Tumor Biol. DOI 10.1007/s13277-015-3513-0
RESEARCH ARTICLE
Expression profiling of cancer-related galectins in acute myeloid leukemia Asmaa A. El Leithy 1 & Reham Helwa 2 & Magda M. Assem 1 & Nagwa H. A. Hassan 2
Received: 13 January 2015 / Accepted: 27 April 2015 # International Society of Oncology and BioMarkers (ISOBM) 2015
Abstract Acute myeloid leukemia (AML) is the most common type of leukemia in adults with the lowest survival rate of all the leukemias. It is a heterogeneous disease in which a variety of cytogenetic and molecular alterations have been identified. Some galectins were previously reported to have important roles in cancer-like neoplastic transformation, tumor cell survival, angiogenesis, and tumor metastasis. Previous studies have showed that some galectin family members play a role in various types of leukemia. The present study aims at evaluating and clarifying the diagnostic and prognostic value of the expression of cancer-related galectins in relation to the clinicopathological characters of AML patients. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect expression profile of eight galectin family members (galectin-1, -2, -3, -4, -8, -9, -12, and -13) in 53 newly diagnosed de novo AML patients. The samples were collected from the inpatient clinic at National Cancer Institute (NCI), Cairo University (CU), diagnosed between July 2012 and May 2013. Our results show that patients with lower LGALS12 gene expression have a lower overall survival than those with higher expression (P value 6.94 PLT (*10^9/L) PLT (*10^9/L) ≤27 >27 Initial BM blast (%) Initial BM blast ≤54 % >54 % Initial BM promyelocyte Present (0 % blast)
n
%
36 11
76.5 23.5
*47
*7 4 3
57 43
25 5 1
81 16 3
15 17 5 16
28.3 32.1 9.4 30.2
*31
Median
Range
29.75
1.75–414
26 27 Mean 6.94
49.1 50.9 SD ±1.99
27 26 Median 27
50.9 49.1 Range 3–302
27 26 Median 54 %
50.9 49.1 Range 0–98
27 26
50.9 49.1
5
9.4
AML acute myeloid leukemia, FAB French–American–British classification of acute myeloid leukemia
LGALS9, LGALS12, and LGALS13 by qRT-PCR. Peripheral blood (PB) samples from both AML and healthy donors were collected on Trizol and frozen at −80 °C until use. The expression of LGALS1, 2, 3, 4, 8, 9, 12, and 13 was determined before treatment. Among the 53 patients, 45 (84.9 %) received standard induction chemotherapy 3+7 type regimen (doxorubicin 45 mg/m2 per day on days 1 to 3 and cytarabine 100 mg/
Tumor Biol. Table2 Immunophenotyping (IPT) of AML patients
IPT*
n
%
CD 117 present CD34 present MHC CLASSII present CD7 present CD14 present
20 20 25 5 9
37.7 37.7 47.2 9,4 17
2 2 1 5 4 3
3.8 3.8 1.9 9,4 7.5 5.7
CD2 present HLA DR present CD64 present CD4 present CD11c present CD19 present
m2 per day on days 1 to 7). Twenty-six out of 45 patients (57.78 %) reached a complete remission (CR), 3 patients (5.7 %) received 2+5 type regimen (doxorubicin 45 mg/m2 per day on days 1 to 2 and cytarabine 100 mg/m2 per day on days 1 to 5). Two out of the three patients (66.7 %) reached CR. The remaining 5 patients received AIDA protocol (ATRA (45 mg/m2/day) associated with intravenous idarubicin (IDA) (12 mg/m2/day)×3 days), and 2 out of 5 patients (40 %) reached CR.
RNA isolation and qRT-PCR The total cellular RNA from peripheral blood samples was purified using Biozol Total RNA Extraction Reagent (BioFlux) and reversely transcribed to cDNA. The qRT-PCR was performed using SYBR Green Real Time PCR master mix (EXPRESS SYBR® GreenER™ qPCR Supermix, universal (Invitrogen™)) according to the manufacturer’s instruction on Mx3000P QPCR system (Agilent Technologies, California, USA). The sequences of the forward and reverse primers for LGALS1, 2, 3, 4, 8, 9, 12, 13 and GAPDH are shown in Table 3. The primers were retrieved from PrimerBank, Massachusetts General Hospital, The Center for Computational and Integrative Biology, Harvard Medical School [11–14]. The CT values were obtained and normalized to GAPDH. Then, the fold changes were calculated using 2−ΔΔCT method. All of the CT values were in the linear range of detection.
