CG&D
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cell Growth & Differentiation

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kazansky, A. V.
Right arrow Articles by Rosen, J. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kazansky, A. V.
Right arrow Articles by Rosen, J. M.
Cell Growth & Differentiation Vol. 12, 1-7, January 2001
© 2001 American Association for Cancer Research


Articles

Signal Transducers and Activators of Transcription 5B Potentiates v-Src-mediated Transformation of NIH-3T3 Cells

Alexander V. Kazansky and Jeffrey M. Rosen1

Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030-3498

Abstract

Previously, we reported that whereas both signal transducers and activators of transcription (STAT) 5A and STAT5B can be activated with respect to tyrosine phosphorylation and DNA binding potential by Src kinase, only STAT5B was translocated to the nucleus, where it presumably activates unique downstream responses. To help elucidate the functional consequences of STAT5B activation by v-src, the properties of stably transfected NIH-3T3 cells containing both an intact and a dominant negative, COOH-terminal-truncated isoform of STAT5B were investigated. STAT5B enhanced the transforming potential of v-Src as reflected by both an increase in focus formation and growth in soft agar. STAT5B also enhanced v-Src-induced cell cycle progression and cell motility in NIH-3T3 cells. Furthermore, the dominant negative, COOH-terminal-truncated isoform of STAT5B was able to partially suppress v-Src-mediated cell transformation. These results support the hypothesis that STAT5B may enhance Src/Abl-induced tumorigenesis. Accordingly, the equilibrium between STAT5B and STAT5A and their naturally occurring truncated forms may therefore play a key role in the etiology of certain cancers.

Introduction

Protein tyrosine kinases have been implicated in the regulation of both proliferation and differentiation of mammary cells. Deregulation of many non-receptor tyrosine kinases results in a variety of pathological conditions including cancer (1, 2, 3) . In fact, a number of primary tumors and tumor-derived cell lines including breast cancer, colon cancer, melanoma, and sarcoma have been shown to possess elevated Src tyrosine kinase activity (4, 5, 6, 7) . Src and its family members are required for mitogenesis initiated by several growth factor receptors, including epidermal growth factor receptor (8 , 9) , platelet-derived growth factor receptor (10 , 11) , basic fibroblast growth factor receptor (12 , 13) , and colony-stimulating factor 1 receptor (8 , 14) . It is now well established that Src kinases play an important role in cell cycle control, cell proliferation and differentiation, and cell adhesion and movement (15) . Additional roles for Src kinases have been reported recently in the control of cell survival (16) and angiogenesis (17) .

In mammalian cells, seven STAT2 proteins have been described (18) . This family of transcription factors becomes activated by tyrosine and serine phosphorylation. After tyrosine phosphorylation on a single tyrosine residue (located at approximately amino acid 700), STATs dimerize and translocate into the nucleus, where they bind to specific DNA elements and regulate transcription of the respective target genes.

It has been demonstrated that in addition to their signaling functions in normal cells, STATs can also participate in oncogenesis (19) . Originally, cytokine receptor-mediated activation of the JAK family of tyrosine kinases was identified as the primary mechanism of STAT protein activation. More recently, a number of reports have correlated STAT activation with the activity of non-receptor proto-oncogenic tyrosine kinases such as v-Src (20, 21, 22) , v-Abl (23) , Lyn (24) , Lsk (25) , Bcr/Abl (26) , and Fes (27) . In particular, STAT3 activation has been shown to be required for transformation of mammalian fibroblasts (19 , 28) , and it was suggested that STAT3 can function as an oncogene (29) . There is some evidence that v-Src and Bcr/Abl do not activate JAK kinases but instead may be directly associated with STATs (30 , 31) . Furthermore, activation of Src kinases by cytokines may not always be dependent on JAK kinase activation. For example, stimulation of c-Src by prolactin is independent of JAK2 (32) .

In previous studies (33) we observed that STAT5B contains a unique sequence that may be a potential Src/Abl kinase recognition site. Immediately proximal to this site was a putative, additional nuclear localization domain. We demonstrated that whereas both STAT5A and STAT5B could be activated with respect to their tyrosine phosphorylation and DNA binding potential by Src kinase, only STAT5B was translocated to the nucleus, where it presumably activates downstream responses.

In the present study, we demonstrate that STAT5B accelerates v-Src oncogenic activity and, to a limited extent, cell growth. More importantly, STAT5B dramatically increases v-Src-induced tumorigenicity and cell motility. Furthermore, STAT5B significantly enhances Src-induced cell cycle progression in NIH-3T3 cells. Finally, a COOH-terminal-truncated, potentially dominant negative form of STAT5B is able to partially suppress these effects of v-Src. These results support the hypothesis that STAT5B may enhance Src/Abl-induced tumorigenesis. Accordingly, the equilibrium between STAT5B and STAT5A and their naturally occurring truncated forms may, therefore, play a key role in the etiology of certain cancers.

