Comparison of outcomes in high-risk prostate cancer patients treated with low-/high-dose-rate brachytherapy plus external beam radiotherapy.

BACKGROUND: Although brachytherapy is a standard treatment option for patients with high-risk prostate cancer, only a few studies have compared low-dose-rate brachytherapy (LDR-BT) and high-dose-rate brachytherapy (HDR-BT). We applied propensity score-based inverse probability treatment weighting (IPTW) to compare oncological outcomes for LDR-BT and HDR-BT. METHODS: We retrospectively assessed prognosis in 392 patients with high-risk localized prostate cancer who had undergone brachytherapy plus external beam radiation. IPTW was applied to adjust the Kaplan-Meier survival analyses and Cox proportional hazards regression analyses, with the goal of minimizing bias from patient background. RESULTS: The IPTW-adjusted Kaplan-Meier survival analyses showed no statistically significant differences for time to biochemical recurrence, clinical progression, castration-resistant prostate cancer, or death from any cause. The IPTW-adjusted Cox regression analyses also showed that the modality of brachytherapy was not an independent factor in these oncological outcomes. Notably, the two groups differed regarding complications; LDR-BT was associated with a higher rate of acute grade ≥ 2 GU toxicity, and late grade 3 toxicity was noted only in HDR-BT. CONCLUSION: Our analysis of long-term outcomes in patients with high-risk localized prostate cancer shows no significant differences in oncological outcomes between LDR-BT and HDR-BT, but some differences in toxicity, and offers patients and clinicians useful information in deciding management strategies for high-risk localized prostate cancer.

The prognostic significance of the clinical T stage and Grade Group in patients with locally advanced prostate cancer treated via high-dose-rate brachytherapy and external beam radiation.

BACKGROUND: Although the optimal management of locally advanced prostate cancer (PCa) remains unclear, local definitive therapy, thus combined radiotherapy and androgen deprivation, is one option. We evaluated the long-term outcomes of patients with locally advanced PCa who underwent high-dose-rate brachytherapy (HDR-BT) and external beam radiation therapy (EBRT). METHODS: We retrospectively analyzed 173 patients with locally advanced PCa (cT3a-4N0-1M0) who underwent HDR-BT and EBRT. We employed Cox's proportional hazards models to identify pre-treatment predictors of oncological outcomes. Treatment outcomes (biochemical recurrence-free survival [BCRFS], clinical progression-free survival [CPFS], and castration-resistant prostate cancer-free survival [CRPCFS] were compared according to the combination of the pre-treatment predictors. RESULTS: The 5-year BCRFS, CPFS, and CRPCFS rates were 78.5, 91.7, and 94.4% respectively; there were two PCa deaths. Multivariate analysis revealed that the clinical T stage (cT3b and cT4) and Grade Group (GG) 5 status were independent risk factors for poor BCRFS, CPFS, and CRPCFS. In the GG ≤ 4 group, the Kaplan-Meier curves for BCRFS, CPFS, and CRPCFS revealed excellent outcomes. However, in the GG5 group, patients with cT3b and cT4 PCa evidenced significantly poorer oncological outcomes than those with cT3a PCa. CONCLUSION: The clinical T stage and GG status were significantly prognostic of oncological outcomes in patients with locally advanced PCa. In patients of GG ≤ 4 PCa, HDR-BT was effective even in patients with cT3b or cT4 PCa. However, in patients with GG5 PCa, careful monitoring is essential, particularly of patients with cT3b or cT4 PCa.

Patients with PSA below 0.2 ng/mL at 8 years post high-dose-rate brachytherapy have an extremely low risk of subsequent recurrence.

