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At least 793 records · Page 44Linked to original sources
PubMed2002

Inhibition of autocrine fibroblast growth factor signaling by the adenovirus-mediated expression of an antisense transgene or a dominant negative receptor in human glioma cells in vitro.

Autocrine fibroblast growth factor (FGF) signaling was genetically manipulated in human gliomas by an adenovirus-mediated strategy. Antisense inhibition of endogenous basic FGF (bFGF) expression showed inhibition of the proliferation of human glioma cells (U251MG, NMC-G1) without promoting apoptosis. The reduction in proliferation in response to antisense inhibition was reversed with an additional supplement of exogenous bFGF. On the other hand, the overexpression of a kinase defective mutant of the type I FGF receptor (dominant negative FGF receptor) resulted in not only growth inhibition but also marked apoptosis in U251MG cells. In the cells expressing a dominant negative FGF receptor, the reduction in cell number was not reversed by the exogenous bFGF supplement. Our data further implicated the significance of an autocrine FGF signaling loop in human gliomas. Cell survival activity may largely depend on the receptor-mediated pathway, which should be considered in the development of the molecular based therapeutics.

Adenoviruses, Human↗
PubMed2002

Role of the autocrine chemokines MIP-1alpha and MIP-1beta in the metastatic behavior of murine T cell lymphoma.

The ESb-MP T-cell line is a highly malignant murine lymphoma, which preferentially metastasizes toward the kidney. This could be a result of the local production of monocyte chemoattractant protein-1 (MCP-1) and regulated on activation, normal T expressed and secreted (RANTES), which are chemotactic for ESb-MP cells. Here, we demonstrate that ESb-MP cells are already responsive to the chemotactic activity of macrophage inflammatory protein-1alpha (MIP-1alpha) and MIP-1beta from 1 ng/ml onward. Moreover, upon stimulation with lipopolysaccharide (LPS) or virus, ESb-MP cells themselves produce significant amounts of MIP-1 ( approximately 200 ng/ml). Indeed, the major autocrine chemoattractants, isolated from ESb-MP cells, were intact MIP-1alpha and MIP-1beta. Pretreatment with LPS or addition of MIP-1 inhibited the in vitro migration of ESb-MP cells toward various chemokines. Moreover, compared with untreated lymphoma cells, LPS-treated cells produced significantly less metastasis in mice. The results represented here suggest that the role of chemokines in attracting tumor cells at secondary sites depends on a balance between autocrine-produced and tissue-derived chemokines. This delicate balance should be considered in the design of antichemokine strategies in different tumor types.

Animals↗
PubMed2003

Acetylcholine is synthesized by and acts as an autocrine growth factor for small cell lung carcinoma.

It is well established that small cell lung carcinomas (SCLCs) express receptors for acetylcholine (ACh) and that stimulation of these receptors by nicotine or other cholinergic agonists stimulates cell growth via activation of nicotinic cholinergic receptors (nAChRs) and/or muscarinic cholinergic receptors (mAChRs). The aim of this study was to determine whether SCLC cells synthesize and secrete ACh and respond to endogenous ACh to create a functioning cholinergic autocrine loop. Reverse transcription-PCR was used to screen a panel of SCLC cell lines for components of cholinergic signaling. Choline acetyltransferase (ChAT) and the vesicular ACh transporter (VAChT), as well as alpha3, alpha5, alpha7, beta2, and beta4, nAChR subunits and M3 and M5 mAChRs, were found to be present in most of the SCLC cell lines tested. Real-time PCR showed that mRNA levels for ChAT, VAChT, and alpha7 and beta2 nAChR subunits varied significantly among different SCLC cell lines tested. The H82 cell line was found to express the highest levels of ChAT, and that cell line was chosen for additional studies of ACh release and cell proliferation. ACh was easily detectable in H82 cell culture media, and levels of ACh were increased by the acetylcholinesterase inhibitor neostigmine. Vesamicol, an inhibitor of VAChT, and hemicholinium-3, an inhibitor of choline transport, both reduced H82 cell ACh basal release in a dose-dependent manner. In parallel with the reductions of ACh release, vesamicol and hemicholinium-3 also decreased H82 cell proliferation. H82 cell proliferation was also inhibited by the muscarinic and nicotinic antagonists atropine and mecamylamine, respectively, in dose- and time-dependent manners. Finally, archival cases of SCLC were screened by immunohistochemistry for expression of ChAT. Thirteen of 26 tumors screened were positive for ChAT. These findings demonstrate that SCLC can synthesize, secrete, and degrade ACh and that released ACh stimulates SCLC cell growth. Identification of this new autocrine loop provides a potential new target for therapeutic intervention.

Acetylcholine↗
PubMed2003

Overexpression of the autocrine motility factor/phosphoglucose isomerase induces transformation and survival of NIH-3T3 fibroblasts.

Autocrine motility factor (AMF)/phosphoglucose isomerase (PGI) is a ubiquitous cytosolic enzyme and is produced as a leaderless secretory protein, released from cells via a nonclassical pathway. AMF/PGI acts extracellularly as a potent mitogen/cytokine (CXXC, chemokine). Increased expression of AMF/PGI and its receptor/CXXC-R has been found in a wide spectrum of malignancies, and is associated with cancer progression and metastasis. To directly elucidate the functional role of AMF/PGI on cell motility and neoplastic transformation, we stably transfected AMF/PGI cDNA into NIH-3T3 cells. Ectopic overexpression of AMF/PGI results in its secretion and activation via a constitutive autocrine activation loop that renders the cells highly motile, acquiring a transformed phenotype in vitro and tumorigenicity in vivo. The transformed phenotype of AMF/PGI-transfected cells leads in part resistance to induction of apoptosis induced by serum starvation, through the activation of phosphatidylinositol 3'-kinase/Akt signaling pathway and down-regulation of caveolin-1 expression. Overexpression of this housekeeping gene induces resistance to apoptosis and neoplastic transformation, and, thus, AMF/PGI represents a novel class of oncogenic protein.

3T3 Cells↗
PubMed1999

[Effects of blocking the TGF alpha-EGFR autocrine loop on the growth of human pancreatic carcinoma cells in vitro].

OBJECTIVE: Investigate the effects of blocking the TGF alpha-EGFR autocrine loop on the growth of human pancreatic carcinoma. METHODS: The pCMV-AS-EGFR, a recombinant vector expressing antisense EGFR under the control of human CMV promotor was constructed and transfected the transformant PC-7/AS-TGF alpha cell line cells, which had been transfected by a recombinant retroviral vector expressing antisense TGF alpha. G418 resistant colonies were isolated and identified as PC-7/AS-TGF alpha/AS-EGFR. The integration and expression of exogenous and endogenous genes were detected by Southern blot and Northern blot analysis. Apoptosis was detected by DNA fragmentation, flow cytometry and in situ cell death detection. RESULTS: The cells which were double-transfected by the recombinant vectors showed the integration and expression of exogenous genes, and the downregulation of endogenous EGFR and cyclin D1 mRNA. 125I-EGF ligand binding test showed the binding affinity of the EGFR on the cell surface also reduced. The inhibition effect of cotransfecting of antisense TGF alpha and antisense EGFR was remarkable as compared with that of antisense TGF alpha alone. The incorporation rate of 3H-TdR reduced from 25% to 14.5%, and the growth inhibition rate increased from 78.6% to 86.0%. The ability of soft agar colony-formation was completely suppressed. CONCLUSIONS: These observations strongly support that the blockage of the expression of autocrine growth factor TGF alpha and its receptor EGFR was a potent way in circumventing the malignant properties of the pancreatic carcinoma cells.

Cell Division↗
PubMed2002

[Autocrine regulation for transforming growth factor-beta 1 by fibroblast in vitro].

