AMPK α1 Downregulates ROS Levels Through Regulating Trx Leading to Dysfunction of Apoptosis in Non-Small Cell Lung Cancer

Daohui Gong,^1,* Ying Li,^2,* Yuxiu Wang,^1,* Beiyuan Chi,¹ Jun Zhang,¹ Jianjun Gu,¹ JunJun Yang,¹ Xingxiang Xu,¹ Suwei Hu,³ Lingfeng Min<sup>1

1</sup>Department of Respiratory Medicine, Northern Jiangsu People’s Hospital, Clinical Medical College of Yangzhou University, Yangzhou, Jiangsu, People’s Republic of China; ²Department of Medical Oncology, Northern Jiangsu People’s Hospital, Clinical Medical College of Yangzhou University, Yangzhou, Jiangsu, People’s Republic of China; ³Medical Genetic Center, Yangzhou Maternal and Child Health Care Service Centre, The Affiliated Hospital of Yangzhou University Medical College, Yangzhou, Jiangsu, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Lingfeng Min
Department of Respiratory Medicine, Northern Jiangsu People’s Hospital, Clinical Medical College of Yangzhou University, Nantong West Road 98, Yangzhou, Jiangsu 225001, People’s Republic of China
Tel +86-18051061783
Email minlingfeng@126.com
Suwei Hu
Medical Genetic Center, Yangzhou Maternal and Child Health Care Service Centre, The Affiliated Hospital of Yangzhou University Medical College, Yangzhou, Jiangsu 225002, People’s Republic of China
Tel +86-18912137872
Email husuwei2004@126.com

Purpose: AMP-activated protein kinase α 1 (AMPK α 1) associates closely with cancers. However, the relationship between AMPK α 1 and non-small cell lung cancer (NSCLC) is not fully understood. In this study, we aim to explore the role and mechanism of AMPK α 1 in NSCLC initiation and progression.
Materials and Methods: A total of 165 clinical NSCLC specimens were included in the formalin-fixed and paraffin-embedded (FFPE) lung cancer tissue arrays. The expression levels of AMPK α 1 and thioredoxin (Trx) in NSCLC cancer tissues and adjacent non-tumor lung tissues were measured through using immunohistochemistry. MTT assay was used to detect cell proliferation. Intracellular ROS levels were measured by using H2DCFDA reagent. Lentiviruses including LV-PRKAA1-RNAi, LV-PRKAA1 and a negative LV-control were used to infect A549 cells to modulate AMPK α 1 expression in vitro. Immunoblotting was used to determine the modulation relationship between AMPK α 1 and Trx. Log rank test and Kaplan–Meier survival analysis were performed to evaluate the significances of AMPK α 1 and Trx expression levels on NSCLC patients’ prognoses.
Results: AMPK α 1 was highly expressed in NSCLC cancer tissues and correlated with poor prognosis in patients with NSCLC. In A549 cells, overexpression of AMPK α 1 promoted proliferation, suppressed ROS levels and inhibited apoptosis. Moreover, inhibition of AMPK α 1 expression achieved the opposite effects. Trx was significantly overexpressed in NSCLC cancer tissues; furthermore, Trx expressed much more in cytoplasm when compared with cell nucleus. Trx expression levels were positively correlated with AMPK α 1 expression levels in NSCLC tissues. AMPK α 1 could regulate Trx in A549 cells. No significant correlations were observed between Trx expression variances and prognoses in NSCLC patients. Combination of AMPK α 1 and Trx had no advantage in predicting prognoses of NSCLC patients.
Conclusion: These results suggest that AMPK α 1 serves a carcinogenic role at least in part through the regulation of Trx expression, and thus represents a potential treatment target in patients with NSCLC.

Keywords: AMPK α 1, ROS, apoptosis, non-small cell lung cancer