[Changes in peripheral blood 25 - hydroxyvitamin D3, Th17 cells, and CD4+ regulatory T cells and their clinical significance in patients with primary biliary cirrhosis]

Objective: To investigate the changes in peripheral blood 25-hydroxyvitamin D₃[25-(OH)D₃], CD4⁺regulatory T (Treg) cells, and Th17 cells in patients with primary biliary cirrhosis (PBC) and their mechanism of action in PBC. Methods: A total of 22 patients with PBC were enrolled and the male/female ratio was 1:21, with a mean age of 61±12 years. There were 7 healthy volunteers matched for age in the normal control group. Electrochemiluminescence immunoassay was used to measure the peripheral blood 25-(OH)D₃level in the PBC group and normal control group, and flow cytometry was used to analyze the changes in Th17 cells and CD4⁺Treg cells. The t-test, rank sum test, Pearson correlation analysis, or Spearman's rank correlation analysis was used for statistical analysis according to the type of the data. Results: The PBC group had a significantly lower serum 25-(OH)D₃level than the normal control group (9.49±3.65 vs 27.35±2.35 ng/ml,P< 0.01). Compared with the normal control group, the PBC group had a significantly higher percentage of Th17 cells (2.05%±1.17% vs 0.99%±0.12%,P< 0.01) and a significantly lower percentage of CD4⁺Treg cells (2.54%±1.14% vs 3.78%±0.51%,P< 0.05); there was a significant difference in Th17/Treg ratio between the PBC group and the normal control group (1.00±0.63 vs 0.26±0.02,P< 0.01). In the PBC group, peripheral blood 25-(OH)D3 was not correlated with Th17 cells or Th17/Treg ratio (r= -0.062 and -0.328,P> 0.05), while it was positively correlated with the percentage of CD4⁺Treg cells (r= 0.468,P< 0.05). Conclusion: Patients with PBC have significant reductions in peripheral blood 25-(OH)D₃and percentage of CD4⁺Treg cells, a significant increase in the percentage of Th17 cells, and immune unbalance of Th17 cells and CD4⁺Treg cells. 25-(OH)D₃can upregulate the percentage of CD4⁺Treg cells and thus affect the development and progression of PBC, and exogenous vitamin D may improve immune function in PBC patients.

p63α protein up-regulates heat shock protein 70 expression via E2F1 transcription factor 1, promoting Wasf3/Wave3/MMP9 signaling and bladder cancer invasion

Bladder cancer (BC) is the sixth most common cancer in the United States and is the number one cause of death among patients with urinary system malignancies. This makes the identification of invasive regulator(s)/effector(s) as the potential therapeutic targets for managing BC a high priority. p63 is a member of the p53 family of tumor suppressor genes/proteins, plays a role in the differentiation of epithelial tissues, and is believed to function as a tumor suppressor. However, it remains unclear whether and how p63 functions in BC cell invasion after tumorigenesis. Here, we show that p63α protein levels were much higher in mouse high-invasive BC tissues than in normal tissues. Our results also revealed that p63α is crucial for heat shock protein 70 (Hsp70) expression and subsequently increases the ability of BC invasion. Mechanistic experiments demonstrated that p63α can transcriptionally up-regulate Hsp70 expression, thereby promoting BC cell invasion via the Hsp70/Wasf3/Wave3/MMP-9 axis. We further show that E2F transcription factor 1 (E2F1) mediates p63α overexpression-induced Hsp70 transcription. We also found that p63α overexpression activates E2F1 transcription, which appears to be stimulated by p63α together with E2F1. Collectively, our results demonstrate that p63α is a positive regulator of BC cell invasion after tumorigenesis, providing significant insights into the biological function of p63α in BC and supporting the notion that p63α might be a potential target for invasive BC therapy.

[Clinical features and gene mutations in epilepsy of infancy with migrating focal seizures]

Objective: To summarize the clinical features and gene mutations of epilepsy of infancy with migrating focal seizures (EIMFS). Method: Clinical features and electroencephalograms(EEG)of 9 patients with EIMFS of Peking University First Hospital from May 2015 to January 2016 were analyzed. Candidate gene mutations were screened by next generation sequencing. Result: Among the 9 patients, 3 were males and 6 were females. Two patients had family history. Seizure onset age was 2 days to 3 months after birth (median age 35 days). Migrating focal seizure was presented. Seizures manifested as eyes and(or)head deviation, involuntary blinking, swallowing, trembling or stiffness of limbs, hand clenching, flushing and cyanosis of lips, etc. Four patients had a history of status epilepticus. All 9 patients had psychomotor delay. EEG of all patients presented relatively slow background; during interictal phase, there were multi-focal epileptic discharges, which dominated one hemisphere or brain region; seizures were recorded in all 9 cases, which manifested eyes or(and)head deviation, stiffening or trembling of limbs, lip smacking, etc. Corresponding EEG showed low-medium-amplitude fast waves that originated from some brain regions and migrated to other regions. Cranial magnetic resonance imaging (MRI) was abnormal in 4 cases, which predominantly showed white matter dysplasia and enlargement of subarachnoid spaces. Two cases carried heterozygous missense mutations of SCN1A gene, while 3 cases carried heterozygous missense mutations of KCNT1 gene, all of which were de novo. One case carried compound heterozygous mutation of TBC1D24 gene(p.Gln207*, p. Ala289Va). Gene mutation was not found in 3 cases. All patients used multiple antiepileptic drugs (AED) and their seizures were not controlled. Follow-up ranged from 2 months to 5 years and 8 months, during which 4 were found dead. Two were lost to follow-up. Conclusion: EIMFS is clinically characterized by early onset, which is usually within 3 months after birth, migrating focal seizures, psychomotor delay, bad response to AED and high death rate. The interictal EEG showed multi-focal discharges, while ictal EEG shows migrating multifocal discharges. Genetic analysis can assist in diagnosis and genetic counseling.

[Clinical and neuroimaging features of acute encephalopathy after status epilepticus in Dravet syndrome]

Objective: To investigate the clinical and neuroimaging characteristics of acute encephalopathy (AE) after status epilepticus (SE) of patients with Dravet syndrome (DS). Method: The clinical data of DS patients who had AE (coma ≥24 h) after SE were retrospectively collected from February 2005 to August 2016 in Peking University First Hospital and SCN1A gene tests were performed.The clinical and neuroimaging features were summarized. Result: Twenty-two patients (9 males and 13 females) with AE were collected among 412 DS patients during follow-up.Of which 18 patients had SCN1A gene mutations while the remaining 4 patients had no SCN1A gene mutations.The onset age of AE was between 6 months and 10 years.The duration of SE varied between 40 minutes and 9 hours.Prior to the onset of SE, twenty-one patients had high fever, and one patient had normal temperature.Coma lasted from 2 days to 20 days.Nine patients died after the AE, and 13 patients survived with massive neurological regression.From AE to the last visit, the median time of follow-up was 2 years and 3 months (from 7 months to 4 years and 4 months). Nine of 13 survivors had varied improvement in motor, language and cognition, while the remaining 4 patients had no significant improvement.After AE, there were 6 patients with seizure-free, 4 patients with reduced seizures, and 3 patients with no change in seizure frequency, moreover, spasm occurred in 2 patients.Six patients had brain magnetic resonance imaging (MRI) in acute phase and showed bilateral (2 patients) or unilateral (4 patients) hemisphere edema, accompanied by subcortical white matter hyperintense signal in T1 and T2 weighted images in two patients.The neuroimaging of 13 survivors demonstrated diverse cortical atrophy during recovery phase, among which 4 patients showed cerebellar atrophy, one patient had right pontine atrophy, 4 patients accompanied by signal abnormalities in subcortical and periventricular white matter, 2 patients showed right hippocampal sclerosis, and one patient showed signal abnormalities in bilateral basal ganglia. Conclusion: SE is more prone to occur in Dravet patients who have high fever.It may result in AE or even death in severe cases.Survivors will leave severe neurological sequelae.The neuroimaging shows brain edema in acute phase.In recovery phase the neuroimaging shows diverse brain atrophy, moreover, a few patients may be associated with cerebellar or pontine atrophy, hippocampal sclerosis or abnormal signals in white matter or basal ganglia.

