Impact of devascularization and tissue procurement on cell number and RNA integrity in prostatectomy tissue

Defining best practices for tissue procurement in immuno-oncology clinical trials: consensus statement from the Society for Immunotherapy of Cancer Surgery Committee

Immunotherapy is now a cornerstone for cancer treatment, and much attention has been placed on the identification of prognostic and predictive biomarkers. The success of biomarker development is dependent on accurate and timely collection of biospecimens and high-quality processing, storage and shipping. Tumors are also increasingly used as source material for the generation of therapeutic T cells. There have been few guidelines or consensus statements on how to optimally collect and manage biospecimens and source material being used for immunotherapy and related research. The Society for Immunotherapy of Cancer Surgery Committee has brought together surgical experts from multiple subspecialty disciplines to identify best practices and to provide consensus on how best to access and manage specific tissues for immuno-oncology treatments and clinical investigation. In addition, the committee recommends early integration of surgeons and other interventional physicians with expertise in biospecimen collection, especially in clinical trials, to optimize the quality of tissue and the validity of correlative clinical studies in cancer immunotherapy.

A New Technique in Fresh Prostate Cancer Tissue Biobanking Based on MRI-Transrectal Ultrasound Fusion Biopsy

OBJECTIVE

To present and validate a new technique for biobanking fresh-frozen prostate cancer tissue based on MRI-transrectal ultrasound fusion biopsy.

MATERIALS AND METHODS

From August 2014 to August 2016, patients with elevated levels of PSA and at least 1 suspicious lesion on MRI were invited to this study. Each MRI-suspicious lesion was biopsied repeatedly for at least 2 cores in the same location. These repeated cores were labelled A/A', B/B', etc. The A/B cores were submitted for histologic assessment, and the corresponding A'/B' cores were stored in an -80°C freezer for biobanking. Sixty biobanked samples were processed for histologic assessment to compare their pathologic parameters with their corresponding paraffin samples. Another 20 biobanked samples were processed for RNA quality evaluation.

RESULTS

Fifty-six of the 60 selected banking samples matched their corresponding paraffin samples for benign vs malignant diagnosis, leading an overall concordance rate of 93.3%. There was no significant difference between banking samples and the corresponding paraffin samples in cancer percentage and Gleason score. The RNA Integrity Number value ranged from 6.8 to 9.3 (mean 7.89).

CONCLUSION

The current study demonstrates that the histologic identity of the banked prostate biopsy sample can be accurately predicted by its corresponding paraffin samples. MRI-TRUS fusion biopsy based biobanking method is highly efficient, timesaving, and has high quality tissues both at the histologic and RNA integrity levels.

Fast prostate retrieval in robot-assisted laparoscopic prostatectomy for next-generation biobanking

Robotic-assisted laparoscopic radical prostatectomy (RALP) has become the most widespread treatment for organ-confined prostate cancer. Here, we describe a fast specimen retrieval technique for RALP to obtain high-quality tissue specimen with minimal warm ischemia time for next-generation biobanking. Here, we show that using fast retrieval technique, short warm ischemia times can be achieved while not increasing the surgical time. Patients undergoing RALP with written informed consent participated in Helsinki Urological Bank study. Previously operated RALP patients and those, who were not willing to participate in the study, served as a control group. The study consisted of 1685 patients, 684 in fast retrieval and 1001 in control group. We developed a novel fast retrieval technique in which fascia is opened for camera port according to the prostate size and a running suture is placed and tightened against the camera port in the beginning of the operation. Immediately after prostate is freed from attachments, suture is loosened and the prostate is extirpated inside the endoscopic bag through the camera port fascial opening, then the fascial suture is again tightened against the camera port and the RALP procedure is completed. The mean warm ischemia times in fast retrieval group were 20 min 18 s and 22 min 30 s, respectively, in patients without and with lymphadenectomy. The mean console and surgery times with and without lymphadenectomy were similar in both groups. There were no technique-related complications associated with Fast Retrieval procedure. Tissue integrity test results for the RNA and DNA quality showed good quality for the specimen. Fast retrieval technique can easily and safely be utilized to maximize usefulness of RALP tissue specimen in downstream biobank applications.

Gene Expression in Single Cells Isolated from the CWR-R1 Prostate Cancer Cell Line and Human Prostate Tissue Based on the Side Population Phenotype

Defining biological signals at the single cell level can identify cancer initiating driver mutations. Techniques to isolate single cells such as microfluidics sorting and magnetic capturing systems have limitations such as: high cost, labor intense, and the requirement of a large number of cells. Therefore, the goal of our current study is to identify a cost and labor effective, reliable, and reproducible technique that allows single cell isolation for analysis to promote regular laboratory use, including standard reverse transcription PCR (RT-PCR).

In the current study, we utilized single prostate cells isolated from the CWR-R1 prostate cancer cell line and human prostate clinical specimens, based on the ATP binding cassette (ABC) transporter efflux of dye cycle violet (DCV), side population assay. Expression of four genes: ABCG2; Aldehyde dehydrogenase1A1 (ALDH1A1); androgen receptor (AR); and embryonic stem cell marker, Oct-4, were determined.

Results from the current study in the CWR-R1 cell line showed ABCG2 and ALDH1A1 gene expression in 67% of single side population cells and in 17% or 100% of non-side population cells respectively. Studies using single cells isolated from clinical specimens showed that the Oct-4 gene is detected in only 22% of single side population cells and in 78% of single non-side population cells. Whereas, AR gene expression is in 100% single side population and non-side population cells isolated from the same human prostate clinical specimen.

These studies show that performing RT-PCR on single cells isolated by FACS can be successfully conducted to determine gene expression in single cells from cell lines and enzymatically digested tissue. While these studies provide a simple yes/no expression readout, the more sensitive quantitative RT-PCR would be able to provide even more information if necessary.