Canine and human sarcomas exhibit predominant FGFR1 expression and impaired viability after inhibition of signaling.

Fibroblast growth factor receptors (FGFRs) are important in malignant progression of several human epithelial tumors. However, little is known about FGFRs in canine or human soft tissue sarcomas. Thus, our aim was to investigate expression of FGFRs and their involvement in cell survival in sarcomas of both species. FGFR1-4 and FGFRL1 transcripts as well as IIIb/IIIc splice variants of FGFR1-3 were evaluated in 3 canine- and 6 human sarcoma cell lines and 19 spontaneous canine sarcomas by SYBRqPCR. FGFR1 protein expression was assessed by immunohistochemistry. Growth inhibitory effects of FGFR1 inhibitor PD166866 and dominant negative recombinant FGFR adenoviral expression constructs (dnFGFR) on tumor cell lines were analyzed. Profiling of multiple FGFR transcripts detected comparable co-expression in most of human and canine sarcoma cell lines and canine tumor specimens. This indicates existence of closely related regulation mechanisms for FGFR expression in sarcomas of both species. FGFR1 with splice variant IIIc was consistently expressed with highest transcript levels. In 88% of the spontaneous tumor samples a heterogeneous FGFR1 protein expression was observed. Significant growth inhibition and cell death was seen after infection with dnFGFR1 in canine and human sarcoma cells, but not with dnFGFR3 and 4. PD166866 showed selective cytotoxicity with IC50 values between 12.1 and 26.4 µM. FGFR1 inhibition blocked ligand-induced tyrosine phosphorylation of ERK1/2 mitogen-activated protein kinase isoforms. This study emphasizes the important role FGFR1, especially splice variant IIIc, likely plays in sarcomas. Inhibitory small molecules could be of potential use for targeted therapy in aggressive sarcomas of both species.

Prolonged hyperthermic intraperitoneal chemotherapy duration with 90 minutes cisplatin might increase overall survival in gastric cancer patients with peritoneal metastases.

BACKGROUND: Advanced gastric cancer with synchronous peritoneal metastases (GC-PM) is associated with a poor prognosis. Although cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is a promising approach, only a limited number of Western studies exist. AIM: To investigate the clinicopathological outcomes of patients who underwent CRS-HIPEC for GC-PM. METHODS: A retrospective analysis of patients with GC-PM was conducted. All patients were seen at the Department of General and Visceral Surgery, Hospital Barmherzige Brüder, Regensburg, Germany between January 2011 and July 2021 and underwent CRS-HIPEC. Preoperative laboratory results, the use of neoadjuvant trastuzumab, and the details of CRS-HIPEC, including peritoneal carcinomatosis index, completeness of cytoreduction, and surgical procedures were recorded. Disease-specific (DSS), and overall survival (OS) of patients were calculated. RESULTS: A total of 73 patients were included in the study. Patients treated with neoadjuvant trastuzumab (n = 5) showed longer DSS (P = 0.0482). Higher white blood cell counts (DSS: P = 0.0433) and carcinoembryonic antigen levels (OS and DSS: P < 0.01), and lower hemoglobin (OS and DSS: P < 0.05) and serum total protein (OS: P = 0.0368) levels were associated with shorter survival. Longer HIPEC duration was associated with more advantageous median survival times [60-min (n = 59): 12.86 mo; 90-min (n = 14): 27.30 mo], but without statistical difference. To obtain additional data from this observation, further separation of the study population was performed. First, propensity score-matched patient pairs (n = 14 in each group) were created. Statistically different DSS was found between patient pairs (hazard ratio = 0.2843; 95% confidence interval: 0.1119-0.7222; P = 0.0082). Second, those patients who were treated with trastuzumab and/or had human epidermal growth factor receptor 2 positivity (median survival: 12.68 mo vs 24.02 mo), or had to undergo the procedure before 2016 (median survival: 12.68 mo vs 27.30 mo; P = 0.0493) were removed from the original study population. CONCLUSION: Based on our experience, CRS-HIPEC is a safe and secure method to improve the survival of advanced GC-PM patients. Prolonged HIPEC duration may serve as a good therapy for these patients.

Alternative Splicing of Fibroblast Growth Factor Receptor IgIII Loops in Cancer.

Alternative splicing of the IgIII loop of fibroblast growth factor receptors (FGFRs) 1-3 produces b- and c-variants of the receptors with distinctly different biological impact based on their distinct ligand-binding spectrum. Tissue-specific expression of these splice variants regulates interactions in embryonic development, tissue maintenance and repair, and cancer. Alterations in FGFR2 splicing are involved in epithelial mesenchymal transition that produces invasive, metastatic features during tumor progression. Recent research has elucidated regulatory factors that determine the splice choice both on the level of exogenous signaling events and on the RNA-protein interaction level. Moreover, methodology has been developed that will enable the in depth analysis of splicing events during tumorigenesis and provide further insight on the role of FGFR 1-3 IIIb and IIIc in the pathophysiology of various malignancies. This paper aims to summarize expression patterns in various tumor types and outlines possibilities for further analysis and application.