The Tumor Immune Microenvironment in Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is a type of kidney cancer that arises from the cells lining the tubes of the kidney. The tumor immune microenvironment (TIME) of ccRCC is a complex interplay of various immune cells, cytokines, and signaling pathways. One of the critical features of the ccRCC TIME is the presence of infiltrating immune cells, including T cells, B cells, natural killer cells, dendritic cells, and myeloid-derived suppressor cells. Among these cells, CD8+ T cells are particularly important in controlling tumor growth by recognizing and killing cancer cells. However, the TIME of ccRCC is also characterized by an immunosuppressive environment that hinders the function of immune cells. Several mechanisms contribute to the immunosuppressive nature of the ccRCC TIME. For instance, ccRCC cells produce cytokines such as interleukin-10 (IL-10) and transforming growth factor-beta (TGF-ß), which suppress immune cell activation and promote the differentiation of regulatory T cells (Tregs). Tregs, in turn, dampen the activity of effector T cells and promote tumor growth. In addition, ccRCC cells can express programmed death-ligand 1 (PD-L1), which interacts with the programmed cell death protein 1 (PD-1) receptor on T cells to inhibit their function. In addition, other immune checkpoint proteins, such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and lymphocyte activation gene 3 (LAG-3), also contribute to the immunosuppressive milieu of the ccRCC TIME. Finally, the hypoxic and nutrient-poor microenvironment of ccRCC can stimulate the production of immunosuppressive metabolites, such as adenosine and kynurenine, which further impair the function of immune cells. Understanding the complex interplay between tumor cells and the immune system in the ccRCC TIME is crucial for developing effective immunotherapies to treat this disease.

Inhibition of GLI2 with antisense-oligonucleotides: A potential therapy for the treatment of bladder cancer.

The sonic hedgehog (SHH) signaling pathway plays an integral role in the maintenance and progression of bladder cancer (BCa) and SHH inhibition may be an efficacious strategy for BCa treatment. We assessed an in-house human BCa tissue microarray and found that the SHH transcription factors, GLI1 and GLI2, were increased in disease progression. A panel of BCa cell lines show that two invasive lines, UM-UC-3 and 253J-BV, both express these transcription factors but UM-UC-3 produces more SHH ligand and is less responsive in viability to pathway stimulation by recombinant human SHH or smoothened agonist, and less responsive to inhibitors including the smoothened inhibitors cyclopamine and SANT-1. In contrast, 253J-BV was highly responsive to these manipulations. We utilized a GLI1 and GLI2 antisense oligonucleotide (ASO) to bypass pathway mechanics and target the transcription factors directly. UM-UC-3 decreased in viability due to both ASOs but 253J-BV was only affected by GLI2 ASO. We utilized the murine intravesical orthotopic human BCa (mio-hBC) model for the establishment of noninvasive BCa and treated tumors with GLI2 ASO. Tumor size, growth rate, and GLI2 messenger RNA and protein expression were decreased. These results suggest that GLI2 ASO may be a promising new targeted therapy for BCa.

A prospective randomized pilot study evaluating an ERAS protocol versus a standard protocol for patients treated with radical cystectomy and urinary diversion for bladder cancer.

PURPOSE: There is a lack of evidence demonstrating the benefits of using enhanced recovery after surgery protocols (ERAS). Here, we propose to use a randomized clinical pilot study to demonstrate the benefits and feasibility of implementing ERAS versus standard protocols (SP) in patients undergoing radical cystectomy (RC) and urinary diversion. METHODS: 27 consecutive patients undergoing RC were included in the study. 12 patients were prospectively randomized to follow an ERAS protocol and 15 patients followed an SP. Duration of hospital stay, time to first flatulence and bowel movement, complications and 30 day readmission rates, as well as subjective outcomes such as postoperative pain, nausea, bowel symptoms, quality of life (QoL), and patient experience and satisfaction were evaluated. RESULTS: Patients following ERAS had a significantly shorter: hospital stay, time to flatulence, and time to bowel movement than patients following SP. No major complications were reported. Only one patient in the ERAS group was readmitted for bowel obstruction, and no patients were readmitted in the SP group. Patients under ERAS reported lower postoperative pain scores. Mean Functional Assessment of Cancer Therapy Bladder Cancer score decreased and mean Expanded Prostate Cancer Index Composite, bowel symptom score increased in the SP group at the time of discharge compared to prior to surgery. CONCLUSIONS: This study shows the feasibility of a randomized pilot study assessing ERAS compared to SP post RC. ERAS protocol provided evidence of significant benefits over SP with similar complication rates. This study suggests the need for a clinical trial of assessing ERAS protocols after RC.