OBJECTIVES: We have analyzed the long-term follow-up data of patients with prostate cancer (PCa) who underwent high-dose-rate brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) combined with long-term androgen deprivation therapy (ADT). The objective was to determine the optimal time for cessation of PSA monitoring after HDR-BT. METHODS: We included 309 patients with clinical stage T1c-T4 N0-1 M0 PCa who received HDR-BT and EBRT combined with long-term ADT between 2005 and 2018. We stratified the patients based on their prostate-specific antigen (PSA) levels and identified the factors associated with biochemical recurrence (BCR) and clinical progression (CP). RESULTS: The median follow-up duration was 98 months (range: 31-207 months). Among the 306 patients, 76 developed BCR and 47 developed CP subsequently. We found that the PSA levels at 3, 5, and 8 years significantly correlated with the oncological outcomes of brachytherapy. No patient with a PSA level ≤ 0.2 ng/mL at 8 years later developed BCR or CP. CONCLUSION: Our long-term data suggest that in the presence of a PSA level ≤ 0.2 ng/mL at 8 years later, PSA monitoring may be safely discontinued due to the extremely low risk of subsequent oncological events. The data presented in this study will assist clinicians in determining the optimal management strategy for patients with PCa following HDR-BT and EBRT combined with long-term ADT.

Clinical benefit of continuing pembrolizumab treatment beyond progression in patients with metastatic urothelial carcinoma.

BACKGROUND: There has been no clinical evidence to justify continued pembrolizumab therapy beyond progression in patients with metastatic urothelial carcinoma (UC). MATERIALS AND METHODS: We conducted a multicenter retrospective study evaluating the clinical efficacy of continued use of pembrolizumab beyond progression in patients with metastatic UC. Data from 51 patients with metastatic UC, who developed progression during second-line pembrolizumab therapy, were analyzed. Progression was defined based on the Immunotherapy Response Evaluation Criteria in Solid Tumors. The outcome was overall survival (OS). The association between continued treatment, OS, and the risk of all-cause mortality was tested using log-rank test, conventional and time-dependent Cox regression models. RESULTS: No significant difference in patient characteristics was noted between patients continuing pembrolizumab beyond progression (N = 21) and those discontinuing pembrolizumab (N = 30). Median OS was significantly longer in the continuation group (17.8 vs. 8.8 months; P = 0.038). A multivariable conventional Cox regression model identified continued pembrolizumab administration as a significant independent prognostic factor of all-cause mortality (hazard ratio [HR]: 0.21, 95% confidence interval [CI]: 0.05-0.90, P = 0.036), irrespective of the time from treatment initiation to progression and concurrent clinical progression. Further, longer duration of pembrolizumab treatment beyond progression was independently associated with a reduced risk of all-cause mortality in a multivariable time-dependent Cox regression model, when used as a time-dependent variable (HR: 0.07, 95% CI: 0.01-0.45, P = 0.006). CONCLUSIONS: Continued pembrolizumab administration beyond progression might be beneficial in patients with metastatic UC who were clinically stable.

[A Case of Metastatic Ureteral Cancer Treated with Pembrolizumab without Relapse of Ocular Myasthenia Gravis].

A 77-year-old man complaining of gross hematuria was referred to our hospital for further examination and treatment. The contrast-enhanced computed tomographic (CT) scan revealed a left ureteral tumor, multiple bladder tumors, para-aortic lymph node metastasis, left supraclavicular lymph node metastasis, multiple liver metastases, and multiple lung metastases. Transurethral resection was performed. One of the multiple bladder tumors, located at the bladder neck, was pathologically diagnosed as urothelial carcinoma, pT1, high grade, G2．We diagnosed the patient with metastatic ureteral cancer (T4N2M1, stage IV). We stated gemcitabine, cisplatin (GC) therapy, but stopped after the first course due to gemcitabine drug eruption. We changed the regimen to methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) therapy and the cycle was completed without complications. However, CT scan showed disease progression. After palliative irradiation of the primary lesion, we administered pembrolizumab. Although he was asymptomatic, we diagnosed him with ocular myasthenia gravis because of a high level of serum anti-acetylcholine receptor antibodies and a temporary ptosis in his past history. In spite of the possibility of relapse of myasthenia gravis, treatment with pembrolizumab was continued with his consent since there were no other treatment options. After two courses of pembrolizumab, he was hospitalized due to disease progression and died about three weeks after admission. Myasthenia gravis is a possible immune-related adverse event of pembrolizumab, However, there have been few reports on the successful treatment with this agent in patients with previously diagnosed myasthenia gravis. We report, here, a case of metastatic ureteral carcinoma safely treated with pembrolizumab without relapse of ocular myasthenia gravis.

