Gefitinib-Integrated Regimen versus Chemotherapy Alone in Heavily Pretreated Patients with Epidermal Growth Factor Receptor-Mutated Lung Adenocarcinoma: A Case-Control Study

Gefitinib Represses JAK-STAT Signaling Activated by CRTC1-MAML2 Fusion in Mucoepidermoid Carcinoma Cells

BACKGROUND

Gefitinib is well-known as a tyrosine kinase inhibitor targeting non-smalllung- cancer (NSCLC) containing EGFR mutations. However, its effectiveness in treating mucoepidermoid carcinoma (MEC) without such EGFR mutations suggests additional targets.

OBJECTIVE

The CRTC1-MAML2 (C1-M2) fusion typical for MEC has been proposed to be a gefitinib target.

METHODS

To test this hypothesis, we developed a set of siRNAs to down-regulate C1-M2 expression. RNA-seq and Western blot techniques were applied to analyze the effects of gefitinib and siC1-M2 on the transcriptome of and the phosphorylation of tyrosine kinases in a MEC cell line H292.

RESULTS

Deep-sequencing transcriptome analysis revealed that gefitinib extensively inhibited transcription of genes in JAK-STAT and MAPK/ERK pathways. Both siC1-M2 and gefitinib inhibited the phosphorylation of multiple signaling kinases in these signaling pathways, indicating that gefitinib inhibited JAK-STAT and MAPK/ERK pathways activated by C1-M2 fusion. Moreover, gefitinib inhibition of EGFR and MAPK/ERK was more effective than that of AKT, JAK2 and STATs, and their dependence on C1-M2 could be uncoupled. Taken together, our results suggest that gefitinib simultaneously represses phosphorylation of multiple key signaling proteins which are activated in MEC, in part by C1-M2 fusion. Gefitinib-repressed kinase phosphorylation explains the transcriptional repression of genes in JAK-STAT and MAPK/ERK pathways.

CONCLUSION

These findings provide new insights into the efficacy of gefitinib in treating mucoepidermoid carcinoma, and suggest that a combination of gefitinib and other inhibitors specifically against C1-M2 fusion could be more effective.

[Comparison of Effectiveness of Gefitinib, Erlotinib, and Afatinib in Advanced Non-small Cell Lung Cancer Patients with EGFR Mutation Positive in Indonesian Population]

Background and objective

EGFR-tyrosine kinase inhibitors (EGFR-TKIs) were used to treat non-small cell lung cancer (NSCLC) patients with EGFR mutation positive. This study aims to compare the effectiveness of first line TKIs; gefitinib, erlotinib, and afatinib in the treatment of advanced stage NSCLC patients with EGFR mutation positive in the Indonesian population.

Methods

A retrospective cohort study of 88 NSCLC patients with EGFR mutation positive treated with gefitinib (n=59), erlotinib (n=22), and afatinib (n=7) was performed in national cancer hospital in Indonesia.Inclusion criteria were stage Ⅲb or Ⅳ NSCLC with adenocarcinoma subtype. Subjects less than 18 years or with a history of other malignancy were excluded. Outcomes were treatment response, progression-free survival (PFS), and mortality rate.

Results

Complete response, partial response, and stable disease were shown in 1.1%, 35.2%, and 31.8% of subjects, respectively. There were 31.8% of subjects developed progressive disease during treatment. Regarding EGFR mutation positive profile, a total of 56.8% subjects had deletion in exon 19, 42% subjects had mutation in exon 21, and rare mutation in exon 18 was found in 3.4% of total subjects. Demography and clinical characteristics had no significant association with the risk of progressive disease. The median PFS of subjects was 11 months (95%CI: 6.8-15.2 months). There was no statistical difference of PFS between treatment groups.

Conclusion

Gefitinib, erlotinib, and afatinib have similar effectiveness in advanced stage NSCLC with EGFR mutation positive. Afatinib tends to be associated with longer PFS but further investigation is required.