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.

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.

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.

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.

Influence of the interaction between nodal fibroblast and breast cancer cells on gene expression.

Our aim was to evaluate the interaction between breast cancer cells and nodal fibroblasts, by means of their gene expression profile. Fibroblast primary cultures were established from negative and positive lymph nodes from breast cancer patients and a similar gene expression pattern was identified, following cell culture. Fibroblasts and breast cancer cells (MDA-MB231, MDA-MB435, and MCF7) were cultured alone or co-cultured separated by a porous membrane (which allows passage of soluble factors) for comparison. Each breast cancer lineage exerted a particular effect on fibroblasts viability and transcriptional profile. However, fibroblasts from positive and negative nodes had a parallel transcriptional behavior when co-cultured with a specific breast cancer cell line. The effects of nodal fibroblasts on breast cancer cells were also investigated. MDA MB-231 cells viability and migration were enhanced by the presence of fibroblasts and accordingly, MDA-MB435 and MCF7 cells viability followed a similar pattern. MDA-MB231 gene expression profile, as evaluated by cDNA microarray, was influenced by the fibroblasts presence, and HNMT, COMT, FN3K, and SOD2 were confirmed downregulated in MDA-MB231 co-cultured cells with fibroblasts from both negative and positive nodes, in a new series of RT-PCR assays. In summary, transcriptional changes induced in breast cancer cells by fibroblasts from positive as well as negative nodes are very much alike in a specific lineage. However, fibroblasts effects are distinct in each one of the breast cancer lineages, suggesting that the inter-relationships between stromal and malignant cells are dependent on the intrinsic subtype of the tumor.

Reciprocal changes in gene expression profiles of cocultured breast epithelial cells and primary fibroblasts.

The importance of epithelial-stroma interaction in normal breast development and tumor progression has been recognized. To identify genes that were regulated by these reciprocal interactions, we cocultured a nonmalignant (MCF10A) and a breast cancer derived (MDA-MB231) basal cell lines, with fibroblasts isolated from breast benign-disease adjacent tissues (NAF) or with carcinoma-associated fibroblasts (CAF), in a transwell system. Gene expression profiles of each coculture pair were compared with the correspondent monocultures, using a customized microarray. Contrariwise to large alterations in epithelial cells genomic profiles, fibroblasts were less affected. In MDA-MB231 highly represented genes downregulated by CAF derived factors coded for proteins important for the specificity of vectorial transport between ER and golgi, possibly affecting cell polarity whereas the response of MCF10A comprised an induction of genes coding for stress responsive proteins, representing a prosurvival effect. While NAF downregulated genes encoding proteins associated to glycolipid and fatty acid biosynthesis in MDA-MB231, potentially affecting membrane biogenesis, in MCF10A, genes critical for growth control and adhesion were altered. NAFs responded to coculture with MDA-MB231 by a decrease in the expression of genes induced by TGFbeta1 and associated to motility. However, there was little change in NAFs gene expression profile influenced by MCF10A. CAFs responded to the presence of both epithelial cells inducing genes implicated in cell proliferation. Our data indicate that interactions between breast fibroblasts and basal epithelial cells resulted in alterations in the genomic profiles of both cell types which may help to clarify some aspects of this heterotypic signaling.

Gene expression profile of residual breast cancer after doxorubicin and cyclophosphamide neoadjuvant chemotherapy.

