Assessment of vascular endothelial growth factor in formalin fixed, paraffin embedded colon cancer specimens by means of a well-based reverse phase protein array

Clinicopathologic and protein markers distinguishing the “polymerase epsilon exonuclease” from the “copy number low” subtype of endometrial cancer

Objective

The need to perform genetic sequencing to diagnose the polymerase epsilon exonuclease (POLE) subtype of endometrial cancer (EC) hinders the adoption of molecular classification. We investigated clinicopathologic and protein markers that distinguish the POLE from the copy number (CN)-low subtype in EC.

Methods

Ninety-one samples (15 POLE, 76 CN-low) were selected from The Cancer Genome Atlas EC dataset. Clinicopathologic and normalized reverse phase protein array expression data were analyzed for associations with the subtypes. A logistic model including selected markers was constructed by stepwise selection using area under the curve (AUC) from 5-fold cross-validation (CV). The selected markers were validated using immunohistochemistry (IHC) in a separate cohort.

Results

Body mass index (BMI) and tumor grade were significantly associated with the POLE subtype. With BMI and tumor grade as covariates, 5 proteins were associated with the EC subtypes. The stepwise selection method identified BMI, cyclin B1, caspase 8, and X-box binding protein 1 (XBP1) as markers distinguishing the POLE from the CN-low subtype. The mean of CV AUC, sensitivity, specificity, and balanced accuracy of the selected model were 0.97, 0.91, 0.87, and 0.89, respectively. IHC validation showed that cyclin B1 expression was significantly higher in the POLE than in the CN-low subtype and receiver operating characteristic curve of cyclin B1 expression in IHC revealed AUC of 0.683.

Conclusion

BMI and expression of cyclin B1, caspase 8, and XBP1 are candidate markers distinguishing the POLE from the CN-low subtype. Cyclin B1 IHC may replace POLE sequencing in molecular classification of EC.

Body mass index and cyclin B1, caspase 8, and X-box binding protein 1 are candidate markers distinguishing between the polymerase epsilon exonuclease (POLE) and copy number (CN)-low subtypes of endometrial cancer. Cyclin B1 immunohistochemistry expression was significantly higher in the POLE than in the CN-low subtype and may substitute POLE sequencing.

Gel formulations of Merremia mammosa (Lour.) accelerated wound healing of the wound in diabetic rats

Background and aim

The treatment of diabetic ulcers is difficult because of defective blood vessels and frequent co-occurrence of bacterial infections. In a previous study, we found a water fraction of Merremia mammosa (Lour.) (Mm(Lour.)) had beneficial effects on wound healing in diabetic rats. This study aimed to evaluate the influence of different gelling agents added to Mm(Lour.) water fraction gel on wound healing treatment in diabetic rats.

Experimental procedure

Diabetic Wistar rats were divided into the following five groups: 1. positive control (Neomycin Sulfate 0.5% and Placenta Extract 10%), 2. negative control (distilled water), and 10% water fraction of Mm(Lour.) extract in 3. HPMC, 4. Carbopol, and 5. CMC Na gelling agents. The wound was made by the Morton method and treatment applied every other day for 25 days, then the wound healing process was observed. Data were observed and analysed using appropriate statistic tools.

Results

Histopathology observation, VEGF expression and hydroxyproline levels showed a significant acceleration of wound healing in all treatment groups compared to the negative control group. This study showed all of Mm(Lour.) gel formulations could restore the delayed healing process on wound in diabetic rats and were equally effective in accelerating wound healing. CMC Na was the most preferable because it did not irritate.

Conclusion

The results suggest that Mm(Lour.) water fraction in CMC Na gelling agent provided an option to be developed as a topical drug on diabetic wound healing treatment, showed by enhancement of collagen synthesis and angiogenesis.

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Merremia mammosa (Lour.) gel accelerated wound healing in the diabetic rat model.

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Negative-control and each other groups had significant different healing.

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Positive-control and treatment groups had insignificant different healing.

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The safest and suggested gelling agent as a topical drug was CMC Na.

Role of VEGF, CD105, and CD31 in the Prognosis of Colorectal Cancer Cases

INTRODUCTION

Colorectal cancer (CRC) incidence is increasing globally. It is ranked as the second most common cancer in women and the third most in men. Angiogenesis plays a significant role in the development and spread of colorectal cancer. Angiogenesis has been proposed as a prognostic marker in a variety of human neoplasms. In this regard, markers of angiogenic endothelial cells are emerging as targets for cancer therapy.

