Research Initiation Award: Molecular Mechanisms for DCLK1 Tumorigenesis Revealed by Pathway Analysis using RNA Sequencing Data

Research Initiation Awards provide support for junior and mid-career faculty at Historically Black Colleges and Universities who are building new research programs or redirecting and rebuilding existing research programs. It is expected that the award helps to further the faculty member's research capability and effectiveness, improve research and teaching at the home institution, and involves undergraduate students in research experiences.

The award to Tougaloo College proposes a study of stem cell markers which play a role in the growth and chemical resistance of cancer cells. The proposed work will study the molecular mechanisms of different forms of these cells to better understand the origin of tumors. The research will provide a research opportunity for Tougaloo College undergraduates.

Doublecortin-like kinase 1 (DCLK1) is a putative cancer stem cells marker with 5 isoforms. DCLK1 is up regulated and plays critical roles in the initiation and progression of multiple cancers. However, which isoform of DCLK1 is more closely correlated with tumorigenesis and chemoresistance, and the underlying molecular mechanisms are unclear.

The long-term goal of the lab is to develop a comprehensive understanding of DCLK1. The overall objectives of this proposal are to: 1) reveal and compare association of different DCLK1 isoforms with stemness of cancer cells; and 2) discover molecular mechanisms of different DCLK1 isoforms in tumorigenesis and chemoresistance using RNA seq technology.

The current hypothesis is that different DCLK1 isoforms may correlate differently with tumorigenesis and chemoresistance of cancers. The rational is that DCLK1 protein was up-regulated in clinical cancer samples, but the promoter region of DCLK1 isoform 1 (DCLK1-I1) was epigenetically imprinted. The discrepancy of protein and gene expression strongly suggests that specific DCLK1 isoform(s) are more closely associated with tumorigenesis and chemoresistance of cancers.

To achieve our goals, 1): isogenic DCLK1 isoform (I1- I5) over-expressing cells will be established using colorectal cancer cell lines with different genetic background. Association of each isoform with stemness of cells will be determined; 2) modifications of transcriptome profiles in the isogenic DCLK1 isoform (I1- I5) over-expressing cells will be determined using RNA Seq technology.

Differentially expressed genes will be identified and used for pathway analysis to establish the molecular networks of individual DCLK1 isoforms; and 3) cells will be treated with 5-Fu and transcriptome profiles will be determined using RNA seq technology. Differentially expressed genes will be identified and used for pathway analysis to reveal the molecular mechanism for chemoresistance.

With successful completion of the proposal, it is expected that specific DCLK1 isoform(s) which contributes to the tumorigenesis and chemoresistance of cancer cells will be identified.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.