Multi-Scale Investigation of Human Renal Tissue in Three Dimensions

Histopathology as a diagnostic mainstay for tissue evaluation is strictly a 2D technology. Combining and supplementing this technology with 3D imaging has been proposed as one future avenue towards refining comprehensive tissue analysis. To this end, we have developed a laboratory-based X-ray method allowing for the investigation of tissue samples in three dimensions with isotropic volume information. To assess the potential of our method for micro-morphology evaluation, we selected several kidney regions from three patients with cystic kidney disease, obstructive nephropathy and diabetic glomerulopathy. Tissue specimens were processed using our in-house-developed X-ray eosin stain and investigated with a commercial microCT and our in-house-built NanoCT. The microCT system provided overview scans with voxel sizes of [Formula: see text] and the NanoCT was employed for higher resolutions including voxel sizes from [Formula: see text] to 210 nm. We present a methodology allowing for a precise micro-morphologic investigation in three dimensions which is compatible with conventional histology. Advantages of our methodology are its versatility with respect to multi-scale investigations, being laboratory-based, allowing for non-destructive imaging and providing isotropic volume information. We believe, that after future developmental work this method might contribute to advanced multi-modal tissue diagnostics.

Revealing the Microscopic Structure of Human Renal Cell Carcinoma in Three Dimensions

For fully characterizing renal cell carcinoma (RCC), information about the 3D tissue microstructure is essential. Histopathology, which represents the current diagnostic gold standard, is destructive and only provides 2D information. 3D X-ray histology endeavors to overcome these limitations by generating 3D data. In a laboratory environment, most techniques struggle with limited resolution and the weak X-ray attenuation contrast of soft tissue. We recently developed a laboratory-based method combining nanoscopic X-ray CT with a cytoplasm-specific X-ray stain. Here, we present the application of this method to human RCC biopsies. The NanoCT slices enable pathological characterization of crucial structures by reproducing tissue morphology with a similar detail level as corresponding histological light microscopy images. Beyond that, our data offer deeper insights into the 3D configuration of the tumor. By demonstrating the compatibility of the X-ray stain with standard pathological stains, we highlight the feasibility of integrating staining based NanoCT into the pathological routine.

Grating-based phase-contrast CT (PCCT): histopathological correlation of human liver cirrhosis and hepatocellular carcinoma specimen

AIMS

To correlate signal intensities in grating-based phase-contrast CT (PCCT) images obtained at a synchrotron light source and a conventional X-ray source with tissue components in human liver cirrhosis and hepatocellular carcinoma (HCC) specimen.

METHODS

Study approval was obtained by the institutional review board. Human specimen of liver cirrhosis and HCC were imaged at experimental grating-based PCCT setups using either a synchrotron radiation source or a conventional X-ray tube. Tissue samples were sectioned and processed for H&E and Elastica van Gieson staining. PCCT and histological images were manually correlated. Depending on morphology and staining characteristics tissue components like fibrosis, HCC, inflammation, connective tissue and necrosis were differentiated and visually correlated with signal intensity in PCCT images using a 5-point Likert scale with normal liver parenchyma as a reference.

RESULTS

Grating-based PCCT images of human cirrhotic liver and HCC specimen showed high soft-tissue contrast allowing correlation with histopathological sections. Signal intensities were similar in both setups independent of the nature of the radiation source. Connective tissue and areas of haemorrhage displayed the highest signal intensities, fibrotic liver tissue the lowest.

CONCLUSIONS

Grating-based PCCT provides comparable results for the characterisation of human specimen of liver cirrhosis and HCC using either a synchrotron light source or a conventional X-ray tube. Due to its high soft-tissue contrast and its applicability to conventional X-ray tubes grating-based PCCT holds potential for preclinical research and virtual histology applications.

Quantitative assessment and clinical relevance of kallikrein-related peptidase 5 mRNA expression in advanced high-grade serous ovarian cancer

Background

In ovarian cancer, dysregulation of mRNA expression of several components of the family of the kallikrein-related peptidases (KLKs) is observed. In this study, we have analyzed the KLK5 mRNA expression pattern in tumor tissue of patients suffering from high-grade serous ovarian cancer stage FIGO III/IV. Moreover, we have correlated the KLK5 mRNA levels with clinical outcome.

Methods

We assessed the mRNA expression levels of KLK5 in tumor tissue of 138 patients using quantitative PCR (qPCR). The mRNA levels were correlated with KLK5 antigen tumor tissue levels measured by ELISA (available for 41 of the 138 patients), established clinical features as well as patients’ outcome, using Chi-square-tests, Mann-Whitney U-tests and Spearman rank calculations as well as Cox regression models, Kaplan-Meier survival analysis and the log-rank test.

Results

A highly significant correlation between the mRNA expression levels and protein levels of KLK5 in tumor tissues was observed (r_s = 0.683, p < 0.001). In univariate Cox regression analysis, elevated KLK5 mRNA expression was remarkably associated with reduced progression-free survival (PFS; p = 0.047), but not with overall survival (OS). Association of KLK5 mRNA expression with PFS was validated in silico using The Cancer Genome Atlas. For this, Affymetrix-based mRNA data (n = 377) were analyzed applying the Kaplan-Meier Plotter tool (p = 0.027). In multivariable Cox analysis, KLK5 mRNA values revealed a trend towards statistical significance for PFS (p = 0.095), whereas residual tumor mass (0 mm vs. > 0 mm), but not ascites fluid volume (≤500 ml vs. > 500 ml), remained an independent indicator for both OS and PFS (p < 0.001, p = 0.005, respectively).