Heatmap visualization The mRNA expression as fold changes was clustered using Multi Experiment Viewer [15]. Expression levels of all genes were visualized in the same green–black–red scheme in order to evaluate relative expression levels in all samples.
Table 3 The sequences of the forward and reverse primers for LGALS1, 2, 3, 4, 8, 9, 12, 13 & GAPDH Gene
Primer sequence
LGALS1 Primer forward Primer reverse LGALS2
TCGCCAGCAACCTGAATCTC GCACGAAGCTCTTAGCGTCA
Primer forward Primer reverse LGALS3 Primer forward Primer reverse LGALS4 Primer forward Primer reverse LGALS8 Primer forward Primer reverse LGALS9 Primer forward Primer reverse LGALS12 Primer forward Primer reverse LGALS13
ATGACGGGGGAACTTGAGGT CAGGTTCAGCTTGTCTGTCC
Primer forward Primer reverse GAPDH Primer forward Primer reverse
TATTGCCTTCCGTTTCCGAGT GGCACGTAGTCTGTTGTCTCC
ATGGCAGACAATTTTTCGCTCC GCCTGTCCAGGATAAGCCC CGACGCTGCCTTACTACCAG CCAACCACAAAGTTCACGAAGA ATACGTGGGCATGTTCCTAGT CGGCCCTTTTGAAACGAGG GGACGGACTTCAGATCACTGT CCATCTTCAAACCGAGGGTTG GCCTGGGCAGGTCATCATAG GAGTTCTGTCTGCGAAGGAGG
CTGGGCTACACTGAGCACC AAGTGGTCGTTGAGGGCAATG
Statistical analysis Data was analyzed using SPSS win (Statistical Package for Social Science), version 21. Numerical data was expressed as mean and standard deviation (SD), median, and range as appropriate. Qualitative data was expressed as frequency and percentage. Chi-square (Fisher’s exact) test was used to examine the relation between qualitative variables as appropriate. Comparison between groups with respect to numerical variables was made using Student’s t test for not normally distributed variables while Mann–Whitney U test has been used for not normally distributed variables. Survival analysis was made using Kaplan–Meier method. Comparison between two survival curves used log rank test, P value ≤0.05 was considered significant, and all test was two-tailed. P value was corrected using Benferroni adjustment to avoid hyperinflation of type 1 error resulting from multiple comparisons. Overall survival (OS) was calculated from date of diagnosis till date of death or last follow-up. Disease-free survival (DFS)
Tumor Biol.
The profiling of LGALS1, 2, 3, 4, 8, 9, 12, and 13 in PB cells of the AML patients exhibited differential expression comparable to normal controls. The fold changes of the studied galectins were then analyzed to define lower and higher expression groups as shown later in the results. The expression profiling of LGALS1, 2, 3, 4, 8, 9, 12, and 13 is shown in a descending order of downregulation in Table 4. The fold changes were then subjected to clustering analysis as shown in Fig. 1.
