Reduced Basal Nitric Oxide Production Induces Precancerous Mammary Lesions via ERBB2 and TGFβ

Sci Rep. 2019 Apr 30;9(1):6688. doi: 10.1038/s41598-019-43239-x.


One third of newly diagnosed breast cancers in the US are early-stage lesions. The etiological understanding and treatment of these lesions have become major clinical challenges. Because breast cancer risk factors are often linked to aberrant nitric oxide (NO) production, we hypothesized that abnormal NO levels might contribute to the formation of early-stage breast lesions. We recently reported that the basal level of NO in the normal breast epithelia plays crucial roles in tissue homeostasis, whereas its reduction contributes to the malignant phenotype of cancer cells. Here, we show that the basal level of NO in breast cells plummets during cancer progression due to reduction of the NO synthase cofactor, BH4, under oxidative stress. Importantly, pharmacological deprivation of NO in prepubertal to pubertal animals stiffens the extracellular matrix and induces precancerous lesions in the mammary tissues. These lesions overexpress a fibrogenic cytokine, TGFβ, and an oncogene, ERBB2, accompanied by the occurrence of senescence and stem cell-like phenotype. Consistently, normalization of NO levels in precancerous and cancerous breast cells downmodulates TGFβ and ERBB2 and ameliorates their proliferative phenotype. This study sheds new light on the etiological basis of precancerous breast lesions and their potential prevention by manipulating the basal NO level.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers
  • Breast / metabolism
  • Breast / pathology
  • Breast Neoplasms / diagnostic imaging
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism*
  • Breast Neoplasms / pathology
  • Disease Susceptibility
  • Epithelial Cells / metabolism
  • Epithelial Cells / pathology
  • Female
  • Gene Expression
  • Humans
  • Mice
  • Neoplastic Stem Cells / metabolism
  • Neoplastic Stem Cells / pathology
  • Nitric Oxide / biosynthesis*
  • Nitric Oxide Synthase Type I / metabolism
  • Nitric Oxide Synthase Type II / metabolism
  • Nitric Oxide Synthase Type III / metabolism
  • Oxidative Stress
  • Precancerous Conditions / genetics*
  • Precancerous Conditions / metabolism*
  • Precancerous Conditions / pathology
  • Receptor, ErbB-2 / genetics*
  • Receptor, ErbB-2 / metabolism
  • Transforming Growth Factor beta / genetics*
  • Transforming Growth Factor beta / metabolism


  • Biomarkers
  • Transforming Growth Factor beta
  • Nitric Oxide
  • NOS2 protein, human
  • NOS3 protein, human
  • Nitric Oxide Synthase Type I
  • Nitric Oxide Synthase Type II
  • Nitric Oxide Synthase Type III
  • ERBB2 protein, human
  • Receptor, ErbB-2