Bladder cancer

LncRNAs in necroptosis: Deciphering their role in cancer pathogenesis and therapy

Necroptosis, a controlled type of cell death that is different from apoptosis, has become a key figure in the aetiology of cancer and offers a possible target for treatment. A growing number of biological activities, including necroptosis, have been linked to long noncoding RNAs (lncRNAs), a varied family of RNA molecules with limited capacity to code for proteins. The complex interactions between LncRNAs and important molecular effectors of necroptosis, including mixed lineage kinase domain-like pseudokinase (MLKL) and receptor-interacting protein kinase 3 (RIPK3), will be investigated. We will explore the many methods that LncRNAs use to affect necroptosis, including protein-protein interactions, transcriptional control, and post-transcriptional modification. Additionally, the deregulation of certain LncRNAs in different forms of cancer will be discussed, highlighting their dual function in influencing necroptotic processes as tumour suppressors and oncogenes. The goal of this study is to thoroughly examine the complex role that LncRNAs play in controlling necroptotic pathways and how that regulation affects the onset and spread of cancer. In the necroptosis for cancer treatment, this review will also provide insight into the possible therapeutic uses of targeting LncRNAs. Techniques utilising LncRNA-based medicines show promise in controlling necroptotic pathways to prevent cancer from spreading and improve the effectiveness of treatment.

Complement Regulatory Protein CD46 Manifests a Unique Role in Promoting the Migration of Bladder Cancer Cells

CD46 is a membrane-bound complement regulatory protein (mCRP) possessing a regulatory role with the complement system. CD46 protects the host cells from damage by complement. Expression of CD46 is also highly maintained in many cancers, including bladder cancers, and thus functions as a receptor for many cancer therapeutic viruses. In this study we report a unique role of CD46 as a progression factor of cancer cells in bladder cancers. Resulting data from a DNA microarray using CD46-altered HT1376 bladder cancers demonstrated a pool of target genes, including complement C3 α chain (C3α), matrix Gla protein (MGP), AFAP-AS1, follicular dendritic cell secreted protein (FDCSP), MAM domain containing 2 (MAMDC2), gamma-aminobutyric acid A receptor pi (GABRP), transforming growth factor, beta-induced (TGFBI), a family of cytochrome P450 (CYP24A1), sialic acid binding Ig-like lectin 6 (SIGLEC6), metallothionein 1E (MT1E), and several members of cytokeratins. Subsequent studies using quantitative RT-PCR and Western blot analyses confirmed CD46-mediated regulation of C3α, MGP, and keratin 13 (KRT13). MGP and KRT13 are known to be involved in cell migration and cancer cell metastasis. A cell migration assay demonstrated that CD46 enhanced migratory potential of bladder cancer cells. Taken all together, this report demonstrated that CD46 is generally overexpressed in bladder cancers and plays a unique role in the promotion of cancer cell migration. Further detailed studies are needed to be performed to clarify the action mechanism of CD46 and its application to cancer therapeutics.

Role of the long non-coding RNAs in regulation of Gemcitabine response in tumor cells

Chemotherapy is widely used as one of the first line therapeutic methods in cancer patients. However, chemotherapeutic resistance is one of the most common problems in cancer patients, which leads to the therapeutic failure and tumor relapse. Considering the side effects of chemotherapy drugs in normal tissues, it is required to investigate the molecular mechanisms involved in drug resistance to improve the therapeutic strategies in cancer patients. Long non-coding RNAs (lncRNAs) have pivotal roles in regulation of cellular processes associated with drug resistance. LncRNAs deregulations have been frequently reported in a wide range of chemo-resistant tumors. Gemcitabine (GEM) as a nucleoside analog has a wide therapeutic application in different cancers. However, GEM resistance is considered as a therapeutic challenge. Considering the role of lncRNAs in the occurrence of GEM resistance, in the present review we discussed the molecular mechanisms of lncRNAs in regulation of GEM response among cancer patients. It has been reported that lncRNAs have mainly an oncogenic role as the inducers of GEM resistance through direct or indirect regulation of transcription factors, autophagy, polycomb complex, and signaling pathways such as PI3K/AKT, MAPK, WNT, JAK/STAT, and TGF-β. This review paves the way to present the lncRNAs as non-invasive markers to predict GEM response in cancer patients. Therefore, lncRNAs can be introduced as the efficient markers to reduce the possible chemotherapeutic side effects in GEM resistant cancer patients and define a suitable therapeutic strategy among these patients.

In Vitro and In Vivo Antitumor Efficacy of Hizikia fusiforme Celluclast Extract against Bladder Cancer

Various physiological benefits have been linked to Hizikia fusiforme (HF), an edible brown seaweed. Here, fucose-containing sulfated polysaccharides were extracted from celluclast-processed HF (SPHF) and their antitumor efficacy against bladder cancer was evaluated in vitro and in vivo. SPHF possesses high sulfated polysaccharide and fucose contents and free radical scavenging activities compared to those of celluclast-processed HF extracts (CHF). SPHF inhibited bladder cancer EJ cell proliferation via G1-phase cell cycle arrest. This was due to the induction of p21WAF1 expression associated with the downregulation of CDKs and cyclins. Moreover, JNK phosphorylation was identified as an SPHF-mediated signaling molecule. SPHF treatment also hindered the migration and invasion of EJ cells by inhibiting MMP-9 expression, which was attributed to the repression of transcriptional binding to NF-κB, AP-1, and Sp-1 in the MMP-9 promoter region. In an animal study, SPHF treatment suppressed EJ tumor growth in xenograft mice similarly to cisplatin. Furthermore, no toxicity signs were found after weight loss assessment, biochemical tests, and organ tissue immunostaining during oral administration of 20–200 mg/kg SPHF for 20 days. Therefore, our study demonstrates the antitumor efficacy of SPHF in vitro and in vivo, thus highlighting its potential for bladder cancer treatment development.

An improved mouse orthotopic bladder cancer model exhibiting progression and treatment response characteristics of human recurrent bladder cancer

Nonmuscle-invasive (superficial) bladder cancer is generally treated via surgical removal, followed by adjuvant therapy (bacillus Calmette-Guerin). However, bladder cancer can often recur, and in a substantial number of recurrent cases, the cancer progresses and metastasizes. Furthermore, residual microtumors following excision may lead to an increased risk of recurrence. An in vivo model mimicking the pattern of urinary bladder microtumor regrowth may provide an effective experimental system for improving postsurgical treatment outcomes. A mouse bladder cancer model established using orthotopic transplant of UM-UC-3 human urinary bladder carcinoma cells has been established, however, to the best of our knowledge, no report has investigated sequential histological changes, including early-phase changes and treatment responses in bladder cancer. In the present study, the efficiency of the model was optimized and the sequential changes were examined using histopathology and in situ imaging. The therapeutic effects of cisplatin (CDDP) and gemcitabine (GEM) were also examined, which are drugs that are often used for follow-up chemotherapy. Tumor-seeding efficiency reached 90-100%, with muscle layer and bladder lumen invasion occurring in ~21 days, using the following modifications: i) Shallow catheter insertion to mitigate bladder wall damage; ii) bladder pretreatment using prewarmed trypsin, followed by light urethral clamping and body temperature maintenance for more efficient removal of transitional epithelium; and iii) seeding with UM-UC-3 cells (rather than HT1376, 5637 or T24 tumor cells) in a medium supplemented with Matrigel. Transplant with UM-UC-3 cells resulted in isolated microlesions that progressed into tumors, invading the bladder lumen and muscle layer to the serosal surface. Tumor growth was markedly reduced by weekly intravenous injections of CDDP and partially suppressed by GEM. Therefore, this model is reliable, and pathological progression and treatment responses recapitulate the features of recurrent human bladder cancer.

