Objective    To study whether the multiple antigen peptides (MAPs) of heparanase (Hpa) can elicit stronger Hpa-specific cytotoxic T lymphocyte (CTL) responses against various tumors

in vitro

.     Methods    Dendritic cells (DCs) were pulsed with HLA-A2.1-restricted Hpa MAPs an

d Hpa single peptides to induce Hpa-specific CTLs. The lysis of KATO-Ⅲ gastric cancer cells

U2OS osteogenic sarcoma cells

SW480 colon cancer cells

HepG2 liver cancer cells

MCF-7 breast cancer cells

HepG2/HLA-A2.1 liver cancer cells

and MCF-7/Hpa breast cancer cells by Hpa-specific CTLs was examined by 4-h standard

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Cr release assay. The IFN-γ production of the effector cells was tested with ELISPOT.     Results    Compared with those induced by Hpa single peptides

the CTLs induced by Hpa MAPs had stronger specific lysis effects on Hpa- and HLA-A2.1-positive tumor cells (KATO-Ⅲ

U2OS

and SW480)

by more than 16% at the maximum effector/target (E/T) ratio. Neither Hpa-negative MCF-7 cells nor HLA-A2.1-negative HepG2 cells were lysed by the CTLs. The effector cells induced by Hpa MAPs

however

could lyse HepG2/HLA-A2.1 cells (HLA-A2.1-positive) and MCF-7/Hpa cells (Hpa-positive)

and had stronger specific lysis effects than those induced by Hpa single peptides

by more than 18% at the maximum E/T ratio. Hpa MAPs could not elicit lysis of auto-logous lymphocytes and DCs. Compared with Hpa single peptides

Hpa MAPs could increase the frequency of IFN-γ-producing T cells.     Conclusions    This study shows that Hpa MAPs can elicit stronger specific and nonspecific antitumor immune responses by Hpa-specific CTLs.