Comparison of expression patterns of shell matrix protein genes in the mantle tissues between high- and low-quality pearl-producing recipients of the pearl oyster, Pinctada fucata

The production of a cultured pearl is the result of a complex interplay between the donor and recipient oysters. However, there is a paucity of information on the relationship between donor and recipient oyster gene expression patterns and pearl quality. Shell matrix proteins affect not only the formation of the shell, but also that of the pearls. We compared the gene expression patterns of five shell matrix proteins (msi60, nacrein, msi31, prismalin-14, and aspein) in the mantle edge (ME), which forms the prismatic layer, and the mantle center (MC), which forms the nacreous layer, between high- (HP) and low quality pearl- (LP) producing recipient oysters. After culturing for about two months, ME and MC tissues were collected from nine recipient oysters: four with HP, five with LP. In the ME, the average threshold cycle (ΔC(T)) for aspein was higher in HP than in LP (t-test, p = 0.03). Additionally, in the MC, the average ΔC(T) for msi60 was lower in HP than in LP (p = 0.06). This means the relative expression level of msi60 in the mantle of HP was higher than that of LP, and expression level of aspein in the mantle of HP was lower than that of LP. Pearl quality was closely related to the expression patterns of shell matrix protein genes of recipient oysters.     

The effect of protein intake on the potential activity of the lysosomal vacuolar system in the cat.

1. Experiments were conducted to examine the relationship between protein intake and protein degradation in the liver of cats. 2. The cats were fed either a low protein/high carbohydrate diet (LP) or a high protein diet devoid of carbohydrate (HP). 3. The potential proteolytic activity of the lysosomal vacuolar system in the liver was assessed by both indirect (osmotic fragility of hepatic lysosomes) and direct (stereological measurement of lysosomal volume) methods. 4. The results from both tests indicated a significantly lower autophagic activity of the lysosomal system in the LP fed animals than in the HP fed cats. 5. This suppression of lysosomal protein degradation may represent an important mechanism for the conservation of proteins by the cat when low protein diets are fed.     

Absorption of a protein gavage in Zucker lean rats. Influence of protein content in the diet.

The rate of protein absorption was measured in Zucker lean rats. Rats were fed with a bolus that contained ca. 300 mg of 14C-labelled protein at the beginning of the light cycle. Blood was extracted from the portal vein at intervals up to 9 hours after gavage. Label incorporation into tissue protein was monitored. The digestion and absorption of protein was slow, and 9 hours after the gavage, 20% of the bolus remained in the stomach. Forty percent of the protein was absorbed in the first hour. This was followed first by a linear absorption process, then by the amino acid incorporation into tissue proteins. The appearance of label in the portal vein increased progressively for up to four hours, shifting to a progressive decrease that coincides with the maintenance of this label in the tissues. The skin, the striated muscle and the liver showed the highest amounts of labelled proteins. The application of this model to animals fed low-(LP) or high-protein (HP) content diets showed that the HP group digested the protein faster than the LP group, and that catabolism of the amino acids was higher in the HP group. The LP group digested protein much more slowly than the RD (control) group, but protein accretion was more efficient.     

Intrauterine growth retarded progeny of pregnant sows fed high protein:low carbohydrate diet is related to metabolic energy deficit

High and low protein diets fed to pregnant adolescent sows led to intrauterine growth retardation (IUGR). To explore underlying mechanisms, sow plasma metabolite and hormone concentrations were analyzed during different pregnancy stages and correlated with litter weight (LW) at birth, sow body weight and back fat thickness. Sows were fed diets with low (6.5%, LP), adequate (12.1%, AP), and high (30%, HP) protein levels, made isoenergetic by adjusted carbohydrate content. At -5, 24, 66, and 108 days post coitum (dpc) fasted blood was collected. At 92 dpc, diurnal metabolic profiles were determined. Fasted serum urea and plasma glucagon were higher due to the HP diet. High density lipoprotein cholesterol (HDLC), %HDLC and cortisol were reduced in HP compared with AP sows. Lowest concentrations were observed for serum urea and protein, plasma insulin-like growth factor-I, low density lipoprotein cholesterol, and progesterone in LP compared with AP and HP sows. Fasted plasma glucose, insulin and leptin concentrations were unchanged. Diurnal metabolic profiles showed lower glucose in HP sows whereas non-esterified fatty acids (NEFA) concentrations were higher in HP compared with AP and LP sows. In HP and LP sows, urea concentrations were 300% and 60% of AP sows, respectively. Plasma total cholesterol was higher in LP than in AP and HP sows. In AP sows, LW correlated positively with insulin and insulin/glucose and negatively with glucagon/insulin at 66 dpc, whereas in HP sows LW associated positively with NEFA. In conclusion, IUGR in sows fed high protein:low carbohydrate diet was probably due to glucose and energy deficit whereas in sows with low protein:high carbohydrate diet it was possibly a response to a deficit of indispensable amino acids which impaired lipoprotein metabolism and favored maternal lipid disposal.     

