Cancer Res 2010; 70: 8715C25

Cancer Res 2010; 70: 8715C25. manifestation. We then analyzed the growth and apoptosis of cells transfected with saRNA under the treatment of TKI to investigate whether saRNAs can reverse TKI resistance by upregulating PTEN expression. Results The functional saRNA we designed could upregulate PTEN expression. The H\157 cells transfected with saRNA grew slower in the presence of TKI drugs than the cells that were not transfected with saRNA. The apoptosis rate was also obviously higher. Conclusions Our study proves that loss of PTEN expression is an important mechanism of TKI resistance. It is possible to control TKI resistance by upregulating PTEN expression using RNA activation technology. 0.05 was considered statistically significant. Results Screening of functional saRNA We synthesized five pairs of candidate saRNAs and transfected them into the H\157 cells. We then analyzed the effect of saRNA on PTEN expression by RT\PCR. Three of the five pairs of candidate saRNA could upregulate PTEN expression. dsPTEN\1067 can enhance PTEN expression more than twice (Fig ?(Fig11 and Table 3). Open in a separate window Physique 1 Phosphatase and tensin homolog (PTEN) expression by reverse transcriptase\polymerase chain reaction. DS, double strand; GAPDH, glyceraldehyde 3\phosphate dehydrogenase. Table 3 Effect of saRNA to PTEN expression by RT\PCR 0.05). This result may suggest that reconstruction of PTEN expression will restore the cell’s sensitivity to TKI. Open in a separate window Physique 3 Cell growth curve of gefitinib treated H\157 cell after saRNA transfection. DS, double strand. saRNA increased gefitinib\induced apoptosis After gefitinib treatment, the apoptosis rate of H\157 cells that were not transfected with saRNA was 0.33 0.14%. The apoptosis rate of H\157 cells transfected with the dsControl was 1.74 0.17%. After transfection with functional saRNA, the apoptosis rate of the H\157 cells increased to 17.82 2.37% (F = 32.06, 0.05). This result illustrates that saRNA can promote apoptosis by upregulating PTEN expression when Glycolic acid treated with gefitinib (Fig ?(Fig44). Open in a separate window Physique 4 saRNA increased gefitinib\induced apoptosis. (a) Mock group, (b) control group, and (c) saRNA group. Conversation Recently, more and more studies have suggested that PTEN expression dysfunction contributes to TKI resistance in NSCLC patients. PTEN is an important tumor suppressor gene, which can inhibit tumor proliferation by inhibiting P13K/Akt pathway activation.9, 10, 11 PTEN is a common node of multiple signal pathways. If the gene mutates or has lower expression, its tumor suppressor function will be lost. Bidkhori 2011; 61: 134.) CA Malignancy J Clin 2011; 61: 69C90. [PubMed] [Google Scholar] 2. NSCLC Meta\Analyses Collaborative Group . Chemotherapy in addition to supportive care improves survival in advanced non\small\cell lung malignancy: A systemic review and meta\analysis of individual patient data from 16 randomized controlled trials. J Clin Oncol 2008; 26: 4617C25. [PMC free article] [PubMed] [Google Scholar] 3. Mok TS, Wu YL, Thongprasert S em et al. /em Gefitinib or carboplatin\paclitaxel in pulmonary adenocarcinoma. N Engl J Med 2009; 361: 947C57. [PubMed] [Google Scholar] 4. Mitsudomi T, Morita S, Yatabe Y em et al. /em Gefitinib versus cisplatin plus docetaxel in patients with non\small\cell lung malignancy harbouring mutations of the epidermal growth factor receptor (WJTOG3405): An open label, randomised phase 3 trial. Lancet Oncol 2010; 11: 121C8. [PubMed] [Google Scholar] 5. Maemondo M, Inoue A, Kobayashi K em et al. /em Gefitinib or chemotherapy for non\small\cell lung malignancy with mutated EGFR. N Engl J Med Glycolic acid 2010; 362: 2380C8. [PubMed] [Google Scholar] 6. Sharma SV, Bell DW, Settleman J, Haber DA. Epidermal growth factor receptor mutations in lung malignancy. Nat Rev Malignancy 2007; 7: 169C81. [PubMed] [Google Scholar] 7. Wu YL, Sun Y, Liao ML em et al. /em [The processing of epidermal growth factor receptor mutation lung malignancy.] Xun Zheng Yi Xue 2011; 11: 65C8 . (In Chinese.) [Google Scholar] 8. Engelman JA, J?nne PA. Mechanisms of acquired resistance to epidermal Glycolic acid growth factor receptor tyrosine.