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PubMed2000

IGF-I and procollagen alpha1(I) are coexpressed in a subset of mesenchymal cells in active Crohn's disease.

This study tested the hypothesis that insulin-like growth factor I (IGF-I) expression is increased at sites of fibrosis in diseased intestine of patients with Crohn's disease (CD). IGF-I mRNA was quantified by RNase protection assay in uninvolved and involved intestine of 13 CD patients (10 ileum, 3 colon) and 7 ulcerative colitis (UC) patients (colon). In situ hybridization histochemistry compared the localization of IGF-I and procollagen alpha1(I) mRNAs. Masson's trichrome staining and immunohistochemistry for IGF-I precursor, alpha-smooth muscle actin (A), vimentin (V), desmin (D), and c-kit were used to examine the mesenchymal cell subtypes that express IGF-I and collagen in uninvolved and involved ileum and colon of CD patients and "normal" ileum and colon from noninflammatory controls. IGF-I mRNA was elevated in involved ileum and colon of patients with CD but not in involved colon of patients with UC. IGF-I and procollagen alpha1(I) mRNA showed overlapping distribution within fibrotic submucosa and muscularis propria of involved CD ileum and colon. In involved CD intestine, increased IGF-I precursor expression localized to mesenchymal cells in regions of tissue disorganization and fibrosis in muscularis mucosa, submucosa, and muscularis propria. In these regions, there were increased numbers of V(+) cells relative to normal or uninvolved intestine. Increased IGF-I expression was localized to cells with a phenotype typical of fibroblasts (V(+)/A(-)/D(-)), myofibroblasts (V(+)/A(+)/D(+)), and, to a lesser extent, cells with normal enteric smooth muscle phenotype (V(-)/A(+)/D(+)). We conclude that increased IGF-I expression in multiple mesenchymal cell subtypes and increased numbers of cells with fibroblast/myofibroblast phenotype are involved in fibrosis associated with CD.

Cells, Cultured↗
PubMed1995

Ontogeny of type I procollagen expression during human fetal lung development.

The cellular sites of type I procollagen (PCI) production were investigated during fetal and early postnatal human lung development. PCI-synthesizing cells and sites of recent collagen deposition were visualized by immunoperoxidase staining of lung tissue with monoclonal antibodies to human PCI. In selected cases, serial sections were also examined by in situ hybridization to establish the cellular sites of PCI gene expression and mRNA accumulation. PCI cytoplasmic immunostaining generally correlated with sites of mRNA accumulation and with known sites of interstitial collagen deposition, including the adventitial and muscular layers of large blood vessels, submesothelial and peribronchial connective tissue, perichondrium, and interstitial matrix. However, we also observed developmental changes in relative PCI expression for each of these compartments, heterogeneity in the level of PCI expression by cells within individual anatomic subcompartments, and variations in the level of PCI expression along the length of pulmonary blood vessels and airways. These studies emphasize the complexity of developmentally regulated alterations in procollagen production during lung development.

Blood Vessels↗
PubMed1994

Serum propeptides of type I and III procollagens in renal transplant recipients. A comparison of cyclosporine and azathioprine treatment.

Chronic cyclosporine nephrotoxicity is characterized morphologically by cortical interstitial fibrosis. The most important collagens involved in renal fibrosis are collagen types I and III. In order to estimate the synthesis of type III and type I collagens, we analyzed serum levels of the amino-terminal propeptide of type III procollagen (PIIINP) and the carboxy-terminal propeptide of type I procollagen (PICP) in 11 renal transplant recipients receiving cyclosporine (group CY) and a comparable group of 16 renal transplant recipients treated with azathioprine (group AZ). In addition, 27 healthy subjects and 15 patients with chronic renal disease and reduced renal function (group CRD) were examined. The cyclosporine-treated patients had serum PIIINP and PICP similar to the azathioprine-treated patients. Both groups of renal transplant recipients had significantly increased serum PIIINP compared to healthy controls (2p < 0.01) and serum PIIINP levels similar to group CRD in which serum PIIINP was also elevated compared to healthy controls (2p < 0.01). Mean serum PIIINP levels were: group CY 0.81 U/l (n = 11); group AZ 0.98 U/l (n = 16); controls 0.62 U/l (n = 27); and group CRD 1.06 U/l (n = 15). The renal graft recipients--both cyclosporine- and azathioprine-treated patients--had significantly increased PICP serum levels compared to healthy controls, but the patients with chronic renal disease had serum PICP levels which did not differ from that of healthy controls. Mean serum PICP levels were: group CY174 micrograms/l; group AZ151 micrograms/l; controls 106 micrograms/l; and group CRD119 micrograms/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1996

Changes in serum type I and III procollagen levels in children with chronic renal failure.