Role of STAT3 and FOXO1 in the Divergent Therapeutic Responses of Non-metastatic and Metastatic Bladder Cancer Cells to miR-145

Although miR-145 is the most frequently downregulated miRNA in bladder cancer, its exact stage association and downstream effector have not been defined. Here, we found that miR-145 was upregulated in human patients with bladder cancer with lymph node metastasis and in metastatic T24T cell line. Forced expression of miR-145 promoted anchorage-independent growth of T24T cells accompanied by the downregulation of forkhead box class O1 (FOXO1). In contrast, in non-metastatic T24 cells, miR-145 overexpression inhibited cell growth with upregulation of FOXO1, and the knockdown of FOXO1 abolished the miR-145-mediated inhibition of cell growth. Mechanistic studies revealed that miR-145 directly bound to and attenuated 3'-untranslated region (UTR) activity of foxo1 mRNA in both T24 and T24T cells. Interestingly, miR-145 suppressed STAT3 phosphorylation at Tyr705 and increased foxo1 promoter transcriptional activity in T24 cells, but not in T24T cells, suggesting a role of STAT3 in the divergent responses to miR-145. Supporting this was our finding that STAT3 knockdown mimicked miR-145-mediated upregulation of FOXO1 in T24T cells and inhibition of anchorage-independent growth. Consistently, ectopic expression of miR-145 promoted tumor formation of xenograft T24T cells, whereas such promoting effect became inhibitory due to specific knockdown of STAT3. Together, our findings demonstrate the stage-specific association and function of miR-145 in bladder cancers and provide novel insights into the therapeutic targeting of miR-145. Mol Cancer Ther; 16(5); 924-35. ©2017 AACR.

XIAP BIR domain suppresses miR-200a expression and subsequently promotes EGFR protein translation and anchorage-independent growth of bladder cancer cell

BACKGROUND

The X-linked inhibitor of apoptosis protein (XIAP) is a well-known potent apoptosis suppressor and also participates in cancer cell biological behaviors, therefore attracting great attentions as a potential antineoplastic therapeutic target for past years. Anti-IAP therapy is reported to be closely related to epidermal growth factor receptor (EGFR) expression level. However, whether and how XIAP modulates EGFR expression remains largely unknown.

METHODS

Human XIAP was knockdown with short-hairpin RNA in two different bladder cancer cell lines, T24T and UMUC3. Two XIAP mutants, XIAP ∆BIR (deletion of N-terminal three BIR domains) and XIAP ∆RING (deletion of C-terminal RING domain and keeping the function of BIR domains), were generated to determine which domain is involved in regulating EGFR.

RESULTS

We found here that lacking of XIAP expression resulted in a remarkable suppression of EGFR expression, consequently leading to the deficiency of anchorage-independent cell growth. Further study demonstrated that BIR domain of XIAP was crucial for regulating the EGFR translation by suppressing the transcription and expression of miR-200a. Mechanistic studies indicated that BIR domain activated the protein phosphatase 2 (PP2A) activity by decreasing the phosphorylation of PP2A at Tyr307 in its catalytic subunit, PP2A-C. Such activated PP2A prevented the deviant phosphorylation and activation of MAPK kinases/MAPKs, their downstream effector c-Jun, and in turn inhibiting transcription of c-Jun-regulated the miR-200a.

CONCLUSIONS

Our study uncovered a novel function of BIR domain of XIAP in regulating the EGFR translation, providing significant insight into the understanding of the XIAP overexpression in the cancer development and progression, further offering a new theoretical support for using XIAP BIR domain and EGFR as targets for cancer therapy.

Abstract 5241: Nitric oxide-releasing naproxen prevents muscle invasive bladder cancer

