Linc-RoR promotes MAPK/ERK signaling and confers estrogen-independent growth of breast cancer

Background

The conversion from estrogen-dependent to estrogen-independent state of ER+ breast cancer cells is the key step to promote resistance to endocrine therapies. Although the crucial role of MAPK/ERK signaling pathway in estrogen-independent breast cancer cell growth is well established, the underlying mechanism is not fully understood.

Methods

In this study, we profiled lncRNA expression against a focused group of lncRNAs selected from lncRNA database. CRISPR/Cas9 was employed to knockout (KO) linc-RoR in MCF-7 cells, while rescue experiments were carried out to re-express linc-RoR in KO cells. Colony formation and MTT assays were used to examine the role of linc-RoR in estrogen-independent growth and tamoxifen resistance. Western blot and qRT-PCR were used to determine the change of protein and lncRNA levels, respectively. The expression of DUSP7 in clinical specimens was downloaded from Oncomine (www.oncomine.org) and the dataset from Kaplan-Meier Plotter (http://kmplot.com) was used to analyze the clinical outcomes in relation to DUSP7.

Results

We identified that linc-RoR functions as an onco-lncRNA to promote estrogen-independent growth of ER+ breast cancer. Under estrogen deprivation, linc-RoR causes the upregulation of phosphorylated MAPK/ERK pathway which in turn activates ER signaling. Knockout of linc-RoR abrogates estrogen deprivation-induced ERK activation as well as ER phosphorylation, whereas re-expression of linc-RoR restores all above phenotypes. Moreover, we show that the ERK-specific phosphatase Dual Specificity Phosphatase 7 (DUSP7), also known as MKP-X, is involved in linc-RoR KO-induced repression of MAPK/ERK signaling. Interestingly, linc-RoR KO increases the protein stability of DUSP7, resulting in repression of ERK phosphorylation. Clinical data analysis reveal that DUSP7 expression is lower in ER+ breast cancer samples than that in ER- breast cancer. Moreover, downregulation of DUSP7 expression is associated with poor patient survival.

Conclusion

Taken together, these results suggest that linc-RoR promotes estrogen-independent growth and activation of MAPK/ERK pathway of breast cancer cells by regulating the ERK-specific phosphatase DUSP7. Thus, this study might help not only in establishing a role for linc-RoR in estrogen-independent and tamoxifen resistance of ER+ breast cancer, but also suggesting a link between linc-RoR and MAPK/ERK pathway.

     

Every exercise bout matters: linking systemic exercise responses to breast cancer control

Purpose

Aryl hydrocarbon receptor (AhR) inhibits estrogen receptor (ER) pathway, which may suppress estrogen-dependent cell proliferation. However, the correlation between AhR stimulation and intratumoral estrogen synthesis, especially through aromatase, has not been reported to date. In the present study, we examined this correlation in breast cancer cells.

Methods

We examined AhR and aromatase immunoreactivity in 29 patients with invasive ductal carcinoma. We performed in vitro studies using three breast carcinoma cell lines, MCF-7, T47D, and MDA-MB-231.

Results

AhR stimulation induced the mRNA expression of the aromatase gene in vitro in three breast carcinoma cell lines, and increased estrogen synthesis in MCF-7 cell line. Results of microarray analysis showed that AhR-induced aromatase expression was associated with BRCA1 induction. Analysis of patients with breast cancer showed a significant positive correlation between intratumoral AhR and aromatase status. We also compared the effects of AhR stimulation on the induction of intratumoral estrogen synthesis and inhibition of the ER signaling pathway, because AhR exerts contradictory effects on estrogen action in breast carcinoma cells. AhR-induced aromatase expression persisted for a significantly longer duration than AhR-induced ER pathway inhibition. Moreover, breast carcinoma cells treated with an AhR agonist tended to show earlier cell proliferation after removing the agonist than cells not treated with the AhR agonist.

Conclusion

The results of the present study suggest that AhR stimulates estrogen-dependent progression of breast carcinoma by inducing aromatase expression under some conditions. These results provide new insights on the possible roles of environmental toxins in breast cancer development.

