Combined targeting of HER-2 and HER-3 represents a promising therapeutic strategy in colorectal cancer

Background

Abrogation of growth factor-dependent signaling represents an effective therapeutic strategy for patients with colorectal cancer (CRC). Here we evaluated the effectiveness of targeting the epidermal growth factor (EGF) receptors HER-2 and HER-3 in the three cell lines LS513, LS1034 and SW837.

Methods

Treatment with HER-2-specific antibodies trastuzumab and pertuzumab resulted in a mild reduction of cellular viability. In contrast, the antibody-drug conjugate T-DM1 mediated a strong and dose-dependent decrease of viability and Akt phosphorylation.

Results

The most striking effects were observed with the dual tyrosine kinase inhibitor lapatinib, and the Pan-ErbB inhibitor afatinib. Selectively, the effect of EGF receptor inhibition was augmented by a combination with 5-fluorouracil and oxaliplatin. Finally, high expression of HER-3 was detected in 121 of 172 locally advanced rectal cancers (70.3%). In conclusion, inhibition of EGF receptors effectively blocks downstream signaling and significantly impairs viability of CRC cells. However, the effectiveness of receptor inhibition highly depends on the inhibitors’ mode of action, as targeting HER-2 alone is not sufficient.

Conclusion

Since HER-2 and HER-3 are expressed in a relevant number of patients, targeting both receptors may represent a promising therapeutic strategy for CRC.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-6051-0) contains supplementary material, which is available to authorized users.

Physical basis of the 'magnification rule' for standardized Immunohistochemical scoring of HER2 in breast and gastric cancer

Background

Detection of HER2/neu receptor overexpression and/or amplification is a prerequisite for efficient anti-HER2 treatment of breast and gastric carcinomas. Immunohistochemistry (IHC) of the HER2 protein is the most common screening test, thus precise and reproducible IHC-scoring is of utmost importance. Interobserver variance still is a problem; in particular in gastric carcinomas the reliable differentiation of IHC scores 2+ and 1+ is challenging.

Herein we describe the physical basis of what we called the ‘magnification rule’: Different microscope objectives are employed to reproducibly subdivide the continuous spectrum of IHC staining intensities into distinct categories (1+, 2+, 3+).

Methods

HER2-IHC was performed on 120 breast cancer biopsy specimens (n = 40 per category). Width and color-intensity of membranous DAB chromogen precipitates were measured by whole-slide scanning and digital morphometry. Image-analysis data were related to semi-quantitative manual scoring according to the magnification rule and to the optical properties of the employed microscope objectives.

Results

The semi-quantitative manual HER2-IHC scores are correlated to color-intensity measured by image-analysis and to the width of DAB-precipitates. The mean widths ±standard deviations of precipitates were: IHC-score 1+, 0.64 ± 0.1 μm; score 2+, 1.0 ± 0.23 μm; score 3+, 2.14 ± 0.4 μm. The width of precipitates per category matched the optical resolution of the employed microscope objective lenses: Approximately 0.4 μm (40×), 1.0 μm (10×) and 2.0 μm (5×).

Conclusions

Perceived intensity, width of the DAB chromogen precipitate, and absolute color-intensity determined by image-analysis are linked. These interrelations form the physical basis of the ‘magnification rule’: 2+ precipitates are too narrow to be observed with 5× microscope objectives, 1+ precipitates are too narrow for 10× objectives. Thus, the rule uses the optical resolution windows of standard diagnostic microscope objectives to derive the width of the DAB-precipitates. The width is in turn correlated with color-intensity. Hereby, the more or less subjective estimation of IHC scores based only on the staining-intensity is replaced by a quasi-morphometric measurement. The principle seems universally applicable to immunohistochemical stainings of membrane-bound biomarkers that require an intensity-dependent scoring.

Electronic supplementary material

The online version of this article (10.1186/s13000-018-0696-x) contains supplementary material, which is available to authorized users.

The Prognostic Value of Tyrosine Kinase SRC Expression in Locally Advanced Rectal Cancer

The cellular sarcoma gene (SRC) is a proto-oncogene encoding for a tyrosine kinase. SRC expression was determined in locally advanced rectal adenocarcinoma tissue from pretreatment biopsies and resection specimens. The expression level was correlated with clinicopathological parameters to evaluate the predictive and prognostic capacity.

For this monocentric analysis 186 patients with locally advanced rectal cancer (median: 63.7 years; 130 men (69.9%), 56 women (30.1%)) were included. Patients with a carcinoma of the upper third of the rectum were treated with primary tumor resection (n=27; 14.5%). All other patients received a preoperative chemoradiotherapy (CRT) with 50.4 Gy and concomitant 5-fluorouracil (5-FU) or 5-FU+oxaliplatin followed by postoperative chemotherapy with 5-FU or 5-FU+oxaliplatin. SRC expression was determined with immunohistochemical staining from pretreatment biopsies (n=152) and residual tumor tissue from the resection specimens (n=163). The results were correlated with clinicopathological parameters and long-term follow-up.

The expression of SRC was determined in pretherapeutic biopsies (mean H-Score: 229) and resection specimens (mean H-Score: 254). High SRC expression in pretherapeutic tumor samples significantly correlated with a negative postoperative nodal status (p=0.005). Furthermore an increased protein expression in residual tumor tissue was associated with fewer distant metastases (p=0.04). The overexpression of SRC in pretreatment tumor biopsies showed also a trend for a longer cancer-specific survival (CSS; p=0.05) and fewer local relapses (p=0.06) during long-term follow-up.

High SRC expression in rectal cancer seems to be associated with a better long-term outcome. This finding could help in the future to stratify patients for a recurrence risk adapted postoperative treatment.

HER-2 and HER-3 expression in liver metastases of patients with colorectal cancer

OBJECTIVE

In this study, we evaluate the frequency of HER-2 and HER-3 expression in liver metastases from patients with colorectal cancer (CRLM). We analyzed the potential of HER-2 and HER-3 as therapeutic targets and evaluated their prognostic value.

PATIENTS AND METHODS

Overall 208 patients with CRLM were enrolled. HER-2 and HER-3 expression were determined in metastatic tissue of diagnostic punch biopsies (n = 29) or resection specimens (n = 179). The results of immunohistochemistry (IHC) scoring and In-situ-hybridization (ISH)-amplification were correlated with clinical parameters and for the 179 resected patients with cancer-specific (CSS) and overall survival (OS). The mean follow-up time was 56.7 months.

RESULTS

Positivity of HER-2 status (IHC score 2+/ISH+ and IHC 3+) was found in 8.2% of CRLM. High expression of HER-3 (IHC score 2+ and IHC 3+) was detected in 75.0% of liver metastases. CSS after liver surgery was determined and was independent from the HER-2 status (p = 0.963); however HER-3 was prognostic with a favorable course for patients showing an overexpression of HER-3 (p = 0.037).

CONCLUSIONS

HER-2 overexpression occurs in only 8% of patients with CRLM but with 75% of cases HER-3 is frequently overexpressed in CRLM. Therefore, HER-2 and particularly HER-3 could serve as novel targets to be addressed within multimodal treatment approaches.

β-catenin-independent WNT signaling and Ki67 in contrast to the estrogen receptor status are prognostic and associated with poor prognosis in breast cancer liver metastases

Liver metastasis development in breast cancer patients is common and confers a poor prognosis. So far, the prognostic significance of surgical resection and clinical relevance of biomarker analysis in metastatic tissue have barely been investigated. We previously demonstrated an impact of WNT signaling in breast cancer brain metastasis. This study aimed to investigate the value of established prognostic markers and WNT signaling components in liver metastases. Overall N = 34 breast cancer liver metastases (with matched primaries in 19/34 cases) were included in this retrospective study. Primaries and metastatic samples were analyzed for their expression of the estrogen (ER) and progesterone receptor, HER-2, Ki67, and various WNT signaling-components by immunohistochemistry. Furthermore, β-catenin-dependent and -independent WNT scores were generated and analyzed for their prognostic value. Additionally, the influence of the alternative WNT receptor ROR on signaling and invasiveness was analyzed in vitro. ER positivity (HR 0.09, 95 % CI 0.01–0.56) and high Ki67 (HR 3.68, 95 % CI 1.12–12.06) in the primaries had prognostic impact. However, only Ki67 remained prognostic in the metastatic tissue (HR 2.46, 95 % CI 1.11–5.44). Additionally, the β-catenin-independent WNT score correlated with reduced overall survival only in the metastasized situation (HR 2.19, 95 % CI 1.02–4.69, p = 0.0391). This is in line with the in vitro results of the alternative WNT receptors ROR1 and ROR2, which foster invasion. In breast cancer, the value of prognostic markers established in primary tumors cannot directly be translated to metastases. Our results revealed β-catenin-independent WNT signaling to be associated with poor prognosis in patients with breast cancer liver metastasis.

