Limits...
CXXC5 (retinoid-inducible nuclear factor, RINF) is a potential therapeutic target in high-risk human acute myeloid leukemia.

Astori A, Fredly H, Aloysius TA, Bullinger L, Mansat-De Mas V, de la Grange P, Delhommeau F, Hagen KM, Récher C, Dusanter-Fourt I, Knappskog S, Lillehaug JR, Pendino F, Bruserud Ø - Oncotarget (2013)

Bottom Line: Furthermore, patients with low-risk cytogenetic abnormalities showed significantly lower levels compared to patients with high-risk abnormalities, and high RINF/CXXC5/ mRNA levels were associated with decreased overall survival for patients receiving intensive chemotherapy for newly diagnosed AML.This association with prognosis was seen both when investigating (i) an unselected patient population as well as for patients with (ii) normal cytogenetic and (iii) core-binding factor AML.The association with adverse prognosis together with the antiapoptotic effect of CXXC5/RINF suggests that targeting of CXXC5/RINF should be considered as a possible therapeutic strategy, especially in high-risk patients who show increased expression in AML cells compared with normal hematopoietic cells.

View Article: PubMed Central - PubMed

Affiliation: Inserm, U1016, Institut Cochin, F-75014, Paris, France.

ABSTRACT
The retinoid-responsive gene CXXC5 localizes to the 5q31.2 chromosomal region and encodes a retinoid-inducible nuclear factor (RINF) that seems important during normal myelopoiesis. We investigated CXXC5/RINF expression in primary human acute myeloid leukemia (AML) cells derived from 594 patients, and a wide variation in CXXC5/RINF mRNA levels was observed both in the immature leukemic myeloblasts and in immature acute lymphoblastic leukemia cells. Furthermore, patients with low-risk cytogenetic abnormalities showed significantly lower levels compared to patients with high-risk abnormalities, and high RINF/CXXC5/ mRNA levels were associated with decreased overall survival for patients receiving intensive chemotherapy for newly diagnosed AML. This association with prognosis was seen both when investigating (i) an unselected patient population as well as for patients with (ii) normal cytogenetic and (iii) core-binding factor AML. CXXC5/RINF knockdown in AML cell lines caused increased susceptibility to chemotherapy-induced apoptosis, and regulation of apoptosis also seemed to differ between primary human AML cells with high and low RINF expression. The association with adverse prognosis together with the antiapoptotic effect of CXXC5/RINF suggests that targeting of CXXC5/RINF should be considered as a possible therapeutic strategy, especially in high-risk patients who show increased expression in AML cells compared with normal hematopoietic cells.

Show MeSH

Related in: MedlinePlus

Stress-induced spontaneous in vitro apoptosis and lenalidomide-induced apoptosis in primary human AML cells, a comparison of patients with high and low RINF expressionPrimary human AML cells were derived from 9 patients with low and 9 patients with high RINF expression. (LEFT) Primary AML cells with low RINF expression were mainly necrotic after 18 hours in vitro culture in medium alone, and the leukemic cells from these patients showed a low level of viable as well as apoptotic (see the figure for lenalidomide) cells both in cultures prepared in medium alone and cultures with lenalidomide. In contrast, for patients with high RINF expression a higher viability was seen after culture in medium alone. However, as shown in the figure an increased fraction of apoptotic cells was then detected for high-RINF patients when cells were cultured in the presence of lenalidomide compared with the corresponding cultures for low-RINF patients (see the figure; Mann Whitney U-test, p=0.0004), and at the same time the viability further decreased and the fraction of necrotic cells increased for the high-RINF patients. Thus, maximal viability reduction is achieved by spontaneous apoptosis alone for low-RINF patients but for high-RINF patients combined spontaneous and lenalidomide-induced apoptosis is required to achieve the maximal reduction. (RIGHT) The calreticulin exposure of AML cells cultured with lenalidomide 0.1 μM was determined by flow cytometry [11]. A dye-exclusion Dead/Live Viability/Vitality analysis was used to separate the leukemic cells into these two major subsets, and calreticulin expression could thereby be analyzed separately for dead and viable cells. The figure compares calreticulin exposure after culture with lenalidomide (mean fluorescence intensity, MFI) for the dead cells derived from patients with high and low RINF expression (Mann Whitney U-test, p=0.035). The two patient groups showed no difference in calreticulin exposure when analyzing viable cells, and there was no difference after culture in medium alone either (data not shown)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3824541&req=5

