Luminal Breast Cancer Subtypes Research Articles

Clinical Proteomics of Breast Cancer Reveals a Novel Layer of Breast Cancer Classification.

Breast cancer classification has been the focus of numerous worldwide efforts, analyzing the molecular basis of breast cancer subtypes and aiming to associate them with clinical outcome and to improve the current diagnostic routine. Genomic and transcriptomic profiles of breast cancer have been well established, however the proteomic contribution to these profiles has yet to be elucidated. In this work, we utilized mass spectrometry-based proteomic analysis on more than 130 clinical breast samples to demonstrate intertumor heterogeneity across three breast cancer subtypes and healthy tissue. Unsupervised analysis identified four proteomic clusters, among them, one that represents a novel luminal subtype characterized by increased PI3K signaling. This subtype was further validated using an independent protein-based dataset, but not in two independent transcriptome cohorts. These results demonstrate the importance of deep proteomic analysis, which may affect cancer treatment decision making.Significance: These findings utilize extensive proteomics to identify a novel luminal breast cancer subtype, highlighting the added value of clinical proteomics in breast cancer to identify unique features not observable by genomic approaches. Cancer Res; 78(20); 6001-10. ©2018 AACR.

Liver-Type Glutaminase is an Essential and Druggable Metabolic Node in Defined Breast Cancer Subtypes

A key strategy targeting the metabolic changes underlying tumorigenesis involves inhibiting the glutaminase isozyme GLS to disrupt glutamine catabolism. However, identifying patient groups for this approach remains a challenge. Here, we define the roles of GLS and its less studied counterpart liver-type glutaminase (GLS2) in breast cancer. We find that GLS2 is upregulated and essential for TCA cycle anaplerosis, cell proliferation, and tumorigenesis in luminal-subtype breast cancers, which account for >70% of disease incidence, and that it mediates resistance to GLS-selective inhibitors. Although GLS is overexpressed in basal-subtype breast cancers, sensitivity to GLS inhibitors depends on glutamate efflux through the xCT antiporter. These findings establish an important role for GLS2 in tumorigenesis and suggest patient stratification approaches for glutaminase-targeted therapy.

The pleiotropic effects of TNFα in breast cancer subtypes is regulated by TNFAIP3/A20.

TNFα is a pleiotropic cytokine which fuels tumor cell growth, invasion, and metastasis in some malignancies, while in others it induces cytotoxic cell death. However, the molecular mechanism by which TNFα exerts its diverse effects on breast cancer subtypes remains elusive. Using in vitro assays and mouse xenografts, we show here that TNFα contributes to the aggressive properties of triple negative breast cancer (TNBC) cell lines via upregulation of TNFAIP3(A20). In a striking contrast, TNFα induces a potent cytotoxic cell death in luminal (ER+) breast cancer cell lines which fail to upregulate A20 expression. Overexpression of A20 not only protects luminal breast cancer cell lines from TNFα-induced cell death via inducing HSP70-mediated anti-apoptotic pathway but also promotes a robust EMT/CSC phenotype by activating the pStat3-mediated inflammatory signaling. Furthermore, A20 overexpression in luminal breast cancer cells induces aggressive metastatic properties in mouse xenografts via generating a permissive inflammatory microenvironment constituted by granulocytic-MDSCs. Collectively, our results reveal a mechanism by which A20 mediates pleiotropic effects of TNFα playing role in aggressive behaviors of TNBC subtype while its deficiency results in TNFα-induced apoptotic cell death in luminal breast cancer subtype.