Integrins and EGFR coordinately regulate the pro-apoptotic protein Bim to prevent anoikis

Epithelial cells must adhere to the extracellular matrix (ECM) for survival, as detachment from matrix triggers apoptosis or anoikis. Integrins are major mediators of adhesion between cells and ECM proteins, and transduce signals required for cell survival. Recent evidence suggests that integrin receptors are coupled to growth factor receptors in the regulation of multiple biological functions; however, mechanisms involved in coordinate regulation of cell survival are poorly understood and mediators responsible for anoikis have not been well characterized. Here, we identify the pro-apoptotic protein Bim as a critical mediator of anoikis in epithelial cells. Bim is strongly induced after cell detachment and downregulation of Bim expression by RNA interference (RNAi) inhibits anoikis. Detachment-induced expression of Bim requires a lack of beta(1)-integrin engagement, downregulation of EGF receptor (EGFR) expression and inhibition of Erk signalling. Overexpressed EGFR was uncoupled from integrin regulation, resulting in the maintenance of Erk activation in suspension, and a block in Bim expression and anoikis. Thus, Bim functions as a key sensor of integrin and growth factor signals to the Erk pathway, and loss of such coordinate regulation may contribute to tumour progression.     

Identity of urinary trypsin inhibitor-binding protein to link protein

Urinary trypsin inhibitor (UTI), a Kunitz-type protease inhibitor, directly binds to some types of cells via cell-associated UTI-binding proteins (UTI-BPs). Here we report that the 40-kDa protein (UTI-BP(40)) was purified from the cultured human chondrosarcoma cell line HCS-2/8 by UTI affinity chromatography. Purified UTI-BP(40) was digested with trypsin, and the amino acid sequences of the peptide fragments were determined. The sequences of six tryptic fragments of UTI-BP(40) were identical to subsequences present in human link protein (LP). Authentic bovine LP and UTI-BP(40) displayed identical electrophoretic and chromatographic behavior. The UTI-binding properties of UTI-BP(40) and LP were indistinguishable. Direct binding and competition studies strongly demonstrated that the NH(2)-terminal fragment is the UTI-binding part of the LP molecule, that the COOH-terminal UTI fragment (HI-8) failed to bind the NH(2)-terminal subdomain of the LP molecule, and that LP and UTI-BP(40) exhibited significant hyaluronic acid binding. These results demonstrate that UTI-BP(40) is identical to LP and that the NH(2)-terminal domain of UTI is involved in the interaction with the NH(2)-terminal fragment of LP, which is bound to hyaluronic acid in the extracellular matrix.     

Dose-dependent differential upregulation of CCN1/Cyr61 and CCN3/NOV by the gap junction protein Connexin43 in glioma cells

Gap junctions form channels that allow exchange of materials between cells and are composed of transmembrane protein subunits called connexins. While connexins are believed to mediate cellular signaling by permitting intercellular communication to occur, there is also increasing evidence that suggest connexins may mediate growth control via a junction-independent mechanism. Connexin43 (Cx43) is the most abundant gap junction protein found in astrocytes, and gliomas exhibit reduced Cx43 expression. We have previously observed that restoration of Cx43 levels in glioma cells led to increased expression of CCN3 (NOV) proteins. We now report that overexpression of Cx43 in C6-glioma cells (C6-Cx43) also upregulates the expression of CCN1 (Cyr61). Both CCN1 and CCN3 belong to the Cyr61/Connective tissue growth factor/Nephroblastoma-overexpressed (CCN) family of secretory proteins. The CCN proteins are tightly associated with the extracellular matrix and have important roles in cell proliferation and migration. CCN1 promotes growth in glioma cells, as shown by the increased proliferation rate of CCN1-overexpressing C6 cells. In addition to its effect on cell growth, CCN1 also increased the motility of glioma cells in the presence of extracellular substrates such as fibronectin. Gliomas expressing high levels of Cx43 preferentially upregulated CCN3 which resulted in reduced growth rate. CCN3 could also be observed in Cx43 gap junction plaques in confluent C6-Cx43H culture at the stationary phase of their growth. Our results suggest that the dissimilar growth characteristics between high and low Cx43 expressors may be due to differential regulation of CCN3 by varying levels of Cx43.     