Bladder cancer is the second most common and a leading cause of death among genitourinary cancers worldwide. Particularly, untreated muscle invasive bladder cancer has high mortality (&gt;85% patients) leading to death within 2 years of diagnosis. Preventing this deadly form is highly imperative since the currently available options to patients with invasive disease remained essentially unchanged and no effective drugs have been approved in past two decades. Several non-steroidal anti-inflammatory agents (NSAIDs) have shown promising chemopreventive activity in many cancers. The common adverse events with NSAIDs, especially gastrointestinal (GI) morbidities, including complications in both upper and lower GI tract drives the need for development of safer agents. To overcome this various nitric oxide (NO)-linked NSAIDs have been synthesized. Here we investigated the NO-releasing Naproxen (NO-Naproxen) with proven anti-inflammatory and GI protecting effects for its efficacy in preventing bladder cancer. Transgenic mouse model (UPII-SV40T; n = 30/group) that develop muscle invasive urothelial tumors were generated, genotyped and fed modified AIN-76A diet containing NO-naproxen (0, 300 and 600 ppm) starting at 6 weeks of age. At 40 weeks age, control (0 ppm) and experimental diet (300 and 600 ppm) fed mice were euthanized and urinary bladders were analyzed. Control diet fed male and female transgenic mice developed high grade, invasive transitional cell carcinoma (TCC) of bladder resulting in significant increase in bladder weights (140.2±9.8 mg; p&lt;0.0001 and 34.2+0.8 mg; p&lt;0.0001 respectively) compared with wild type mice (27.3±0.8 mg and 14.8±0.53 mg). These tumors had a significant disregulation of proliferation, cell cycle markers and antioxidant enzymes similar to human tumors. NO-Naproxen administered mice had normal body weight gain; and gross tissue analysis and showed no signs of overt toxicities. Treatment of transgenic mice with NO-Naproxen led to significant suppression of bladder weight in both genders (up to 58% in males, p&lt;0.0001; up to 21% in females, p&lt;0.005) compared to control group. While there was no dose-dependent increase in tumor inhibition, mice on NO-Naproxen diet had developed significantly less muscle invasive tumors suggesting inhibitory effect of treatment on disease progression. Urothelial tumor progression to invasive TCC was inhibited in both male (up to 54%; p&lt;0.005) and females mice (up to 85%; p&lt;0.0001) of the experimental diet groups. Molecular analysis of urothelial tumors via real-time PCR, IHC and/or western blotting showed inhibitory effect of NO-Naproxen on proliferation and inflammatory markers (PCNA, Cyclins, COX2, and IL1b) and showed modulation of antioxidant enzymes (CAT, GPx, GST, NQO1, and SOD3). Our results suggest that NO-Naproxen may be a promising agent for preventing urothelial TCC and warrants further investigation. (Supported in part by NCI-CN53300)

Citation Format: Venkateshwar Madka, Altaf Mohammed, Qian Li, Yuting Zhang, Stanley Lightfoot, Xue-Ru Wu, Vernon Steele, Levy Kopelovich, Chinthalapally V. Rao. Nitric oxide-releasing naproxen prevents muscle invasive bladder cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5241.

[Genotype and phenotype of female Dravet syndrome with PCDH19 mutations]

OBJECTIVE

To explore the genotype and phenotype of female Dravet syndrome (DS) patients with PCDH19 mutations.

METHOD

Clinical data of all DS patients seen at Pediatric Department of Peking University First Hospital from February 2005 to May 2015 were prospectively collected. Genomic DNAs were extracted from the patients and their family members. Female DS patients without SCN1A mutation were enrolled. PCR and Sanger sequencing were performed to identify PCDH19 mutations. Clinical data of DS patients with PCDH19 mutations were summarized.

RESULT

Five different heterozygous PCDH19 mutations were identified in six unrelated patients of 75 SCN1A-negative female DS patients (8%), among whom five patients had de novo mutations and one patient's mutation was inherited from her affected mother. Three missense mutations and two insertion mutations were all located in exon 1. Mean age of onset of the six patients with PCDH19 mutations was 6.8 months (range 5-9 months). Onset of seizures were triggered by fever in four patients, after vaccination in one and without fever in one. Generalized tonic clonic seizure (GTCS) was the first seizure type in four patients and focal seizure with secondary generalized tonic clonic seizures in the remaining two. During the course, all patients presented multiple seizure types including generalized tonic clonic seizures and focal seizures in all six patients, myoclonic seizures in three, absence seizures and atonic seizures in one respectively. In all patients, seizures manifested fever-sensitive and in clusters. Seizures were always in brief duration, in most less than 5 minutes, except one experienced twice status epilepticus triggered by fever. Six patients had development delay after the seizure onset, two with autism spectrum disorder, three with ataxia.

