The RNA Methyltransferase METTL3 Promotes Endothelial Progenitor Cell Angiogenesis in Mandibular Distraction Osteogenesis via the PI3K/AKT Pathway

Research progress on N6-Methyladenosine modification in angiogenesis, vasculogenic mimicry, and therapeutic implications in breast cancer

N6-methyladenosine (m6A) modification is the most common epitranscriptomic modification in eukaryotic RNA and has garnered extensive attention in the context of breast cancer research. The m6A modification significantly impacts tumorigenesis and tumor progression by regulating RNA stability, splicing, translation, and degradation. In this review we summarize recent advances in understanding the roles of m6A modification in the mechanisms underlying angiogenesis and vasculogenic mimicry in breast cancer. We review how m6A modification and associated transcripts influence relevant factors by affecting key factors and signaling pathways, highlighting the interactions among m6A "writers," "erasers," and "readers," and their overall impact on tumor angiogenesis and vasculogenic mimicry, as well as potential new therapeutic targets.

Esketamine alleviates depressive-like behavior in neuropathic pain mice through the METTL3-GluA1 pathway

Esketamine, a newly developed antidepressant, is the subject of this research which seeks to explore its impact on depressive symptoms in neuropathic pain mice and the potential molecular mechanisms involved. Through transcriptome sequencing and bioinformatics analysis combined with in vivo studies, it was identified that esketamine markedly boosts the levels of the m6A methyltransferase METTL3 and the AMPA receptor GluA1 subunit. Esketamine activates METTL3, allowing it to bind with GluA1 mRNA, promoting m6A modification, thereby enhancing GluA1 expression at synapses. Through this mechanism, esketamine may reduce depressive-like behavior in neuropathic pain mice, providing new insights into the potential applications of esketamine and novel therapeutic avenues for neuropathic pain and depressive behavior.

Semaphorin-4D signaling in recruiting dental stem cells for vascular stabilization

BACKGROUND

Achieving a stable vasculature is crucial for tissue regeneration. Endothelial cells initiate vascular morphogenesis, followed by mural cells that stabilize new vessels. This study investigated the in vivo effects of Sema4D-Plexin-B1 signaling on stem cells from human exfoliated deciduous teeth (SHED)-supported angiogenesis, focusing on its mechanism in PDGF-BB secretion. We also explored macrophages as an endogenous source of Sema4D for vascular stabilization.

METHODS

The in vivo Matrigel plug angiogenesis assay was conducted to examine the impact of Sema4D on vessel formation and stabilization supported by SHED. Knockdown of Plexin-B1 in human umbilical vein endothelial cells (HUVECs) and PDGFR-β inhibitors were utilized to explore the fundamental regulatory mechanisms. Furthermore, the m6A methylation levels of total RNA and the expression of Methyltransferase-like 3 (METTL3) were assessed under conditions of Sema4D treatment in vitro. An ELISA was employed to measure the levels of Sema4D in the supernatants derived from THP-1 cell-mediated macrophages. Additionally, a three-dimensional vasculature-on-a-chip microfluidic device was used to investigate the role of M2c macrophage-derived Sema4D in the stabilization of vascular structures.

RESULTS

Sema4D induced the formation of a greater number of perfused vessels by HUVECs and enhanced the coverage of these vessels by SM22α-positive SHED (SM22α+SHED). Conversely, the knockdown of the Plexin-B1 receptor in HUVECs or inhibition of PDGFR-β reversed the Sema4D-induced vascular stabilization, thereby confirming the regulatory role of the Plexin-B1/PDGF-BB axis in the recruitment of mural cells mediated by Sema4D. Mechanistically, Sema4D was found to upregulate the expression of methyltransferases, specifically METTL3, and to elevate the level of m6A modification in HUVECs. This modification was determined to be critical for enhancing PDGF-BB secretion, suggesting that Sema4D activates an epigenetic regulatory mechanism. Additionally, we investigated the secretion of Sema4D by various macrophage phenotypes, identifying that M2c macrophages secrete significant levels of Sema4D. This secretion recruited SM22α+SHED as mural cells by inducing endothelial PDGF production on a vasculature-on-a-chip platform, indicating a potential role for macrophages in facilitating vascular stabilization.

CONCLUSIONS

Sema4D acts on Plexin-B1, inducing METTL3-mediated PDGF-BB secretion to recruit SHED to stabilize vessels. Macrophages could be a key source of Sema4D for vascular stabilization.

