ENTPD1-AS1–miR-144-3p-mediated high expression of COL5A2 correlates with poor prognosis and macrophage infiltration in gastric cancer

BACKGROUND

Gastric cancer (GC) is a malignant tumor with high morbidity and mortality. Expression of COL5A2 is significantly elevated in GC. Abnormal expression of noncoding RNAs (ncRNAs) have been found in GC, including microRNA (miRNA) and long noncoding RNA (lncRNA). Competing endogenous RNA network plays an important regulatory role in GC. However, its specific regulatory mechanism has not been elucidated.

AIM

To gain insight into the ncRNA regulatory mechanism and immune microenvironment related to COL5A2 in GC.

METHODS

RNA sequencing data and clinical information from The Cancer Genome Atlas data portal were used to analyze the expressions of COL5A2, miRNA and lncRNA related to the prognosis of GC. Cox regression analysis and Kyoto Encyclopedia of Genes and Genomes analysis were performed to assess the risk factors and relevant function of COL5A2. StarBase was used to predict the interaction of miRNA–lncRNA or miRNA–mRNA in GC. The relationship between COL5A2, miR-144-3p and ENTPD1-AS1 were verified by dual luciferase reporter assay. The association of COL5A2 with immune cell infiltration were analyzed using the Tumor Immune Estimation Resource database and single sample gene set enrichment analysis. The expression of COL5A2 and macrophages in paired GC tissues were detected by immunohistochemical staining.

RESULTS

We verified that the upregulation of COL5A2 expression was associated with the prognosis of GC and was an independent risk factor for GC. miR-144-3p was downregulated and correlated with the prognosis of GC. miR-144-3p regulated the expression of COL5A2 through direct interaction with COL5A2. ENTPD1-AS1 was elevated in GC and competitively bound to miR-144-3p, thus inhibiting the expression of miR-144-3p. ENTPD1-AS1 enhanced the expression of COL5A2 through sponging miR-144-3p. Compared to paired normal tissue, COL5A2 expression was upregulated at the protein level, especially in the middle and late stages of GC. The high expression of COL5A2 was positively linked to macrophage infiltration in GC.

CONCLUSION

COL5A2 regulated by ENTPD1-AS1–miR-144-3p was associated with poor prognosis and macrophage infiltration in GC. This could be a new biomarker and therapeutic target in GC.

Long noncoding RNA CRNDE promotes proliferation, migration and invasion in prostate cancer through miR-101/Rap1A

Prostate cancer (Pca) is the second frequent malignancy in men. Long noncoding RNAs (lncRNAs) have been reported to play essential roles in the progression of cancers, including Pca. LncRNA colorectal neoplasia differentially expressed (CRNDE) has been found to affect tumorigenesis in many cancers. However, the exact role and mechanism of CRNDE in Pca remain poorly understood. 64 Pca patients were recruited in this study. PC3 and 22RV1 cells were used in vitro experiments. The expressions of CRNDE, microRNA-101 (miR-101), and Ras-related protein 1A (Rap1A) were detected in vivo and in vitro by quantitative real-time polymerase chain reaction and western blot, respectively. Cell proliferation, apoptosis, migration, and invasion were investigated through cell counting kit-8, flow cytometry, and Transwell assays, respectively. The interaction between miR-101 and CRNDE or Rap1A was explored by bioinformatics analysis and luciferase reporter assay. High expression of CRNDE was shown in Pca tissues and cells and predicted poor outcomes of patients. Overexpression of CRNDE promoted cell proliferation, migration, and invasion but decreased apoptosis in Pca cells, while its knockdown showed an opposite effect. CRNDE was a decoy of miR-101 and its effect on Pca progression was reversed by miR-101. Rap1A was identified as a target of miR-101 and it attenuated the effect of miR-101 on Pca development. Moreover, the Rap1A protein level was positively regulated by CRNDE, which was weakened by miR-101. CRNDE contributed to cell proliferation, migration, and invasion by regulating the miR-101/Rap1A axis in Pca, providing a novel strategy for Pca treatment.