DNA Replication Licensing Protein MCM10 Promotes Tumor Progression and Is a Novel Prognostic Biomarker and Potential Therapeutic Target in Breast Cancer.

Breast cancer is one of the most common malignancies in women worldwide. In breast cancer, the cell proliferation rate is known to influence the cancer malignancy. Recent studies have shown that DNA replication initiation/licensing factors are involved in cancer cell proliferation as well as cancer cell migration and invasion. Licensing factors have also been reported as important prognostic markers in lung, prostrate, and bladder cancers. Here, we studied the role of MCM10, a novel licensing factor, in breast cancer progression. From the public database, NCBI, we investigated six independent breast cancer patient cohorts, totaling 1283 patients. We observed a significant association between high MCM10 mRNA expression with tumor grading and patients' survival time. Most importantly, using breast cancer cohorts with available treatment information, we also demonstrated that a high level of MCM10 is associated with a better response to conventional treatment. Similarly, in in vitro studies, the expression level of MCM10 in breast cancer cell lines is significantly higher compared to paired normal breast epithelium cells. Knockdown of MCM10 expression in the cancer cell line showed significantly decreased tumorigenic properties such as cell proliferation, migration and anchorage independence. The MCF7 breast cancer cell line, after MCM10 expression knockdown, showed significantly decreased tumorigenic properties such as cell proliferation, migration, and anchorage independent growth. Mechanistically, MCM10 expression is observed to be regulated by an Estrogen Receptor (ER) signaling pathway, where its expression is suppressed by the inhibition of the ER or serum withdrawal. Our results suggest that MCM10 plays an important role in breast cancer progression and is a potential prognostic/predictive biomarker and therapeutic target for breast cancer patients.

Anti-tumor effects of a 'human & mouse cross-reactive' anti-ADAM17 antibody in a pancreatic cancer model in vivo.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of tumor amongst all human cancers due to late diagnosis and resistant to treatment with chemotherapy and radiation. Preclinical and clinical studies have revealed that ErbB family for example epidermal growth factor receptor (EGFR) is a validated molecular target for pancreatic cancer prevention and therapy. The ErbB signaling cascade is regulated by a member of the ADAM (a disintegrin and metalloprotease) family, namely ADAM17, by enzymatic cleavage of precursor ligands into soluble cytokines and growth factors. Mouse genetic studies have demonstrated that ADAM17 is required for PDAC development. In this study, we evaluated the anti-tumor effects of A9(B8) IgG - the first specific 'human and mouse cross-reactive' ADAM17 inhibitory antibody on pancreatic malignant transformation. We found that inhibition of ADAM17 with A9(B8) IgG efficiently suppressed the shedding of ADAM17 substrates both in vivo and in vitro. Furthermore, we demonstrated that administration of A9(B8) IgG significantly suppressed motility in human pancreatic cancer cells and also significantly delayed tumorigenesis in the Pdx1Cre;KrasG12D;Trp53fl/+PDAC mouse model. Inhibition of ADAM17 with A9(B8) IgG particularly affected the progression of pre-invasive pancreatic lesions to advanced PDAC in mice. Taken together, the preclinical data presented here will provide a starting point for clinical applications of ADAM17 targeted therapy.

The prognostic significance of Cdc6 and Cdt1 in breast cancer.

DNA replication is a critical step in cell proliferation. Overexpression of MCM2-7 genes correlated with poor prognosis in breast cancer patients. However, the roles of Cdc6 and Cdt1, which work with MCMs to regulate DNA replication, in breast cancers are largely unknown. In the present study, we have shown that the expression levels of Cdc6 and Cdt1 were both significantly correlated with an increasing number of MCM2-7 genes overexpression. Both Cdc6 and Cdt1, when expressed in a high level, alone or in combination, were significantly associated with poorer survival in the breast cancer patient cohort (n = 1441). In line with this finding, the expression of Cdc6 and Cdt1 was upregulated in breast cancer cells compared to normal breast epithelial cells. Expression of Cdc6 and Cdt1 was significantly higher in ER negative breast cancer, and was suppressed when ER signalling was inhibited either by tamoxifen in vitro or letrozole in human subjects. Importantly, breast cancer patients who responded to letrozole expressed significantly lower Cdc6 than those patients who did not respond. Our results suggest that Cdc6 is a potential prognostic marker and therapeutic target in breast cancer patients.

Temporal establishment of neural cell identity in vivo and in vitro.

Understanding cell fate specification is particularly useful because it enables biologists to generate specific neural cell types for treating currently untreatable neurological diseases. Traditionally, lineage-specific progenitors are generated in vitro from pluripotent cells, after which they may be channeled into more mature cell types in a stage-specific manner, which is similar to the way cells behave during development. However, the emergence of induced pluripotent stem cells means that specific cell types can be generated directly from fibroblasts or other somatic cell types, thus bypassing all of the necessary steps that happen in vivo. Based on this information, the present review first explores the regulatory circuitry that drives cell fate specification over time in vivo. In particular, it describes how the appearance of specific neuronal and glial cell types is governed by an intrinsic biological clock, followed by a discussion of how this can be achieved through the temporal expression of intracellular regulators in relation to cell-specific Dnase I hypersensitivity sites, promoters and enhancers. Cell fate acquisition in vitro was then examined in an attempt to evaluate whether the temporal regulation neural cell fate in vivo is still relevant to the generation of reprogrammed neural stem cells and neurons. Copyright © 2016 John Wiley & Sons, Ltd.