Long Non-Coding RNA MAPK8IP1P2 Inhibits Lymphatic Metastasis of Thyroid Cancer by Activating Hippo Signaling via Sponging miR-146b-3p

Pien Tze Huang Inhibits Migration and Invasion of Hepatocellular Carcinoma Cells by Repressing PDGFRB/YAP/CCN2 Axis Activity

OBJECTIVE

To investigate the effects of Pien Tze Huang (PZH) on the migration and invasion of HCC cells and underlying molecular mechanism.

METHODS

Cell counting kit-8 (CCK-8) was applied to evaluate the cell viabilities of SMMC-7721, SK-Hep-1, C3A and HL-7702 (6 × 103 cells/well) co-incubated with different concentrations of PZH (0, 0.2, 0.4, 0.6, 0.8 mg/mL) for 24 h. Transwell, wound healing assay, CCK-8 and Annexin V-FITC/PI staining were conducted to investigate the effects of PZH on the migration, invasion, proliferation and apoptosis of SK-Hep-1 and SMMC-7721 cells (650 µ g/mL for SK-Hep-1 cells and 330 µ g/mL for SMMC-7721 cells), respectively. In vivo, lung metastasis mouse model constructed by tail vein injection of HCC cells was used for evaluating the anti-metastasis function of PZH. SK-Hep-1 cells (106 cells/200 µ L per mice) were injected into B-NDG mice via tail vein. Totally 8 mice were randomly divided into PZH and control groups, 4 mice in each group. After 2-d inoculation, mice in the PZH group were administered with PZH (250 mg/kg, daily) and mice in the control group received only vehicle (PBS) from the 2nd day after xenograft to day 17. Transcriptome analysis based on RNA-seq was subsequently used for deciphering anti-tumor mechanism of PZH. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were applied to verify RNA-seq results. Luciferase reporter assay was performed to examine the transcriptional activity of yes-associated protein (YAP).

RESULTS

PZH treatment significantly inhibited the migration, invasion, proliferation and promoted the apoptosis of HCC cells in vitro and in vivo (P<0.01). Transcriptome analysis indicated that Hippo signaling pathway was associated with anti-metastasis function of PZH. Mechanical study showed PZH significantly inhibited the expressions of platelet derived growth factor receptor beta (PDGFRB), YAP, connective tissue growth factor (CCN2), N-cadherin, vimentin and matrix metallopeptidase 2 (MMP2, P<0.01). Meanwhile, the phosphorylation of YAP was also enhanced by PZH treatment in vitro and in vivo. Furthermore, PZH played roles in inhibiting the transcriptional activity of YAP.

CONCLUSION

PZH restrained migration, invasion and epithelial-mesenchymal transition of HCC cells through repressing PDGFRB/YAP/CCN2 axis.

m6A reader IGF2BP2 promotes lymphatic metastasis by stabilizing DPP4 in papillary thyroid carcinoma

Lymph node metastasis (LNM) is a major cause of locoregional recurrence of papillary thyroid carcinoma (PTC). However, the mechanisms responsible for LNM are unclear. Aberrant N6-methyladenosine (m6A) RNA modification plays a vital role in cancer progression and metastasis, and whether m6A modification regulates LNM in PTC remains to be determined. This study showed that IGF2BP2 was upregulated in PTC and positively associated with LNM. Functionally, IGF2BP2 knockdown significantly inhibited PTC cell proliferation and invasion in vitro, and vice versa. Moreover, IGF2BP2 knockdown significantly inhibited lymphatic metastasis in vivo. Mechanistically, Human m6A epitranscriptomic microarray, MeRIP, and RIP assays demonstrated that IGF2BP2 activated the NF-KB pathway by enhancing DPP4 stability in an m6A-dependent manner. Furthermore, IGF2BP2 knockdown increased the sensitivity of PTC cells to cisplatin therapy to a certain extent, while its overexpression produced the opposite effects. Overall, this study uncovers that IGF2BP2 promotes lymphatic metastasis via stabilizing DPP4 in an m6A-dependent manner, and provides new insights for understanding the mechanism of lymphatic metastasis in PTC.

