Patient-Specific Tumor Microenvironment Models

The heterogeneity of cancer makes it difficult to predict the prognosis of treatment. There is still a lack of preclinical model systems that reflect the clinical characteristics of patients who have heterogenetic tumors. Advances in 3-dimentional (3D) cell culture are leading to discoveries that occur in the development and progression of cancer that has not been known. There are many models including patient-derived xenograft, patient-derived organoid and spheroid, patient-derived explant, scaffold-based model, and system-based model. Each 3D model has its strengths and limitations. One model cannot answer every question, so it seems most reasonable to approach multiple models when studying cancer heterogeneity. Hopefully, 3D tumor modeling will make tremendous progress on this path by fusion of innovative biomaterials and advanced modeling techniques that can partially mimic the heterogeneous environment of real tumors.

Clinical Implications of Urinary Microbiome in Bladder Cancer

Microbiomes are known to have a beneficial effect on human health by promoting the effective removal of improperly functioning immune cells and protecting the host from pathogen infection. On the other hand, these microbiomes are also known as the causative agent of numerous malignant tumors. Until now, the bladder has been regarded as aseptic, but the concept of the “sterile bladder” has been changed with the discovery of living bacteria embedded in the bladder with the recent development of polymerase chain reaction and culture techniques. This paper referred to the relationship between microbiome and bladder cancer. Microbiome will be able to be seen as a non-invasive biomarker to predict the success rate of intravesical bacillus Calmette-Guerin instillation treatment in patients of bladder cancer.

Does intraoperative frozen section really predict significant positive surgical margins after robot-assisted laparoscopic prostatectomy? A retrospective study / 亚洲男科学杂志(英文版)

We investigated the relationship between positive surgical margin (PSM)-related factors and biochemical recurrence (BCR) and the ability of intraoperative frozen sections to predict significant PSM in patients with prostate cancer. The study included 271 patients who underwent robot-assisted laparoscopic prostatectomy with bilateral nerve sparing and maximal urethral preservation. Intraoperative frozen sections of the periurethra, dorsal vein, and bladder neck were analyzed. The ability of PSM-related factors to predict BCR and significant PSM was assessed by logistic regression. Of 271 patients, 108 (39.9%) had PSM and 163 (60.1%) had negative margins. Pathologic Gleason score ≥8 (18.9% vs 7.5%, P = 0.015) and T stage ≥T3a (51.9%vs 24.6%, P < 0.001) were significantly more frequent in the PSM group. Multivariate analysis showed that Gleason pattern ≥4 (vs <4; hazard ratio: 4.386; P = 0.0004) was the only significant predictor of BCR in the PSM cohort. Periurethral frozen sections had a sensitivity of 83.3% and a specificity of 84.2% in detecting PSM with Gleason pattern ≥4. Multivariate analysis showed that membranous urethra length (odds ratio [OR]: 0.79, P = 0.0376) and extracapsular extension of the apex (OR: 4.58, P = 0.0226) on magnetic resonance imaging (MRI) and positive periurethral tissue (OR: 17.85, P < 0.0001) were associated with PSM of the apex. PSM with Gleason pattern ≥4 is significantly predictive of BCR. Intraoperative frozen sections of periurethral tissue can independently predict PSM, whereas sections of the bladder neck and dorsal vein could not. Pathologic examination of these samples may help predict significant PSM in patients undergoing robot-assisted laparoscopic prostatectomy with preservation of functional outcomes.

The Effects of Recombinant Bacillus Calmette-Guérin Resistant to Antimicrobial Peptides on Orthotopic Bladder Cancer Mouse Model

Purpose@#Although Mycobacterium bovis Bacillus Calmette-Guérin (BCG) is the most widely used bladder cancer immunotherapy, innate immune responses involving antimicrobial peptides (AMPs) cause BCG failure. Here, we developed genetically modified recombinant BCG (rBCG) strains which escape AMPs and evaluate the efficacy and effects of rBCG. @*Materials and Methods@#We constructed rBCG strains expressing Streptococcal inhibitor of complement (Sic), which confers resistance to human α-defensin-1 and cathelicidin, and d-alanyl carrier protein ligase (dltA), which confers resistance to cationic AMPs. Sic and dltA were separately cloned into the pMV306 plasmid and introduced into BCG via electroporation. The efficacy of the Sic and dltA gene electroporation into BCG was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). The internalization rates and anticancer effects of the rBCG strains containing Sic (rBCG-Sic) and dltA (rBCG-dltA) was evaluated by the orthotopic bladder cancer mouse model. @*Results@#The cycle quantification (Cq) values of rBCG-Sic (y=-4.8823x+13.645, R2=0.9996) and rBCG-dltA (y=-5.438x+11.641, R2=0.9995) were inverse correlations to the amount of Sic and dltA genes dose dependently. The mean introduction proportions of Sic and dltA genes into BCG by electroporation were 22.2%, 27.5% and showed constant efficacy. In the orthotopic bladder cancer mouse model, the relative internalization number of rBCG-Sic, and rBCG-dltA into bladder cell in mouse bladder were higher than that of BCG and the tumor volume at rBCG-Sic were lower than at BCG and rBCG-dltA at 11, 14 and 18 days. @*Conclusions@#Our results showed that constructed rBCG-Sic and rBCG-dltA by electroporation and the rBCG-Sic and rBCG-dltA can effectively escape BCG-stimulated AMPs, and significantly improved immunotherapeutic tools to treat bladder cancer in orthotopic bladder cancer mouse model.