Structure and function of the receptor-like protein kinases of higher plants

Cell surface receptors located in the plasma membrane have a prominent role in the initiation of cellular signalling. Recent evidence strongly suggests that plant cells carry cell surface receptors with intrinsic protein kinase activity. The plant receptor-like protein kinases (RLKs) are structurally related to the polypeptide growth factor receptors of animals which consist of a large extracytoplasmic domain, a single membrane spanning segment and a cytoplasmic domain of the protein kinase gene family. Most of the animal growth factor receptor protein kinases are tyrosine kinases; however, the plant RLKs all appear to be serine/threonine protein kinases. Based on structural similarities in their extracellular domains the RLKs fall into three categories: the S-domain class, related to the self-incompatibility locus glycoproteins of Brassica; the leucine-rich repeat class, containing a tandemly repeated motif that has been found in numerous proteins from a variety of eukaryotes; and a third class that has epidermal growth factor-like repeats. Distinct members of these putative receptors have been found in both monocytyledonous plants such as maize and in members of the dicotyledonous Brassicaceae. The diversity among plant RLKs, reflected in their structural and functional properties, has opened up a broad new area of investigation into cellular signalling in plants with far-reaching implications for the mechanisms by which plant cells perceive and respond to extracellular signals.     

CAGE,a cancer/testis antigen,induces c-FLIP<Subscript>L</Subscript> and Snail to enhance cell motility and increase resistance to an anti-cancer drug

Cancer associated gene (CAGE) regulates expression of epithelial-mesenchymal transition (EMT)-related proteins through extracellular regulated kinase (ERK), Akt and nuclear factor κB (NF-kB) in mouse B16F10 melanoma cells. Snail, a EMT-related protein, mediates the effect of CAGE on the induction of matrix metalloproteinase-2 (MMP-2) and cancer cell motility. C-Flice inhibitory protein mediates the effect of CAGE on the induction of MMP-2 and cell motility by the induction of Snail. CAGE was shown to protect cells against celastrol, an anti-cancer agent. Celastrol-resistant B16F10 melanoma cells had a higher expression level of c-FLIP_L and Snail as compared with a sensitive cell line. Youngmi Kim and Hyunmi Park contributed equally to this work.     

SPARC, a matricellular protein: at the crossroads of cell-matrix.

SPARC is a multifunctional glycoprotein that belongs to the matricellular group of proteins. It modulates cellular interaction with the extracellular matrix (ECM) by its binding to structural matrix proteins, such as collagen and vitronectin, and by its abrogation of focal adhesions, features contributing to a counteradhesive effect on cells. SPARC inhibits cellular proliferation by an arrest of cells in the G1 phase of the cell cycle. It also regulates the activity of growth factors, such as platelet-derived growth factor (PDGF), fibroblast growth factor (FGF)-2, and vascular endothelial growth factor (VEGF). The expression of SPARC in adult animals is limited largely to remodeling tissue, such as bone, gut mucosa, and healing wounds, and it is prominent in tumors and in disorders associated with fibrosis. The crystal structure of two of the three domains of the protein has revealed a novel follistatin-like module and an extracellular calcium-binding (EC) module containing two EF-hand motifs. The follistatin-like module and the EC module are shared by at least four other proteins that comprise a family of SPARC-related genes. Targeted disruption of the SPARC locus in mice has shown that SPARC is important for lens transparency, as SPARC-null mice develop cataracts shortly after birth. SPARC is a prototypical matricellular protein that functions to regulate cell-matrix interactions and thereby influences many important physiological and pathological processes.     