Results

Generation of Stably Cotransfected Cell Lines.
To test the effect of STAT5 on v-Src-inducible transformation, we used bicistronic vectors pEFIRES-N or pEFIRES-P (34) . In these vectors, both the recombinant cDNA and the antibiotic resistance gene (to neomycin or to puromycin) are transcribed as a single transcript driven by the human polypeptide chain elongation factor 1{alpha} promoter. The presence of an internal ribosome entry site ensures that any clones that are resistant to the selected antibiotic also express high levels of recombinant protein encoded by the cDNA cloned upstream from the antibiotic resistance gene. STAT5 cDNAs for STAT5B, STAT5A, and STAT5B{Delta}40 [the naturally occurring COOH-terminal-truncated form of STAT5B lacking the transactivation domain (35) ] were cloned into the vector containing the neomycin resistance gene. v-src cDNA was inserted into a vector encoding the puromycin resistance gene. NIH-3T3 cells were then transfected with the v-Src- and STAT5-containing plasmids, and clones resistant to puromycin and to neomycin were selected. Expression of the corresponding proteins was confirmed by Western blot analysis (data not shown).

STAT5B Accelerates v-src-inducible Focus Formation.
To study the role of STAT5 in v-src-inducible cell transformation, a focus formation assay was first used, which, in the case of v-Src transformation, has been reported to correlate well with growth in soft agar and tumorigenesis (36) . NIH-3T3 cells coexpressing STAT5B and v-Src began forming foci as early as 40 h after plating (Fig. 1A)Citation and formed large colonies after 3 days (Fig. 1B)Citation . Cells expressing v-Src alone, v-Src in combination with STAT5A, or v-Src in combination with the truncated form of STAT5B (STAT5{Delta}B) did not form foci during this time period (Fig. 1)Citation . Normally, NIH-3T3 cells expressing v-Src began to form foci only after 7–9 days, when they were plated at identical cell densities. Expression of STAT5 proteins without v-Src did not induce focus formation (data not shown). Thus, STAT5B appears to accelerate v-Src-inducible transformation of NIH-3T3 cells.



View larger version (92K):
[in this window]
[in a new window]
 
Fig. 1. STAT5B accelerates v-Src-inducible transformation. NIH-3T3 cell lines were stably cotransfected with various combinations of different forms of STAT5 and oncogenic v-Src kinase using bicistronic vectors pEFIRES-N or pEFIRES-P. Stably cotransfected NIH-3T3 cells (105 cells/35-mm-diameter dish) were plated and photographed after (A) 40 h or (B) 3 days of incubation in media supplemented with 2 µg/ml puromycin and 800 µg/ml G418. NP, vectors pEFIRES-N and pEFIRES-P; vSrc, v-Src in pEFIRES-P vector; N, vector pEFIRES-N; 5B, STAT5B; 5{Delta}B, STAT5{Delta}B; 5A, STAT5A.

 
STAT5B Increases the Transforming Potential of v-src.
To further examine the role of STAT5 in v-Src-inducible cell transformation, soft agar assays were performed to measure anchorage-independent growth (37) using NIH-3T3 cells stably transfected with the plasmid constructs described above. NIH-3T3 cells transformed with empty vectors or those expressing STAT5B alone did not form colonies in soft agar (data not shown). As expected, v-Src-transformed cells did form colonies. Cells that express STAT5B in addition to v-Src, however, formed almost three times as many colonies as those expressing v-Src alone. In contrast to wild-type STAT5B, the COOH-terminal truncated form of STAT5B (STAT5{Delta}B) resulted in >50% suppression of v-Src-inducible colony formation. However, STAT5A in combination with v-Src did not significantly change the transforming potential compared with v-Src alone (Fig. 2)Citation .



View larger version (87K):
[in this window]
[in a new window]
 
Fig. 2. STAT5B increases the transforming potential of v-Src in soft agar colony-forming assay. Stably cotransfected NIH-3T3 cells (104 cells; see the Fig. 1Citation legend) were plated into 2 ml of 0.3% soft agar with 2 µg/ml puromycin and 800 µg/ml G418 in triplicate. Colonies were counted and photographed after 11days of incubation. Data are expressed as the means ± SD of triplicate assays.

 
STAT5B Minimally Promotes Cell Growth in the Absence of Serum.
In the presence of serum, cell proliferation assays did not reveal significant changes in growth between normal, v-Src-transformed NIH-3T3 cells and cells expressing the different STAT5 isoforms in addition to v-Src (data not shown). In the absence of serum, however, v-Src significantly increased cell proliferation compared with control cells (Fig. 3)Citation . STAT5B in combination with v-Src also resulted in increased cell growth, but these results were not significantly different as compared with v-Src-transformed cells alone. Interestingly, however, the COOH-terminal truncated form of STAT5B (STAT5{Delta}B), when expressed together with v-Src, decreased cell growth by 50% even when compared with cells transformed with the control vectors (Fig. 3)Citation .



View larger version (19K):
[in this window]
[in a new window]
 
Fig. 3. STAT5B minimally promotes cell growth in the absence of serum. Cell proliferation assays of stably transfected NIH-3T3 cells were performed using CellTiter 96 AQ (Promega). Cells (see the Fig. 1Citation legend) were plated in 98-well plates (2 x 103 cells/well) in triplicate for 12 h in complete medium and then seeded for 36 h without serum. The experiment was repeated twice. 1 is the relative value of the absorbance of the cells transfected alone with control vectors. Error bars, SD.