Comprehensive lymph node morphometry in rectal cancer using acetone compression

Aims

Acetone compression (AC) is an elution compression technique for the comprehensive pathological examination of fatty tissue. Here AC is combined with digital morphometry to evaluate the impact of preoperative (neoadjuvant) chemoradiotherapy (neoCRT) on lymph node (LN) numbers and morphology in locally advanced rectal cancer. AC is compared with complete embedding of the mesorectal fat (whole mesorectal embedding (WME)) to exclude artificial alterations and to the standard technique, manual dissectioning (MD).

Methods

320 rectal cancer specimens were subjected to LN morphometry. Neoadjuvant CRT was applied in 204 specimens. LNs were prepared either with AC (n=138), WME (n=51) or MD (n=131). 8523 LNs were assessed including 530 nodes with metastases.

Results

LN prepared by AC and WME showed similar morphologies. AC revealed reduced LN sizes in neoCRT specimens compared with primary resection (2.2; 2.4 mm, p=0.049) while the LN number was comparable (27; 30/specimen). AC yielded 28 LN/specimen on average, MD yielded 22 LN (p<0.001). In neoCRT specimens, MD yielded less LN compared with primary resection (19; 25). MD detected less small LN (<2 mm; MD: 25%; AC: 56%) while 24 of the 135 LN metastases found by AC were ≤2 mm in diameter.

Conclusions

AC does not alter LN morphology and is especially suited to retrieve small LN after neoadjuvant CRT of rectal cancer. Neoadjuvant multimodality treatment caused reduced LN sizes while the LN numbers were not affected. When compared with MD, AC proved more reliable in the retrieval of LN from rectal cancer specimens after neoCRT.

HER2 and HER3 expression in hepatic metastases of colorectal cancer: New targets for specific treatment approaches?

567

Background: Even though treatment options for coloretal cancer liver metastases have improved with the implementation of multimodal strategies and new agents, progression of distant metastases is still limiting the prognosis of affected patients. In this context we investigated the expression of HER2 and HER3 in patients with metastatic colorectal cancer and primary tumors. Methods: In this study 226 consecutive patients with hepatic metastases of colorectal cancer were included. HER2 and HER3 expression were determined in the tissue from resected metastases and—if available—in primary tumors. Immunohistochemical scoring (IHC 0 to IHC 3) and S-ISH-amplification-detection (for HER2) were used to determine the HER2 and HER3 status. Results: A positive HER2 status was found in 8.4% of all hepatic metastases; an overexpression of HER-3 in 74,8% of all cases. There was a high congruence of the expression pattern of HER2 and HER3 between hepatic metastases and available primary tumors (>90%). Conclusions: HER2 amplification and HER3 overexpression is detectable in a significant proportion of hepatic metastases of colorectal cancer. These results suggest that innovative new targeted treatment agents might be possible opportunities for the specific therapy of patients with HER2/HER3 positive metastatic colorectal cancer and should be further assessed within prospective clinical trials.

Oxaliplatin-Induced Leukocytoclastic Vasculitis under Adjuvant Chemotherapy for Colorectal Cancer: Two Cases of a Rare Adverse Event

Leukocytoclastic vasculitis is a multicausal systemic inflammatory disease of the small vessels, histologically characterized by inflammation and deposition of both nuclear debris and fibrin in dermal postcapillary venules. The clinical picture typically involves palpable purpura of the lower legs and may be associated with general symptoms such as fatigue, arthralgia and fever. Involvement of the internal organs, most notably the kidneys, the central nervous system or the eyes, is possible and determines the prognosis. Oxaliplatin-induced leukocytoclastic vasculitis is a very rare event that limits treatment options in affected patients. We report 2 patients who developed the condition under chemotherapy for advanced rectal and metastatic colon carcinoma, respectively; a termination of the therapy was therefore necessary. While current therapies for colorectal cancer include the combination of multimodal treatment with new and targeted agents, rare and unusual side effects elicited by established agents also need to be taken into account for the clinical management.

Evaluation of EGFR protein expression by immunohistochemistry using H-score and the magnification rule: re-analysis of the SATURN study

INTRODUCTION

The phase III SATURN study demonstrated that first-line maintenance erlotinib extended progression-free survival (PFS) and overall survival (OS) versus placebo in patients with advanced non-small cell lung cancer (NSCLC). Analysis of epidermal growth factor receptor (EGFR) expression by immunohistochemistry (IHC) found no significant interaction between EGFR IHC status and PFS (p = 0.63) or OS (p = 0.52). The FLEX study of first-line cetuximab plus chemotherapy demonstrated that EGFR IHC expression was predictive of improved OS with cetuximab when assessed by H-score with a magnification rule. This novel method was used to reassess samples from SATURN.

METHODS

The H-score method assigned a score of 0-300 to each patient, based on the percentage of cells stained at different intensities viewed at various magnifications. The discriminatory threshold was set at 200, per the FLEX study, and existing samples were re-read and classed as low (H-score < 200) or high (≥200) EGFR expression. PFS and OS were re-analyzed based on these new classifications.

RESULTS

In the overall and EGFR wild-type populations, erlotinib provided a consistent survival benefit versus placebo. Hazard ratios (HRs) in the overall population were similar between EGFR IHC-positive and -negative patients for median PFS (HR 0.68 [95% confidence interval (CI) 0.53-0.86] and 0.76 [95% CI 0.62-0.93], respectively) and OS (HR 0.80 [95% CI 0.62-1.05] and 0.80 [95% CI 0.64-1.01] for IHC-positive and IHC-negative, respectively). In the EGFR wild-type population, HRs were again similar between EGFR IHC-positive and -negative subpopulations for PFS (HR 0.69 [95% CI 0.51-0.95] and 0.84 [95% CI 0.63-1.12], respectively) and OS (HR 0.78 [95% CI 0.55-1.10] and 0.76 [95% CI 0.55-1.05], respectively).

CONCLUSIONS

These data suggest that EGFR IHC does not have value as a marker to predict erlotinib benefit in the first-line maintenance setting for advanced NSCLC.

[Translational research and diagnostics of melanoma]

Although early stage malignant melanoma (MM) has a favorable prognosis five year survival rate is poor (<10%) in patients suffering from distant metastases. Due to molecular typing of MM recently high response rates were achieved in metastatic MM by using specific inhibitors directed against the mutated form of BRAF kinase, e.g. Vemurafinib and Dabrafinib. Therefore BRAF mutation analysis has become standard of care in advanced MM and pathologists are urged to provide a quality guaranteed molecular diagnostics. However, squamous neoplasias (e. g., keratoacanthomas) and recurrences of MM mostly within 6 months during targeted therapy point to the need of further translational research. Thus new drugs, such as MEK inhibitors, based on the MAP-kinase pathway downstream of BRAF have already effectively been used. Finally, the impact of molecular characteristics in different subtypes of MM (acral, mucosal, uveal) will be discussed with respect to their specific mutational spectrum (e.g. cKIT , NRAS , GNAQ).

Reproducibility of immunohistochemical scoring for epidermal growth factor receptor expression in non-small cell lung cancer: round robin test

CONTEXT

The addition of cetuximab to first-line chemotherapy substantially prolonged survival in patients with advanced non-small cell lung cancer whose tumors expressed high levels of epidermal growth factor receptor (EGFR; immunohistochemistry score of ≥200 on a scale of 0-300).

OBJECTIVE

To evaluate the interobserver reproducibility of this EGFR immunohistochemistry scoring system, based on both the tumor cell membrane staining intensity (graded 0-3+) and the percentage of cells staining at each intensity.

