Exosomal long non-coding RNA TRPM2-AS promotes angiogenesis in gallbladder cancer through interacting with PABPC1 to activate NOTCH1 signaling pathway

BACKGROUND

Abnormal angiogenesis is crucial for gallbladder cancer (GBC) tumor growth and invasion, highlighting the importance of elucidating the mechanisms underlying this process. LncRNA (long non-coding RNA) is widely involved in the malignancy of GBC. However, conclusive evidence confirming the correlation between lncRNAs and angiogenesis in GBC is lacking.

METHODS

LncRNA sequencing was performed to identify the differentially expressed lncRNAs. RT-qPCR, western blot, FISH, and immunofluorescence were used to measure TRPM2-AS and NOTCH1 signaling pathway expression in vitro. Mouse xenograft and lung metastasis models were used to evaluate the biological function of TRPM2-AS during angiogenesis in vivo. EDU, transwell, and tube formation assays were used to detect the angiogenic ability of HUVECs. RIP, RAP, RNA pull-down, dual-luciferase reporter system, and mass spectrometry were used to confirm the interaction between TRPM2-AS, IGF2BP2, NUMB, and PABPC1.

RESULTS

TRPM2-AS was upregulated in GBC tissues and was closely related to angiogenesis and poor prognosis in patients with GBC. The high expression level and stability of TRPM2-AS benefited from m6A modification, which is recognized by IGF2BP2. In terms of exerting pro-angiogenic effects, TRPM2-AS loaded with exosomes transported from GBC cells to HUVECs enhanced PABPC1-mediated NUMB expression inhibition, ultimately promoting the activation of the NOTCH1 signaling pathway. PABPC1 inhibited NUMB mRNA expression through interacting with AGO2 and promoted miR-31-5p and miR-146a-5p-mediated the degradation of NUMB mRNA. The NOTCH signaling pathway inhibitor DAPT inhibited GBC tumor angiogenesis, and TRPM2-AS knockdown enhanced this effect.

CONCLUSIONS

TRPM2-AS is a novel and promising biomarker for GBC angiogenesis that promotes angiogenesis by facilitating the activation of the NOTCH1 signaling pathway. Targeting TRPM2-AS opens further opportunities for future GBC treatments.

TRPM2-AS promotes the malignancy of osteosarcoma cells by targeting miR-15b-5p/PPM1D axis

Osteosarcoma (OS) is a malignant tumor with a low survival rate and a high incidence rate worldwide. Although research has reported the involvement of long non-coding RNAs (lncRNAs) in the pathogenesis of OS cells, the role of TRPM2-AS, miR-15b-5p, and PPM1D in OS progression remains unclear. This study aimed to examine the interaction of the TRPM2-AS/miR-15b-5p/PPM1D axis in OS cells to gain new insights into the molecular mechanism and pathogenesis of OS. After performing in vitro functional assays, we discovered that TRPM2-AS was overexpressed in OS cells. TRPM2-AS silencing impaired OS cell viability, proliferation, and migration, while it induced apoptosis in OS cells in vitro. Our experimental analysis also revealed that PPM1D is a direct target of miR-15b-5p. TRPM2-AS silencing was found to reverse the tumorigenic effect of the miR-15b-5p inhibitor, while the miR-15b-5p inhibitor restored the inhibition of OS caused by silencing PPM1D. Moreover, our findings revealed that miR-15b-5p exerted its tumor-suppressive role by directly targeting PPM1D. In conclusion, this study suggests that TRPM2-AS could promote OS cell malignancy by sponging miR-15b-5p/PPM1D axis.

