Limits...
Potentiation of tumour apoptosis by human growth hormone via glutathione production and decreased NF-kappaB activity.

Cherbonnier C, Déas O, Carvalho G, Vassal G, Dürrbach A, Haeffner A, Charpentier B, Bénard J, Hirsch F - Br. J. Cancer (2003)

Bottom Line: However, despite similarities in the molecular events following Fas and TNF-alpha receptor engagement, we report that U937 cells, genetically engineered to constitutively produce hGH, were made more sensitive to TNF-alpha-induced apoptosis than parental cells.These findings were confirmed in vivo, in nude mice bearing U937 tumours coinjected with recombinant hGH and the NF-kappaB -inducing anticancer drug daunorubicin, to avoid the in vivo toxicity of TNF-alpha.This study therefore highlights one of the various properties of hGH that may have potential clinical implications.

View Article: PubMed Central - PubMed

Affiliation: INSERM U542/Paris XI University, Villejuif Cedex, France.

ABSTRACT
In addition to its primary role as growth factor, human growth hormone (hGH) can also participate in cell survival, as already documented by its protective effect on human monocytes or human promyelocytic leukaemia U937 cells exposed to a Fas-mediated cell death signal. However, despite similarities in the molecular events following Fas and TNF-alpha receptor engagement, we report that U937 cells, genetically engineered to constitutively produce hGH, were made more sensitive to TNF-alpha-induced apoptosis than parental cells. This was due to overproduction of the antioxidant glutathione, which decreased the nuclear factor (NF)-kappaB activity known to control the expression of survival genes. These findings were confirmed in vivo, in nude mice bearing U937 tumours coinjected with recombinant hGH and the NF-kappaB -inducing anticancer drug daunorubicin, to avoid the in vivo toxicity of TNF-alpha. This study therefore highlights one of the various properties of hGH that may have potential clinical implications.

Show MeSH

Related in: MedlinePlus

In vivo effect of hGH on daunorubicin treatment of engrafted tumours. Small tumour fragments obtained from U937-Neo tumours were transplanted subcutaneously in previously irradiated nude Swiss mice. Tumour-bearing mice either received i.p. injections of saline solution or subcutaneous injections of rhGH alone, or the highest subtoxic dose of daunorubicin (1.5 mg kg−1) with or without 5 mg kg−1 of rhGH. (A) Tissue sections from mice treated as above were submitted to TUNEL assay. Note the significant number of stained nuclei in tumours from rhGH- and daunorubicin-treated animals, indicating a high apoptosis rate in these animals. (B) The same tumours were assessed for NF-κB activation, as evidenced by the presence of the P65 subunit in the nuclei. Note the lower number of stained nuclei in tumours from mice treated with rhGH and daunorubicin, compared with daunorubicin-treated animals. (C) Tumour volumes were measured in each group of mice. The measurement was stopped when a mouse died or was killed because of a tumour volume exceeding 2000 mm3. Each line represents the mean±s.e.m. of the tumour volumes (*P<0.05 and **P<0.01, when comparing daunorubicin-treated mice to mice receiving daunorubicin and rhGH). (D) Kaplan-Meier curve comparing the different groups of mice with a tumour volume below 300 mm3. PBS-injected mice (….), daunomycine-injected mice (.-.-.-.-.) hGH-injected mice (- - -) and daunomycine+hGH-injected mice (---).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2376966&req=5

fig5: In vivo effect of hGH on daunorubicin treatment of engrafted tumours. Small tumour fragments obtained from U937-Neo tumours were transplanted subcutaneously in previously irradiated nude Swiss mice. Tumour-bearing mice either received i.p. injections of saline solution or subcutaneous injections of rhGH alone, or the highest subtoxic dose of daunorubicin (1.5 mg kg−1) with or without 5 mg kg−1 of rhGH. (A) Tissue sections from mice treated as above were submitted to TUNEL assay. Note the significant number of stained nuclei in tumours from rhGH- and daunorubicin-treated animals, indicating a high apoptosis rate in these animals. (B) The same tumours were assessed for NF-κB activation, as evidenced by the presence of the P65 subunit in the nuclei. Note the lower number of stained nuclei in tumours from mice treated with rhGH and daunorubicin, compared with daunorubicin-treated animals. (C) Tumour volumes were measured in each group of mice. The measurement was stopped when a mouse died or was killed because of a tumour volume exceeding 2000 mm3. Each line represents the mean±s.e.m. of the tumour volumes (*P<0.05 and **P<0.01, when comparing daunorubicin-treated mice to mice receiving daunorubicin and rhGH). (D) Kaplan-Meier curve comparing the different groups of mice with a tumour volume below 300 mm3. PBS-injected mice (….), daunomycine-injected mice (.-.-.-.-.) hGH-injected mice (- - -) and daunomycine+hGH-injected mice (---).

Mentions: To extend and validate this study in vivo, we decided to use the anticancer drug daunorubicin, as TNF-α, one of the main cytokines involved in sepsis (reviewed in Dinarello, 2000), may induce devastating effects after in vivo injection. Moreover, daunorubicin, widely used in clinical practice, is able to induce apoptosis and activate NF-κB in our cells (Cherbonnier et al, 2002). We therefore decided to study the effect of exogenous recombinant hGH on chemotherapy delivered to nude mice engrafted with parental unmodified U937 tumours. In order to verify the proposed mechanism explaining the effect of hGH, in vivo, we first examined in situ apoptosis in the various groups of mice defined in Materials and Methods. A TUNEL assay reported in Figure 5AFigure 5


Potentiation of tumour apoptosis by human growth hormone via glutathione production and decreased NF-kappaB activity.

