Nucleoside analogs and use thereof in therapeutic treatment

A method of treating a subject having cancer of plasma cell origin or adenocarcinoma or a disease selected from the group consisting of Kaposi's Sarcoma (KS), multicentric Castleman's Disease (MCD), primary effusion lymphoma (PEL), diffuse large B-cell lymphomas, multiple myeloma, and plasmablastic lymphomas, the method comprising:

• (i) determining if the subject has an abnormally high level of expression of Adenosine Kinase (ADK) compared to cells or tissues of a healthy control subject;
• and (ii) if the subject is identified as having an abnormally high level of expression of ADK, administering to said subject an effective amount of a therapeutic compound, wherein the therapeutic compound has the following chemical structure:
• wherein:
• A1 is O;
• A2, A3, A4, and As are N;
• Y is methyl or ethyl;
• R1 and R2 are H;
• X1 and X2 are independently selected from the group consisting of hydrogen, hydroxy, and acyloxy;
• and
• X3 is selected from the group consisting of hydroxy, phosphate, acyloxy, and benzyloxy (BnO);
• wherein, optionally, X1 and X2 are taken together to form a 1,3-dioxolane ring optionally substituted with methyl groups at the 2-position;
• or, optionally, X2 and X3 are taken together to form a cyclic monophosphate.