Crosstalk between the lncRNA UCA1 and microRNAs in cancer

Long non-coding RNAs (lncRNAs) are a major subset of highly conserved non-coding RNAs (ncRNAs) that consist of at least 200 nucleotides and have limited protein-coding potential. Cumulative data have shown that lncRNAs are deregulated in many types of cancer and may control pathophysiological processes of cancer at various levels, including transcription, post-transcription and translation. Recently, lncRNAs have been demonstrated to interact with microRNAs (miRNAs), another major subset of ncRNAs, which regulate physiological and pathological processes by inhibiting target mRNA translation or promoting mRNA degradation. The lncRNA urothelial carcinoma-associated 1 (UCA1) has recently gained much attention as it is overexpressed in many types of cancer and is involved in carcinogenesis. Here, we review the crosstalk between UCA1 and miRNAs during the pathogenesis of cancer, with a focus on cancer-cell proliferation, invasion, drug resistance, and metabolism.

MicroRNA-133b suppresses bladder cancer malignancy by targeting TAGLN2-mediated cell cycle

MicroRNAs (miRNAs), a group of small noncoding RNAs, are widely involved in the regulation of gene expression via binding to complementary sequences at 3'-untranslated regions (3'-UTRs) of target messenger RNAs. Recently, downregulation of miR-133b has been detected in various human malignancies. Here, the potential biological role of miR-133b in bladder cancer (BC) was investigated. In this study, we found the expression of miR-133b was markedly downregulated in BC tissues and cell lines (5637 and T24), and was correlated with poor overall survival. Notably, transgelin 2 (TAGLN2) was found to be widely upregulated in BC, and overexpression of TAGLN2 also significantly increased risks of advanced TMN stage. We further identified that upregulation of miR-133b inhibited glucose uptake, invasion, angiogenesis, colony formation and enhances gemcitabine chemosensitivity in BC cell lines by targeting TAGLN2. Additionally, we showed that miR-133b promoted the proliferation of BC cells, at least partially through a TAGLN2-mediated cell cycle pathway. Our results suggest a novel miR-133b/TAGLN2/cell cycle pathway axis controlling BC progression; a molecular mechanism which may offer a potential therapeutic target.

Evaluation of Cell-free DNA in Urine as a Marker for Bladder Cancer Diagnosis

The diagnosis and follow-up of bladder cancer are mainly based on cystoscopy, an invasive method which could be negative in case of flat malignancies such as carcinoma in situ. Other noninvasive diagnostic methods have not yet given satisfactory results. There is a need for a reliable yet noninvasive method for the detection of bladder cancer. Our aim was to investigate whether cell-free DNA quantified in urine (ucf-DNA) could be a useful marker for the diagnosis of bladder cancer.

A standard urine test was performed in 150 naturally voided morning urine samples that were processed to obtain a quantitative evaluation of ucf-DNA. Leukocyturia and/or bacteriuria were found in 18 subjects, who were excluded from the study. Statistical analysis was performed on 45 bladder cancer patients and 87 healthy subjects. Ucf-DNA was extracted from urine samples by a spin column-based method and quantified using four different methods: GeneQuant Pro (Amersham Biosciences, Pittsburg, PA, USA), Quant-iT™ DNA high-sensitivity assay kit (Invitrogen, Carlsbad, CA, USA), Real-Time PCR (Applied Biosystems, Foster City, CA, USA), and NanoDrop 1000 (NanoDrop Technologies, Houston, TX, USA). Median free DNA quantification did not differ statistically between bladder cancer patients and healthy subjects.

A receiver-operating characteristic (ROC) curve was developed to evaluate the diagnostic performance of ucf-DNA quantification for each method. The area under the ROC curve was 0.578 for GeneQuant Pro, 0.573 for the Quant-iT™ DNA high-sensitivity assay kit, 0.507 for Real-Time PCR, and 0.551 for NanoDrop 1000, which indicated that ucf-DNA quantification by these methods is not able to discriminate between the presence and absence of bladder cancer. No association was found between ucf-DNA quantification and tumor size or tumor focality.

In conclusion, ucf-DNA isolated by a spin column-based method and quantified by GeneQuant Pro, Quant-iT™ DNA high-sensitivity assay kit, Real-Time PCR or NanoDrop 1000 does not seem to be a reliable marker for the diagnosis of bladder cancer.

LncRNA UCA1 in anti-cancer drug resistance

The pivotal role of the long non-coding RNA (lncRNA) urothelial carcinoma associated 1 (UCA1) in anti-cancer drug resistance has been confirmed in many cancers. Overexpression of lncRNA UCA1 correlates with resistance to chemotherapeutics such as cisplatin, gemcitabine, 5-FU, tamoxifen, imatinib and EGFR-TKIs, whereas lncRNA UCA1 knockdown restores drug sensitivity. These studies highlight the potential of lncRNA UCA1 as a diagnostic and prognostic biomarker, and a therapeutic target in malignant tumors. In this review, we address the role of lncRNA UCA1 in anti-cancer drug resistance and discuss its potential in future clinical applications.

Anti-tumor effect of Radix Paeoniae Rubra extract on mice bladder tumors using intravesical therapy

Radix Paeoniae Rubra (RPR) is the dried root of Paeonia lactiflora Pallas and Paeonia veitchii Lynch, and is a herbal medicine that is widely used in traditional Chinese medicine for the treatment of blood-heat and blood-stasis syndrome, similarly to Cortex Moutan. The present study identified the same three components in RPR and Cortex Moutan extracts. In addition, it has been reported that RPR has an anti-cancer effect. Bladder cancer is the seventh most common type of cancer worldwide. Due to the high recurrence rate, identifying novel drugs for bladder cancer therapy is essential. In the present study, RPR extract was evaluated as a bladder cancer therapy in vitro and in vivo. The present results revealed that RPR extract reduced the cell viability of bladder cancer cells with a half maximal inhibitory concentration of 1-3 mg/ml, and had an extremely low cytotoxic effect on normal urothelial cells. Additionally, RPR decreased certain cell cycle populations, predominantly cells in the G1 phase, and caused a clear sub-G increase. In a mouse orthotopic bladder tumor model, intravesical application of RPR extract decreased the bladder tumor size without altering the blood biochemical parameters of the mice. In summary, the present results demonstrate the anti-proliferative properties of RPR extract on bladder cancer cells, and its anti-bladder tumor effect in vivo. Compared to Cortex Moutan extract, RPR extract may provide a more effective alternative therapeutic strategy for the intravesical therapy of superficial bladder cancer.

Guizhi Fuling Wan as a Novel Agent for Intravesical Treatment for Bladder Cancer in a Mouse Model

Alternative intravesical agents are required to overcome the side effects currently associated with the treatment of bladder cancer. This study used an orthotopic bladder cancer mouse model to evaluate Guizhi Fuling Wan (GFW) as an intravesical agent. The effects of GFW were compared with those of mitomycin-C (Mito-C) and bacille Calmette-Guérin (BCG). We began by evaluating the response of the mouse bladder cancer cell line MB49 to GFW treatment, with regard to cell viability, cell cycle progression and apoptosis. MB49 cells were subsequently implanted into the urothelial walls of the bladder in female C57BL/6 mice. The success of the model was confirmed by the appearance of hematuria and tumor growth in the bladder. Intravesical chemotherapy was administered in accordance with a published protocol. In vitro data revealed that GFW arrested MB49 cell cycle in the G0/G1 phase, resulting in the suppression of cell proliferation and induced apoptosis. One possible mechanism underlying these effects is an increase in intracellular reactive oxygen species (ROS) levels leading to the activation of ataxia telangiectasia-mutated (ATM)/checkpoint kinase 2 (CHK2) and ATM/P53 pathways, thereby mediating cell cycle progression and apoptosis, respectively. This mouse model demonstrates the effectiveness of GFW in the tumor growth, with results comparable to those achieved by using BCG and Mito-C. Furthermore, GFW was shown to cause only mild hematuria. The low toxicity of the compound was confirmed by a complete lack of lesions on bladder tissue, even after 10 consecutive treatments using high concentrations of GFW. These results demonstrate the potential of GFW for the intravesical therapy of bladder cancer.

1α,25(OH)2D3 differentially regulates miRNA expression in human bladder cancer cells

Bladder cancer is the fourth most commonly diagnosed cancer in men and eighth leading cause of cancer-related death in the US. Epidemiological and experimental studies strongly suggest a role for 1α,25(OH)2D3 in cancer prevention and treatment. The antitumor activities of 1α,25(OH)2D3 are mediated by the induction of cell cycle arrest, apoptosis, differentiation and the inhibition of angiogenesis and metastasis. miRNAs play important regulatory roles in cancer development and progression. However, the role of 1α,25(OH)2D3 in the regulation of miRNA expression and the potential impact in bladder cancer has not been investigated. Therefore, we studied 1α,25(OH)2D3-regulated miRNA expression profiles in human bladder cancer cell line 253J and the highly tumorigenic and metastatic derivative line 253J-BV by miRNA qPCR panels. 253J and 253J-BV cells express endogenous vitamin D receptor (VDR), which can be further induced by 1α,25(OH)2D3. VDR target gene 24-hydroxylase was induced by 1α,25(OH)2D3 in both cell lines, indicating functional 1α,25(OH)2D3 signaling. The miRNA qPCR panel assay results showed that 253J and 253J-BV cells have distinct miRNA expression profiles. Further, 1α,25(OH)2D3 differentially regulated miRNA expression profiles in 253J and 253J-BV cells in a dynamic manner. Pathway analysis of the miRNA target genes revealed distinct patterns of contribution to the molecular functions and biological processes in the two cell lines. In conclusion, 1α,25(OH)2D3 differentially regulates the expression of miRNAs, which may contribute to distinct biological functions, in human bladder 253J and 253J-BV cells. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.

14-3-3σ attenuates RhoGDI2-induced cisplatin resistance through activation of Erk and p38 in gastric cancer cells

Rho GDP dissociation inhibitor 2 (RhoGDI2) promotes tumor growth and malignant progression and enhances chemoresistance of gastric cancer. Recently, we noted an inverse correlation between RhoGDI2 and 14-3-3σ expression, which suggests that 14-3-3σ is a target of gastric cancer metastasis and the chemoresistance-promoting effect of RhoGDI2. Herein, we evaluated whether 14-3-3σ is regulated by RhoGDI2 and is functionally important for the RhoGDI2-induced cisplatin resistance of gastric cancer cells. We used highly metastatic and cisplatin-resistant RhoGDI2-overexpressing SNU-484 cells and observed decreased 14-3-3σ mRNA and protein expression. Depletion of 14-3-3σ in SNU-484 control cells enhanced cisplatin resistance, whereas restoration of 14-3-3σ in RhoGDI2-overexpressing SNU-484 cells impaired cisplatin resistance in vitro and in vivo. We also found that the phosphorylation levels of Erk and p38 kinases significantly decreased in RhoGDI2-overexpressing SNU-484 cells and recovered after 14-3-3σ expression, and that decreased activities of these kinases were critical for RhoGDI2-induced cisplatin resistance. In conclusion, 14-3-3σ is a RhoGDI2-regulated gene that appears to be important for suppressing the chemoresistance of gastric cancer cells.

Cortex Moutan Induces Bladder Cancer Cell Death via Apoptosis and Retards Tumor Growth in Mouse Bladders

Cortex Moutan is the root bark of Paeonia suffruticosa Andr. It is the herbal medicine widely used in Traditional Chinese Medicine for the treatment of blood-heat and blood-stasis syndrome. Furthermore, it has been reported that Cortex Moutan has anticancer effect. In this study, the Cortex Moutan extract was evaluated in bladder cancer therapy in vitro and in vivo. Cortex Moutan extract reduces cell viability with IC50 between 1~2 mg/ml in bladder cancer cells, and it has lower cytotoxicity in normal urotheliums. It arrests cells in G1 and S phase and causes phosphatidylserine expression in the outside of cell membrane. It induces caspase-8 and caspase-3 activation and poly(ADP-ribose) polymerase degradation. The pan caspase inhibitor z-VAD-fmk reverses Cortex Moutan-induced cell death. Cortex Moutan also inhibits cell invasion activity in 5637 cells. In mouse orthotopic bladder cancer model, intravesical application of Cortex Moutan decreases the bladder tumor size without altering the blood biochemical parameters. In summary, these results demonstrate the antiproliferation and anti-invasion properties of Cortex Moutan in bladder cancer cells and its antibladder tumor effect in vivo. Cortex Moutan may provide an alternative therapeutic strategy for the intravesical therapy of superficial bladder cancer.

MicroRNA Profile to Predict Gemcitabine Resistance in Bladder Carcinoma Cell Lines

MicroRNAs (miRNA) are small, noncoding RNAs with important regulatory roles in development, differentiation, cell proliferation, and death as well as the complex process of acquired drug resistance. The goal of this study was to identify specific miRNAs and their potential protein targets that confer acquired resistance to gemcitabine in urothelial carcinoma of the bladder (UCB) cell lines. Gemcitabine-resistant cells were established from 6 cell lines following exposure to escalating concentrations of the drug and by passaging cells in the presence of the drug over a 2- to 3-month period. Differential miRNA expression was identified in a microarray format comparing untreated controls with resistant cell lines, representing the maximum tolerated concentration, and results were validated via qRT-PCR. The involvement of specific miRNAs in chemoresistance was confirmed with transfection experiments, followed by clonogenic assays and Western blot analysis. Gemcitabine resistance was generated in 6 UCB cell lines. Microarray analysis comparing miRNA expression between gemcitabine-resistant and parental cells identified the differential expression of 66 miRNAs. Confirmation of differential expression was recorded via qRT-PCR in a subset of these miRNAs. Within this group, let-7b and let-7i exhibited decreased expression, while miR-1290 and miR-138 displayed increased expression levels in gemcitabine-resistant cells. Transfection of pre-miR-138 and pre-miR-1290 into parental cells attenuated cell death after exposure to gemcitabine, while transfection of pre-miR-let-7b and pre-miR-let-7i into the resistant cells augmented cell death. Mucin-4 was up-regulated in gemcitabine-resistant cells. Ectopic expression of let-7i and let-7b in the resistant cells resulted in the down-regulation of mucin-4. These results suggest a role for miRNAs 1290, 138, let-7i, and let-7b in imparting resistance to gemcitabine in UCB cell lines in part through the modulation of mucin-4. Alterations in these miRNAs and/or mucin-4 may constitute a potential therapeutic strategy for improving the efficacy of gemcitabine in UCB.

Multivariate analysis of the prognostic significance of resection weight after transurethral resection of bladder tumor for non-muscle-invasive bladder cancer

PURPOSE

Tumor size and multiplicity are known to be important prognostic factors in non-muscle-invasive bladder cancer (NMIBC). However, evaluation of accurate tumor size is subjective and difficult. Furthermore, there are limitations to the objectification of tumor volume in the case of multiple lesions. In this study, we investigated the relation between resection weight after transurethral resection of bladder tumor (TURBT) and the prognosis of NMIBC.

MATERIALS AND METHODS

This was a retrospective analysis of 406 patients diagnosed with pTa or pT1 bladder tumors after TURBT between September 1999 and May 2010. The patient's age, sex, underlying diseases, cancer stage, grade, multiplicity, tumor size, lymphovascular invasion, and resection weight were analyzed in relation to cancer progression and recurrence. The resection weight was weighted after formaldehyde fixation.

RESULTS

The mean follow-up time was 76.9 months (range, 12 to 167 months) in 406 patients diagnosed as having NMIBC. Mean resection weight was 4.5 g (range, 0.1 to 35.0 g). The cancer recurred in 99 patients (24.4%), and disease progression was noted in 30 patients (7.4%). Resection weight was categorized as greater than or less than 2 g by use of receiver operator characteristic curves. Cancer grade (p=0.022) and multiplicity (p=0.043) were significantly related to cancer recurrence in the analysis with Cox's multivariate proportional hazard model. Cancer grade (p=0.001) and resection weight (p=0.018) were related to disease progression.

CONCLUSIONS

Resection weight after TURBT was significantly related to progression of NMIBC. Resection weight was an independent factor of progression. Further management should be considered if the resection weight exceeds 2 g.

Urothelial bladder cancer with cavitary lung metastases

Transitional cell carcinoma (TCC) of the bladder tends to remain superficial; however, in 5% to 20% of cases, it progresses to muscle invasion and, more rarely, can metastasize. TCC of the bladder primarily spreads via regional lymphatics. The most common sites of distant metastases of TCC are the liver, lung, mediastinum and bone. Longterm survival of patients with metastatic bladder cancer is rare. Patterns of pulmonary metastasis include multiple nodules, a solitary mass or interstitial micronodule. When multiple nodules are present, they are round and well-circumscribed, without calcification or cavitation. An unusual case of rapidly metastatic TCC to the lung causing large cavitary masses and nodules is presented. Imaging performed after the patient began chemotherapy revealed widespread necrosis of the metastatic cavitary masses causing moderate volume hemoptysis.

Surveillance and treatment of non-muscle-invasive bladder cancer in the USA

Seventy percent of newly diagnosed bladder cancers are classified as non-muscle-invasive bladder cancer (NMIBC) and are often associated with high rates of recurrence that require lifelong surveillance. Currently available treatment options for NMIBC are associated with toxicities that limit their use, and actual practice patterns vary depending upon physician and patient characteristics. In addition, bladder cancer has a high economic and humanistic burden in the United States (US) population and has been cited as one of the most costly cancers to treat. An unmet need exists for new treatment options associated with fewer complications, better patient compliance, and decreased healthcare costs. Increased prevention of recurrence through greater adherence to evidence-based guidelines and the development of novel therapies could therefore result in substantial savings to the healthcare system.

Proteomics-based strategy to delineate the molecular mechanisms of RhoGDI2-induced metastasis and drug resistance in gastric cancer

Rho GDP dissociation inhibitor 2 (RhoGDI2) was initially identified as a regulator of the Rho family of GTPases. Our recent works suggest that RhoGDI2 promotes tumor growth and malignant progression, as well as enhances chemoresistance in gastric cancer. Here, we delineate the mechanism by which RhoGDI2 promotes gastric cancer cell invasion and chemoresistance using two-dimensional gel electrophoresis (2-DE) on proteins derived from a RhoGDI2-overexpressing SNU-484 human gastric cancer cell line and control cells. Differentially expressed proteins were identified using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF-MS). In total, 47 differential protein spots were identified; 33 were upregulated, and 14 were downregulated by RhoGDI2 overexpression. Upregulation of SAE1, Cathepsin D, Cofilin1, CIAPIN1, and PAK2 proteins was validated by Western blot analysis. Loss-of-function analysis using small interference RNA (siRNA) directed against candidate genes reveals the need for CIAPIN1 and PAK2 in RhoGDI2-induced cancer cell invasion and Cathepsin D and PAK2 in RhoGDI2-mediated chemoresistance in gastric cancer cells. These data extend our understanding of the genes that act downstream of RhoGDI2 during the progression of gastric cancer and the acquisition of chemoresistance.

PLCγ is required for RhoGDI2-mediated cisplatin resistance in gastric cancer

Rho GDP dissociation inhibitor 2 (RhoGDI2) is a regulator of the Rho family GTPases. Recent work from our laboratory suggests that RhoGDI2 expression potentially enhances resistance to cisplatin as well as promotes tumor growth and malignant progression in gastric cancer. In this study, we demonstrate that phospholipase C-gamma (PLCγ) is required for RhoGDI2-mediated cisplatin resistance and cancer cell invasion in gastric cancer. The levels of phosphorylated PLCγ are markedly enhanced in RhoGDI2-overexpressing SNU-484 cells and, by contrast, repressed in RhoGDI2-depleted MKN-28 cells. Depletion of PLCγ expression or inhibition of its activity not only significantly increases cisplatin-induced apoptosis but also suppresses the invasive ability of RhoGDI2-overexpressing SNU-484 cells. Taken together, our results suggest that PLCγ plays a key role in RhoGDI2-mediated cisplatin resistance and cell invasion in gastric cancer cells.

