Mutations in FGFR3 and PIK3CA, singly or combined with RAS and AKT1, are associated with AKT but not with MAPK pathway activation in urothelial bladder cancer

The genetic duet of concurrent RASAL1 and PTEN alterations promotes cancer aggressiveness by cooperatively activating the PI3K-AKT pathway

The significance of the prominent tumor suppressor gene for RAS protein activator-like 1 (RASAL1) could be better understood by combined genetic, clinical, and functional studies. Here, we investigated the oncogenic and clinical impacts of genetic alterations of RASAL1, particularly when coexisting with genetic alterations of the gene for phosphatase and tensin homolog (PTEN), in 9924 cancers of 33 types in the TCGA database. We found common concurrent genetic alterations of the two genes, which were cooperatively associated with activation of the phosphatidylinositol 3-kinase (PI3K)-AKT pathway, with cancer progression and mortality rates being 46.36% and 31.72% with concurrent gene alterations, versus 29.80% and 16.93% with neither gene alteration (HR 1.64, 95% CI 1.46-1.84 and 1.77, 95% CI 1.53-2.05), respectively. This was enhanced by additional tumor protein p53 (TP53) gene alterations, with cancer progression and mortality rates being 47.65% and 34.46% with coexisting RASAL1, PTEN, and TP53 alterations versus 25.30% and 13.11% with no alteration (HR 2.21, 95% CI 1.92-2.56 and 2.76, 95% CI 2.31-3.30), respectively. In the case of breast cancer, this genetic trio was associated with a triple-negative risk of 68.75% versus 3.83% with no genetic alteration (RR 17.94, 95% CI 9.60-33.51), consistent with the aggressive nature of triple-negative breast cancer. Mice with double knockouts of Rasal1 and Pten displayed robust Pi3k pathway activation, with the development of metastasizing malignancies, while single gene knockout resulted in only benign neoplasma. These results suggest that RASAL1, like PTEN, is a critical player in negatively regulating the PI3K-AKT pathway; defect in RASAL1 causes RAS activation, thus initiating the PI3K-AKT pathway signaling, which cannot terminate with concurrent PTEN defects. Thus, the unique concurrent RASAL1 and PTEN defects drive oncogenesis and cancer aggressiveness by cooperatively activating the PI3K-AKT pathway. This represents a robust genetic mechanism to promote human cancer.

Clinicopathological characteristics, molecular landscape, and biomarker landscape for predicting the efficacy of PD-1/PD-L1 inhibitors in Chinese population with mismatch repair deficient urothelial carcinoma: a real-world study

Urothelial carcinoma (UC) with deficient mismatch repair (dMMR) is a specific subtype of UC characterized by the loss of mismatch repair (MMR) proteins and its association with Lynch syndrome (LS). However, comprehensive real-world data on the incidence, clinicopathological characteristics, molecular landscape, and biomarker landscape for predicting the efficacy of PD-1/PD-L1 inhibitors in the Chinese patients with dMMR UC remains unknown. We analyzed 374 patients with bladder urothelial carcinoma (BUC) and 232 patients with upper tract urothelial carcinoma (UTUC) using tissue microarrays, immunohistochemistry, and targeted next-generation sequencing. Results showed the incidence of dMMR UC was higher in the upper urinary tract than in the bladder. Genomic analysis identified frequent mutations in KMT2D and KMT2C genes and LS was confirmed in 53.8% of dMMR UC cases. dMMR UC cases displayed microsatellite instability-high (MSI-H) (PCR method) in 91.7% and tumor mutational burden-high (TMB-H) in 40% of cases. The density of intratumoral CD8+ T cells correlated with better overall survival in dMMR UC patients. Positive PD-L1 expression was found in 20% cases, but some patients positively responded to immunotherapy despite negative PD-L1 expression. Our findings provide valuable insights into the characteristics of dMMR UC in the Chinese population and highlights the relevance of genetic testing and immunotherapy biomarkers for treatment decisions.

Receptor Tyrosine Kinase Pathway and Infiltrating Urothelial Carcinoma

Receptor tyrosine kinase pathway is frequently searched for cancer causing mutations in tumors. Emerging targeted therapies are gleam of hope for them. Infiltrating urothelial carcinoma can have many morphological aspects according to their differentiation/variants. To evaluate KRAS, BRAF, and PIK3CA mutations and HER2, EGFR, and p16 expression, we divided urothelial carcinomas into two groups: differentiated/variants (n = 12) and conventional (n = 12). We compared results with clinical, demographic, histopathologic features and survival rates. No statistically significant results could be obtained in the comparison of histopathologic properties/survival rates with mutation analysis and EGFR, HER2, and p16 status. Differentiated/variants urothelial carcinoma showed higher EGFR expression (P < 0.001). Glandular differentiation was the most frequent type, followed by squamous and sarcomatoid differentiation. We observed the most common mutation at KRAS with a propensity for urothelial carcinoma with glandular differentiation. More than one mutation/high protein expression was seen in some tumors. Targeted therapies for KRAS mutation can be effective at urothelial carcinoma with glandular differentiation. Heterologous expression of relevant proteins and genes can be a cause for targeted treatment obstacle. The determination of the molecular characters of tumors is a guide in creating targeted treatment algorithms and in choosing the patient.

Aspirin increases the efficacy of gemcitabine in pancreatic cancer by modulating the PI3K/AKT/mTOR signaling pathway and reversing epithelial‑mesenchymal transition

Gemcitabine is regarded as a standard medication for patients with pancreatic cancer. The aim of the present study was to investigate the impact of aspirin (ASA) on the efficacy of gemcitabine in pancreatic cancer and the potential mechanism. The SW1990 and BxPC-3 human pancreatic cell lines were treated with 2 mmol/l ASA and/or 1 mg/l gemcitabine. The effects of the treatments were tested on the viability, migration and invasion of the cells using MTT, wound healing and Transwell invasion assays. In addition, cell apoptosis was evaluated via flow cytometry with Annexin V-FITC/PI and the western blotting of Bax and Bcl-2. The expression of epithelial-mesenchymal transition (EMT)-associated proteins and activation of the PI3K/AKT/mTOR pathway were also assessed using western blotting. The results reveal that ASA increased the efficacy of gemcitabine in reducing the proliferation, migration and invasion of pancreatic cancer cells and increasing their apoptosis. These effects are associated with inhibition of the PI3K/AKT/mTOR pathway and the reversal of EMT. Thus, the combined use of ASA and gemcitabine is suggested to be a potential therapeutic strategy for patients with pancreatic cancer.

Progress in the Research and Targeted Therapy of ErbB/HER Receptors in Urothelial Bladder Cancer

Bladder cancer is a lethal malignancy and a majority of bladder cancer arise from urothelial cells. Infiltration and metastasis are barriers for the radical cystectomy to achieve favored outcome and are the main cause of death. Systemic therapy, including chemotherapy, targeted therapy, and immunotherapy, is fundamental for these patients. erbB/HER receptors are found to be overexpressed in a subgroup of urothelial carcinoma, targeting erbB/HER receptors in these patients was found to be an efficient way in the era of genetic testing. To evaluate the role of erbB/HER receptors in bladder cancer, we reviewed the literature and ongoing clinical trials as regards to this topic to unveil the context of erbB/HER receptors in bladder cancer, which probably help to solidate the theoretical basis and might instruct further research.

Characteristics of upper urinary tract urothelial carcinoma in the context of bladder cancer: a narrative review

Urothelial carcinomas (UC) arise from the urothelium that covers the proximal urethra, urinary bladder, and the upper urinary tract. In daily routine and clinical trials UC originating from different locations are often treated and investigated in the same manner. However, differences between the two locations seem to be apparent and may question in handling them as a single oncologic entity. In this review we discuss similarities and differences between bladder and upper urinary tract UC and consider their potential impact on treatment strategies. Despite similarities of UC in the bladder (BC) and the upper urinary tract (UTUC), clinicopathologic and molecular differences may question to generally assemble both as a single tumor entity. Treatment standards for UTUC are often adopted from BC. However, a specific investigation in the former may still be meaningful as shown by the example of adjuvant cisplatin based chemotherapy. In conclusion, future investigations should prioritize the understanding of the tumor biology of both BC and UTUC. This may reveal which UTUC can be treated according to treatment standards of BC and in which cases, a separate approach may be more appropriate.

Integrated in silico MS-based phosphoproteomics and network enrichment analysis of RASopathy proteins

Background

RASopathies are a group of syndromes showing clinical overlap caused by mutations in genes affecting the RAS-MAPK pathway. Consequent disruption on cellular signaling leads and is driven by phosphoproteome remodeling. However, we still lack a comprehensive picture of the different key players and altered downstream effectors.