TRPM2-AS promotes paclitaxel resistance in prostate cancer by regulating FOXK1 via sponging miR-497-5p

Chemoresistance seriously hinders the treatment efficiency of human cancers, including prostate cancer (PCa). Multiple long noncoding RNAs (lncRNAs) were involved in drug resistance in PCa. We aimed to explore the function of transient receptor potential cation channel subfamily M member 2 (TRPM2) antisense RNA (TRPM2-AS) in paclitaxel (PTX) resistance in PCa. Our results showed that TRPM2-AS was increased in PTX-resistant PCa cells. TRPM2-AS knockdown accelerated cell apoptosis and inhibited cell proliferation, migration, invasion, and PTX resistance in PTX-resistant PCa cells. MiR-497-5p was bound to TRPM2-AS and its inhibition reversed the effects of TRPM2-AS knockdown on cell progression and PTX resistance in PTX-resistant PCa cells. FOXK1 was identified as a target of miR-497-5p and FOXK1 overexpression showed similar effects on cell progression and PTX resistance with miR-497-5p inhibition in PTX-resistant PCa cells. In conclusion, TRPM2-AS knockdown suppressed cell progression and PTX resistance in PTX-resistant PCa cells by miR-497-5p/FOXK1 axis.

Long non-coding RNA TRPM2-AS regulates microRNA miR-138-5p and PLAU (Plasminogen Activator, Urokinase) to promote the progression of gastric adenocarcinoma

Gastric adenocarcinoma (GAC) is a common malignant tumor, accounting for 95% of gastric cancers. However, the effects and regulatory mechanisms of long non-coding RNA TRPM2-AS (TRPM2-AS) in GAC have not been fully explored. Our study investigates the action mechanism of TRPM2-AS in GAC. After performing quantitative Real-Time polymerase chain reaction or western blotting, we found that the levels of TRPM2-AS and Plasminogen Activator, Urokinase (PLAU) were upregulated in GAC, whereas the level of miR-138-5p was downregulated. Cell function experiments proved that silencing TRPM2-AS suppressed proliferation and migration and induced apoptosis in GAC cells. Bioinformatic analysis and luciferase assay identified the interaction between TRPM2-AS, miR-138-5p, and PLAU. In addition, the inhibitory effect of silencing TRPM2-AS on GAC cells could be partially relieved by PLAU overexpression. In conclusion, our study revealed that TRPM2-AS sponging miR-138-5p to upregulate PLAU could contribute to GAC progression, which might be useful for identifying biomarkers for GAC therapy.

Abbreviation

Gastric adenocarcinoma (GAC); Long non-coding RNA (lncRNA); lncRNA TRPM2 antisense RNA (TRPM2-AS); Plasminogen Activator, Urokinase (PLAU); Wild-type (WT); mutant (MUT).

Long Noncoding RNA TRPM2-AS Promotes the Growth, Migration, and Invasion of Retinoblastoma via miR-497/WEE1 Axis

Long noncoding RNAs (lncRNAs) exhibit vital roles in many types of cancer, including retinoblastoma (RB), the most common primary intraocular malignancy tumor of infancy. A novel lncRNA TRPM2-AS has been demonstrated to be related to multiple cancers; however, its role in RB remains unclear. Here, we aimed to investigate the function of TRPM2-AS in RB. In this study, TRPM2-AS expression in 35 human RB tissues and RB cell lines was detected by real-time PCR. And, the relationship between its expression and clinicopathological characteristics of RB patients was analyzed. RB cells’ proliferation, migration, invasion, apoptosis, and cell cycle were explored after silencing TRPM2-AS. The mechanism of TRPM2-AS in RB was focused on miR-497/WEE1 axis. Additionally, the role and mechanism of TRPM2-AS were confirmed in a xenograft mouse model. We found TRPM2-AS expression was enhanced in RB tissues and cells. And, higher TRPM2-AS expression was related to advanced clinical stage and optic nerve invasion in patients. Downregulation of TRPM2-AS significantly inhibited proliferation, migration, and invasion, elevated apoptosis, attenuated G2/M phase arrest in RB cells, and suppressed tumor growth in vivo. TRPM2-AS acted as a ceRNA for miR-497 to positively regulate WEE1 expression. miR-497 inhibitor or WEE1 overexpression dramatically reversed the effects of TRPM2-AS downregulating on the malignant phenotypes of RB cells. Therefore, TRPM2-AS is an oncogenic lncRNA in RB, and it functions largely through the miR-497/WEE1 pathway. Despite the limited sample size, this study indicates that TRPM2-AS may be a candidate target in RB therapies.

