Expression Of Pim-1and C-myc In Multiple Myeloma

Objectives:Pim is a kind of proto-oncogene, which encodes a protein is a serine/threonine kinase, mainly related to the regulation of cell cycle,proteins transcriptionand translation, apoptosis, regulation of cell metabolism and resistance protein,all thefunctions are closely related to tumorigenesis. Pim family consists of Pim-1, Pim-2,Pim-3,whic encode different proteins belong to the calcium/calmodulin-dependentprotein kinase family according to choose different transcription sites. But they do nothave the same expression in different tissues.Pim-1is highly expressed in hematopoieticcells, Pim-2is mainly expressed in brain and lymphocytes, and Pim-3is rich in kidney,breast and brain cells.The literature had shown that myeloma cell lines expressingdifferent levels of Pim-1, Pim-2, and Pim-3. C-myc oncogene is located on humanchromosome8q24, and has the versatile function of transcription factors, may enhancecell proliferation and inhibit differentiation of cells and promote cell cycle progressionand inhibition of apoptosis.C-myc gene can be activated by amplification andchromosomal translocations or rearrangement and has an important association withtumor development. C-myc is upregulated in many kind of human tumors, includingacute leukemia,breast cancer, osteosarcoma, whereas in small mouse plasma cell tumorsand in patients of multiple myeloma were found rearrangement and overexpression ofC-myc. This topic is to detect the expression of Pim-1and C-myc in multiple myelomapatients by RT-PCR and Western Blot, and to explore the possible role of Pim-1andC-myc in the pathogenesis of multiple myeloma and to provide new ideas for multiplemyeloma treatments.Methods:1.Choosing patients visiting to the hospital with newly diagnosed MM with bone marrow specimens of22cases from2012Jul. to2013Sep. as the experimentalgroup, and10cases of patients diagnosed iron deficiency anemia with bone marrowfrom2013Jan. to2013Sep. as normal control group.2. Bone marrow was obtained to2ml, anticoagulated by EDTA-2K, and then isolated lymphocytes from mononuclearcells. At last, mononuclear cell suspension were made and stored at-80℃sparerefrigerator.3. The total RNA was extracted from the mononuclear cells, then tested theratio of A260/A280by spectrophotometer to determine the purity of RNAsamples,made sure that the ratio between1.8-2.0. At last, All RNA samples wasreversed transcription into cDNA,then was stored-80℃refrigerator for preservation orfor PCR amplification.4.Selecting GAPDH as the internal reference gene,pim-1andC-myc DNA primes were designed by DNASTAR software,synthetised by ShanghaiSANGON biological company,which were used for PCR amplification of Pim-1mRNAand C-myc mRNA.5. Analyzed the expression and differences between Pim-1mRNAand C-myc mRNA by1.5%agarose gel electrophoresis and Bio-Image AnalysisSystem.6. Detected the expression of Pim-1and C-mycl protein in Western Blot.Results: Pim-1mRNA expression levels of newly diagnosed multiple myelomapatients decreased significantly comparing to the control group. The expression ofPim-1mRNA and protein levels in newly diagnosed MM patients was significantlyhigher than the control group. C-myc mRNA and protein levels in newly diagnosedMM patients was significantly higher expression level.Conclusion: The expression of Pim-1and C-myc in MM was a significant differencecompared with the control group and associate with a number of clinical indicators andstage, which may promote the growth of myeloma cells through multiple pathways suchas inhibit apoptosis, and the two has a coordinating role in the development of multiplemyeloma.