Urothelial Research Articles

Cell Line-Based Human Bladder Organoids with Bladder-like Self-Organization-A New Standardized Approach in Bladder Cancer Research.

Three-dimensional tumor models have gained significant importance in bladder cancer (BCa) research. Organoids consisting of different cell types better mimic solid tumors in terms of 3D architecture, proliferation, cell-cell interaction and drug responses. We developed four organoids from human BCa cell lines with fibroblasts and smooth muscle cells of the bladder, aiming to find models for BCa research. The organoids were characterized in terms of cytokeratins, vimentin, α-actin and KI67 by immunoreactivity. Further, we studied ligand-dependent activation of the Wnt/β-catenin pathway and investigated the responses to anti-tumor therapies. The organoids mimicked the structure of an inverse bladder wall, with outside urothelial cells and a core of supportive cells. The cytokeratin staining patterns and proliferation rate were in conjunction with the origins of the BCa cells. RT-112 even showed stratification of the epithelium. Treatment with Wnt10B led to increased β-catenin (active) levels in high-grade organoids, but not in low-grade BCa cells. Doxorubicin treatment resulted in clearly reduced viability (10-30% vs. untreated). In contrast, the effectivity of radiotherapy depended on the proliferation status of BCa cells. In conclusion, cell-line-based organoids can form bladder-like structures and reproduce in vivo features such as urothelial differentiation and stratification. Thus, they can be useful tools for functional studies in BCa and anti-cancer drug development.

The Relationship Between PD-1(rs2227981) and PD-L1(rs2890658) Polymorphisms and Urothelial Cell Carcinoma.

Background Urothelial cell carcinoma, which is believed to develop from the urothelium (transitional epithelium), is the most common aggressive tumor and accounts for the ten most prevalent cancers in the world. The risk factors for urothelial cell carcinoma are aging, smoking, gender, and genetic alternations. Programmed cell death1 (PD-1) has been widely described as a negative regulator of T-cells by sending inhibitory signals to the T-cell. Through PD-1 binding with PD-L1 (ligand for PD-1), an inhibitory signal is propagated to the T cell. The polymorphisms of PD-1 and PD-L1 lead to an efficient T-cell response and affect an anti-tumor reaction. The polymorphisms of PD-1 and PD-L1 could also affect the carcinogenesis of human cancer, including urothelial cell carcinoma. Therefore, in this study, we evaluated the relation between PD-1(rs2227981) and PD-L1(rs2890658) polymorphisms and the carcinogenesis of urothelial cell carcinoma. Materials and methods This study was conducted using 211 healthy controls and 256 cases of urothelial cell carcinoma among the Japanese population. The DNA samples were extracted from the peripheral white blood cells of each subject. The genotype was detected by using the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method. Results C/T (Adjusted OR 1.55, 95% CI:1.02-2.35) and C/T+T/T (OR 1.46, 95% CI:1.01-2.12) genotypes of PD-1 rs2227981 were significant and risk factors for urothelial cancer.Male with A/A genotype in PD-L1 and CT genotype in PD-1 has a significant higher risk factor compared with other genotypes (Adjusted OR 1.83, 95% CI:1.05-3.21). Conclusions and discussion We found that C/T(PD-1) and "A/A (PD-L1) and C/T(PD-1)" were predominant in urothelial cell carcinoma cases. This indicates that C/T(PD-1) and "A/A (PD-L1) and C/T(PD-1)" genotypes could increase susceptibility to urothelial cell carcinoma. However, since our findings indicated that the effects of PD-1 and PD-L1 polymorphisms included discrepancies, additional research will be needed to evaluate the relationship between human cancer and PD-1 and PD-L1 polymorphisms. This is the first study that seeks to find the relation between PD-1(rs2227981) and PD-L1(rs2890658) polymorphisms concerning urothelial cell carcinoma among the Japanese population.