Serum levels of carboxyterminal propeptide of type I procollagen (PICP) and aminoterminal propeptide of type III procollagen (PIIINP) can be used as markers of bone formation and the evaluation of children with growth disorders. We measured the serum levels of these collagens with radioimmunoassay in 24 children aged between 4 and 14 years with chronic renal failure (CRF; n = 12 dialysis, n = 12 nondialysis) and 12 age-matched healthy controls, to find out whether these parameters have a prognostic or therapeutic value in monitoring the growth retardation in CRF. Mean serum PIIINP levels in the dialysis patients were higher than in the control group; the difference between the groups was statistically significant (p < 0.05). It seemed that the pubertal stage of the patients did not affect the levels of PICP and PIIINP. There was no significant correlation between PICP and PIIINP in any patients. Neither PICP nor PIIINP correlated with the height z-score or bone age. It was concluded that the increased serum PIIINP levels in renal patients might be accepted as a poor prognostic factor leading to progressive renal failure and end-stage renal disease. Further investigations into the effects of these collagens on growth failure associated with CRF are needed.

Adolescent↗
PubMed1993

Basic fibroblast growth factor in the extracellular matrix suppresses collagen synthesis and type III procollagen mRNA levels in arterial smooth muscle cell cultures.

To determine the effects of an intact extracellular matrix on collagen synthesis, arterial smooth muscle cells (SMCs) were plated sparsely on a cell-free, SMC-derived matrix and examined the following day. Collagen synthesis during a 5-hour incubation by cells on the matrix was reduced to 67% of the control values obtained from cultures on plastic. Total protein synthesis was unaffected. Treatment of the matrix with heparitinase to remove basic fibroblast growth factor (bFGF) before seeding the SMCs abolished the inhibitory effect of the matrix on collagen synthesis. The inhibitory effect was also eliminated by treating the matrix with a neutralizing polyclonal antibody directed against bFGF. Collagen synthesis by SMC cultures grown in wells coated with purified bFGF was only 61% that of control cultures, whereas total protein synthesis remained unchanged. Slot-blot analysis revealed that the relative message level for alpha 1(III) procollagen was reduced in cultures grown on the preexisting matrix or on plastic precoated with bFGF, whereas the alpha 1(I) procollagen message was unaffected. These results demonstrate the ability of the extracellular matrix to modulate the synthesis of collagen by arterial SMCs and indicate that bFGF in the matrix is responsible for these effects.

Animals↗
PubMed1990

Serum aminoterminal type III procollagen peptide reflects repair after acute myocardial infarction.

In 16 patients with acute myocardial infarction and in 15 controls, procollagen type III aminoterminal peptide in serum (PIIINP) was measured consecutively. Serum PIIINP was increased on the second to third postinfarction day (p less than 0.01) and remained elevated for more than 4 months. Peak values were observed on the third to seventh postinfarction day. The individual peak changes were correlated to infarction size calculated from serum CK-MB and serum lactate dehydrogenase (p = 0.60, p = 0.02). The changes in distribution of PIIINP-related antigens in serum after gel chromatography were similar to changes observed during wound healing in humans. PIIINP is cleaved off procollagen type III during the biosynthesis of type III collagen, which characterizes the early stages of repair and inflammation. Our findings suggest that serum PIIINP reflects the repair processes and scar formation following acute myocardial infarction. The serum PIIINP alterations in acute myocardial infarction differ essentially from the changes in myocardial enzymes reflecting myocardial injury. Serum PIIINP may therefore provide new and clinically relevant information on the healing of myocardial infarction.

Adult↗
PubMed1987

Deposition and cross-linking of newly synthesized type IV procollagen in lung matrix.

