Figure 6.

Asbestos-specific genes and protein altered in BEAS-2B cells. Steady-state mRNA levels were measured by QRT-PCR in BEAS-2B cells exposed to asbestos and silica at 2 doses (75 and 150 × 10⁶ µm²/cm²) for 24 h. Genes significantly altered by asbestos only were (A) SEMA3A (Semaphorin 3A), (B) TFRC (Transferrin receptor C). Gene expression levels were normalized to the housekeeping gene RPL13A (Ribosomal protein L13A). Values represent mean ± SEM. *P < 0.05 versus unexposed controls (N = 3), (C) Western blot of TFRC protein levels (90 kDa) and house keeper GAPDH (37 kDa) after exposure to asbestos (75 × 10⁶ µm²/cm²) or silica (150 × 10⁶ µm²/cm²) for 48 h. Densitometry represents relative levels of TFRC normalized to GAPDH (N = 2) and graphs are representative of two to three repeat experiments.