CONCLUSION

PCDH19 is another important gene of DS after SCN1A, mutations mainly occurred de novo. PCDH19 gene mutation should be routinely screened in female DS patients without SCN1A mutation. The clinical features of female DS patients with PCDH19 mutations include that the main seizures types are generalized tonic clonic seizures and focal seizures, seizures occurr in clusters and fever-sensitive, short seizure duration, rare status epilepticus, common development delay and some may manifest autism spectrum disorders.

Role of isoenzyme M2 of pyruvate kinase in urothelial tumorigenesis

The conversion of precancerous lesions to full-fledged cancers requires the affected cells to surpass certain rate-limiting steps. We recently showed that activation of HRAS proto-oncogene in urothelial cells of transgenic mice causes simple urothelial hyperplasia (SUH) which is persistent and whose transition to low-grade papillary urothelial carcinoma (UC) must undergo nodular urothelial hyperplasia (NUH). We hypothesized that NUH, which has acquired fibrovascular cores, plays critical roles in mesenchymal-to-epithelial signaling, breaching the barriers of urothelial tumor initiation. Using proteomics involving two-dimensional gel electrophoresis, immunoblotting with pan-phosphotyrosine antibody and MALDI-mass spectrometry, we identified isoform 2 of pyruvate kinase (PKM2) as the major tyrosine-phosphorylated protein switched on during NUH. We extended this finding using specimens from transgenic mice, human UC and UC cell lines, establishing that PKM2, but not its spliced variant PKM1, was over-expressed in low-grade and, more prominently, high-grade UC. In muscle-invasive UC, PKM2 was co-localized with cytokeratins 5 and 14, UC progenitor markers. Specific inhibition of PKM2 by siRNA or shRNA suppressed UC cell proliferation via increased apoptosis, autophagy and unfolded protein response. These results strongly suggest that PKM2 plays an important role in the genesis of low-grade non-invasive and high-grade invasive urothelial carcinomas.

Sequential and compartmentalized action of Rabs, SNAREs, and MAL in the apical delivery of fusiform vesicles in urothelial umbrella cells

As major urothelial differentiation products, uroplakins are targeted to the apical surface of umbrella cells. Via the sequential actions of Rabs 11, 8, and 27b and their effectors, uroplakin vesicles are transported to a subapical zone above a K20 network and fuse, via a SNARE-mediated and MAL-facilitated step, with the urothelial apical membrane.

Uroplakins (UPs) are major differentiation products of urothelial umbrella cells and play important roles in forming the permeability barrier and in the expansion/stabilization of the apical membrane. Further, UPIa serves as a uropathogenic Escherichia coli receptor. Although it is understood that UPs are delivered to the apical membrane via fusiform vesicles (FVs), the mechanisms that regulate this exocytic pathway remain poorly understood. Immunomicroscopy of normal and mutant mouse urothelia show that the UP-delivering FVs contained Rab8/11 and Rab27b/Slac2-a, which mediate apical transport along actin filaments. Subsequently a Rab27b/Slp2-a complex mediated FV–membrane anchorage before SNARE-mediated and MAL-facilitated apical fusion. We also show that keratin 20 (K20), which forms a chicken-wire network ∼200 nm below the apical membrane and has hole sizes allowing FV passage, defines a subapical compartment containing FVs primed and strategically located for fusion. Finally, we show that Rab8/11 and Rab27b function in the same pathway, Rab27b knockout leads to uroplakin and Slp2-a destabilization, and Rab27b works upstream from MAL. These data support a unifying model in which UP cargoes are targeted for apical insertion via sequential interactions with Rabs and their effectors, SNAREs and MAL, and in which K20 plays a key role in regulating vesicular trafficking.