Aberrantly Expressed lncRNA LINC00847 May Serve as a Promising Prognostic Factor for Thyroid Cancer

Thyroid cancer is a tumor that occurs in the head and neck, which originates from the thyroid follicular epithelial cells. The current research is discussed and elaborated from the perspective of molecular prognostic biomarkers to gain a deeper understanding of the molecular mechanism of thyroid cancer and to provide more effective treatment and prognostic methods for patients. Thyroid cancer patients were explored from histological, cellular and clinical levels. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of LINC00847 and miR-146b-5p in the tissues and cells of the subjects. Cell growth and thyroid cancer progression were determined by the cell counting kit-8 (CCK-8) and transwell assays. The LINC00847 sponge miR-146b-5p was assessed by bioinformatics tools and luciferase reporter assay, and the Kaplan-Meier method and multivariate Cox regression analysis suggested the prognostic value of high expression of LINC00847. In thyroid cancer tissues and cells, the expression of LINC00847 was decreased. Overexpression of LINC00847 remarkably inhibited the proliferation level, migration ability and invasion ability of thyroid cancer cells. Besides, miR-146b-5p was upregulated in thyroid cancer tissues and cells. It was confirmed that LINC00847 targeting miR-146b-5p had a regulatory effect on the progression of thyroid cancer, and LINC00847 was negatively correlated with miR-146b-5p. LINC00847 may be considered a meaningful prognostic marker to influence tumor growth through sponge miR-146b-5p, which provides a new basis for the prognosis and treatment of thyroid cancer.

The STING-IRF3 Signaling Pathway, Mediated by Endoplasmic Reticulum Stress, Contributes to Impaired Myocardial Autophagic Flux After Ischemia/Reperfusion

ABSTRACT

This study aimed to determine whether endoplasmic reticulum (ER) stress is involved in impaired autophagy after myocardial ischemia/reperfusion (M-I/R) and elucidate the underlying mechanisms. The expression levels of stimulator of interferon gene (STING) and interferon regulatory transcription factor 3 (IRF3) phosphorylation increased in M-I/R heart tissues and hypoxia-treated/reoxygenation-treated H9c2 cells. The ER stress inhibitor 4-phenylbutyric acid (4-PBA) significantly suppressed the stimulation of STING-IRF3 transcription and alleviated cardiac dysfunction caused by M-I/R injury. In addition, 4-PBA reversed ischemia-induced/reperfusion-induced autophagic flux dysfunction, as demonstrated by a decrease in p 62 and LC3 levels. Similarly, the protective effect of STING deficiency on myocardial cell damage was achieved by the recovery of autophagic flux. Conversely, the protective effect of 4-PBA against hypoxia/reoxygenation injury in cardiomyocytes was offset by STING overexpression, wherein the activated STING-IRF3 pathway promoted the expression of Rubicon (a negatively-regulated autophagic molecule) by binding to the Rubicon promoter. Rubicon ablation effectively counteracts the adverse effects of STING overexpression in cardiomyocytes. The data showed that STING-IRF3 signaling of ER stress receptors is particularly important in the progression of physiological M-I/R caused by the inhibition of autophagic flow in vivo and in vitro.

The emerging roles of long noncoding RNAs in lymphatic vascular development and disease

Recent advances in RNA sequencing technologies helped uncover what was once uncharted territory in the human genome-the complex and versatile world of long noncoding RNAs (lncRNAs). Previously thought of as merely transcriptional "noise", lncRNAs have now emerged as essential regulators of gene expression networks controlling development, homeostasis and disease progression. The regulatory functions of lncRNAs are broad and diverse, and the underlying molecular mechanisms are highly variable, acting at the transcriptional, post-transcriptional, translational, and post-translational levels. In recent years, evidence has accumulated to support the important role of lncRNAs in the development and functioning of the lymphatic vasculature and associated pathological processes such as tumor-induced lymphangiogenesis and cancer metastasis. In this review, we summarize the current knowledge on the role of lncRNAs in regulating the key genes and pathways involved in lymphatic vascular development and disease. Furthermore, we discuss the potential of lncRNAs as novel therapeutic targets and outline possible strategies for the development of lncRNA-based therapeutics to treat diseases of the lymphatic system.