Figure 4: Stress-induced spontaneous in vitro apoptosis and lenalidomide-induced apoptosis in primary human AML cells, a comparison of patients with high and low RINF expressionPrimary human AML cells were derived from 9 patients with low and 9 patients with high RINF expression. (LEFT) Primary AML cells with low RINF expression were mainly necrotic after 18 hours in vitro culture in medium alone, and the leukemic cells from these patients showed a low level of viable as well as apoptotic (see the figure for lenalidomide) cells both in cultures prepared in medium alone and cultures with lenalidomide. In contrast, for patients with high RINF expression a higher viability was seen after culture in medium alone. However, as shown in the figure an increased fraction of apoptotic cells was then detected for high-RINF patients when cells were cultured in the presence of lenalidomide compared with the corresponding cultures for low-RINF patients (see the figure; Mann Whitney U-test, p=0.0004), and at the same time the viability further decreased and the fraction of necrotic cells increased for the high-RINF patients. Thus, maximal viability reduction is achieved by spontaneous apoptosis alone for low-RINF patients but for high-RINF patients combined spontaneous and lenalidomide-induced apoptosis is required to achieve the maximal reduction. (RIGHT) The calreticulin exposure of AML cells cultured with lenalidomide 0.1 μM was determined by flow cytometry [11]. A dye-exclusion Dead/Live Viability/Vitality analysis was used to separate the leukemic cells into these two major subsets, and calreticulin expression could thereby be analyzed separately for dead and viable cells. The figure compares calreticulin exposure after culture with lenalidomide (mean fluorescence intensity, MFI) for the dead cells derived from patients with high and low RINF expression (Mann Whitney U-test, p=0.035). The two patient groups showed no difference in calreticulin exposure when analyzing viable cells, and there was no difference after culture in medium alone either (data not shown)

Mentions: We compared apoptosis induction during in vitro culture for the 9 patients with the highest and the 9 patients with the lowest RINF expression in the Norwegian cohort (see Fig. 1). The leukemic cells were cultured for 18 hours before the frequencies of viable, apoptotic and necrotic cells were determined. In vitro cultured primary AML cells show spontaneous or stress-induced apoptosis that varies considerably between patients [9, 10]; this was also true both for the AML cells with low (median viability 22.5%, range 1.1-66.6%) and high (median viability 44.2%, range 9.6-56.2%) RINF expression. The viability in drug-free cultures was also compared with cells cultured with lenalidomide 0.1, 0.5, 1.0 μM. For cells with low RINF expression, there was a low viability after culture in medium alone and the viability seemed to have reached a plateau and was not further decreased by lenalidomide (lenalidomide 1.0 μM; median viability 15.5%, range 1.4-53.9%). In contrast, for AML cells with high RINF expression, the viability after culture in medium alone was higher and lenalidomide caused a statistically significant and dose-dependent further decrease in viability (lenalidomide 0.1 μM, no significant effect; lenalidomide 0.5 μM, median viability 31.6%, range 7.0-57.3%, p=0.0098; lenalidomide 1.0 μM, median viability 31.6, range 6.8-50.8; p=0.0078) compared with the corresponding drug-free cultures (median viability 44,2%, see above). The low-RINF patients showed a similar low level of viable and apoptotic cells both after culture in medium alone and in the presence of lenalidomide, whereas the lenalidomide-induced decrease in viability for the high-RINF patients was associated with an increased fraction of apoptotic cells compared with the corresponding cultures for low-RINF patients (Fig. 4; Mann-Whitney U-test, p=0.0004). To conclude, low-RINF patients achieved a maximal decrease in viability by spontaneous in vitro apoptosis alone, whereas for high-RINF patients the maximal decrease in viability required combined spontaneous and lenalidomide-induced apoptosis.