Type IV procollagen (PC) is a major structural component of alveolar basement membranes; however, the mechanisms of type IV deposition in lung matrix have not been defined. We have examined the deposition and cross-linking of newly synthesized type IV in slices of adult rat lung. Type IV was rapidly deposited and selectively and covalently cross-linked in lung matrix. After a 4-h labeling with radioactive L-proline, greater than 40% of the newly synthesized type IV was insoluble in neutral salt buffers or 2 M guanidine-HCl (GuHCl). Re-extraction of the GuHCl residue in the presence of 10 mM dithiothreitol (DTT) recovered greater than 80% of the remaining type IV. By contrast, less than 20% of the total type IV PC was solubilized with 1 M NaCl containing as much as 50 mM DTT. The GuHCl plus DTT extracts contained pro alpha chains and aggregates of pro alpha chains stabilized by nondisulfide cross-links involving the pepsin-sensitive carboxy-terminal domain of the pro alpha 1 (IV) chain. There was a time-dependent increase in the recovery of type IV participating in intermolecular disulfide and nondisulfide bonds, and in the recovery of cross-linked amino-terminal domains (i.e., "7S-collagen"). Our results further support the hypothesis that the intact secreted form of type IV PC is a major structural subunit of pulmonary basement membranes, and demonstrate that the rapid insolubilization of type IV in lung matrix involves the formation of strong noncovalent interactions that are stabilized by intermolecular disulfide and nondisulfide bonds involving the terminal domains of type IV procollagen.

Animals↗
PubMed1992

Serum and bronchoalveolar lavage of N-terminal type III procollagen peptides in idiopathic pulmonary fibrosis.

Collagen deposition is a prime determinant of clinical course in idiopathic pulmonary fibrosis (IPF). Identification of a marker of connective tissue metabolism would significantly enhance the ability to stage the disease and monitor the course of these patients. Prior studies of IPF have indicated that N-terminal Type III procollagen peptide (N-PIIIP) levels in blood and bronchoalveolar lavage BAL fluid are elevated. We hypothesized that elevated levels of procollagen peptides are a marker of enhanced collagen deposition, which is associated with interstitial fibrosis characterizing active disease. The purpose of the present study was to explore the relationship between N-PIIIP recovery and physiologic parameters of lung function. N-PIIIP levels in sera and bronchoalveolar lavage (BAL) from 24 patients with IPF and 29 volunteers were measured by radioimmunoassay. The extent of disease in IPF was assessed by clinical history, physical examination, chest radiograph, pulmonary physiology evaluation, and confirmatory open-lung biopsy. The severity of disease was graded using a previously described clinical, radiologic, and physiologic (CRP) scoring system. N-PIIIP normalized to albumin was higher in BAL than in serum for both volunteers (1.6-fold; p less than 0.05) and IPF patients (24-fold; p less than 0.05), consistent with local pulmonary production. BAL N-PIIIP was significantly elevated in IPF patients, whether expressed as concentration (healthy volunteer 0.11 +/- 0.06 ng/ml; IPF, 5.0 +/- 14.4; mean +/- SD; p less than 0.05) or normalized to albumin (healthy volunteer, 2.8 +/- 1.2; IPF, 73 +/- 106; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1998

Cadmium inhibits proteoglycan and procollagen production by cultured human lung fibroblasts.

Chronic inhalation of cadmium at the workplace or in cigarette smoke is associated with emphysema, a disease characterized by extensive disruption of lung connective tissue. We have previously shown that cadmium, at noncytotoxic doses, inhibits fibroblast procollagen production in vitro, with maximal inhibitory effects of 69 +/- 6% (P < 0.01) at 30 &microM cadmium chloride (CdCl2). In this paper we show that at similar doses, cadmium also inhibits proteoglycan synthesis, with values reduced by between 36 +/- 4% (P < 0.01) and 42 +/- 6% (P < 0.01) for proteoglycans secreted into the culture media and associated with the cell layer, respectively. The greatest inhibition was obtained for the major matrix-associated proteoglycans, versican, decorin, and the large heparan sulfate proteoglycans, with synthesis values reduced by between 60 and 70%. Biglycan and other heparan sulfate proteoglycans were also affected, with synthesis values reduced by between 25 and 45%. In contrast, total protein synthesis was unaffected. Furthermore, effects of cadmium at the protein level were mirrored by reduction in messenger RNA levels for alpha1(I) procollagen, versican, and decorin. These data support the hypothesis that cadmium may play an important role in the pathogenesis of emphysema associated with chronic inhalation of cadmium fumes by inhibiting the production of connective tissue proteins.