Mechanistic insights into vascular biology via methyltransferase-like 3-driven N6-adenosine methylation of RNA

Recent advancements in the mechanistic comprehension of vascular biology have concentrated on METTL3-mediated N6-methyladenosine modification of RNA, which modulates a spectrum of RNA functionalities with precision. Despite extensive investigations into the roles and mechanisms of METTL3 within vascular biology, a holistic review elucidating their interconnections remains absent. This analysis endeavors to meticulously scrutinize the involvement of METTL3 in both the physiological and pathological paradigms of vascular biology. The findings of this review indicate that METTL3 is indispensable for vascular development and functionality, predominantly through its regulatory influence on pericytes, endothelial cells, vascular smooth muscle cells, and hematopoietic stem cells. Conversely, aberrant METTL3 activity is implicated as a risk factor, diagnostic biomarker, and therapeutic target for vascular pathologies. This comprehensive review offers an exhaustive synthesis of METTL3's role in vascular biology, addressing existing knowledge gaps and serving as an essential reference for future research and potential clinical applications.

m6A and beyond: RNA modifications shaping angiogenesis

RNA modifications are crucial post-transcriptional processes that significantly influence gene expression, RNA stability, nuclear transport, and translational capacity. Angiogenesis, the formation of new blood vessels, is a physiological process that is dysregulated in many pathological conditions, including ocular diseases, immune disorders, and cancer. In this review, we compile the current understanding of the intricate relationship between various RNA modifications and angiogenic mechanisms, spotlighting emerging evidence that underscore their pivotal regulatory roles in both physiological and pathological angiogenesis. Furthermore, we delve into recent advances in innovative therapeutic approaches that target RNA modifications to modulate angiogenesis, offering insights into their potential as novel treatment modalities.

Thrombopoietin improves the functions of bone marrow endothelial progenitor cells via METTL16/Akt signalling of haematological patients with chemotherapy-induced thrombocytopenia

Bone marrow endothelial progenitor cells (BM EPCs) are crucial in supporting haematopoietic regeneration, while the BM EPCs of haematological patients with chemotherapy-induced thrombocytopenia (CIT) are unavoidably damaged. Therefore, the present study aimed to examine the effect of thrombopoietin (TPO) on the recovery of BM EPCs of CIT patients and to identify the underlying mechanisms. The cell functions were determined by 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (Dil)-acetylated low-density lipoprotein (Dil-Ac-LDL) uptake and fluorescein isothiocyanate (FITC)-labeled Ulex europaeus agglutinin-I (FITC-UEA-I) binding assay, as well as proliferation, migration and tube formation experiments. Endothelial cells were transfected with METTL16 lentivirus, followed by methylated RNA immunoprecipitation sequencing. Zebrafish with vascular defect was used as the in vivo model. TPO significantly improved the quantity and functions of BM EPCs from CIT patients in vitro and restored the subintestinal vein area of zebrafish with vascular defect in vivo. Mechanically, TPO enhanced the BM EPC functions through Akt signal mediated by METTL16, which was downregulated in BM EPCs of CIT patients and involved in the regulation of endothelial functions. The present study demonstrates that TPO improves the recovery of BM EPCs from CIT patients with haematological malignancies via METTL16/Akt signalling, which provides new insights into the role of TPO in treating CIT in addition to direct megakaryopoiesis.

The role of m6A in angiogenesis and vascular diseases

Angiogenesis, whether physiological or pathological, plays a pivotal role in various physiological and disease conditions. This intricate process relies on a complex and meticulously orchestrated signal transduction network that connects endothelial cells, their associated parietal cells (VSMCs and pericytes), and various other cell types, including immune cells. Given the significance of m6A and its connection to angiogenesis and vascular disease, researchers must adopt a comprehensive and ongoing approach to their investigations. This study aims to ascertain whether a common key mechanism of m6A exists in angiogenesis and vascular diseases and to elucidate the potential application of m6A in treating vascular diseases.

RNA N6‑methyladenosine methyltransferase WTAP promotes the differentiation of endothelial progenitor cells

N6-methyladenosine (m6A) serves a critical role in regulating gene expression and has been associated with various diseases; however, its role in the differentiation of endothelial progenitor cells (EPCs) remains unclear. The present study used liquid chromatography with tandem mass spectrometry and immunofluorescence assays to quantify the levels of m6A in human peripheral blood-derived EPCs (HPB-EPCs) before and after differentiation into mature cells. The present study performed Cell Counting Kit 8, Transwell, and tube formation assays to determine the effects of overexpression and knockdown of Wilms' tumor 1-associated protein (WTAP) on HPB-EPCs. The results revealed that the level of m6A modification was significantly increased during HPB-EPCs differentiation, and WTAP exhibited the most significant alteration among the enzymes involved in m6A regulation. When WTAP was overexpressed in HPB-EPCs, cell proliferation, invasion, and the formation of tubes were improved, whereas WTAP knockdown yielded the opposite effects. In conclusion, the present study highlighted the involvement of m6A in regulating EPC differentiation, with WTAP acting as a promoter of EPC differentiation.

