Stromal Cell Signature Associated with Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer.

Breast cancer stromal compartment, may influence responsiveness to chemotherapy. Our aim was to detect a stromal cell signature (using a direct approach of microdissected stromal cells) associated with response to neoadjuvant chemotherapy (neoCT) in locally advanced breast cancer (LABC). The tumor samples were collected from 44 patients with LABC (29 estrogen receptor (ER) positive and 15 ER negative) before the start of any treatment. Neoadjuvant chemotherapy consisted of doxorubicin and cyclophosphamide, followed by paclitaxel. Response was defined as downstaging to maximum ypT1a-b/ypN0. The stromal cells, mainly composed of fibroblast and immune cells, were microdissected from fresh frozen tumor samples and gene expression profile was determined using Agilent SurePrint G3 Human Gene Expression microarrays. Expression levels were compared using MeV (MultiExperiment Viewer) software, applying SAM (significance analysis of microarrays). To classify samples according to tumor response, the order of median based on confidence statements (MedOr) was used, and to identify gene sets correlated with the phenotype downstaging, gene set enrichment analysis (GSEA). Nine patients presented disease downstaging. Eleven sequences (FDR 17) were differentially expressed, all of which (except H2AFJ) more expressed in responsive tumors, including PTCHD1 and genes involved in abnormal cytotoxic T cell physiology, TOX, LY75, and SH2D1A. The following four pairs of markers could correctly classify all tumor samples according to response: PTCHD1/PDXDC2P, LOC100506731/NEURL4, SH2D1A/ENST00000478672, and TOX/H2AFJ. Gene sets correlated with tumor downstaging (FDR < 0.01) were mainly involved in immune response or lymphocyte activation, including CD47, LCK, NCK1, CD24, CD3E, ZAP70, FOXP3, and CD74, among others. In locally advanced breast cancer, stromal cells may present specific features of immune response that may be associated with chemotherapy response.

Immunoexpression of claudins 4 and 7 among invasive breast carcinoma subtypes: A large diagnostic study using tissue microarray.

Molecular phenotyping and tissue microarray (TMA) studies have identified distinct invasive breast carcinoma subtypes: Luminal A, luminal B, enriched with overexpressed human epidermal growth factor receptor 2 (HER-2) and triple-negative, i.e., negative for HER-2, as well as for estrogen and progesterone receptor (ER and PR, respectively) expression. These subtypes are useful in clinical management, since they bear distinct prognoses and predictive responses to targeted therapy. However, although molecular profiling provides important prognostic indicators, breast cancer risk stratification remains a challenge in triple-negative cases. What is referred to as claudin-low subtype was identified as a triple-negative subset that is associated with more aggressive tumor behavior and worse prognosis. However, the immunohistochemical expression of claudins has not yet been standardized. Our objective was to verify whether the immunoexpression of claudins 4 and 7 (the main claudins specifically expressed in human breast tissue) in TMA is associated with survival and prognosis in luminal A, HER-2 and triple-negative molecular subtypes. In this diagnostic study, we investigated ER/PR receptor status, HER-2, claudin 4 and 7 expression and stem cell CD44/24 profiles, and verified the association with prognosis and survival outcomes in 803 invasive breast carcinoma cases arranged in four TMAs. Among these, 503 (62.6%) were positive for claudin 4 and 369 (46.0%) for claudin 7. Claudin 4 exhibited the lowest expression in luminal A and triple-negative subtypes, and the highest frequency of expression in HER-2-enriched subtypes, whereas claudin 7 staining was not associated with any subtype. The stem cell phenotype was not associated with subgroups or claudins 4 and 7. Claudin immunoexpression profile was not able to distinguish between patients with better or worse prognosis, and it was not correlated to triple-negative cases. Therefore, it may be concluded that the immunoexpression of claudins 4 and 7, individually or within the usual immunohistochemical context (ER, PR and HER-2), does not provide additional prognostic information on breast cancer subtypes.

Somatic mutations in early onset luminal breast cancer.