AIM OF THE WORK

The aim of this study is to evaluate the prognostic impact of tumor angiogenesis assessed by microvessel density (MVD) counting using CD31 and CD105 along with VEGF immunostaining in colorectal cancer patients.

METHODS

VEGF, CD31, and CD105 expressions were evaluated using immunohistochemical staining in 50 patients with colorectal cancer. The relationship between their expressions and clinicopathological factors and outcome of patients were analyzed.

RESULTS

The VEGF expression (70% of the cases) correlated significantly with larger tumor size, higher grade, and advanced tumor stage (p = 0.006, p < 0.001, p < 0.001), respectively. The mean MVD was 24.2 ± VMD by CD105 (p = 0.10.65 019 for CD105, 19.2 ± 8.41 for CD31, respectively. MVD by CD31 (p = 0.023)) and was significant predictive factors for overall survival. Furthermore, the VEGF expression (p = < 0.001) was a significant predictive factor for DFS. There was a statistically significant association between the recurrence rates with both VEGF and CD105 (p < 0.001) but not significant with CD31.

CONCLUSION

CRC patients with high VEGF, CD105, and CD31 expression showed poor prognosis. The immunohistochemical markers could be used for stratification of patients into low-risk and high-risk groups.

Effect of metronidazole ophthalmic solution on corneal neovascularization in a rat model

PURPOSE

To evaluate the effect of metronidazole ophthalmic solutions on corneal neovascularization (CNV) in a rat model.

METHODS

A chemical burn was created in the right central cornea of 40 rats. Animals were randomized and distributed into four study groups (n = 10 rats per group) designated Met_0.1%, Met_0.5%, sham, and untreated groups. Chemical-burned corneas in the Met_0.1% and Met_0.5% groups received ophthalmic solutions of 0.1 and 0.5% metronidazole, respectively. Corneas in the sham group received phosphate-buffered saline (metronidazole diluent). All treated eyes received ophthalmic solution at intervals of 6 h, for up to 30 days. Untreated corneas received no treatment. CNV was evaluated postinjury using corneal photographs at different evaluation time points. The main CNV outcome measures were: burn intensity, index of CNV, and percentage of vascularized corneal area. Five rats from each group were euthanized, on days 15 and 30; the samples were collected for histological analyses. Differences with P < 0.05 were considered significant.

RESULTS

CNV was observed in the eyes from day 7 postinjury. However, the indices of CNV for the Met_0.1% and Met_0.5% groups were smaller than those for the sham and untreated groups (P < 0.05). Furthermore, corneas treated with 0.1 or 0.5% metronidazole had smaller vascularized areas compared to control corneas. On histological study, the presence of blood vessels confirmed clinical outcomes.

CONCLUSIONS

Regular instillation of 0.1 or 0.5% metronidazole had a significant inhibitory effect for CNV on chemical burns induced in a rat model.

A melanin-bleaching methodology for molecular and histopathological analysis of formalin-fixed paraffin-embedded tissue

Removal of excessive melanin from heavily pigmented formalin-fixed paraffin-embedded (FFPE) melanoma tissues is essential for histomorphological and molecular diagnostic assessments. Although there have been efforts to address this issue, current methodologies remain complex and time-consuming, and are not suitable for multiple molecular applications. Herein, we have developed a robust and rapid melanin-bleaching methodology for FFPE tissue specimens. Our approach is based on quick bleaching (15 min) at high temperature (80 °C) with 0.5% diluted hydrogen peroxide (H2O2) in Tris-HCl, PBS, or Tris/Tricine/SDS buffer. Immunostaining for Ki-67 and HMB45 was enhanced by bleaching with 0.5% H2O2 in Tris/Tricine/SDS and Tris-HCl, respectively. In addition to histopathological applications, our approach also facilitates recovery of protein and nucleic acid from archival melanin-rich FFPE tissue sections. Protein extracted from bleached FFPE tissues was compatible with western blotting using anti-human GAPDH and AKT antibodies. Our bleaching condition significantly improved RNA quality compared with unbleached tissues without compromising the yield. Notably, the RNA/DNA obtained from bleached tissues was suitable for end point PCR and real-time quantitative RT-PCR. In conclusion, this improved melanin-bleaching method enhances and simplifies immunostaining procedures, and facilitates the use of melanin-rich FFPE tissues for histomorphological and PCR amplification-based molecular assays.