Comparison of the Immunotherapy Response Evaluation Criteria in Solid Tumours (iRECIST) with RECIST for capturing treatment response of patients with metastatic urothelial carcinoma treated with pembrolizumab.

OBJECTIVE: To evaluate the clinical usefulness of Immunotherapy Response Evaluation Criteria in Solid Tumours (iRECIST) in patients with metastatic urothelial carcinoma (UC) treated with pembrolizumab. The iRECIST is designed to accurately capture the tumour response treated with immunotherapy. PATIENTS AND METHODS: We conducted a multicentre retrospective study evaluating the clinical utility of iRECIST in 91 patients with metastatic UC treated with second-line pembrolizumab. The objective response (OR) and time to progression (TTP) in accordance with both iRECIST and RECIST version 1.1 were compared with overall survival (OS) and risk of all-cause mortality, and analysed using log-rank and multivariable Cox regression models, respectively. Predictive performance of the criteria was studied using Harrell's concordance index (c-index). The clinical usefulness of each criterion was compared using decision curve analysis. RESULTS: Of 57 patients with progressive disease per RECIST, a considerable number of patients were reclassified to immune stable disease (six, 10.5%), immune partial response (two, 3.5%), and immune complete response (two, 3.5%) per iRECIST. Multivariable Cox regression models showed that both OR (hazard ratio [HR] 0.10, 95% confidence interval [CI] 0.03-0.35; P = 0.001) and TTP (HR 0.59, 95% CI 0.46-0.77; P < 0.001) per iRECIST were significantly associated with all-cause mortality. Furthermore, iRECIST had a significant, increased predictability of OS compared with RECIST (OR, c-index: 0.70, increase: 0.04, P = 0.046; TTP, c-index: 0.88, increase: 0.07, P = 0.039). On decision curve analysis, iRECIST presented better net benefit gains than did RECIST. CONCLUSIONS: Compared with RECIST, iRECIST could more accurately predict OS of patients with metastatic UC treated with pembrolizumab. The iRECIST has the potential to be a new standard for tumour response evaluation of these patients.

Differential expression of androgen receptor variants in hormone-sensitive prostate cancer xenografts, castration-resistant sublines, and patient specimens according to the treatment sequence.

BACKGROUND: Androgen receptor variants (AR-vs), especially AR-v7 and AR-v 5, 6, and 7 exon-skipped (AR-v567es), are reportedly key players in the development of castration-resistant prostate cancer (CRPC). We previously established a mouse xenograft model (JDCaP) from a metastatic skin lesion from a Japanese patient with CRPC and that was revealed to exhibit androgen sensitivity. In the present study, we established multiple castration-resistant xenograft models from JDCaP mice to investigate the biological features of CRPC. METHODS: Tissue from JDCaP mice was transplanted into male and female nude mice, and after serial passaging, castration-resistant sublines (JDCaP-CR2M and JDCaP-CR4M in male mice, JDCaP-CR2F and JDCaP-CR4F in female mice) were established. We investigated anti-androgen and testosterone sensitivity and the messenger RNA expression pattern of full-length AR and AR-vs. In addition, we compared AR protein levels of patient specimens among primary, local-recurrent, and two skin-metastatic tumors. RESULTS: All JDCaP-CR sublines showed continuous growth following the administration of bicalutamide, although the effects of testosterone varied among sublines. Parental JDCaP and JDCaP-CR2M, JDCaP-CR4M, and JDCaP-CR4F sublines expressed AR-v7, whereas JDCaP-CR2F exhibited elevated AR-v567es expression resulting from genomic deletion, which was confirmed by DNA sequencing. Moreover, we confirmed AR-v7 expression in the tumor of the original patient after androgen-deprivation therapy. CONCLUSIONS: Each JDCaP-CR subline showed different AR-v-expression patterns, with JDCaP-CR2F expressing AR-v567es due to genomic deletion. Our results indicated that AR-vs emerged after androgen-deprivation therapy and appeared essential for acquisition of castration resistance.

