Evidences Suggesting Involvement of Viruses in Oral Squamous Cell Carcinoma

Table 1

Overview of HPV gene products (E) early and (L) late.

Gene product	Description
E1	Helicase function; essential for viral replication and control of gene transcription.
E2	Viral transcription factor; essential for viral replication and control of gene transcription.
E4	Interaction with cytoskeleton proteins; viral assembly.
E5	Growth stimulation by interaction with growth factor receptors; downregulation surface HLA class I molecules.
E6	Cell immortalization; p-53 degradation; telomerase activation; antiapoptotic effect; induction of genomic instability.
E7	Cell immortalization; interaction with pRb and pRb-associated pocket proteins; transactivation of E2F dependent promoters; induction of genomic instability.
L1	Major capsid proteins.
L2	Minor capsid protein; role in recruiting viral genomes for encapsidation; involvement in nuclear transport of viral DNA.