Insulin-like growth factor-II overexpression in MCF-7 cells induces phenotypic changes associated with malignant progression

It has been proposed that the insulin-like growth factors (IGFs) can act as autocrine and/or paracrine growth promoters in breast cancer. To investigate this hypothesis, we infected early passage MCF-7 cells with a retroviral vector containing the coding sequence for the IGF-II preprohormone along with a constitutive cytomegalovirus promoter sequence. These cells do not normally express IGF-I or IGF-II. After infection with the retroviral vector, several single cell clones were analyzed. Seven of nine isolated clones expressed very high levels of IGF-II mRNA. Biologically active IGF-II protein was easily detectable in the medium conditioned by the IGF-II-expressing clones, and IGF receptors were down-regulated in these. All IGF-II-expressing clones showed marked morphological changes in anchorage-dependent culture, growing in large clumps and as free-floating colonies. The cells also cloned in soft agar in the absence of estrogen, while the wild-type MCF-7 cells and control cells infected with an irrelevant DNA sequence showed none of these properties. alpha IR-3, an antibody that blocks the type I IGF receptor, inhibited the growth of IGF-II-expressing clones in serum-free medium. This model demonstrates that IGF-II can serve as an autocrine growth stimulant in breast cancer epithelial cells and that IGF-II overexpression may be capable of mediating malignant progression in human breast cancer.

Growth factor messenger RNA expression by human breast fibroblasts from benign and malignant lesions

Breast tumors are a complex mix of epithelial, stromal, and vascular elements. We examined primary cultures of breast fibroblasts derived from benign and malignant lesions for expression of various growth factors. All fibroblast cultures, regardless of whether they were derived from benign or malignant lesions, expressed platelet-derived growth factor A chain, basic fibroblast growth factor, fibroblast growth factor 5, and transforming growth factor beta 1 mRNA. None expressed platelet-derived growth factor B chain or transforming growth factor alpha mRNA. However, examination of mRNA expression for the insulin-like growth factors revealed that 7 of 8 fibroblasts derived from benign lesions expressed insulin-like growth factor I (IGF-I) mRNA, while only 1 of 9 fibroblasts derived from malignancies expressed IGF-I mRNA. The opposite picture was seen for insulin-like growth factor II (IGF-II) mRNA expression, in which 1 of 9 benign-derived fibroblasts expressed IGF-II mRNA, while 5 of 9 malignant-derived fibroblasts expressed IGF-II. This correlated with previous in situ hybridization data, which showed IGF-I mRNA expression confined to the stroma of benign breast tissue. PDGF treatment of tumor fibroblasts resulted in a 3-fold increase in IGF-II mRNA. Thus there was an apparent dichotomy between IGF-I mRNA expression in the majority of fibroblasts derived from benign lesions and IGF-II mRNA expression in the majority of tumor-derived fibroblasts. Since the insulin-like growth factors are potent mitogens for breast tumor epithelial cells, this further supports the notion of a paracrine growth-promoting role for the insulin-like growth factors in breast lesions and suggests that IGF-II may be the more important growth promoter in malignant lesions.

Repair of the severely contracted socket with meshed skin graft and semi-rigid conformer

Nine severely contracted sockets were reconstructed using a meshed skin graft in conjunction with a semi-rigid conformer-stent. Particularly useful following unsuccessful surgery with mucosal grafting, or in cases where for some reason mucosal grafts cannot be obtained, this technique is superior to current procedures utilizing nonmeshed split-thickness skin grafts.