Methods

An in silico interactome of RASopathy proteins was generated using pathway enrichment analysis/STRING tool, including identification of main hub proteins. We also integrated phosphoproteomic and immunoblotting studies using previous published information on RASopathy proteins and their neighbors in the context of RASopathy syndromes. Data from Phosphosite database (www.phosphosite.org) was collected in order to obtain the potential phosphosites subjected to regulation in the 27 causative RASopathy proteins. We compiled a dataset of dysregulated phosphosites in RASopathies, searched for commonalities between syndromes in harmonized data, and analyzed the role of phosphorylation in the syndromes by the identification of key players between the causative RASopathy proteins and the associated interactome.

Results

In this study, we provide a curated data set of 27 causative RASopathy genes, identify up to 511 protein–protein associations using pathway enrichment analysis/STRING tool, and identify 12 nodes as main hub proteins. We found that a large group of proteins contain tyrosine residues and their biological processes include but are not limited to the nervous system. Harmonizing published RASopathy phosphoproteomic and immunoblotting studies we identified a total of 147 phosphosites with increased phosphorylation, whereas 47 have reduced phosphorylation. The PKB signaling pathway is the most represented among the dysregulated phosphoproteins within the RASopathy proteins and their neighbors, followed by phosphoproteins implicated in the regulation of cell proliferation and the MAPK pathway.

Conclusions

This work illustrates the complex network underlying the RASopathies and the potential of phosphoproteomics for dissecting the molecular mechanisms in these syndromes. A combined study of associated genes, their interactome and phosphorylation events in RASopathies, elucidates key players and mechanisms to direct future research, diagnosis and therapeutic windows.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01934-x.

Perspective: Humanized Pig Models of Bladder Cancer

Bladder cancer (BC) is the 10th most common neoplasia worldwide and holds expensive treatment costs due to its high recurrence rates, resistance to therapy and the need for lifelong surveillance. Thus, it is necessary to improve the current therapy options and identify more effective treatments for BC. Biological models capable of recapitulating the characteristics of human BC pathology are essential in evaluating the effectiveness of new therapies. Currently, the most commonly used BC models are experimentally induced murine models and spontaneous canine models, which are either insufficient due to their small size and inability to translate results to clinical basis (murine models) or rarely spontaneously observed BC (canine models). Pigs represent a potentially useful animal for the development of personalized tumors due to their size, anatomy, physiology, metabolism, immunity, and genetics similar to humans and the ability to experimentally induce tumors. Pigs have emerged as suitable biomedical models for several human diseases. In this sense, the present perspective focuses on the genetic basis for BC; presents current BC animal models available along with their limitations; and proposes the pig as an adequate animal to develop humanized large animal models of BC. Genetic alterations commonly found in human BC can be explored to create genetically defined porcine models, including the BC driver mutations observed in the FGFR3, PIK3CA, PTEN, RB1, HRAS, and TP53 genes. The development of such robust models for BC has great value in the study of pathology and the screening of new therapeutic and diagnostic approaches to the disease.

Dose-Dense Methotrexate, Vinblastine, Doxorubicin, and Cisplatin With or Without Panitumumab in Patients With Advanced Urothelial Carcinoma: Multicenter, Randomized, French Unicancer GETUG/AFU 19 Study

This study looked at whether epidermal growth factor receptor inhibition by the monoclonal antibody panitumumab could increase the efficacy of standard chemotherapy in advanced urothelial cancer. Results were disappointing, with higher toxicity and no improvement in efficacy in the combination arm.

BACKGROUND

Epidermal growth factor receptor (EGFR) overexpression is frequent and associated with poor outcome in urothelial carcinoma. EGFR inhibition could improve the antitumor activity of chemotherapy.

PATIENTS AND METHODS

Patients with advanced, treatment-naïve, histologically confirmed advanced urothelial carcinoma and no HRAS or KRAS mutation in the primary tumor received dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (dd-MVAC) without or with the anti-EGFR monoclonal antibody panitumumab (Pmab). A randomized (1:2) phase II design was used with progression-free survival (PFS) as the primary endpoint.

RESULTS

Ninety-seven eligible patients were randomized; 96 patients were evaluable for toxicity and 87 for efficacy. The median PFS were 6.8 months (95% confidence interval [CI], 6.3-9.2) for dd-MVAC and 5.7 months (95% CI, 4.6-6.4 months) for dd-MVAC+Pmab. For both immunohistochemical and molecular definition of basal/squamous-like (BASQ) tumors, no difference was observed in objective response rates or PFS between the two arms in BASQ and non-BASQ tumors.

CONCLUSION

dd-MVAC+Pmab was associated with more serious adverse events and no improvement in efficacy outcomes.

Diagnostic value of a comprehensive, urothelial carcinoma-specific next-generation sequencing panel in urine cytology and bladder tumor specimens

BACKGROUND

Urine cytology can reliably diagnose high-grade urothelial carcinoma (HGUC) but not low-grade urothelial carcinoma (LGUC), and a more sensitive test is needed. Previously, a pilot study highlighted the possible diagnostic utility of next-generation sequencing (NGS) in identifying both LGUC and HGUC in urine cytology specimens.

METHODS

Twenty-eight urine ThinPrep cytology specimens and preceding or subsequent bladder tumor biopsy/resection specimens obtained within 3 months were included in the study (LGUC, n = 15; HGUC, n = 13). A customized, bladder-specific NGS panel was performed; it covered 69 frequently mutated or altered genes in urothelial carcinoma (UC) that were reported by The Cancer Genome Atlas and the Catalogue of Somatic Mutations in Cancer.

RESULTS

The sequencing results were compared between the urine cytology specimens and the corresponding bladder tumor biopsies/resections. TP53 was the most frequently identified mutation in HGUC cases (11 of 13 [85%]). PIK3CA and KDM6A were the most frequently identified mutations in LGUC: they occurred in 7 of 15 cases (47%) and in 6 of 15 cases (40%), respectively. Additional frequent mutations identified in the panel included ARID1A (n = 5), EP300 (n = 4), LRP1B (n = 3), ERBB2 (n = 2), STAG2 (n = 2), FGFR3 (n = 3), MLL (n = 2), MLL3 (n = 2), CREBBP1 (n = 1), RB1 (n = 1), and FAT4 (n = 1). Overall, the concordance between the cytology and surgical specimens was 75%. The sensitivity and specificity for identifying mutations in urine cytology specimens were 84% and 100%, respectively.

CONCLUSIONS

A bladder-specific NGS panel increases the sensitivity and specificity of urine cytology's diagnostic utility in both low- and high-grade tumors and may serve as a noninvasive surveillance method in the follow-up of patients with UC harboring known mutations.

Divergent molecular profile of PIK3CA gene in arsenic-associated bladder carcinoma

The activation of PIK3CA in bladder carcinoma (BlCa) with its recurrent mutations in exon 9 and 20 were well reported. But the association of arsenic on the activation of the pathway is not well elucidated. Therefore, we aimed to analyse the effect of arsenic on the genetic (copy number variation/mutation) and expression profiles of PIK3CA in primary BlCa samples. Infrequent amplification (16%) of the PIK3CA locus was observed, with higher frequency among the arsenic-high (AsH) than arsenic-low (AsL) samples. Frequent (54%) tumour-specific mutations in exon 9 and 20 of PIK3CA were observed in the BlCa samples with prevalent (47%) C>T transition mutations. Exon 9 and 20 harboured 48% and 73% of the total mutations, respectively, with 37% in E542K/E545K and 25% of the mutation in H1047Y/R. Though mutation frequency in AsH and AsL was found to be comparable, we observed some arsenic-specific mutation at c.1633G>A, c.1634A>C (E545K) and c.2985C>T and c.3130G>T mutations, as well as prevalent transverse mutations of A>C and G>T in AsH group. Furthermore, 73% of the BlCa samples showed overexpression (mRNA/protein) of PIK3CA with genetic alterations (amplification/mutation), significantly (P = 0.01) higher in AsH group. However, 36% of the samples showed overexpressed PIK3CA, independent of mutation or amplification, signifying a transcriptional upregulation of PIK3CA gene. Therefore, the expression status of NFκB, a transcription factor of PIK3CA, was assessed and found to be significantly correlated with the overexpression of PIK3CA (mRNA/protein) in AsH group. Similarly, the expression pattern of pAKT1 (Thr 308) was also found to be significantly correlated with PIK3CA overexpression. Finally, AsH patients with the overexpression of PIK3CA or NFκB had the worst overall survival, signifying a strong impact of arsenic on this pathway and outcome of the patients. Thus, our study showed that the arsenic-associated differential molecular profile of PIK3CA/AKT1/NFkB in BlCa has an important role in the molecular pathogenesis of the disease.