The Current Progress of Tetrahedral DNA Nanostructure for Antibacterial Application and Bone Tissue Regeneration

Recently, programmable assembly technologies have enabled the application of DNA in the creation of new nanomaterials with unprecedented functionality. One of the most common DNA nanostructures is the tetrahedral DNA nanostructure (TDN), which has attracted great interest worldwide due to its high stability, simple assembly procedure, high predictability, perfect programmability, and excellent biocompatibility. The unique spatial structure of TDN allows it to penetrate cell membranes in abundance and regulate cellular biological properties as a natural genetic material. Previous studies have demonstrated that TDNs can regulate various cellular biological properties, including promoting cells proliferation, migration and differentiation, inhibiting cells apoptosis, as well as possessing anti-inflammation and immunomodulatory capabilities. Furthermore, functional molecules can be easily modified at the vertices of DNA tetrahedron, DNA double helix structure, DNA tetrahedral arms or DNA tetrahedral cage structure, enabling TDN to be used as a nanocarrier for a variety of biological applications, including targeted therapies, molecular diagnosis, biosensing, antibacterial treatment, antitumor strategies, and tissue regeneration. In this review, we mainly focus on the current progress of TDN-based nanomaterials for antimicrobial applications, bone and cartilage tissue repair and regeneration. The synthesis and characterization of TDN, as well as the biological merits are introduced. In addition, the challenges and prospects of TDN-based nanomaterials are also discussed.

Combination treatment of Danggui Buxue Decoction and endothelial progenitor cells can enhance angiogenesis in rats with focal cerebral ischemia and hyperlipidemia

ETHNOPHARMACOLOGICAL RELEVANCE

Danggui Buxue Decoction (DBD) is a classic prescription of traditional Chinese medicine that is mainly used for treating clinical anemia for more than 800 years. This prescription has been utilized for nourishing "Qi" and enriching "Blood" for women suffering from menopausal symptoms. Meanwhile, DBD has the role of improving angiogenesis and promoting the neuroprotective functions. Bone marrow-derived endothelial progenitor cells (EPCs) was suboptimal to treat the focal cerebral ischemia (FCI). Thus, it's may be a novel strategy of DBD combined with EPCs transplantation for the FCI.

AIM OF THE STUDY

To investigate the mechanistic effects of DBD in combination with EPCs transplantation to improve behavioral function of the FCI and hyperlipidemia.

MATERIALS AND METHODS

We used rats with hyperlipidemia to develop a FCI model using photo-thrombosis, and treated the DBD in combination with EPCs transplantation. We adopted the Modified Neurological Severity Score to evaluate the neurological deficit, undertook the 2,3,5-triphenyltetrazolium chloride staining to calculate the total infarct volume. We carried out the RT-qPCR, Immunohistochemical analyses, TUNEL, ELISA, and Western blotting to measure the gene and protein levels which related to anti-apoptosis mechanisms and angiogenesis.

RESULTS

Administration of DBD in combination with EPCs transplantation was found to improve behavioral function, reducing the infarct volume and decrease the level of total-cholesterole (TC) and low-density lipoprotein-cholesterol (LDL-C). Treatment of DBD plus EPCs increased the mRNA and protein expression of vascular endothelial growth factor A, fibroblastic growth factor-2, and angiopoietin-1 and decreased the apoptosis of endothelial cells by activating the phosphoinositide 3-kinase/protein kinase B/Bcl-xL/Bcl-2 associated death promoter (PI3K/Akt/BAD) pathway and promoting activation of the extracellular signal-regulated kinase (ERK) pathway, which induced angiogenesis directly.

CONCLUSIONS

Our findings provided that DBD administration combined with EPCs transplantation promoted reconstruction of nervous function. This was achieved by enhancing expression of the growth factors related to anti-apoptosis mechanisms and angiogenesis thanks to regulation of the PI3K/Akt/BAD and ERK signaling pathways, and might be relate to the lowering of TC and LDL-C levels.