Administration, Inhalation↗
PubMed1983

Restriction fragment length polymorphism associated with the pro alpha 2(I) gene of human type I procollagen. Application to a family with an autosomal dominant form of osteogenesis imperfecta.

One cloned complementary DNA and one genomic subclone were used to detect restriction fragment length polymorphism associated with the pro alpha 2(I) gene for human type I procollagen. The restriction fragments obtained from examination of 30-122 chromosomes confirmed previous indications that the pro alpha 2(I) gene is found in a single copy in the human haploid genome. One highly polymorphic site was detected with EcoRI in the 5'-half of the gene. The restriction site polymorphism at the site had an allelic frequency of 0.38, and it generated two fragments of 10.5 and 3.5 kilobase in homozygous individuals. The restriction fragment length polymorphism generated at the EcoRI site was used to study affected and non-affected individuals in four generations of a family with an autosomal dominant form of osteogenesis imperfecta. The data demonstrated a linkage of the phenotype to a pro alpha 2(I) allele with a lod score of 2.41 at a recombination fraction (theta) of 0. The data therefore provided presumptive evidence that osteogenesis imperfecta in this family is caused by a mutation in the pro alpha 2(I) gene or some contiguous region of the genome. The relatively high frequency of polymorphism at the EcoRI site makes it useful for studying a broad range of genetic disorders in which mutations in type I procollagen are suspected. In addition, the polymorphic site should provide useful markers for linkage studies with other loci located on human chromosome 7.

DNA Restriction Enzymes↗
PubMed1986

A monoclonal antibody to the carboxyterminal domain of procollagen type I visualizes collagen-synthesizing fibroblasts. Detection of an altered fibroblast phenotype in lungs of patients with pulmonary fibrosis.

Excessive collagen deposition plays a critical role in the development of fibrosis, and early or active fibrosis may be more susceptible to therapeutic intervention than later stages of scarring. However, at present there is no simple method for assessing the collagen-synthesizing and secreting activity of fibroblasts in human tissues. Type I procollagen carboxyterminal domains are proteolytically removed during collagen secretion. Thus, antibodies to these domains should stain fibroblasts synthesizing type I collagen but not extracellular collagen fibrils which could mask the signal from the cells. We developed and characterized a monoclonal antibody (Anti-pC) specific for the carboxyterminal propeptide of type I procollagen. To determine the relationship between Anti-pC staining and collagen synthesis, we stained embryonic and adult chicken tendon. Embryonic chick tendon fibroblasts actively synthesizing type I collagen stained heavily with Anti-pC, while quiescent adult tendon fibroblasts did not stain with Anti-pC. Wounded adult tendons developed fibroblasts that stained with Anti-pC at the wound site. Thus, Anti-pC specifically visualized fibroblasts actively synthesizing collagen. Lung biopsies from patients with fibrotic lung disease were stained with Anti-pC. Interstitial and intraalveolar fibroblasts in biopsies from patients with active fibrosis stained intensely with Anti-pC, while normal human lung was unstained. The absence of staining in normal lung supports the hypothesis that fibrosis is associated with an altered collagen-synthesizing phenotype of tissue fibroblasts. Anti-pC may provide a useful clinical tool for assessing fibrogenic activity at sites of tissue injury.

Antibodies, Monoclonal↗
PubMed1991

Immunoelectron microscopic localization of collagens type I, V, VI and of procollagen type III in human periodontal ligament and cementum.

We examined the ultrastructural localization of collagens Type I, V, VI and of procollagen Type III in decalcified and prefixed specimens of the periodontal ligament and cementum, by immunoelectron microscopy using ultra-thin cryostat sections. Immunostaining for collagen Type I was pronounced on the major cross-striated fibrils entering cementum and in cementum proper, whereas staining for procollagen Type III was almost exclusively observed on the major fibrils in the periodontal ligament situated more remote from cementum. Reactivity for collagen Type V was limited to aggregated, unbanded filamentous material of about 12 nm diameter that was found mainly in larger spaces between bundles of cross-striated collagen fibrils and occasionally on single microfibrils that apparently originated from the ends of the major collagen fibrils, which may support the concept of this collagen as a component of core fibrils. Collagen Type VI was present as microfilaments appearing to interconnect single cross-striated fibrils. In the densely packed fibril bundles of the periodontal ligament, no collagen type VI was detected. Neither Type V or Type VI collagen was observed in cementum.

