The effect of polycomb chromobox (Cbx) proteins in cancer is context-dependent. The Chromobox homolog 8 (CBX8) was originally characterized as a transcriptional repressor, which inhibits cell proliferation in Ink4a-Arf-dependent and -independent manner. However, the role of CBX8 in colorectal cancer remains unknown. Here, we found that high CBX8 expression was associated with a low rate of distant metastasis and good prognosis in CRC patients, even though CBX8 was up-regulated in CRC cell lines and clinical samples. Knockdown of CBX8 inhibited CRC proliferation in vitro and in vivo, mostly by increasing p53 and its downstream effectors. However, knockdown of CBX8 enhanced CRC migration, invasion and metastasis in vitro and in vivo, in part through direct up-regulation of integrin β4 (ITGB4) that in turn decreased RhoA activity. Collectively, the knockdown of CBX8 inhibited CRC proliferation, while promoting its metastasis, thus exerting paradoxical effects in CRC progression.
The cytoplasmic CBX4 protein may be a useful prognostic biomarker and a potential therapeutic target for HCC.
Background Metastasis is the primary cause of tumor death in renal cell carcinoma (RCC). Improved diagnostic markers of metastasis are critically needed for RCC. MicoRNAs are demonstrated to be stable and significant biomarkers for several malignancies. In this study, we aimed to explore the metastasis related microRNAs and its mechanism in RCC. Methods The relationship between microRNAs expression and prognosis and metastasis of RCC patients were explored by data mining through expression profiles from The Cancer Genome Atlas (TCGA). A total of 80 RCC tissues and adjacent normal kidney tissues were obtained from Department of Urology, Peking University First Hospital. Expression of microRNA-200b (miR-200b) in RCC tissues and cell lines were determined by bioinformatic data mining and quantitative real-time PCR (qRT-PCR). The effects of miR-200b on cell proliferation, migration and invasion were determined by cell counting kit-8 and colony formation assay, wound healing assay and Boyden chamber assay. Mouse cell-derived xenograft and patient-derived xenograft model were also performed to evaluate the effects of miR-200b on tumor growth and metastasis in vivo . The molecular mechanism of miR-200b function was investigated using bioinformatic target predication and high-throughput cDNA sequencing (RNA-seq) and validated by luciferase reporter assay, qRT-PCR, Western blot and immunostaining in vitro and in vivo . Findings Our findings indicates that miR-200b is frequently downregulated and have potential utility as a biomarker of metastasis and prognosis in RCC. Interestingly, ectopic expression of miR-200b in the Caki-1 and OSRC-2 cell lines suppresses cell migration and invasion in vitro as well as tumor metastases in vivo . However, miR-200b has no effect on cell proliferation in vitro and tumor growth in vivo . In addition, bioinformatics target predication and RNA-seq results reveals that Laminin subunit alpha 4 ( LAMA4 ) is one target of miR-200b and significantly inhibited by miR-200b in vitro and in vivo . Interpretation These results demonstrate a previously undescribed role of miR-200b as a suppressor of tumor metastasis in RCC by directly destabilizing LAMA4 mRNA.
Mutations of BRCA1-associated protein 1 (BAP1), a nuclear-localized deubiquitinating enzyme, had been documented in multiple human cancers. However, its role and clinical relevance in colorectal cancer is unknown. The purpose of this study was to reveal the prognostic significance of BAP1 in colorectal cancer. We performed quantitative PCR and Western blotting analyses to examine BAP1 expression in 8 cases of CRC tissues and matched adjacent non-cancerous tissues. And immunohistochemistry was used to evaluate BAP1 expression in archived 252 paraffin-embedded CRC specimens. We found that the mRNA and protein levels of BAP1 were down-regulated in 6 out of 8 cases of CRC tissues compared with their adjacent non-cancerous tissues. The BAP1 expression was closely correlated with age (p = 0.037), clinical stage (p = 0.001), T classification (p < 0.001), N classification (p < 0.001), and pathologic differentiation (p = 0.008) and histological type (p = 0.047) in CRC. The CRC patients with lower BAP1 expression survived shorter than those with higher BAP1 expression. Importantly, multivariate analysis demonstrated that BAP1 expression was an independent prognostic factor for CRC (p = 0.037). Collectively, we provide the first evidence that reduced BAP1 expression is associated with poor prognosis of CRC and BAP1 may serve as a novel prognostic biomarker for CRC.