Correlated with better prognosis, CSTA inhibits metastasis of nasopharyngeal carcinoma cells via suppressing AKT signaling through promoting METTL3 degradation

BACKGROUND

Metastasis is one of the main obstacles impeding the survival of nasopharyngeal carcinoma (NPC) patients, with the molecular mechanism underlying NPC metastasis still unclear.

RESULTS

In this study, Cystatin A (CSTA) was found downregulated in NPC tissues with metastasis compared with those without metastasis. Shorter overall survival and distant metastasis-free survival were found in NPC patients with lower CSTA expression. Using functional assays, we found that CSTA prevented both the in vitro motility of NPC cells and their ability to metastasize in vivo. Transcriptome sequencing and western blot analysis revealed that CSTA inhibited the phosphorylation of AKT. Moreover, activating AKT using AKT agonist SG79 rescued the motility of CSTA-overexpressing NPC cells, whereas, treatment with AKT inhibitor MK2206 inhibited the motility of CSTA-knockdown NPC cells. Mechanically, immunoprecipitation coupled mass spectrometry found that CSTA interacted with the N6-adenosine-methyltransferase subunit METTL3 and promoted its ubiquitin-proteasome-mediated degradation following the upregulation of NKX3-1 and LHPP, which are negative regulators of AKT. Furthermore, knock-down of NKX3-1 and LHPP enhanced the motility of CSTA-overexpressing NPC cells.

CONCLUSIONS

The inhibitory effect of CSTA upon NPC metastasis mainly depended on suppressing AKT signaling by the upregulation of NKX3-1 and LHPP expression resulting from the binding between CSTA and METLL3. Our study suggests that the CSTA-METLL3-NKX3-1/LHPP-AKT axis could be of therapeutic value for inhibiting NPC metastasis.

METTL3 Promotes Endothelium-Mesenchymal Transition of Pulmonary Artery Endothelial Cells by Regulating TRPC6/Calcineurin/NFAT Signaling Pathways

Background

Endothelium-mesenchymal transition (EndMT) is a process of phenotypic and functional transition from activated endothelial cells to mesenchymal cells. Recently, EndMT has been proved to be one of the main pathological mechanisms of pulmonary artery hypertension (PAH). However, the molecular mechanism is not clear.

Methods

Primary rat pulmonary arterial endothelial cells (rPAECs) were isolated from Sprague-Dawley rats and verified by CD31 immunofluorescence staining. rPAECs were exposed to hypoxic conditions to induce EndMT. RNA and protein levels in cells were detected by RT-qPCR and Western blot. The migration ability was verified by the transwell assay. The RIP experiment was used to test the m6A modification of TRPC6 mRNA and the binding relationship between TRPC6 and METTL3. Calcineurin/NFAT signaling was measured by using commercial kits.

Results

METTL3 was found to be highly expressed by hypoxia treatment in a time-dependent manner. Knockdown of METTL3 significantly suppressed cell migration, downregulated the levels of interstitial cell-related markers like α-SMA and vimentin, and increased the levels of endothelial cell markers including CD31 and VE-cadherin. Mechanistically, METTL3 increased TRPC6 expression by enhancing the m6A modification of TRPC6 mRNA, thus activating calcineurin/NFAT signaling. Our experiments showed that METTL3 silencing mediated the inhibitory roles in the hypoxia-mediated EndMT process, which were significantly reversed by TRPC6/calcineurin/NFAT signaling activation.

Conclusion

Our results elucidated that METTL3 knockdown inhibited the hypoxia-mediated EndMT process by inactivating TRPC6/calcineurin/NFAT signaling.

Hsp20 Promotes Endothelial Progenitor Cell Angiogenesis via Activation of PI3K/Akt Signaling Pathway under Hypoxia

BACKGROUND

Mandibular distraction osteogenesis (MDO) is a kind of endogenous tissue engineering technology that lengthens the jaw and opens airway so that a patient can breathe safely and comfortably on his or her own. Endothelial progenitor cells (EPCs) are crucial for MDO-related angiogenesis. Moreover, emerging evidence suggests that heat shock protein 20 (Hsp20) modulates angiogenesis under hypoxic conditions. However, the specific role of Hsp20 in EPCs, in the context of MDO, is not yet known. The aim of this study was to explore the expression of Hsp20 during MDO and the effects of Hsp20 on EPCs under hypoxia.

