Pharmacogenomics: Biomarker-Directed Therapy for Bladder Cancer

Combined expression of JHDM1D/KDM7A gene and long non-coding RNA RP11-363E7.4 as a biomarker for urothelial cancer prognosis

Bladder cancer is the tenth most frequently diagnosed cancer globally. Classification of high- or low-grade tumors is based on cytological differentiation and is an important prognostic factor. LncRNAs regulate gene expression and play critical roles in the occurrence and development of cancer, however, there are few reports on their diagnostic value and co-expression levels with genes, which may be useful as specific biomarkers for prognosis and therapy in bladder cancer. Thus, we performed a marker lesion study to investigate whether gene/lncRNA expression in urothelial carcinoma tissues may be useful in differentiating low-grade and high-grade tumors. RT-qPCR was used to evaluate the expression of the JHDM1D gene and the lncRNAs CTD-2132N18.2, SBF2-AS1, RP11-977B10.2, CTD-2510F5.4, and RP11-363E7.4 in 20 histologically diagnosed high-grade and 10 low-grade tumors. A protein-to-protein interaction network between genes associated with JHDM1D gene was constructed using STRING website. The results showed a moderate (positive) correlation between CTD-2510F5.4 and CTD2132N18.2. ROC curve analyses showed that combined JHDM1D and RP11-363E7.4 predicted tumor grade with an AUC of 0.826, showing excellent accuracy. In conclusion, the results indicated that the combined expression of JHDM1D and RP11-363E7.4 may be a prognostic biomarker and a promising target for urothelial tumor therapy.

Identification and Validation of N6-Methyladenosine-Related Biomarkers for Bladder Cancer: Implications for Immunotherapy

N6-methyladenosine (m⁶A) has emerged as one of the most important modifications of RNA. Based on the expression of 23 different modes of m⁶A regulatory factors, we identified three different m⁶A modification patterns in bladder cancer. The effects of the three different modes of m⁶A modification on clinicopathological characteristics, immune cell infiltration levels and expression levels of immune checkpoint genes were comprehensively analyzed. In addition, the effects of different modes of m⁶A modification on the therapeutic efficacy of anti-PD-L1 immunotherapy (atezolizumab) are also discussed. Our results confirm that m⁶A methylation plays an important role in immune cell recruitment in the tumor microenvironment of bladder cancer, which influences the efficacy of anti-PD-L1 therapy for bladder cancer. We further confirmed the important role of FTO protein in the biological function of bladder cancer cells by performing in vitro experiments. FTO functions as an oncogene in bladder cancer cells, and upon FTO knockdown, the level of m⁶A enzyme activity in bladder cancer cells was significantly increased, apoptosis was increased, and cell proliferation and cell invasion were reduced. In addition, our study also confirmed that K216H and K216E are probably important targets for regulating FTO. We provide new insights into the regulatory pathways of the immune microenvironment and the methylation function of m⁶A in bladder cancer, which will help in designing novel diagnostic methods, prognostic tools, and therapeutic targets.

Enhanced Expression of CNTD2/CCNP Predicts Poor Prognosis in Bladder Cancer Based on the GSE13507

Bladder cancer is one of the most common urogenital malignancies in the world, and there are no adequate prognostic indicators. CNTD2 is one of the atypical cyclins, which may be related to the cell cycle and even the development of cancers. Early studies have shown that CNTD2 is closely related to the occurrence and development of many malignant tumors. However, the mechanism of CNTD2 in bladder cancer has not been reported. In our research, we explored the different expressions of CNTD2 between 411 bladder cancers and 19 normal bladder tissues based on the TCGA dataset. CNTD2-related signaling pathways were identified through the GSEA. We analyzed the associations of CNTD2 expression and bladder cancer progression and survival using GSE13507. Compared with 19 cases of normal bladder tissue, CNTD2 gene expression was increased in 411 cases of bladder cancer. The high expression of CNTD2 strongly correlated with grade (P < 0.0001), T classification (P = 0.0001), N classification (P = 0.00011), M classification (P = 0.044), age (P = 0.027), and gender (P = 0.0012). Bladder cancer patients with high CNTD2 expression had shorter overall survival (P < 0.001). In the meantime, univariate and multivariate analyses showed that the increased expression of CNTD2 was an independent factor for poor prognosis in bladder cancer patients (P < 0.001 and P < 0.001, respectively). CNTD2 expression is closely related to bladder cancer progression, and the high expression of CNTD2 may be an adverse biomarker in bladder cancer patients.

Consequences of Biomarker Analysis on the Cost-Effectiveness of Cetuximab in Combination with FOLFIRI as a First-Line Treatment of Metastatic Colorectal Cancer: Personalised Medicine at Work

BACKGROUND

Therapies may be more efficacious when targeting a patient subpopulation with specific attributes, thereby enhancing the cost-effectiveness of treatment. In the CRYSTAL study, patients with metastatic colorectal cancer (mCRC) were treated with cetuximab plus FOLFIRI or FOLFIRI alone until disease progression, unacceptable toxic effects or withdrawal of consent.

