The Effect of DNA Methylation on TP73 Expression in Tumorgenesis

Abstract: The Effect of DNA Methylation on TP73 Expression in Tumorgenesis Nujuma Moussa, Zhixing Yao, Zaki A. Sherif Department of Biochemistry & Molecular Biology, Howard University College of Medicine TP73 is a member of the TP53 family of proteins that acts as a transcription factor to help regulate cellular distress. This tumor protein may play a dual role as a tumor suppressor and tumor promoter. The TP73 gene is mapped to chromosome 1p36, a frequently deleted region in neuroblastoma and other types of tumors. While mutations in the TP53 gene are commonly known to cause noxious cancers, 30% of cancers result from the overexpression of TP73. In our lab, we examined the role of TP73 in the formation of neuroblastoma, a type of cancer that begins in the nerve tissue atop the adrenal gland of kidneys in children. Normal fibroblast cell lines (HS27) and tumor kidney cells (IMR32 and SK-N-SH) were grown in their respective growth media. DNA and RNA of both cell types were extracted using standard procedures. RNA expression was analyzed by RT-PCR and DNA methylation was analyzed by bisulfite sequencing. The expressions of TP73 gene and its protein were analyzed by gel electrophoresis and immunohistochemistry respectively. We found that the TP73 gene was expressed in all of the neuroblastoma cells, but there was no evidence of its expression in the normal cell lines. Subsequent methylation studies revealed that TP73 was expressed in neuroblastoma cells but not in non-cancerous cells due to silencing by DNA methylation. In conclusion, the absence of TP73 in normal cells is in part due to DNA methylation implying that TP73 plays a role in the promotion and/or progression of carcinogenesis.https://scholarscompass.vcu.edu/uresposters/1288/thumbnail.jp

Weak compactness of almost limited operators

The paper is devoted to the relationship between almost limited operators and weakly compacts operators. We show that if $F$ is a $\sigma$-Dedekind complete Banach lattice then, every almost limited operator $T:E\rightarrow F$ is weakly compact if and only if $E$ is reflexive or the norm of $F$ is order continuous. Also, we show that if $E$ is a $\sigma$-Dedekind complete Banach lattice then the square of every positive almost limited operator $T:E\rightarrow E$ is weakly compact if and only if the norm of $E$ is order continuous.Comment: 5 page

A 2-Dimensional Cellular Automaton for Agents Moving from Origins to Destinations

We develop a two-dimensional cellular automaton (CA) as a simple model for agents moving from origins to destinations. Each agent moves towards an empty neighbor site corresponding to the minimal distance to its destination. The stochasticity or noise ($p$) is introduced in the model dynamics, through the uncertainty in estimating the distance from the destination. The friction parameter $"\mu"$ is also introduced to control the probability that the movement of all agents involved to the same site (conflict) is denied at one time step. This model displays two states; namely the freely moving and the jamming state. If $\mu$ is large and $p$ is low, the system is in the jamming state even if the density is low. However, if $\mu$ is large and $p$ is high, a freely moving state takes place whenever the density is low. The cluster size and the travel time distributions in the two states are studied in detail. We find that only very small clusters are present in the freely moving state while the jamming state displays a bimodal distribution. At low densities, agents can take a very long time to reach their destinations if $\mu$ is large and $p$ is low (jamming state); but long travel times are suppressed if $p$ becomes large (freely moving state).Comment: 10 pages, 12 figure