[PMC free article] [PubMed] [Google Scholar] 16. investigate whether saRNAs can reverse TKI resistance by upregulating PTEN expression. Results The functional saRNA we CD300C designed could upregulate PTEN expression. The H\157 cells transfected with saRNA grew slower in the presence of TKI drugs than the cells that were not transfected with saRNA. The apoptosis rate was also obviously higher. Conclusions Our study proves that loss of PTEN expression is an important mechanism of TKI resistance. It is possible to control TKI resistance by upregulating PTEN expression using RNA activation technology. 0.05 was considered statistically significant. Results Screening of functional saRNA We synthesized five pairs of candidate saRNAs and transfected them into the H\157 cells. We then analyzed the effect of saRNA on PTEN expression by RT\PCR. Three of the five pairs of candidate saRNA could upregulate PTEN expression. dsPTEN\1067 can enhance PTEN expression more than twice (Fig ?(Fig11 and Table 3). Open in a separate window Physique 1 Phosphatase and tensin homolog (PTEN) expression by reverse transcriptase\polymerase chain reaction. DS, double strand; GAPDH, glyceraldehyde 3\phosphate dehydrogenase. Table 3 Effect of saRNA to PTEN expression by RT\PCR 0.05). This result may suggest that reconstruction of PTEN expression will restore the cell’s sensitivity to TKI. Open in a separate window Physique 3 Cell growth curve of gefitinib treated H\157 cell after saRNA transfection. DS, double strand. saRNA increased gefitinib\induced apoptosis After gefitinib treatment, the apoptosis rate of H\157 cells that were not transfected with saRNA was 0.33 0.14%. The apoptosis rate of H\157 cells transfected with the dsControl was 1.74 0.17%. After transfection with functional saRNA, the apoptosis rate of the H\157 cells increased to 17.82 2.37% (F = 32.06, 0.05). This result illustrates that saRNA can promote apoptosis by upregulating PTEN expression when treated with gefitinib (Fig ?(Fig44). Open in a separate window Physique 4 saRNA increased gefitinib\induced apoptosis. (a) Mock group, (b) control group, and (c) saRNA group. Conversation Recently, more and more studies have suggested that PTEN expression dysfunction contributes to TKI resistance in NSCLC patients. PTEN is an important tumor suppressor gene, which can inhibit tumor proliferation by inhibiting P13K/Akt pathway activation.9, 10, 11 PTEN is a common node of multiple signal pathways. If the gene mutates or has lower expression, its tumor suppressor function will be lost. Bidkhori 2011; 61: 134.) CA Malignancy J Clin 2011; 61: 69C90. [PubMed] [Google Scholar] 2. NSCLC Meta\Analyses Collaborative Group . Chemotherapy in addition to supportive care improves survival in advanced non\small\cell lung malignancy: A systemic review and meta\analysis of individual patient data from 16 randomized controlled trials. J Clin Oncol 2008; 26: 4617C25. [PMC free article] [PubMed] [Google Scholar] 3. Mok TS, Wu YL, Thongprasert S em et al. /em Gefitinib or carboplatin\paclitaxel in pulmonary adenocarcinoma. N Engl J Med 2009; 361: 947C57. [PubMed] [Google Scholar] 4. Mitsudomi T, Morita S, Yatabe Y em et al. /em Gefitinib versus cisplatin plus docetaxel in patients with non\small\cell lung malignancy harbouring mutations of the epidermal growth factor receptor (WJTOG3405): An open label, randomised phase 3 Glycolic acid trial. Lancet Oncol 2010; 11: 121C8. [PubMed] [Google Scholar] 5. Maemondo M, Inoue A, Kobayashi K em et al. /em Gefitinib or chemotherapy for non\small\cell lung malignancy with mutated EGFR. N Engl J Med 2010; 362: 2380C8. [PubMed] [Google Scholar] 6. Sharma SV, Bell DW, Settleman J, Haber DA. Epidermal growth factor receptor mutations in lung malignancy. Nat Rev Malignancy 2007; 7: 169C81. [PubMed] [Google Scholar] 7. Wu YL, Sun Y, Liao ML em et al. /em [The processing of epidermal growth factor receptor mutation lung malignancy.] Xun Zheng Yi Xue 2011; 11: 65C8 . (In Chinese.) [Google Scholar] 8. Engelman JA, J?nne PA. Mechanisms of acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors in non\small cell lung malignancy. Clin Malignancy Res 2008; 14: 2895C9. [PubMed] [Google.