Clinical Implications of Urinary Microbiome in Bladder Cancer

Microbiomes are known to have a beneficial effect on human health by promoting the effective removal of improperly functioning immune cells and protecting the host from pathogen infection. On the other hand, these microbiomes are also known as the causative agent of numerous malignant tumors. Until now, the bladder has been regarded as aseptic, but the concept of the “sterile bladder” has been changed with the discovery of living bacteria embedded in the bladder with the recent development of polymerase chain reaction and culture techniques. This paper referred to the relationship between microbiome and bladder cancer. Microbiome will be able to be seen as a non-invasive biomarker to predict the success rate of intravesical bacillus Calmette-Guerin instillation treatment in patients of bladder cancer.

Application of Bioprinting to Cancer Research

Three-dimensional (3D) printing is an additive manufacturing process by which precursor materials are deposited layer by layer to form complex 3D geometries from computer-aided designs, and bioprinting offers the ability to create 3D architecture living cells. Bioprinting methods have been developed rapidly pattern living cells, biological macromolecules, and biomaterials, and an advantage of the 3D microenviroment over traditional 2-dimensional cell culture is the ability to obtain more accurate and reliable data from model about tumor formation, progression, and response to anticancer therapies. This review focuses on recent advances in the use of biopriniting technologies for cancer research, bioprinting physiologically relevant testing platforms for anticancer drug development, and computational modeling for improvement bioprinting technique.

The Overdiagnosis of Kidney Cancer in Koreans and the Active Surveillance on Small Renal Mass

While overtreatment in medical services had been the topic of interest among the medical community for a long time, there are numerous academic papers concerning over-diagnosis nowadays. The use of imaging studies for screening might lead to over-diagnosis of small renal masses (SRMs) therefore the incidence of kidney cancer increased 5 times higher than that of mortality in Korea between 2000 and 2011. The best treatment for SRMs had been debated and the present strategies include surgery, local treatment, and active surveillance. Competing risks to mortality should be considered to determine initial management strategies, and a period of initial active surveillance in patients with SRMs is safe. Tumor growth rate is the primary driver for delayed intervention of SRMs patients, and the risk of metastasis on active surveillance for SRMs is 1%–2% at 2-year follow-up.

Low-Dose Unenhanced Computed Tomography with Iterative Reconstruction for Diagnosis of Ureter Stones

PURPOSE: To study the clinical application of low-dose unenhanced computed tomography with iterative reconstruction technique (LDCT-IR) on renal colic in the emergency department. MATERIALS AND METHODS: We conducted a prospective, single-blinded, randomized, and non-inferiority study. From March 2014 to August 2015, 112 patients with renal colic were included, and were randomized to either LDCT-IR (n=46) or standard-dose unenhanced CT (SDCT) (n=66) groups. The accuracy of urolithiasis diagnosis was the primary endpoint of this study. Radiation dose, size and location of the stone, hydronephrosis, other diseases except urolithiasis, and results of treatment were analyzed between the two groups. RESULTS: The average effective dose radiation of SDCT was approximately four times higher than that of LDCT-IR (6.52 mSv vs. 1.63 mSv, p < 0.001). There was no significant difference in the accuracy of ureteral stone diagnosis between the two groups (LDCT-IR group: 96.97% vs. SDCT group: 98.96%, p=0.392). No significant difference was observed regarding the size and location of a stone, hydronephrosis, and diagnosis of other diseases, except urolithiasis. False negative results were found in two LDCT-IR patients and in one SDCT patient. In these patients, stones were misread as vascular calcification, and were difficult to diagnose because evidence of hydronephrosis and ureteral dilatation was not found. CONCLUSION: LDCT-IR, as a first-line imaging test, was non-inferior to SDCT with respect to diagnosis of ureter stones, and was clinically available for the evaluation of renal colic.

