Table 1

The response to treatment in different APL models

PML-RARα
PLZF-RARα
RAlowRAmediumRAhighAs2O3RAmedium/As2O3RAlowRAhigh
Ex vivo        
    Differentiation ++ +++ − +++ 
    Degradation − +++ +++ +++ +++ − +++ 
    LIC loss − +++ +++ +++ +++ − +++ 
In vivo        
    Differentiation ++ +++ +++ ++ ++ +++ 
    Degradation − ++ +++ ++ +++ − ++ 
    LIC loss − ++ +++ +* +++ − 
In patients        
    Differentiation +++ +++ +++ ++ +++ ++ ++ 
    Cure − +++ +++ +++ − −/+ 
PML-RARα
PLZF-RARα
RAlowRAmediumRAhighAs2O3RAmedium/As2O3RAlowRAhigh
Ex vivo        
    Differentiation ++ +++ − +++ 
    Degradation − +++ +++ +++ +++ − +++ 
    LIC loss − +++ +++ +++ +++ − +++ 
In vivo        
    Differentiation ++ +++ +++ ++ ++ +++ 
    Degradation − ++ +++ ++ +++ − ++ 
    LIC loss − ++ +++ +* +++ − 
In patients        
    Differentiation +++ +++ +++ ++ +++ ++ ++ 
    Cure − +++ +++ +++ − −/+ 

The loss of LICs is assessed by serial replating ex vivo or transplantation in vivo.

Ex vivo indicates PML-RARA-transformed murine hematopoietic progenitor cells in methylcellulose cultures; in vivo, APL transgenic murine models.

*

As2O3 displays attenuated effects in mice due to dosage or pharmacokinetics issues.

Rare patients have been reported to respond to RA treatment by itself.