DNA synthesis inhibition via incorporation into DNA

"DNA synthesis inhibition via incorporation into DNA" is not a specific molecular target but rather describes a **mechanism of action** by which certain drugs—primarily nucleoside or nucleotide analogues—inhibit cell proliferation. These compounds resemble natural nucleotides and are incorporated by cellular or viral DNA polymerases during replication. Once incorporated, they often lack the necessary chemical groups for further chain elongation, resulting in premature termination of the newly synthesized strand. This mechanism is exploited therapeutically in both oncology (to halt rapidly dividing cancer cells) and antiviral therapy (to block viral genome replication). Examples include fludarabine, gemcitabine, cytarabine for cancer; acyclovir and ganciclovir for herpesviruses; vidarabine; and foscarnet as a non-nucleoside inhibitor that blocks polymerase activity directly. The approach can lead to side effects such as myelosuppression or organ toxicity depending on drug specificity and off-target effects[2][3]. Note on correctness: "DNA synthesis inhibition via incorporation into DNA" refers to a pharmacological process/mechanism rather than an individual protein/gene/receptor/enzyme target. It does not correspond to a canonical molecular entity but instead describes how certain drugs act at the molecular level. Therefore, it should not be considered a standard therapeutic target name—this entry is best mapped to specific enzymes like "DNA polymerase alpha," "viral DNA polymerase," etc., depending on context[1][2][5].

Nucleoside analogues are incorporated into growing DNA chains, lacking a 3′ hydroxyl group, which leads to chain termination and inhibition of further elongation[2][3]. Some drugs mimic pyrophosphate and directly inhibit the activity of viral or cellular DNA polymerases[3].