Heran Deng

Mir-30 reduction maintains self-renewal and inhibits apoptosis in breast tumor-initiating cells

Accumulating evidence indicates that a sub-population of cancer cells with stem-like properties, termed tumor-initiating cells (T-ICs), exist in many different kinds of malignancies, which have a pivotal role in tumorigenesis, tumor progression, metastasis and post-treatment relapse. However, how the stem-like properties of T-ICs are regulated remains obscure. Our previous study showed that reduction of let-7 microRNA (miRNA) in breast tumor-initiating cells (BT-ICs) contributes to the maintenance of their self-renewal capacity and undifferentiated status. In this study we show the effect of mir-30 reduction on the stem-like features of BT-ICs. Similar to let-7, mir-30 is reduced in BT-ICs, and the protein level of Ubc9 (ubiquitin-conjugating enzyme 9) and ITGB3 (integrin β3), the target genes of mir-30, is markedly upregulated. Enforced constitutive expression of mir-30 in BT-ICs inhibits their self-renewal capacity by reducing Ubc9, and induces apoptosis through silencing ITGB3. On the contrary, blocking the miRNA with a specific antisense oligonucleotide (ASO) in differentiated breast cancer cells revived their self-renewal capacity. Furthermore, ectopic expression of mir-30 in BT-IC xenografts reduces tumorigenesis and lung metastasis in nonobese diabetic/severe combined immunodeficient mice, whereas blocking mir-30 expression enhances tumorigenesis and metastasis. Together, our data suggest mir-30 as one of the important miRNAs in regulating the stem-like features of T-ICs.

Reduced Let-7a Is Associated with Chemoresistance in Primary Breast Cancer

Chemotherapy resistance remains an important problem in the breast cancer clinic. The ability to predict the patients who would respond to a distinct therapy would help to optimize tailored treatment options. miRNAs can mediate a number of genes in response to drug-induced acute cellular stress. Several studies suggest that let-7 miRNA may be involved in the chemosensitivity of cancer cell lines in vitro. However, it is not known whether this phenomenon occurs in clinical breast tumors. The present study showed that lower let-7a expression was associated with epirubicin resistance in primary breast tumors. Moreover, upregulation of let-7a expression sensitized resistant breast tumor cell lines to epirubicin by enhancing cellular apoptosis in vitro. Collectively, these findings indicate that lower expression of let-7a miRNA can induce chemoresistance in breast cancer by enhancing cellular apoptosis and suggest that let-7a may be used as a therapeutic target to modulate epirubicin-based chemotherapy resistance.

Comparison of ER/PR and HER2 statuses in primary and paired liver metastatic sites of breast carcinoma in patients with or without treatment

PurposeThe aim of this study was to determine whether estrogen receptor (ER)/progesterone receptor (PR) and human epidermal growth factor receptor type 2 (HER2) statuses between primary tumors and paired liver metastatic localizations of breast carcinoma were modified by treatment or during the natural metastatic process.MethodsER, PR, and HER2 expressions were analyzed on paired tissue specimens taken from the primary and the liver metastatic tumors in breast cancer patients. The first group included 46 women who presented with T1–T4, N0–N3, M0 breast carcinoma when first diagnosed and were treated by neoadjuvant therapy or directly underwent surgery, then received postoperative treatment and developed liver metastasis several months/years later. The second group included 12 patients with liver metastatic breast carcinoma when first diagnosed for breast cancer. HER2 status was determined by immunohistochemistry as well as fluorescence in situ hybridization.ResultsAmong the 46 patients in the first group, the ER/PR and HER2 statuses (when considered as a whole histological subtype) were changed between primary tumor and liver metastatic lesions in 12 patients (26.1%). While ER and PR status were modified in 14 (30.4%) and 25 (54.3%) patients, respectively, there were only 5 (10.9%) cases showed a discrepancy in the HER2 status. In the second group, the ER/PR and HER2 statuses (when considered as a whole subtype) were consistent between primary and liver metastatic tumor in 10 of 12 (83.3%) patients. ER, PR, and HER2 statuses were modified in 0 of 12 (0%), 4 of 12 (33.3%), and 1 of 12 (8.3%) cases, respectively.ConclusionsER/PR and HER2 statuses between primary and liver metastatic lesions of breast carcinoma can be modified after treatment but are stable in most cases during the natural metastatic process.

