Up-regulation of pS2 expression during the development of adenocarcinomas but not squamous cell carcinomas of the uterine cervix, independently of expression of c-jun or oestrogen and progesterone receptors

Differentiating rectal carcinoma by an immunohistological analysis of carcinomas of pelvic organs based on the NCBI Literature Survey and the Human Protein Atlas database

The treatments and prognoses of pelvic organ carcinomas differ, depending on whether the primary tumor originated in the rectum, urinary bladder, prostate, ovary, or uterus; therefore, it is essential to diagnose pathologically the primary origin and stages of these tumors. To establish the panels of immunohistochemical markers for differential diagnosis, we reviewed 91 of the NCBI articles on these topics and found that the results correlated closely with those of the public protein database, the Human Protein Atlas. The results revealed the panels of immunohistochemical markers for the differential diagnosis of rectal adenocarcinoma, in which [+] designates positivity in rectal adenocarcinoma and [-] designates negativity in rectal adenocarcinoma: from bladder adenocarcinoma, CDX2[+], VIL1[+], KRT7[-], THBD[-] and UPK3A[-]; from prostate adenocarcinoma, CDX2[+], VIL1[+], CEACAM5[+], KLK3(PSA)[-], ACPP(PAP)[-] and SLC45A3(prostein)[-]; and from ovarian mucinous adenocarcinoma, CEACAM5[+], VIL1[+], CDX2[+], KRT7[-] and MUC5AC[-]. The panels of markers distinguishing ovarian serous adenocarcinoma, cervical carcinoma, and endometrial adenocarcinoma were also represented. Such a comprehensive review on the differential diagnosis of carcinomas of pelvic organs has not been reported before. Thus, much information has been accumulated in public databases to provide an invaluable resource for clinicians and researchers.

Trastuzumab reverses letrozole resistance and amplifies the sensitivity of breast cancer cells to estrogen

In this study, we investigated adaptive mechanisms associated with aromatase inhibitor (AI) resistance in breast cancer cells and show that sensitivity to AIs can be extended through dual inhibition of estrogen receptor (ER) and human epidermal receptor-2 (Her-2) signaling. We used human ER-positive breast cancer cells stably transfected with the aromatase gene (MCF-7Ca). These cells grow as tumors in nude mice and are inhibited by AIs. Despite continued treatment, tumors eventually become insensitive to AI letrozole. The cells isolated from these long-term letrozole-treated tumors (LTLT-Ca) were found to have decreased ERalpha levels. Our results suggest that LTLT-Ca cells survive estrogen deprivation by activation of Her-2/mitogen-activated protein kinase (MAPK) pathway. Here, we show that trastuzumab (antibody against Her-2; IC(50) = 0.4 mg/mL) was very effective in restoring the ERalpha levels and sensitivity of LTLT-Ca cells to endocrine therapy by down-regulation of Her-2/MAPK pathway and up-regulation of ERalpha. In contrast, trastuzumab was ineffective in the parental hormone-responsive MCF-7Ca cells (IC(50) = 4.28 mg/mL) and xenografts. By blocking Her-2, trastuzumab also up-regulates ERalpha and aromatase expression and hypersensitized MCF-7Ca cells to E(2). We show that trastuzumab is beneficial in hormone-refractory cells and xenografts by restoring ER, implicating Her-2 as a negative regulator of ERalpha. In xenograft studies, the combination of trastuzumab plus letrozole is equally effective in inhibiting growth of MCF-7Ca tumors as letrozole alone. However, on the acquisition of resistance and increased Her-2 expression, the combination of letrozole plus trastuzumab provided superior benefit over letrozole or trastuzumab alone.

Transcription factor Egr1 acts as an upstream regulator of beta-catenin signalling through up-regulation of TCF4 and p300 expression during trans-differentiation of endometrial carcinoma cells