expression profiling and response to chemotherapy showed no statistically significant association in all types of galectins. The median follow-up time was 1.25 months (ranging from 0.5 to 13.5 months); OS of AML patients is shown in Fig. 2. There is no statistically significant association between AML patient OS and clinicolaboratory data of studied group as shown in Table 5. Relation of OS and gene expression is shown in Table 6; patients with lower LGALS12 gene expression have a lower OS than those with higher expression (P value 29.75 Hb (g/dL) ≤6.94 >6.94 PLT (*10^9/L) ≤27
27 47 36 11
0.396
2.204
0.351 0.551
1.678 NR
15 17 5 16
0.350 0.441 0.800 0.304
1.743 2.204 NR 1.678
26 27
0.505 0.300
6.776 1.678
27 26
0.412 0.382
2.204 1.743
27
0.464
5.395
>27 Initial BM blast ≤54 % >54 % Initial BM promyelocyte Present (0 % blast) Absent (0 % promyelocyte)
26
0.340
1.678
27 26
0.497 0.313
5.395 1.217
5 48
0.800 0.368
NR 1.743
*NR means not reached OS
0.952
0.318
0.497
0.390
0.871
0.531
0.100
0.211
Tumor Biol. Table 6 Relation of overall survival (OS) and gene expression of studied group
Gene expression
n
Proportion surviving at 6 months
26 27
0.383 0.438
1.678 2.204
15
0.583
10.658
Downregulation LGALS3 Upregulation Downregulation LGALS4 Upregulation Downregulation LGALS8 Upregulation Downregulation LGALS9 Upregulation Downregulation LGALS12 Upregulation Downregulation LGALS13 Upregulation
38
0.334
1.743
10 43
0.549 0.359
NR 1.678
8 45
0.750 0.355
NR 1.678
19 34
0.237 0.489
1.118 2.368
25 28
0.303 0.481
1.184 2.368
6 47
1.711 0.461
NR 1.678
11
0.273
1.678
Downregulation
42
0.428
2.368
LGALS1 Upregulation Downregulation LGALS2 Upregulation
value 0.993
0.195
0.130
0.144
0.116
0.239
0.026
0.591
mammary cancer cells [23] and alter the cell cycle when added to human T lymphocytes [24]. On the other hand, it was also found that galectin-1 was associated with disease progression. It is also secreted by myeloid cells and was suggested to influence leukemic B cell biology [25]. In our study, galectin-1 was downregulated in 50.9 % of AML samples. According to the previous publication, the downregulation of galectin-1 could be a favor for cancer cells to skip apoptosis/cell cycle arrest. Fig. 3 OS and its relation to LGALS12 expression
Median survival estimate (months)
Also, in previous studies, galectin-3 was reported to be downregulated during progression of different types of solid tumors [26–29]. On the other side, others have reported higher expression levels of galectin-3 in tumors of the pancreas [30], thyroid [31], colon [32], and gastric tissues [33]. According to previous studies, alteration in galectin-3 gene expression can lead to promotion or inhibition of tumor proliferation, differentiation, or metastasis, depending on the cell types and tumors [26]. However, galectin-3 is highly expressed by chronic
Tumor Biol. Fig. 4 Disease-free survival of all AML patients
Table 7 Relation of disease-free survival (DFS) and clinicolaboratory data of studied group
Variable
n
Proportion surviving at 6 months
Median survival estimate (months)
All Gender Male Female Age ≤40
30
0.774
8.882
16 14
0.856 0.682
8.882 NR
15
0.857
8.882
>40 FLT3-ITD W/W W/ITD FAB classification M0&M1 M2 M3 M4 Initial CBC TLC (*10^9/L) ≤29.75 >29.75 Hb (g/dL) ≤6.94 >6.94 PLT (*10^9/L) ≤27
15 27 21 6
0.727
NR
0.774 0.667
8.882 NR
6 10 3 11
0.800 0.750 NR 0.771
NR NR NR NR
16 14
0.685 0.909
8.388 10.855
15 15
0.755 0.779
NR 8.882
16
0.848
8.882
>27 Initial BM blast ≤54 % >54 % Initial BM promyelocyte Present (0 % blast) Absent (0 % promyelocyte)
14
0.682
10.855
18 12
0.779 0.379
NR 7.895
3 27
NR 0.749
NR NR
P value − 0.732
0.666
0.846
0.559
0.307
0.917
0.905
0.316
0.251
**Number of patients achieved CR is 30
Tumor Biol. Table 8 Relation of disease-free survival (DFS) and gene expression of studied group
Gene expression
n
Proportion surviving at 6 months
Median survival estimate (months)
14 16
0.786 0.800
8.882 10.855
10
0.889
10.855
Downregulation LGALS3 Upregulation Downregulation LGALS4 Upregulation Downregulation LGALS8 Upregulation Downregulation LGALS9 Upregulation Downregulation LGALS12 Upregulation Downregulation LGALS13 Upregulation
20
0.728
8.882
8 22
0.833 0.745
NR 8.388
6 24
0.500 0.733
10.855 8.388
8 22
0.857 0.752
8.882 NR
12 18
0.875 0.728
8.882 8.388
6 24
0.667 0.699
NR 8.882
4
0.667
8.882
Downregulation
26
0.782
10.855