Conclusions

These results obtained with a homogenous patient group with all patients suffering from advanced high-grade serous ovarian cancer support previous results suggesting elevated KLK5 mRNA levels as an unfavorable marker in ovarian cancer.

Kallikrein-related peptidases 4, 5, 6 and 7 regulate tumour-associated factors in serous ovarian cancer

BACKGROUND

Tissue kallikrein-related peptidases 4, 5, 6 and 7 (KLK4-7) strongly increase the malignancy of ovarian cancer cells. Deciphering their downstream effectors, we aimed at finding new potential prognostic biomarkers and treatment targets for ovarian cancer patients. KLK4-7-transfected (OV-KLK4-7) and vector-control OV-MZ-6 (OV-VC) ovarian cancer cells were established to select differentially regulated factors.

METHODS

With three independent approaches, PCR arrays, genome-wide microarray and proteome analyses, we identified 10 candidates (MSN, KRT19, COL5A2, COL1A2, BMP5, F10, KRT7, JUNB, BMP4, MMP1). To determine differential protein expression, we performed western blot analyses, immunofluorescence and immunohistochemistry for four candidates (MSN, KRT19, KRT7, JUNB) in cells, tumour xenograft and patient-derived tissues.

RESULTS

We demonstrated that KLK4-7 clearly regulates expression of MSN, KRT19, KRT7 and JUNB at the mRNA and protein levels in ovarian cancer cells and tissues. Protein expression of the top-upregulated effectors, MSN and KRT19, was investigated by immunohistochemistry in patients afflicted with serous ovarian cancer and related to KLK4-7 immunoexpression. Significant positive associations were found for KRT19/KLK4, KRT19/KLK5 and MSN/KLK7.

CONCLUSION

These findings imply that KLK4-7 exert key modulatory effects on other cancer-related genes and proteins in ovarian cancer. These downstream effectors of KLK4-7, MSN and KRT19 may represent important therapeutic targets in serous ovarian cancer.

Elevated tumor tissue protein expression levels of kallikrein-related peptidases KLK10 and KLK11 are associated with a better prognosis in advanced high-grade serous ovarian cancer patients

Several members of the KLK family have been proposed to modulate various tumor-relevant processes. Previously, we have shown that in advanced high-grade serous ovarian cancer tissue high KLK11 mRNA levels were significantly associated with prolonged overall and progression-free patients' survival. Furthermore, KLK11 mRNA expression positively correlated with KLK10 mRNA. In the present study, we examined the prognostic value for both KLK10 and KLK11 on the protein expression level by immunohistochemistry (IHC). A cohort encompassing 159 patient tumor samples afflicted with advanced high-grade (FIGO III/IV) serous ovarian cancer, present on tissue microarrays (TMA), was analyzed. For estimation of KLK10 and KLK11 immunoreactivity, an automated digital IHC image analysis algorithm was selected to quantify the antibody staining intensity in the tissues via an immunoreactive score (IRS). In line with the results obtained by mRNA analysis, KLK10 protein expression values were significantly and positively correlated with KLK11 protein expression values. In Kaplan-Meier analyses, both elevated KLK10, KLK11, and the combination of KLK10 and KLK11 protein levels were significantly linked with prolonged overall survival (OS). The addition of KLK10, KLK11 or the KLK10+KLK11 combination IRS to the base model in multivariate Cox analysis demonstrated that high KLK11 and KLK10+KLK11 protein expression levels, apart from clinical parameters, remained favorable independent predictive markers for OS. In conclusion, in the present study, we have validated the coordinate expression of KLK10 and KLK11 in advanced high-grade serous ovarian cancer. Furthermore, both increased KLK10 and KLK11 protein expression is associated with favorable prognosis in this major ovarian cancer subtype. The combined KLK10+KLK11 marker performed even stronger than KLK10 or KLK11 alone.

ALDH1 as a prognostic marker for lymph node metastasis in OSCC

Long-term survival in cases of head and neck squamous cell carcinoma, particularly oral squamous cell carcinoma (OSCC), remains a rare achievement in the field of clinical oncology. In recent years, the theory of cancer stem cells (CSCs) has emerged and been used to offer explanations for tumour recurrence and metastasis. The present aim was to investigate the role of aldehyde dehydrogenase 1 (ALDH1) as a CSC-marker for OSCC and to determine the role of p16^ink4a, which is also a surrogate marker of human papilloma virus (HPV), in the expression of ALDH1. The study cohort comprised of 186 surgically-treated cases of OSCC. The primaries were located in the oral cavity. The expression of the CSC marker (CSCM) ALDH1 was evaluated via immunohistochemistry (IHC) of a tissue microarray. HPV detection was performed by polymerase chain reaction and an HPV Array kit. Furthermore, the IHC expression of p16^ink4a was also analysed. Risk regression models as the Kruskal Wallis test was used to assess the association of CSCM and p16^ink4a expression with tumour size and lymph node metastasis, and cox proportional hazards were analysed. Additionally, coexpression of the markers ALDH1 and p16^ink4a was analysed with regard to associations with tumour classification. Overall, high expression of ALDH1 in lymph nodes was significantly associated with Union for International Cancer Control (UICC) stage IV (P=0.044) and T4 stage cancer (P=0.03). p16^ink4a positivity, in cases of HPV negativity, was associated with worse survival rate compared with that of the total cohort (P=0.048). Collectively the data indicate that ALDH1 expression may be suitable for detection of unfavourable prognosis in OSCC patients, based in part on its apparent role as a marker of metastasis. HPV status was not statistically predictive of patient outcome or CSCM expression; however, p16^ink4a remains a potential marker in HNSCC Further in vitro studies with ALDH1 and p16^ink4a should be performed to evaluate the expression of ALDH1 and HPV in cell culture and to clarify the role of ALDH1 as a marker for increased invasiveness of OSCC cells.

