[Comparison of the Efficacy and Safety of Icotinib with Standard Second-line Chemotherapy in Previously Treated Advanced Non-small Cell Lung Cancer]

Inhibition of miR-22 enhanced the efficacy of icotinib plus pemetrexed in a rat model of non-small cell lung cancer

Objective(s):

To investigate the role of miR-22 in the efficacy of combined icotinib (BPI-2009H) and pemetrexed (LY-231514) on tumor growth and apoptosis in rats with non-small cell lung cancer (NSCLC).

Materials and Methods:

Rats were injected with HCC827 cells, which were transfected with anti-miR-22, followed by the treatment of BPI-2009H and/or LY-231514. MTT assay was used to detect the inhibition rate of HCC827 cells. qRT-PCR was performed to examine miR-22 expression in HCC827 cells and lung tumor tissues. Moreover, immunohistochemistry and Western blotting were performed to detect the related-molecule expressions, while TUNEL staining was used to observe cell apoptosis of lung tumor tissues.

Results:

MiR-22 expression was decreased in HCC827 cells after the treatment of BPI-2009H or LY-231514 in a dose-dependent manner. Both BPI-2009H and LY-231514 increased the inhibition rate of HCC827 cells, which was enhanced by anti-miR-22 with decreased IC50 values. Furthermore, the decreased expression of miR-22 was found after the treatment of BPI-2009H or/and LY-231514 in lung tumor tissues. In addition, the expressions of PCNA, Ki67, and Bcl-2 were reduced, but Bax and Caspase-3 were increased in treated rats, typically in those rats treated with the combination of anti-miR-22, BPI-2009H, and LY-231514.

Conclusion:

Inhibition of miR-22 could enhance the efficacy of icotinib combined with pemetrexed in rats with NSCLC, providing a new perspective for NSCLC therapy.

Glutathione S-transferase genes variants and glioma risk: A case-control and meta-analysis study

Background: The glutathione S-transferase (GST) genes encode enzymes that metabolize carcinogenic compounds, and their variants, GSTP1 (Ile105Val and Ala114Val), GSTT1 (null/present), and GSTM1 (null/present), reduce enzyme activity that may affect the risk of developing cerebral glioma. This study undertook a case-control study and a meta-analysis to evaluate associations between these GST gene variants and the risk of glioma. Methods: The study enrolled 384 glioma patients (194 men and 190 women; mean age, 48.3 ± 9.2 years) and 340 healthy controls (174 men and 166 women; mean age, 46.5 ± 9.8 years). The amplification refractory mutation system assay was performed to identify GST gene variants of all 724 subjects. A meta-analysis enrolled 15 studies (including our case-control results) was performed. Results: Our case-control study found that the frequency of GSTP1 Ile105Val Val/Val genotype was significantly higher in the glioma group than that in the healthy controls (11.7% vs. 6.4%) (OR=1.50; 95% CI=1.05-2.04; P=0.01); the frequency of the Val/Ile + Ile/Ile genotypes was different from glioma patients and controls (88.3% vs. 93.6%) (OR=1.47(1.04-2.10); P=0.015); there were no associations between GSTP1 Ala114Val, GSTT1 (null/present) and GSTM1 (null/present) variants and glioma risk. Our meta-analysis confirmed that the GSTP1 Ile105Val variant was associated with an overall increased glioma risk. Moreover, our meta-analysis also confirmed the GSTP1 Ala114Val and GSTT1 null/present variants were associated with an increased glioma risk in the Caucasian population, rather than the Asian population. Conclusions: This study showed that GST gene variants were associated with an increased risk of glioma with ethnic differences. Future large-scale, multi center, controlled, prospective studies are required to support these findings and to determine how these GST gene variants may affect the pathogenesis of glioma.

Clinical efficacy of icotinib in lung cancer patients with different EGFR mutation status: a meta-analysis

Icotinib is a novel and the third listed epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), which exerts a good anti-tumor efficacy on non-small cell lung cancer (NSCLC). The efficacy of EGFR-TKIs has been shown to be associated with the EGFR mutation status, especially exon 19 deletion (19Del) and exon 21 L858R mutation. Therefore, a meta-analysis was performed to assess the efficacy of icotinib in NSCLC patients harboring EGFR mutations (19Del or L858R) and wild type (19Del and L858R loci wild type). A total of 24 studies were included for comparing the objective response rate (ORR) in the EGFR wild type and mutant patients treated with icotinib. The ORRs of EGFR mutant patients (19Del or L858R) are better than those of EGFR wild type patients (OR = 7.03(5.09-9.71), P < 0.00001). The pooling ORs from 21 studies on the disease control rate (DCR) in EGFR mutant patients are better than those of EGFR wild type patients (OR = 10.54(5.72-19.43), P < 0.00001). Moreover, the ORRs of EGFR 19Del patients are better than those of EGFR L858R patients after pooling ORs of 12 studies (OR = 2.04(1.12-3.73), P = 0.019). However, there was no significant difference on DCRs of EGFR 19Del patients and those of EGFR L858R patients (OR = 2.01(0.94-4.32), P = 0.072). Our findings indicated that compared with EGFR wild type patients, EGFR mutant patients have better ORRs and DCRs after icotinib treatment; EGFR 19Del patients treated with icotinib have better ORRs than EGFR L858R patients. EGFR mutation status is a useful biomarker for the evaluation of icotinib efficacy in NSCLC patients.