Nucleolin inhibits Fas ligand binding and suppresses Fas-mediated apoptosis in vivo via a surface nucleolin-Fas complex.

Resistance to Fas-mediated apoptosis is associated with poor cancer outcomes and chemoresistance. To elucidate potential mechanisms of defective Fas signaling, we screened primary lymphoma cell extracts for Fas-associated proteins that would have the potential to regulate Fas signaling. An activation-resistant Fas complex selectively included nucleolin. We confirmed the presence of nucleolin-Fas complexes in B-cell lymphoma cells and primary tissues, and the absence of such complexes in B-lymphocytes from healthy donors. RNA-binding domain 4 and the glycine/arginine-rich domain of nucleolin were essential for its association with Fas. Nucleolin colocalized with Fas on the surface of B-cell lymphoma cells. Nucleolin knockdown sensitized BJAB cells to Fas ligand (FasL)-induced and Fas agonistic antibody-induced apoptosis through enhanced binding, suggesting that nucleolin blocks the FasL-Fas interaction. Mice transfected with nucleolin were protected from the lethal effects of agonistic anti-mouse Fas antibody (Jo2) and had lower rates of hepatocyte apoptosis, compared with vector and a non-Fas-binding mutant of nucleolin. Our results show that cell surface nucleolin binds Fas, inhibits ligand binding, and thus prevents induction of Fas-mediated apoptosis in B-cell lymphomas and may serve as a new therapeutic target.

Deployment of cisplatin in Veterans with oropharyngeal cancer: toxicity and impact on oncologic outcomes.

Objective: Cisplatin forms the backbone of systemic chemotherapy treatment for oropharyngeal squamous cell carcinoma (OPSCC). The ideal cisplatin dosing regimen remains yet to be fully defined for achieving optimal efficacy and toxicity profiles in patients with comorbidity. Methods: We retrospectively reviewed oncologic and toxicity data for patients with OPSCC treated at the Michael E. DeBakey Veterans Affairs Medical Center between 2000 and 2020 who initiated curative intent, definitive chemo-radiation with one of three single agent regimens: high dose (HD) cisplatin, low dose (LD) cisplatin or cetuximab. Results: Patients with HPV-associated tumors and nonsmokers demonstrated improved overall and disease-free survival along with locoregional and distant metastatic control regardless of chemotherapy regimen. Regardless of regimen selection, patients which received a cumulative cisplatin dose ≥200 mg/m2 had a lower rate of distant metastasis. The HD regimen resulted in a greater fraction (75% vs. 50%) of patients receiving a cumulative cisplatin dose ≥200 mg/m2 and a comparable measured toxicity burden compared to the LD regimen. Conclusions: Both HD and LD cisplatin regimens can be safely delivered to a Veteran OPSCC patient population which should allow for straightforward application of conclusions drawn from completed and active clinical trials testing cisplatin regimens. Level of Evidence: 4.

Benefits and harms of CT screening for lung cancer: a systematic review.

CONTEXT: Lung cancer is the leading cause of cancer death. Most patients are diagnosed with advanced disease, resulting in a very low 5-year survival. Screening may reduce the risk of death from lung cancer. OBJECTIVE: To conduct a systematic review of the evidence regarding the benefits and harms of lung cancer screening using low-dose computed tomography (LDCT). A multisociety collaborative initiative (involving the American Cancer Society, American College of Chest Physicians, American Society of Clinical Oncology, and National Comprehensive Cancer Network) was undertaken to create the foundation for development of an evidence-based clinical guideline. DATA SOURCES: MEDLINE (Ovid: January 1996 to April 2012), EMBASE (Ovid: January 1996 to April 2012), and the Cochrane Library (April 2012). STUDY SELECTION: Of 591 citations identified and reviewed, 8 randomized trials and 13 cohort studies of LDCT screening met criteria for inclusion. Primary outcomes were lung cancer mortality and all-cause mortality, and secondary outcomes included nodule detection, invasive procedures, follow-up tests, and smoking cessation. DATA EXTRACTION: Critical appraisal using predefined criteria was conducted on individual studies and the overall body of evidence. Differences in data extracted by reviewers were adjudicated by consensus. RESULTS: Three randomized studies provided evidence on the effect of LDCT screening on lung cancer mortality, of which the National Lung Screening Trial was the most informative, demonstrating that among 53,454 participants enrolled, screening resulted in significantly fewer lung cancer deaths (356 vs 443 deaths; lung cancer−specific mortality, 274 vs 309 events per 100,000 person-years for LDCT and control groups, respectively; relative risk, 0.80; 95% CI, 0.73-0.93; absolute risk reduction, 0.33%; P = .004). The other 2 smaller studies showed no such benefit. In terms of potential harms of LDCT screening, across all trials and cohorts, approximately 20% of individuals in each round of screening had positive results requiring some degree of follow-up, while approximately 1% had lung cancer. There was marked heterogeneity in this finding and in the frequency of follow-up investigations, biopsies, and percentage of surgical procedures performed in patients with benign lesions. Major complications in those with benign conditions were rare. CONCLUSION: Low-dose computed tomography screening may benefit individuals at an increased risk for lung cancer, but uncertainty exists about the potential harms of screening and the generalizability of results.

