Extending the ophthalmological phenotype of Galloway-Mowat syndrome with distinct retinal dysfunction: a report and review of ocular findings.

BACKGROUND: Galloway-Mowat syndrome (GMS) is a rare autosomal recessive condition first described in 1968 and characterized by microcephaly and infantile onset of central nervous system (CNS) abnormalities resulting in severely delayed psychomotor development, cerebellar atrophy, epilepsy, and ataxia, as well as renal abnormalities such as nephrotic syndrome, proteinuria, end-stage renal disease (ESRD), and hiatal hernia. CASE PRESENTATION: We describe a GMS case diagnosed with homozygous missense mutation in the WDR73 gene, with absence of renal abnormalities. We expanded the clinical phenotype of GMS with WDR73 gene defect to include retinal dysfunction with missense mutation and developmental dysplasia of the hip. We compared eye findings of our case to previously reported cases, and we present an electroretinogram (ERG) picture for the first time in the literature. CONCLUSION: We recommend that clinicians screen patients with GM syndrome for retinal dysfunction and that a skeletal survey should be done to detect developmental dysplasia of the hip (DDH) so as to provide for early intervention.

CHEK2 represses breast stromal fibroblasts and their paracrine tumor-promoting effects through suppressing SDF-1 and IL-6.

BACKGROUND: Active fibroblasts, the predominant and the most active cells of breast cancer stroma, are responsible for tumor growth and spread. However, the molecular mediators and pathways responsible for stromal fibroblast activation, and their paracrine pro-carcinogenic effects are still not well defined. The CHEK2 tumor suppressor gene codes for a protein kinase, which plays important roles in the cellular response to various genotoxic stresses. METHODS: Immunoblotting, quantitative RT-PCR and Immunofluorescence were used to assess the expression of CHEK2 in different primary breast fibroblasts and in tissues. The effect of CHEK2 on the expression and secretion of SDF-1 and IL-6 was evaluated by immunoblotting and ELISA. The WST-1 colorimetric assay was used to assess cell proliferation, while the BD BioCoat Matrigel invasion chambers were utilized to determine the effects of CHEK2 on the migratory and the invasiveness capacities of breast stromal fibroblasts as well as breast cancer cells. RESULTS: We have shown that CHEK2 is down-regulated in most cancer-associated fibroblasts (CAFs) as compared to their corresponding tumor counterpart fibroblasts (TCFs) at both the mRNA and protein levels. Interestingly, CHEK2 down-regulation using specific siRNA increased the expression/secretion of both cancer-promoting cytokines SDF-1 and IL-6, and transdifferentiated stromal fibroblasts to myofibroblasts. These cells were able to enhance the proliferation of non-cancerous epithelial cells, and also boosted the migration/invasion abilities of breast cancer cells in a paracrine manner. The later effect was SDF-1/IL-6-dependent. Importantly, ectopic expression of CHEK2 in active CAFs converted these cells to a normal state, with lower migration/invasion capacities and reduced paracrine pro-carcinogenic effects. CONCLUSION: These results indicate that CHEK2 possesses non-cell-autonomous tumor suppressor functions, and present the Chk2 protein as an important mediator in the functional interplay between breast carcinomas and their stromal fibroblasts.

Breast stromal fibroblasts from histologically normal surgical margins are pro-carcinogenic.

There is evidence that normal breast stromal fibroblasts (NBFs) suppress tumour growth, while cancer-associated fibroblasts (CAFs) promote tumourigenesis through functional interactions with tumour cells. Little is known about the biology and the carcinogenic potential of stromal fibroblasts present in histologically normal surgical margins (TCFs). Therefore, we first undertook gene expression analysis on five CAF/TCF pairs from breast cancer patients and three NBF samples (derived from mammoplasties). This comparative analysis revealed variation in gene expression between these three categories of cells, with a TCF-specific gene expression profile. This variability was higher in TCFs than in their paired CAFs and also NBFs. Cytokine arrays show that TCFs have a specific secretory cytokine profile. In addition, stromal fibroblasts from surgical margins expressed high levels of α-SMA and SDF-1 and exhibited higher migratory/invasiveness abilities. Indirect co-culture showed that TCF cells enhance the proliferation of non-cancerous mammary epithelial cells and the epithelial-to-mesenchymal transition of breast cancer cells. Moreover, TCF and CAF cells increased the level of PCNA, MMP-2 and the phosphorylated/activated form of Akt in normal breast luminal fibroblasts in a paracrine manner. Furthermore, TCFs were able to promote the formation and growth of humanized orthotopic breast tumours in nude mice. Interestingly, these TCF phenotypes and the extent of their effects were intermediate between those of NBFs and CAFs. Together, these results indicate that stromal fibroblasts located in non-cancerous tissues exhibit a tumour-promoting phenotype, indicating that their presence post-surgery may play important roles in cancer recurrence.