Figure 7.

Lrig1 suppresses growth of ER-positive breast cancer cells and correlates with prolonged relapse-free survival. Hormone starved T47D (A) and ZR75-1 (B) cells were treated with either scramble control or Lrig1 siRNA and then treated with E2 for 48 hours. Cell viability was measured using the MTT assay. The growth of E2 treated/scramble control cells was normalized to 1.0. (C) Representative western blot depicting efficiency of Lrig1 knockdown. (D) and (E) Association between Lrig1 expression and relapse-free survival (RFS) was determined. Patients were divided into groups based on Lrig1 expression levels. Two grouping systems were used: (D) tertiles; (E) cutoffs determined by mixed model (MM) clustering. Kaplan-Meier survival analysis was then performed for RFS with these expression groups as a factor. Significant survival differences between the groups were determined by log rank (Mantel-Cox) test (linear trend for factor levels). Events beyond 10 years were censored.