Real-world experience with 5-aminolevulinic acid for the photodynamic diagnosis of bladder cancer: Diagnostic accuracy and safety

Targeting tumour surface collage with hydrogel probe: a new strategy to enhance intraoperative imaging sensitivity and stability of bladder cancer

PURPOSE

The incomplete resection of non-muscle invasive bladder cancer (NMIBC) augments the risk of disease recurrence. Imaging-guided surgery by molecular probes represents a pivotal strategy for mitigating postoperative recurrence. Traditional optical molecular probes, primarily composed of antibodies/peptides targeting tumour cells and fluorescent groups, are challenged by the high heterogeneity of NMIBC cells, leading to inadequate probe sensitivity. We have developed a collagen-adhesive probe (CA-P) to target the collagen within the tumour microenvironment, aiming to address the issue of insufficient imaging sensitivity.

METHODS

The distribution characteristics of collagen in animal bladder cancer models and human bladder cancer tissues were explored. The synthesis and properties of CA-P were validated. In animal models, the imaging performance of CA-P was tested and compared with our previously reported near-infrared probe PLSWT7-DMI. The clinical translational potential of CA-P was assessed using human ex vivo bladder tissues.

RESULTS

The distribution of collagen on the surface of tumour cells is distinct from its expression in normal urothelium. In vitro studies have demonstrated the ability of the CA-P to undergo a "sol-gel" transition upon interaction with collagen. In animal models and human ex vivo bladder specimens, CA-P exhibits superior imaging performance compared to PLSWT7-DMI. The sensitivity of this probe is 94.1%, with a specificity of 81%.

CONCLUSION

CA-P demonstrates the capability to overcome tumour cell heterogeneity and enhance imaging sensitivity, exhibiting favorable imaging outcomes in preclinical models. These findings provide a theoretical basis for the application of CA-P in intraoperative navigation for NMIBC.

Location-specific diagnostic efficiency of photodynamic diagnosis-guided biopsy in bladder mapping biopsies

BACKGROUND

Photodynamic diagnosis (PDD)-assisted transurethral resection of bladder tumors (TURBT) has emerged as a promising complementary tool to white light (WL) cystoscopy, potentially improving cancer detection and replacing conventional mapping biopsies. This study aimed to investigate the diagnostic accuracy of PDD by anatomical locations in mapping biopsies through lesion-based analysis.

METHODS

PDD and WL findings were prospectively recorded in 102 patients undergoing mapping biopsies and PDD-assisted TURBT using oral 5-aminolevulinic acid. We evaluated 673 specimens collected from flat tumor or normal-looking lesions on WL cystoscopy, after excluding 98 specimens collected from papillary or nodular tumors.

RESULTS

Among the 673 lesions, cancer was detected in 110 (16%) by lesion-based analysis. PDD demonstrated significantly higher sensitivity (65.5% vs. 46.4%, p < 0.001) and negative predictive value (92.5% vs. 89.5%, p < 0.001) compared to WL. The sensitivity of PDD findings varied by location: posterior (100%), right (78.6%), dome (73.3%), left (70.6%), trigone (58.8%), bladder neck (41.7%), anterior (40.0%), and prostatic urethra (25.0%). Incorporating targeted biopsies of specific locations (bladder neck, anterior, and prostatic urethra) into the PDD-guided biopsies, regardless of PDD findings, significantly increased the overall sensitivity from 65.5% to 82.7% (p = 0.001).

CONCLUSIONS

This study first demonstrated the detection rate of location-specific mapping biopsies using PDD, revealing difficulties in accuracy assessment in areas susceptible to tangential fluorescence. While PDD-guided biopsy improves cancer detection compared to WL cystoscopy even for flat tumors or normal-looking lesions, more careful decisions, including mapping biopsies, may be beneficial for an assessment in these tangential areas.

Effect of extending the period from oral administration of 5-aminolevulinic acid hydrochloride to photodynamic diagnosis during transurethral resection for non-muscle invasive bladder cancer on diagnostic accuracy and safety: a single-arm multicenter phase III trial

BACKGROUND

In Japan, the authorized period (2-4 h) between oral administration of 5-aminolevulinic acid hydrochloride (5-ALA) and transurethral resection for non-muscle invasive bladder cancer (NMIBC) may restrict photodynamic diagnosis (PDD) usage. Therefore, this prospective, single-arm, phase III study aimed to evaluate the diagnostic accuracy and safety of PDD at an extended administration period (4-8 h).