The impact of time to metastasis on overall survival in patients with prostate cancer.

PURPOSE: Time to metastasis is often used as a surrogate parameter of treatment success in clinical trials for prostate cancer. However, it has not been shown that there is a clear correlation between time to metastasis and overall survival. Our objective was to evaluate the impact of time to metastasis on OS in patients with prostate cancer. METHODS: Between 2008 and 2015, 269 patients with mPCa were included in this retrospective study with a median follow-up of 7.1 years. Patients were divided into three groups: (1) Presentation with metastasis within three months of initial diagnosis (de-novo-M); (2) patients free of metastasis initially but developed metastasis more than 6 months prior to castration resistance (CSPC-M); (3) patients who developed metastasis within 6 months of becoming castration resistant or after (CRPC-M). RESULTS: There was a significant decrease in OS when metastases were present at diagnosis (median 6.39 years) compared to CRPC-M (19.07) and CSPC-M (18.19 years). De-novo-M and CSPC-M showed a longer OS from occurrence of metastasis to death when compared to CRPC-M, although reaching CRPC earlier. There was no difference in OS between the groups once castration resistance was reached. Time from initial diagnosis to metastasis and to CRPC was correlated with OS and remained important prognosticators in multivariate Cox-regression (p < 0.01 for both). CONCLUSIONS: Time from diagnosis to CRPC (all patients) and time to metastasis (for CRPC-M and CSPC-M patients) are significant prognosticators of overall survival and are therefore valid surrogates in a study setting. Therefore, time to CRPC should be prolonged as long as possible.

Magnetically-actuated drug delivery device (MADDD) for minimally invasive treatment of prostate cancer: An in vivo animal pilot study.

BACKGROUND: The vast majority of prostate cancer presents clinically localized to the prostate without evidence of metastasis. Currently, there are several modalities available to treat this particular disease. Despite radical prostatectomy demonstrating a modest prostate cancer specific mortality benefit in the PIVOT trial, several novel modalities have emerged to treat localized prostate cancer in patients that are either not eligible for surgery or that prefer an alternative approach. METHODS: Athymic nude mice were subcutaneously inoculated with prostate cancer cells. The mice were divided into four cohorts, one cohort untreated, two cohorts received docetaxel (10 mg/kg) either subcutaneously (SC) or intravenously (IV) and the fourth cohort was treated using the magnetically-actuated docetaxel delivery device (MADDD), dispensing 1.5 µg of docetaxel per 30 min treatment session. Treatment in all three therapeutic arms (SC, IV, and MADDD) was administered once weekly for 6 weeks. Treatment efficacy was measured once a week according to tumor volume using ultrasound. In addition, calipers were used to assess tumor volume. RESULTS: Animals implanted with the device demonstrated no signs of distress or discomfort, neither local nor systemic symptoms of inflammation and infection. Using an independent sample t-test, the tumor growth rate of the treated tumors was significant when compared to the control. Post hoc Tukey HSD test results showed that the mean tumor growth rate of our device cohort was significantly lower than SC and control cohorts. Moreover, IV cohort showed slight reduction in mean tumor growth rates than the ones from the device cohort, however, there was no statistical significance in tumor growth rate between these two cohorts. Furthermore, immunohistochemistry demonstrated an increased cellular apoptosis in the MADDD treated tumors and a decreased proliferation when compared to the other cohorts. In addition, IV cohort showed increased treatment side effects (weight loss) when compared to the device cohort. Finally, MADDD showed minimal expression of CD45 comparable to the control cohort, suggesting no signs of chronic inflammation. CONCLUSIONS: In conclusion, this study showed for the first time that MADDD, clearly suppressed tumor growth in local prostate cancer tumors. This could potentially be a novel clinical treatment approach for localized prostate cancer.