OBJECTIVE: To explore the autocrine regulation for the transforming growth factor-beta 1(TGF-beta 1) by the fibroblasts in vitro. METHODS: Fibroblasts were cultured in vitro which isolated from the normal prepuce by circumcision. TGF-beta 1 concentration were determined with ELISA for the different passages and the different time at the same passage. RESULTS: The TGF-beta 1 concentration was different for the distinct passage of fibroblasts and achieved the peak (450 ng/L) at the sixth passage. Among the same fibroblasts, the TGF-beta 1 concentration was different in the various days and passage of the summit (680 ng/L) on the fifth day, which was 2.5 times as high as that of the first day. CONCLUSION: The fibroblasts possess the ability of autocrine of the TGF-beta 1 and have some regularity. It will provide the theory basis for the research about TGF-beta 1 regulation mechanism and the medical application about salvia miltiorrhiza.

Cell Division↗
PubMed2001

[Effect of Autocrine VEGF on Chronic Myeloid Leukemia Cell Line K562]

Vascular endothelial growth factor (VEGF) is a specific mitogen for vascular endothelial cells. It has been associated with angiogenesis, growth, metastasis and poor prognosis in solid tumors. Lately, it has been known that VEGF expression is higher in bone marrow from chronic myeloid leukemia (CML) patients than that in normal subjects. However, it is not clarified that the effect of VEGF on the abnormal proliferation of CML cells. In order to explore the effect of autocrine VEGF on CML cells, K562 cells were transfected with the VEGF(121) cDNA sense vector (K562/S) or with the VEGF(121) cDNA antisense vector (K562/As). K562 cells were transfected with the pcDNA(3) vector (K562/V) as the control. Cell proliferation was determined by MTT and colony forming assay in vitro. Flow cytometric Annexin-V-FITC/PI dual labeling technique was performed to observe the effect of VEGF(121) cDNA transfection on apoptosis of K562 cells. Results indicated that K562/S transfectants exhibited a 3-fold increase in VEGF secretion, and K562/As transfectants exhibited a 49% reduction in VEGF secretion. K562/As showed a reduced growth rate and colony forming efficiency as compared to K562/V. K562/S showed an increasing growth rate and colony forming efficiency as compared to K562/V. K562/As had more apoptotic cells than K562/V and K562/S in the same culture condition. These data suggest that VEGF plays an important role in the abnormal proliferation and apoptosis in CML cells through an autocrine mechanism.

Journal Article↗
PubMed1992

Role of autocrine and paracrine factors in thyroid follicle growth.

Basic fibroblast growth factor (bFGF), insulin like growth factor I and II and transforming growth factor beta (TGF-beta) are assumed to be of importance in the paracrine and autocrine regulation of thyroid growth and function. Using in vitro cultures of isolated intact porcine thyroid follicles, we here present data that support a possible autocrine action of bFGF on proliferation, a possible explanation for the observed potentiation of EGF-stimulated growth by IGF-I, and results on the release and regulation of release of TGF-beta. For growth experiments, thyroid follicles (2 x 10(5) cells) were incubated for 6 days followed by cell counting. For the analysis of EGF binding sites, follicles were preincubated with and without IGF-I (10 ng/mL) for 48 h at 37 degrees C, incubated with 125I-EGF (5 nCi/well) and unlabeled EGF (0.1-500 ng/mL) for 24 h at 4 degrees C (2 x 10(5) cells/well); binding characteristics were calculated from Scatchard analysis. The TGF-beta bioactivity in untreated and acid treated media conditioned with thyroid follicles for 3 days (2 x 10(7) cells) was analyzed with a bioassay using mink lung epithelial cells. Basic FGF (0.1-1 ng/mL) dose-dependently stimulated the proliferation of thyroid follicles up to 135.0 +/- 6.1%; this effect was additive with IGF-I (10 ng/mL) but not with EGF (2 ng/mL). The IGF-I (10 ng/mL) just moderately increased proliferation (128.3 +/- 16%), but potentiated EGF (1 ng/mL)-stimulated growth (from 183.0 +/- 11.0% to 314.0 +/- 3.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Transforming growth factor-alpha acts as an autocrine growth factor in ovarian carcinoma cell lines.