DESIGN

In parts 1 (initial feasibility study) and 2 of this 2-part round robin test, sections of different non-small cell lung cancer tissue microarrays were stained in a central reference laboratory. Following reference evaluation, EGFR expression in 30 selected tumor cores was characterized in serial sections by lung cancer pathology specialists. The reproducibility of scoring by different raters was assessed. Analysis of between-rater agreement was based on the allocation of EGFR immunohistochemistry scores into low- (<200) and high- (≥200) EGFR expression groups.

RESULTS

After discussion with raters of the issues impacting reproducibility identified in part 1 and following adjustment of processes, part 2 of the round robin test showed a high interobserver agreement in EGFR immunohistochemistry scoring, with an overall concordance rate of 90.9% and a mean κ coefficient of 0.812. Specimens with a reference EGFR immunohistochemistry score of lower than 200 and of 200 or higher showed mean concordance rates of 94.7% and 85.6%, respectively.

CONCLUSIONS

After appropriate training, assessing EGFR expression by this immunohistochemistry-based method allowed a highly reproducible allocation of non-small cell lung cancers into clinically relevant high- or low-EGFR expression groups.

Pyloric gland adenoma of the cystic duct with malignant transformation: report of a case with a review of the literature

Background

Pyloric gland adenoma consists of closely packed pyloric-type glands lined by mucus-secreting cells. To date, approximately 230 cases have been reported, mostly of gastric localization with a tumour size up to 3.5 cm and a mean age of occurrence around 70 years. Adenocarcinoma develops in about 40% of cases and may be difficult to detect due to relatively mild nuclear atypia.

Case presentation

We present the first case of a pyloric gland adenoma of the cystic duct in a 62-year-old male patient and demonstrate the clinicopathologic characteristics, including radiographic, molecular, and cytogenetic findings. The 2 cm-tumour developed in the cystic duct and protruded into the hepatic and common bile duct. On microscopic examination, it displayed closely packed pyloric-type glands, and focal architectural distortion with mild nuclear atypia. Immunohistochemically, it expressed MUC1, MUC5AC, MUC6 and p53, but not MUC2 and CD10. The Ki67-proliferation index was 25%. Furthermore, high-grade intraepithelial neoplasia was observed in the surrounding bile duct. We detected chromosomal gains at 7p, 7q11q21, 15q, 16p, 20, losses at 6p23pter, 6q, 18, and amplifications at 1q and 6p21p22 in the pyloric gland adenoma by comparative genomic hybridization. A KRAS codon 12 mutation (c.35G>T; p.G12V) was detected in the pyloric gland adenoma and in the adjacent dysplasia by sequencing analysis. The diagnosis of pyloric gland adenoma was established with transition into well-differentiated adenocarcinoma and high-grade biliary intraepithelial neoplasia.

Conclusion

Pyloric gland adenoma evolving in the cystic duct is a rare differential diagnosis of obstructive bile duct tumours. Other premalignant bile duct lesions may be associated. Due to the risk of developing adenocarcinoma, surgical resection should be performed.

Enrichment of CD133-expressing cells in rectal cancers treated with preoperative radiochemotherapy is an independent marker for metastasis and survival

BACKGROUND

The transmembrane glycoprotein CD133 (cluster of differentiation 133; also known as Prominin or PROM1) has been described as a potential stem cell marker in colorectal cancer and is associated with higher tumorigenic potential and resistance to radiochemotherapy (RCT). In this study, CD133 expression was evaluated in pre-RCT tumor biopsies and the corresponding post-RCT surgical specimens from patients with locally advanced rectal adenocarcinoma, and expression levels were correlated with histopathologic features and clinical follow-up.

METHODS

One hundred twenty-six patients with International Union Against Cancer (UICC) stage II/III rectal cancer who received preoperative 5-fluorouracil (5-FU)-based RCT within the German Rectal Cancer Trials were investigated. Pre-RCT and post-RCT CD133 expression levels were determined using immunohistochemistry and were correlated with histopathologic parameters, tumor regression grade, cancer recurrence, and patient survival.

RESULTS

Compared with pre-RCT biopsies, significantly higher CD133 expression was observed in tumor specimens (P = .01). However, no correlations were observed for either biopsies or tumor specimens between CD133 expression levels, histopathologic characteristics, or survival. In matched analyses of corresponding biopsy/tumor pairs, patients who had an increased fraction of CD133-expressing (CD133+) cells after preoperative RCT had significantly higher residual tumor stages (P = .02) and lower histopathologic tumor regression (P < .01). Moreover, these patients had significantly reduced disease-free survival and cancer-specific overall survival in univariate analysis (P < .001 and P = .004, respectively) and multivariate analysis (P = .003 and P = .024, respectively).

CONCLUSIONS

The enrichment of CD133+ cancer cells during preoperative RCT was correlated with minor local tumor response, increased distant cancer recurrence, and decreased survival. The current results indicate that the up-regulation of intratumoral CD133 expression, in contrast to absolute pre-RCT and post-RCT CD133 levels, plays an important role in tumor progression and metastasis in patients with rectal cancer who are receiving neoadjuvant RCT.

Cetuximab, capecitabine, oxaliplatin, and radiotherapy as preoperative triple treatment for rectal cancer (CET-CAPOX-RT-Phase-I/II Study): Influence on long-term survival and relevance of biomarkers

e14162

Background: Preoperative application of cetuximab and radiochemotherapy combined with 5-FU+oxaliplatin (CET-CAPOX-RT-phase-I/II-study) failed to increase the complete remission rate (pCR, primary endpoint) in rectal cancers. Here, we report longterm survival in respect of biomarkers. Methods: In 45 of 53 patients (85%) total mesorectal excision (TME) was performed with curative intention. Disease-/progression-free survival (DFS/PFS) and overall cancer specific survival (CSS) were correlated with clinicopathological findings (e.g. tumor regression grading (TRG), KRAS-, HER-2-, Ki67-, EGFR-, IGF1R-, Src-, PTEN-, Survivin-, XIAP- and thymidylatesynthase(TS)-status). Results: After triple RCT, ypUICC stages were 0 (4x), I (17x), II (10x), III (14x) and IV (7x); RCT-induced T-level- (49%) and UICC-downcategorizing (53%) correlated with major (38% TRG 3-4) versus minor response (62.3% TRG 0-2) (p=0.005 and p=0.02, respectively). During follow-up (63 months) 7/53 patients with M1-status at surgery died. In 45 patients with M0-status no locoregional failure but in 5 patients metastatic recurrences were detected. DFS at 1, 3 and 5 years was 90.7% (CI: 82.5-99.8), 88.3% (CI: 79.2-98.5) and 88.3% (CI: 79.2-98.5); the CSS was 97.6% (CI: 93.1-100), 95.2% (CI: 89-100), and 90.3% (CI: 82-99.8), respectively. Patients with ypN0-status demonstrated better DFS (p=0.027), PFS (p=0.024) and CSS (p=0.016). KRAS mutations (33%) had no prognostic influence but a positive HER-2-status (18%) seemed to be associated with better CSS (p=0.11). High Ki-67-expression (p=0.09) as well as the loss of RCT-induced Survivin-downregulation (p=0.05) correlated with reduced CSS. No prognostic influence was found for EGFR-, IGF1R-, Src-, PTEN-, XIAP- and TS-expression. Conclusions: The disappointing pCR rate of the CET-CAPOX-RT-phase-I/II-study did not translate to poor longterm survival.

HER2 status in locally advanced rectal cancer and metachronous metastases: Opportunity for a new therapeutic approach?