MiR-221/222 promote epithelial-mesenchymal transition by targeting Notch3 in breast cancer cell lines

Basal-like breast cancer (BLBC) is an aggressive subtype with a strong tendency to metastasize. Due to the lack of effective chemotherapy, BLBC has a poor prognosis compared with luminal subtype breast cancer. MicroRNA-221 and -222 (miR-221/222) are overexpressed in BLBC and associate with metastasis as well as poor prognosis; however, the mechanisms by which miR-221/222 function as oncomiRs remain unknown. Here, we report that miR-221/222 expression is inversely correlated with Notch3 expression in breast cancer cell lines. Notch3 is known to be overexpressed in luminal breast cancer cells and inhibits epithelial to mesenchymal transition (EMT). We demonstrate that miR-221/222 target Notch3 by binding to its 3′ untranslated region and suppressing protein translation. Ectopic expression of miR-221/222 significantly promotes EMT, whereas overexpression of Notch3 intracellular domain attenuates the oncogenic function of miR-221/222, suggesting that miR-221/222 exerts its oncogenic role by negatively regulating Notch3. Taken together, our results elucidated that miR-221/222 promote EMT via targeting Notch3 in breast cancer cell lines suggesting that miR-221/222 can serve as a potential therapeutic target in BLBC.

Additional Nodal Disease Prediction in Breast Cancer with Sentinel Lymph Node Metastasis Based on Clinicopathological Features.

The standard-of-care in breast cancer (BC) with positive sentinel lymph node (SLN) metastasis includes complete axillary lymph node dissection (ALND); however, almost half of such cases have no further tumor burden. This study aimed to assess the clinicopathological factors that predict non-SLN metastasis to define subgroups of SLN-positive patients in whom the axilla may be staged by SLN biopsy alone, while avoiding unnecessary overtreatment. The records of 191 patients with histologically-proven primary BC who underwent a positive (SLN) biopsy between 2005 and 2017 were reviewed. Patients with at least one tumor-involved SLN who underwent completion ALND were enrolled. Demographic and clinicopathological characteristics, including age, primary tumor size and histological grade, lymphovascular invasion, ratio of positive SLNs to the harvested SLNs, SLN metastasis size, and molecular subtype classification according to immunohistochemical biomarker status [estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)], were evaluated. Data were collected retrospectively and analyzed using the Mann-Whitney and Chi-square tests (statistical significance: p<0.05). The incidence of non-SLN metastasis associated with positive SLN was 48.6% (93/191). The risk of additional nodal spread correlated with high sentinel nodal ratio >0.67 [odds ratio (OR)=2.55, p=0.032], luminal BC subtype (OR=2.67, p=0.06), HER2 overexpression (OR=0.4, p=0.016), and ER+PR-HER2- profile (OR=2.95, p=0.027). There was a tendency (statistically insignificant; p>0.05) toward higher incidence of non SLN metastasis with increasing age and histological grade, which could be attributed to the small sample size. According to this study, sentinel nodal ratio and BC subtypes as per ER, PR, and HER2 status significantly predicted the likelihood of additional lymphatic involvement. Validation of these parameters in prospective studies is indicated, and may help individualize treatment modalities.

Collagen analysis by second-harmonic generation microscopy predicts outcome of luminal breast cancer.

Second-harmonic generation microscopy represents an important tool to evaluate extracellular matrix collagen structure, which undergoes changes during cancer progression. Thus, it is potentially relevant to assess breast cancer development. We propose the use of second-harmonic generation images of tumor stroma selected on hematoxylin and eosin-stained slides to evaluate the prognostic value of collagen fibers analyses in peri and intratumoral areas in patients diagnosed with invasive ductal breast carcinoma. Quantitative analyses of collagen parameters were performed using ImageJ software. These parameters presented significantly higher values in peri than in intratumoral areas. Higher intratumoral collagen uniformity was associated with high pathological stages and with the presence of axillary lymph node metastasis. In patients with immunohistochemistry-based luminal subtype, higher intratumoral collagen uniformity and quantity were independently associated with poorer relapse-free and overall survival, respectively. A multivariate response recursive partitioning model determined 12.857 and 11.894 as the best cut-offs for intratumoral collagen quantity and uniformity, respectively. These values have shown high sensitivity and specificity to differentiate distinct outcomes. Values of intratumoral collagen quantity and uniformity exceeding the cut-offs were strongly associated with poorer relapse-free and overall survival. Our findings support a promising prognostic value of quantitative evaluation of intratumoral collagen by second-harmonic generation imaging mainly in the luminal subtype breast cancer.

