A novel role for BRCA1 in regulating breast cancer cell spreading and motility.

BRCA1 C-terminal (BRCT) domains in BRCA1 are essential for tumor suppressor function, though the underlying mechanisms remain unclear. We identified ezrin, radixin, and moesin as BRCA1 BRCT domain-interacting proteins. Ezrin-radixin-moesin (ERM) and F-actin colocalized with BRCA1 at the plasma membrane (PM) of cancer cells, especially at leading edges and focal adhesion sites.

Monoclonal antibody 14C5 targets integrin alphavbeta5.

This study identifies and characterizes the antigen recognized by monoclonal antibody (mAb) 14C5. We compared the expression of antigen 14C5 with the expression of eight integrin subunits (alpha1, alpha2, alpha3, alphav, beta1, beta2, beta3, and beta4) and three integrin heterodimers (alphavbeta3, alphavbeta5, and alpha5beta1) by flow cytometry. Antigen 14C5 showed a similar expression to alphavbeta5 in eight different epithelial cancer cell lines (A549, A2058, C32, Capan-2, Colo16, HT-1080, HT-29, and SKBR-3).

Anti-biotin antibodies offer superior organelle-specific labelling of mitochondria over avidin or streptavidin.

A number of endogenously biotinylated proteins are found in both cytosol and mitochondria of mammalian cells from many tissues, including liver, spleen, pancreas, kidney, and intestine. Therefore, caution should be taken when using the biotin detection system. Endogenous biotin can interfere with staining systems that employ the use of biotin-avidin- or biotin-streptavidin-based detection systems and may therefore result in high, non-specific background staining.

Biodistribution and planar gamma camera imaging of (123)I- and (131)I-labeled F(ab')(2) and Fab fragments of monoclonal antibody 14C5 in nude mice bearing an A549 lung tumor.

Unlabelled: Detection of antigen 14C5, involved in substrate adhesion and highly expressed on the membrane of many carcinomas, including lung cancer, provides important diagnostic information that can influence patient management. The aim of this study was to evaluate the biodistribution and planar gamma camera imaging characteristics of radioiodinated F(ab')(2) and Fab fragments of monoclonal antibody (mAb) 14C5 in tumor-bearing mice.

Methods: F(ab')(2) and Fab 14C5 fragments were radioiodinated using the Iodo-Gen method.

In vitro and in vivo targeting properties of iodine-123- or iodine-131-labeled monoclonal antibody 14C5 in a non-small cell lung cancer and colon carcinoma model.

Purpose: The monoclonal antibody (mAb) 14C5 is a murine IgG1 directed against a yet undefined molecule involved in cell substrate adhesion found on the surface of malignant breast cancer tissue. mAb 14C5 is able to inhibit cell substrate adhesion and invasion of breast cancer cells in vitro. In normal tissues as well as in the stroma surrounding in situ carcinomas of the breast, no expression of the antigen 14C5 occurs.

Human immunodeficiency virus Nef induces rapid internalization of the T-cell coreceptor CD8alphabeta.

Human immunodeficiency virus (HIV) Nef is a membrane-associated protein decreasing surface expression of CD4, CD28, and major histocompatibility complex class I on infected cells. We report that Nef strongly down-modulates surface expression of the beta-chain of the CD8alphabeta receptor by accelerated endocytosis, while CD8 alpha-chain expression is less affected. By mutational analysis of the cytoplasmic tail of the CD8 beta-chain, an FMK amino acid motif was shown to be critical for Nef-induced endocytosis.

Phosphorylated BRCA1 is predominantly located in the nucleus and mitochondria.

Multiple copies of the mitochondrial genome in eukaryotic cells are organized into protein-DNA complexes called nucleoids. Mitochondrial genome repair mechanisms have been reported, but they are less well characterized than their nuclear counterparts. To expand our knowledge of mitochondrial genome maintenance, we have studied the localization of the BRCA1 protein, known to be involved in nuclear repair pathways.

Radiolabeling, biodistribution, and dosimetry of (123)I-mAb 14C5: a new mAb for radioimmunodetection of tumor growth and metastasis in vivo.

Unlabelled: This study reports on the in vitro evaluation, biodistribution, and dosimetry of (123)I-labeled monoclonal antibody (mAb) 14C5, a new antibody-based agent proposed for radioimmunodetection of tumor growth and metastasis in vivo.

Methods: (123)I-mAb 14C5 was prepared by direct iodination and tested for stability in vitro. Binding assays were performed on human SK-BR-3 and HeLa carcinoma cells to investigate the antigen expression, antibody affinity, and kinetics of tracer binding.

Neurofibromin is actively transported to the nucleus.

Mutations in the neurofibromatosis type 1 (NF1) tumor suppressor gene predispose individuals to a variety of benign and malignant tumors. Many tumor suppressors 'shuttle' between the nucleus and the cytoplasm, thus regulating their function. By expressing different NF1 constructs in COS-7 cells (encompassing exons 28-49 and fused to the green fluorescent protein), we identified a functional nuclear localization signal (NLS) in exon 43.

The role of heregulin-alpha as a motility factor and amphiregulin as a growth factor in wound healing.

Wound healing is a complex process of which growth and motility are essential features. The aim of this study was to search for keratinocyte-derived secreted factors that may play a role in these mechanisms, and their corresponding receptors. Growth and motility factors were purified from conditioned medium from cultured primary keratinocytes.