 
STAT5B Enhances Cell Survival.
In a recent report, Wong et al. (16) demonstrated that src kinases are essential for the control of cell survival. The combination of STAT5B and v-Src dramatically increased cell survival in serum-free media. After 3 days of serum withdrawal, a significantly greater number of viable cells was observed among cells cotransfected with v-Src and STAT5B than cells transfected with v-Src and empty pEFIRES-N vector (Fig. 4)Citation . After 1 month of serum withdrawal, many cells expressing both v-Src and STAT5B were still alive, whereas those expressing v-Src alone were dead. The truncated form of STAT5B had the opposite effect: after 3 days of serum withdrawal, all of the cells expressing v-Src and STAT5{Delta}B were nonviable (Fig. 4)Citation .



View larger version (135K):
[in this window]
[in a new window]
 
Fig. 4. The combination of v-Src and STAT5B significantly increases cell survival in serum-free media. Stably cotransfected cells (see the Fig. 1Citation legend) were photographed after 3 days of growth with complete media (+BCS) or after 3 days in serum-free media (-BCS) using phase-contrast microscopy.

 
STAT5B Increases Cell Cycle Progression through G1 in v-src-transformed Cells.
v-Src is capable of stimulating cells to progress out of G0 and is also required for cells to complete G1 in the absence of growth factors (38) . Flow cytometric analysis was therefore performed to measure cell cycle progression in these stably transfected NIH-3T3 cells. It was observed that quiescent serum-starved NIH-3T3 cells transformed with empty vectors (Fig. 5Citation A, NP) arrested in the G1 phase of the cell cycle. After 24 h of starvation, only 3.5–6.5% of the cells were seen in the S + G2 phases of the cell cycle (Fig. 5A)Citation . Transformation by v-Src increased cell cycle progression (Fig. 5A)Citation , and coexpression of STAT5B and v-Src significantly enhanced the number of cells in S + G2 (Fig. 5A)Citation . After 5 days of serum deprivation, expression of STAT5B resulted in a 3-fold greater number of cells in S + G2 compared with cells expressing v-Src alone (Fig. 5B)Citation .



View larger version (23K):
[in this window]
[in a new window]
 
Fig. 5. STAT5B increases cell cycle progression through G1 in v-Src-transformed cells. NIH-3T3 cells stably cotransfected with various combinations of different forms of STAT5 and v-Src (see the Fig. 1Citation legend) at 70–80% confluence were serum-starved for (A) 24 h or (B) 5 days. At the indicated times, cells were fixed with ethanol and stained with propidium iodide. The cell populations were analyzed for DNA content using a flow cytometer. The cell cycle distribution of the profiles was quantitated using the computer program for this flow cytometer and is shown in a bar diagram presenting the percentage of cells in S + G2 phases. The experiment was repeated twice, with each experiment performed in duplicate. Error bars, SD.

 
STAT5B Induces Increased Cell Motility in Response to v-src Activation.
Cell motility is a required step in the acquisition and maintenance of tumor cell invasion and metastasis. Therefore, we investigated cell motility of these stably transfected cell lines using a modified Boyden chamber assay (see "Materials and Methods"). As expected, v-Src-transformed cells exhibited an increased motility compared with control cells (16) . Furthermore, STAT5B expression increased the cell motility of v-Src-transformed cells by approximately 3-fold (Fig. 6)Citation . Interestingly, the COOH-terminal truncated form of STAT5B (STAT5{Delta}B) did not exert any detectable effect on v-Src-transformed cells in this experiment.



View larger version (20K):
[in this window]
[in a new window]
 
Fig. 6. STAT5B induces cell motility in response to v-Src activation. Cell migration assays in which cells migrate through a gelatin-coated 10-µm-pore size filter modified Boyden chamber were performed as described in "Materials and Methods." Cell suspensions (5 x 106 cells/500 µl) were added to the top compartment. DMEM/10% BCS was added to the lower compartment. After 12 h, the number of cells that had migrated to the lower compartment was determined.

 
Discussion

The tumorigenic phenotype is characterized by the ability of cells to continuously proliferate in the absence of constant stimulation by growth factors. Tumor progression can be viewed as progression of tumorigenic cells toward an autonomous state, where they may no longer be dependent on paracrine interactions. It is not always apparent whether a specific gene is important in control of malignancy or is involved only in tumor initiation (reviewed in Ref. 39 ).

Recent studies suggest that activated STATs participate in oncogenesis (40) . Transformation by tyrosine kinase fusion genes associated with human leukemia has been persistently linked to activation of STAT5. For example, Bcr/Abl expression leads to STAT1 and STAT5 activation (26 , 30 , 41 , 42) . STAT5 is also activated by the Tel/platelet-derived growth factor ß receptor (PDGFßR), Tel/Abl, and Huntingtin Interacting Protein I/PDGFßR oncogenic fusion proteins (43 , 44) .

Although STAT5A and STAT5B share 93% identity at the amino acid level, in previous studies we observed that only STAT5B was able to translocate to the nucleus in response to Src and Abl kinase activation (33) . Studies of STAT5A and STAT5B knockout mice have also revealed significantly different phenotypes. STAT5A knockout mice showed impaired mammary gland development and lactation and a partial defect in T-cell growth. In contrast, STAT5B knockout mice are characterized by impaired sexual dimorphism and defects in T-cell growth and in natural killer cell development (45, 46, 47, 48) . However, there are differences in the phenotypes of mice with STAT5A or STAT5B mutations reported by different groups of investigators (49) that may be due to differences in the strain backgrounds used or the exact mutation constructed.

