How virus persistence can initiate the tumorigenesis process

Table 1 Oncogenic viruses are latent/persistent viruses

Virus	EBV	HHV-8	HPV	HBV	HCV	HTLV-1
Associated tumor(s): viral protein(s) expressed	BL: EBNA-1	KS: vFLIP, vCYC, LANA-1	Anogenital, oral, skin and laryngeal cancers: E6, E7	HCC: HBx	HCC: CP10, NS3, NS5	ATL: tax
	NPC, TCL: EBNA1 + LMP1	PEL, MCD: vFLIP, vCYC, LANA-1, LANA-2, vIL-6
	HL: EBNA1 + LMP1-2
	PTLD: EBNA1-6 + LMP1-2
Persistency	Always	Always	20% infected subjects	90%-95% infected newborns	70%-85% infected subjects	Always
				5% infected adults
Period between infection and tumor onset	10-20 yr	10-20 yr	5-20 yr	10-30 yr	10-30 yr	20-30 yr

EBV: Epstein-Barr virus; HHV-8: Human herpesvirus 8, also named Kaposi sarcoma virus; HPV: Human papillomavirus; HBV: Hepatatis B virus; HCV: Hepatitis C virus; HTLV-1: Human T-cell leukemia virus 1; BL: Burkitt lymphoma; NPC: Nasopharyngeal carcinoma; TCL: T cell lymphoma; HL: Hodgkin lymphoma; PTLD: Posttransplant lymphoprolipherative disorder; KS: Kaposi sarcoma; PEL: Primary effusion lymphoma; MCD: Multicentric Castleman’s disease; HCC: Hepatocellular carcinoma; ATL: Adult T-cell leukemia.

Table 2 Viral proteins inducing genetic damage

Virus	EBV	HHV-8	HPV	HBV	HCV	HTLV-1
Latent proteins	EBNA-1	LANA-1[64]	E6, E7[66,67]	Naturally occurring pre-S mutants[68]	-	-
	EBNA-3C	v-CYC[65]
	LMP-1[63]
Lytic proteins	BZLF-1[69]	-	E1, E2[71,72]	HBx[73,74]	Core	Tax[76,77]
	BGLF-5[70]				NS3[23,62]
					NS5[75]

EBV: Epstein-Barr virus; HHV-8: Human herpesvirus 8, also named Kaposi sarcoma virus; HPV: Human papillomavirus; HBV: Hepatatis B virus; HCV: Hepatitis C virus; HTLV-1: Human T-cell leukemia virus 1.

Table 3 Virus products controlling cellular epigenetic modifications

Virus	EBV	HHV-8	HPV	HBV	HCV	HTLV-1
	EBNA-3A, EBNA-3C[78]	LANA-1[81]	E6[83]	HBx[85,86]	Core[87]	Tax[88]
	LMP-1[79]	microRNA[82]	E7[84]
	LMP-2[80]

EBV: Epstein-Barr virus; HHV-8: Human herpesvirus 8, also named Kaposi sarcoma virus; HPV: Human papillomavirus; HBV: Hepatatis B virus; HCV: Hepatitis C virus; HTLV-1: Human T-cell leukemia virus 1.