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1.
Nat Commun ; 10(1): 3935, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477716

RESUMO

Mucinous ovarian carcinoma (MOC) is a unique subtype of ovarian cancer with an uncertain etiology, including whether it genuinely arises at the ovary or is metastatic disease from other organs. In addition, the molecular drivers of invasive progression, high-grade and metastatic disease are poorly defined. We perform genetic analysis of MOC across all histological grades, including benign and borderline mucinous ovarian tumors, and compare these to tumors from other potential extra-ovarian sites of origin. Here we show that MOC is distinct from tumors from other sites and supports a progressive model of evolution from borderline precursors to high-grade invasive MOC. Key drivers of progression identified are TP53 mutation and copy number aberrations, including a notable amplicon on 9p13. High copy number aberration burden is associated with worse prognosis in MOC. Our data conclusively demonstrate that MOC arise from benign and borderline precursors at the ovary and are not extra-ovarian metastases.

2.
Sci Rep ; 9(1): 13924, 2019 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-31558772

RESUMO

Ovarian cancer (OVCA) patients with suboptimal residual disease (RD) and advanced stages have poor survival. pGSN is an actin binding protein which protects OVCA cells from cisplatin-induced death. There is an urgent need to discover reliable biomarkers to optimize individualized treatment recommendations. 99 plasma samples with pre-determined CA125 were collected from OVCA patients and pGSN assayed using sandwich-based ELISA. Associations between CA125, pGSN and clinicopathological parameters were examined using Fisher's exact test, T test and Kruskal Wallis Test. Univariate and multivariate Cox proportional hazard models were used to statistically analyze clinical outcomes. At 64 µg/ml, pGSN had sensitivity and specificity of 60% and 60% respectively, for the prediction of RD where as that of CA125 at 576.5 U/mL was 43.5% and 56.5% respectively. Patients with stage 1 tumor had increased levels of pre-operative pGSN compared to those with tumor stage >1 and healthy subjects (P = 0.005). At the value of 81 µg/mL, pGSN had a sensitivity and specificity of 75% and 78.4%, respectively for the detection of early stage OVCA. At the value of 0.133, the Indicator of Stage 1 OVCA (ISO1) provided a sensitivity of 100% at a specificity of 67% (AUC, 0.89; P < 0.001). In the multivariate Cox regression analysis, pGSN (HR, 2.00; CI, 0.99-4.05; P = 0.05) was an independent significant predictor of progression free survival (PFS) but not CA125 (HR, 0.68; CI, 0.41-1.13; P = 0.13). Pre-operative circulating pGSN is a favorable and independent biomarker for early disease detection, RD prediction and patients' prognosis.

3.
PLoS Med ; 16(7): e1002847, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31265453

RESUMO

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.

4.
Biopreserv Biobank ; 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31194579

RESUMO

The Canadian Tissue Repository Network (CTRNet) Biobank Certification Program was first launched in 2011 to foster translational research through improved access to high quality biospecimens. This was accomplished by creating and providing biobank education and through the establishment and deployment of common standards to harmonize biospecimen quality and approaches to governance. The CTRNet program comprises registration and certification steps as two linked phases. In the two-step registration phase, the biobank is registered into the system, and an individual completes an overview educational module. In the subsequent certification phase, biobanks undergo a seven-step process, including inviting team members, assigning and completing relevant education modules, uploading documents, and undergoing a documentation audit. As of June 2018, there were 251 biobanks engaged in the CTRNet program, 193 had completed registration, and 40 were fully certified. Over 3/4 of these biobanks completed registration within a week and over 1/3 completed certification within a month. Among registered biobanks, 163 were associated with North American institutions, while 30 were from other international locations, including Australia, Europe, and Asia. The CTRNet program enables biobanks to adopt standards with a flexible approach to accommodate different types of biobanks and a measured investment of effort, creating the foundation for increased access to high quality biospecimens.

5.
Integr Biol (Camb) ; 11(4): 130-141, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31172192

RESUMO

Multicellular tumour spheroids are an ideal in vitro tumour model to study clonal heterogeneity and drug resistance in cancer research because different cell types can be mixed at will. However, measuring the individual response of each cell population over time is challenging: current methods are either destructive, such as flow cytometry, or cannot image throughout a spheroid, such as confocal microscopy. Our group previously developed a wide-field fluorescence hyperspectral imaging system to study spheroids formed and cultured in microfluidic chips. In the present study, two subclones of a single parental ovarian cancer cell line transfected to express different fluorophores were produced and co-culture spheroids were formed on-chip using ratios forming highly asymmetric subpopulations. We performed a 3D proliferation assay on each cell population forming the spheroids that matched the 2D growth behaviour. Response assays to PARP inhibitors and platinum-based drugs were also performed to follow the clonal evolution of mixed populations. Our experiments show that hyperspectral imaging can detect spheroid response before observing a decrease in spheroid diameter. Hyperspectral imaging and microfluidic-based spheroid assays provide a versatile solution to study clonal heterogeneity, able to measure response in subpopulations presenting as little as 10% of the initial spheroid.

6.
Am J Pathol ; 189(7): 1451-1461, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31202437

RESUMO

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.

7.
Nat Commun ; 10(1): 2556, 2019 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-31186408

RESUMO

Senescence is a tumor suppression mechanism defined by stable proliferation arrest. Here we demonstrate that the known synthetic lethal interaction between poly(ADP-ribose) polymerase 1 inhibitors (PARPi) and DNA repair triggers p53-independent ovarian cancer cell senescence defined by senescence-associated phenotypic hallmarks including DNA-SCARS, inflammatory secretome, Bcl-XL-mediated apoptosis resistance, and proliferation restriction via Chk2 and p21 (CDKN1A). The concept of senescence as irreversible remains controversial and here we show that PARPi-senescent cells re-initiate proliferation upon drug withdrawal, potentially explaining the requirement for sustained PARPi therapy in the clinic. Importantly, PARPi-induced senescence renders ovarian and breast cancer cells transiently susceptible to second-phase synthetic lethal approaches targeting the senescence state using senolytic drugs. The combination of PARPi and a senolytic is effective in preclinical models of ovarian and breast cancer suggesting that coupling these synthetic lethalities provides a rational approach to their clinical use and may together be more effective in limiting resistance.


Assuntos
Proliferação de Células/efeitos dos fármacos , Senescência Celular , Reparo do DNA , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Mutações Sintéticas Letais , Antineoplásicos/farmacologia , Apoptose , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológico
8.
Nat Commun ; 10(1): 2666, 2019 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-31209254

RESUMO

Ran is a nucleocytoplasmic shuttle protein that is involved in cell cycle regulation, nuclear-cytoplasmic transport, and cell transformation. Ran plays an important role in cancer cell survival and cancer progression. Here, we show that, in addition to the nucleocytoplasmic localization of Ran, this GTPase is specifically associated with the plasma membrane/ruffles of ovarian cancer cells. Ran depletion has a drastic effect on RhoA stability and inhibits RhoA localization to the plasma membrane/ruffles and RhoA activity. We further demonstrate that the DEDDDL domain of Ran is required for the interaction with serine 188 of RhoA, which prevents RhoA degradation by the proteasome pathway. Moreover, the knockdown of Ran leads to a reduction of ovarian cancer cell invasion by impairing RhoA signalling. Our findings provide advanced insights into the mode of action of the Ran-RhoA signalling axis and may represent a potential therapeutic avenue for drug development to prevent ovarian tumour metastasis.


Assuntos
Carcinoma Epitelial do Ovário/patologia , Membrana Celular/metabolismo , Neoplasias Ovarianas/patologia , Proteína ran de Ligação ao GTP/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Linhagem Celular Tumoral , Feminino , Técnicas de Silenciamento de Genes , Humanos , Invasividade Neoplásica/patologia , Domínios Proteicos , Estabilidade Proteica , Proteólise , Serina/metabolismo , Transdução de Sinais , Proteína ran de Ligação ao GTP/genética
9.
Radiat Oncol ; 14(1): 60, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31018850

RESUMO

BACKGROUND: Intraductal carcinoma of the prostate (IDC-P) is an independent biomarker of recurrence and survival with particular treatment response, yet no study has tested its response to radiotherapy. The aim of our project was to test the impact of adjuvant radiotherapy (ART) in patients with localized to locally advanced prostate cancer (PC) and IDC-P. MATERIALS AND METHODS: We performed a retrospective study of men with pT2-T3 PC treated by radical prostatectomy (RP) with or without ART, from two centres (1993-2015). Exclusion criteria were the use of another type of treatment prior to biochemical recurrence (BCR), and detectable prostate- specific antigen (PSA) following RP or ART. Primary outcome was BCR (2 consecutive PSA ≥ 0.2 ng/ml). Patients were grouped by treatment (RPonly/RP + ART), IDC-P status, and presence of high-risk features (HRF: Grade Groups 4-5, positive margins, pT3 stage). RESULTS: We reviewed 293 RP specimens (median follow-up 99 months, 69 BCR). Forty-eight patients (16.4%) were treated by RP + ART. Multivariate Cox regression for BCR indicated that IDC-P had the strongest impact (hazard ratio [HR] = 2.39, 95% confidence interval [CI]:1.44-3.97), while ART reduced the risk of BCR (HR = 0.38, 95%CI: 0.17-0.85). Other HRF were all significant except for pT3b stage. IDC-P[+] patients who did not receive ART had the worst BCR-free survival (log-rank P = 0.023). Furthermore, IDC-P had the same impact on BCR-free survival as ≥1 HRF (log-rank P = 0.955). CONCLUSION: Men with IDC-P who did not receive ART had the highest BCR rates, and IDC-P had the same impact as ≥1 HRF, which are often used as ART indications. Once validated, ART should be considered in patients with IDC-P.


Assuntos
Carcinoma Intraductal não Infiltrante/radioterapia , Recidiva Local de Neoplasia/radioterapia , Neoplasias da Próstata/radioterapia , Radioterapia Adjuvante/mortalidade , Carcinoma Intraductal não Infiltrante/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Prognóstico , Neoplasias da Próstata/patologia , Estudos Retrospectivos , Taxa de Sobrevida
10.
J Pathol Clin Res ; 5(3): 177-188, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30924313

RESUMO

The aim of this study was to describe the expression of special AT-rich sequence-binding protein 2 (SATB2) in ovarian endometrioid carcinoma (EC). SATB2 is a nuclear matrix-associated transcription factor that is associated with abnormal expression in certain cancers but has not been reported for ovarian carcinoma. SATB2 mRNA and protein expression was first assessed in a pilot cohort of 26 samples by Affymetrix microarray and by routine immunohistochemistry on a small tissue microarray. A large multicenter validation cohort representing the well-characterized cases of 235 ovarian EC from the Canadian Ovarian Experimental Unified Resource (COEUR) was then used to validate this result and to assess the prognostic impact of SATB2 expression. SATB2 staining was scored as negative, weak, moderate, and strong intensity, and by percentage of stained cells. No SATB2 expression was observed in clear cell carcinomas but 10% (n = 3) of the ECs in the pilot cohort showed SATB2 expression. In the validation cohort, strong expression was observed in 11% of ECs, while weak or moderate expression levels were detected in 12% of cases. Evaluation of SATB2 expression with clinicopathological parameters revealed an association with patient age and Federation International of Gynecology and Obstetrics grade but not with disease stage or postoperative residual disease. Any expression of SATB2, independent of intensity, was also associated with longer survival and improved progression-free survival with hazard ratio (HR) = 0.14 (95% CI 0.03-0.56) and HR = 0.16 (95% CI 0.02-1.24) respectively. A greater beneficial effect was observed in patients with stage III/IV disease compared to patients with stage I/II disease. Furthermore, direct comparison of SATB2 with other reported prognostic biomarkers such as progesterone receptor, CDX2 and ß-catenin within this cohort showed that SATB2 had the strongest association with survival. Given the current lack of accurate prognostic factors for these patients, SATB2 has promising clinical utility and warrants further study.

11.
J Immunother Cancer ; 7(1): 86, 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30922393

RESUMO

BACKGROUND: Permanence of front-line management of lung cancer by immunotherapies requires predictive companion diagnostics identifying immune-checkpoints at baseline, challenged by the size and heterogeneity of biopsy specimens. METHODS: An innovative, tumor heterogeneity reducing, immune-enriched tissue microarray was constructed from baseline biopsies, and multiplex immunofluorescence was used to profile 25 immune-checkpoints and immune-antigens. RESULTS: Multiple immune-checkpoints were ranked, correlated with antigen presenting and cytotoxic effector lymphocyte activity, and were reduced with advancing disease. Immune-checkpoint combinations on TILs were associated with a marked survival advantage. Conserved combinations validated on more than 11,000 lung, breast, gastric and ovarian cancer patients demonstrate the feasibility of pan-cancer companion diagnostics. CONCLUSIONS: In this hypothesis-generating study, deepening our understanding of immune-checkpoint biology, comprehensive protein-protein interaction and pathway mapping revealed that redundant immune-checkpoint interactors associate with positive outcomes, providing new avenues for the deciphering of molecular mechanisms behind effects of immunotherapeutic agents targeting immune-checkpoints analyzed.

12.
Int J Gynecol Pathol ; 2019 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-30789501

RESUMO

The origin of serous endometrial intraepithelial carcinoma (SEIC) is debated, due to its premalignant and independently malignant nature. It often arises next to endometrial serous carcinoma (ESC), with a propensity for polypoid growth. We aimed to better characterize this discrepancy by analyzing the clinical, histologic, and immunohistochemical features of polypoid carcinoma associated with SEIC (P-SEIC), and compared them with usual endometrial serous carcinoma without SEIC (UESC). Consecutive patients with P-SEIC were recruited and compared with UESC controls from our institutional research center. Clinical, histologic, and immunohistochemical (IHC, ER, PR, P53, Napsin-A, WT1, P16) were analyzed. BRCA testing results and familial history were also extracted from clinical databases. Welch T test, Pearson χ, and Fisher exact test were performed in SPSS version 23. A total of 37 P-SEIC and 25 UESC were the basis of a case-control study. P-SEIC was associated with more bilateral ovarian involvement (P=0.026), yet showed lower rates of myometrial invasion (P=0.002). P-SEIC showed a statistically different IHC profile: p53+, p16+, ER+, PR+, and WT-1+, and high rates of Napsin-A, while UESC was p53+, p16+, WT-1-, Napsin-A-, with lower rates of ER and PR. We also identified 2 patients who received prophylactic salpingo-oophorectomy for BRCA mutations and who subsequently developed P-SEIC with its unique IHC pattern. Our results suggest different underlying expression profiles and possibly diverging molecular signatures between both P-SEIC and UESC. If confirmed in further molecular studies, it could lead to a distinct molecular subclass.

13.
Lab Chip ; 19(4): 693-705, 2019 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-30671574

RESUMO

There is an urgent need and strong clinical and pharmaceutical interest in developing assays that allow for the direct testing of therapeutic agents on primary tissues. Current technologies fail to provide the required sample longevity, throughput, and integration with standard clinically proven assays to make the approach viable. Here we report a microfluidic micro-histological platform that enables ex vivo culture of a large array of prostate and ovarian cancer micro-dissected tissue (MDT) followed by direct on-chip fixation and paraffination, a process we term paraffin-embedding lithography (PEL). The result is a high density MDT-Micro Array (MDTMA) compatible with standard clinical histopathology that can be used to analyse ex vivo tumor response or resistance to therapeutic agents. The cellular morphology and tissue architecture are preserved in MDTs throughout the 15 day culture period. We also demonstrate how this methodology can be used to study molecular pathways involved in cancer by performing in-depth characterization of biological and pharmacological mechanisms such as p65 nuclear translocation via TNF stimuli, and to predict the treatment outcome in the clinic via MDT response to taxane-based therapies.


Assuntos
Técnicas Analíticas Microfluídicas , Neoplasias Ovarianas/diagnóstico , Inclusão em Parafina , Neoplasias da Próstata/diagnóstico , Animais , Antineoplásicos/farmacologia , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Proliferação de Células/efeitos dos fármacos , Desenho de Equipamento , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos , Técnicas Analíticas Microfluídicas/instrumentação , Neoplasias Experimentais/diagnóstico , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Inclusão em Parafina/instrumentação , Prognóstico , Neoplasias da Próstata/tratamento farmacológico , Taxoides/farmacologia , Resultado do Tratamento , Células Tumorais Cultivadas
14.
Histopathology ; 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30403298

RESUMO

The association between progesterone receptor (PR) expression and improved outcome of ovarian cancer patients has been reported with conflicting results (1). To clarify the prognostic role of PR expression patients, Luo et al. (1) performed a meta-analysis of 28 published studies. The authors found that PR expression detected by immunohistochemistry (IHC) was associated with favorable overall survival (hazard ratio [HR] = 0.86) combining studies not stratified by histotypes. This article is protected by copyright. All rights reserved.

15.
Cancers (Basel) ; 10(10)2018 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-30314329

RESUMO

BACKGROUND: Patients with locally advanced or recurrent prostate cancer typically undergo androgen deprivation therapy (ADT), but the benefits are often short-lived and the responses variable. ADT failure results in castration-resistant prostate cancer (CRPC), which inevitably leads to metastasis. We hypothesized that differences in tumor transcriptional programs may reflect differential responses to ADT and subsequent metastasis. RESULTS: We performed whole transcriptome analysis of 20 patient-matched Pre-ADT biopsies and 20 Post-ADT prostatectomy specimens, and identified two subgroups of patients (high impact and low impact groups) that exhibited distinct transcriptional changes in response to ADT. We found that all patients lost the AR-dependent subtype (PCS2) transcriptional signatures. The high impact group maintained the more aggressive subtype (PCS1) signal, while the low impact group more resembled an AR-suppressed (PCS3) subtype. Computational analyses identified transcription factor coordinated groups (TFCGs) enriched in the high impact group network. Leveraging a large public dataset of over 800 metastatic and primary samples, we identified 33 TFCGs in common between the high impact group and metastatic lesions, including SOX4/FOXA2/GATA4, and a TFCG containing JUN, JUNB, JUND, FOS, FOSB, and FOSL1. The majority of metastatic TFCGs were subsets of larger TFCGs in the high impact group network, suggesting a refinement of critical TFCGs in prostate cancer progression. CONCLUSIONS: We have identified TFCGs associated with pronounced initial transcriptional response to ADT, aggressive signatures, and metastasis. Our findings suggest multiple new hypotheses that could lead to novel combination therapies to prevent the development of CRPC following ADT.

16.
BMC Urol ; 18(1): 78, 2018 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-30200929

RESUMO

BACKGROUND: Refinement of parameters defining prostate cancer (PC) prognosis are urgently needed to identify patients with indolent versus aggressive disease. The Canadian Prostate Cancer Biomaker Network (CPCBN) consists of researchers from four Canadian provinces to create a validation cohort to address issues dealing with PC diagnosis and management. METHODS: A total of 1512 radical prostatectomy (RP) specimens from five different biorepositories affiliated with teaching hospitals were selected to constitute the cohort. Tumoral and adjacent benign tissues were arrayed on tissue microarrays (TMAs). A patient clinical database was developed and includes data on diagnosis, treatment and clinical outcome. RESULTS: Mean age at diagnosis of patients in the cohort was 61 years. Of these patients, 31% had a low grade (≤6) Gleason score (GS), 55% had GS 7 (40% of 3 + 4 and 15% of 4 + 3) and 14% had high GS (≥8) PC. The median follow-up of the cohort was 113 months. A total of 34% had a biochemical relapse, 4% developed bone metastasis and 3% of patients died from PC while 9% died of other causes. Pathological review of the TMAs confirmed the presence of tumor and benign tissue cores for > 94% of patients. Immunohistochemistry and FISH analyses, performed on a small set of specimens, showed high quality results and no biorepository-specific bias. CONCLUSIONS: The CPCBN RP cohort is representative of real world PC disease observed in the Canadian population. The frequency of biochemical relapse and bone metastasis as events allows for a precise assessment of the prognostic value of biomarkers. This resource is available, in a step-wise manner, for researchers who intend to validate prognostic biomarkers in PC. Combining multiple biomarkers with clinical and pathologic parameters that are predictive of outcome will aid in clinical decision-making for patients treated for PC.

17.
Cancer Res ; 78(19): 5561-5573, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30072396

RESUMO

Intrinsic and acquired resistance to cisplatin remains a primary hurdle to treatment of high-grade serous ovarian cancer (HGSOC). Cisplatin selectively kills tumor cells by inducing DNA crosslinks that block replicative DNA polymerases. Single-stranded DNA (ssDNA) generated at resulting stalled replication forks (RF) is bound and protected by heterotrimeric replication protein A (RPA), which then serves as a platform for recruitment and activation of replication stress response factors. Cells deficient in this response are characterized by extensive ssDNA formation and excessive RPA recruitment that exhausts the available pool of RPA, which (i) inhibits RPA-dependent processes such as nucleotide excision repair (NER) and (ii) causes catastrophic failure of blocked RF. Here, we investigated the influence of RPA availability on chemosensitivity using a panel of human HGSOC cell lines. Our data revealed a striking correlation among these cell lines between cisplatin sensitivity and the inability to efficiently repair DNA via NER, specifically during S phase. Such defects in NER were attributable to RPA exhaustion arising from aberrant activation of DNA replication origins during replication stress. Reduced RPA availability promoted Mre11-dependent degradation of nascent DNA at stalled RF in cell lines exhibiting elevated sensitivity to cisplatin. Strikingly, defective S-phase NER, RF instability, and cisplatin sensitivity could all be rescued by ectopic overexpression of RPA. Taken together, our findings indicate that RPA exhaustion represents a major determinant of cisplatin sensitivity in HGSOC cell lines.Significance: The influence of replication protein A exhaustion on cisplatin sensitivity harbors important implications toward improving therapy of various cancers that initially respond to platinum-based agents but later relapse due to intrinsic or acquired drug resistance. Cancer Res; 78(19); 5561-73. ©2018 AACR.

18.
Analyst ; 143(16): 3829-3840, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-29999046

RESUMO

Tumor spheroids represent a realistic 3D in vitro cancer model because they provide a missing link between monolayer cell culture and live tissues. While microfluidic chips can easily form and assay thousands of spheroids simultaneously, few commercial instruments are available to analyze this massive amount of data. Available techniques to measure spheroid response to external stimuli, such as confocal imaging and flow cytometry, are either not appropriate for 3D cultures, or destructive. We designed a wide-field hyperspectral imaging system to analyze multiple spheroids trapped in a microfluidic chip in a single acquisition. The system and its fluorescence quantification algorithm were assessed using liquid phantoms mimicking spheroid optical properties. Spectral unmixing was tested on three overlapping spectral entities. Hyperspectral images of co-culture spheroids expressing two fluorophores were compared with confocal microscopy and spheroid growth was measured over time. The system can spectrally analyze multiple fluorescent markers simultaneously and allows multiple time-points assays, providing a fast and versatile solution for analyzing lab on a chip devices.

19.
CMAJ ; 190(23): E710-E717, 2018 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-29891475

RESUMO

BACKGROUND: Understanding the complex interaction of risk factors that increase the likelihood of developing common diseases is challenging. The Canadian Partnership for Tomorrow Project (CPTP) is a prospective cohort study created as a population-health research platform for assessing the effect of genetics, behaviour, family health history and environment (among other factors) on chronic diseases. METHODS: Volunteer participants were recruited from the general Canadian population for a confederation of 5 regional cohorts. Participants were enrolled in the study and core information obtained using 2 approaches: attendance at a study assessment centre for all study measures (questionnaire, venous blood sample and physical measurements) or completion of the core questionnaire (online or paper), with later collection of other study measures where possible. Physical measurements included height, weight, percentage body fat and blood pressure. Participants consented to passive follow-up through linkage with administrative health databases and active follow-up through recontact. All participant data across the 5 regional cohorts were harmonized. RESULTS: A total of 307 017 participants aged 30-74 from 8 provinces were recruited. More than half provided a venous blood sample and/or other biological sample, and 33% completed physical measurements. A total of 709 harmonized variables were created; almost 25% are available for all participants and 60% for at least 220 000 participants. INTERPRETATION: Primary recruitment for the CPTP is complete, and data and biosamples are available to Canadian and international researchers through a data-access process. The CPTP will support research into how modifiable risk factors, genetics and the environment interact to affect the development of cancer and other chronic diseases, ultimately contributing evidence to reduce the global burden of chronic disease.

20.
BMC Health Serv Res ; 18(1): 430, 2018 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-29884180

RESUMO

BACKGROUND: Over the last decade, active surveillance has proven to be a safe approach for patients with low-risk prostate cancer. Although active surveillance presents several advantages for both patients and the health care system, all eligible patients do not adopt this approach. Our goal was to evaluate the factors that influence physicians to recommend active surveillance and the barriers that impact adherence to this approach. METHODS: Focus groups (n = 5) were held with physicians who provided care for men with low-risk prostate cancer and had engaged in conversations with men and their families about active surveillance. The experience of health care professionals (HCPs) was captured to understand their decisions in proposing active surveillance and to reveal the barriers and facilitators that affect the adherence to this approach. A content analysis was performed on the verbatim transcripts from the sessions. RESULTS: Although physicians agreed that active surveillance is a suitable approach for low-risk prostate cancer patients, they were concerned about the rapidly evolving and non-standardized guidelines for patient follow-up. They pointed out the need for additional tools to appropriately identify proper patients for whom active surveillance is the best option. Urologists and radiation-oncologists were keen to collaborate with each other, but the role of general practitioner remained controversial once patients were referred to a specialist. CONCLUSIONS: Integration of more reliable tools and/or markers in addition to more specific guidelines for patient follow-up would increase the confidence of both patients and physicians in the choice of active surveillance.


Assuntos
Padrões de Prática Médica , Neoplasias da Próstata/terapia , Conduta Expectante , Adulto , Idoso , Atitude do Pessoal de Saúde , Comportamento de Escolha , Tomada de Decisão Clínica , Comunicação , Feminino , Grupos Focais , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Seleção de Pacientes , Médicos de Família , Prática Profissional , Radio-Oncologistas , Urologistas , Adulto Jovem
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