The experiments described above demonstrate that activation of STAT5B accelerates focus formation of v-Src-transformed cells. This acceleration may reflect the participation of STAT5B in tumor progression. The assay measuring anchorage-independent growth of cells revealed that STAT5B increases the transforming potential of v-Src, demonstrating a possible role of STAT5B in enhancement of tumorigenesis. Although endogenous STAT5B or STAT5A proteins were not readily detectable in NIH-3T3 cells, the overexpression of the dominant negative truncated form of STAT5B (STAT5{Delta}B) suppressed v-Src-inducible colony formation by more than 50%. We reported previously (33) that whereas constitutively active c-Src bound to STAT5, it did not directly phosphorylate STAT5. Thus, the inhibition of the transforming potential of v-Src by STAT5{Delta}B might be due to a competitive inhibition of Src action on other potential substrates. STAT5B in combination with v-Src induced cell growth, but not to an extent sufficient to explain the observed acceleration of focus formation. This presumably also reflects the additional effects of STAT5B and v-Src on cell survival and cell motility and possibly reflects effects on cell-cell interactions and the actin cytoskeleton.

A number of different studies have also demonstrated the direct participation and requirement of STAT3 in transformation in response to Src kinase activation in NIH-3T3 cells (19 , 28 , 29) . Therefore, there is a possibility that STAT5B and STAT3 may cooperate in the process of transformation. Thus, the functional importance of STAT3/STAT5 heterodimers in Src transformation needs to be investigated further.

Src kinase is known to influence cell survival (16) . In this study, we observed that STAT5B dramatically increased the survival of v-Src-transformed cells grown in serum-free media, whereas STAT5{Delta}B exerted the opposite effect. This property of STAT5B suggests that it may be an important player in the process of tumor progression in certain cell types. Studies using STAT5A knockout mice have also suggested a role for STAT5A as a survival factor during mammary gland development and tumorigenesis (50) .

v-Src is capable of stimulating quiescent cells out of G0 and progression through the G1 phase of the cell cycle (38) . Our results demonstrate that STAT5B significantly enhances this stimulation, which is detectable as early as 24 h after serum withdrawal. After 5 days of serum starvation, the percentage of cells in S + G2 in v-src-transformed cells decreased by 3-fold, whereas it did not change significantly in cells expressing STAT5B and v-src.

The distinction between oncogenesis and tumor progression is critical when one is determining whether a gene is important in controlling steps associated with malignancy or is simply involved in tumor formation (39 , 51) . One of incontrovertible hallmarks of malignancy is the ability to invade through the basement membrane and/or to metastasize. Motility is a required step in the acquisition and maintenance of tumor cell invasion and metastasis. Accordingly, approximately a 3-fold increase in cell motility was observed as a consequence of the expression of STAT5B in v-Src-transformed cells.

In some cases, STAT5 activation is both necessary and sufficient for disease pathology. For example, activation by Tel/JAK2 of STAT5 target genes can significantly affect cell proliferation. However, in other situations (Bcr/Abl or v-Abl), STAT5 may not play a critical role, although its activation is a hallmark of these leukemias (52) . In this situation, STAT5 may potentiate the malignant phenotype but is not required for transformation. In agreement with these in vivo observations, the present experiments also provide evidence that STAT5B can serve to accelerate and enhance tumor formation but is not necessarily required for the initiation of transformation. STAT5B has the ability to potentiate tumor progression in certain cell types and may therefore be required for malignant progression. In addition, these studies suggested that participation of STAT5B in these processes is due to increased cell cycle progression. Recent in vivo studies have indicated that T cells from STAT5 knockout mice display impaired proliferation and failed to undergo cell cycle progression or to express some of the genes controlling cell cycle progression (52 , 53) .

Based on previous observations (33) and the present results, we hypothesize that inappropriate regulation of STAT5 may play an important role in the etiologies of certain cancers. If this occurs by aberrant regulation of JAK kinase activity, both STAT5A and STAT5B may be involved in signal transduction and possibly in potentiation of cell transformation. On the other hand, if the cancer arises due to the inappropriate activation of Src/Abl kinases, STAT5B may be primarily involved in potentiating transformation. STAT5B may not be required for the initiation of transformation but instead may help facilitate malignant progression.

Materials and Methods

Plasmids.
STAT5B, STAT5{Delta}B, and STAT5A were cloned into the bicistronic vector pEFIRES-N (34) . v-Src cDNA was kindly provided by Drs. Hiromitsu Hanafusa and D. Besser (The Rockefeller University, New York, NY) and cloned into pEFIRES-P vector (34) . Bicistronic vectors were kindly provided by Dr. Steven Hobbs (Cancer Research Campaign Center for Cancer Therapeutics, Institute of Cancer Research, London, United Kingdom).

Tissue Culture.
NIH-3T3 cells were grown in DMEM (JRH Biosciences) supplemented with 10% BCS. LipofectAMINE Plus reagent (Life Technologies, Inc.) was used for all transfections. Transformants were selected with 2 ng/ml puromycin (Sigma) and 800 ng/ml G418 sulfate (Geneticin; Life Technologies, Inc.).

Focus Formation Assay.
Stably cotransfected NIH-3T3 cells (105 cells/35-mm-diameter dish) were plated and seeded for 40 h and for 3 days in medium supplied with puromycin and G418 (see above). Cells were photographed using phase-contrast microscopy.