Insulin-like growth factors in human breast cancer

Several protooncogenes and suppressor genes and a variety of growth factors and their receptors have been shown to be mutated, deleted, or activated in human breast cancer. These changes may account for the unregulated growth of breast carcinoma cells. Insulin-like growth factors I and II (IGF-I, IGF-II) belong to a family of polypeptides with growth promoting properties and structural homology to insulin. They exert their mitogenic effects by binding to the IGF-I receptor and activating its tyrosine protein kinase. Other proteins that specifically bind the IGFs include the plasma membrane IGF-II receptor, which also binds lysosomal hydrolases, and several IGF-binding proteins which may serve to modulate IGF interactions with receptors. Breast cancer cell lines express IGF-I and IGF-II receptors and different patterns of binding proteins. IGF-I and IGF-II are each mitogenic for subsets of breast cancer cell lines. This effect is inhibited by antibodies directed against the IGF-I receptor. In breast tumors, IGF-I is expressed by stromal cells, but not carcinoma cells; it is not expressed by breast cancer cell lines. IGF-I is therefore a potential paracrine regulator of breast cancer cell growth. Similarly, IGF-II is expressed in breast tumors, predominantly in stromal cells, but sometimes also in carcinoma cells and in a subset of cell lines. Thus, IGF-II is also a potential paracrine regulator of breast cancer cell growth; in addition, it can be an autocrine regulator in some breast cancer cells.

Intravitreal suture: a complication of pterygium surgery

Among the complications associated with pterygium surgery, scleral perforation is mentioned in cases where subconjunctival tissue must be separated from the sclera. We present a case in which such a perforation and consequent suturing resulted in an intravitreous migration of a suture. We believe this is the first report of such a complication following pterygium surgery.

The insulin-like growth factors, their receptors, and their binding proteins in human breast cancer

Various investigators have shown that the IGFs are mitogens for breast cancer cells. The expression of the IGF receptors is seen in most breast cancer cell lines and tissues, suggesting that most breast cancers have the ability to respond to the IGFs. Although authentic IGF-I is not expressed by breast cancer cell lines, it is possible that an IGF-related peptide that can be detected immunologically is expressed. Furthermore, in estrogen responsive xenotransplants, changes in the level of IGF-II mRNA correlate directly with estrogen-mediated changes in tumor growth. These observations suggest that IGF-II may be important in tumorigenesis and may serve as an autocrine growth stimulator of breast cancer cells. When human breast cancer tissues are studied, IGF-I and IGF-II mRNA expression are commonly seen. However, in situ hybridization studies suggest that IGF-I mRNA is expressed mainly by the stromal elements, while IGF-II mRNA can be found both in stroma and malignant epithelial cells. These observations support the studies done with breast cancer cell lines; IGF-I may stimulate cells via a paracrine pathway, while IGF-II may act as both an autocrine and paracrine growth factor. In addition, IGF-BPs are commonly expressed by breast cancer cells in culture, and it is possible that expression of the IGF-BPs act to modulate the effects of either IGF-I or IGF-II. We propose that the IGFs are important stimulators of breast cancer cells and that their growth promoting effects may be mediated by autocrine, paracrine, or endocrine mechanisms. Furthermore, interactions between the stroma and malignant epithelial cells may be important in regulating the growth of breast cancer. The biological importance of a fibroblast-epithelial cell interaction has been demonstrated in a normal mouse mammary cell line; morphological and functional changes in epithelial cells were induced when the cells were in direct contact with fibroblasts. Similar mechanisms may be important in malignant breast epithelial cells. For example, many breast cancer cells produce platelet-derived growth factor (PDGF) yet have no PDGF receptor. PDGF has been demonstrated to increase IGF-I production by fibroblasts, and a dual paracrine pathway involving PDGF and IGF-I expression by epithelial cells and stromal cells could be envisioned. The pathways through which the IGF system may function in human breast cancer are schematically represented in figure 1. Further work in our laboratory is directed at clarifying the role for the IGFs in breast cancer growth.

General assay for phosphoproteins in cerebrospinal fluid: a candidate marker for paraneoplastic cerebellar degeneration

The components of protein phosphorylation systems (protein kinases, protein phosphatases, and their phosphoprotein substrates) are highly enriched in neuronal cells compared with other cell types. We exploited this relative neuronal enrichment of protein phosphorylation system components to develop a general assay technique for putative protein kinase substrates (phosphoproteins) in human cerebrospinal fluid. Using this cerebrospinal fluid phosphoprotein assay, we have detected a putative protein kinase C substrate protein of apparent Mr 60 kd in 6 of 14 patients with paraneoplastic cerebellar degeneration but not in any of 55 patients with a variety of other neurological diseases. Phosphoproteins in cerebrospinal fluid may provide novel and unique markers for the diagnosis or staging of neuronal diseases as well as offer potential insights into the biochemical characterization of affected neuronal populations.

