Tianjin Medical Journal ›› 2021, Vol. 49 ›› Issue (2): 113-118.doi: 10.11958/20200999

• Cell and Molecular Biology •     Next Articles

Expression and biological function of NNMT in stroma of lung adenocarcinoma #br#

JU Wei-wei, YU Sheng-jin, LIN Li-juan, SHAO Zhi-xiang, ZHANG Qi-fang, JIANG Li-li   

  1. 1 Laboratory of Molecular Medicine, School of Medicine, Liaodong University, Dandong 118003, China;
    2 Department of Pathology, Dandong First Hospital

  • Received:2020-04-14 Revised:2020-10-22 Published:2021-02-15 Online:2021-02-02

Abstract:

Objective To investigate the expression level of nicotinamide N-methyltransferase (NNMT) in the stroma
of lung cancer, and the influence of overexpressed NNMT on the biological function of lung adenocarcinoma cells.
Methods(1) Tissue specimens were collected from 150 patients with lung adenocarcinoma. Immunohistochemical staining
was used to detect the NNMT expression level in cancer tissues and stromal cells, and the relationship between NNMT
expression and the clinicopathological characteristics and prognosis of the patients were analyzed. (2) A lung fibroblast cell
line HFL-1 with stable NNMT expression was constructed by the transfection of overexpressed NNMT plasmid (NNMT
group) and control plasmid (control group) respectively. The expression levels of NNMT were detected by real-time
fluorescence quantitative PCR (qPCR), immunofluorescence and Western blot assay. (3) The culture supernatant of the overexpressed NNMT and the control group of HFL-1 cells were collected and co-cultured with lung adenocarcinoma A549 and
PC9 cells, respectively. Then, the effects of the two kind of culture supernatant on the proliferation, clonal formation and
migration of A549 and PC9 cells were compared through cell proliferation experiment, plate clonal formation experiment,
scratch healing experiment and Transwell migration experiment.
Results(1) Immunohistochemical staining showed that
NNMT was highly expressed in 65 cancer cell samples and 83 mesenchymal cell samples of 150 patients. The NNMT
expression was higher in patients with lymph node metastasis and pathological stage Ⅲ-Ⅳ. The overall survival rate was
significantly lower in patients with high expression of NNMT in tumor stroma than those with low expression of NNMT. (2)
HFL-1 cells with stable overexpression of NNMT were successfully constructed. Western blot assay, qPCR and cell
immunofluorescence staining indicated that the NNMT expression was higher in the NNMT group than that in the control
group. (3) Cell co-culture results showed that compared with the control group, the culture medium of lung fibroblast cell
line expressing NNMT could significantly promote the proliferation, clone formation and migration of A549 and PC9 cells.
ConclusionNNMT is closely related to the malignant progression of lung adenocarcinoma, which may be a potential target
for tumor-targeted biological therapy.


Key words: lung neoplasms, adenocarcinoma, nicotinamide N-methyltransferase, prognosis, stromal cells, A549 cells,
cell line, tumor,
neoplasm invasiveness, cell movement

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