BackgroundTumor suppressive let-7 miRNAs are universally down-regulated in human hepatocellular carcinoma (HCC) versus normal tissues; however, the roles and related molecular mechanisms of let-7 in HCC stem cells are poorly understood.MethodsWe examined the inhibitory effect of let-7 miRNAs on the proliferation of MHCC97-H and HCCLM3 hepatic cancer cells by using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, which was further confirmed by apoptosis and cell cycle studies. The sphere-forming assay was used to study the effects of let-7a on stem like cells. Through western blot, immunofluorescence and the luciferase-reporter assay, we explored the activity of epithelial-mesenchymal transition (EMT) signaling factors in HCC cells. qRT-PCR was applied to detect miRNA expression levels in clinical tissues.ResultsLet-7a effectively repressed cell proliferation and viability, and in stem-like cells, also let-7a decreased the efficiency of sphere formation.in stem-like cells. The suppression of EMT signaling factors in HCC cells contributed to let-7’s induced tumor viability repression and Wnt activation repression. Besides, Wnt1 is critical and essential for let-7a functions, and the rescue with recombinant Wnt1 agent abolished the suppressive roles of let-7a on hepatospheres. In clinical HCC and normal tissues, let-7a expression was inversely correlated with Wnt1 expression.ConclusionsLet-7 miRNAs, especially let-7a, will be a promising therapeutic strategy in the treatment of HCC through eliminating HCC stem cells, which could be achieved by their inhibitory effect on the Wnt signaling pathway.

BackgroundAdvanced non-small cell lung cancer (NSCLC) patients often develop thromboembolic events, including cerebral infarction (CI). However, the relationship between advanced NSCLC and CI has not been thoroughly investigated. We examined the association between advanced NSCLC and CI and risk factors for CI in advanced or post-operative recurrent NSCLC patients.MethodsWe retrospectively investigated 515 patients diagnosed with advanced or post-operative recurrent NSCLC at Juntendo University Hospital between April 2009 and March 2014.ResultsAmong the 515 patients evaluated, 15 patients (2.9 %) developed CI after diagnosis of advanced or post-operative recurrent NSCLC. Univariate and multivariate analyses were conducted, and brain metastasis was the only significant independent risk factor for CI (odds ratio 5.24, 95 % confidence interval 1.72–16.10, p = 0.004). The incidence was 6.3 % in these patients. The median survival time was 36 days, and 1-year survival rate was 6.7 % after development of CI. Overall survival from diagnosis of advanced NSCLC or post-operative recurrence was significantly shorter in patients with CI than in patients without CI (223 days versus 895 days; HR, 3.46; 95 % confidence interval, 2.04–6.02; p = 0.001).ConclusionsThe incidence of CI is high in advanced or post-operative recurrent NSCLC, and is especially higher in patients with brain metastasis than in those without brain metastasis. Moreover, CI may affect patient’s prognosis. Careful monitoring for the development of CI in patients with advanced or post-operative recurrent NSCLC is needed, especially for patients with brain metastasis.