Vascularization Methods for Tissue Engineers

Tissue engineering is limited by our inability to adequately vascularize tissues post implantation because all tissue-engineered substitutes (with the exception of cornea and cartilage) require a vascular network to provide the nutrient and oxygen supply needed for their survival. This review gives a brief overview of the processes and factors involved in the vascularization and angiogenesis and summarizes the different strategies to overcome the issue of slow vascularization and angiogenesis in a range of tissue-engineered substitutes. Moreover, we will announce some potential future plans.

Daily Mean Temperature and Urolithiasis Presentation in Six Cities in Korea: Time-Series Analysis

Seasonal variation in urinary stone presentation is well described in the literature. However, previous studies have some limitations. To explore overall cumulative exposure-response and the heterogeneity in the relationships between daily meteorological factors and urolithiasis incidence in 6 major Korean cities, we analyzed data on 687,833 urolithiasis patients from 2009 to 2013 for 6 large cities in Korea: Seoul, Incheon, Daejeon, Gwangju, Daegu, and Busan. Using a time-series design and distributing lag nonlinear methods, we estimated the relative risk (RR) of mean daily urolithiasis incidence (MDUI) associated with mean daily meteorological factors, including the cumulative RR for a 20-day period. The estimated location-specific associations were then pooled using multivariate meta-regression models. A positive association was confirmed between MDUI and mean daily temperature (MDT), and a negative association was shown between MDUI and mean daily relative humidity (MDRH) in all cities. The lag effect was within 5 days. The multivariate Cochran Q test for heterogeneity at MDT was 12.35 (P = 0.136), and the related I2 statistic accounted for 35.2% of the variability. Additionally, the Cochran Q test for heterogeneity and I2 statistic at MDHR were 26.73 (P value = 0.148) and 24.7% of variability in the total group. Association was confirmed between daily temperature, relative humidity and urolithiasis incidence, and the differences in urolithiasis incidence might have been partially attributable to the different frequencies and the ranges in temperature and humidity between cities in Korea.

The Present and Future of the Cancer Microenvironment Bioprinting

Cancer is the tissue complex consisted with heterogeneous cellular compositions, and microenvironmental cues. During the various stages of cancer initiation, development, and metastasis, cell–cell interactions as well as cell-extracellular matrix play major roles. Conventional cancer models both 2-dimensional and 3-dimensional (3D) present numerous limitations, which restrict their use as biomimetic models for drug screening and fundamental cancer biology studies. Recently, bioprinting biofabrication platform enables the creation of high-resolution 3D structures. Moreover this platform has been extensively used to model multiple organs and diseases, and this versatile technique has further found its creation of accurate models that figure out the complexity of the cancer microenvironment. In this review we will focus on cancer biology and limitations with current cancer models and we discuss vascular structures bioprinting that are critical to the construction of complex 3D cancer organoids. We finally conclude with current literature on bioprinting cancer models and propose future perspectives.

Daily Mean Temperature Affects Urolithiasis Presentation in Seoul: a Time-series Analysis

This study aimed to investigate the overall cumulative exposure-response and the lag response relationships between daily temperature and urolithiasis presentation in Seoul. Using a time-series design and distributing lag nonlinear methods, we estimated the relative risk (RR) of urolithiasis presentation associated with mean daily temperature, including the cumulative RR for a 20 days period, and RR for individual daily lag through 20 days. We analyzed data from 14,518 patients of 4 hospitals emergency department who sought medical evaluation or treatment of urolithiasis from 2005-2013 in Seoul. RR was estimated according to sex and age. Associations between mean daily temperature and urolithiasis presentation were not monotonic. Furthermore, there was variation in the exposure-response curve shapes and the strength of association at different temperatures, although in most cases RRs increased for temperatures above the 13℃ reference value. The RRs for urolothiasis at 29℃ vs. 13℃ were 2.54 in all patients (95% confidence interval [CI]: 1.67-3.87), 2.59 in male (95% CI, 1.56-4.32), 2.42 in female (95% CI, 1.15-5.07), 3.83 in male less than 40 years old (95% CI, 1.78-8.26), and 2.47 in male between 40 and 60 years old (95% CI, 1.15-5.34). Consistent trends of increasing RR of urolithiasis presentation were observed within 5 days of high temperatures across all groups. Urolithiasis presentation increased with high temperature with higher daily mean temperatures, with the strongest associations estimated for lags of only a few days, in Seoul, a metropolitan city in Korea.