FGFR3 – a Central Player in Bladder Cancer Pathogenesis?

The identification of mutations in FGFR3 in bladder tumors in 1999 led to major interest in this receptor and during the subsequent 20 years much has been learnt about the mutational profiles found in bladder cancer, the phenotypes associated with these and the potential of this mutated protein as a target for therapy. Based on mutational and expression data, it is estimated that >80% of non-muscle-invasive bladder cancers (NMIBC) and ∼40% of muscle-invasive bladder cancers (MIBC) have upregulated FGFR3 signalling, and these frequencies are likely to be even higher if alternative splicing of the receptor, expression of ligands and changes in regulatory mechanisms are taken into account. Major efforts by the pharmaceutical industry have led to development of a range of agents targeting FGFR3 and other FGF receptors. Several of these have entered clinical trials, and some have presented very encouraging early results in advanced bladder cancer. Recent reviews have summarised the drugs and related clinical trials in this area. This review will summarise what is known about the effects of FGFR3 and its mutant forms in normal urothelium and bladder tumors, will suggest when and how this protein contributes to urothelial cancer pathogenesis and will highlight areas that may benefit from further study.

PIK3CA Is Regulated by CUX1, Promotes Cell Growth and Metastasis in Bladder Cancer via Activating Epithelial-Mesenchymal Transition

PIK3CA is a key component of phosphatidylinositol 3-kinase (PI3K) pathway that its involvement in tumorigenesis has been revealed by previous research. However, its functions and potential mechanisms in bladder cancer are still largely undiscovered. Tissue microarray (TMA) with 66 bladder cancer patients was surveyed via immunohistochemistry to evaluate the level of PIK3CA and CUX1 and we found upregulation of PIK3CA in bladder cancer tissue and patients with higher level of PIK3CA presented with poorer prognosis. Overly expressed PIK3CA promoted growth, migration, invasion, and metastasis of bladder cancer cells and knockdown of PIK3CA had the opposite effect. Gain-of-function and loss-of-function studies showed that PIK3CA expression was facilitated by CUX1, leading to activation of epithelial-mesenchymal transition (EMT), accompanied by upregulated expression of Snail, β-catenin, Vimentin and downregulated expression of E-cadherin in the bladder cancer cell lines. Besides, over-expressed CUX1 could restore the expression of downregulated Snail, β-catenin, Vimentin and E-cadherin which was induced by PIK3CA knockdown. These results revealed that PIK3CA overexpression in bladder cancer was regulated by the transcription factor CUX1, and PIK3CA exerted its biological effects by activating EMT.

Role of tyrosine kinases in bladder cancer progression: an overview

Background

Bladder cancer (BCa) is a frequent urothelial malignancy with a high ratio of morbidity and mortality. Various genetic and environmental factors are involved in BCa progression. Since, majority of BCa cases are diagnosed after macroscopic clinical symptoms, it is required to find efficient markers for the early detection. Receptor tyrosine-kinases (RTKs) and non-receptor tyrosine-kinases (nRTKs) have pivotal roles in various cellular processes such as growth, migration, differentiation, and metabolism through different signaling pathways. Tyrosine-kinase deregulations are observed during tumor progressions via mutations, amplification, and chromosomal abnormalities which introduces these factors as important candidates of anti-cancer therapies.

Main body

For the first time in present review we have summarized all of the reported tyrosine-kinases which have been significantly associated with the clinicopathological features of BCa patients.

Conclusions

This review highlights the importance of tyrosine-kinases as critical markers in early detection and therapeutic purposes among BCa patients and clarifies the molecular biology of tyrosine-kinases during BCa progression and metastasis.

Genomic variation as a marker of response to neoadjuvant therapy in locally advanced rectal cancer

There is variation in the responsiveness of locally advanced rectal cancer to neoadjuvant chemoradiation, from complete response to total resistance. This study compared genetic variation in rectal cancer patients who had a complete response to chemoradiation versus poor response, using tumor tissue samples sequenced with genomics analysis software. Rectal cancer patients treated with chemoradiation and proctectomy June 2006-March 2017 were grouped based on response to chemoradiation: those with no residual tumor after surgery (CR, complete responders, AJCC-CPR tumor grade 0, n = 8), and those with poor response (PR, AJCC-CPR tumor grade two or three on surgical resection, n = 8). We identified 195 variants in 83 genes in tissue specimens implicated in colorectal cancer biopathways. PR patients showed mutations in four genes not mutated in complete responders: KDM6A, ABL1, DAXX-ZBTB22, and KRAS. Ten genes were mutated only in the CR group, including ARID1A, PMS2, JAK1, CREBBP, MTOR, RB1, PRKAR1A, FBXW7, ATM C11orf65, and KMT2D, with specific discriminating variants noted in DMNT3A, KDM6A, MTOR, APC, and TP53. Although conclusions may be limited by small sample size in this pilot study, we identified multiple genetic variations in tumor DNA from rectal cancer patients who are poor responders to neoadjuvant chemoradiation, compared to complete responders.

TP53 codon 72 polymorphism is associated with FGFR3 and RAS mutation in non-muscle-invasive bladder cancer

Objective

TP53, a well-known tumor-suppressor gene in bladder carcinogenesis, has a functional single-nucleotide polymorphism on codon 72. The aim of this study was to elucidate the association between TP53 codon 72 polymorphism and somatic mutations in bladder cancer.

Material and methods

Germline TP53 codon 72 polymorphism and somatic mutations of 50 cancer-associated genes were analyzed in 103 bladder cancer patients (59 non-muscle-invasive and 44 muscle-invasive), using Taqman genotyping assay and target sequencing, respectively. The expression of FGF-FGFR signaling pathway genes was analyzed by RNA sequencing of frozen tissue.

Results

The allele frequency of TP53 codon 72 in our cohort was 37, 42, and 21% for Arg/Arg, Arg/Pro, and Pro/Pro, respectively. Interestingly, the prevalence of FGFR3 mutation was higher in patients with the Arg allele, whereas that of the RAS mutation was higher in patients without the Arg allele. The same association was seen in non-muscle-invasive bladder cancer (NMIBC) patients and no differences were observed in muscle-invasive bladder cancer patients. In NMIBC, FGFR1 expression was higher in patients without the Arg allele and FGFR3 expression was higher in patients with the Arg allele.

Conclusion

The germline TP53 codon 72 polymorphism was associated with mutations of FGFR3 or RAS and expression of FGFR1 and FGFR3 in NMIBC. These findings provide new insight into the molecular mechanisms underlying the influence of the genetic background on carcinogenesis in bladder cancer.

KMT2D inhibits the growth and metastasis of bladder Cancer cells by maintaining the tumor suppressor genes

KMT2D, a kind of histone H3 lysine 4 (H3K4) methyltransferase, its abnormal expression confirmed to be associated with diverse tumors, but is lack of defined role in bladder cancer (BC). KMT2D mutation was analyzed using several databases. Immunohistochemistry and clinicopathological analysis of KMT2D in 51 paired of BC tissues and corresponding normal tissues were used to evaluate the relationship between KMT2D and BC. The effects of silencing or over-expressing KMT2D on HTB-9 and T24 cell viability, migration and invasion were performed using MTT, wound scratch and Transwell, respectively. Also, bladder cancer mouse model was established by hypodermic injection of the BC cells. Associated expressions of methylation genes, oncogenes and tumor suppressors were assessed by western blot and quantitative real-time PCR. KMT2D was frequent mutation in various tumors, including BC. It was negative expression in BC tissues and cells, also implicated with tumor stages and lymph node metastasis. In silencing KMT2D HTB-9 and T24 cells, cell viability, migration and invasion were notably promoted. Meanwhile, knockdown of KMT2D benefited to solid tumor formation in vivo. However, over-expressing KMT2D represented contrary results. Especially, KMT2D over-expression induced the activity of H3K4 monomethylation (me1), and effectively enhanced PTEN and p53 expressions as well as repressed STAG2 expression. Meanwhile, KMT2D had no obvious effect on Survivin. This work suggested an anti-tumor role for KMT2D in vitro and in vivo, as well as provided a possible tumor inhibition mechanism in which KMT2D enhanced H3K4me1 activity to support the expressions of tumor suppressors.