LGALS1 Upregulation Downregulation LGALS2 Upregulation
P value 0.744
0.618
0.412
0.391
0.546
0.532
0.175
0.809
myelogenous leukemia (CML) cells in the bone marrow. Interestingly, in a previous study, it was found that coculturing bone marrow stromal cells with CML cell lines induced the expression of galectin-3 and caused drug resistance in vitro. Similarly, it was also reported that galectin-3 upregulation in CML cells increases their proliferative and chemotactic capacity and their resistance to therapeutic drugs. In addition to this, galectin-3 facilitates CML cell migration and long-term residence in the bone marrow [34]. In AML, upregulation of galectin-3 in bone marrow was reported to be an independent poor prognostic factor, irrespective of age, leukocyte counts, or karyotype, and might serve as a new biomarker in AML [7]. This was not the case in the present study where galectin-3 was downregulated in the peripheral blood in 81.1 % of AML in the present cohort. This difference could be attributed to three reasons, first the fact that galectin-3 expression in the bone marrow is different than in the peripheral blood. Second, the difference could be due to the difference in ethnicity as our cases were Egyptians and there were Taiwan, or due to the different AML biology. Galectin-8 binds to integrins, inhibits cell adhesion, and induces apoptosis [35]. Moreover, Nagy et al. reached that galectin-8 plays a significant role in the biology of human colon cancers where a malignant colon tissue exhibits a
significantly lower galectin-8 concentration than normal or benign tissue within colon cancers [36]. Also, galectin-8 was identified as a major target for tumor-specific monoclonal antibodies raised against prostate and lung cancers [37, 38]. Downregulation of galectin-8 in 64.2 % of our samples could reflect one possible mechanism of evading apoptosis in AML patients. Rechreche et al. identified the human galectin-4 as a downregulated gene during colorectal carcinogenesis [39], where it was upregulated in hepatocellular carcinomas [40] and in gastric cancer cells with increased metastatic potential [41], as compared to the low level in the corresponding normal tissues. Hereby, ours is the first study to report down-expression of galectin-4 in the peripheral blood of AML (in 84.9 % of 53 patients). Moreover, by comparing the expression profile of the studied galectins and the clinical characteristics of AML patients, the expression of galectin-4 was found to be statistically associated with patient age. The expression of galectin-4 was higher in younger age group of AML (adjusted P value
RESEARCH ARTICLE
Expression profiling of cancer-related galectins in acute myeloid leukemia Asmaa A. El Leithy 1 & Reham Helwa 2 & Magda M. Assem 1 & Nagwa H. A. Hassan 2
Received: 13 January 2015 / Accepted: 27 April 2015 # International Society of Oncology and BioMarkers (ISOBM) 2015
Abstract Acute myeloid leukemia (AML) is the most common type of leukemia in adults with the lowest survival rate of all the leukemias. It is a heterogeneous disease in which a variety of cytogenetic and molecular alterations have been identified. Some galectins were previously reported to have important roles in cancer-like neoplastic transformation, tumor cell survival, angiogenesis, and tumor metastasis. Previous studies have showed that some galectin family members play a role in various types of leukemia. The present study aims at evaluating and clarifying the diagnostic and prognostic value of the expression of cancer-related galectins in relation to the clinicopathological characters of AML patients. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect expression profile of eight galectin family members (galectin-1, -2, -3, -4, -8, -9, -12, and -13) in 53 newly diagnosed de novo AML patients. The samples were collected from the inpatient clinic at National Cancer Institute (NCI), Cairo University (CU), diagnosed between July 2012 and May 2013. Our results show that patients with lower LGALS12 gene expression have a lower overall survival than those with higher expression (P value 6.94 PLT (*10^9/L) PLT (*10^9/L) ≤27 >27 Initial BM blast (%) Initial BM blast ≤54 % >54 % Initial BM promyelocyte Present (0 % blast)
n
%
36 11
76.5 23.5
*47
*7 4 3
57 43
25 5 1
81 16 3
15 17 5 16
28.3 32.1 9.4 30.2
*31
Median
Range
29.75
1.75–414
26 27 Mean 6.94