Soft Agar Colony Formation Assay.
The soft agar assay was performed mainly as described previously (37) . Stably cotransfected NIH-3T3 cells (104 cells) were plated into 2 ml of soft agar (BiTek; Difco) containing DMEM, 10% BCS, 2 µg/ml puromycin, and 800 µg/ml G418 on top of 0.6% agar containing DMEM, 10% BCS, 2 µg/ml puromycin, and 800 µg/ml G418. These assays were carried out in parallel with three replicates. Colonies were counted and photographed after 11 days of incubation.

Cell Proliferation Assay.
Cell proliferation assays of stably transfected NIH-3T3 cells were performed using the calorimetric MTS assay CellTiter 96 AQ (Promega, Madison, WI). Cells were plated in 98-well plates (2 x 103 cells/well). Cells were analyzed after 12 h of growth in complete media and 36 h in serum-free media according to the manufacturer’s protocol.

Cell Cycle Analysis.
Cell cycle distribution experiments were performed with an EPICS XL flow cytometer (Beckman Coulter). A total of 3–5 x 105 cells were pelleted by centrifugation and resuspended in 0.5 ml of PBS. During vortexing, 5 ml of ice-cold ethanol were added. The cell suspension was incubated overnight at 4°C. The fixed cells were pelleted by centrifugation and resuspended in 0.75 ml of PBS. RNase A (Boehringer Mannheim) was added to a final concentration of 0.1 mg/ml, and cells were incubated at 37°C for 30 min. After the addition of propidium iodide (Boehringer Mannheim) to a final concentration of 0.05 mg/ml, the DNA content of cells was analyzed by flow cytometry (fluorescence-activated cell sorting). The distribution of cells in different phases of the cell cycle was quantitated with the computer program for this flow cytometer (System II version 3.0) and is shown in a bar diagram (see Fig. 5Citation ) presenting the percentage of cells in S + G2 phases. The experiment was repeated twice, with each run performed in duplicate.

Cell Migration Assay.
Cell migration was determined using a modified Boyden chamber containing a polycarbonate membrane (6.5-mm diameter; 10-um pores; Transwell; Costar, Cambridge, MA; Ref. 54 ). The membrane was coated with gelatin. Cell suspensions (5 x 105 cells/500 µl DMEM) were added to the top compartment. The lower compartment was filled with DMEM containing 10% BCS. The chamber was then incubated at 37°C in a 5% CO2 atmosphere. After 12 h, the number of cells that had migrated to the lower compartment was counted under a phase-contrast microscope after trypsinization. The experiment was performed twice, and each run was performed in triplicate.

Footnotes

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

1 To whom requests for reprints should be addressed, at Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3498. E-mail: jrosen{at}bcm.tmc.edu Back

2 The abbreviations used are: STAT, signal transducers and activators of transcription; JAK, Janus-activated kinase; BCS, bovine calf serum. Back

Received for publication 7/19/00. Revision received 11/ 3/00. Accepted for publication 11/ 6/00.

