Treatment of liposarcomas using a combination of thiazolidinediones and retinoid X receptor selective agonists

A composition comprising at least one thiazolidenedione and at least one retinoid X receptor (RXR) selective agonist, wherein said thiazolidenedione has the structure I, wherein structure I is as follows:

• wherein:
• each of X1, X2, X3, X4, X5 and X6 is independently carbon, nitrogen, oxygen or sulfur, with the proviso that at least three of the atoms forming the ring are carbon,
• A is:
• —Yn—(CR″R″)m—Z,
• —Yn—(CR″R″)m′—O—(CR″R″)m″—Z, or
• —Yn—(CR″R″)m′—N(R′″)—(CR″R″)m″—Z,
• wherein:
• Y is —O— or —S—,
• n is 0 or 1,
• each R″ is independently hydrogen, lower alkyl, substituted lower alkyl, hydroxy, lower alkoxy, thioalkyl, halogen, trifluoromethyl, cyano, nitro, amino, carboxyl, carbamate, sulfonyl or sulfonamide,
• R′″ is hydrogen, lower alkyl or substituted alkyl,
• m falls in the range of 1 up to 15, each m′ falls independently in the range of 1 up to 8,
• each m″ falls independently in the range of 0 up to 12, and
• Z is a thiazolidenedionyl moiety;
• R2 is hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, alkylaryl, substituted alkylaryl, alkenylaryl, substituted alkenylaryl, alkynylaryl, substituted alkynylaryl, arylalkyl, substituted arylalkyl, arylalkenyl, substituted arylalkenyl, arylalkynyl, substituted arylalkynyl, oxyalkyl, poly(alkylene oxide), substituted poly(alkylene oxide), poly(alkylene sulfide), substituted poly(alkylene sulfide), poly(alkylene amine) or substituted poly(alkylene amine);
• R3 is hydrogen, hydroxy, halogen, alkoxy, lower alkyl, substituted lower alkyl, alkenyl, substituted alkenyl, alkynyl or substituted alkynyl;
• R4 is hydrogen, formyl, acyl, lower alkyl or substituted lower alkyl;
• R5 is hydrogen, hydroxy, lower alkoxy, lower alkyl, substituted lower alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl or halogen;
• and
• R6 is hydrogen, hydroxy, lower alkoxy, lower alkyl, substituted lower alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl or halogen.