NEAT1 promotes colon cancer progression through sponging miR-495-3p and activating CDK6 in vitro and in vivo

Recently, increasing evidence has indicated lncRNAs are powerful regulators in the progression of multiple tumors. Dysregulation of lncRNA NEAT1 has been recognized in many cancer types. Meanwhile, the studies on NEAT1 function have suggested that NEAT1 can serve as a crucial oncogene. Nevertheless, the investigation of NEAT1 in colon cancer is still few. In our study, the function of NEAT1 was studied in colon cancer. As we observed, NEAT1 level was obviously elevated in colon cancer cells. Then, HCT-116 and SW620 cells were stably infected with shRNA-NEAT1 for 48 hr. As exhibited, silence of NEAT1 could greatly repress colon cancer cell progression. Apoptosis of colon cancer cells was triggered and the cell cycle progression was remarkably inhibited by downregulation of NEAT1. Interestingly, as exhibited, miR-495-3p was obviously decreased in colon cancer cells and it significantly suppressed colon cancer progression. Subsequently, miR-495-3p was predicted as a target of NEAT1. CDK6 was speculated as the target of miR-495-3p and miR-495-3p modulated its expression negatively. Finally, it was indicated that NEAT1 promoted colon cancer development through modulating miR-495-3p and CDK6 in vivo. Taken these together, we reported that NEAT1 could sponge miR-495-3p to contribute to colon cancer progression through activating CDK6.     

LncRNA SNHG20 contributes to cell proliferation and invasion by upregulating ZFX expression sponging miR-495-3p in gastric cancer

Long noncoding RNAs (lncRNAs) exert key regulators in cancer development and progression. The functional significance of lncRNA small nucleolar RNA host gene 20 (SNHG20) was reported in gastric cancer (GC); however, the underlying molecular mechanism in GC development is largely unknown. Here, our results showed that the lncRNA SNHG20 expression was significantly higher in GC tissues compared with adjacent normal tissues by quantitative real-time PCR (qRT-PCR) analysis. Higher lncRNA SNHG20 expression was highly associated with tumor size and lymphatic metastasis of patients. Patients with higher lncRNA SNHG20 expression predicted a short disease-free survival (DFS) and overall survival (OS). Furthermore, lncRNA SNHG20 expression negatively associated with miR-495-3p expression and regulated miR-495-3p expression. Function assays confirmed that lncRNA SNHG20 knockdown using RNA interference suppressed cell proliferation and invasion of GC by negatively regulating miR-495-3p expression. Moreover, we demonstrated that lncRNA SNHG20 inhibited zinc finger protein X-linked (ZFX) expression by negatively miR-495-3p expression in GC cells. In vivo, the current study also indicated that lncRNA SNHG20 knockdown reduced the tumor growth by downregulating ZFX expression. Thus, our results implied that inhibition of SNHG20/miR-495-3p/ZFX axis may provide valuable target for GC treatment.     

miR-200b-3p in plasma is a potential diagnostic biomarker in oral squamous cell carcinoma

Context: Circulating MicroRNAs (miRNAs) are emerging as novel biomarkers for tumour.

Objective: Evaluate the diagnostic potential of plasma miR-200b-3p in oral squamous cell carcinoma (OSCC).

Materials and methods: miR-200b-3p was detected by qRT-PCR in paired pre-operative and post-operative plasmas from 80 OSCC patients and 80 healthy controls.

Results: Plasma miR-200b-3p was significantly upregulated in OSCC, and it was higher in WHO II/III grade than WHO I grade. The AUC of miR-200b-3p for OSCC was 0.9173. miR-200b-3p was significantly downregulated after surgery. High miR-200b-3p expression was associated with poor prognosis.

