All reported mutations in ALAS2, which encodes the rate-regulating enzyme of erythroid heme biosynthesis, cause X-linked sideroblastic anemia. We describe eight families with ALAS2 deletions, either c.1706-1709 delAGTG (p.E569GfsX24) or c.1699-1700 delAT (p.M567EfsX2), resulting in frameshifts that lead to replacement or deletion of the 19-20 C-terminal residues of the enzyme. Prokaryotic expression studies show that both mutations markedly increase ALAS2 activity. These gain-of-function mutations cause a previously unrecognized form of porphyria, X-linked dominant protoporphyria, characterized biochemically by a high proportion of zinc-protoporphyrin in erythrocytes, in which a mismatch between protoporphyrin production and the heme requirement of differentiating erythroid cells leads to overproduction of protoporphyrin in amounts sufficient to cause photosensitivity and liver disease.

The Karyopherin proteins are involved in nucleo-cytoplasmic trafficking and are critical for protein and RNA subcellular localization. Recent studies suggest they are important in nuclear envelope component assembly, mitosis and replication. Since these are all critical cellular functions, alterations in the expression of the Karyopherins may have an impact on the biology of cancer cells. In this study, we examined the expression of the Karyopherins, Crm1, Karyopherin b1 (Kpnb1) and Karyopherin a2 (Kpna2), in cervical tissue and cell lines. The functional significance of these proteins to cancer cells was investigated using individual siRNAs to inhibit their expression. Microarrays, quantitative RT-PCR and immunofluorescence revealed significantly higher expression of Crm1, Kpnb1 and Kpna2 in cervical cancer compared to normal tissue. Expression levels were similarly elevated in cervical cancer cell lines compared to normal cells, and in transformed epithelial and fibroblast cells. Inhibition of Crm1 and Kpnb1 in cancer cells significantly reduced cell proliferation, while Kpna2 inhibition had no effect. Noncancer cells were unaffected by the inhibition of Crm1 and Kpnb1. The reduction in proliferation of cancer cells was associated with an increase in a subG1 population by cell cycle analysis and Caspase-3/7 assays revealed increased apoptosis. Crm1 and Kpnb1 siRNA-induced apoptosis was accompanied by an increase in the levels of growth inhibitory proteins, p53, p27, p21 and p18. Our results demonstrate that Crm1, Kpnb1 and Kpna2 are overexpressed in cervical cancer and that inhibiting the expression of Crm1 and Kpnb1, not Kpna2, induces cancer cell death, making Crm1 and Kpnb1 promising candidates as both biomarkers and potential anticancer therapeutic targets. ' 2008 Wiley-Liss, Inc.Key words: cervical cancer; nuclear transport proteins; Crm1; Karyopherin b1; Karyopherin a2Cervical cancer is the second most common cancer among women worldwide, 1 with nearly 80% of cases occurring in developing countries. 2 The primary risk factor in the development of the disease is infection with the Human Papillomavirus (HPV), 3,4 and more than 90% of cervical cancers carry high-risk HPV DNA. 4,5 The HPV E6 and E7 oncoproteins are responsible for cancer development, and evidence has shown that they alone are sufficient to immortalize human foreskin keratinocytes. 6 Their continued expression is essential for maintaining the transformed state. 6 HPV E6 and E7 promote cellular transformation by binding to and blocking the functions of the cell cycle regulatory proteins, p53 and pRb, respectively. 7,8 Prophylactic vaccines against lowrisk (HPV6, 11) and high-risk (HPV16 and 18) HPV types have recently been developed. 9 They rely on the vaccination of women before exposure to the virus; hence, their benefit to women already infected with HPV is still unclear, as well as their benefit to women infected with HPV types other than HPV6, 11, 16 and 18.Although the high-risk HPV proteins are the causative agents behind cervical cance...

Mesenchymal stromal/stem cells (MSCs) represent an area being intensively researched for tissue engineering and regenerative medicine applications. MSCs may provide the opportunity to treat diseases and injuries that currently have limited therapeutic options, as well as enhance present strategies for tissue repair. The cellular environment has a significant role in cellular development and differentiation through cell–matrix interactions. The aim of this study was to investigate the behavior of adipose-derived MSCs (ad-MSCs) in the context of a cell-derived matrix so as to model the in vivo physiological microenvironment. The fibroblast-derived extracellular matrix (fd-ECM) did not affect ad-MSC morphology, but reduced ad-MSC proliferation. Ad-MSCs cultured on fd-ECM displayed decreased expression of integrins α2 and β1 and subsequently lost their multipotency over time, as shown by the decrease in CD44, Octamer-binding transcription factor 4 (OCT4), SOX2, and NANOG gene expression. The fd-ECM induced chondrogenic differentiation in ad-MSCs compared to control ad-MSCs. Loss of function studies, through the use of siRNA and a mutant Notch1 construct, revealed that ECM-mediated ad-MSCs chondrogenesis requires Notch1 and β-catenin signaling. The fd-ECM also showed anti-senescence effects on ad-MSCs. The fd-ECM is a promising approach for inducing chondrogenesis in ad-MSCs and chondrogenic differentiated ad-MSCs could be used in stem cell therapy procedures.