PO5 Breast cancer subtypes in Chinese Australian women

Background & purpose: It has been suggested that Chinese patients with breast cancer present at a younger age than their Western counterparts with tumour pathological characteristics that carry a less favourable outcome1. This study aims to investigate if a substantial difference in luminal breast cancer subtypes exists between Chinese Australian women and the overall Western population as reported in medical literature.

Comparison of some salivary biomarkers between luminal and triple negative subtypes after surgical removal of invasive ductal carcinoma

Luminal (L) and triple negative (TN) subtypes of breast cancer (BC) are recorded in Iraqi women which have different incidence, treatment, progression, and metastases. This study is aimed to compare some risk factors and salivary biomarkers between them. Only premenopausal Iraqi women with invasive ductal carcinoma (IDC) are involved in this study. Based on histopathologic and immunohistochemistry (IHC) report carried out by hospital itself, the age, Subtype and grade of tumor were recorded, while waist/hip ratio, secretory status, and salivary levels of Ca 15-3, total protein (TP), and PH were determined 2-3 weeks after surgery and before starting therapy. Results revealed that luminal is the predominant subtype of IDC and constitute about 80.5% and the rest (19.5%) is TN subtype, however HER-2 subtype didn’t recorded. Also women with TN are presented at age 40.7 year which is significantly (P ˂ 0.05) lower than that in (L) subtype (47.1 year). All TN cases are non-secretor and presented at grade 3 and their saliva is more acidic and containing higher levels of Ca 15-3, and TP than those in (L) cases. Our results suggested that saliva can be used as an alternative diagnostic sample in differentiation between various subtypes of IDC, and secretory status of patients may be contribute in determining the subtype of BC.

Can Histological Grade and Mitotic Index Replace Ki67 to Determine Luminal Breast Cancer Subtypes?

Introduction:Breast cancer can be classified into subtypes based on immunohistochemical markers, with Ki67 expression levels being used to divide luminal BC tumors in luminal A and B subtypes; however, Ki67 is not routinely determined due to a lack of standardization.Objective:To evaluate histological grade and Eliminate: the mitotic index to determine if they can be used as an alternative method to Ki67 staining for luminal subtype definition.Methods:We evaluated estrogen receptor positive breast cancer tissue samples. Pathological analysis included determination of Ki67. A low level of Ki67 was defined as <14% positive cells.Results:We evaluated 151 breast cancer samples; 24 (15,9%) were classified as I; 74 as HG II (49%), and 53 (35,1%) as HG III. The median value for Ki67 was 13% (range: <1% - 82%) and for MI was 2 (0-12). Histological grade I tumors exhibited Ki67 values significantly lower than HG II and III tumors (Anova, Tamhane test p=0,001). A higher Ki67 value was related to a higher MI (Rho Sperman p=0,336; R2= 0,0273). ROC curve analysis determined that a MI ≥ 3 had a sensibility of 61.9% and specificity of 66.7% in predicting a high Ki67 value (≥14%) (area under the curve: 0,691; p =0,0001). A HG I tumor or HG II-III with MI ≤2, had a high probability of corresponding to a LA tumor (76,3%), as defined using Ki67 expression, while the probability of a LB subtype was higher with HG II-III and a MI ≥3 (57.4%). Global discrimination was 68.1%.Conclusions:For the LA subtype, our predictive model showed a good correlation of HG and MI with the classification based on Ki67<14%. In the LB subtype, the model showed a weak correlation; therefore Ki67 determination seems to be needed for this group of patients.