The potential of transforming growth factor-alpha (TGF-alpha) to function as an autocrine growth factor was evaluated in numerous ovarian carcinoma cell lines. All 17 lines which were examined expressed the epidermal growth factor receptor and 16 cell lines, in addition, concomitantly secreted TGF-alpha. Radioimmunoassay of processed serum-free-conditioned medium indicated TGF-alpha concentrations ranging from 16 to 197 pg/ml, or 1.5 to 95 ng/10(8) cells. 125I-TGF-alpha bound to a single class of high-affinity-binding sites on the surface of the cells. The dissociation constant for the 125I-TGF-alpha/epidermal growth factor receptor complex ranged from 0.21 to 5.3 nM with receptor numbers from 3,500 to 96,000/cell, depending upon the cell line. The growth of 8 ovarian cell lines was stimulated in a dose-dependent manner when grown in the presence of exogenous TGF-alpha. Growth in 4 of 5 cell lines capable of serum-free propagation was inhibited from 28 to 56% when cultured in medium containing a TGF-alpha-neutralizing monoclonal antibody. These results support the view that TGF-alpha is an autocrine growth factor for cell lines derived from ovarian cancers of epithelial origin and suggest a potential role for TGF-alpha in the pathogenesis or progression of the disease.

Cell Division↗
PubMed1992

Suramin inhibits the growth of human rhabdomyosarcoma by interrupting the insulin-like growth factor II autocrine growth loop.

Suramin is a polysulfonated naphthyl-urea with antineoplastic activity that binds various peptide growth factors. Since we previously demonstrated that insulin-like growth factor II (IGF-II) is an autocrine growth factor in human rhabdomyosarcoma (RMS), we studied the effect of suramin on the growth of human RMS cells. Suramin caused a dose-dependent decrease of RMS cell number grown either in 10% fetal bovine serum or in serum-free medium (half-maximal effective dose in mitogenic assays, 1.6 x 10(-4) and 9 x 10(-5) M, respectively). IGF-II and IGF-I added to RMS cells in the presence of suramin reversed the suramin-induced inhibition of cell growth. Since IGF-II exerts its mitogenic effects on RMS cells by binding to the type I receptor, we performed radioreceptor assays using 125I-IGF-I and found that suramin displaced 125I-IGF-I from the type I IGF receptor. There was an excellent correlation between the doses of suramin effective in inhibiting the growth of RMS cells and those that displaced the binding of IGF-I. Our data indicate that suramin exerts its effect on RMS cell growth by interfering with the binding of IGF-II to the type I IGF receptor, thereby interrupting the IGF-II autocrine growth in these cells. Disrupting autonomous growth of RMS may be a promising novel therapeutic approach.

Antineoplastic Agents↗
PubMed1992

Interleukin-5 is an autocrine growth factor for Epstein-Barr virus-transformed B lymphocytes.

Because of the recent finding that interleukin-5 (IL-5) is produced by Epstein-Barr virus-transformed B lymphocytes (EBV-B cells), we performed studies to ascertain whether EBV-B cells might use IL-5 by an autocrine mechanism. EBV-B cells known to be IL-5 producers were capable of responding to addition of exogenous IL-5 by dose-related augmented proliferation. The addition of a neutralizing anti-IL-5 antibody reduced these effects and also dose-dependently inhibited proliferation and reduced viability of unsupplemented EBV-B cells, having a maximum effect at about 120 hours. In contrast, no stimulatory effect of IL-5 was noted on Burkitt's lymphoma cell lines, nor were these lines growth-inhibited by anti-IL-5 antibody. With biotinylated IL-5, (b-IL-5) second labeling with streptavidin-FITC, and flow cytometric analysis, binding of IL-5 to EBV-B cells cultured in fresh medium was demonstrated and could be competed for by excess unlabeled IL-5, suggesting the presence of IL-5-specific binding sites. Binding of IL-5 was reduced on cells cultured for longer periods before study but could be restored by extensively washing cells before labeling them with b-IL-5, suggesting that surface binding sites had become occupied by endogenously produced IL-5. These findings support a role for IL-5 in autocrine support of EBV-B cell growth.