References

  1. Ihle J. N., Kerr I. M. Jaks and Stats in signaling by the cytokine receptor superfamily. Trends Genet., 11: 69-74, 1995.[Medline]
  2. Pendergast A. Nuclear tyrosine kinases: from Abl to WEE1. Curr. Opin. Cell Biol., 8: 174-181, 1996.[Medline]
  3. Erpel T., Courtneidge S. Src family protein tyrosine kinases and cellular signal transduction pathways. Curr. Opin. Cell Biol., 7: 176-182, 1995.[Medline]
  4. Mao W., Irby R., Coppola D., Fu L., Wloch M., Turner J., Yu H., Garcia R., Jove R., Yeatman T. Activation of c-Src by receptor tyrosine kinases in human colon cancer cells with high metastatic potential. Oncogene, 15: 3083-3090, 1997.[Medline]
  5. Rosen N., Bolen J. B., Schwartz A. M., Cohen P., DeSeau V., Israel M. A. Analysis of pp60 c-src protein kinase activity in human tumor cell lines and tissues. J. Biol. Chem., 261: 13754-13759, 1986.[Abstract/Free Full Text]
  6. Ottenhoff-Kalff A., Rijksen G., van Beurden E., Hennipman A., Michels A., Staal G. Characterization of protein tyrosine kinases from human breast cancer: involvement of the c-src oncogene product. Cancer Res., 52: 4773-4778, 1992.[Abstract/Free Full Text]
  7. Talamonti M., Roh M., Curley S., Gallick G. Increase in activity and level of pp60c-src in progressive stages of human colorectal cancer. J. Clin. Invest., 91: 53-60, 1993.
  8. Roche S., Koegl M., Barone M. V., Roussel M. F., Courtneidge S. A. DNA synthesis induced by some but not all growth factors requires src family protein tyrosine kinases. Mol. Cell. Biol., 15: 1102-1109, 1995.[Abstract/Free Full Text]
  9. Wilson L., Luttrell D., Parsons J., Parsons S. pp60c-src tyrosine kinase, myristylation, and modulatory domains are required for enhanced mitogenic responsiveness to epidermal growth factor seen in cells overexpressing c-src. Mol. Cell. Biol., 9: 1536-1544, 1989.[Abstract/Free Full Text]
  10. Kypta R., Goldberg Y., Ulug E., Courtneidge S. Association between the PDGF receptor and members of the src family of tyrosine kinases. Cell, 62: 481-492, 1990.[Medline]
  11. Twamley G., Kypta R., Hall B., Courtneidge S. Association of Fyn with the activated platelet-derived growth factor receptor: requirements for binding and phosphorylation. Oncogene, 7: 1893-1901, 1992.[Medline]
  12. Landgren E., Blume-Jensen P., Courtneidge S., Claesson-Welsh L. Fibroblast growth factor receptor-1 regulation of Src family kinases. Oncogene, 10: 2027-2035, 1995.[Medline]
  13. Zhan X., Plourde C., Hu X., Friesel R., Maciag T. Association of fibroblast growth factor receptor-1 with c-Src correlates with association between c-Src and cortactin. J. Biol. Chem., 269: 20221-20224, 1994.[Abstract/Free Full Text]
  14. Courtneidge S., Dhand R., Pilat D., Twamley G., Waterfield M., Roussel M. Activation of Src family kinases by colony stimulating factor-1, and their association with its receptor. EMBO J., 12: 943-950, 1993.[Medline]
  15. Thomas S. M., Brugge J. S. Cellular functions regulated by Src family kinases. Annu. Rev. Cell Dev. Biol., 13: 513-609, 1997.[Medline]
  16. Wong B. R., Besser D., Kim N., Arron J. R., Vologodskaia M., Hanafusa H., Choi Y. TRANCE, a TNF family member, activates Akt/PKB through a signaling complex involving TRAF6 and c-Src. Mol. Cell, 4: 1041-1049, 1999.[Medline]
  17. Eliceiri B. P., Paul R., Schwartzberg P. L., Hood J. D., Leng J., Cheresh D. A. Selective requirement for Src kinases during VEGF-induced angiogenesis and vascular permeability. Mol. Cell, 4: 915-924, 1999.[Medline]
  18. Darnell J. E., Jr. STATs and gene regulation. Science (Washington DC), 277: 1630-1635, 1997.[Abstract/Free Full Text]
  19. Turkson J., Bowman T., Garcia R., Caldenhoven E., De Groot R., Jove R. Stat3 activation by Src induces specific gene regulation and is required for cell transformation. Mol. Cell. Biol., 18: 2545-2552, 1998.[Abstract/Free Full Text]
  20. Garcia R., Yu C., Hudnall A., Catlett R., Nelson K., Smithgall T., Fujita D., Ethier S., Jove R. Constitutive activation of Stat3 in fibroblasts transformed by diverse oncoproteins and in breast carcinoma cells. Cell Growth Differ., 8: 1267-1276, 1997.[Abstract]
  21. Cao X., Tay A., Guy G., Tan Y. Activation and association of Stat3 with Src in v-Src-transformed cell lines. Mol. Cell. Biol., 16: 1595-1603, 1996.[Abstract/Free Full Text]
  22. Yu C-L., Meyer D. J., Campbell G. S., Larner A. C., Carter-Su C., Schwartz J., Jove R. Enhanced DNA-binding activity of a Stat3-related protein in cells transformed by the src oncoprotein. Science (Washington DC), 269: 81-83, 1995.[Abstract/Free Full Text]
  23. Danial N., Pernis A., Rothman P. Jak-STAT signaling induced by the v-abl oncogene. Science (Washington DC), 269: 1875-1877, 1995.[Abstract/Free Full Text]
  24. Chin H., Arai A., Wakao H., Kamiyama R., Miyasaka N., Miura O. Lyn physically associates with the erythropoietin receptor and may play a role in activation of the stat5 pathway. Blood, 91: 3734-3745, 1998.[Abstract/Free Full Text]
  25. Lund T., Garcia R., Medveczky M., Jove R., Medveczky P. Activation of STAT transcription factors by herpesvirus Saimiri Tip-484 requires p56lck. J. Virol., 71: 6677-6682, 1997.[Abstract/Free Full Text]
  26. Carlesso N., Frank D., Griffin J. Tyrosyl phosphorylation and DNA binding activity of signal transducers and activators of transcription (STAT) proteins in hematopoietic cell lines transformed by Bcr/Abl. J. Exp. Med., 183: 811-820, 1996.[Abstract/Free Full Text]
  27. Nelson K., Rogers J., Bowman T., Jove R., Smithgall T. Activation of STAT3 by the c-Fes protein-tyrosine kinase. J. Biol. Chem., 273: 7072-7077, 1998.[Abstract/Free Full Text]