     

New Insights in Estrogen Receptor (ER) Biology and Implications for Treatment

Purpose of Review

Estrogen receptor-positive (ER+) breast cancer represents the majority of breast cancer diagnoses and is the leading cause of cancer death in women. Endocrine therapy is the principal treatment strategy for ER+ breast cancer. However, resistance to endocrine therapy, either de novo or acquired, is commonly observed, resulting in disease relapse and progression. This review will focus on recent progress in our understanding of ER biology and the implications for treatments.

Recent Findings

Advances in genomic technology and laboratory investigations have led to the identification of somatic mutations, including treatment-emergent ESR1 mutations, and aberrant activation of growth factor receptor signaling pathways and cell cycle machinery that are associated with estrogen-independent proliferation and resistance to endocrine therapy. A plethora of molecularly targeted agents are being developed to overcome these resistance mechanisms, among which inhibitors against the mammalian target of rapamycin (mTOR) and cyclin-dependent kinases (CDK) 4/6 are now in clinical use.

Summary

Advances in our understanding of ER biology have impacted the treatment landscape of ER+ breast cancer. Ongoing biomarker research on tumor specimens and cell-free tumor DNA will continue to generate important biological insight toward improving individualized treatment strategies for patients with ER+ breast cancer.

     

Amphiregulin regulates proliferation and migration of HER2-positive breast cancer cells

Purpose

Tumor initiation and progression rely on cellular proliferation and migration. Many factors are involved in these processes, including growth factors. Amphiregulin (AREG) is involved in normal mammary development and the development of estrogen receptor (ER)-positive breast cancer. The aim of this project was to determine if AREG is involved in the proliferation and progression of HER2-positive breast cancer.

Methods

Mouse cell lines MMTV-neu, HC-11 and COMMA-D, as well as human cell lines MCF10A, SKBR3, HCC1954 and BT474 were used. Real-time PCR was used to quantify AREG expression and neutralizing antibodies were used to reduce the autocrine/paracrine effects of AREG. Transfections using siRNA and shRNA were used to knockdown AREG expression in the cancer cell lines. Free-floating sphere formation, colony forming, scratch wound and Transwell assays were used to assess the proliferation, tumor forming and migratory capacities of transfected cancer cells.

Results

We found AREG expression in both normal epithelial cell lines and tumor-derived cell lines. Knockdown of AREG protein expression resulted in reduced sphere sizes and reduced sphere numbers in both mouse and human cancer cells that overexpress erbB2/HER2. AREG was found to be involved in cancer cell migration and invasion. In addition, we found that AREG expression knockdown resulted in different migration capacities in normal and erbB2/HER2 overexpressing cancer cells.

Conclusions

Based on our results we conclude that AREG is involved in regulating the proliferation and migration of erbB2/HER2-positive breast cancer cells.

     

Raptor localization predicts prognosis and tamoxifen response in estrogen receptor-positive breast cancer

Purpose

Deregulated PI3K/mTOR signals can promote the growth of breast cancer and contribute to endocrine treatment resistance. This report aims to investigate raptor and its intracellular localization to further understand its role in ER-positive breast cancer.

Methods

Raptor protein expression was evaluated by immunohistochemistry in 756 primary breast tumors from postmenopausal patients randomized to tamoxifen or no tamoxifen. In vitro, the MCF7 breast cancer cell line and tamoxifen-resistant MCF7 cells were studied to track the raptor signaling changes upon resistance, and raptor localization in ERα-positive cell lines was compared with that in ERα-negative cell lines.

Results

Raptor protein expression in the nucleus was high in ER/PgR-positive and HER2-negative tumors with low grade, features associated with the luminal A subtype. Presence of raptor in the nucleus was connected with ERα signaling, here shown by a coupled increase of ERα phosphorylation at S167 and S305 with accumulation of nuclear raptor. In addition, the expression of ERα-activated gene products correlated with nuclear raptor. Similarly, in vitro we observed raptor in the nucleus of ERα-positive, but not of ER-negative cells. Interestingly, raptor localized to the nucleus could still be seen in tamoxifen-resistant MCF7 cells. The clinical benefit from tamoxifen was inversely associated with an increase of nuclear raptor. High cytoplasmic raptor expression indicated worse prognosis on long-term follow-up.

Conclusion

We present a connection between raptor localization to the nucleus and ERα-positive breast cancer, suggesting raptor as a player in stimulating the growth of the luminal A subtype and a possible target along with endocrine treatment.