Antibodies↗
PubMed1992

Role of autocrine and paracrine production of granulocyte-macrophage colony-stimulating factor and interleukin-1 beta in the autonomous growth of acute myeloblastic leukaemia cells--studies using purified CD34-positive cells.

The blast cells from some patients with acute myeloblastic leukemia (AML) proliferate autonomously in vitro. We have previously identified four groups of AML blasts based upon their growth characteristics in vitro, in particular the degree of autonomous growth. We have now measured the production of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-1 beta (IL-1 beta) by AML cells with different growth characteristics, using two sensitive enzyme-linked immunosorbent assays. Our results show a correlation between the capacity of AML blasts to produce GM-CSF and IL-1 beta and the ability to grow autonomously in vitro. Blasts from cells with no autonomous growth (n = 5) secreted low or undetectable amounts of GM-CSF and IL-1 beta. Blasts with totally autonomous growth (n = 10) secreted the highest levels of GM-CSF (mean 2469 pg/10(3) cells) and IL-1 beta (mean 3156 pg/10(6) cells). Whereas blasts with partially autonomous growth (n = 9) secreted intermediate levels of GM-CSF (mean 270 pg/10(6) cells) and IL-1 beta (mean 931 pg/10(6) cells). In order to determine whether GM-CSF production was autocrine or the consequence of paracrine secretion by differentiated leukemic cells, we studied the degree of autonomous growth and production of GM-CSF by CD34-positive blasts from eight patients whose unfractionated cells produced GM-CSF. We found that CD34-positive blasts from six of these cases grew autonomously to a degree comparable to that of the unfractionated cells, and that CD34-positive blasts produced GM-CSF either autonomously or in response to recombinant IL-1 beta. Our data suggests that in the majority of cases, CD34-positive blasts are capable of autonomous growth and autocrine GM-CSF production, however this is variably regulated by the paracrine production of IL-1 beta by CD34-negative cells.

Antigens, CD↗
PubMed2003

[Effect of autocrine vascular endothelial growth factor on the biological activity of acute myeloid leukemia cell line HL-60].

OBJECTIVE: To explore the effect of autocrine vascular endothelial growth factor (VEGF) on the abnormal proliferation of HL-60 cells. METHODS: HL-60 cells were transfected via lipofictamine with the VEGF(165) cDNA sense vector (HL-60/ VEGF(165)) and with the PcDNA3.1(-)-vector (HL-60/neo) as the control. Reverse transcription-polymerase chain reaction (RT-PCR) was used for detecting VEGF mRNA in the transfected cells. VEGF concentrations in the cell culture supernatant were determined by enzyme-linked immunosorbent assay (ELISA), and cell proliferation was determined by MTT assay and colony-forming assay in vitro. Flow cytometric Annexin-V-FITC/ PI dual-labeling technique was employed to observe the effect of VEGF(165) cDNA transfection on the apoptosis of HL-60 cells. RESULTS: The levels of VEGF mRNA expression by HL-60/VEGF(165) cells were higher than HL-60/neo, with the mean VEGF quantity in the supernatant of HL-60/VEGF(165) cell culture being 399.07+/-12.45 ng/L, which was 2-fold higher than that in the supernatant of HL-60/neo cells (184.45+/-10.53 ng/L) (P<0.01). The growth rate of HL-60/VEGF(165) cells was significantly accelerated as compared with that of the control cells, and the colony formation capacity of the former cells also increased significantly (P<0.05), with the average colony number of 157.00+/-17.00/500 cells vs 110.00+/-12.90/500 cells of HL-60/neo cells. Less apoptotic cells were identified among HL-60/VEGF(165) cells than in HL-60/neo cells in the same culture condition. CONCLUSION: Autocrine VEGF plays an important role in the proliferation and apoptosis of acute myeloid leukemia cells.