METHODS

Mandibular distraction osteogenesis and mandibular bone defect (MBD) canine model were established. The expression of CD34, CD133, HIF-1α, and Hsp20 in callus was detected by immunofluorescence on day 14 after surgery. Canine bone marrow EPCs were cultured, with or without optimal cobalt chloride (CoCl2) concentration. Hypoxic effects, caused by CoCl2, were evaluated by means of the cell cycle, cell apoptosis, transwell cell migration, and tube formation assays. The Hsp20/KDR/PI3K/Akt expression levels were evaluated via immunofluorescence, RT-qPCR, and western blot. Next, EPCs were incorporated with either Hsp20-overexpression or Hsp20-siRNA lentivirus. The resulting effects were evaluated as described above.

RESULTS

CD34, CD133, HIF-1α, and Hsp20 were displayed more positive in the callus of MDO compared with MBD. In addition, hypoxic conditions, generated by 0.1 mM CoCl2, in canine EPCs, accelerated cell proliferation, migration, tube formation, and Hsp20 expression. Hsp20 overexpression in EPCs significantly stimulated cell proliferation, migration, and tube formation, whereas Hsp20 inhibition produced the opposite effect. Additionally, the molecular mechanism was partly dependent on the KDR/PI3K/Akt pathway.

CONCLUSION

In summary, herein, we present a novel mechanism of Hsp20-mediated regulation of canine EPCs via Akt activation in a hypoxic microenvironment.

m6A transferase METTL3 regulates endothelial-mesenchymal transition in diabetic retinopathy via lncRNA SNHG7/KHSRP/MKL1 axis

Diabetic retinopathy is one of the microvascular complications in diabetic patients and the leading cause of blindness worldwide. The levels of METTL3, lncRNA SNHG7, KHSRP, MKL1, endothelial and mesenchymal markers were determined by RT-qPCR or western blot assays in vitro and in vivo. H&E staining was used to observe the retinal structure in a mouse model of DR. The expression levels of METTL3 and SNHG7 were significantly downregulated in DR patients, DR mice and high glucose-induced HRMECs cells. Notably, METTL3 installed the m6A modification and enhanced the stability of SNHG7. Besides, METTL3 inhibited HRMECs EndoMT by promoting the expression of SNHG7. Additionally, SNHG7 was found to weaken MKL1 mRNA stability by binding to the RNA-binding protein KHSRP. Furthermore, we verified that METTL3 regulated EndoMT in DR through the SNHG7/MKL1 axis. We conclude that METTL3 regulates endothelial-mesenchymal transition in DR via the SNHG7/KHSRP/MKL1 axis, providing a new target for DR treatment.

The Role of N6-Methyladenosine Modification in Microvascular Dysfunction

Microvascular dysfunction (MVD) has long plagued the medical field despite improvements in its prevention, diagnosis, and intervention. Microvascular lesions from MVD increase with age and further lead to impaired microcirculation, target organ dysfunction, and a mass of microvascular complications, thus contributing to a heavy medical burden and rising disability rates. An up-to-date understanding of molecular mechanisms underlying MVD will facilitate discoveries of more effective therapeutic strategies. Recent advances in epigenetics have revealed that RNA methylation, an epigenetic modification, has a pivotal role in vascular events. The N⁶-methylation of adenosine (m⁶A) modification is the most prevalent internal RNA modification in eukaryotic cells, which regulates vascular transcripts through splicing, degradation, translation, as well as translocation, thus maintaining microvascular homeostasis. Conversely, the disruption of the m⁶A regulatory network will lead to MVD. Herein, we provide a review discussing how m⁶A methylation interacts with MVD. We also focus on alterations of the m⁶A regulatory network under pathological conditions. Finally, we highlight the value of m⁶A regulators as prognostic biomarkers and novel therapeutic targets, which might be a promising addition to clinical medicine.

METTL3 dual regulation of the stability of LINC00662 and VEGFA RNAs promotes colorectal cancer angiogenesis

PURPOSE

The angiogenesis is among the primary factors that affect tumor recurrence and distant organ metastasis in colorectal cancer (CRC). N6-methyladenosine (m6A) modification is one of the most common chemical modifications in eukaryotic mRNA, especially at the post-transcriptional level. Methyltransferase-like 3 (METTL3) promoting angiogenesis in a variety of tumors has been reported. However, the mechanism of how METTL3 dual-regulates the stability of long non-coding RNAs (lncRNAs) and vascular-related factor RNAs to affect angiogenesis in CRC is unclear.