In breast cancer patients, primary chemotherapy is associated with the same survival benefits as adjuvant chemotherapy. Residual tumors represent a clinical challenge, as they may be resistant to additional cycles of the same drugs. Our aim was to identify differential transcripts expressed in residual tumors, after neoadjuvant chemotherapy, that might be related with tumor resistance. Hence, 16 patients with paired tumor samples, collected before and after treatment (4 cycles doxorubicin/cyclophosphamide, AC) had their gene expression evaluated on cDNA microarray slides containing 4,608 genes. Three hundred and eighty-nine genes were differentially expressed (paired Student's t-test, pFDR<0.01) between pre- and post-chemotherapy samples and among the regulated functions were the JNK cascade and cell death. Unsupervised hierarchical clustering identified one branch comprising exclusively, eight pre-chemotherapy samples and another branch, including the former correspondent eight post-chemotherapy samples and other 16 paired pre/post-chemotherapy samples. No differences in clinical and tumor parameters could explain this clustering. Another group of 11 patients with paired samples had expression of selected genes determined by real-time RT-PCR and CTGF and DUSP1 were confirmed more expressed in post- as compared to pre-chemotherapy samples. After neoadjuvant chemotherapy some residual samples may retain their molecular signature while others present significant changes in their gene expression, probably induced by the treatment. CTGF and DUSP1 overexpression in residual samples may be a reflection of resistance to further administration of AC regimen.

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.

25(OH)D3 and 1,25(OH)2D3 serum concentration and breast tissue expression of 1alpha-hydroxylase, 24-hydroxylase and Vitamin D receptor in women with and without breast cancer.

1,25(OH)2D3 is an antiproliferative agent that may inhibit proliferation of breast cancer (BC) cells in vitro and BC development in animals. Epidemiological studies have shown a high incidence of BC in people less exposed to solar rays. To unravel the role of Vitamin D3 in BC patients, we have investigated serum levels of 25(OH)D3 and its active form 1,25(OH)2D3 as well as tissue expression of 1alpha-hydroxylase, 24-hydroxylase, and Vitamin D-receptor (VDR), determined by semiquantitative RT-PCR, in 88 Brazilian BC patients and 35 women without cancer (submitted to mammoplasties or resection of benign lesions). Median age of women with and without cancer was 51 and 46 years, respectively, and the majority of BC patients were classified as clinical stage II (67%). Although no differences in 25(OH)D3 serum concentration were found, 1,25(OH)2D3 (40+/-21 pg/ml) levels in BC patients were lower than in women without cancer (53+/-23). Our results indicate that 24-hydroxylase, VDR and 1alpha-hydroxylase mRNA tissue expression is similar in both groups and no correlation between 24-hydroxylase, 1alpha-hydroxylase, and VDR expression in breast tumors was found. A low 1,25(OH)2D3 serum concentration seems to be associated to breast cancer, however, the mechanism involved in this regulation is still unclear.

JDP1 (DNAJC12/Hsp40) expression in breast cancer and its association with estrogen receptor status.

The members of the DnaJ/Hsp40 proteins are highly conserved through evolution, expressed in several tissues and act as co-chaperone regulating protein folding, transport, translational initiation and gene expression. Recently, using cDNA microarray we identified differences in the expression of the JDP1 (DNAJC12) gene, a member of the DnaJ/Hsp40 family, between ER-positive and ER-negative breast tumours. In this study, using quantitative real-time PCR (qPCR) we evaluated the expression pattern of the JDP1 gene in a series of 72 primary breast tumours and investigated the effects of 17beta-estradiol on the expression of the JDP1 in MCF-7 breast cancer cells. Three patterns of JDP1 mRNA expression were identified in the primary breast tumours analysed: normal expression was found in 14% of the cases, under-expression in 50%, and over-expression in 36% of the cases. High levels of JDP1 mRNA expression were significantly associated with estrogen receptor-positive status (p=0.02). No relationship was found between JDP1 mRNA expression and any other clinicopathological characteristics of the patients. Sequence analysis of the promoter region of the JDP1 gene revealed the presence of potential estrogen response elements (EREs), suggesting it to be under the control of estrogen action. We also assessed the effects of 17beta-estradiol (10 nM) on JDP1 mRNA expression in MCF-7 breast cancer cells. The JDP1 transcripts were found to be up-regulated in a time-dependent fashion in MCF-7 cells exposed to 17beta-estradiol treatment. Here we show for the first time that JDP1 is a estrogen target gene and that its expression might be used as a marker of the ER transactivation activity and may have a predictive value for response to hormonal therapy.

Gene expression profile associated with response to doxorubicin-based therapy in breast cancer.