Apoptosis↗
PubMed2003

Autocrine growth of Epstein-Barr virus-positive gastric carcinoma cells mediated by an Epstein-Barr virus-encoded small RNA.

Although 5-10% of gastric carcinoma (GC) cases worldwide are associated with EBV, a human herpesvirus, it is still not clear what the precise contribution of the virus is to the pathogenesis of EBV-positive GC. Here we report that EBV infection induces expression of insulin-like growth factor 1 (IGF-I) in the GC-derived EBV-negative cell line NU-GC-3 and that the secreted IGF-I acts as an autocrine growth factor. Transfection of individual EBV latent genes into NU-GC-3 cells revealed that the EBV-encoded small RNA (EBER) was responsible for IGF-I expression. Addition of recombinant IGF-I accelerated growth of NU-GC-3 cells, whereas growth of the EBV-converted NU-GC-3 cells was blocked by treatment with an anti-IGF-I antibody. These results suggest that IGF-I induced by EBER acts as an autocrine growth factor for EBV-positive GC. These findings seem to be operative in vivo, as EBV-positive GC biopsies consistently express IGF-I, whereas EBV-negative GC biopsies do not. EBER is invariably expressed in EBV-associated malignancies including GC. The present findings strongly suggest that EBV directly affects the pathogenesis of EBV-positive GC and underline the importance of RNA molecules on cell growth regulation.

Cell Division↗
PubMed2003

Overexpression of basic fibroblast growth factor and autocrine stimulation in acute myeloid leukemia.

Basic fibroblast growth factor (bFGF) is known to play a critical role in tumorigenesis of solid tumors. The importance of bFGF in hematological malignancies such as acute myeloid leukemia (AML) remains to be elucidated. Therefore, we determined bFGF protein expression by immunohistochemical analyses in bone marrow biopsies of patients with newly diagnosed, untreated AML. The expression of bFGF was significantly increased in AML patients [n = 81; median, 3.0 (interquartile range, 1.8-3.9) arbitrary units (AU)] as compared with controls [n = 18; 1.9 (1.5-2.3) AU]. The degree of bFGF expression did not correlate with microvessel density. bFGF/FGF receptor mRNA and bFGF protein were detected in different AML cell lines. To study autocrine growth stimulation of AML blasts, the AML cell lines HL-60, M-07e, and KG-1 were incubated with bFGF. A significant dose-dependent increase in proliferation and colony formation was observed. These effects were abrogated by the addition of a polyclonal anti-bFGF antibody. In conclusion, increased expression of bFGF in the bone marrow of AML patients seems to play an important role in the pathophysiology of AML by promoting autocrine growth stimulation of leukemic blasts.

Acute Disease↗
PubMed1992

Role of insulin-like growth factor-I in the autocrine regulation of cell growth in TT human medullary thyroid carcinoma cells.

Since the TT human medullary thyroid carcinoma cell line required fewer exogenous growth factors (serum), we investigated whether this line has an autocrine mechanism by examining the effects of antibodies directed toward insulin-like growth factor I (IGF-I) and its receptor on TT cell growth in serum-free conditions. Treating cells with anti-IGF-I antibody for four days reduced the cell number by more than 50% compared with a nonimmune IgG control. Furthermore, a monoclonal antibody to the IGF-I receptor suppressed DNA synthesis when determined by a [3H]thymidine incorporation assay. Exogenous IGF-I (20 ng/mL) stimulated [3H]thymidine incorporation in serum-free medium; approximately 70% of the IGF-I-induced stimulation was blocked by the presence of the receptor antibody. Treating TT cells with IGF-I for 48 hours increased the cell population in the S phase by 62% when analyzed by flow cytometry. These data suggest that TT cells might respond to endogenously produced IGF-I and therefore provide an in vitro model for autocrine regulation of human tumor cell growth by IGF-I.