Breast cancer arising in very young patients may be biologically distinct; however, these tumors have been less well studied. We characterized a group of very young patients (≤ 35 years) for BRCA germline mutation and for somatic mutations in luminal (HER2 negative) breast cancer. Thirteen of 79 unselected very young patients were BRCA1/2 germline mutation carriers. Of the non-BRCA tumors, eight with luminal subtype (HER2 negative) were submitted for whole exome sequencing and integrated with 29 luminal samples from the COSMIC database or previous literature for analysis. We identified C to T single nucleotide variants (SNVs) as the most common base-change. A median of six candidate driver genes was mutated by SNVs in each sample and the most frequently mutated genes were PIK3CA, GATA3, TP53 and MAP2K4. Potential cancer drivers affected in the present non-BRCA tumors include GRHL2, PIK3AP1, CACNA1E, SEMA6D, SMURF2, RSBN1 and MTHFD2. Sixteen out of 37 luminal tumors (43%) harbored SNVs in DNA repair genes, such as ATR, BAP1, ERCC6, FANCD2, FANCL, MLH1, MUTYH, PALB2, POLD1, POLE, RAD9A, RAD51 and TP53, and 54% presented pathogenic mutations (frameshift or nonsense) in at least one gene involved in gene transcription. The differential biology of luminal early-age onset breast cancer needs a deeper genomic investigation.

Breast-conserving surgery in locally advanced breast cancer submitted to neoadjuvant chemotherapy. Safety and effectiveness based on ipsilateral breast tumor recurrence and long-term follow-up.

OBJECTIVE:: To evaluate ipsilateral breast tumor recurrence after breast-conserving surgery for locally advanced breast cancer. METHODS:: A retrospective observational cohort study was performed in patients with locally advanced breast cancer submitted to breast-conserving surgery after neoadjuvant chemotherapy based on an adriamycin-cyclophosphamide-paclitaxel regimen. We evaluated the clinical, pathologic, immunohistochemistry, and surgical factors that contribute to ipsilateral breast tumor recurrence and locoregional recurrence. A Kaplan-Meier analysis and Cox model were used to evaluate the main factors related to disease-free survival. RESULTS:: Of the 449 patients who received neoadjuvant chemotherapy, 98 underwent breast-conserving surgery. The average diameter of the tumors was 5.3 cm, and 87.2% reached a size of up to 3 cm. Moreover, 86.7% were classified as clinical stage III, 74.5% had T3-T4 tumors, 80.5% had N1-N2 axilla, and 89.8% had invasive ductal carcinoma. A pathologic complete response was observed in 27.6% of the tumors, and 100.0% of samples had free margins. The 5-year actuarial overall survival rate was 81.2%, and the mean follow-up was 72.8 months. The rates of ipsilateral breast tumor recurrence and locoregional recurrence were 11.2% and 15.3%, respectively. Multifocal morphology response was the only factor related to ipsilateral breast tumor recurrence disease-free survival (p=0.04). A multivariate analysis showed that the pathologic response evaluation criteria in solid tumors (RECIST)-breast cutoff was the only factor related to locoregional recurrence disease-free survival (p=0.01). CONCLUSIONS:: Breast-conserving surgery is a safe and effective therapy for selected locally advanced breast tumors.

Breast-conserving surgery in locally advanced breast cancer submitted to neoadjuvant chemotherapy. Safety and effectiveness based on ipsilateral breast tumor recurrence and long-term follow-up

OBJECTIVE: To evaluate ipsilateral breast tumor recurrence after breast-conserving surgery for locally advanced breast cancer. METHODS: A retrospective observational cohort study was performed in patients with locally advanced breast cancer submitted to breast-conserving surgery after neoadjuvant chemotherapy based on an adriamycin-cyclophosphamide-paclitaxel regimen. We evaluated the clinical, pathologic, immunohistochemistry, and surgical factors that contribute to ipsilateral breast tumor recurrence and locoregional recurrence. A Kaplan-Meier analysis and Cox model were used to evaluate the main factors related to disease-free survival. RESULTS: Of the 449 patients who received neoadjuvant chemotherapy, 98 underwent breast-conserving surgery. The average diameter of the tumors was 5.3 cm, and 87.2% reached a size of up to 3 cm. Moreover, 86.7% were classified as clinical stage III, 74.5% had T3-T4 tumors, 80.5% had N1-N2 axilla, and 89.8% had invasive ductal carcinoma. A pathologic complete response was observed in 27.6% of the tumors, and 100.0% of samples had free margins. The 5-year actuarial overall survival rate was 81.2%, and the mean follow-up was 72.8 months. The rates of ipsilateral breast tumor recurrence and locoregional recurrence were 11.2% and 15.3%, respectively. Multifocal morphology response was the only factor related to ipsilateral breast tumor recurrence disease-free survival (p=0.04). A multivariate analysis showed that the pathologic response evaluation criteria in solid tumors (RECIST)-breast cutoff was the only factor related to locoregional recurrence disease-free survival (p=0.01). CONCLUSIONS: Breast-conserving surgery is a safe and effective therapy for selected locally advanced breast tumors.