HER-2 positive breast cancer is associated with an increased risk of positive cavity margins after initial lumpectomy

BackgroundThe effect of breast cancer subtype on margin status after lumpectomy remains unclear. This study aims to determine whether approximated breast cancer subtype is associated with positive margins after lumpectomy, which could be used to determine if there is an increased risk of developing local recurrence (LR) following breast-conserving surgery.MethodsWe studied 1,032 consecutive patients with invasive cancer who received lumpectomies and cavity margin (CM) assessments from January 2003 to November 2012. The following data were collected: patient age, cT stage, pT stage, grade, status of CM, lymph node status, menopausal status, ER, PR, HER-2, and Ki67, as well as the presence of extensive intraductal component (EIC) and lymphovascular invasion (LVI). A χ2 test was used to compare categorical baseline characteristics. Univariate and multivariate logistic regression analyses were performed to evaluate associations between pathologic features of CM status. Kaplan-Meier actuarial cumulative rates of LR (ipsilateral in-breast) were calculated.ResultsA total of 7,884 pieces of marginal tissue were collected from 1,032 patients, and 209 patients had positive CMs. Of the patients tested, 52.3% had luminal A subtype, 14.9% were luminal B, 12.8% were luminal-HER-2, 8.1% were HER-2 enriched, and 11.8% were triple negative. Univariate analysis showed that EIC (P <0.001), LVI (P = 0.026), pN stage (N1 vs. N0: P = 0.018; N3 vs. N0: P <0.001), and luminal B (P = 0.001) and HER-2 (P <0.001) subtypes were associated with positive CMs. Multivariable analysis indicated that only EIC (P <0.001), pN stage (P = 0.003), and HER-2 subtype (P <0.001) were significantly correlated with positive CMs. On multivariable analysis, HER-2 subtype was an independent prognostic factor in LR (P = 0.031).ConclusionsThe HER-2 subtype was the predictive factor most associated with positive CMs and an independent prognostic factor for LR. This result suggests that the increased risk of LR in HER-2 breast cancer is due to an increased microscopic invasive tumor burden, which is indicated by margin status after lumpectomy.

Clinical Predictive Models for Chemotherapy-Induced Febrile Neutropenia in Breast Cancer Patients: A Validation Study

Background Predictive models for febrile neutropenia (FN) would be informative for physicians in clinical decision making. This study aims to validate a predictive model (Jenkin’s model) that comprises pretreatment hematological parameters in early-stage breast cancer patients. Patients and Methods A total of 428 breast cancer patients who received neoadjuvant/adjuvant chemotherapy without any prophylactic use of colony-stimulating factor were included. Pretreatment absolute neutrophil counts (ANC) and absolute lymphocyte counts (ALC) were used by the Jenkin’s model to assess the risk of FN. In addition, we modified the threshold of Jenkin’s model and generated Model-A and B. We also developed Model-C by incorporating the absolute monocyte count (AMC) as a predictor into Model-A. The rates of FN in the 1st chemotherapy cycle were calculated. A valid model should be able to significantly identify high-risk subgroup of patients with FN rate >20%. Results Jenkin’s model (Predicted as high-risk when ANC≦3.1*10∧9/L;ALC≦1.5*10∧9/L) did not identify any subgroups with significantly high risk (>20%) of FN in our population, even if we used different thresholds in Model-A(ANC≦4.4*10∧9/L;ALC≦2.1*10∧9/L) or B(ANC≦3.8*10∧9/L;ALC≦1.8*10∧9/L). However, with AMC added as an additional predictor, Model-C(ANC≦4.4*10∧9/L;ALC≦2.1*10∧9/L; AMC≦0.28*10∧9/L) identified a subgroup of patients with a significantly high risk of FN (23.1%). Conclusions In our population, Jenkin’s model, cannot accurately identify patients with a significant risk of FN. The threshold should be changed and the AMC should be incorporated as a predictor, to have excellent predictive ability.

