Surface expression of squamous cell carcinoma antigen (SCCA) can be increased by the preS1(21-47) sequence of hepatitis B virus.
A variant of the serpin squamous cell carcinoma antigen (SCCA) has been identified as a hepatitis B virus binding protein and high expression of SCCA has recently been found in hepatocarcinoma. Since HBV is involved in liver carcinogenesis, experiments were carried out to examine the effect of HBV preS1 envelope protein on SCCA expression. Surface and intracellular staining for SCCA was assessed by FACS analysis. Preincubation of HepG2 cells and primary human hepatocytes with preS1 protein or with preS1(21-47) tetrameric peptide significantly increased the surface expression of SCCA, without modification of its overall cellular burden, suggesting a surface redistribution of the serpin. An increase in HBV binding and internalization was observed after pre-incubation of the cells with preS1 preparations, compared to cells preincubated with medium alone. Pretreatment of cells with DMSO, while not influencing SCCA basal expression, was responsible for an increase in the efficiency of HBV internalization and this effect was additive to that obtained after incubation with preS1 preparations. In conclusion, the HBV preS1(21-47) sequence is able to induce overexpression of SCCA at the cell surface facilitating virus internalization, while the increased efficiency of HBV entry following DMSO addition is not mediated by SCCA.
Ruvoletto
M G
MG
Clinica Medica 5, Università di Padova, via Giustiniani 2, 35128 Padova, Italy.
Tono
N
N
Clinica Medica 5, Università di Padova, via Giustiniani 2, 35128 Padova, Italy.
Carollo
D
D
Immunologia Clinica, Dipartimento di Medicina Clinica e Sperimentale, Università di Padova, via Giustiniani 2, 35128 Padova, Italy.
Vilei
T
T
Clinica Medica 1, Università di Padova, via Giustiniani 2, 35128 Padova, Italy.
Trentin
L
L
Immunologia Clinica, Dipartimento di Medicina Clinica e Sperimentale, Università di Padova, via Giustiniani 2, 35128 Padova, Italy.
Muraca
M
M
Dipartimento di Scienze Mediche e Chirurgiche, Università di Padova, via Giustiniani 2, 35128 Padova, Italy.
Marino
M
M
Xeptagen Spa, via Olivetti, 1 Pozzuoli (Na), Italy.
Gatta
A
A
Clinica Medica 5, Università di Padova, via Giustiniani 2, 35128 Padova, Italy.
Fassina
G
G
Xeptagen Spa, via Olivetti, 1 Pozzuoli (Na), Italy.
Pontisso
P
P
Clinica Medica 5, Università di Padova, via Giustiniani 2, 35128 Padova, Italy.
D000951:Antigens, Neoplasm / Q000235:genetics*; D000954:Antigens, Surface / Q000235:genetics; D014408:Biomarkers, Tumor / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D017931:DNA Primers; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D015967:Gene Expression Regulation, Viral / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D016133:Polymerase Chain Reaction; D015843:Serpins
D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D014408:Biomarkers, Tumor; D017931:DNA Primers; D015843:Serpins; C051072:squamous cell carcinoma-related antigen