Research Papers:
Significance of BRAF CD133 gene mutations in colorectal cancer
Yan Guo1, Xing-Feng Qi2, Yuan-Ying Liu3, De-Hua Zeng2, Xu-Zhou Wang2, Yi-Chun Wang4, Sara Javidiparsijani5, Guirong Wang5, Jun-Ming Luo1,4 and Ying-Hao Yu2
1Department of Pathology, Qinghai Provincial People’s Hospital, Xining, Qinghai 810007, PR China
2Department of Pathology, Fuzhou General Hospital at Nanjing Military Region of Chinese People's Liberation Army (PLA), Fuzhou, Fujian 350025, PR China
3Department of Pathology, The First People’s Hospital of Longyan, Longyan, Fujian 364000, PR China
4Department of Anesthesiology, The Affiliated Hunan Provincial Tumor Hospital at Central South University, Changsha, Hunan 410013, PR China
5SUNY Upstate Medical University, Department of Surgery, Syracuse, NY 13210, USA
Correspondence to:
Ying-Hao Yu, email: [email protected]
Jun-Ming Luo, email: [email protected]
Keywords: colorectal cancer; tissue microarray; BRAF; CD133; immunohistochemistry
Received: September 11, 2017 Accepted: March 14, 2018 Published:
ABSTRACT
A total of 376 colectomy specimens for colorectal cancer (CRC) from 400 patients were collected and used for building the microtissue chips by using several techniques such as microtissue array; immunohistochemistry (IHC) for CD133, BRAF direct sequencing and life-time follow up and the clinicopathological characteristics as well as the prognosis. High levels of CD133 and BRAF expression had significant correlation with tumor differentiation and lymph node metastasis (P < 0.05). The survival analysis showed that 3 year survival rate was lower in CD133 and BRAF were also lower in high expressing group than the low expressing group (P < 0.01). By Spearman correlation analysis it was found that there was certain correlation between CD133 expression and mutated BRAF (r = 0.505). Total mutated BRAF gene was 7.5% (11/146) in CRC, the mutation was significantly associated with staging and survival, and was statistically significant (P < 0.05).
Core tip: From our data, the tissue microarray technique provides a reliable method to investigate biomarker expression by offering a rapid, economic and accurate screening of tissue specimens on a large scale. CD133 expression in colorectal cancer was significantly higher, and is closely related to tumor differentiation and lymph node metastasis; CD133 can be used as a judgment index of prognosis of patients with colorectal cancer; the higher expression indicated the worse prognosis. There were some degrees of concordance between strongly positive BRAF (IHC) and gene mutation. High BRAF expression by IHC cases should be further investigated by direct sequencing to assess BRAF gene status in colorectal cancer. Patients with BRAF mutation might constitute potential candidates for targeted therapy with humanized monoclonal antibodies.