The use of desiccation to treat Staphylococcus aureus biofilm-infected wounds.

Chronic wounds colonized with biofilm present a major burden to our healthcare system. While the current paradigm for wound healing is to maintain a moist environment, we sought to evaluate the effects of desiccation, and the ability of honey to desiccate wounds, on wound healing characteristics in Staphylococcus aureus biofilm wounds. In vivo biofilm wound healing after exposure to open-air desiccation, honey, molasses, and saline was analyzed using a rabbit ear model of S. aureus biofilm wounds previously developed by our group. Wound morphology was examined using scanning electron microscopy and granulation tissue deposition was measured using light microscopy with hematoxylin and eosin staining. Viable bacterial counts in rabbit ear biofilm wounds and scabs were measured using a drop dilution method. In vitro S. aureus growth curves were established using tryptic soy broth containing honey and glycerol. Gene expression analysis of rabbit ear wounds was performed using reverse transcription quantitative PCR. Rabbit ear S. aureus biofilm wounds exposed to open-air desiccation, honey, and molasses developed a dry scab, which displaced the majority of biofilm bacteria off of the wound bed. Wounds treated with open-air desiccation, honey, and molasses expressed lower levels of the inflammatory markers tumor necrosis factor-α and interleukin-1ß at postoperative day 12 compared with wounds treated with saline, and had increased levels of granulation tissue formation. In vitro growth of S. aureus in tryptic soy broth was inhibited by the presence of honey to a greater extent than by the presence of osmolality-matched glycerol. Desiccation of chronic wounds colonized with biofilm via exposure to open air or honey leads to improved wound healing by decreasing bacterial burden and inflammation, and increasing granulation tissue formation. The ability of honey to help heal chronic wounds is at least in part due to its ability to desiccate bacterial biofilm, but other factors clearly contribute.

Systemic administration of hemoglobin improves ischemic wound healing.

BACKGROUND: Oxygen plays multifaceted roles in wound healing, including effects on cell proliferation, collagen synthesis, angiogenesis, and bacterial killing. Oxygen deficit is a major factor in the pathogenesis of chronic wounds. MATERIALS AND METHODS: We present a novel mechanism for oxygen delivery to ischemic wounds by systemic administration of an oxygen carrier substitute derived from bovine hemoglobin (IKOR 2084) in our ischemic rabbit ear wound model. The wound healing indexes, including epithelial gap and neo-granulation tissue area, were histologically analyzed. In situ expression of endothelial cells (CD31+) and proliferative cells (Ki-67+) were examined by immunohistochemistry analysis. The messenger RNA expression of collagen I, III, and vascular endothelial growth factor was measured by quantitative RT-PCR. Sirius Red staining was implemented for detection of collagen deposition, and terminal deoxynucleotidyl transferase dUTP nick end labeling analysis was performed to examine dermal cellular apoptosis. RESULTS: Systemic administration of IKOR 2084 significantly improved oxygen tension of ischemic tissue. When compared with saline controls, IKOR 2084 treatment enhanced wound repair as demonstrated by a reduced epithelial gap and increased granulation tissue area. The expression of Ki-67+, CD31+, vascular endothelial growth factor and collagen was also enhanced by IKOR 2084 administration. Moreover, apoptosis analysis in the wounds showed that cell survival in the dermis was increased by systemic IKOR 2084 administration. CONCLUSIONS: Our study suggests that systemic delivery of IKOR 2084 ameliorates hypoxic state, subsequently promotes angiogenesis, cellular proliferation, and collagen synthesis, attenuates hypoxia-induced apoptosis, and improved ischemic wound healing.

Is Engineered Tissue the Future of Bladder Reconstruction: Con.

Tissue engineering, once promising, faces significant technical challenges. Current limitations impede progression of the field, as evidenced by clinical trial failures over the past decades. Existing established surgical techniques remain the only proven, successful, and durable methods for bladder reconstruction.

Adjuvant therapy for renal cell carcinoma: 2023 Canadian Kidney Cancer Forum consensus statement.