Discussion and conclusion: Plasma miR-200b-3p could be a potential diagnostic biomarker for OSCC.     

lncRNA NEAT1 facilitates melanoma cell proliferation,migration, and invasion via regulating miR-495-3p and E2F3

Melanoma contributes a lot to skin cancer-related deaths. lncRNAs are implicated in various diseases, including melanoma. lncRNA NEAT1 is frequently dysregulated and can play important roles in multiple cancers. Nevertheless, little has been studied about the function of NEAT1 in melanoma progression. In our present research, we displayed NEAT1 was overexpressed in melanoma cells. A series of functional assays showed that overexpression of NEAT1 promoted the proliferation, migration, and invasion of melanoma cells. By contrast, NEAT1 knockdown obviously restrained melanoma cell progression. Mechanistically, it was revealed that NEAT1 could directly bind with miR-495-3p, which led to a negative effect on miR-495-3p levels. In addition, miR-495-3p was significantly decreased in melanoma cells. Furthermore, E2F3 was postulated as the target of miR-495-3p and overexpression of this miR could suppress the levels of E2F3. Meanwhile, it was exhibited that melanoma cell proliferation, migration, and invasion induced by E2F3 silence was abrogated by miR-495-3p. Moreover, an in vivo xenograft nude mice model was established using A375 cells and it was indicated that NEAT1 promoted melanoma progression in vivo via regulating the miR-495-3p/E2F3 axis. In conclusion, we suggest that NEAT1 exerts an oncogenic effect on melanoma development via inhibition of miR-495-3p and induction of E2F3. NEAT1 might serve as a crucial prognostic biomarker of melanoma.     

Long noncoding RNA TUG1 regulates the development of oral squamous cell carcinoma through sponging miR-524-5p to mediate DLX1 expression as a competitive endogenous RNA

Long noncoding RNA (lncRNA) exerts a potential regulatory role in tumorigenesis. LncRNA TUG1 expression remains high in oral squamous cell carcinoma (OSCC) tissues. However, its biological mechanism in OSCC remains unknown. In this study, TUG1 expression in OSCC cells was detected by quantitative real-time polymerase chain reaction. Proliferative and migratory potentials of OSCC cells were determined by Cell Counting Kit 8, 5-Ethynyl-2′- deoxyuridine (EdU), and Transwell assay, respectively. We identified the potential target of TUG1 through bioinformatics and dual-luciferase reporter gene assay. Furthermore, their interaction and functions in regulating the development of OSCC were clarified by western blot and RNA immunoprecipitation assay. Our results demonstrated a high expression of TUG1 in OSCC cells. Overexpression of TUG1 markedly accelerated proliferative and migratory potentials of OSCC cells. Besides, TUG1 could positively regulate the expression of distal-less homeobox 1 (DLX1) by competing with miR-524-5p. These results indicated that TUG1 participated in the development of OSCC as a competing endogenous RNA to competitively bind to miR-524-5p and thus mediate DLX1 expression.     

Long noncoding RNA NEAT1 sponges miR-495-3p to enhance myocardial ischemia-reperfusion injury via MAPK6 activation

The biological function of long noncoding RNA NEAT1 has been revealed in a lot of diseases. Nevertheless, it is still not yet clear whether NEAT1 can modulate the process of myocardial ischemia–reperfusion injury (M-I/R). Here, we reported that NEAT1 was able to sponge miR-495-3p to contribute to M-I/R injury through activating mitogen-activated protein kinase 6 (MAPK6). First, elevated expression of NEAT1 was revealed in M-I/R injury mice, meanwhile, lactate dehydrogenase (LDH) and creatine kinase-muscle/brain (CK-MB) were also upregulated in the serum. Meanwhile, as previously reported, miR-495 serves as a tumor suppressor or an oncogenic miRNA in different types of cancer. Currently, we found miR-495-3p was remarkably reduced in M-I/R mice. Additionally, NEAT1 was significantly induced whereas miR-495-3p was greatly reduced by H₂O₂ treatment in H9C2 cells. Moreover, loss of NEAT1 in H9C2 cells could repress the viability and proliferation of cells. For another, overexpression of NEAT1 exhibited an opposite phenomenon. Furthermore, LDH release and caspase-3 activity were obviously triggered by upregulation of NEAT1 while suppressed by NEAT1 knockdown. miR-495-3p was indicated and validated as a target of NEAT1 using the analysis of bioinformatics. Interestingly, we observed that miR-495-3p mimics repressed tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-18 protein expression while their levels were enhanced by the inhibition of miR-495-3p in H9c2 cells. Subsequently, it was manifested that MAPK6 was a target of miR-495-3p, which could exert a lot in the NEAT1/miR-495-3p-mediated M-I/R injury. Overall, our results implied that NEAT1 contributed to M-I/R injury via the modulation of miR-495-3p and MAPK6.     