Correction to: MicroRNA expression profiling for the prediction of resistance to neoadjuvant radiochemotherapy in squamous cell carcinoma of the esophagus

Following publication of the original article [1], the authors reported that for one of the authors, Stephanie E. Combs, the middle name was accidentally omitted. They also reported that for two of the authors, Daniel Habermehl and Stephanie E. Combs, two affiliations were accidentally omitted. In this Correction the incorrect and correct author name are shown and the two omitted affiliations are listed.

Increased intraepithelial CD3+ T-lymphocytes and high PD-L1 expression on tumor cells are associated with a favorable prognosis in esophageal squamous cell carcinoma and allow prognostic immunogenic subgrouping

Esophageal squamous cell carcinoma (ESCC) is the most common esophageal cancer associated with poor prognosis and additional therapeutic strategies must be implemented to optimize ESCC treatment. Meanwhile, the important biologic role and potential prognostic and therapeutic implications of a tumors immunologic microenvironment (IM) have been recognized in various cancers.In order to investigate the contexture and the prognostic relevance of the IM in ESCC, we immunohistochemically evaluated the extent of overall/intraepithelial TILs (CD3+/CD8+) and of PD-1 / PD-L1 expression in a cohort of 125 therapy-naive ESCCs, additionally assessing PD-L1 copy number status via fluorescence in-situ hybridization.High intraepithelial CD3+ TILs (CD3ihigh) and high PD-L1 expression on tumor cells (PD-L1high) were each significantly associated with improved overall- (OS) (CD3+: p = 0.019; PD-L1: p = 0.028), disease specific- (DSS) (CD3+: p = 0.05; PD-L1: p = 0.006) and disease free survival (DFS) (CD3+: p = 0.009; PD-L1: p < 0.001). CD3ihigh- and PD-L1high cases were significantly associated with one another (p < 0.001). Subgrouping of ESCC revealed decreased OS (p = 0.031), DSS (p = 0.012) and DFS (p < 0.001) for CD3ilow/PD-L1low cancers.Our data not only associate CD3ihigh- and PD-L1high ESCC with a beneficial outcome, but also demonstrate PD-L1high- and CD3ihigh status to be closely intertwined. Furthermore, our study demarcates a prognostically unfavorable, "non-immunoreactive" CD3ilow / PD-L1low ESCC-subgroup, potentially forming the basis for an immune-based stratification of ESCC.

Impact of HPV infection on oral squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinomas (HNSCC) are often divided by their aetiology. Noxae associated collectives are compared with the human papilloma virus (HPV)-associated group, whereas different localisations of oral (OSCC) and oropharyngeal (OPSCC) squamous cell carcinomas are mostly discussed as one single group. Our aim was to show that classification by aetiology is not appropriate for OSCC.

RESULTS

HPV DNA was detected by PCR in 7 (3.47%) patients, and we identified 12 (5.94%) positive (+) cases by p16INK4a immunostaining. Only 4 (1.98%) of the p16INK4a+ cases were + for HPV using PCR. Our homogenous collective of OSCC allowed us to compare HPV+ and HPV negative (-) patients without creating bias for tumour localisation, age, gender or tumour stage.

MATERIALS AND METHODS

After testing OSCC samples for HPV positivity, we compared the results of two commonly used HPV detection methods, p16INK4a immunostaining and HPV DNA-related PCR, on 202 OSCC patients. HPV subtypes were determined with an HPV LCD Array Kit. Clinicopathological features of the patients were analysed, and the disease specific survival rates (DSS) for HPV+ and HPV- patients were obtained.

CONCLUSIONS

p16INK4a immunostaining is a not a reliable HPV detection method for OSCC. Positive p16INK4a immunostaining did not agree with + results from PCR of HPV DNA. Furthermore, the influence of HPV-related oncogenic transformation in OSCC is overestimated. The significance of HPV infection remains clinically unclear, and its influence on survival rates is not relevant to OSCC cases.

CD274/PD-L1 gene amplification and PD-L1 protein expression are common events in squamous cell carcinoma of the oral cavity

Immunomodulatory therapies, targeting the immune checkpoint receptor-ligand complex PD-1/PD-L1 have shown promising results in early phase clinical trials in solid malignancies, including carcinomas of the head and neck. In this context, PD-L1 protein expression has been proposed as a potentially valuable predictive marker. In the present study, expression of PD-L1 and PD-1 was evaluated by immunohistochemistry in 80 patients with predominantly HPV-negative oral squamous cell carcinomas and associated nodal metastasis. In addition, CD274/PD-L1 gene copy number status was assessed by fluorescence in situ hybridization analysis. PD-L1 expression was detected in 36/80 (45%) cases and concordance of PD-L1 expression in primary tumor and corresponding nodal metastasis was present in only 20/28 (72%) cases. PD-1 expression was found in tumor-infiltrating lymphocytes (TILs) but not in tumor cells. CD274/PD-L1 gene amplification was detected in 19% of cases, with high level PD-L1 amplification present in 12/80 (15%), and low level amplification in 3/80 (4%). Interestingly, CD274/PD-L1 gene amplification was associated with positive PD-L1 immunostaining in only 73% of cases. PD-L1 copy number status was concordant in primary tumor and associated metastases. Clinically, PD-L1 tumor immunopositivity was associated with a higher risk for nodal metastasis at diagnosis, overall tumor related death und recurrence. Based on our findings we propose to include PD-L1 copy number status in addition to protein status in screening programs for future clinical trials with immunotherapeutic strategies targeting the PD-1/PD-L1 axis.