  28. Bromberg J., Horvath C., Besser D., Lathem W., Darnell J. J. Stat3 activation is required for cellular transformation by v-src. Mol. Cell. Biol., 18: 2553-2558, 1998.[Abstract/Free Full Text]
  29. Bromberg J. F., Wrzeszczynska M. H., Devgan G., Zhao Y., Pestell R. G., Albanese C., Darnell J. E., Jr. Stat3 as an oncogene. Cell, 98: 295-303, 1999.[Medline]
  30. Ilaria R., van Ettens R. P210 and P190BCR/ABL induce the tyrosine phosphorylation and DNA binding activity of multiple specific STAT family members. J. Biol. Chem., 271: 31704-31710, 1996.[Abstract/Free Full Text]
  31. Frank D., Varticovski L. BCR/Abl leades to the constitutive activation of Stat proteins and shares an epitope with typrosine phosphorylated Stats. Leukemia (Baltimore), 10: 1724-1730, 1996.[Medline]
  32. Fresno Vara J. A., Carretero M. V., Geronimo H., Ballmer-Hofer K., Martin-Perez J. Stimulation of c-Src by prolactin is independent of Jak2. Biochem. J., 345: 7-24, 2000.
  33. Kazansky A., Kabotyanski E., Wyszomierski S., Mancini M., Rosen J. Differential effects of prolactin and src/abl kinases on the nuclear translocation of STAT5B and STAT5A. J. Biol. Chem., 274: 22484-22492, 1999.[Abstract/Free Full Text]
  34. Hobbs S., Jitrapakdee S., Wallace J. C. Development of a bicistronic vector driven by the human polypeptide chain elongation factor 1{alpha} promoter for creation of stable mammalian cell lines that express very high levels of recombinant proteins. Biochem. Biophys. Res. Commun., 252: 368-372, 1998.[Medline]
  35. Ripperger J. A., Fritz S., Richter K., Hocke G. M., Lottspeich F., Fey G. H. Transcription factors Stat3 and Stat5b are present in rat liver nuclei late in an acute phase response and bind interleukin-6 response elements. J. Biol. Chem., 270: 29998-30006, 1995.[Abstract/Free Full Text]
  36. Jove R., Hanafusa T. Cell transformation by the viral src oncogene. Annu. Rev. Cell Biol., 3: 31-56, 1987.
  37. MacAuley A., Pawson T. Cooperative transforming activities of ras, myc, and src viral oncogenes in nonestablished rat adrenocortical cells. J. Virol., 62: 4712-4721, 1988.[Abstract/Free Full Text]
  38. Wyke A. W., Cushley W., Wyke J. A. Mitogenesis by v-Src: a need for active oncoprotein both in leaving G0 and in completing G1 phases of the cell cycle. Cell. Growth Differ., 4: 671-678, 1993.[Abstract]
  39. Welch D. R., Rinker-Schaeffer C. W. What defines a useful marker of metastasis in human cancer?. J. Natl. Cancer Inst., 91: 1351-1353, 1999.[Free Full Text]
  40. Bowman T., Garcia R., Jove R. STATs in oncogenesis. Oncogene, 19: 2474-2488, 2000.[Medline]
  41. Chai S. K., Nichols G. L., Rothman P. Constitutive activation of JAKs and STATs in BCR-Abl-expressing cell lines and peripheral blood cells derived from leukemic patients. J. Immunol., 159: 4720-4728, 1997.[Abstract]
  42. Shuai K., Halpern J., ten Hoeve J., Rao X., Sawyers C. L. Constitutive activation of STAT5 by the BCR-ABL oncogene in chronic myelogenous leukemia. Oncogene, 13: 247-254, 1996.[Medline]
  43. Okuda K., Golub T. R., Gilliland D. G., Griffin J. D. p210BCR/ABL, p190BCR/ABL, and TEL/ABL activate similar signal transduction pathways in hematopoietic cell lines. Oncogene, 13: 1147-1152, 1996.[Medline]
  44. Ross T. S., Gilliland D. G. Transforming properties of the Huntingtin interacting protein 1/platelet-derived growth factor ß receptor fusion protein. J. Biol. Chem., 274: 22328-22336, 1999.[Abstract/Free Full Text]
  45. Teglund S., McKay C., Schuetz E., van Deursen J. M., Stravopodis D., Wang D., Brown M., Bodner S., Grosveld G., Ihle J. N. Stat5a and Stat5b proteins have essential and nonessential, or redundant, roles in cytokine responses. Cell, 93: 841-850, 1998.[Medline]
  46. Socolovsky M., Fallon A. E., Wang S., Brugnara C., Lodish H. F. Fetal anemia and apoptosis of red cell progenitors in Stat5a-/-5b-/- mice: a direct role for Stat5 in Bcl-XL induction. Cell, 98: 181-191, 1999.[Medline]
  47. Nakajima H., Liu X. W., Wynshaw-Boris A., Rosenthal L. A., Imada K., Finbloom D. S., Hennighausen L., Leonard W. J. An indirect effect of Stat5a in IL-2-induced proliferation: a critical role for Stat5a in IL-2-mediated IL-2 receptor {alpha} chain induction. Immunity, 7: 691-701, 1997.[Medline]
  48. Imada K., Bloom E. T., Nakajima H., Horvath-Arcidiacono J. A., Udy G. B., Davey H. W., Leonard W. J. Stat5b is essential for natural killer cell-mediated proliferation and cytolytic activity. J. Exp. Med., 188: 2067-2074, 1998.[Abstract/Free Full Text]
  49. Takeda K., Akira S. STAT family of transcription factors in cytokine-mediated biological responses. Cytokine Growth Factor Rev., 11: 199-207, 2000.[Medline]
  50. Humphreys R. C., Hennighausen L. Signal transducer and activator of transcription 5a influences mammary epithelial cell survival and tumorigenesis. Cell Growth Differ., 10: 685-694, 1999.[Abstract/Free Full Text]
  51. Fidler I. J., Radinsky R. Search for genes that suppress cancer metastasis. J. Natl. Cancer Inst. (Bethesda), 88: 1700-1703, 1996.[Free Full Text]
  52. Levy D., Gilliland D. Divergent roles of STAT1 and STAT5 in malignancy as revealed by gene disruptions in mice. Oncogene, 19: 2505-2510, 2000.[Medline]
  53. Moriggl R., Topham D. J., Teglund S., Sexl V., McKay C., Wang D., Hoffmeyer A., van Deursen J., Sangster M. Y., Bunting K. D., Grosveld G. C., Ihle J. N. Stat5 is required for IL-2-induced cell cycle progression of peripheral T cells. Immunity, 10: 249-259, 1999.[Medline]
  54. Cary L. A., Chang J. F., Guan J. L. Stimulation of cell migration by overexpression of focal adhesion kinase and its association with Src and Fyn. J. Cell Sci., 109: 1787-1794, 1996.[Abstract/Free Full Text]