Impact of Breast Cancer Subtype Defined by Immunohistochemistry Hormone Receptor and HER2 Status on the Incidence of Immediate Postmastectomy Reconstruction

Abstract Immediate postmastectomy reconstruction has become an increasingly popular choice for breast cancer patients recently. However, whether molecular subtype of cancer impacts the incidence of breast reconstruction is unclear. We aimed to investigate the association between breast cancer subtype defined by immunohistochemistry hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status and recent rates of immediate postmastectomy reconstruction in the United States. The National Cancer Institutes Surveillance, Epidemiology, and End Results (SEER) database was used to evaluate stage I–III breast cancer patients with different subtypes who underwent either mastectomy alone or mastectomy plus reconstruction between 2010 and 2012. Univariate and multivariate analyses were conducted to identify factors influencing the incidence of immediate reconstruction. Of 47,123 women included, 33.1% (10,712/32,376) of HR+/HER2−, 33.1% (1912/5768) of HR+/HER2+, 29.6% (850/2875) of HR−/HER2+, and 27.7% (1689/6104) of triple negative breast cancer patients received immediate breast reconstruction (chi-square test, P < 0.001), respectively. Thus, HER2-overexpressing and triple negative breast cancer patients received significantly less breast reconstruction. After adjusting for demographic, socioeconomic, geographic, or clinicopathologic factors, HER2-overexpressing (OR 0.896, 95% CI 0.817–0.984) and triple negative (OR 0.806, 95% CI 0.751–0.866) breast cancer patients remained less likely to undergo immediate postmastectomy reconstruction compared with HR+/HER2− or HR+/HER2+ patients. No significant difference was found in the type of reconstruction among different subtypes. Subgroup analysis showed that the difference of breast reconstruction rates among distinct subtypes varied with different grade and stage groups, and the association between breast cancer subtype and the reconstruction rate was not significant in low grade and early stage patients. This population-based study determined that breast cancer subtype was an independent predictor for the utilization of immediate postmastectomy reconstruction. Patients with HER2-overexpressing or triple negative breast cancer subtype that has relatively higher risk of local recurrence, were less likely to receive immediate breast reconstruction than those with luminal tumors. Further studies are needed to disclose more underlying reasons of different reconstruction incidences for distinct subtypes of breast cancer.

Combined Let-7a and H19 Signature: A Prognostic Index of Progression-Free Survival in Primary Breast Cancer Patients

Purpose The long non-coding RNA H19, a conservatively imprinted gene, acts as a molecular sponge for the let-7 family, which has been identified as a set of tumor suppressors. However, the combined prognostic value of H19 and let-7a signature in breast cancer patients remains unclear. Methods In this research we assessed the prognostic value of the combined H19 and let-7a signature in breast cancer patients by retrospectively reviewing that data of 79 patients who underwent neoadjuvant chemotherapy; we also investigated the expression and function of H19 in breast cancer cell lines in vitro. Survival data were calculated using the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate survival analyses were conducted using the Cox proportional hazards regression method. As determined using X-tile, the optimal cutoff value for the risk score to assess progression-free survival (PFS) based on the combined signature was –0.1. Results Patients with an overall positive treatment response had higher let-7a and lower H19 levels. In addition, let-7a expression was negatively correlated with H19 expression. Patients with a risk score of >–0.1 had shorter overall survival and PFS. In vitro data showed that chemoresistant cell lines exhibit higher H19 and lower let-7a levels and knockdown H19 restores paclitaxel sensitivity. Conclusion Our results suggest that the combined let-7a and H19 signature is a novel prognostic factor for breast cancer patients treated with neoadjuvant chemotherapy.