Prognostic evaluation of vitamin D deficiency in breast cancer patients: a pilot study in India

Background : Vitamin D deficiency has been associated with poor prognosis in breast cancer. A new molecular classification of breast cancer is being increasingly used that is based on expression of estrogen receptors, progesterone receptors and Her2/neu amplification and is found to correlate well with prognosis and outcome of disease. The present study was designed to determine serum vitamin D deficiency in these molecular subtypes of breast cancer. Methods: Estimation of serum vitamin D levels by chemiluminiscence was done in a cohort of 99 breast cancer patients and 25 age matched healthy controls. Breast cancer patients were further grouped into luminal A, luminal B, Her2/neu enriched and triple negative subtypes based on immunohistochemistry results. Non-parametric tests were performed to compare vitamin D levels in different groups. Results: 54.6%, 60%, 66.6% and 84.2% of patients with luminal A, luminal B, Her2/neu enriched and triple negative subtypes respectively were found to be vitamin D deficient (<20ng/mL) as compared to only 20% in healthy controls. More aggressive Her2/neu enriched and triple negative subtype patients had significantly lower serum vitamin D levels than the luminal subtypes of breast cancer. Conclusion: Vitamin D deficiency is more prevalent and significantly lower levels are found in more aggressive subtypes of breast cancer. Vitamin D supplementation must be considered in these forms of breast cancer to improve outcome.

BRIP1 overexpression is correlated with clinical features and survival outcome of luminal breast cancer subtypes.

In Oman, breast cancer is most common, representing approximately more than 25% of all cancers in women. Relatively younger populations of patients (25–40 years) present surprisingly with an aggressive phenotype and advanced tumor stages. In this study, we investigated differential gene expressions in Luminal A, Luminal B, triple-negative and Her2+ breast cancer subtypes and compared data to benign tumor samples. We identified a potential candidate gene BRIP1, showing differential expression in the four breast cancer subtypes examined, suggesting that BRIP1 has the profile of a useful diagnostic marker, suitable for targeted therapeutic intervention. RT-qPCR and Western blotting analysis showed higher BRIP1 expression in luminal samples as compared to triple-negative subtype patient’s samples. We further screened BRIP1 for eventual mutations/SNPs/deletions by sequencing the entire coding region. Four previously identified polymorphisms were detected, one within the 5′-UTR region (c.141-64G > A) and three in the BRCA-binding domain (c.2755T > C, c.2647G > A and c.3411T > C). Kaplan–Meier analysis revealed that patients with overexpression of BRIP1 displayed a poor survival rate (P < 0.05). BRIP1 has a dual function of an oncogene and a tumor suppressor gene in addition to its role as a potential biomarker to predict survival and prognosis. Data obtained in this study suggest that BRIP1 can plausibly have an oncogenic role in sporadic cancers.

GATA3 frameshift mutation promotes tumor growth in human luminal breast cancer cells and induces transcriptional changes seen in primary GATA3 mutant breast cancers.

The GATA3 transcription factor is one of the most frequently mutated genes in breast cancer. Heterozygous mutations, mostly frameshifts, are seen in 15% of estrogen receptor positive breast cancers, the subtype in which these mutations are almost exclusively found. Mouse studies have shown that Gata3 is critical for breast development and that GATA3 gene dosage affects breast tumor progression. Human patient data have shown that high Gata3 expression, a feature of luminal subtype breast cancers, is associated with a better prognosis. Although the frequency of GATA3 mutation suggests an important role in breast cancer development or progression, there is little understanding of how mutations in GATA3 affect its function in luminal breast epithelial cells and what gene expression changes result as a consequence of the mutations. Here, using gene editing, we have created two sets of isogenic human luminal breast cancer cell lines with and without a hotspot truncating GATA3 mutation. GATA3 mutation enhanced tumor growth in vivo but did not affect sensitivity to clinically used hormonal therapies or chemotherapeutic agents. We identified genes with upregulated and downregulated expression in GATA3 mutant cells, a subset of which was concordantly differentially expressed in GATA3 mutant primary luminal breast cancers. Addback of mutant GATA3 recapitulated mutation-specific gene expression changes and enhanced soft agar colony formation, suggesting a gain of function for the mutant protein.