Long non-coding RNAs modulate tumor microenvironment to promote metastasis: novel avenue for therapeutic intervention

Cancer is a devastating disease and the primary cause of morbidity and mortality worldwide, with cancer metastasis responsible for 90% of cancer-related deaths. Cancer metastasis is a multistep process characterized by spreading of cancer cells from the primary tumor and acquiring molecular and phenotypic changes that enable them to expand and colonize in distant organs. Despite recent advancements, the underlying molecular mechanism(s) of cancer metastasis is limited and requires further exploration. In addition to genetic alterations, epigenetic changes have been demonstrated to play an important role in the development of cancer metastasis. Long non-coding RNAs (lncRNAs) are considered one of the most critical epigenetic regulators. By regulating signaling pathways and acting as decoys, guides, and scaffolds, they modulate key molecules in every step of cancer metastasis such as dissemination of carcinoma cells, intravascular transit, and metastatic colonization. Gaining a good knowledge of the detailed molecular basis underlying lncRNAs regulating cancer metastasis may provide previously unknown therapeutic and diagnostic lncRNAs for patients with metastatic disease. In this review, we concentrate on the molecular mechanisms underlying lncRNAs in the regulation of cancer metastasis, the cross-talk with metabolic reprogramming, modulating cancer cell anoikis resistance, influencing metastatic microenvironment, and the interaction with pre-metastatic niche formation. In addition, we also discuss the clinical utility and therapeutic potential of lncRNAs for cancer treatment. Finally, we also represent areas for future research in this rapidly developing field.

Long non-coding RNA MFSD4A-AS1 promotes lymphangiogenesis and lymphatic metastasis of papillary thyroid cancer

Lymphatic metastasis is the leading cause responsible for recurrence and progression in papillary thyroid cancer (PTC), where dysregulation of long non-coding RNAs (lncRNAs) has been extensively demonstrated to be implicated. However, the specific lymphatic node metastatsis-related lncRNAs remain not identified in PTC yet. Lymphatic node metastatsis-related lncRNA, MFSD4A-AS1, was explored in the PTC dataset from The Cancer Genome Atlas and our clinical samples. The roles of MFSD4A-AS1 in lymphatic metastasis were investigated in vitro and in vivo. Bioinformatic analysis, luciferase assay and RNA immunoprecipitation assay were performed to identify the potential targets and the underlying pathway of MFSD4A-AS1 in lymphatic metastasis of PTC. MFSD4A-AS1 was specifically upregulated in PTC tissues with lymphatic metastasis. Upregulating MFSD4A-AS1 promoted mesh formation and migration of human umbilical vein endothelial cells and invasion and migration of PTC cells. Importantly and consistently, MFSD4A-AS1 promoted lymphatic metastasis of PTC cells in vivo by inducing the lymphangiogenic formation and enhancing the invasive capability of PTC cells. Mechanistic dissection further revealed that MFSD4A-AS1 functioned as competing endogenous RNA to sequester miR-30c-2-3p, miR-145-3p and miR-139-5p to disrupt the miRNA-mediated inhibition of vascular endothelial growth factors A and C, and further activated transforming growth factor (TGF)-β signaling by sponging miR-30c-2-3p that targeted TGFBR2 and USP15, both of which synergistically promoted lymphangiogenesis and lymphatic metastasis of PTC. Our results unravel novel dual mechanisms by which MFSD4A-AS1 promotes lymphatic metastasis of PTC, which will facilitate the development of anti-lymphatic metastatic therapeutic strategy in PTC.

miR‑146b‑5p activation of hepatic stellate cells contributes to the progression of fibrosis by directly targeting HIPK1