A highly tumorigenic and malignant sub-population of HCC containing tumor-initiating cells (TICs) are defined by high self-renewal and sphere formation ability. Lysyl oxidase (LOX) regulates various factors involved in extracellular matrix (ECM) maintenance, migration and angiogenesis. Certain reports have demonstrated the role of LOX in ECM crosslinking, however, the cancer-promoting effects of LOX in HCC remain unclear, and whether LOX has a role in the regulation of angiogenesis in HCC TICs has not been elucidated. In the current study, RNA sequencing using next-generation sequencing technology and bioinformatics analyses revealed that LOX gene expression was significantly upregulated in cell spheres. Sphere cells may form tumors with more vascular enrichment compared with tumors produced from adherent cells, as observed in a mouse xenograft model. LOX expression is correlated with increased vascular endothelial growth factor (VEGF) and platelet-derived growth factor, as demonstrated by analyses of The Cancer Genome Atlas and Gene Expression Omnibus databases. Conditioned media obtained from LOX-overexpressing tumor cells stimulated angiogenesis via secreted VEGF and enhanced the tube formation capacity of endothelial cells. Furthermore, these functional behaviors were blocked by the LOX inhibitor β-aminopropionitrile. These findings provide novel mechanistic insight into the pivotal role of LOX in the regulation of TICs in HCC. Combination of LOX inhibitor with sorafenib is a potentially advantageous strategy for HCC therapy.
Objective To investigate the effects of Baduanjin exercise for type 2 diabetes mellitus. Methods Literature retrieval was performed in several databases, including PubMed, EMBASE, Cochrane Library, CNKI, Wanfang Data Information Site, CBM, and VIP from inception to April 2017. Randomized controlled trials on evaluating the effects of Baduanjin exercise were identified. The primary outcomes were glycosylated hemoglobin, fasting blood-glucose, and postprandial plasma glucose. Review Manager 5.2 (RevMan 5.2) and Stata V.13.0 software were conducted for data analysis. Results The results of the meta-analysis indicated that the effects of type 2 diabetes mellitus were favoring Baduanjin plus conventional therapy, when compared with the routine treatment. Baduanjin plus conventional therapy lowered the level of glycosylated hemoglobin, fasting blood-glucose, postprandial plasma glucose, TC, TG, and LDL-C and improved HDL-C. Adverse events were not mentioned in all included studies. No publication bias was detected by Begg's and Egger's test and no single study affected the overall result by influence analysis. Conclusions Evidence from meta-analysis suggested that Baduanjin exercise plus conventional therapy has a positive effect on type 2 diabetes mellitus. However, more rigorously designed and large sample RCTs are required to confirm the efficacy and safety in further studies.
Abstract. MicroRNAs serve a critical role in human hepatocellular carcinoma (HCC) progression. However, the exact role of microRNA-143 (miR-143) in HCC remains unclear. The current study investigates the molecular mechanism of miR-143 in HCC. In cultured HepG2 and Bel7402 cell lines, miR-143 levels were raised by lentivirus transduction. This significantly inhibited HCC progression in terms of cell invasion and proliferation in both HepG2 and Bel7402 cell lines (P<0.05). MiR-143 also significantly decreased tumor implantation in vivo (P<0.05). Regulation of miR-143 on its direct target, GATA-binding factor 6 (GATA6), was investigated by multiple strategies, including dual-luciferase assay, quantitative polymerase chain reaction and western blot analysis. The results indicated that miR-143 was downregulated in both HCC cell lines and human tumors. GATA6 was identified as the downstream target of miR-143 in HCC, and overexpressing GATA6 was able to counter the tumor-suppressive effect of miR-143 on HCC in HepG2 and Bel7402 cells by significantly increasing proliferation and invasion rates (P<0.05). Therefore, a novel epigenetic pathway was identified in which miR-143 may suppress the malignancy of HCC by targeting GATA6.
Background This study aimed to investigate the possible role of inhibiting chromobox protein homologue 4 (CBX4) to deregulate of cancer stem cells (CSCs) and to evaluate the contribution of these molecules to sorafenib resistance in advanced hepatocellular carcinoma (HCC). Methods HCC cell lines and a xenograft mouse model with resistance to sorafenib were employed to analyse the effects of miR424 on CSC characteristics. RNA expression was analysed by RT-PCR and next-generation sequencing in a cohort of HCC cancer patients and sorafenib-resistant (SR) cell lines, respectively, to validate the key microRNAs and targets in the network. Results MicroRNA and mRNA profiles of SR cell lines identified miR424 and its direct target CBX4 as significantly associated with stem-cell-like properties, poor survival, and clinical characteristics. Functional experiments demonstrated that miR424 suppressed CBX4 and CBX4 induced nuclear translocation of YAP1 protein but was not associated with protein production. When YAP1 and CBX4 were modulated with CA3 and UNC3866, tumorigenicity and stem-like properties were extremely inhibited, thus indicating that these compounds exerted a strong anti-tumour effect in vivo against SR HCC cells. Conclusions Our results revealed that blocking CBX4 expression is critical in response to sorafenib resistance with advanced HCC.
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