3600

Background: Even though the implementation of multimodal treatment strategies including neoadjuvant radiochemotherapy (RCT) has led to improved survival distant metastases are still limiting the prognosis of rectal cancer patients. In this context, we investigated the HER-2 status in rectal cancer patients, UICC stages II and III. Our aim was to assess the HER-2 positivity rate in primary tumors and metachronous metastases. Methods: In this study 264 rectal cancer patients (192 male, 72 female; median age 64 years) from phase-II/-III-trials of the German Rectal Cancer Study Group (CAO/ARO/AIO-94 and 04) were included. HER-2 status was determined pretherapeutically in tumor biopsies as well as resection specimens and metachronous metastases (n=27) using immunohistochemistry (IHC0 to IHC3+) scoring and S-ISH-amplification detection. Tumors with IHC3+ or S-ISH ratio ?2.0 were classified as HER-2 positive; results were correlated with clinicopathological parameters and long-term survival. Results: A positive HER-2 status was found in 12.4% of pre-treatment biopsies, in 29.3% of the resection specimens and 22.2% (n=6) of metastases. With a median follow-up of 46.5 months patients with HER-2-positivity showed better disease free survival (p=0.06) and cancer-specific survival (CSS, p=0.05). The 5-years survival rate was 96.4% (HER-2-positive) versus 79.5% (HER-2-negative). In multivariate analyses HER-2 status was as an independent (p=0.0053) predictor for CSS along with (y)pN-status (p<0.0001) and R-status (p=0.023). Conclusions: HER-2 amplification is detectable in a significant proportion (about 30%) of primary tumors of patients with advanced rectal cancer. Furthermore HER-2 amplification was detectable in 22% of resected metachronous metastases during follow-up. Therefore HER-2 represents a promising target and should be further assessed within prospective clinical trials.

HER2/neu expression in locally advanced rectal cancer cUICC II/III and its correlation with long-term prognosis

493

Background: With the implementation of multimodal treatment strategies including neoadjuvant radiochemotherapy (RCT), the prognosis of locally advanced rectal cancer has been improved over the last two decades. Most actual clinical trials aim to further develop therapy by intensification of agents administered. We examined Her2/neu in rectal cancer patients to evaluate its expression as a potential drug target as well as its capacity as predictive and prognostic biomarker.

Methods: Two-hundred-seventy-seven patients (205 male, 72 female; median age 63.5 years) with locally advanced rectal cancer (cUICC-II/III) were included in this study. Preoperative RCT (50.4 Gy and concomitant either 5-FU or 5-FU and oxaliplatin) was administered in 236 patients followed by surgical resection with total mesorectal excision (TME). Another 41 patients received postoperative RCT. All patients were treated within phase-II/-III-trials of the German Rectal Cancer Study Group or analogous to these standardized protocols. Her2-/neu expression from pre-treatment biopsies and corresponding resection specimens were assessed by immunohistochemical staining and SISH-analysis.

Results: A positive Her-2/neu expression was found in 12.3% of all pre-treatment tumor biopsy samples and in 28.7% of the resection specimens. The correlation of the pre-treatment Her-2/neu status did not show a significant correlation with the grade of tumor regression. However, patients with a higher Her-2/neu protein expression as measured in the resection specimen showed a significant survival benefit (p=0.0277) compared with patients having low intratumoral Her-2/neu expression during the follow-up (median 43 months). The 10-year survival rate was 73.2% (Her-2/neu positive) versus 60.1% (Her-2/neu negative).

Conclusions: The proportion of patients with a positive Her-2/neu status is relevant in rectal cancer. Her-2/neu might potentially serve as a promising drug target in rectal cancer and should be further assessed within prospective clinical trials. Furthermore the Her-2/neu status seems to be a valuable prognostic marker within the multimodal treatment of advanced rectal cancer.

Simultaneous aberrations of single CDKN2A network components and a high Rb phosphorylation status can differentiate subgroups of primary cutaneous B-cell lymphomas

The cyclin-dependent kinase inhibitor 2A (CDKN2A) gene on chromosome 9p21 encodes p16 (INK4A), the inhibitor of the CDK4/retinoblastoma (Rb) cell proliferation pathway, as well as p14 (ARF), which controls p53-dependent pathways. Inactivation of p16 has previously been associated with the prognostically unfavourable primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL, LT). In this work, we analysed 22 tumors [nine primary cutaneous follicle centre lymphomas (PCFCL), seven primary cutaneous marginal zone lymphomas (PCMZL) and six PCLBCL, LT] not only for alterations of the p16 gene but also for p14, p53 and Rb by fluorescence in situ hybridization (FISH) and immunohistochemistry. In most PCLBCL, LT (4/6) alterations of CDKN2A (two biallelic deletions, one monoallelic deletion and one trisomy 9) and in addition the highest frequency of deletions of p53 (3/6) and Rb (3/6) were detected. p16 was not expressed but very high levels of phosphorylated Rb, indicating a functional effect of genomic CDKN2A alterations on the protein level in PCLBCL, LT. Regarding the p14/p53 axis, PCLBCL, LT showed a variable expression. Neither PCFCL nor PCMZL showed alterations of CDKN2A and also deletions of p53 or Rb were extremely rare in these subtypes. Exclusively in PCMZL, p53 protein was consistently lacking. In conclusion, only PCLBCL, LT is characterized by a high frequency of aberrations of the CDKN2A network components in both important tumor suppressor pathways regulated by the CDKN2A gene. Moreover, PCLBCL, LT appears to be distinguishable from PCMZL not only by its level of p53 expression but also by its stage of Rb phosphorylation. The latter may also apply to a subgroup of PCFCL.

Thymidylate synthase as a prognostic biomarker for locally advanced rectal cancer after multimodal treatment

Purpose

For years, 5-fluorouracil (5-FU) has been the backbone of radiochemotherapy (RCT) of locally advanced rectal cancer. Its main target, thymidylate synthase (TS), is speculated to be an important biomarker for response prediction and long-term prognosis. In this study, we analyzed TS expression in the rectal cancer tissue of 208 patients to evaluate its predictive/prognostic potential.

Methods

All patients included were diagnosed with locally advanced adenocarcinoma of the rectum (UICC II and III) and were treated within randomized clinical trials of the German Rectal Cancer Study Group. Preoperative RCT (50.4 Gy and concomitant either 5-FU or 5-FU and oxaliplatin) was administered in 167 patients followed by surgical resection with total mesorectal excision (TME). Another 41 patients received postoperative RCT. TS levels and further clinicopathological parameters were assessed in univariate and multivariate analyses. Additionally, a TS gene polymorphism was analyzed with respect to the intratumoral protein levels.

Results

Low TS expression in pretreatment biopsies correlated with impaired patient survival (p = 0.015). Analysis of a 28-bp repeat revealed a correlation between the *3/*3 genotype and high TS expression in pretherapeutic biopsies. In this study, a correlation of TS expression and grade of RCT-induced tumor regression was not found. Histopathological examination confirmed a complete tumor remission in 16 patients (9.6%).

Analyses of the resection specimen indicated an unfavorable prognosis for patients with low intratumoral TS expression in case of detected lymph node metastases (p = 0.04).

Conclusions

TS can serve as a prognostic biomarker indicating an unfavorable prognosis for patients with low TS expression.

Electronic supplementary material

The online version of this article (doi:10.1245/s10434-011-1608-4) contains supplementary material, which is available to authorized users.

Chemokine-mediated distribution of dendritic cell subsets in renal cell carcinoma

Background

Renal cell carcinoma (RCC) represents one of the most immunoresponsive cancers. Antigen-specific vaccination with dendritic cells (DCs) in patients with metastatic RCC has been shown to induce cytotoxic T-cell responses associated with objective clinical responses. Thus, clinical trials utilizing DCs for immunotherapy of advanced RCCs appear to be promising; however, detailed analyses concerning the distribution and function of DC subsets in RCCs are lacking.

Methods

We characterized the distribution of the different immature and mature myeloid DC subsets in RCC tumour tissue and the corresponding normal kidney tissues. In further analyses, the expression of various chemokines and chemokine receptors controlling the migration of DC subsets was investigated.

Results

The highest numbers of immature CD1a+ DCs were found within RCC tumour tissue. In contrast, the accumulation of mature CD83+/DC-LAMP+ DCs were restricted to the invasive margin of the RCCs. The mature DCs formed clusters with proliferating T-cells. Furthermore, a close association was observed between MIP-3α-producing tumour cells and immature CCR6+ DC recruitment to the tumour bed. Conversely, MIP-3β and SLC expression was only detected at the tumour border, where CCR7-expressing T-cells and mature DCs formed clusters.