BackgroundGalectin-1 (gal-1) belongs to the family of β-galactoside-binding proteins which primarily recognizes the Galβ1-4GlcNAc sequences of oligosaccharides associated with several cell surface glycoconjugates. The lectin recognizes correspondent glycoepitopes on human breast cancer cells. Galectin-1 is expressed both in normal and malignant tissues. Lymphatic organs naturally possessing high rates of apoptotic cells, express high levels of Galectin-1. Furthermore galectin-1 can initiate T cell apoptosis. Binding of galectin-1 to trophoblast tumor cells presenting the oncofetal Thomsen-Friedenreich (TF) carbohydrate antigen inhibits tumor cell proliferation. In this study we examined the impact galectin-1 has in vitro on cell proliferation, apoptotic potential and metabolic activity of MCF-7 and T-47D breast cancer cells in dependence to their expression of the Thomsen-Friedenreich (TF) tumor antigen.MethodsFor proliferation and apoptosis assays cells were grown in presence of 10, 30 and 60 μg gal-1/ml medium. Cell proliferation was determined by a BrdU uptake ELISA.Detection of apoptotic cells was done by M30 cyto death staining, in situ nick translation and by a nucleosome ELISA method. Furthermore we studied the impact galectin-1 has on the metabolic activity of MCF-7 and T-47D cells in a homotypic three-dimensional spheroid cell culture model mimicking a micro tumour environment.ResultsGal-1 inhibited proliferation of MCF-7 cells (strong expression of the TF epitope) but did not significantly change proliferation of T-47D cells (weak expression of the TF epitope). The incubation of MCF-7 cells with gal-1 raised number of apoptotic cells significantly. Treating the spheroids with 30 μg/ml galectin-1 in addition to standard chemotherapeutic regimes (FEC, TAC) resulted in further suppression of the metabolic activity in MCF-7 cells whereas T-47D cells were not affected.ConclusionsOur results demonstrate that galectin-1 can inhibit proliferation und metabolic cell activity and induce apoptosis in breast tumor cell lines with high expression levels of the Thomsen-Friedenreich (TF) antigen in monolayer and spheroid cell culture models.

BackgroundGenes in inflammatory pathways play a pivotal role in the development of colorectal cancer. We conducted a two-stage case-control study and aimed at screening the colorectal cancer-associated genetic variations in inflammatory genes.MethodsTwenty-three candidate variants were genotyped in 952 primary colorectal cancer cases and 875 cancer-free controls from eastern China. Promising single nucleotide polymorphisms were further genotyped in 518 cases and 554 controls from middle China. Expression quantitative trait loci and differential gene expression analyses were performed for the associated gene.Resultsrs2282151 presented consistently significant associations with the risk of colorectal cancer in both stages (odds ratio (95 % confidence interval) = 1.30 (1.16–1.46), risk allele = C, Pcombined = 8.9E-6). Gene expression quantitative trait loci analyzes uncovered consistent cis-regulatory signals which showed that the C allele of rs2282151 was associated with increased expression level of heat shock protein 90 alpha family class B member 1 (HSP90AB1). Then we found that the mRNA expression levels of HSP90AB1 were significantly higher in tumor tissues than normal tissues (fold-change = 1.83) in 28 pairs of colorectal tissue samples. The expression difference was consistent with data from online datasets. Additionally, we observed notable peaks of H3K27ac and H3K4me3 near the first intron of HSP90AB1 using ChIP-seq data from multiple cell lines (including HCT116).ConclusionsOur findings indicate that the C allele of the novel colorectal cancer-associated variant rs2282151 is associated with increased expression levels of HSP90AB1, which is expressed higher in colorectal tumor tissues than in normal tissues.

BackgroundWe previously reported that IL-6 and transglutaminase 2 (TG2) were expressed in more aggressive basal-like breast cancer cells, and TG2 and IL-6 expression gave these cells stem-cell-like phenotypes, increased invasive ability, and increased metastatic potential. In the present study, the underlying mechanism by which IL-6 production is induced in luminal-type breast cancer cells was evaluated, and TG2 overexpression, IL-1β stimulation, and IL-6 expression were found to give cancerous cells a hormone-independent phenotype.MethodsLuminal-type breast cancer cells (MCF7 cells) were stably transfected with TG2. To evaluate the requirement for IL-6 neogenesis, MCF7 cells were stimulated with various cytokines. To evaluate tumorigenesis, cancer cells were grown in a three-dimensional culture system and grafted into the mammary fat pads of NOD/scid/IL-2Rγ−/− mice.ResultsIL-1β induced IL-6 production in TG2-expressing MCF7 cells through an NF-kB-, PI3K-, and JNK-dependent mechanism. IL-1β increased stem-cell-like phenotypes, invasiveness, survival in a three-dimensional culture model, and estrogen-independent tumor growth of TG2-expressing MCF7 cells, which was attenuated by either anti-IL-6 or anti-IL-1β antibody treatment.ConclusionWithin the inflammatory tumor microenvironment, IL-1β increases luminal-type breast cancer cell aggressiveness by stimulating IL-6 production through a TG2-dependent mechanism.