en زیست شناسی ملکولی Molecular Biology مقالات اصلی Original Article <strong><em>Bac</em></strong><strong><em>kground:</em></strong> Cyclooxygenase-2 (COX-2) main product is Prostaglandin E2 (PGE2) which cause mitogenesis and inflammation. COX-2 is the product of prostaglandin-endoperoxide synthase 2 (<em>PTGS2</em>) gene expression. COX-2 dysregulation can cause angiogenesis, differentiation, and promotion of cancer and its suppression related to control of the tumor&#39;s size, number, and cell shape. This study focused on the association of COX-2 expression with colorectal carcinoma (CRC) among Iranian patients on mRNA level and in the Cancer Genome Atlas Program (TCGA) colon and rectum RNAseq dataset, and its relation with pathological features.<br> <br> <strong><em>Methods:</em></strong> <em>PTGS2</em> expression was assayed by quantitative-PCR method from 90 tissue samples collected from 45 participants. The control samples come from the non-tumor area of the same patients. The data analyzed based on &Delta;&Delta;Cq. The <em>PTGS2</em>-RNAseq data extracted and analyzed by UCSC Xena browser, and its association assessed the occurrence of CRC and invasive-features.<br> <br> <strong><em>Results:</em></strong> <em>PTGS2</em> showed very significant over-expression in tumor tissues (p< 0.0001) with an N-fold expression of 2.25. But, there was not any significant association between <em>PTGS2</em> and CRC invasive-pathological features such as Lymphatic, vascular and perineural invasion, the Grades of cancer, and Pathologic-M in both parts of this study.<br> <br> <strong><em>Conclusions:</em></strong> The increase in <em>PTGS2</em> is related to the occurrence of CRC among patient samples. But in both part of this study, <em>PTGS2</em> is not an invasive factor, and it does not affect the cell differentiation of tumors and metastasis. Based on the high N-fold for patient samples, it can be a strong candidate as a CRC initiator biomarker. Cyclooxygenase-2, Gene expression profiling, Neoplasm invasion, Prostaglandins, TCGA-data. 442 451 http://rbmb.net/browse.php?a_code=A-10-631-1&slc_lang=en&sid=1 Tahereh Zahedi Tahereh Zahedi zahedi.tahereh@gmail.com 100319475328460017758 100319475328460017758 No Department of Molecular and Cell Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Mazandaran, Iran. Abasalt Hosseinzadeh Colagar Abasalt Hosseinzadeh Colagar acolagar@yahoo.com 100319475328460017759 100319475328460017759 Yes Department of Molecular and Cell Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Mazandaran, Iran. Habibollah Mahmoodzadeh Habibollah Mahmoodzadeh hmahmoodzadeh@tums.ac.ir 100319475328460017760 100319475328460017760 No Department of Surgical Oncology, Cancer Institute, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran.