Role of N-glycosylation in oral cancer

Oral squamous cell carcinoma represents more than 90% head and neck cancers with high incidence rate and morbidity. To date, little is known about the molecular mechanisms responsible for OSCC initiation and progression to advanced disease. Thus, identifying key pathways involved in OSCC pathobiology is likely to lead to the identification of new druggable targets and future anti-cancer therapies. Work from our laboratory has linked the metabolic pathway of protein N-glycosylation with OSCC biology. Specifically, overexpression of the first N-glycosylation gene, DPAGT1, in human OSCC tumor specimens was shown to be associated with aberrant activation of canonical Wnt signaling and inhibition of mature E-cadherin junctions. The purpose of this study was to examine how increased N-glycosylation was associated with OSCC growth and metastatic properties in cellular and murine models. We show that high level of DPAGT1 expression correlates with increased cell surface modification of malignant OSCC HSC-3 cells with complex N-glycans. Further, HSC-3 cells are hypersenitive to the N-glycosylation inhibitor, tunicamycin, suggesting that aggressive properties of OSCC cells depend, in part, on the N-glycosylation pathway. Lastly, we show that orthotopic HSC-3 cell-derived tumor xenografts are inhibited by tunicamycin both in overall growth and metastases, indicating that targeting DPAGT1 and N-glycosylation may represent a new strategy for the treatment of OSCC in human patients

Network Coding: Connections Between Information Theory And Estimation Theory

In this paper, we prove the existence of fundamental relations between information theory and estimation theory for network-coded flows. When the network is represented by a directed graph G=(V, E) and under the assumption of uncorrelated noise over information flows between the directed links connecting transmitters, switches (relays), and receivers. We unveil that there yet exist closed-form relations for the gradient of the mutual information with respect to different components of the system matrix M. On the one hand, this result opens a new class of problems casting further insights into effects of the network topology, topological changes when nodes are mobile, and the impact of errors and delays in certain links into the network capacity which can be further studied in scenarios where one source multi-sinks multicasts and multi-source multicast where the invertibility and the rank of matrix M plays a significant role in the decoding process and therefore, on the network capacity. On the other hand, it opens further research questions of finding precoding solutions adapted to the network level.Comment: IEEE Wireless Communications and Networking Conference (WCNC), April, 201

Piggybacking Codes for Network Coding: The High/Low SNR Regime

We propose a piggybacking scheme for network coding where strong source inputs piggyback the weaker ones, a scheme necessary and sufficient to achieve the cut-set upper bound at high/low-snr regime, a new asymptotically optimal operational regime for the multihop Amplify and Forward (AF) networks