Effect of undegradable protein concentration in the post-weaning diet on body growth and reproductive development of Assaf rams

Twenty-four growing Assaf lambs, divided into four groups of six animals, were used to study the effect of the undegradable protein content of the post-weaning diet on feed intake, body growth and reproductive development. From week 1 to week 21, the four groups were fed ad libitum as follows: group LL was given barley straw and low protein concentrate (LP); group HH was given barley straw and high protein concentrate (HP); group LH was given barley straw and LP concentrate from week 1 to 11 (period 1) and barley straw and HP concentrate from week 12 to 21 (period 2); group HL was given barley straw and HP concentrate in period 1 and barley straw and LP concentrate in period 2. From week 22 to week 26 (period 3), all animals received the same amount of hay and LP concentrate. Barley straw intake was not significantly (P>0.05) affected by dietary treatments. In the 1st period, average concentrate intake and live body weight gain (LWG) were greater in lambs fed HP than LP supplement. In the 2nd period, concentrate intake was not significantly (P>0.05) affected by type of supplement, but LWG was greater for lambs fed HP than LP supplement. Scrotal circumference in week 11 was significantly (P<0.05) lower in lambs fed LP supplement than in lambs fed HP supplement. No significant differences (P>0.05) due to dietary treatments were observed on scrotal circumference in weeks 21 and 25. Dietary treatments had no significant (P>0.05) effect on either circulating concentration of testosterone or ejaculate characteristics. In conclusion, results from this study suggest that supplementing diets with undegradable protein enhanced performance throughout the breeding period and accelerated testis growth. Nevertheless, final testis size, pattern of circulating testosterone and sperm output were unaffected by dietary treatments.     

Direct analysis of the extracellular proteome from two strains of Helicobacter pylori

Helicobacter pylori extracellular proteins are of interest because of possible roles in pathogenesis, host recognition, and vaccine development. We utilized a unique approach by growing two strains (including one nonsequenced strain) in a defined serum-free medium and directly analyzing the proteins present in the culture supernatants by LC-MS/MS. Over 125 proteins were identified in the extracellular proteomes of two H. pylori strains. Forty-five of these proteins were enriched in the extracellular fraction when compared to soluble cell-associated protein samples. Our analysis confirmed and expanded on the previously reported H. pylori extracellular proteome. Extracellular proteins of interest identified here included cag pathogenicity island protein Cag24 (CagD); proteases HP0657 and HP1012; a polysaccharide deacetylase, HP0310, possibly involved in the hydrolysis of acetyl groups from host N-acetylglucosamine residues or from residues on the cell surface; and HP0953, an uncharacterized protein that appears to be restricted to Helicobacter species that colonize the gastric mucosa. In addition, our analysis found eight previously unidentified outer membrane proteins and two lipoproteins that could be important cell surface proteins.     

SPARC, a matricellular protein: at the crossroads of cell-matrix communication.

SPARC is a multifunctional glycoprotein that belongs to the matricellular group of proteins. It modulates cellular interaction with the extracellular matrix (ECM) by its binding to structural matrix proteins, such as collagen and vitronectin, and by its abrogation of focal adhesions, features contributing to a counteradhesive effect on cells. SPARC inhibits cellular proliferation by an arrest of cells in the G1 phase of the cell cycle. It also regulates the activity of growth factors, such as platelet-derived growth factor (PDGF), fibroblast growth factor (FGF)-2, and vascular endothelial growth factor (VEGF). The expression of SPARC in adult animals is limited largely to remodeling tissue, such as bone, gut mucosa, and healing wounds, and it is prominent in tumors and in disorders associated with fibrosis. The crystal structure of two of the three domains of the protein has revealed a novel follistatin-like module and an extracellular calcium-binding (EC) module containing two EF-hand motifs. The follistatin-like module and the EC module are shared by at least four other proteins that comprise a family of SPARC-related genes. Targeted disruption of the SPARC locus in mice has shown that SPARC is important for lens transparency, as SPARC-null mice develop cataracts shortly after birth. SPARC is a prototypical matricellular protein that functions to regulate cell-matrix interactions and thereby influences many important physiological and pathological processes.     

Multimerization of polyomavirus middle-T antigen.