Histologic variants associated with biological aggressiveness and poor prognosis in patients treated with radical cystectomy

BACKGROUND

The prognostic value of histologic variants (HV) after radical cystectomy (RC) remains controversial. We evaluated the clinicopathological features and prognosis in patients with pure urothelial carcinoma (UC) and HV following RC.

METHODS

From 1990 to 2015, 286 patients with bladder cancer were treated with RC at six Kitasato University-affiliated hospitals. All patients were divided into two groups: pure UC and HV, which contained pure variants and mixed-type UC with variant pattern. A comparison of patient characteristics between the two groups was made to assess the clinicopathological features, and statistical analyses were performed to investigate prognosis in the two groups.

RESULTS

Of the 286 patients, 226 (79%) had pure UC, while 60 (21%) had HV. Of all HV, pure variants accounted for 45% (n = 27). The prevalence of lymph node involvement, locally advanced stage (≥ pT3), positive soft tissue surgical margin and lymphovascular invasion were significantly higher in patients with HV than in those with pure UC. Patients with HV showed worse disease-free survival and cancer-specific survival than those with pure UC (P = 0.009 and 0.003, respectively). In multivariate analysis, HV and lymph node involvement were independent predictors of worse disease-free survival (P = 0.017 and 0.001, respectively). HV, locally advanced stage, lymph node involvement, and positive soft tissue surgical margin were also confirmed as independent predictors of worse cancer-specific survival (P = 0.011, 0.012, 0.003 and 0.010, respectively.).

CONCLUSIONS

HV was associated with greater biological aggressiveness and worse prognosis than pure UC.

Anti-cancer Effects of a Chemically Modified miR-143 on Bladder Cancer by Either Systemic or Intravesical Treatment

We developed a novel chemically modified miR-143 (miR-143#12), and with it we investigated the contribution of miR-143 to the pathogenesis of bladder cancer (BC), in which miR-143 is extremely downregulated. Since miR-143 silenced K-RAS and RAS effector-signaling molecules Erk and Akt, we performed the ectopic expression of miR-143 in human BC 253J-BV cells, and we examined the growth inhibition and the mechanism of it in vitro and in orthotopic model mice. As a result, miR-143#12 induced a marked growth inhibition with apoptosis through impairing RAS-signaling networks, including SOS1, which exchanges guanosine diphosphate (GDP)/RAS for active guanosine triphosphate (GTP)/RAS. In the in vivo study, miR-143#12 exhibited a marked anti-tumor activity by either systemic or intravesical administration with polyionic copolymer (PIC) as the carrier, compared with the activity obtained by use of lipofection. These findings raised the possibility that the chemically modified miR-143#12 would be a candidate of microRNA (miRNA) medicine for BC delivered by intravesical infusion.

Three dimensional primary cultures for selecting human breast cancers that are sensitive to the anti-tumor activity of ipatasertib or taselisib in combination with anti-microtubule cytotoxic drugs

Two inhibitors of phosphatidylinositol 3-kinase (PI3K) pathway taselisib, targeting the mutant PI3K-subunit-alpha (PI3KA) and ipatasertib, AKT-inhibitor, are currently under clinical investigation in breast cancer (BC) patients. We have previously demonstrated the anti-tumor efficacy of these anti-PI3K/AKT-inibitors in combination with anti-microtubule drugs in human BC cell lines, through a complete cytoskeleton disorganization. In this work, we generated ex-vivo three-dimensional (3D) cultures from human BC as a model to test drug efficacy and to identify new molecular biomarkers for selection of BC patients suitable for anti-PI3K/AKT-inibitors treatment. We have established 3D cultures from 25/27 human BC samples, in which the ability of growth in vitro replicates the clinical and biological aggressiveness of the original tumors. According to the results of next generation sequencing analysis, a direct correlation was found between PI3KA mutations and the sensitivity in 3D models in vitro to taselisib and ipatasertib alone and combined with anti-microtubule agents. Moreover, mutations in HER and MAPK families related genes, including EGFR, KRAS and BRAF, were found in resistant samples, suggesting their potential role as negative predictive factors of response to these agents. Thus, we demonstrated that ex vivo 3D cultures from human BC patients allow a rapid and efficient drug screening for chemotherapies and targeted agents in genetically selected patients and represent an innovative model to identify new biomarkers of drug resistance.

Genomic Characterization of Upper-Tract Urothelial Carcinoma in Patients With Lynch Syndrome

PURPOSE

Patients with Lynch syndrome (LS) have a significantly increased risk of developing upper-tract urothelial carcinoma (UTUC). Here, we sought to identify differences in the patterns of mutational changes in LS-associated versus sporadic UTUCs.

PATIENTS AND METHODS

We performed targeted sequencing of 17 UTUCs from patients with documented LS-associated germline mutations (LS-UTUCs) using the Memorial Sloan Kettering Integrated Molecular Profiling of Actionable Cancer Targets targeted exon capture assay and compared the results with those from a recently characterized cohort of 82 patients with sporadic UTUC.

RESULTS

Patients with LS-UTUC were significantly younger, had had less exposure to tobacco, and more often presented with a ureteral primary site compared with patients with sporadic UTUC. The median number of mutations per tumor was significantly greater in LS-UTUC tumors than in tumors from the sporadic cohort (58; interquartile range [IQR], 47-101 v 6; IQR, 4-10; P < .001), as was the MSIsensor score (median, 25.1; IQR, 17.9-31.2 v 0.03; IQR, 0-0.44; P < .001). Differences in the genetic landscape were observed between sporadic and LS-associated tumors. Alterations in KMT2D, CREBBP, or ARID1A or in DNA damage response and repair genes were present at a significantly higher frequency in LS-UTUC. CIC, NOTCH1, NOTCH3, RB1, and CDKN1B alterations were almost exclusive to LS-UTUC. Although FGFR3 mutations were identified in both cohorts, the R248C hotspot mutation was highly enriched in LS-UTUC.

CONCLUSION

LSand sporadic UTUCs have overlapping but distinct genetic signatures. LS-UTUC is associated with hypermutation and a significantly higher prevalence of FGFR3 R248C mutation. Prospective molecular characterization of patients to identify those with LS-UTUC may help guide treatment.

Differential Expression of FGFRs Signaling Pathway Components in Bladder Cancer: A Step Toward Personalized Medicine

Variations Improper activation and inappropriate expression of fibroblast growth factor receptors (FGFRs) in cancer suggests that they can act as therapeutic targets. Fibroblast growth factor receptor inhibitors are currently employed in clinical trials of different cancers. Regarding the essence and the importance of the personalized medicine, mainly mirrored by remarkable inter-individual variations in different populations, we aimed to perform a pilot study to address FGFR1 and FGFR3 expression levels and their correlation with the clinicopathological features in Iranian patients with bladder cancer (BC). Paired tumor and adjacent non tumor tissue samples along with their clinico-pathological parameters were obtained from 50 cases diagnosed with BC in different stages and grades. The mRNA expressions of FGFR1 and FGFR3 in tissue samples were determined by real-time polymerase chain reaction (real-time PCR). The expression levels of FGFR3 were significantly higher in tumor tissues when compared to adjacent normal tissues (p = 0.007), regardless of the stages and grades of the tumor. Over expression was associated with cigarette smoking (p = 0.037) and family history for cancer (p = 0.004). Decreased expression of FGFR1 was observed, remarkably evident in high-grade tumors (p = 0.047), while over expression was detected in low-grade samples. This pilot study clearly suggests that in Iranian BC patients FGFR1 and FGFR3 expression patterns are different, and also highly distinctive with regard to the tumor’s stage and grade. Such particular expression patterns may indicate their special values to be employed for interventional studies aiming targeted therapy. Further studies with a larger sample size are needed to validate our results.

Expression levels of FGFR3 as a prognostic marker for the progression of primary pT1 bladder cancer and its association with mutation status

The present study examined the utility of fibroblast growth factor receptor 3 (FGFR3) mutation status and gene expression as a prognostic marker in primary pT1 bladder cancer (BC). A total of 120 patients with primary pT1 BC were enrolled. FGFR3 mutation status was determined by direct sequencing and FGFR3 mRNA expression level was determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. The results were compared with the clinicopathological parameters, and the prognostic value of FGFR3 was evaluated by Kaplan-Meier analysis and a multivariate Cox regression test. FGFR3 mutations were identified in 48/120 (40.0%) patients with pT1 BC. FGFR3 mRNA expression level was significantly higher in those with BC harboring FGFR3 mutations (P<0.001). Low FGFR3 expression level was associated with high-grade tumors and cancer progression (P=0.006 and P=0.001), whereas FGFR3 mutation status was not associated with cancer progression. Kaplan-Meier analysis revealed a similar result (log-rank, P<0.001). Multivariate analysis identified low FGFR3 expression level (odds ratio, 3.300; 95% confidence interval, 1.310-8.313; P=0.011) as an independent predictor of cancer progression. Stratification by exon site of FGFR3 mutations yielded significant differences in mRNA expression level. None of the patients with BC harboring FGFR3 mutations in exon 9 demonstrated disease progression. The mRNA expression level of the FGFR3 gene may be used to precisely identify subsets of patients with pT1 BC that have a relatively better prognosis. The prognostic influences of FGFR3 mutations may be modulated by the exon site of FGFR3 mutations.