LncRNA SNHG1 regulates immune escape of renal cell carcinoma by targeting miR-129-3p to activate STAT3 and PD-L1

Immune escape of renal cell carcinoma (RCC) impacts patient survival. However, the molecular mechanism of long noncoding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) in RCC immune escape remains unclear. Quantitative real-time PCR and western blotting results revealed that the expression of lncRNA SNHG1 and STAT3 were upregulated in RCC tissues and cells and that the expression of miR-129-3p was downregulated. Enzyme-linked immunosorbent assay results revealed the increased levels of immune-related factors (interferon-γ, tumour necrosis factor α, and interleukin-2) in RCC tissues. SNHG1 knockdown or miR-129-3p overexpression inhibited the proliferation and invasion of A498 and 786-O cells, while the proliferation and cytotoxicity of CD8⁺ T cells increased, which promoted the secretion of immune-related factors. STAT3 overexpression decreased the protective effect of miR-129-3p overexpression on RCC cell immune escape. In addition, miR-129-3p knockdown and STAT3 overexpression decreased the protective effect of lncRNA SNHG1 knockdown on RCC cell immune escape. In addition, PD-L1 expression was downregulated after lncRNA SNHG1 knockdown but upregulated after miR-129-3p knockdown and STAT3 overexpression. Dual-luciferase assays showed that lncRNA SNHG1 targets miR-129-3p, and miR-129-3p targets STAT3. RNA pull-down and RNA immunoprecipitation assays verified the regulatory relationship between SNHG1 and STAT3. In vivo, shSNHG1 prolonged the overall survival of RCC tumour model mice and inhibited RCC tumour growth and immune escape but increased CD8⁺ T cell infiltration in mice. Our findings provide an experimental basis for elucidating the molecular mechanisms of immune escape by RCC and reveal a novel target to treat this disease.     

Histone methylation antagonism drives tumor immune evasion in squamous cell carcinomas

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miR-204-5p regulates cell proliferation,invasion, and apoptosis by targeting IL-11 in esophageal squamous cell carcinoma

Esophageal cancer (EC) is the world's eighth most common malignant neoplasm and is ranked as the sixth leading cause of death related to cancer. Aberrant microRNA (miRNA) expression has been reported to be associated with esophageal squamous cell carcinoma. However, the molecular mechanism of miR-204-5p in esophageal squamous cell carcinoma (ESCC) is not clear. Therefore, the aim of this study was to investigate the potential role of miR-204-5p in ESCC. In the present study, we found that miR-204-5p could affect ESCC proliferation, invasion, apoptosis, and cell cycle in cell and mouse models. A dual-luciferase reporter assay showed that miR-204-5p expression was negatively correlated with interleukin-11 (IL-11) expression. IL-11 overexpression reversed the suppressive effects of miR-204-5p in the cell lines. These results indicated that miR-204-5p functions as a tumor suppressor by directly targeting IL-11 in ESCC.     