Clinical significance of subepithelial growth patterns in non-muscle invasive bladder cancer

BACKGROUND

We evaluated the clinical significance and prognostic value of histopathological features of bladder cancer, such as subepithelial growth patterns and tumor growth pattern at the invasion front.

METHODS

In total, 130 patients newly diagnosed with non-muscle invasive bladder cancer and underwent transurethral resection between 1998 and 2009 were enrolled. Subepithelial growth patterns consisting of endophytic growth pattern (EGP) and von Brunn's nest involvement (VBNI) were investigated using hematoxylin and eosin-stained slides, and their frequency of occurrence, prognostic value, and correlation with other clinicopathological features was evaluated.

RESULTS

EGP and VBNI were found in 40 (30.8%) and 5 (3.9%) of the 130 cases, respectively. Of the 26 pT1 tumors, the growth pattern at the invasion front was trabecular in 17 (65.4%) and infiltrative in 9 (34.6%). Although 8 (47.1%) of 17 trabecular tumors coexisted with EGP, no cases with infiltrative tumors had EGP (p = 0.023). VBNI correlated with high tumor grades (p = 0.006) and lymphovascular involvement (p = 0.026). The multivariate Cox proportional hazards analysis revealed that tumor diameter less than 3 cm (p = 0.04) and intravesical bacillus Calmette-Guérin therapy (p = 0.004) were independent favorable prognostic factors for recurrence-free survival, whereas tumor stage was an independent poor prognostic factor for disease progression (p = 0.006).

CONCLUSIONS

Subepithelial growth patterns were not a significant prognostic factor in this study. Additionally, no tumors with an infiltrative growth pattern coexisted with EGP, suggesting that determining the presence of EGP might be helpful for managing non-muscle invasive bladder cancers.

RhoGDI2 confers gastric cancer cells resistance against cisplatin-induced apoptosis by upregulation of Bcl-2 expression

Rho GDP dissociation inhibitor (RhoGDI)2 has been identified as a regulator of Rho family GTPase. Recently, we suggested that RhoGDI2 could promote tumor growth and malignant progression in gastric cancer. In this study, we demonstrate that RhoGDI2 contributes to another important feature of aggressive cancers, i.e., resistance to chemotherapeutic agents such as cisplatin. Forced expression of RhoGDI2 attenuated cisplatin-induced apoptosis, whereas RhoGDI2 depletion showed opposite effects in vitro. Moreover, the increased anti-apoptotic effect of RhoGDI2 on cisplatin was further validated in RhoGDI2-overexpressing SNU-484 xenograft model in nude mice. Furthermore, we identified Bcl-2 as a major determinant of RhoGDI2-mediated cisplatin resistance in gastric cancer cells. Depletion of Bcl-2 expression significantly increased cisplatin-induced apoptosis in RhoGDI2-overexpressing gastric cancer cells, whereas overexpression of Bcl-2 blocked cisplatin-induced apoptosis in RhoGDI2-depleted gastric cancer cells. Overall, these findings establish RhoGDI2 as an important therapeutic target for simultaneously enhancing chemotherapy efficacy and reducing metastasis risk in gastric cancer.

RNAi-based therapeutics targeting survivin and PLK1 for treatment of bladder cancer

Harnessing RNA interference (RNAi) to silence aberrant gene expression is an emerging approach in cancer therapy. Selective inhibition of an overexpressed gene via RNAi requires a highly efficacious, target-specific short interfering RNA (siRNA) and a safe and efficient delivery system. We have developed siRNA constructs (UsiRNA) that contain unlocked nucleobase analogs (UNA) targeting survivin and polo-like kinase-1 (PLK1) genes. UsiRNAs were encapsulated into dialkylated amino acid-based liposomes (DiLA(2)) containing a nor-arginine head group, cholesteryl hemisuccinate (CHEMS), cholesterol and 1, 2-dimyristoyl-phosphatidylethanolamine-polyethyleneglycol 2000 (DMPE-PEG2000). In an orthotopic bladder cancer mouse model, intravesical treatment with survivin or PLK1 UsiRNA in DiLA(2) liposomes at 1.0 and 0.5 mg/kg resulted in 90% and 70% inhibition of survivin or PLK1 mRNA, respectively. This correlated with a dose-dependent decrease in tumor volumes which was sustained over a 3-week period. Silencing of survivin and PLK1 mRNA was confirmed to be RNA-induced silencing complex mediated as specific cleavage products were detected in bladder tumors over the duration of the study. This report suggests that intravesical instillation of survivin or PLK1 UsiRNA can serve as a potential therapeutic modality for treatment of bladder cancer.

UBE2M-mediated p27(Kip1) degradation in gemcitabine cytotoxicity

Gemcitabine (2'-deoxy-2', 2'-difluorocytidine; Gem) is a nucleoside anti-metabolite and is commonly used for treating various human cancers including human bladder carcinoma. Gemcitabine not only functions as a suicide nucleoside analog but also inhibits DNA polymerase activity and results in the termination of chain elongation. Using 2-dimensional gel electrophoresis analysis, a Gem-induced protein was identified as UBE2M (a.k.a. UBC12), a NEDD8 conjugation E2 enzyme which contributes to protein degradation. Gem induced UBE2M expression at both RNA and protein levels in several human cancer cell lines. The induction of UBE2M by Gem was accompanied by a reduction in p27(Kip1) protein levels, which could be restored by silencing UBE2M expression with siRNA or by treating cells with the proteasome inhibitor MG132, indicating that UBE2M mediates Gem-induced p27(Kip1) protein degradation. The induction of UBE2M and reduction of p27(Kip1) by Gem were prevented by the PI3K inhibitor LY294002. These results indicate that PI3K activity is necessary for Gem-induced UBE2M expression and that UBE2M facilitates degradation of p27(Kip1). Notably, silencing of UBE2M expression reduced Gem sensitivity in NTUB1 cells, suggesting that UBE2M mediates in part cell sensitivity to Gem, possibly by degradation of p27(Kip1). Analysis of Gem-resistant sub lines also showed that loss of UBE2M and increased p27(Kip1) expression were associated with the acquisition of drug resistance. In conclusion, our results demonstrate a role for UBE2M in mediating cytotoxicity of gemcitabine in human urothelial carcinoma cells while also suggesting a potential function of p27(Kip1) in drug resistance.

A new approach to percutaneous coronary revascularization in patients requiring undeferrable non-cardiac surgery

BACKGROUND

Optimal strategy for patients who need coronary revascularization before undeferrable non-cardiac surgery is still unknown. We performed a pilot study of dual antiplatelet therapy discontinuation followed by major non-cardiac surgery and endovascular aortic repair early after successful endothelial-progenitor cell-capture coronary stent deployment.

