J Cancer 2015; 6(12):1222-1229. doi:10.7150/jca.11279

Research Paper

The Expression of CD9 and PIK3CD is Associated with Prognosis of Follicular Lymphoma

Tieying Dong*1, Zhaoliang Liu*1,2, Shu Zhao1, Chengyi Hu, Yupeng Liu, WenJie Ma1, Qingyuan Zhang1#✉

1. Department of Internal Medicine, The Third Affiliated Hospital of Harbin Medical University, Haping Road 150 of Nangang District, Harbin, Heilongjiang Province 150081, China
2. Cancer Research Institute, Harbin Medical University, Harbin, China
3. Cancer Research Institute of Heilongjiang, Harbin, China
# This experiment was performed in the Oncology Key Lab of the Department of Higher Education of Heilongjiang Province Institution of Higher Education.
* These authors contributed equally to this work and should be considered co-first authors.

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Dong T, Liu Z, Zhao S, Hu C, Liu Y, Ma W, Zhang Q. The Expression of CD9 and PIK3CD is Associated with Prognosis of Follicular Lymphoma. J Cancer 2015; 6(12):1222-1229. doi:10.7150/jca.11279. Available from http://www.jcancer.org/v06p1222.htm

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Background: Follicular lymphoma (FL) frequently develops drug-resistance and transforms into more aggressive subtypes over time. It is urgent to find prognostic biomarkers and disclose signaling pathways that have potential to be drug targets. In this study, we investigated the association of FL prognosis with the expression of 2 proteins: PIK3CD, a PI3K pathway component, and CD9, a tetraspanin family member.

Method: The expression of PIK3CD and CD9 were examined on 76 FL tumor tissues and 15 normal tissues with Immunohistochemistry. Chi-square test, Cox proportional hazards model, and Kaplan-Meier estimates were used to analyze the relationships of CD9 and PIK3CD expression and major clinicopathological features.

Result: PIK3CD expression was significantly higher, whereas CD9 expression was significantly lower in the 76 FL specimens than normal tissues. Concomitantly, low CD9 or high PIK3CD expression is associated with high degrees of Ann Arbor stages. In agreement with this, PIK3CD is an unfavorable and CD9 is a favorable factor for progression-free survival (PFS). Interestingly, PIK3CD expression is negatively correlated with CD9 expression, and the PIK3CD-high/CD9-low was significantly associated with short PFS when the 2 factors were combined together. Lastly, CD9 expression was significant higher in patients with bone marrow infiltration (BMI) than those without BMI.

Conclusion: Both CD9 and PIK3CD are prognostic markers of FL. The negative correlation between CD9 and PIK3CD expression suggests that there may be crosstalks of the 2 proteins in FL.

Keywords: CD9, PI3KCD, Follicular Lymphoma, Prognosis, Bone Marrow Infiltration