality rate among head and neck squamous cell carcinoma. This study was designed to investigate the biological effect of long noncoding RNA (lncRNA) MSC antisense RNA 1 (MSC-AS1) on LSCC development and the underlying mechanism. The expression and prognostic value of lncRNAs in head and neck squamous cell carcinoma were predicted in the bioinformatics tools. The overexpression of MSC-AS1 in LSCC patients predicted a poor prognosis. Depletion of MSC-AS1 using shRNA repressed the malignant phenotype of AMC-HN-8 and TU-177 cells. MSC-AS1, mainly localized in the nucleus, interacted closely with the transcription factor CCCTC-binding factor (CTCF). CTCF played anti-tumor effects in vitro and in vivo. Ataxin-7 (ATXN7) was predicted to be a downstream target of CTCF, whose expression was negatively controlled by MSC-AS1. MSC-AS1 was found to block the expression of CTCF, thereby repressing ATXN7. Finally, MSC-AS1 overexpression in LSCC was governed by YTH domain-containing protein 1 (YTHDC1)-mediated m6A modification. In summary, our research identified the YTHDC1/MSC-AS1/CTCF/ATXN7 axis in LSCC development, which indicated that MSC-AS1 is an attractive biomarker in the LSCC treatment.

DNA methylation-related lncRNAs predict prognosis and immunotherapy response in gastric cancer

BACKGROUND

LncRNAs and DNA methylation are both key regulators of tumorigenesis and immune regulation. However, the interaction between lncRNA and DNA methylation, their regulation and their clinical and immune relevance in gastric cancer (GC) remain unclear.

METHODS

In this study, we identified DNA methylation regulator-related lncRNAs through Pearson correlation analysis in The Cancer Genome Atlas datasets. Univariate Cox regression was used to screen DNA methylationrelated prognostic lncRNAs. Further, through least absolute shrinkage and selection operator Cox regression, a prognostic model based on 13 lncRNAs was established. Survival analysis and receiver operating characteristic curve analysis verified the accuracy of the model in predicting the survival of GC patients. Univariate and multivariate analyses also confirmed that the risk score obtained from the risk model could be applied as an independent prognostic factor for patients with GC. Furthermore, based on the risk score and other clinicopathological characteristics that can be used as independent prognostic factors, we constructed a nomogram that could accurately determine the survival time of each patient. In addition, a lncRNA score was constructed using a principal component analysis algorithm to quantify the DNA methylation-related lncRNA expression patterns of individual tumors.

RESULTS

We found that a higher lncRNA score indicated a worse the prognosis and was associated with a reduced tumor mutation burden and immunosuppression. A low lncRNA score was related to an increase in neoantigen load and an increase in the anti-PDL1/CTLA4 immunotherapy response. Additionally, a low lncRNA score was related to a significant therapeutic advantage and clinical benefit.

CONCLUSIONS

This study describes a DNA methylation regulator-related lncRNA signature model, which provides a new approach for predicting therapeutic response and patient stratification in GC. Assessing lncRNA expression patterns in individual tumors will contribute to enhancing our understanding of tumor microenvironment infiltration and guide more effective immunotherapy strategies.

Novel Therapeutics in Nonalcoholic Fatty Liver Disease: A Focus on Adult Stem Cells

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder that is associated with abnormal accumulation of fat in the liver, which can lead to a wide variety of pathological liver defects and associated insulin resistance (IR), obesity, hypertension, dyslipidemia, diabetes, and cardiovascular disease. The molecular mechanisms that cause the initiation and progression of NAFLD are not fully understood. Increased lipolysis and de novo hepatic lipid synthesis lead to oxidative stress induced by reactive oxygen species and inflammation. Both these two entities could be interrelated and be an important mechanistic pathway, which can lead to tissue injury and hepatic cell death. Mechanisms for worsening of NAFLD include mitochondrial abnormalities, downregulation of glutathione (GSH), decreased activity of GSH-dependent antioxidants, accumulation of activated macrophages, hepatic inflammation, systemic inflammation, IR, and poorly controlled type 2 diabetes mellitus. Although no specific therapy has been approved for NAFLD, we review the latest medical therapeutics with emphasis on stem cell-based possibilities based on the presumed pathophysiology of NAFLD.

Identification of a CD4+ conventional T cells-related lncRNAs signature associated with hepatocellular carcinoma prognosis, therapy, and tumor microenvironment

Background

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide, and CD4+ T lymphocytes can inhibit hepatocarcinogenesis and mediate tumor regression. However, few studies have focused on the prognostic power of CD4+ Tconv-related lncRNAs in HCC patients.

Method

We obtained data from TCGA and GEO databases and identified CD4+Tconv-related lncRNAs in HCC. The risk score was constructed using lasso regression and the model was validated using two validation cohorts. The RS was also assessed in different clinical subgroups, and a nomogram was established to further predict the patients' outcomes. Furthermore, we estimated the immune cell infiltration and cancer-associated fibroblasts (CAFs) through TIMER databases and assessed the role of RS in immune checkpoint inhibitors response.

