ABSTRACT
Objective To investigate the presences of regulatory T cells (Treg) and natural killer T cell (NKT)-like T cells in the peripheral blood of healthy subjects and patients with newly diagnosed cancer. Methods Patients were enrolled into four groups: healthy subjects (Group A), patients without cancer (Group B), patients with newly diagnosed stage Ⅰ~Ⅱ cancer (Group C), and patients with newly diagnosed stage Ⅲ~Ⅳ cancer (Group D). Flow cytometry was performed to detect the percentage of CD4+ CD25high CD127low cells in CD4+ T lymphocytes (Treg) and the percentage of CD3+ CD56+ cells in CD3+ T lymphocytes (NKT-like). Results The percentage of Treg cells in CD4+T lymphocytes was(6.72 ± 3.16)%, (6.49 ± 2.83)%,(6.80 ± 3.07)%and (7.63 3.47)% in Group A, B, C and D, respectively, with no significant differences among these groups (P>0.05). However, the percentage of CD3+CD56+T cells in CD3+T lymphocytes was (3.13 ± 1.66)%, (2.56 ± 1.27)%,(7.22 ± 2.70)% and (7.72 ± 3.10)% in Group A, B, C and D, respectively, with marked increases in Group C and D compared to those in Group A and B (P < 0.05). Conclusion Patients with newly diagnosed cancer demonstrated increasing trends in the percentage of peripheral NKT-like cells.
ABSTRACT
Objective To investigate the effects of MEK1 specific inhibitor PD98059 on oxaliplatin-treated colorectal cancer cells and the potential mechanism. Methods Cell proliferation was assessed by MTT assay after transfecting MEK1 active plasmid into LoVo cells. LoVo cells were treated with oxaliplatin or PD98059, and the proliferation was assessed by MTT assay. PUMA expression and ERK activity were determined by Western blot. Apoptosis was assessed by Hoechst 33258 dye after PUMA expression was suppressed. Results Increasing activity of ERK enhanced the proliferation of LoVo cells. The activity of ERK was suppressed by oxaliplatin. PD98059 and oxaliplatin decreased the proliferation rate of LoVo cells synergistically. PUMA expression increased after PD98059 and oxaliplatin treatment. The suppression of PUMA expression by stably transfecting PUMA anti-sense vector decreased apoptosis induced by oxaliplatin and PD98059. Conclusion PD98059 enhances the effects of oxaliplatin on colorectal cancer cells mediated by PUMA expression.