METHODS

From January 2022 to May 2023, 161 patients with NMIBC were enrolled from eight hospitals. The primary endpoint was the blue light (BL) sensitivity of pathologically positive biopsies. The secondary endpoints were a comparison of the specificity and positive and negative prediction rates under BL and white light (WL) conditions.

RESULTS

A total of 1242 specimens comprising 337 histological NMIBC specimens were analyzed. BL-sensitivity was 95.3%. Its lower limit of 95% confidence interval (92.4-97.3%) exceeded the threshold (70%) of non-inferiority to authorized usage. Sensitivity and specificity were significantly higher and lower for BL than those for WL (95.3% vs. 61.1%, P < 0.001; 52.7% vs. 95.2%, P < 0.001), respectively. The positive and negative predictive rates were significantly lower and higher for BL than those for WL (42.9% vs. 82.7%, P < 0.001; 96.8% vs. 86.8%, P < 0.001), respectively. Of the 145 patients receiving 5-ALA, 136 (93.8%) and 75 (51.7%) experienced 377 adverse events and 95 adverse reactions, respectively, most of which were grade 1 or 2.

CONCLUSION

For extended period, the efficacy of PDD for NMIBC was similar to that of authorized period, in terms of higher sensitivity and lower specificity compared with WL, and the safety was acceptable.

Full-course NIR-II imaging-navigated fractionated photodynamic therapy of bladder tumours with X-ray-activated nanotransducers

The poor 5-year survival rate for bladder cancers is associated with the lack of efficient diagnostic and treatment techniques. Despite cystoscopy-assisted photomedicine and external radiation being promising modalities to supplement or replace surgery, they remain invasive or fail to provide real-time navigation. Here, we report non-invasive fractionated photodynamic therapy of bladder cancer with full-course real-time near-infrared-II imaging based on engineered X-ray-activated nanotransducers that contain lanthanide-doped nanoscintillators with concurrent emissions in visible and the second near-infrared regions and conjugated photosensitizers. Following intravesical instillation in mice with carcinogen-induced autochthonous bladder tumours, tumour-homing peptide-labelled nanotransducers realize enhanced tumour regression, robust recurrence inhibition, improved survival rates, and restored immune homeostasis under X-ray irradiation with accompanied near-infrared-II imaging. On-demand fractionated photodynamic therapy with customized doses is further achieved based on quantifiable near-infrared-II imaging signal-to-background ratios. Our study presents a promising non-invasive strategy to confront the current bladder cancer dilemma from diagnosis to treatment and prognosis.

Probe-guided endoscopic system for 5-aminolevulinic acid-based photodynamic diagnosis in cholangiocarcinoma

BACKGROUND AND AIM

The diagnostic accuracy for cholangiocarcinoma (CCA) is inadequate, necessitating the exploration of novel diagnostic approaches. Protoporphyrin IX (Pp IX), a metabolic product of 5-aminolevulinic acid (5-ALA), emits red fluorescence upon blue light exposure. Because it accumulates selectively in cancer cells, photodynamic diagnosis using 5-ALA (5-ALA-PDD) has been integrated into clinical practice for diverse cancer types. Nevertheless, there is currently no device capable of capturing Pp IX-derived fluorescence for real-time 5-ALA-PDD within the biliary tract, largely due to challenges in device miniaturization.

METHODS

To investigate the feasibility of real-time 5ALA-PDD in CCA, we developed two essential components of the cholangioscopy system: a small-diameter flexible camera and a light guide for emitting blue light. We evaluated the detectability of Pp IX fluorescence using these devices in experimental gels and animal models.

RESULTS

Our camera and light guide were smoothly inserted into the lumen of existing cholangioscopes. Incorporating a long-pass filter at the camera tip enabled efficient detection of red fluorescence without significantly impacting white-light observation. The integration of these devices facilitated clear visualization of red fluorescence from gels containing Pp IX at concentrations of 5 μM or higher. Additionally, when observing subcutaneous human CCA tumor models in nude mice treated with 5-ALA, we successfully demonstrated distinct red fluorescence from Pp IX accumulation in tumors compared to peritumoral subcutaneous areas.