[A Case of Metachronous Cancer Originating from Five Different Organs].

Advances and improvements in the early detection, diagnosis, and treatment modalities have increased the opportunities to treat multiple primary malignancies. Herein, we report a male patient with five metachronous cancers. The patient had initially undergone partial tongue resection for tongue cancer in 2003 at the age of 57 years and was subsequently diagnosed with acute promyelocytic leukemia, duodenal cancer, prostate cancer, and bladder cancer, over a period of 13 years. The patient underwent androgen deprivation therapy and palliative radiation therapy for the management of metastatic prostate cancer in 2016. The poor prognosis of the patient was thought to be related to be the prostate cancer because the other cancers were either in remission or localized. The occurrence of five metachronous cancers is extremely rare, and this is the fourth case to be reported in the Japanese literature.

Two sisters reveal autosomal recessive inheritance of epidermodysplasia verruciformis: a case report.

BACKGROUND: Epidermodysplasia verruciformis is a rare genodermatosis characterized by a unique susceptibility to cutaneous human papillomaviruses infection. Most patients show autosomal recessive patterns of inheritance. CASE PRESENTATION: We report a case of two sisters with clinically epidermodysplasia verruciformis specific lesions on the face, neck, trunk, and extremities. PCR analysis indicated the presence of human papillomavirus type 5 in the lesions. Electron microscopic examination showed viral-like particles in keratinocyte nuclei and the stratum corneum of the epidermodysplasia verruciformis lesions. In addition, we examined the EVER1 and EVER2 genes using eight different primer pairs without finding any nonsense or frameshift mutations in the gDNA from lymphocytes of the elder sister. CONCLUSIONS: In this report, the patient's parents did not have epidermodysplasia verruciformis lesions or a consanguineous marriage. EV did not develop in the elder sister until five years of age, so the parents did not perceive EV as an inherited disease. The probability that EV developed in both sisters was only 6.25%. Thus, it is rare for both sisters to develop epidermodysplasia verruciformis lesions considering that the parents were presumed to be carriers and the disease reveal an autosomal recessive pattern of inheritance.

Bone-Modifying Agents in Patients With High-Risk Metastatic Castration-Sensitive Prostate Cancer Treated With Abiraterone Acetate.

Importance: The association between the use of bone-modifying agents (BMAs) and the outcomes among patients with metastatic castration-sensitive prostate cancer (mCSPC) treated with abiraterone acetate plus prednisone (AAP) remains unclear. Objective: To investigate the association between BMA use and the outcomes of patients with mCSPC receiving AAP. Design, Setting, and Participants: In this cohort study, a post hoc analysis of individual participant data from the LATITUDE trial was performed. The LATITUDE trial, a phase 3 randomized clinical trial, aimed to assess the efficacy of AAP and androgen deprivation therapy (ADT) vs dual-placebo and ADT in patients with high-risk mCSPC (data cutoff, August 15, 2018). Eligible patients had newly diagnosed prostate cancer with metastases and at least 2 of 3 high-risk factors (Gleason score ≥8, presence of ≥3 lesions on bone scan, or presence of measurable visceral metastasis). The trial was conducted at 235 sites in 34 countries. Data for the present study were evaluated from July 18 to September 23, 2023. Exposures: Use of BMAs was defined as the administration of bisphosphonates and denosumab within 90 days before and after randomization. Main Outcomes and Measures: The primary outcomes were time to skeletal-related events (SREs) and overall survival (OS). An SRE was defined as a clinical or pathological fracture, spinal cord compression, palliative radiation to bone, or surgery involving bone. Differences in these outcomes were examined using the restricted mean survival time from inverse probability of treatment weighting-adjusted Kaplan-Meier curves, estimated until the last event was observed (longest time observed, 63.9 months). Treatment × covariate interactions were analyzed using weighted Cox proportional hazards regression models for the total cohort. Results: In the total cohort of 1199 patients (956 [79.7%] younger than 75 years), 597 (49.8%) received AAP and ADT, including 474 (79.4%) younger than 75 years and 384 (64.3%) with more than 10 bone metastases (AAP cohort); 602 (50.2%) were treated with dual placebo and ADT, including 482 (80.1%) younger than 75 years and 377 (62.6%) with more than 10 bone metastases (ADT cohort). In the AAP cohort, 132 patients (22.1%) received BMAs, while in the ADT cohort, 131 (21.8%) did. Zoledronic acid was the most frequently administered BMA in both the AAP (93 [70.5%]) and the ADT (88 [67.2%]) cohorts. During the median follow-up of 51.8 (IQR, 47.2-57.0) months in the AAP cohort, BMA use was associated with a longer time to SRE (difference, 7.8 [95% CI, 4.2-11.3] months) but not with OS (difference, 1.6 [95% CI, -2.5 to 5.8] months). In the ADT cohort, BMA use was associated with both time to SRE (difference, 9.3 [95% CI, 5.2-13.3] months) and OS (difference, 5.5 [95% CI, 3.2-9.8] months). No evidence was found that the outcomes of BMA varied by AAP or ADT (hazard ratio for time to SRE, 0.99 [95% CI, 0.48-2.08]; P = .99 for interaction; hazard ratio for OS, 1.31 [95% CI, 0.88-1.96]; P = .18 for interaction). Conclusions and Relevance: The findings of this cohort study suggest that use of BMAs was associated with a longer time to SRE in patients with high-risk mCSPC treated with ADT, with or without AAP, suggesting that BMA use might provide benefits to this population.