Expression of proteins FGFR3, PI3K, AKT, p21Waf1/Cip1 and cyclins D1 and D3 in patients with T1 bladder tumours: clinical implications and prognostic significance

OBJECTIVE

To determine the differential protein expression of biomarkers FGFR3, PI3K (subunits PI3Kp110α, PI3KClassIII, PI3Kp85), AKT, p21Waf1/Cip1 and cyclins D1 and D3 in T1 bladder cancer versus healthy tissue and to study their potential role as early recurrence markers.

MATERIAL AND METHOD

This is a prospective study that employed a total of 67 tissue samples (55 cases of T1 bladder tumours that underwent transurethral resection and 12 cases of adjacent healthy mucosa). The protein expression levels were assessed using Western blot, and the means and percentages were compared using Student's t-test and the chi-squared test. The survival analysis was conducted using the Kaplan-Meier method and the log-rank test.

RESULTS

Greater protein expression was detected for FGFR3, PI3Kp110α, PI3KClassIII, cyclins D1 and D3 and p21Waf1/Cip1 in the tumour tissue than in the healthy mucosa. However, these differences were not significant for PI3Kp85 and AKT. We observed statistically significant correlations between early recurrence and PI3Kp110α, PI3KClassIII, PI3Kp85 and AKT (P=.003, P=.045, P=.050 and P=.028, respectively), between the tumour type (primary vs. recurrence) and cyclin D3 (P=.001), between the tumour size and FGFR3 (P=.035) and between multifocality and cyclin D1 (P=.039). The survival analysis selected FGFR3 (P=.024), PI3Kp110α (P=.014), PI3KClassIII (P=.042) and AKT (P=.008) as markers of early-recurrence-free survival.

CONCLUSIONS

There is an increase in protein expression levels in bladder tumour tissue. The overexpression of FGFR3, PI3Kp110α, PI3KClassIII and AKT is associated with increased early-recurrence-free survival for patients with T1 bladder tumours.

Incidence and effect of variant histology on oncological outcomes in patients with bladder cancer treated with radical cystectomy

INTRODUCTION

We sought to describe incidence of histological variants after radical cystectomy (RC) due to bladder cancer (BCa). Moreover, we investigated survival outcomes accounting for this parameter.

METHODS

We retrospectively evaluated data from 1,067 patients with BCa treated with RC between 1990 and 2013 at a single tertiary care referral center. All specimen were evaluated by dedicated uropathologists. Univariable and multivariable Cox regression analyses tested the effect of different histopathological variant on recurrence, cancer-specific mortality (CSM), and overall mortality (OM) after accounting for all available confounders.

RESULTS

Of 1,067 patients, 729 (68.3%) harbored pure urothelial BCa while 338 (31.7%) were found to have a variant. Considering uncommon variants, 21 (2.0%) were sarcomatoid, 10 (0.9%) lymphoepitelial, 19 (1.8%) small cell, 109 (10.2%) squamous, 89 (8.3%) micropapillary, 23 (2.2%) glandular, 34 (3.2%) mixed variants, and 33 (3.1%) were found with other types of variants. With a median follow-up of 6.2 years, 343 recurrence, 365 CSM, and 451 OM were recorded, respectively. At multivariable Cox regression analyses, the presence of small cell variant was associated with higher recurrence (hazard ratio [HR] = 3.47, P<0.001), CSM (HR = 3.30, P<0.04), and OM (HR = 2.97, P<0.003) as compared with pure urothelial cancer. Conversely, no survival differences were recorded considering other histological variants (all P> 0.1).

CONCLUSION

Our study confirms that histological variant is not an infrequent event at RC specimen. However, in our single-center series, only patients found with small cell variant were associated with a negative effect on survival after RC.

Development and Application of a Microfluidics-Based Panel in the Basal/Luminal Transcriptional Characterization of Archival Bladder Cancers

In the age of personalized medicine stratifying tumors into molecularly defined subtypes associated with distinctive clinical behaviors and predictable responses to therapies holds tremendous value. Towards this end, we developed a custom microfluidics-based bladder cancer gene expression panel for characterization of archival clinical samples. In silico analysis indicated that the content of our panel was capable of accurately segregating bladder cancers from several public datasets into the clinically relevant basal and luminal subtypes. On a technical level, our bladder cancer panel yielded robust and reproducible results when analyzing formalin-fixed, paraffin-embedded (FFPE) tissues. We applied our panel in the analysis of a novel set of 204 FFPE samples that included non-muscle invasive bladder cancers (NMIBCs), muscle invasive disease (MIBCs), and bladder cancer metastases (METs). We found NMIBCs to be mostly luminal-like, MIBCs to include both luminal- and basal-like types, and METs to be predominantly of a basal-like transcriptional profile. Mutational analysis confirmed the expected enrichment of FGFR3 mutations in luminal samples, and, consistently, FGFR3 IHC showed high protein expression levels of the receptor in these tumors. Our bladder cancer panel enables basal/luminal characterization of FFPE tissues and with further development could be used for stratification of bladder cancer samples in the clinic.

A place for precision medicine in bladder cancer: targeting the FGFRs

Bladder tumors show diverse molecular features and clinical outcome. Muscle-invasive bladder cancer has poor prognosis and novel approaches to systemic therapy are urgently required. Non-muscle-invasive bladder cancer has good prognosis, but high recurrence rate and the requirement for life-long disease monitoring places a major burden on patients and healthcare providers. Studies of tumor tissues from both disease groups have identified frequent alterations of FGFRs, including mutations of FGFR3 and dysregulated expression of FGFR1 and FGFR3 that suggest that these may be valid therapeutic targets. We summarize current understanding of the molecular alterations affecting these receptors in bladder tumors, preclinical studies validating them as therapeutic targets, available FGFR-targeted agents and results from early clinical trials in bladder cancer patients.

FGFR3-TACC3 fusion proteins act as naturally occurring drivers of tumor resistance by functionally substituting for EGFR/ERK signaling

The epidermal growth factor receptor (EGFR) is a clinically validated target in head and neck squamous cell carcinoma (HNSCC), where EGFR-blocking antibodies are approved for first-line treatment. However, as with other targeted therapies, intrinsic/acquired resistance mechanisms limit efficacy. In the FaDu HNSCC xenograft model, we show that combined blockade of EGFR and ERBB3 promotes rapid tumor regression, followed by the eventual outgrowth of resistant cells. RNA sequencing revealed that resistant cells express FGFR3-TACC3 fusion proteins, which were validated as drivers of the resistant phenotype by several approaches, including CRISPR-mediated inactivation of FGFR3-TACC3 fusion genes. Interestingly, analysis of signaling in resistant cell lines demonstrated that FGFR3-TACC3 fusion proteins promote resistance by preferentially substituting for EGFR/RAS/ERK signaling rather than ERBB3/PI3K/AKT signaling. Furthermore, although FGFR3-TACC3 fusion proteins promote resistance of additional EGFR-dependent HNSCC and lung cancer cell lines to EGFR blockade, they are unable to compensate for inhibition of PI3K signaling in PIK3CA-mutant HNSCC cell lines. Validation of FGFR3-TACC3 fusion proteins as endogenous drivers of resistance in our screen provides strong evidence that these fusions are capable of substituting for EGFR signaling. Thus, FGFR3-TACC3 fusion proteins may represent a novel mechanism of acquired resistance in EGFR-dependent cancers of multiple cell lineages.

A cultured approach to canine urothelial carcinoma: molecular characterization of five cell lines

Background

Urothelial carcinoma (UC), also known as transitional cell carcinoma (TCC), of the bladder is the most common neoplasm affecting the canine urogenital system. To facilitate study of the disease in vitro, cell line models have been established from primary tumor biopsies. Their resemblance to the primary disease, however, has not been well defined. In the present study, we evaluated five canine UC cell lines via oligonucleotide array comparative genomic hybridization (oaCGH), fluorescence in situ hybridization (FISH), and gene expression analysis.