METHODS AND RESULTS

Thirty consecutive patients underwent coronary angioplasty plus stenting, before upcoming endovascular or surgical procedures requiring early interruption of antiplatelet therapy. An optimal acute procedural result was observed in all patients. Antiplatelet therapy was stopped before surgery in all patients, achieving an average antiplatelet therapy time of 12.2 ± 3.9 days. Surgery was performed after antiplatelet therapy interruption at an average time interval from revascularization of 17.2 ± 3.9 days. No patient suffered cardiac events during the perioperative period. At thirty day follow-up after surgery there were no cardiac events in all patients.

CONCLUSIONS

Our preliminary data might suggest a role for EPC-capture stent in patients requiring surgical procedures early after coronary stent placement. Further studies on larger population are needed to confirm the clinical impact of our findings.

Preoperative lymph-node staging of invasive urothelial bladder cancer with 18F-fluorodeoxyglucose positron emission tomography/computed axial tomography and magnetic resonance imaging: correlation with histopathology

OBJECTIVE

The treatment and prognosis of bladder cancer are based on the depth of primary tumour invasion and the presence of metastases. A highly accurate preoperative tumour, node, metastasis (TNM) staging is critical to proper patient management and treatment. This study retrospectively investigated the value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed axial tomography (¹⁸F-FDG PET/CT) and magnetic resonance imaging (MRI) for preoperative N staging of bladder cancer. Material and methods. From June 2006 to January 2008, 48 consecutive patients diagnosed with bladder cancer were referred to preoperative staging including MRI and ¹⁸F-FDG PET/CT. Eighteen out of 48 patients underwent radical cystoprostatectomy including removal of lymph nodes for histology, and were included in the study. Values of ¹⁸F-FDG PET/CT and MRI for regional N staging were compared to histopathology findings, the gold standard. Results. ¹⁸F-FDG PET/CT and MRI were performed in 18 patients. The specificities for detection of lymph-node metastases for MRI and ¹⁸F-FDG PET/CT were 80% (n = 15) and 93.33% (n = 15), respectively. The negative predictive values were 80% (n = 15) and 87.5% (n = 16) for MRI and ¹⁸F-FDG PET/CT, respectively. The differences in specificity and negative predictive values were not statistically significant. Conclusions. No significant statistical difference between ¹⁸F-FDG PET/CT and MRI for preoperative N staging of urothelial bladder cancer was found in the study. However, the trend of the data indicates an advantage of ¹⁸F-FDG PET/CT over MRI. Larger prospective studies are needed to elucidate the role of ¹⁸F-FDG PET/CT in N staging of bladder cancer.

Combretastatin A-4 inhibits cell growth and metastasis in bladder cancer cells and retards tumour growth in a murine orthotopic bladder tumour model

BACKGROUND AND PURPOSE

Bladder cancer is a highly recurrent cancer after intravesical therapy, so new drugs are needed to treat this cancer. Hence, we investigated the anti-cancer activity of combretastatin A-4 (CA-4), an anti-tubulin agent, in human bladder cancer cells and in a murine orthotopic bladder tumour model.

EXPERIMENTAL APPROACH

Cytotoxicity of CA-4 was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, propidium iodide (PI) staining assay and clonogenic survival assay. In vivo microtubule assembly assay, cell cycle analyses, Western blot and cell migration assay were used to study the mechanism of CA-4. The effect of intravesical CA-4 therapy on the development of tumours was studied in the murine orthotopic bladder tumour model.

KEY RESULTS

CA-4 inhibited microtubule polymerization in vivo. Cytotoxic IC(50) values of CA-4 in human bladder cancer cells were below 4 nM. Analyses of cell-cycle distribution showed CA-4 obviously induced G(2)-M phase arrest with sub-G(1) formation. The analyses of apoptosis showed that CA-4 induced caspase-3 activation and decreased BubR1 and Bub3 in cancer cells. In addition to apoptosis, CA-4 was also found to induce the formation of multinucleated cells. CA-4 had a significantly reduced cell migration in vitro. Importantly, the in vivo study revealed that intravesical CA-4 therapy retarded the development of murine bladder tumours.

CONCLUSIONS AND IMPLICATIONS

These data demonstrate that CA-4 kills bladder cancer cells by inducing apoptosis and mitotic catastrophe. It inhibited cell migration in vitro and tumour growth in vivo. Hence, CA-4 intravesical therapy could provide another strategy for treating superficial bladder cancers.

Vitamin D in combination cancer treatment

As a steroid hormone that regulates mineral homeostasis and bone metabolism, 1α, 25-dihydroxycholecalciferol (calcitriol) also has broad spectrum anti-tumor activities as supported by numerous epidemiological and experimental studies. Calcitriol potentiates the anti-tumor activities of multiple chemotherapeutics agents including DNA-damaging agents cisplatin, carboplatin and doxorubicin; antimetabolites 5-fluorouracil, cytarabine, hydroxyurea, cytarabine and gemcitabine; and microtubule-disturbing agents paclitaxel and docetaxel. Calcitriol elicits anti-tumor effects mainly through the induction of cancer cell apoptosis, cell cycle arrest, differentiation, angiogenesis and the inhibition of cell invasiveness by a number of mechanisms. Calcitriol enhances the cytotoxic effects of gamma irradiation and certain antioxidants and naturally derived compounds. Inhibition of calcitriol metabolism by 24-hydroxylase promotes growth inhibition effect of calcitriol. Calcitriol has been used in a number of clinical trials and it is important to note that sufficient dose and exposure to calcitriol is critical to achieve anti-tumor effect. Several trials have demonstrated that safe and feasible to administer high doses of calcitriol through intermittent regimen. Further well designed clinical trials should be conducted to better understand the role of calcitriol in cancer therapy.

1,25D3 enhances antitumor activity of gemcitabine and cisplatin in human bladder cancer models

BACKGROUND

1,25 dihydroxyvitamin D3 (1,25D3) potentiates the cytotoxic effects of several common chemotherapeutic agents. The combination of gemcitabine and cisplatin is a current standard chemotherapy regimen for bladder cancer. The authors investigated whether 1,25D3 could enhance the antitumor activity of gemcitabine and cisplatin in bladder cancer model systems.

METHODS

Human bladder cancer T24 and UMUC3 cells were pretreated with 1,25D3 followed by gemcitabine and cisplatin. Apoptosis was assessed by annexin V staining. Caspase activation was examined by immunoblot analysis and substrate-based caspase activity assay. The cytotoxic effects were examined by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and in vitro clonogenic assay. p73 protein levels were assessed by immunoblot analysis. Knockdown of p73 was achieved by siRNA. The in vivo antitumor activity was assessed by in vivo excision clonogenic assay and tumor regrowth delay in the T24 xenograft model.

