title: The Expression of CD9 and PIK3CD is Associated with Prognosis of Follicular Lymphoma.
abstract: 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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: 1. Department of Internal Medicine, The Third Affiliated Hospital of Harbin Medical University, Haping Road 150 of Nangang District, Harbin, Heilongjiang Province 150081, China.
authors.forename: Tieying
authors.initials: T
authors.lastname: Dong
authors.affiliation: 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.
authors.forename: Zhaoliang
authors.initials: Z
authors.lastname: Liu
authors.affiliation: 1. Department of Internal Medicine, The Third Affiliated Hospital of Harbin Medical University, Haping Road 150 of Nangang District, Harbin, Heilongjiang Province 150081, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhao
authors.affiliation: 1. Department of Internal Medicine, The Third Affiliated Hospital of Harbin Medical University, Haping Road 150 of Nangang District, Harbin, Heilongjiang Province 150081, China.
authors.forename: Chengyi
authors.initials: C
authors.lastname: Hu
authors.affiliation: 1. Department of Internal Medicine, The Third Affiliated Hospital of Harbin Medical University, Haping Road 150 of Nangang District, Harbin, Heilongjiang Province 150081, China.
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Liu
authors.affiliation: 1. Department of Internal Medicine, The Third Affiliated Hospital of Harbin Medical University, Haping Road 150 of Nangang District, Harbin, Heilongjiang Province 150081, China.
authors.forename: WenJie
authors.initials: W
authors.lastname: Ma
authors.affiliation: 1. Department of Internal Medicine, The Third Affiliated Hospital of Harbin Medical University, Haping Road 150 of Nangang District, Harbin, Heilongjiang Province 150081, China.
authors.forename: Qingyuan
authors.initials: Q
authors.lastname: Zhang
keywords: Bone Marrow Infiltration; CD9; Follicular Lymphoma; PI3KCD; Prognosis