The PI3K-AKT-mTOR signaling pathway mediates the cytoskeletal remodeling and epithelial-mesenchymal transition in bladder outlet obstruction

ObjectivePartial bladder outlet obstruction(pBOO) is the most common cause of lower urinary tract symptoms (LUTS) and significantly affects the quality of life. Long-term pBOO can cause changes in bladder structure and function, referred to as bladder remodeling. The pathogenesis of pBOO-induced bladder remodeling has yet to be fully understood, so effective treatment options are lacking. Our study aimed to explore how pBOO-induced bladder remodeling brings new strategies for treating pBOO. MethodsA rat model of pBOO was established by partial ligation of the bladder neck, and the morphological changes and fibrosis changes in the bladder tissues were detected by H&E and Masson trichrome staining. Furthermore, EMT(epithelial-mesenchymal transition) related indicators and related pathway changes were further examined after TGF- β treatment of urothelial cells SV-HUC-1. Finally, the above indicators were tested again after using the PI3K inhibitor. Subsequently, RNA sequencing of bladder tissues to identify differential genes and related pathways enrichment and validated by immunofluorescence and western blotting analysis. ResultsThe pBOO animal model was successfully established by partially ligating the bladder neck. H&E staining showed significant changes in the bladder structure, and Masson trichrome staining showed significantly increased collagen fibers. RNA sequencing results significantly enriched in the cytoskeleton, epithelial-mesenchymal transformation, and the PI3K-AKT-mTOR signaling pathway. Immunofluorescence and western blotting revealed EMT and cytoskeletal remodeling in SV-HUC-1 cells after induction of TGF- β and in the pBOO bladder tissues. The western blotting showed significant activation of the PI3K-AKT-mTOR signaling pathway in SV-HUC-1 cells after induction of TGF-β and in pBOO bladder tissues. Furthermore, EMT and cytoskeletal damage were partially reversed after PI3K pathway inhibition using PI3K inhibitors. ConclusionsIn the pBOO rat model, the activation of the PI3K-AKT-mTOR signaling pathway can mediate the cytoskeletal remodeling and the EMT to induce fibrosis in the bladder tissues. PI3K inhibitors partially reversed EMT and cytoskeletal damage.

Unexpected Discoveries: Uncovering Incidental Tumors in Simple Nephrectomy Specimens

ObjectivesWe aimed to evaluate the characteristics of patients with incidental kidney tumors detected in the pathological examination performed after simple nephrectomy due to a non-functioning kidney. Patients and methodsThe pathology results of nephrectomy specimens from patients who underwent simple nephrectomy with the diagnosis of non-functioning kidney between January 2012 and March 2021 were retrospectively analyzed. Data regarding demographic information, imaging methods, and clinical and histopathological features of the patients were collected. The number of patients with incidental renal tumors was determined. ResultsA total of 163 patients with nonfunctioning kidneys who underwent simple nephrectomy between January 2012 and March 2021 were included in the study. Sixty-nine (42.3%) patients were male and 94 (57.7%) patients were female. The most common complaint was flank pain (60.7%). The cause of the nonfunctioning kidney was urinary stones in 116 (71.2%) patients and ureteropelvic/ureterovesical junction stenosis in 21 (10.1%) patients. Incidental renal tumors were detected in 21 (12.9%) patients. Papillary adenoma was the most common renal tumor and was detected in 11 patients. Four patients had renal cell carcinoma and 4 patients had urothelial cell carcinoma (UCC). Three of the patients with UCC had high grade invasive UCC with squamous differentiation and 1 patient had low grade papillary UCC. ConclusionIn non-functioning kidneys, kidney tumors may be overlooked due to radiological and clinical diagnostic difficulties. Therefore, careful macroscopic and microscopic histopathological evaluation is necessary to detect incidental renal tumors.

Enhancing tumour content and tumour cell count using microdissection contributes to higher detection rate of genetic mutations by next-generation sequencers

BackgroundNext-generation sequencing (NGS) analysis is becoming indispensable for the treatment of advanced lung cancer. NGS analysis requires a large number of cancer cell-containing tissues; however, it is often difficult for small biopsies to obtain the required quantities. In microdissection, only the tumour parts of a tissue specimen are obtained, which thereby increases the tumour content and tumour cell count of the tissue specimen. In this study, we investigated the extent to which the detection rate of genetic mutations changes by increasing the tumour content using microdissection. Patients and methodsThis is a retrospective study. In the genetic panel test using the Oncomine Dx Target Test (ODxTT), participants were divided into two groups: before (group A; April 2021–March 2022) and after (group B; April 2022–December 2022) the introduction of microdissection. The submission criteria for ODxTT were tumour content and tumour cell count >30 % and >2000 in group A, and >40 % and >5000 in group B, respectively. We compared the rate of genetic mutations detected using ODxTT between the two groups. ResultsThis study included 214 consecutive ODxTT cases between April 2021 and December 2022. In group A (n = 112), 65 cases were adenocarcinoma, 84 involved lung tissue, and 64 underwent bronchoscopic sampling, whereas in group B (n = 102), 55 cases were adenocarcinoma, 91 cases involved lung tissue, and 79 cases underwent bronchoscopic sampling. Furthermore, genetic mutations were detected in 39 of 112 cases (35 %) in group A and 59 of 102 cases (58 %) in group B, which was statistically higher in group B (P = 0.0006). Genetic mutations were detected in 45 of 55 adenocarcinoma cases in group B. The genetic mutations detected in epidermal growth factor rescepor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS), and mesenchymal epithelial transition (MET) were higher in group B. ConclusionIncreasing the number of tumour cells and tumour content can enhance the detection rate of genetic mutations using ODxTT.

