Dysregulation of the Receptor Activator of NF-κB Ligand and Osteoprotegerin Production Influence the Apoptosis of Multiple Myeloma Patients’ Bone Marrow Stromal Cells Co-Cultured with Myeloma Cells

A novel and sensitive ratiometric fluorescent quantum dot-based biosensor for alkaline phosphatase detection in biological samples via the inner-filter effect

Alkaline phosphatase (ALP) is an important biomarker whose abnormal level in activity is associated with hepatobiliary, skeletal, and renal diseases as well as cancer. Herein, we synthesized ZnSe@ZnS quantum dots (ZnSe@ZnS QDs) and Mn-doped ZnS quantum dots (Mn:ZnS QDs) as fluorophores to establish the ratiometric fluorescent assay for ALP activity detection in biological samples. p-Nitrophenyl phosphate (PNPP) was used as a substrate for ALP, and the overlaps between absorption spectra of PNPP and excitation spectra of QDs resulted in sharp fluorescence quenching. Under the catalysis of ALP, PNPP was hydrolyzed into p-nitrophenol (PNP), which caused a red shift of absorption band of PNPP and fluorescence recovery of Mn:ZnS QDs (585 nm). However, the overlaps between absorption spectra of PNP and emission spectra of ZnSe@ZnS QDs led a further quenching of ZnSe@ZnS QDs (405 nm). Therefore, the ratiometric fluorescent signals (F ₅₈₅/F ₄₀₅) were associated with activity of ALP based on bidirectional responses of QDs to the concentration of PNPP. Under the optimum conditions, the method exhibited a good linear relationship from 4 to 96 U per L (R ² = 0.9969) with the detection limit of 0.57 U per L. Moreover, the method was successfully applied for detecting the ALP activity in a complex biological matrix (human serum and HepG2 cells) with impressive specificity. In particular, the complicated chemical modifications of QDs and pretreatments of biological samples were not required in the whole detection procedures. Therefore, it not only provided a sensitive, specific and simple approach to clinical ALP activity detection, but it also provided support for early diagnosis of diseases.

Platycodin D inhibits proliferation, migration and induces chemosensitization through inactivation of the NF-κB and JAK2/STAT3 pathways in multiple myeloma cells

Multiple myeloma (MM) is a malignancy characterized by the proliferation of malignant plasma cells. Platycodin D (PLD) is a triterpenoid saponin that exerts anti-tumour activity through multiple mechanisms. However, the role of PLD in MM remains unknown. Here, we investigated the effect of PLD on MM cell lines NCI-H929 and U266B1, and elucidated the underlying molecular mechanism. Cell Counting Kit-8 assay showed that the proliferation of NCI-H929 and U266B1 cells was significantly decreased after PLD treatment. Transwell assay confirmed that PLD treatment suppressed migration of NCI-H929 and U266B1 cells. Flow cytometry results indicated that the apoptotic rates of bortezomib (BTZ)-treated NCI-H929 and U266B1 cells were markedly increased after PLD treatment. Western blot analysis revealed that bcl-2 expression was decreased, while bax expression was increased in PLD-treated NCI-H929 and U266B1 cells compared with that in BTZ-treated cells. Furthermore, PLD treatment blocked the activation of nuclear factor-kappa B (NF-κB) and Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signalling pathways in NCI-H929 cells. Taken together, these data showed that PLD inhibited proliferation and migration, and enhanced chemosensitization to BTZ through inactivation of the NF-κB and JAK2/STAT3 pathways in MM cell lines. These findings indicated that PLD might serve as a novel therapeutic agent for the treatment of MM.

Human umbilical cord blood-derived stromal cells: a new resource for the proliferation and apoptosis of myeloma cells

BACKGROUND/OBJECTIVE

Bone marrow stromal cells (BMSCs) can support multiple myeloma (MM) disease progression and resistance to chemotherapy. The proliferation of MM cells may be suppressed by modifying the hematopoietic microenvironment (HME). We have previously isolated human umbilical cord blood-derived stromal cells (hUCBDSCs) and observed that hUCBDSCs suppressed proliferation and induced apoptosis in KM3 cells. To examine the mechanism by which hUCBDSCs drive the inhibition of MM, KM3 cells were co-cultured with hUCBDSCs.

METHODS

Interleukin (IL)-6 and soluble IL-6 receptor (sIL-6R) expression levels were measured by enzyme-linked immunosorbent assay. The expression levels of membrane IL-6 receptor (mIL-6R), intercellular cell adhesion molecule-1 (ICAM-1), B-cell lymphoma/leukemia-2 (Bcl-2), and Bcl-XL as well as the location of nuclear factor κB (NF-κB) were assessed by laser confocal microscopy. The expression profiles of mIL-6R and ICAM-1 were also more precisely examined by flow cytometry, and Bcl-2, Bcl-XL and inhibitor kappa B expression levels were analyzed by western blot. The mRNA expression levels of IL-6R, ICAM-1, Bcl-2, and Bcl-XL were assessed by real-time polymerase chain reaction. NF-κB DNA-binding activity was examined by electrophoretic mobility shift assay.

RESULTS

The protein expression levels of both sIL-6R and mIL-6R were reduced in culture conditions when KM3 cells were co-cultured with hUCBDSCs; moreover, the mRNA expression levels of IL-6R were also reduced. Nuclear translocation of the NF-κB p65 subunit was inhibited in KM3 cells by co-culture with hUCBDSCs. Moreover, hUCBDSCs inhibited NF-κB DNA-binding activity, thereby resulting in the downregulation of NF-κB-regulated proteins.

CONCLUSION

hUCBDSCs can suppress proliferation and induce apoptosis in KM3 cells by both downregulating IL-6R expression and inhibiting NF-κB activity.

Serum levels of osteoprotegerin in the spectrum of nonalcoholic fatty liver disease

OBJECTIVE

Osteoprotegerin (OPG) is a member of the tumor necrosis factor superfamily with pleiotropic effects on inflammation, endocrine function and the immune system. Reduced OPG levels are related to insulin resistance. We tested the hypothesis that serum levels of OPG may be associated with nonalcoholic fatty liver disease (NAFLD).

MATERIAL AND METHODS

Four groups of patients were enrolled in the present study: subjects with definite nonalcoholic steatohepatitis (NASH, n = 56), borderline NASH (n = 26), simple fatty liver (n = 17) and healthy controls without evidence of liver disease (n = 58). Serum levels of OPG were measured by ELISA.

RESULTS

Concentrations of OPG were significantly lower in patients with definite NASH (median: 45 pg/mL, p < 0.001) and borderline NASH (57 pg/mL, p < 0.001) than in controls (92 pg/mL). The area under the ROC curve for distinguishing between steatohepatitis (definite NASH plus borderline NASH) and healthy controls using OPG was 0.82. The use of a cut-off level < 74 pg/mL for serum OPG levels yielded sensitivity and specificity values of 75.6% and 75.9%, respectively.

CONCLUSIONS

Serum osteoprotegerin concentrations are reduced in patients with the more severe forms of NAFLD and may serve as a noninvasive biomarker to identify patients with NASH.