Characteristics of EGFR Mutant Cell Lines.

Table 3 shows the clinico-pathologic and molecular data for the 10 NSCLC cell lines, which harbor EGFR mutations. These cell lines are arranged in decreasing order of gefitinib sensitivity. Mutations were exclusively seen in adenocarcinoma and never smokers or patients with low tobacco exposure (��10 pack years or PY). The primary activating EGFR mutations in all 10 cases were either deletions of exon 19 (n = 7) or L858R mutation in exon 21 (n = 3). Three cell lines also had a second mutation, either T790M resistance associated mutation in exon 20 (n = 2) or homozygous deletion of the PTEN gene. Contradictory data are available for the gender for the patient from whom the PC-9 cell line was originated �C the surgeon informed us that the patient was female while the distributing institution states that it was from a male (personal communication from Dr. Harubumi Kato, Tokyo Medical University, Japan). Cell lines considered resistant to gefitinib (IC50>1 ��M) are indicated in red. Rank order is the sensitivity of cell lines to gefitinib in descending order with 1 being the most sensitive. Abbreviations: EA �C East Asian, W �C White, PY �C pack years, Del �C deletion.