     

Tree nut,peanut, and peanut butter intake and risk of postmenopausal breast cancer: The Netherlands Cohort Study

Purpose

Nut intake has been associated with reduced mortality and risk of cardiovascular diseases, but there is only limited evidence on cancer. We investigated the relationship between nut intake and risk of postmenopausal breast cancer, and estrogen/progesterone receptor (ER/PR) subtypes.

Methods

In The Netherlands Cohort Study, 62,573 women aged 55–69 years provided information on dietary and lifestyle habits in 1986. After 20.3 years of follow-up, 2,321 incident breast cancer cases and 1,665 subcohort members were eligible for multivariate case-cohort analyses.

Results

Total nut intake was significantly inversely related to ER negative (ER??) breast cancer risk, with HR 0.55 (95% CI 0.33–0.93) for those consuming at least 10 g nuts/day versus non-consumers (p trend?=?0.025). There were no significant inverse associations with ER?+?or total breast cancer. While there was no variation between PR subtypes, the ER–PR- subtype was also significantly inversely associated with nut intake, with HR 0.53 (95% CI 0.29–0.99), p trend?=?0.037. Intake of peanuts and tree nuts separately was also inversely related to ER?? breast cancer subtypes, while no associations were found with peanut butter intake.

Conclusions

Our findings suggest an inverse association between nut intake and ER?? breast cancer, and no association with total or hormone receptor-positive subtypes.

     

Non-hormonal Chemoprevention

Purpose of review

Potential strategies for prevention of breast cancer include lifestyle modification, preventive therapies (i.e., chemoprevention), and surgical prevention. Several therapies (such as selective estrogen response modifiers and aromatase inhibitors) have been shown to prevent breast cancer. However, tolerability and toxicity limit use and these therapies only prevent estrogen receptor–positive (ER) disease. There is emerging data regarding prevention properties of several non-hormonal agents. These agents generally have lower toxicities and seem to be effective for reduction of both ER+ and ER? disease and are often approved for use in other diseases. The purpose of this review is to discuss the data supporting the potential role of these non-hormonal agents for breast cancer prevention.

Recent findings

Several studies have demonstrated the potential of aspirin, vitamin D, metformin, and bisphosphonates to prevent breast cancer.

Summary

The outlined studies support biological mechanisms and show epidemiologic associations but randomized controlled trials are necessary before any of these agents can be recommended for breast cancer prevention. Given the wide spread use of these agents, significant consideration to trial design is needed (i.e., focus on high-risk populations and use of biomarker endpoints). Another important consideration may be the investigation of combinations of agents as suggested by others.

     

Estrogen receptor quantitative measures and breast cancer survival

Purpose

While the estrogen receptor (ER) is the single most widely used biomarker to evaluate breast cancer outcomes, aspects of ER marker biology remain poorly understood. We sought to determine whether quantitative measures of ER, such as protein expression and intensity, were associated with survival, or with survival disparities experienced by Hispanic women.

Methods

A case-cohort study included a 15% random sample of invasive breast cancer cases diagnosed from 1997 to 2009 in six New Mexico counties and all deaths due to breast cancer-related causes. Pathology reports and tissue microarrays served as sources of ER information. Analyses were restricted to women with ≥1% ER immunohistochemical staining. Hazard ratios (HR) and 95% confidence intervals (CI) for breast cancer death were estimated using Cox proportional hazards models.

Results

Included women represented 4336 ER+ breast cancer cases and 448 deaths. Median follow-up was 93 months. ER percent expression was not associated with breast cancer survival after adjustment for standard prognostic factors (p trend = 0.76). ER intensity remained a strong and independent risk factor for breast cancer survival in multivariate analyses: Women whose tumors expressed ER at intensity = 2 (HR 0.6; 95% CI 0.4–1.0) or 3 (HR 0.5; 95% CI 0.2–0.9) had a reduced risk of breast cancer mortality, compared to ER intensity = 1 (p trend = 0.02). Neither ER protein expression nor intensity influenced Hispanic survival disparities.

Conclusions

Estrogen receptor percent positive staining is not independently related to breast cancer survival after adjustment for other survival-related factors. ER intensity, in contrast, demonstrates promise for prognostic utility.

