Aberrant expression of immature truncated O-glycans is a characteristic feature observed on virtually all epithelial cancer cells, and a very high frequency is observed in early epithelial premalignant lesions that precede the development of adenocarcinomas. Expression of the truncated O-glycan structures Tn and sialyl-Tn is strongly associated with poor prognosis and overall low survival. The genetic and biosynthetic mechanisms leading to accumulation of truncated O-glycans are not fully understood and include mutation or dysregulation of glycosyltransferases involved in elongation of O-glycans, as well as relocation of glycosyltransferases controlling initiation of O-glycosylation from Golgi to endoplasmic reticulum. Truncated O-glycans have been proposed to play functional roles for cancer-cell invasiveness, but our understanding of the biological functions of aberrant glycosylation in cancer is still highly limited. Here, we used exome sequencing of most glycosyltransferases in a large series of primary and metastatic pancreatic cancers to rule out somatic mutations as a cause of expression of truncated O-glycans. Instead, we found hypermethylation of core 1 β3-Gal-T-specific molecular chaperone, a key chaperone for O-glycan elongation, as the most prevalent cause. We next used gene editing to produce isogenic cell systems with and without homogenous truncated O-glycans that enabled, to our knowledge, the first polyomic and side-by-side evaluation of the cancer O-glycophenotype in an organotypic tissue model and in xenografts. The results strongly suggest that truncation of O-glycans directly induces oncogenic features of cell growth and invasion. The study provides support for targeting cancer-specific truncated O-glycans with immunotherapeutic measures.epigenetics | glycans | skin | pancreas | keratinocyte
Fibroblasts in the tumor stroma are well recognized as having an indispensable role in carcinogenesis, including in the initiation of epithelial tumor formation. The association between cancer cells and fibroblasts has been highlighted in several previous studies. Regulation factors released from cancer-associated fibroblasts (CAFs) into the tumor microenvironment have essential roles, including the support of tumor growth, angiogenesis, metastasis and therapy resistance. A mutual interaction between tumor-induced fibroblast activation, and fibroblast-induced tumor proliferation and metastasis occurs, thus CAFs act as tumor supporters. Previous studies have reported that by developing fibroblast-targeting drugs, it may be possible to interrupt the interaction between fibroblasts and the tumor, thus resulting in the suppression of tumor growth, and metastasis. The present review focused on the reciprocal feedback loop between fibroblasts and cancer cells, and evaluated the potential application of anti-CAF agents in the treatment of cancer.
Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide and ranks second in China. The prognosis of HCC remains dismal mainly because of its late diagnosis, especially in patients with coexisting chronic liver diseases. To identify serum biomarkers for HCC, sera from 20 healthy volunteers, 20 hepatitis B virus (HBV) infected patients and 20 HCC patients were selected for screening study and same number of sera into the same three groups were used for validation study. A strategy including sonication, albumin and immunoglobulin G (IgG) depletion and desalting was optimized for screening differentially expressed proteins of low abundance in serum. By 2-DE image analysis and MALDI-TOF-MS/MS identification, eight proteins including heat-shock protein 27 (HSP27), alpha-fetoprotein (AFP), alpha-1 antitrypsin, clusterin, caeruloplasmin, haptoglobin alpha2 chain, tranferrin and transthyretin were found significantly changed among the healthy, HBV and HCC groups. Further validation study by Western blot showed the detection of HSP27 in 90% HCC sera and two HBV sera, but in none of normal sera. Thus, 2-DE based serum proteome analysis can be useful in the screening of serum biomarkers for HCC and HSP27 could aid in the diagnosis of HCC though further validation is needed.