High Sensitivity of an Ha-RAS Transgenic Model of Superficial Bladder Cancer to Metformin Is Associated with ∼240-Fold Higher Drug Concentration in Urine than Serum

While pharmacoepidemiologic and laboratory studies have supported the hypothesis that the antidiabetic drug metformin may be useful in treating or preventing cancer, there is limited evidence to suggest which specific cancer sites may be particularly sensitive. Sensitivity likely is determined both by features of tumor pathophysiology and by pharmacokinetic factors. We used UPII-mutant Ha-ras transgenic mice that develop hyperplasia and low-grade, papillary urothelial cell carcinoma to determine whether metformin has activity in a model of superficial bladder cancer. Metformin significantly improved survival, reduced urinary tract obstruction, reduced bladder weight (a surrogate for tumor volume), and led to clear activation of AMP α kinase and inhibition of mTOR signaling in neoplastic tissue. We investigated the basis of the unusual sensitivity of this model to metformin, and observed that following oral dosing, urothelium is exposed to drug concentrations via the urine that are approximately 240-fold higher than those in the circulation. In addition, we observed that bladder cancer cell lines (RT4, UMUC-3, and J82) with homozygous deletion of either TSC1 or PTEN are more sensitive to metformin than those (TEU2, TCCSUP, and HT1376) with wild-type TSC1 and PTEN genes. Our findings provide a strong rationale for clinical trials of oral metformin in treatment of superficial bladder cancer.

Loss of FOXA1 Drives Sexually Dimorphic Changes in Urothelial Differentiation and Is an Independent Predictor of Poor Prognosis in Bladder Cancer

We previously found loss of forkhead box A1 (FOXA1) expression to be associated with aggressive urothelial carcinoma of the bladder, as well as increased tumor proliferation and invasion. These initial findings were substantiated by The Cancer Genome Atlas, which identified FOXA1 mutations in a subset of bladder cancers. However, the prognostic significance of FOXA1 inactivation and the effect of FOXA1 loss on urothelial differentiation remain unknown. Application of a univariate analysis (log-rank) and a multivariate Cox proportional hazards regression model revealed that loss of FOXA1 expression is an independent predictor of decreased overall survival. An ubiquitin Cre-driven system ablating Foxa1 expression in urothelium of adult mice resulted in sex-specific histologic alterations, with male mice developing urothelial hyperplasia and female mice developing keratinizing squamous metaplasia. Microarray analysis confirmed these findings and revealed a significant increase in cytokeratin 14 expression in the urothelium of the female Foxa1 knockout mouse and an increase in the expression of a number of genes normally associated with keratinocyte differentiation. IHC confirmed increased cytokeratin 14 expression in female bladders and additionally revealed enrichment of cytokeratin 14-positive basal cells in the hyperplastic urothelial mucosa in male Foxa1 knockout mice. Analysis of human tumor specimens confirmed a significant relationship between loss of FOXA1 and increased cytokeratin 14 expression.

Divergent behaviors and underlying mechanisms of cell migration and invasion in non-metastatic T24 and its metastatic derivative T24T bladder cancer cell lines

Previous studies on cancer cell invasion were primarily focused on its migration because these two events were often considered biologically equivalent. Here we found that T24T cells exhibited higher invasion but lower migration abilities than T24 cells. Expression of Rho-GDPases was much lower and expression of SOD2 was much higher in T24T cells than those in T24 cells. Indeed, knockdown of SOD2 in T24T cells can reverse the cell migration but without affecting cell invasion. We also found that SOD2 inhibited the JNK/c-Jun cascade, and the inhibition of c-Jun activation by ectopic expression of TAM67 impaired Rho-GDPases expression and cell migration in T24T shSOD2 cells. Further, we found that Sp1 can upregulate SOD2 transcription in T24T cells. Importantly, matrix metalloproteinase-2 (MMP-2) was overexpressed in T24T and participated in increasing its invasion, and MMP-2 overexpression was mediated by increasing nuclear transport of nucleolin, which enhanced mmp-2 mRNA stability. Taken together, our study unravels an inverse relationship between cell migration and invasion in human bladder cancer T24T cells and suggests a novel mechanism underlying the divergent roles of SOD2 and MMP-2 in regulating metastatic behaviors of human bladder T24T in cell migration and invasion.

