Clusterin expression in medullary thyroid carcinoma is inversely correlated with the presence of lymph node metastases.

Clusterin (CLU) is a sulfated glycoprotein implicated in many physiological and pathological processes, including tumorigenesis. Several studies have reported the overexpression of CLU in human neoplasm, examined by immunohistochemistry. However, there are no extensive data on its role in the thyroid. Here we investigate CLU expression in thyroid tumors, and the potential correlation between this expression and clinicopathological parameters. Immunohistochemistry with anti-CLU was performed on paraffin sections from 39 thyroid tumors. Only medullary thyroid carcinomas (MTCs) were positive (n = 5). To confirm these results, 130 further cases (including 4 C-cell hyperplasia), their matched lymph node metastases (46 cases), and lymph node recurrences (10 cases) were analyzed. All MTCs were subdivided according to World Health Organization classification. Cytoplasmic positivity was scored qualitatively (weak, moderate, strong) and quantitatively on a 5-tier scale from 0, 1+ (<10% of cells positive) to 5+ (>75%). Statistical analysis was performed. CLU was expressed in normal C cells, C-cell hyperplasia, all MTCs, their lymph node metastases, and recurrences. There was a strong association between CLU score and the cellular type (P < .004). CLU score was inversely correlated with the presence of lymph node metastases (P < .0001). There were no differences between primary and metastatic or recurrent tumors. CLU expression is related to the cellular type and inversely correlated with the presence of lymph node metastases, which could represent a new positive prognostic factor.

Proliferation and ovarian hormone signaling are impaired in normal breast tissues from women with BRCA1 mutations: benefit of a progesterone receptor modulator treatment as a breast cancer preventive strategy in women with inherited BRCA1 mutations.

Women with inherited BRCA1 mutations have an elevated risk (40-80%) for developing breast and ovarian cancers. Reproductive history has been reported to alter this risk, suggesting a relationship between ovarian hormone signaling and BRCA1-related tumor development. BRCA1 interactions with estrogen receptor (ER) and progesterone receptor (PR) signaling were previously described in human breast cancer cell lines and mouse models. However, few studies have examined the effect of ovarian hormone regulation in normal human breast tissues bearing a heterozygous BRCA1 mutation. This study compares the proliferation level (Ki67) and the expression of ER, PR, and of the PR target gene, fatty acid synthase (FASN), in histologically normal breast tissues from women with BRCA1 mutations (BRCA1+/mut, n=23) or without BRCA1 mutations (BRCA1+/+, n=28). BRCA1+/mut tissues showed an increased proliferation and impaired hormone receptor expression with a marked loss of the PR isoform, PR-B. Responses to estradiol and progesterone treatments in BRCA1+/mut and BRCA1+/+ breast tissues were studied in a mouse xenograft model, and showed that PR and FASN expression were deregulated in BRCA1+/mut breast tissues. Progesterone added to estradiol treatment increased the proliferation in a subset of BRCA1+/mut breast tissues. The PR inhibitor, ulipristal acetate (UPA), was able to reverse this aberrant progesterone-induced proliferation. This study suggests that a subset of women with BRCA1 mutations could be candidates for a UPA treatment as a preventive breast cancer strategy.

Erratum to: Loss of glucocorticoid receptor activation is a hallmark of BRCA1-mutated breast tissue.

Erratum to: Breast Cancer Res Treat (2013),142:283­296,DOI 10.1007/s10549-013-2722-8. In the original publication of the article, the blot corresponding to the total P38 protein content for the conditions siCtl and siBRCA1 in Fig. 7a was incorrectly laid out. The corrected Fig. 7a is given in this erratum.The

Activation of EGFR, HER2 and HER3 by neurotensin/neurotensin receptor 1 renders breast tumors aggressive yet highly responsive to lapatinib and metformin in mice.

A present challenge in breast oncology research is to identify therapeutical targets which could impact tumor progression. Neurotensin (NTS) and its high affinity receptor (NTSR1) are up regulated in 20% of breast cancers, and NTSR1 overexpression was shown to predict a poor prognosis for 5 year overall survival in invasive breast carcinomas. Interactions between NTS and NTSR1 induce pro-oncogenic biological effects associated with neoplastic processes and tumor progression. Here, we depict the cellular mechanisms activated by NTS, and contributing to breast cancer cell aggressiveness. We show that neurotensin (NTS) and its high affinity receptor (NTSR1) contribute to the enhancement of experimental tumor growth and metastasis emergence in an experimental mice model. This effect ensued following EGFR, HER2, and HER3 over-expression and autocrine activation and was associated with an increase of metalloproteinase MMP9, HB-EGF and Neuregulin 2 in the culture media. EGFR over expression ensued in a more intense response to EGF on cellular migration and invasion. Accordingly, lapatinib, an EGFR/HER2 tyrosine kinase inhibitor, as well as metformin, reduced the tumor growth of cells overexpressing NTS and NTSR1. All cellular effects, such as adherence, migration, invasion, altered by NTS/NTSR1 were abolished by a specific NTSR1 antagonist. A strong statistical correlation between NTS-NTSR1-and HER3 (p< 0.0001) as well as NTS-NTSR1-and HER3- HER2 (p< 0.001) expression was found in human breast tumors. Expression of NTS/NTSR1 on breast tumoral cells creates a cellular context associated with cancer aggressiveness by enhancing epidermal growth factor receptor activity. We propose the use of labeled NTS/NTSR1 complexes to enlarge the population eligible for therapy targeting HERs tyrosine kinase inhibitor or HER2 overexpression.

Neurotensin (NTS) and its receptor (NTSR1) causes EGFR, HER2 and HER3 over-expression and their autocrine/paracrine activation in lung tumors, confirming responsiveness to erlotinib.

