The Terry Fox Research Institute Canadian Prostate Cancer Biomarker Network: an analysis of a pan-Canadian multi-center cohort for biomarker validation

Optimization of tissue microarray technique for breast cancer patients: a short communication

Background

Tissue microarray (TMA) is a novel technique for studying different types of cancer tissues in one block. TMA is not yet established in Syria, so we aimed in this project to apply and set the most optimal conditions of TMA creation of breast cancer tissues at the Pathology Department of our institute.

Materials and Methods

Eighty-eight blocks of breast cancer tissues were selected, considering the inclusion criteria. The tissue specimens of breast cancer patients were manually placed in the block by punching a core from a paraffin block, which was then released into a recipient block using a small trocar. Three different conditions were tested on the constructed TMA block.

Results

We determined the most effective parameters that proved high quality: incubating the newly constructed block at a temperature of 43°C for 24 h in the oven and then cutting it the next day after cooling it to room temperature; also, cutting with a 5 μm thickness created the preferable stained slides later. CD3 staining showed high expression of tumor-infiltrating lymphocytes among triple-negative breast cancer patients and high expression of CD3 in triple-negative cancer patients.

Conclusion

The optimization of parameters presented in our study resulted in perfect TMA generation and successful immunohistochemistry staining for cancer research at our institution.

UGT2B28 accelerates prostate cancer progression through stabilization of the endocytic adaptor protein HIP1 regulating AR and EGFR pathways

The androgen inactivating UGT2B28 pathway emerges as a predictor of progression in prostate cancer (PCa). However, the clinical significance of UGT2B28 tumoral expression and its contribution to PCa progression remain unclear. Using the Canadian Prostate Cancer Biomarker Network biobank (CPCBN; n = 1512), we analyzed UGT2B28 tumor expression in relation to clinical outcomes in men with localized PCa. UGT2B28 was overexpressed in tumors compared to paired normal adjacent prostatic tissue and was associated with inferior outcomes. Functional analyses indicated that UGT2B28 promoted cell proliferation, and its expression was regulated by the androgen receptor (AR)/ARv7. Mechanistically, UGT2B28 was shown to be a protein partner of the endocytic adaptor protein huntingtin-interacting protein 1 (HIP1), increasing its stability and priming AR/epidermal growth factor receptor (EGFR) pathways, leading to ERK1/2 activation triggering cell proliferation and epithelial-to-mesenchymal transition (EMT). HIP1 knockdown in UGT2B28 positive cells, and dual pharmacological targeting of AR and EGFR pathways, abolished cell proliferative advantages conferred by UGT2B28. In conclusion, UGT2B28 is a prognosticator of progression in localized PCa, regulates both AR and EGFR oncogenic signaling pathways via HIP1, and therefore can be therapeutically targeted by using combination of existing AR/EGFR inhibitors.

Elevated Expression of Glycerol-3-Phosphate Phosphatase as a Biomarker of Poor Prognosis and Aggressive Prostate Cancer

The limitations of the biomarker prostate-specific antigen (PSA) necessitate the pursuit of biomarkers capable of better identifying high-risk prostate cancer (PC) patients in order to improve their therapeutic management and outcomes. Aggressive prostate tumors characteristically exhibit high rates of glycolysis and lipogenesis. Glycerol 3-phosphate phosphatase (G3PP), also known as phosphoglycolate phosphatase (PGP), is a recently identified mammalian enzyme, shown to play a role in the regulation of glucose metabolism, lipogenesis, lipolysis, and cellular nutrient-excess detoxification. We hypothesized that G3PP may relieve metabolic stress in cancer cells and assessed the association of its expression with PC patient prognosis. Using immunohistochemical staining, we assessed the epithelial expression of G3PP in two different radical prostatectomy (RP) cohorts with a total of 1797 patients, for whom information on biochemical recurrence (BCR), metastasis, and mortality was available. The association between biomarker expression, biochemical recurrence (BCR), bone metastasis, and prostate cancer-specific survival was established using log-rank and multivariable Cox regression analyses. High expression of G3PP in PC epithelial cells is associated with an increased risk of BCR, bone metastasis, and PC-specific mortality. Multivariate analysis revealed high G3PP expression in tumors as an independent predictor of BCR and bone metastasis development. High G3PP expression in tumors from patients eligible for prostatectomies is a new and independent prognostic biomarker of poor prognosis and aggressive PC for recurrence, bone metastasis, and mortality.

A Novel Six-Gene Signature for Prognosis Prediction in Ovarian Cancer

Ovarian cancer (OC) is the most malignant tumor in the female reproductive tract. Although abundant molecular biomarkers have been identified, a robust and accurate gene expression signature is still essential to assist oncologists in evaluating the prognosis of OC patients. In this study, samples from 367 patients in The Cancer Genome Atlas (TCGA) database were subjected to mRNA expression profiling. Then, we used a gene set enrichment analysis (GSEA) to screen genes correlated with epithelial–mesenchymal transition (EMT) and assess their prognostic power with a Cox proportional regression model. Six genes (TGFBI, SFRP1, COL16A1, THY1, PPIB, BGN) associated with overall survival (OS) were used to construct a risk assessment model, after which the patients were divided into high-risk and low-risk groups. The six-gene signature was an independent prognostic biomarker of OS for OC patients based on the multivariate Cox regression analysis. In addition, the six-gene model was validated with samples from the Gene Expression Omnibus (GEO) database. In summary, we established a six-gene signature relevant to the prognosis of OC, which might become a therapeutic tool with clinical applications in the future.