Non-small cell lung cancer in the era of immunotherapy.

Immunotherapy for non-small cell lung cancer (NSCLC) has revolutionized treatment for those with advanced disease, and recent data have emerged providing evidence for its benefits in earlier stages of the disease. Several pivotal clinical trials provide compelling data that adaptive immune cells may be highly effective and possibly even curative for NSCLC. Immune checkpoint inhibitors (ICIs) can unleash highly reactive memory immune responses to tumor antigens with durable effects against advanced or recurrent disease. Despite these encouraging results, many critical questions remain in the field including, for example, how to identify the subsets of NSCLC patients who most benefit from ICI treatment, and how ICI efficacy might be enhanced by utilizing combinations or sequencing of agents. A deeper understanding of biological mechanisms involved in lung cancer offers a unique opportunity to further explore the interaction between the adaptive immune landscape and NSCLC. Given the high incidence of lung cancer in Veterans and many Veterans being treated with immunotherapy for this disease, it is timely to have their adequate representation in future clinical trials. New clinical trials focused on Veterans can assist in exploring ways to mitigate resistant mechanisms as well as to investigate predictive and prognostic biomarkers for response to ICIs and other treatments. This paper will review current data and indications for immunotherapy in NSCLC, introduce new areas of research within immunotherapy, and discuss its applicability to the Veteran population.

Persistent ethnicity-associated disparity in anti-tumor effectiveness of immune checkpoint inhibitors despite equal access.

We reviewed response to immune checkpoint inhibitors (ICI) of 207 patients with diagnoses of lung or head and neck cancer treated with chemotherapy/ICI combination therapy and ICI monotherapy between 2015 and 2020 at one of three clinical pavilions associated with the Dan L. Duncan Comprehensive Cancer Center at Baylor College of Medicine. Two of these pavilions (Harris Health System and the Michael E. DeBakey Veterans Affairs Medical Center) serve large minority populations and provide equal access to care regardless of means. 174 patients had a diagnosis of lung cancer (non-small cell or small cell) and 33 had a diagnosis of head and neck squamous cell carcinoma (HNSCC). 38% self-identified as Black, 45% as non-Hispanic White, and 18% as Hispanic. The objective response rate (ORR) was similar for lung cancer (35.057%) and HNSCC patients (30.3%) (p=0.894). The ORR for Hispanic and Black patients was lower compared to non-Hispanic White patients (H 27.0%, B 32.5%, W 38.7%; H vs. W p=0.209; B vs. W p=0.398). When considering only patients treated with ICI monotherapy, the ORR for Hispanic patients dropped further to 20.7% while the ORR of Black and non-Hispanic White patients remained about the same (B 29.3% and W 35.9%, H vs. W p=0.133; B vs. W p=0.419). Immune related adverse events were the lowest in the Hispanic population occurring in only 30% of patients compared to 40% of patients in the Black cohort and 50% of the non-Hispanic White cohorts.

System level changes in gene expression in maturing bladder mucosa.