Results

Comparison of genome wide DNA copy number profiles of the cell lines with primary biopsy specimens revealed redundancies in genomic aberrations, indicating that the cell lines retain the gross genomic architecture of primary tumors. As in the primary tumors, gain of canine chromosomes 13 and 36 and loss of chromosome 19 were among the most frequent aberrations evident in the cell lines. FISH analysis revealed chromosome structural aberrations, including tandem duplications, bi-armed chromosomes, and chromosome fusions, suggesting genome instability during neoplastic transformation. Gene expression profiling highlighted numerous differentially expressed genes, including many previously shown as dysregulated in primary canine UC and human bladder cancer. Pathway enrichment analysis emphasized pathways suspected to be at the crux of UC pathogenesis, including xenobiotic and lipid compound metabolism.

Conclusions

These data support valid use of the canine UC cell lines evaluated by confirming they provide an accurate and practical means to interrogate the UC at a molecular level. Moreover, the cell lines may provide a valuable model for furthering our understanding of aberrant metabolic pathways in UC development.

Electronic supplementary material

The online version of this article (doi:10.1186/s40575-015-0028-3) contains supplementary material, which is available to authorized users.

A Modeling Approach to Explain Mutually Exclusive and Co-Occurring Genetic Alterations in Bladder Tumorigenesis

Relationships between genetic alterations, such as co-occurrence or mutual exclusivity, are often observed in cancer, where their understanding may provide new insights into etiology and clinical management. In this study, we combined statistical analyses and computational modeling to explain patterns of genetic alterations seen in 178 patients with bladder tumors (either muscle-invasive or non-muscle-invasive). A statistical analysis on frequently altered genes identified pair associations, including co-occurrence or mutual exclusivity. Focusing on genetic alterations of protein-coding genes involved in growth factor receptor signaling, cell cycle, and apoptosis entry, we complemented this analysis with a literature search to focus on nine pairs of genetic alterations of our dataset, with subsequent verification in three other datasets available publicly. To understand the reasons and contexts of these patterns of associations while accounting for the dynamics of associated signaling pathways, we built a logical model. This model was validated first on published mutant mice data, then used to study patterns and to draw conclusions on counter-intuitive observations, allowing one to formulate predictions about conditions where combining genetic alterations benefits tumorigenesis. For example, while CDKN2A homozygous deletions occur in a context of FGFR3-activating mutations, our model suggests that additional PIK3CA mutation or p21CIP deletion would greatly favor invasiveness. Furthermore, the model sheds light on the temporal orders of gene alterations, for example, showing how mutual exclusivity of FGFR3 and TP53 mutations is interpretable if FGFR3 is mutated first. Overall, our work shows how to predict combinations of the major gene alterations leading to invasiveness through two main progression pathways in bladder cancer.

Somatic Copy Number Abnormalities and Mutations in PI3K/AKT/mTOR Pathway Have Prognostic Significance for Overall Survival in Platinum Treated Locally Advanced or Metastatic Urothelial Tumors

BACKGROUND

An integrative analysis was conducted to identify genomic alterations at a pathway level that could predict overall survival (OS) in patients with advanced urothelial carcinoma (UC) treated with platinum-based chemotherapy.

PATIENTS AND METHODS

DNA and RNA were extracted from 103 formalin-fixed paraffin embedded (FFPE) invasive high-grade UC samples and were screened for mutations, copy number variation (CNV) and gene expression analysis. Clinical data were available from 85 cases. Mutations were analyzed by mass-spectrometry based on genotyping platform (Oncomap 3) and genomic imbalances were detected by comparative genomic hybridization (CGH) analysis. Regions with threshold of log2 ratio ≥0.4, or ≤0.6 were defined as either having copy number gain or loss and significantly recurrent CNV across the set of samples were determined using a GISTIC analysis. Expression analysis on selected relevant UC genes was conducted using Nanostring. To define the co-occurrence pattern of mutations and CNV, we grouped genomic events into 5 core signal transduction pathways: 1) TP53 pathway, 2) RTK/RAS/RAF pathway, 3) PI3K/AKT/mTOR pathway, 4) WNT/CTNNB1, 5) RB1 pathway. Cox regression was used to assess pathways abnormalities with survival outcomes.

RESULTS

35 samples (41%) harbored mutations on at least one gene: TP53 (16%), PIK3CA (9%), FGFR3 (2%), HRAS/KRAS (5%), and CTNNB1 (1%). 66% of patients had some sort of CNV. PIK3CA/AKT/mTOR pathway alteration (mutations+CNV) had the greatest impact on OS (p=0.055). At a gene level, overexpression of CTNNB1 (p=0.0008) and PIK3CA (p=0.02) were associated with shorter OS. Mutational status on PIK3CA was not associated with survival. Among other individually found genomic alterations, TP53 mutations (p=0.07), mTOR gain (p=0.07) and PTEN overexpression (p=0.08) have a marginally significant negative impact on OS.

CONCLUSIONS

Our study suggests that targeted therapies focusing on the PIK3CA/AKT/mTOR pathway genomic alterations can generate the greatest impact in the overall patient population of high-grade advanced UC.

Functions of Fibroblast Growth Factor Receptors in cancer defined by novel translocations and mutations

The four receptor tyrosine kinases (RTKs) within the family of Fibroblast Growth Factor Receptors (FGFRs) are critical for normal development but also play an enormous role in oncogenesis. Mutations and/or abnormal expression often lead to constitutive dimerization and kinase activation of FGFRs, and represent the primary mechanism for aberrant signaling. Sequencing of human tumors has revealed a plethora of somatic mutations in FGFRs that are frequently identical to germline mutations in developmental syndromes, and has also identified novel FGFR fusion proteins arising from chromosomal rearrangements that contribute to malignancy. This review details approximately 200 specific point mutations in FGFRs and 40 different fusion proteins created by translocations involving FGFRs that have been identified in human cancer. This review discusses the effects of these genetic alterations on downstream signaling cascades, and the challenge of drug resistance in cancer treatment with antagonists of FGFRs.

Mutations in TERT promoter and FGFR3 and telomere length in bladder cancer

Mutations in the promoter of the telomerase reverse transcriptase (TERT) and fibroblast growth factor receptor 3 (FGFR3) genes constitute the most recurrent somatic alterations in urothelial carcinoma of bladder. In this study, we screened DNA from 327 urothelial bladder carcinomas from well-documented patients, with different stages and grades and known TERT promoter mutational status, for FGFR3 alterations and measured relative telomere length (RTL). Although, the frequency of the TERT promoter mutations was higher than those in FGFR3; however, the alterations at the two loci occurred together more frequently than per chance [Odds ratio (OR) = 4.93, 95% CI = 2.72-8.92, p < 0.0001]. While tumors with TERT promoter and FGFR3 mutations had shorter RTL than those without mutations (p < 0.0001), the TERT promoter mutations in conjunction with the common allele of the rs2853669 polymorphism defined sub-group of patients with an observed decreased overall survival (OR = 2.15, 95% CI = 1.00-4.61) and increased recurrence in patients with TaG1+TaG2 disease categories (OR = 3.68, 95%CI = 1.12-12.05). The finding of shorter telomeres in tumors with TERT promoter and/or FGFR3 mutations than without mutations implies mechanistic relevance of telomere biology in cancer progression. The observed association with recurrence and survival shows that the TERT promoter mutations can potentially be used as markers to refine selection of patients for different treatments. The overwhelming frequency of the TERT promoter mutations also represents a case for development of an eventual therapeutic target.

Molecular biology of bladder cancer: new insights into pathogenesis and clinical diversity

Urothelial carcinoma of the bladder comprises two long-recognized disease entities with distinct molecular features and clinical outcome. Low-grade non-muscle-invasive tumours recur frequently but rarely progress to muscle invasion, whereas muscle-invasive tumours are usually diagnosed de novo and frequently metastasize. Recent genome-wide expression and sequencing studies identify genes and pathways that are key drivers of urothelial cancer and reveal a more complex picture with multiple molecular subclasses that traverse conventional grade and stage groupings. This improved understanding of molecular features, disease pathogenesis and heterogeneity provides new opportunities for prognostic application, disease monitoring and personalized therapy.

