Paradoxical effects of arsenic in the lungs

Abstract

High levels (> 100 ug/L) of arsenic are known to cause lung cancer; however, whether low (≤ 10 ug/L) and medium (10 to 100 ug/L) doses of arsenic will cause lung cancer or other lung diseases, and whether arsenic has dose-dependent or threshold effects, remains unknown. Summarizing the results of previous studies, we infer that low- and medium-concentration arsenic cause lung diseases in a dose-dependent manner. Arsenic trioxide (ATO) is recognized as a chemotherapeutic drug for acute promyelocytic leukemia (APL), also having a significant effect on lung cancer. The anti-lung cancer mechanisms of ATO include inhibition of proliferation, promotion of apoptosis, anti-angiogenesis, and inhibition of tumor metastasis. In this review, we summarized the role of arsenic in lung disease from both pathogenic and therapeutic perspectives. Understanding the paradoxical effects of arsenic in the lungs may provide some ideas for further research on the occurrence and treatment of lung diseases.

Keywords: Arsenic; Lung; Pathogenic effect; Therapeutic effect.

Fig. 1

Arsenic metabolism pathway in the human body. 1. iAs (III) is methylated by arsenic-3-methyltransferase (AS3MT), using s-adenosylmethionine (SAM) as a methyl donor to form monomethylarsonic acid (MMAsV). 2. MMAV is reduced to monomethyl arsonous form (MMAsIII), which is then methylated by AS3MT to form dimethylarsinic acid (DMAsV)

Fig. 2

The anti-cancer mechanisms of ATO