Related Experiment Video
Updated: Mar 14, 2026
Deficient Pms2, ERCC1, Ku86, CcOI in Field Defects During Progression to Colon Cancer
Published on: July 28, 2010
Decreased expression of p73 in colorectal cancer
Anna Kotulak, Agata Wronska, Jaroslaw Kobiela
1Department of Histology, Medical University of Gdansk, Gdansk. pwierzb@gumed.edu.pl.
Introduction:
The colorectal cancer (CRC) is one of the most frequent cancer in Poland and worldwide. This disease is characterized by distinct genetic alterations. p73 belongs to the p53 gene family; however, its role in the pathogenesis of CRC has not been completely understood. p73 gene encodes several mRNA variants and protein isoforms with its longest and fully functional p73a (mRNA) and TAp73a (protein) isoform. The aim of the study was to investigate p73 gene expression at the mRNA (p73a) and protein (TAp73a) levels in CRC.
Material And Methods:
Small sections of the crc tumor tissue and macroscopically unchanged colon mucosa and submucosa from the dissection margin were collected from 23 patients diagnosed with CRC. p73 mRNA levels were measured by Real-time PCR (QPCR) method and the expression level of TAp73a protein was assessed by Western blotting (WB) and immunohistochemical (IHC) staining.
Results:
We found a 37% decrease in the level of p73a mRNA in neoplastically changed (tumor) compared with unchanged normal colon tissue from the surgical margin (p = 0.041). No correlations were found between mRNA levels in cancer tissue and clinical-pathological parameters. The semi-quantification of TAp73a protein revealed lower and higher TAp73a protein contents in 11/23 and 12/23 of tumor samples, respectively, when compared with the median value of TAp73a protein in normal colon tissue (p = 0.61). The level of TAp73a protein level was 5 times lower in poorly differentiated cancer cells (G3) in comparison to moderately differentiated ones (G2; p = 0.02). No statistically significant correlations were observed between the level of the TAp73a protein and clinical-pathological patients' characteristics. The IHC analysis of TAp73a protein presence in CRC samples showed decreased immunoreactivity when compared with matched sections of the unchanged colon wall in 4/9 patients, similar intensity of the IHC reaction in 4/9 patients and increased immunoreactivity in 1/9 patients. The TAp73a protein was localized mainly in the cytoplasm of the cancer cells. No statistically significant correlations between IHC results and clinical-pathological features of the patients were found.
Conclusions:
The obtained results suggest that the p73 gene may play a role as a tumor suppressor in the CRC progression.
Related Concept Videos
02:23Abnormal Proliferation
01:23Negative Regulator Molecules
01:12Loss of Tumor Suppressor Gene Functions
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
02:36DNA Damage can Stall the Cell Cycle
02:36DNA Damage Can Stall the Cell Cycle
01:19Interactions Between Signaling Pathways
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...