Conclusion

Increased numbers of immature DCs were observed within the tumour tissue of RCCs, whereas mature DCs were found in increased numbers at the tumour margin. Our results strongly implicate that the distribution of DC subsets is controlled by local lymphoid chemokine expression. Thus, increased expression of MIP-3α favours recruitment of immature DCs to the tumour bed, whereas de novo local expression of SLC and MIP-3β induces accumulation of mature DCs at the tumour margin forming clusters with proliferating T-cells reflecting a local anti-tumour immune response.

Exophytic benign mixed epithelial stromal tumour of the kidney: case report of a rare tumour entity

Background

Mixed epithelial and stromal tumour (MEST) represents a recently described benign composite neoplasm of the kidney, which predominantly affects perimenopausal females. Most tumours are benign, although rare malignant cases have been observed.

Case report

A 47-year-old postmenopausal female presented to the urologist with flank pain. A CT scan of the abdomen showed a 30-mm-in-diameter uniform mass adjacent to the pelvis of the left kidney. Surgical exploration showed a tumour arising from the lower anterior hilus of the left kidney. The tumour could be excised by preserving the kidney. By intraoperative frozen section the tumour showed characteristic features of MEST with epithelial-covered cysts embedded in an "ovarian-like" stroma. Additional immunohistochemistry investigations showed expression for hormone receptors by the stromal component of the tumour.

Discussion

MEST typically presents in perimenopausal women as a primarily cystic mass. Commonly, the tumour arises from the renal parenchyma or pelvis. The tumour is composed of an admixture of cystic and sometimes more solid areas. The stromal cells typically demonstrate an ovarian-type stroma showing expression for the estrogen and progesterone receptors.

Conclusion

MEST represents a distinctive benign tumour entity of the kidney, which affects perimenopausal woman. The tumour should be distinguished from other cystic renal neoplasms. By imaging studies it is difficult to distinguish between a benign or malignant nature of the tumour. Thus, intraoperative frozen section is necessary for conservative surgery, since the overall prognosis is favourable and renal function can be preserved in most cases.

[Active surveillance of localized prostate cancer. Significance of prostate core needle biopsies]

Today, more than 80% of men diagnosed with prostate cancer (PCA) by PSA screening do not die from the sequelae of their disease. About 70% present with early, organ-confined cancer and almost half of them are small (<5 cm(3)) without evidence of progression over years (insignificant PCA). It is assumed that screening brings the diagnosis of PCA forward by about 9 years and that in almost one third of these cases immediate radical prostatectomy or radiotherapy would result in overtreatment. Thus, the treatment strategy of "active surveillance" with selective but delayed intervention for patients with organ-confined PCA could be an attractive alternative to the known curative therapy options. However, a prerequisite of such a therapeutic approach would be a precise identification of patients at high risk for cancer progression. Careful work-up of prostate core needle biopsies including improved pre-embedding preparation and detailed interpretation are of the utmost importance. A Gleason score < or =6 and tumor in only one or two cores are considered predictive of organ-confined cancer. Pathologists should concentrate on correct Gleason scoring in core needle biopsies and identification of lesions that exclude a patient from active surveillance.

Sinushistiozytose mit massiver Lymphadenopathie (Rosai-Dorfman-Erkrankung)

Sinus histiocytosis with massive lymphadenopathy (SHML) is a rare, painless lymphoproliferative disorder of unknown origin with a usually benign course. About 40% of the patients show an extranodal involvement with skin being the most common site in 27% of these patients. We describe a patient with widespread disease involving the respiratory tract, kidneys and skin. Histopathology revealed the characteristic features of SHML with emperipolesis and immunohistochemical positivity of histiocytes for S100 and macrophage-associated antigens.

Cathepsin K deficiency partially inhibits, but does not prevent, bone destruction in human tumor necrosis factor-transgenic mice

OBJECTIVE

Cathepsin K is believed to have an eminent role in the pathologic resorption of bone. However, several studies have shown that other proteinases also participate in this process. In order to clarify the contribution of cathepsin K to the destruction of arthritic bone, we applied the human tumor necrosis factor (hTNF)-transgenic mouse model, in which severe polyarthritis characterized by strong osteoclast-mediated bone destruction develops spontaneously.

METHODS

Arthritis was evaluated in hTNF-transgenic mice that were either wild-type for cathepsin K (CK(+/+)), heterozygous for cathepsin K (CK(+/-)), or deficient in cathepsin K (CK(-/-)). Arthritic knee joints were prepared for standard histologic assessment aimed at establishing a semiquantitative score for joint destruction and quantification of the area of bone erosion. Additionally, microfocal computed tomography was performed to visualize bone destruction in mice with the different CK genotypes. CK(+/+) and CK(-/-) osteoclasts were generated in vitro, and their proteinase expression profiles were compared by complementary DNA array analysis, real-time polymerase chain reaction, and activity assays.

RESULTS

Although the area of bone erosion was significantly reduced in hTNF-transgenic CK(-/-) mice, the absence of cathepsin K did not completely protect against inflammatory bone lesions. Several matrix metalloproteinases (MMPs) and cathepsins were expressed by in vitro-generated CK(-/-) osteoclasts, without marked differences from CK(+/+) osteoclasts. MMP activity was detected in CK(-/-) osteoclasts, and MMP-14 was localized by immunohistochemistry in inflammatory bone erosions in hTNF-transgenic CK(-/-) mice, suggesting MMPs as potential contributors to bone destruction. Additionally, we detected a reduction in osteoclast formation in cathepsin K-deficient mice, both in vitro and in vivo.

CONCLUSION

The results of our experiments raise doubts about a crucial role of cathepsin K in arthritic bone destruction.

Signal transducer and activator of transcription 1 decoy oligodeoxynucleotide suppression of contact hypersensitivity

BACKGROUND

Cytokines play a pivotal role in allergy development through activating signaling mechanisms, such as the Janus kinase/signal transducer and activator of transcription (STAT) pathway, which controls the expression of numerous proinflammatory genes.

OBJECTIVE

In comparison with 2 different corticosteroids and a calcineurin inhibitor, the efficacy of a STAT1 decoy oligodeoxynucleotide (dODN)-containing ointment on hapten-induced contact hypersensitivity was examined in 3 different animal models.

METHODS

After sensitization, the test compounds were administered before hapten challenge, after hapten challenge, or both to different sites of the animal skin. Subsequent erythema and edema formation was scored macroscopically, microscopically, or by a shift in ear weight. Biopsy specimens were taken and processed for histopathology, immunohistochemistry, and real-time PCR analyses.

RESULTS

Treatment with the STAT1 dODN but not the corresponding control ODN markedly improved the clinical signs of inflammation in all 3 animal models in a dose-related manner. In guinea pig skin this was accompanied by a distinct decrease in leukocyte infiltration into the dermis after 24 hours. In addition, expression of CD40, IFN-gamma, IL-1beta, IL-8, IL-12, and TNF-alpha was strongly attenuated. The dODN was equally effective in the domestic pig model when administered therapeutically, and its preventive effect in the mouse model lasted for more than 48 hours.

CONCLUSIONS

Altogether, treatment with the dODN proved to be at least as effective as treatment with the reference compounds.

Transcriptional profiling of transurethral resection samples provides insight into molecular mechanisms of hormone refractory prostate cancer

The molecular mechanisms for hormone-resistant prostate cancer progression still remain elusive, mainly due to the limited availability of corresponding tissue. As transurethral resection (TUR) is a common palliative therapy for patients with hormone refractory prostate cancer (HRPC) who have subvesical obstruction, we aimed to demonstrate that TUR samples can be used to identify significantly affected biological pathways during the switch to HRPC using oligonucleotide microarray analysis. Among the most significantly deregulated pathways in HRPC, we observed an induction of oxidative phosphorylation and a repression of cytoskeletal components.