Stem Cells In Urology: A Promising Development For The Treatment Of Urological Disorders.

Madam, It was fascinating to read the latest research published in the Journal of Pakistan Medical Association (JPMA) on the utilisation of stem cells in urology. The study had some amazing findings, and I believe it has the power to revolutionise the treatment of urological disorders.1 Recent advances in stem cell research have opened new possibilities for treating various urological conditions. For example, findings have shown that stem cells can be used to promote tissue regeneration and repair in patients with urinary incontinence or erectile dysfunction.2 Additionally, stem cells can regenerate damaged renal tissue, offering the latest treatment options for patients with kidney disease.4 Apromising area of research includes use of mesenchymal stem cells (MSCs) to treat urological conditions. MSCs are multipotent cells that can specify into various cell types, including muscles, bones, and cartilage. They have been shown to up level the symptoms and improve quality of life in patients with urinary incontinence,They may also be very effective in treating a variety of urological conditions.2 One more area of research entails the use of induced pluripotent stem cells (iPSCs) in urology. iPSCs are reprogrammed from adult cells, like skin cells, into an embryonic-like state. They are differentiated into various cell types, making them a potentially important tool for regenerative medicine. Research has shown that iPSCs can be used to produce functional urothelial cells, which line the urinary tract and play a major role in bladder function.5 Overall, stem cell research in urology is a developing area that shows promise. It offers new treatment varieties for patients with urological conditions and has the potential to improve their quality of life. I strongly believe that this research will be of great interest to clinicians and researchers in this urology field, and I look forward to seeing further more developments in this exciting area of medicine. It is also important to note that further research is strongly needed to fully explore the potential of stem cells in urology. This includes examining the long-term safety standards and efficacy of stem cell therapy, as well as identifying the optimal stem cell sources and delivery methods for variety of urological conditions. I strongly believe that ongoing research will continue to shed light on these important questions.

Study on arsenic speciation, bioaccessibility, and gut microbiota in realgar-containing medicines by DGT technique and artificial gastrointestinal extraction (PBET) combine with simulated human intestinal microbial ecosystem (SHIME)

It is well-known that several Chinese patent medicines use realgar as a specific component. People are more aware of the health dangers associated with realgar since it includes arsenic. Previous research overstated the arsenic toxicity of realgar-containing Chinese prescription medications because little thought was given to the influence of arsenic bioaccessibility by gut microbiota. In light of this, this study examined the total content, bioaccessibility and speciation of targeted medications while also examining intestinal epithelial transit utilizing the diffusive gradients in thin-films (DGT). All samples contained arsenic, and the bioaccessibilities of the colon, intestine and gastric regions ranged from 0.19% to 1.73%, 0.25–1.88% and 0.21–1.70% respectively. The range of DGT-bioaccessibility is 0.01–0.0018%. Three steps of analysis were conducted on inorganic As(III) and As(V). In health risk assessment, the ADDs and HQs of DGT-bioaccessibility were below the threshold levels when compared to computing average daily intake dose (ADD) and hazard quotient (HQ) by bioaccessibility of gastric, intestinal and colon. Additionally, Proteobacteria and Firmicutes were discovered to be the two predominant kinds of gut microbes in this study. Under arsenic exposure, the abundance of Christensenellaceae, Desulfovibrionaceae and Akkermansiaceae increased, but the quantity of Rikenellaceae decreased. These findings revealed that alterations in gut microbiota had an impact on host metabolism.

Immunohistochemical expression of TROP‑2 (TACSTD2) on the urothelial carcinoma of the urinary bladder and other types of cancer.

In metastatic or locally advanced urothelial carcinoma (UC), therapeutic options have been limited to chemotherapy and immune checkpoint inhibitors. Novel targets and drugs such as antibody drug conjugates have been developed, and enfortumab vedotin targeting nectin-4 and sacituzumab govitecan (SG) targeting trophoblast cell surface antigen 2 (TROP-2), the protein product of the TACSTD2 gene, have been approved. The expression of TROP-2 was investigated within UC and other types of carcinomas, and within the tissue of different healthy organs to understand treatment responses and toxicities. The expression of TROP-2 in the tissues of 42 patients with UC, 13 patients with other types of cancer and in the normal tissues of 11 patients was retrospectively analyzed. Immunohistochemical staining of the TROP-2 protein was performed on a BenchMark ULTRA IHC/ISH System (Roche Tissue Diagnostics; Roche Diagnostics, Ltd.) according to accredited staining protocols in a routine immunohistochemistry accredited and certified facility of the laboratory of immunohistochemistry at the Institute of Pathology (Gerhard-Domagk Institute)- University Hospital Muenster (UKM)-Muenster-Germany]. Different expression levels of TROP-2 were observed, and the highest expression rate of TROP-2 was observed in UC, independent of the tumor stage. However, normal urothelial cells had similar expression levels. Except for ductal carcinoma in situ, the expression of TROP-2 was reduced in other types of cancer and in the healthy tissues from other organs, including pancreas, gall bladder, colon and prostate. Given the treatment response based on the expression level of TROP-2, SG would be effective in almost all cases of UC. However, it would also have an effect on the normal urothelium.

PD-L1 (CD274) promoter hypomethylation predicts immunotherapy response in metastatic urothelial carcinoma

ABSTRACT PD-L1 status assessed by immunohistochemistry (IHC) has failed to reliably predict outcomes for patients with metastatic urothelial carcinoma (mUC) on immune checkpoint blockade (ICB). PD-L1 promoter methylation is an epigenetic mechanism that has been shown to regulate PD-L1 mRNA expression in various malignancies. The aim of our present study was to evaluate the predictive potential of PD-L1 promoter methylation status (mPD-L1) in ICB-treated mUC compared to conventional IHC-based PD-L1 assessment. We quantified mPD-L1 in formalin-fixed and paraffin-embedded tissue sections using an established quantitative methylation-specific PCR assay (qMSP) in a well-characterized multicenter ICB-treated cohort comprising N = 107 patients with mUC. Additionally, PD-L1 protein expression in tumor tissues was assessed using regulatory approved IHC protocols. The effect of pharmacological hypomethylation by the DNA methyltransferase inhibitor decitabine in combination with interferon-γ stimulation in urothelial carcinoma cell lines was investigated by IHC and FACS. mPD-L1 hypomethylation predicted objective response rate at the first staging on ICB. Patients with tumors categorized as PD-L1 hypomethylated (lower quartile) showed significantly prolonged progression-free (PFS) and overall survival (OS) after ICB initiation. In contrast, PD-L1 protein expression status neither correlated with response nor survival. In multivariable Cox regression analyses, PD-L1 promoter hypermethylation remained an independent predictor of unfavorable PFS and OS. In urothelial carcinoma cell lines, pharmacological demethylation led to an upregulation of membranous PD-L1 expression and an enhanced inducibility of PD-L1 expression by interferon γ. Hypomethylation of the PD-L1 promoter is a promising predictive biomarker for response to ICB in patients with mUC.

The First Ever Robotic-Assisted Laparoscopic Radical Nephrectomy with Inferior Vena Cava Thrombectomy Performed in Thailand: A Case Report of Atypical Presentation of Urothelial Carcinoma with Tumor Thrombus