RESULTS

1,25D3 pretreatment enhanced gemcitabine and cisplatin-induced apoptosis and the activities of caspases 8, 9, and 3 in T24 and UMUC3 cells. 1,25D3 synergistically reduced gemcitabine and cisplatin-suppressed surviving fraction in T24 cells. 1,25D3, gemcitabine, or cisplatin induced p73 accumulation, which was enhanced by gemcitabine and cisplatin or 1,25D3 and gemcitabine and cisplatin. p73 expression was lower in human primary bladder tumor tissue compared with adjacent normal tissue. Knockdown of p73 increased clonogenic capacity of T24 cells treated with 1,25D3, gemcitabine and cisplatin, or 1,25D3 and gemcitabine and cisplatin. 1,25D3 and gemcitabine and cisplatin combination enhanced tumor regression compared with 1,25D3 or gemcitabine and cisplatin alone.

CONCLUSIONS

1,25D3 potentiates gemcitabine and cisplatin-mediated growth inhibition in human bladder cancer models in vitro and in vivo, which involves p73 induction and apoptosis.

Variation of keratin 7 expression and other phenotypic characteristics of independent isolates of cadmium transformed human urothelial cells (UROtsa)

This laboratory has shown that a human urothelial cell line (UROtsa) transformed by cadmium (Cd(2+)) produced subcutaneous tumor heterotransplants that resemble human transitional cell carcinoma (TCC). In the present study, additional Cd(2+) transformed cell lines were isolated to determine if independent exposures of the cell line to Cd(2+) would result in malignantly transformed cell lines possessing similar phenotypic properties. Seven independent isolates were isolated and assessed for their doubling times, morphology, ability to heterotransplant subcutaneously and in the peritoneal cavity of nude mice, and for the expression of keratin 7. The 7 cell lines all displayed an epithelial morphology with no evidence of squamous differentiation. Doubling times were variable among the isolates, being significantly reduced or similar to those of the parental cells. All 7 isolates were able to form subcutaneous tumor heterotransplants with a TCC morphology, and all heterotransplants displayed areas of squamous differentiation of the transitional cells. The degree of squamous differentiation varied among the isolates. In contrast to subcutaneous tumor formation, only 1 isolate of the Cd(2+) transformed cells (UTCd#1) was able to effectively colonize multiple sites within the peritoneal cavity. An analysis of keratin 7 expression showed no correlation with squamous differentiation for the subcutaneous heterotransplants generated from the 7 cell lines. Keratin 7 was expressed in 6 of the 7 cell lines and their subcutaneous tumor heterotransplants. Keratin 7 was not expressed in the cell line that was able to form tumors within the peritoneal cavity. These results show that individual isolates of Cd(2+) transformed cells have both similarities and differences in their phenotype.

Chemosensitivity profile assay of circulating cancer cells: prognostic and predictive value in epithelial tumors

The prognostic value associated with the detection of circulating tumor cells (CTCs) in metastatic breast cancer by the CellSearch technology raise additional issues regarding the biological value of this information. We postulated that a drug-resistance profile of CTCs may predict response to chemotherapy in cancer patients and therefore could be used for patient selection. One hundred 5 patients with diagnosis of carcinoma were enrolled in a prospective trial. CTCs were isolated from peripheral blood, and positive samples were evaluated for the expression of a panel of genes involved in anticancer drugs resistance. The drug-resistance profile was correlated with disease-free survival (DFS; patients in adjuvant setting) and time to progression (TTP; metastatic patients) in a 24-months follow-up. Objective response correlation was a secondary end point. Fifty-one percent of patients were found positive for CTCs while all blood samples from healthy donors were negative. The drug-resistance profile correlates with DFS and TTP (p < 0.001 in both). Sensitivity of the test: able to predict treatment response in 98% of patients. Specificity of the test: 100%; no sample from healthy subject was positive for the presence of CTCs. Positive and negative predictive values were found to be 96.5 and 100%, respectively. We identified a drug-resistance profile of CTCs, which is predictive of response to chemotherapy, independent of tumor type and stage of disease. This approach may represent a first step toward the individualization of chemotherapy in cancer patients.

Clinical experience with survivin as a biomarker for urothelial bladder cancer

OBJECTIVES

This study was carried out as a prospective pilot study to evaluate the potential of survivin mRNA measurement in patients suspicious for urothelial bladder cancer (BC). Data were also analyzed for possible influences of secondary urological findings on survivin measurements.

METHODS

Survivin was measured by an mRNA assay in voided urine samples of 50 patients with suspicion of new or recurrent BC prior to transurethral resection. Sample evaluation was possible in 49 cases. Histopathology revealed no malignancy in 17 (35%) and BC in 32 (65%) patients. Survivin mRNA was quantitated by real-time PCR from frozen cell pellets of centrifuged urine samples. A ROC analysis of the survivin data was performed.

RESULTS

ROC analysis identified the best cut-off level at 10,000 mRNA copies, resulting in a sensitivity of 53% and a specificity of 88%. Seven of the 20 pTa tumors (35%), all four pT1 (100%) and all four muscle-invasive tumors (100%) were detected. Of four patients with carcinoma in situ (Cis), 50% could be identified. Only two patients (4%) were assessed as false positive. Histologically confirmed cystitis and concomitant urological findings (inflammatory cells in urine, microhematuria and others) had no detectable influence on survivin measurements.

CONCLUSION

In present group of patients, survivin was a reliable biomarker for high-grade urothelial BC (sensitivity 83%), but not for low grade (sensitivity 35%) urothelial BC with a high specificity (88%). No confounders influencing the results of survivin measurements could be identified.

Loss of 15-hydroxyprostaglandin dehydrogenase expression contributes to bladder cancer progression

Prostaglandin E2, which is known to contribute to cancer progression, is inactivated by the catabolic enzyme, 15-hydroxyprostaglandin dehydrogenase (PGDH), which has tumor-suppressor activity in lung, colon, breast, and gastric cancers. Therefore, we evaluated the expression of PGDH in human bladder cancer tissue specimens and cell lines. Immunoperoxidase staining of bladder cancer tissues demonstrated that (1) PGDH is highly expressed by normal urothelial cells but (2) reduced in many low stage (Ta/Tis) bladder cancers, and (3) PGDH is completely lost in most invasive bladder cancers. Of eight cancer cell lines tested, only two relatively well-differentiated bladder cancer cell lines, RT4 and UM-UC9, expressed PGDH. Moreover, inhibition of PGDH expression in well-differentiated RT4 cells using small inhibitory RNA or short hairpin RNA resulted in a more aggressive phenotype with increased motility and anchorage-independent growth. Additionally, PGDH knockdown affected prostaglandin E2 signaling as measured by cAMP generation. These data indicate that loss of PGDH expression contributes to a more malignant bladder cancer phenotype and may be necessary for bladder cancer development and/or progression.

