Journal of Research in Medical and Dental Sciences 2018, Volume 6, Issue 3, Page No: 78-84 Copyright CC BY-NC-ND 4.0 Available Online at: www.jrmds.in eISSN No. 2347-2367: pISSN No. 2347-2545 Journal of Research in Medical and Dental Science | Vol. 6 | Issue 3 | May 2018 78 Decreased Expression of KAI1 in Colorectal Cancer Significantly Associate with the Cancer Metastasis Shahla Mohammad Ganji 1 *, Atieh Saligheh 1 , Shahram Shafiepour 1 , Fatemeh Ashrafi 2 , Majid Pornour 3 1 Department of Molecular Medicine, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran 2 Department of Microbiology, Tehran North branch, Islamic Azad University, Tehran, Iran 3 Photo Healing and Regeneration Research Group, Medical Laser Research Center, Academic Center for Education, Culture and Research (ACECR), Tehran, Iran DOI: 10.5455/jrmds.20186312 ABSTRACT The dramatic increase in the prevalence of colorectal cancer is the most serious health challenges in the world. The higher rate of morbidity for this cancer is positively correlated with metastasis. For reduction in morbidity and alleviation of cancer pain, early detection is inevitable. Recently, it has been shown that KAI1 /CD82 gene has a critical role in the suppression of metastasis. Thus, a change in KAI1 expression is important and could be used as a useful marker for the identification of several cancers such as colorectal, prostate and breast cancer. In this survey, we obtained 52 cancer specimens from different stages of cancer (stages 1, 2, 3 and 4) and ten normal specimens as control from unrelated patients were included in this study. The patients in the study were asked to fill in a questionnaire regarding the concept of consent. Real‑time reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) were performed for evaluating gene expression at RNA and protein level, respectively. The results were analyzed by using a one-way ANOVA followed by post-hoc tests. Real-time RT-PCR quantification and IHC analysis revealed that the expression of KAI1 was significantly increased in the patient compared with the control (P = 0.036). Further comparison of the data showed that the difference was profound between these two groups; stage1 and stage3 with respect to the KAI1 gene expression (P <0.05). Key words: KAI1, Metastasis, Colorectal Cancer HOW TO CITE THIS ARTICLE: Shahla Mohammad Ganji*, Atieh Saligheh, Shahram Shafiepour, Fatemeh Ashrafi, Majid Pornour Decreased Expression of KAI1 in Colorectal Cancer Significantly Associate with the Cancer Metastasis, J Res Med Dent Sci, 2018, 6 (3):78- 84, DOI: 10.5455/jrmds.20186312 Corresponding author: Shahla Mohammad Ganji e-mail: shahla@nigeb.ac.ir Received: 12/01/2018 Accepted: 19/02/2018 INTRODUCTION KAI1 orCD82 is known as a tumor suppressor gene and suppressor of the metastasis by inhibiting proliferation and invasion of the cancerous cells [1]. Studies have shown that KAI1 level of expression could be considered among the beneficial markers for evaluating the metastatic tumors function. KAI1 was subject to evaluation In a wide range of tumors during the past decade. The results have shown that KAI1 is expressed in all normal tissues, while the expression could be different in various tissues. The expression of KAI1 in solid tumors could be considered as a good prognosis factor for identification of the advanced stages of cancer (clinically). In Studies have indicated an inverse relationship between levels of KAI1 expression and progression toward invasion in many types of cancers, such as prostate colon, lung, liver, and thyroid cancers, respectively. Also, there is an inverse relationship between the amount of KAI1