49.1 50.9 SD ±1.99
27 26 Median 27
50.9 49.1 Range 3–302
27 26 Median 54 %
50.9 49.1 Range 0–98
27 26
50.9 49.1
5
9.4
AML acute myeloid leukemia, FAB French–American–British classification of acute myeloid leukemia
LGALS9, LGALS12, and LGALS13 by qRT-PCR. Peripheral blood (PB) samples from both AML and healthy donors were collected on Trizol and frozen at −80 °C until use. The expression of LGALS1, 2, 3, 4, 8, 9, 12, and 13 was determined before treatment. Among the 53 patients, 45 (84.9 %) received standard induction chemotherapy 3+7 type regimen (doxorubicin 45 mg/m2 per day on days 1 to 3 and cytarabine 100 mg/
Tumor Biol. Table2 Immunophenotyping (IPT) of AML patients
IPT*
n
%
CD 117 present CD34 present MHC CLASSII present CD7 present CD14 present
20 20 25 5 9
37.7 37.7 47.2 9,4 17
2 2 1 5 4 3
3.8 3.8 1.9 9,4 7.5 5.7
CD2 present HLA DR present CD64 present CD4 present CD11c present CD19 present
m2 per day on days 1 to 7). Twenty-six out of 45 patients (57.78 %) reached a complete remission (CR), 3 patients (5.7 %) received 2+5 type regimen (doxorubicin 45 mg/m2 per day on days 1 to 2 and cytarabine 100 mg/m2 per day on days 1 to 5). Two out of the three patients (66.7 %) reached CR. The remaining 5 patients received AIDA protocol (ATRA (45 mg/m2/day) associated with intravenous idarubicin (IDA) (12 mg/m2/day)×3 days), and 2 out of 5 patients (40 %) reached CR.
RNA isolation and qRT-PCR The total cellular RNA from peripheral blood samples was purified using Biozol Total RNA Extraction Reagent (BioFlux) and reversely transcribed to cDNA. The qRT-PCR was performed using SYBR Green Real Time PCR master mix (EXPRESS SYBR® GreenER™ qPCR Supermix, universal (Invitrogen™)) according to the manufacturer’s instruction on Mx3000P QPCR system (Agilent Technologies, California, USA). The sequences of the forward and reverse primers for LGALS1, 2, 3, 4, 8, 9, 12, 13 and GAPDH are shown in Table 3. The primers were retrieved from PrimerBank, Massachusetts General Hospital, The Center for Computational and Integrative Biology, Harvard Medical School [11–14]. The CT values were obtained and normalized to GAPDH. Then, the fold changes were calculated using 2−ΔΔCT method. All of the CT values were in the linear range of detection.
Heatmap visualization The mRNA expression as fold changes was clustered using Multi Experiment Viewer [15]. Expression levels of all genes were visualized in the same green–black–red scheme in order to evaluate relative expression levels in all samples.
Table 3 The sequences of the forward and reverse primers for LGALS1, 2, 3, 4, 8, 9, 12, 13 & GAPDH Gene
Primer sequence
LGALS1 Primer forward Primer reverse LGALS2
TCGCCAGCAACCTGAATCTC GCACGAAGCTCTTAGCGTCA
Primer forward Primer reverse LGALS3 Primer forward Primer reverse LGALS4 Primer forward Primer reverse LGALS8 Primer forward Primer reverse LGALS9 Primer forward Primer reverse LGALS12 Primer forward Primer reverse LGALS13
ATGACGGGGGAACTTGAGGT CAGGTTCAGCTTGTCTGTCC
Primer forward Primer reverse GAPDH Primer forward Primer reverse
TATTGCCTTCCGTTTCCGAGT GGCACGTAGTCTGTTGTCTCC
ATGGCAGACAATTTTTCGCTCC GCCTGTCCAGGATAAGCCC CGACGCTGCCTTACTACCAG CCAACCACAAAGTTCACGAAGA ATACGTGGGCATGTTCCTAGT CGGCCCTTTTGAAACGAGG GGACGGACTTCAGATCACTGT CCATCTTCAAACCGAGGGTTG GCCTGGGCAGGTCATCATAG GAGTTCTGTCTGCGAAGGAGG
CTGGGCTACACTGAGCACC AAGTGGTCGTTGAGGGCAATG
Statistical analysis Data was analyzed using SPSS win (Statistical Package for Social Science), version 21. Numerical data was expressed as mean and standard deviation (SD), median, and range as appropriate. Qualitative data was expressed as frequency and percentage. Chi-square (Fisher’s exact) test was used to examine the relation between qualitative variables as appropriate. Comparison between groups with respect to numerical variables was made using Student’s t test for not normally distributed variables while Mann–Whitney U test has been used for not normally distributed variables. Survival analysis was made using Kaplan–Meier method. Comparison between two survival curves used log rank test, P value ≤0.05 was considered significant, and all test was two-tailed. P value was corrected using Benferroni adjustment to avoid hyperinflation of type 1 error resulting from multiple comparisons. Overall survival (OS) was calculated from date of diagnosis till date of death or last follow-up. Disease-free survival (DFS)
Tumor Biol.