EGFR and Cortactin: Markers for potential double target therapy in oral squamous cell carcinoma

Survival periods of patients following surgical therapy of oral squamous cell carcinoma (OSCC) have previously been demonstrated to decrease over recent decades. Epidermal growth factor receptor (EGFR) and Cortactin are molecular markers that are important in tumour progression and development, and interact within the EGF pathway. Although EGFR antibody therapy exists, sufficient efforts for increased survival are still lacking due to the present limited response rates. The aim of the present study was to examine the association between EGFR and Cortactin expression on survival rates of OSCC patients and to determine whether EGFR and Cortactin expression levels are associated with advanced tumor sizes and lymphnode-metastases. In total, 222 OSCC patients were included in the study. EGFR and Cortactin expression in tumor tissue was evaluated by immunohistochemistry. Cox regression was used for survival analysis. Categories were tested for associations by using cross tabs (Chi-square test). Groups were compared by the non-parametric Mann Whitney U-test. Probabilities of less than 0.05 were considered significant and significant expression of Cortactin was observed in Advanced Union Internationale Contre le Cancer stage (P=0.032), including advanced tumour stage (P=0.021) and lymph node metastasis (P=0.049). High Cortactin expression was significantly associated with poorer survival rates (P=0.037). Further Cortactin expression was not associated with extracapsular spread, however EGFR exhibited a significant association (P=0.034). Neither EGFR nor Cortactin expression was correlated to grading. EGFR and Cortactin co-expression was demonstrated to be significantly associated with poorer survival rates in OSCC patients, suggesting that identification of predictive biomarkers for adjuvant therapies are of primary concern in OSCC. In particular, efficient dual-target therapy may act as an appropriate therapy to improve survival time for patients at advanced OSCC tumor stages.

Clinical relevance of kallikrein-related peptidase 6 (KLK6) and 8 (KLK8) mRNA expression in advanced serous ovarian cancer

Most members of the kallikrein-related peptidase family have been demonstrated to be dysregulated in ovarian cancer and modulate tumor growth, migration, invasion, and resistance to chemotherapy. In the present study, we assessed the mRNA expression levels of KLK6 and KLK8 by quantitative PCR in 100 patients with advanced serous ovarian cancer FIGO stage III/IV. A pronounced correlation between KLK6 and KLK8 mRNA expression (rs = 0.636, p < 0.001) was observed, indicating coordinate expression of both peptidases. No significant associations of clinical parameters with KLK6, KLK8, and a combined score KLK6+KLK8 were found. In univariate Cox regression analysis, elevated mRNA levels of KLK6 were significantly linked with shortened overall survival (OS) (hazard ratio [HR] = 2.07, p = 0.007). While KLK8 values were not associated with patients' outcome, high KLK6+KLK8 values were significantly associated with shorter progression-free survival (HR = 1.82, p = 0.047) and showed a trend towards significance in the case of OS (HR = 1.82, p = 0.053). Strikingly, in multivariable analysis, elevated KLK6 mRNA values, apart from residual tumor mass, remained an independent predictive marker for poor OS (HR = 2.33, p = 0.005). As KLK6 mRNA and protein levels correlate, KLK6 may represent an attractive therapeutic target for potent and specific inhibitors of its enzymatic activity.

Tumour budding activity and cell nest size determine patient outcome in oral squamous cell carcinoma: proposal for an adjusted grading system

AIMS

Oral squamous cell carcinoma (OSCC) is a common malignancy with a variable clinical course. One of the established survival predictors in carcinomas in general is tumour grade; in OSCC, however, grading according to the World Health Organization (WHO) has no independent prognostic impact. Recently, a novel grading scheme associated with high impact on patient outcome has been proposed for squamous cell carcinoma of the lung.

METHODS AND RESULTS

To probe whether this scheme could be applied to the upper aerodigestive tract, we retrospectively evaluated 157 chemo- and radiotherapy-naive OSCCs with complete clinical follow-up data and standardized treatment for tumour budding activity (BA), cell nest size (CNS), extent of keratinization, stromal content, nuclear size and mitotic count. Histomorphological characteristics were correlated with clinicopathological data and patient outcome. As in squamous cell carcinoma of the lung, high BA and small CNS were correlated significantly with shortened overall, disease-specific and disease-free survival. A three-tiered grading system based on a sum score of these two prognostic markers proved to be a strong age-, stage- and sex-independent prognosticator for survival with a hazard ratio for overall survival of 2.1 for intermediately differentiated (G2) tumours and 3.4 for poorly differentiated (G3) tumours compared to well-differentiated (G1) tumours (P < 0.001).

CONCLUSIONS

We recapitulated and validated almost exactly the strong prognostic impact of a grading algorithm proposed recently for squamous cell carcinoma of the lung in OSCC. Our data may pave the way for a prognostically highly relevant future squamous cell carcinoma grading system broadly applicable in the aerodigestive tract.

