Colorectal cancer (CRC) is one of the most common malignancies, and the main cause of death from CRC is tumor metastasis. m1A RNA modification plays critical role in many biological processes. However, the role of m1A modification in CRC remains unclear. Here, we find that the m1A demethylase alkB homolog 1, histone H2A dioxygenase (ALKBH1) is overexpressed in CRC and is associated with metastasis and poor prognosis. Upregulation of ALKBH1 expression promotes CRC metastasis in vitro and in vivo. Mechanistically, knockdown of ALKBH1 results in a decrease in methyltransferase 3, N6‐adenosine‐methyltransferase complex catalytic subunit (METTL3) expression, probably due to m1A modification of METTL3 mRNA, followed by m6A demethylation of SMAD family member 7 (SMAD7) mRNA. In addition, downregulation of SMAD7 establishes an aggressive phenotype. More importantly, the cell migration and invasion defects caused by ALKBH1 depletion or METTL3 depletion are significantly reversed by SMAD7 silencing. Considering these results collectively, we propose that ALKBH1 promotes CRC metastasis by destabilizing SMAD7 through METTL3.
1 January 2021 in International Journal of Biological Sciences
Metastasis is a key factor that affects the prognosis of colorectal cancer (CRC), and patients with metastasis have limited treatment options and poor prognoses. EGF, latrophilin, and seven transmembrane domains containing 1 (ELTD1/ADGRL4) are members of the adhesion G protein-coupled receptor (aGPCR) superfamily. In this study, high expression of ELTD1 was correlated with lymph node metastasis and poor outcomes in CRC patients. Both in vitro and in vivo studies showed that ELTD1 markedly promoted the invasion and metastasis of CRC. Moreover, ELTD1 accelerated the transcriptional activity of MMP2, which could rescue the impaired invasiveness of CRC cells caused by the downregulation of ELTD1 expression. In conclusion, our study suggests that ELTD1 might be a potential novel target for the treatment of CRC metastasis.
Background: Distant metastasis is the main cause of mortality in colorectal cancer (CRC) patients. N1‐methyladenosine (m1A) is a type of epitranscriptome modification. While its regulatory effect on mRNA and its role in CRC metastasis remain unclear.Methods: The m1A methylation profile of mRNAs in CRC was revealed by m1A methylated RNA immunoprecipitation sequencing. The expression of MFAP2 in tumor tissues was measured by immunohistochemistry and then correlated with the clinical characteristics and prognosis of CRC patients. The role of MFAP2 in the invasiveness of CRC cells was evaluated by transwell assays and peritoneal metastatic model in nude mice. The downstream targets of MFAP2 was screened by mass spectrometry analysis. Then the role of MFAP2‐CLK3 signaling axis was verified by cotransfecting MFAP2 siRNA and CLK3 plasmid in CRC cells.Results: Microfibril associated protein 2 (MFAP2) mRNA was overexpressed and m1A‐hypermethylated in CRC. High expression of MFAP2 was closely related to lymph node metastasis and distant metastasis, leading to poor prognosis in patients with CRC. In vivo and in vitro studies showed that silencing of MFAP2 inhibited the migration, invasion and metastasis of CRC cells. CDC Like Kinase 3 (CLK3) was a potential downstream target of MFAP2. Further studies showed that MFAP2 depletion might induce autophagic degradation of CLK3, and the role of MFAP2 in the invasiveness of CRC cells was dependent on CLK3.Conclusions: Our results uncover a newly identified MFAP2‐CLK3 signaling axis, which is a potential therapeutic target for CRC metastasis.
Currently, WeChat is widely used in disease education for patients with Crohn’s disease (CD) in China. It is beneficial for the patients to actively engage in their disease management. In this study, we examined the source and expectations of disease information for Chinese CD patients, analysing the content of popular WeChat public accounts and their potential association with medication adherence. Between November 24th, 2017 and April 10th, 2018, online questionnaires were sent to CD patients from eight different large urban hospitals in China. In all, 436 patients with CD were surveyed, and 342 patients responded. Patients most frequently visited Baidu (65%), WeChat (61%) and medical websites such as Haodaifu (35%) when searching for IBD-related information. Among ten WeChat IBD public accounts, the China Crohn’s and Colitis Foundation (CCCF) (73%), “IBD Academic Officer” (21%) and “IBD in love” (21%) were the most popular. CD patients were most interested in information from the internet about diet and day-to-day health-related living with IBD (83%), an introduction to the disease (80%), and medication advances and side effects (80%). The correlation between the information provided by the top five WeChat public accounts and patients’ expectations was low. Additionally, most patients (64%) had greater confidence in overcoming the disease after learning about CD through their internet searches. Medical adherence was also related to internet access and income (p < 0.05). WeChat has become a major source of information for IBD education in China, but the content of WeChat didn’t fully meet patients’ expectations. Therefore, future initiatives should aim to provide high-quality information that based on patients’ demands.