The role of oncoplastic breast conserving treatment for locally advanced breast tumors. A matching case-control study.

BACKGROUND: Breast conserving surgery (BCS) after neoadjuvant chemotherapy (NC) in patients with locally advanced breast cancer (LABC) is an infrequent procedure. In these patients the association with BCS and oncoplastic surgery (OS) is reported as a possible procedure in case-series, but there are limited case-control studies. METHODS: A matched case-control study evaluated LABC submitted to NC and BCS. We evaluated 78 patients submitted to doxorubicin-cyclophosphamide regimen followed by paclitaxel regimen. The match case-control proportion was 2:1 and the patients were selected by tumor size, clinical T stage and year of diagnosis. RESULTS: 52 underwent classic BCS and 26 OS. The average size tumor was 5.25 cm and 88.5% of the tumors were larger than 3 cm. The clinical and pathological group characteristics were similar, except the weight of surgical specimens (p = 0.004), and surgical margins (p = 0.06), which were higher in OS group. The rate of complete pathologic response was 26.9%. 97.4% received postoperative radiotherapy. At 67.1 months of follow up, 10.2% had local recurrence (LR) and 12.8% locoregional recurrence (LRR) and 19.2% died because disease progression. The overall survival at 60 months was 81.7%. After surgery the disease free-survival at 60 months was 76.5%. The was no difference between groups related to pathologic response (p = 0.42), LR (p = 0.71), LRR (p = 1.00), overall survival (p = 0.99) and disease specific survival (p = 0.87). CONCLUSION: This study corroborates the fact that OS is a safety procedure for LABC, offering the similar oncologic results observed in patients submitted to classic BCS.

Docosahexaenoic Acid Modulates a HER2-Associated Lipogenic Phenotype, Induces Apoptosis, and Increases Trastuzumab Action in HER2-Overexpressing Breast Carcinoma Cells.

In breast cancer, lipid metabolic alterations have been recognized as potential oncogenic stimuli that may promote malignancy. To investigate whether the oncogenic nature of lipogenesis closely depends on the overexpression of HER2 protooncogene, the normal breast cell line, HB4a, was transfected with HER2 cDNA to obtain HER2-overexpressing HB4aC5.2 cells. Both cell lines were treated with trastuzumab and docosahexaenoic acid. HER2 overexpression was accompanied by an increase in the expression of lipogenic genes involved in uptake (CD36), transport (FABP4), and storage (DGAT) of exogenous fatty acids (FA), as well as increased activation of "de novo" FA synthesis (FASN). We further investigate whether this lipogenesis reprogramming might be regulated by mTOR/PPARγ pathway. Inhibition of the mTORC1 pathway markers, p70S6 K1, SREBP1, and LIPIN1, as well as an increase in DEPTOR expression (the main inhibitor of the mTOR) was detected in HB4aC5.2. Based on these results, a PPARγ selective antagonist, GW9662, was used to treat both cells lines, and the lipogenic genes remained overexpressed in the HB4aC5.2 but not HB4a cells. DHA treatment inhibited all lipogenic genes (except for FABP4) in both cell lines yet only induced death in the HB4aC5.2 cells, mainly when associated with trastuzumab. Neither trastuzumab nor GW9662 alone was able to induce cell death. In conclusion, oncogenic transformation of breast cells by HER2 overexpression may require a reprogramming of lipogenic genetic that is independent of mTORC1 pathway and PPARγ activity. This reprogramming was inhibited by DHA.

Somatic mutations in breast and serous ovarian cancer young patients: a systematic review and meta-analysis.

OBJECTIVE: our aim was to evaluate whether somatic mutations in five genes were associated with an early age at presentation of breast cancer (BC) or serous ovarian cancer (SOC). METHODS: COSMIC database was searched for the five most frequent somatic mutations in BC and SOC. A systematic review of PubMed was performed. Young age for BC and SOC patients was set at ≤ 35 and ≤ 40 years, respectively. Age groups were also classified in < 30 years and every 10 years thereafter. RESULTS: twenty six (1,980 patients, 111 younger) and 16 studies (598, 41 younger), were analyzed for BC and SOC, respectively. In BC, PIK3CA wild type tumor was associated with early onset, not confirmed in binary regression with estrogen receptor (ER) status. In HER2-negative tumors, there was increased frequency of PIK3CA somatic mutation in older age groups; in ER-positive tumors, there was a trend towards an increased frequency of PIK3CA somatic mutation in older age groups. TP53 somatic mutation was described in 20% of tumors from both younger and older patients; PTEN, CDH1 and GATA3 somatic mutation was investigated only in 16 patients and PTEN mutation was detected in one of them. In SOC, TP53 somatic mutation was rather common, detected in more than 50% of tumors, however, more frequently in older patients. CONCLUSION: frequency of somatic mutations in specific genes was not associated with early-onset breast cancer. Although very common in patients with serous ovarian cancer diagnosed at all ages, TP53 mutation was more frequently detected in older women.

