CTCF-induced upregulation of LINC01207 promotes gastric cancer progression via miR-1301-3p/PODXL axis

METTL3-deficiency Suppresses Neural Apoptosis to Induce Protective Effects in Cerebral I/R Injury via Inhibiting RNA m6A Modifications: A Pre-clinical and Pilot Study

N6-Methyladenosine (m6A) RNA methylation involves in regulating the initiation, progression and aggravation of cerebral ischemia-reperfusion (I/R) injury, however, the detailed functions and mechanisms by which m6A drives cerebral I/R injury are not fully understood. This study found that methyltransferase-like 3 (METTL3) m6A-dependently regulated cerebral I/R injury trough regulating a novel LncRNA ABHD11-AS1/miR-1301-3p/HIF1AN/HIF-1α axis. Specifically, the middle cerebral artery occlusion (MCAO)/reperfusion mice models and glucose deprivation (OGD)/reoxygenation (RX) astrocyte cell models were respectively established, and we verified that METTL3, ABHD11-AS1 and HIF1AN were upregulated, whereas miR-1301-3p and HIF-1α were downregulated in both MCAO/reperfusion mice tissues and OGD/RX astrocytes. Mechanical experiments confirmed that METTL3 m6A dependently increased stability and expression levels of ABHD11-AS1, and elevated ABHD11-AS1 sponged miR-1301-3p to upregulate HIF1AN, resulting in the downregulation of HIF-1α. Moreover, silencing of METTL3 rescued MCAO/reperfusion and OGD/RX-induced oxidative stress-associated cell apoptosis and cell cycle arrest in both mice brain tissues in vivo and the mouse primary astrocytes in vitro, which were abrogated by overexpressing ABHD11-AS1 and downregulating miR-1301-3p. Taken together, our study firstly reported a novel METTL3/m6A/ ABHD11-AS1/miR-1301-3p/HIF1AN/HIF-1α signaling cascade in regulating the progression of cerebral I/R injury, and future work will focus on investigating whether the above genes can be used as biomarkers for the treatment of cerebral I/R injury by performing clinical studies.

Inhibition of CCCTC Binding Factor-Programmed Cell Death Ligand 1 Axis Suppresses Emergence of Chemoresistance Induced by Gastric Cancer-Derived Mesenchymal Stem Cells

Background

Gastric cancer (GC) is the third leading cause of cancer-associated deaths worldwide. Stromal cells, especially mesenchymal stem cells (MSCs), play significant roles in the development of therapy resistance depending on their paracrine function. The PD-1/PD-L1 crosstalk between cancer and immune cells has been well studied. Emerging evidence suggests that PD-L1 also contributes to tumor resistance to therapy.

Methods

Cell survival and apoptosis were assessed using CCK-8, colony formation, and flow cytometry assays. Protein alterations were analyzed via Western blot. Gene knockdown and overexpression were achieved with siRNA/shRNA and lentiviral infection, respectively. Drug effects on tumors in vivo were assessed with xenografts in nude mice. In addition, GC patient samples after chemotherapy treatment were collected to observe the relationship between chemotherapy effect and CTCF or PD-L1.

Results

In response to 5-fluorouracil or paclitaxel treatment, GCMSC-CM enhanced the cell viability and decreased the apoptosis rate. Furthermore, blocking PD-L1 or CTCF in GC cells prevented GCMSC-induced drug resistance accompanied by a decline in cell stemness. Consistent with these in vitro observations, mice treated with GCMSC-CM showed a lower sensitivity to 5-fluorouracil. In addition, high expression of CTCF and PD-L1 was associated with poor chemotherapy progression in the clinic.

Conclusion

Study results demonstrate a mechanism where GCMSC-CM promotes GC chemoresistance by upregulating CTCF-PD-L1 and provide strong evidence in support of targeting CTCF-PD-L1 signaling as a strategy to prevent resistance in the clinic.