CONCLUSION

The integration of our device combination holds promise for real-time 5-ALA-PDD in human CCA, potentially enhancing the diagnostic accuracy for this complex condition.

Advanced optical imaging techniques for bladder cancer detection and diagnosis: a systematic review

OBJECTIVES

To systematically assess the current available literature concerning advanced optical imaging methods for the detection and diagnosis of bladder cancer (BCa), focusing particularly on the sensitivity and specificity of these techniques.

METHODS

First a scoping search was performed to identify all available optical techniques for BCa detection and diagnosis. The optical imaging techniques used for detecting BCa are: the Storz professional image enhancement system (IMAGE1 S), narrow-band imaging (NBI), photoacoustic imaging (PAI), autofluorescence imaging (AFI), photodynamic diagnosis (PDD), and scanning fibre endoscopy (SFE). The staging and grading techniques for BCa are: optical coherence tomography (OCT), confocal laser endomicroscopy (CLE), Raman spectroscopy, endocytoscopy, and non-linear optical microscopy (NLO). Then a systematic literature search was conducted using MEDLINE, EMBASE and Web of Science from inception to 21 November 2023. Articles were screened and selected by two independent reviewers. Inclusion criteria were: reporting on both the sensitivity and specificity of a particular technique and comparison to histopathology, and in the case of a detection technique comparison to white light cystoscopy (WLC).

RESULTS

Out of 6707 articles, 189 underwent full-text review, resulting in 52 inclusions. No articles met criteria for IMAGE1 S, PAI, SFE, Raman spectroscopy, and endocytoscopy. All detection techniques showed higher sensitivity than WLC, with NBI leading (87.8-100%). Overall, detection technique specificity was comparable to WLC, with PDD being most specific (23.3-100%). CLE and OCT varied in sensitivity and specificity, with OCT showing higher specificity for BCa diagnosis, notably for carcinoma in situ (97-99%) compared to CLE (62.5-81.3%). NLO demonstrated high sensitivity and specificity (90-97% and 77-100%, respectively) based on limited data from two small ex vivo studies.

CONCLUSIONS

Optical techniques with the most potential are PDD for detecting and OCT for staging and grading BCa. Further research is crucial to validate their integration into routine practice and explore the value of other imaging techniques.

Photodynamic Diagnosis and Therapy in Non-Muscle-Invasive Bladder Cancer

Bladder cancer (BC) possesses distinct molecular profiles that influence progression depending on its biological nature and delivered treatment intensity. Muscle-invasive BC (MIBC) and non-MIBC (NMIBC) demonstrate great intrinsic heterogeneity regarding different prognoses, survival, progression, and treatment outcomes. Transurethral resection of bladder tumor (TURBT) is the standard of care in treating NMIBC and serves both diagnostic and therapeutic purposes despite the prevalent recurrence and progression among many patients. In particular, flat urothelial carcinoma in situ and urothelial carcinoma with lamina propria invasion are the major precursors of MIBC. A new-generation photosensitizer, 5-Aminolevulinic acid (5-ALA), demonstrates high tumor specificity by illuminating the tumor lesion with a specific wavelength of light to produce fluorescence and has been studied for photodynamic diagnosis to detect precise tumor areas by TURBT. Additionally, it has been applied for treatment by producing its cytotoxic reactive oxygen species, as well as screening for urological carcinomas by excreting porphyrin in the blood and urine. Moreover, 5-ALA may contribute to screening before and after TURBT in NMIBC. Here, we summarize the updated evidence and ongoing research on photodynamic technology for NMIBC, providing insight into the potential for improving patient outcomes.

Incidence and predictors of intraoperative hypotension during transurethral bladder tumor resection with oral 5-aminolevulinic acid

OBJECTIVES

To analyze the incidence and risk factors of intraoperative hypotension related to photodynamic diagnosis-assisted transurethral resection of bladder tumor (PDD-TURBT) with oral 5-aminolevulinic acid (5-ALA).

METHODS

We retrospectively analyzed 487 patients with bladder tumors who underwent PDD-TURBT (n = 184) or conventional TURBT (conv-TURBT) (n = 303) between 2018 and 2021. Intraoperative hypotension was defined as hypotension requiring vasopressors during TURBT, and its incidence was compared between the two groups. Potential risk factors of intraoperative hypotension, including preoperative change in mean arterial pressure (MAP), were further investigated in patients receiving PDD-TURBT.

