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Background: Tumor cells are considered to have an aberrant cell state, and some evidence indicates different development states appearing in the tumorigenesis. Embryonic development and stem cell differentiation are ordered processes in which the sequence of events over time is highly conserved. The "cancer attractor" concept integrates normal developmental processes and tumorigenesis into a high-dimensional "cell state space", and provides a reasonable explanation of the relationship between these two biological processes from theoretical viewpoint. However, it is hard to describe such relationship by using existed experimental data; moreover, the measurement of different development states is also difficult. Results: Here, by applying a novel time-ordered linear model based on a co-bisector which represents the joint direction of a series of vectors, we described the trajectories of development process by a line and showed different developmental states of tumor cells from developmental timescale perspective in a cell state space. This model was used to transform time-course developmental expression profiles of human ESCs, normal mouse liver, ovary and lung tissue into "cell developmental state lines". Then these cell state lines were applied to observe the developmental states of different tumors and their corresponding normal samples. Mouse liver and ovarian tumors showed different similarity to early development stage. Similarly, human glioma cells and ovarian tumors became developmentally "younger". Conclusions: The time-ordered linear model captured linear projected development trajectories in a cell state space. Meanwhile it also reflected the change tendency of gene expression over time from the developmental timescale perspective, and our finding indicated different development states during tumorigenesis processes in different tissues. [ABSTRACT FROM AUTHOR]

Staphylococcus Aureus Filtrate Preparation (SAFP) is a preparation of low-virulence strain of Staphylococcus aureus. In our study, we aimed to determine the anti-tumor activity of SAFP in vivo and explore the potential mechanism. Our study evaluated the anti-tumor activity of SAFP in four cancer cell models in vivo and determined its up-regulatory effects on mice immune system in vivo. It showed that 7.2 ng/10 g SAFP could inhibit the progression of murine hepatoma H22 and sarcoma S180, and the tumor inhibition rates achieved 48.1 and 35.7%, respectively. In human non-small cell lung cancer A549 and hepatoma BEL7402 xenograft athymic mice models, T/C of 7.2 ng/10 g SAFP group reached 41.0% in A549 model and 21.0% in BEL7402 model. Meanwhile, SAFP also significantly increased the proliferation of cultured mice splenocytes to 162.1%, and 7.2 ng/kg SAFP significantly ( P < 0.001) raised the activity of NK cells, elevated the serum level of IL-2, TNF-α and IFN-γ in mice. SAFP exhibited high efficiency in inhibiting the growth of cancer cells in a dose-dependent manner, which possibly attributed to its regulatory effects of immune system. [ABSTRACT FROM AUTHOR]

Head and neck squamous cell carcinoma (HNSCC) is characterized by significant genomic instability that could lead to clonal diversity. Intratumor clonal heterogeneity has been proposed as a major attribute underlying tumor evolution, progression, and resistance to chemotherapy and radiation. Understanding genetic heterogeneity could lead to treatments specific to resistant and metastatic tumor cells. To characterize the degree of intratumor genetic heterogeneity within a single tumor, we performed whole-genome sequencing on three separate regions of an human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma and two separate regions from one corresponding cervical lymph node metastasis. This approach achieved coverage of approximately 97.9%of the genome across all samples. In total, 5701 somatic point mutations (SPMs) and 4347 small somatic insertions and deletions (indels) were detected in at least one sample. Ninety-two percent of SPMs and 77% of indels were validated in a second set of samples adjacent to the discovery set. All five tumor samples shared 41% of SPMs, 57%of the 1805 genes with SPMs, and 34 of 55 cancer genes. The distribution of SPMs allowed phylogenetic reconstruction of this tumor's evolutionary pathway and showed that the metastatic samples arose as a late event. The degree of intratumor heterogeneity showed that a single biopsy may not represent the entiremutational landscape of HNSCC tumors. This approachmay be used to further characterize intratumor heterogeneity in more patients, and their sample-to-sample variations could reveal the evolutionary process of cancer cells, facilitate our understanding of tumorigenesis, and enable the development of novel targeted therapies. [ABSTRACT FROM AUTHOR]