Aberrant Expression of miR-1301 in Human Cancer

miR-1301 is a newly discovered miRNA, which is abnormally expressed in 14 types of tumors. miR-1301 inhibits 23 target genes, forms a ceRNA network with 2 circRNAs and 8 lncRNAs, and participates in 6 signaling pathways, thereby affecting tumor cell proliferation, invasion, metastasis, apoptosis, angiogenesis, etc. Abnormal expression of miR-1301 is often associated with poor prognosis of cancer patients. In addition, miR-1301 is related to the anti-tumor effect of epirubicin on osteosarcoma and imatinib on chronic myeloid leukemia(CML) and can enhance the cisplatin sensitivity of ovarian cancer. This work systematically summarizes the abnormal expression and prognostic value of miR-1301 in a variety of cancers, depicts the miR-1301-related signaling pathways and ceRNA network, and provides potential clues for future miR-1301 research.

Long non-coding RNA GAS5 inhibits osteogenic differentiation through miR-382-3p/TAF1 signaling

Background: Long non-coding RNAs (lncRNAs) have been confirmed as important regulators during osteogenic differentiation. Previous researches have disclosed that growth arrest-specific transcript 5 (GAS5) can promote the osteogenic differentiation of human bone marrow mesenchyml stem cells (hBMSCs), but the underlying regulatory mechanism of GAS5 during the osteogenic differentiation of hBMSCs is unclear. Methods: Osteogenic differentiation was induced in hBMSCs by using osteogenic medium (OM). Gene expression was assessed by RT-qPCR or western blot assays as needed. ALP activity, ALP staining and ARS staining assays were performed to evaluate the impact of GAS5, microRNA-382-3p (miR-382-3p) and TATA-box binding protein associated factor 1 (TAF1) on osteogenic differentiation in vitro. The interaction among GAS5, miR-382-3p and TAF1 was determined by RIP, ChIP and luciferase reporter assays. Results: Expression of GAS5 (transcript variant 2) was down-regulated during the osteogenic differentiation of hBMSCs and its overexpression retarded the osteogenic differentiation of hBMSCs. GAS5 inhibited miR-382-3p through targeting RNA-directed microRNA degradation (TDMD). MiR-382-3p down-regulation partially offset the promoted osteogenic differentiation of hBMSCs upon GAS5 silencing. TAF1 negatively modulated osteogenic differentiation and it activated GAS5 transcription so as to form a positive GAS5/miR-382-3p/TAF1 feedback loop in hBMSCs. Conclusion: This research was the first to reveal that the GAS5/miR-382-3p/TAF1 feedback loop inhibited the osteogenic differentiation of hBMSCs, which provided new clues for exploring the mechanism of osteogenic differentiation and disclosed the potential of GAS5 as a promising target during osteogenic differentiation.

Long non-coding RNA CCDC183-AS1 regulates gastric cancer AGS cell proliferation, migration, and invasion by targeting miR-1301-3p

BACKGROUND

The long noncoding RNA (lncRNA) CCDC183-AS1 is up-regulated in hepatocellular carcinoma and promotes the progression of hepatocellular carcinoma. However, the effect of CCDC183-AS1 on gastric cancer and its molecular mechanism are unknown. Starbase prediction shows that CCDC183-AS1 may target miR-1301-3p. We hypothesized that CCDC183-AS1 can target and regulate miR-1301-3p to affect the proliferation, migration, and invasion of gastric cancer cells, thereby affecting the development of gastric cancer.

AIM

To investigate the effect of CCDC183-AS1 on the proliferation, migration, and invasion of gastric cancer AGS cells and the underlying molecular mechanism.

METHODS

Thirty gastric cancer tissues and matched adjacent normal tissues were collected at our hospital. RT-qPCR was used to detect the expression of CCDC183-AS1 and miR-1301-3p in the collected tissues. MTT assay was used to detect cell proliferation in AGS cells, and transwell assay was used to detect cell migration and invasion. Western blot was used to detect the protein expression of CyclinD1, MMP-2, MMP-9, and p21. Small interfering RNA targeting CCDC183-AS1 (si-CCDC183-AS1) and miR-1301-3p were transfected into AGS cells, respectively, and the changes in cell proliferation, migration, and invasion were detected using the above methods. StarBase prediction showed that the sequence of lncRNA CCDC183-AS1 contains nucleotide sequences complementary to miR-1301-3p, and the targeting relationship was confirmed by dual luciferase report assay.