PURPOSE: This study was designed to identify genes that could predict response to doxorubicin-based primary chemotherapy in breast cancer patients. EXPERIMENTAL DESIGN: Biopsy samples were obtained before primary treatment with doxorubicin and cyclophosphamide. RNA was extracted and amplified and gene expression was analyzed using cDNA microarrays. RESULTS: Response to chemotherapy was evaluated in 51 patients, and based on Response Evaluation Criteria in Solid Tumors guidelines, 42 patients, who presented at least a partial response (> or =30% reduction in tumor dimension), were classified as responsive. Gene profile of samples, divided into training set (n = 38) and independent validation set (n = 13), were at first analyzed against a cDNA microarray platform containing 692 genes. Unsupervised clustering could not separate responders from nonresponders. A classifier was identified comprising EMILIN1, FAM14B, and PBEF, which however could not correctly classify samples included in the validation set. Our next step was to analyze gene profile in a more comprehensive cDNA microarray platform, containing 4,608 open reading frame expressed sequence tags. Seven samples of the initial training set (all responder patients) could not be analyzed. Unsupervised clustering could correctly group all the resistant samples as well as at least 85% of the sensitive samples. Additionally, a classifier, including PRSS11, MTSS1, and CLPTM1, could correctly distinguish 95.4% of the 44 samples analyzed, with only two misclassifications, one sensitive sample and one resistant tumor. The robustness of this classifier is 2.5 greater than the first one. CONCLUSION: A trio of genes might potentially distinguish doxorubicin-responsive from nonresponsive tumors, but further validation by a larger number of samples is still needed.

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.

[Molecular biology in the prostate neoplasia]. / Biologia molecular das neoplasias de próstata.

Prostate cancer (PC) is one of the main causes of disease and death and represents the second cause of death among men in Brazil. Benign prostate hyperplasia is a progressive and prevalent disease. It is estimated that men present around 50% and 90% of histological evidences of prostate hyperplasia at 50 and 80 years, respectively. While the pathogenesis of prostate neoplasias has been closely related to androgen and their specific nuclear receptor, the molecular mechanisms of cell growth, differentiation and apoptosis processes are still not clearly established. Co-activators and co-repressors could also contribute to prostate carcinogenesis by their binding to nuclear receptors or by interacting with the transcriptional machinery in order to increase the transcription of target genes. AR and type 2 5alpha reductase polymorphisms seem to be associated to the risk for PC. In addition, apoptosis and cellular cycle regulator genes, as well as growth factors, have been reported to be associated with the prostate tumorigenesis. Therefore, changes on the gene expression of normal tissue may be associated to the development of malign phenotype and these genes could be regarded as candidates of prognosis markers. The number of these genes increases every day but the present data needs further studies and correlation with the disease progression.

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.

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.

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.

Differentially expressed genes and estrogen receptor status in breast cancer.

There is a large and increasing body of experimental and clinical data supporting the involvement of estrogen on the proliferation of hormone-dependent breast tumors. Estrogen acts via its receptor (ER) stimulating cellular proliferation. ER and progesterone receptor (PR), which is regulated by estrogen via ER, have been used as prognostic markers in the clinical management of breast cancer patients. The aim of the present study was the identification of tumor-associated genes differentially expressed in breast tumors regarding the presence or absence of ER and PR. Using the technique of differential display reverse transcriptase-polymerase chain reaction (DDRT-PCR) we have isolated and cloned 127 cDNA fragments that showed differential expression in either ER+/PR+ or ER-/PR- breast tumors. Sequencing analysis of these clones revealed that 119 cDNAs had homology with known sequences in the National Center of Biotechnology Information (NCBI) and 8 were novel, showing no homology to known genes. Among these differentially expressed transcripts are metabolic enzymes, ribosomal proteins, transcription factors, hypothetical proteins, cell cycle regulators, cytoskelectum related genes, cell adhesion and motility genes. Differences in gene expression profiles are likely to explain the phenotypic differences between hormone-responsive and hormone-unresponsive breast tumors.