RESULTS

The median age was 72 years, 392 patients (81%) were male, and 203 (42%) had hypertension. TURBT was performed under general and spinal anesthesia in 76 (16%) and 411 (84%) patients, respectively. The incidence of intraoperative hypotension was significantly higher in PDD-TURBT compared to conv-TURBT (43% vs. 17%, respectively). The median change in MAP until the induction of anesthesia was +6.5 mmHg (range: -29.0 to +46.3) in the PDD-TURBT group and +14.7 mmHg (range: -35.3 to +67.7) in the conv-TURBT group, showing a significantly smaller increase in the PDD-TURBT group (p < 0.001). In the multivariable analysis for PDD-TURBT patients, advanced age, general anesthesia, and lower MAP change (<+6.5 mmHg) until anesthesia induction were significantly associated with intraoperative hypotension (p = 0.0104, <0.001, and <0.001, respectively).

CONCLUSIONS

Intraoperative hypotension occurred more frequently in patients who underwent PDD-TURBT than in those who underwent conv-TURBT. Using oral 5-ALA decreases preoperative blood pressure elevation and may be responsible for intraoperative hypotension.

Real-world experience with 5-aminolevulinic acid for photodynamic diagnosis of bladder cancer (3rd report): Cost impact of transurethral resection of bladder tumor in Japan

BACKGROUND

Photodynamic diagnosis-assisted transurethral resection of bladder tumor (PDD-TURBT) showed improvement of diagnostic accuracy and treatment efficacy compared to white light TURBT (WL-TURBT). While PDD-TURBT is highly effective, PDD-TURBT requires the use of PDD device and light-sensitive substance precursor, which increases the medical cost compared to WL-TURBT. In this study, the impact on health care economic costs were examined between PDD-TURBT and WL-TURBT.

METHODS

Of the total 265 patients, 88 patients for WL-TURBT and 105 patients for PDD-TURBT were available for analysis. Costs were also examined between 34 patients without false-positives and 36 patients with false-positives with a follow-up period of at least 200 days. To compare costs between the two treatments, we calculated the cost/person/year of TURBT using Japanese Diagnosis Procedure Combination and Per-Diem Payment System (DPC/PDPS).

RESULTS

The total number of surgeries including the first TURBT was 135 (47 recurrences) in the WL-TURBT group and 133 (28 recurrences) in the PDD-TURBT group. The cost per person for hospitalization and surgery was 366,310 Japanese yen (JPY) for the WL-TURBT and 501,930 JPY for the PDD-TURBT. The cost per person per year was 491,622 JPY in the WL-TURBT group and 506,405 JPY in the PDD-TURBT group. Regarding false-positives, the cost per person per year was 494,544 JPY in the group without false-positives and 328,086 JPY in the group with false-positives.

CONCLUSIONS

Although PDD-TURBT is cost more than WL-TURBT for one surgical hospitalization, the cost per person per year for PDD-TURBT and WL-TURBT is cost-neutral.

Transurethral resection of bladder cancer with or without fluorescence

PURPOSE OF REVIEW

Transurethral resection of bladder cancer (TURBT) is in its standard form an inherently imperfect technique. Fluorescence-guided photodynamic diagnosis (PDD) represents one way to improve the outcome by enhancing tumour detection. Fluorescence has been used in connection with bladder cancer since the 1970s, with a number of studies being published since then. However, the method is still not recommended as a standard part of TURBT mainly because of the limited level of evidence of concerned studies, questionable cost-effectiveness and even contradictory results. The review lists the latest articles covering this topic.

RECENT FINDINGS

Several recently published meta-analyses reviewed a series of randomized controlled trials (RCTs) concerning PDD assisted TURBT. Results were generally supporting the positive effect on reduction of recurrence rate. However, the mentioned meta-analyses are overlapping in terms of reviewed RCT that provide only a low level of evidence according to a recent Cochrane review. Supposed limitations of PDD (timing of the procedure, low specificity) and possible solutions are also covered.

SUMMARY

Most of the published data confirmed reduced early recurrence rate after PDD assisted TURBT comparing to standard TURBT. Its impact on late recurrence rate, progression rate or cost-effectiveness has not been sufficiently demonstrated.