The profiling of LGALS1, 2, 3, 4, 8, 9, 12, and 13 in PB cells of the AML patients exhibited differential expression comparable to normal controls. The fold changes of the studied galectins were then analyzed to define lower and higher expression groups as shown later in the results. The expression profiling of LGALS1, 2, 3, 4, 8, 9, 12, and 13 is shown in a descending order of downregulation in Table 4. The fold changes were then subjected to clustering analysis as shown in Fig. 1.
expression profiling and response to chemotherapy showed no statistically significant association in all types of galectins. The median follow-up time was 1.25 months (ranging from 0.5 to 13.5 months); OS of AML patients is shown in Fig. 2. There is no statistically significant association between AML patient OS and clinicolaboratory data of studied group as shown in Table 5. Relation of OS and gene expression is shown in Table 6; patients with lower LGALS12 gene expression have a lower OS than those with higher expression (P value 29.75 Hb (g/dL) ≤6.94 >6.94 PLT (*10^9/L) ≤27
27 47 36 11
0.396
2.204
0.351 0.551
1.678 NR
15 17 5 16
0.350 0.441 0.800 0.304
1.743 2.204 NR 1.678
26 27
0.505 0.300
6.776 1.678
27 26
0.412 0.382
2.204 1.743
27
0.464
5.395
>27 Initial BM blast ≤54 % >54 % Initial BM promyelocyte Present (0 % blast) Absent (0 % promyelocyte)
26
0.340
1.678
27 26
0.497 0.313
5.395 1.217
5 48
0.800 0.368
NR 1.743
*NR means not reached OS
0.952
0.318
0.497
0.390
0.871
0.531
0.100
0.211
Tumor Biol. Table 6 Relation of overall survival (OS) and gene expression of studied group
Gene expression
n
Proportion surviving at 6 months
26 27
0.383 0.438
1.678 2.204
15
0.583
10.658
Downregulation LGALS3 Upregulation Downregulation LGALS4 Upregulation Downregulation LGALS8 Upregulation Downregulation LGALS9 Upregulation Downregulation LGALS12 Upregulation Downregulation LGALS13 Upregulation
38
0.334
1.743
10 43
0.549 0.359
NR 1.678
8 45
0.750 0.355
NR 1.678
19 34
0.237 0.489
1.118 2.368
25 28
0.303 0.481
1.184 2.368
6 47
1.711 0.461
NR 1.678
11
0.273
1.678
Downregulation
42
0.428
2.368
LGALS1 Upregulation Downregulation LGALS2 Upregulation
value 0.993
0.195
0.130
0.144
0.116
0.239
0.026
0.591
mammary cancer cells [23] and alter the cell cycle when added to human T lymphocytes [24]. On the other hand, it was also found that galectin-1 was associated with disease progression. It is also secreted by myeloid cells and was suggested to influence leukemic B cell biology [25]. In our study, galectin-1 was downregulated in 50.9 % of AML samples. According to the previous publication, the downregulation of galectin-1 could be a favor for cancer cells to skip apoptosis/cell cycle arrest. Fig. 3 OS and its relation to LGALS12 expression
Median survival estimate (months)
Also, in previous studies, galectin-3 was reported to be downregulated during progression of different types of solid tumors [26–29]. On the other side, others have reported higher expression levels of galectin-3 in tumors of the pancreas [30], thyroid [31], colon [32], and gastric tissues [33]. According to previous studies, alteration in galectin-3 gene expression can lead to promotion or inhibition of tumor proliferation, differentiation, or metastasis, depending on the cell types and tumors [26]. However, galectin-3 is highly expressed by chronic
Tumor Biol. Fig. 4 Disease-free survival of all AML patients
Table 7 Relation of disease-free survival (DFS) and clinicolaboratory data of studied group
Variable
n
Proportion surviving at 6 months
Median survival estimate (months)
All Gender Male Female Age ≤40
30
0.774
8.882
16 14
0.856 0.682
8.882 NR
15
0.857
8.882
>40 FLT3-ITD W/W W/ITD FAB classification M0&M1 M2 M3 M4 Initial CBC TLC (*10^9/L) ≤29.75 >29.75 Hb (g/dL) ≤6.94 >6.94 PLT (*10^9/L) ≤27