OBJECTIVE

To determine if stratified use of cetuximab based on genetic biomarker detection improves cost-effectiveness.

METHODS

We used individual patient data from CRYSTAL to compare the cost-effectiveness, cost per life-year (LY) and cost per quality-adjusted LY (QALY) gained of cetuximab plus FOLFIRI versus FOLFIRI alone in three cohorts of patients with mCRC: all randomised patients (intent-to-treat; ITT), tumours with no detectable mutations in codons 12 and 13 of exon 2 of the KRAS protein ('KRAS wt') and no detectable mutations in exons 2, 3 and 4 of KRAS and exons 2, 3 and 4 of NRAS ('RAS wt'). Survival analysis was conducted using RStudio, and a cost-utility model was modified to allow comparison of the three cohorts.

RESULTS

The deterministic base-case ICER (cost per QALY gained) was £130,929 in the ITT, £72,053 in the KRAS wt and £44,185 in the RAS wt cohorts for cetuximab plus FOLFIRI compared with FOLFIRI alone. At a £50,000 willingness-to-pay threshold, cetuximab plus FOLFIRI has a 2.8, 20 and 63% probability of being cost-effective for the ITT, KRAS wt and RAS wt cohorts, respectively, versus FOLFIRI alone.

CONCLUSION

Screening for mutations in both KRAS and NRAS may provide the most cost-effective approach to patient selection.

Knockdown of fibrous sheath interacting protein 1 expression reduces bladder urothelial carcinoma cell proliferation and induces apoptosis via inhibition of the PI3K/AKT pathway

Background

FSIP1 plays a vital role in tumorigenesis and cancer progression. In bladder cancer, FSIP1 overexpression was associated with poor prognosis of bladder urothelial carcinoma. In this study, we investigated whether FSIP1 is essential in the progression of bladder cancer and the mechanism by which it mediates this effect.

Methods

FSIP1 expression was knocked down in bladder cancer cells using lentiviral-mediated short hairpin RNA (shRNA). FSIP1 expression was detected using Western blotting, immunohistochemistry (IHC), and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The effects of FSIP1 knockdown on tumor cells were assessed using colony formation, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and flow cytometry (FCM) apoptosis assays in vitro and BALB/c nude mouse xenograft model in vivo.

Results

The findings suggested that FSIP1 protein was highly expressed in bladder cancer cell lines. Knockdown of FSIP1 resulted in reduced tumor cell viability, cell cycle arrest at G₀/G₁ phase and apoptosis of bladder cancer cell lines (P<0.05). Moreover, knockdown of FSIP1 expression suppressed the tumor formation and growth of bladder cancer xenografts (P<0.05). At the gene level, knockdown of FSIP1 expression downregulated the activity of the PI3K/AKT signaling pathway.

Conclusion

This study demonstrated that knockdown of FSIP1 suppressed bladder cancer cell malignant behaviors in vitro and in vivo through the inhibition of the PI3K/AKT signaling pathway, suggesting that targeting FSIP1 could be further evaluated as a potential therapeutic strategy in bladder cancer.

The Rho GTPase signalling pathway in urothelial carcinoma

Urothelial carcinoma remains a clinical challenge: non-muscle-invasive disease has a high rate of recurrence and risk of progression, and outcomes for patients with advanced disease are poor, owing to a lack of effective systemic therapies. The Rho GTPase family of enzymes was first identified >30 years ago and contains >20 members, which are divided into eight subfamilies: Cdc42, Rac, Rho, RhoUV, RhoBTB, RhoDF, RhoH, and Rnd. Rho GTPases are molecular on-off switches, which are increasingly being understood to have a critical role in a number of cellular processes, including cell migration, cell polarity, cell adhesion, cell cycle progression, and regulation of the cytoskeleton. This switch is an evolutionarily conserved system in which GTPases alternate between GDP-bound (inactive) and GTP-bound (active) forms. The activities of these Rho GTPases are many, context-dependent, and regulated by a number of proteins that are being progressively elucidated. Aberrations of the Rho GTPase signalling pathways have been implicated in various malignancies, including urothelial carcinoma, and understanding of the role of Rho GTPases in these diseases is increasing. This signalling pathway has the potential for therapeutic targeting in urothelial carcinoma. Research in this area is nascent, and much work is necessary before current laboratory-based research can be translated into the clinic.

Comprehensive Molecular Characterization of Muscle-Invasive Bladder Cancer

We report a comprehensive analysis of 412 muscle-invasive bladder cancers characterized by multiple TCGA analytical platforms. Fifty-eight genes were significantly mutated, and the overall mutational load was associated with APOBEC-signature mutagenesis. Clustering by mutation signature identified a high-mutation subset with 75% 5-year survival. mRNA expression clustering refined prior clustering analyses and identified a poor-survival "neuronal" subtype in which the majority of tumors lacked small cell or neuroendocrine histology. Clustering by mRNA, long non-coding RNA (lncRNA), and miRNA expression converged to identify subsets with differential epithelial-mesenchymal transition status, carcinoma in situ scores, histologic features, and survival. Our analyses identified 5 expression subtypes that may stratify response to different treatments.