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rIFN-gamma-mediated growth suppression of platinum-sensitive and -resistant ovarian tumor cell lines not dependent upon arginase inhibition.

Melichar B, Hu W, Patenia R, Melicharová K, Gallardo ST, Freedman R - J Transl Med (2003)

Bottom Line: However, supplementation of the medium with polyamine pathway products did not interfere with the growth-inhibitory effects of rIFN-gamma EOC cells.CONCLUSIONS: Increased arginase activity, specifically identified with arginase II, is present in most of the tested EOC cell lines. rIFN-gamma inhibits or stimulates arginase activity in certain EOC cell lines, though the decrease in arginase activity does not appear to be associated with the in vitro antiproliferative activity of rIFN-gamma.Since cells within the stroma of EOC tissues could also contribute to arginine metabolism following treatment with rIFN-gamma or rIFN-gamma-inducers, it would be helpful to examine these effects in vivo.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Gynecologic Oncology, The University of Texas, M,D, Anderson Cancer Center, Houston, Texas, U,S,A. rfreedma@mdanderson.org

ABSTRACT
BACKGROUND: Arginine metabolism in tumor cell lines can be influenced by various cytokines, including recombinant human interferon-gamma (rIFN-gamma), a cytokine that shows promising clinical activity in epithelial ovarian cancer (EOC). METHODS: We examined EOC cell lines for the expression of arginase in an enzymatic assay and for transcripts of arginase I and II, inducible nitric oxide synthase (iNOS), and indoleamine 2,3-dioxygenase (IDO) by reverse transcription-polymerase chain reaction. The effects of rIFN-gamma on arginase activity and on tumor cell growth inhibition were determined by measuring [3H]thymidine uptake. RESULTS: Elevated arginase activity was detected in 5 of 8 tumor cell lines, and analysis at the transcriptional level showed that arginase II was involved but arginase I was not. rIFN-gamma reduced arginase activity in 3 EOC cell lines but increased activity in the 2008 cell line and its platinum-resistant subline, 2008.C13. iNOS transcripts were not detected in rIFN-gamma-treated or untreated cell lines. In contrast, IDO activity was induced or increased by rIFN-gamma. Suppression of arginase activity by rIFN-gamma in certain cell lines suggested that such inhibition might contribute to its antiproliferative effects. However, supplementation of the medium with polyamine pathway products did not interfere with the growth-inhibitory effects of rIFN-gamma EOC cells. CONCLUSIONS: Increased arginase activity, specifically identified with arginase II, is present in most of the tested EOC cell lines. rIFN-gamma inhibits or stimulates arginase activity in certain EOC cell lines, though the decrease in arginase activity does not appear to be associated with the in vitro antiproliferative activity of rIFN-gamma. Since cells within the stroma of EOC tissues could also contribute to arginine metabolism following treatment with rIFN-gamma or rIFN-gamma-inducers, it would be helpful to examine these effects in vivo.

No MeSH data available.


Related in: MedlinePlus

Expression of arginase II (A) and IDO (B) in EOC cell lines. The cells were treated with rIFN-γ or left untreated. RNA was extracted and RT-PCR performed as described in Materials and Methods. Shown are the results obtained for HEY cells treated with rIFN-γ (lane 1), control untreated HEY cells (lane 2), OVCAR3 cells treated with rIFN-γ (lane 3), control OVCAR3 cells (lane 4), CAOV3 cells treated with rIFN-γ (lane 5), control CAOV3 cells (lane 6), SKOV3 cells treated with IFN-γ (lane 7), control SKOV3 cells (lane 8), 2008.13 treated with rIFN-γ (lane 9), control 2008.C13 cells (lane 10), 2008 cells treated with rIFN-γ (lane 11), control 2008 cells (lane 12). M: molecular weight marker.
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Figure 2: Expression of arginase II (A) and IDO (B) in EOC cell lines. The cells were treated with rIFN-γ or left untreated. RNA was extracted and RT-PCR performed as described in Materials and Methods. Shown are the results obtained for HEY cells treated with rIFN-γ (lane 1), control untreated HEY cells (lane 2), OVCAR3 cells treated with rIFN-γ (lane 3), control OVCAR3 cells (lane 4), CAOV3 cells treated with rIFN-γ (lane 5), control CAOV3 cells (lane 6), SKOV3 cells treated with IFN-γ (lane 7), control SKOV3 cells (lane 8), 2008.13 treated with rIFN-γ (lane 9), control 2008.C13 cells (lane 10), 2008 cells treated with rIFN-γ (lane 11), control 2008 cells (lane 12). M: molecular weight marker.