Insulin-like growth factor I expression by tumors of neuroectodermal origin with the t(11;22) chromosomal translocation. A potential autocrine growth factor

Expression of insulin-like growth factor I (IGF-I) mRNA by some tumor cell lines of neuroectodermal origin has been described. To further explore the significance of IGF-I mRNA expression in these tumors, a more extensive analysis was performed. Most (9 of 10) neuroectodermal tumor cell lines with a t(11;22) translocation (primitive neuroectodermal tumor [PNET], Ewing's sarcoma, esthesioneuroblastoma) expressed IGF-I mRNA, whereas 0 of 15 cell lines without the translocation (PNET, neuroblastoma) expressed IGF-I. Furthermore, inasmuch as all neuroblastoma (12 of 12) cell lines examined expressed IGF-II RNA, the pattern of IGF expression could distinguish between these closely related tumors. CHP-100, a PNET cell line with the t(11;22) translocation, was shown to secrete both IGF-I protein and an IGF binding protein, IGFBP-2. This cell line also expressed the type I IGF receptor mRNA, and blockade of this receptor by a monoclonal antibody (alpha IR3) inhibited serum-free growth. These data demonstrate that IGF-I expression is a property of neuroectodermal tumors with a t(11;22) translocation and that interruption of an IGF-I autocrine loop inhibits the growth of these tumor cells.

[Ultrasonographic diagnosis of amniotic band syndrome in pregnancy]

The amniotic band syndrome comprises a heterogenous group of congenital deformities which originate from rupture of the amnion during the early stages of fetal development. The diagnosis of the syndrome in the newborn is difficult because of the wide spectrum of anomalies, and its resemblance to other genetic or developmental deformities. The prenatal diagnosis of the syndrome is possible when there is ultrasonographic demonstration of multiple, nonembryological anomalies, with or without visualization of amniotic bands floating in the amniotic fluid. We recently diagnosed prenatally 3 fetuses affected by this condition. 2 were members of different twin pregnancies who presented with severe multiple malformations, and the other was a singleton with a big facial cleft and Pierre-Robin syndrome.

Pefloxacin efficacy in gram-negative bacillary meningitis

Sixteen patients with acute meningitis caused by Gram-negative bacteria were treated with pefloxacin intravenously. The age range of the patient group was six months to 85 years with a mean age of 40 years; three patients were children. In all but two patients meningitis was a complication of neurosurgical operations and fourteen of the sixteen had received prior therapy which was not successful. The causative organisms were: Pseudomonas aeruginosa (5), Acinetobacter calcoaceticus (4), Klebsiella pneumoniae (3), Enterobacter cloacae (2), Citrobacter diversus (1) and Salmonella group C (1). Pefloxacin was administered intravenously 800 mg twice a day to the adult patients (mean dosage of 21( +/- 6.7) mg/kg body weight) for a mean period ( +/- S.D.) of 11( +/- 4) days. The mean cerebrospinal fluid concentration of pefloxacin was 8.8( +/- 5.0) mg/l which was 54% of the mean peak serum concentration (16.3( +/- 8.8]. The mean MIC and MBC of the causative organisms were 1.1( +/- 1.2) mg/l and 1.64( +/- 1.2) mg/l. Thirteen patients (87%) were cured or clinically improved and twelve (80%) were bacteriologically cured. One patient failed, another patient had reinfection and one was not assessable. No side effects were observed. In the present study pefloxacin offered an efficacious and safe treatment of Gram-negative meningitis following failure of other antibiotic therapy.