Careless talk costs lives: fibroblast growth factor receptor signalling and the consequences of pathway malfunction

Since its discovery 40 years ago, fibroblast growth factor (FGF) receptor (FGFR) signalling has been found to regulate fundamental cellular behaviours in a wide range of cell types. FGFRs regulate development, homeostasis, and repair and are implicated in many disorders and diseases; and indeed, there is extensive potential for severe consequences, be they developmental, homeostatic, or oncogenic, should FGF-FGFR signalling go awry, so careful control of the pathway is critically important. In this review, we discuss the recent developments in the FGF field, highlighting how FGFR signalling works in normal cells, how it can go wrong, how frequently it is compromised, and how it is being targeted therapeutically.

Complex interactions between the components of the PI3K/AKT/mTOR pathway, and with components of MAPK, JAK/STAT and Notch-1 pathways, indicate their involvement in meningioma development

We investigated the significance of PI3K/AKT/mTOR pathway and its interactions with MAPK, JAK/STAT and Notch pathways in meningioma progression. Paraffin-embedded tissue from 108 meningioma patients was analysed for the presence of mutations in PIK3CA and AKT1. These were correlated with the expression status of components of the PI3K/AKT/mTOR pathway, including p85α and p110γ subunits of PI3K, phosphorylated (p)-AKT, p-mTOR, p-p70S6K and p-4E-BP1, as well as of p-ERK1/2, p-STAT3 and Notch-1, clinicopathological data and patient survival. A mutation in PIK3CA or AKT1 was found in around 9 % of the cases. Higher grade meningiomas displayed higher nuclear expression of p-p70S6K; higher nuclear and cytoplasmic expression of p-4E-BP1 and of Notch-1; lower cytoplasmic expression of p85αPI3K, p-p70S6K and p-ERK1/2; and lower PTEN Histo-scores (H-scores). PTEN H-score was inversely correlated with recurrence probability. In univariate survival analysis, nuclear expression of p-4E-BP1 and absence of p-ERK1/2 expression portended adverse prognosis, whereas in multivariate survival analysis, p-ERK1/2 expression emerged as an independent favourable prognostic factor. Treatment of the human meningioma cell line HBL-52 with the PI3K inhibitor LY294002 resulted in reduction of p-AKT, p-p70S6K and p-ERK1/2 protein levels. The complex interactions established between components of the PI3K/AKT/mTOR pathway, or with components of the MAPK, JAK/STAT and Notch-1 pathways, appear to be essential for facilitating and fuelling meningioma progression.

MiR-133b regulates bladder cancer cell proliferation and apoptosis by targeting Bcl-w and Akt1

Background

MiR-133b is a muscle-specific microRNA; it has a role in the formation of cardiocytes and the expression of myocardium ion channels by regulating target genes. Many human malignant tumors demonstrate a low expression of miR-133b, as noted in colorectal, lung, esophagus and bladder cancers, but the role of miR-133b in bladder cancer is unknown.

Methods

The expression of miR-133b in clinical bladder cancer specimens and adjacent normal tissues was confirmed by stem-loop RT-PCR. We also analyzed the relationship between miR-133b expression and clinicopathological factors of bladder cancer. Bcl-w and Akt1 protein expression in 41 bladder cancer specimens and adjacent normal tissues was detected by Western blot. After transfection of miR-133b mimics or inhibitor into a T24 human bladder cancer cell line, Bcl-w and Akt1 protein and mRNA expression were examined by Western blot and RT-PCR, respectively. The effect of miR-133b on T24 cell proliferation and apoptosis was measured by CCK-8 tests and flow cytometry, respectively.

Results

The expression of miR-133b in bladder cancer tissues from 41 patients was significantly down-regulated (P < 0.01); low expression of miR-133b was strongly associated with high-grade bladder cancer (P < 0.01). Bcl-w and Akt1 proteins were significantly overexpressed in bladder cancer tissues versus adjacent normal tissues (P < 0.01 for both). The expression of Akt1 and Bcl-w proteins and Akt1 mRNA, in T24 cells was significantly down-regulated or up-regulated after transfection of miR-133b mimics or inhibitor, respectively; however, there was no significant difference in Bcl-w mRNA expression. Transfection of HEK-293 T cells with miR-133b significantly suppressed a luciferase-reporter containing the Bcl-w or Akt 1 3′-untranslated regions. MiR-133b mimics significantly inhibited T24 cell proliferation, as well as increased T24 cell apoptosis (P < 0.05 and P < 0.01, respectively) while the miR-133b inhibitor increased and decreased these, respectively (P < 0.05 for both).

Conclusions

MiR-133b may play a very important role in the proliferation and apoptosis of T24 cells by regulating the expression of Bcl-w and Akt1.

Fibroblast growth factor receptor 3 activation plays a causative role in urothelial cancer pathogenesis in cooperation with Pten loss in mice

Although somatic mutations and overexpression of the tyrosine kinase fibroblast growth factor receptor 3 (FGFR3) are strongly associated with bladder cancer, evidence for their functional involvement in the pathogenesis remains elusive. Previously we showed that activation of Fgfr3 alone is not sufficient to initiate urothelial tumourigenesis in mice. Here we hypothesize that cooperating mutations are required for Fgfr3-dependent tumourigenesis in the urothelium and analyse a mouse model in which an inhibitor of Pi3k-Akt signalling, Pten, is deleted in concert with Fgfr3 activation (UroIICreFgfr3(+/) (K644E) Pten(flox) (/flox)). Two main phenotypical characteristics were observed in the urothelium: increased urothelial thickness and abnormal cellular histopathology, including vacuolization, condensed cellular appearance, enlargement of cells and nuclei, and loss of polarity. These changes were not observed when either mutation was present individually. Expression patterns of known urothelial proteins indicated the abnormal cellular differentiation. Furthermore, quantitative analysis showed that Fgfr3 and Pten mutations cooperatively caused cellular enlargement, while Pten contributed to increased cell proliferation. Finally, FGFR3 overexpression was analysed along the level of phosphorylated mTOR in 66 T1 urothelial tumours in tissue microarray, which supported the occurrence of functional association of these two signalling pathways in urothelial pathogenesis. Taken together, this study provides evidence supporting a functional role of FGFR3 in the process of pathogenesis in urothelial neoplasms. Given the wide availability of inhibitors specific to FGF signalling pathways, our model may open the avenue for FGFR3-targeted translation in urothelial disease.

Patient-derived xenografts reveal limits to PI3K/mTOR- and MEK-mediated inhibition of bladder cancer

BACKGROUND

Metastatic bladder cancer is a serious condition with a 5-year survival rate of approximately 14 %, a rate that has remained unchanged for almost three decades. Thus, there is a profound need to identify the driving mutations for these aggressive tumors to better determine appropriate treatments. Mutational analyses of clinical samples suggest that mutations in either the phosphoinositide-3 kinase (PI3K)-AKT-mammalian target of rapamycin (mTOR) or RAS/MEK/ERK pathways drive bladder cancer progression, although it remains to be tested whether the inhibition of either (or both) of these pathways can arrest PI3K/mTOR- or Ras-driven proliferation.

METHODS

Herein, we used several bladder cancer cell lines to determine drug sensitivity according to genetic background and also studied mouse models of engrafted UM-UC-3 cells and patient-derived xenografts (PDXs) to test PI3K/mTOR and MEK inhibition in vivo.

RESULTS

Inhibition of these pathways utilizing PF-04691502, a PI3K and mTOR inhibitor, and PD-0325901, a MEK inhibitor, slowed the tumor growth of PDX models of bladder cancer. The growth inhibitory effect of combination therapy was similar to that of the clinical maximum dose of cisplatin; mechanistically, this appeared to predominantly occur via drug-induced cytostatic growth inhibition as well as diminished vascular endothelial growth factor secretion in the tumor models. Kinase arrays of tumors harvested after treatment demonstrated activated p53 and Axl as well as STAT1 and STAT3.

CONCLUSION

Taken together, these results indicate that clinically relevant doses of PF-04691502 and PD-0325901 can suppress bladder tumor growth in PDX models, thus offering additional potential treatment options by a precision medicine approach.

