Differential Regulation of Gene Expression of Alveolar Epithelial Cell Markers in Human Lung Adenocarcinoma-Derived A549 Clones

Table 2

Gene expression in A549 parental cells.

Cell type

Early mesoderm

Endoderm

Lung progenitor cells

Basal cells

Ciliated cells

Goblet cells

Clara cells

Alveolar type I cells

Alveolar type II cells

Cancer stem cells

Days of cultures

Marker genes

TTF-1

d1

—

—

—

+

—

+

+

+

+

—

+

+

—

+

d2

—

—

—

+

—

+

+

+

+

—

—

+

—

+

d3

—

—

—

+

—

+

+

+

+

—

—

+

—

+

d4

—

—

—

+

—

+

+

+

—

—

—

+

—

++

RT-PCR results shown in Figure 1(b) were quantified and normalized by ribosomal 18S. The relative ratio of each gene expression level was evaluated by the lowest expression level among the samples as 1. —: not detected; +: 1–2.5-fold; ++: over 2.5-fold.