Cherbonnier C, Déas O, Carvalho G, Vassal G, Dürrbach A, Haeffner A, Charpentier B, Bénard J, Hirsch F - Br. J. Cancer (2003)

In vivo effect of hGH on daunorubicin treatment of engrafted tumours. Small tumour fragments obtained from U937-Neo tumours were transplanted subcutaneously in previously irradiated nude Swiss mice. Tumour-bearing mice either received i.p. injections of saline solution or subcutaneous injections of rhGH alone, or the highest subtoxic dose of daunorubicin (1.5 mg kg−1) with or without 5 mg kg−1 of rhGH. (A) Tissue sections from mice treated as above were submitted to TUNEL assay. Note the significant number of stained nuclei in tumours from rhGH- and daunorubicin-treated animals, indicating a high apoptosis rate in these animals. (B) The same tumours were assessed for NF-κB activation, as evidenced by the presence of the P65 subunit in the nuclei. Note the lower number of stained nuclei in tumours from mice treated with rhGH and daunorubicin, compared with daunorubicin-treated animals. (C) Tumour volumes were measured in each group of mice. The measurement was stopped when a mouse died or was killed because of a tumour volume exceeding 2000 mm3. Each line represents the mean±s.e.m. of the tumour volumes (*P<0.05 and **P<0.01, when comparing daunorubicin-treated mice to mice receiving daunorubicin and rhGH). (D) Kaplan-Meier curve comparing the different groups of mice with a tumour volume below 300 mm3. PBS-injected mice (….), daunomycine-injected mice (.-.-.-.-.) hGH-injected mice (- - -) and daunomycine+hGH-injected mice (---).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2376966&req=5

fig5: In vivo effect of hGH on daunorubicin treatment of engrafted tumours. Small tumour fragments obtained from U937-Neo tumours were transplanted subcutaneously in previously irradiated nude Swiss mice. Tumour-bearing mice either received i.p. injections of saline solution or subcutaneous injections of rhGH alone, or the highest subtoxic dose of daunorubicin (1.5 mg kg−1) with or without 5 mg kg−1 of rhGH. (A) Tissue sections from mice treated as above were submitted to TUNEL assay. Note the significant number of stained nuclei in tumours from rhGH- and daunorubicin-treated animals, indicating a high apoptosis rate in these animals. (B) The same tumours were assessed for NF-κB activation, as evidenced by the presence of the P65 subunit in the nuclei. Note the lower number of stained nuclei in tumours from mice treated with rhGH and daunorubicin, compared with daunorubicin-treated animals. (C) Tumour volumes were measured in each group of mice. The measurement was stopped when a mouse died or was killed because of a tumour volume exceeding 2000 mm3. Each line represents the mean±s.e.m. of the tumour volumes (*P<0.05 and **P<0.01, when comparing daunorubicin-treated mice to mice receiving daunorubicin and rhGH). (D) Kaplan-Meier curve comparing the different groups of mice with a tumour volume below 300 mm3. PBS-injected mice (….), daunomycine-injected mice (.-.-.-.-.) hGH-injected mice (- - -) and daunomycine+hGH-injected mice (---).
Mentions: To extend and validate this study in vivo, we decided to use the anticancer drug daunorubicin, as TNF-α, one of the main cytokines involved in sepsis (reviewed in Dinarello, 2000), may induce devastating effects after in vivo injection. Moreover, daunorubicin, widely used in clinical practice, is able to induce apoptosis and activate NF-κB in our cells (Cherbonnier et al, 2002). We therefore decided to study the effect of exogenous recombinant hGH on chemotherapy delivered to nude mice engrafted with parental unmodified U937 tumours. In order to verify the proposed mechanism explaining the effect of hGH, in vivo, we first examined in situ apoptosis in the various groups of mice defined in Materials and Methods. A TUNEL assay reported in Figure 5AFigure 5

Bottom Line: However, despite similarities in the molecular events following Fas and TNF-alpha receptor engagement, we report that U937 cells, genetically engineered to constitutively produce hGH, were made more sensitive to TNF-alpha-induced apoptosis than parental cells.These findings were confirmed in vivo, in nude mice bearing U937 tumours coinjected with recombinant hGH and the NF-kappaB -inducing anticancer drug daunorubicin, to avoid the in vivo toxicity of TNF-alpha.This study therefore highlights one of the various properties of hGH that may have potential clinical implications.

View Article: PubMed Central - PubMed

Affiliation: INSERM U542/Paris XI University, Villejuif Cedex, France.

ABSTRACT
In addition to its primary role as growth factor, human growth hormone (hGH) can also participate in cell survival, as already documented by its protective effect on human monocytes or human promyelocytic leukaemia U937 cells exposed to a Fas-mediated cell death signal. However, despite similarities in the molecular events following Fas and TNF-alpha receptor engagement, we report that U937 cells, genetically engineered to constitutively produce hGH, were made more sensitive to TNF-alpha-induced apoptosis than parental cells. This was due to overproduction of the antioxidant glutathione, which decreased the nuclear factor (NF)-kappaB activity known to control the expression of survival genes. These findings were confirmed in vivo, in nude mice bearing U937 tumours coinjected with recombinant hGH and the NF-kappaB -inducing anticancer drug daunorubicin, to avoid the in vivo toxicity of TNF-alpha. This study therefore highlights one of the various properties of hGH that may have potential clinical implications.

Show MeSH
Related in: MedlinePlus