Reciprocal modulation of lymphoma growth by Wnt3a and SFRP4. (A-B) Lentiviral short hairpin (sh)-mediated silencing of Wnt3a decreased expansion capacity of OCI Ly3 lymphoma cells in suspension culture (A) (**P < .001 after day 17, 2-way ANOVA) and reduced CFU after seeding 1 × 103 single cells in semisolid media (B) (**P < .001; ***P < .0001; 2-way ANOVA). (C) Outspread colony morphology of sh-scramble OCI-Ly3 controls, tight, vs condensed growth pattern of Wnt3a-silenced cells. (D) Reduced tumor formation from shWnt3a variants after implantation in ovo (2 left columns, ***P < .0001; 1-way ANOVA). (E) Loss of tumorigenicity also after implantation of SP cells from the shWnt3a-1 variant cell line (n = 3, *P = .048; paired Student t test) as well as from admixtures of SP cells of shWnt3a variant cells with wild-type non-SP cells (SP shWnt3a/nonSPwt: 4% SP cells, 96% non-SP cells; D, third column; ****P < .0001; 1-way ANOVA). (F-G) Recombinant SFRP4 reduced CFU activity from OCI Ly3 (F) (2-sided Student t test, ****P < .001) and reduced the proportion of SP cells in suspension culture (G) (OCI Ly3, 2-sided Student t test, P = .033).
