Figure 3. Homozygous LKB1 deletions occur in majority of cervical cancer cell lines.

(A) MLPA; see Figure 1 for probe details. HeLa, MS751, SiHa, and HT3 (and HeLa subclone HeLaS3) contain distinctive homozygous deletions. C4I harbors a monoallelic deletion, as evidenced by contiguous probes with half-intensity signals. (B) Southern analysis of control DNA, above cell lines, C33 (no deletion by MLPA) and HPV16/E6E7-immortalized endocervical cells from a normal patient (Endo = End1/E6E7; ATCC #CRL-2615). (C) Western analysis. LKB1 protein is undetectable in lines harboring homozygous deletions and decreased by ∼50% in C4I, consistent with monoallelic loss.