Transitional increase in growth fraction estimated by Ki-67 index after irradiation to human tumor in xenograft.

Abstract

The cell kinetics of human tumor cells (HSG) in vivo were estimated by Ki-67 index to analyze the biological behavior of quiescent cells after irradiation. The increment of Ki-67 index was dose-dependent up to 15 Gy irradiation. The Ki-67 index of tumor cells increased gradually from 35+/-5.0% before irradiation to 56+/-5.0% at day 5 after single irradiation of 15 Gy. Flow-cytometric study showed that the G1 population was decreased and the G2M population was elevated at day 5 after the irradiation. In fractionated irradiation, the time-course in the change of the Ki-67 index was similar to that of single irradiation. It was likely that tumor cells were recruited into the cell cycle from quiescent phase after irradiation. We consider the Ki-67 index to be a reliable indicator of growth fraction and useful to estimate the cell kinetics of irradiated tumors in vivo. The growth fraction estimated by Ki-67 index during radiotherapy is expected to be useful in predicting tumor response to radiation therapy.

• Authors: Takeo Takahashi, Takashi Nakano, Kuniyuki Oka, Koichi Ando
• Journal: Anticancer research (Anticancer Res) 2004 Jan-Feb Vol. 24 Issue 1 Pg. 107-10 ISSN: 0250-7005 [Print] Greece
• PMID: 15015583 (Publication Type: Journal Article)

Chemical References

• Ki-67 Antigen

Topics

• Animals
• Cell Division (radiation effects)
• Dose-Response Relationship, Radiation
• Flow Cytometry
• G1 Phase (radiation effects)
• Humans
• Ki-67 Antigen (metabolism)
• Mice
• Mice, Inbred BALB C
• Mice, Nude
• Neoplasm Transplantation
• Salivary Gland Neoplasms (metabolism, pathology, radiotherapy)
• Transplantation, Heterologous