Analysis of tumors formed in nude mice. (A) The
tumorigenicity of HSYzeo, HSYR2/R1, and HSYR2-IIIb. There was no
significant difference between the tumor growth of HSYzeo
(□) and HSYR2/R1 (▵) (P >
0.05). In contrast, there was a significant reduction in growth rate of
HSYR2-IIIb-derived tumors (○) as compared with those of
HSYzeo- and HSYR2/R1-derived tumors (P < 0.001).
For each group, the mean ± SE was plotted. (B1)
Tumors developed from HSYR2-IIIb exhibited predominant gland-like and
acinar-like structures surrounded by stromal cells (arrowhead). In some
areas, apoptotic bodies were observed in the nuclei of the
tumor cells (circled) (original magnification: ×100).
(B2) On TUNEL examination, tissue section of
HSYR2-IIIb-derived tumor showed positive signals in tumor cells
(arrowhead) (original magnification: ×200). The histological
appearances of HSYR2/R1-derived (B3) and
HSYzeo-derived (B4) tumors exhibited typical adenocarcinomas
with a solid and trabecular pattern (original magnification: ×100).