Assessment of kallikrein-related peptidase 5 (KLK5) protein expression in tumor tissue of advanced ovarian cancer patients by immunohistochemistry and ELISA: correlation with clinical outcome

Members of the human kallikrein-related peptidase (KLK) family, including KLK5, have been reported to play an important role in ovarian cancer progression. In the present study, we assessed KLK5 protein expression in ovarian cancer tissues by immunohistochemistry (IHC) and ELISA, and analyzed its association with clinicopathologic parameters and disease outcome in 95 patients with advanced ovarian cancer FIGO stage III/IV. KLK5 immunoexpression was evaluated in ovarian cancer tissue microarrays by IHC using a manual semiquantitative scoring system. KLK5 antigen levels were determined in ovarian cancer tumour tissue extracts by ELISA. KLK5 protein is expressed in ovarian cancer tissue by stromal and tumor cells. Mean KLK5 immunoscore values in tumor cells (KLK5-Tc; 5.7, range 0 to 12) were higher compared to stromal cells (KLK5-Sc; 1.2, range 0 to 9) but the correlation between KLK5-Tc and KLK5-Sc was rather low (rs = 0.34, P < 0.05). No significant associations of clinicopathological parameters with KLK5-Tc, KLK5-Sc, the combined overall score KLK5-Tc+Sc, or ELISA (KLK5-E) expression values were determined, except for KLK5-E protein expression with advanced age and high nuclear grade (G3). In univariate Cox regression analysis, elevated expression levels of KLK5-Sc are significantly linked with both prolonged overall survival (OS) (hazard ratio [HR] = 0.6, P = 0.046) and progression-free survival (PFS) (HR = 0.54, P = 0.032) of advanced ovarian cancer patients. KLK5-Tc and KLK5-Tc+Sc scores as well as the KLK5-E values were not associated with patients' outcome. In multivariable analysis, KLK5-Sc expression was found to be statistically significant for PFS. Patients with elevated KLK5-Sc had a two-fold lower risk of disease recurrence (HR = 0.53, P = 0.037) as compared to patients with low KLK5-Sc. For KLK5-Sc and OS, a trend towards statistical significance was observed (HR = 0.62, P = 0.077). These results indicate that KLK5 overexpression by stromal cells (KLK5-Sc) may be a positive modulator lowering aggressiveness of ovarian cancer.

Computerized analysis of enhancement kinetics for preoperative lymph node staging in rectal cancer using dynamic contrast-enhanced magnetic resonance imaging

For this feasibility study, dynamic contrast-enhanced magnetic resonance imaging (dceMRI) was performed preoperatively in 9 patients with histologically proven rectal carcinoma. A total of 41 lymph nodes detected were matched to histopathology. Their contrast enhancement patterns were evaluated using computer-aided analysis and categorized in persistent, plateau, and washout curve type. Highest diagnostic accuracy for detecting malignancy was observed, when less than 31.8% of the voxels within a lymph node demonstrated a washout curve (sensitivity/specificity of 81.8%/89.7%; area under the curve, AUC=0.87). In comparison, conventional size measurements revealed lower AUC of 0.81 (sensitivity/specificity of 75%/72.4%). We conclude that dceMRI might be of diagnostic value for preoperative lymph node staging.

Expression analysis of heat shock protein 90 (HSP90) and Her2 in colon carcinoma

PURPOSE

The molecular chaperone heat shock protein 90 (HSP90) plays an important role in several types of tumors also participating in the modulation of the activity of receptor tyrosine kinases activity such as members of the Her family. We evaluated the significance of HSP90 and Her2 expression in colon cancer.

METHODS

HSP90 and Her2 expression was determined by immunohistochemistry and by fluorescence in situ hybridization (FISH) on 355 primary resected colon carcinomas. Results were correlated with pathologic features (Union for International Cancer Control (UICC) pTNM category, tumor localisation, tumor differentiation), additional molecular genetic characteristics (BRAF, KRAS mutational status, mismatch repair genes (MMR)), and survival.

RESULTS

HSP90 immunoreactivity was observed in various degrees. Fifty-one cases (14 %) were positive for Her2 (score 2+ and 3+) with 16/43 cases with Her2 2+ staining pattern showing amplification of Her2 determined by FISH. There was a significant correlation between high HSP90 expression and Her2 overexpression (p = 0.011). High HSP90 expression was associated with earlier tumor stages (p = 0.019), absence of lymph node (p = 0.006), and absence of distant metastases (p = 0.001). Patients with high tumoral HSP90 levels had a better survival (p = 0.032), but this was not independent from other prognostic relevant pathologic parameters. Her2 expression was not associated with any of the investigated histopathological, molecular, or clinical parameters.

CONCLUSIONS

High HSP90 levels are reflecting lower malignant potential in colon cancer. Her2 positivity can be observed in a small number of cases. Targeting HSP90 and/or Her2 may be an alternative therapeutic approach in colon cancer in a subset of patients.

Evaluation of intraoperative cytological assessment of bone resection margins in patients with oral squamous cell carcinoma

BACKGROUND

Frozen sections are routinely applied to control for adequate resection margins. In cases in which carcinoma infiltrates bone, the intraoperative microscopic assessment of bone margins remains challenging due to technical difficulties to section native bone. The objective of the current study was to evaluate an intraoperative cytological approach to control bone resection margins in patients with bone-infiltrating oral squamous cell carcinomas.

METHODS

A total of 174 cytological preparations obtained from bone margins of bone-infiltrating oral squamous cell carcinomas (28 patients) were assessed intraoperatively and compared with the corresponding histological findings. In a validation cohort (45 patients) the intraoperative cytological assessment of bone resection margins (ICAB) (104 margins) was evaluated as a diagnostic tool for routine clinical application.

RESULTS

In the first patient cohort, the ICAB revealed 95.3% sensitivity and 96% specificity. The results provided an accuracy of 95.7% with a significant correlation noted between cytological and histological results (κ, 0.91; P < .001), and a positive predictive value and negative predictive value of 93.8% and 96.9%, respectively. In the validation cohort, ICAB revealed 80% sensitivity and 98.9% specificity with 98% accuracy. There was a significant correlation found between cytological and histological results (κ, 0.91; P < .001), providing a positive predictive value and negative predictive value of 80% and 98%, respectively. ICAB could predict final resection status at bone margins with 80% sensitivity and 97.5% specificity. A significant correlation was found between the cytological and histological resection status at bone margins (κ, 0,75; P < .001).

