scholarly journals Elevation of cell cycle control proteins during spontaneous immortalization of human keratinocytes.

1993 ◽  
Vol 4 (2) ◽  
pp. 185-194 ◽  
Author(s):  
R H Rice ◽  
K E Steinmann ◽  
L A deGraffenried ◽  
Q Qin ◽  
N Taylor ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Early Stage ◽  
Cell Cycle Control ◽  
Normal Karyotype ◽  
Microscopic Appearance ◽  
Colony Forming Efficiency ◽  
Forming Efficiency

A human line of spontaneously immortalized keratinocytes (SIK cells) has been derived from ostensibly normal epidermis and has proven useful in dissecting molecular changes associated with immortalization. The original cultures had a normal karyotype and a colony forming efficiency of approximately 3% through 10 passages. At passage 15, after which normal strains ordinarily senesce, these cells continued vigorous growth and gradually increased in colony forming efficiency, stabilizing at approximately 30% by passage 40. During the early stage of increasing colony forming efficiency, the cells acquired a single i(6p) chromosomal aberration and 5- to 10-fold increases in expression of the cell-cycle control proteins cyclin A, cyclin B, and p34cdc2. Additional chromosomal aberrations accumulated at later passages (i(8q) and +7), but the i(6p) and the increased expression of cell-cycle proteins were maintained, raising the possibility that these features were important for immortalization. Regulation of cell growth and differentiation in the cultures appeared minimally altered compared with normal keratinocytes as judged by their microscopic appearance and generation of abortive colonies, sensitivity to growth suppression by transforming growth factor-beta and tetradecanoylphorbol acetate, and dependence upon epidermal growth factor for progressive growth.

Early gene responses to transforming growth factor-beta in cells lacking growth-suppressive RB function

1991 ◽  
Vol 11 (10) ◽  
pp. 4952-4958
Author(s):  
A Zentella ◽  
F M Weis ◽  
D A Ralph ◽  
M Laiho ◽  
J Massagué
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Lung Epithelial Cells ◽  
Early Gene ◽  
Tgf Beta ◽  
Suppressive Function ◽  
Growth Factor Beta ◽  
Pai 1

The growth-suppressive function of the retinoblastoma susceptibility gene product, RB, has been implicated in the mediation of growth inhibition and negative regulation of certain proliferation related genes by transforming growth factor-beta 1 (TGF-beta 1). Early gene responses to TGF-beta 1 were examined in order to determine their dependence on the cell cycle and on the growth-suppressive function of RB. TGF-beta 1, which rapidly elevates the steady-state level of junB and PAI-1 mRNAs and decreases that of c-myc mRNA, induces these responses in S-phase populations of Mv1Lu lung epithelial cells containing RB in a phosphorylated state. Since in this state RB is presumed to lack growth-suppressive activity, the response to TGF-beta 1 was also examined in DU145 human prostate carcinoma cells whose mutant RB product lacks growth-suppressive function. In these cells, TGF-beta 1 also decreases c-myc expression at the transcription initiation level. These results suggests that the c-myc, junB, and PAI-1 responses to TGF-beta 1 are not restricted to the G1 phase of the cell cycle and that down-regulation of c-myc expression by TGF-beta 1 can occur through a mechanism independent from the growth-suppressive function of RB.

scholarly journals Early gene responses to transforming growth factor-beta in cells lacking growth-suppressive RB function.

1991 ◽  
Vol 11 (10) ◽  
pp. 4952-4958 ◽  
Author(s):  
A Zentella ◽  
F M Weis ◽  
D A Ralph ◽  
M Laiho ◽  
J Massagué
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Lung Epithelial Cells ◽  
Early Gene ◽  
Tgf Beta ◽  
Suppressive Function ◽  
Growth Factor Beta ◽  
Pai 1

The growth-suppressive function of the retinoblastoma susceptibility gene product, RB, has been implicated in the mediation of growth inhibition and negative regulation of certain proliferation related genes by transforming growth factor-beta 1 (TGF-beta 1). Early gene responses to TGF-beta 1 were examined in order to determine their dependence on the cell cycle and on the growth-suppressive function of RB. TGF-beta 1, which rapidly elevates the steady-state level of junB and PAI-1 mRNAs and decreases that of c-myc mRNA, induces these responses in S-phase populations of Mv1Lu lung epithelial cells containing RB in a phosphorylated state. Since in this state RB is presumed to lack growth-suppressive activity, the response to TGF-beta 1 was also examined in DU145 human prostate carcinoma cells whose mutant RB product lacks growth-suppressive function. In these cells, TGF-beta 1 also decreases c-myc expression at the transcription initiation level. These results suggests that the c-myc, junB, and PAI-1 responses to TGF-beta 1 are not restricted to the G1 phase of the cell cycle and that down-regulation of c-myc expression by TGF-beta 1 can occur through a mechanism independent from the growth-suppressive function of RB.

scholarly journals High expression of transforming growth factor-beta long cell cycle times and a unique clustering of S-phase cells in patients with acute promyelocytic leukemia [see comments]