Pefloxacin versus ceftazidime in therapy of soft tissue infections in compromised patients

Soft tissue infections in compromised patients are frequently caused by Gram-negative organisms and particularly by Pseudomonas aeruginosa. These pathogens are effectively eradicated by pefloxacin as well as by ceftazidime. The effectiveness and safety of these two agents were compared in a prospective randomized study in 67 patients with soft tissue infections. Underlying conditions included malignant diseases, diabetes mellitus and chronic renal failure. The infections included: post operative infection, septic foot, soft tissue abscess and cellulitis. Thirty-three patients were treated with intravenous ceftazidime for a mean duration of ten days. More than half the 34 patients given pefloxacin were treated only orally for a mean period of 13 days. The clinical and bacteriological outcomes were similar in both groups. There was clinical cure or improvement in 26 pefloxacin cases and in 23 ceftazidime cases, failure in six pefloxacin cases and in seven ceftazidime and relapse in two pefloxacin and in three ceftazidime patients. The bacteriological responses were eradication in 23 pefloxacin cases and in 22 ceftazidime cases, persistence in five pefloxacin cases and in six ceftazidime cases, relapse in one pefloxacin case and in none of the ceftazidime group, reinfection in four pefloxacin cases and in three ceftazidime cases and there was one unassessed patient in the pefloxacin group and two in the ceftazidime group. Nausea and vomiting occurred in three patients and elevation of liver enzymes in another patient; all side effects were observed only in the pefloxacin treated patients. These results suggest that oral pefloxacin could offer an alternative to intravenous ceftazidime in half the compromised patients with tissue infections. However, adverse reactions due to pefloxacin administration should be watched for during such therapy.

Modulation of EGF receptor expression by differentiating agents in human colon carcinoma cell lines

The existence of an autocrine loop for self-stimulation of growth in malignant cells has been proposed for transforming growth factor-alpha (TGF alpha) and its receptor, the epidermal growth factor (EGF) receptor, in a variety of malignant cell types. Expression of both has been described in colon carcinoma. In order to investigate whether there is a correlation between TGF alpha and EGF receptor mRNA expression and differentiation, we studied the effects of differentiating agents on seven human colon carcinoma cell lines. All of the lines responded to the differentiating agents. In four of the seven lines there was increased EGF receptor mRNA two to five days after treatment with 2 mM sodium butyrate. In three of these lines TGF alpha mRNA and protein were also increased. In the one cell line treated with the differentiating agents DMF and DMSO, EGF receptor mRNA was also increased. [125I]-EGF binding to the cells was measured before and after treatment with butyrate. In two of three cell lines, increased EGF receptor mRNA was accompanied by a 2.4-fold increase in the number of binding sites per cell. In SW620 cells, no EGF receptor binding was detected before or after butyrate treatment. In the two cell lines in which butyrate increased EGF receptor binding, simultaneous treatment with EGF did not enhance growth. These data demonstrate increased expression of the TGF alpha/EGF receptor system after differentiation of colon carcinoma cell lines and suggest that their expression may be characteristic of a differentiated phenotype.

A patient's ingenuity in the management of lagophthalmos

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Intermittent self-catheterization

The geriatric population is a challenge to those health professionals who are willing enough to give them a chance. Growing old is just that, a growth process. We should break the pattern of neglecting growth and promoting regression. In 1916, Cabot and Crabtree had foresight into the future of intermittent catheterization when they said, in reference to urinary tract infections, that "there is no subject in which there is so little uniformity of opinion and so much confusion." Through continued education and research, we hope to reverse negative attitudes. With more uniformity in their care, the geriatric population can continue to live a comfortable, socially acceptable life.

Insulin-like growth factor receptor expression and function in human breast cancer

The insulin-like growth factors IGF-I and IGF-II are potent mitogens for several breast tumor cell lines in culture. Additionally, both IGF-I and IGF-II mRNAs are easily detected in the majority of breast tumor specimens examined, while no breast cancer epithelial cell lines we have studied express authentic IGF-I mRNA, and few lines express IGF-II mRNA. Although receptors for insulin, IGF-I, and IGF-II have been described, there is significant cross-reactivity between the various receptors and ligands in the insulin/insulin-like growth factor family, and it is not clear which receptor or receptors are responsible for the biological effects of these growth factors in this system. Using an RNase protection assay, we examined breast tumor specimens and breast cancer epithelial cell lines for expression of mRNA encoding the type I and type II IGF receptors as well as the insulin receptor. Virtually all of the specimens examined expressed mRNA for all three receptors. We then examined estrogen-dependent MCF-7 cells for the mitogenic effects of IGF-I and II in the presence of antibodies to both the type I and type II receptors. alpha IR-3, a monoclonal antibody which blocks the type I receptor, abolished the mitogenic effects of both IGF-I and IGF-II. It did not, however, block the mitogenic effects of insulin. We conclude that type I and type II IGF receptors are ubiquitously expressed in breast cancer, and our experiments with MCF-7 cells suggest the mitogenic effects of both IGF-I and IGF-II are mediated via the type I IGF receptor.