INTRODUCTION: Several recent randomized trials evaluated the impact of adjuvant immune checkpoint inhibitor (ICI)-based therapy on post-surgical outcomes in renal cell carcinoma (RCC), with disparate results. The objective of this consensus statement is to provide data-driven guidance regarding the use of ICIs after complete resection of clear-cell RCC in a Canadian context. METHODS: An expert panel of genitourinary medical oncologists, urologic oncologists, and radiation oncologists with expertise in RCC management was convened in a dedicated session during the 2022 Canadian Kidney Cancer Forum in Toronto, Canada. Topic statements on the management of patients after surgery for RCC, including counselling, risk stratification, indications for medical oncology referral, appropriate followup, eligibility and management for adjuvant ICIs, as well as treatment options for patients with recurrence who received adjuvant immunotherapy, were discussed. Participants were asked to vote if they agreed or disagreed with each statement. Consensus was achieved if greater than 75% of participants agreed with the topic statement. RESULTS: A total of 22 RCC experts voted on 14 statements. Consensus was achieved on all topic statements. The panel felt patients with clear-cell RCC at increased risk of recurrence after surgery, as per the Keynote-564 group definitions, should be counselled about recurrence risk by a urologist, should be informed about the potential role of adjuvant ICI systemic therapy, and be offered referral to discuss risks and benefits with a medical oncologist. The panel felt that one year of pembrolizumab is currently the only regimen that should be considered if adjuvant therapy is selected. Panelists emphasized current opinions are based on disease-free survival given the available results. Significant uncertainty regarding the benefit and harms of adjuvant therapy remains, primarily due to a lack of consistent benefit observed across similar trials of adjuvant ICI-based therapies and immature overall survival (OS) data. CONCLUSIONS: This consensus document provides guidance from Canadian RCC experts regarding the potential role of ICI-based adjuvant systemic therapy after surgery. This rapidly evolving field requires frequent evidence-based re-evaluation.

SPARC/SFN interaction, suppresses type I collagen in dermal fibroblasts.

We previously suggested that keratinocyte releasable factors might modulate the wound healing process by regulating the expression of key extracellular matrix components such as collagenase (matrix metalloproteinase-1) and type I collagen in fibroblasts. The first one, we called it keratinocyte-derived anti-fibrogenic factor (KDAF), identified as stratifin (SFN) also named 14-3-3σ, revealing a strong collagenase activity. However, the second factor, which we named keratinocyte-derived collagen-inhibiting factor(s) (KD-CIF) that has shown to control the synthesis of type I collagen, was not known. Upon conducting a series of systematic protein purification methods followed by mass spectroscopy, two proteins: secreted protein acidic rich in cystein (SPARC) and SFN were identified in keratinocyte-conditioned media. Using co-immunoprecipitation and 3D modeling, we determined that SFN and SPARC form a complex thereby controlling the type I collagen synthesis and expression in fibroblasts. The levels of these proteins in fibrotic tissues (animal and human) were also evaluated and a differential expression of these proteins between normal and fibrotic tissue confirmed their potential role in development of fibrotic condition. In conclusion, this study describes for the first time an interaction between SPARC and SFN that may have implications for the regulation of matrix deposition and prevention of dermal fibrotic conditions such as hypertrophic scars and keloid.

Dermal fibroblasts influence the expression profile of 14-3-3 proteins in human keratinocytes.

We have previously demonstrated that the release of some of the 14-3-3 isoforms from keratinocytes is able to influence the expression of key matrix metalloproteinases (MMPs) in dermal fibroblasts. Conversely, in this study we aimed to investigate whether dermal fibroblasts possess the ability to modulate the expression of 14-3-3 proteins in keratinocytes. In order to address this question, human keratinocytes and dermal fibroblasts were harvested and co-cultured. Intra- and extracellular levels of 14-3-3 proteins (ß, η, γ, and σ) were analyzed using western blot analysis, and the gene expression was further assessed by quantitative real-time polymerase chain reaction. Gene analysis revealed an up-regulation of all four 14-3-3 isoforms of interest. In addition, the findings of this study reveal a significant increase in the intracellular levels of 14-3-3 γ and σ in keratinocytes co-cultured with fibroblasts compared to those of the mono-cultured control keratinocytes. Mechanistic investigations also demonstrated the capacity of several mitogen-activated protein kinase-specific inhibitors to markedly reduce induction of 14-3-3 σ in keratinocytes stimulated with fibroblast-conditioned medium. The study concluded that dermal fibroblasts possess the ability to influence the expression of several 14-3-3 isoforms (notably γ and σ) in keratinocytes, suggesting that the two cell types might be capable of bi-directionally influencing the protein expression of one another in vivo.

