Diallyl disulfide (DADS) is a natural organosulfur compound isolated from garlic. DADS has various biological properties, including anticancer, antiangiogenic, and antioxidant effects. However, the anticancer mechanisms of DADS in human esophageal carcinoma have not been elucidated, especially in vivo. In this study, MTT assay showed that DADS significantly reduced cell viability in human esophageal carcinoma ECA109 cells, but was relatively less toxic in normal liver cells. The pro–apoptotic effect of DADS on ECA109 cells was detected by Annexin V-FITC/propidium iodide (PI) staining. Flow cytometry analysis showed that DADS promoted apoptosis in a dose-dependent manner and the apoptosis rate could be decreased by caspase-3 inhibitor Ac-DEVD-CHO. Xenograft study in nude mice showed that DADS treatment inhibited the growth of ECA109 tumor in both 20 and 40 mg/kg DADS groups without obvious side effects. DADS inhibited ECA109 tumor proliferation by down-regulating proliferation cell nuclear antigen (PCNA). DADS induced apoptosis by activating a mitochondria-dependent pathway with the executor of caspase-3, increasing p53 level and Bax/Bcl-2 ratio, and downregulating the RAF/MEK/ERK pathway in ECA109 xenograft tumosr. Based on studies in cell culture and animal models, the findings here indicate that DADS is an effective and safe anti-cancer agent for esophageal carcinoma.

Esophageal-gastric junction adenocarcinoma (AEG) is an aggressive tumor with high incidence and dismal prognosis worldwide. Despite significant advances in therapeutic strategies, the 5-year survival rate still remains low. Diallyl disulfide (DADS), which is one of the major volatile components isolated from garlic, has been shown to have multi-targeted antitumor activities in a variety of cancer cells. However, the exact anti-metastatic effects and underlying molecular mechanisms of DADS in AEG have not been elucidated. The present study demonstrated that DADS inhibited cell viability of OE19 cells with low cytotoxicity to healthy hepatocytes, L02 cells, in vitro. Non-toxic doses of DADS were ≤10 µg/ml for a 24-h treatment. Our data showed that these non-toxic doses of DADS were found to block the metastasis of OE19 cells by suppressing MMPs, increasing u-PA and TIMPs, as well as altering the balance of MMPs/TIMPs, which at least in part resulted from the suppression of NF-κB and PI3K/AKT signaling pathways. The present study provides a previously neglected insight into the investigation of DADS in suppressing tumor metastasis and its underlying molecular mechanisms in vitro. Hence, DADS could be a promising anticancer agent for anti-metastatic treatment of AEG in the future.

The emerging single-cell Hi-C technology provides opportunities to study dynamics of chromosomal organization. How to construct a pseudotime path using single-cell Hi-C contact matrices to order cells along developmental trajectory is a challenging topic, since these matrices produced by the technology are inherently high dimensional and sparse, they suffer from noises and biases, and the topology of trajectory underlying them may be diverse. We present scHiCPTR, an unsupervised graph-based pipeline to infer pseudotime from single-cell Hi-C contact matrices. It provides a workflow consisting of imputation and embedding, graph construction, dual graph refinement, pseudotime calculation and result visualization. Beyond the few existing methods, scHiCPTR ties to optimize graph structure by two parallel procedures of graph pruning, which help reduce the spurious cell links resulted from noises and determine a global developmental directionality. Besides, it has an ability to handle developmental trajectories with multiple topologies, including linear, bifurcated and circular ones, and is competitive with methods developed for single-cell RNA-seq data. The comparative results tell that our scHiCPTR can achieve higher performance in pseudotime inference, and the inferred developmental trajectory exhibit a reasonable biological significance. scHiCPTR is freely available at https://github.com/lhqxinghun/scHiCPTR. Supplementary data are available at Bioinformatics online.

Editorial: Tumor immune microenvironment topographies for prediction and evaluation: unlock the mystery of the therapeutic effects and adverse events of tumor immunotherapy