CONCLUSIONS

ICAB could supplement intraoperative frozen sections of soft tissue margins as a standard procedure to control for adequate resection at bone margins.

Activation of the PI3K/AKT pathway correlates with prognosis in stage II colon cancer

Background:

Patients with UICC/AJCC stage II colon cancer have a high 5-year overall survival rate after surgery. Nevertheless, a significant subgroup of patients develops tumour recurrence. Currently, there are no clinically established biomarkers available to identify this patient group. We applied reverse-phase protein arrays (RPPA) for phosphatidylinositide-3-kinase pathway activation mapping to stratify patients according to their risk of tumour recurrence after surgery.

Methods:

Full-length proteins were extracted from formalin-fixed, paraffin-embedded tissue samples of 118 patients who underwent curative resection. RPPA technology was used to analyse expression and/or phosphorylation levels of six major factors of the phosphatidylinositide-3-kinase pathway. Oncogenic mutations of KRAS and BRAF, and DNA microsatellite status, currently discussed as prognostic markers, were analysed in parallel.

Results:

Expression of phospho-AKT (HR=3.52; P=0.032), S6RP (HR=6.3; P=0.044), and phospho-4E-BP1 (HR=4.12; P=0.011) were prognostic factors for disease-free survival. None of the molecular genetic alterations were significantly associated with prognosis.

Conclusions:

Our data indicate that activation of the PI3K/AKT pathway evidenced on the protein level might be a valuable prognostic marker to stratify patients for their risk of tumour recurrence. Beside adjuvant chemotherapy targeting of upregulated PI3K/AKT signalling may be an attractive strategy for treatment of high-risk patients.

Imaging liver lesions using grating-based phase-contrast computed tomography with bi-lateral filter post-processing

X-ray phase-contrast imaging shows improved soft-tissue contrast compared to standard absorption-based X-ray imaging. Especially the grating-based method seems to be one promising candidate for clinical implementation due to its extendibility to standard laboratory X-ray sources. Therefore the purpose of our study was to evaluate the potential of grating-based phase-contrast computed tomography in combination with a novel bi-lateral denoising method for imaging of focal liver lesions in an ex vivo feasibility study. Our study shows that grating-based phase-contrast CT (PCCT) significantly increases the soft-tissue contrast in the ex vivo liver specimens. Combining the information of both signals – absorption and phase-contrast – the bi-lateral filtering leads to an improvement of lesion detectability and higher contrast-to-noise ratios. The normal and the pathological tissue can be clearly delineated and even internal structures of the pathological tissue can be visualized, being invisible in the absorption-based CT alone. Histopathology confirmed the presence of the corresponding findings in the analyzed tissue. The results give strong evidence for a sufficiently high contrast for different liver lesions using non-contrast-enhanced PCCT. Thus, ex vivo imaging of liver lesions is possible with a polychromatic X-ray source and at a spatial resolution of ∼100 µm. The post-processing with the novel bi-lateral denoising method improves the image quality by combining the information from the absorption and the phase-contrast images.

Evaluation of the potential of phase-contrast computed tomography for improved visualization of cancerous human liver tissue

PURPOSE

Phase-contrast X-ray computed tomography (PCCT) is currently investigated and developed as a potentially very interesting extension of conventional CT, and can offer several advantages for specific indications in diagnostic imaging. Current absorption-based computed tomography (CT) without the application of contrast material is limited in the detection of minor density differences in soft-tissue. The purpose of this study is to test whether PCCT can improve soft tissue contrast in healthy and tumorous human liver specimens.

MATERIALS AND METHODS

Two specimens of human liver (one healthy and one metastasized liver sample) were imaged with brilliant X-ray beam at the synchrotron radiation source ESRF in Grenoble, France. For correlation the same specimens were imaged with a magnetic resonance imaging system at 1.5 T. The histopathology confirmed our findings in the corresponding sections of the specimens.

RESULTS

In the phase-contrast CT images we observed a significantly enhanced soft-tissue contrast when compared to simultaneously recorded standard absorption CT measurements. Further, we found that the pathological and morphological information in the PCCT reconstructions show significant improvement when compared to those performed on MRI. Based on matching of prominent features, a good correlation between PCCT and the histological section is demonstrated; especially the tumor capsule and the surrounding vascular structures are visible in PCCT. In addition, our study revealed the ability of PCCT to visualize the blood vessels structure in the tumorous liver without the need of any contrast agents.

CONCLUSION

Grating-based PCCT significantly improves the soft-tissue contrast in ex-vivo liver specimens and holds the potential to overcome the need of contrast materials for visualization of the tumor vascularization.

Epidermal growth factor receptor, phosphatidylinositol-3-kinase catalytic subunit/PTEN, and KRAS/NRAS/BRAF in primary resected esophageal adenocarcinomas: loss of PTEN is associated with worse clinical outcome