Targeting mTOR and p53 Signaling Inhibits Muscle Invasive Bladder Cancer In Vivo

Urothelial tumors, accompanied by mutations of the tumor suppressor protein TP53 and dysregulation of mTOR signaling, are frequently associated with aggressive growth and invasiveness. We investigated whether targeting these two pathways would inhibit urothelial tumor growth and progression. Six-week-old transgenic UPII-SV40T male mice (n = 15/group) were fed control diet (AIN-76A) or experimental diets containing mTOR inhibitor (rapamycin, 8 or 16 ppm), p53 stabilizing agent [CP31398 (CP), 150 ppm], or a combination. Mice were euthanized at 40 weeks of age. Urinary bladders were collected and evaluated to determine tumor weight and histopathology. Each agent alone, and in combination, significantly inhibited tumor growth. Treatment with rapamycin alone decreased tumor weight up to 67% (P < 0.0001). Similarly, CP showed approximately 77% (P < 0.0001) suppression of tumor weight. The combination of low-dose rapamycin and CP led to approximately 83% (P < 0.0001) inhibition of tumor weight. There was no significant difference in tumor weights between rapamycin and CP treatments (P > 0.05). However, there was a significant difference between 8 ppm rapamycin and the combination treatment. Tumor invasion was also significantly inhibited in 53% (P < 0.005) and 66% (P < 0.0005) mice after 8 ppm and 16 ppm rapamycin, respectively. However, tumor invasion was suppressed in 73% (P < 0.0001) mice when CP was combined with 8 ppm rapamycin. These results suggest that targeting two or more pathways achieve better treatment efficacy than a single-agent high-dose strategy that could increase the risk of side effects. A combination of CP and rapamycin may be a promising method of inhibiting muscle-invasive urothelial transitional cell carcinoma.

Cigarette side-stream smoke lung and bladder carcinogenesis: inducing mutagenic acrolein-DNA adducts, inhibiting DNA repair and enhancing anchorage-independent-growth cell transformation

Second-hand smoke (SHS) is associated with 20-30% of cigarette-smoke related diseases, including cancer. Majority of SHS (>80%) originates from side-stream smoke (SSS). Compared to mainstream smoke, SSS contains more tumorigenic polycyclic aromatic hydrocarbons and acrolein (Acr). We assessed SSS-induced benzo(a)pyrene diol epoxide (BPDE)- and cyclic propano-deoxyguanosine (PdG) adducts in bronchoalveolar lavage (BAL), lung, heart, liver, and bladder-mucosa from mice exposed to SSS for 16 weeks. In SSS exposed mice, Acr-dG adducts were the major type of PdG adducts formed in BAL (p < 0.001), lung (p < 0.05), and bladder mucosa (p < 0.001), with no significant accumulation of Acr-dG adducts in heart or liver. SSS exposure did not enhance BPDE-DNA adduct formation in any of these tissues. SSS exposure reduced nucleotide excision repair (p < 0.01) and base excision repair (p < 0.001) in lung tissue. The levels of DNA repair proteins, XPC and hOGG1, in lung tissues of exposed mice were significantly (p < 0.001 and p < 0.05) lower than the levels in lung tissues of control mice. We found that Acr can transform human bronchial epithelial and urothelial cells in vitro. We propose that induction of mutagenic Acr-DNA adducts, inhibition of DNA repair, and induction of cell transformation are three mechanisms by which SHS induces lung and bladder cancers.

ATDC/TRIM29 Drives Invasive Bladder Cancer Formation through miRNA-Mediated and Epigenetic Mechanisms

Bladder cancer is a common and deadly malignancy but its treatment has advanced little due to poor understanding of the factors and pathways that promote disease. ATDC/TRIM29 is a highly expressed gene in several lethal tumor types, including bladder tumors, but its role as a pathogenic driver has not been established. Here we show that overexpression of ATDC in vivo is sufficient to drive both noninvasive and invasive bladder carcinoma development in transgenic mice. ATDC-driven bladder tumors were indistinguishable from human bladder cancers, which displayed similar gene expression signatures. Clinically, ATDC was highly expressed in bladder tumors in a manner associated with invasive growth behaviors. Mechanistically, ATDC exerted its oncogenic effects by suppressing miR-29 and subsequent upregulation of DNMT3A, leading to DNA methylation and silencing of the tumor suppressor PTEN. Taken together, our findings established a role for ATDC as a robust pathogenic driver of bladder cancer development, identified downstream effector pathways, and implicated ATDC as a candidate biomarker and therapeutic target.