title: [miR-202 contributes to sensitizing MM cells to drug significantly via activing JNK/SAPK signaling pathway].
abstract: Objective:To explore the role of miR-202 in multiple myeloma (MM) cells, and study the regulation of miR-202 on drug sensitivity of MM cells.Methods:miR-202 and BAFF mRNA levels were detected by real-time PCR. U266 cells were transfected with miR-202-mimics, miR-202-inhibitor, siBAFF and their negative controls. After above treatments, protein levels of Bcl-2 family and MAPK signaling pathway were detected by Western blot analysis, and the proliferation and apoptosis ability of MM cells were examined by WST-1, Annexin V-FLUOS assay, respectively.Results:The results showed that the expression of miR-202 in CD138+ MM cells (0.304±0.354) and U266 cells (0.052± 0.009) were lower than in normal controls (3.550 ± 1.126) (P<0.001,P=0.009), whereas BAFF mRNA levels (5.700 ± 0.734, 9.576 ± 2.887) were higher than in normal controls (1.819 ± 0.853) (P<0.001,P= 0.006). The proliferation ability of U266 cells transfected with miR-202 mimics was significantly inhibited than in control group [(56.04±0.021)%vs(18.89±0.32)%,P=0.002]. The result of Western blot showed that the expression of Bcl-2 decreased by about 24%, and the expression of Bax increased by about 124% in cells transfected with miR-202 mimics. The apoptosis rate in cells transfected with miR-202 mimics was significantly more than in control group [(49.60±4.89)%vs(26.20±1.28)%,P=0.029]. The apoptosis rate in miR-202 mimics combined with Bort group (51.23±5.41)% was higher as compared with Bort treatment alone (31.70±4.40)% or miR-202 mimics control combined with Bort group (27.94±4.04)%, (P=0.047,P= 0.028), whereas the apoptosis rate in miR-202 mimics combined with Thal or Dex had no significant difference compared with miR-202 mimics control [(11.66±1.91)%vs(10.63±1.74)%,P=0.700; (16.35± 1.32)%vs(17.43 ± 1.95)%,P=0.400]. The inhibitory rate of cell growth in miR-202 mimics combined with Bort group was higher as compared with Bort treatment alone [(36.93±5.98)%vs(18.18±4.10)%,P= 0.029]. The expressions of p-JNK protein decreased in U266 cells transfected with miR-202 mimics and treated with Bort.Conclusion:miR-202 mimics combined with Bort could inhibit proliferation and induce apoptosis of U266 cells through negative regulating target gene BAFF, which further inhibited the JNK/SAPK signaling pathway.
authors.affiliation: Laboratory Medicine Center, Affiliated Hospital of Nantong University, Nantong Jiangsu 226001, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: X J
authors.initials: XJ
authors.lastname: Shen
authors.forename: X H
authors.initials: XH
authors.lastname: Wu
authors.forename: H
authors.initials: H
authors.lastname: Cong
authors.forename: H B
authors.initials: HB
authors.lastname: Ni
authors.forename: S Q
authors.initials: SQ
authors.lastname: Ju
authors.affiliation: Laboratory Medicine Center, Affiliated Hospital of Nantong University, Nantong Jiangsu 226001, China.
authors.forename: J Y
authors.initials: JY
authors.lastname: Su
mesh_terms: D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D006801:Humans; D020935:MAP Kinase Signaling System; D035683:MicroRNAs / Q000502:physiology*; D009101:Multiple Myeloma / Q000188:drug therapy*; D012333:RNA, Messenger; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D014162:Transfection
chemical_list: D051017:Apoptosis Regulatory Proteins; C569392:MIRN202 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger