High quantum efficiency ruthenium coordination complex photosensitizer for improved radiation-activated Photodynamic Therapy

Traditional external light-based Photodynamic Therapy (PDT)'s application is limited to the surface and minimal thickness tumors because of the inefficiency of light in penetrating deep-seated tumors. To address this, the emerging field of radiation-activated PDT (radioPDT) uses X-rays to trigger photosensitizer-containing nanoparticles (NPs). A key consideration in radioPDT is the energy transfer efficiency from X-rays to the photosensitizer for ultimately generating the phototoxic reactive oxygen species (ROS). In this study, we developed a new variant of pegylated poly-lactic-co-glycolic (PEG-PLGA) encapsulated nanoscintillators (NSCs) along with a new, highly efficient ruthenium-based photosensitizer (Ru/radioPDT). Characterization of this NP via transmission electron microscopy, dynamic light scattering, UV-Vis spectroscopy, and inductively coupled plasma mass-spectroscopy showed an NP size of 120 nm, polydispersity index (PDI) of less than 0.25, high NSCs loading efficiency over 90% and in vitro accumulation within the cytosolic structure of endoplasmic reticulum and lysosome. The therapeutic efficacy of Ru/radioPDT was determined using PC3 cell viability and clonogenic assays. Ru/radioPDT exhibited minimal cell toxicity until activated by radiation to induce significant cancer cell kill over radiation alone. Compared to protoporphyrin IX-mediated radioPDT (PPIX/radioPDT), Ru/radioPDT showed higher capacity for singlet oxygen generation, maintaining a comparable cytotoxic effect on PC3 cells.

Endothelial phosphoinositide 3-kinase-β inactivation confers protection from immune-mediated vascular injury

Heart transplant and recipient survival are limited by immune cell-mediated injury of the graft vasculature. We examined the role of the phosphoinositide 3-kinase-β (PI3Kβ) isoform in endothelial cells (EC) during coronary vascular immune injury and repair in mice. In minor histocompatibility-antigen mismatched allogeneic heart grafts, a robust immune response was mounted to each wild-type, PI3Kβ inhibitor-treated, or endothelial-selective PI3Kβ knockout (ECβKO) graft transplanted to wild-type recipients. However, microvascular EC loss and progressive occlusive vasculopathy only developed in control, but not PI3Kβ-inactivated hearts. We observed a delay in inflammatory cell infiltration of the ECβKO grafts, particularly in the coronary arteries. Surprisingly, this was accompanied by an impaired display of proinflammatory chemokine and adhesion molecules by the ECβKO ECs. In vitro, tumor necrosis factor α-stimulated endothelial ICAM1 and VCAM1 expression was blocked by PI3Kβ inhibition or RNA interference. Selective PI3Kβ inhibition also blocked tumor necrosis factor α-stimulated degradation of inhibitor of nuclear factor kappa Bα and nuclear translocation of nuclear factor kappa B p65 in EC. These data identify PI3Kβ as a therapeutic target to reduce vascular inflammation and injury.

Loss of apelin blocks the emergence of sprouting angiogenesis in experimental tumors

Angiogenesis inhibitor drugs targeting vascular endothelial growth factor (VEGF) signaling to the endothelial cell (EC) are used to treat various cancer types. However, primary or secondary resistance to therapy is common. Clinical and pre-clinical studies suggest that alternative pro-angiogenic factors are upregulated after VEGF pathway inhibition. Therefore, identification of alternative pro-angiogenic pathway(s) is critical for the development of more effective anti-angiogenic therapy. Here we study the role of apelin as a pro-angiogenic G-protein-coupled receptor ligand in tumor growth and angiogenesis. We found that loss of apelin in mice delayed the primary tumor growth of Lewis lung carcinoma 1 and B16F10 melanoma when combined with the VEGF receptor tyrosine kinase inhibitor, sunitinib. Targeting apelin in combination with sunitinib markedly reduced the tumor vessel density, and decreased microvessel remodeling. Apelin loss reduced angiogenic sprouting and tip cell marker gene expression in comparison to the sunitinib-alone-treated mice. Single-cell RNA sequencing of tumor EC demonstrated that the loss of apelin prevented EC tip cell differentiation. Thus, apelin is a potent pro-angiogenic cue that supports initiation of tumor neovascularization. Together, our data suggest that targeting apelin may be useful as adjuvant therapy in combination with VEGF signaling inhibition to inhibit the growth of advanced tumors.

FGD5 regulates endothelial cell PI3 kinase-β to promote neo-angiogenesis

Angiogenesis is required in embryonic development and tissue repair in the adult. Vascular endothelial growth factor (VEGF) initiates angiogenesis, and VEGF or its receptor is targeted therapeutically to block pathological angiogenesis. Additional pro-angiogenic cues, such as CXCL12 acting via the CXCR4 receptor, co-operate with VEGF/VEGFR2 to cue vascular patterning. We studied the role of FGD5, an endothelial Rho GTP/GDP exchange factor (RhoGEF), to regulate CXCR4-dependent signals in the endothelial cell (EC). Patient-derived renal cell carcinomas produce a complex milieu of growth factors that stimulated sprouting angiogenesis and endothelial tip cell differentiation ex vivo that was blocked by EC FGD5 loss. In a simplified model, CXCL12 augmented sprouting and tip gene expression under conditions where VEGF was limiting. CXCL12-stimulated tip cell differentiation was dependent on PI3 kinase (PI3K)-β activity. Knockdown of EC FGD5 abolished CXCR4 signaling to PI3K-β and Akt. Further, inhibition of Rac1, a Rho GTPase required for PI3K-β activity, recapitulated the signaling defects of FGD5 deficiency, suggesting that FGD5 may regulate PI3K-β activity through Rac1. Overexpression of a RhoGEF deficient, Dbl domain-deleted FGD5 mutant reduced CXCL12-stimulated Akt phosphorylation and failed to rescue PI3K signaling in native FGD5-deficient EC, indicating that FGD5 RhoGEF activity is required for FDG5 function. Endothelial expression of mutant PI3K-β with an inactivated Rho binding domain confirmed that CXCL12-stimulated PI3K activity in EC requires Rac1-GTP co-regulation. Together, this data identify the role of FGD5 to generate Rac1-GTP to regulate pro-angiogenic CXCR4-dependent PI3K-β signaling in EC. Inhibition of FGD5 activity may complement current angiogenesis inhibitor drugs.

PEG-PLGA nanospheres loaded with nanoscintillators and photosensitizers for radiation-activated photodynamic therapy

Photodynamic Therapy (PDT) is an effective treatment modality for cancers, with Protoporphyrin IX (PPIX)-based PDT being the most widely used to treat cancers in patients. However, PDT is limited to superficial, thin (few mm in depth) lesions that can be accessed by visible wavelength light. Interstitial light-delivery strategies have been developed to treat deep-seated lesions (i.e. prostate cancer). The most promising of these are X-ray-induced scintillation nanoparticles, which have shown potential benefits for PDT of deep-seated tumors. Herein, the design and use of a new nanoscintillator-based radiation-activated PDT (radioPDT) system is investigated in the treatment of deep-seated tumors. Poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PEG-PLGA) nanospheres were loaded with a scintillator (LaF₃:Ce³⁺) and photosensitizer (PPIX) to effect radioPDT. UV-Vis spectroscopy and electron microscopy studies demonstrated efficient encapsulation of nanoscintillators and PPIX (>90% efficiency) into the PEG-PLGA nanospheres. The nanoparticles were uniform in size and approximately 100 nm in diameter. They were highly stable and functional for up to 24 h under physiological conditions and demonstrated slow release kinetics. In vitro and in vivo toxicity studies showed no appreciable drug toxicity to human skin fibroblast (GM38), prostate cancer cells (PC3), and to C57/BL mice. Cell uptake studies demonstrated accumulation of the nanoparticles in the cytoplasm of PC3 cells. When activated, fluorescent resonant energy transfer (FRET) was evident via fluorescent spectroscopy and singlet oxygen yield. Determination of stability revealed that the nanoparticles were stable for up to 4 weeks. The nanoparticle production was scaled-up with no change in properties. This nanoparticle represents a unique, optimally designed therapeutic and diagnostic agent (theranostic) agent for radioPDT with characteristics capable of potentially augmenting radiotherapy for deep-seated tumors and integrating into current cancer radiotherapy.

The FABP12/PPARγ pathway promotes metastatic transformation by inducing epithelial-to-mesenchymal transition and lipid-derived energy production in prostate cancer cells

Early stage localized prostate cancer (PCa) has an excellent prognosis; however, patient survival drops dramatically when PCa metastasizes. The molecular mechanisms underlying PCa metastasis are complex and remain unclear. Here, we examine the role of a new member of the fatty acid‐binding protein (FABP) family, FABP12, in PCa progression. FABP12 is preferentially amplified and/or overexpressed in metastatic compared to primary tumors from both PCa patients and xenograft animal models. We show that FABP12 concurrently triggers metastatic phenotypes (induced epithelial‐to‐mesenchymal transition (EMT) leading to increased cell motility and invasion) and lipid bioenergetics (increased fatty acid uptake and accumulation, increased ATP production from fatty acid β‐oxidation) in PCa cells, supporting increased reliance on fatty acids for energy production. Mechanistically, we show that FABP12 is a driver of PPARγ activation which, in turn, regulates FABP12's role in lipid metabolism and PCa progression. Our results point to a novel role for a FABP‐PPAR pathway in promoting PCa metastasis through induction of EMT and lipid bioenergetics.

Inactivation of endothelial cell phosphoinositide 3-kinase β inhibits tumor angiogenesis and tumor growth

Angiogenesis inhibitors, such as the receptor tyrosine kinase (RTK) inhibitor sunitinib, target vascular endothelial growth factor (VEGF) signaling in cancers. However, only a fraction of patients respond, and most ultimately develop resistance to current angiogenesis inhibitor therapies. Activity of alternative pro-angiogenic growth factors, acting via RTK or G-protein coupled receptors (GPCR), may mediate VEGF inhibitor resistance. The phosphoinositide 3-kinase (PI3K)β isoform is uniquely coupled to both RTK and GPCRs. We investigated the role of endothelial cell (EC) PI3Kβ in tumor angiogenesis. Pro-angiogenic GPCR ligands were expressed by patient-derived renal cell carcinomas (PD-RCC), and selective inactivation of PI3Kβ reduced PD-RCC-stimulated EC spheroid sprouting. EC-specific PI3Kβ knockout (ΕC-βKO) in mice potentiated the sunitinib-induced reduction in subcutaneous growth of LLC1 and B16F10, and lung metastasis of B16F10 tumors. Compared to single-agent sunitinib treatment, tumors in sunitinib-treated ΕC-βKO mice showed a marked decrease in microvessel density, and reduced new vessel formation. The fraction of perfused mature tumor microvessels was increased in ΕC-βKO mice suggesting immature microvessels were most sensitive to combined sunitinib and PI3Kβ inactivation. Taken together, EC PI3Kβ inactivation with sunitinib inhibition reduces microvessel turnover and decreases heterogeneity of the tumor microenvironment, hence PI3Kβ inhibition may be a useful adjuvant antiangiogenesis therapy with sunitinib.

Apelin directs endothelial cell differentiation and vascular repair following immune-mediated injury

Sustained, indolent immune injury of the vasculature of a heart transplant limits long-term graft and recipient survival. This injury is mitigated by a poorly characterized, maladaptive repair response. Vascular endothelial cells respond to proangiogenic cues in the embryo by differentiation to specialized phenotypes, associated with expression of apelin. In the adult, the role of developmental proangiogenic cues in repair of the established vasculature is largely unknown. We found that human and minor histocompatibility-mismatched donor mouse heart allografts with alloimmune-mediated vasculopathy upregulated expression of apelin in arteries and myocardial microvessels. In vivo, loss of donor heart expression of apelin facilitated graft immune cell infiltration, blunted vascular repair, and worsened occlusive vasculopathy in mice. In vitro, an apelin receptor agonist analog elicited endothelial nitric oxide synthase activation to promote endothelial monolayer wound repair and reduce immune cell adhesion. Thus, apelin acted as an autocrine growth cue to sustain vascular repair and mitigate the effects of immune injury. Treatment with an apelin receptor agonist after vasculopathy was established markedly reduced progression of arterial occlusion in mice. Together, these initial data identify proangiogenic apelin as a key mediator of coronary vascular repair and a pharmacotherapeutic target for immune-mediated injury of the coronary vasculature.

Outcomes and prognosticators of stage 4 renal cell carcinoma with pathological T4 primary lesion using a large, Canadian, multi-institutional database

INTRODUCTION

The primary objective of this study was to evaluate outcomes and prognosticators in patients who underwent radical nephrectomy (RN) or cytoreductive nephrectomy (CN), depending on the clinical stage of disease preoperatively, with a pathological T4 (pT4) renal cell carcinoma (RCC) outcome. There is little data on the outcome of this specific subset of patients.

METHODS

From 2009-2016, we identified patients in the Canadian Kidney Cancer information system (CKCis) who underwent RN or CN and were found to have pT4 RCC. Clinical, operative, and pathological variables were analyzed with univariable and multivariable Cox proportional hazard models to identify factors associated with overall survival (OS). Survival curves were created using Kaplan-Meier methods and compared using the log-rank test.

RESULTS

A total of 82 patients were included in the study cohort. Median patient age was 62 years (interquartile range [IQR] 55, 70). Fifty (61%) patients had clear-cell histology and 14 (17%) had sarcomatoid characteristics. Median followup was 12 months (IQR 3, 24). At last followup, eight (10%) patients are alive with no evidence of disease, 27 (33%) are alive with disease, four (5%) were lost to followup, 36 (44%) died of disease, and seven (8%) died of other causes. Tumor histological subtype (clear-cell vs. non-clear-cell) (p=0.0032), larger tumor size (cm) (p=0.012), and Fuhrman grade (G4 vs. G2-G3) (p=0.045) were significantly associated with mortality in a multivariable Cox regression model.

CONCLUSIONS

For patients with pT4 RCC after RN or CN, survival is poor. Sarcomatoid features, non-clear-cell histology, and presence of systemic symptoms were associated with worse OS.

Renal transplant anastomotic pseudoaneurysms: Case report of open repair and endovascular management

Introduction

Anastomotic pseudoaneurysm is one of the rarest vascular complications after renal transplant surgery. Therapeutic options include open surgical repair or endovascular stenting.

Case presentation

Case 1 had pseudoaneurysm involving external iliac artery and was managed by jump graft to allograft using cadaveric donor iliac arteries and patch angioplasty repair of external iliac artery after excising pseudoaneurysm. Case 2 had undergone orthotopic renal transplant with spleno‐renal arterial anastomosis and developed a massive pseudoaneurysm proximal to spleno‐renal arterial anastomosis. This patient underwent endovascular stenting preserving allograft vascularity and graft function. Outcome in both patients was successful with normalization of renal function to baseline levels.

Conclusion

Treatment of renal transplant anastomotic pseudoaneurysms is difficult and associated with high rates of graft loss. Open surgery is the gold standard providing several possibilities for arterial reconstruction preserving graft and limb circulation. Endovascular treatment should be considered in high‐risk surgical patients with favorable anatomy.

Human Sertoli cells support high levels of Zika virus replication and persistence

Zika virus is a teratogenic mosquito-transmitted flavivirus that is associated with birth defects in newborns and Guillain–Barré syndrome in adults. The virus can also be sexually transmitted, but currently, very little is known about the cell types supporting virus replication and persistence in human testes. Using primary cell cultures, we observed that Sertoli but not Leydig cells are highly susceptible to Zika virus infection, a process that is dependent on the TAM family receptor Axl. In cell culture, Sertoli cells could be productively infected with Zika virus for at least 6-weeks. Infection of Sertoli cells resulted in dramatic changes to the transcriptional profile of these cells. The most upregulated mRNA in infected cells was basic fibroblast growth factor (FGF2), a cytokine that was found to enhance Zika virus replication and support viral persistence. Together these findings provide key insights into understanding how Zika virus persists in the male reproductive tract and in turn may aid in developing antiviral therapies or strategies to minimize sexual transmission of this pathogen.

Deletion of F4L (ribonucleotide reductase) in vaccinia virus produces a selective oncolytic virus and promotes anti-tumor immunity with superior safety in bladder cancer models

Bladder cancer has a recurrence rate of up to 80% and many patients require multiple treatments that often fail, eventually leading to disease progression. In particular, standard of care for high-grade disease, Bacillus Calmette-Guérin (BCG), fails in 30% of patients. We have generated a novel oncolytic vaccinia virus (VACV) by mutating the F4L gene that encodes the virus homolog of the cell-cycle-regulated small subunit of ribonucleotide reductase (RRM2). The F4L-deleted VACVs are highly attenuated in normal tissues, and since cancer cells commonly express elevated RRM2 levels, have tumor-selective replication and cell killing. These F4L-deleted VACVs replicated selectively in immune-competent rat AY-27 and xenografted human RT112-luc orthotopic bladder cancer models, causing significant tumor regression or complete ablation with no toxicity. It was also observed that rats cured of AY-27 tumors by VACV treatment developed anti-tumor immunity as evidenced by tumor rejection upon challenge and by ex vivo cytotoxic T-lymphocyte assays. Finally, F4L-deleted VACVs replicated in primary human bladder cancer explants. Our findings demonstrate the enhanced safety and selectivity of F4L-deleted VACVs, with application as a promising therapy for patients with BCG-refractory cancers and immune dysregulation.

Benchmarking quality for renal cancer surgery: Canadian Kidney Cancer information system (CKCis) perspective

INTRODUCTION

There is a lack of validated quality metrics to evaluate the care of patients receiving surgery for renal cell carcinoma (RCC). To address this, the Kidney Cancer Research Network of Canada defined a list of quality indicators (QI) to assess hospital-level performance. We have case-mix adjusted these QIs to benchmark RCC surgical care at Canadian academic centres.

METHODS

The Canadian Kidney Cancer information system (CKCis) was used to measure six QIs: laparoscopic approach proportion (LA), partial nephrectomy proportion (PN), partial nephrectomy in patients with chronic kidney disease (CKDPN), positive margin rate (PMR), partial nephrectomy complication rate (PNCx), and warm ischemia time (WIT). To benchmark performance, indirect standardization (observed-to-expected ratio) methodology was employed using multivariate regression models.

RESULTS

Multivariate models for LA, PN, and CKDPN demonstrated good discrimination and were used for benchmarking. National averages of 74% (70-78%), 73% (70-75%), and 70% (67-74%) for the LA, PN, and CKDPN QIs, respectively, were determined and used to benchmark individual hospital performance. Overall, three (23%), two (15%), and two (15%) hospitals performed below expected for LA, PN, and CKDPN, respectively. Hospital identity was an independent predictor of LA, PN, and CKDPN (p<0.001).

CONCLUSIONS

Significant variability between CKCis hospitals for three RCC surgical QIs exists. Using the CKCis infrastructure may provide a framework for institution-level audit feedback for quality improvement. Greater CKCis capture rates and further data supporting the construct validity of these QIs are required to extend the use of this dataset to real-world quality initiatives.

Post-transplant lymphoproliferative disorder and management of residual mass post chemotherapy: Case report

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Post-transplant lymphoproliferative disorder (PTLD).

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Residual mass post rituximab therapy.

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Surgical management.

Introduction

Post-transplant lymphoproliferative disorder (PTLD) is a rare complication. It represents a spectrum of lymphoid proliferations which occur in the setting of immunosuppression and organ transplantation. There are no reported cases or recommendations for the treatment of residual masses post rituximab of PTLD.

Presentation of case

A patient with a long standing history of immunosuppression due to multiple kidney transplants starting in 1979, presented with a very large palpable hard abdominal mass (2004) after a fourth renal transplant. There was a past history of heavy immune suppression. CT scans revealed a conglomerate mass involving the right native kidney and two prior right sided renal allografts that crossed the midline. Biopsy of the large right retroperitoneal mass revealed large B cell lymphoma (CD 20 positive); consistent with post-transplant lymphoproliferative disorder (PTLD).

Discussion

Management of bulky PTLD, in a highly sensitized, heavily immune suppressed patient is not well described in the literature. The mainstay of therapy is IR and Ritixumab (R) monotherapy and combination R-CHOP. CHOP chemotherapy has an associated mortality rate of up to 38%. Radiotherapy is often considered over surgery and surgery has been most frequently used when associated with bowel complications. In this case report we describe upfront Ritiximab followed by consolidation resection and cytotoxic chemotherapy as a management strategy to reduce toxicity.

Conclusion

The approach taken by our surgical team illustrates the benefits of disease debulking in certain cases of PTLD, by guiding further therapy and spacing and reducing chemotherapy in immune suppressed patients.

Positive surgical margins during partial nephrectomy for renal cell carcinoma: Results from Canadian Kidney Cancer information system (CKCis) collaborative

INTRODUCTION

We sought to determine the incidence, risk factors, and prognosis for patients with positive surgical margin (PSM) during partial nephrectomy (PN) for renal cell carcinoma (RCC).

METHODS

From the Canadian Kidney Cancer information system (CKCis) database, a historical cohort of PN patients with PSM were identified and compared to negative surgical margin (NSM). Risk factors for PSM were examined through multivariable logistic regression. Kaplan-Meier curves were used to compare progression-free survival.

RESULTS

Of 1103 patients, 972 (88.1%), 71 (6.4%), and 60 (5.4%) had NSM, PSM, and unknown status, respectively. Median patient age and tumour size were 61 years and 3.0 cm for both groups. From multivariable analysis, pathological stage ≥T3 (odds ratio [OR] 2.51; 95% confidence interval [CI] 1.13-5.60) and Fuhrman grade 4 (OR 5.35; 95% CI 1.11-25.72) were associated with PSM, whereas age, operative technique, and tumour size were not. Forty-nine (5.0%) patients from the NSM cohort and seven (9.9%) from the PSM cohort had a local/systemic progression of disease (adjusted hazard ratio [HR] 1.4; 95% CI 0.6-3.6). There were three (0.3%) cancer-related deaths in the NSM group and none in the PSM group. After median followup of 19 (interquartile range [IQR] 5-42) and 15 (IQR 7-30) months, 855 (91.4%) and 61 (89.7%) patients were alive in the NSM and PSM groups, respectively.

CONCLUSIONS

PSM occurred in 6.4% of PNs performed for RCC in this pan-Canadian cohort. Higher stage and grade are associated with a higher risk of positive margin. The small association between a PSM and progression suggests that complete nephrectomy is not necessary in patients with a PSM. The main study limitations are lack of nephrometry score and possible reporting bias.

Primary Metastatic Squamous Cell Carcinoma of the Male Urethra Presenting with Scrotal Abscess and Subsequent Development of Fournier's Gangrene

This male patient presented with a scrotal abscess and urinary obstruction. The patient's history included a perineal abscess and the development of urethrocutaneous fistulae (watering-can perineum). He underwent multiple debridement procedures without resolution. During the fifth debridement for Fournier's gangrene, a biopsy revealed invasive squamous cell carcinoma. The patient was bedridden because of the large mass, a wide en bloc resection with lymphadenectomy and reconstruction was performed revealing a large (22 cm) squamous cell carcinoma originating from the urethra. He also received palliative chemoradiotherapy and hip hemiarthroplasty. Unfortunately, he succumbed to the disease. Given the recognized relationship between inflammation and the development of cancer, it is important to entertain a differential diagnosis of cancer, especially with erosive infections. This case report highlights the all too common late presentation of urethral cancer. Interestingly, despite correction of the bedridden state with palliative surgery, the patient did not perceive an improvement in quality of life based on the FACT-G questionnaire.

Disease progression and kidney function after partial vs. radical nephrectomy for T1 renal cancer

PURPOSE

Partial nephrectomy (PN) for early stage renal cancer preserves renal function better than radical nephrectomy (RN) and is generally considered oncologically similar. The Intergroup European Organisation for Research and Treatment of Cancer trial comparing outcomes after PN vs. RN, however, showed reduced overall survival in the PN group. Our aim was to evaluate recurrence, death, and renal function after PN vs. RN for T1 tumors in a Canadian population.

MATERIALS AND METHODS

From 2000 to 2015, 2,358 patients with a first occurrence of a clinical T1 renal cancer who underwent PN or RN were identified from the Canadian Kidney Cancer Information System. Clinical, surgical, and pathologic parameters were analyzed. Time to progression was compared after PN vs. RN using a Cox proportional hazards model, adjusted for pertinent variables.

RESULTS

Inclusion criteria were met in 1,615 PN and 743 RN. Preoperative characteristics appeared similar in both groups. Time to progression was not different after PN vs. RN, adjusted for potential confounders (hazard ratio = 1.17 [95% CI: 0.8-1.72, P = 0.42]). Postoperative estimated glomerular filtration rate at 1 and 3 years was significantly greater for PN vs. RN in a linear regression model, accounting for preoperative estimated glomerular filtration rate.

CONCLUSIONS

These results suggest that progression-free survival after PN and RN in patients with T1 renal cancer was similar, but that there was better preservation of renal function after PN. This suggests that both PN and RN have similar oncological efficiency, and that selection of surgical approach should be based on other factors such as technical feasibility, potential complications, and preservation of renal function.

Monitoring photodynamic therapy with photoacoustic microscopy

Abstract. We present our work on examining the feasibility of monitoring photodynamic therapy (PDT)-induced vasculature change with acoustic-resolution photoacoustic microscopy (PAM). Verteporfin, an FDA-approved photosensitizer for clinical PDT, was utilized. With a 60-μm-resolution PAM system, we demonstrated the capability of PAM to monitor PDT-induced vasculature variations in a chick chorioallantoic membrane model with topical application and in a rat ear with intravenous injection of the photosensitizer. We also showed oxygen saturation change in target blood vessels due to PDT. Success of the present approach may potentially lead to the application of PAM imaging in evaluating PDT efficacy, guiding treatment, and predicting responders from nonresponders.

Endothelial Cell mTOR Complex-2 Regulates Sprouting Angiogenesis

Tumor neovascularization is targeted by inhibition of vascular endothelial growth factor (VEGF) or the receptor to prevent tumor growth, but drug resistance to angiogenesis inhibition limits clinical efficacy. Inhibition of the phosphoinositide 3 kinase pathway intermediate, mammalian target of rapamycin (mTOR), also inhibits tumor growth and may prevent escape from VEGF receptor inhibitors. mTOR is assembled into two separate multi-molecular complexes, mTORC1 and mTORC2. The direct effect of mTORC2 inhibition on the endothelium and tumor angiogenesis is poorly defined. We used pharmacological inhibitors and RNA interference to determine the function of mTORC2 versus Akt1 and mTORC1 in human endothelial cells (EC). Angiogenic sprouting, EC migration, cytoskeleton re-organization, and signaling events regulating matrix adhesion were studied. Sustained inactivation of mTORC1 activity up-regulated mTORC2-dependent Akt1 activation. In turn, ECs exposed to mTORC1-inhibition were resistant to apoptosis and hyper-responsive to renal cell carcinoma (RCC)-stimulated angiogenesis after relief of the inhibition. Conversely, mTORC1/2 dual inhibition or selective mTORC2 inactivation inhibited angiogenesis in response to RCC cells and VEGF. mTORC2-inactivation decreased EC migration more than Akt1- or mTORC1-inactivation. Mechanistically, mTORC2 inactivation robustly suppressed VEGF-stimulated EC actin polymerization, and inhibited focal adhesion formation and activation of focal adhesion kinase, independent of Akt1. Endothelial mTORC2 regulates angiogenesis, in part by regulation of EC focal adhesion kinase activity, matrix adhesion, and cytoskeletal remodeling, independent of Akt/mTORC1.

Surgical management of stage T1 renal tumours at Canadian academic centres

INTRODUCTION

The proportion of patients with stage 1 renal tumours receiving partial nephrectomy is considered a quality of care indicator. The objective of this study was to characterize surgical practice patterns at Canadian academic institutions for the treatment of these tumours.

METHODS

The Canadian Kidney Cancer Information System (CKCis) is a multicentre collaboration of 13 academic institutions in Canada. All patients with pathologic stage T1 renal tumours in CKCis were identified. Descriptive statistics were performed to characterize practice patterns over time. Associations between patient, tumour, and treatment factors with the use of partial nephrectomy were determined.

RESULTS

From 1988 to April 2014, 1453 patients with pathologic stage 1 renal tumours were entered in the CKCis database. Of these, 977 (67%) patients had pT1a tumours; of these, 765 (78%) received partial nephrectomy. Of the total number of patients (1453), 476 (33%) had pT1b tumours; of these, 204 (43%) received partial nephrectomy. The use of partial nephrectomy increased over time from 60% to 90% for pT1a tumours and 20% to 60% for pT1b tumours. Stage pT1b (relative risk [RR] 0.56, 95% confidence interval [CI] 0.50-0.63) and minimally invasive surgical approach (RR 0.78, 95% CI 0.73-0.84 for pT1a and RR 0.23, 95% CI 0.17-0.30 for pT1b) were associated with decreased use of partial nephrectomy. Most patient factors including age, gender, body mass index, hypertension, and renal function were not significantly associated with use of partial nephrectomy (p > 0.05).

CONCLUSION

Almost all pT1a and most pT1b renal tumours managed surgically at academic centres in Canada receive partial nephrectomy. The use of partial versus radical nephrectomy appears to occur independently of patient age and comorbid status, which may indicate that urologists are performing partial nephrectomy whenever technically feasible based on tumour factors. Although the ideal proportion patients receiving partial nephrectomy cannot be determined, treatment distribution observed in this cohort may indicate an achievable case distribution among experienced surgeons.

Detecting functional changes with [(18)F]FAZA in a renal cell carcinoma mouse model following sunitinib therapy

BACKGROUND

The multitargeting tyrosine kinase inhibitor (TKI) sunitinib is currently the first-line drug therapy for metastasizing renal cell carcinoma (RCC). TKIs have profound effects on tumor angiogenesis, leading to modifications of the tumor microenvironment. The goal of this study was to determine whether these treatment-induced changes can be detected with [(18)F]FAZA.

METHODS

The present study utilized positron emission tomography (PET) to analyze tumor oxygenation status during and after sunitinib therapy in the murine Caki-1 RCC tumor model. Dynamic and static scans were performed, as well as ex vivo biodistributions at 3 h post injection (p.i.). Immunohistochemical analysis of tumor tissue was carried out for the quantification of pimonidazole binding and the hypoxia-associated factors CD-31, Ki-67, and Von Willebrand factor (VWF). In addition, in vitro cellular uptake studies were done to analyze the direct effects of sunitinib on the Caki-1 cells.

RESULTS

During therapy with sunitinib (40 mg/kg/day), uptake of [(18)F]FAZA into Caki-1 mice decreased by 46 ± 5% (n = 4; 5 days) at 3 h post injection (p.i.) during the first study and 22 ± 5% (n = 8; 9 days) during the long-term study, indicating a decrease in the tumor's hypoxia level. However, when drug therapy was stopped, this effect was reversed completely, and the tumor [(18)F]FAZA uptake increased to 126 ± 6% (n = 6) of the control tumor uptake, indicative of an even higher level of tumor hypoxia compared to the therapy starting point. Sunitinib had no direct effect on [(18)F]FAZA uptake into Caki-1 cells in vitro.

CONCLUSION

[(18)F]FAZA PET could be used to monitor drug response during sunitinib therapy in RCC and may guide combination therapies based on the tumor's hypoxia status.

Layered gadolinium-based nanoparticle as a novel delivery platform for microRNA therapeutics

Specific expression patterns of microRNA (miRNA) molecules have been linked to cancer initiation, progression, and metastasis. The accumulating evidence for the role of oncogenic or tumor-suppressing miRNAs identified the need for nano-scaled platform that can help deliver nucleotides to modulate miRNAs. Here we report the synthesis of novel layered gadolinium hydroxychloride (LGdH) nanoparticles, a member of the layered double hydroxide (LDH) family, with physiochemical properties suitable for cell uptake and tracing via magnetic resonance (MR) imaging. As a proof of concept, we demonstrate the inhibition of mature miRNA-10b in metastatic breast cancer cell line using LGdH nanoparticle as a delivery platform. Through characterization analysis, we show that nanoparticles are easily and stably loaded with anti-miRNA oligonucleotides (AMO) and efficiently penetrate cell membranes. We demonstrate that AMOs delivered by LGdH nanoparticles remain functional by inducing changes in the expression of its downstream effector and by curbing the invasive properties. Furthermore, we demonstrate the traceability of LGdH nanoparticles via T1 weighted MR imaging. LGdH nanoparticles, which are biocompatible with cells in vitro, provide a promising multifunctional platform for microRNA therapeutics through their diagnostic, imaging, and therapeutic potentials.

Using the Delphi technique to improve clinical outcomes through the development of quality indicators in renal cell carcinoma

PURPOSE

Optimal quality of care is needed for ideal outcomes. In renal cell carcinoma (RCC), there is a lack of information defining optimal care. This is particularly important in RCC, with increased complexity of care and a need for coordination among providers. The goal of this study was to identify quality indicators (QIs) and measures of quality care across the RCC disease spectrum.

MATERIALS AND METHODS

A modified Delphi technique was used to select QIs that are relevant and practical to RCC care. This technique involved an expert panel of 13 urologic and medical oncologists who participated in two e-mail questionnaires and an in-person meeting to review and prioritize potential QIs. These potential QIs were identified from a systematic literature review or were suggested by panel members.

RESULTS

From 233 literature citations, 34 possible QIs were identified; 24 additional potential QIs were suggested. A final set of 23 QIs was established. These are distributed across the RCC disease spectrum as follows (number of QIs in parentheses): screening (n=1), diagnosis/prognosis (n=3), surgical for localized disease (n=6), surgery for advanced disease (n=3), systemic therapy (n=6), and follow-up (n=2). In addition, two QIs related to survival outcomes (overall and progression-free survival) were selected.

CONCLUSION

A systematic, consensus-based approach was used to determine relevant QIs in RCC care. These 23 QIs will provide a means of evaluating the quality of RCC care in an effort to improve outcomes in patients. The next step will be to establish a means of measuring each QI based on defined or yet-to-be-defined benchmarks.

The biodistribution and pharmacokinetic evaluation of choline-bound gold nanoparticles in a human prostate tumor xenograft model

PURPOSE

Gold nanoparticles (GNPs) have attracted significant attention in the treatment of cancer due to their potential as novel radiation enhancers, particularly when functionalized with various targeting ligands. The aim of this study was to assess the biodistribution and pharmacokinetic characteristics of a novel choline-bound GNP (choline-GNP) stabilized with polyethelenimine (PEI).

METHODS

Choline bound to 27 nm diameter GNPs was characterized using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Toxicity of choline-GNPs was examined on DU-145 prostate cancer cells using an MTT assay. Using balb/c mice bearing flank DU-145 prostate tumors, choline-GNPs bio-distribution was measured using inductively coupled mass spectroscopy (ICP-MS). Blood, heart, lung, liver, spleen, brain, kidney and tumor gold content were examined at multiple time points over a 24-hour period after tail vein injection.

RESULTS

An MTT assay using DU-145 prostate cancer cells yielded a 95% cell viability 72 hours after choline-GNP administration. The tumor GNP area under the concentration-time curve during the first 4 hours (AUC0-4) was 2.2 µg/ml h, representing 13% of the circulating blood GNP concentration over the same time period. The maximum intra-tumor GNP concentration observed was 1.4% of the injected dose per gram of tumor tissue (%ID/g) one hour post injection.

CONCLUSIONS

GNPs functionalized with choline demonstrates a viable future nanoparticle platform with increased intra-tumor uptake as compared to unconjugated GNPs. Decreased intra-hepatic accumulation appears to be the reason for the improved systemic bioavailability. The next logical translational investigation will incorporate external beam radiation with the observed maximum intra-tumor uptake.

Antitumor Efficacy of Intravesical BCG, Gemcitabine, Interferon-α and Interleukin-2 as Mono- or Combination-Therapy for Bladder Cancer in an Orthotopic Tumor Model

Objective:

To reduce adverse effects and improve efficacy of intravesical BCG for bladder cancer, alternative treatment options were investigated in an orthotopic rat tumor model.

Methods:

Superficial bladder cancer was established in syngeneic female rat bladders by instillation of AY-27 cells. Animals were randomly assigned to treatment groups including dose escalation of intravesical BCG with or without interferon-α (IFN-α) or interleukin-2 (IL-2); or graded doses of gemcitabine alone; or BCG plus gemcitabine. Treatments were given twice weekly for 3 weeks. Rats in control groups received saline instillations. Treatment response was monitored by animals’ well-being, survival days, tumor growth inhibition, and histological examination at necropsy.

Results:

Rats receiving monotherapy with intravesical BCG, gemcitabine, or IFN-α, attained significantly better survival and tumor reduction compared with control (P = 0.002; 0.001; 0.002, respectively, Log-rank Test). A dose-dependent treatment response was observed in animals with established bladder tumor receiving escalated BCG instillations. Only high-dose BCG significantly improved animal survival. Although high-dose BCG plus gemcitabine or IFN-α did not increase benefit over monotherapies, low-dose BCG plus IL-2 did show improved efficacy (P = 0.01).

Conclusion:

Intravesical monotherapies with gemcitabine and IFN-α were as effective as BCG for treatment of early non-muscle-invasive urothelial bladder cancer in this immune competent rat model. Combining these agents with high-dose BCG did not further increase efficacy. However, combining low-dose BCG with IL-2 enhanced BCG effectiveness.

Malignant spinal cord compression secondary to testicular seminoma at the time of initial presentation and at relapse while on surveillance

We report cases of 2 pure seminoma patients who developed metastatic spinal cord compressions. One patient was diagnosed at age 33 years with stage 1 seminoma and, after undergoing an orchidectomy, chose to be followed on a surveillance protocol. He was lost to follow-up and presented again 22 months later with back pain, leg weakness and sensory loss when his disease recurred as a spinal cord compression. He was treated with urgent surgical decompression and subsequent standard chemotherapy. More than 2 years posttreatment, he is disease-free with normal neurologic function in his lower extremities. The second patient presented at age 44 years with back pain and rapid loss of leg strength and sensation. Investigations revealed a malignant cord compression with lymphatic and vertebral body metastases. On physical examination, the patient was found to have a 6-cm left testicular mass. He was treated with emergency radiotherapy to the region of his cord compression followed by a left inguinal orchidectomy. Pathology confirmed a pure classic seminoma. Postoperatively, he received standard chemotherapy and eventually regained neurologic function in his legs. Although it is rare for malignant spinal cord compression to occur in seminoma patients-either as the initial presentation of disease or as a site of disease recurrence in stage 1 patients on surveillance-it is crucial to consider seminoma as a possible etiology in young men diagnosed with malignant spinal cord compression because timely contemporary treatments for seminoma will cure most of these patients and offer them excellent functional recovery.

Rhabdomyolysis following renal autotransplantation

A 26-year-old male body builder diagnosed with renal artery stenosis and middle aortic syndrome underwent an autotransplantation with bench reconstruction and end-to-end anastomosis using the hypogastric artery. Shortly after the procedure, the patient developed rhabdomyolysis and renal insufficiency, possibly related to his increased muscle mass, potentially greater susceptibility to hypertrophic skeletal muscle cells or his unique vascular condition. We review the risk factors, diagnosis, management and outcome of a case of rhabdomyolysis in a male patient who underwent autotransplantation for renal vascular hypertension.

Urothelial cancer cell response to combination therapy of gemcitabine and TRAIL

High-risk superficial urothelial carcinoma of the bladder (UCB) is commonly treated with intravesical bacillus Calmette-Guerin (BCG), but with significant side effects. We recently showed that the tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) exhibited high therapeutic potential against UCB cells and with only limited toxic effects in normal cells. However, many cancer cells are refractory to TRAIL during monotherapy. Therefore, our experimental aim was to develop combinatorial approaches with other pro- apoptotic agents to reactivate apoptosis in resistant phenotypes. We demonstrate that UCB cells varied in their response to TRAIL, and the effect was caspase-dependent (reduced or abrogated by pre-incubation of cells with caspase-inhibitor peptides). In contrast wortmannin, a PI3K/Akt inhibitor, enhanced the TRAIL effect. Furthermore, combination therapy of TRAIL with low dose gemcitabine markedly enhanced UCB cell response (except in the TRAIL-resistant HT1376 cell line). The enhanced response was both time- and concentration-dependent and asymptotic at gemcitabine concentration >1 µmol/l. To define the mechanisms underlying gemcitabine-augmented TRAIL action, we evaluated the expression of several proteins regulating the apoptotic pathway. Gemcitabine-augmented TRAIL effect was associated with inhibition of the Bcl-2 protein (intrinsic signalling) along with activation of the caspase (extrinsic) cascade. The combined maximal stimulation of both the intrinsic and extrinsic signalling pathways also appeared to overcome the survival (PI3K/Akt) pathway as evident by the lack of response to wortmannin. Our semisolid multicellular-spheroid model showed that TRAIL and gemcitabine selectively caused UCB cells to undergo apoptosis without affecting normal cells, and both appeared to penetrate deeply enough to allow for combination intravesical therapy.

Adverse renal outcomes in subjects undergoing nephrectomy for renal tumors: a population-based analysis

BACKGROUND

There has been increasing interest in determining renal outcomes after nephrectomy for renal tumors. Previous studies have not assessed all relevant risk factors, including proteinuria.

OBJECTIVE

We sought to determine the risk and predictors for the development of adverse renal outcomes in a population-based cohort of subjects undergoing partial or complete nephrectomy.

DESIGN, SETTING, AND PARTICIPANTS

A large population-based data set was used to identify all subjects undergoing nephrectomy in Alberta, Canada, from 2002 to 2007 using administrative codes. Comorbid conditions were determined using validated algorithms, and baseline estimated glomerular filtration rate (eGFR) and proteinuria status were determined.

MEASUREMENTS

Postsurgical outcomes of end-stage renal disease, acute dialysis, chronic kidney disease (CKD) (eGFR <30 ml/min per 1.73 m(2)), and rapidly progressive CKD (eGFR <60 ml/min per 1.73 m(2) and eGFR loss ≥4 ml/min per 1.73 m(2) per year) were assessed. The risk and risk factors for developing the composite renal outcome were determined using a multivariable Cox proportional hazards model.

RESULTS AND LIMITATIONS

Of 1151 subjects, 10.5% developed an adverse renal outcome over a mean of 32 mo. Complete (vs partial) nephrectomy was associated with a hazard ratio (HR) of 1.75 (95% confidence interval [CI], 1.02-2.99) for the primary outcome, as was lower baseline eGFR. Subjects with proteinuria were more likely to experience the primary outcome (42% vs 9%), conferring an adjusted HR of 2.40 (95% CI, 1.47-3.88).

CONCLUSIONS

Clinically important adverse renal outcomes are common in patients undergoing nephrectomy for renal tumors. In addition to baseline eGFR and the extent of the renal mass removed, proteinuria is a strong independent risk factor. Assessment of proteinuria, in addition to other risk factors, should be performed to inform prognosis and the optimal treatment strategy.

Response of bladder carcinoma cells to TRAIL and antisense oligonucleotide, Bcl-2 or clusterin treatments

PURPOSE

Bladder transitional cell carcinoma is the second most common urological malignancy, of which 80% are superficial disease limited to the bladder. Superficial bladder transitional cell carcinoma has a high propensity for recurrence and progression after initial resection, necessitating adjuvant intravesical therapy. TRAIL (tumor necrosis factor-related apoptosis inducing ligand) can selectively induce apoptosis in most tumor cells while sparing normal cells. TRAIL drives not only the death receptor pathway, but also the mitochondrial pathway through Bid. Due to the anti-apoptotic functions of Bcl-2 and clusterin on the mitochondrial apoptotic pathway the effects of down-regulating these proteins were examined in partially TRAIL resistant bladder transitional cell carcinoma cell lines.

MATERIALS AND METHODS

Antisense oligonucleotides targeting Bcl-2 and clusterin were used alone or combined with TRAIL and cytotoxicity was examined by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolim bromide) proliferation assay. Apoptotic pathway signals were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis/Western blotting after the various combination treatments. All statistical tests were 2 sided.

RESULTS

Although no direct correlation between TRAIL sensitivity and the relative expression levels of Bcl-2 and clusterin was found in the bladder transitional cell carcinoma cell lines examined, antisense oligonucleotide mediated the down-regulation of Bcl-2 and clusterin, increasing the sensitivity of the partially resistant cells to TRAIL. This was mediated through increased apoptotic signaling of the mitochondrial pathway, as evident by the increased activation of caspase-9 and 3, and cleaved DFF45. There was no benefit of combined antisense oligonucleotide therapy.

CONCLUSIONS

This study provides proof of principle that TRAIL combined with antisense oligonucleotide-Bcl-2 may have potential as a novel future treatment strategy for bladder transitional cell carcinoma.

Laser photoablation of renal pelvic tumours

We evaluated the clinical effects of the Zeiss OPMILAS (Oberkochen, Germany) multi-yttrium-aluminum-garnet (YAG) laser in the treatment of renal pelvic tumours as an alternative to nephroureterectomy. Four patients with evidence of transitional cell carcinoma (TCC) in the renal pelvis and a previous history of TCC of the bladder or opposite renal pelvis were treated with the Zeiss OPMILAS multi-YAG laser. Three patients underwent a retrograde ureteroscopic approach and 1 patient required percutaneous resection. Two wavelengths were used: 1060 nm continuous coagulative mode and 1440 nm pulsed ablative mode. The patients were followed for 12, 24, 76 and 84 months, respectively. Two patients showed no evidence of recurrence as determined by cystoscopy, retrograde pyelography and selective pelvic urine cytology. One patient experienced a recurrence of TCC requiring subsequent treatment. The ureteroscopic approach was associated with fewer complications and a more rapid recovery, compared with the percutaneous approach. All patients with solitary kidneys avoided dialysis.

Distribution of photosensitizers in bladder cancer spheroids: implications for intravesical instillation of photosensitizers for photodynamic therapy of bladder cancer

PURPOSE

Uniform intratumor distribution of sufficient photosensitizer is one of the important aspects of photodynamic therapy for solid tumors.

METHODS

Multicellular spheroids derived from a human transitional cell carcinoma cell line (MGHU3) were used as a surrogate system of tiny solid tumors to study intratumor distribution of photosensitizers. Photosensitizers included Photofrin, hypocrellins (HBEA-R1/R2, HBBA-R2), aluminum phthalocyanine chloride (AlPC), benzoporphyrin derivative monoacid ring A (BPD-MA), protoporphyrin-IX (PpIX), and liposomal formulations of HBBA-R2 and BPD-MA. Spheroids were incubated with various doses of the above drugs for 1-4 hours, and were examined by confocal microscopy.

RESULTS

Histology showed all cells were healthy in spheroids less than 400 microm in diameter. Scanning electron microscopy showed tight cell-to-cell interdigitation in spheroids. HBEA-R1/R2 distributed more uniformly in spheroids than other drugs. Free hypocrellins and BPD-MA penetrated spheroids centripetally deeper than AlPC, Photofrin, and PpIX. Liposomal HBBA-R2 and BPD-MA penetrated less than their free formulations.

CONCLUSIONS

The spheroids mimic solid tumors prior to neovascularization. Based on drug distribution in spheroids, hypocrellins and BPD-MA appear superior to Photofrin, AlPC and PpIX for intravesical administration for bladder cancer phototherapy.

A NOVEL INTRAVESICAL THERAPY FOR SUPERFICIAL BLADDER CANCER IN AN ORTHOTOPIC MODEL: ONCOLYTIC REOVIRUS THERAPY

PURPOSE

To our knowledge this is the first report of intravesical oncolytic reovirus for therapy of superficial bladder cancer in an orthotopic bladder tumor model. Superficial bladder carcinomas are often multifocal and have high recurrences after surgical resection. In 20% of cases intravesical immunotherapy fails to prevent recurrence and complications from bacillus Calmette-Guerin (BCG) are common. Human reovirus is an oncolytic virus that selectively destroys cancer cells with an activated Ras pathway. We examined the ability of this virus to kill bladder cancer cells in vitro and inhibit tumor growth in vivo.

MATERIALS AND METHODS

Following cytotoxicity assays in vitro dose escalation of intravesical reovirus was tested for tumor control and toxicity in a rat model. Treatments were done twice weekly for 3 weeks. In parallel intravesical BCG was studied. Animals were monitored on a daily basis for health status and by routine urine cytology. Animals underwent necropsy at study end point and appropriate tissues were taken for histology.

RESULTS

Side effects in reovirus groups were minor compared with BCG complications. Tumor response (animal survival) was 90% 100 days after tumor implantation in reovirus treated animals, whereas the highest survival in BCG treated groups was 50%. Animals treated with reovirus had significantly higher tumor-free survival than those treated with immunotherapy or normal saline (log rank test p = 0.0002 and 0.04, respectively).

CONCLUSIONS

Intravesical reovirus is safe and effective in this animal model and it may have clinical applications for bladder cancer treatment.

Light dosimetry for multiple cylindrical diffusing sources for use in photodynamic therapy

Since prostatic carcinoma is usually multifocal within the prostate, effective photodynamic therapy (PDT) of prostatic carcinoma is expected to require the photochemical destruction of the entire organ. Accurate light dosimetry will be essential to avoid damage to proximal sensitive tissue such as the rectum. The prostate will be illuminated using interstitial cylindrical fibreoptic light sources and, because of the limited transparency of prostate tissue, these sources will be mounted in a parallel array analogous to the source array used in brachytherapy. Both source spacing and the light delivered to each source will control light dosimetry from a parallel array of fibreoptic sources implanted into tissue. Clinical PDT will require dose planning in order to determine the position and illumination of each source prior to treatment, but unfortunately few methods of predicting light fluence from cylindrical interstitial sources currently exist. In this paper, a novel light fluence model is used to predict tissue transillumination resulting from cylindrical interstitial sources. The cylindrical source is modelled as a finite array of infinitesimal small sources using Christian Huygens' famous single-slit diffraction model. We show that this source model when combined with a robust derivation of fluence in a spherical geometry using diffusion theory, accurately predicts fluence levels from a single cylindrical source in a variety of media. This method is found to retain its accuracy near the sources. With a simple extension, this fluence model is used to predict the light fluence levels from an array of three sources and the predicted fluence is found to compare favourably with experimental data.

Assessment of different transfection parameters in efficiency optimization

Achieving optimal transfection efficiency is the most critical step in overcoming the primary obstacle to success in nonviral-mediated gene therapy. Several transfection parameters were being examined including the effects of different types of transfection media, glucose concentration, reporter DNA concentration, and incubation time in lipotransfectant. Efficiency of transfection obtained was highest for Opti-MEM I (29 +/- 2.28%; p = 0.001) followed by M199 (24 +/- 1.54%; p = 0.009), both of which performed significantly better than DMEM (14 +/- 0.28%) as a transfection medium. The rate of transfection was affected by glucose levels in only DMEM with higher efficiency achieved using low glucose containing DMEM (17 +/- 0.38%) than its counterpart. Furthermore, transfection rate and cell viability were severely hampered by lengthened exposure to transfection complexes, leading to an overall mean efficiency of 5 +/- 0.87%. However, doubling the DNA content in the transfection mixture did not significantly change the mean rate of transfection in M199 medium (24 +/- 1.54% to 27 +/- 1.54%; p = 0.273). The overall range of mean efficiency acquired with our protocol under different transfection conditions was between 14% and 29%. Hopefully results from this study will further potential success in nonviral-mediated gene transfer.

Leiomyosarcoma of the bladder in a retinoblastoma patient

We report a rare case of leiomyosarcoma in the bladder which occurred in an 18-year-old female with a prior history of retinoblastoma (RB). Molecular characterization of this tumor displayed a homozygous RB deletion and a reduced P53 expression. These results suggest that the loss of RB and P53 may have contributed to the initiation and/or progression of the leiomyosarcoma of the bladder in this patient.

In vitro senescence occurring in normal human endothelial cells can be rescued by ectopic telomerase activity

Telomerase activation is a means to delay in vitro replicative senescence in human cells via telomere maintainence; however, this enzymatic activity is virtually absent in almost all normal somatic cells. As a result, cell senesce, leading to an eventual loss of graft function. Aging allografts, either due to cell injury related to transplantation and/or the use of organs from older donors, pose a threat to the long-term survival of a graft as constitutive cells of an aging organ have a much reduced ability to thrive after transplantation. In our study, human endothelial cells were found to undergo replicative senescence in culture with an increase in the percentage of senescent cells (beta-gal staining at pH 6) and a decrease in both the fraction of S-phase cycling cells and the proliferative index measured using CFDA-SE dye. Aging endothelial cells also demonstrated slow rates of proliferation and migration compared to younger cells. Unlike control cells that were transfected with an irrelevant gene vector, telomerase-transfected endothelial cells recovered rapidly after media replacement in cultures that had been serum starved for 2 weeks. Telomerase-transfected cells also retained a high proliferative index comparable to young cells as opposed to untransfected control cells. This young phenotype provided by telomerase expression through restoration of the telomeres may help to increase the longevity of organ transplants.

The effect of photodynamic therapy on rat urinary bladder with orthotopic urothelial carcinoma

OBJECTIVE

To assess the effect of whole-bladder photodynamic therapy (PDT) on a rat model with orthotopic superficial bladder cancer, as PDT is an alternative intravesical therapy for treating superficial bladder cancer, based on an interaction between a photosensitizer and light energy to induce oxygen radicals that destroy tissue by lipid peroxidation.

MATERIALS AND METHODS

In all, 76 female Fischer F344 rats were inoculated intravesically with AY-27 tumour cells. After establishing superficial tumour, 24 rats were treated with PDT using aminolaevulinic acid (ALA)-induced protoporphyrin IX as a photosensitizer, and a continuous-wave argon pumped-dye laser (638 nm). At 4 h after intravenous (300 mg/kg) or intravesical (100 mg/mL) administration of ALA the bladders were intravesically exposed to a 40 J/cm(2) light dose; 12 rats received no ALA but were exposed to the same light dose. Before administering ALA, urine cytology samples were taken for analysis. At 3 or 21 days the treated rats were killed and morphological changes in the bladder walls analysed by light microscopy. Forty rats served as controls to examine the presence of tumour.

RESULTS

The tumour established in 33 of 40 rats (83%) in the controls, but after PDT with intravesical ALA there was carcinoma in only in one of 12 (P < 0.001, Pearson's chi(2) test). After PDT with intravenous ALA there was carcinoma in five of 11 rats (P = 0.063, Pearson's chi2 test). In the control group of 12 rats receiving only light energy there was carcinoma in three (P = 0.001, Pearson's chi(2) test). Histologically, at 3 days after PDT there was only mild superficial damage in all six rats treated intravesically. Bladder wall destruction reached the muscular layer, with an abscess in one of six rats treated intravenously. After 3 weeks of PDT there was muscular necrosis with perforation and abscess from catheterization two of six rats treated intravesically and in three the bladder wall totally recovered. In the intravenous group the bladder walls were normal or had only mild superficial damage. Cytology of the urine sediment failed to detect half the tumours in the treatment groups.

CONCLUSION

These results support the use of PDT with intravesical ALA-induced protoporphyrin X for treating superficial bladder carcinoma. Intravesical was better than intravenous ALA in eradicating bladder carcinoma with PDT.

Selective reovirus killing of bladder cancer in a co-culture spheroid model

Up to 50% of the transitional cell carcinomas (TCC) express an activated EGF pathway involving MAP/MEK and RAF kinase thus providing a novel means to selectively eliminate transformed cells expressing such proteins. This EGF pathway expression phenotype was also confirmed in our MGH-U3 and room temperature-112 human TCC cell lines, which makes them a suitable model target for the reovirus oncolysis. We report here on an in vitro assay of co-culture spheroids using either human or rat TCC cells with their corresponding fibroblasts to examine the potential of viral selective lysis for TCC. Reovirus, a respiratory enteric orphan virus, which mammals are exposed to early in life, was used in this study. Selective killing of transformed versus normal cells was assayed by time-lapse photography, vital dye staining, immunohistochemistry, and MTT assay. In this in vitro bladder cancer model, reovirus selectively destroyed the transformed cells by lysis or induction of apoptosis. Based on these findings we have initiated an in vivo pre-clinical study on intravesical administration of reovirus in an animal model to further explore the effect of reovirus-mediated oncolysis of TCC.

Gene therapy: a lipofection approach for gene transfer into primary endothelial cells

Despite the great potential of gene therapy to become a new treatment modality in future medicine, there are still many limitations to overcome before this gene approach can pass to the stage of human trial. The foremost obstacle is the development of a safe, efficient, and efficacious vector system for in vivo gene application. This study evaluated the efficacy of lipofection as a gene delivery vehicle into primary endothelial cells. Transfection efficiency of several lipid-based reagents (Effectene, Fugene 6, DOTAP) was examined at experimental temperatures of 37 degrees C, 24 degrees C, and 6 degrees C. Human umbilical vein endothelial cells (HUVECs) were transfected with the enhanced green fluorescent protein (EGFP) using precise amounts of DNA (Effectene, 0.2 microg; Fugene 6, 0.5 microg; DOTAP, 2.5 microg) and lipids (Effectene, 10 microl; Fugene 6, 6 microl; DOTAP, 15 microl) optimized in our laboratory. Duration of incubation in the DNA/lipid transfection mixture varied for each lipid transfectant as follows: 5 h for both Fugene 6 and DOTAP and 3 h for Effectene. Efficiency of transfection was quantified by microscopic evaluation of EFGP expression in a minimum of 100 cells per group. Transfection efficiencies achieved with these lipofection agents were 34 +/- 1.3% (mean +/- SEM), 33 +/- 1.4%, and 18 +/- 1.5% for Effectene, Fugene 6, and DOTAP, respectively, at 37 degrees C. Transfection results were lower at 24 degrees C with mean efficiencies of 26 +/- 2.4% for Effectene, 14 +/- 2.9% for Fugene 6, and 15 +/- 3.2% for DOTAP. Furthermore, mean efficiencies at 6 degrees C were 6 +/- 0.5%, 8 +/- 1.5%, and 6 +/- 0.0% for Effectene, Fugene 6, and DOTAP, respectively. Efficiency of transfection appeared to be temperature dependent (ANOVA; p < 0.0001). In spite of a significant decrease (37 degrees C vs. 24 degrees C: p < 0.0001; 37 degrees C vs. 6 degrees C: p < 0.0001; 24 degrees C vs. 6 degrees C: p < 0.0115) in transfection efficiency at low temperatures, the successful in vitro gene manipulation renders lipofection a potential gene delivery strategy for in vivo gene therapy.

Whole bladder photodynamic therapy for orthotopic superficial bladder cancer in rats: a study of intravenous and intravesical administration of photosensitizers

PURPOSE

Photodynamic therapy after intravenous injection of Photofrin (QLT Phototherapeutics, Vancouver, British Columbia, Canada) results in a contracted bladder and skin photosensitivity, which limits its clinical application. In an attempt to overcome these limitations photodynamic therapy after intravesical instillation of Photofrin or 5-aminolevulinic acid (ALA) in an orthotopic rat bladder tumor model was explored and compared with intravenous Photofrin for photodynamic therapy efficacy and phototoxicity.

MATERIALS AND METHODS

At 2 weeks after bladder implantation of 1.5 x 10(6) AY-27 tumor cells animals were randomly grouped. Photofrin was administered (5 mg./kg. intravenously and 2 mg./ml. intravesically). The ALA concentration for intravesical instillation was 300 mM. Whole bladder photodynamic therapy with graded doses of light (lambda = 630 nm.) was performed 4 hours after drug administration. Tumor control and complications were evaluated.

RESULTS

Photodynamic therapy with intravenous Photofrin plus 100 J./cm.(2) light resulted in severe bladder damage. Of 10 rats 6 died and 2 of the 10 that received 50 J./cm.(2) died. There were no photodynamic therapy related deaths in groups receiving intravesical instillation of Photofrin or ALA that also received 50 to 100 J./cm.(2) Median survival in rats treated with ALA intravesically plus 75 J./cm.(2) (77 days), Photofrin intravesically plus 50 (67) or 100 J./cm.(2) (76) and Photofrin intravenously plus 50 J./cm.(2) (60) were significantly different from that in controls (44).

CONCLUSIONS

Intravesical instillation of Photofrin or ALA can achieve the same photodynamic therapy efficacy as intravenous Photofrin in this orthotopic rat bladder tumor model with less phototoxicity to normal tissues.