Adolescent↗
PubMed1996

Ultrastructural localization of the C-propeptide released from type II procollagen in fetal bovine growth plate cartilage.

We used immunochemical and immunoelectron gold techniques to determine whether the C-propeptide previously identified in the matrix of endochondral cartilage (CPII) was still a part of the Type 11 procollagen molecule or had been released from it. Guanidinium hydrochloride extraction, followed by SDS-PAGE and Western blotting techniques and immunoelectron localization, revealed that predominantly only the released form (hereafter referred to as released CPII) was detected. The ultrastructural distribution of this CPII was examined with affinity-purified antibodies and with immunogold or immunoperoxidase localization techniques in the presence or absence of embedding resins. These methods yielded similar results. Although no significant amount of this CPII was retained in the matrix after guanidinium hydrochloride extraction, it was present in two recognizable sites under normal conditions, i.e., locally concentrated in a random association with collagen fibrils in the nonmineralized matrix and mainly concentrated in interfibrillar mineralizing sites in the mineralized matrix. These results suggest that the C-propeptide that has been released from Type II procollagen associates with collagen fibrils and then preferentially associates with mineralizing sites when these form in the endochondral cartilage. The significance of this preference for mineral is not known but may have something to do with its high affinity for hydroxyapatite.

Animals↗
PubMed1994

Aminoterminal propeptide of type III procollagen in cord blood and amniotic fluid of appropriate-for-gestational-age infants: a predictor of age-related fetal growth rate.

Procollagen propeptide serum levels reflect the rate of collagen production. Because the prenatal period is unrivaled in terms of relative amounts of collagen synthesized per unit of time, this life episode must be the most sensitive period for the study of these biochemical markers of growth variability. N-terminal propeptide of type III procollagen (PIIINP) concentration was measured by two different methods (Fab'-fragment and whole antibody-based RIA assay) on paired samples of cord serum and amniotic fluid from a study cohort of 602 perinates with gestational age ranging from 20 to 41 wk. The aim of this study is to assess the clinical usefulness of the PIIINP assay for the evaluation of fetal somatic growth variation during the second half of normal pregnancies. It was demonstrated that the PIIINP level in cord serum, as well as in amniotic fluid, reflects age-related growth activity in "healthy" fetuses (n = 504) with normal intrauterine growth. This reflection was independent of the cumulative body mass or length already attained at the time of investigation. The PIIINP concentration closely mirrors the shape of the fetal somatic growth velocity curve, expressed as weight-specific gain (g/kg/d) during the second half of pregnancy. It can be concluded that PIIINP level in cord blood or amniotic fluid of fetuses with normal intrauterine growth is an interesting parameter for the assessment of maturity-related fetal growth potential.

Amniotic Fluid↗
PubMed1995

Prognostic value of serum hyaluronic acid and type I and III procollagen propeptides in extrahepatic biliary atresia.

Although portoenterostomy has greatly improved the prognosis of extrahepatic biliary atresia (EHBA), 10-20% of patients still die before 5 y of age, and the only treatment option is liver transplantation (LT). To investigate whether these patients may be identified at an early stage, when the changes of successful LT are optimal, we have measured serum concentrations of hyaluronic acid (HA), the amino-terminal propeptide of type III procollagen (PIIINP) and the carboxy-terminal and amino-terminal propeptides of type I procollagen (PICP, PINP) in 24 selected patients with EHBA, both before portoenterostomy and then every 6 mo until death (n = 10, age at death = 7-20 mo), LT (n = 6, age at LT = 1.1-4.8 y) or 5 y of age (n = 8). Raised serum HA above 200 micrograms/L before portoenterostomy identified those patients who would die or require LT in the first 5 y of life with a positive predictive value of 88%; after portoenterostomy, longitudinal changes in HA reflected clinical status in each patient. None of the other three markers was of prognostic value, and only PIIINP showed any relationship with clinical status, and then only up to 1.5 y. Interestingly, PINP (but not PICP) tended to be low in all patients before portoenterostomy and may reflect impaired bone collagen metabolism during early skeletal changes in EHBA. This study therefore suggests that measurement of serum HA may be a useful complementary test in EHBA, particularly in identifying, at an early stage, those patients who should be considered for LT.