Somatic mutations in breast and serous ovarian cancer young patients: a systematic review and meta-analysis / Mutações somáticas em pacientes jovens com câncer de mama e epitelial de ovário: revisão e metanálise

Summary Objective: our aim was to evaluate whether somatic mutations in five genes were associated with an early age at presentation of breast cancer (BC) or serous ovarian cancer (SOC). Methods: COSMIC database was searched for the five most frequent somatic mutations in BC and SOC. A systematic review of PubMed was performed. Young age for BC and SOC patients was set at ≤35 and ≤40 years, respectively. Age groups were also classified in <30years and every 10 years thereafter. Results: twenty six (1,980 patients, 111 younger) and 16 studies (598, 41 younger), were analyzed for BC and SOC, respectively. In BC, PIK3CA wild type tumor was associated with early onset, not confirmed in binary regression with estrogen receptor (ER) status. In HER2-negative tumors, there was increased frequency of PIK3CA somatic mutation in older age groups; in ER-positive tumors, there was a trend towards an increased frequency of PIK3CA somatic mutation in older age groups. TP53 somatic mutation was described in 20% of tumors from both younger and older patients; PTEN, CDH1 and GATA3 somatic mutation was investigated only in 16 patients and PTEN mutation was detected in one of them. In SOC, TP53 somatic mutation was rather common, detected in more than 50% of tumors, however, more frequently in older patients. Conclusion: frequency of somatic mutations in specific genes was not associated with early-onset breast cancer. Although very common in patients with serous ovarian cancer diagnosed at all ages, TP53 mutation was more frequently detected in older women.

Resumo Objetivo: avaliar se mutações somáticas em câncer de mama e seroso de ovário estão associados com pacientes jovens. Métodos: com base no COSMIC, foram selecionados os cinco genes mais frequentes mutados em câncer de mama e seroso de ovário. Em seguida, realizou-se uma revisão sistemática no PubMed. Pacientes jovens foram classificadas com ≤35 anos e ≤40 anos para câncer de mama e seroso de ovário, respectivamente. Classificaram-se também as pacientes em grupos etários de ≤30 anos, separados a cada 10 anos. Resultados: vinte e seis (1.980 pacientes, 111 jovens) e 16 estudos (598, 41 jovens) foram selecionados para câncer de mama e seroso de ovário, respectivamente. Em câncer de mama, pacientes jovens apresentaram baixa frequência de mutações somáticas em PIK3CA. Tumor HER2 negativo foi associado a mutações somáticas em PIK3CA no grupo etário mais avançado, e em tumores ER positivos foi observada uma tendência a essa associação. Mutações somáticas em TP53 foram observadas em 20% dos tumores, em ambos os grupos (≤35 anos vs. ≥35 anos). Mutações somáticas em PTEN, CDH1 e GATA3 foram analisadas em 16 pacientes e apenas uma apresentou mutação em PTEN. Em câncer seroso de ovário, mutações somáticas em TP53 foram detectadas em mais que 50% dos tumores; entretanto, foram mais frequentes em pacientes idosas. Conclusão: a frequência de mutações somáticas nos genes selecionados não foi associada com pacientes jovens. Embora muito comum em pacientes com câncer seroso de ovário, mutações somáticas em TP53 foram mais frequentes em pacientes mais velhas.

Specific upregulation of RHOA and RAC1 in cancer-associated fibroblasts found at primary tumor and lymph node metastatic sites in breast cancer.