PURPOSE: Bladder problems clinically present early in life as birth defects that often lead to kidney failure and late in life as overactive bladder, incontinence and related disorders. We investigated the transcriptome of mouse bladder mucosa at juvenile and adult stages by microarray to identify the pathways associated with normal, healthy growth and maturation. We hypothesized that understanding these pathways could be key to achieving bladder regeneration or reawakening normal function in the elderly population. MATERIALS AND METHODS: RNA was isolated from the mucosa at 3, 6, 20 and 30 weeks postnatally. Affymetrix® Mouse 430 v2 arrays were used to profile the expression of approximately 45,000 genes. The software program Statistical Analysis of Microarrays was used to identify genes that significantly changed during the time course. RESULTS: No genes were significantly up-regulated during maturation. However, 66 well annotated genes demonstrated a statistically significant downward trend, of which 10 of 10 were confirmed by quantitative polymerase chain reaction. The main functions affected by age were transcription, regulation of cellular processes, neurogenesis, blood vessel development and cell differentiation. Notable genes included collagens, Mmp2, SPARC and several transcription factors, including Crebbp, Runx1, Klf9, Mef2c, Nrp1, Pex1 and Tcf4. These molecules were indirectly regulated by inferred Tgfb1 and Egf growth factors. Analysis of gene promoter regions for overrepresented upstream transcription factor binding sites identified specificity protein 1 and epidermal growth factor receptor-specific transcription factor as potentially major transcriptional regulators driving maturation related changes. CONCLUSIONS: These findings identify a coherent set of genes that appear to be down-regulated during urothelial maturation. These genes may represent an attractive target for bladder regeneration or for treating age related loss of function.

Hepatitis B Virus Screening and Management for Patients With Cancer Prior to Therapy: ASCO Provisional Clinical Opinion Update.

PURPOSE: This Provisional Clinical Opinion update presents a clinically pragmatic approach to hepatitis B virus (HBV) screening and management. PROVISIONAL CLINICAL OPINION: All patients anticipating systemic anticancer therapy should be tested for HBV by 3 tests-hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc) total immunoglobulin (Ig) or IgG, and antibody to hepatitis B surface antigen-but anticancer therapy should not be delayed. Findings of chronic HBV (HBsAg-positive) or past HBV (HBsAg-negative and anti-HBc-positive) infection require HBV reactivation risk assessment.Patients with chronic HBV receiving any systemic anticancer therapy should receive antiviral prophylactic therapy through and for minimum 12 months following anticancer therapy. Hormonal therapy alone should not pose a substantial risk of HBV reactivation in patients with chronic HBV receiving hormonal therapy alone; these patients may follow noncancer HBV monitoring and treatment guidance. Coordination of care with a clinician experienced in HBV management is recommended for patients with chronic HBV to determine HBV monitoring and long-term antiviral therapy after completion of anticancer therapy.Patients with past HBV infection undergoing anticancer therapies associated with a high risk of HBV reactivation, such as anti-CD20 monoclonal antibodies or stem-cell transplantation, should receive antiviral prophylaxis during and for minimum 12 months after anticancer therapy completion, with individualized management thereafter. Careful monitoring may be an alternative if patients and providers can adhere to frequent, consistent follow-up so antiviral therapy may begin at the earliest sign of reactivation. Patients with past HBV undergoing other systemic anticancer therapies not clearly associated with a high risk of HBV reactivation should be monitored with HBsAg and alanine aminotransferase during cancer treatment; antiviral therapy should commence if HBV reactivation occurs.Additional information is available at www.asco.org/supportive-care-guidelines.

The use of short tandem repeat profiling to characterize human bladder cancer cell lines.

