YY1 is regulated by ALKBH5-mediated m6A modification and promotes autophagy and cancer progression through targeting ATG4B

VCP enhances autophagy-related osteosarcoma progression by recruiting USP2 to inhibit ubiquitination and degradation of FASN

Osteosarcoma (OS) is a highly aggressive malignant tumor with a high rate of disability and mortality rates, and dysregulated autophagy is a crucial factor in cancer. However, the molecular mechanisms that regulate autophagy in OS remain unclear. This study aimed to explore key molecules that affect autophagy in OS and their regulatory mechanisms. We found that fatty acid synthase (FASN) was significantly increased in activated autophagy models of OS and promoted OS proliferation in an autophagy-dependent manner, as detected by LC3 double-labeled fluorescence confocal microscopy, western blotting, transmission electron microscopy (TEM), and cell functional experiments. Furthermore, co-immunoprecipitation combined with mass spectrometry (Co-IP/MS), ubiquitination modification, molecular docking, and protein truncation methods were used to identify FASN-interacting proteins and analyze their effects on OS. Valosin-containing protein (VCP) enhanced the FASN stability by recruiting ubiquitin specific peptidase-2 (USP2) to remove the K48-linked ubiquitin chains from FASN; domain 2 of VCP and the amino acid sequence () of USP2 were critical for their interactions. Gain- and loss-of-function experiments showed that the inhibition of FASN or USP2 attenuated the stimulatory effect of VCP overexpression on autophagy and the malignant phenotypes of OS cells in vitro and in vivo. Notably, micro-CT indicated that VCP induced severe bone destruction in nude mice, which was abrogated by FASN or USP2 downregulation. In summary, VCP recruits USP2 to stabilize FASN by deubiquitylation, thereby activating autophagy and promoting OS progression. The identification of the VCP/USP2/FASN axis, which mediates autophagy regulation, provides important insights into the underlying mechanisms of OS and offers potential diagnostic and therapeutic strategies for patients with OS.

Autophagy: a critical mechanism of N6-methyladenosine modification involved in tumor progression and therapy resistance

N6-Methyladenosine (m6A) is an evolutionarily highly conserved epigenetic modification that affects eukaryotic RNAs, especially mRNAs, and m6A modification is commonly linked to tumor proliferation, progression, and therapeutic resistance by participating in RNA metabolism. Autophagy is an intracellular degradation and recycling biological process by which cells remove damaged organelles, protein aggregates, and other intracellular wastes, and release nutrients to maintain cell survival when energy is scarce. Recent studies have shown that m6A modification plays a critical role in the regulation of autophagy, affecting the initiation of autophagy, the formation and assembly of autophagosomes, and lysosomal function by regulating critical regulatory molecules involved in the process of autophagy. Moreover, autophagy can also affect the expression of the three types of regulators related to m6A, which in turn affects the levels of their target genes via m6A modification. Thus, m6A modification and autophagy form a sophisticated regulatory network through mutual regulation, which plays an important role in tumor progression and therapeutic resistance. In this manuscript, we reviewed the effects of m6A modification on autophagy as well as the effects of autophagy on m6A modification and the roles of the m6A-autophagy axis in tumor progression and therapy resistance. Additionally, we summarized the value and application prospects of key molecules in the m6A-autophagy axis in tumor diagnosis and therapy.

Transcription factor Yin Yang 1 enhances epithelial-mesenchymal transition, migration, and stemness of non-small cell lung cancer cells by targeting sonic hedgehog

Non-small cell lung cancer (NSCLC) is a frequent type of lung cancer. Transcription factor Yin Yang 1 (YY1), an endogenous transcription factor containing zinc finger structure, can accelerate NSCLC progression. However, the impact of YY1 on the stemness of NSCLC cells and the mechanism of promoting NSCLC cell progression is unclear. YY1 and Sonic hedgehog (Shh) expressions were monitored by RT-qPCR, western blot, and immunohistochemistry. Overall survival was tested through Kaplan-Meier analysis. The interaction between YY1 and Shh was confirmed. Then, cell migration, stemness, and epithelial-mesenchymal transition (EMT) were assessed with functional experiments in vitro and in vivo. YY1 and Shh were highly expressed in NSCLC tissues and positively correlated with the poor OS of NSCLC patients. Functional experiments denoted that YY1 or Shh overexpression could accelerate EMT, migration, and stemness of NSCLC cells, and YY1 or Shh knockdown played the opposite role to its overexpression. Mechanism analysis disclosed that Shh, as a target gene of YY1, was positively related to YY1. The rescued experiment manifested that Shh silencing could reverse the induction effect of YY1 overexpression on EMT, migration, and stemness of NSCLC cells. In vivo experiments also confirmed that YY1 could accelerate tumor growth and EMT and weaken apoptosis. YY1 promotes NSCLC EMT, migration, and stemness by Shh, which might be novel diagnostic markers and therapeutic targets for NSCLC therapy.

Dysregulation of autophagy in gastric carcinoma: Pathways to tumor progression and resistance to therapy

The considerable death rates and lack of symptoms in early stages of gastric cancer (GC) make it a major health problem worldwide. One of the most prominent risk factors is infection with Helicobacter pylori. Many biological processes, including those linked with cell death, are disrupted in GC. The cellular "self-digestion" mechanism necessary for regular balance maintenance, autophagy, is at the center of this disturbance. Misregulation of autophagy, however, plays a role in the development of GC. In this review, we will examine how autophagy interacts with other cell death processes, such as apoptosis and ferroptosis, and how it affects the progression of GC. In addition to wonderful its role in the epithelial-mesenchymal transition, it is engaged in GC metastasis. The role of autophagy in GC in promoting drug resistance stands out. There is growing interest in modulating autophagy for GC treatment, with research focusing on natural compounds, small-molecule inhibitors, and nanoparticles. These approaches could lead to breakthroughs in GC therapy, offering new hope in the fight against this challenging disease.

YTHDF1 in Tumor Cell Metabolism: An Updated Review

With the advancement of research on m6A-related mechanisms in recent years, the YTHDF protein family within m6A readers has garnered significant attention. Among them, YTHDF1 serves as a pivotal member, playing a crucial role in protein translation, tumor proliferation, metabolic reprogramming of various tumor cells, and immune evasion. In addition, YTHDF1 also exerts regulatory effects on tumors through multiple signaling pathways, and numerous studies have confirmed its ability to assist in the reprogramming of the tumor cell-related metabolic processes. The focus of research on YTHDF1 has shifted in recent years from its m6A-recognition and -modification function to the molecular mechanisms by which it regulates tumor progression, particularly by exploring the regulatory factors that interact with YTHDF1 upstream and downstream. In this review, we elucidate the latest signaling pathway mechanisms of YTHDF1 in various tumor cells, with a special emphasis on its distinctive characteristics in tumor cell metabolic reprogramming. Furthermore, we summarize the latest pathological and physiological processes involving YTHDF1 in tumor cells, and analyze potential therapeutic approaches that utilize YTHDF1. We believe that YTHDF1 represents a highly promising target for future tumor treatments and a novel tumor biomarker.