Alterations in Polyamine Metabolism in Patients With Lymphangioleiomyomatosis and Tuberous Sclerosis Complex 2-Deficient Cells

Chest. 2019 Dec;156(6):1137-1148. doi: 10.1016/j.chest.2019.05.038. Epub 2019 Jul 9.


Background: Lymphangioleiomyomatosis (LAM), a destructive lung disease that affects primarily women, is caused by loss-of-function mutations in TSC1 or TSC2, leading to hyperactivation of mechanistic/mammalian target of rapamycin complex 1 (mTORC1). Rapamycin (sirolimus) treatment suppresses mTORC1 but also induces autophagy, which promotes the survival of TSC2-deficient cells. Based on the hypothesis that simultaneous inhibition of mTORC1 and autophagy would limit the availability of critical nutrients and inhibit LAM cells, we conducted a phase 1 clinical trial of sirolimus and hydroxychloroquine for LAM. Here, we report the analyses of plasma metabolomic profiles from the clinical trial.

Methods: We analyzed the plasma metabolome in samples obtained before, during, and after 6 months of treatment with sirolimus and hydroxychloroquine, using univariate statistical models and machine learning approaches. Metabolites and metabolic pathways were validated in TSC2-deficient cells derived from patients with LAM. Single-cell RNA-Seq was employed to assess metabolic enzymes in an early-passage culture from an LAM lung.

Results: Metabolomic profiling revealed changes in polyamine metabolism during treatment, with 5'-methylthioadenosine and arginine among the most highly upregulated metabolites. Similar findings were observed in TSC2-deficient cells derived from patients with LAM. Single-cell transcriptomic profiling of primary LAM cultured cells revealed that mTORC1 inhibition upregulated key enzymes in the polyamine metabolism pathway, including adenosylmethionine decarboxylase 1.

Conclusions: Our data demonstrate that polyamine metabolic pathways are targeted by the combination of rapamycin and hydroxychloroquine, leading to upregulation of 5'-methylthioadenosine and arginine in the plasma of patients with LAM and in TSC2-deficient cells derived from a patient with LAM upon treatment with this drug combination.

Trial registry:; No.: NCT01687179; URL: Partners Human Research Committee, protocol No. 2012P000669.

Keywords: 5′-methylthioadenosine; angiomyolipoma; arginine; autophagy; hydroxychloroquine; lymphangioleiomyomatosis; mechanistic/mammalian target of rapamycin complex 1; metabolomics; polyamines; rapamycin; single-cell transcriptomics; sirolimus; tuberous sclerosis.

Publication types

  • Clinical Trial, Phase I

MeSH terms

  • Antibiotics, Antineoplastic / therapeutic use*
  • Female
  • Humans
  • Lung Neoplasms / blood
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / metabolism*
  • Lymphangioleiomyomatosis / blood
  • Lymphangioleiomyomatosis / drug therapy*
  • Lymphangioleiomyomatosis / metabolism*
  • Polyamines / metabolism*
  • Sirolimus / therapeutic use*
  • Tuberous Sclerosis Complex 2 Protein / deficiency*
  • Tumor Cells, Cultured


  • Antibiotics, Antineoplastic
  • Polyamines
  • TSC2 protein, human
  • Tuberous Sclerosis Complex 2 Protein
  • Sirolimus

Associated data