Clinical Significance of Intraductal Carcinoma of the Prostate After High-Dose Brachytherapy With External Beam Radiation Therapy: A Single Institution Series and an Updated Meta-Analysis.

BACKGROUND: We compared oncological outcomes between prostate cancer (PCa) patients with and without intraductal carcinoma of the prostate (IDC-P) after high-dose-rate brachytherapy (HDR-BT) with external beam radiation therapy (EBRT). METHODS: We performed a retrospective analysis of 138 patients with clinically high-risk, very high-risk, or locally advanced PCa who received HDR-BT with EBRT. Of these, 70 (50.7 %) patients were diagnosed with IDC-P; 68 (49.3 %) patients with acinar adenocarcinoma of prostate. The oncological outcomes, including biochemical recurrence-free survival (BCRFS) and clinical progression-free survival (CPFS), were assessed using Kaplan-Meier curves. Additionally, Cox proportional hazards models were used to identify significant prognostic indicators or biochemical recurrence (BCR). Meta-analysis of existing literatures was performed to evaluate the risk of BCR in patients with IDC-P after radiation therapy, compared to those without IDC-P. RESULTS: Kaplan-Meier curves demonstrated significantly inferior BCRFS and CPFS in patients with IDC-P. Multivariate analysis revealed that IDC-P and Grade Group 5 status were associated with increased BCR risk. in our meta-analysis, IDC-P was associated with BCR (HR = 2.13, P = .003). CONCLUSION: Amongst the patients who received HDR-BT, patients with IDC-P displayed significantly more rapid disease progression, compared with patients who did not have IDC-P.

Pathophysiology of urinary incontinence in murine models.

Urethral closure mechanisms under stress conditions consist of passive urethral closure involving connective tissues, fascia and/or ligaments in the pelvis and active urethral closure mediated by hypogastric, pelvic and pudendal nerves. Furthermore, we have previously reported that the active urethral closure mechanism might be divided into two categories: (i) the central nervous control passing onto Onuf's nucleus under sneezing or coughing; and (ii) the bladder-to-urethral spinal reflex under Valsalva-like stress conditions, such as laughing, exercise or lifting heavy objects. There are over 200 million people worldwide with urinary incontinence, a condition that is associated with a significant social impact and reduced quality of life. Therefore, basic research for urinary continence mechanisms in response to different stress conditions can play an essential role in developing treatments for stress urinary incontinence. It has been clinically shown that the etiology of stress urinary incontinence is divided into urethral hypermobility and intrinsic sphincter deficiency, which could respectively correspond to passive and active urethral closure dysfunction. In this review, we summarize the representative stress urinary incontinence animal models and the methods to measure leak point pressures under stress conditions, and then highlight stress-induced urinary continence mechanisms mediated by active urethral closure mechanisms, as well as future pharmacological treatments of stress urinary incontinence. In addition, we introduce our previous reports including sex differences in urethral closure mechanisms under stress conditions and urethral compensatory mechanisms to maintain urinary continence after pudendal nerve injury in female rats.

