title: Plasma mRNA expression levels of BRCA1 and TS as potential predictive biomarkers for chemotherapy in gastric cancer.
abstract: OBJECTIVE
  Personalized chemotherapy based on predictive biomarkers can maximize efficacy. However, tumor tissue obtained at the time of initial diagnosis will not reflect genetic alterations observed at the time of disease progression. We have examined whether plasma mRNA levels can be a surrogate for tumor levels in predicting chemosensitivity.
  
  
  METHODS
  In 150 gastric cancer patients, mRNA levels of BRCA1 and TS were assessed in plasma and paired tumor tissue. The Mann-Whitney U-test was used to compare mRNA expression levels between tumor samples exhibiting in vitro sensitivity or resistance to docetaxel and pemetrexed. All statistical tests were two-sided.
  
  
  RESULTS
  There were significant correlations between plasma and tumor mRNA levels of BRCA1 (rho = 0.696, P < 0.001) and TS (rho = 0.620, P < 0.001). BRCA1 levels in plasma (docetaxel-sensitive: 1.25; docetaxel-resistant: 0.50, P < 0.001) and tumor (docetaxel-sensitive: 8.81; docetaxel-resistant: 4.88, P < 0.001) were positively associated with docetaxel sensitivity. TS levels in plasma (pemetrexed-sensitive: 0.90; pemetrexed-resistant: 1.82, P < 0.001) and tumor (pemetrexed-sensitive: 6.56; pemetrexed-resistant: 16.69, P < 0.001) were negatively associated with pemetrexed sensitivity.
  
  
  CONCLUSIONS
  Plasma mRNA expression levels mirror those in the tumor and may have a promising role as potential predictive biomarkers for chemotherapy.
authors.affiliation: The Comprehensive Cancer Centre of Drum Tower Hospital, Medical School of Nanjing University, Clinical Cancer Institute of Nanjing University, 321 Zhongshan Rd, Nanjing, 210008, China. shenjie2008nju@163.com.
authors.forename: Jie
authors.initials: J
authors.lastname: Shen
authors.affiliation: The Comprehensive Cancer Centre of Drum Tower Hospital, Medical School of Nanjing University, Clinical Cancer Institute of Nanjing University, 321 Zhongshan Rd, Nanjing, 210008, China. weijianju2008@163.com.
authors.forename: Jia
authors.initials: J
authors.lastname: Wei
authors.affiliation: Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China. guanwenxiannj@163.com.
authors.forename: Wenxian
authors.initials: W
authors.lastname: Guan
authors.affiliation: Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China. haonju@163.com.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China. dingyitaonju@163.com.
authors.forename: Yitao
authors.initials: Y
authors.lastname: Ding
authors.affiliation: The Comprehensive Cancer Centre of Drum Tower Hospital, Medical School of Nanjing University, Clinical Cancer Institute of Nanjing University, 321 Zhongshan Rd, Nanjing, 210008, China. qianxiaopingnju@163.com.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Qian
authors.affiliation: The Comprehensive Cancer Centre of Drum Tower Hospital, Medical School of Nanjing University, Clinical Cancer Institute of Nanjing University, 321 Zhongshan Rd, Nanjing, 210008, China. yulixianj@163.com.
authors.forename: Lixia
authors.initials: L
authors.lastname: Yu
authors.affiliation: The Comprehensive Cancer Centre of Drum Tower Hospital, Medical School of Nanjing University, Clinical Cancer Institute of Nanjing University, 321 Zhongshan Rd, Nanjing, 210008, China. zouzhengyunnju@163.com.
authors.forename: Zhengyun
authors.initials: Z
authors.lastname: Zou
authors.affiliation: The Comprehensive Cancer Centre of Drum Tower Hospital, Medical School of Nanjing University, Clinical Cancer Institute of Nanjing University, 321 Zhongshan Rd, Nanjing, 210008, China. lixiudihz@163.com.
authors.forename: Li
authors.initials: L
authors.lastname: Xie
authors.affiliation: Pangaea Biotech, Dexeus University Institute, Barcelona, Spain. carlotacosta@163.com.
authors.forename: Carlota
authors.initials: C
authors.lastname: Costa
authors.affiliation: Department of Medicine, University of California, San Francisco, CA, USA. tbivona@medicine.ucsf.edu.
authors.forename: Trever
authors.initials: T
authors.lastname: Bivona
authors.affiliation: Pangaea Biotech, Dexeus University Institute, Barcelona, Spain. rrosell@iconcologia.net.|Catalan Institute of Oncology, Medical Oncology Service, Hospital Germans Trias i, Pujol, Ctra Canyet s/n, Badalona, 08916, Spain. rrosell@iconcologia.net.
authors.forename: Rafael
authors.initials: R
authors.lastname: Rosell
authors.affiliation: The Comprehensive Cancer Centre of Drum Tower Hospital, Medical School of Nanjing University, Clinical Cancer Institute of Nanjing University, 321 Zhongshan Rd, Nanjing, 210008, China. baoruiliu@nju.edu.cn.
authors.forename: Baorui
authors.initials: B
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000235:genetics*; D015331:Cohort Studies; D005260:Female; D019398:Genes, BRCA1; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012333:RNA, Messenger / Q000097:blood*; D013274:Stomach Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000235:genetics; D013940:Thymidylate Synthase / Q000235:genetics*
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D013940:Thymidylate Synthase