Autoantibodies↗
PubMed1992

Density-dependent responsiveness to autocrine growth factors of Epstein-Barr virus transformed human B lymphocytes.

Analysis of the growth requirements of Epstein-Barr virus (EBV)-transformed B lymphocytes shows that interleukin 1 and thioredoxin, a disulfide reducing enzyme, are able to induce a marked increase in DNA synthesis in the early phases of in vitro culture. By contrast, interleukin 6 induces a steady increase in DNA synthesis comparable to that observed with crude conditioned supernatant. Furthermore, EBV-transformed B cells exhibit a density-dependent responsiveness to autocrine growth factors, thus suggesting that growth regulation of EBV-transformed B cells might result from the interplay between different self-stimulating soluble factors and from the competence of the cells to respond to autocrine growth factors.

B-Lymphocytes↗
PubMed2005

Genetic manipulation of stromal cell-derived factor-1 attests the pivotal role of the autocrine SDF-1-CXCR4 pathway in the aggressiveness of breast cancer cells.

Stromal cell-derived factor-1 (SDF-1), via its receptor CXCR4, has been implicated in metastasis of cancer, including breast cancer. Exogenous SDF-1 is known to regulate locomotion, chemotaxis and adhesion. The knowledge regarding the effect of autocrine SDF-1 on breast cancer cells is not available. The current study evaluated the effects of SDF-1 on the biological behaviour of breast cancer cells by genetically modifying the expression of SDF-1 in breast cancer cells. Two human breast cancer cell lines (MDA-MB-231 and MDA-MB-435s) and a human fetal lung fibroblast cell line (MRC5) were used. The expression of SDF-1 and the SDF-1 receptor, CXCR4 in the cell lines were studied. Expression cassettes of human SDF-1 and hammerhead ribozyme transgenes specifically targeting human SDF-1 were constructed and used to over-express SDF-1 or to knockout the expression of SDF-1 in cancer cells, respectively. Invasiveness, migration and growth of the genetically modified cells were assessed. SDF-1 was expressed in wild-type human breast cancer cell line MDA-MB-435s and fibroblast cell line MRC5, but not in MDA-MB-231 cell line. In contrast, CXCR4 expression was observed in all three cell lines tested. The ability of invasion and migration was significantly reduced in SDF-1 knockout MDA-MB-435s cells, compared with wild-type and vector control cells (p<0.01). On the other hand, SDF-1 transfected MDA-MB-231epsilonSDF1+/+ cells that stably expressed SDF-1 showed a different behaviour from MDA-MB-231SDF1+/- (plasmid control) and wild-type MDA-MB-231 cells, both being SDF-1 negative. MDA-MB-231epsilonSDF1+/+ cells displayed a higher degree of invasiveness and migration, compared with wild-type and MDA-MB-231SDF+/- cells (p<0.01). Furthermore, SDF1-knockout MDA-MB-435s cells showed a slower growth rate over a 7-day period compared with the respective control and wild-type MDA-MB-435s cells. In contrast, the growth of the SDF-1 transfected MDA-MB-231SDF1+/+ cells was markedly enhanced when compared with wild-type and vector control cells. Breast cancer cell lines, when equipped with the autocrine SDF-1-CXCR4 signal pathway, display aggressive behaviour, including an increase in invasiveness, migration together with faster growth. SDF-1, together with its receptor CXCR4 may provide important information for predicting the aggressive nature and constitute important therapeutic targets in human breast cancer.

Breast Neoplasms↗