Emerging photodynamic/sonodynamic therapies for urological cancers: progress and challenges

Photodynamic therapy (PDT), and sonodynamic therapy (SDT) that developed from PDT, have been studied for decades to treat solid tumors. Compared with other deep tumors, the accessibility of urological tumors (e.g., bladder tumor and prostate tumor) makes them more suitable for PDT/SDT that requires exogenous stimulation. Due to the introduction of nanobiotechnology, emerging photo/sonosensitizers modified with different functional components and improved physicochemical properties have many outstanding advantages in cancer treatment compared with traditional photo/sonosensitizers, such as alleviating hypoxia to improve quantum yield, passive/active tumor targeting to increase drug accumulation, and combination with other therapeutic modalities (e.g., chemotherapy, immunotherapy and targeted therapy) to achieve synergistic therapy. As WST11 (TOOKAD® soluble) is currently clinically approved for the treatment of prostate cancer, emerging photo/sonosensitizers have great potential for clinical translation, which requires multidisciplinary participation and extensive clinical trials. Herein, the latest research advances of newly developed photo/sonosensitizers for the treatment of urological cancers, and the efficacy, as well as potential biological effects, are highlighted. In addition, the clinical status of PDT/SDT for urological cancers is presented, and the optimization of the photo/sonosensitizer development procedure for clinical translation is discussed.

Compact Smartphone-Based Laser Speckle Contrast Imaging Endoscope Device for Point-of-Care Blood Flow Monitoring

Laser speckle contrast imaging (LSCI) is a powerful visualization tool for quantifying blood flow in tissues, providing simplicity of configuration, ease of use, and intuitive results. With recent advancements, smartphone and camera technologies are suitable for the development of smartphone-based LSCI applications for point-of-care (POC) diagnosis. A smartphone-based portable LSCI endoscope system was validated for POC diagnosis of vascular disorders. The endoscope consisted of compact LED and laser illumination, imaging optics, and a flexible fiberscope assembled in a 3D-printed hand-held cartridge for access to body cavities and organs. A smartphone’s rear camera was mounted thereto, enabling endoscopy, LSCI image acquisition, and processing. Blood flow imaging was calibrated in a perfused tissue phantom consisting of a microparticle solution pumped at known rates through tissue-mimicking gel and validated in a live rat model of BBN-induced bladder cancer. Raw LSCI images successfully visualized phantom flow: speckle flow index showed linearity with the pump flow rate. In the rat model, healthy and cancerous bladders were distinguishable in structure and vasculature. The smartphone-based low-cost portable mobile endoscope for monitoring blood flow and perfusion shows promise for preclinical applications and may be suitable for primary diagnosis at home or as a cost-effective POC testing assay.

Comparison between 5-aminolevulinic acid photodynamic diagnosis and narrow-band imaging for bladder cancer detection

BACKGROUND

To compare 5-aminolevulinic acid (5-ALA)-mediated photodynamic diagnosis (PDD) with narrow-band imaging (NBI) for cancer detection during transurethral resection of bladder tumour (TURBT).

METHODS

Between June 2018 and October 2020, 114 patients and 282 lesions were included in the analysis. Patients were orally administered 5-ALA (20 mg/kg) 2 h before TURBT. The bladder was inspected with white light (WL), PDD, and NBI for each patient, and all areas positive by at least one method were resected or biopsied. The imaging data were then compared to the pathology results.

RESULTS

The sensitivities of WL, PDD, and NBI for detecting urothelial carcinoma were 88.1%, 89.6%, and 76.2%, respectively. The specificity, positive predictive value, and negative predictive value for detecting urothelial carcinoma were 47.5%, 80.9%, and 61.3%, respectively, for WL; 22.5%, 74.5%, and 46.2%, respectively, for PDD; and 46.3%, 78.2%, and 43.5%, respectively, for NBI. PDD was significantly more sensitive than NBI for all lesions (p < 0.001) and carcinoma in situ (CIS) lesions (94.6% vs. 54.1%, p < 0.001).

CONCLUSIONS

PDD can increase the detection rate of bladder cancer, compared to NBI, by greater than 10%. Therefore, 100% of CIS lesions can be detected by adding PDD to WL.

