CircASPH Enhances Exosomal STING to Facilitate M2 Macrophage Polarization in Colorectal Cancer

Exosomes are considered a mediator of communication within the tumor microenvironment (TME), which modulates cancer progression through transmitting cargos between cancer cells and other cancer-related cells in TME. Circular RNAs (circRNAs) have emerged to be regulators in colorectal cancer (CRC) progression, but most of them have not been discussed in CRC. This study aims to investigate the role of circRNA aspartate beta-hydroxylase (circASPH) in CRC progression and its correlation with exosome-mediated TME. At first, we determined that circASPH was upregulated in CRC samples and cell lines. Functionally, the circASPH deficiency suppressed the malignant processes of CRC cells and also inhibited in vivo tumor growth via enhancing antitumor immunity. Mechanically, circASPH facilitated macrophage M2 polarization by upregulating exosomal stimulator of interferon genes (STING). CircASPH interacted with insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) to stabilize IGF2BP2 protein, therefore enhancing the stability of m6A-modified STING mRNA. In turn, coculture of STING-overexpressed macrophages recovered the suppression of silenced circASPH on the malignancy of CRC cells both in vitro and in vivo. Our study demonstrated that circASPH enhances exosomal STING to facilitate M2 macrophage polarization, which further accelerates CRC progression. The findings support circASPH as a promising therapeutic target for CRC treatment.

CircASPH promotes KGN cells proliferation through miR-375/MAP2K6 axis in Polycystic Ovary Syndrome

Polycystic Ovary Syndrome (PCOS) is a kind of endocrine disorder which is prevalent in adult women, so exploring more biomarkers for PCOS is imperative. Recently, circular RNA and microRNA are confirmed to be related with PCOS development. Whether circular RNA ASPH (circASPH) is involved in PCOS need to be studied further. We utilized RT‐qPCR to measure the expression levels of circASPH, miR‐375 and MAP2K6 in PCOS patients and normal group. The effects of circASPH and miR‐375 on KGN cells proliferation and apoptosis were observed by CCK‐8 assay, EdU incorporation assay and apoptosis assay, separately. Then Dual‐luciferase reporter assay was carried out to verify the circASPH/miR375 axis and miR375/MAP2K6 axis. The interaction between circASPH and MAP2K6 were detected with the support of RT‐qPCR and Western blot. We found circASPH and MAP2K6 were both over‐expressed in PCOS patients, while miR‐375 was in the opposite direction. Moreover, miR‐375 was negatively regulated by circASPH, while MAP2K6 was positively regulated by circASPH. In addition, circASPH directly targeted miR‐375, which targeted MAP2K6. More than that, the knockdown of circASPH repressed KGN cells proliferation and enhanced apoptosis, while the silence of miR‐375 reversed the above effects. In conclusion, circASPH promotes KGN cells proliferation through miR‐375/MAP2K6 axis in PCOS, and they are thought‐provoking biomarkers for PCOS diagnosis and therapy.