Alterations of the epidermal growth factor receptor (EGFR) can be observed in a significant subset of esophageal adenocarcinomas (EACs), and targeted therapy against EGFR may become an interesting approach for the treatment of these tumors. Mutations of KRAS, NRAS, BRAF, and phosphatidylinositol-3-kinase catalytic subunit (PIK3CA) and deregulation of PTEN expression influence the responsiveness against anti-EGFR therapy in colorectal carcinomas. We investigated the prevalence of these events in a collection of 117 primary resected EACs, correlated the findings with EGFR expression and amplification, and determined their clinicopathologic impact. KRAS mutations were detected in 4 (3%) of 117 tumors (3× G12D and 1 G12V mutation). One tumor had a PIK3CA E545K mutation. Neither NRAS nor BRAF mutations were detected. Sixteen (14%) of 117 cases were negative for PTEN expression, determined by immunohistochemistry. Loss of PTEN was observed predominantly in advanced tumor stages (P = .004). There was no association between PTEN and EGFR status. Loss of PTEN was associated with shorter overall and disease-free survival (P < .001 each) and also an independent prognostic factor in multivariate analysis (P = .015). EGFR status had no prognostic impact in this case collection. In summary, loss of PTEN can be detected in a significant subset of EAC and is associated with an aggressive phenotype. Therefore, PTEN may be useful as a prognostic biomarker. In contrast, mutations of RAS/RAF/PIK3CA appear only very rarely, if at all, in EAC. A possible predictive role of PTEN in anti-EGFR treatment warrants further investigations, whereas determination of RAS/RAF/PIK3CA mutations may only have a minor impact in this context.

Evidence of prognostic relevant expression profiles of heat-shock proteins and glucose-regulated proteins in oesophageal adenocarcinomas

A high percentage of oesophageal adenocarcinomas show an aggressive clinical behaviour with a significant resistance to chemotherapy. Heat-shock proteins (HSPs) and glucose-regulated proteins (GRPs) are molecular chaperones that play an important role in tumour biology. Recently, novel therapeutic approaches targeting HSP90/GRP94 have been introduced for treating cancer. We performed a comprehensive investigation of HSP and GRP expression including HSP27, phosphorylated (p)-HSP27((Ser15)), p-HSP27((Ser78)), p-HSP27((Ser82)), HSP60, HSP70, HSP90, GRP78 and GRP94 in 92 primary resected oesophageal adenocarcinomas by using reverse phase protein arrays (RPPA), immunohistochemistry (IHC) and real-time quantitative RT-PCR (qPCR). Results were correlated with pathologic features and survival. HSP/GRP protein and mRNA expression was detected in all tumours at various levels. Unsupervised hierarchical clustering showed two distinct groups of tumours with specific protein expression patterns: The hallmark of the first group was a high expression of p-HSP27((Ser15, Ser78, Ser82)) and low expression of GRP78, GRP94 and HSP60. The second group showed the inverse pattern with low p-HSP27 and high GRP78, GRP94 and HSP60 expression. The clinical outcome for patients from the first group was significantly improved compared to patients from the second group, both in univariate analysis (p = 0.015) and multivariate analysis (p = 0.029). Interestingly, these two groups could not be distinguished by immunohistochemistry or qPCR analysis. In summary, two distinct and prognostic relevant HSP/GRP protein expression patterns in adenocarcinomas of the oesophagus were detected by RPPA. Our approach may be helpful for identifying candidates for specific HSP/GRP-targeted therapies.

Amniotic membrane as part of a skin substitute for full-thickness wounds: an experimental evaluation in a porcine model

BACKGROUND

We evaluated the use of human amniotic membrane (HAM) as a graft material for the treatment of iatrogenic full-thickness (FT) skin wounds in a porcine model with a view to reducing donor site morbidity in free flap transfer.

METHODS

Forty experimental FT-wounds were covered with an autologous split-thickness skin graft (STSG) alone or in combination with a mono- or multilayer HAM or Integra(®). Untreated wounds served as controls. Clinical evaluation and biopsy-sampling for histological and immunohistochemical staining with von-Willebrand-factor (vWF) antibody, laminin antibody, Ki-67 antibody, and smooth muscle actin (αSMA) antibody were performed on days 5, 7, 10, 20, 40, and 60 after surgical intervention.

RESULTS

Considerable disparities in the estimated criteria were observed between the various treatment groups of the FT-wounds. The use of HAM was found to have an accelerating impact on re-epithelialization. The multilayered amnion membrane showed better results than the Integra(®) and monolayer technique in terms of contraction rate, inflammation, and scarring and seemed useful as a dermal substitute in FT-wounds giving comparable results to STSG coverage alone.

CONCLUSIONS

This study demonstrates the successful application of HAM as part of a skin substitute in FT-wounds in minipigs. The results offer promise as a simple and effective technique for the application of multilayer HAM in iatrogenic human skin defects and the acceleration of wound healing.

High HSP27 and HSP70 expression levels are independent adverse prognostic factors in primary resected colon cancer

BACKGROUND

The expression of Heat Shock Proteins (HSPs) is increased in various cancers and has been shown to correlate with biological tumor behaviour. This study aimed to investigate the impact of HSP70, HSP60 and HSP27 expression in colon cancer.

MATERIAL AND METHODS

HSP expression was determined by immunohistochemistry on a tissue microarray with 355 primary resected colon carcinomas of all stages. Expression patterns were correlated with pathologic features (UICC pTNM category, tumor grading) and survival.

RESULTS

Expression of HSP27, HSP60 and HSP70 ranged from negative to high. There was no correlation between HSP27, HSP60 and HSP70 expression among each other and with UICC pT category, presence of lymph node or distant metastases or tumor grading. High HSP70 expression was associated with worse overall survival (p < 0.001) and was an independent prognostic factor (p = 0.004) in multivariate analysis including the pathological parameters mentioned above. For patients without lymph node or distant metastases (UICC stages I/II) and with complete tumor excision, HSP70 expression was the only independent prognostic factor for survival (p = 0.001) and superior to UICC pT category. In left sided UICC stage I/II carcinomas, high HSP27 expression also had adverse prognostic impact and was an independent prognostic factor (p = 0.016) besides HSP70 (p = 0.002).