Assessment of a panel of tumor markers for the differential diagnosis of benign and malignant effusions by well-based reverse phase protein array

Background

The differential diagnosis of benign and malignant effusion is often hampered by low cell content or insufficiently preserved tumor cells. In this study, we evaluated the combined diagnostic value of six tumor markers measured by well-based reverse-phase protein array (RPPA) for diagnosis of malignant effusion.

Methods

A total of 114 patients (46 with malignant effusions, 32 with probable malignant effusions, and 36 with benign effusions) were enrolled. Expressional levels of MUC1, EMA, Pan-CK, HSP90, TGF-β and CA125 were determined by well-based RPPA.

Results

Median relative expression of MUC1, Pan-CK and EMA were significantly higher in malignant effusion than those in probable malignant or benign (p < 0.001, p = 0.003, p < 0.001, respectively), whereas the level of TGF-β in malignant effusions were significantly lower than that in the other groups (p = 0.005). For predicting malignancy, EMA presented the best areas under the curve of 0.728 followed by MUC1 of 0.701. The sensitivity of 52.0% for MUC1 and 48.0% for EMA were not better than cytology. However, sensitivity, negative predictive value, and accuracy of the tumor marker panel were better than cytology by 14.7%, 7.5%, and 6.1%, respectively.

Conclusions

Tumor marker panel measured by well-based RPPA showed values in the differential diagnosis between benign and malignant effusions. Further large scale studies need to be performed to evaluate the utility of this panel of markers.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1433424467160224

Electronic supplementary material

The online version of this article (doi:10.1186/s13000-015-0290-4) contains supplementary material, which is available to authorized users.

A well-based reverse-phase protein array of formalin-fixed paraffin-embedded tissue

Biomarkers from tissue-based proteomic studies directly contribute to defining disease states as well as promise to improve early detection or provide for further targeted therapeutics. In the clinical setting, tissue samples are preserved as formalin-fixed paraffin-embedded (FFPE) tissue blocks for histological examination. However, proteomic analysis of FFPE tissue is complicated due to the high level of covalently cross-linked proteins arising from formalin fixation. To address these challenges, we developed well-based reverse-phase protein array (RPPA). This approach is a robust protein isolation methodology (29.44 ± 7.8 μg per 1 mm(3) of FFPE tissue) paired with a novel on electrochemiluminescence detection system. Protein samples derived from FFPE tissue by means of laser capture dissection, with as few as 500 shots, demonstrate measurable signal differences for different proteins. The lysates coated to the array plate, dried up and vacuum-sealed, remain stable up to 2 months at room temperature. This methodology is directly applicable to FFPE tissue and presents the direct opportunity of addressing hypothesis within clinical trials and well-annotated clinical tissue repositories.

HER-2 assessment in formalin-fixed paraffin-embedded breast cancer tissue by well-based reverse phase protein array

Background

The human epidermal growth factor receptor-2 (HER-2) expression level is a critical element for determining the prognosis and management of breast cancer. HER-2 targeted therapy in breast cancer depends on the reliable assessment of HER-2 expression status but current standard methods are lacking a rigorous quantitative assay. To address this challenge, we developed an assessment of HER-2 expression method by well-based reverse phase protein array (RPPA).

Results

Well-based RPPA is based on a robust protein isolation methodology paired with a novel electrochemiluminescence detection system. HER-2 value of well-based RPPA significantly correlated with dot blotting results (R² = 0.939). By well-based RPPA, we successfully detected HER-2 expression in 76 human breast formalin-fixed paraffin-embedded tissue samples. We observed 93.4% (71/76) concordance between well-based RPPA and current HER-2 immunohistochemical assessment guideline. When the cutoff level of HER-2 value was set to 0.689 (HER-2/GAPDH) on the basis of receiver-operating characteristic curve, the area under the curve was 0.975 (95% CI, 0.941-1.000). Sensitivity and specificity of well-based RPPA was 92.1% and 94.7%, respectively.

Conclusions

HER-2 value by well-based RPPA was correlated with the current HER-2 status guideline, suggesting that this normalized HER-2 assessment may offer advantages over unnormalized current immunohistochemical assessment methods.