Modulation of endometrial transforming growth factor beta (TGFbeta) by tamoxifen

Transforming growth factor beta (TGFbeta) immunoreactivity was determined in endometria from non-drug-therapy and tamoxifen-treated patients. Sections were scored for pathology and quantity image analysis performed to determine levels of glandular- or fibrosis-associated TGFbeta1. Tamoxifen-treated patients displayed greater levels of endometrial dysplasia and glandular hyperplasia, in addition to a statistically significant (P<0.0001) elevation in gland-associated TGFbeta1 protein.     

Insulin-like factor of growth (IGFI), insulin-like growth factor binding protein 3 (IGFBP3) and transforming growth factor beta1 (TGF-beta1) in patients with locally-advanced and metastatic cancer of prostate

The paper deals with a study of growth factors in blood serum from patients with locally-advanced and metastatic cancer of prostate prior to treatment. Twelve months after diagnosis was made, the data were compared with the initial indices. Immunoenzymatic assay was used in combination with the existing standard procedures of examination of cancer patients. Data were compared with clinico-morphological and serologic evidence on tumor process using medico-biological statistics.     

Prohibitin and cofilin are intracellular effectors of transforming growth factor beta signaling in human prostate cancer cells

A proteomic analysis was pursued to identify new signaling effectors of transforming growth factor beta1 (TGF-beta1) that serve as potential intracellular effectors of its apoptotic action in human prostate cancer cells. The androgen-sensitive and TGF-beta-responsive human prostate cancer cells, LNCaP T beta RII, were used as in vitro model. In response to TGF-beta, significant posttranslational changes in two proteins temporally preceded apoptotic cell death. TGF-beta mediated the nuclear export of prohibitin, a protein involved in androgen-regulated prostate growth, to the cytosol in the LNCaP T beta RII cells. Cofilin, a protein involved in actin depolymerization, cell motility, and apoptosis, was found to undergo mitochondrial translocation in response to TGF-beta before cytochrome c release. Loss-of-function approaches (small interfering RNA) to silence prohibitin expression revealed a modest decrease in the apoptotic response to TGF-beta and a significant suppression in TGF-beta-induced cell migration. Silencing Smad4 showed that the cellular localization changes associated with prohibitin and cofilin action in response to TGF-beta are independent of Smad4 intracellular signaling.     

Induction of transforming growth factor beta in hormonally treated human prostate cancer.

Transforming growth factor beta-1 (TGF-beta 1) has been proposed as a mediator of tumour growth in a number of tumours and cell lines including prostate, and in a recent study was shown to be up-regulated in the stroma of breast cancer tissue following treatment with the anti-oestrogen tamoxifen. Immunolocalisation of the intracellular form of TGF-beta 1 confirmed that the source of the stromal TGF-beta 1 was the peritumoral fibroblasts. We present here the results of a study in which five patients with hormonally unresponsive prostatic carcinoma and seven patients responding to a luteinising hormone-releasing hormone analogue had prostate biopsies taken before and during treatment. These were stained for TGF-beta expression prior to treatment and at either relapse or 3 months later respectively. Six of seven clinically responding tumours and three of five relapsed tumours showed up-regulation of extracellular TGF-beta 1, again primarily in the stroma, with no apparent up-regulation of intracellular TGF-beta 1, TGF-beta 2 or TGF-beta 3. These data illustrate that the epithelial growth inhibitor TGF-beta 1 can be induced by hormonal manipulation in prostate cancer in vivo, and may continue to be up-regulated even after relapse. This suggests that relapse of hormonally treated prostate cancer may be associated with a failure of the epithelium to respond to stromal TGF-beta 1.     

Mifepristone-induced secretion of transforming growth factor beta1-induced apoptosis in prostate cancer cells

