Photomicrograph of HAK-1B cells cultured for 72 hours on a Lab-Tek Chamber slide.

<p>(A) Without PEG-IFN-α2a in culture medium. (B) With 4,194 ng/mL of PEG-IFN-α2a in culture medium. Apoptotic cells (short arrows) characterized by cytoplasmic shrinkage, chromatic condensation and nuclear fragmentation were noted (HE staining, X 200). </p

Photomicrograph of resected HAK-1B tumor.

<p>(A) Tumor cells are replaced with large granulation tissue at the middle of resected tumor. (arrowheads, HE staining, X20). (B) Artery-like blood vessels in the tumor (arrow, HE staining, X200). (C) Artery-like blood vessel in the tumor (arrow, CD34/α-SMA double-immunostain, X200).</p

Time-course change in estimated tumor volumes of subcutaneously transplanted HAK-1B (A) or KIM-1 (B) tumors in nude mice in Experiment 1.

<p>The mice received a subcutaneous injection of 0.06 (▲), 0.6 (○), 6 (●), or 60 (∆) µg of PEG-IFN-α2a, or medium alone (Control) (□), once a week for 2 consecutive weeks. The arrows show the days of injection. The figures represent average ± SE. *<i>P</i> < 0.0001, versus the other groups. †<i>P</i> < 0.01, versus the other groups. </p

Anti-proliferative effect of PEG-IFN-α2a.

<p>(A) Chronological changes in relative viable cell number (% of the control) after adding 4,194 ng/mL of PEG-IFN-α2a. Growth was suppressed with time in 8 cell lines. (B) 96 hours after adding 10 different concentrations of PEG-IFN-α2a. Cell proliferation was suppressed in a dose-dependent manner in 11 cell lines. The suppression was significant (<i>P</i> < 0.0001~0.05) in the ranges of 0.016~4,194 ng/mL of PEG-IFN-α2a in HAK-6, 0.256~4,194 ng/mL in KYN-3 and HAK-1A, 4.096~4,194 ng/mL in KIM-1, KYN-1, HAK-1B, HAK-2 and KMCH-2, 16.4~4,194 ng/mL in KYN-2, HAK-5 and KMCH-1, 262~4,194 ng/mL in HAK-4, and at 4,194 ng/mL in HAK-3 (Student <i>t</i>-test). Eight samples were used in each experiment (n = 8). The experiment was repeated at least 3 times for each cell line. The figures represent average ± SE of the experiments. </p

Photomicrograph of subcutaneous human HCC tumor in nude mice that was developed after the injection of HAK-1B cells.

<p>(A) A control mouse that received culture medium alone. The tumor shows a compact arrangement of tumor cells and a sinusoid-like structure in the stroma. (B) A mouse that received a s.c. injection of 0.06 μg of PEG-IFN-α2a. There are some apoptotic tumor-cells characterized by shrinkage and eosinophilic change in the cytoplasm, chromatin condensation and/or fragmentation of nuclei (arrows, HE staining, X200). (C) The same tumor as shown in (B). There are some TUNEL-positive cells showing brown nuclei (arrows, stained by the TUNEL technique, X200).</p