Results

We constructed a CD4+ Tconv-related lncRNAs risk score, including six lncRNAs (AC012073.1, AL031985.3, LINC01060, MKLN1-AS, MSC-AS1, and TMCC1-AS1), and the RS had good predictive ability in validation cohorts and most clinical subgroups. The RS and the T stage were included in the nomogram with optimum prediction and the model had comparable OS prediction power compared to the AJCC. Patients in the high-risk group had a poor immune response phenotype, with high infiltrations of macrophages, CAFs, and low infiltrations of NK cells. Immunotherapy and chemotherapy response analysis indicated that low-risk group patients had good reactions to immune checkpoint inhibitors.

Conclusion

We constructed and validated a novel CD4+ Tconv-related lncRNAs RS, with the potential predictive value of HCC patients' survival and immunotherapy response.

Development and Validation of a Novel Mitochondrion and Ferroptosis-Related Long Non-Coding RNA Prognostic Signature in Hepatocellular Carcinoma

Mitochondrion and ferroptosis are related to tumorigenesis and tumor progression of hepatocellular carcinoma (HCC). Therefore, this study focused on exploring the participation of lncRNAs in mitochondrial dysfunction and ferroptosis using public datasets from The Cancer Genome Atlas (TCGA) database. We identified the mitochondrion- and ferroptosis-related lncRNAs by Pearson’s analysis and lasso-Cox regression. Moreover, real-time quantitative reverse transcription PCR (RT-qPCR) was utilized to further confirm the abnormal expression of these lncRNAs. Based on eight lncRNAs, the MF-related lncRNA prognostic signature (LPS) with outstanding stratification ability and prognostic prediction capability was constructed. In addition, functional enrichment analysis and immune cell infiltration analysis were performed to explore the possible functions of lncRNAs and their impact on the tumor microenvironment. The pathways related to G2M checkpoint and MYC were activated, and the infiltration ratio of regulatory T cells and M0 and M2 macrophages was higher in the high-risk group. In conclusion, these lncRNAs may affect mitochondria functions, ferroptosis, and immune cell infiltration in HCC through specific pathways, which may provide valuable insight into the progression and therapies of HCC.

DDX5 and DDX17—multifaceted proteins in the regulation of tumorigenesis and tumor progression

DEAD-box (DDX)5 and DDX17, which belong to the DEAD-box RNA helicase family, are nuclear and cytoplasmic shuttle proteins. These proteins are expressed in most tissues and cells and participate in the regulation of normal physiological functions; their abnormal expression is closely related to tumorigenesis and tumor progression. DDX5/DDX17 participate in almost all processes of RNA metabolism, such as the alternative splicing of mRNA, biogenesis of microRNAs (miRNAs) and ribosomes, degradation of mRNA, interaction with long noncoding RNAs (lncRNAs) and coregulation of transcriptional activity. Moreover, different posttranslational modifications, such as phosphorylation, acetylation, ubiquitination, and sumoylation, endow DDX5/DDX17 with different functions in tumorigenesis and tumor progression. Indeed, DDX5 and DDX17 also interact with multiple key tumor-promoting molecules and participate in tumorigenesis and tumor progression signaling pathways. When DDX5/DDX17 expression or their posttranslational modification is dysregulated, the normal cellular signaling network collapses, leading to many pathological states, including tumorigenesis and tumor development. This review mainly discusses the molecular structure features and biological functions of DDX5/DDX17 and their effects on tumorigenesis and tumor progression, as well as their potential clinical application for tumor treatment.

Construction and Validation of a Necroptosis-Related Signature Associated With the Immune Microenvironment in Liver Hepatocellular Carcinoma

Background: Liver hepatocellular carcinoma (LIHC) is a widespread and often deadly neoplasm. There is increasing evidence that necroptosis mediates numerous tumor-associated behaviors, as well as the regulation of the tumor microenvironment, suggesting its use as a biomarker for tumor prognosis.

Methods: Data on mRNA expression and necroptosis regulators were acquired from the TCGA and KEGG databases, respectively. Clinical liver hepatocellular carcinoma (LIHC) patient data and information on the expression of necroptosis regulators were processed by unsupervised cluster analysis was performed on LIHC patients together with necroptotic regulator expression and, differentially expressed necroptosis-related genes (DENRGs) were identified by comparing the two clusters. A signature based on eight DENRGs was constructed and verified through independent data sets, and its relationship with the tumor microenvironment was investigated.

