ERß1 Sensitizes and ERß2 Desensitizes ERα-Positive Breast Cancer Cells to the Inhibitory Effects of Tamoxifen, Fulvestrant and Their Combination with All-Trans Retinoic Acid.

Adjuvant endocrine therapy (AET) is the treatment of choice for early-stage estrogen receptor alpha (ERα)-positive breast cancer (BC). However, almost 40% of tamoxifen-treated cases display no response or a partial response to AET, thus increasing the need for new treatment options and strong predictors of the therapeutic response of patients at high risk of relapse. In addition to ERα, BC research has focused on ERß1 and ERß2 (isoforms of ERß), the second ER isotype. At present, the impact of ERß isoforms on ERα-positive BC prognosis and treatment remains elusive. In the present study, we established clones of MCF7 cells constitutively expressing human ERß1 or ERß2 and investigated their role in the response of MCF7 cells to antiestrogens [4-hydroxytamoxifen (OHΤ) and fulvestrant (ICI182,780)] and retinoids [all-trans retinoic acid (ATRA)]. We show that, compared to MCF7 cells, MCF7-ERß1 and MCF7-ERß2 cells were sensitized and desensitized, respectively, to the antiproliferative effect of the antiestrogens, ATRA and their combination and to the cytocidal effect of the combination of OHT and ATRA. Analysis of the global transcriptional changes upon OHT-ATRA combinatorial treatment revealed uniquely regulated genes associated with anticancer effects in MCF7-ERß1 cells and cancer-promoting effects in MCF7-ERß2 cells. Our data are favorable to ERß1 being a marker of responsiveness and ERß2 being a marker of resistance of MCF7 cells to antiestrogens alone and in combination with ATRA.

Experimental Intestinal Stenosis Alters Crohn's Disease-Like Intestinal Inflammation in Ileitis-Prone Mice.

BACKGROUND: Clinical observations indicate that mechanical factors contribute to the expression or recurrence of Crohn's disease. We investigated whether the creation of an intestinal stenosis could alter the severity of the expected Crohn-like ileitis, in a Crohn's disease animal model, the TNFΔare/+ mouse. METHODS: Thirty-six, 6-weeks-old TNFΔare/+ mice, were divided into 3 intervention groups: triple suture, single suture and sham. In the terminal ileum, in the first group, a triple suture stenosis was created, whereas, in the second, a loose suture was placed. Same triple-suture stenosis was performed on twelve wild type mice. All animals were sacrificed at 6 weeks post-operatively and the ileum parts were evaluated histopathologically. A summative total ileitis score was applied in each sample using a bespoke semiquantitative histological scoring system for the Crohn-like changes. RESULTS: The triple suture stenosis induced significant muscular hypertrophy proximal to interventional site which was more prominent in TNFΔare/+ than wild type mice. In triple suture group, the total ileitis score was significantly increased proximal to the intervention as compared to the single suture (P: 0.004) and the sham groups (P: 0.013). The total ileitis score distally, was unaffected, regardless of the experimental intervention. Intestinal stenosis did not induce intestinal inflammation in wild type mice. CONCLUSION: The creation of a stenosis in the terminal ileum of TNFΔare/+ mice alters Crohn-like inflammation. We assume that mechanical forces, such as intraluminal pressure, may contribute as important co-factors to the pathophysiology of Crohn's disease in genetically predisposed subjects.

The brominated flame retardants TBECH and DPTE alter prostate growth, histology and gene expression patterns in the mouse.

The brominated flame retardants (BFRs), 1,2-dibromo-4-(1,2 dibromoethyl)cyclohexane (TBECH) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE) bind to the androgen receptor (AR). in vitro bioassays have shown that TBECH is a potent androgen agonist while DPTE is a potent AR antagonist. Both TBECH and DPTE alter gene expression associated with AR regulation. However, it remains to be determined if TBECH and DPTE can affect the prostate. For this reason, we exposed CD1 mice to a 1:1 mixture of TBECH diastereomers α and ß, a 1:1 mixture of γ and δ, and to DPTE, and tested their effects on prostate growth, histology and gene expression profiles. Castrated mice were used to study the androgenic effects of TBECHαß and TBECHγδ while the antagonistic effects of DPTE were studied in non-castrated mice. We observed that testosterone and TBECHγδ increased body and prostate weights while TBECHαß affected neither of them; and that DPTE had no effect on body weight but reduced prostate weight drastically. Histomorphometric analysis of the prostate revealed epithelial and glandular alterations in the TBECHγδ group comparable to those in testosterone group while alterations in the TBECHαß group were less pronounced. DPTE displayed androgen antagonist activity reminiscent of castration. The transcription profile of the prostate was altered by castration and exposure to testosterone and to TBECHγδ reversed several of these changes. Testosterone and TBECHγδ also regulated the expression of several androgen responsive genes implicated in prostate growth and cancer. While DPTE resulted in a drastic reduction in prostate weight, it only affected a small number of genes. The results indicate that TBECHγδ and DPTE are of high human health concern as they may contribute to changes in prostate growth, histology and function.

