[Expression of SOX11 mRNA in mantle cell lymphoma and its clinical significance].

OBJECTIVE: To investigate the expression level of SOX11 mRNA in mantle cell lymphoma (MCL) and other B-cell non-Hodgkin lymphoma (B-NHL) and its prognostic value in MCL. METHODS: The expression level of SOX11 mRNA in 80 B-NHL patients were determined by real-time quantitative RT-PCR, GAPDH was used as internal control. The dispersion of SOX11 expression ratio of groups with different prognostic factors was described by Mann-Whitney U test. RESULTS: The SOX11 mRNA expression level was 2.90 (0.75 - 4.63) in 80 B-NHL patients, and the expression level was significantly higher in MCL than that in other B-NHL (P = 0.014). The SOX11 expression level was statistically lower in the group of MCL with hyperleukocytosis, 12 trisomy, MYC amplification and therapeutic effect < PR (P = 0.042, 0.013, 0.028, 0.009) than that of MCL in other group. But SOX11 expression was not associated with MCL international prognostic index (MIPI) (P = 0.333), lactate dehydrogenase (LDH) (P = 0.790), ATM mutation (P = 0.865) and P53 deletion (P = 0.116). The progression free survival (PFS) and overall survival (OS) were significantly longer in the MCL patients with high level of SOX11 than that of other MCL patients. CONCLUSION: There was statistically significant differences in SOX11 mRNA expression between MCL with other B-NHL. SOX11 maybe a good prognostic factor in MCL.

[Cytogenetic abnormality of chromosome 13q14 in 112 patients with multiple myeloma detected by using LSI-RB1 and LSI-D13S319 probes].

Chromosome 13q14 deletion is one of the most common cytogenetic abnormalities in multiple myeloma (MM). LSI (locus-specific identification)-RB1 (13q14.1-14.2 region) and LSI-D13S319 (13q14.3 region) probes are usually used to detect 13q14 deletion. The aims of this study was to compare the incidence of chromosome 13q14.1-14.2 and 13q14.3 deletion and to detect 13q14 deletion size and number of involved cells in MM patients. The chromosome 13q14 region was detected by fluorescence in situ hybridization using probes LSI-RB1 and LSI-D13S319 in plasma cells of 112 MM patients. The results showed that 47.3% (53 out of 112) MM patients had both LSI-RB1 and LSI-D13S319 13q14 deletion (cut-off value: 7%), and the deletion rates detected by probes LSI-RB1 and LSI-D13S319 were accordant. The positive rates of 13q14 deletion were 46.4% and 47.3% respectively when the cut-off level was increased to 20%, and the corresponding rate was 98%. MM patients carrying 13q14 deletion showed 18% - 98% (median value: 72.5%) and 22% - 98.5% (median value: 76.5%) of deleted nuclei involving the RB1 and the D13S319 locus (P = 0.38). There were 67.9% (36 out of 53) and 66% (35 out of 53) cases carrying > 65% of 13q14.1-14.2 and 13q14.3 deleted nuclei as high proportion deletion patients, respectively (P = 0.188). The positive rate of the high proportion deletion patients had still no difference between LSI-RB1 and LSI-D13S319 groups when the cut-off value was defined as 85% (P = 0.439). In conclusion, in this cohort of 112 MM patients, there was no significant difference between the LSI-RB1and LSI-D13S319 probes to detect 13q14 deletion. Both LSI-RB1 and LSI-D13S319 probes can be selected to detect 13q14 deletion in MM patients. All the 53 MM patients with 13q14 deletion had deletions of 13q14.1-14.2 and 13q14.3 regions, which is a large deletion as one of the important characters in MM patients with 13q14 deletion.

[Regulation of miRNA-15a/-16 expression on the drug resistance of myeloma cells].

OBJECTIVE: To explore the effects and mechanism of bone marrow stromal cells (BMSCs) on the drug resistance of multiple myeloma (MM). METHODS: Fresh untreated MM patient (5 samples) and health donor (5 samples) bone marrow samples were collected from May 2011 to July 2011 at our hospital. Their BMSCs were separated respectively. The supernatant expression of cytokines in BMSCs was detected by enzyme-linked immunosorbent assay (ELISA). Myeloma cells were co-cultured with BMSCs and treated with melphalan or bortezomib. Cell proliferation and miRNA-15a/-16 expression of myeloma cells were measured in different culture conditions with thiazoyl blue tetrazolium bromide (MTT) assay and quantitative real-time PCR (qRT-PCR). miRNA-15a was transfected into myeloma cells. And the miRNA-15a functions on cell cycle and cell apoptosis were detected by flow cytometry. RESULTS: ELISA assay showed that cytokine IL-6 and VEGF were at higher levels in MM-BMSCs than healthy BMSCs ((189 ± 9) vs (115 ± 15) pg/ml, (1497 ± 40) vs (1239 ± 21) pg/ml, both P < 0.05). The miRNA-15a/-16 expressions of myeloma cells were up-regulated after the treatment of melphalan and bortezomib (all P < 0.05). However, the miRNA-15a/-16 up-regulation by melphalan or bortezomib became inhibited when MM cells were co-cultured with MM-BMSCs (melphalan: 4.690 ± 0.050 vs 34.440 ± 4.100, 0.760 ± 0.070 vs 12.030 ± 1.020, bortezomib: 1.440 ± 0.230 vs 11.480 ± 1.488, 0.880 ± 0.040 vs 3.680 ± 0.420, all P < 0.05). Furthermore, IL-6 suppressed the expression of miRNA-15a/-16 in a dose and time-dependent pattern. The transfection of miRNA-15a led to the arrest of MM cell cycle in G(1)/S phase. CONCLUSIONS: BMSCs suppress the proliferation of myeloma cells and regulate the drug sensitivity of myeloma cells through the inhibited expression of miRNA-15a/-16. IL-6 plays a pivotal role in the occurrence of drug resistance.

