We have identified and validated a potential cancer drug target gene, GOI02101, which shows a specific role in anchorage-independent growth of cancer cells. Several potential oncology drug target genes were identified originally through integration of Inverse Genomics technology with pathway analysis. Inverse Genomics technology utilizes a randomized library of ribozymes, catalytic RNAs expressed in cells that cleave target mRNAs, which are then screened for a change in phenotype related to cellular transformation. By comparing genetic profiles of several ribozyme-containing cells with a desirable therapeutic phenotype to control cells, we can expand our drug target gene population. These potential oncology drug target genes are subsequently validated through an array of phenotypic assays, including anchorage independent growth, a key indicator of cellular transformation. Anchorage-independent growth is assayed by a variety of methods including colony formation in soft agar. Besides the number of colonies that form, colony size also may be affected by the treatment being analyzed. Using the Qcount automated colony counting device, we discovered a more dramatic phenotypic change resulting from knockdown of GOI02101 than that which can be shown by traditional soft agar colony quantitation. Knockdown of this gene results in a decrease in colony number as well as size, indicating a role for the targeted gene in both anchorage-independent growth initiation and colony maintenance. However, knockdown of GOI02101 did not affect anchorage-dependent growth of cancer cells, supporting a specific role of this gene in cellular transformation. The distinct effect of GOI02101 gene knockdown on anchorage-independent growth gives us further insight into the pathways affected by expression of this gene and indicates that this gene is an excellent target for therapeutic intervention in cancer.

[Proc Amer Assoc Cancer Res, Volume 45, 2004]