Successful therapy should induce apoptosis in prostate cancer cells irrespective of their androgen response. We have investigated the possibility of utilizing Mifepristone and Tamoxifen as treatment options for prostate cancer cells. Because preliminary results demonstrated induction of apoptosis by these drugs, the mechanism of induction of apoptosis was investigated. LNCaP-C4 prostate cancer cells were treated with Mifepristone and/or Tamoxifen. To confirm cytotoxic effects, nude mice with LNCaP-C4 xenografts were treated with Mifepristone and Tamoxifen. Cell viability was assayed using Sulforhodamine B (SRB) assay and DNA fragmentation was measured by ELISA. Culture media from vehicle- and drug-treated cells were collected and secretion of transforming growth factor beta1 (TGFbeta1) was estimated by ELISA. Role of TGFbeta1 was confirmed by inhibiting its function using TGFbeta1 antibody or M6P, which blocked activation of TGFbeta1. Apoptotic effects were determined by immunoblots of cytochrome c levels in cytosol and by in vitro colorimetric assay of caspase-3 activity. Results showed that although both drugs induced apoptosis in LNCaP-C4 cells, Mifepristone was more effective. The effects of these drugs on xenografts confirmed in vitro results. It was hypothesized that drug-induced secretion of TGFbeta1 may be responsible for induction of apoptosis. Neutralization of TGFbeta1 with an antibody or blocking the activation of TGFbeta1 by M6P abrogated the effects of Mifepristone and Tamoxifen confirming our hypothesis. Furthermore, treatment with Mifepristone and/or Tamoxifen released cytochrome c into the cytoplasm and induced activity of caspase-3, providing evidence that the drug-stimulated secretion of TGFbeta1 was responsible for induction of apoptosis in these cells. In conclusion, both Mifepristone and Tamoxifen induced apoptosis mediated through TGFbeta1. However, no critical advantage was noted by the addition of Tamoxifen to Mifepristone treatment.     

Analysis of specific gene mutations in the transforming growth factor-beta signal transduction pathway in human ovarian cancer

Several proteins, including transforming growth factor beta (TGF-beta) receptor type I (RI), TGF-beta receptor type II (RII), Smad2, Smad3, and Smad4/DPC4, have been identified in the transduction pathway of the tumor suppressor TGF-beta. Mutations in TGF-beta RI, TGF-beta RII, Smad2, and Smad4/DPC4 genes are associated with several human cancers. The present study examines these gene mutations in 32 human ovarian cancers and 14 patient-matched normal tissues. For the first time, mutations in the Smad2 and Smad4 genes were analyzed in relation to human ovarian cancer. Gene mutations of TGF-beta RI, TGF-beta RII, Smad2, and Smad4 were analyzed using specific primers by PCR-single-strand conformational polymorphism (SSCP), and the results revealed a frameshift mutation at codons 276-277 (CTCTGG-->CTGCGTGG) in exon 5 of TGF-beta RI in 10 of 32 tumor samples (31.3%). This mutation was associated with reduced or absent expression of TGF-beta RI protein and p53 protein in tumor tissues. We detected SSCP variants of TGF-beta RII in exon 2 in 20 of 32 tumors. Sequence analysis of these variants revealed an A to G transition at the seventh band of intron 2. In this A to G polymorphism in intron 2, 12 samples (37.5%) had A/A alleles, 12 (37.5%) had A/G alleles, and 8 (25%) had G/G alleles. We detected Smad2 SSCP variants in exon 4 in 12 of 32 tumors (37.5%). Sequence analysis revealed a 2-bp deletion in the polypyrimidine tract of intron 3, which is located at position -39 to -56 in the splice acceptor site of the intron 3-exon 4 junction. No SSCP variants were detected in the Smad4 gene. These findings suggest that mutations in the TGF-beta RI and in its signal transduction pathway are likely responsible for human ovarian carcinogenesis.     

Versican accumulation in human prostatic fibroblast cultures is enhanced by prostate cancer cell-derived transforming growth factor beta1

We have previously demonstrated that peritumoral stromal matrix derived from prostate cancer patients who relapse after radical surgery contains elevated levels of versican. The purpose of this study was to determine whether prostate cancer cells control stromal cell secretion of versican. Serum-free conditioned medium from three prostate adenocarcinoma cell lines, LNCaP, PC3, and DU145, was added to cultures of fibroblasts established from prostatic tissue of patients with benign prostatic hyperplasia, and the medium was harvested at 24, 48, and 72 h. Immunoblotting with an antiversican core protein antibody revealed that prostatic fibroblast medium harvested at 72 h contained increased levels of versican after treatment with either LNCaP-, PC3- or DU145-conditioned medium (2.5-, 4.5-, and 5-fold, respectively) compared with control cultures. This increase in versican in the culture medium was not observed after coincubation with transforming growth factor beta1-neutralizing antisera. The results of this study suggest that prostate tumor cells induce host stromal cells to secrete increased versican levels via a paracrine mechanism mediated by transforming growth factor beta1.     

