Enrichment of FGFR3-TACC3 Fusions in Patients With Bladder Cancer Who Are Young, Asian, or Have Never Smoked

The roles of FGFR3 and c-MYC in urothelial bladder cancer

Bladder cancer is one of the most frequently occurring cancers worldwide. At diagnosis, 75% of urothelial bladder cancer cases have non-muscle invasive bladder cancer while 25% have muscle invasive or metastatic disease. Aberrantly activated fibroblast growth factor receptor (FGFR)-3 has been implicated in the pathogenesis of bladder cancer. Activating mutations of FGFR3 are observed in around 70% of NMIBC cases and ~ 15% of MIBCs. Activated FGFR3 leads to ligand-independent receptor dimerization and activation of downstream signaling pathways that promote cell proliferation and survival. FGFR3 is an important therapeutic target in bladder cancer, and clinical studies have shown the benefit of FGFR inhibitors in a subset of bladder cancer patients. c-MYC is a well-known major driver of carcinogenesis and is one of the most commonly deregulated oncogenes identified in human cancers. Studies have shown that the antitumor effects of FGFR inhibition in FGFR3 dependent bladder cancer cells and other FGFR dependent cancers may be mediated through c-MYC, a key downstream effector of activated FGFR that is involved tumorigenesis. This review will summarize the current general understanding of FGFR signaling and MYC alterations in cancer, and the role of FGFR3 and MYC dysregulation in the pathogenesis of urothelial bladder cancer with the possible therapeutic implications.

Landscape of targeted therapies for advanced urothelial carcinoma

Bladder cancer (BC) is the tenth most common malignancy globally. Urothelial carcinoma (UC) is a major type of BC, and advanced UC (aUC) is associated with poor clinical outcomes and limited survival rates. Current options for aUC treatment mainly include chemotherapy and immunotherapy. These options have moderate efficacy and modest impact on overall survival and thus highlight the need for novel therapeutic approaches. aUC patients harbor a high tumor mutation burden and abundant molecular alterations, which are the basis for targeted therapies. Erdafitinib is currently the only Food and Drug Administration (FDA)-approved targeted therapy for aUC. Many potential targeted therapeutics aiming at other molecular alterations are under investigation. This review summarizes the current understanding of molecular alterations associated with aUC targeted therapy. It also comprehensively discusses the related interventions for treatment in clinical research and the potential of using novel targeted drugs in combination therapy.

E-cadherin and FGFR3 are risk factors determining prognosis of patients with bladder urothelial carcinoma

OBJECTIVE

To explore the diagnostic value of the combined detection of E-cadherin and FGFR3 in patients with bladder urothelial carcinoma and their correlation with patient prognosis.

METHODS

The study retrospectively analyzed the case data of 96 patients with bladder urothelial carcinoma treated at the Yixing Guanlin Hospital from June 2018 to June 2020. Tumor tissue of each patient and matched healthy tissue were collected for immunohistochemical staining. Differences in FGFR3 and E-cadherin expression were identified between tumor and healthy tissues. The influence of clinical characteristics on the recurrence was analyzed using a univariate analysis. Then, a multivariate logistic regression analysis was performed to analyze the risk factors for recurrence in patients with bladder urothelial carcinoma. The diagnostic value of FGFR3, E-cadherin and their combination for disease recurrence and prognosis was analyzed. The correlation of FGFR3 and E-cadherin expression with disease recurrence was discussed.

RESULTS

The positive expression of FGFR3 in the cancer tissues was significantly higher than that in the adjacent tissue, while the positive expression of E-cadherin showed the opposite (P<0.05). Logistic regression analysis showed that tumor size, TNM stage, pathological grade, FGFR3 and E-cadherin were risk factors for the recurrence of bladder urothelial carcinoma (P<0.05). The area under the curve of FGFR3 combined with E-cadherin in evaluating prognosis and recurrence was 0.957. Correlation analysis revealed that FGFR3 was significantly and positively correlated with the patients' prognostic recurrence while E-cadherin was negatively correlated with it.

CONCLUSION

FGFR3 and E-cadherin are risk factors affecting the prognosis of patients with bladder urothelial carcinoma, and they are associated with the outcome of bladder cancer.

Molecularly Targeted Therapy towards Genetic Alterations in Advanced Bladder Cancer

Despite the introduction of immune checkpoint inhibitors and antibody-drug conjugates to the management of advanced urothelial carcinoma, the disease is generally incurable. The increasing incorporation of next-generation sequencing of tumor tissue into the characterization of bladder cancer has led to a better understanding of the somatic genetic aberrations potentially involved in its pathogenesis. Genetic alterations have been observed in kinases, such as FGFRs, ErbBs, PI3K/Akt/mTOR, and Ras-MAPK, and genetic alterations in critical cellular processes, such as chromatin remodeling, cell cycle regulation, and DNA damage repair. However, activating mutations or fusions of FGFR2 and FGFR3 remains the only validated therapeutically actionable alteration, with erdafitinib as the only targeted agent currently approved for this group. Bladder cancer is characterized by genomic heterogeneity and a high tumor mutation burden. This review highlights the potential relevance of aberrations and discusses the current status of targeted therapies directed at them.

Receptor Tyrosine Kinases and Their Signaling Pathways as Therapeutic Targets of Curcumin in Cancer

Receptor tyrosine kinases (RTKs) are transmembrane cell-surface proteins that act as signal transducers. They regulate essential cellular processes like proliferation, apoptosis, differentiation and metabolism. RTK alteration occurs in a broad spectrum of cancers, emphasising its crucial role in cancer progression and as a suitable therapeutic target. The use of small molecule RTK inhibitors however, has been crippled by the emergence of resistance, highlighting the need for a pleiotropic anti-cancer agent that can replace or be used in combination with existing pharmacological agents to enhance treatment efficacy. Curcumin is an attractive therapeutic agent mainly due to its potent anti-cancer effects, extensive range of targets and minimal toxicity. Out of the numerous documented targets of curcumin, RTKs appear to be one of the main nodes of curcumin-mediated inhibition. Many studies have found that curcumin influences RTK activation and their downstream signaling pathways resulting in increased apoptosis, decreased proliferation and decreased migration in cancer both in vitro and in vivo. This review focused on how curcumin exhibits anti-cancer effects through inhibition of RTKs and downstream signaling pathways like the MAPK, PI3K/Akt, JAK/STAT, and NF-κB pathways. Combination studies of curcumin and RTK inhibitors were also analysed with emphasis on their common molecular targets.