Picornavirus 3C Proteins Intervene in Host Cell Processes through Proteolysis and Interactions with RNA

The Picornaviridae family comprises a large group of non-enveloped viruses with enormous impact on human and animal health. The picornaviral genome contains one open reading frame encoding a single polyprotein that can be processed by viral proteases. The picornaviral 3C proteases share similar three-dimensional structures and play a significant role in the viral life cycle and virus-host interactions. Picornaviral 3C proteins also have conserved RNA-binding activities that contribute to the assembly of the viral RNA replication complex. The 3C protease is important for regulating the host cell response through the cleavage of critical host cell proteins, acting to selectively 'hijack' host factors involved in gene expression, promoting picornavirus replication, and inactivating key factors in innate immunity signaling pathways. The protease and RNA-binding activities of 3C are involved in viral polyprotein processing and the initiation of viral RNA synthesis. Most importantly, 3C modifies critical molecules in host organelles and maintains virus infection by subtly subverting host cell death through the blocking of transcription, translation, and nucleocytoplasmic trafficking to modulate cell physiology for viral replication. Here, we discuss the molecular mechanisms through which 3C mediates physiological processes involved in promoting virus infection, replication, and release.

Personalized medicine in colorectal cancer

Colorectal cancer (CRC) is a heterogeneous disease with various genetic and epigenetic factors leading to difficulties in response to both the therapy and drug resistance. Moreover, even in tumors with similar histopathological characteristics, different responses and molecular features could be observed because of the genetic basis and its interactions with the living environment. Through personalized medicine, we can classify patients into separate groups according to their genetic and epigenetic features and their susceptibility for a specific disease which could help with choosing the best therapeutic approach. In this review, genetic and epigenetic factors that cause heterogeneity in colorectal cancer are evaluated and proper drug administration in both chemotherapy and target therapy are suggested.