     

Quantitative determination,by real-time reverse transcription polymerase chain reaction,of aromatase mRNA in invasive ductal carcinoma of the breast

Background

Estrogen is a mitogenic factor that is implicated in the genesis and progression of breast cancer via its binding to estrogen receptor (ER)-α. Synthesis of estrogen in situ is believed to be catalyzed mainly by aromatase. Previous studies comparing the relative contributions from tumor cells and stromal cells to local estrogen synthesis, as assessed by immunohistochemical analysis, were quite controversial and no consistent relationship was found between the presence of aromatase and any clinicopathologic factor. In addition, previous studies into aromatase gene expression and clinicopathologic factors are limited.

Methods

We assessed the level of expression of aromatase mRNA, using quantitative real-time RT-PCR, in 162 cases of invasive ductal carcinoma of the breast. Associations between aromatase expression and different clinicopathologic factors were sought.

Results

It was found that aromatase mRNA was expressed at significantly higher levels in patients older than 50 years, in those without axillary lymph node involvement, in those with tumor size less than 2 cm, and in ER-α positive tumors. However, no relationship was found between aromatase mRNA expression and any other clinicopathologic factor, including histologic grade and progesterone receptor status. Patients with high levels of expression of aromatase mRNA tended to have a better prognosis than did those patients with low expression.

Conclusion

These findings imply that ER-α and aromatase may be coexpressed in endocrine responsive patients. They may also indicate that aromatase expression could be a marker of endocrine responsiveness, and it may have prognostic implications for breast cancer progression.

     

Androgen receptor expression and breast cancer mortality in a population-based prospective cohort

Purpose

The increase in clinical trials with androgen receptor (AR)-targeting drugs emphasizes the need of clarifying the role of AR expression in different breast cancer subtypes. AR confers good prognosis in estrogen receptor positive (ER+) breast cancer, but its role in ER-negative (ER?) breast cancer is unclear. The aim of this study was to elaborate on previous findings of a differential prognostic role for AR depending on ER status, using breast cancer mortality (BCM) as endpoint, in a population-based cohort from the Malmö Diet and Cancer Study.

Methods

Immunohistochemical AR expression was assessed in 910 women with invasive breast cancer diagnosed 1991–2010, supplemented with clinicopathological information, vital status, and cause of death, with the last follow-up in December 2014 (median 10 years). Survival analyses according to AR status and AR/ER combinations were performed.

Results

AR expression was available for 671 tumors. AR+ (n = 573, 85%) was associated with favorable established tumor markers and lower BCM in univariable analysis, especially during the first 5 years following diagnosis [HR 0.4; 95% confidence intervals (CI) 0.2–0.7]. Multivariable analysis for short-term follow-up indicated higher BCM among patients with AR+ER? tumors (HR 3.5; 95% CI 1.4–9.1) than other AR and ER combinations.

Conclusions

AR expression added prognostic information to ER expression with respect to short-term prognosis. The worst prognosis was seen for patients with AR+/ER? tumors in short-term follow-up, supporting the pre-specified hypothesis. However, larger cohorts are needed for further characterization of the role of AR expression in ER? breast cancer.

     

Antitumor and anticancer stem cell activities of eribulin mesylate and antiestrogens in breast cancer cells

Background

Eribulin mesylate (eribulin), a non-taxane microtubule dynamic inhibitor, has been widely used in the treatment of patients with advanced or metastatic breast cancer. The combined antitumor and anticancer stem cell (CSC) activities of eribulin with endocrine therapeutic agents have not yet been examined in breast cancer cells. We herein investigated the combined effects of eribulin and antiestrogens.

Methods

A panel of eight breast cancer cell lines, including five estrogen receptor (ER)-positive and three ER-negative cell lines, was used. These cells were treated with eribulin and/or the antiestrogen, 4-hydroxytamoxifen or fulvestrant. Their growth inhibitory activities and effects on cell cycle progression, apoptosis, and the CSC population were investigated. CSCs were detected using the CD44/CD24/EpCAM, Aldefluor, and mammosphere assays.

