Congrés Annuel : Programme général Association des Urologues du Québec

摘要

Introduction et objectifs : The lethal and incurable form of prostate cancer (PC) is the castration resistant state that develops when patients progress while on hormone therapy. New strategies based on targeted drugs are increasingly gaining clinical acceptance, and may be appropriate throughout PC progression, including the later stages. However, an important consideration is matching the most appropriate drug to a patient’s tumour characteristics. While response biomarkers (theranostics) are being developed to address this problem, a more direct solution would be to use a low-cost high throughput empirical testing platform. Recent developments in engineering have permitted the design and production of a new generation of microfluidic devices capable of trapping micrometer-size tumour samples and maintaining their viability over several days. We hypothesize that these devices are particularly well suited to meet the challenges of pre-clinical drug testing. Matériels et méthodes : For the xenograft microbiopsy model, 22Rv1 or PC3 cells were mixed with matrigel, to allow the formation of denser tumours, prior to sub-cutaneous injection into the flank of male SCID mice. Mice were sacrificed before or when tumour size reached the limit point of 2500 mm3 and xenografts were immediately processed to produce numerous cylindrical microbiopsies (from 50 to 150 per tumour). Five xenograft microbiopsies were introduced into each microfluidic device and trapped in five independent wells. To follow the xenograft microbiopsy response to treatments, we applied 5 mM of CellTracker Green dye (live cell dye) for 40 minutes followed by 2 mM 7AAD (late apoptotic and dead cell dye) for an additional 20 minutes. Samples were observed directly in the microfluidic device by confocal microscopy. All xenograft microbiopsies were imaged in different z-sections (～ 10 mm step). For each z-section the mortality fraction (dead cells/total cells) was determined using an image-processing program (Matlab). Samples were then collected to quantify cell survival and apoptosis by fluorescence-activated cell sorting (FACS). Résultats : Over the last year, we have developed a technique to precisely cut cylindrical tumour tissue samples (cylinders of 300 mm in diameter and 300 mm in length) by adapting traditional vibratome slicing techniques. We have also designed a microfluidic chip, with five independent microfluidic channels capable of holding up to 25 cylindrical PC samples in designated traps (five samples per channel). Samples can then be exposed to four specific chemotherapeutic agents or four different doses of the same agent plus a non-treated control. We demonstrated that xenograft microbiopsy sections obtained using our virbratome-based method can be loaded in the microsystems and maintained with high viability (75% to 95%) for up to seven days in such microsystems. We also demonstrated the feasibility of drug testing in our microsystems by the treatment of 22Rv1 and PC3 microbiopsies using different doses of docetaxel (from 1 nM to 100 nM). Conclusions : With an increasing array of various therapeutics at hand, it is essential to classify or sort patients based on sound instruments and data when choosing a drug treatment. It is essential to maximize clinical response while minimizing treatment toxicities. Testing patient biopsy material should allow for direct empirical evaluation of therapeutic responses to a wide concentration and variety of agents. This rapid and directed approach would support clinical decision-making and allow the tailoring of therapeutic strategies for individual patients within an acceptable time frame. This would reduce not only the economic burden on the health care system but also the inconvenience and risk of exposing patients to drugs with little chance of success and the optimization of therapies in patients more likely to respond. Can Urol Assoc J. 2014 Sep-Oct; 8(9-10): 361–375. ? Reconstruction de tissu vaginal en utilisant la méthode d’auto-assemblage Can Urol Assoc J. 2014 Sep-Oct; 8 (9-10) : 364–365. Reconstruction de tissu vaginal en utilisant la méthode d’auto-assemblage *Frédérick Bouchard, (resident) , Hazem Orabi, (fellow) , Amélie Morissette, (autre) , Guillaume Taillon, (autre) , Alexandre Rousseau, (autre) , Geneviève Bernard, (autre) , Stéphane Chabaud, (autre) , and Stéphane Bolduc, (urologue) CHU de Québec - LOEX (Laboratoire d’Organogenèse Expérimentale), Québec Author information ? Copyright and License information ? Copyright Copyright: ? 2014 Canadian Urological Association or its licensors