Treatment Results of High-dose-rate Brachytherapy and External Beam Radiation With Long-term Androgen Deprivation Therapy for Patients With Metastatic Prostate Cancer.

BACKGROUND/AIM: A recent clinical trial indicated the usefulness of local radiation therapy of the prostate in patients with low-volume metastatic prostate cancer. High-dose-rate brachytherapy (HDR-BT) is used mainly for high-risk, localized, and locally advanced cases. However, few studies exist on the efficacy of HDR-BT and external beam radiation therapy (EBRT) for metastatic prostate cancer. PATIENTS AND METHODS: We conducted a retrospective analysis of 39 patients diagnosed with regional lymph node metastasis and/or a limited number of metastases who underwent HDR-BT and EBRT with long-term androgen deprivation therapy. We utilized Cox's proportional hazards models to identify predictors of oncological outcomes. Treatment outcomes, including biochemical recurrence-free survival (BCRFS), clinical progression-free survival (CPFS), and castration-resistant prostate cancer-free survival (CRPCFS), were compared according to the clinical stage. RESULTS: The median follow-up duration was 49 months (range=23-136 months). The 5-year BCRFS, CPFS, CRPCFS, and cancer-specific survival rates were 62.2%, 67.2%, 83.2%, and 93.4%, respectively. Based on Kaplan-Meier analysis, N1M0 and N0-1M1b showed favorable outcomes compared with N1M1a. Multivariate analysis revealed that N1M1a prostate cancer was an independent risk factor for poor BCRFS, CPFS, and CRPCFS. CONCLUSION: HDR-BT and EBRT with androgen deprivation therapy is a feasible approach for patients with newly diagnosed regional and low-metastatic-burden prostate cancer. However, in our cohort M1a prostate cancer had significantly inferior outcomes. A well-controlled prospective study is imperative to confirm our results.

Time-dependent changes in bladder function and plantar sensitivity in a rat model of fibromyalgia syndrome induced by hydrochloric acid injection into the gluteus.

OBJECTIVE: To examine the correlation between muscular pain and bladder hypersensitivity in order to clarify the pathogenesis of comorbidity of bladder pain syndrome/interstitial cystitis with other chronic pain conditions such as fibromyalgia syndrome (FMS). MATERIALS AND METHODS: Under isoflurane anaesthesia, 0.2 mL of hydrochloric acid (HCl) solution (pH 4.0) was injected into the bilateral gluteus muscles of female Sprague-Dawley rats to produce an FMS model, as the gluteus is one of the specific tender points in patients with FMS. Control rats received saline injection (0.2 mL). The mechanical sensitivity of the plantar was evaluated using the mean number of bilateral hindlimb withdrawals in response to tactile stimulation with a 2.0-g von Frey filament at 1, 2 and 3 weeks after the HCl injection. In a separate rat group, cystometry was performed with the rats awake during saline infusion (0.06 mL/min) into the bladder before and after 1% lidocaine injection (0.2 mL) into the bilateral gluteus 1, 2 and 3 weeks after the HCl injection. RESULTS: The mean number of hindlimb withdrawals was significantly higher in FMS rats than in controls at 1 and 2 weeks. Using cystometry, we found that the intercontraction interval (ICI) and voided volume (VV) were significantly lower in FMS rats than in controls at 1 and 2 weeks. In addition, the voiding threshold pressure, ICI and VV were significantly higher after lidocaine injection in FMS rats, but not in controls, at 1 and 2 weeks. CONCLUSIONS: HCl injection (pH 4.0) into the gluteus can induce plantar hypersensitivity and urinary frequency for up to 2 weeks after the injection, suggesting that somatic (gluteus)-to-visceral (bladder) cross-sensitization might underlie bladder hypersensitivity in patients with FMS. Moreover, intervention at specific tender points outside the bladder could be effective in treating urinary frequency because lidocaine injection into the gluteus normalized bladder function in FMS rats for up to 2 weeks.