Results

The 50 % growth inhibitory concentrations of eribulin were 0.38–2.64 nM for the eight cell lines tested. Eribulin exhibited significant antitumor activity under estrogen-supplemented conditions in ER-positive breast cancer cells. The combined antitumor activity of eribulin with an antiestrogen was evaluated using the combination index. The combination index was 0.43–1.46 for ER-positive cell lines. The additive antitumor effect of eribulin with 4-OHT was only significant in MCF-7 cells. Eribulin induced the accumulation of G2/M and apoptosis, while antiestrogens induced the retardation of G1–S cell cycle and apoptosis, respectively. Estrogen markedly increased the proportion of CSCs, whereas antiestrogens inhibited increases in ER-positive cell lines. Moreover, eribulin decreased the proportion of CSCs in either ER-positive or ER-negative cell lines. The combined treatment of eribulin with an antiestrogen did not additively decrease the proportion of CSCs in ER-positive cell lines.

Discussion

The results of the present study demonstrated that eribulin had potent antitumor effects on estrogen-stimulated ER-positive breast cancer cells and the combined treatment of eribulin with an antiestrogen resulted in a weakly additive antitumor effect. We herein suggested for the first time that eribulin exhibited anti-CSC effects on either ER-positive or ER-negative breast cancer cells.

     

Co-targeting the HER and IGF/insulin receptor axis in breast cancer,with triple targeting with endocrine therapy for hormone-sensitive disease

Purpose

Interactions between HER2, estrogen receptor (ER), and insulin-like growth factor I receptor (IGF1R) are implicated in resistance to monotherapies targeting these receptors. We have previously shown in pre-clinical studies synergistic anti-tumor effects for co-targeting each pairwise combination of HER2, IGF1R, and ER. Strikingly, synergy for HER2/IGF1R targeting occurred not only in a HER2+ model, but also in a HER2-normal model. The purpose of the current study was therefore to determine the generalizability of synergistic anti-tumor effects of co-targeting HER2/IGF1R, the anti-tumor activity of triple-targeting HER2/IGF1R/ER in hormone-dependent cell lines, and the effect of using the multi-targeting drugs neratinib (pan-HER) and BMS-754807 (dual IGF1R/insulin receptor).

Methods

Proliferation and apoptosis assays were performed in a large panel of cell lines representing varying receptor expression levels. Mechanistic effects were studied using phospho-protein immunoblotting. Analyses of drug interaction effects were performed using linear mixed-effects regression models.

Results

Enhanced anti-proliferative effects of HER/IGF-insulin co-targeting were seen in most, though not all, cell lines, including HER2-normal lines. For ER+ lines, triple targeting with inclusion of anti-estrogen generally resulted in the greatest anti-tumor effects. Double or triple targeting generally resulted in marked increases in apoptosis in the sensitive lines. Mechanistic studies demonstrated that the synergy between drugs was correlated with maximal inhibition of Akt and ERK pathway signaling.

Conclusions

Dual HER/IGF-insulin targeting, and triple targeting with inclusion of anti-estrogen drugs, shows striking anti-tumor activity across breast cancer types, and drugs with broader receptor specificity may be more effective than single receptor selective drugs, particularly for ER? cells.

     

Diabetes and breast cancer mortality in Black women

Purpose

Breast cancer mortality is higher in Black women than in White women. The prevalence of type 2 diabetes mellitus is also higher, yet data on whether diabetes affects breast cancer mortality in this population are lacking. We investigated the relation of diabetes at the time of breast cancer diagnosis to breast cancer mortality in the Black Women’s Health Study, a prospective cohort study.

Methods

1,621 Black women with invasive breast cancer diagnosed in 1995–2013 were followed by mailed questionnaires and searches of the National Death Index. Multivariable Cox regression analysis was used to compute hazard ratios (HRs) for diabetes in relation to breast cancer mortality and all-cause mortality, with adjustment for age, stage, treatment modality, estrogen receptor (ER) status, and body mass index.

Results

There were 368 deaths during follow-up, of which 273 were due to breast cancer. Breast cancer mortality was significantly increased in women who had been diagnosed with diabetes at least 5 years before breast cancer occurrence, HR 1.86 (95% CI 1.20–2.89), with elevations observed for both ER+ and ER? breast cancer. All-cause mortality was also higher in diabetics, with HRs of 1.54 (95% CI 1.12–2.07) overall and 2.26 (95% CI 1.62–3.15) for ≥5-year duration of diabetes relative to non-diabetics.