Blood ◽  
1992 ◽  
Vol 79 (4) ◽  
pp. 1037-1048 ◽  
Author(s):  
A Raza ◽  
N Yousuf ◽  
A Abbas ◽  
A Umerani ◽  
A Mehdi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Bone Marrow ◽  
Growth Factor ◽  
Acute Promyelocytic Leukemia ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Promyelocytic Leukemia ◽  
S Phase ◽  
Tgf Beta ◽  
Growth Factor Beta

Expression of transforming growth factor-beta (TGF-beta), which inhibits the proliferation of hematopoietic progenitors, was investigated simultaneously with cell cycle characteristics in 63 bone marrow biopsies from 23 cases with acute promyelocytic leukemia (APL). Bromodeoxyuridine (BrdU) was administered to every patient (17 newly diagnosed) for determination of the labeling index (LI) and the durations of S-phase (Ts) and the cell cycle (Tc) of leukemic promyelocytes. APL cases had lower LI both in the bone marrow aspirate (6.1% v 11.4%, P = .008) and biopsy (21.1% v 28.0%, P = .001) and longer Tc (93.6 hours v 56.0 hours, P = .002) when compared with other French-American-British subtypes. TGF-beta expression (detected by a monoclonal anti-TGF-beta 2/beta 3 antibody) was dramatically high, especially in interstitial areas of the biopsies. S-phase cells were found as geographically restricted islands of proliferation (GRIPs) in 20 of 22 cases. Weekly biopsies showed an increment in TGF-beta on day 7 of therapy in 13 of 17 cases, while in vivo differentiation was noted in 9 of 15. We conclude that the presence of high TGF-beta expression may explain the biologic basis for the slowly cycling nature of leukemic promyelocytes in APL as well as the unique clustering of S- phase cells observed in GRIPs.

scholarly journals High expression of transforming growth factor-beta long cell cycle times and a unique clustering of S-phase cells in patients with acute promyelocytic leukemia [see comments]

Blood ◽  
1992 ◽  
Vol 79 (4) ◽  
pp. 1037-1048
Author(s):  
A Raza ◽  
N Yousuf ◽  
A Abbas ◽  
A Umerani ◽  
A Mehdi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Bone Marrow ◽  
Growth Factor ◽  
Acute Promyelocytic Leukemia ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Promyelocytic Leukemia ◽  
S Phase ◽  
Tgf Beta ◽  
Growth Factor Beta

Abstract Expression of transforming growth factor-beta (TGF-beta), which inhibits the proliferation of hematopoietic progenitors, was investigated simultaneously with cell cycle characteristics in 63 bone marrow biopsies from 23 cases with acute promyelocytic leukemia (APL). Bromodeoxyuridine (BrdU) was administered to every patient (17 newly diagnosed) for determination of the labeling index (LI) and the durations of S-phase (Ts) and the cell cycle (Tc) of leukemic promyelocytes. APL cases had lower LI both in the bone marrow aspirate (6.1% v 11.4%, P = .008) and biopsy (21.1% v 28.0%, P = .001) and longer Tc (93.6 hours v 56.0 hours, P = .002) when compared with other French-American-British subtypes. TGF-beta expression (detected by a monoclonal anti-TGF-beta 2/beta 3 antibody) was dramatically high, especially in interstitial areas of the biopsies. S-phase cells were found as geographically restricted islands of proliferation (GRIPs) in 20 of 22 cases. Weekly biopsies showed an increment in TGF-beta on day 7 of therapy in 13 of 17 cases, while in vivo differentiation was noted in 9 of 15. We conclude that the presence of high TGF-beta expression may explain the biologic basis for the slowly cycling nature of leukemic promyelocytes in APL as well as the unique clustering of S- phase cells observed in GRIPs.

scholarly journals Transforming growth factor beta inhibits the proliferation of the blast cells of acute myeloblastic leukemia

Blood ◽  
1988 ◽  
Vol 72 (1) ◽  
pp. 159-164 ◽  
Author(s):  
N Tessier ◽  
T Hoang
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Acute Myeloblastic Leukemia ◽  
Negative Regulator ◽  
Thymidine Uptake ◽  
Tgf Beta ◽  
Bladder Cell ◽  
Growth Factor Beta

Abstract The effect of transforming growth factor beta (TGF beta) on proliferation and differentiation of peripheral blast precursors in acute myeloblastic leukemia (AML) was investigated. TGF beta induced a dose-dependent inhibition of blast clonogenic cells in suspension and methylcellulose cultures in the presence of optimal concentrations of stimulators provided by conditioned media from the bladder cell line HTB9 (HTB9-CM) or the recombinant granulocyte-macrophage colony- stimulating factor (GM-CSF). On removal of TGF beta, blast clonogenic cell proliferation recovers to the same level as that observed in control cultures, indicating that the effect is reversible. There was no induction of cell differentiation, as indicated by morphological and functional studies (production of superoxyde anions). Cell cycle analysis by thymidine uptake and flow cytometry with a DNA binding dye indicated that TGF beta caused a delay in progression into S and G2/M phases of the cell cycle without affecting cell viability. Thus, TGF beta appears to have a cytostatic rather than cytolytic effect on blast precursors and might therefore play a role as a negative regulator in hematopoiesis.

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