Loss of Forkhead box P1 (FOXP1) protein expression confers a poor prognosis in sporadic and familial breast cancer patients, and the FOXP1 gene maps to a tumor suppressor locus at chromosome 3p14. Although correlation studies have indicated that FOXP1 has a role in tumor suppression, determination of the regulatory mechanism of FOXP1 is required to establish its function in breast cancer. It has previously been identified that FOXP1 is regulated by estrogen in breast cancer and that treatment with bisphenol A is effective for regulating the transformation of the normal human breast epithelial cell line, MCF‑10F. In addition, FOXO‑regulated activation of FOXP1 inhibits the apoptosis of MCF‑10F cells following tamoxifen and Akt inhibitor VIII administration. The present study indicates that FOXP1 regulation occurs via a PI3K/Akt/p70S6 kinase (p70S6K) signaling pathway. Following treatment with wortmannin, an inhibitor of phosphatidylinositol 3‑kinase (PI3K)/Akt, MCF7 and MDA‑MB‑231 breast cancer cells demonstrated decreased FOXP1 protein expression levels; this result was also observed in the small interfering (si)RNA silencing of Akt. By contrast, overexpression of Akt resulted in increased FOXP1 protein expression levels in the MDA‑MB‑231 cells compared with the control cell lysates. Furthermore, treatment with rapamycin, a specific inhibitor of the mammalian target of rapamycin/p70S6K cascade, resulted in decreased FOXP1 expression in the MCF7 cells, but not in the MDA‑MB‑231 cells, which were resistant to rapamycin‑induced inhibition. In addition, silencing of p70S6K using siRNA produced a marked decrease in FOXP1 expression. These data indicate that FOXP1 protein expression is regulated by a PI3K/Akt/p70S6K signaling cascade in breast cancer.
Leukocyte adhesion deficiency type I is a rare primary immunodeficiency disorder characterized by mutations in the ITGB2 gene encoding CD18. We present clinical and immunological features of 15 patients with leukocyte adhesion deficiency type 1 (LAD-1). Targeted next-generation sequencing was performed with either a primary immunodeficiency gene panel comprising 266 genes or a small LAD-panel consisting of five genes for genetic analysis. To measure the expression level of integrins on the leukocyte surface, flow cytometry analysis was performed. The median age of the patients at diagnosis was 3 (1–48) months. Eleven (73%) of the 15 patients had a LAD-1 diagnosis in their first 6 months and 14 (93%) patients had consanguineous parents. Delayed separation of the umbilical cord was present in 80% (n = 12) of the patients in our cohort, whereas omphalitis was observed in 53% (n = 8) of the patients. Leukocytosis with neutrophil predominance was observed in 73% (n = 11) patients. Nine distinct variants in the ITGB2 gene in 13 of the 15 patients with LAD-1 were characterized, two of which (c.305_306delAA and c.779_786dup) are novel homozygous mutations of ITGB2. Four unrelated patients from Syria had a novel c.305_306delAA mutation that might be a founder effect for patients of Syrian origin. Four (27%) patients underwent hematopoietic stem cell transplantation. Two patients died because of HSCT complications and the other two are alive and well. Early differential diagnosis of the patients is critical in the management of the disease and genetic evaluation provides a basis for family studies and genetic counseling.
Urothelial bladder cancer is a major cause of morbidity and mortality worldwide, causing an estimated 150 000 deaths per year. Whilst non-muscle-invasive bladder tumours can be effectively treated, with high survival rates, many tumours recur, and some will progress to muscle-invasive disease with a much poorer long-term prognosis. Thus, there is a pressing need to understand the molecular transitions occurring within the progression of bladder cancer to an invasive disease. Tumour invasion is often associated with a down-regulation of E-cadherin expression concomitant with a suppression of cell:cell junctions, and decreased levels of E-cadherin expression have been reported in higher grade urothelial bladder tumours. We find that expression of E-cadherin in a panel of bladder cancer cell lines correlated with the presence of cell:cell junctions and the level of PAK5 expression. Interestingly, exogenous PAK5 has recently been described to be associated with cell:cell junctions and we now find that endogenous PAK5 is localised to cell junctions and interacts with an E-cadherin complex. Moreover, depletion of PAK5 expression significantly reduced junctional integrity. These data suggest a role for PAK5 in maintaining junctional stability and we find that, in both our own patient samples and a commercially available dataset, PAK5mRNA levels are reduced in human bladder cancer compared with normal controls. Taken together, the present study proposes that PAK5 expression levels could be used as a novel prognostic marker for bladder cancer progression.