Background: Robotic-assisted surgery was proposed as an alternative to open surgery for management of inferior vena cava (IVC) thrombus together with radical nephrectomy in complex renal mass. Here, the authors reported the first case of this type to be managed via this surgical technique in Thailand. Case Report: A 76-year-old Thai female presented with right renal mass with tumor thrombus in the IVC extending 3 cm above the level of the renal vein. The presumed diagnosis was renal cell carcinoma of the right kidney with level 2 tumor thrombus in IVC, clinical staging T3bN0M0. The patient underwent robotic-assisted laparoscopic IVC thrombectomy together with right radical nephrectomy at Siriraj Hospital (Bangkok, Thailand) in May 2020. Results: The operation proceeded uneventfully without immediate complication. The postoperative reduction of IVC diameter was approximately 30%. Total IVC clamp time was 50 minutes, operative time was five hours, with docking time of 20 minutes and console time of 250 minutes, estimated intraoperative blood loss was 2,600 mL, and length of hospital stay was four days. At 30-days and 90-days postoperation, no thromboembolic event or compromising lower extremity venous return was detected. The pathological report revealed high-grade urothelial cell carcinoma with invasion into perinephric fat. Carcinoma involvement was observed in the tumor thrombus and IVC wall (T4N0M0). Conclusion: Robotic-assisted surgery of the IVC is a complex operation that requires robotic surgical proficiency and a highly experienced team. The observed success in the present case demonstrated the feasibly of this procedure in Thailand. Additional benefits include less postoperative pain, reduced blood loss, smaller surgical wound size, and shorter length of hospital stay. Keywords: Robotic-assisted laparoscopic radical nephrectomy; Inferior vena cava thrombectomy; Thailand

Dielectric properties of urine in relation to bladder cancer.

Many studies have investigated the dielectric properties of human and animal tissues, particularly to differentiate between normal cells and tumors. However, these studies are invasive as tissue samples have to be excised to measure the properties. This study aims to investigate the dielectric properties of urine in relation to bladder cancer, which is safe and non-invasive to patients. 30 healthy subjects and 30 bladder cancer patients were recruited. Their urine samples were subjected to urinalysis and cytology assessment. A vector network analyzer was used to measure the dielectric constant (Ɛ') and loss factor (Ɛ″) at microwave frequencies of between 0.2 and 50GHz at 25°C, 30°C and 37°C. Significant differences in Ɛ' and Ɛ″ were observed between healthy subjects and patients, especially at frequencies of between 25 and 40GHz at 25°C. Bladder cancer patients had significant lower Ɛ' and higher Ɛ″ compared with healthy subjects. The Ɛ' was negatively correlated with urinary exfoliated urothelial cell number, and Ɛ″ was positively correlated. The study achieved a receiver operating characteristic area under curve (ROC-AUC) score of 0.69099 and an optimum accuracy of 75% with a sensitivity of 80% and a specificity of 70%. The number of exfoliated urothelial cell had significant effect on the dielectric properties, especially in bladder cancer patients. Urinary dielectric properties could potentially be used as a tool to detect bladder cancer.

UCHL1-PKM2 axis dysregulation is associated with promoted proliferation and invasiveness of urothelial bladder cancer cells.

Bladder cancer is one of the most common type of cancers globally, and the majority of cases belong to urothelial bladder carcinoma (UBC) type. Current researches have demonstrated that multiple genomic abnormalities are related to the sensitivity of cisplatin-based chemotherapy in bladder cancer patients. Previous findings have indicated a controversial role of Ubiquitin Carboxy-Terminal Hydrolase L1 (UCHL1) in malignancy, so we aimed to further explore the role of UCHL1 in UBC. UBC cell lines and The Cancer Genome Atlas (TCGA) in-silico datasets were utilized to investigate UCHL1 expression pattern and functional as well as prognostic impacts in UBC cancer cell line models and patients. UCHL1 overexpression and silencing vectors and subsequent immunoprecipitation/ubiquitination experiments in combination of cellular functional assays were conducted to explore UCHL1-PKM2 interaction axis and its significance in UBC malignancy. UCHL1 was significantly up-regulated in UBC cancer cells and UCHL1 high-expression was associated with higher pathology/clinical grade and significantly inferior overall prognosis of UBC patients. UCHL1 interacted with PKM2 and enhanced PKM2 protein level through inhibition of PKM2 protein degradation via ubiquitination process. UCHL1-PKM2 interaction significantly promoted UBC cellular proliferation, metastasis and invasion activities. UCHL1-PKM2 interaction played an interesting role in UBC tumor cell proliferation, migration and metastasis. Our study suggests PKM2-targeted treatment might have a potential value in metastatic malignancy therapy development in the future.

Current and Emerging Strategies to Treat Urothelial Carcinoma.