CXXC5 (retinoid-inducible nuclear factor, RINF) is a potential therapeutic target in high-risk human acute myeloid leukemia.

Astori A, Fredly H, Aloysius TA, Bullinger L, Mansat-De Mas V, de la Grange P, Delhommeau F, Hagen KM, Récher C, Dusanter-Fourt I, Knappskog S, Lillehaug JR, Pendino F, Bruserud Ø - Oncotarget (2013)

Stress-induced spontaneous in vitro apoptosis and lenalidomide-induced apoptosis in primary human AML cells, a comparison of patients with high and low RINF expressionPrimary human AML cells were derived from 9 patients with low and 9 patients with high RINF expression. (LEFT) Primary AML cells with low RINF expression were mainly necrotic after 18 hours in vitro culture in medium alone, and the leukemic cells from these patients showed a low level of viable as well as apoptotic (see the figure for lenalidomide) cells both in cultures prepared in medium alone and cultures with lenalidomide. In contrast, for patients with high RINF expression a higher viability was seen after culture in medium alone. However, as shown in the figure an increased fraction of apoptotic cells was then detected for high-RINF patients when cells were cultured in the presence of lenalidomide compared with the corresponding cultures for low-RINF patients (see the figure; Mann Whitney U-test, p=0.0004), and at the same time the viability further decreased and the fraction of necrotic cells increased for the high-RINF patients. Thus, maximal viability reduction is achieved by spontaneous apoptosis alone for low-RINF patients but for high-RINF patients combined spontaneous and lenalidomide-induced apoptosis is required to achieve the maximal reduction. (RIGHT) The calreticulin exposure of AML cells cultured with lenalidomide 0.1 μM was determined by flow cytometry [11]. A dye-exclusion Dead/Live Viability/Vitality analysis was used to separate the leukemic cells into these two major subsets, and calreticulin expression could thereby be analyzed separately for dead and viable cells. The figure compares calreticulin exposure after culture with lenalidomide (mean fluorescence intensity, MFI) for the dead cells derived from patients with high and low RINF expression (Mann Whitney U-test, p=0.035). The two patient groups showed no difference in calreticulin exposure when analyzing viable cells, and there was no difference after culture in medium alone either (data not shown)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3824541&req=5