Comparison of the effects of argon and neodymium:YAG laser iridotomy on prostaglandin E2 and blood-aqueous barrier disruption

We compared in rabbits the effects of laser iridotomy by either argon or neodymium (Nd):YAG laser on prostaglandin E2 (PGE2) production by the iris/ciliary body, its accumulation in the aqueous humor and the aqueous protein levels. PGE2 production by the iris/ciliary body, following exposure to argon or Nd:YAG laser, was similarly enhanced, with peak levels of 22.8 +/- 4.7 and 24.1 +/- 8.2 ng/mg, respectively. An increase in aqueous PGE2 levels was more pronounced in the argon as compared with the Nd:YAG group, with peak levels of 56.7 +/- 17.3 and 20.0 +/- 7.7 ng/ml, respectively. PGE2 production correlated well with aqueous PGE2 levels in the argon group, but not in the Nd:YAG group. Protein accumulated in the aqueous humor following irradiation by both types of laser light, with higher levels occurring in the argon group. These results are indicative of possible differences in the extent of the inflammatory reaction induced by the application of argon and Nd:YAG laser light to the iris.

Identification of an alternate type I insulin-like growth factor receptor beta subunit mRNA transcript

Several studies have suggested that heterogeneity exists in the type I insulin-like growth factor (IGF) receptor beta subunit. We have examined type I IGF receptor mRNA transcripts by ribonuclease (RNase) protection assay to determine if the heterogeneity could result from alternative splicing of the gene. An area that corresponded to the nucleotide sequence just upstream of the region encoding the transmembrane domain of the beta subunit was identified as being a potential site of alteration in the transcript. Since the 5' and 3' ends were known, polymerase chain reaction was used to clone a cDNA that included this region. Analysis revealed that an alternate type I IGF receptor mRNA transcript with a 3-base pair deletion could account for the results of the RNase protection assay. The deletion changes the amino acid sequence at position 899 substituting Arg for a Thr-Gly. Furthermore, this alternate transcript was ubiquitously found in tissue and cell line RNAs. Although the identified transcript cannot fully account for the documented heterogeneity in type I IGF receptor beta subunit sizes, the results suggest that a form of the beta subunit with an alternate primary sequence may exist.

Expression of insulin-like growth factor-II mRNA in fetal kidney and Wilms' tumor. An in situ hybridization study

The pattern of insulin-like growth factor II (IGF-II) mRNA expression in developing kidney and Wilms' tumor was examined with in situ hybridization. In developing kidney, IGF-II was primarily expressed in blastemal cells and lost with their differentiation. In triphasic Wilms' tumor, a similar relationship was found. But in a monomorphous Wilms', tumor cells with epithelial differentiation expressed IGF-II mRNA. These data suggest that IGF-II may be involved in fetal nephrogenesis, that its expression is inversely coupled to normal epithelial differentiation, and that this differentiation may be aberrantly regulated in Wilms' tumor.

Modulation of the expression of a multidrug resistance gene (mdr-1/P-glycoprotein) by differentiating agents