PURPOSE: Cross-contamination of cell lines is a serious but often unrecognized problem. We describe the authentication of a panel of transitional cell carcinoma cell lines using the short tandem repeat profiling technique to detect cross-contamination. MATERIALS AND METHODS: Genomic DNA was isolated from UM-UC-1, UM-UC-2, UM-UC-3 (ATCC), UM-UC-6, UM-UC-9, UM-UC-10, UM-UC-11, UM-UC-13, UM-UC-14, UM-UC-16, T24 and KU7 cell lines. Short tandem repeat loci (D3S1358, D16S539, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317 and D7S820) and a segment of the X-Y homologous gene amelogenin were co-amplified by polymerase chain reaction. Profiling was done using POP-4TM performance optimized polymer 4 (Applied Biosystems) with an ABI Prism 310 genetic analyzer. DNA sequencing of TP53 and immunohistochemistry for p53 were performed in UM-UC-3 and UM-UC-3-GFP. RESULTS: All cell lines had a unique short tandem repeat profile except UM-UC-2 and T24, which were virtually identical. T24 short tandem repeat profiles matched those of early passage number UM-UC-2. Stable transfection of the green fluorescence protein marker gene did not alter UM-UC-6, UM-UC-14 or KU7 profiles. However, the short tandem repeat profile for UM-UC-3-GFP was different from that of UM-UC-3. DNA sequencing showed a difference in TP53 between UM-UC-3 and UM-UC-3-GFP, confirming that UM-UC-3-GFP is not derived from UM-UC-3. CONCLUSIONS: Short tandem repeat profiling provides a unique genetic signature of human cell lines that does not significantly change with passage or green fluorescence protein transduction. Using short tandem repeat profiling we noted that the cell line UM-UC-2 is T24. DNA fingerprinting using short tandem repeat profiling is an easy and reliable tool that can be used to verify cell lines.

Phase III prevention trial of fenretinide in patients with resected non-muscle-invasive bladder cancer.

PURPOSE: The study aims to evaluate the efficacy and toxicity of fenretinide in preventing tumor recurrence in patients with transitional cell carcinoma (TCC) of the bladder. EXPERIMENTAL DESIGN: We conducted a multicenter phase III, randomized, placebo-controlled trial of fenretinide (200 mg/day orally for 12 months) in patients with non-muscle-invasive bladder TCC (stages Ta, Tis, or T1) after transurethral resection with or without adjuvant intravesical Bacillus Calmette-Guerin (BCG). Patients received cystoscopic evaluation and bladder cytology every 3 months during the 1-year on study drug and a final evaluation at 15 months. The primary endpoint was time to recurrence. RESULTS: A total of 149 patients were enrolled; 137 were evaluable for recurrence. The risk of recurrence was considered to be "low" in 72% (no prior BCG) and intermediate or high in 32% (prior BCG) of the evaluable patients. Of the lower-risk group, 68% had solitary tumors and 32% had multifocal, low-grade papillary (Ta, grade 1 or grade 2) tumors. The 1-year recurrence rates by Kaplan-Meier estimate were 32.3% (placebo) versus 31.5% (fenretinide; P = 0.88 log-rank test). Fenretinide was well tolerated and had no unexpected toxic effects; only elevated serum triglyceride levels were significantly more frequent on fenretinide (versus placebo). The Data Safety and Monitoring Board recommended study closure at 149 patients (before reaching the accrual goal of 160 patients) because an interim review of the data showed a low likelihood of detecting a difference between the two arms, even if the original accrual goal was met. CONCLUSIONS: Although well tolerated, fenretinide did not reduce the time-to-recurrence in patients with Ta, T1, or Tis TCC of the bladder.

Predictors of benefits from frontline chemoimmunotherapy in stage IV non-small-cell lung cancer: a meta-analysis.

Background: Immune checkpoint inhibitors (ICIs) have dramatically expanded the therapeutic landscape of non-small-cell lung cancer (NSCLC). In a previous study, gender, smoking history, and PD-L1 status were found to influence the efficacy of single-agent ICI in NSCLC. This meta-analysis evaluated the clinical and molecular factors that could predict a benefit from adding ICIs to first-line chemotherapy in metastatic NSCLC. Patients and Methods: The pooled hazard ratio (HR) of progression-free survival (PFS) and overall survival (OS) among the selected subgroups were analyzed using the random effects model. The correlation between PD-L1 expression and outcome was analyzed by meta-regression. Results: Seven phase III randomized controlled trials comparing chemo-immunotherapy (CIT) with chemotherapy in untreated stage 4 NSCLC were included. CIT evenly improved PFS irrespective of age, gender, histology, smoking history, and performance status. Among patients with baseline hepatic metastasis treated with Atezolizumab-containing CIT, PFS improvement was only detected with the addition of Bevacizumab. Whereas patients with EGFR/ALK-driven cancer exhibited greater PFS with the addition of ICI to a Bevacizumab (BEV)-based regimen, the derived benefit was no longer statistically significant among those treated with non-BEV-based regimens. Although the superior PFS conferred by CIT was noticeable across all PD-L1 expression subgroups, this benefit correlated with PD-L1 level and was more pronounced in the "PD-L1 high" cohort. Except for patients harboring EGFR/ALK aberrations or squamous histology, CIT consistently improved OS across the other selected subgroups. Conclusions: The survival advantage associated with first-line CIT in metastatic NSCLC was observed in different patient populations, including those for which single-agent ICI has marginal therapeutic benefit. Our findings support the role of chemotherapy with or without VEGF blockade as enhancers of ICI activity in NSCLC.