Silencinglnc-ASAH2B-2Inhibits Breast Cancer Cell Growthviathe mTOR Pathway

Background/Aim: Persistent activation of the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (mTOR) pathway is an important mechanism in resistance of breast cancer to endocrine therapy. Although everolimus has potent inhibitory effects on the mTOR pathway, it has demonstrated only modest clinical activity as a single agent. Whether long noncoding (lnc) RNA is involved in everolimus resistance is unknown. Materials and Methods: Cell viability, colony formation and cell proliferation experiments were used to measure the effects of long noncoding RNA N-acylsphingosine amidohydrolase 2B-2 (lnc-ASAH2B-2) knockdown in BT474 and MCF7 breast cancer cells. Results: lnc-ASAH2B-2 was up-regulated by everolimus in cells with and without serum, and reduction of lnc-ASAH2B-2 expression was able to inhibit proliferation of BT474 and MCF7 cells. Conclusion: lnc-ASAH2B-2 was up-regulated after everolimus exposure and efficiently regulated breast cancer cell growth by activating the mTOR pathway, which may reduce the effect of everolimus, providing evidence that lnc-ASAH2B-2 might be a new therapeutic target for breast cancer.

Risk of second breast cancers after lobular carcinoma in situ according to hormone receptor status

Background Although subsequent breast cancer risk after primary lobular carcinoma in situ (LCIS) has been studied intensively, whether the risk of second breast cancer after first LCIS varies with hormone receptor (HR) status of primary tumor remains unclear. Methods We identified 10,304 women with primary pure unilateral LCIS between 1998 and 2007 from the Surveillance, Epidemiology and End Results (SEER) 18 Registries. Kaplan–Meier estimates of 5 or 10-year probabilities of second ipsilateral breast cancers (IBCs) and contralateral breast cancers (CBCs) were calculated. Multivariable Cox proportional model was performed to identify impact of HR status of primary LCIS, and other demographic, clinicopathologic or treatment characteristics on risk of second IBCs or CBCs. Results Of the 10,304 women with primary LCIS included in this study, 9949 (96.5%) patients had HR+ tumors, and 355 (3.5%) had HR- tumors. Multivariable-adjusted analyses showed that although there was no difference in risk of total second IBCs between women with HR+ and HR- LCIS (P = 0.152), patients with HR+ LCIS had a statistically lower risk of second invasive IBCs compared to those with HR- LCIS (hazard ratio 0.356, 95% CI 0.141–0.899, P = 0.029). Women with primary HR+ LCIS had lower risks of both second total and invasive CBCs compared to those with HR- LCIS (total CBCs: hazard ratio 0.340, 95% CI 0.228–0.509, P<0.001; invasive CBCs: hazard ratio 0.172, 95% CI 0.108–0.274, P<0.001). Additionally, black women had a 2-fold risk of developing subsequent total IBCs than white women (P = 0.028). Conclusions This population-based study demonstrated that the risk of second breast cancers was significantly increased in women with HR- first LCIS compared to those with HR+ LCIS. These findings warrant intensive surveillance for second breast cancers in HR- LCIS survivors.

Assessing second echelon lymph nodes during sentinel lymph node biopsy: Can we have more accurate axillary treatment for breast cancer patients?

Sentinel lymph node biopsy (SLNB) is the standard treatment for breast cancer patients with clinically negative axilla. For patients with positive sentinel lymph nodes, axillary lymph node dissection (ALND) was required. However, approximately a half of the SLNs-positive patients were found to have clear axillary lymph nodes after ALND, indicating that they had received unnecessary ALND without therapeutic benefit. Therefore, we propose a hypothesis for solution of this clinical problem. We defined the second echelon lymph nodes (SELNs) as those nodes receiving lymphatic drainage directly from the SLNs. For patients with positive-SLNs, SELNs can be biopsy and assessed. If SELNs are negative, no more ALND was needed in these patients even if their SLNs are positive. If our hypothesis were confirmed to be true, we can tailored our axillary treatment to more breast cancer patients, avoiding unnecessary ALND and its complications.