METHODS

64 paired CRC and adjacent normal tissues were collected. In vitro, quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC), actinomycin assay, methylated RNA immunoprecipitation (MeRIP) experiment,3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) and colony formation assay were performed. The functions were also studied in zebrafish model animals in vivo.

RESULTS

We found that the vascular endothelial growth factor A(VEGFA), METTL3 and LINC00662 RNAs were highly expressed in CRC, and that METTL3 was significantly positively correlated with LINC00662 and VEGFA. The protein expression levels of CD31, CD34, VEGFA, m6A and METTL3 were all significantly increased in the CRC tissues. The angiogenesis experiments both in vivo and in vitro found that METTL3 and LINC00662 promoted angiogenesis in CRC. The actinomycin assay indicated that METTL3 maintained the stability of LINC00662 and VEGFA RNAs. In addition, the MeRIP experiment confirmed that the LINC00662 and VEGFA RNAs had METTL3-enriched sites.

CONCLUSION

These findings suggest that METTL3 and LINC00662 may both serve as diagnostic and prognostic predictive biomarkers for CRC and potential targets for anti-vascular therapy.

Emerging roles of the RNA modifications N6-methyladenosine and adenosine-to-inosine in cardiovascular diseases

Cardiovascular diseases lead the mortality and morbidity disease metrics worldwide. A multitude of chemical base modifications in ribonucleic acids (RNAs) have been linked with key events of cardiovascular diseases and metabolic disorders. Named either RNA epigenetics or epitranscriptomics, the post-transcriptional RNA modifications, their regulatory pathways, components, and downstream effects substantially contribute to the ways our genetic code is interpreted. Here we review the accumulated discoveries to date regarding the roles of the two most common epitranscriptomic modifications, N6-methyl-adenosine (m6A) and adenosine-to-inosine (A-to-I) editing, in cardiovascular disease.

Research Progress for RNA Modifications in Physiological and Pathological Angiogenesis

As a critical layer of epigenetics, RNA modifications demonstrate various molecular functions and participate in numerous biological processes. RNA modifications have been shown to be essential for embryogenesis and stem cell fate. As high-throughput sequencing and antibody technologies advanced by leaps and bounds, the association of RNA modifications with multiple human diseases sparked research enthusiasm; in addition, aberrant RNA modification leads to tumor angiogenesis by regulating angiogenesis-related factors. This review collected recent cutting-edge studies focused on RNA modifications (N⁶-methyladenosine (m⁶A), N⁵-methylcytosine (m⁵C), N⁷-methylguanosine (m⁷G), N¹-methyladenosine (m¹A), and pseudopuridine (Ψ)), and their related regulators in tumor angiogenesis to emphasize the role and impact of RNA modifications.

METTL3-Mediated m6A Modification of lncRNA MALAT1 Facilitates Prostate Cancer Growth by Activation of PI3K/AKT Signaling

Accumulating data show that N6-methyladenosine (m⁶A) methyltransferase METTL3 and long noncoding RNA MALAT1 act pivotal roles in multiple malignancies including prostate cancer (PCa). However, the role and molecular mechanism underlying METTL3-mediated m⁶A modification of MALAT1 in PCa remain undocumented. The association of METTL3 and MALAT1 expression with clinicopathological characteristics and prognosis in patients with PCa was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, and public The Cancer Genome Atlas (TCGA) dataset. The in vitro and in vivo experiments were executed to investigate the role of METTL3 in PCa. m⁶A dot blot, methylated RNA immunoprecipitation (MeRIP), RIP, and qRT-PCR assays were employed to observe METTL3-mediated m⁶A modification of MALAT1. The effects of METTL3 on MALAT1-mediated PI3K/AKT pathway were assessed by Western blot analysis. As a result, we found that METTL3 was significantly upregulated in PCa tissues and high expression of METTL3 was associated with Gleason score and tumor recurrence in patients with PCa. Knockdown of METTL3 markedly repressed growth and invasion of PCa cells in vitro and in vivo, whereas ectopic expression of METTL3 showed the opposite effects. Moreover, knockdown of METTL3 decreased the total m⁶A levels of PCa cells as well as the MALAT1 m⁶A levels, leading to reduced MALAT1 expression. Overexpression of MALAT1 reversed METTL3 knockdown-induced antitumor effects and PI3K/AKT signaling inactivation. MALAT1 harbored a positive correlation with METTL3 expression and tumor recurrence in PCa. In conclusion, our findings demonstrate that METTL3-mediated m⁶A modification of lncRNA MALAT1 promotes growth and invasion of PCa cells by activating PI3K/AKT signaling.