Identification of gene signature for treatment response to guide precision oncology in clear-cell renal cell carcinoma.

Clear-cell renal cell carcinoma (ccRCC) is a common therapy resistant disease with aberrant angiogenic and immunosuppressive features. Patients with metastatic disease are treated with targeted therapies based on clinical features: low-risk patients are usually treated with anti-angiogenic drugs and intermediate/high-risk patients with immune therapy. However, there are no biomarkers available to guide treatment choice for these patients. A recently published phase II clinical trial observed a correlation between ccRCC patients' clustering and their response to targeted therapy. However, the clustering of these groups was not distinct. Here, we analyzed the gene expression profile of 469 ccRCC patients, using featured selection technique, and have developed a refined 66-gene signature for improved sub-classification of patients. Moreover, we have identified a novel comprehensive expression profile to distinguish between migratory stromal and immune cells. Furthermore, the proposed 66-gene signature was validated using a different cohort of 64 ccRCC patients. These findings are foundational for the development of reliable biomarkers that may guide treatment decision-making and improve therapy response in ccRCC patients.

Y-box binding protein-1 is crucial in acquired drug resistance development in metastatic clear-cell renal cell carcinoma.

BACKGROUND: Renal cell carcinoma (RCC) is a highly vascular tumor and patients with low risk metastatic RCC of clear-cell histological sub-type (mccRCC) are treated with tyrosine-kinase inhibitors (TKIs), sunitinib, as the first-line of treatment. Unfortunately, TKI resistance eventually develops, and the underlying molecular mechanism is not well understood. METHODS: RCC cell-line with metastatic clear-cell histology (Caki-1), and patient samples were analysed to identify the role of Y-box binding protein 1 (YB-1) and ATP-binding cassette sub-family B member 1 (ABCB-1) in acquired sunitinib-resistance development. Caki-1 was conditioned with increasing sunitinib doses to recapitulate acquired resistance development in clinics. Sunitinib-conditioned and wild-type Caki-1 were subjected to cell viability assay, scratch assay, chicken embryo chorioallantoic membrane engraftment and proteomics analysis. Classical biochemical assays like flow cytometry, immunofluorescent staining, immunohistochemical staining, optical coherence tomography imaging, Western Blot and RT-PCR assays were applied to determine the possible mechanism of sunitinib-resistance development and the effect of drug treatments. Publicly available data was also used to determine the role of YB-1 upregulation in ccRCC and the patients' overall survival. RESULTS: We demonstrate that YB-1 and ABCB-1 are upregulated in sunitinib-resistant in vitro, ex vivo, in vivo and patient samples compared to the sensitive samples. This provides evidence to a mechanism of acquired sunitinib-resistance development in mccRCC. Furthermore, our results establish that inhibiting ABCB-1 with elacridar, in addition to sunitinib, has a positive impact on reverting sunitinib-resistance development in in vitro, ex vivo and in vivo models. CONCLUSION: This work proposes a targeted therapy (elacridar and sunitinib) to re-sensitize sunitinib-resistant mccRCC and, possibly, slow disease progression.

Profile of exosomes related proteins released by differentiated and undifferentiated human keratinocytes.