TRPM2-AS Promotes Bladder Cancer by Targeting miR-22-3p and Regulating GINS2 mRNA Expression

Background

Bladder cancer (BLCA) refers to the malignancy growth that spreads from the bladder linings to the bladder muscles. However, the impact of miR-22-3p and lncRNA TRPM2-AS on this tumor has generated divergent views in the literature. This research aimed to study the effects of lncRNA TRPM2-AS on BLCA and its interaction with miR-22-3p and GINS2 mRNA.

Methods

qRT-PCR was employed to measure the expression of TRPM2-AS, miR-22-3p and GINS2 mRNA in bladder tissues and cells. The subcellular localization of TRPM2-AS in T24 and 5637 cell lines was identified using a cell fractionation system. Luciferase assay, RIP assay and RNA pull-down assay were later performed to validate the direct binding relationship between TRPM2-AS, miR-22-3p and GINS2 mRNA. Several experiments were conducted to determine the viability, proliferation, colony formation and apoptosis of the cell lines.

Results

Findings indicated that TRPM2-AS was significantly upregulated in BLCA tissues and cell lines. Apart from that, it was observed that TRPM2-AS knockdown significantly inhibited the viability, proliferation and colony formation of BCLA cells, but it promoted the apoptosis of the BCLA cells. A significant downstream target of TRPM2-AS, miR-22-3p was found to show a lower expression level in BLCA tissues and cell lines. However, the inhibition of miR-22-3p considerably enhanced BLCA cell phenotypes. As well as discovering that GINS2 mRNA was a downstream target of miR-22-3p and was significantly upregulated in BLCA, experimental results also indicated that the knockdown of GINS2 suppressed BLCA cell phenotypes.

Conclusion

This research confirmed that TRPM2-AS could promote BCLA by binding to miR-22-3p to increase GINS2 expression. This novel interactome in BLCA cell lines might provide more insights into BLCA therapy.

LncRNA TRPM2-AS promotes ovarian cancer progression and cisplatin resistance by sponging miR-138-5p to release SDC3 mRNA

The role of TRPM2-AS lncRNA in OvC has not been explored. This study aimed to investigate whether and how TRPM2-AS contributes to the progression of OvC. First, qRT-PCR was employed to measure the expression of TRPM2-AS, miR-138-5p and SDC3 in OvC samples. A xenograft formation assay was subsequently performed to detect the tumor growth in vivo. The cell viability, colony formation, cell migration, cell invasion and cell apoptosis were later evaluated using a series of experiments. The western blot assay was utilized to detect the SDC3 protein expression and cell-apoptosis markers. Luciferase reporter gene assay, RIP, and RNA pull-down assays were performed to identify the association between TRPM2-AS, miR-138-5p and SDC3. Findings indicated that the expression of TRPM2-AS and SDC3 was significantly upregulated in OvC tissues and cells, while miR-138-5p expression was significantly downregulated in OvC samples. Unlike miR-138-5p, TRPM2-AS and SDC3 were found to promote OvC development. It was also found that TRPM2-AS could sponge miR-138-5p to release SDC3, thus promoting OvC progression. Apart from that, we discovered that both sh-TRPM2-AS and cisplatin could enhance the apoptosis of OvC cells. Overall, our findings suggested that the TRPM2-AS/miR-138-5p/SDC3 axis was closely associated with OvC tumorigenesis and cisplatin resistance.

Inhibition of gastric cancer cell apoptosis by long noncoding RNA TRPM2-AS via mitogen-activated protein kinase and activators of transduction-3

BACKGROUND AND AIM

Long noncoding RNA TRPM2-AS has emerged as a novel regulator in cancer initiation and progression of various cancers. However, the function and underlying mechanism of TRPM2-AS in the progression of gastric cancer (GC) remain poorly understood.

METHODS

GEO and TCGA databases were used for isolation of differential lncRNA expression. TRPM2-AS expression levels in GC tissues and cells were measured by quantitative polymerase chain reaction method. TRPM2-AS subcellular location was detected by fluorescence in situ hybridization analysis. The functional roles of TRPM2-AS in cells were analyzed by loss and gain function assays.