The Prognostic Value of Luminal Subtypes of Breast Cancer and their Impact on the Patient's Outcome

The Prognostic Value of Luminal Subtypes of Breast Cancer and their Impact on the Patient's Outcome

The exon 38-containing ARHGEF11 splice isoform is differentially expressed and is required for migration and growth in invasive breast cancer cells.

Breast cancer invasion involves the loss of cell-cell junctions and acquisition of an invasive, migratory phenotype, and breast cancer cells of the basal intrinsic subtype are more invasive and metastatic than breast cancer cells of other subtypes. ARHGEF11 is a RhoGEF that was previously shown to bind to the tight junction protein ZO-1 at perijunctional actomyosin ring (PJAR), a network of cortically organized actin and myosin filaments associated with junctional complexes that regulates cell-cell adhesion and polarization. We show here that ARHGEF11 shows splice isoform expression that differs according to the intrinsic subtype of breast cancer cells and that controls their invasive phenotype. Luminal subtype breast cancer cells express the isoform of ARHGEF11 lacking exon 38 (38-), which binds to ZO-1 at PJAR and is necessary for formation and maintenance of cell-cell junctions. Basal subtype breast cancer cells express the isoform of ARHGEF11 containing exon 38 (38+), which does not bind to ZO-1 and which drives cell migration and motility. Depletion of ARHGEF11 in basal subtype breast cancer cells is sufficient to alter cell morphology from a mesenchymal stellate form with extensive cell protrusions to a cobblestone-like epithelial form, and to suppress growth and survival both in vitro and in vivo. These findings show that the expression of the particular splice isoform of ARHGEF11 is critically linked to the malignant phenotype of breast cancer cells, identifying ARHGEF11 exon 38(+) as a biomarker and target for therapy of breast cancer.

Different prognosis of young breast cancer patients in their 20s and 30s depending on subtype: a nationwide study from the Korean Breast Cancer Society

Numerous studies have demonstrated that breast cancer in young women (BCY) has unfavorable prognostic features and more unfavorable subtypes. However, few studies have evaluated the effect of subtype disparities on breast cancer prognosis by age, especially for BCY. We analyzed breast cancer mortality stratified by tumor subtype according to age among patients younger than 50years. Data from the Korean Breast Cancer Society Registry for patients diagnosed with invasive breast cancer when aged less than 50years between 2003 and 2010 were reviewed retrospectively. We identified 30,793 patients with breast cancer who were eligible for analysis. Of these, 793 (2.6%) were aged 20-29 and 8926 (28.8%) were aged 30-39. Median follow-up duration was 84months. Mean age was 42.4years. Patients in their 20s were more likely to have cancer of advanced stage and higher nuclear grade, present with lymphovascular invasion, and have unfavorable subtypes. Patients in the 20s group showed worse prognosis. In multivariate analysis for overall survival (OS), the hazard ratio (HR) for patients in the 20s group was higher than that for the 30s and 40s groups, and patients with triple-negative breast cancer (TNBC) showed higher HR than patients with HER-2 or luminal subtype (all p<0.0001). When stratified by subtype, luminal subtype showed significantly worse prognosis in the 20s group than the 30s and 40s groups, whereas HER-2 and TNBC subtypes showed no significant difference. Patients in their 20s with breast cancer had unfavorable characteristics and worse prognosis than patients in their 30s and 40s. When stratified by tumor subtype, patients in their 20s with luminal subtype of breast cancer showed worse prognosis than older patients, whereas HER-2 and TNBC subtypes showed no significant differences.

Breast cancer subtype discrimination using standardized 4-IHC and digital image analysis.

