Related Experiment Video
Updated: Jun 16, 2026
07:33
In vitro Organoid Culture of Primary Mouse Colon Tumors
Published on: May 17, 2013
Distinct genetic alterations in colorectal cancer
Hassan Ashktorab1, Alejandro A Schäffer, Mohammad Daremipouran
1Department of Medicine and Cancer Center, Howard University, College of Medicine, Washington, DC, United States of America. hashktorab@howard.edu
Plos One
|February 4, 2010
Summary
African American colon cancer patients show distinct genomic copy number aberrations, including chromosome X amplification and deletions on chromosomes 4, 8, and 18. These chromosomal instability (CIN) differences may explain disparities in colorectal cancer (CRC) between populations.
Area of Science:
- Genomics
- Cancer Biology
- Population Genetics
Background:
- Colorectal cancer (CRC) development is linked to chromosomal instability (CIN), involving DNA amplifications and deletions.
- Significant epidemiological and clinical disparities exist between African American (AA) and Caucasian CRC patients.
- Understanding genomic differences in AA CRC tumors is crucial for addressing these disparities.
Purpose of the Study:
- To determine genomic copy number aberrations in sporadic CRC tumors from African American patients.
- To investigate potential genetic explanations for observed disparities in CRC between African Americans and Caucasians.
Main Methods:
- Genome-wide array comparative genome hybridization (aCGH) using a 105k chip was applied to 15 AA CRC samples.
- Comparative analysis was performed with aCGH data from Caucasian patients and a list of colon cancer (CAN) genes.
- Identification of copy number aberrations, including amplifications and deletions.
Main Results:
- An average of 20 aberrations per patient was observed, with more amplifications than deletions.
- Frequent deletions occurred on chromosomes 4, 8, and 18.
- Frequent duplications were identified on chromosomes 7, 8, 13, 20, and X.
- The CIN profile in AAs differed from that in Caucasians.
Conclusions:
- Prominent aberrations in AA CRC include chromosome X amplification (in males) and deletions on chromosomes 4, 8, and 18.
- Specific CAN genes were frequently altered in AAs, with EXOC4, EPHB6, GNAS, MLL3, and TBX22 being commonly deleted, and HAPLN1, ADAM29, SMAD2, and SMAD4 commonly amplified.
- The distinct CIN profile observed in African Americans may play a significant role in their colorectal cancer development and progression.
Related Concept Videos
02:21Cancers Originate from Somatic Mutations in a Single Cell
Cancer arises from mutations in the critical genes that allow healthy cells to escape cell cycle regulation and acquire the ability to proliferate indefinitely. Though originating from a single mutation event in one of the originator cells, cancer progresses when the mutant cell lines continue to gain more and more mutations, and finally, become malignant. For example, chronic myelogenous leukemia (CML) develops initially as a non-lethal increase in white blood cells, which progressively...
02:21Cancers Originate from Somatic Mutations in a Single Cell
Cancer arises from mutations in the critical genes that allow healthy cells to escape cell cycle regulation and acquire the ability to proliferate indefinitely. Though originating from a single mutation event in one of the originator cells, cancer progresses when the mutant cell lines continue to gain more and more mutations, and finally, become malignant. For example, chronic myelogenous leukemia (CML) develops initially as a non-lethal increase in white blood cells, which progressively...
02:07Tumor Progression
Tumor progression is a phenomenon where the pre-formed tumor acquires successive mutations to become clinically more aggressive and malignant. In the 1950s, Foulds first described the stepwise progression of cancer cells through successive stages.
Colon cancer is one of the best-documented examples of tumor progression. Early mutation in the APC gene in colon cells causes a small growth on the colon wall called a polyp. With time, this polyp grows into a benign, pre-cancerous tumor. Further...
Colon cancer is one of the best-documented examples of tumor progression. Early mutation in the APC gene in colon cells causes a small growth on the colon wall called a polyp. With time, this polyp grows into a benign, pre-cancerous tumor. Further...
01:11Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...
01:05Cancer-Critical Genes II: Tumor Suppressor Genes
Genes usually encode proteins necessary for the proper functioning of a healthy cell. Mutations can often cause changes to the gene expression pattern, thereby altering the phenotype.
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
01:39Mutations
Overview