Alterations in the signaling pathways of epidermal growth factor receptors (HERs) are associated with tumor aggressiveness. Neurotensin (NTS) and its high affinity receptor (NTSR1) are up regulated in 60% of lung cancers. In a previous clinical study, NTSR1 overexpression was shown to predict a poor prognosis for 5 year overall survival in a selected population of stage I lung adenocarcinomas treated by surgery alone. In a second study, shown here, the frequent and high expression of NTSR1 was correlated with a pejorative prognosis in 389 patients with stage I to III lung adenocarcinoma, and was an independent prognosis marker. Interactions between NTS and NTSR1 induce pro-oncogenic biological effects associated with neoplastic processes and tumor progression. Here we highlight the cellular mechanisms activated by Neurotensin (NTS) and its high affinity receptor (NTSR1) contributing to lung cancer cell aggressiveness. We show that the NTS autocrine and/or paracrine regulation causes EGFR, HER2, and HER3 over-expression and activation in lung tumor cells. The EGFR and HER3 autocrine activation is mediated by MMP1 activation and EGF "like" ligands (HB-EGF, Neuregulin 1) release. By establishing autocrine and/or paracrine NTS regulation, we show that tumor growth is modulated according to NTS expression, with a low growth rate in those tumors that do not express NTS. Accordingly, xenografted tumors expressing NTS and NTSR1 showed a positive response to erlotinib, whereas tumors void of NTSR1 expression had no detectable response. This is consistent with the presence of a NTS autocrine loop, leading to the sustained activation of EGFR and responsible for cancer aggressiveness. We propose the use of NTS/NTSR1 tumor expression, as a biomarker for the use of EGFR tyrosine kinase inhibitors in patients lacking EGFR mutation.

Clusterin expression in gastrointestinal neuroendocrine tumours is highly correlated with location and is helpful in determining the origin of liver metastases.

AIMS: Clusterin (CLU) is a sulphated glycoprotein implicated in many physiological and pathological processes, including tumorigenesis. We have previously demonstrated that CLU is highly expressed in pancreatic neuroendocrine tumours (NETs). The aims of this study were: to investigate CLU expression in gastrointestinal NETs; the potential correlation between this expression and different clinicopathological parameters; and its usefulness in the differential diagnosis of liver metastases. METHODS AND RESULTS: Immunohistochemistry using an anti-CLU antibody was performed on paraffin sections from 108 primary NETs [G3 (13 cases), G2 (18 cases), and G1 (77 cases), according to the 2010 WHO classification] and 60 metastases. Cytoplasmic positivity was scored qualitatively and quantitatively. The pattern of staining was also assessed. Two-step statistical analyses (univariate and multivariate logistic regression) were performed. More than 90% of small-intestine NETs were completely negative. The probability of obtaining a positive CLU score was higher for the appendix, the stomach, the duodenum and the rectum than for the small intestine and colon. All G3 NETs and most G2 NETs were negative as compared with G1. CLU expression in the metastatic foci was identical to that of the primary tumour. CONCLUSIONS: Clusterin expression in gastrointestinal NETs is highly correlated with location and probably also with grading, in both the primary tumour and metastases. Underexpression of CLU in small-intestine NETs is helpful for identifying the origin of liver metastases: a strong CLU score in a liver biopsy makes the small intestine highly unlikely as a primary site.

Loss of glucocorticoid receptor activation is a hallmark of BRCA1-mutated breast tissue.

Glucocorticoids (GCs) regulate cell homeostasis and can affect carcinogenesis. An inherited germline mutation in the BRCA1 gene, a tumor suppressor gene, confers a predisposition to breast and ovarian cancers. BRCA1 participates in the maintenance of genome stability through DNA repair, in cellular homeostasis through gene transcription, and in signaling regulation. The interaction between BRCA1 and the glucocorticoid receptor (GR) signaling pathway was studied in normal breast tissues and triple-negative breast cancers from BRCA1 mutation carriers. A loss of the active Ser211 phosphorylated form of GR was found in the mutant as compared to the non-mutant. In in vitro studies, the BRCA1 status in breast cancer cell lines regulates GC-dependent proliferation/apoptosis and impacts GC-dependent gene expression. The lack of BRCA1 inhibited dexamethasone actions on its target genes' expression and the opposite effect was seen with BRCA1 overexpression. BRCA1 overexpression enhances MAPK p38 phosphorylation, resulting in an amplification of GR phosphorylation on Ser 211 and GR basal expression. Our results indicate that BRCA1 is essential to develop an efficient GC signalization. GR P-Ser211 levels may constitute an important diagnostic factor for screening BRCA1 loss of expression in tumors from BRCA1 mutation carriers as well as in sporadic BRCAness tumors. This marker may help to optimize therapeutic strategies.

Perivascular epithelioid cell tumor: the first malignant case report in the pancreas.

Pancreatic perivascular epithelioid cell tumors (PEComas) are exceedingly rare neoplasms, <10 cases have been described; all were benign and occurring mostly in women. We report the first malignant pancreatic PEComa in a patient with BRCA2 mutation. A 51-year-old woman with a medical and familial history of breast adenocarcinoma, who was tested positive for BRCA2 mutation, presented with a recent history of jaundice. Imaging studies were consistent with endocrine or secondary tumor. Pathologic examination of fine needle aspiration biopsy and Whipple procedure revealed a 6-cm intrapancreatic PEComa, invading the duodenal wall with extensive necrosis and vascular invasion, leading to classify this PEComa into "malignant" category. The patient developed liver metastases 6 months after surgery. Although mostly benign, thorough sampling of the PEComa is mandatory, to rule out malignant behavior whatever the location of the tumor is.