Long-term effect on EMT6 tumors in mice induced by combination of laser immunotherapy and surgery

Integr Cancer Ther. 2011 Dec;10(4):368-73. doi: 10.1177/1534735410387597. Epub 2010 Dec 8.

Abstract

Laser immunotherapy (LI) has been demonstrated to be a promising modality for cancer treatment. The present study was designed to further investigate the impact of LI combined with surgery. LI consists of a near-infrared laser, a light-absorbing dye (indocyanine green, ICG), and an immunostimulant (glycated chitosan, GC). ICG and GC were intratumorally injected, followed by laser irradiation. Female BALB/c mice bearing EMT6 tumor cells were divided into 4 groups: control, LI, LI followed by immediate surgery resection of residual tumor (LI + S(0wk)), and LI followed by surgical removal of residual tumor after 1 week (LI + S(1wk)). Successfully treated mice from all treatment groups were rechallenged twice with 10(5) and 5 × 10(5) EMT6 cells, respectively. The LI + S(1wk) group had the highest survival rate (72%) after 90 days, whereas the mice survival rates of the LI + S(0wk), LI, and control groups were 50%, 46%, 0%, respectively. The median survival times of control, LI, LI + S(0wk), and LI + S(1wk) groups were 32, 66, 74, and 90 days, respectively. Survival rates of the treated mice after the first and second tumor rechallenges, ranging from 73% to 95%, were not significantly different among the 4 groups (P > .05). The results show that LI is a useful tool for the treatment of tumor-bearing mice. Long-term antitumor effect can be induced by LI. They also indicate that combination of LI with surgery can further improve the therapeutic efficiency of LI.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptive Immunity*
  • Animals
  • Chitosan / therapeutic use
  • Female
  • Immunotherapy*
  • Indocyanine Green / therapeutic use
  • Kaplan-Meier Estimate
  • Lasers, Semiconductor / therapeutic use*
  • Mammary Neoplasms, Experimental / immunology
  • Mammary Neoplasms, Experimental / surgery
  • Mammary Neoplasms, Experimental / therapy*
  • Mice
  • Mice, Inbred BALB C
  • Sarcoma / therapy*
  • Time Factors

Substances

  • glycated chitosan
  • Chitosan
  • Indocyanine Green