CircTIMELESS regulates the proliferation and invasion of lung squamous cell carcinoma cells via the miR-136-5p/ROCK1 axis

Numerous studies demonstrate that circular RNAs (circRNAs) are critical regulators of the occurrence and progression of tumors. However, research on the involvement of circRNAs in lung squamous cell carcinoma (LUSC) is limited. In our study, circTIMELESS (also named hsa_circ_0000408 in the Human circRNA Database) was upregulated in both LUSC tissues and LUSC cells, and circTIMELESS expression was positively associated with the TNM stage. Moreover, circTIMELESS silencing markedly suppressed invasion in vitro and disrupted proliferation in vitro as well as in vivo. Additional investigations have shown that circTIMELESS functions as a miR-136-5p “sponge” and regulates miR-136-5p expression. Furthermore, the impact of miR-136-5p upregulation was consistent with the results of circTIMELESS silencing, both of which inhibited the proliferation and invasion of LUSC cells. Additional results showed that Rho-associated coiled-coil containing protein kinase 1 (ROCK1) is targeted by miR-136-5p. The results of recovery experiments showed that ROCK1 overexpression partly rescued the impact of circTIMELESS silencing and miR-136-5p upregulation on proliferation and invasion. Consequently, our findings confirmed that circTIMELESS exists in LUSC and acts as a tumor promoter through the miR-136-5p/ROCK1 axis. Based on these findings, circTIMELESS may be potentially utilized as a therapeutic target for LUSC.     

Circular RNA circDVL1 inhibits clear cell renal cell carcinoma progression through the miR-412-3p/PCDH7 axis

Clear cell renal cell carcinoma (ccRCC) is a primary kidney cancer with high aggressive phenotype and extremely poor prognosis. Accumulating evidence suggests that circular RNAs (circRNAs) play pivotal roles in the occurrence and development of various human cancers. However, the expression, clinical significance and regulatory role of circRNAs in ccRCC remain largely unclear. Here we report that circDVL1 to be reduced in the serums and tissues from ccRCC patients, and to negatively correlate with ccRCC malignant features. Overexpression of circDVL1 inhibits proliferation, induces G1/S arrest, triggers apoptosis, and reduces migration and invasion in different ccRCC cells in vitro. Correspondingly, circDVL1 overexpression suppresses ccRCC tumorigenicity in a mouse xenograft model. Mechanistically, circDVL1 serves as a sponge for oncogenic miR-412-3p, thereby preventing miR-412-3p-mediated repression of its target protocadherin 7 (PCDH7) in ccRCC cells. Collectively, our results demonstrate that circDVL1 exerts tumor-suppressive function during ccRCC progression through circDVL1/miR-412-3p/PCDH7 axis, and suggest that circDVL1 could be a novel diagnostic and prognositc marker and therapeutic target for ccRCC.     

Circ_0000052/miR-382-3p axis induces PD-L1 expression and regulates cell proliferation and immune evasion in head and neck squamous cell carcinoma

A better understanding of the mechanisms underlying PD-L1 aberrant expression in head and neck squamous cell carcinoma (HNSCC) will help reveal predictive biomarkers and overcome resistance to treatment. In this study, the prognostic significance of PD-L1 in forty-five HNSCC archival samples was determined by qRT-PCR. The biological function associated with malignant behaviour was assessed by PD-L1 depletion, miR-382-3p re-expression and regulation of circ_0000052. The interactions of PD-L1-miRNA and miRNA-circRNA were determined by qRT-PCR, Western blot analysis, dual-luciferase reporter assays and RNA immunoprecipitation assays. PD-L1 was highly expressed in patient samples and cancer cell lines. Higher levels of PD-L1 were associated with patient recurrences and play a pivotal role in regulating cell proliferation, migration, invasion, clonogenicity and apoptosis. In addition to demonstrating that the IFN-γ/JAK2/STAT1 signalling pathway can induce PD-L1 overexpression in HNSCC, a novel mechanism by which upregulated circ_0000052 mediates PD-L1 overexpression was also demonstrated. To do this, circ_0000052 competitively binds to miR-382-3p and alleviates its repression of PD-L1. This leads to overexpression of PD-L1, causing the aggressiveness of the cells. Our data demonstrate that circ_0000052 is oncogenic, and the circ_0000052/miR-382-3p/PD-L1 axis is critical in HNSCC progression. The manipulation of circRNAs/miRNAs in combination with anti-PD-L1 therapy may improve personalized disease management.