CONCLUSION

High HSP70 and HSP27 expression is associated with worse clinical outcome in colon cancer. Determination of tumoral HSP70 and HSP27 may be used as additional biomarker for risk stratification especially for UICC stage I/II patients.

Treatment of peritoneal carcinomatosis by targeted delivery of the radio-labeled tumor homing peptide bi-DTPA-[F3]2 into the nucleus of tumor cells

Background

α-particle emitting isotopes are effective novel tools in cancer therapy, but targeted delivery into tumors is a prerequisite of their application to avoid toxic side effects. Peritoneal carcinomatosis is a widespread dissemination of tumors throughout the peritoneal cavity. As peritoneal carcinomatosis is fatal in most cases, novel therapies are needed. F3 is a tumor homing peptide which is internalized into the nucleus of tumor cells upon binding to nucleolin on the cell surface. Therefore, F3 may be an appropriate carrier for α-particle emitting isotopes facilitating selective tumor therapies.

Principal Findings

A dimer of the vascular tumor homing peptide F3 was chemically coupled to the α-emitter ²¹³Bi (²¹³Bi-DTPA-[F3]₂). We found ²¹³Bi-DTPA-[F3]₂ to accumulate in the nucleus of tumor cells in vitro and in intraperitoneally growing tumors in vivo. To study the anti-tumor activity of ²¹³Bi-DTPA-[F3]₂ we treated mice bearing intraperitoneally growing xenograft tumors with ²¹³Bi-DTPA-[F3]₂. In a tumor prevention study between the days 4–14 after inoculation of tumor cells 6×1.85 MBq (50 µCi) of ²¹³Bi-DTPA-[F3]₂ were injected. In a tumor reduction study between the days 16–26 after inoculation of tumor cells 6×1.85 MBq of ²¹³Bi-DTPA-[F3]₂ were injected. The survival time of the animals was increased from 51 to 93.5 days in the prevention study and from 57 days to 78 days in the tumor reduction study. No toxicity of the treatment was observed. In bio-distribution studies we found ²¹³Bi-DTPA-[F3]₂ to accumulate in tumors but only low activities were found in control organs except for the kidneys, where ²¹³Bi-DTPA-[F3]₂ is found due to renal excretion.

Conclusions/Significance

In conclusion we report that ²¹³Bi-DTPA-[F3]₂ is a novel tool for the targeted delivery of α-emitters into the nucleus of tumor cells that effectively controls peritoneal carcinomatosis in preclinical models and may also be useful in oncology.

The prostanoid EP2 receptor agonist butaprost increases uveoscleral outflow in the cynomolgus monkey

PURPOSE

To investigate the ocular hypotensive effect of the prostanoid EP2 receptor agonist butaprost and to establish its mechanism of action.

METHODS

All experiments were performed in cynomolgus monkeys after topical application of butaprost (0.1%). The effects of butaprost on aqueous humor flow were determined by fluorophotometry. Total outflow facility was measured by the two-level, constant-pressure perfusion method, and uveoscleral outflow was determined by perfusion of FITC-labeled dextran through the anterior chamber. Effects on ocular morphology were studied after tissue fixation with transcardial perfusion by paraformaldehyde and immersion fixation of the globe, in animals subjected to long-term treatment with butaprost. Conscious ocular normotensive monkeys and monkeys with unilateral ocular hypertension were used for intraocular pressure (IOP) studies.

RESULTS

Butaprost had no significant effect on aqueous humor flow or total outflow facility in ocular normotensive monkeys. Uveoscleral outflow was significantly higher in the butaprost treated eyes than in vehicle treated eyes, 1.03 +/- 0.20 vs. 0.53 +/- 0.18 microL.min(-1). After a 1-year treatment with butaprost, the morphology of the ciliary muscle was changed, showing increased spaces between ciliary muscle bundles and the apparent formation of new outflow channels. In many instances, changes were observed in the trabecular meshwork as well. Butaprost, in a single 0.1% dose, decreased IOP significantly in ocular normotensive monkeys and reduced IOP in laser-induced glaucomatous monkey eyes to the same level as that in the ocular normotensive contralateral eyes.

CONCLUSIONS

The prostanoid EP2 receptor agonist butaprost appears to lower IOP by increasing uveoscleral outflow, according to both physiological and morphologic findings. Although the prostanoid EP2 receptor is structurally and functionally distinct from the FP receptor, the effects of EP2 and FP receptor stimulation on aqueous humor outflow are similar.

In vivo characterization of endothelial cell activation in a transgenic mouse model of Alzheimer’s disease

Alzheimer's disease (AD) is the most common cause of dementia worldwide. AD is characterized by an excessive cerebral amyloid deposition leading to degeneration of neurons and eventually to dementia. It has been shown by epidemiological studies that cardiovascular drugs with an anti-angiogenic effect can influence the outcome of AD patients. Therefore, it has been speculated that in AD angiogenesis in the brain vasculature may play an important role. Here we report that in the brain of APP23 mice--a transgenic model of AD--after deposition of amyloid in blood vessels endothelial cell activation occurs in an age-dependent manner. Amyloid deposition is followed by the expression of beta3-integrin, a specific marker molecule of activated endothelium. The beta3-integrin expression is restricted to amyloid-positive vessels. Moreover, homogenates of the brains of APP23 mice induced the formation of new vessels in an in vivo angiogenesis assay. Vessel formation could be blocked by the VEGF antagonist SU 4312 as well as by statins, suggesting that these drugs may interfere with endothelial cell activation in AD. In conclusion our results indicate that amyloid deposition in the vasculature leads to endothelial cell apoptosis and endothelial cell activation, which can be modulated by anti-angiogenic drugs.