Objective        To determine the methylation status of protocadherin-10 (PCDH10) in multiple myeloma (MM) patients and MM cell lines KM3 and RPMI-8226

and investigate the effect of its methylation on PCDH10 silence.       Methods        A total of 44 MM tissue samples from January to December 2010 hospitalized in our department were collected. Bone marrow tissues of 9 age- and sex-matched patients with mild anemia obtained by conventional bone marrow biopsy served as control. The expression of PCDH10 gene was detected by RT-PCR in above tissue samples

and multiple myeloma cell lines KM3 and RPMI-8226. Methylation-sensitive PCR (MSP) was used to test the methylation of PCDH10 CpG islands. Then

after the KM3 and RPMI-8226 cells were treated with 5-aza-2′-deoxycytidine and trichostatin A (Aza and TSA

A+T)

the changes of PCDH10 were studied by RT-PCR and MSP.       Results        PCDH10 was expressed well in normal population while extensive mildly expressed in MM patients and cell lines. Among the 44 patients (23 females

21 males)

77.27% (34/44) whom presented methylation of PCDH10. Furthermore

A+T restored PCDH10 expression in myeloma cell lines.       Conclusion        DNA methylation may play a key role in the silence of PCDH10 gene in multiple myeloma

and may be involved in the incidence of myeloma.