Differences in 5-Aminolevulinic Acid-Induced Hemodynamic Changes between Patients Undergoing Neurosurgery and Urological Surgery

Introduction:

Oral 5-aminolevulinic acid (5-ALA) is often used for photodynamic diagnosis-assisted glioma or bladder tumor surgery. 5-ALA affects blood pressure (BP). In fact, hypotension is a well-known adverse effect of 5-ALA in urology. However, information regarding 5-ALA-induced hemodynamic changes in neurosurgery remains limited. Furthermore, the duration of hypotension and how 5-ALA affects the heart rate (HR) are yet to be determined. Thus, in this study, we aimed to elucidate 5-ALA-induced perioperative hemodynamic changes in neurosurgery and urological surgery by examining real-world data.

Methods:

Consecutive patients who underwent neurosurgery (neurosurgery patients; 5-ALA-pretreated vs. non-pretreated [17 vs. 16], from January 2014 to March 2021) and urological surgery (urological surgery patients; 5-ALA-pretreated vs. non-pretreated [26 vs. 101], from August 2018 to September 2020) were enrolled. Differences in hemodynamics were evaluated using the linear mixed model. BP and HR in 5-ALA-pretreated patients were compared with those in non-pretreated patients. Differences in 5-ALA-induced preoperative BP changes were compared between the neurosurgery patients and urological surgery patients.

Results:

5-ALA scarcely affected the hemodynamics in neurosurgery patients, whereas 5-ALA-induced hemodynamic changes were clearly observed in urological surgery patients. Hemodynamic parameters were found to be not significantly different between 5-ALA-pretreated and non-pretreated neurosurgery patients. The preoperative, intraoperative, and postoperative BP in 5-ALA-pretreated urological surgery patients were significantly lower than those in the non-pretreated patients. Preoperatively, two 5-ALA-pretreated urological surgery patients had severe postural hypotension (systolic BP <50 mmHg), and one of them did not continue with the surgery because of prolonged severe hypotension. The BP in 5-ALA-pretreated urological surgery patients tended to be persistently lower for 9 h after 5-ALA pretreatment. The preoperative and postoperative HR values were higher in 5-ALA-pretreated urological surgery patients. Cumulative incidences of BP reduction and HR elevation were significantly higher in 5-ALA-pretreated urological surgery patients. The preoperative BP reduction in 5-ALA-pretreated urological surgery patients was significantly larger than that in neurosurgery patients.

Conclusions:

5-ALA-induced hemodynamics may differ between neurosurgery patients and urological surgery patients. 5-ALA may affect BP for at least 9 h.

Accumulation of Uroporphyrin I in Necrotic Tissues of Squamous Cell Carcinoma after Administration of 5-Aminolevulinic Acid

5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) fluorescence is widely used for the intraoperative detection of malignant tumors. However, the fluorescence emission profiles of the accompanying necrotic regions of these tumors have yet to be determined. To address this, we performed fluorescence and high-performance liquid chromatography (HPLC) analyses of necrotic tissues of squamous cancer after 5-ALA administration. In resected human lymph nodes of metastatic squamous cell carcinoma, we found a fluorescence peak at approximately 620 nm in necrotic lesions, which was distinct from the PpIX fluorescence peak at 635 nm for viable cancer lesions. Necrotic lesions obtained from a subcutaneous xenograft model of human B88 oral squamous cancer also emitted the characteristic fluorescence peak at 620 nm after light irradiation: the fluorescence intensity ratio (620 nm/635 nm) increased with the energy of the irradiation light. HPLC analysis revealed a high content ratio of uroporphyrin I (UPI)/total porphyrins in the necrotic cores of murine tumors, indicating that UPI is responsible for the 620 nm peak. UPI accumulation in necrotic tissues after 5-ALA administration was possibly due to the failure of the heme biosynthetic pathway. Taken together, fluorescence imaging of UPI after 5-ALA administration may be applicable for the evaluation of tumor necrosis.

Glypican-1 as a target for fluorescence molecular imaging of bladder cancer

OBJECTIVES

To investigate whether anti-glypican-1 antibody Miltuximab conjugated with near-infrared dye IRDye800CW can be used for in vivo fluorescence imaging of urothelial carcinoma.