[Solitary adrenal metastasis of bladder carcinoma : a case report].

A 64-year-old man underwent chemotherapy after radical cystectomy for bladder cancer (UC, G3, pT3aN1M0). Three years later, computed tomography showed a left adrenal mass, and we performed left adrenalectomy. Histological findings showed that the adrenal mass was a metastasis of the bladder cancer. Over 6 years after salvage chemotherapy, the patient had no evidence of metastasis to other parts of the body. In the case of a solitary metastasis of bladder cancer, surgical resection should be positively considered.

Crystal structure of an Exo-1,5-{alpha}-L-arabinofuranosidase from Streptomyces avermitilis provides insights into the mechanism of substrate discrimination between exo- and endo-type enzymes in glycoside hydrolase family 43.

Exo-1,5-α-L-arabinofuranosidases belonging to glycoside hydrolase family 43 have strict substrate specificity. These enzymes hydrolyze only the α-1,5-linkages of linear arabinan and arabino-oligosaccharides in an exo-acting manner. The enzyme from Streptomyces avermitilis contains a core catalytic domain belonging to glycoside hydrolase family 43 and a C-terminal arabinan binding module belonging to carbohydrate binding module family 42. We determined the crystal structure of intact exo-1,5-α-L-arabinofuranosidase. The catalytic module is composed of a 5-bladed ß-propeller topologically identical to the other family 43 enzymes. The arabinan binding module had three similar subdomains assembled against one another around a pseudo-3-fold axis, forming a ß-trefoil-fold. A sugar complex structure with α-1,5-L-arabinofuranotriose revealed three subsites in the catalytic domain, and a sugar complex structure with α-L-arabinofuranosyl azide revealed three arabinose-binding sites in the carbohydrate binding module. A mutagenesis study revealed that substrate specificity was regulated by residues Asn-159, Tyr-192, and Leu-289 located at the aglycon side of the substrate-binding pocket. The exo-acting manner of the enzyme was attributed to the strict pocket structure of subsite -1, formed by the flexible loop region Tyr-281-Arg-294 and the side chain of Tyr-40, which occupied the positions corresponding to the catalytic glycon cleft of GH43 endo-acting enzymes.

Antibody to varicella-zoster virus immediate-early protein 62 augments allodynia in zoster via brain-derived neurotrophic factor.

Varicella-zoster virus (VZV) expresses immediate-early protein 62 (IE62), and zoster is associated with neuropathic pain. Brain-derived neurotrophic factor (BDNF) is involved in the neuronal mechanism underlying pain hypersensitivity. Zoster is associated with prodrome and the robust production of booster antibody to VZV. We hypothesized that the intrathecal production of antibody to IE62 cross-reacting with BDNF and the nerve injury by skin lesions may augment allodynia in zoster by enhancing BDNF activity. One of three monoclonal antibodies against the 268-556 peptide of IE62 recognized BDNF. Immunological cross-reactivity between IE62 and BDNF and the effects of anti-IE62 monoclonal antibody (anti-IE62 MAb) cross-reactivity with BDNF on BDNF activity in cultured neurons were examined. Anti-IE62 MAb and anti-BDNF MAbs recognized the 414-429 peptide of IE62 and the BDNF dimer. Anti-IE62 MAb significantly augmented BDNF-related transcription in neurons and the morphological development of spinal dorsal horn neurons. Sera from patients recognized IE62 and BDNF and enhanced BDNF activity in neurons. The effect of anti-IE62 antibody on mechanical allodynia was characterized by the threshold of allodynia using von Frey filaments in a spinal nerve injury (SNI) in mice. The administration of anti-IE62 MAb to or immunization with cross-reacting IE62 protein to mice significantly enhanced mechanical allodynia on the side with SNI but not on the uninjured side. Anti-IE62 antibody augmented BDNF activity in neurons and allodynia in mice with SNI. The intrathecal production of anti-IE62 antibody augmenting BDNF activity and peripheral nerve injury by zoster may participate in the pathogenesis of allodynia in zoster.

