Comparison of Adipogenesis and Adipocyte Functions of 3T3-L1 Cells and Human Bone Marrow Mesenchymal Stem Cells In Vitro / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To compare the adipogenesis and the adipocyte function between 3T3-L1 cells and human bone marrow mesenchymal stem cells (MSCs) in vitro.</p><p><b>METHODS</b>By density gradient centrifugation and adherent culture, the MSCs were isolated from human bone marrow and purified. The cell morphology was observed under an inverted microscope. After the induction of adipogenic differentiation, the differentiation level was detected by oil red O staining and OD values. The expression of PPARγ, FABP4 and C/EBPα mRNA was detected by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Adipocytes and THP-1 cells were co-cultured by adding 1 µg/ml cytarabine. The ability of chemotherapy resistance was measured after 48 h.</p><p><b>RESULTS</b>The Oil Red O staining and measuring the absorbance showed that the lipid content in 3T3-L1 cells group was more than that in MSCs group, and the OD value was higher than that in MSCs group (P < 0.05). The results of qRT-PCR showed that the relative expression of PPARγ, FABP4 and C/EBPα mRNA of 3T3-L1-derived adipocytes was higher than that of human bone marrow MSCs-derived adipocytes (P < 0.05). Coculture experiments showed that the number of viable THP-1 cells in the group containing adipocytes was more than that in the control group (P < 0.05). The difference between 3T3-L1 cell group and MSC group was statistically significant (P < 0.05).</p><p><b>CONCLUSION</b>The ability of adipogenesis of 3T3-L1 cells is higher than that of human bone marrow MSCs in vitro. Adipocytes can protect THP-1 cell line against cytarabine, and the effect of adipocytes from 3T3-L1 cell group is greater than that from the human bone marrow MSC group.</p>

Metformin Influences the Effect of Adipocytes on Leukemia Cell Chemoresistance through Regulation of Adipogenesis / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of metformin on 3T3-L1 preadipocyte's differentiation and consequently observe the anti-proliferative effects of metformin-treated adipocytes on leukemia cells.</p><p><b>METHODS</b>Different concentrations of metformin were added in 3T3-L1 preadipocytes to induce maturation, the matured adipocytes were detected by oil red O staining and quantified by absorbance value (OD). Real-time PCR was used to detect the mRNA expression level of the key adipogenic genes PPARγ, C/EBPα and FABP4(ap2). The adipocytes were co-cultured with GFP+-THP-1 cells, 1 µg/ml of cytarabine(Ara-C) was added and incubated for 48 hours, the flow cytometry was used to detect the apoptosis rate of GFP+-THP-1 cells. Adipocyte supernatant was collected and mixed with equal volume of tumor lysat medium (RPMI 1640) at 1:1 to culture tumor cells. The leukemia cell proliferation activity was detected by CCK-8; after 48 hours of adding 1 µg/ml Ara-C, the protective effect on chemotherapy was assayed by using cytometer.</p><p><b>RESULTS</b>The metformin lowered the OD value, and the expression levels of both adipogenic genes C/EBPα and FABP4 were lower than those of controls, while the expression level of PPARγ mRNA was not significantly changed, the apoptosis rate of leukemia cells co-caltured with metformin-treated adipocytes was higher than that of co-cultured cells without metformin treatment. The adipocytes promoted the leukimia cell proliferation and protected leukemia cells from chemotherapy, which could be abrogated by metformin.</p><p><b>CONCLUSION</b>The metformin can inhibit the differentiation of 3T3-L1 preadipocytes into adipocytes, and can regulate the protective effect of adipocytes on the apoptosis, proliferation and chemotherapy of leukemia cells.</p>

Research advances on abnormal marrow fibre in leukemia / 中国实验血液学杂志

The genesis and development of leukemia not only associate to intrinsic factors, but also relate with the fibrous hyperplasia in the bone marrow. This review mainly focuses on the interaction between fiber-producing cells and leukemia cells, the relationship between fibrous hyperplasia and prognosis of leukemia, the regulation of TGF-beta, PDGF and other cytokines, the underlying mechanism of fibrous hyperplasia so as to explore the potential therapeutic targets for improving the prognosis of leukemia.

Correlation between ALIP-like cluster and fibrous proliferation in bone marrow of patients with acute myeloid leukemia in CR phase / 中国实验血液学杂志

This study was purposed to elucidate the prognostic values of ALIP (abnormal location of immature precursors)-like clusters and fibrous proliferation in bone marrow of AML patients in CR phase and the correlation between them. The bone marrow biopsy sections from 47 AML patients during admitting to relapse or till lost follow-up were examined retrospectively. The 47 patients were divided into pre-relapsed group and non-relapsed group according to relapse or not at end of follow-up. The concentration of ALIP-like cluster and reticulin fiber density (RFD) in sections were compared between the two groups respectively, the prognostic value of these two factors and the underlying relationship between them were estimated by statistical analysis. The results showed that ALIP-like cluster was (3.46 ± 2.71)/mm(2) during CR and RFD was (2.76% ± 1.50%) in pre-relapsed cases, which both were higher than those in non-relapsed cases (P < 0.05). Cases with ALIP-like cluster over 4/mm(2) or with RFD>1.68% showed high relapse rates of 89.5% or 95.2% respectively. RFD were (2.47% ± 2.48%) and (2.44% ± 2.23%) in cases with >4/mm(2) or ≤ 4/mm(2) respectively, there was no statistical significance (P > 0.05) . Meanwhile, the amount of ALIP-like cluster in CR not related with the paired RFD (r = 0.057, P > 0.05). It is concluded that both ALIP-like cluster in CR and RFD are poor prognostic factors for heralding early relapse. However, ALIP-like cluster and RFD show no correlation, and suggest that forming of ALIP not depends on fibrogenesis.

Influence of pre-ALIP number and its distance from trabeculae on AML relapse / 中国实验血液学杂志

This study was purposed to detect the abnormal quantity and localization of pre-ALIP in bone marrow of acute myelocytic leukemia patients (AML) during the complete remission (CR) and investigate their correlation with AML relapse. The bone marrow biopsy and prognosis of 62 patients with CR were retrospectively analyzed. The bone marrow was divided into the pre-relapse group and the no-relapse group according to prognosis of patients. In order to clarify the correlation of abnormal quantity and localization of pre-ALIP with AML relapse, the number of single and double-cluster precursor cells and the sum of both were calculated, and their distance from bone trabeculae was surveyed with the computer image segment method. The results showed that the number of pre-ALIP in pre-relapse group (11 ± 11.71/mm(2)) and no-relapse group (8.33 ± 9.17/mm(2)) were more than that in normal control group (5.29 ± 4.00) (P < 0.01). The number of pre-ALIP more than 11/mm(2) was observed in 17 among all AML patients, and out of them 12 patients with pre-ALIP number >11/mm(2) (70.6) were found in the pre-relapse group, which was higher than that in no-relapse group (P < 0.05). While the distance between pre-ALIP and trabeculae [(341.31 ± 266.16) µm] in pre-relapse group showed the tendency of migrating to the intermediate zone of bone trabeculae, compared with that in no-relapse group [(242.41 ± 174.65) µm, P < 0.01]. Moreover, about 77.8 of 18 patients showed the distance of pre-ALIP from trabeculae was more than 341 µm in the pre-relapse group, and significantly higher than that in no-relapse group (P < 0.01). It is concluded that the average number of "pre-ALIP" more than 11/mm(2) or the average distance from trabeculae longer than 341 µm in bone marrow sections during CR may be the indicators for early relapse of AML.