The Expression Analysis of Intestinal Cancer Stem Cell Marker Lgr5 in Colorectal Cancer Patients and the Correlation with Histopathological Markers
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Cancer stem cells (CSCs) have frequently been utilized in the cell characterization and identified responsible for tumor development, metastasis, recurrence, and chemoresistance. CSC surface markers function in cancer cell signaling and are indicated as potential biomarkers for cancer diagnosis and prognosis. As well, dysregulation of cancer-related signaling pathways could promote CSC development and progression. Our aim was to evaluate the expression of colorectal CSC markers and their correlation with cancer proliferation and angiogenesis.
In this case-control study, total RNA was extracted from a total of 74 colorectal tumors and 74 adjacent normal tissue biopsies. Then, using a quantitative real-time PCR, the relative expression levels of Lgr5 and Lrig1 were measured in all malignant and healthy samples. Also, immunohistochemical (IHC) staining of tumor tissues was performed for Ki-67 (proliferation) and CD34 (angiogenesis) markers, and the immunoexpression staining scores were obtained. The diagnostic value of the genes was evaluated using receiver operating characteristic (ROC) curve. Possible correlation between CSC markers and immunohistochemical markers in CRC was analyzed by Pearson’s correlation test and linear regression.
The expression level of Lgr5 in tumor samples showed a significant increase compared with normal samples (p < 0.001) with a fold change of 2.54 (± 0.182). However, there was no significant difference in the relative expression of Lrig1 gene in tissue samples of healthy subjects and patients. The analysis of the ROC showed an AUC of 0.92 for Lgr5 and sensitivity 80% and specificity 96%. Further analysis revealed a significant correlation between mRNA levels of Lgr5 and immunoexpression of Ki-67 (r2 = 0.680, p < 0.001).
The high expression levels of Lgr5 found in tumor tissues were correlated with histological parameters, indicating a significant role in CRC development and diagnosis.
KeywordsAngiogenesis Cancer stem cell Colorectal cancer Lgr5 Lrig1 Proliferation
This study was supported by Iran University of Medical Sciences (Grant No. 28672).
Compliance with Ethical Standards
The study was approved by the ethics committee of Iran University of Medical Sciences (ethical code: IR.IUMS.REC 95-02-182-28672). All the individuals completed the informed consent forms.
Conflict of Interest
The authors declare that they have no conflict of interest.
- 2.Mobini GR, et al. Transforming growth factor beta-induced factor 2-linked X (TGIF2LX) regulates two morphogenesis genes, Nir1 and Nir2 in human colorectal. Acta Medica Iranica. 2016:302–7.Google Scholar
- 9.Takebe N, Ivy SP. Controversies in cancer stem cells: targeting embryonic signaling pathways. Clin Cancer Res. 2010:1078–0432 CCR-09-2934.Google Scholar
- 23.Takahashi-Yanaga F, Kahn M. Targeting Wnt signaling: can we safely eradicate cancer stem cells? Clin Cancer Res. 2010:1078–0432 CCR-09-2943.Google Scholar
- 24.Puppa G, Sonzogni A, Colombari R, Pelosi G. TNM staging system of colorectal carcinoma: a critical appraisal of challenging issues. Archives of Pathology & Laboratory Medicine. 2010;134(6):837–52.Google Scholar
- 27.Wolff AC, Hammond ME, Schwartz JN, Hagerty KL, Allred DC, Cote RJ, et al. American Society of Clinical Oncology/College of American Pathologists guideline recommendations for human epidermal growth factor receptor 2 testing in breast cancer. Arch Pathol Lab Med. 2007;131(1):18–43.PubMedGoogle Scholar
- 32.Bergamaschi A, Kim YH, Wang P, Sørlie T, Hernandez-Boussard T, Lonning PE, et al. Distinct patterns of DNA copy number alteration are associated with different clinicopathological features and gene-expression subtypes of breast cancer. Genes Chromosom Cancer. 2006;45(11):1033–40.PubMedCrossRefGoogle Scholar
- 48.Dame MK, et al. Identification, isolation, and characterization of human LGR5-positive colon adenoma cells. Development. 2018;145.Google Scholar
- 52.Hermann PC, et al. Cancer stem cells in solid tumors. In: Seminars in cancer biology. Amsterdam: Elsevier; 2010.Google Scholar