This article has been cited by other articles:


Home page
Genes & CancerHome page
I. Paul, S. Bhattacharya, A. Chatterjee, and M. K. Ghosh
Current Understanding on EGFR and Wnt/{beta}-Catenin Signaling in Glioma and Their Possible Crosstalk
Genes & Cancer, November 1, 2013; 4(11-12): 427 - 446.
[Abstract] [Full Text] [PDF]


Home page
J Biol ChemHome page
I. Dhennin-Duthille, R. Nyga, S. Yahiaoui, V. Gouilleux-Gruart, A. Regnier, K. Lassoued, and F. Gouilleux
The Tumor Suppressor hTid1 Inhibits STAT5b Activity via Functional Interaction
J. Biol. Chem., February 18, 2011; 286(7): 5034 - 5042.
[Abstract] [Full Text] [PDF]


Home page
Clin. Cancer Res.Home page
P. Koppikar, V. W. Y. Lui, D. Man, S. Xi, R. L. Chai, E. Nelson, A. B.J. Tobey, and J. R. Grandis
Constitutive Activation of Signal Transducer and Activator of Transcription 5 Contributes to Tumor Growth, Epithelial-Mesenchymal Transition, and Resistance to Epidermal Growth Factor Receptor Targeting
Clin. Cancer Res., December 1, 2008; 14(23): 7682 - 7690.
[Abstract] [Full Text] [PDF]


Home page
Nucleic Acids ResHome page
B. Basham, M. Sathe, J. Grein, T. McClanahan, A. D'Andrea, E. Lees, and A. Rascle
In vivo identification of novel STAT5 target genes
Nucleic Acids Res., June 1, 2008; 36(11): 3802 - 3818.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
T. K. Lee, K. Man, R. T.P. Poon, C. M. Lo, A. P. Yuen, I. O. Ng, K. T. Ng, W. Leonard, and S. T. Fan
Signal Transducers and Activators of Transcription 5b Activation Enhances Hepatocellular Carcinoma Aggressiveness through Induction of Epithelial-Mesenchymal Transition.
Cancer Res., October 15, 2006; 66(20): 9948 - 9956.
[Abstract] [Full Text] [PDF]


Home page
ScienceHome page
Y. Qiao, H. Molina, A. Pandey, J. Zhang, and P. A. Cole
Chemical rescue of a mutant enzyme in living cells.
Science, March 3, 2006; 311(5765): 1293 - 1297.
[Abstract] [Full Text] [PDF]


Home page
Mol Cancer ResHome page
M. Shi, J. C. Cooper, and C.-L. Yu
A Constitutively Active Lck Kinase Promotes Cell Proliferation and Resistance to Apoptosis through Signal Transducer and Activator of Transcription 5b Activation
Mol. Cancer Res., January 1, 2006; 4(1): 39 - 45.
[Abstract] [Full Text] [PDF]


Home page
J. Cell Sci.Home page
M. C. Frame
Newest findings on the oldest oncogene; how activated src does it
J. Cell Sci., March 1, 2004; 117(7): 989 - 998.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
A. V. Kazansky, D. M. Spencer, and N. M. Greenberg
Activation of Signal Transducer and Activator of Transcription 5 is Required for Progression of Autochthonous Prostate Cancer: Evidence from the Transgenic Adenocarcinoma of the Mouse Prostate System
Cancer Res., December 15, 2003; 63(24): 8757 - 8762.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
S. Xi, Q. Zhang, W. E. Gooding, T. E. Smithgall, and J. R. Grandis
Constitutive Activation of Stat5b Contributes to Carcinogenesis in Vivo
Cancer Res., October 15, 2003; 63(20): 6763 - 6771.
[Abstract] [Full Text] [PDF]


Home page
J Biol ChemHome page
M. T. Kloth, K. K. Laughlin, J. S. Biscardi, J. L. Boerner, S. J. Parsons, and C. M. Silva
STAT5b, a Mediator of Synergism between c-Src and the Epidermal Growth Factor Receptor
J. Biol. Chem., January 10, 2003; 278(3): 1671 - 1679.
[Abstract] [Full Text] [PDF]


Home page
BloodHome page
M. Buitenhuis, B. Baltus, J.-W. J. Lammers, P. J. Coffer, and L. Koenderman
Signal transducer and activator of transcription 5a (STAT5a) is required for eosinophil differentiation of human cord blood-derived CD34+ cells
Blood, January 1, 2003; 101(1): 134 - 142.
[Abstract] [Full Text] [PDF]


This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kazansky, A. V.
Right arrow Articles by Rosen, J. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kazansky, A. V.
Right arrow Articles by Rosen, J. M.


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cell Growth & Differentiation