Building a Canadian Translational Bladder Cancer Research Network

Bladder cancer research has historically lagged behind efforts in other disease sites with substantial underfunding relative to the heavy morbidity and mortality suffered by patients. Alongside increasing advocacy however, more recent advances in our understanding of the molecular biology of bladder cancer has ushered in a period of renaissance with exciting prospects for novel, precise diagnostics and therapeutics. Given significant and diverse assets within the research community across Canada, an inaugural translational research forum was convened to identify research gaps and strengths, and to formalize investigational themes that would be apposite for multi-institutional collaboration. The virtual meeting brought together a multi-disciplinary network of genitourinary cancer researchers, including clinicians and basic scientists, and entailed detailed environmental scans of the Canadian clinical and translational research landscape as well as selected “elevator pitches” of potential research themes. The results of these discussions are detailed herein and have provided the impetus to formalize the Canadian Bladder Cancer Research Network (CBCRN). Working groups have been created to focus future multi-institutional collaborations in four inter-related initiatives: biomarker development, epigenetic targeting, immuno-oncology and the microbiome.

Validation of the prognostic value of NF-κB p65 in prostate cancer: A retrospective study using a large multi-institutional cohort of the Canadian Prostate Cancer Biomarker Network

BACKGROUND

The identification of patients with high-risk prostate cancer (PC) is a major challenge for clinicians, and the improvement of current prognostic parameters is an unmet clinical need. We and others have identified an association between the nuclear localization of NF-κB p65 and biochemical recurrence (BCR) in PC in small and/or single-centre cohorts of patients.

METHODS AND FINDINGS

In this study, we accessed 2 different multi-centre tissue microarrays (TMAs) representing cohorts of patients (Test-TMA and Validation-TMA series) of the Canadian Prostate Cancer Biomarker Network (CPCBN) to validate the association between p65 nuclear frequency and PC outcomes. Immunohistochemical staining of p65 was performed on the Test-TMA and Validation-TMA series, which include PC tissues from patients treated by first-line radical prostatectomy (n = 250 and n = 1,262, respectively). Two independent observers evaluated the p65 nuclear frequency in digital images of cancer tissue and benign adjacent gland tissue. Kaplan-Meier curves coupled with a log-rank test and univariate and multivariate Cox regression models were used for statistical analyses of continuous values and dichotomized data (cutoff of 3%). Multivariate analysis of the Validation-TMA cohort showed that p65 nuclear frequency in cancer cells was an independent predictor of BCR using continuous (hazard ratio [HR] 1.02 [95% CI 1.00-1.03], p = 0.004) and dichotomized data (HR 1.33 [95% CI 1.09-1.62], p = 0.005). Using a cutoff of 3%, we found that this biomarker was also associated with the development of bone metastases (HR 1.82 [95% CI 1.05-3.16], p = 0.033) and PC-specific mortality (HR 2.63 [95% CI 1.30-5.31], p = 0.004), independent of clinical parameters. BCR-free survival, bone-metastasis-free survival, and PC-specific survival were shorter for patients with higher p65 nuclear frequency (p < 0.005). As the small cores on TMAs are a limitation of the study, a backward validation of whole PC tissue section will be necessary for the implementation of p65 nuclear frequency as a PC biomarker in the clinical workflow.

CONCLUSIONS

We report the first study using the pan-Canadian multi-centre cohorts of CPCBN and validate the association between increased frequency of nuclear p65 frequency and a risk of disease progression.

Optimization of Tissue Microarrays from Banked Human Formalin-Fixed Paraffin Embedded Tissues in the Cancer Research Setting

The tissue microarray (TMA) is a powerful tool for cancer biomarker discovery and validation. Tens to hundreds of samples can be evaluated simultaneously for molecular marker status at the protein or nucleic acid level. Although fully automated or semiautomated technologies for TMA creation provide excellent precision with respect to core transfer, they do not obviate the need for technical expertise to successfully generate high-quality TMA blocks and derivative sections. We have leveraged our expanding bank of formalin-fixed paraffin embedded paired tumor and normal tissues in our academic cancer center to provide a rich source of input material for cancer research TMAs. In this study, we report a stepwise optimization of TMA generation parameters, including paraffin wax selection, tempering protocol, and sectioning conditions, to achieve the best ribbon sectioning.

CCN3/Nephroblastoma Overexpressed Is a Functional Mediator of Prostate Cancer Bone Metastasis That Is Associated with Poor Patient Prognosis

Prostate cancer (PC) commonly metastasizes to the bone, resulting in pathologic fractures and poor prognosis. CCN3/nephroblastoma overexpressed is a secreted protein with a known role in promoting breast cancer metastasis to bone. However, in PC, CCN3 has been ascribed conflicting roles; some studies suggest that CCN3 promotes PC metastasis, whereas others argue a tumor suppressor role for CCN3 in this disease. Indeed, in the latter context, CCN3 has been shown to sequester the androgen receptor (AR) and suppress AR signaling. In the present study, we demonstrate that CCN3 functions as a bone-metastatic mediator, which is dependent on its C-terminal domain for this function. Analysis of tissue microarrays comprising >1500 primary PC patient radical prostatectomy specimens reveals that CCN3 expression correlates with aggressive disease and is negatively correlated with the expression of prostate-specific antigen, a marker of AR signaling. Together, these findings point to CCN3 as a biomarker to predict PC aggressiveness while providing clarity on its role as a functional mediator of PC bone metastasis.