Analysis of the expression of biomarkers in urinary bladder cancer using a tissue microarray.

Dysregulation of Akt, PTEN, Drg-1, Cx-26, and L-plastin expression appear to be important in the progression of various cancers. Their expression in bladder cancer has not been well characterized. To assess the expression of these genes and their relationship to the outcome of bladder cancer, we used a bladder cancer tissue microarray (TMA) of 251 transitional cell carcinomas. We quantitated immunohistochemical staining of each protein using both automated and manual methods and correlated the expression levels with the clinicopathologic characteristics of the tumor and patient survival. Overall, the results from both automated and manual analyses were similar. We found a significant correlation between the expression of PTEN, Cx-26 and L-plastin with known clinically important pathologic features of bladder cancer (tumor grade, stage, and growth pattern). Aberrant localization patterns of Cx-26 and Drg-1 were observed in bladder tumors. There was also a significant correlation in expression among pAkt, PTEN, and L-plastin. Although the expression of these genes correlated with factors known to be associated with patient outcome, none of them was an independent predictor of progression-free or overall survival.

Forced COX-2 expression induces PGE(2) and invasion in immortalized urothelial cells.

OBJECTIVES: Cyclooxygenase 2 (COX-2) is aberrantly expressed in multiple tumor types including bladder cancer and is associated with enhanced growth, resistance to apoptosis, invasion, and angiogenesis. To evaluate the mechanisms through which COX-2 expression alters normal urothelium, we transfected the SV-40 immortalized human urothelial cell line SV-HUC with COX-2. METHODS: SV-HUC cells were stably transfected with a plasmid containing COX-2 under a CMV promoter. Following isolation of monoclonal transfectants, COX-2 expression was determined by Western and Northern analyses. Prostaglandin E2 (PGE2) in the culture supernatant was measured by ELISA. Cell growth was measured by crystal violet assay. Cellular invasion through Matrigel and anchorage-independent growth in 0.4% agarose were assessed. Tumorigenicity was evaluated by subcutaneous injection of cells in nude mice with and without Matrigel. RESULTS: Four of 12 clones stably overexpressing COX-2 at high levels relative to vector-transfected control cells were chosen for further study. Cell growth rates of these 4 clones were higher than vector control cells. PGE(2) production was elevated in 3 of these 4 clones, and PGE2 levels correlated significantly with invasion through Matrigel. COX-2-transfected cells did not form colonies in soft agarose or tumors in nude mice. CONCLUSIONS: Forced COX-2 expression in SV-HUC immortalized urothelial cells contributes to increased PGE2 production and increased invasion through Matrigel. However, it is insufficient to induce malignant transformation.

Nivolumab Treatment for Cancers in the HIV-infected Population.