Breast cancer is a heterogeneous disease. Surrogate classification of intrinsic subtypes of invasive carcinomas by combined immunohistochemistry for estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki67 (4-IHC) has increased steadily since the 2011 St Gallen symposium, due to its rapid subtyping of tumors at a reasonable cost. An important step in improving 4-IHC reproducibility and reliability will be to provide reference values from the routine use of standardized 4-IHC followed by image analysis. The aims of the current study were (1) to analyze invasive breast carcinomas using standardized 4-IHC and quantitative image analysis and (2) to compare the results obtained in the classification of biological subtypes using current Ki67 and PR threshold values proposed by different authors to sub-classifying the luminal A-like and the luminal B-like (HER2-negative) subtypes. Five hundred twenty-one tumors were analyzed by standardized immunohistochemistry, with automatic image analysis, and HER2 FISH technique. Positivity for ER was found in 82.7% and for PR in 70.1% of cases. Using the Allred scoring system, hormone receptor results showed a bimodal distribution, particularly for ER. HER2 positivity was found in 15.7% of cases, and the mean Ki67 score was 32.3%. Using the most recently proposed surrogate definitions for the classification of luminal breast cancer subtypes, the percentages of different subtypes that we found were similar to those published with genomic platforms: 40.7% luminal A-like, 32.4% luminal B-like/HER2-negative, 9.8% luminal B-like/HER2-positive, 6.0% HER2-positive, and 11.1% triple negative. Standardized 4-IHC with automatic image analysis constitutes a low-cost method for surrogate definitions of biological subtypes of breast cancer that delivers accurate results in a day.

Assessment of Ki67 expression for breast cancer subtype classification and prognosis in the Nurses' Health Study.

Ki67 is a proliferation marker commonly assessed by immunohistochemistry in breast cancer, and it has been proposed as a clinical marker for subtype classification, prognosis, and prediction of therapeutic response. However, the clinical utility of Ki67 is limited by the lack of consensus on the optimal cut point for each application. We assessed Ki67 by immunohistochemistry using Definiens digital image analysis (DIA) in 2653 cases of incident invasive breast cancer diagnosed in the Nurses' Health Study from 1976 to 2006. Ki67 was scored as continuous percentage of positive tumor cells, and dichotomized at various cut points. Multivariable hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox regression models for distant recurrence, breast cancer-specific mortality and overall mortality in relation to luminal subtypes defined with various Ki67 cut points, adjusting for breast cancer prognostic factors, clinico-pathologic features and treatment. DIA was highly correlated with manual scoring of Ki67 (Spearman correlation ρ=0.86). Mean Ki67 score was higher in grade-defined luminal B (12.6%), HER2-enriched (17.9%) and basal-like (20.6%) subtypes compared to luminal A (8.9%). In multivariable-adjusted models, luminal B tumors had higher breast cancer-specific mortality compared to luminal A cancer classified using various cut points for Ki67 positivity including the 14% cut point routinely reported in the literature (HR 1.38, 95% CI 1.11-1.72, p=0.004). There was no significant difference in clinical outcomes for ER- tumors according to Ki67 positivity defined at various cut points. Assessment of Ki67 in breast tumors by DIA was a robust and quantitative method. Results from this large prospective cohort study provide support for the clinical relevance of using Ki67 at the 14% cut point for luminal subtype classification and breast cancer prognosis.

Wound fluids affect miR-21, miR-155 and miR-221 expression in breast cancer cell lines, and this effect is partially abrogated by intraoperative radiation therapy treatment.