Urothelial cell carcinoma (UCC, bladder cancer, BC) remains a difficult-to-treat malignancy with a rising incidence worldwide. In the U.S., UCC is the sixth most incident neoplasm and ~90% of diagnoses are made in those >55 years of age; it is ~four times more commonly observed in men than women. The most important risk factor for developing BC is tobacco smoking, which accounts for ~50% of cases, followed by occupational exposure to aromatic amines and ionizing radiation. The standard of care for advanced UCC includes platinum-based chemotherapy and programmed cell death (PD-1) or programmed cell death ligand 1 (PD-L1) inhibitors, administered as frontline, second-line, or maintenance therapy. UCC remains generally incurable and is associated with intrinsic and acquired drug and immune resistance. UCC is lethal in the metastatic state and characterized by genomic instability, high PD-L1 expression, DNA damage-response mutations, and a high tumor mutational burden. Although immune checkpoint inhibitors (ICIs) achieve long-term durable responses in other cancers, their ability to achieve similar results with metastatic UCC (mUCC) is not as well-defined. Here, we discuss therapies to improve UCC management and how comprehensive tumor profiling can identify actionable biomarkers and eventually fulfill the promise of precision medicine for UCC patients.

A novel in vivo model of ureteral fibrosis induced by calcium oxalate beads in C57BL/6J mice.

The global incidence of ureteroliths in humans is increasing, particularly posing a problem in developed countries. The most common stone type is calcium oxalate, which is associated with a high recurrence rate. In veterinary medicine, stones are the most common cause of ureteral obstruction in cats, accounting for 72-87% of cases. In cats, stones cause irreversible ureteral damage, necessitating stone treatment as well as ureteral therapy. However, the mechanisms underlying the ureteral damage caused by stones remain unclear. Therefore, this study aimed to create a mouse model suitable for studying the ureteral fibrosis caused by oxalate stones by artificially embedding calcium oxalate in the ureter. Pathological tissue analysis was used to compare normal ureters without ligation and ureters with sham or oxalate bead implantation. The ureters of the sham and oxalate bead groups showed granulation tissue formation, transitional epithelium exfoliation, and densely packed connective tissue in the proprietary and muscle layer regions. Particularly in the oxalate bead group, infiltration of degenerated neutrophils, presence of foreign body giant cells, and hyperplasia of the transitional epithelium were observed. The proportion of fibrosis was higher in the oxalate group than in the sham group. Overall, this mouse model created using oxalate bead implantation has the potential to efficiently induce ureteral obstruction. This mouse model is expected to be used for elucidating the molecular mechanisms of ureteral fibrosis and evaluating therapeutic drugs in future.

SAT220 Rare Case Of Pembrolizumab Induced Primary Hypoparathyroidism

Abstract Disclosure: S.G. Goud: None. A. Siddiqui: None. M. Alkhathlan: None. C.Y. Fan: None. Introduction: Immune checkpoint inhibitors such as pembrolizumab (Keytruda) used in the treatment of various cancers are associated with immune mediated endocrinopathies, among which thyroid dysfunction and pituitary hypophysitis are common, whereas hypoparathyroidism is rare. We report a case of primary hypoparathyroidism and hypocalcemia with pembrolizumab. Clinical Case: 58-year-old male with metastatic urothelial cell carcinoma, status post neoadjuvant chemotherapy with gemcitabine and cisplatin in 2017, followed by radical cystectomy with recurrence of metastasis in 2018, who was started on Keytruda every three weeks. After 10 months, he developed immune mediated hypothyroidism treated with levothyroxine. After 33 months on Keytruda, he developed hematochezia with constipation and intermittent abdominal pain. Colonoscopy showed findings consistent with autoimmune colitis; Keytruda was held and colitis was treated with tapering steroids. Surveillance imaging showed stable disease, so Keytruda continued to be held. After 7 months of holding Keytruda, on routine blood work he had a critically low calcium level of 5.5 mg/dl (8.4-10.2 mg/dl) with tingling and numbness in his hands, muscle spasms, generalized weakness, and fatigue for the past few weeks. On exam there was no Trousseau’s sign, Chvostek's sign, or gait ataxia. Hemodynamically stable. Labs showed lowest corrected calcium of 5.5, normal renal function, low vitamin D of 8 ng/ml (30-100 ng/ml), elevated phosphorus of 6.3 mg/dl (2.5-4.5 mg/dl), and normal magnesium. PTH was frankly low at 12.7 pg/ml (15-65 pg/ml), indicating primary hypoparathyroidism. ACTH stimulation test was normal. Retrospective review of the labs from oncology office records showed gradual, progressive hypocalcemia for a few months prior to presentation, with calcium levels ranging between 6.7 to 7.7 mg/dl. Of note, calcium prior to pembrolizumab was normal at 9.4 mg/dl. He was treated with IV calcium gluconate and then transitioned to calcium carbonate (CaCO3) 500 mg TID, calcitriol 0.5 mg BID, and Vit D 50,000 IU twice weekly. Hydrochlorothiazide (HCTZ) added as calcium remained low. After three days calcium improved to 7 mg/dl range and he was discharged. Calcium levels checked periodically after discharge ranged from 8 to 9 mg/dl (8.4-10.2 mg/dl), and phosphorus levels normalized. CaCO3 dose was adjusted accordingly, Vit D was changed to 50,000 IU weekly based on a level of 71 ng/dl after 3 months, and HCTZ was discontinued after 6 months. PTH was still low at 9.7 pg/ml (15-65 pg/ml) 6 months after discharge, off pembrolizumab for over a year. Calcium sensing receptor (CaSR) activating antibody was not checked in our case. Conclusion: It is important clinicians be aware of the risk for hypocalcemia and its unpredictable presentation to help with timely recognition and management. Presentation: Saturday, June 17, 2023