Molecular analysis of hormone refractory prostate cancer biopsies supports the rationale of using mTOR inhibitors

21126

Background: The aim of our group is to identify molecular signatures in samples of hormone refractory prostate cancer (HRPC) patients (pts) that lead to novel rationales for medical treatment. We have previously shown that transurethral resections (TUR) of the prostate in HRPC pts are useful specimens for gene expression profiling using microarrays (ASCO 2006). Aim of this study was to prove the feasibility of gene expression profiling on prostate biopsies and to develop a standardised tissue handling protocol in order to facilitate multicenter research. Methods: Biopsy material and corresponding TUR chips or classical specimens from 8 pts with HRPC, 13 pts with localized PCA, 6 pts with benign prostatic hyperplasia (BPH) and 11 pts without cancer or BPH were investigated and compared. The tumor type and content was evaluated by a pathologist. Tissues were preserved in liquid nitrogen or RNAlater. Different tissue lysis and RNA purification methods were compared by the quantity (NanoDrop measurement) and quality (Bioanalyser, Agilent) of isolated RNA. Gene expression profiling occurred on Affymetrix HG-FOCUS arrays. Results: Most reliable gene expression results were obtained by biopsy lysis in Trizol using the QIAshredder. A total of more than 1 μg RNA was isolated from one biopsy. RNA quality fulfilled pre-defined criteria such as a 28S/18S rRNA ratio of > 0.8, an area under the curve of > 10% and a RNA integrity number > 6.5. A comparison of HRPC and PCA samples clearly confirmed previous results of a deregulation of protein biosynthesis (translation initiation and elongation factors, ribosome biogenesis) and PI3K signalling pathway components. Conclusions: Gene expression profiling supports the induction of the PI3K-AKT-mTOR pathway in HRPC. A standardised protocol for gene expression profiling from prostate biopsy samples applicable for translational research programs within multicenter clinical trials is now available. As a part of a clinical phase II trial that aims to investigate survival benefits on HRPC pts treated with docetaxel ± RAD001, a translational research program is now set up in parallel to identify biomarkers for response prediction using microarray gene expression analysis from prostate biopsies.

No significant financial relationships to disclose.

Follicular dendritic cell sarcoma of the spleen

Diagnosis of primary spindle cell tumors of the spleen is challenging because of the limited immunologic and cytogenetic characterization of this rare entity. We report a case of primary follicular dendritic cell (FDC) sarcoma of the spleen in a 44-year-old woman. Indications for FDC included positive staining for CD21, Ki-M4P, CD14, and fascin. Expression of both standard FDC markers CD23 and CD35 was detected immunohistochemically using tyramide signal amplification. Cytogenetic analysis revealed multiple clonal chromosomal aberrations involving unbalanced translocations of chromosomes X, 3, 5, 7, 8, 9, and 10, leading to net gains at 3q, 7p, 8q, and 9q and net losses at Xp, 8p, 9p, and 10p. Loss at Xp has been described previously in another tumor with FDC features, suggesting that this aberration might play a common role in this malignancy.

STAT-1 decoy oligonucleotide improves microcirculation and reduces acute rejection in allogeneic rat small bowel transplants

During acute rejection leukocyte-endothelial cell interaction fuelled by costimulatory molecules such as the CD40/CD154 receptor/ligand dyad disrupts microcirculation of the small bowel. Downregulating endothelial CD40 expression by employing a decoy oligonucleotide (dODN) neutralizing the transcription factor signal transducer and activator of transcription-1 (STAT-1) may protect the graft. Therefore allogenic small bowel transplantation was performed in the Brown Norway to Lewis rat model. Graft vessels were pretreated with STAT-1 dODN, mutant control ODN (20 microM) or vehicle (n=8). CD40 antisense ODN and scrambled control ODN-treated transplants served as target control (n=3 each). Intravital microscopy, histology, immunohistochemistry and Western blot analyses were performed 7 days later. Functional capillary density, red blood cell velocity and perfusion index in STAT-1 dODN and CD40 antisense ODN-treated transplants were improved whereas stasis index was reduced. Leukocyte-endothelial cell interaction showed no difference. Histological parameters of rejection, infiltrating CD3-positive cells and apoptotic bodies were also reduced in STAT-1 dODN and CD40 antisense ODN-treated transplants 7 days post-transplantation. CD40 protein abundance was reduced to less than 10% of control in STAT-1 dODN-treated grafts. STAT-1 dODN blockade of CD40 expression improves mucosal perfusion, reduces graft rejection, T-cell infiltration and apoptosis in rat small bowel allografts during acute rejection.

Parvovirus B19 detected in Rosai-Dorfman disease in nodal and extranodal manifestations

Sinus histiocytosis with massive lymphadenopathy (SHML), also designated as Rosai-Dorfman disease (RDD), is a rare benign reactive lymphoproliferative disorder. It is defined by a characteristic histopathology with sinus histiocytosis and haemophagocytosis known as emperipolesis. In histiocytes S100 is strongly expressed, whereas CD1a staining typically is negative. The disease mainly manifests at a single lymph node; however, multilocular and extranodal affection can occur. Causative infectious agents, and virus infections in particular, have repeatedly been suspected, although until now the origin of the disease has been unclear. Four cases of RDD (two nodal sites and two extranodal upper respiratory tract sites) were analysed for parvovirus B19 (B19) infection by immunohistochemistry to detect B19 capsid proteins VP1/VP2. In all the four cases, huge numbers of B19-positive cells were partly detected. The positive cells were identified either as lymphocytes or, in one extranodal case, also as respiratory epithelial cells. This is the first report of B19 infection in RDD tissue, indicating that B19 may be associated with the pathogenesis of SHML.

Prevention of TNFα-associated myocardial dysfunction resulting from cardiopulmonary bypass and cardioplegic arrest by glucocorticoid treatment

OBJECTIVE

Cardiac surgery on cardiopulmonary bypass (CPB) results in progressive myocardial dysfunction, despite unimpaired coronary blood flow, and is associated with increased myocardial tumor necrosis factor-alpha (TNFalpha) expression. We investigated whether anti-inflammatory treatment prevents increased TNFalpha expression and myocardial dysfunction after CPB.

METHODS AND RESULTS

Baseline systemic hemodynamics, myocardial contractile function, aortic and coronary blood flow were measured in anesthetized pigs. Then, placebo (PLA; saline; n=7) or methylprednisolone (MP; 30 mg/kg; n=6) was infused intravenously and CPB was instituted. Global ischemia was induced for 10 min by aortic cross-clamping, followed by 1 h of cardioplegic cardiac arrest. After declamping and reperfusion, CPB was terminated after a total of 3 h. Measurements were repeated at 15 min, 4 h, and 8 h following termination of CPB. Systemic TNFalpha-plasma concentrations and left ventricular TNFalpha expression were analyzed. With unchanged coronary blood flow in both groups, a progressive loss of myocardial contractile function to 38+/-2% of baseline (p<0.01) and cardiac index to 48+/-6% of baseline (p<0.01) at 8 h after CPB in PLA was attenuated in MP (myocardial function: 72+/-3%, p<0.01 vs PLA; cardiac index: 78+/-6%, p<0.05 vs PLA). Systemic TNFalpha was increased at 8 h in PLA compared to MP (243+/-34 vs 90+/-34 pg/ml, p<0.05). Myocardial TNFalpha was increased at 8 h after CPB compared to baseline and MP (p<0.05). Myocardial TNFalpha immunostaining was more pronounced in PLA than in MP (p<0.05), with TNFalpha-mRNA localization predominantly to cardiomyocytes.

CONCLUSIONS

Methylprednisolone attenuates both systemic and myocardial TNFalpha increases and progressive myocardial dysfunction induced by cardiac surgery, suggesting a key role for TNFalpha.

Increased number of mature dendritic cells in Crohn's disease: evidence for a chemokine mediated retention mechanism

BACKGROUND AND AIMS

Activation of T cells by dendritic cells (DC) is thought to play a pivotal role in induction and maintenance of Crohn's disease. Detailed analyses however concerning the phenotype and maturation of DC as well as the mechanisms underlying their recruitment are still lacking for Crohn's disease.

METHODS

Different myeloid and plasmacytoid DC subsets were characterised by immunohistochemistry. Expression of the so-called "lymphoid" chemokines CCL19, CCL20, and CCL21 was determined by real time reverse transcription-polymerase chain reaction in Crohn's disease and normal controls. Furthermore, expression of CCL19, CCL20, and CCL21 as well as their receptors CCR6 (for CCL20) and CCR7 (for CCL19 and CCL21) was characterised by immunohistochemistry and, in addition, their cellular localisation was determined by double immunofluorescence investigations.