RESULTS

By using bioinformatics and quantitative polymerase chain reaction methods, TRPM2-AS expression levels were proved to be upregulated in GSE70880 dataset, TCGA database, and 26 GC tissues, which was partly induced by SP1. The results of clinical assays showed that TRPM2-AS could be an indicator for early-stage GC diagnosis. Fluorescence in situ hybridization analysis showed that TRPM2-AS was located in both nucleus and cytoplasm. Functional experiments displayed that knockdown of TRPM2-AS inhibited proliferation, migration, and invasion in GC cells. Furthermore, depression of TRPM2-AS suppressed cell growth though promotion of cell apoptosis. The expression levels of cleaved PARP, caspase 9, caspase 3, and Bax were significantly increased in BGC823 with TRPM2-AS knockdown. In addition, knockdown of TRPM2-AS reduced and phosphorylate signal transducer and activator of transcription 3 and increased and phosphorylate p38 mitogen-activated protein kinase.

CONCLUSIONS

This study demonstrated that SP1-regulated TRPM2-AS is involved in GC cell apoptosis probably via p38 mitogen-activated protein kinase and signal transducer and activator of transcription 3 pathways, indicating that TRPM2-AS might be a potential therapeutic target in GC.

Long non-coding RNA TRPM2-AS sponges microRNA-138-5p to activate epidermal growth factor receptor and PI3K/AKT signaling in non-small cell lung cancer

Background

Long non-coding RNAs (lncRNAs) can play pivotal roles in tumor progression by acting as microRNA (miRNA) sponges. This study aimed to investigate the association of a novel lncRNA, TRPM2-AS, with the miR-138-5p/EGFR axis in the development of non-small cell lung cancer (NSCLC).

Methods

Sixty NSCLC tissues and paired adjacent non-tumor tissues were analyzed. The relative expression levels of TRPM2-AS, miR138-5p, and epidermal growth factor receptor (EGFR) and the interactions between them were analyzed. The NSCLC cell lines NCI-H1299 and A549 were transfected with TRPM2-AS shRNA/pcDNA, and miR-138-5p mimics. Cell proliferation, migration, invasion, and apoptosis were examined in response to different transfection conditions. Dual-luciferase reporter assay was performed to identify the target interactions between TRPM2-AS, miR-138-5p, and EGFR. A549 cells stably transfected with shRNA were injected into BALB/c null nude mice to establish a tumor xenograft model.

Results

TRPM2-AS was up-regulated in NSCLC tumors and cell lines. Cell proliferation, migration, and invasion were inhibited in NSCLC cells treated with sh-TRPM2-AS, while apoptosis was induced. The targeting of TRPM2-AS by miR138-5p and miR138-5p by EGFR were validated with dual-luciferase reporter assay. TRPM2-AS was found to be negatively correlated with miR138-5p but positively correlated with EGFR. PI3K/AKT/mTOR was activated by pcDNA-EGFR but inactivated by miR-138-5p mimics. In the tumor xenograft mouse model, sh-TRPM2-AS suppressed tumor formation, reduced the expression of EGFR and Ki67, and promoted tumor cell apoptosis.

Conclusions

Our results suggested that TRPM2-AS can increase the levels of EGFR via sponging miR-138-3p; this promoted NSCLC cell proliferation, migration, and invasion in vitro, and exacerbated tumors in vivo. These findings highlight TRPM2-AS/miR-138-5p as a potential target for reducing drug resistance in patients with NSCLC.

TRPM2-AS promotes cancer cell proliferation through control of TAF15

BACKGROUND

Colorectal cancer (CRC) ranks the third among all common malignancy worldwide. Long noncoding RNAs (lncRNAs) have been demonstrated as implicated in CRC, but the roles of many lncRNAs in CRC remain unclear. Exploration of lncRNA TRMP2-AS and its nearby gene in CRC progress was the focus of current study.

