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Tumor suppressor genes are frequently deleted or mutated in lung cancer. The RNA-binding motif protein 10 (RBM10) gene has the ability to suppress tumor activity, but the role of RBM10 during the development of lung cancer has yet to be elucidated. The current study investigated the expression levels of RBM10 in non-tumor and tumor tissues obtained from patients with adenocarcinoma using reverse transcription-polymerase chain reaction and western blot analysis, and identified a reduction in RBM10 expression in lung tumor tissue. To investigate the in vitro and in vivo function of RBM10, A549 human non-small cell lung cancer cells were transfected with the pcDNA-RBM10 vector. Flow cytometry was used to analyze the levels of apoptosis in the transfected cells. Western blot analysis was used to evaluate the expression of B-cell lymphoma 2 (Bcl-2), cleaved caspase-3, caspase-9 and poly (ADP-ribose) polymerase (PARP) proteins in A549 cells and tissues from the A549 xenograft Bagg Albino coat (BALB/c) nude mice model. RBM10 mRNA levels were significantly decreased in adenocarcinoma cells, but not in the non-tumor tissues. The A549 cells and tumor tissues exhibited significant growth inhibition following transfection with the pcDNA-RBM10 vector, which was determined using a cell proliferation assay. Flow cytometry analysis of cells stained with Annexin V/propidium iodide indicated that the overexpression of RBM10 induced apoptosis in A549 cells. The present study demonstrated that the expression levels of Bcl-2 protein were decreased and the expression levels of cleaved caspase-3, caspase-9 and PARP proteins were significantly increased in the A549 cells and cells from ex vivo tumor tissues that were injected with RBM10 vector-containing Salmonella enterica subspecies enterica serovar typhimurium. Notably, the current study identified that the accumulated and stable overexpression of RBM10 in the xenograft BALB/c nude mice model significantly inhibited the tumor growth rate. These results may provide novel insights into the use of RBM10 for lung cancer diagnosis and therapy. [ABSTRACT FROM AUTHOR]

Background/Aims: Colorectal cancer (CRC) is the third most common type of cancer worldwide. Sprouty proteins are modulators of mitogeninduced signal transduction processes and therefore can influence the process of cancerogenesis. The encoded protein of Sprouty homolog 4 (SPRY4) is associated with various human cancers. However, its biological role and clinical significance in CRC development and progression are unknown. Methods: The aim of this study was to evaluate the expression and biological role of SPRY4 in colorectal cancer. qRT-PCR was performed to investigate the expression of SPRY4 in tumor tissues and corresponding non tumor colorectal tissues from 70 patients. The effect of SPRY4 on proliferation was evaluated by MTT and colony formation assays. CRC cells transfected with SPRY4 were injected into nude mice to study the effect of SPRY4 on tumorigenesis in vivo. Results: The lower expression of SPRY4 was remarkably correlated with deep tumor invasion and advanced TNM stage. Multivariate analyses revealed that SPRY4 expression served as an independent predictor for overall survival. Using 5-aza treatment, we also observed that SPRY4 expression can be affected by DNA methylation. Further experiments revealed that overexpressed SPRY4 significantly inhibited CRC cell proliferation both in vitro and in vivo. Conclusion: Our study demonstrated that SPRY4 is involved in the development and progression of colorectal cancer by regulating cell proliferation and shows that SPRY4 may be a potential diagnostic and prognostic target in patients with colorectal cancer. [ABSTRACT FROM AUTHOR]