RESULTS

Compared with adjacent normal tissues, the expression levels of CCDC183-AS1 and miR-1301-3p in gastric cancer tissues were significantly increased and decreased, respectively (P < 0.05). Inhibition of CCDC183-AS1 or overexpression of miR-1301-3p reduced the proliferation, migration, and invasion of AGS cells, decreased the expression levels of CyclinD1, MMP-2, and MMP-9, and increased the expression level of p21 (P < 0.05). CCDC183-AS1 targeted the expression of miR-1301-3p. Down-regulation of miR-1301-3p reversed the effect of inhibition of CCDC183-AS1 expression on the proliferation, migration, and invasion of AGS cells.

CONCLUSION

Inhibition of CCDC183-AS1 regulates the proliferation, migration, and invasion of gastric cancer AGS cells via targeted up-regulation of miR-1301-3p expression.

Long non-coding RNA LINC01207 promotes cell proliferation and migration but suppresses apoptosis and autophagy in oral squamous cell carcinoma by the microRNA-1301-3p/lactate dehydrogenase isoform A axis

Long noncoding RNAs (lncRNAs) have been reported to participate in the progression of various cancers, including oral squamous cell carcinoma (OSCC). This study aims to find out whether lncRNA LINC01207 regulates the progression of OSCC. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was conducted to evaluate gene expression in OSCC cells and tissues. Cell viability, proliferation, migration, apoptosis, and autophagy were detected using Cell Counting Kit-8 (CCK-8), colony formation, Transwell assays, flow cytometry, and western blot analysis. Luciferase reporter and RNA immunoprecipitation (RIP) assays were conducted to assess the interactions among genes. We found that LINC01207 was overexpressed in OSCC cells and tissues. LINC01207 silencing inhibited OSCC cell proliferation and migration but promoted apoptosis and autophagy, and LINC01207 overexpression had an opposite result. LINC01207 interacted with microRNA-1301-3p (miR-1301-3p) while lactate dehydrogenase isoform A (LHDA) was targeted by miR1301-3p. Effects caused by LINC01207 downregulation on OSCC cells were reversed by overexpression of LDHA. Overall, LINC01207 promotes OSCC progression via the miR-1301-3p/LDHA axis

Roles of ncRNAs as ceRNAs in Gastric Cancer

Although ignored in the past, with the recent deepening of research, significant progress has been made in the field of non-coding RNAs (ncRNAs). Accumulating evidence has revealed that microRNA (miRNA) response elements regulate RNA. Long ncRNAs, circular RNAs, pseudogenes, miRNAs, and messenger RNAs (mRNAs) form a competitive endogenous RNA (ceRNA) network that plays an essential role in cancer and cardiovascular, neurodegenerative, and autoimmune diseases. Gastric cancer (GC) is one of the most common cancers, with a high degree of malignancy. Considerable progress has been made in understanding the molecular mechanism and treatment of GC, but GC’s mortality rate is still high. Studies have shown a complex ceRNA crosstalk mechanism in GC. lncRNAs, circRNAs, and pseudogenes can interact with miRNAs to affect mRNA transcription. The study of the involvement of ceRNA in GC could improve our understanding of GC and lead to the identification of potential effective therapeutic targets. The research strategy for ceRNA is mainly to screen the different miRNAs, lncRNAs, circRNAs, pseudogenes, and mRNAs in each sample through microarray or sequencing technology, predict the ceRNA regulatory network, and, finally, conduct functional research on ceRNA. In this review, we briefly discuss the proposal and development of the ceRNA hypothesis and the biological function and principle of ceRNAs in GC, and briefly introduce the role of ncRNAs in the GC’s ceRNA network.