Clarithromycin Synergistically Enhances Thalidomide Cytotoxicity in Myeloma Cells.

Clarithromycin (CAM) is a macrolide antibiotic that is widely used in the treatment of respiratory tract infections, sexually transmitted diseases and infections caused by the Helicobacter pylori and Mycobacterium avium complex. Recent studies showed that CAM was highly effective against multiple myeloma (MM) when used in combination with immunomodulatory drugs and dexamethasone. However, the related mechanism is still unknown. As 3 immunomodulatory agents are all effective in the respective regimen, we postulated that CAM might enhance the effect of immunomodulatory drugs. We evaluated the interaction effects of CAM and thalidomide on myeloma cells. Taking into consideration that thalidomide did not affect the proliferation of myeloma cells in vitro, we cocultured myeloma cells with peripheral blood monocytes and evaluated the effects of CAM and thalidomide on the cocultured cell model. Data showed that thalidomide and CAM synergistically inhibited the proliferation of the cells. On this same model, we also found that thalidomide and CAM synergistically decreased the secretion of tumor necrosis factor-α and interleukin-6. This might be caused by the effect of the 2 drugs on inhibiting the activation of ERK1/2 and AKT. These data suggest that the efficacy of CAM against MM was partly due to its synergistic action with the immunomodulatory agents.

[Establishment and Management of Multiple Myeloma Specimen Bank Applied for Molecular Biological Researches].

OBJECTIVE: To establish a multiple myeloma specimen bank applied for molecular biological researches and to explore the methods of specimen collection, transportation, storage, quality control and the management of specimen bank. METHODS: Bone marrow and blood samples were collected from multiple myeloma patients, plasma cell sorting were operated after the separation of mononuclear cells from bone marrow specimens. The plasma cells were divided into 2 parts, one was added with proper amount of TRIzol and then kept in -80 °C refrigerator for subsequent RNA extraction, the other was added with proper amount of calf serum cell frozen liquid and then kept in -80 °C refrigerator for subsequent cryopreservation of DNA extraction after numbered respectively. Serum and plasma were separated from peripheral blood, specimens of serum and plasma were then stored at -80 °C refrigerator after registration. Meantime, the myeloma specimen information management system was established, managed and maintained by specially-assigned persons and continuous modification and improvement in the process of use as to facilitate the rapid collection, management, query of the effective samples and clinical data. RESULTS: A total of 244 portions plasma cells, 564 portions of serum, and 1005 portions of plasma were collected, clinical characters were documented. CONCLUSION: A multiple myeloma specimen bank have been established initially, which can provide quality samples and related clinical information for molecular biological research on multiple myeloma.

Activity of fibroblast growth factor receptor inhibitors TKI258, ponatinib and AZD4547 against TPR­FGFR1 fusion.

8p11 myeloproliferative syndrome (EMS) is a rare disease characterized by the constitutive activation of fibroblast growth factor receptor 1 (FGFR1). To date, four cases of EMS with the chromosomal translocation, t(1;8)(q25;p11.2), have been reported. In the present study, TPR­FGFR1­expressing Baf3 cells were established and confirmed by polymerase chain reaction. To identify the most promising drug for EMS, the activities and associated mechanism of three tyrosine kinase inhibitors (TKIs), TKI258, ponatinib and AZD4547, against TPR­FGFR1 were tested by MTT assay, flow cytometry and western blot. The data demonstrated that TPR­FGFR1 was localized in the cytoplasm, and was able to transform interleukin-3-dependent hematopoietic Baf3 cells into growth factor­independent cells. All of the three TKIs markedly inhibited the proliferation of TPR­FGFR1­expressing Baf3 cells, and the activation of FGFR1 and the downstream signaling molecules, extracellular signal­regulated kinase 1/2, phospholipiase Cγ and signal transducer and activator of transcription 5. AZD4547 was the most efficient drug, and TKI258 was the least. By contrast, no significant difference was found among the three drugs on their effect on cell apoptosis. Taken together, the data obtained in the present study suggested that AZD4547 had increased potency, compared with TKI258 and ponatinib, for the treatment of EMS.

[Application Value of CD138 MACS-FISH in the Genetic Diagnosis of Plasma Cell Dyscrasia].

OBJECTIVE: To investigate the cytogenetic characteristics of the various plasma cell dyscrasia using the CD138 MACS-FISH, to elucidate the application value of MACS-FISH in the genetic diagnosis of plasma cell dyscrasia, and to explore the standardization of FISH detection for plasma cell dyscrasia. METHODS: A total of 232 patients with newly diagnosed plasma cell dyscrasia were collected, including 203 cases of MM, 24 cases of AL amyloidosis and 5 cases of MGUS, whose cytogenetic abnormalities were detected by MACS-FISH, and the differences of the positive detection rates of chromosome karyotype analysis, C-FISH and MACS-FISH in MM cytogenetic abnormality were compared. The sensitivity of C-FISH and MACS-FISH were analyzed and compared according to the proportion of bone marrow plasma cells. The correlation between the positive cell rates of C-FISH and MACS-FISH and the proportion of plasma cells were analyzed respectively. The differences in the clone size detected by C-FISH and MACS-FISH were compared. RESULTS: The incidence of cytogenetic abnormality of MM, AL amyloidosis and MGUS detected by MACS-FISH were 85.9%, 62.5%, 60%, respectively. The incidence rate of MM cytogenetic abnormality detected by Chromosome karyotype analysis and C-FISH were 20.0% and 64.7%, respectively, which were significantly lower than that of MACS-FISH(P<0.001). The positive rate of 14q32 translocation, del(14q32), t(11;14), +17p13 and the coexistence of 2 and ≥3 kinds of cytogenetic abnormalities detected by MACS-FISH were significantly higher than that detected by C-FISH(P<0.05). When the plasma cell ratio was less than or equal to 5%, the positive detection rate of MACS-FISH was significantly higher than that of C-FISH (P=0.001), and there was no significant difference in different plasma cell proportion group of MACS-FISH. However, when the plasma cell ratio was less than or equal to 5%, the positive detection rate of C-FISH detection was significantly lower than that of the other 3 groups (P=0.013,P=0.001,P<0.001). The positive cell rates of all cytogenetic abnormalities in C-FISH group and +1q21 and 14q32 translocation in MACS-FISH group were significantly positively correlated with the proportion of plasma cells(P<0.05). The clone size of various cytogenetic abnormalities in MACS-FISH group were significantly higher than that in C-FISH group(P<0.001). CONCLUSION: MACS-FISH may significantly enhance the detection rate of cytogenetic abnormalities in various plasma cell dyscrasia, and it can better reflect the cytogenetic abnormality of plasma cell dyscrasia and its clone size. MACS-FISH may be recommended as a standard method for the genetic diagnosis of plasma cell dyscrasia, the risk stratification of MM and SMM, as well as the genetic diagnosis and research of MGUS and AL amyloidosis.