Growing evidences showed that lncRNAs abnormally expressed in cancer tissues and played irreplaceable roles in tumorigenesis, progression and metastasis. In present study, researchers from Yangzhou University aimed to identify lncRNA expression signature that can predict biochemical recurrence-free (BCR-free) survival of prostate cancer (PCa) patients.
A total of 291 patients with pathologic confirmed PCa in The Cancer Genome Atlas dataset were recruited and included. With the specific risk score formula, patients were further classified into high-risk group and low-risk group. Kaplan-Meier survival analyses and Cox regression analyses were performed to determine the association between lncRNA signature and survival outcomes. Gene Set Enrichment Analysis (GSEA) was carried out to identify the potentially associated biological processes and signaling pathway.
Overall, 126 differentially expressed lncRNAs were found with more than twofold changes and p value of FDR <0.01. Among which, four lncRNAs were identified to be significantly associated with BCR-free survival. Then, using a risk score based on the signature of these four lncRNAs, the researchers divided the patients into low-risk and high-risk groups with significantly different BCR-free survival and disease-free survival. Further multivariate Cox regression analyses revealed that the four-lncRNA signature was independent of age, AJCC T stage, lymphonodus status, Gleason score, margin and adjuvant postoperative radiotherapy. GSEA suggested that this signature was involved in cell proliferation.
Four-lncRNA risk score analysis of the TCGA patients
The distribution of four-lncRNA risk score, BCR status and lncRNA expression signature were analyzed in the entire TCGA patients (n = 291). a Four-lncRNA risk score distribution; b Patients’ BCR status and time. The dotted line in the middle of (a, b) divided the patients into low-risk and high-risk group. In high-risk group, the patients had a higher BCR rate (32/146 vs. 9/145, p < 0.001) and a shorter BCR-free survival time (log rank p = 0.001). c Heatmap of the four-lncRNA expression profiles. As the risk score rising, the expression value of RP11-108P20.4 and RP11-757G1.6 lowered, and the other two lncRNAs ascended. Rows represent lncRNAs in signature, and columns represent patients. d Kaplan–Meier estimates of BCR-free survival of patients with prostate cancer in TCGA dataset using the four-lncRNA signature. BCR biochemical recurrence