Acquired resistance to multiple natural products in vitro is mediated by P-glycoprotein (Pgp). Expression of this protein has been demonstrated in some normal tissues and in tumor samples obtained from both untreated and treated patients. In situ hybridizations with RNA probes have demonstrated higher levels of expression of mdr-1/Pgp in well-differentiated tumors and in well-differentiated areas in tumors with mixed histologies. Expression of mdr-1/Pgp in human colon carcinoma cell lines was increased by the differentiating agents sodium butyrate, dimethyl sulfoxide, and dimethylformamide. In the SW-620 cell line addition of sodium butyrate resulted in a rapid induction of mdr-1/Pgp mRNA that was sustained for the duration of the exposure. The levels of P-glycoprotein were measured by immunoblotting and were also increased. Similar results were obtained in three other cell lines including the HCT-15 line. This induction occurred without alterations in nuclease sensitivity. Discontinuation of sodium butyrate was followed by a rapid fall in the levels of mRNA. The levels of P-glycoprotein returned to normal with a half-life of about 24 h. In spite of a 20-25-fold increase in the level of mdr-1/Pgp mRNA and P-glycoprotein, the SW-620 cell line did not demonstrate increased resistance to doxorubicin and vinblastine or decreased accumulation of vinblastine. In contrast, in the HCT-15 cell line, a 5-fold increase of mdr-1/Pgp was accompanied by a comparable fall in vinblastine accumulation which was reversed by verapamil. In the SW-620 cell line, the induced protein could be photolabeled using [3H]azidopine. Expression of mdr-1/Pgp appears to correlate with the degree of differentiation. However, its induction is not always accompanied by expression of the multidrug-resistance phenotype.

Nutritional factors associated with benign breast disease etiology: a case-control study

Between 1977 and 1980, 854 biopsied cases of benign breast disease (BBD) and 755 matched surgical and 723 matched neighborhood controls subjects were interviewed in Israel by using a detailed food frequency questionnaire. Cases were classified according to degree of ductal atypia (Black-Chablon grading system). Women with atypic lesions (grades greater than or equal to 3) reported a higher intake of all types of foods compared with both control series. Further analyses indicated that the increased consumption was due primarily to foods containing greater than or equal to 10% fat. Odds ratios associated with the highest fat consumption quartile were close to 3.0. There was a trend for increasing saturated fatty acid consumption with increasing ductal atypica. After adjusting for hormonal and demographic confounders, the association with fat intake was strengthened. Because atypic BBD has been reported to be a precursor of breast cancer, our findings lend support to the hypothesis that dietary fat is a risk factor for breast cancer.

Selective expression of alternative lck mRNAs in human malignant cell lines

The lck protein tyrosine kinase is normally expressed in a cell type-specific fashion, with mRNA being confined to cells of lymphoid lineage. Despite this highly specific pattern of expression in normal tissues, lck mRNA has also been detected in selected cell lines derived from human nonlymphoid neoplasms. In this study we explored the mechanisms underlying the expression of lck mRNA within human nonlymphoid neoplastic cell lines. We determined that lck mRNA expression was correlated with transcriptional activation and that there was no evidence for genomic rearrangement or amplification within the lck coding region to account for the expression of lck mRNA in the nonlymphoid neoplastic cell lines. The lck gene has previously been shown to contain two distinct promoter elements. In this study, we demonstrated that lck-producing cell lines derived from human nonlymphoid neoplasms expressed transcripts initiated exclusively from the 3'-most promoter element (3' promoter). In contrast, lymphoid cell lines derived from nonmalignant sources expressed lck transcripts exclusively initiated from the 5'-most promoter element (5' promoter). Most cell lines derived from human lymphoid neoplasms express lck transcripts initiated from both the 5' and 3' promoters in various ratios. Thus, lck expression in a variety of malignant cell lines results from a selective induction of transcription from the 3' promoter.

AIDS in the elderly: a case and its implications

Although acquired immunodeficiency syndrome (AIDS) remains relatively uncommon in the elderly, there are serious and unique implications associated with the diagnosis of AIDS in this age group. The most common mode of transmission is transfusion. With the growing number of elderly, an increase in AIDS in the elderly will occur despite improved screening methods. Dementia is a serious morbidity associated with AIDS in the elderly, which presents considerable diagnostic and ethical dilemmas. A case is presented which illustrates the geriatric multidisciplinary team approach to the care of a 90-year-old man with AIDS.

Pefloxacin treatment of meningitis caused by gram-negative bacteria

Ten patients with acute meningitis caused by gram-negative bacteria were treated with pefloxacin intravenously for a mean period of 10 days. Eight patients responded clinically to pefloxacin treatment, and the causative organisms were eradicated from the cerebrospinal fluid in 9 of the 10 patients. Pefloxacin may offer a new, efficacious, and safe therapy for gram-negative meningitis.