title: Association between low expression levels of interleukin-9 and colon cancer progression.
abstract: Although interleukin (IL)-9 has been extensively studied in inflammation and autoimmune diseases, the expression level of IL-9 in colon cancer and its clinical significance are less well established. In total, 15 healthy donors (HDs) and 60 patients who had been diagnosed with colon cancer that had undergone a surgical resection were enrolled in the study. The plasma levels of IL-9 in the HDs and cancer patients were detected by the liquid chip technique, while the expression levels of IL-9 in the colon cancer tissues and normal tissues were analyzed using immunohistochemistry (IHC) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Finally, the difference in the expression levels of IL-9 between the patients classified as tumor-node-metastasis stage I-II and stage III-IV was compared. The results demonstrated that the plasma levels of IL-9 in the patients with colon cancer were significantly lower when compared with the HDs (1.29 vs. 2.53 pg/ml, P<0.05). Furthermore, according to the IHC and RT-qPCR results, low expression levels of IL-9 were observed in the colon cancer tissues when compared with the normal tissues (P<0.05). With regard to the plasma and tumor tissue samples, patients diagnosed with stage III-IV colon cancer expressed lower levels of IL-9 compared with the stage I-II patients (P<0.05). In conclusion, low expression levels of IL-9 were observed in the tissue and plasma samples collected from the colon cancer patients, and the decreased expression of IL-9 was shown to correlate with colon cancer progression.
authors.affiliation: Department of Gastroenterological Surgery, Cancer Center of Guangzhou Medical University, Guangzhou, Guangdong 510095, P.R. China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Colorectal and Anal Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Colorectal and Anal Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
authors.forename: Sen
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Colorectal and Anal Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
keywords: colon cancer; interleukin-9; tumor-node-metastasis stage