RESULTS

Colonic tissue affected by Crohn's disease was characterised by an increased number of mature myeloid DC forming clusters with proliferating T cells. In keeping with their advanced maturation, DC possess the chemokine receptor CCR7. Increased expression of the CCR7 ligands CCL19 by DC themselves as well as CCL21 by reticular cells and lymphatic vessels was observed in Crohn's disease, thereby causing the matured DC to be trapped at the site of inflammation.

CONCLUSION

Our results demonstrate that autocrine and paracrine actions of lymphoid chemokines in Crohn's disease may lead to increased numbers of mature DC away from their usual migration to lymphoid organs and result in the development of a tertiary lymphatic tissue within the bowel wall maintaining the autoimmune inflammation in Crohn's disease.

Subcellular localization of rat Abca5, a rat ATP-binding-cassette transporter expressed in Leydig cells, and characterization of its splice variant apparently encoding a half-transporter

Several transporters belonging to the ABCA subfamily of ABC (ATP-binding cassette) proteins are involved in lipid trafficking. Human ABCA5 and its rat orthologue, rAbca5, represent recently identified subfamily members whose substrate spectrum remains to be defined. The elucidation of (sub)cellular rAbca5 distribution would be expected to provide a basis for optimization of functional analyses. In the present study, we applied in situ hybridization to examine rAbca5 mRNA distribution within sections of rat testis, a tissue expressing high levels of rAbca5 mRNA. We found rAbca5 mRNA to be predominantly expressed in interstitial Leydig cells, which are major sites of testosterone synthesis. To investigate rAbca5 subcellular localization, we constructed expression vectors yielding rAbca5 fused either to EGFP (enhanced green fluorescent protein) or to a peptide bearing the viral V5 epitope. During rAbca5 cDNA cloning, we discovered a splice variant sequence (rAbca5 V20+16), predicted to give rise to a truncated, half-size transporter, which was highly homologous with a human splice variant described by us previously. Quantitative RT (reverse transcription)-PCR demonstrated that the rAbca5 splice variant was expressed in numerous tissues (including testis, brain and lungs), its cDNA amounting to 2.6-11.2% of total rAbca5 cDNA. Transfection of individual rAbca5-EGFP, rAbca5 splice variant-EGFP or transporter-V5 expression plasmids along with organelle marker plasmids into HEK-293 cells (human embryonic kidney 293 cells) revealed that both rAbca5 and splice variant fusion proteins co-localized with marker protein for the Golgi apparatus. Expression of rAbca5 mRNA in Leydig cells, intracellular localization of rAbca5-EGFP/rAbca5-V5 and involvement of rAbca5-related proteins in lipid transport suggest that rAbca5 may participate in intracellular sterol/steroid trafficking.

The maturation-dependent production of interleukin-16 is impaired in monocyte-derived dendritic cells from atopic dermatitis patients but is restored by inflammatory cytokines TNF-alpha and IL-1beta

BACKGROUND

Maturation of dendritic cells (DCs) influences important DC functions such as production of cytokines. Recently, DCs were identified as a source of interleukin-16 (IL-16), a chemotactic factor for DCs themselves, CD4+ T cells, and eosinophils. There is evidence that DC-derived IL-16 may contribute to the pathogenesis of atopic dermatitis (AD).

OBJECTIVE

To investigate the production of IL-16 during differentiation of monocytes into DCs in healthy individuals and patients with AD.

METHODS

IL-16 production was investigated by quantitative real-time RT-PCR, intracellular cytokine staining, immunoblotting, and ELISA.

RESULTS

DCs generated from peripheral monocytes by 5-day culture in the presence of IL-4 and granulocyte/macrophage colony-stimulating factor acquired the capability to synthesize, store, and secrete IL-16. Storage and release of IL-16 was further enhanced during final DC maturation induced by additional 3-day culture with tumor necrosis factor-alpha (TNF-alpha) and monocyte-conditioned medium. Maturation, as determined by up-regulation of CD83 and CD86 surface expression, and production of IL-16, but not production of IL-10 and IL-12p40 was impaired in day 8 DCs derived from AD patients compared to those from healthy donors. Stimulation of day 8 DCs from AD patients with TNF-alpha and IL-1beta enhanced the expression of CD83 and CD86 and restored the production of IL-16.

CONCLUSIONS

Signals involved in the activation and maturation of DCs enhance their capacity to produce IL-16. Functional abnormalities present in patients with AD at the monocyte level may account for impaired maturation and IL-16 production of monocyte-derived DCs.

CD4+ CD56+ blastic tumor of the skin: cytogenetic observations and further evidence of an origin from plasmocytoid dendritic cells

We here report on a case of a blastic tumor, recently described to belong to a new entity sharing phenotypic similarities with blood derived plasmocytoid dendritic cells and formerly regarded as belonging to the group of natural killer cell lymphomas. Besides immunophenotypic characteristics such as the absence of T- cell markers and almost complete absence of markers of the myeloid lineage, these tumors express CD4, CD56 and CD123, the receptor for interleukin-3. Moreover, using the comparative genomic hybridisation technique, CGH, we demonstrate a gain of chromosome 7q, 22 and a loss of chromosome 3p and 13q. Since this type of hematologic disorder often shows its primary manifestation in the skin and often runs a rapidly fatal course, it is important to distinguish this from other types of primary cutaneous lymphomas.

Human skin mast cells express H2 and H4, but not H3 receptors

Mast cells generate and release histamine during anaphylactic reactions, and there is pharmacological evidence that histamine regulates this process via specific receptors. Therefore, we examined human leukemic (HMC-1) and normal skin mast cells for the expression of all four currently known histamine receptors. Both cell types expressed H2 and H4 receptors at mRNA and protein levels, whereas H3 receptor specific mRNA and receptor protein was undetectable. Similarly, immunohistochemistry of cutaneous tissue showed an absence of H3 receptor in these cells. Despite transcription of mRNA, H1 receptor protein was only moderately expressed in HMC-1 cells and was virtually absent in skin mast cells. Furthermore, only H1, H2, and H4 receptors were detectable by Western blot analysis of HMC-1 cells. Radiolabeled histamine binding was strongly inhibited only by H2 (ranitidine)- and H3/H4 (FUB 108)-specific antagonists. Histamine-induced increase of cAMP was inhibited by the H2 receptor antagonist famotidine, whereas induction of IP3 was not observed, making signaling via the H1 receptor unlikely. These data show that human mast cells constitutively express primarily H2 and H4 receptors and that H2 receptors are functionally linked to cellular processes. They provide new insights into the mechanisms that govern auto- and paracrine histamine-induced mast cell functions.

Glucocorticoid receptor expression in inflammatory bowel disease: evidence for a mucosal down-regulation in steroid-unresponsive ulcerative colitis

BACKGROUND

Glucocorticoids (GC) play a major role in the attenuation of inflammation. Glucocorticoid receptor (GR) expression is an important determinant of steroid sensitivity.

AIMS

To investigate whether GR mRNA expression is altered in inflammatory bowel disease, and whether GR mRNA expression correlates with disease activity and may predict response to GC therapy.

METHODS

Mucosal biopsies were taken from 33 patients with ulcerative colitis, 21 with Crohn's disease and 11 controls. Peripheral blood mononuclear cells were isolated from 24 ulcerative colitis and 18 Crohn's disease patients and 11 controls. GR mRNA was measured by quantitative reverse transcriptase polymerase chain reaction (RT-PCR), and correlated to endoscopic findings, clinical activity and outcome of GC therapy. In a subset of subjects GR localisation was shown by immunohistochemistry.

RESULTS

In patients with inflammatory bowel disease GR expression was not different from controls. However, GR was decreased in biopsies from ulcerative colitis patients with impaired GC response. The inhibitory subtype GRbeta was expressed 100-1000 times lower than GRalpha. GR immunoreactivity was identified in immune and epithelial cells except for colonic crypts.

CONCLUSION

In inflammatory bowel disease systemic and mucosal GR mRNA expression is not altered. However, in ulcerative colitis patients, low mucosal GR expression may predict the outcome of GC therapy. The low expression of GRbeta challenges its role in steroid refractoriness in inflammatory bowel disease.