Preparation and in-vitro bioactivity of a novel superantigen conjugate targeting bladder carcinoma

Objectives

Superantigens have shown potent effects against bladder tumours by inducing Vβ-specific T-lymphocyte proliferation and massive cytokine release but therapeutic benefit is compromised by cytotoxicity towards non-malignant cells and hypotoxicity to major histocompability complex (MHC) II-negative tumour cells. We are therefore interested in a conjugate preparation of a monoclonal antibody (MAb)—superantigens conjugate for which these drawbacks would be resolved.

Methods

The Fab fragment of the anti-bladder carcinoma MAb BDI-1 was conjugated to one member of the staphylococcal enterotoxin A (SEA) superantigen using the chemical conjugating reagent, N-succinimidyl 3-(2-pyridyldithio) propionate.

Results

After HPLC purification through a Superdex-200 gel column, another peak with a molecular mass of 250 KDa was observed before Fab and SEA were eluted. Indirect immunocytochemical analysis and immunofluorescence tests showed that the cell membranes of most human bladder cancer cells were positively stained only by the conjugate, confirming the ability of the conjugate to target human bladder carcinoma. Peripheral blood mononuclear cell proliferation and cytokine release were similar with the conjugate and SEA. Cytotoxicity targeting in MHC II-negative bladder cancer cell lines, evaluated by flow cytometry, showed significant differences between the conjugate and SEA, whereas there was no difference in the Lovo colon cancer cell line.

Conclusions

These findings indicate the conjugate of SEA protein and BDI-1 Fab fragment was prepared successfully and targeted bladder carcinoma in vitro.

A single-arm, multicenter, open-label phase 2 study of lapatinib as the second-line treatment of patients with locally advanced or metastatic transitional cell carcinoma

BACKGROUND

The treatment of recurrent transitional cell carcinoma (TCC) remains an unmet clinical need. This study assessed lapatinib, a dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) and HER-2, as second-line therapy in patients with locally advanced or metastatic TCC.

METHODS

This was a single-arm, multicenter, open-label, prospective phase 2 study. Patients with TCC whose disease progressed on prior platinum-based chemotherapy received lapatinib until disease progression or unacceptable toxicity, with evaluations for response by Response Evaluation Criteria In Solid Tumors criteria performed every 8 weeks. The primary endpoint of the current study was objective tumor response rate. Secondary endpoints included safety, time to disease progression, and overall survival.

RESULTS

Fifty-nine patients were enrolled in the study, 25 of whom (42%) could not be evaluated for response. The primary endpoint of an objective response rate (ORR) >10% was observed in 1.7% (95% confidence interval [95% CI], 0.0%-9.1%) of patients; however, 18 (31%; 95% CI, 19%-44%) patients achieved stable disease (SD). The median time to disease progression and overall survival (OS) were 8.6 weeks (95% CI, 8.0 weeks-11.3 weeks) and 17.9 weeks (95% CI, 13.1 weeks-30.3 weeks), respectively. Clinical benefit (ORR and SD) was found to be correlated with EGFR overexpression (P = .029), and, to some extent, HER-2 overexpression. The median OS was significantly prolonged in patients with tumors that overexpressed EGFR and/or HER-2 (P = .0001). Lapatinib was well tolerated.

CONCLUSIONS

The study was considered to be negative because it did not meet its primary endpoint; however, further analysis demonstrated an improvement in OS in a subset of patients with tumors overexpressing EGFR and/or HER-2, which is encouraging and warrants further investigation.

A chemosensitivity test to individualize intravesical treatment for non-muscle-invasive bladder cancer

OBJECTIVE

To describe the design of a new chemosensitivity assay based on the expression of genes involved in the resistance to standard intravesical regimens, to allow individualization of therapy for high-risk non-muscle-invasive bladder cancer.

PATIENTS AND METHODS

To date, 35 patients with high-risk non-muscle-invasive bladder cancer have been enrolled, all candidates for transurethral resection of the bladder (TURB) followed by intravesical treatment. The intravesical regimen was chosen according to the risk profile of each patient. All patients were evaluated by cystoscopy 3 and 6 months after TURB. According to the molecular characterization of each tumour, our team of molecular oncologists determined for each patient a molecular profile of chemosensitivity to BCG, mitomycin c, anthracyclines and gemcitabine. This profile was then correlated to the response to intravesical therapy 6 months after TURB.

RESULTS

This chemosensitivity test was able to predict response to treatment in 96% of patients. The assay is easy to perform, inexpensive and quick.

CONCLUSION

Our results, although preliminary, are encouraging for the future of an individualized therapeutic approach, with the aim to provide a higher treatment success rate while sparing patients unnecessary toxicity from drugs that are not suited for their tumours.

Functional interactions of Cu-ATPase ATP7B with cisplatin and the role of ATP7B in the resistance of cells to the drug

Cisplatin is a widely used chemotherapeutic agent for treatment of ovarian, testicular, lung, and stomach cancers. The initial response to the drug is robust; however, tumor cells commonly develop resistance to cisplatin, which complicates treatment. Recently, overexpression of the Cu-ATPase ATP7B in ovary cells was linked to the increased cellular resistance to cisplatin; and the role for Cu-ATPases in the export of cisplatin from cells was proposed. Our results support functional interactions between cisplatin and ATP7B but argue against the active transport through the copper translocation pathway as a mechanism of drug resistance. In hepatocytes, we observed no correlation between the levels of endogenous ATP7B and the resistance of cells to cisplatin. Unlike copper, cisplatin does not induce trafficking of ATP7B in hepatoma cells, neither does it compete with copper in a transport assay. However, cisplatin binds to ATP7B and stimulates catalytic phosphorylation with EC(50) similar to that of copper. Mutations of the first five N-terminal copper-binding sites of ATP7B do not inhibit the cisplatin-induced phosphorylation of ATP7B. In contrast, the deletion of the first four copper-binding sites abolishes the effect of cisplatin on the ATP7B activity. Thus, cisplatin binding to ATP7B and/or general changes in cellular copper homeostasis are likely contributors to the increased resistance to the drug. The link between changes in copper homeostasis and cisplatin resistance was confirmed by treating the Huh7 cells with copper chelator and increasing their resistance to cisplatin.cisplatin.

UCA1, a non-protein-coding RNA up-regulated in bladder carcinoma and embryo, influencing cell growth and promoting invasion

A non-protein-coding RNA, UCA1, has been cloned from human bladder TCC cell line BLZ-211 by using 5' and 3' RACE. The UCA1 full-length cDNA was 1442 bp. RT-PCR analysis indicated that UCA1 is an embryonic development and bladder cancer-associated RNA. The proliferative, migrative, invasive, and drug resistance behaviors of human bladder TCC cell line BLS-211 were enhanced by exogenous UCA1 expression in vitro. Several potential target genes of UCA1 were identified through microarray analysis. Moreover, the expression of UCA1 also increased tumorigenic potential of BLS-211 cells in nude mice. Results from the present study suggested that UCA1 might play a pivotal role in bladder cancer progression and embryonic development.