Figure 4: Stress-induced spontaneous in vitro apoptosis and lenalidomide-induced apoptosis in primary human AML cells, a comparison of patients with high and low RINF expressionPrimary human AML cells were derived from 9 patients with low and 9 patients with high RINF expression. (LEFT) Primary AML cells with low RINF expression were mainly necrotic after 18 hours in vitro culture in medium alone, and the leukemic cells from these patients showed a low level of viable as well as apoptotic (see the figure for lenalidomide) cells both in cultures prepared in medium alone and cultures with lenalidomide. In contrast, for patients with high RINF expression a higher viability was seen after culture in medium alone. However, as shown in the figure an increased fraction of apoptotic cells was then detected for high-RINF patients when cells were cultured in the presence of lenalidomide compared with the corresponding cultures for low-RINF patients (see the figure; Mann Whitney U-test, p=0.0004), and at the same time the viability further decreased and the fraction of necrotic cells increased for the high-RINF patients. Thus, maximal viability reduction is achieved by spontaneous apoptosis alone for low-RINF patients but for high-RINF patients combined spontaneous and lenalidomide-induced apoptosis is required to achieve the maximal reduction. (RIGHT) The calreticulin exposure of AML cells cultured with lenalidomide 0.1 μM was determined by flow cytometry [11]. A dye-exclusion Dead/Live Viability/Vitality analysis was used to separate the leukemic cells into these two major subsets, and calreticulin expression could thereby be analyzed separately for dead and viable cells. The figure compares calreticulin exposure after culture with lenalidomide (mean fluorescence intensity, MFI) for the dead cells derived from patients with high and low RINF expression (Mann Whitney U-test, p=0.035). The two patient groups showed no difference in calreticulin exposure when analyzing viable cells, and there was no difference after culture in medium alone either (data not shown)
Mentions: We compared apoptosis induction during in vitro culture for the 9 patients with the highest and the 9 patients with the lowest RINF expression in the Norwegian cohort (see Fig. 1). The leukemic cells were cultured for 18 hours before the frequencies of viable, apoptotic and necrotic cells were determined. In vitro cultured primary AML cells show spontaneous or stress-induced apoptosis that varies considerably between patients [9, 10]; this was also true both for the AML cells with low (median viability 22.5%, range 1.1-66.6%) and high (median viability 44.2%, range 9.6-56.2%) RINF expression. The viability in drug-free cultures was also compared with cells cultured with lenalidomide 0.1, 0.5, 1.0 μM. For cells with low RINF expression, there was a low viability after culture in medium alone and the viability seemed to have reached a plateau and was not further decreased by lenalidomide (lenalidomide 1.0 μM; median viability 15.5%, range 1.4-53.9%). In contrast, for AML cells with high RINF expression, the viability after culture in medium alone was higher and lenalidomide caused a statistically significant and dose-dependent further decrease in viability (lenalidomide 0.1 μM, no significant effect; lenalidomide 0.5 μM, median viability 31.6%, range 7.0-57.3%, p=0.0098; lenalidomide 1.0 μM, median viability 31.6, range 6.8-50.8; p=0.0078) compared with the corresponding drug-free cultures (median viability 44,2%, see above). The low-RINF patients showed a similar low level of viable and apoptotic cells both after culture in medium alone and in the presence of lenalidomide, whereas the lenalidomide-induced decrease in viability for the high-RINF patients was associated with an increased fraction of apoptotic cells compared with the corresponding cultures for low-RINF patients (Fig. 4; Mann-Whitney U-test, p=0.0004). To conclude, low-RINF patients achieved a maximal decrease in viability by spontaneous in vitro apoptosis alone, whereas for high-RINF patients the maximal decrease in viability required combined spontaneous and lenalidomide-induced apoptosis.

Bottom Line: Furthermore, patients with low-risk cytogenetic abnormalities showed significantly lower levels compared to patients with high-risk abnormalities, and high RINF/CXXC5/ mRNA levels were associated with decreased overall survival for patients receiving intensive chemotherapy for newly diagnosed AML.This association with prognosis was seen both when investigating (i) an unselected patient population as well as for patients with (ii) normal cytogenetic and (iii) core-binding factor AML.The association with adverse prognosis together with the antiapoptotic effect of CXXC5/RINF suggests that targeting of CXXC5/RINF should be considered as a possible therapeutic strategy, especially in high-risk patients who show increased expression in AML cells compared with normal hematopoietic cells.

View Article: PubMed Central - PubMed

Affiliation: Inserm, U1016, Institut Cochin, F-75014, Paris, France.

ABSTRACT
The retinoid-responsive gene CXXC5 localizes to the 5q31.2 chromosomal region and encodes a retinoid-inducible nuclear factor (RINF) that seems important during normal myelopoiesis. We investigated CXXC5/RINF expression in primary human acute myeloid leukemia (AML) cells derived from 594 patients, and a wide variation in CXXC5/RINF mRNA levels was observed both in the immature leukemic myeloblasts and in immature acute lymphoblastic leukemia cells. Furthermore, patients with low-risk cytogenetic abnormalities showed significantly lower levels compared to patients with high-risk abnormalities, and high RINF/CXXC5/ mRNA levels were associated with decreased overall survival for patients receiving intensive chemotherapy for newly diagnosed AML. This association with prognosis was seen both when investigating (i) an unselected patient population as well as for patients with (ii) normal cytogenetic and (iii) core-binding factor AML. CXXC5/RINF knockdown in AML cell lines caused increased susceptibility to chemotherapy-induced apoptosis, and regulation of apoptosis also seemed to differ between primary human AML cells with high and low RINF expression. The association with adverse prognosis together with the antiapoptotic effect of CXXC5/RINF suggests that targeting of CXXC5/RINF should be considered as a possible therapeutic strategy, especially in high-risk patients who show increased expression in AML cells compared with normal hematopoietic cells.

Show MeSH
Related in: MedlinePlus