Design, synthesis, and biological evaluation of new raloxifene analogues of improved antagonist activity and endometrial safety.

Raloxifene agonism of estrogen receptor (ER) in post-menopausal endometrium is not negligible. Based on a rational drug design workflow, we synthesized 14 analogues of raloxifene bearing a polar group in the aromatic ring of the basic side chain (BSC) and/or changes in the bulkiness of the BSC amino group. Analogues with a polar BSC aromatic ring and amino group substituents of increasing volume displayed increasing ER antagonism in Ishikawa cells. Analogues with cyclohexylaminoethoxy (13a) or adamantylaminoethoxy BSC (13b) lacking a polar aromatic ring displayed high ER-binding affinity and ER antagonism in Ishikawa cells higher than raloxifene and similar to fulvestrant (ICI182,780). The endometrial surface epithelium of immature female CD1 mice injected with 13b was comparable to that of vehicle-treated mice, while that of mice treated with estradiol, raloxifene or 13b in combination with estradiol was hyperplastic. These findings indicate that raloxifene analogues with a bulky BSC amino group could provide for higher endometrial safety treatment of the menopausal syndrome.

Experimental Models of Partial Intestinal Obstruction in Young Mice: Establishment, and Evaluation.

BACKGROUND: Partial small bowel obstruction (SBO) is a common, potentially hazardous, surgical entity caused by numerous factors in humans. A number of techniques have been reported as efficient to simulate partial SBO in murine models. However, there is little data concerning their long-term survival. Our study presents a novel technique and evaluates its long-term efficiency compared with other commonly used techniques. MATERIALS AND METHODS: Sixty C57BL/6 mice aged 6 to 8 wk were randomly divided into five intervention groups: ligation, intestinal ring, partial ligation, microclips, and the novel triple suture technique. The ring groups were subdivided into narrow, medium, and wide ring and partial ligation groups were subdivided at 1/3, 1/2, and 2/3 of the lumen. Survival cutoff time was set at 4 wk. Animals were then euthanized and small bowel muscle layer thickness was histopathologically evaluated. RESULTS: None of the animals of the ligation and the ring groups reached the cutoff survival time. The mortality rate of the partial ligation and the microclips groups at the 4-week period were 33.3% and 0%, respectively. However, elimination of the performed intervention was revealed at the time of euthanasia and no alterations of the muscle layer were revealed at histopathology. The "triple suture" group had a survival rate of 90% until euthanasia and the sutures were apparent in all cases. Macroscopic evaluation showed small to mild proximal lumen dilatation in 6 of 10 animals. Histopathological evaluation of the specimens confirmed the partial obstruction. CONCLUSIONS: The "triple suture" technique is a new, robust, reliable, and inexpensive technique for experimental long-standing partial SBO, with very low mortality.

Merkel cell carcinoma of unknown primary site; case presentation and review of the literature.

Merkel cell carcinoma (MCC) is a rare skin malignancy associated with sun exposure and considered as a Neuroendocrine Tumor due to its characteristic histologic features. However there is increasing number of reports of Unknown Primary MCC's (UPMCC). Although initially UPMCC was considered a variant of known primary MCC, there is growing evidence that it could represent a different clinical entity. We present the case of a 60 year-old male patient who was referred to our department for surgical management of lymph node disease for UPMCC. The patient had undergone excisional biopsy of an inguinal lump, which was found to be an infiltrated lymph node by MCC. The patient underwent full imaging staging including a PET/CT, which failed to identify a primary site, and revealed only intra-abdominal lymph node disease. The patient underwent extended retroperitoneal and inguinal lymph node dissection and remains free of recurrence 16 months postoperatively.