[Comparative study of genetic aberrations in human multiple myeloma cell lines and newly diagnosed MM by fluorescence in situ hybridization].

Multiple myeloma (MM) is a neoplasm of a terminally differentiated B-cell. Human myeloma cell lines were shown to be suitable model systems for use in various fields of the biological sciences. This study was aimed to investigate the genetic aberrations in human multiple myeloma cell lines. Interphase fluorescence in situ hybridization (FISH) with probes for the regions containing 13q14 (RB-1), 13q14.3 (D13S19), 14q32 (IGHC/IGHV) , 1q12 (CEP1), 17p13 (TP53) were was used to detect 7 HMCL and 85 cases of newly diagnosed MM. FISH with LSI IGH/CCND1 , LSI IGH/FGFR3 and LSI IGH/MAF probes were used to detect t(11;14) (q13;q32) , t(4;14) (p16;q32) and t(14;16) (q32;q23) in HMCL and MM with 14q32 rearrangement. The results showed that molecular cytogenetic aberrations were found in all 7 HMCL, six (85.7%) HMCL simultaneously had 13q14, 13q14.3 deletion. Chromosome 1q21 abnormality was found in six (33.3%) HMCL with at least 3 copies amplifications. Illegitimate 14q32 rearrangement was found in five (71.4%) HMCL, including one with t(11;14), two with t(4;14) and three with t(14;16). 17p13 deletion was detected in 5 HMCL. Chromosomal changes were observed in 85.9% of the 85 cases of newly diagnosed MM. The del(13), 1q12 amplification, del(17p), 14q32 rearrangement, t(11;14), t(4;14), t(14;16) were present in 44.7%, 52.9%, 20%, 62.4%, 27.1%, 24.7% and 3.5% of the patients respectively. There was no significant difference in the prevalence of genetic abnormalities of del(13q), 14q32 rearrangement, 1q12 amplification, t(11;14), t(4;14) except del(17p) and t(14;16). It is concluded that HMCL representative of the most aggressive phase of plasma cell neoplasms accumulated a large amount of genetic aberrations. Loss of p53 are strikingly common in HMCL suggesting that the impairment of the P53 tumor suppressor pathway is an important contributor to extramedullary tumor expansion.

[Effect of mesenchymal stem cells on multiple myeloma cells growth and inhibition of bortezomib induced cell apoptosis].

OBJECTIVE: To investigate the role of mesenchymal stem cells (BMSCs) in multiple myeloma (MM) bone marrow (BM) microenrivonment and their effect on myeloma cells survival and bortezomib induced apoptosis. METHODS: BMSCs were derived from BM of untreated myeloma patients (MM-BMSCs) and healthy donors (HD-BMSCs), respectively. The phenotype, proliferation time and cytokine secretion of MM-BMSCs were detected and compared with HD-BMSCs. Then BMSCs were co-cultured with myeloma cell line NCI-H929 and bortezomib in vitro. The NCI-H929 cells proliferation and bortezomib induced cell apoptosis were investigated. RESULTS: MM-BMSCs and HD-BMSCs were isolated successfully. The phenotype of MM-BMSCs was similar to that of HD-BMSCs. Expressions of CD73, CD105, CD44 and CD29 were positive, but those of CD31, CD34, CD45 and HLA-DR (< 1%) negative. The proliferation time of MM-BMSCs was longer than that of HD-BMSCs (82 h vs 62 h, P < 0.05). Moreover, over-expressions of IL-6 and VEGF in MM-BMSCs culture supernatant were detected as compared with that in HD-BMSCs [(188.8 ± 9.4) pg/ml vs (115.0 ± 15.1) pg/ml and (1497.2 ± 39.7) pg/ml vs (1329.0 ± 21.1) pg/ml, respectively]. MM- BMSCs supported survival of the myeloma cells NCI-H929 and protected them from bortezomib induced cell apoptosis. CONCLUSIONS: MM-BMSCs is benefit for myeloma cells proliferation and against cell apoptosis induced by bortezomib. Over-expression of IL-6 and VEGF maybe play a critical role in these effects.