The identification of novel genes involved in proliferation and malignant transformation has been greatly enhanced through positional cloning after localization of chromosomal regions that are deleted (designated as loss of heterozygosity-LOH-or allelic deletion) during malignant transformation. The GI tract is no exception and indeed, identification of critical genes such as APC for adenomatous polyposis coli (chromosome 5q), p53 (chromosome 17p), DCC for deleted in colon cancer (chromosome 18q), and Smad4 (chromosome 18q). Recognizing that other chromosomal regions are frequently deleted in the progression premalignant to malignant states in the colon, we have meticulously identified a new target region of allelic loss on chromosome 22q that is involved in human colorectal carcinogenesis. Fine genetic and physical mapping with microsatellite DNA markers demonstrates that the genetic length of this interval on chromosome 22q13 is 0.57 cM which corresponds to approximately 425 kb, recognized as substantial progress in human genomics and genetics projects. In addition, we have generated clones from a BAC (bacterial artificial chromosomes) library that potentially spans this contig. We hypothesize that other genes exist whose encoded proteins harbor critical genetic, biological and biochemical properties that ultimately are important in the maintenance of intestinal epithelial cell homeostasis and linked to progression to adenomatous polyp and cancer. We are collaborating closely with Dr. James Gusella s group, renowned for their contributions in neurogenetics and chromosome 22q studies. Therefore, to achieve the identification of the gene through widely available positional cloning technologies and attain its subsequent molecular characterization, we will pursue well-integrated Specific Aims:: (1) To complete the physical and genetic definition of the chromosome 22q13 region with BAC clones. We will identify candidate genes from the BAC clones using exon trapping and when necessary, cDNA selection, followed by DNA sequencing. (2) To identify the chromosome 22q13 candidate gene from among other genes in the region, each candidate gene will be studied for tumor-specific alterations (mutations) using with PCR-SSCP followed by DNA sequencing of SSCP variants. (3) To evaluate gene expression at the RNA level, Northern blotting and in situ hybridization will be performed on human tissues. In aggregate, our novel preliminary data lay the foundation for applying timely positional cloning strategies to identify the chromosome 22q gene and ultimately, leading to mechanistic insights and translational applications.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK056645-02
Application #
6363056
Study Section
General Medicine A Subcommittee 2 (GMA)
Program Officer
Hamilton, Frank A
Project Start
2000-03-01
Project End
2004-02-29
Budget Start
2001-03-01
Budget End
2002-02-28
Support Year
2
Fiscal Year
2001
Total Cost
$232,854
Indirect Cost
Name
University of Pennsylvania
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Chatterji, Priya; Hamilton, Kathryn E; Liang, Shun et al. (2018) The LIN28B-IMP1 post-transcriptional regulon has opposing effects on oncogenic signaling in the intestine. Genes Dev 32:1020-1034
Mizuno, Rei; Chatterji, Priya; Andres, Sarah et al. (2018) Differential Regulation of LET-7 by LIN28B Isoform-Specific Functions. Mol Cancer Res 16:403-416
Chatterji, Priya; Rustgi, Anil K (2018) RNA Binding Proteins in Intestinal Epithelial Biology and Colorectal Cancer. Trends Mol Med 24:490-506
Giroux, VĂ©ronique; Stephan, Julien; Chatterji, Priya et al. (2018) Mouse Intestinal Krt15+ Crypt Cells Are Radio-Resistant and Tumor Initiating. Stem Cell Reports 10:1947-1958
Andres, Sarah F; Williams, Kathy N; Rustgi, Anil K (2018) The Molecular Basis of Metastatic Colorectal Cancer. Curr Colorectal Cancer Rep 14:69-79
Zhou, Jin; Wu, Zhong; Wong, Gabrielle et al. (2017) CDK4/6 or MAPK blockade enhances efficacy of EGFR inhibition in oesophageal squamous cell carcinoma. Nat Commun 8:13897
Heeg, Steffen; Das, Koushik K; Reichert, Maximilian et al. (2016) ETS-Transcription Factor ETV1 Regulates Stromal Expansion and Metastasis in Pancreatic Cancer. Gastroenterology 151:540-553.e14
Hamilton, Kathryn E; Chatterji, Priya; Lundsmith, Emma T et al. (2015) Loss of Stromal IMP1 Promotes a Tumorigenic Microenvironment in the Colon. Mol Cancer Res 13:1478-86
Madison, Blair B; Jeganathan, Arjun N; Mizuno, Rei et al. (2015) Let-7 Represses Carcinogenesis and a Stem Cell Phenotype in the Intestine via Regulation of Hmga2. PLoS Genet 11:e1005408
Schnepp, Robert W; Khurana, Priya; Attiyeh, Edward F et al. (2015) A LIN28B-RAN-AURKA Signaling Network Promotes Neuroblastoma Tumorigenesis. Cancer Cell 28:599-609

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