2263

FGFR2

fibroblast growth factor receptor 2;FGFR2;fibroblast growth factor receptor 2

BEK fibroblast growth factor receptor|FGF receptor|FGFR2-AHCYL1 fusion kinase protein|bacteria-expressed kinase|hydroxyaryl-protein kinase|keratinocyte growth factor receptor|protein tyrosine kinase, receptor like 14|soluble FGFR4 variant 4

10q26

protein-coding

OBJECTIVE: To investigate the role of fibroblast growth factor receptor-2 (FGFR2) splice variant FGFR2IIIc in the regulation of mesenchymal-epithelial transition (MET) in doxorubicin-resistant bladder cancer cells. METHODS: A doxorubicin-resistant human bladder cell line (253J/DOX) was generated from the bladder cancer cell line 253J by being continuously exposed to gradually increasing doses of doxorubicin. Chemosensitivity to doxorubicin was determined by MTT assay. The expressions of P-glycoprotein and FGFR2IIIc were evaluated by Western blotting and real-time RT-PCR, respectively. Changes in E-cadherin and vimentin were detected by Western blot analysis. Migration ability of 253J and 253J/DOX cells was analyzed by in vitro wound healing assay. RESULTS: The resistant cells, 253J/DOX, were more resistant to doxorubicin than the parent cells. Western blotting and RT-PCR analysis indicated the higher levels of P-glycoprotein and FGFR2IIIc in 253J/DOX cells (P<0.05). Additionally, compared with the 253J cells, 253J/DOX cells presented the upregulation of E-cadherin, the downregulation of vimentin and the inhibition of migration ability. CONCLUSION: FGFR2IIIc-induced MET in chemoresistant bladder cancer cells may play an important role in the formation of metastatic lesions.

BACKGROUND: Despite being the most common pelvic gynecologic malignancy in industrialized countries, no targeted therapies are available for patients with metastatic endometrial carcinoma. In order to improve treatment, underlying molecular characteristics of primary and metastatic disease must be explored. METHODOLOGY/PRINCIPAL FINDINGS: We utilized the mass spectrometric-based mutation detection technology OncoMap to define the types and frequency of point somatic mutations in endometrial cancer. 67 primary tumors, 15 metastases corresponding to 7 of the included primary tumors and 11 endometrial cancer cell lines were screened for point mutations in 28 known oncogenes. We found that 27 (40.3%) of 67 primary tumors harbored one or more mutations with no increase in metastatic lesions. FGFR2, KRAS and PIK3CA were consistently the most frequently mutated genes in primary tumors, metastatic lesions and cell lines. CONCLUSIONS/SIGNIFICANCE: Our results emphasize the potential for targeting FGFR2, KRAS and PIK3CA mutations in endometrial cancer for development of novel therapeutic strategies.

The prognosis of gastric cancer patients with peritoneal metastasis is very poor. Recent findings suggest that use of trastuzumab, a monoclonal antibody-based agent that targets human epidermal growth factor receptor 2 (HER2), may improve the prognosis of gastric cancer patients with HER2 overexpression and/or gene amplification. However, whether these mechanisms of HER2 upregulation are present in gastric cancer patients with peritoneal metastasis is unclear. The status of HER2 expression in a cohort of samples obtained from 35 gastric cancer patients with peritoneal metastasis was investigated using immunohistochemistry and fluorescence in situ hybridization. In 18 cases, we also investigated the influence of induction chemotherapy on HER2 overexpression. The frequency of HER2 overexpression and gene amplification was 2.9 % (1/35) in peritoneal metastatic lesions. There was concurrence in HER2 status in the samples examined prior to and following induction of chemotherapy. Most samples from the gastric cancer patients with peritoneal metastasis did not show HER2 amplification and/or overexpression. Although our study size was small, these results suggest that trastuzumab, which is critically dependent on HER2 expression, might not be an effective agent for these patients. Consequently, other therapeutic approaches for these patients must be developed.

BACKGROUND: Despite being the most common pelvic gynecologic malignancy in industrialized countries, no targeted therapies are available for patients with metastatic endometrial carcinoma. In order to improve treatment, underlying molecular characteristics of primary and metastatic disease must be explored. METHODOLOGY/PRINCIPAL FINDINGS: We utilized the mass spectrometric-based mutation detection technology OncoMap to define the types and frequency of point somatic mutations in endometrial cancer. 67 primary tumors, 15 metastases corresponding to 7 of the included primary tumors and 11 endometrial cancer cell lines were screened for point mutations in 28 known oncogenes. We found that 27 (40.3%) of 67 primary tumors harbored one or more mutations with no increase in metastatic lesions. FGFR2, KRAS and PIK3CA were consistently the most frequently mutated genes in primary tumors, metastatic lesions and cell lines. CONCLUSIONS/SIGNIFICANCE: Our results emphasize the potential for targeting FGFR2, KRAS and PIK3CA mutations in endometrial cancer for development of novel therapeutic strategies.

Epithelial splicing regulatory protein 1 (ESRP1) binds the FGFR-2 auxiliary cis-element ISE/ISS-3, located in the intron between exon IIIb and IIIc, and primarily promotes FGFR-2 IIIb expression. Here we assessed the role of ESRP1 in pancreatic ductal adenocarcinoma (PDAC). Immunohistochemical analysis was performed using anti-ESRP1, FGFR-2 IIIb and FGFR-2 IIIc antibodies in 123 PDAC cases. ESRP1 expression vector and small interference RNA (siRNA) targeting ESRP1 were transfected into human PDAC cells, and cell growth, migration and invasion were analyzed. In vivo heterotopic and orthotopic implantations using ESRP1 overexpression clones were performed and effects on pancreatic tumor volumes and hepatic and pulmonary metastases determined. ESRP1 immunoreactivity was strong in the nuclei of cancer cells in well-to-moderately differentiated PDACs but weak in poorly differentiated cancers. Well-to-moderately differentiated cancers also exhibited high FGFR-2 IIIb and low FGFR-2 IIIc expression, whereas this ratio was reversed in the poorly differentiated cancers. Increased ESRP1 expression was associated with longer survival in comparison with low ESRP1 expression, and PANC-1 cells engineered to express ESRP1 exhibited increased FGFR-2 IIIb expression and decreased migration and invasion in vitro, whereas ESRP1 siRNA-transfected KLM-1 cells exhibited increased FGFR-2 IIIc expression and increased cell growth, migration and invasion. In vivo, ESRP1-overexpressing clones formed significantly fewer liver metastases as compared with control clones. ESRP1 regulates the expression pattern of FGFR-2 isoforms, attenuates cell growth, migration, invasion and metastasis, and is a favorable prognostic factor in PDAC. Therefore, devising mechanisms to upregulate ESRP1 may exert a beneficial therapeutic effect in PDAC.