Affimer-mediated locking of p21-activated kinase 5 in an intermediate activation state results in kinase inhibition

Kinases are important therapeutic targets, and their inhibitors are classified according to their mechanism of action, which range from blocking ATP binding to covalent inhibition. Here, a mechanism of inhibition is highlighted by capturing p21-activated kinase 5 (PAK5) in an intermediate state of activation using an Affimer reagent that binds in the P+1 pocket. PAK5 was identified from a non-hypothesis-driven high-content imaging RNAi screen in urothelial cancer cells. Silencing of PAK5 resulted in reduced cell number, G1/S arrest, and enlargement of cells, suggesting it to be important in urothelial cancer cell line survival and proliferation. Affimer reagents were isolated to identify mechanisms of inhibition. The Affimer PAK5-Af17 recapitulated the phenotype seen with siRNA. Co-crystallization revealed that PAK5-Af17 bound in the P+1 pocket of PAK5, locking the kinase into a partial activation state. This mechanism of inhibition indicates that another class of kinase inhibitors is possible.

Insect cell‐derived human CD200‐Fc increases zonula occludens‐1 tight junction protein in urothelial carcinoma cells

AbstractCD200 is a ligand that interacts with the CD200 receptor 1, with an anti‐inflammatory effect. CD200 inhibits the nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) pathway, attenuating the inflammatory response and maintaining barrier function. In this study, human CD200 was fused with the fragment crystallizable (Fc) region of human immunoglobulin G (IgG) to generate the recombinant CD200‐Fc protein, produced in insect cells using the baculovirus expression vector system. The CD200‐Fc gene was cloned under the control of the polyhedrin promoter in the pFastBac‐1 vector of the baculovirus expression vector system. Immunoblot analysis confirmed the expression of CD200‐Fc in insect cells. The CD200‐Fc protein was successfully purified using protein A affinity chromatography. 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay revealed that purified CD200‐Fc protein inhibited the proliferation of TCCSUP cells, a bladder epithelial cancer cell expressing CD200 receptor 1, at concentrations of 1, 10 and 100 ng/mL. Quantitative real‐time reverse transcription PCR (qRT‐PCR) and immunoblot analyses confirmed that the mRNA and protein levels of zonula occludens‐1, a tight junction protein for barrier protection in epithelial tissues, were increased in TCCSUP cells treated with insect cell‐derived CD200‐Fc. These results suggest that insect cell‐derived CD200‐Fc could alter zonula occludens‐1 expression in bladder epithelial cancer cells, enhancing the function of the cell barrier protein, which could inhibit cancer metastasis. Taken together, the baculovirus expression vector system can be applied to express antitumor therapeutic CD200‐Fc protein for the inhibition of bladder cancer.

Systemic Treatment for Advanced and Metastatic Non-Clear Cell Renal Cell Carcinoma: Examining Modern Therapeutic Strategies for a Notoriously Challenging Malignancy.