Conclusions

Our results present the first solid evidence of a positive association of type 2 diabetes with breast cancer mortality in Black women. Given the higher prevalence and earlier onset of type 2 diabetes in Black women, it is likely that diabetes contributes to racial disparities in breast cancer mortality.

     

UBAP2L silencing inhibits cell proliferation and G2/M phase transition in breast cancer

Background

Ubiquitin-associated protein 2-like (UBAP2L) contains a ubiquitin-associated domain near its N-terminus, which has been demonstrated to be overexpressed in multiple tumors, including hepatocellular carcinoma and colorectal carcinoma but its role has not been well studied in breast cancer. Thus, this study was designed to evaluate whether UBAP2L can serve as a potential molecular target for breast cancer therapy.

Methods

The expression of UBAP2L was determined in breast cancer tissues and cell lines by Western blotting and Oncomine database mining. Then the expression of UBAP2L was silenced using RNA interference and the effects of UBAP2L knockdown on breast cancer cell proliferation and cell cycle progression by MTT and colony formation assay, and Flow cytometry, respectively.

Results

We found the expression of UBAP2L was significantly up-regulated in breast cancer tissues and cell lines. Knockdown of UBAP2L suppressed cell proliferation, impaired colony formation ability and induced cell cycle arrest at G2/M phase. At molecular levels, knockdown of UBAP2L increased p21 expression, but decreased the expression of CDK1 and Cyclin B1 in breast cancer cells.

Conclusion

Our findings suggest that UBAP2L plays an important role in breast cancer cell proliferation and might serve as a potential target for breast cancer treatment.

     

The prolyl oligopeptidase inhibitor SUAM-14746 attenuates the proliferation of human breast cancer cell lines in vitro

Background

Prolyl oligopeptidase (POP, EC 3.4.1.26) is a serine peptidase that hydrolyzes post-proline peptide bonds in peptides that are <30 amino acids in length. We previously reported that POP inhibition suppressed the growth of NB-1 human neuroblastomas cells and KATO III human gastric cancer cells. POP activity is commonly elevated in many cancers, which includes breast cancer. However, the effect of POP inhibition as a candidate breast cancer therapy is unknown.

Methods

The effects of POP inhibition and knockdown on the proliferation of cultured human estrogen receptor-positive (ER+) MCF7 and T47D, and ER-negative (ER?) MDA-MB-231 breast cancer cell lines and the MCF12A non-tumorigenic epithelial cell line were tested by analyzing their influence on cell proliferation (WST-1 assay), cell viability (trypan blue exclusion assay), and cell cycle arrest (cell cycle analysis, cell cycle regulator proteins expression).

Results

POP-specific inhibitors 3-({4-[2-(E)-styrylphenoxy]butanoyl}-l-4-hydroxyprolyl)-thiazolidine (SUAM-14746) and benzyloxycarbonyl-thiopropyl-thioprolinal and RNAi-mediated POP knockdown inhibited the proliferation of MCF7 cells without inducing cell death. SUAM-14746-induced growth inhibition was also observed in T47D and MDA-MB-231 cells, but not in MCF12A cells. This growth inhibition was associated with G₁ phase arrest; reduced cyclin D1 and D3, cyclin-dependent kinase 4 (CDK4), E2F1, and retinoblastoma protein (pRb) expression; and increased cyclin-dependent kinase inhibitor 1B (p27^kip1) expression. Moreover, the SUAM-14746-mediated cell cycle arrest of MCF7 cells was associated with increased pRb2/p130 protein expression and an increase in the number of cells in the quiescent G₀ state, as defined by low RNA levels.

Conclusions

SUAM-14746 inhibited breast cancer cell growth in a cytostatic manner without inducing lethality, and POP-specific inhibitors may be an effective treatment against ER+ and ER? breast cancer.

     

African American patients with breast cancer have worse prognosis than white patients in certain subtypes and stages

Purpose

Racial disparity of breast cancer in each subtype and substage is not clear.

Methods

We reviewed 156,938 patients with breast cancer from 2010 to 2012 from the National Cancer Institute Surveillance, Epidemiology, and End Results database. Breast cancer was subtyped by hormone receptor (HR) and human epidermal growth factor 2 (HER2) status as HR+/HER2?, HR+/HER2+, HR?/HER2+, and HR?/HER2?.