The oncogenic protein of polyomavirus, middle-T antigen, associated with cell membranes and interacts with a variety of cellular proteins involved in mitogenic signalling. Middle-T antigen may therefore mimic the function of cellular tyrosine kinase growth factor receptors, like the platelet-derived growth factor or epidermal growth factor receptor. Growth factor receptor signalling is initiated upon the binding of a ligand to the extracellular domain of the receptor. This results in activation of the intracellular tyrosine kinase domain of the receptor, followed by receptor phosphorylation, presumably as a consequence of dimerization of two receptor molecules. Similar to middle-T antigen, phosphorylation of growth factor receptors leads to recruitment of cellular signalling molecules downstream in the signalling cascade. In this study, we investigated whether middle-T antigen, similar to tyrosine kinase growth factor receptors, is able to form dimeric signalling complexes. We found that association with cellular membranes was a prerequisite for multimerization, most likely dimer formation. A chimeric middle-T antigen carrying the membrane-targeting sequence of the vesicular stomatitis virus G protein instead of the authentic polyomavirus sequence still dimerized. However, mutants of middle-T antigen unable to associate with 14-3-3 proteins, like d18 and S257A, did not form dimers but were still oncogenic. This indicates that both membrane association and binding of 14-3-3 are necessary for dimer formation of middle-T antigen but that only the former is essential for cell transformation.     

The hepatitis C virus non-structural protein NS5A alters the trafficking profile of the epidermal growth factor receptor

Hepatitis C virus (HCV) frequently establishes a persistent infection, leading to chronic liver disease. The NS5A protein has been implicated in this process as it modulates a variety of intracellular signalling pathways that control cell survival and proliferation. In particular, NS5A associates with several proteins involved in the endocytosis of the epidermal growth factor receptor (EGFR) and has been previously shown to inhibit epidermal growth factor (EGF)-stimulated activation of the Ras–Erk pathway by a mechanism that remains unclear. As EGFR signalling involves trafficking to late endosomes, we investigated whether NS5A perturbs EGFR signalling by altering receptor endocytosis. We demonstrate that NS5A partially localizes to early endosomes and, although it has no effect on EGF internalization, it colocalizes with the EGFR and alters its distribution. This redistribution correlates with a decrease in the amount of active EGF–EGFR ligand–receptor complexes present in the late endosomal signalling compartment and also results in a concomitant increase in the total levels of EGFR. These observations suggest that NS5A controls EGFR signalling by diverting the receptor away from late endosomes. This represents a novel mechanism by which a viral protein attenuates cell signalling and suggests that NS5A may perturb trafficking pathways to maintain an optimal environment for HCV persistence.     

Changes in UCP expression in tissues of Zucker rats fed diets with different protein content

The effect of dietary protein content on the uncoupling proteins (UCP) 1, 2 and 3 expression in a number of tissues of Zucker lean and obese rats was studied. Thirty-day-old male Zucker lean (Fa/?) and obese (fa/fa) rats were fed on hyperproteic (HP, 30% protein), standard (RD, 17% protein) or hypoproteic (LP, 9% protein) diets ad libitum for 30 days. Although dietary protein intake affected the weights of individual muscles in lean and obese animals, these weights were similar. In contrast, huge differences were observed in brown adipose tissue (BAT) and liver weights. Lean rats fed on the LP diet generally increased UCP expression, whereas the HP group had lower values. Obese animals, HP and LP groups showed higher UCP expression in muscles, with slight differences in BAT and lower values for UCP3 in subcutaneous adipose tissue. The mean values of UCP expression in BAT of obese rats were lower than in their lean counterpart, whereas the expression in skeletal muscle was increased. Thus, expression of UCPs can be modified by dietary protein content, in lean and obese rats. A possible thermogenic function of UCP3 in muscle and WAT in obese rats must be taken into account.     

SPARC, a matricellular protein: at the crossroads of cell–matrix communication: [Matrix Biology (2000) 569–580]

The publisher regrets that the above article was published with several typographical errors. The corrected version appears on the following pages. SPARC is a multifunctional glycoprotein that belongs to the matricellular group of proteins. It modulates cellular interaction with the extracellular matrix (ECM) by its binding to structural matrix proteins, such as collagen and vitronectin, and by its abrogation of focal adhesions, features contributing to a counteradhesive effect on cells. SPARC inhibits cellular proliferation by an arrest of cells in the G1 phase of the cell cycle. It also regulates the activity of growth factors, such as platelet-derived growth factor (PDGF), fibroblast growth factor (FGF)-2, and vascular endothelial growth factor (VEGF). The expression of SPARC in adult animals is limited largely to remodeling tissue, such as bone, gut mucosa, and healing wounds, and it is prominent in tumors and in disorders associated with fibrosis. The crystal structure of two of the three domains of the protein has revealed a novel follistatin-like module and an extracellular calcium-binding (EC) module containing two EF-hand motifs. The follistatin-like module and the EC module are shared by at least four other proteins that comprise a family of SPARC-related genes. Targeted disruption of the SPARC locus in mice has shown that SPARC is important for lens transparency, as SPARC-null mice develop cataracts shortly after birth. SPARC is a prototypical matricellular protein that functions to regulate cell–matrix interactions and thereby influences many important physiological and pathological processes.     

