Nicole J. Caixeiro

New frontiers in circulating tumor cell analysis: A reference guide for biomolecular profiling toward translational clinical use

Circulating tumor cells (CTCs) are now routinely isolated from blood, and measurement of CTC concentrations appears to correlate well with survival in patients with cancer. Interrogation of the molecular profile of CTCs for expression of protein biomarkers, genetic variants and gene expression provides opportunities to use this information to guide personalized treatment, monitor therapy and detect emerging resistance. However, successful application of profiling techniques requires analyses that deliver a reliable and clinically relevant representation of a patients cancer as it changes with time. Here, we comprehensively review the current knowledge of therapeutically relevant biomarkers in isolated CTCs obtained by fluorescence imaging and genomic profiling approaches. The reviewed data support the notion that molecular profiling of CTCs will provide a reliable representation or surrogate index of tumor burden. Large‐scale translational trials, many currently in progress, will provide critical data to progress CTC analysis toward wider clinical use in personalized treatment.

Quality assessment and preservation of RNA from biobank tissue specimens: a systematic review

It is well recognised that genomic, proteomic and biomarker studies require properly annotated and well-characterised biospecimens. Consequently, this necessitates biobanks to collect, store and distribute biospecimens under stringent quality control and assurance measures. However, despite this realisation, there remains a lack of standardisation in quality management among biobanks and consensus as to which quality indicators provide the optimal molecular diagnostic performance tools and information for biospecimens. In an attempt to identify key factors that predict tissue specimen integrity and quality, this systematic review investigated the measures reported in the literature, which characterised the collection, processing and storage of high-quality tissue specimens. Our findings demonstrated RNA integrity, alone, may not be an effective measure of tissue quality. Furthermore, the frequently reported parameters related to biospecimen integrity, such as storage time, temperature, time to cryopreservation and tissue morphology were also not effective indicators of quality control and assurance. These findings suggest that it is unlikely that a single marker will provide the optimal diagnostic and performance information for biospecimens, but rather, a panel of markers assessing the molecular integrity of the lifespan of the biospecimen is required. Further work is needed to identify which factors predict specimen integrity and quality in biobanked tissue specimens.

Health professionals’ opinions on supporting a cancer biobank: identification of barriers to combat biobanking pitfalls

Although rarely acknowledged, a successful biobank is highly dependent on the support of the health professionals who assist the biobank in all aspects of its activities. In many cases, the lack of health professional support can be a limiting factor in the biobanking process of collecting and processing high-quality biospecimens. The aim of this study was to determine the attitudes of health professionals towards cancer biobanking. Using a 5-point Likert scale questionnaire, important aspects of biobanking, including accrual, quality, knowledge, responsiveness, impact, access, trust, governance and accreditation, were investigated. In total, 95 of 124 health and medical practitioners who were approached participated in this study (77% response rate). Health professionals in general supported the aims of biobanking with 56% of participants showing willingness to create a biobank and recruit donors (accrual), 85% understanding the importance in the storage and distribution of biospecimens (quality), 88% having an appreciation for the role of a biobank in furthering cancer research (knowledge), 70% showing awareness of the use of biospecimens in future research initiatives (responsiveness) and 73% demonstrating support for a biobank with proper control, authority and credibility measures in place (governance and accreditation). Overall, provided that proper information about the activities of the biobank and researcher access was transparent, health professionals were very willing to support cancer biobanking. These findings may assist in developing strategies for the establishment and maintenance of biobanks and aid the implementation of more effective policies and procedures to embed biobanking into routine hospital practices.

Silencing the mannose 6‐phosphate/IGF‐II receptor differentially affects tumorigenic properties of normal breast epithelial cells

Although loss of the mannose 6‐phosphate/insulin‐like growth factor‐II receptor (M6P/IGF‐IIR) in breast cancer is believed to play a role in tumorigenesis, it has not been demonstrated that M6P/IGF‐IIR loss is sufficient to confer a malignant phenotype in an untransformed cell. We investigated the impact of M6P/IGF‐IIR silencing using phenotypically normal (MCF‐10A) and oncogenically transformed (MCF‐10T, the c‐Ha‐ras transformed derivative of MCF‐10A) human breast epithelial cell lines as model systems. In both cell lines, silencing of M6P/IGF‐IIR increased cell proliferation and motility, with the effects being more pronounced in MCF‐10A cells. Although anchorage‐independent growth was increased by M6P/IGF‐IIR silencing in MCF‐10T cells, MCF‐10A cells did not acquire the ability to grow in soft agar. Conversely, reduced M6P/IGF‐IIR expression increased the invasive potential of MCF‐10A cells, but did not enhance the already high rate of invasion of MCF‐10T cells. M6P/IGF‐IIR silencing had no effect on basal or IGF‐II‐stimulated IGF‐I receptor (IGF‐IR) or AKT phosphorylation in either cell line, but both were abrogated by IGF‐IR kinase inhibition, which also reduced the stimulatory effect of M6P/IGF‐IIR silencing on proliferation under basal and IGF‐II‐stimulated conditions in both cell lines. However, cell motility was neither stimulated by IGF‐II nor reduced by IGF‐IR inhibition, suggesting that potentiation of specific tumorigenic features in response to M6P/IGF‐IIR silencing involves IGF‐II‐ dependent and ‐independent mechanisms. Collectively, these data suggest that M6P/IGF‐IIR silencing alone is insufficient to confer a tumorigenic phenotype, but can enhance tumorigenicity in an already transformed cell.