P70S6K and Elf4E Dual Inhibition Is Essential to Control Bladder Tumor Growth and Progression in Orthotopic Mouse Non-muscle Invasive Bladder Tumor Model

We investigated how the dual inhibition of the molecular mechanism of the mammalian target of the rapamycin (mTOR) downstreams, P70S6 kinase (P70S6K) and eukaryotic initiation factor 4E (eIF4E), can lead to a suppression of the proliferation and progression of urothelial carcinoma (UC) in an orthotopic mouse non-muscle invasive bladder tumor (NMIBT) model. A KU-7-luc cell intravesically instilled orthotopic mouse NMIBC model was monitored using bioluminescence imaging (BLI) in vivo by interfering with different molecular components using rapamycin and siRNA technology. We then analyzed the effects on molecular activation status, cell growth, proliferation, and progression. A high concentration of rapamycin (10 microM) blocked both P70S6K and elF4E phosphorylation and inhibited cell proliferation in the KU-7-luc cells. It also reduced cell viability and proliferation more than the transfection of siRNA against p70S6K or elF4E. The groups with dual p70S6K and elF4E siRNA, and rapamycin reduced tumor volume and lamina propria invasion more than the groups with p70S6K or elF4E siRNA instillation, although all groups reduced photon density compared to the control. These findings suggest that both the mTOR pathway downstream of eIF4E and p70S6K can be successfully inhibited by high dose rapamycin only, and p70S6K and Elf4E dual inhibition is essential to control bladder tumor growth and progression.

P70S6K and Elf4E Dual Inhibition Is Essential to Control Bladder Tumor Growth and Progression in Orthotopic Mouse Non-muscle Invasive Bladder Tumor Model

We investigated how the dual inhibition of the molecular mechanism of the mammalian target of the rapamycin (mTOR) downstreams, P70S6 kinase (P70S6K) and eukaryotic initiation factor 4E (eIF4E), can lead to a suppression of the proliferation and progression of urothelial carcinoma (UC) in an orthotopic mouse non-muscle invasive bladder tumor (NMIBT) model. A KU-7-luc cell intravesically instilled orthotopic mouse NMIBC model was monitored using bioluminescence imaging (BLI) in vivo by interfering with different molecular components using rapamycin and siRNA technology. We then analyzed the effects on molecular activation status, cell growth, proliferation, and progression. A high concentration of rapamycin (10 microM) blocked both P70S6K and elF4E phosphorylation and inhibited cell proliferation in the KU-7-luc cells. It also reduced cell viability and proliferation more than the transfection of siRNA against p70S6K or elF4E. The groups with dual p70S6K and elF4E siRNA, and rapamycin reduced tumor volume and lamina propria invasion more than the groups with p70S6K or elF4E siRNA instillation, although all groups reduced photon density compared to the control. These findings suggest that both the mTOR pathway downstream of eIF4E and p70S6K can be successfully inhibited by high dose rapamycin only, and p70S6K and Elf4E dual inhibition is essential to control bladder tumor growth and progression.

The Internalization of Bacillus Calmette-Guerin (BCG) in Bladder Cancer Cells May be Inhibited by Human beta-defensin 3

PURPOSE: To investigate whether secretion of human beta-defensin 3 (HBD-3) is induced by bacillus Calmette-Guerin (BCG) and to determine whether HBD-3 affects BCG internalization in bladder cancer cells. MATERIALS AND METHODS: RTPCR analysis was used to determine whether HBD-3 mRNA increases after incubation with BCG. HBD-3 proteins in 5637 and T24 human bladder cancer cell lines were assayed by ELISA. The internalization rate was evaluated by double immunofluorescence assay and confocal microscopy to test the optimal dose of HBD-3 for BCG internalization. We also investigated the difference in internalization rates and cell viability between recombinant HBD-3 protein, anti-HBD-3 antibody, and HBD-3 plus anti-HBD-3 antibody pretreatments. RESULTS: BCG induced HBD-3 mRNA expression and HBD-3 production dose and time-dependently in bladder cancer cells and affected BCG internalization. Pretreatment with recombinant HBD-3 protein lowered internalization of BCG dose-dependently. Moreover, anti-HBD-3 antibody prevented the effect of HBD-3 on BCG internalization in bladder cancer cells. The internalization rate of BCG pretreated with anti-HBD-3 antibody was higher than that in the control. The BCG internalization rate in cells pretreated with anti-HBD-3 antibody plus recombinant HBD-3 protein was higher than that in the control. BCG decreased bladder cancer cell viability, and anti-HBD-3 antibody prevented the inhibitory role of HBD-3 on the anti-proliferative effects of M. bovis BCG in bladder cancer cells. CONCLUSIONS: Bladder cancer cells produce HBD-3 when they are infected by BCG to defend themselves against BCG internalization, which plays an important role during the initiation and propagation of the immunotherapeutic response in bladder cancer cells.