Mentions: Arginase activity varied among EOC cell lines. There was no apparent relationship between the expression of arginase activity in EOC tumor cell lines and the expression of the Ki-67 antigen. Arginase activity was lower (less than 0.2 μg urea per mg protein) in 3 EOC cell lines – HEY, SKOV3, and OVCAR3 and higher in 2774, CAOV3, NMP-1, and 2008, and in its platinum-resistant subline, 2008.C13 (Table 1). Arginase activity was also higher in the NMP-1 cell line, the cisplatin-resistant subline of OVCAR3. Arginase activity decreased markedly after treatment of 2774, NMP-1, and CAOV3 cells with rIFN-γ. In contrast, rIFN-γ treatment leads to an increase of arginase activity in 2008 and its cisplatin-resistant subline 2008.C13. iNOS expression was examined because NG-hydroxy-L-arginine and NO produced by the activity of this enzyme are known inhibitors of arginase activity. However, the addition of NMMA, an iNOS inhibitor did not abolish rIFN-γ-induced changes in arginase activity (Table 2), which is consistent with the RT-PCR data showing an absence of iNOS expression. Analysis of mRNA transcripts from all 6 EOC cell lines shows that arginase II was the enzyme responsible for the arginase activity (Fig. 2A). Treatment of the cell cultures with rIFN-γ did not increase arginase II transcript expression in any of the 6 cell lines tested. IDO, which is constitutively expressed in the EOC cell lines (Figs. 2A and 2B), was increased by more than two-fold in 5 of the 6 ovarian cancer cell lines treated with IFN-γ (Fig. 2B). In contrast to arginase II and IDO, arginase I and iNOS were not detected in any of these cell lines when cultured in medium alone or with rIFN-γ (data not shown).


rIFN-gamma-mediated growth suppression of platinum-sensitive and -resistant ovarian tumor cell lines not dependent upon arginase inhibition.

Melichar B, Hu W, Patenia R, Melicharová K, Gallardo ST, Freedman R - J Transl Med (2003)

Expression of arginase II (A) and IDO (B) in EOC cell lines. The cells were treated with rIFN-γ or left untreated. RNA was extracted and RT-PCR performed as described in Materials and Methods. Shown are the results obtained for HEY cells treated with rIFN-γ (lane 1), control untreated HEY cells (lane 2), OVCAR3 cells treated with rIFN-γ (lane 3), control OVCAR3 cells (lane 4), CAOV3 cells treated with rIFN-γ (lane 5), control CAOV3 cells (lane 6), SKOV3 cells treated with IFN-γ (lane 7), control SKOV3 cells (lane 8), 2008.13 treated with rIFN-γ (lane 9), control 2008.C13 cells (lane 10), 2008 cells treated with rIFN-γ (lane 11), control 2008 cells (lane 12). M: molecular weight marker.
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Related In: Results  -  Collection

