Effect of Knockdown of CD44 Expression by shRNA On Biologicalfeatures of Activated B-Cell-Like Diffuse Large B Cell Lymphoma Cell Line

To study the effect of CD44 down-regulation with lentivirus-mediated small hairpin RNA (shRNA) interference on the biological features of activated B-cell-like diffuse large B-cell lymphoma (DLBCL) cell line SUDHL-2.

Lentiviral vector for RNAi of CD44, which contained green fluorescent protein(GFP) was constructed. Package cells phoenix293 was used to produce virus stocks. Then SUDHL-2 cells were infected with the recombinant lentivirus and the cells with CD44 knock-down were selected by FACS for GFP expression. CD44 expression in the cells was determined by RT-PCR and FACS. The proliferation, apoptosis and invasion were evaluated by MTT methods, FACS and transwell migration assay, respectively.

DNA sequencing demonstrated that the lentivirus RNAi vector was constructed successfully. Clones of SUDHL-2 cells infected with the recombinant lentivirus were selected and exhibited substantial knock-down of CD44 mRNA and protein expression compared with the control cells. The proliferation ability of cloned SUDHL-2 cells were inhibited. The apoptosis rates at early and late phase were 6. 26%, 36. 40% respectively in cloned SUDHL-2 cells and in control cells were 2. 9%, 2. 56% at early phase and 6. 1%, 6. 58% at late phase. The migrating number of cloned SUDHL-2 cells(34. 53±8. 05)% was also significantly decreased compared with the control cells, 78. 67±2. 64% and 78. 00±6. 13% (P=0. 290).

The lentivirus-mediated shRNA of CD44 is efficient in down-regulating CD44 expression and inducing apoptosis, inhibiting proliferation and invasiveness of SUDHL-2 cells, suggesting that CD44 might have an oncogene role in the tumorigenesis and progression of ABC-DLBCL.

No relevant conflicts of interest to declare.