ORIGINAL ARTICLE Dysregulation of helper T lymphocytes in esophageal squamous cell carcinoma (ESCC) patients is highly associated with aberrant production of miR-21 Hadiseh Samiei 1 & Bizhan Sadighi-Moghaddam 2,3 & Saeed Mohammadi 4,5 & Abdolsamad Gharavi 6,7 & Sara Abdolmaleki 8 & Ayyoob Khosravi 5,9 & Parviz Kokhaei 2,10 & Hadi Bazzazi 9,11 & Ali Memarian 7 # Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Dysregulation of helper T (Th) cell subsets has been contributed to the initiation and propagation of esophageal squamous cell carcinoma (ESCC). Different microRNAs (miRNAs) have been reported to control the development and functions of tumor-associated immune cells in ESCC. Here, we aimed to assess the IL-10, TGF-β, IFN-γ, and IL-17a-producing CD3+CD8- T cells in association whit miR-21, miR-29b, miR-106a, and miR-155 expression in ESCC patients. A total of 34 ESCC patients including 12 newly diagnosed (ND) and 22 under-treatment (UT) cases and also 34 age-matched healthy donors were enrolled. Flow cytometric characterization of stimulated T cells was performed by staining of the cells with fluorescent conjugated specific anti-human CD3 and CD8 cell surface markers as well as IL-17a, IFN-γ, IL-10, and TGF-β intracytoplasmic cytokines. Circulating RNA was extracted from the plasma, and qRT-PCR was used to evaluate the expression of microRNAs. TGF-β plasma levels were also assessed by ELISA. Results showed that the frequency of Th cells was significantly reduced in patients. A significant increase in Treg as well as Th17 cells population in both patient subgroups was observed. ND patients showed elevated level of Th1 cells and IL-10. However the mean expression of IFN-γ was significantly decreased in Th cells. We also detected higher level of miR-21 in the ESCC patients which was significantly correlated with different subsets of Th cells. Our findings revealed that immune response related to the Th cells is highly impaired in ESCC patients. Association between miR-21 and Th subsets could be correlated with the impairment of anti-tumor immunity and ESCC pathogenesis, which could be potentially used as an important target for immunotherapeutic approaches. Keywords Esophageal squamous cell carcinoma (ESCC) . Helper T cells . Immunoregulation . miR-21 . miR-29b * Ali Memarian alimemarian@goums.ac.ir 1 Student Research Committee, Department of Immunology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran 2 Cancer Research Center, Semnan University of Medical Sciences, Semnan, Iran 3 Department of Immunology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran 4 Infectious Diseases Research Center, Golestan University of Medical Sciences, Gorgan, Iran 5 Stem Cell Research center, Golestan University of Medical Sciences, Gorgan, Iran 6 Digestive Oncology Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran 7 Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences, Gorgan, Iran 8 Student Research Committee, Department of Immunology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran 9 Department of Molecular Medicine, School of Advanced Technologies in Medicine, Golestan University of Medical Sciences, Gorgan, Iran 10 Immune and Gene Therapy Laboratory, Cancer Centre Karolinska, Department of Oncology and Pathology, Karolinska Institute, Stockholm, Sweden 11 Department of Medical Laboratory Sciences, Gorgan Branch, Islamic Azad University, Gorgan, Iran Immunologic Research https://doi.org/10.1007/s12026-019-09079-7