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Figure 2: Expression of arginase II (A) and IDO (B) in EOC cell lines. The cells were treated with rIFN-γ or left untreated. RNA was extracted and RT-PCR performed as described in Materials and Methods. Shown are the results obtained for HEY cells treated with rIFN-γ (lane 1), control untreated HEY cells (lane 2), OVCAR3 cells treated with rIFN-γ (lane 3), control OVCAR3 cells (lane 4), CAOV3 cells treated with rIFN-γ (lane 5), control CAOV3 cells (lane 6), SKOV3 cells treated with IFN-γ (lane 7), control SKOV3 cells (lane 8), 2008.13 treated with rIFN-γ (lane 9), control 2008.C13 cells (lane 10), 2008 cells treated with rIFN-γ (lane 11), control 2008 cells (lane 12). M: molecular weight marker.
Mentions: Arginase activity varied among EOC cell lines. There was no apparent relationship between the expression of arginase activity in EOC tumor cell lines and the expression of the Ki-67 antigen. Arginase activity was lower (less than 0.2 μg urea per mg protein) in 3 EOC cell lines – HEY, SKOV3, and OVCAR3 and higher in 2774, CAOV3, NMP-1, and 2008, and in its platinum-resistant subline, 2008.C13 (Table 1). Arginase activity was also higher in the NMP-1 cell line, the cisplatin-resistant subline of OVCAR3. Arginase activity decreased markedly after treatment of 2774, NMP-1, and CAOV3 cells with rIFN-γ. In contrast, rIFN-γ treatment leads to an increase of arginase activity in 2008 and its cisplatin-resistant subline 2008.C13. iNOS expression was examined because NG-hydroxy-L-arginine and NO produced by the activity of this enzyme are known inhibitors of arginase activity. However, the addition of NMMA, an iNOS inhibitor did not abolish rIFN-γ-induced changes in arginase activity (Table 2), which is consistent with the RT-PCR data showing an absence of iNOS expression. Analysis of mRNA transcripts from all 6 EOC cell lines shows that arginase II was the enzyme responsible for the arginase activity (Fig. 2A). Treatment of the cell cultures with rIFN-γ did not increase arginase II transcript expression in any of the 6 cell lines tested. IDO, which is constitutively expressed in the EOC cell lines (Figs. 2A and 2B), was increased by more than two-fold in 5 of the 6 ovarian cancer cell lines treated with IFN-γ (Fig. 2B). In contrast to arginase II and IDO, arginase I and iNOS were not detected in any of these cell lines when cultured in medium alone or with rIFN-γ (data not shown).

Bottom Line: However, supplementation of the medium with polyamine pathway products did not interfere with the growth-inhibitory effects of rIFN-gamma EOC cells.CONCLUSIONS: Increased arginase activity, specifically identified with arginase II, is present in most of the tested EOC cell lines. rIFN-gamma inhibits or stimulates arginase activity in certain EOC cell lines, though the decrease in arginase activity does not appear to be associated with the in vitro antiproliferative activity of rIFN-gamma.Since cells within the stroma of EOC tissues could also contribute to arginine metabolism following treatment with rIFN-gamma or rIFN-gamma-inducers, it would be helpful to examine these effects in vivo.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Gynecologic Oncology, The University of Texas, M,D, Anderson Cancer Center, Houston, Texas, U,S,A. rfreedma@mdanderson.org

ABSTRACT
BACKGROUND: Arginine metabolism in tumor cell lines can be influenced by various cytokines, including recombinant human interferon-gamma (rIFN-gamma), a cytokine that shows promising clinical activity in epithelial ovarian cancer (EOC). METHODS: We examined EOC cell lines for the expression of arginase in an enzymatic assay and for transcripts of arginase I and II, inducible nitric oxide synthase (iNOS), and indoleamine 2,3-dioxygenase (IDO) by reverse transcription-polymerase chain reaction. The effects of rIFN-gamma on arginase activity and on tumor cell growth inhibition were determined by measuring [3H]thymidine uptake. RESULTS: Elevated arginase activity was detected in 5 of 8 tumor cell lines, and analysis at the transcriptional level showed that arginase II was involved but arginase I was not. rIFN-gamma reduced arginase activity in 3 EOC cell lines but increased activity in the 2008 cell line and its platinum-resistant subline, 2008.C13. iNOS transcripts were not detected in rIFN-gamma-treated or untreated cell lines. In contrast, IDO activity was induced or increased by rIFN-gamma. Suppression of arginase activity by rIFN-gamma in certain cell lines suggested that such inhibition might contribute to its antiproliferative effects. However, supplementation of the medium with polyamine pathway products did not interfere with the growth-inhibitory effects of rIFN-gamma EOC cells. CONCLUSIONS: Increased arginase activity, specifically identified with arginase II, is present in most of the tested EOC cell lines. rIFN-gamma inhibits or stimulates arginase activity in certain EOC cell lines, though the decrease in arginase activity does not appear to be associated with the in vitro antiproliferative activity of rIFN-gamma. Since cells within the stroma of EOC tissues could also contribute to arginine metabolism following treatment with rIFN-gamma or rIFN-gamma-inducers, it would be helpful to examine these effects in vivo.

No MeSH data available.


Related in: MedlinePlus