EGFR alterations and EML4-ALK rearrangement in primary adenocarcinoma of the urinary bladder

The identification of mutations in epidermal growth factor receptor (EGFR) and translocations involving anaplastic lymphoma kinase (ALK) in lung adenocarcinoma has drastically changed understanding of the disease and led to the development of targeted therapies. Adenocarcinoma of the urinary bladder is rare and poorly understood at the molecular level. We undertook this study to determine whether EGFR mutations, increases in EGFR copy number, or ALK translocations are present in these tumors. Twenty-eight cases of primary bladder adenocarcinoma were analyzed. For EGFR mutational analysis, PCR-amplified products were analyzed on the Q24 Pyrosequencer with Qiagen EGFR Pyro Kits. All cases were analyzed via fluorescence in situ hybridization (FISH) using Vysis ALK Break Apart FISH Probes for detection of ALK chromosomal translocation and Vysis Dual Color Probes to assess for increased gene copy number of EGFR. None of the 28 cases examined showed mutational events in EGFR or ALK rearrangements. EGFR polysomy was seen in 10 out of 28 (36%) cases. No correlation with EGFR polysomy was seen in the tumors with respect to age, histologic subtypes, pathologic stage, or lymph node metastasis. In summary, EGFR mutations and ALK rearrangements do not appear to be involved in the development of primary adenocarcinoma of the urinary bladder. A subgroup of cases (36%), however, demonstrated increased gene copy number of EGFR by FISH.

PIK3CA, HRAS and PTEN in human papillomavirus positive oropharyngeal squamous cell carcinoma

Background

Recent genomic evidence suggests frequent phosphatidylinositide 3-kinase (PI3K) pathway activation in human papillomavirus (HPV) positive oropharyngeal squamous cell carcinoma. Mutations/amplification of the gene encoding p110α catalytic subunit of phosphoinositide 3-kinase (PIK3CA), loss of phosphatase and tensin homolog (PTEN) and HRAS mutations are known to activate PI3K pathway.

Methods and results

PIK3CA mutations were identified by Sanger sequencing in 23 of 75 (31%) HPV-positive oropharyngeal carcinomas, including exon 9 (p.E545K [n = 10] and p.E542K [n = 5]) or exon 20 (p.H1047Y, n = 2) mutations. Five rare and one novel (p.R537Q) PIK3CA mutations were identified. HRAS mutation (p.Q61L) was detected in 1 of 62 tested cases. PIK3CA amplification by fluorescence in situ hybridization (FISH) was identified in 4 cases (4/21, 20%), while PTEN loss was seen in 7 (7/21, 33%) cases (chromosome 10 monosomy [n = 4], homozygous deletion [n = 3]).

Conclusions

Overall, genetic alterations that likely lead to PI3K pathway activation were identified in 34 of 75 cases (45%) and did not correlate with disease specific survival. These findings offer a molecular rationale for therapeutic targeting of PI3K pathway in patients with HPV-positive oropharyngeal carcinoma.

PIK3CA mutation is associated with a favorable prognosis among patients with curatively resected esophageal squamous cell carcinoma

PURPOSE

PIK3CA encodes the catalytic subunit of PI3K, p110α. Mutant PIK3CA stimulates the AKT pathway and promotes cancer cell proliferation. PIK3CA mutations have been associated with poor prognosis in patients with colorectal or lung cancer. In contrast, the relationship between PIK3CA mutations and favorable prognoses has been shown in breast cancer. However, the influence of PIK3CA mutations on the prognosis of patients with esophageal squamous cell carcinoma (ESCC) remains unclear.

EXPERIMENTAL DESIGN

Using a nonbiased database of 219 curatively resected ESCCs and eight esophageal cancer cell lines, we evaluated PIK3CA mutational status by pyrosequencing. The expression of p53 and phosphorylated AKT (i.e., AKT activation) was evaluated by immunohistochemistry.

RESULTS

PIK3CA mutations in exon 9 and/or 20 were detected in 46 cases (21%). No ESCC cell line harbored PIK3CA mutations. PIK3CA mutations were significantly associated with phosphorylated AKT expression, but not with p53 expression, sex, age at surgery, tobacco use, alcohol use, or histologic grade. Compared with wild-type PIK3CA cases, patients with PIK3CA mutations in exons 9 and/or 20 experienced significantly better disease-free survival [log-rank P = 0.0089; univariate HR: 0.37, 95% confidence interval (CI): 0.15-0.75, P = 0.0042; multivariate HR: 0.34, 95% CI: 0.10-0.86, P = 0.021] and overall survival (log-rank P = 0.012; univariate HR: 0.38, 95% CI: 0.16-0.78, P = 0.0060; multivariate HR: 0.35, 95% CI: 0.10-0.90, P = 0.028).

CONCLUSION

PIK3CA mutations in ESCC are associated with longer survival, suggesting its role as a prognostic biomarker. Future studies are needed to confirm this association and to elucidate the exact mechanisms by which PIK3CA mutations affect tumor behavior.

New therapeutic targets in the management of urothelial carcinoma of the bladder

Urothelial carcinoma of the bladder, despite the myriad of treatment approaches and our progressively increasing knowledge into its disease processes, remains one of the most clinically challenging problems in modern urological clinical practice. New therapies target biomolecular pathways and cellular mediators responsible for regulating cell growth and metabolism, both of which are frequently overexpressed in malignant urothelial cells, with the intent of inducing cell death by limiting cellular metabolism and growth, creating an immune response, or selectively delivering or activating a cytotoxic agent. These new and novel therapies may offer a potential for reduced toxicity and an encouraging hope for better treatment outcomes, particularly for a disease often refractory or not amenable to the current therapeutic approaches.

A comprehensive immunohistochemical and molecular approach to the PI3K/AKT/mTOR (phosphoinositide 3-kinase/v-akt murine thymoma viral oncogene/mammalian target of rapamycin) pathway in bladder urothelial carcinoma

What's known on the subject? and What does the study add? A few published studies investigating single or various PI3K/AKT/mTOR signalling components have produced inconsistent results. Moreover, PI3K regulatory subunit p85a and activated p70S6K expression levels have not been previously examined in urothelial carcinoma (UC). The present study addresses simultaneously all key members of PI3K/AKT/mTOR signalling cascade supporting a differential implication of PI3K/AKT/mTOR pathway components in urothelial tumorigenesis. Furthermore, we propose p-4E-BP1 as a potential prognostic marker in UC, which might assist the selection of patients more likely to benefit from chemotherapy regimens based on PI3K/AKT/mTOR pathway inhibition. Finally, the present study indicates PIK3CA/AKT1 mutational status as a potential predictive marker for time-to-recurrence.

OBJECTIVE

• To perform a comprehensive simultaneous assessment of all key members of phosphoinositide 3-kinase/v-akt murine thymoma viral oncogene/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway along with AKT homolog 1 (AKT1) and PIK3 catalytic alpha polypeptide (PIK3CA) mutations in bladder urothelial carcinoma (UC). • Published information is limited to a few studies looking into single or various combinations of members of this pathway with inconsistent results. In particular the expression status of phosphorylated (p-)p70S6 kinase (p70S6K) and p85a subunit of PI3K has not been tested in UC.

PATIENTS AND METHODS

• Paraffin-embedded transurethral resection tissue from 113 patients with UC was investigated for the association of p85aPI3K, p-AKT, p-mTOR, p-p70S6K and p-4E-BP1 (eukaryotic initiation factor 4E-binding protein 1) expression status, as well as PIK3CA and AKT1 mutations with p-extracellular signal-regulated kinase 1/2 (ERK1/2), fibroblast growth factor receptor 3 (FGFR3), pathological features, recurrence and cancer-specific survival.

RESULTS

• With the exception of p-p70S6K, all others components of the PI3K/AKT/mTOR pathway were upregulated in UCs as compared with normal urothelium. • p-mTOR expression strongly correlated with its upstream p-AKT and marginally with its downstream p-p70S6K. p85aPI3K and p-ERK1/2 levels were also marginally correlated. • PIK3CA and AKT1 mutations were distinctly uncommon and mutually exclusive, without any association with pathological features. However, the presence of AKT1 mutations was associated with increased FGFR3 levels and was restricted to p85aPI3K immunonegative cases, whereas PIK3CA mutant cases had marginally lower p85aPI3K levels. • The presence of PIK3CA single or combined with AKT1 mutations was associated with shorter recurrence-free survival in univariate survival analysis. An inverse relationship was established between p-4E-BP1 immunopositivity and histological grade or T category, as well as between p-p70S6K levels and T category, the latter relationship being of marginal significance. • p-4E-BP1 nuclear expression was marginally associated with the presence of lymphovascular invasion and adversely affected survival in multivariate, but not in univariate analysis.

CONCLUSIONS

• PI3K/AKT/mTOR signalling components appear to be differentially implicated in urothelial tumorigenesis and, with the exception of p85aPI3K, are unrelated to the PIK3CA or AKT1 mutational status. • Our findings propose p-4E-BP1 as a potential prognostic marker in UC independent of its association with pathological features, which might assist the selection of patients more likely to benefit from PI3K/AKT/mTOR axis inhibition. • PIK3CA/AKT1 mutational status may have a place in the prediction of time-to-recurrence.