The expression of Sprouty1, an inhibitor of fibroblast growth factor signal transduction, is decreased in human prostate cancer

A considerable body of evidence indicates that alterations of fibroblast growth factors (FGFs) and their receptors contribute to prostate cancer progression. Recently, a new family of regulators of FGF activity has been identified. The Sprouty gene family negatively regulates FGF signaling in a variety of systems and could potentially limit the biological activity of FGFs in prostate cancer. Immunohistochemical analysis of normal and neoplastic prostate tissues using tissue microarrays revealed that Sprouty1 protein is down-regulated in approximately 40% of prostate cancers when compared with matched normal prostate. By quantitative real-time PCR analysis, we found that Sprouty1 mRNA levels were significantly decreased in prostate cancers in vivo in comparison with normal prostate. In prostate cancer cell lines, there is loss of the normal up-regulation of Sprouty1 mRNA and protein in response to FGFs. The decrease in Sprouty1 expression in the human prostate cancer, despite elevated levels of FGF ligands and FGF receptors, implies a loss of an important growth regulatory mechanism in prostate cancers that may potentiate the effects of increased FGF and FGF receptor expression in prostate cancer.     

The suppressive effects of type beta transforming growth factor (TGF beta) on primitive murine hemopoietic progenitors are abrogated by interleukin-6 and granulocyte colony-stimulating factor

We examined the effects of type beta transforming growth factor (TGF beta) on colony formation by murine hemopoietic progenitors in methylcellulose culture. TGF beta inhibited colony formation from spleen cells of normal mice supported by interleukin-3 (IL-3) and erythropoietin (Ep). The suppressive effects of TGF beta were more profound on colony formation from cells of 5-fluorouracil (5-FU)-treated mice than those of normal mice. Addition of IL-6 or granulocyte colony-stimulating factor (G-CSF), which act synergistically with IL-3 on dormant progenitors, partially neutralized the inhibition by TGF beta of colony formation from cells of 5-FU-treated mice. We then exposed day-2 post-5-FU marrow cells to these factors for 2 days in serum-free suspension culture, washed, and replated alliquots of cells for analysis of the surviving fractions of the progenitors. While TGF beta almost totally abolished the colony-forming ability of the dormant progenitors, IL-6 and G-CSF abrogated the inhibitory effects of TGF beta. These results indicated that TGF beta and early-acting hemopoietic factors (IL-6 and G-CSF) possess counteracting effects on early progenitors.     

Immunohistochemical staining for transforming growth factor beta 1 associates with disease progression in human breast cancer.

The transforming growth factor beta s (TGF-beta) comprise a family of M(r) 25,000 pluripotent growth factors which have been implicated in the development and progression of human breast cancer. Conflicting data suggest that TGF-beta has the potential to either inhibit or promote the progression of mammary neoplasia. We therefore examined a pathological library of malignant breast biopsy specimens to determine the prevalence and distribution of immunoreactivity with antibodies specific for the three mammalian isoforms of TGF-beta (beta 1, beta 2, and beta 3). We found that intense staining for TGF-beta 1 was positively associated with rate of disease progression, and that this was independent of age, stage, nodal status, or estrogen receptor status (P = 0.009).     

High serum transforming growth factor beta 1 (TGFB1) level predicts better survival in breast cancer

The transforming growth factor beta 1 (TGFB1) is a regulatory cytokine with both tumor suppressor and tumor-promoting effects in breast cancer (BC) cell lines and tissue. Data about level of circulating TGFB1 and its prognostic significance in BC patients is conflicting. The objective of this study is to determine the clinical significance of the serum TGFB1 levels in BC patients. We enrolled 96 female patients with histopathologically diagnosed BC who did not receive chemotherapy (CT) or radiotherapy. Serum TGFB1 levels were measured by ELISA method and compared with 30 healthy controls. The mean serum TGFB1 level of BC patients was significantly higher than controls (0.08 vs. 0.04 ng/ml, p?<?0.001). There was no significant difference according to known disease-related clinicopathological or laboratory parameters. Serum TGFB1 level had a significant impact on overall survival in both univariate (p?=?0.01) and multivariate analysis (p?=?0.013). Serum TGFB1 level is elevated in BC patients and has a favorable prognostic value. However, it has no predictive role on CT response.     

Expression of transforming growth factor beta mRNA isoforms in human breast cancer.

Using an RNAse protection assay, expression of messenger RNA for isoforms of TGF-beta was determined in a series of breast cancers. Of 50 tumours, 45 (90%) expressed TGF-beta 1 mRNA, 39 (78%) expressed TGF-beta 2, and 47 (94%) expressed TGF-beta 3. Patterns of expression varied between different tumours: 37 (74%) cancers expressed all three TGF-beta isoforms, ten (20%) expressed only two isoforms and two expressed TGF-beta 1 alone. One sample showed no evidence of TGF-beta mRNA expression. Although most breast cancers expressed mRNA for at least one isoform of TGF-beta, there were differences in patterns of mRNA expression between individual tumours. The relatively small number of tumours examined precluded detailed analysis between expression and other clinical parameters, but a significant association was identified between one aspect of isoform expression and lymph node status, in that the majority of tumours expressing all three isoforms were associated with lymph node involvement, whereas tumours without one or more isoform were usually lymph node negative (P = 0.025 by Fisher''s exact test).     