The beta-catenin/TCF4/p300 pathway is involved in early signalling for trans-differentiation towards the morular phenotype of endometrial carcinoma cells, but little is known about the upstream regulators. Here we show that transcription factor early growth response 1 (Egr1) acts as an initial mediator through up-regulating the expression of TCF4 and p300. In an endometrial carcinoma cell line with abundant oestrogen receptor alpha, Egr1 expression at both mRNA and protein levels was significantly increased by serum and 17beta-oestradiol stimuli. Serum-stimulated cells also showed increased expression of TCF4 and p300, while inhibition of Egr1 by specific siRNAs resulted in decreased expression. Transfection of Egr1 led to transactivation of TCF4 as well as p300 genes, through specific binding to a promoter region, and thus in turn resulted in nuclear accumulation of beta-catenin mediated by the up-regulating TCF4. The overexpression also caused inhibition of beta-catenin/TCF4/p300-mediated transcription, probably through sequestration of p300. Egr1 promoter activity was increased by serum but not 17beta-oestradiol, in contrast to the marked repression associated with TCF4, p300, and Egr1 itself, indicating that the regulation involves several feedback loops. In clinical samples, cells immunopositive for nuclear Egr1, as well as beta-catenin and TCF4, were found to be sporadically distributed in glandular components of endometrial carcinoma with morules. A significant positive correlation between nuclear beta-catenin and TCF4 was observed, but no such link was evident for Egr1, probably due to the existence of negative feedback regulation. Together, these data indicate that Egr1 may participate in modulation of the beta-catenin/TCF4/p300 signalling pathway as an initial event during trans-differentiation of endometrial carcinoma cells, through its impact on several signalling networks.

[Cytosolic pS2 levels and cellular proliferation in ER-positive and PgR-positive infiltrating ductal carcinomas of the breast]

OBJECTIVE

The trefoil factor 1 (TFF1/pS2) is an estrogen-induced molecule in breast tumours. We wanted to study its expression in ER+ and PgR+ infiltrating ductal carcinomas of the breast (IDCs), and to correlate it with other clinical-biological parameters and the outcome.

MATERIAL AND METHODS

Cytosolic pS2 levels were measured using an IRMA (CIS. Biointernational. France) in 170 tumors. Likewise we determined the cytosolic levels of cathepsin D and tissue-type plasminogen activator (t-PA), as well as the concentrations of the epidermal growth factor receptor (EGFR), erbB2 oncoprotein, CD44v5 and CD44v6 on cell surfaces. Also the tumour size, histological grade (HG), axillary lymph node involvement, distant metastasis, ploidy, DNA index and of cellular synthesis phase (SP) was taken in account.

RESULTS

The pS2-positive (> 5 ng/mg prot.) tumours showed higher concentrations of cathepsin D (p: 0.0043) and t-PA (p: 0.0089) than the pS2-negative ones. Likewise, they were less frequently HG3 (p: 0.0231), SP > 7 % (p: 0.0005) and SP > 14% (p:0.0014). During the follow-up time (r: 1-147; 50,1+/-31,7; median 37 months) the pS2-positive tumors showed a less number of recurrences (5/101 vs 6/69; p: 0.059) but not of deaths by the tumor (1/101 vs 2/69).

CONCLUSIONS

These results support an inverse relationship between pS2 positivity and cellular proliferation in IDCs and suggest a new role of this protein (different of the hormone dependence) in the biology of these breast carcinomas, while further studies will be required to establish the impact of this finding on their outcome.

Prognostic and diagnostic significance of beta-catenin nuclear immunostaining in colorectal cancer

In the present study, we investigated the prognostic and diagnostic significance of beta-catenin nuclear immunostaining in 60 specimens of normal colorectal tissue; 180 specimens of colorectal polyps, adenomas, and carcinomas; and 40 specimens from patients with the simultaneous occurrence of polyps, adenomas, and carcinomas. Additional specimens from 59 patients with colorectal carcinoma and 14 patients with adenoma who subsequently developed carcinoma were examined for possible survival study. Immunohistochemical staining showed that the occurrence of nuclear beta-catenin correlated with the sequential stages in colorectal carcinogenesis, in which positive staining was observed in 0% of normal tissues, 8% of polyps, 92% of adenomas, and 100% of carcinomas. High immunohistochemical scores in colorectal carcinoma were significantly associated with lymph node metastasis and poor survival. Adenomas associated with synchronous or metachronous carcinomas showed significantly higher levels of nuclear beta-catenin compared with adenomas without associated carcinomas. Nuclear translocation of beta-catenin was rare or absent in other types of cytokeratin 20 positive adenocarcinomas examined (99 cases). Thus, it was positive in only 7% of colonic mucinous adenocarcinomas, 3% of pancreatic adenocarcinomas, 8% of ovarian mucinous cystadenocarcinomas, and 0% of gastric adenocarcinomas. However, 100% of primary and metastatic colorectal adenocarcinomas were positive for nuclear staining for beta-catenin. Thus, nuclear staining for beta-catenin may serve as an additional parameter to help distinguish colorectal adenocarcinomas from adenocarcinomas of other tissue sites. Collectively, the present large-scale study has clearly addressed the clinical significance of beta-catenin nuclear translocation with respect to tumor progression, survival, and differential diagnosis.