METHODS

The conjugate, Miltuximab-IRDye800CW, was produced and characterized by size exclusion chromatography and flow cytometry with glypican-1-expressing cells. Balb/c nude mice bearing subcutaneous urothelial carcinoma xenografts were intravenously injected with Miltuximab-IRDye800CW or control IgG-IRDye800CW and imaged daily by fluorescence imaging. After 10 days, tumors and major organs were collected for ex vivo study of the conjugate biodistribution, including its accumulation in the tumor.

RESULTS

The intravenous injection of Miltuximab-IRDye800CW to tumor-bearing mice showed its specific accumulation in the tumors with the tumor-to-background ratio of 12.7 ± 2.4, which was significantly higher than that in the control group (4.6 ± 0.9, P < 0.005). The ex vivo imaging was consistent with the in vivo findings, with tumors from the mice injected with Miltuximab-IRDye800CW being significantly brighter than the organs or the control tumors.

CONCLUSIONS

The highly specific accumulation and retention of Miltuximab-IRDye800CW in glypican-1-expressing tumors in vivo shows its high potential for fluorescence imaging of urothelial carcinoma and warrants its further investigation toward clinical translation.

Efficiency of aminolevulinic acid (ALA)-photodynamic therapy based on ALA uptake transporters in a cell density-dependent malignancy model

The effectiveness of the conventional chemotherapy for cancer are compromised as the cancer cells advances in their malignancy level as they acquired drug resistance. In this study, we aimed to evaluate the efficiency of aminolevulinic acid-photodynamic therapy (ALA-PDT) against cancer of various malignancy levels, indicated by the expression level of receptor associated nuclear factor-κB ligand (RANKL), through the expression levels of ALA uptake transporters. We established a malignancy model by gradually increasing the cell density of cancer cells. Western blotting was used to study the expression levels of RANKL, ALA uptake transporters and the cell density-dependent Yes-associated protein (YAP) under different cell densities. The amount of protoporphyrin (PpIX) produced and cell viability were then studied using high performance liquid chromatography (HPLC) and ALA-PDT assay. Our study showed that the amount of PpIX production doubled in high cell density/cancer malignancy cultures and the effectiveness of ALA-PDT when subjected to light irradiation at 635 nm are significantly at higher cancer malignancy. We observed that the expression levels of ALA uptake transporters and YAP correlated with higher cell density/cancer malignancy, suggesting a possible relationship among these three factors. These findings suggest that ALA-PDT is more effective in cancer cells of higher malignancy due to the upregulation of transporters involved in ALA uptake.

The sustaining of fluorescence in photodynamic diagnosis after the administration of 5-aminolevulinic acid in carcinogen-induced bladder cancer orthotopic rat model and urothelial cancer cell lines

BACKGROUND

The administration of 5-aminolevulic acid hydrochloride (5-ALA·HCl) 3 h (range: 2-4 h) before photodynamic diagnosis (PDD) is recommended for detecting bladder tumors. However, there is insufficient evidence on the time duration for the fluorescence of PDD after oral administration of 5-ALA. We investigated the sustainability of the photodynamic effect and protoporphyrinⅨ (PpⅨ) after 5-ALA administration in a carcinogen-induced bladder tumor rat model and bladder cancer cell lines.

METHODS

The carcinogen-induced bladder tumor orthotopic rat model was established by the administration of N-butyl-N-(4-hydroxybutyl) nitrosamine.

RESULTS

Red fluorescence was visible 2-8 h after the oral administration of 5-ALA in the carcinogen-induced bladder tumor rat model. Plasma and intratissue PpⅨ (nM) progressed to a higher level at 2 h and remained almost constant 2-8 h after oral administration of 5-ALA. The peak fluorescence intensity of PpⅨ was observed 3-4 h after the administration of 5-ALA in bladder cancer cell lines. The accumulated PpⅨ remained for 4 h after the removal of 5-ALA in UMUC3 cells. It was not clearly visible 3 h after the removal of 5-ALA in MGHU3 and T24 cells. The expression level of ferrochelatase was significantly lower in UMUC3 cells than in other cells. Our findings suggest that 5-ALA-assisted PDD (ALA-PDD) can aid in detecting non-muscle-invasive bladder cancer 2-8 h after 5-ALA administration.

CONCLUSION

Urologists might not be required to make excess effort to start ALA-PDD-assisted transurethral resection of bladder tumor after the administration of 5-ALA.