Regulatory T cells and breast cancer: implications for immunopathogenesis

Abstract

Current understanding of the role of several cancer risk factors is more comprehensive, as reported for a number of sites, including the brain, colon, breasts, and ovaries. Despite such advances, the incidence of breast cancer continues to increase worldwide. Signals from the microenviroment have a profound influence on the maintenance or progression cancers. Although T cells present the most important immunological response in tumor growth in the early stages of cancer, they become suppressive CD4(+) and CD8(+) regulatory T cells (Tregs) after chronic stimulation and interactions with tumor cells, thus promoting rather than inhibiting cancer development and progression. Tregs have an important marker protein which is FoxP3, though it does not necessarily confer a Treg phenotype when expressed in CD4(+) T lymphocytes. High Treg levels have been reported in peripheral blood, lymph nodes, and tumor specimens from patients with different types of cancer. The precise mechanisms by which Tregs suppress immune cell functions remain unclear, and there are reports of both direct inhibition through cell-cell contact and indirect inhibition through the secretion of anti-inflammatory mediators such as interleukin. In this review, we present the molecular and immunological aspects of Treg cells in the metastasis of breast cancer.

The correlation of CD19 + CD24 + CD38 + B cells and other clinicopathological variables with the proportion of circulating Tregs in breast cancer patients

“…Although the incidence of breast cancer has increased constantly in developed countries over the past few decades, the mortality caused by breast cancer has decreased in recent years, partly because of improved diagnostic and therapeutic techniques and also better understanding of the pathogenesis of the disease [2]. The prognosis of the disease is strongly associated with tumor stage [3] and could also be predicted by biological characteristics of tumor cells, including expression of hormone receptors (HR) and human epidermal growth factor receptor 2 (HER2) [4].…”

“…In addition, their ability to mediate suppression of cancer's immune response is increasingly recognized [9,10] and studies have found that Tregs play important roles in tumor scape [11]. Elevated proportion of Tregs is present within tumors, lymph nodes and peripheral blood of various types of solid and hematologic cancers including breast cancer [12,13]. Besides, frequency of CD4 ?…”

“…FoxP3 ? cells have been demonstrated to be inversely correlated with the clinical outcomes of breast cancer [13].…”

“…TGF-b1 is secreted by many cells and it is also known as the main cytokine produced by Tregs. Studies have revealed that TGF-b1 implicates in tumor progression including breast cancer [13,15].…”

Negative Association of the HLA-DQB1*02 Allele with Breast Cancer Development among Jordanians

“…Cancer becomes one of the most wide-spreading diseases nowadays (Atoum et al, 2010), breast cancer is the most common female malignancy worldwide, and the second leading cause of cancer mortality among women (Downs-Holmes and Silverman, 2011) accounting for 23% of all cancers (Liang et al, 2008) with more than one million new patients are diagnosed annually (Watanabe et al, 2010). Globally it accounts for 18% of all female cancers (Cantu De Leon et al, 2009).…”