Age Factors↗
PubMed1987

Estrogen regulation of alpha 1(I)-procollagen messenger ribonucleic acid in the rat uterus.

A cDNA library, prepared from mRNA isolated from the uteri of 3-day estradiol-stimulated immature rats, was constructed in pBR322. From this library an estrogen-regulated clone, pERU3, was isolated. This clone contained sequences complementary to uterine mRNA that migrated during gel electrophoresis as a double band of about 5.0 and 5.8 kilobases. Little of this mRNA was seen in several other tissues examined. An increase in the amount of this RNA in uterus was seen 2 h after estradiol treatment, with maximum hybridization occurring, in different experiments, between 18 and 36 h, followed by a decline. Hybridization of the cDNA insert of the pERU3 plasmid with known probes indicated that it coded for alpha 1(I)-procollagen. This conclusion was supported by in vitro translation experiments in which the hybrid-selected mRNA complementary to pERU3 DNA was shown to code for a collagenase-sensitive protein with a size corresponding to that of alpha 1(I)-procollagen. This system, therefore, provides an additional tool for the study of the estrogen regulation of gene expression in the uterus.

Animals↗
PubMed1989

Insulin-like growth factor I regulates type I procollagen messenger ribonucleic acid steady state levels in bone of rats.

RNA extracted from parietal bones of rats was analyzed for the abundance of type I procollagen mRNA by a dot hybridization assay using specific cDNA probes. Hypophysectomized rats, deficient in IGF I, have 4.1-fold lower steady state levels of mRNA encoding the alpha 1 chain of type I collagen when compared to normal rats of the same weight (120 g). Administration of recombinant human insulin-like growth factor I (IGF I) for 6 days restores bone collagen mRNA levels to normal, and a single sc injection of 100 micrograms IGF I results in a 1.9-fold increase of both alpha 1(I) and alpha 2 (I)chain mRNAs after 8 h. Studies with calvaria cells in primary culture and with a bone-derived cell line, PyMS, yielded similar results: IGF I treatment of these osteoblast-like cells for 24 h increased steady state levels of type I procollagen mRNAs. Thus, IGF I appears to contribute to osteoblast mRNA expression for both chains of type I collagen.

Animals↗
PubMed1991

High-affinity androgen binding and androgenic regulation of alpha 1(I)-procollagen and transforming growth factor-beta steady state messenger ribonucleic acid levels in human osteoblast-like osteosarcoma cells.

Clinical observations have demonstrated a positive effect of estrogens and androgens on the maintenance of structural bone integrity. This study examines the direct effects of androgenic hormones on the osteoblast-like human osteosarcoma cell line, HOS TE85. Employing radiolabeled dihydrotestosterone (DHT), 2800 saturable, high-affinity (dissociation constant = 0.66 nM) androgen binding sites were detected per HOS TE85 cell. Androgen binding was specific in that DHT and testosterone (T) displayed significantly greater competition than the progestins, progesterone and medroxyprogesterone. The expression of androgen receptors in HOS TE85 cells was further substantiated by Northern analysis. A human androgen receptor complementary DNA probe revealed a 9.5 kilobase transcript which corresponds to the predominant human androgen receptor transcript detected in human male reproductive tissues. Androgens were also found to elicit biological responses in HOS TE85 cells. Physiological concentrations of DHT and T decreased HOS TE85 cell proliferation as assessed by cell count. This finding suggests that DHT may also play a role in osteoblast differentiation. In support of this hypothesis, treatment with T (24 h, 10 nM) enhanced the abundance of both alpha 1(I)-procollagen messenger RNA (mRNA) (5-fold) and transforming growth factor-beta mRNA (2.2 fold). The nonaromatizable androgen DHT (24 h, 10 nM) elicited an increase in the steady state concentration of alpha 1(I)-procollagen mRNA similar to the increase observed with T treatment. Thus, in addition to the recent discovery of estradiol receptors and estrogenic regulation of HOS TE85 cells, it is now evident that these osteoblast-like osteosarcoma cells also express high affinity androgen binding sites and can respond biologically to androgens.

Androgens↗