Expression of transforming growth factor beta (TGF beta) receptors and expression of TGF beta 1, TGF beta 2 and TGF beta 3 in human small cell lung cancer cell lines.

A panel of 21 small cell lung cancer cell (SCLC) lines were examined for the presence of Transforming growth factor beta receptors (TGF beta-r) and the expression of TGF beta mRNAs. By the radioreceptor assay we found high affinity receptors to be expressed in six cell lines. scatchard analysis of the binding data demonstrated that the cells bound between 4.5 and 27.5 fmol mg-1 protein with a KD ranging from 16 to 40 pM. TGF beta 1 binding to the receptors was confirmed by cross-linking TGF beta 1 to the TGF beta-r. Three classes of TGF beta-r were demonstrated, type I and type II receptors with M(r) = 65,000 and 90,000 and the betaglycan (type III) with M(r) = 280,000. Northern blotting showed expression of TGF beta 1 mRNA in ten, TGF beta 2 mRNA in two and TGF beta 3 mRNA in seven cell lines. Our results provide, for the first time, evidence that a large proportion of a broad panel of SCLC cell lines express TGF beta-receptors and also produce TGF beta mRNAs.     

转化生长因子β1基因多态性与结直肠癌的相关性分析

目的分析转化生长因子β1(TGF-β1)基因多态性与结直肠癌的相关性。方法选取2008年1月至2013年1月间诊治的109例结直肠癌患者为观察组,120例健康体检者作为对照组。分析对比两组TGF-β1基因多态性及其与结直肠癌的相关性。结果两组TGF-β1 869C及869T等位基因频率差异无统计学意义(P>0.05)。观察组患者TGF-β1的509T等位基因频率显著高于对照组(χ~2=6.109,P=0.013)。Logistic回归分析显示,携带TGF-β1(509T)基因是发生结直肠癌的独立危险因素(OR=3.512,95%CI为2.136~5.641)。结论 TGF-β1 509基因与结直肠癌发病相关,其T等位基因可能是结直肠癌发病的危险因素。     

Elimination of colon cancer in germ-free transforming growth factor beta 1-deficient mice

Patients with ulcerative colitis are at risk for colon cancer and frequently have microsatellite instability,which, in turn, is usually associated with inactivation of transforming growth factor (TGF) beta signaling. TGF-beta1 deficiency in mice can lead to colon cancer that is preceded by precancerous lesions having submucosal inflammation and hyperplastic crypts. Germ-free TGF-beta1-deficient mice are free of inflammation, hyperplasia, and cancer, but when reintroduced into a Helicobacter hepaticus-containing specific pathogen-free room, these lesions reappear. Because adenoma/carcinoma but not inflammation/hyperplasia is dependent on the genetic backgrounds tested, colitis is required, but not sufficient, for carcinogenesis. This animal model should provide insight into the protective role of TGF-beta1 in early stages of ulcerative colitis-associated human colon cancer.     

Expression of transforming growth factor beta 1 by human endometrial carcinoma cell lines: inverse correlation with effects on growth rate and morphology

We examined the effects of transforming growth factor beta 1 (TGF-beta 1) on various aspects of the cell biology of human endometrial carcinoma (HEC) cell lines in vitro, as well as the expression of TGF-beta 1 mRNA by these cell lines. Cell lines from eight HEC tumors, representing a variety of histological subtypes, were studied in order to test the generality of conclusions regarding the effects of TGF-beta 1 on this particular tumor cell type. The growth of five HEC cell lines was inhibited by TGF-beta 1 (10 ng/ml), while growth of three cell lines was not inhibited. The effects on growth correlated with morphological alterations induced by TGF-beta 1; the cell lines with inhibited growth displayed a larger, flatter, more contact-inhibited phenotype, while the cell lines whose growth ws not inhibited showed few discernible morphological alterations in response to TGF-beta 1. Northern analysis of TGF-beta 1 mRNA levels revealed that the three HEC cell lines unresponsive to TGF-beta 1 treatment expressed relatively large amounts of TGF-beta 1. Correspondingly, the five HEC cell lines which responded to TGF-beta 1 with growth and morphological changes expressed much lower levels of TGF-beta 1 mRNA. These results suggest that the sensitivity of human HEC cell lines to TGF-beta 1 is variable and that this sensitivity is inversely correlated with the level of expression of TGF-beta 1.