The importance of tumor-stromal cell interactions in breast tumor progression and invasion is well established. Here, an evaluation of differential genomic profiles of carcinoma-associated fibroblasts (CAFs) compared to fibroblasts derived from tissues adjacent to fibroadenomas (NAFs) revealed altered focal adhesion pathways. These data were validated through confocal assays. To verify the possible role of fibroblasts in lymph node invasion, we constructed a tissue microarray consisting of primary breast cancer samples and corresponding lymph node metastasis and compared the expression of adhesion markers RhoA and Rac1 in fibroblasts located at these different locations. Two distinct tissue microarrays were constructed from the stromal component of 43 primary tumors and matched lymph node samples, respectively. Fibroblasts were characterized for their expression of α-smooth muscle actin (α-SMA) and vimentin. Moreover, we verified the level of these proteins in the stromal compartment from normal adjacent tissue and in non-compromised lymph nodes. Our immunohistochemistry revealed that 59 % of fibroblasts associated with primary tumors and 41 % of the respective metastatic lymph nodes (p = 0.271) displayed positive staining for RhoA. In line with this, 57.1 % of fibroblasts associated with primary tumors presented Rac1-positive staining, and the frequency of co-positivity within the lymph nodes was 42.9 % (p = 0.16). Expression of RhoA and Rac1 was absent in fibroblasts of adjacent normal tissue and in compromised lymph nodes. Based on our findings that no significant changes were observed between primary and metastatic lymph nodes, we suggest that fibroblasts are active participants in the invasion of cancer cells to lymph nodes and support the hypothesis that metastatic tumor cells continue to depend on their microenvironment.

MYC is expressed in the stromal and epithelial cells of primary breast carcinoma and paired nodal metastases.

The MYC oncogene is directly involved in the proliferation, metabolism, progression and distant metastasis of breast cancer. Since metastatic spread to the lymph nodes is often the first indication of propensity for metastatic dissemination, the MYC status in nodal disease may represent a decision-making variable. However, the analysis of MYC expression in stromal cells, namely cancer-associated fibroblasts (CAFs), which are known to play a critical role in cancer progression, remains poorly reported. The aim of this study was to determine the expression of MYC and other markers, including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), p53, Ki67, epidermal growth factor receptor (EGFR), phosphorylated AKT (p-AKT) and phospho-mammalian target of rapamycin (p-mTOR) by immunohistochemistry in representative samples from 80 patients with ductal infiltrative breast cancer and 43 paired compromised axillary lymph nodes allocated in tissue microarrays (TMAs). The epithelial and stromal components of primary tumors and respective lymph node metastases were separately analyzed. MYC expression (cytoplasmic and nuclear) was a frequent event in the epithelial and stromal components of the primary tumors. The epithelial cells in the nodal metastases exhibited a trend for decreased MYC expression compared to that in the primary tumors (P=0.08) but retained the original status of the primary tumors for all other markers. The stromal cells were uniformly negative for ER, PR, HER2, p53, Ki67 and EGFR. Comparison of the stromas of primary tumors and respective lymph node metastases revealed a reduced frequency of nuclear MYC in 15% of the cases (P=0.003), whereas p-mTOR followed a similar trend (P=0.09). Analyses of the possible correlations among markers revealed that epithelial nuclear MYC was associated with p53 (P=0.048). This is an original study demonstrating a significant proportion of MYC expression (nuclear or cytoplasmic), as well p-mTOR and p-AKT expression, in the epithelial and stromal components of either the primary tumor or the nodal metastases. CAFs expressing MYC may establish an angiogenic microenvironment supporting cancer survival and facilitating colonization at the nodal metastatic site.

Transcriptional profile of fibroblasts obtained from the primary site, lymph node and bone marrow of breast cancer patients.

Cancer-associated fibroblasts (CAF) influence tumor development at primary as well as in metastatic sites, but there have been no direct comparisons of the transcriptional profiles of stromal cells from different tumor sites. In this study, we used customized cDNA microarrays to compare the gene expression profile of stromal cells from primary tumor (CAF, n = 4), lymph node metastasis (N+, n = 3) and bone marrow (BM, n = 4) obtained from breast cancer patients. Biological validation was done in another 16 samples by RT-qPCR. Differences between CAF vs N+, CAF vs BM and N+ vs BM were represented by 20, 235 and 245 genes, respectively (SAM test, FDR < 0.01). Functional analysis revealed that genes related to development and morphogenesis were overrepresented. In a biological validation set, NOTCH2 was confirmed to be more expressed in N+ (vs CAF) and ADCY2, HECTD1, HNMT, LOX, MACF1, SLC1A3 and USP16 more expressed in BM (vs CAF). Only small differences were observed in the transcriptional profiles of fibroblasts from the primary tumor and lymph node of breast cancer patients, whereas greater differences were observed between bone marrow stromal cells and the other two sites. These differences may reflect the activities of distinct differentiation programs.

MicroRNAs discriminate familial from sporadic non-BRCA1/2 breast carcinoma arising in patients ≤35 years.