Results: Unsupervised cluster analysis demonstrated inherent immune differences among LIHC patients. In all, 1,516 DENRGs were obtained by comparison between the two clusters. In the training set, the final eight genes obtained by univariate, LASSO, and multivariate Cox regression were utilized for constructing the signature. The survival and receiver operating characteristic (ROC) curve achieved satisfactory results in both sets. The high-risk group was characterized by greater immune infiltration and poor prognosis. The results of survival analysis based on the expression of eight DENRGs further confirmed the signature.

Conclusion: We established and validated a risk signature based on eight DERNGs related to the tumor microenvironment. This provides a possible explanation for the different clinical effects of immunotherapy and provides a novel perspective for predicting tumor prognosis in LIHC.

Forsythin regulates cell proliferation, migration, and invasion and expression of inflammatory factors in gastric cancer cells by regulating LINC00342

BACKGROUND

Forsythin is one of the main active components of the traditional Chinese medicine forsythia. It has anti-liver cancer, lung cancer, and kidney cancer effects, but whether it affects the malignant behavior of gastric cancer cells is still unknown. Long intergenic non-coding RNA 00342 (LINC00342) is a long non-coding RNA with increased expression in small cell lung cancer and colorectal cancer, which acts as an oncogene to promote the malignant behavior of these tumor cells, thereby promoting the development of tumors. We hypothesized that forsythin has an anti-gastric cancer effect by inhibiting LINC00342.

AIM

To investigate the effect of forsythin on the cell proliferation, migration, and invasion and the expression of inflammatory factors in gastric cancer cells and the possible mechanism involved.

METHODS

Gastric cancer cells (HGC-27) were cultured in vitro and treated with different doses (5, 10, and 20 μmol/L) of forsythin for 24 h. Cell proliferation was detected by CCK-8 and colony formation assays, and cell migration and invasion were detected by Transwell assay. The protein expression of E-cadherin and N-cadherin in cells was detected by Western blot, and the expression of inflammatory factors TNF-α and IL-6 in cell culture supernatant was detected with commercial kits. qRT-PCR was used to detect the expression of LINC00342 in cells. Fifty-one cases of gastric cancer tissues and adjacent tissues were collected, and qRT-PCR was used to detect the expression of LINC00342 in the tissues. LINC00342 small interfering RNA or overexpression vector was transfected into HGC-27 cells, and the effects of LINC00342 on HGC-27 cell proliferation, migration, and invasion and the expression of inflammatory factors were explored.

RESULTS

Compared with the control group, the proliferation inhibition rate and the protein expression of E-cadherin in HGC-27 cells treated with different doses of forsythin were increased (P < 0.05), but the number of cell clones, migration and invasion, the expression of N-cadherin protein and LINC00342 in the cells, and the expression of TNF-α and IL-6 in the cell culture supernatant were all decreased (P < 0.05). The expression of LINC00342 in gastric cancer tissue was significantly higher than that in adjacent tissues (P < 0.05). After knocking down LINC00342, the proliferation inhibition rate and the protein expression of E-cadherin in HGC-27 cells treated with different doses of forsythin were increased (P < 0.05), but the number of cell clones, migration and invasion, the protein expression of N-cadherin in the cells, and the expression of TNF-α and IL-6 in the cell culture supernatant were decreased (P < 0.05). Overexpression of LINC00342 reversed the effects of forsythin on the cell proliferation, migration, and invasion and the expression of inflammatory factors in HGC-27 cells.

CONCLUSION

Forsythin may inhibit the proliferation, migration, and invasion of gastric cancer HGC-27 cells and the expression of inflammatory factors TNF-α and IL-6 via mechanisms that may be related to the down-regulation of the expression of LINC00342.

lncRNA MSC-AS1 Aggravates Diabetic Nephropathy by Regulating the miR-325/CCNG1 Axis

BACKGROUND

Diabetic nephropathy (DN) is the most common microvascular complication of diabetes and has become the second leading cause of end-stage renal disease in the world. This study aims to clarify the regulatory mechanism of the lncRNA MSC-AS1/miR-325/cyclin G1 (CCNG1) axis in DN.

METHODS

The regulatory mechanism of lncRNA MSC-AS1/miR-325/CCNG1 was evaluated by RT-qPCR, CCK-8 assay, flow cytometry assay, RNA pull-down assay, ELISA, and western blot assay.

RESULTS

Upregulation of lncRNA MSC-AS1 was detected in DN patients and HRMC cells treated with high glucose (HG). Knockdown of lncRNA MSC-AS1 reduced the proliferation, fibrosis, and inflammation of HRMC cells induced by HG. In addition, lncRNA MSC-AS1 acts as a miR-325 sponge in the DN. CCNG1 is the direct target of miR-325, which can be positively regulated by lncRNA MSC-AS1 in DN. More importantly, downregulation of miR-325 and upregulation of CCNG1 can attenuate the protective effect of lncRNA MSC-AS1 knockdown on DN.

CONCLUSION

lncRNA MSC-AS1 aggravates DN by downregulating miR-325 and upregulating CCNG1.