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BACKGROUND: It has been discovered that lncRNA ARAP1-AS1 is upregulated and operates as a tumor promoter in many cancers. However, its pattern of expression and potential mechanism in lung adenocarcinoma (LUAD) is still unknown. METHODS: The levels of lncRNA ARAP1-AS1, miR-8068, and CEACAM5 expressions in LUAD cell lines and tissues were assessed by conducting western blot and RT-qPCR analyses. MiR-8068's potential targeting relationships with lncRNA ARAP1-AS1 and CEACAM5 were ascertained by performing bioinformatics analysis. The interaction of lncRNA ARAP1-AS1 with miR-8068 was validated by means of by RIP and luciferase reporter experiments. CCK-8, cell adhesion, and Transwell migration experiments were conducted to study how lncRNA ARAP1-AS1 affects LUAD cell migration, adhesion, and proliferation. To confirm the function of lncRNA ARAP1-AS1 in vivo, a tumor formation experiment was executed. RESULTS: An elevated expression of lncRNA ARAP1-AS1 was observed among the LUAD cells and tissues. The overexpression of lncRNA ARAP1-AS boosted cell proliferation, adhesion, and migration in LUAD and also favored in vivo tumor growth. MiR-8068 was found to be lncRNA ARAP1-AS1's target gene. MiR-8068 overexpression partially antagonized lncRNA ARAP1-AS1's promotive effect on proliferation, viability, and adhesion. Meanwhile CEACAM5 could alleviate the miR-8068-induced inhibition of tumor growth. The negative correlation of miR-8068 with lncRNA ARAP1-AS1 or CEACAM5 was also revealed. CONCLUSION: To upregulate CEACAM5 expression lncRNA ARAP1-AS1 targeted miR-8068, thus promoting the progression of LUAD. This indicates that the lncRNA ARAP1-AS1/miR-8068/CEACAM5 axis has potential as a therapeutic target in LUAD treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND: CD133 (prominin-1) is the most commonly used molecular marker of the cancer stem cells (CSCs) that maintain tumor progression and recurrence in colorectal cancer. However, the proteome of CSCs directly isolated from colorectal tumors based on CD133 expression has never been investigated. OBJECTIVE: To reveal biomarkers of CD133-positive colorectal CSCs. METHODS: Thirty colorectal tumor samples were collected from patients undergoing bowel resection. CD133-positive and CD133-negative cells were isolated by FACS. Comparative proteomic profiling was performed by LC-MS/MS analysis combined with label-free quantification. Verification of differentially expressed proteins was performed by flow cytometry or ELISA. CD133-knockout Caco-2 and HT-29 cell lines were generated using CRISPR-Cas9 gene editing. RESULTS: LC-MS/MS analysis identified 29 proteins with at least 2.5-fold higher expression in CD133-positive cells versus CD133-negative cells. Flow cytometry confirmed CEACAM5 overexpression in CD133-positive cells in all clinical samples analyzed. S100A8, S100A9, and DEFA1 were differentially expressed in only a proportion of the samples. CD133 knockout in the colon cancer cell lines Caco-2 and HT-29 did not affect the median level of CEACAM5 expression, but led to higher variance of the percentage of CEACAM5-positive cells. CONCLUSIONS: High CEACAM5 expression in colorectal cancer cells is firmly associated with the CD133-positive colorectal CSC phenotype, but it is unlikely that CD133 directly regulates CEACAM5 expression. [ABSTRACT FROM AUTHOR]