The influence of genetic factors may contribute to the poor prognosis of breast cancer (BC) at a very young age. However BRCA1/2 mutations could not explain the majority of cases arising in these patients. MicroRNAs (miRs) have been implicated in biological processes associated with BC. Therefore, we investigated differences in miRs expression between tumors from young patients (≤35 years) with sporadic or familial history and non-carriers of BRCA1/2 mutations. Thirty-six young Brazilian patients were divided into 2 groups: sporadic (NF-BC) or familial breast cancer (F-BC). Most of the samples were classified as luminal A and B and the frequency of subtypes did not differ between familial or sporadic cases. Using real time qPCR and discriminant function analysis, we identified 9 miRs whose expression levels rather than miR identity can discriminate between both patient groups. Candidate predicted targets were determined by combining results from miRWalk algorithms with mRNA expression profiles (n = 91 differently expressed genes). MiR/mRNA integrated analysis identified 91 candidate genes showing positive or negative correlation to at least 1 of the 9 miRs. Co-expression analysis of these genes with 9 miRs indicated that 49 differentially co-expressed miR-gene interactions changes in F-BC tumors as compared to those of NF-BC tumors. Out of 49, 17 (34.6%) of predicted miR-gene interactions showed an inverse correlation suggesting that miRs act as post-transcriptional regulators, whereas 14 (28.6%) miR-gene pairs tended to be co-expressed in the same direction indicating that the effects exerted by these miRs pointed to a complex level of target regulation. The remaining 18 pairs were not predicted by our criteria suggesting involvement of other regulators. MiR-mRNA co-expression analysis allowed us to identify changes in the miR-mRNA regulation that were able to distinguish tumors from familial and sporadic young BC patients non-carriers of BRCA mutations.

Estrogen-responsive genes overlap with triiodothyronine-responsive genes in a breast carcinoma cell line.

It has been well established that estrogen plays an important role in the progression and treatment of breast cancer. However, the role of triiodothyronine (T3) remains controversial. We have previously shown its capacity to stimulate the development of positive estrogen receptor breast carcinoma, induce the expression of genes (PR, TGF-alpha) normally stimulated by estradiol (E2), and suppress genes (TGF-beta) normally inhibited by E2. Since T3 regulates growth hormones, metabolism, and differentiation, it is important to verify its action on other genes normally induced by E2. Therefore, we used DNA microarrays to compare gene expression patterns in MCF-7 breast adenocarcinoma cells treated with E2 and T3. Several genes were modulated by both E2 and T3 in MCF-7 cells (Student's t-test, P < 0.05). Specifically, we found eight genes that were differentially expressed after treatment with both E2 and T3, including amphiregulin, fibulin 1, claudin 6, pericentriolar material 1, premature ovarian failure 1B, factor for adipocyte differentiation-104, sterile alpha motif domain containing 9, and likely ortholog of rat vacuole membrane protein 1 (fold change > 2.0, pFDR < 0.05). We confirmed our microarray results by real-time PCR. Our findings reveal that certain genes in MCF-7 cells can be regulated by both E2 and T3.

TGF-ß1 expression in wound healing is acutely affected by experimental malnutrition and early enteral feeding.

Malnutrition is associated with the delay or failure of healing. We assessed the effect of experimental malnutrition and early enteral feeding with standard diet or diet supplemented with arginine and antioxidants on the levels of mRNA encoding growth factors in acute, open wound healing. Standardised cutaneous dorsal wounds and gastrostomies for enteral feeding were created in malnourished (M, n = 27) and eutrophic control (E, n = 30) Lewis male adult rats. Both M and E rats received isocaloric and isonitrogenous regimens with oral chow and saline (C), standard (S) or supplemented (A) enteral diets. On post-trauma day 7, mRNA levels of growth factor genes were analysed in wound granulation tissue by reverse transcription polymerase chain reaction (RT-PCR). M(C) rats had significantly lower transforming growth factor ß(TGF-ß1 ) mRNA levels than E(C) rats (2·58 ± 0·83 versus 3·53 ± 0·57, P < 0·01) and in comparison with M(S) and M(A) rats (4·66 ± 2·49 and 4·61 ± 2·11, respectively; P < 0·05). VEGF and KGF-7 mRNA levels were lower in M(A) rats than in E(A) rats (0·74 ± 0·16 versus 1·25 ± 0·66; and 1·07 ± 0·45 versus 1·79 ± 0·89, respectively; P≤ 0·04), but did not differ from levels in E(C) and M(C) animals. In experimental open acute wound healing, previous malnutrition decreased local mRNA levels of TGF-ß1 genes, which was minimised by early enteral feeding with standard or supplemented diets.

Comprehensive analysis of BRCA1, BRCA2 and TP53 germline mutation and tumor characterization: a portrait of early-onset breast cancer in Brazil.