Breast cancer is the most common malignant disease occurring in women. Conservative breast cancer surgery followed by radiation therapy is currently the standard treatment for this type of cancer. The majority of metastases occur within the scar, which initiated a series of studies. As a result, clinical trials aimed to assess whether localized radiotherapy, as intraoperative radiotherapy (IORT), may more effective in inhibiting the formation of local recurrence compared with the standard postoperative whole breast radiotherapy. The present study determined the role of postoperative wound fluids (WFs) from patients diagnosed with breast cancer subsequent to breast conserving surgery or breast conserving surgery followed by IORT on the expression of three microRNAs (miRNAs), consisting of miR-21, miR-155 and miR-221, in distinct breast cancer cell lines that represent the general subtypes of breast cancer. It was determined that the miRNAs responsible for breast cancer progression, induction of tumorigenesis and enrichment of the cancer stem cell phenotype, which is responsible for resistance to tumor therapy, were highly upregulated in the human epidermal growth factor receptor 2-positive breast cancer SK-BR-3 cell line following stimulation with WFs. It is worth emphasizing, that those changes were more significant in WFs collected from patients after surgery alone. The BT-549 cell line showed altered expression only of miR-155 following incubation with WFs. Notably, this change was not associated with IORT. Additionally, it was indicated that both WFs and RT-WF strongly downregulated the expression of miR-21, miR-155 and miR-221 in basal/epithelial and luminal subtypes of breast cancer. It was concluded that the present study contributes to an increased understanding of the role of surgical WFs and IORT treatment in the regulation of miRNA expression. This may enable the development of the current knowledge of breast cancer biology subsequent to IORT treatment and substantially to improve the therapy in the future.

Immediate breast reconstruction with omental flap for luminal breast cancer patients: Ten clinical case reports.

Rationale:Luminal subtype breast cancer, accounting for 70 to 80% of all breast cancers, has been reported to be associated with good prognosis. However, for the patients with large mass or worse mass position, omental flap transplantation may provide a new option for breast reconstruction.Patient concerns:Ten patients (6 luminal B1, 2 luminal B2, 2 luminal A), were enrolled into the study, between January 23, 2015 and August 22, 2016. The mean age was 34.6 ± 6.96 (24-44) years old. Immunohistochemistry demonstrated that the tumor cells were positive for estrogen receptor and progestrone receptor.Diagnoses:According to the clinicopathological features, diagnosis of breast cancer patients were made.Interventions:Breast-conserving surgery, laparoscopic greater omentum harvest and vascular anas-tomosis were carried out orderly. Postoperative operative results, cosmetic outcomes, complications, as well as blood supply were investigated for surgery evaluation. Reasonable chemotherapy and irradia-tion were adopted to patients according to the pathological condition.Outcomes:We successfully accomplished breast reconstruction by omental flap transplantation, ex-cept one failed case because of the necrosis of omentum and changed to fat transplantation. The volumes and symmetry of breasts were all satisfied. The blood supply was detected to be fluent. Only one case of slight hematoma and another case of one distant metastasis were observed during fol-low-up period. No arm mordities or arm movement restriction occurred after surgery. Moreover, radia-tion therapy and chemotherapy had no clear effects on the reconstructed breast.Lessons:Immediate breast reconstruction surgery by transplanting omental flap for luminal breast cancer patients can be considered successful based on the excellent clinic outcome.

Large-Scale Analysis of Breast Cancer-Related Conformational Changes in Proteins Using SILAC-SPROX.

Proteomic methods for disease state characterization and biomarker discovery have traditionally utilized quantitative mass spectrometry methods to identify proteins with altered expression levels in disease states. Here we report on the large-scale use of protein folding stability measurements to characterize different subtypes of breast cancer using the stable isotope labeling with amino acids in cell culture and stability of proteins from rates of oxidation (SILAC-SPROX) technique. Protein folding stability differences were studied in a comparison of two luminal breast cancer subtypes, luminal-A and -B (i.e., MCF-7 and BT-474 cells, respectively), and in a comparison of a luminal-A and basal subtype of the disease (i.e., MCF-7 and MDA-MB-468 cells, respectively). The 242 and 445 protein hits identified with altered stabilities in these comparative analyses included a large fraction with no significant expression level changes. This suggests thermodynamic stability measurements create a new avenue for protein biomarker discovery. A number of the identified protein hits are known from other biochemical studies to play a role in tumorigenesis and cancer progression. This not only substantiates the biological significance of the protein hits identified using the SILAC-SPROX approach, but it also helps elucidate the molecular basis for their disregulation and/or disfunction in cancer.