Nivolumab is a standard treatment option in several advanced malignancies, but safety and efficacy are still unknown in patients with human immunodeficiency virus (HIV) infection. We describe a case series of people living with HIV (PLWH) receiving nivolumab in the Veterans Health Administration (VA) and report responses and toxicities. We identified all PLWH who received nivolumab at any VA facility since 2000 in the Corporate Data Warehouse (CDW), which provides nationwide research access to VA electronic medical records. We identified 16 HIV-infected nivolumab recipients. The median number of nivolumab doses received was 6 (range, 1-32). Changes in CD4 count during therapy were variable, with 70% (7/10) of patients experiencing increases. Half of PLWH were treated for non-small-cell lung cancer; 2 for Hodgkin lymphoma (HL), 2 for renal cell carcinoma, and 4 for off-label cancers. For non-small-cell lung cancer, 7 patients had evaluable responses. Although 5 of 7 patients immediately progressed, 1 had a partial response and 1 had stable disease, which were both durable. Two of 16 (14%) PLWH had complete responses; both with HL (2/2 HL, 100%). The prevalence of immune-related adverse effects was 40% overall (6/15); 27% (4/15) had pneumonitis. To our knowledge, this is the largest case series reporting outcomes with nivolumab in PLWH. Outcomes were comparable with those seen in studies of HIV-uninfected patients, and particularly interesting for HL. The reason for the high proportions of immune-related adverse effects is unclear, but needs to be confirmed in larger studies.

Selenium accumulation in prostate tissue during a randomized, controlled short-term trial of l-selenomethionine: a Southwest Oncology Group Study.

PURPOSE: Epidemiologic and clinical data suggest that selenium could prevent prostate cancer, but it has not been shown that supplemental selenium leads to an increased concentration of selenium in prostate tissue compared with adjacent tissue. EXPERIMENTAL DESIGN: We conducted a randomized, controlled, short-term trial of l-selenomethionine (SeMet) versus observation in men with organ-confined prostate cancer. The primary endpoint was the measurement of selenium concentration in prostate tissue and seminal vesicle (SV). We assessed baseline selenium levels in serum and in toenail specimens (reflecting long-term intake) and post-intervention selenium levels in serum, and in prostate and SV tissues using hydride generation atomic fluorescence spectroscopy. RESULTS: Sixty-six eligible patients were randomly assigned to the SeMet (n = 34) or observation (n = 32) arm; both arms had similar baseline patient characteristics. Baseline serum selenium was similar in the two groups (P = 0.64). Baseline toenail selenium levels were slightly higher in the SeMet group than in the control group (P = 0.07). After the intervention, the mean serum selenium level increased 15% in the SeMet arm and was higher than in the observation arm (P = 0.001). The selenium concentration in prostate tissue was 22% higher in the SeMet arm (n = 26) than in the observation arm (n = 25; 1.80 versus 1.47 ppm; P = 0.003, Wilcoxon rank sum test) and remained significantly higher after adjusting for chronic selenium intake (P = 0.021, ANCOVA). SV selenium concentration was similar in both groups (P = 0.384) and was lower than in prostate tissue. CONCLUSIONS: The present study is the first to show that selenium taken as oral supplementation accumulates preferentially in the human prostate gland as opposed to the SV. These findings support the hypothesis that oral selenium supplementation may contribute to the cancer preventive effects of selenium.

Transitional cell hyperplasia and carcinomas in urinary bladders of transgenic mice with keratin 5 promoter-driven cyclooxygenase-2 overexpression.

The inducible form of cyclooxygenase (COX), COX-2, is up-regulated in many epithelial cancers and its prostaglandin products increase proliferation, enhance angiogenesis, and inhibit apoptosis in several tissues. Pharmacologic inhibition and genetic deletion studies showed a marked reduction of tumor development in colon and skin. COX-2 has also been strongly implicated in urinary bladder cancer primarily by studies with nonselective COX- and COX-2-selective inhibitors. We now show that forced expression of COX-2, under the control of a keratin 5 promoter, is sufficient to cause transitional cell hyperplasia (TCH) in 17% and 75% of the heterozygous and homozygous transgenic lines, respectively, in an age-dependent manner. TCH was strongly associated with inflammation, primarily nodules of B lymphocytes; some T cells and macrophage infiltration were also observed. Additionally, transitional cell carcinoma was observed in approximately 10% of the K5.COX-2 transgenic mice; no TCH or transitional cell carcinoma was observed in wild-type bladders. Immunohistochemistry for vascular proliferation and vascular endothelial growth factor showed significant increases above that in wild-type urinary bladders. Our results suggest that overexpression of COX-2 is sufficient to cause hyperplasia and carcinomas in the urinary bladder. Therefore, inhibition of COX-2 should continue to be pursued as a potential chemopreventive and therapeutic strategy.