Molecular evidence of organic ion transporters in the rat adrenal cortex with adrenocorticotropin-regulated zonal expression

Experimental evidence suggested that secretion of steroid hormones from adrenocortical cells involves carrier-mediated transport: Cortisol release from, and uptake of p-[3H]aminohippurate into, bovine adrenocortical cells showed properties of the renal p-[3H]aminohippurate/anion exchanger OAT1. Other poly-specific transporters such as organic anion-transporting polypeptides (oatps) and organic cation transporters (OCTs) could also be involved in steroid hormone release. A homology-cloning procedure was established to detect these transporters in rat adrenal gland cDNA. PCR revealed the presence of OAT1, oatp1, oatp2, and oatp3. In situ hybridization localized OAT1 in the outer zona fasciculata, oatp3 in the zona glomerulosa, and oatp1 and oatp2 in the inner zona fasciculata and outer zona reticularis. An OCT2-specific probe produced signals in the zona glomerulosa and outer zona fasciculata. Pretreatment of rats with ACTH increased the expression of OAT1 mRNA that spread to all zones, and hypophysectomy strongly decreased it. A less pronounced regulation was detected for OCT2 and oatp3. Specific antibodies confirmed the localization of OAT1 in the outer zona fasciculata, supporting a possible role of OAT1 in cortisol release. The zonated distribution of transporters furthermore suggest that oatp1-3 and OCT2 may be important for the endocrine function of rat adrenocortical cells.

Proinflammatory role of fractalkine (CX3CL1) in rheumatoid arthritis

OBJECTIVE

Fractalkine (CX3CL1) represents the sole member of the so-called CX3C chemokines. In rheumatoid arthritis (RA), functional studies suggest a role for this chemokine in monocyte chemotaxis and angiogenesis in the rheumatoid synovium. We analyzed the expression of fractalkine within different T cell subsets of the peripheral blood and expression of its receptor CX3CR1 within the rheumatoid synovium to further characterize its pathogenic role in RA.

METHODS

Peripheral blood mononuclear cells (PBMC) were isolated from 17 patients with RA and analyzed by flow cytometry in comparison to healthy blood donors. To identify the T helper cell cytokine profile of fractalkine-expressing cells, flow cytometric analysis of PBMC was performed after stimulation with PMA and ionomycin. Expression of fractalkine and its receptor was characterized in RA synovium by immunohistochemistry and laser capture microdissection microscopy.

RESULTS

Flow cytometric analysis of fractalkine-expressing T cell subsets revealed a low proportion of fractalkine-expressing CD4+ and CD8+ T cells in both RA patients and controls. In addition, fractalkine was predominantly expressed in CD4+ T cells with a Th1-type cytokine expression profile. In RA synovium, fractalkine was detected in synovial macrophages, dendritic cells, endothelial cells, and a small proportion of T cells. The fractalkine receptor CX3CR1 was found in synovial macrophages, dendritic cells, and T cells as well as in synovial fibroblasts. Fractalkine stimulation of cultured synovial fibroblasts resulted in a marked upregulation of matrix metalloproteinase-2 (MMP-2) production.

CONCLUSION

The results suggest that fractalkine may represent a Th1-type chemokine. Upregulation of MMP-2 production in synovial fibroblasts upon fractalkine stimulation in vitro supports the hypothesis of a proinflammatory role of this chemokine in RA.

Expression of activation-induced, T cell-derived, and chemokine-related cytokine/lymphotactin and its functional role in rheumatoid arthritis

OBJECTIVE

To evaluate the possible role of activation-induced, T cell-derived, and chemokine-related cytokine (ATAC)/lymphotactin (Lptn) in the pathogenesis of rheumatoid arthritis (RA).

METHODS

ATAC/Lptn levels in serum and synovial fluid samples were measured by sandwich enzyme-linked immunosorbent assay. Expression of messenger RNA for ATAC/Lptn in synovial tissues was analyzed by reverse transcription-polymerase chain reaction (PCR) and by in situ hybridization, and was quantitated by real-time PCR. The phenotype of peripheral blood mononuclear cells (PBMCs) expressing ATAC/Lptn was analyzed by intracellular cytokine staining and flow cytometry.

RESULTS

Levels of ATAC/Lptn were similar in sera and synovial fluids from RA patients (n = 20) and osteoarthritis controls (n = 15). In phorbol myristate acetate/ionomycin-stimulated PBMCs, ATAC/Lptn expression was detected in CD8+ T cells and in a significantly increased proportion of CD4+,CD28- T cells from RA patients as compared with healthy controls. In synovial tissues, ATAC/Lptn was predominantly localized in CD3+ T cells in the sublining layer. Lymphocytes, synovial macrophages, and, unexpectedly, fibroblast-like synoviocytes (FLS) were identified as major target cells for ATAC/Lptn in RA synovium, as determined by analysis of the ATAC/Lptn receptor XCR1. In vitro, ATAC/Lptn stimulation of FLS resulted in a marked down-regulation of matrix metalloproteinase 2 production.

CONCLUSION

These data indicate that in RA synovium, ATAC/Lptn is mainly produced by T cells. Considering its function as a lymphocyte-specific chemoattractant, ATAC/Lptn might be a key modulator for T cell trafficking in the pathogenesis of RA. In addition, functional studies suggest that ATAC/Lptn may exert additional immunomodulatory effects in RA.

Agonists of peroxisome proliferator-activated receptor gamma inhibit cell growth in malignant melanoma

Peroxisome proliferator-activated receptor gamma is a member of the nuclear receptor superfamily involved in adipocyte differentiation and glucose homeostasis. There is evidence that peroxisome proliferator-activated receptor gamma may also act as a tumor suppressor. Here, we demonstrate expression of peroxisome proliferator-activated receptor gamma in benign melanocytic naevi, different variants of primary cutaneous melanomas, and melanoma metastases. Peroxisome proliferator-activated receptor gamma protein and peroxisome proliferator-activated receptor gamma1 mRNA were also detected in human melanoma cell lines. The peroxisome proliferator-activated receptor gamma specific agonists 15-deoxy-Delta12,14-prostaglandin J2, troglitazone, and rosiglitazone dose-dependently inhibited cell proliferation in four melanoma cell lines, whereas a specific agonist of peroxisome proliferator-activated receptor alpha had no such effect. At a concentration of 50 microM rosiglitazone, the most potent peroxisome proliferator-activated receptor gamma agonist tested suppressed cell growth by approximately 90%. Apoptosis could be induced in melanoma cell lines by incubation with tumor-necrosis-factor-related apoptosis-inducing ligand. In contrast, the growth inhibitory effect of peroxisome proliferator-activated receptor gamma activation was independent of apoptosis and seemed to occur primarily through induction of cell cycle arrest. Our data indicate that melanoma cell growth may be modulated through peroxisome proliferator-activated receptor gamma.

Cirrhotic livers reveal genetic changes in the MDM2-P14ARF system of cell cycle regulators

The genesis of hepatocellular carcinoma is promoted by changes in the regulatory MDM2-P14ARF system. The incidence of such changes has to date not been analysed in non-tumourous livers showing regenerative proliferation. In the present study, 24 cirrhotic livers of alcohol-, autoimmue disorder- or HCV-caused genesis were screened for MDM2-P14ARF alterations at the level of protein, DNA and mRNA. Using confocal laser scanning microscopy, the absence of MDM2 and P14ARF expression was detected in all samples except three HCV-infected livers (four livers) which contained hepatocytes overexpressing MDM2 (P14ARF) protein. In two of the samples lacking P14ARF expression, laser microdissection and PCR demonstrated deletion of the P14ARF gene. The P14ARF gene amplified from other specimens did not carry mutations. MDM2 splicing variants were present in tissues from alcohol- and autoimmune disorder-induced cirrhoses. Sequencing of full-size mRNA revealed a MDM2 mis-sense mutation in an alcohol-induced cirrhosis. One sample contained regenerative nodules with genetic instability occurring at MDM2 locus D12S83 according to the data of automatic PCR fragment analysis. In summary, this study gives first evidence for different types of MDM2 and P14ARF alterations in cirrhotic livers. We suggest that the changes impair the regulatory MDM2-P14ARF system, thus possibly favouring regenerative proliferation and transformation.