Establishment of an Orthotopic Mouse Non-Muscle Invasive Bladder Cancer Model Expressing the Mammalian Target of Rapamycin Signaling Pathway

We established an orthotopic non-muscle invasive bladder cancer (NMIBC) mouse model expressing the mammalian target of the rapamycin (mTOR) signaling pathway. After intravesical instillation of KU-7-lucs (day 0), animals were subsequently monitored by bioluminescence imaging (BLI) on days 4, 7, 14, and 21, and performed histopathological examination. We also validated the orthotopic mouse model expressing the mTOR signaling pathway immunohistochemically. In vitro BLI photon density was correlated with KU-7-luc cell number (r2 = 0.97, P < 0.01) and in vivo BLI photon densities increased steadily with time after intravesical instillation. The tumor take rate was 84.2%, formed initially on day 4 and remained NMIBC up to day 21. T1 photon densities were significantly higher than Ta (P < 0.01), and histological tumor volume was positively correlated with BLI photon density (r2 = 0.87, P < 0.01). The mTOR signaling pathway-related proteins were expressed in the bladder, and were correlated with the western blot results. Our results suggest successful establishment of an orthotopic mouse NMIBC model expressing the mTOR signaling pathway using KU-7-luc cells. This model is expected to be helpful to evaluate preclinical testing of intravesical therapy based on the mTOR signaling pathway against NMIBC.

Erratum: Correction of Acknowledgement. Establishment of an Orthotopic Mouse Non-Muscle Invasive Bladder Cancer Model Expressing the Mammalian Target of Rapamycin Signaling Pathway

We found an error in our published article.

Changes in Sexual Function in Benign Prostatic Hyperplasia Patients Taking Dutasteride: 1-Year Follow-Up Results

PURPOSE: Sexual adverse events (AEs), a major cause for discontinuing 5alpha-reductase inhibitor (5ARI) therapy for benign prostatic hyperplasia (BPH), are known to occur most frequently early in therapy and appear to decline over time. The aim of this study was to investigate the changes in sexual function occurring with dutasteride treatment during a 1-year follow-up period in Korean men. MATERIALS AND METHODS: Using the International Index of Erectile Function, we prospectively evaluated, after 1, 3, 6, 9, and 12 months of treatment, the changes in sexual function of 55 outpatients (mean age 62.3+/-7.2 years) with BPH (mean volume 48.9+/-16.0 g) who had relatively good erectile function (EF) and were treated with dutasteride for at least 1 year. RESULTS: EF scores showed the most significant decrease at 1 month (p<0.01). Function gradually recovered thereafter but was still significantly decreased after 12 months of treatment (p<0.05). The scores for orgasmic function and sexual desire also showed the most significant reduction at 1 month but were restored to the baseline level at 6 months. No significant correlation was observed between changes in sexual function and prostate-specific antigen level, prostate volume, or International Prostate Symptom Scores. CONCLUSIONS: After 1 month of treatment, dutasteride therapy resulted in a significant reduction in all investigated sexual functions. Overall, recovery in sexual function was noted at 3 months, and orgasmic function and sexual desire were restored to baseline levels at 6 months. However, EF was still significantly reduced at 12 months.

Warfarin-Induced Penile Necrosis in a Patient with Heparin-Induced Thrombocytopenia

A 56-yr-old man with lung adenocarcinoma presented with subsegmental pulmonary thrombosis. Platelet count on presentation was 531x10(9)/L. The patient was anticoagulated with subcutaneous low molecular weight heparin (LMWH). Next day, oral anticoagulation was initiated with 5 mg of warfarin once daily with LMWH and LMWH was discontinued at third hospital day. On the third day of oral anticoagulation therapy, he complained of left leg swelling and prolonged painful penile erection of 24 hr-duration. His platelet count reached a nadir 164x10(9)/L at that time, and the patient had a deficiency of protein C and S, with an activity level of 16% and 20% of normal value. Warfarin was stopped and he underwent penile aspiration. The next day, left leg edema and penile erection was disappeared, but penile and glans penis necrosis was started. This case illustrates that processes underlying heparin-induced thrombocytopenia (HIT) may also underlie warfarin-induced skin necrosis.