Suppression of prostate tumor cell growth by stromal cell prostaglandin D synthase-derived products.

Stromal-epithelial interactions and the bioactive molecules produced by these interactions maintain tissue homeostasis and influence carcinogenesis. Bioactive prostaglandins produced by prostaglandin synthases and secreted by the prostate into seminal plasma are thought to support reproduction, but their endogenous effects on cancer formation remain unresolved. No studies to date have examined prostaglandin enzyme production or prostaglandin metabolism in normal prostate stromal cells. Our results show that lipocalin-type prostaglandin D synthase (L-PGDS) and prostaglandin D2 (PGD2) metabolites produced by normal prostate stromal cells inhibited tumor cell growth through a peroxisome proliferator-activated receptor gamma (PPARgamma)-dependent mechanism. Enzymatic products of stromal cell L-PGDS included high levels of PGD2 and 15-deoxy-delta(12,14)-PGD2 but low levels of 15-deoxy-delta(12,14)-prostaglandin J2. These PGD2 metabolites activated the PPARgamma ligand-binding domain and the peroxisome proliferator response element reporter systems. Thus, growth suppression of PPARgamma-expressing tumor cells by PGD2 metabolites in the prostate microenvironment is likely to be an endogenous mechanism involved in tumor suppression that potentially contributes to the indolence and long latency period of this disease.

Myasthenia Gravis After Nivolumab Therapy for Squamous Cell Carcinoma of the Bladder.

Checkpoint inhibitors have become standard therapy for multiple cancers, and their use will increase in the next year as regulatory approvals for additional indications are expected. It is essential for clinicians to be aware of the potential for rare immune-related adverse effects. Here, we report the case of a new diagnosis of myasthenia gravis (MG) after the use of nivolumab for squamous cell carcinoma of the bladder. A review the literature identified 10 cases of MG diagnosed after programmed cell death protein 1 inhibitor therapy. This is the first case, to our knowledge, reported in association with bladder cancer. The precise diagnosis of MG has important implications on management, as treatment with steroids can transiently worsen myasthenia in nearly 50% of cases.

Selective cyclooxygenase-2 inhibitors inhibit growth and induce apoptosis of bladder cancer.

Selective COX-2 inhibitors such as celecoxib and NS-398 are being evaluated as chemopreventive and therapeutic agents for bladder and other cancers. We investigated the effects of these nonsteroidal anti-inflammatory agents on a panel of bladder cancer cell lines, and assessed their effects on anchorage-dependent and -independent growth, cell cycle, apoptosis and morphology. The human bladder cancer cell lines UM-UC-1, -3, and -6 were assayed for COX-2 expression by Western analysis using a monoclonal antibody to COX-2. UM-UC-1, -3, and -6 cells were grown in the presence of increasing concentrations of NS-398 and celecoxib, and cell growth was quantitated over 7 days by crystal violet elution. The cell lines were treated with NS-398 and celecoxib for 48 h and analyzed by flow cytometry with propidium iodide staining and Br-dUTP staining for apoptosis. Anchorage-independent growth was assessed using an agarose growth assay. Western analysis demonstrated that COX-2 expression in UM-UC-1, -6, and -3 was high, low, and undetectable, respectively. NS-398 and celecoxib produced dose-dependent growth inhibition of UM-UC-1 and -6. Both NS-398 and celecoxib also inhibited anchorage-dependent and -independent growth of UM-UC-3 in a dose-dependent fashion, despite the low basal expression of COX-2 in this cell line. Cell cycle analyses of UM-UC-1 and -6 revealed a 50% reduction in S-phase in the presence of 100 microM NS-398 whereas a smaller reduction in S-phase was noted in UM-UC-3 cells. Furthermore, treatment with 100 microM celecoxib resulted in significant apoptosis in all three cell lines, which was associated with downregulation of Bcl-2. COX-2 selective inhibitors NS-398 and celecoxib produced dose-dependent growth inhibition of bladder cancer cells associated with a significant reduction in S-phase. Induction of apoptosis in all three cell lines by celecoxib was associated with downregulation of Bcl-2. These changes occur independently of COX-2 expression levels suggesting the presence of a COX-2 independent pathway.