RESUMO
Background: Lung adenocarcinoma, as a common histological type in lung cancer, the overall survival is very low, and the prognosis is poor because it is difficult to find and easily recurs. Therefore, this study aimed to explore the role of the secreted protein beta-1,3-N-acetylglucosaminyltransferase 3 (B3GNT3) in the development of lung adenocarcinoma and to evaluate its potential significance for early clinical biomarker screening. Methods: The mRNA expression profiles of patients with lung adenocarcinoma and normal controls were analyzed via The Cancer Genome Atlas (TCGA) database. Serum samples of clinical lung cancer patients and healthy people were obtained, and the differences in B3GNT3 expression in different stages of lung adenocarcinoma and in healthy tissues were compared. Kaplan-Meier (K-M) curves were drawn to clarify the influence of high and low expression of B3GNT3 on the prognosis of patients. Peripheral blood samples from patients with lung adenocarcinoma and healthy people were obtained clinically, and receiver operating characteristic (ROC) curves were drawn to clarify the sensitivity and specificity of B3GNT3 expression for the diagnosis of lung adenocarcinoma. Lung adenocarcinoma cells were cultured in vitro, the expression of B3GNT3 was knocked down by lentivirus infection. The expression of the apoptosis-associated genes was detected by reverse transcription-polymerase chain reaction (RT-PCR). Results: The secreted protein B3GNT3 is significantly differentially expressed in the serum of patients with lung adenocarcinoma versus normal controls. Subgroup analysis according to lung adenocarcinoma clinical stage showed that the higher the clinical stage of lung adenocarcinoma was, the higher the B3GNT3 expression. Enzyme-linked immunosorbent assay (ELISA) revealed that B3GNT3 expression was significantly increased in the serum of patients with lung adenocarcinoma and significantly decreased after surgery. By inhibiting programmed cell death-ligand 1 (PD-L1), the level of apoptosis was significantly increased and the proliferative capacity was significantly inhibited. In contrast, the level of apoptosis was significantly increased and the proliferation ability was significantly inhibited after simultaneous overexpression of B3GNT3 and inhibition of PD-L1. Conclusions: High expression of the secreted protein B3GNT3 in lung adenocarcinoma is closely related to prognosis and can serve as a potential biological marker for the early screening of lung adenocarcinoma.
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BACKGROUND: Sperm-associated antigen 1 (SPAG1) has been identified as a marker of pancreatic cancer progression and promoter of cell motility; however, its role in breast cancer is not completely understood. METHODS: SPAG1 expression in breast cancer tissues and normal tissues was obtained from online databases. Knockdown function assays were designed and conducted to verify the functional role of SPAG1 in breast cancer cell lines. Cell counting and MTT assays were used to assess cell proliferation. Cell flow cytometry assay was used for cell cycle phase arrest, and fluorescence microscopy was used for colony formation assessment. RESULTS: Both the mRNA and protein levels of SPAG1 were significantly higher in the breast cancer tissues than in the normal tissues. In addition, SPAG1 is significantly related to many clinicopathological features of breast cancer, such as age (>51 years), estrogen receptor (ER) (+), progesterone receptor (PR) (+), and nodal status (+), non-triple negative breast cancer (TNBC), not basal-like and not basal-like and not TNBC. Survival analysis indicates that breast cancer patients with low expression of SPAG1 had a significantly better prognosis with relapse-free survival (RFS). Functional experiment analysis revealed that knockdown of SPAG1 suppressed cell proliferation and colony-forming ability. CONCLUSION: Our results suggested a possible role of SPAG1 in breast cancer pathogenesis.
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AIM: Argonaute2 (AGO2) protein is the active part of RNA-induced silencing complex, cleaving the target mRNA strand complementary to their bound siRNA. An increasing number of miRNAs has been identified as essential to angiogenesis of hepatocellular carcinoma (HCC). In this study we investigated how AGO2 affected HCC angiogenesis. METHODS: Human HCC cell lines HepG2, Hep3B, Huh7, SMMC-7721, Bel-7404, MHCC97-H and LM-3, and human umbilical vein endothelial cells (HUVEC) were tested. The expression of AGO2 in HCC cells was knocked down with siRNA and restored using recombinant adenovirus expressing Ago2. The levels of relevant mRNAs and proteins were examined using RT-PCR, Western blot and EILSA. Nude mice were implanted with Huh7 or SMMC-7721 cells, and tumor volumes were measured. After the mice were euthanized, the xenograft tumors were used for immunohistological analysis. RESULTS: In 6 HCC cell lines, AGO2 protein expression was significantly correlated with VEGF expression (r=+0.79), and with VEGF secretion (r=+0.852). Knockdown of Ago2 in Huh7 cells and SMMC-7721 cells substantially decreased VEGF expression, whereas the restoration of AGO2 reversed both VEGF expression and secretion. Furthermore, knockdown of Ago2 significantly up-regulated the expression of PTEN (a tumor suppressor involved in the inhibition of HCC angiogenesis), and vice versa. Moreover, the specific PTEN inhibitor bisperoxovanadate (7, 14, 28 nmol/L) dose-dependently restored the expression of VEGF and the capacity of HCC cells to induce HUVECs to form capillary tubule structures. In the xenograft nude mice, knockdown of Ago2 markedly suppressed the tumor growth and decreased PTEN expression and CD31-positive microvascular in the xenograft tumors. CONCLUSION: A direct relationship exists between the miRNA processing machinery AGO2 and HCC angiogenesis that is mediated by the AGO2/PTEN/VEGF signaling pathway. The results suggest the high value of Ago2 knockdown in anti-angiogenesis therapy for HCC.