15 27 21 6
0.727
NR
0.774 0.667
8.882 NR
6 10 3 11
0.800 0.750 NR 0.771
NR NR NR NR
16 14
0.685 0.909
8.388 10.855
15 15
0.755 0.779
NR 8.882
16
0.848
8.882
>27 Initial BM blast ≤54 % >54 % Initial BM promyelocyte Present (0 % blast) Absent (0 % promyelocyte)
14
0.682
10.855
18 12
0.779 0.379
NR 7.895
3 27
NR 0.749
NR NR
P value − 0.732
0.666
0.846
0.559
0.307
0.917
0.905
0.316
0.251
**Number of patients achieved CR is 30
Tumor Biol. Table 8 Relation of disease-free survival (DFS) and gene expression of studied group
Gene expression
n
Proportion surviving at 6 months
Median survival estimate (months)
14 16
0.786 0.800
8.882 10.855
10
0.889
10.855
Downregulation LGALS3 Upregulation Downregulation LGALS4 Upregulation Downregulation LGALS8 Upregulation Downregulation LGALS9 Upregulation Downregulation LGALS12 Upregulation Downregulation LGALS13 Upregulation
20
0.728
8.882
8 22
0.833 0.745
NR 8.388
6 24
0.500 0.733
10.855 8.388
8 22
0.857 0.752
8.882 NR
12 18
0.875 0.728
8.882 8.388
6 24
0.667 0.699
NR 8.882
4
0.667
8.882
Downregulation
26
0.782
10.855
LGALS1 Upregulation Downregulation LGALS2 Upregulation
P value 0.744
0.618
0.412
0.391
0.546
0.532
0.175
0.809
myelogenous leukemia (CML) cells in the bone marrow. Interestingly, in a previous study, it was found that coculturing bone marrow stromal cells with CML cell lines induced the expression of galectin-3 and caused drug resistance in vitro. Similarly, it was also reported that galectin-3 upregulation in CML cells increases their proliferative and chemotactic capacity and their resistance to therapeutic drugs. In addition to this, galectin-3 facilitates CML cell migration and long-term residence in the bone marrow [34]. In AML, upregulation of galectin-3 in bone marrow was reported to be an independent poor prognostic factor, irrespective of age, leukocyte counts, or karyotype, and might serve as a new biomarker in AML [7]. This was not the case in the present study where galectin-3 was downregulated in the peripheral blood in 81.1 % of AML in the present cohort. This difference could be attributed to three reasons, first the fact that galectin-3 expression in the bone marrow is different than in the peripheral blood. Second, the difference could be due to the difference in ethnicity as our cases were Egyptians and there were Taiwan, or due to the different AML biology. Galectin-8 binds to integrins, inhibits cell adhesion, and induces apoptosis [35]. Moreover, Nagy et al. reached that galectin-8 plays a significant role in the biology of human colon cancers where a malignant colon tissue exhibits a
significantly lower galectin-8 concentration than normal or benign tissue within colon cancers [36]. Also, galectin-8 was identified as a major target for tumor-specific monoclonal antibodies raised against prostate and lung cancers [37, 38]. Downregulation of galectin-8 in 64.2 % of our samples could reflect one possible mechanism of evading apoptosis in AML patients. Rechreche et al. identified the human galectin-4 as a downregulated gene during colorectal carcinogenesis [39], where it was upregulated in hepatocellular carcinomas [40] and in gastric cancer cells with increased metastatic potential [41], as compared to the low level in the corresponding normal tissues. Hereby, ours is the first study to report down-expression of galectin-4 in the peripheral blood of AML (in 84.9 % of 53 patients). Moreover, by comparing the expression profile of the studied galectins and the clinical characteristics of AML patients, the expression of galectin-4 was found to be statistically associated with patient age. The expression of galectin-4 was higher in younger age group of AML (adjusted P value
