Expression of estrogen receptors in non-malignant mammary tissue modifies the association between insulin-like growth factor 1 and breast cancer risk

Associations of circulating insulin-like growth factor-1 and insulin-like growth factor binding protein-3 with the expression of stem cell markers in benign breast tissue

BACKGROUND

The insulin-like growth factor (IGF) pathway is implicated in a naturally occurring process of tissue remodeling during which cells acquire stem cell-like characteristics. We examined associations of circulating IGF-1 and IGF binding protein-3 (IGFBP-3) with expression of CD44, CD24, and ALDH1A1 stem cell markers in benign breast biopsies.

METHODS

This study included 151 cancer-free women with incident biopsy-confirmed benign breast disease and blood samples within the Nurses' Health Study II. The data on reproductive and other BCa risk factors were obtained from biennial questionnaires. Immunohistochemistry (IHC) was done on tissue microarrays. For each core, the IHC expression was assessed using QuPath, and expressed as % of cells that stain positively for a specific marker out of the total cell count. Generalized linear regression was used to examine the associations of plasma IGF-I and IGFBP-3 (continuous log-transformed and quartiles) with log-transformed expression of each marker (in epithelium and stroma), adjusted for BCa risk factors.

RESULTS

In multivariate analysis, continuous circulating IGF-1 and IGFBP-3 measures were not associated with the continuous expression of any of the markers in the epithelium or stroma. Women whose IGFBP-3 levels were in the top quartile appeared to have lower expression of stromal CD24 compared to those in the lowest quartile (β = - 0.38, 95% CI - 0.69, - 0.08, p-trend = 0.06).

CONCLUSIONS

Higher circulating IGFBP-3 levels were associated with lower stromal CD24 expression in benign breast tissue. Our findings provide indirect evidence of the inducing effect of IGF pathway on epithelial-to-mesenchymal transitions and stem cell activity in the breast.

ELF5: A Molecular Clock for Breast Aging and Cancer Susceptibility

Breast cancer is predominantly an age-related disease, with aging serving as the most significant risk factor, compounded by germline mutations in high-risk genes like BRCA1/2. Aging induces architectural changes in breast tissue, particularly affecting luminal epithelial cells by diminishing lineage-specific molecular profiles and adopting myoepithelial-like characteristics. ELF5 is an important transcription factor for both normal breast and breast cancer development. This review focuses on the role of ELF5 in normal breast development, its altered expression throughout aging, and its implications in cancer. It discusses the lineage-specific expression of ELF5, its regulatory mechanisms, and its potential as a biomarker for breast-specific biological age and cancer risk.

The Role of Cow's Milk Consumption in Breast Cancer Initiation and Progression

PURPOSE OF REVIEW

This review evaluates cow milk's impact on breast carcinogenesis by linking recent epidemiological evidence and new insights into the molecular signaling of milk and its constituents in breast cancer (BCa) pathogenesis.

RECENT FINDINGS

Recent prospective cohort studies support the association between cow's milk consumption and the risk of estrogen receptor-α-positive (ER+) BCa. Milk is a complex biological fluid that increases systemic insulin-like growth factor 1 (IGF-1), insulin and estrogen signaling, and interacting hormonal promoters of BCa. Further potential oncogenic components of commercial milk include exosomal microRNAs (miR-148a-3p, miR-21-5p), bovine meat and milk factors, aflatoxin M1, bisphenol A, pesticides, and micro- and nanoplastics. Individuals with BRCA1 loss-of-function mutations and FTO and IGF1 gain-of-function polymorphisms enhancing IGF-1/mTORC1 signaling may be at increased risk for milk-induced ER+ BCa. Recent prospective epidemiological and pathobiochemical studies identify commercial milk consumption as a critical risk factor of ER+ BCa. Large meta-analyses gathering individuals of different ethnic origins with milk derived from dairy cows of varying genetic backgrounds and diverse feeding procedures as well as missing data on thermal processing of milk (pasteurization versus ultra-heat treatment) make multi-national meta-analyses unsuitable for BCa risk estimations in susceptible populations. Future studies are required that consider all vulnerable periods of breast carcinogenesis to cow's milk exposure, beginning during the perinatal period and puberty, since these are the most critical periods of mammary gland morphogenesis. Notwithstanding the need for better studies including detailed information on milk processing and vulnerable periods of human breast carcinogenesis, the available evidence suggests that dietary guidelines on milk consumption may have to be reconsidered.

Lifetime Impact of Cow's Milk on Overactivation of mTORC1: From Fetal to Childhood Overgrowth, Acne, Diabetes, Cancers, and Neurodegeneration

The consumption of cow's milk is a part of the basic nutritional habits of Western industrialized countries. Recent epidemiological studies associate the intake of cow's milk with an increased risk of diseases, which are associated with overactivated mechanistic target of rapamycin complex 1 (mTORC1) signaling. This review presents current epidemiological and translational evidence linking milk consumption to the regulation of mTORC1, the master-switch for eukaryotic cell growth. Epidemiological studies confirm a correlation between cow's milk consumption and birthweight, body mass index, onset of menarche, linear growth during childhood, acne vulgaris, type 2 diabetes mellitus, prostate cancer, breast cancer, hepatocellular carcinoma, diffuse large B-cell lymphoma, neurodegenerative diseases, and all-cause mortality. Thus, long-term persistent consumption of cow's milk increases the risk of mTORC1-driven diseases of civilization. Milk is a highly conserved, lactation genome-controlled signaling system that functions as a maternal-neonatal relay for optimized species-specific activation of mTORC1, the nexus for regulation of eukaryotic cell growth, and control of autophagy. A deeper understanding of milk´s impact on mTORC1 signaling is of critical importance for the prevention of common diseases of civilization.

Role of inflammation in obesity-related breast cancer

Chronic inflammation associated with obesity is now recognized to be an important condition in promoting carcinogenesis and progression in breast cancer patients, mostly in postmenopausal women with tumors expressing estrogen and progesterone receptors. In obese patients, altered levels of several inflammatory mediators regulating aromatase and estrogen expression are one of the mechanisms responsible of increase breast cancer risk. Growing attention has also been paid to the local adipose inflammation and the role played by macrophages as determinants of breast cancer risk recurrence and prognosis. The inflammation-obesity axis offers different molecular signaling pathways for therapeutic interventions and potential pharmacological targets. The increasing rate of obesity worldwide associated with the recent findings linking inflammation and breast cancer urge further investigation.

A preliminary study of pamidronic acid downregulation of angiogenic factors IGF-1/PECAM-1 expression in circulating level in bone metastatic breast cancer patients

Objective

To evaluate the expressions of circulating angiogenic factors affected by pamidronic acid (PA) intravenous infusion in bone metastatic breast cancer patients and the impact on their prognosis.

Methods

Peripheral blood of ten bone metastatic breast cancer patients was collected for serum insulin-like growth factor-1 (IGF-1) and platelet endothelial cell adhesion molecule-1 expression detection just before and 2 days after PA infusion.

Results

Both IGF-1 and platelet endothelial cell adhesion molecule-1 concentrations decreased after PA treatment for 48 hours (P<0.05). Modification was defined as >20% decrease recorded 2 days after PA administration. The decrease of IGF-1 was more significant in breast cancer patients who had received previous hormonotherapy. Moreover, the progression-free survival of first-line chemotherapy treatment of IGF-1 modified patients was longer than that of IGF-1 unmodified patients (P=0.009).

Conclusion

PA treatment could suppress circulating serum IGF-1 and platelet endothelial cell adhesion molecule-1 concentrations; moreover, the prognosis of patients in IGF-1 unmodified group was relatively poor.