Recombinant expression, purification, and functional characterisation of connective tissue growth factor and nephroblastoma-overexpressed protein

The CCN family of proteins, especially its prominent member, the Connective tissue growth factor (CTGF/CCN2) has been identified as a possible biomarker for the diagnosis of fibrotic diseases. As a downstream mediator of TGF-β1 signalling, it is involved in tissue scarring, stimulates interstitial deposition of extracellular matrix proteins, and promotes proliferation of several cell types. Another member of this family, the Nephroblastoma-Overexpressed protein (NOV/CCN3), has growth-inhibiting properties. First reports further suggest that these two CCN family members act opposite to each other in regulating extracellular matrix protein expression and reciprocally influence their own expression when over-expressed. We have established stable HEK and Flp-In-293 clones as productive sources for recombinant human CCN2/CTGF. In addition, we generated an adenoviral vector for recombinant expression of rat NOV and established protocols to purify large quantities of these CCN proteins. The identity of purified human CCN2/CTGF and rat CCN3/NOV was proven by In-gel digest followed by ESI-TOF/MS mass spectrometry. The biological activity of purified proteins was demonstrated using a Smad3-sensitive reporter gene and BrdU proliferation assay in permanent cell line EA•hy 926 cells. We further demonstrate for the first time that both recombinant CCN proteins are N-glycosylated.     

Grb7 signal transduction protein mediates metastatic progression of esophageal carcinoma

We have previously reported the association of tumor cell invasion with expression of growth factor receptor-bound protein 7 (Grb7). This molecule contains a Src homology 2 (SH2) domain and shares structural homology with a cell migration molecule designated Mig-10 found in Caenorhabditis elegans. In the present study, Grb7 expression was analyzed in human esophageal carcinomas with or without metastatic spread. The Grb7 protein was overexpressed in 14 of 31 esophageal carcinomas as compared to the adjacent normal mucosa (45%) and this finding was significantly correlated with the presence of lymph node metastases. We also identified that Grb7 protein in esophageal carcinoma cells was phosphorylated on tyrosine by epidermal growth factor as well as attachment to extracellular matrix proteins including fibronectin. Such fibronectin-dependent phosphorylation of Grb7 was regulated by integrin signaling that leads to the interaction with focal adhesion kinase protein. Furthermore, ectopic expression of a Grb7-SH2 dominant-negative fragment inhibited the fibronectin-dependent phosphorylation of endogenous Grb7, and reduced migration of esophageal carcinoma cells into fibronectin. Our results suggest a role of Grb7 mediated signal transduction in generation of an invasive cell phenotype against extracellular matrix, and thus contributes to metastatic progression of human esophageal carcinoma.     

Redox signalling in anchorage-dependent cell growth

Current data have provided new perspectives concerning the regulation of non-transformed cell proliferation in response to both soluble growth factors and to adhesive cues. Non-transformed cells are anchorage dependent for the execution of the mitotic program and cannot avoid the concomitant signals starting from mitogenic molecules, as growth factors, and adhesive agents belonging to extracellular matrix. Reactive oxygen species play a key role during both growth factor and integrin receptor signalling and these second messengers are recognised to have a synergistic function for anchorage-dependent growth signalling. Redox regulated proteins include protein tyrosine phosphatases and protein tyrosine kinases, although with opposite regulation of their enzymatic activity, and cytoskeletal proteins as beta-actin. In this review we support a role of ROS as key second messengers granting a proper executed mitosis for anchorage-dependent cells, through redox regulation of several downstream targets. Deregulation of these redox pathways may help to guide transformed cells to elude the native apoptotic response to abolishment of signals started by cell/ECM contact, sustaining ectopic anchorage-independent cancer cell growth.