[Cytosolic pS2 levels in 154 non-small-cell lung carcinomas. Correlation with other clinical and biological parameters]

INTRODUCTION

pS2 was first identified as an estrogen induced molecule in a breast cancer cell line, but its gene responds to several growth factors and oncogenic proteins. Its main clinical application lies in breast carcinomas, where it is a molecular marker to identify breast cancer patients who will respond to hormone therapy. This study was performed to evaluate the significance of the pS2 cytosolic levels in non small cell lung carcinomas classified according to different clinical and biological parameters. Likewise, the results obtained were correlated with those observed in normal tissues.

MATERIAL AND METHODS

The study group included 154 non small cell lung carcinomas (59 adenocarcinomas and 95 squamous carcinomas) and 54 normal lung samples. Cathepsin D, pS2, neuron specific enolase (NSE) and CA125 cytosolic concentrations were determined, as well as those of epidermal growth factor receptor (EGFR), erbB2 protein, CD44s, CD44v5 and CD44v6 on cell surface membranes. Likewise, clinical stage, histological grade, ploidy and cellular S-phase fraction were also considered as variables of the study.

RESULTS

We observed cytosolic pS2 values greater than 1 ng/mg protein (positive cutoff) in 18/59 adenocarcinomas and in 10/95 squamous carcinomas (p:0.00177). In adenocarcinomas, pS2 positivity was not correlated with any clinical and biological parameters, but positive cases had lower EGFR (p:0.03770) concentrations and higher CA125 (p:0.01902) levels. In squamous carcinomas, pS2 positivity was associated with lower EGFR (p:0.02270) levels and higher erbB2 protein (p:0,00563) concentrations.

CONCLUSIONS

Our results led us to suggest the following: 1) cytosolic pS2 concentrations are higher in tumoral than in normal samples; 2) adenoarcinomas had higher levels than squamous lung carcinomas; 3) in adenocarcinomas, positivity for pS2 is associated with lower EGFR levels and higher CA125 concentrations suggesting a worse outcome, and 4) in squamous lung tumors, positivity for pS2 was associated with lower EGFR and higher erbB2 oncoprotein concentrations, it not being possible to establish its clinical significance, although it may be correlated with a poor prognosis.

Frequent nuclear beta-catenin accumulation and associated mutations in endometrioid-type endometrial and ovarian carcinomas with squamous differentiation

Focal squamous differentiation is a common feature of endometrioid endometrial and ovarian carcinomas (E-Em and E-Ova Cas). A close association between mutated beta-catenin accumulation and alteration in cellular morphology has recently been demonstrated in murine L cell lines. To clarify the possible role of beta-catenin abnormalities and changes in tumour morphology, 60 grade (G) 1 or G2 E-Em Cas with areas of squamous differentiation (SqD), including morules and squamous metaplastic (SqM) foci, as well as 32 G1 or G2 tumours without such lesions, were investigated and the results compared with findings for c-jun and wnt-1 expression. Twenty-three E-Ova Cas, with and without SqD lesions, were also examined. In E-Em Cas, frequent nuclear beta-catenin accumulation was observed in 22 (84.6%) of 26 tumours with morules and 15 (45.5%) of 33 with SqM foci, in contrast to 4 (12.5%) of 32 without such lesions. Similar findings were also noted for mutations in exon 3 of the beta-catenin gene, involving codons 32, 33, 34, 37, 41, and 45, the single nucleotide substitutions being identical between SqD and the surrounding carcinoma tissue in most informative cases. The mutations were positively related to nuclear immunopositivity, but inversely to membrane expression, while there was no association with the status of c-jun or wnt-1. These E-Ova Cas, nuclear beta-catenin accumulation and mutations were limited to tumours with SqD features, independent of c-jun and wnt-1 status. These data indicate that beta-catenin abnormalities are relatively common in E-Em and E-Ova Cas with SqD features, implying a role in the squamous differentiation of tumour cells, not necessarily related to c-jun and/or wnt-1 status.