Germline mutations in BRCA1, BRCA2 and TP53 genes have been identified as one of the most important disease-causing issues in young breast cancer patients worldwide. The specific defective biological processes that trigger germline mutation-associated and -negative tumors remain unclear. To delineate an initial portrait of Brazilian early-onset breast cancer, we performed an investigation combining both germline and tumor analysis. Germline screening of the BRCA1, BRCA2, CHEK2 (c.1100delC) and TP53 genes was performed in 54 unrelated patients <35 y; their tumors were investigated with respect to transcriptional and genomic profiles as well as hormonal receptors and HER2 expression/amplification. Germline mutations were detected in 12 out of 54 patients (22%) [7 in BRCA1 (13%), 4 in BRCA2 (7%) and one in TP53 (2%) gene]. A cancer familial history was present in 31.4% of the unrelated patients, from them 43.7% were carriers for germline mutation (37.5% in BRCA1 and in 6.2% in the BRCA2 genes). Fifty percent of the unrelated patients with hormone receptor-negative tumors carried BRCA1 mutations, percentage increasing to 83% in cases with familial history of cancer. Over-representation of DNA damage-, cellular and cell cycle-related processes was detected in the up-regulated genes of BRCA1/2-associated tumors, whereas cell and embryo development-related processes were over-represented in the up-regulated genes of BRCA1/2-negative tumors, suggesting distinct mechanisms driving the tumorigenesis. An initial portrait of the early-onset breast cancer patients in Brazil was generated pointing out that hormone receptor-negative tumors and positive familial history are two major risk factors for detection of a BRCA1 germline mutation. Additionally, the data revealed molecular factors that potentially trigger the tumor development in young patients.

Differences in transcriptional effects of 1α,25 dihydroxyvitamin D3 on fibroblasts associated to breast carcinomas and from paired normal breast tissues.

The effects of 1α,25 dihydroxyvitamin D3 (1,25D) on breast carcinoma associated fibroblasts (CAFs) are still unknown. This study aimed to identify genes whose expression was altered after 1,25D treatment in CAFs and matched adjacent normal mammary associated fibroblasts (NAFs). CAFs and NAFs (from 5 patients) were cultured with or without (control) 1,25D 100 nM. Both CAF and NAF expressed vitamin D receptor (VDR) and 1,25D induction of the genomic pathway was detected through up-regulation of the target gene CYP24A1. Microarray analysis showed that despite presenting 50% of overlapping genes, CAFs and NAFs exhibited distinct transcriptional profiles after 1,25D treatment (FDR<0.05). Functional analysis revealed that in CAFs, genes associated with proliferation (NRG1, WNT5A, PDGFC) were down regulated and those involved in immune modulation (NFKBIA, TREM-1) were up regulated, consistent with anti tumor activities of 1,25D in breast cancer. In NAFs, a distinct subset of genes was induced by 1,25D, involved in anti apoptosis, detoxification, antibacterial defense system and protection against oxidative stress, which may limit carcinogenesis. Co-expression network and interactome analysis of genes commonly regulated by 1,25D in NAFs and CAFs revealed differences in their co-expression values, suggesting that 1,25D effects in NAFs are distinct from those triggered in CAFs.

Lipid raft disruption by docosahexaenoic acid induces apoptosis in transformed human mammary luminal epithelial cells harboring HER-2 overexpression.

In HER-2-overexpressing breast cells, HER-2 receptors exist on the cell surface as monomers, homodimers and heterodimers. For signal activation and transduction to occur, HER-2 must be localized to lipid rafts. Therefore, we hypothesized that the amount of lipid rafts on the cell membrane would be a factor in HER-2 signaling. To test this, we used HB4a (an untransformed human mammary epithelial cell line) and HB4aC5.2 cells. HB4aC5.2 cells are HB4a derivatives that have been transfected with five copies of pJ5E.c-ErbB-2 and express approximately 900 times more HER-2 than HB4a cells. In these cells, HER-2 overexpression was accompanied by increased lipid rafts in cell membranes, a hyperactivation of downstream Akt and ERK1/2 proteins, and an increased rate of cell growth compared to HB4a. In addition, HER-2 overexpression was associated with an increased activation of FASN, a key enzyme involved in cellular lipogenesis. Its final product, palmitate, is frequently used to synthesize lipid rafts. We further hypothesized that treatment with docosahexaenoic acid (DHA), an omega-3 fatty acid, would disrupt the lipid rafts and lead to a growth arrest. In HB4aC5.2 cells, but not HB4a cells, we found that DHA treatment disrupted lipid raft; inhibited HER-2 signaling by decreasing activation of Akt, ERK1/2 and FASN proteins; and induced apoptosis. Although little is known about lipid rafts, our data support the idea that disturbances in these microdomains induced by DHA may represent a useful tool for controlling the signaling initiated by HER-2 receptors and its therapeutic potential in the treatment of HER-2 positive breast cancer.

