Circ-AMOTL1 enhances cardiac fibrosis through binding with EIF4A3 and stabilizing MARCKS expression in diabetic cardiomyopathy

Circ_0007534 promotes cholangiocarcinoma stemness and resistance to anoikis through DDX3X-mediated positive feedback regulation of parental gene DDX42

Cholangiocarcinoma (CCA) is a malignancy with an extremely poor prognosis, and much remains unknown about its pathogenesis and treatment modalities. Circular RNA (circRNA) has been proven to play regulatory roles in various tumorigenesis, yet its potential function and mechanism in cholangiocarcinoma require further investigation. This study is the first to identify the aberrant expression and functional role of a novel circRNA, circ_0007534, derived from the DDX42 gene, in cholangiocarcinoma. Compared to the normal control group, the expression of circ_0007534 was significantly elevated in the tissues and cells with CCA and that high expression correlated with lymph node invasion and poor prognosis. Functional experiments indicated that downregulating circ_0007534 markedly inhibited the proliferation, migration, invasion, stemness, and anti-anoikis ability of CCA cells, as well as the tumor growth and liver and lung metastasis in nude mice. Mechanistic studies revealed that DDX42, as the parent gene of circ_0007534, can mutually regulate each other's expression. Predominantly located in the cytoplasm, circ_0007534 can form a complex with the RNA-binding protein DDX3X, which enhances the stability of DDX42 mRNA, thereby upregulating the expression of DDX42. This creates a positive feedback loop among the three, collectively promoting the progression of cholangiocarcinoma. In conclusion, this study sheds light on the pivotal role and molecular mechanism of circ_0007534 in the development of CCA, offering potential new targets for early diagnosis and treatment.

M6A reader YTHDF1 promotes malignant progression of laryngeal squamous carcinoma through activating the EMT pathway by EIF4A3

Laryngeal squamous cell carcinoma (LSCC) is one of the common malignant tumors in the head and neck region, and its high migration and invasion seriously threaten the survival and health of patients. In cancer development, m6A RNA modification plays a crucial role in regulating gene expression and signaling. This study delved into the function and mechanism of the m6A reading protein YTHDF1 in LSCC. It was found that YTHDF1 was highly expressed in the GEO database and LSCC tissues. Cell function experiments confirmed that the downregulation of YTHDF1 significantly inhibited the proliferation, migration, and invasion ability of LSCC cells. Further studies revealed that EIF4A3 was a downstream target gene of YTHDF1, and knockdown of EIF4A3 similarly significantly inhibited the malignant progression of LSCC in both in vivo and in vitro experiments. The molecular mechanism studies suggested that YTHDF1-EIF4A3 may promote the malignant development of LSCC by activating the EMT signaling pathway. This study provides important clues for an in-depth understanding of the pathogenesis of LSCC and is a solid foundation for the discovery of new therapeutic targets and approaches.