Non-clear cell renal cell carcinoma (nccRCC) is a heterogeneous group of malignancies that represents 25% of renal cell carcinoma (RCC) cases. Treatment for non-clear cell histologies is mostly based on evidence from small phase II clinical trials or extrapolated from successful therapies in clear cell RCC because of the low incidence of non-clear cell pathology. Advances in genomic profiling have improved clinicians' understanding of molecular targets for nccRCC, such as altered mesenchymal epithelial transition (MET) gene status and fumarate hydratase (FH) gene inactivation, but patient outcomes remain poor and optimal management of this disease remains unclear. This review assesses outcomes by histologic subtype from 27 prospective and 13 ongoing clinical trials to identify therapeutic strategies for advanced or metastatic nccRCC. Vascular endothelial growth factor tyrosine kinase inhibitors (TKI), such as sunitinib, and mammalian target of rapamycin (mTOR) inhibitors, such as everolimus, have demonstrated efficacy and remain viable treatment options, with a preference for sunitinib. However, everolimus is preferred in patients with chromophobe RCC because folliculin (FLCN) gene mutations upregulate the mTOR pathway. Novel TKIs, such as cabozantinib, show improved outcomes in patients with papillary RCC because of targeted MET inhibition. Platinum-based chemotherapy continues to be the recommended treatment strategy for collecting duct and medullary RCC. Clinically meaningful antitumor activity has been observed across all non-clear cell histologies for immune checkpoint inhibitors, such as nivolumab, pembrolizumab, and ipilimumab. Ongoing trials are evaluating novel tyrosine kinase inhibitor and immunotherapy combination regimens, with an emphasis on the promising MET-inhibitor cabozantinib and pembrolizumab plus lenvatinib.

Обструкция пиелоуретерального сегмента: этиология, патогенез, морфологические особенности.

Introduction. Congenital anomalies of the kidneys and urinary tract cause chronic kidney disease in 7% of cases. The zone of the pyeloureteral segment (PUS) is affected most often. The kidney and ureter originate from two different rudiments, the violation of their connection under the influence of teratogenic or genetically determined causes determines the obstruction of the pelvic-ureteral junction. Materials and methods. The search, analysis and systematization of publications in PubMed databases and eL ibrary.ru using the keywords «hydronephrosis», «etiology», «pathogenesis». As a result, 27 publications were selected, on the basis of which this narrative literature review was prepared. Results and discussion. Among the many causes of pathology of the PUS, there is a violation of the recanalization of this zone, a vicious interaction of the ureteral rudiment and mesanephros, from which the pelvis is differentiated. Genetic studies provide new data for understanding pathogenesis. Pathology of angiotensin receptors, bone morphogenetic protein, TSHZ3, SHH, TBX18, calceneurin genes can lead to PUS stenosis. In the future, genetic discoveries may be the key to preventing the disease. Of all the existing mechanisms for the formation of an obstruction of the PUS, the conflict with the aberrant vessel is proven. Diagnosis, observation, and the timing of surgical treatment are left to the discretion of the specialist. Timely plastic surgery of the PUS zone prevents the formation of nephrosclerosis and chronic kidney disease. Along with the lesion of vascular structures, nephrons in the pathology of PUS, changes occur in the walls of the abdominal system. Retention of urine leads to ulceration, atrophy of the transitional epithelium, hypertrophy of muscle fibers, hyalinosis and overgrowth of connective tissue, which inhibits the contractility of the upper urinary tract and may worsen the result of surgery. Conclusion. Currently, the mechanisms of PUS obstruction formation are not fully disclosed. Information about embryogenesis, the course of pathological processes allows the clinician to optimally approach the treatment of pathology

Savolitinib: A Promising Targeting Agent for Cancer.

Savolitinib is a highly selective small molecule inhibitor of the mesenchymal epithelial transition factor (MET) tyrosine kinase, primarily developed for the treatment of non-small cell lung cancer (NSCLC) with MET mutations. It is also being investigated as a treatment for breast, head and neck, colorectal, gastric, pancreatic, and other gastrointestinal cancers. In both preclinical and clinical studies, it has demonstrated efficacy in lung, kidney, and stomach cancers. Savolitinib is an oral anti-cancer medication taken as a 600 mg dose once daily. It can be used as a monotherapy in patients with non-small cell lung cancer with MET mutations and in combination with epidermal growth factor receptor (EGFR) inhibitors for patients who have developed resistance to them. Furthermore, savolitinib has shown positive results in gastric cancer treatment, particularly in combination with docetaxel. As a result, this review aims to validate its efficacy in NSCLC and suggests its potential application in other gastrointestinal cancers, such as pancreatic cancer, based on related research in gastric and renal cancer.