Our group has previously demonstrated the capacity of human keratinocytes to release 14-3-3sigma into conditioned medium through the mechanism of exosome externalization. In this study the release of other proteins through the same mechanism and the differences in the profiles of 14-3-3 proteins between differentiated (diff-K) and undifferentiated keratinocytes (undiff-K) were investigated. The stimulatory effect of other 14-3-3 isoforms on the expression of MMP-1 in dermal fibroblasts was also evaluated. Exosomes isolated from undiff-K (low Ca(2+)) and diff-K (high Ca(2+)) were subjected to proteomic and Western blot analysis. The results showed that more than 50 different cytoplasmic proteins including all seven 14-3-3 protein isoforms (beta, sigma, eta, epsilon, tau, zeta, and gamma) were released from diff-K through the mechanism of exosome externalization. However, in exosomes of undiff-K only four of the 14-3-3 protein isoforms (beta, eta, zeta, and gamma) were detected. Ca(2+) treatment increased the release of exosomes from undiff-K by at least two times relative to the control. Consistent with this finding, the stimulatory effect of exosomes containing 14-3-3sigma from diff-K had higher MMP-1 stimulatory effect in fibroblasts relative to those exosomes isolated from undiff-K. MMP-1 stimulatory effect of recombinant 14-3-3beta and eta, tested in this study, in dermal fibroblasts, suggests additional anti-fibrogenic factors other than 14-3-3sigma. In conclusion, keratinocytes release many proteins through the mechanism of exosome externalization from which some such as 14-3-3 isoforms may function as extracellular matrix (ECM) modulating factors for dermal fibroblasts. These findings revealed the presence of a novel mechanism by which keratinocytes can potentially interact with fibroblasts.

Keratinocyte-releasable factors increased the expression of MMP1 and MMP3 in co-cultured fibroblasts under both 2D and 3D culture conditions.

Matrix metalloproteinases (MMPs) are key elements in extracellular matrix (ECM) degradation and scar remodeling during the wound-healing process. Our previous data revealed that keratinocyte-releasable factors significantly increased the expression of fibroblast MMPs in monolayer-cultured fibroblasts. In this study, we analyzed the differences in the MMP expressions of fibroblasts in a three-dimensional fibroblast-populated collagen gel (3D FPCG) from that in a two-dimensional monolayer-cultured fibroblasts when both co-cultured with keratinocytes. Differential mRNA and protein expression of fibroblasts were examined by microarray, RT-PCR, and western blot. Our results showed that fibroblasts co-cultured with keratinocytes in a 3D FPCG expressed significantly higher MMP1 and MMP3 at the gene and protein levels. Due to the physiological advantages of a 3D FPCG model to a 2D system, we concluded that the 3D FPCG model may provide a better means of understanding the fibroblast-keratinocyte cross-talk during the wound-healing process.

Primary human keratinocytes externalize stratifin protein via exosomes.

Although, stratifin (SFN) is externalized by keratinocytes and stimulates the expression of matrix metalloproteinase-1 (MMP-1) in fibroblasts, its mechanism of externalization is not known. Here, we hypothesize that keratinocytes have a capacity to release stratifin through externalization of exosomes. To test this hypothesis, exosomes were purified from human keratinocyte conditioned medium (KCM) and analyzed for the presence of SFN by Western blot analysis using lysosomal-associated membrane protein 2 (LAMP-2) and heat shock cognate 70 (hsc70) as exosomal markers. The results showed the presence of SFN in keratinocyte lysate, concentrated KCM and exosomes, but not in concentrated unconditioned medium. Transmission electron microscopic examination revealed the presence of unique "saucer-like" structures characteristic of exosomes whose diameters were <100 nm. Similar to the recombinant SFN, the exosomes associated proteins stimulated MMP-1 expression in fibroblasts. Depletion of the exosomes markedly reduced this MMP-1 stimulatory effect. To further statistically confirm these findings, fibroblasts were treated with three different exosome preparations and the finding showed more than 7.4-fold increase in the level of MMP-1 in the treated cells. Furthermore, we found that approximately 1% of the total proteins contained in exosomes correspond to SFN. In conclusion, this study is the first report showing that keratinocytes have the capacity to produce exosomes through which some intracellular proteins such as SFN, with MMP-1 stimulating activity for fibroblasts, is externalized into keratinocyte microenvironment.

Arterialized venous free flap for reconstruction of burned face.

In this study, a forearm arterialized venous free flap (23 cm x 14 cm) was used in a 25-year-old male with facial burns sequels to reconstruct both cheeks, chin, lips, nose, columnella, nasal tip, and nostrils. It was arterialized by the facial artery to an afferent vein anastomosis. The venous flow was drained by four efferent vein to vein anastomoses. Although it developed small inferior marginal necrosis in the lower lip, the rest of the flap survived with good quality of the skin in both texture and color, with self-delimitation of the different esthetics units of the center of the face such as the nasogenian folds, nostrils, and upper lip filtrum, without the need of additional thinning surgical procedures. From all of the above, the arterialized venous free flap is an alternative reconstructive option for the treatment of burn sequels especially those that include the centrofacial region.