BackgroundDocetaxel resistance remains a major obstacle in the treatment of non-small cell lung cancer (NSCLC). High-mobility group box 1 (HMGB1) has been shown to promote autophagy protection in response to antitumor therapy, but the exact molecular mechanism underlying HMGB1-mediated autophagy has not been clearly defined.MethodsLung adenocarcinoma (LAD) cells were transfected with pcDNA3.1-HMGB1 or HMGB1 shRNA, followed by docetaxel treatment. Cell viability and proliferation were tested by MTT assay and colony formation assay, respectively. Annexin V flow cytometric analysis and western blot analysis of activated caspase3 and cleaved PARP were used to evaluate apoptosis, while immunofluorescence microscopy and transmission electron microscopy were applied to assess autophagy activity. The formation of the Beclin-1-PI3K-III complex was examined by immunoprecipitation analysis. NOD/SCID mice were inoculated with docetaxel-resistant SPC-A1/DTX cells transfected with control or HMGB1 shRNA.ResultsHMGB1 translocated from the nucleus to the cytoplasm in LAD cells exposed to docetaxel and acted as a positive regulator of autophagy, which inhibited apoptosis and increased drug resistance. Suppression of HMGB1 restored the sensitivity of LAD cells to docetaxel both in vivo and in vitro. Mechanistic investigation revealed that HMGB1 promoted the formation of the Beclin-1-PI3K-III complex through activating the mitogen-activated protein kinase (MEK)-extracellular signal-regulated kinase (ERK) signaling pathway, thereby regulating autophagosome formation.ConclusionsOur results demonstrated that HMGB1-regulated autophagy is a significant contributor to docetaxel resistance in LAD cells. Suppression of HMGB1 or limiting HMGB1 cytosolic translocation diminished autophagic protection in response to docetaxel in LAD cells.
In this study, the secondary sequencing was used to profile circRNA expression in the tissue samples from three CRC patients with liver metastasis and three matched CRC patients. After verified some candidates in another 40 CRC and CRC-m samples by qRT-PCR, we further demonstrated that circRNA_0001178 and circRNA_0000826 were significantly upregulated in CRC-m tissues, and both of them had the potential for diagnosing liver metastases from colorectal cancer. Finally, the networks of circRNA-miRNA-mRNA base on these two circRNAs were constructed respectively. This study showed that differentially expressed circRNAs were existed between the tissue samples from colorectal cancer patients with and without liver metastasis. And also suggested that circRNA_0001178 and circRNA_0000826 may serve as a potential diagnostic biomarker for liver metastases from colorectal cancer.Electronic supplementary materialThe online version of this article (10.1186/s12943-018-0932-8) contains supplementary material, which is available to authorized users.
BackgroundDysregulation of microRNAs (miRNAs) have been demonstrated to contribute to carcinogenesis. MiR-143-3p has been identified to function as a tumor suppressor in several tumors, but the role of miR-143-3p in esophageal squamous cell carcinoma (ESCC) has not been intensively investigated. Our aim was to evaluate the potential role of miR-143-3p in the progression of ESCC.MethodsThe expression levels of miR-143-3p and QKI-5 protein were measured in 80 resected ESCC tumor specimens and the clinicopathological significance of these levels determined. We also investigated the role of miR-143-3p in the regulation of QKI-5 expression in ESCC cell lines both in vivo and in vitro.ResultsMiR-143-3p levels were decreased in ESCC clinical samples and low expression of miR-143-3p was significantly associated with poor prognosis in ESCC patients. Ectopic expression of miR-143-3p suppressed proliferation and induced apoptosis in ESCC cells both in vivo and in vitro. Ectopic expression of miR-143-3p also reduced the metastatic potential of cells by selectively regulating epithelial–mesenchymal transition regulatory proteins. Furthermore, QKI-5 isoform was upregulated in ESCC tissues and was a direct target of miR-143-3p. Lastly, re-introduction of QKI-5 expression abrogated the inhibitory effects of miR-143-3p on ESCC cell proliferation and motility.ConclusionsOur results demonstrate that miR-143-3p acts as a tumor-suppressor by targeting QKI-5 in ESCC, suggesting that miR-143-3p is a potential therapy for the treatment of ESCC.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-016-0533-3) contains supplementary material, which is available to authorized users.
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