Results

African American (AA) patients had worse overall survival (OS) and breast cancer cause-specific survival (BCSS) in HR+/HER2? stages III and IV breast cancer and HR?/HER2+ stage IV cancer; they had worse OS but not BCSS in HR+ /HER2? stage II cancer and HR?/HER2? stage II cancer.

Conclusion

AA patients with breast cancer had worse survival in certain subtype and stage, especially in ER+ breast cancer.

     

Cancer-associated fibroblasts affect breast cancer cell gene expression,invasion and angiogenesis

Purpose

It has been reported that stromal cell features may affect the clinical outcome of breast cancer patients. Cancer associated fibroblasts (CAFs) represent one of the most abundant cell types within the breast cancer stroma. Here, we aimed to explore the influence of CAFs on breast cancer gene expression, as well as on invasion and angiogenesis.

Methods

qRT-PCR was used to evaluate the expression of several cancer progression related genes (S100A4, TGFβ, FGF2, FGF7, PDGFA, PDGFB, VEGFA, IL-6, IL-8, uPA, MMP2, MMP9, MMP11 and TIMP1) in the human breast cancer-derived cell lines MCF-7 and MDA-MB-231, before and after co-culture with CAFs. Stromal mononuclear inflammatory cell (MIC) MMP11 expression was used to stratify primary tumors. In addition, we assessed the in vitro effects of CAFs on both MDA-MB-231 breast cancer cell invasion and endothelial cell (HUVEC) tube formation.

Results

We found that the expression levels of most of the genes tested were significantly increased in both breast cancer-derived cell lines after co-culture with CAFs from either MMP11+ or MMP11- MIC tumors. IL-6 and IL-8 showed an increased expression in both cancer-derived cell lines after co-culture with CAFs from MMP11+ MIC tumors. We also found that the invasive and angiogenic capacities of, respectively, MDA-MB-231 and HUVEC cells were increased after co-culture with CAFs, especially those from MMP11+ MIC tumors.

Conclusions

Our data indicate that tumor-derived CAFs can induce up-regulation of genes involved in breast cancer progression. Our data additionally indicate that CAFs, especially those derived from MMP11+ MIC tumors, can promote breast cancer cell invasion and angiogenesis.

     

Association of reproductive history with breast tissue characteristics and receptor status in the normal breast

Introduction

Reproductive history has been associated with breast cancer risk, but more knowledge of the underlying biological mechanisms is needed. Because of limited data on normal breast tissue from healthy women, we examined associations of reproductive history and established breast cancer risk factors with breast tissue composition and markers of hormone receptors and proliferation in a nested study within the Karolinska Mammography project for risk prediction for breast cancer (Karma).

Materials and methods

Tissues from 153 women were obtained by ultrasound-guided core needle biopsy as part of the Karma project. Immunohistochemical staining was used to assessed histological composition of epithelial, stromal and adipose tissue, epithelial and stromal oestrogen receptor (ER) and progesterone receptor (PR) status, and Ki-67 proliferation status. An individualised reproductive score including parity, number of pregnancies without birth, number of births, age at first birth, and duration of breastfeeding, was calculated based on self-reported reproductive history at the time of the Karma study entry. All analyses were adjusted for age and BMI.

Results

Cumulated reproductive score was associated with increased total epithelial content and greater expression of epithelial ER. Parity was associated with greater epithelial area, increased epithelial–stromal ratio, greater epithelial ER expression and a lower extent of stromal proliferation. Increasing numbers of pregnancies and births were associated with a greater epithelial area in the entire study set, which remained significant among postmenopausal women. Increasing numbers of pregnancies and births were also associated with a greater expression of epithelial ER among postmenopausal women. Longer duration of breastfeeding was associated with greater epithelial area and greater expression of epithelial PR both in the entire study set and among postmenopausal women. Breastfeeding was also positively associated with greater epithelial ER expression among postmenopausal women. Prior use of oral contraceptives was associated with lower epithelial–stromal ratio amongst all participants and among pre- and postmenopausal women separately.

Conclusion

Reproductive risk factors significantly influence the epithelial tissue compartment and expression of hormone receptors in later life. These changes remain after menopause. This study provides deeper insights of the biological mechanisms by which reproductive history influences epithelial area and expression of hormone receptors, and as a consequence the risk of breast cancer.