Impact of Dose-Effect in Smoking on the Effectiveness of Pembrolizumab in Patients with Metastatic Urothelial Carcinoma.

BACKGROUND: Subgroup analysis of KEYNOTE-045 suggested that cigarette smoking had a positive impact on the effectiveness of pembrolizumab in patients with advanced urothelial carcinoma (UC), whereas studies on other cancers treated with immune checkpoint inhibitors reported inconsistent results. OBJECTIVES: This study aimed to examine the association between smoking-related factors and the effectiveness of pembrolizumab in patients with metastatic UC. PATIENTS AND METHODS: This multicenter retrospective study was conducted using data from 95 patients with metastatic UC treated with pembrolizumab. The primary outcomes were progression and all-cause mortality. Time-to-event outcomes were compared with smoking history and lifetime smoking exposure at treatment initiation. Survival curves were compared using the log-rank test, with hazard ratios (HRs) estimated from Cox regression models. Cubic spline regression analysis was used to depict event hazards. RESULTS: We identified 32 (34.7%) patients with heavy smoking exposure (≥ 25 pack-years). Moreover, 19 (20.0%), 36 (37.9%), and 40 (42.1%) patients were current, former, and never smokers, respectively. Multivariable models showed that heavy smoking exposure was significantly associated with lower risk of progression (HR 0.58; 95% confidence interval (CI) 0.35-0.97; P = 0.047) and all-cause mortality (HR 0.30; 95% CI 0.11-0.82; P = 0.019). Cubic spline regression analyses revealed a dose-effect relationship. No significant association was observed between smoking history alone and effectiveness of pembrolizumab. CONCLUSIONS: Lifetime smoking exposure plays a significant role in the effectiveness of pembrolizumab in patients with metastatic UC.

A beta-l-Arabinopyranosidase from Streptomyces avermitilis is a novel member of glycoside hydrolase family 27.

Arabinogalactan proteins (AGPs) are a family of plant cell surface proteoglycans and are considered to be involved in plant growth and development. Because AGPs are very complex molecules, glycoside hydrolases capable of degrading AGPs are powerful tools for analyses of the AGPs. We previously reported such enzymes from Streptomyces avermitilis. Recently, a beta-l-arabinopyranosidase was purified from the culture supernatant of the bacterium, and its corresponding gene was identified. The primary structure of the protein revealed that the catalytic module was highly similar to that of glycoside hydrolase family 27 (GH27) alpha-d-galactosidases. The recombinant protein was successfully expressed as a secreted 64-kDa protein using a Streptomyces expression system. The specific activity toward p-nitrophenyl-beta-l-arabinopyranoside was 18 micromol of arabinose/min/mg, which was 67 times higher than that toward p- nitrophenyl-alpha-d-galactopyranoside. The enzyme could remove 0.1 and 45% l-arabinose from gum arabic or larch arabinogalactan, respectively. X-ray crystallographic analysis reveals that the protein had a GH27 catalytic domain, an antiparallel beta-domain containing Greek key motifs, another antiparallel beta-domain forming a jellyroll structure, and a carbohydrate-binding module family 13 domain. Comparison of the structure of this protein with that of alpha-d-galactosidase showed a single amino acid substitution (aspartic acid to glutamic acid) in the catalytic pocket of beta-l-arabinopyranosidase, and a space for the hydroxymethyl group on the C-5 carbon of d-galactose bound to alpha-galactosidase was changed in beta-l-arabinopyranosidase. Mutagenesis study revealed that the residue is critical for modulating the enzyme activity. This is the first report in which beta-l-arabinopyranosidase is classified as a new member of the GH27 family.