Development of a murine intravesical orthotopic human bladder cancer (mio-hBC) model.

We have developed a murine intravesical orthotopic human bladder cancer (mio-hBC) model for the establishment of superficial urothelial cell carcinomas. In this model we catheterize female atyhmic nude mice and pre-treat the bladder with poly-L-lysine for 15 minutes, followed by intravesical instillation of luciferase-transfected human UM-UC-3 cells. Cancer cells are quantified by bioluminescent imaging which has been validated by small animal ultrasound. Poly-L-lysine pre-treatment increased engraftment rate (84.4%) and resulted in faster growing tumors than trypsin pre-treatment. In addition, tumors respond through a decrease in growth and increase in apoptosis to chemotherapy with mitomycin C. Previous intravesical models utilized KU7 cells which have been later determined to be of non-bladder origin. They display markers consistent with HeLa cells, requiring a need for a true intravesical bladder model. Efficient engraftment and rapid superficial growth patterning of the human bladder tumor differentiate this in vivo orthotopic model from previous bladder models.

The role of netrin-1 in metastatic renal cell carcinoma treated with sunitinib.

INTRODUCTION: Clear-cell renal cell carcinoma (ccRCC) is the sixth most common malignancy in men in North America. Since ccRCC is a malignancy dependent on neovascularization, current first line systemic therapies like sunitinib, target the formation of new vessels allowing nutrient deprivation and cell death. However, recent studies have shown that patients develop resistance after approximately 1 year of treatment and show disease progression while on therapy. Therefore, we propose to identify the protein(s) responsible for increased migration with the aim of developing a new therapy that will target the identified protein and potentially slow down the progression of the disease. MATERIAL AND METHODS: Human renal cancer cell lines (Caki-1, Caki-2, ACHN) were treated with increasing doses of sunitinib to develop a sunitinib-conditioned renal cell carcinoma cell line. mRNA microarray and qPCR were performed to compare the differences in gene expression between Caki-1 sunitinib-conditioned and non-conditioned cells. NTN1 was assessed in our in vivo sunitinib-conditioned mouse model using immunostaining. xCELLigence and scratch assays were used to evaluate migration and MTS was used to evaluate cell viability. RESULTS: Human renal cell carcinoma sunitinib-conditioned cell lines showed upregulation of netrin-1 in microarray and q-PCR. Increased migration was demonstrated in Caki-1 sunitinib-conditioned cells when compared to the non-treated ones as well as, increased endothelial cell migration. Silencing of netrin-1 in sunitinib-conditioned Caki-1 cells did not demonstrate a significant reduction in cell migration. CONCLUSION: Netrin-1 is highly upregulated in renal cell carcinoma treated with sunitinib, but has no influence on cell viability or cell migration in metastatic RCC.

Calcium-sensing receptor (CaSR) promotes development of bone metastasis in renal cell carcinoma.

Bone metastasis is an important prognostic factor in renal cell carcinoma (RCC). The calcium-sensing receptor (CaSR) has been associated with bone metastasis in several different malignancies. We analyzed the impact of CaSR in bone metastasis in RCC in vitro and in vivo. The RCC cell line 786-O was stably transfected with the CaSR gene and treated with calcium alone or in combination with the CaSR antagonist NPS2143. Afterwards migration, adhesion, proliferation and prominent signaling molecules were analyzed. Calcium treated CaSR-transfected 768-O cells showed an increased adhesion to endothelial cells and the extracellular matrix components fibronectin and collagen I, but not to collagen IV. The chemotactic cell migration and proliferation was also induced by calcium. The activity of SHC, AKT, ERK, P90RSK and JNK were enhanced after calcium treatment of CaSR-transfected cells. These effects were abolished by NPS2143. Development of bone metastasis was evaluated in vivo in a mouse model. Intracardiac injection of CaSR-transfected 768-O cells showed an increased rate of bone metastasis. The results indicate CaSR as an important component in the mechanism of bone metastasis in RCC. Therefore, targeting CaSR might be beneficial in patients with bone metastatic RCC with a high CaSR expression.