[Thyroid hormone profile in breast cancer patients in postmenopause]. / Perfil dos hormônios da tireoide em pacientes com câncer de mama em estado de menopausa.

OBJECTIVE: The aim of this study was to determine thyroid hormone (TH) profile in postmenopausal patients with breast cancer (BC). SUBJECTS AND METHODS: 12 CaM patients stages I or II, without interventions that could interfere with tumor progression were selected, as well as and a control group with 18 postmenopausal women without CaM. We measured serum anti-thyroperoxidase antibody (TPOAB), thyroid-stimulating hormone (TSH), free thyroxine (T4L), estradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH), before and after surgery, besides immunohistochemistry for estrogen (ER) and progesterone (PR) receptors. RESULTS: Four patients with CaM showed changes in thyroid hormone profile: two had hyperthyroidism, one hypothyroidism, and one was positive for TPO-AB. All of them positive for ER and PR. TSH levels in breast cancer patients were not different from levels found in the control group (1.89 ± 1.56 vs. 2.86 ± 3.12 mIU/mL), but the levels of T4L in patients with CaM were statistically higher than those of the control group (1.83 ± 0.57 vs. 1.10 ± 0.20 ng/dL). CONCLUSION: These results reinforce the need for assessment of thyroid status in CaM patients, since in the absence of E2, changes in clinical HTs can act in E2-controlled processes.

Perfil dos hormônios da tireoide em pacientes com câncer de mama em estado de menopausa / Thyroid hormone profile in breast cancer patients in postmenopause

OBJETIVO: Verificar o perfil dos hormônios tireóideos (HTs) em pacientes pós-menopausa portadoras de carcinoma de mama (CaM). SUJEITOS E MÉTODOS: Participaram 12 pacientes com CaM em estádio I ou II sem intervenções que pudessem interferir na progressão tumoral e um grupo controle com 18 pacientes em pós-menopausa sem CaM. Foram dosados os níveis séricos de anticorpo antitiroperoxidase (TPOAB), hormônio estimulante da tireoide (TSH), tiroxina livre (T4L), estradiol (E2), hormônio folículo estimulante (FSH) e hormônio luteinizante (LH) antes e após a cirurgia, e realizada a imunoistoquímica dos receptores de estrógeno (ER) e progesterona (PR). RESULTADOS: Quatro pacientes com CaM apresentaram alterações do perfil hormonal tireoidiano: dois hipertireoidismo, um hipotireoidismo e positividade TPO-AB, todas com ER e PR positivos. Os níveis de TSH dessas pacientes não foram diferentes dos níveis encontrados no grupo controle (1,89 ± 1,56 vs. 2,86 ± 3,12 mUI/mL), porém os níveis de T4L nas pacientes com CaM foram estatisticamente maiores que o controle (1,83 ± 0,57 vs. 1,10 ± 0,20 ng/dL). CONCLUSÃO: Esses resultados reforçam a necessidade de avaliação do status tireoidiano em pacientes com CaM, uma vez que, na ausência de E2, mudanças clínicas nos HTs podem atuar em vias controladas pelo E2.

OBJECTIVE: The aim of this study was to determine thyroid hormone (TH) profile in postmenopausal patients with breast cancer (BC). SUBJECTS AND METHODS: 12 CaM patients stages I or II, without interventions that could interfere with tumor progression were selected, as well as and a control group with 18 postmenopausal women without CaM. We measured serum anti-thyroperoxidase antibody (TPOAB), thyroid-stimulating hormone (TSH), free thyroxine (T4L), estradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH), before and after surgery, besides immunohistochemistry for estrogen (ER) and progesterone (PR) receptors. RESULTS: Four patients with CaM showed changes in thyroid hormone profile: two had hyperthyroidism, one hypothyroidism, and one was positive for TPO-AB. All of them positive for ER and PR. TSH levels in breast cancer patients were not different from levels found in the control group (1.89 ± 1.56 vs. 2.86 ± 3.12 mIU/mL), but the levels of T4L in patients with CaM were statistically higher than those of the control group (1.83 ± 0.57 vs. 1.10 ± 0.20 ng/dL). CONCLUSION: These results reinforce the need for assessment of thyroid status in CaM patients, since in the absence of E2, changes in clinical HTs can act in E2-controlled processes.