Premium
Inhibition of Ki‐67 in a renal cell carcinoma severe combined immunodeficiency disease mouse model is associated with induction of apoptosis and tumour growth inhibition
Author(s) -
Kausch Ingo,
Jiang Hai,
Ewerdwalbesloh Nina,
Doehn Christian,
Krüger Stefan,
Sczakiel Georg,
Jocham Dieter
Publication year - 2005
Publication title -
bju international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.773
H-Index - 148
eISSN - 1464-410X
pISSN - 1464-4096
DOI - 10.1111/j.1464-410x.2005.05312.x
Subject(s) - severe combined immunodeficiency , apoptosis , cancer research , cell growth , growth inhibition , cell culture , biology , immunohistochemistry , in vivo , pathology , microbiology and biotechnology , medicine , biochemistry , genetics
OBJECTIVE To evaluate the effects of suppressing the expression of Ki‐67 (expressed in proliferating cells) by antisense oligonucleotides (asON) directed against Ki‐67 (which specifically inhibit the proliferation of tumour cells and tumour growth in cell culture and in subcutaneous murine tumour models) on the growth, cell viability and angiogenic activity of a preclinical renal cell carcinoma (RCC) severe combined immunodeficiency disease (SCID) mouse model. MATERIALS AND METHODS Human RCC cells (SK‐RC‐35) were incubated with asON and control ON in the presence of a cationic lipid in monolayer cell culture. To test Ki‐67 as a target for antitumour therapy in more complex models, asON were administered to three‐dimensional RCC (SK‐RC‐35) spheroid cultures and to SCID mice bearing subcutaneous SK‐RC‐35 xenografts. For animal studies, 1 × 10 6 SK‐RC‐35 cells were implanted subcutaneously. Subsequently, asON or ON were injected intraperitoneally daily for 14 days at 10 mg/kg/day. Tumour size, weight and status of metastasis were documented daily and after death, respectively. The number of apoptotic cells, Ki‐67‐positive cells and the microvessel density in tumour sections was determined immunohistochemically. Quantitative reverse transcription‐polymerase chain reaction of Ki‐67 mRNA was also assessed for the tumours. RESULTS Treatment of RCC cells with asON resulted in a specific inhibition of cell growth in monolayer and spheroid cell culture. Systemic administration of Ki‐67‐directed asON significantly decreased tumour growth ( P = 0.009) in SCID mice. Immunohistochemical staining of tumour specimens showed stronger inhibition of Ki‐67‐positive cells in asON‐treated tumours (mean 27.8%) than in controls (mean 42.5–57%). Furthermore, there were about twice as many apoptotic cells after asON treatment. There was no significant difference among treatment groups for microvessel density. CONCLUSION These results indicate that Ki‐67 represents a suitable antiproliferative target, and that asON are a potent agent inhibiting tumour growth and apoptosis, but not tumour vascularization, in human RCC.