The present study aimed to explore the biological functions of microRNA (miR)-146b-5p and homeodomain interacting protein kinase 1 (HIPK1) in the progression of hepatic fibrosis (HF) and to identify the underlying mechanism. A rat HF model was established by administering a subcutaneous injection of carbon tetrachloride (CCl₄). Relative levels of miR-146b-5p and HIPK1 in fibrotic rat liver tissues and the rat hepatic stellate cell (HSC) line HSC-T6 were measured by quantitative reverse transcription PCR, western blotting and immunohistochemistry. Following activation of HSC-T6 cells by lipopolysaccharide (LPS) induction, cell viability was examined by MTT assay. Transfection of miR-146b-5p mimic or inhibitor into HSC-T6 cells was performed, with the aim to identify the influence of miR-146b-5p on HSC-T6 cell behavior. The targeting relationship between miR-146b-5p and HIPK1 was predicted by TargetScan 7.2 and StarBase 3.0 and it was later verified by a dual-luciferase reporter assay. Through lentivirus transfection, the biological function of HIPK1 in regulating the progression of HF and the underlying mechanism were investigated. The results showed that miR-146b-5p was upregulated in liver tissues of rats with HF and activated HSC-T6 cells, while HIPK1 was downregulated in liver tissues of rats with HF and activated HSC-T6 cells. miR-146b-5p was able to upregulate the activation markers of LPS-induced HSC-T6 cells, upregulate COL1A1 and TGF-β, increase cell viability and contribute to fibrosis progression. HIPK1 was validated as the direct target of miR-146b-5p and its overexpression could effectively reduce the effect of miR-146b-5p in contribution to the progression of HF. In conclusion, miR-146b-5p was significantly upregulated during the progression of HF. By targeting and downregulating HIPK1, miR-146b-5p could significantly activate HSCs, upregulate COL1A1 and TGF-β and contribute to fibrosis progression. miR-146b-5p is a potential biomarker and therapeutic target for HF.

Regulation of RASSF by non-coding RNAs in different cancers

Ras-association domain family (RASSF) proteins are tumor suppressors and have gained phenomenal limelight because of their mechanistic role in the prevention/inhibition of carcinogenesis and metastasis. Decades of research have demystified wide ranging activities of RASSF molecules in multiple stages of cancers. Although major fraction of RASSF molecules has tumor suppressive roles, yet there is parallel existence of proof-of-concept about moonlighting activities of RASSF proteins as oncogenes. RASSF proteins tactfully rewire signaling cascades for prevention of cancer and metastasis but circumstantial evidence also illuminates oncogenic role of different RASSF proteins in different cancers. In this review we have attempted to provide readers an overview of the complex interplay between non-coding RNAs and RASSF proteins and how these versatile regulators shape the landscape of carcinogenesis and metastasis.

Long noncoding RNA MRPL23-AS1 suppresses anoikis in salivary adenoid cystic carcinoma in vitro

Distant lung metastasis is the main factor that affects the survival rate of patients with salivary adenoid cystic carcinoma (SACC). Anoikis resistance is a feature of tumor cells that easily metastasize. The long non-coding RNA (lncRNA) MRPL23 antisense RNA 1 (MPRL23-AS1) is related to lung metastasis in SACC, but its role in anoikis resistance is unknown.After altering MPRL23-AS1 expression in SACC cells, anoikis resistance was detected by calcein AM/PI staining and annexin V/PI flow cytometry. The apoptosis marker activated caspase-3 and the bcl-2/bax ratio were detected by Western blotting. The relationship between MPRL23-AS1 and the promoter of the potential downstream target gene p19INK4D was identified by chromatin immunoprecipitation (ChIP)-PCR assay. p19INK4D expression in patient tissues was determined using qRT-PCR and immunohistochemistry.The functional experiments showed that MPRL23-AS1 could promote anoikis resistance in vitro. MRPL23-AS1 recruited the EZH2 to the promoter region of p19INK4D, inhibited p19INK4D expression, and promoted tumor cell anoikis resistance. p19INK4D overexpression did not affect anoikis in attached cells; however, it attenuated the anoikis resistance effect of MPRL23-AS1 in suspension cells. p19INK4D expression was significantly lower in SACC tissues than in normal tissues.The novel MRPL23-AS1/p19INK4D axis may be a potential SACC biomarker or therapeutic target.

The potential roles and mechanisms of non-coding RNAs in cancer anoikis resistance

Increasing evidence indicates that anoikis resistance is a critical process for metastasis of cancer cells, making it the attractive therapeutic target for cancer benefit. Anoikis resistance is widely regulated by various factors, such as signaling pathways, integrins switch, and non-coding RNAs (ncRNAs). ncRNAs composed of microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are frequently dysregulated in a variety of human malignancies and are closely related to anoikis resistance of cancer cells. Based on the available literature, we reviewed the molecular basis underlying ncRNAs modulating cancer cells anoikis resistance, which may contribute to a better understanding of cancer metastasis and provide new beneficial therapeutic strategies against cancer.