METHODS

The expression of TRPM2-AS and its nearby mRNA TRPM2 was measured by using RT-qPCR. The protein levels of TRPM2 and TAF15 were determined using western blot. Cell proliferation was detected by using CCK-8, colony formation and EdU assays. The interaction between TAF15 and TRPM2-AS or TRPM2 was evaluated by RNA pull-down and RIP assays. The TRPM2 mRNA stability was probed using the transcriptional inhibitor Actinomycin D.

RESULTS

TRPM2-AS was significantly upregulated in CRC cells. Knock-down of TRPM2-AS inhibited CRC cell proliferation. Mechanically, TRPM2-AS directly interacted with RNA-binding protein (RBP) TAF15 and thus maintained the mRNA stability of TRPM2. TRPM2 was a prerequisite for TRPM2-AS to exert its promoting function in CRC cell proliferation.

CONCLUSION

This research demonstrated that TRPM2-AS facilitated proliferation of CRC cells by enhancing TAF15-mediated mRNA stability of TRPM2, unmasking the role of TRPM2-AS in CRC.

TRPM2-AS inhibits the growth, migration, and invasion of gliomas through JNK, c-Jun, and RGS4

Gliomas are a group of brain cancers with high mortality and morbidity. Understanding the molecular mechanisms is important for the prevention or treatment of gliomas. The present study was to investigate the effects and mechanisms of long noncoding RNA TRPM2-AS in gliomas proliferation, migration, and invasion. We first compared the levels of TRPM2-AS in 111 patients with glioma to that of the normal control group by a quantitative polymerase chain reaction. The results indicated a significant increase of TRPM2-AS in patients with glioma (2.43 folds of control, p = .0135). MTT methods, wound healing assays, transwell analysis, and clone formation analysis indicated the overexpression of TRPM2-AS promoted the proliferation, migration, and invasion of U251 and U87 cells, while downregulation of TRPM2-AS inhibited the cell proliferation, migration, and invasion significantly (p < .05). To further uncover the mechanisms, bioinformatics analysis was conducted on the expression profiles, GSE40687 and GSE4290, from the Gene Expression Omnibus database. One hundred fifty-six genes were differentially expressed in both datasets (FC > 2.0; p = .05). Among these differentially expressed genes, the level of RGS4 messenger RNA was drastically regulated by TRPM2-AS. Further western-blot analysis indicated the increase of RGS4 protein expression and decrease of p-JNK/JNK and p-c-Jun/c-Jun ratio after TRPM2-AS overexpression. On the other hand, inhibition of TRPM2-AS by small interfering RNA suppressed the expression of RGS4 and promoted the ratios of p-JNK/JNK and p-c-Jun/c-Jun. The present work indicated the mechanisms of the participation of TRPM2-AS in the progression of gliomas might, at least partly, be related to JNK, c-Jun, and RGS4. Our work provided new insights into the underlying mechanisms of glioma cellular functions.

Long non-coding RNA TRPM2-AS as a potential biomarker for hepatocellular carcinoma

BACKGROUND

There is increasing evidence that long non-coding RNAs are involved in hepatocellular carcinoma (HCC) tumorigenesis. The expression level of TRPM2-AS in HCC and its clinical association remain poorly defined.

METHOD

qRT-PCR was performed to detect the expression of TRPM2-AS in 108 HCC patients. The correlations between TRPM2-AS expression and clinicopathological factors and prognosis were evaluated. The inference of TRPM2-AS to the proliferation and apoptosis of HCC cells was detected.

AIMS

The aim of our study was to explore the expression of TRPM2-AS in hepatocellular carcinoma (HCC) and the relation with prognosis and clinical features.

RESULTS

The expression of TRPM2-AS was higher in most HCC tissues and was significantly correlated with tumor size, AJCC stage, tumor differentiation, and the prognosis of HCC patients. Interfering TRPM2-AS expression using siRNA significantly inhibited cell proliferation and promoted cell apoptosis in two HCC cell lines.

CONCLUSION

Long non-coding RNA TRPM2-AS is upregulated in HCC and represents a new biomarker for HCC and the inhibition of TRPM2-AS promotes apoptosis in HCC cells in vitro.