The gene encoding R-spondin 4 (RSPO4), a secreted protein implicated in Wnt signaling, is mutated in inherited anonychia.

Anonychia and hyponychia congenita (OMIM 206800) are rare autosomal recessive conditions in which the only presenting phenotype is the absence or severe hypoplasia of all fingernails and toenails. After determining linkage to chromosome 20p13, we identified homozygous or compound heterozygous mutations in the gene encoding R-spondin 4 (RSPO4), a secreted protein implicated in Wnt signaling, in eight affected families. Rspo4 expression was specifically localized to developing mouse nail mesenchyme at embryonic day 15.

Antisense RNA inhibition of cathepsin L expression reduces tumorigenicity of malignant cells.

Several tumour-forming cell lines are known to overproduce the lysosomal cysteine peptidase cathepsin L. We have used an antisense approach to investigate whether inhibition of cathepsin L overexpression in two malignant cell lines (myeloma SP cells and L cells) reduces their tumorigenic potential. Two different cDNA fragments of murine cathepsin L were inserted in the antisense direction into the pcDNA3 vector, and SP and L cells were stably transfected with these plasmid constructs.

Expression of acid cysteine proteinase inhibitor (ACPI) in the normal human prostate, benign prostatic hyperplasia and adenocarcinoma.

Acid cysteine proteinase inhibitor (ACPI or cystatin A) is a protein (12 kDa) which inhibits the action of several cysteine proteinases, e.g. cathepsins B, H, L and S.

Acid cysteine proteinase inhibitor in cutaneous lymphocytic infiltrates.

Acid cysteine proteinase inhibitor (ACPI, cystatin A) is normally present in squamous epithelium and dendritic cells of lymphoid follicles. Its expression is altered both in proliferative and malignant squamous epithelium and in neoplastic lymphoid follicles. The expression of ACPI in the lymphoid infiltrates of cutaneous psuedolymphomas and B-cell lymphomas was studied.